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Post-irradiation examination of a fuel pin using a microscopic X-ray system: Measurement of carbon deposition and pin metrology | The use of ionising radiation to image nuclear fuel: A review | Dosimetric Factors Used for Thoracic X-Ray Radiotherapy are not Predictive of the Occurrence of Radiation Pneumonitis after Carbon-Ion Radiotherapy | eng_Latn | 15,500 |
Effect of chlorophyllin on gamma ray induced micronuclei in polychromatic erythrocytes of murine peripheral blood determined by the ABC strategy. | Influence of the Leaf Extract of Mentha arvensis Linn. (Mint) on the Survival of Mice Exposed to Different Doses of Gamma Radiation | Exogenous growth factors do not affect the development of individually cultured murine embryos | eng_Latn | 15,501 |
Commercializable power source using heterogeneous hydrino catalysts | Validation of the Observation of Soft X-ray Continuum Radiation from Low-Energy Pinch Discharges in the Presence of Molecular Hydrogen | Evidence against a role for platelet-derived molecules in liver regeneration after partial hepatectomy in humans | eng_Latn | 15,502 |
Dosimetric properties of Gafchromic(R) EBT films in medical carbon ion beams. | Report of a National Cancer Institute special panel: Characterization of the physical parameters of particle beams for biological research | Dosimetric Factors Used for Thoracic X-Ray Radiotherapy are not Predictive of the Occurrence of Radiation Pneumonitis after Carbon-Ion Radiotherapy | eng_Latn | 15,503 |
Azomethine H colorimetric method for determining dissolved boron in water | Removal of boron from aqueous solution using magnetic carbon nanotube improved with tartaric acid | Dosimetric Factors Used for Thoracic X-Ray Radiotherapy are not Predictive of the Occurrence of Radiation Pneumonitis after Carbon-Ion Radiotherapy | eng_Latn | 15,504 |
Improving the prediction model for Cherenkov light generation by irradiated nuclear fuel assemblies in wet storage for enhanced partial-defect verification capability | On the inclusion of light transport in prediction tools for Cherenkov light intensity assessment of irradiated nuclear fuel assemblies | Oral spray wintertime vitamin D3 supplementation has no impact on inflammation in Gaelic footballers | eng_Latn | 15,505 |
Correlations between spectroradiometric and spectrophotometric colors of all-ceramic materials. | Color and hardness changes in artificial white spot lesions after resin infiltration | Dosimetric Factors Used for Thoracic X-Ray Radiotherapy are not Predictive of the Occurrence of Radiation Pneumonitis after Carbon-Ion Radiotherapy | eng_Latn | 15,506 |
Does Occupational Exposure of Shahid Dastghieb International Airport Workers to Radiofrequency Radiation Affect Their Short Term Memory and Reaction Time? | Cancer in Korean War Navy Technicians: Mortality Survey after 40 Years | Absence of CCR8 does not impair the response to ovalbumin-induced allergic airway disease. | eng_Latn | 15,507 |
A Numerical Method Charactering the Electromechanical Properties of Particle Reinforced Composite Based on Statistics | Electromechanical coupling in dielectric elastomer actuators | Dosimetric Factors Used for Thoracic X-Ray Radiotherapy are not Predictive of the Occurrence of Radiation Pneumonitis after Carbon-Ion Radiotherapy | eng_Latn | 15,508 |
Re-evaluation of correction factors of a primary standard graphite calorimeter in 60Co gamma ray beams as a basis for the appointment of the BEV absorbed dose rate to water reference value. | Effect of temperature on longevity of Diaphorina citri (Hemiptera: Liviidae) studied by microcalorimeter | Adipose Lipolysis Unchanged by Preexercise Carbohydrate Regardless of Glycemic Index | eng_Latn | 15,509 |
Monitoring radiation damage in the ATLAS Silicon Tracker | ATLAS Pixel Radiation Monitoring with HVPP4 System | It is premature to test older drivers with the SIMARD-MD | eng_Latn | 15,510 |
Studies of the ablation plume arising in 193 nm laser irradiation of graphite in vacuum | Complementary Characterization of Laser-Induced Plasmas by Optical Emission Spectroscopy and Triple Langmuir Probe | The Effects of Low-Level Laser Therapy, 670 nm, on Epiphyseal Growth in Rats | eng_Latn | 15,511 |
Measurement of the Energy-Dependent Angular Response of the ARES Detector System and Application to Aerial Imaging | A Rotating Scatter Mask for Inexpensive Gamma-Ray Imaging in Orphan Source Search: Simulation Results | Delayed Reactive Distractor Suppression in Aging Populations | eng_Latn | 15,512 |
Monitoring wax deposition in pipelines is of particular importance for oil extraction companies. In this work, a new gamma-ray tomography system based on using a rod CsI(Na) scintillator and 137Cs gamma source was developed to view the cross section of oil pipelines. The system can estimate the interaction position of gamma-rays by measuring light attenuation in the rod scintillator using two photomultiplier tubes coupled to its ends. Therefore, despite the simple structure of the employed detector, it can act as a position-sensitive instrument. In order to test the proposed tomography system, a selection of desired polyethylene round-bar pieces (as different wax thicknesses) was prepared to be placed in iron pipes, and their projections at different angles were acquired to construct cross-sectional images as well. The results showed that the designed system had the ability to scan the interior of the pipes and determine wax thickness with an error between 2.4% and 11.4%.Monitoring wax deposition in pipelines is of particular importance for oil extraction companies. In this work, a new gamma-ray tomography system based on using a rod CsI(Na) scintillator and 137Cs gamma source was developed to view the cross section of oil pipelines. The system can estimate the interaction position of gamma-rays by measuring light attenuation in the rod scintillator using two photomultiplier tubes coupled to its ends. Therefore, despite the simple structure of the employed detector, it can act as a position-sensitive instrument. In order to test the proposed tomography system, a selection of desired polyethylene round-bar pieces (as different wax thicknesses) was prepared to be placed in iron pipes, and their projections at different angles were acquired to construct cross-sectional images as well. The results showed that the designed system had the ability to scan the interior of the pipes and determine wax thickness with an error between 2.4% and 11.4%. | Industrial tomography system needs a fast data acquisition, as well as high accuracy and precision scanning control which is operated in an automated manner. In this research, the data were acquired from 2 detector fan beam scanning method. This design consists of: gamma ray source from Cs-137 isotope having 30 mCi activity, scintillation detector made of NaI(Tl) crystal connected to Ludlum M2200 radiation counter, and motion system made up of source rotator and detector rotator with each motion corresponds to one motor. The scanning system was controlled by Arduino Mega as a microcontroller and LabView as a graphical user interface. Microcontroller was used to actuate motors, read encoders, and communicate serially with radiation counter and PC. Motors were able to rotate the source and detector with angle starting from 1° around the center of rotation and take time about 1 second per degree rotation. Radiation counting resulted in 1.47% statistical error for 1-second counting time and decreased to 0.99% as counting time is increased to 2 seconds. The reconstructed image from the proposed fan beam method resulted in poorer quality than from the parallel beam method with the same pixel size. However, for nearly same quality of the image, the proposed method required less scan time. Spatial resolution of both methods could identify the holes within phantom with diameters starting from 1 cm. | By using a superluminescent diode as the light source and a depolariser inside the fibre coil, a constant scale factor is achieved without using polarisation control elements. For long-term behaviour an RMS-bias drift of 10 degrees/h is obtained. | eng_Latn | 15,513 |
Uranium in groundwater samples collected from Punjab state, India was determined using radiometric methods (extractive liquid scintillation and Cerenkov counting). Experimental conditions were optimized by studying the effect of sample pH, quenching and amount of extracting agent added to the scintillation cocktail on recovery of uranium. To ensure the accuracy of results, both radiometric methods were compared with non radiometric method such as adsorptive stripping voltammetry and found to be very good agreement. The distinct advantage of proposed radiometric methods is almost 100 % effective especially extractive liquid scintillation for simultaneous measurement of alpha and beta emitting radionuclides with fast and simple sample preparation. | A method utilizing solvent extraction coupled with liquid scintillation spectrometry has been developed for the assay of uranium and thorium in fertilizers and phosphate-containing minerals and chemicals. Trioctylphosphine oxide in toluene is used to extract uranium and thorium from a perchloric and nitric acid solution, with phosphate interference being suppressed by the addition of aluminum ion. The uranium and thorium are stripped from this solution, and uranium is separated from the thorium by selective reextraction of uranium into a scintillator with Adogen 364 (tertiary amine) sulfate. The thorium remaining in the aqueous is reextracted into another scintillator with (primary) 1-nonyldecylamine sulfate. Both nuclides are counted separately in a high-resolution liquid scintillation spectrometer. The sensitivity of the counting method is enhanced by the use of pulse-shape rejection of the beta--gamma background. Results indicate a detection threshold of 0.0038 pCi of uranium (1.1 part/10/sup 8/) with a 1000-min counting time. Reproducibility of +- 2.5% was found at the 50-ppM level. For thorium detection, thresholds are 4 part/10/sup 13/ for the same counting time with +- 3.0% average recovery of /sup 230/Th and 7 part/10/sup 8/ of /sup 232/Th. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 15,514 |
This review of low dose–induced whole-body effects, especially cancer, shows: 1) Biological systems appear in hierarchy levels of organization, from atoms to molecules, to cells, to tissues and organs, to the whole system; 2) System responses to low-level exposures depend on: quality and number of energy depositions in tissue micromasses (microdoses) being potential triggers to damage and protection; time interval between two microdose events per exposed micromass, that determines cellular responses to the preceding microdose; and responses to microdose events in the system being the target, with the balance between damage and benefit determining the net effect; 3) System responses to acute or chronic low-level exposures evolve from damage to the basic molecular level, mainly to DNA of stem cells, and from adaptive responses that may occur in the whole body. Damage may propagate to successive higher levels of organization, meeting protective barriers which may become upregulated by adaptive responses. The balance between damage and protection at each level per individual depends on tissue dose. At single tissue doses below ≅ 0.1 Gy net benefit tends to outweigh detriment. Thus, progression of damage to clinical disease is not linear; 4) Quality and extent of system responses are under genetic control. Thus, system net responses expectedly vary among individuals; 5) The balance between health risk and benefit of low-level exposure for a given individual may become predictable by gene-expression profiles in control and irradiated cells of this individual; and 6) Clinical trials applying individualized low-level irradiation are justified. | Previous research has demonstrated that adding a very small gamma-ray dose to a small alpha radiation dose can completely suppress lung cancer induction by alpha radiation (a gamma-ray hormetic effect). Here we investigated the possibility of gamma-ray hormesis during low-dose neutron irradiation, since a small contribution to the total radiation dose from neutrons involves gamma rays. Using binucleated cells with micronuclei (micronucleated cells) among in vitro monoenergetic-neutron-irradiated human lymphocytes as a measure of residual damage, we investigated the influence of the small gamma-ray contribution to the dose on suppressing residual damage. We used residual damage data from previous experiments that involved neutrons with five different energies (0.22–, 0.44–, 1.5–, 5.9–, and 13.7-million electron volts [MeV]). Corresponding gamma-ray contributions to the dose were approximately 1%, 1%, 2%, 6%, and 6%, respectively. Total absorbed radiation doses were 0, 10, 50, and 100 mGy for each neutron s... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,515 |
For measurements of the neutron-induced fission cross section of 242Pu, large-area (42cm2) 242Pu targets were prepared on Ti-coated Si wafers by means of constant current density molecular plating. Radiochemical separations were performed prior to the platings. Quantitative deposition yields (>95%) were determined for all targets by means of alpha-particle spectroscopy. Layer densities in the range of 100-150μg/cm2 were obtained. The homogeneity of the targets was studied by radiographic imaging. A comparative study between the quality of the layers produced on the Ti-coated Si wafers and the quality of layers grown on normal Ti foils was carried out by applying scanning electron microscopy and energy dispersive X-ray spectroscopy. Ti-coated Si wafers resulted clearly superior to Ti foils in the production of homogeneous 242Pu layers with minimum defectivity. | The prompt γ -ray spectrum of fission fragments is important in understanding the dynamics of the fission process, as well as for nuclear engineering in terms of predicting the γ -ray heating in nuclear reactors. The γ -ray spectrum measured from the fission fragments of the spontaneous fission of 242 Pu will be presented here. A fission chamber containing in total 37mg of 242 Pu was used as active sample. The γ -quanta were detected with high time- and energy-resolution using LaBr3 and HPGe detectors, respectively, in coincidence with spontaneous fission events detected by the fission chamber. The acquired γ -ray spectra were corrected for the detector response using the spectrum stripping method. About 70 million fission events were detected which results in a very low statistical uncertainty and a wider energy range covered compared to previous measurements. The prompt fission γ -ray spectrum measured with the HPGe detectors shows structures that allow conclusions about the nature of γ -ray transitions in the fission fragments. The average photon multiplicity of 8.2 and the average total energy release by prompt photons per fission event of about 6.8 MeV were determined for both detector types. | This paper reports a fabrication process for the deposition of a polymer insulation layer on the sidewall of through silicon vias in wafer level packaging. The novolac resin based glue was used as precursor to prepare the insulation layer. The glue is a Newtonian fluid and has low viscosity (24 mPa*s @ 100 l/s) as well as low contact angle (25.9°) to silicon. The resultant polymer insulation layer has a shearing strength as high as 25.8 Kg/mm2. Furthermore, the polymer insulation layer exhibits good uniformity in thickness and roughness over the whole 8″ wafer. On the conformal coating of the polymer insulation layer, the Ti/Cu seed layer and Cu conductive layer were fabricated by PVD and electroplating. Therefore, all the results show that the polymer materials could be a reliable and economical solution for the TSV insulator in the view of wafer level packaging. | eng_Latn | 15,516 |
When high frequency (constant potential) x-ray units are operated at the same kV as conventional half-wave rectified (single pulse) generators, image contrast decreases. The contrast can be restored by lowering the kV. The decrease needed to achieve the same contrast as with a conventional 65 kVp unit is shown to be 5–8kV. Contrast was evaluated using an ivory phantom with a continuously varying thickness of 0–9.6 mm and determined both experimentally and theoretically. The theoretical calculations were based on energy spectra measured for both types of generator by means of a Compton spectrometer. The theoretical results are in excellent agreement with the experiments demonstrating that knowing the complete energy spectrum of primary photons, time-consuming measurements can be replaced with calculations. A consequence of this study is that current Swedish national regulations as to the minimum permitted kilovoltage in intra-oral dental radiography may have to be adjusted. | The influence on image contrast, tube load and patient mean absorbed dose of different ways of shaping diagnostic X-ray spectra by placing filters in the beam is derived fro two radiographic models (abdominal screen-film radiography and intra-oral, dental radiography) using a computational model. The filters are compared at either equal tube load (keeping tube potential constant) or equal contrast (adjusting the tube potential with the different filters), but always at equal energy imparted per unit area to the image receptor. Compared at equal tube load and relative to standard aluminum filtration, reductions in the mean absorbed dose in the patient of 15-25% can be achieved using filters of Cu, Ti, W and Au (increasing the tube load by 30-40% compared with standard aluminium filtration). However, contrast is also reduced by 7%. Compared at equal contrast, the dose reductions are smaller, about 10%. Filters of copper are generally recommended, as are filters of aluminium. The use of bandpass filters (K-edge filters) should be restricted to examinations where the need for substantial variation in tube potential from patient to patient is small. The benefit of using thicker filters than those commonly used today (increasing tube load by factors of 1.4-2.0 compared with no added filter) is small as the dose reduction is most rapid for small initial values of added filters, and the increase in tube load increases steadily with increasing filter thickness. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,517 |
Various trace elements in different types of arsenic (orpiment, As 2 S 3 ; realgar, As 4 S 4 ; lorandite, TlAsS 2 ), antimony (stibnite, Sb 2 S 3 ), copper (brochantite, Cu 4 SO 4 (OH) 6 ; chalcanthite, CuSO 4 ·5H 2 O; chalcopyrite, CuFeS 2 ; covellite, CuS; native copper, Cu) and iron based geological materials (hematite, Fe 2 O 3 ; pyrite, FeS 2 ; chalcopyrite, CuFeS 2 ) were determined using k 0 -method of neutron activation analysis ( k 0 -NAA) in both forms: instrumental ( k 0 -INAA) and radiochemical ( k 0 -RNAA). In order to avoid interferences from the matrix element (As, Sb, Cu and Fe), various procedures were applied for its removal. Elimination of the matrix element enabled investigation from 35 to 47 trace elements in the samples using short (up to few minutes) and long (up to 20 hours) irradiations in typical irradiation channels of TRIGA reactor. The minerals were collected from various localities within the Republic of Macedonia, except covellite, which was obtained from Bor, Serbia. | Analytical radiochemistry of neutron-activated samples, as practiced during past decades at the Jožef Stefan Institute Ljubljana, is outlined. The paper reviews achievements made in both elemental analysis and analyses of long-lived radionuclides, in variety of sample types. The presented analytical procedures include application of diverse chemical separations, multiple irradiations of samples, use of various nuclear reactions and detection modes for particular measurands, and determination of elements that are difficult to be determined by neutron activation analysis (NAA). Useful practical applications of neutron-activated tracers for chemical yield determinations, as unique feature of radiochemical NAA in comparison with non-nuclear analytical methods, are also addressed. | Gallstone disease is a major health problem in many parts of the world. In Nigeria, however, only a few cases of gallstone disease are reported. Minor/trace elements are reported to play a significant role in the formation of gallstones. This study was conducted to assess the minor elements in gallstone of Nigerian patients who had cholecystectomy in our institution using particle-induced X-ray emission (PIXE) technique. We also compare the findings with previous reports from outside Nigeria. Fourteen patients who had cholecystectomy for calculous cholecystitis at Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria, between March 2006 and July 2008, had the stone retrieved. The stones were analyzed for trace elements at the Center for Energy Research and Developments of the University using PIXE experiments. Certified standard reference material, NIST 1577a (bovine liver), was equally analyzed to confirm the accuracy of the experimental procedure. Computer code GUPIXWIN was used to analyze the data. Fourteen elements, phosphorus, sulfur, chlorine, potassium, calcium, manganese, iron, copper, zinc, bromide, lead, titanium, rubidium, and strontium, were detected in most of the samples. The concentrations of the elements varied in the different samples, ranging from a few parts per million to a few percent. Ca was the major constituent of all samples. The black sand-like samples had very high levels of P, S, K, and Pb, which were different from a previous report. The distribution of trace elements in stones in Nigeria patients is different from previous report outside Nigeria, and this may have some role in the occurrence of gallstones in the black African. | eng_Latn | 15,518 |
A new rapid method for the determination of {sup 226}Ra in environmental samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for emergency response or routine sample analyses. The need for rapid analyses in the event of a Radiological Dispersive Device or Improvised Nuclear Device event is well-known. In addition, the recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid analyses for radionuclides in environmental samples in the event of a nuclear accident. {sup 226}Ra (T1/2 = 1,620 years) is one of the most toxic of the long-lived alpha-emitters present in the environment due to its long life and its tendency to concentrate in bones, which increases the internal radiation dose of individuals. The new method to determine {sup 226}Ra in environmental samples utilizes a rapid sodium hydroxide fusion method for solid samples, calcium carbonate precipitation to preconcentrate Ra, and rapid column separation steps to remove interferences. The column separation process uses cation exchange resin to remove large amounts of calcium, Sr Resin to remove barium and Ln Resin as a final purification step to remove {sup 225}Ac and potential interferences. The purified {supmore » 226}Ra sample test sources are prepared using barium sulfate microprecipitation in the presence of isopropanol for counting by alpha spectrometry. The method showed good chemical recoveries and effective removal of interferences. The determination of {sup 226}Ra in environmental samples can be performed in less than 16 h for vegetation, concrete, brick, soil, and air filter samples with excellent quality for emergency or routine analyses. The sample preparation work takes less than 6 h. {sup 225}Ra (T1/2 = 14.9 day) tracer is used and the {sup 225}Ra progeny {sup 217}At is used to determine chemical yield via alpha spectrometry. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory radium particles are effectively digested. The preconcentration and column separation steps can also be applied to aqueous samples with good results.« less | For preparedness purposes, a fast and reliable method is essential to quickly assess radioactive fallout in the environment. The rapid determination of certain nuclides such as alpha-emitting actinides is necessary to make initial environmental and agricultural advisories. Therefore, a method using a preconcentration resin and low energy gamma-spectrometry was developed to a fast determination of certain nuclides in soil samples. The preconcentration resin allows samples to be partially purified and then directly measured by gamma-spectrometry without further extraction or separation. The initial gamma-measurement provides fast and accurate determination of certain nuclides such as 241Am and 235U which are normally analyzed by alpha-spectrometry, but require additional time-consuming purification and separation steps. After gamma-spectrometry, the sample may be further processed and analyzed by traditional methods to determine actinides or other nuclides more precisely. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,519 |
A new single-channel detector system has been developed to perform routine quality assurance of 60Co and high-energy therapy machines. This detector is composed of an orange plastic scintillator, optically coupled to a radiation-resistant polycarbonate light pipe and a shielded silicon photodiode imbedded in a hollow solid water phantom block. No temperature and pressure corrections are required. Stability results were consistent with standard deviations fluctuating from 0.03% up to 0.09% for 60Co and from 0.05% up to 0.18% for other high energies. This device provides a quick, easy and reliable beam output check remotely, using an automatic reset based on a radiation triggering system device, storing multiple sequential readings. The reproducibility of this detector was checked on a daily and weekly basis at different energies (60Co, 6 MV and 18 MV x-rays and 6, 9, 12, 16 and 20 MeV electron beams). These results were found to be consistent with those obtained using an ion chamber. Other characteristics of this detector, including the consequences of the radiation-induced light in the light pipe (stem effect) and the radiation damage on this system are briefly discussed. | This paper describes an experimental setup designed for sensing the luminescent light coming from an organic plastic scintillator stimulated with ionizing radiation. This device is intended to be a part of a complete dosimeter system for characterization of small radiation fields which is the project of the doctoral thesis of the medical physicist at the Radiation Oncology facility of Hospital San Vicente Fundación in conjunction with the Universidad de Antioquia of Medellín Colombia. Some preliminary results predict a good performance of the unit, but further studies must be conducted in order to have a completed evaluation of the system. This is the first step in the development of an accuracy tool for measurement of non-standard fields in the Radiotherapy or Radiosurgery processes. | This paper reports the concentrations of 137Cs, hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethanes (DDT) and its main degradation products, δ3C, and organic carbon in pond sediments (0–210 cm, sectioned by 2–20 cm interval) and surface soils (the 0–3 cm horizon) collected in 2010 from Chenjia catchment, which is located in Yanting county in the hilly central Sichuan of China. α-, β-, and γ-HCH, DDT, and DDD were not detected throughout the sediment profile. Trace concentrations of δ-HCH (0.89–29.31 ng g−1) and p,p′-DDE (1.85–6.02 ng g−1) were detected only in top 40 cm sediment. The 137Cs fallout peak in 1963 (corresponding to the 55–60 cm depth), the sedimentary signature left by the last year of HCH use in 1989 (an additional indicator at 20–25 cm), and the obvious original channel bed prior to the construction of the pond in 1956 were used as temporal markers to estimate changes in average sedimentation rate between different periods due to changes in land use. Continuous, marked decrease in average sedimentation rate (i.e., 3.79, 1.35 and 1.07 cm year−1 in 1956–1963, 1963–1989, and 1989–2010, respectively) over time was observed, probably due to the reforestation, abandoning of steep sloping farmland for afforestation and natural re-vegetation (implementation of the Grain for Green Program), and the conversion of part of gently sloping farmland terraces to orchard land since the 1980s, especially since the 1990s. This was corroborated by the observed decrease (more negative) in δ13C of sediment towards the surface, which indicates increased relative contribution of eroded soil particles coming from slopes with increased tree cover in sediment source area. Combined use of 137Cs, δ-HCH, and δ13C record in sediments has been demonstrated to be a powerful approach to reconstruction of response in sedimentation rate to historical land use changes. | eng_Latn | 15,520 |
Since the terrorist events of the 11th September 2001, the world as it was once known was changed forever. It was these catastrophic terrorist actions over fifteen years ago that saw the dawn of a new era with heightened security across many everyday areas of society that had not previously witnessed such scrutiny or control. Coupling this elevated risk of physical and technical aggression with the ever-increasing global per capita energy demand – there has been witnessed a continually growing reliance on nuclear energy for baseline power generation, a form of electricity production that requires both the necessary international safeguards and controls for its safe use. As more and more of the global energy budget is provided by low-carbon sources (over highly-polluting fossil fuels), the volume of nuclear material in existence will grow substantially – requiring considerable attention and policy to ensure its long-term safety and security. This commentary describes the vast range of policy challenges faced by the nuclear industry resulting from the rapid technological advancements being made across society, and how these directly (and indirectly) affect global nuclear security, as well as providing a thorough discussion on how best these challenges may be overcome. | This paper describes a prototype of a compact environmental radiation surveillance instrument designed for a Ranger unmanned aerial vehicle. The instrument, which can be used for tracking a radioactive plume, mapping fallout and searching for point sources, consists of three different detector types (GM, NaI(Tl) and CZT) and an air sampling unit. In addition to the standard electronics for data acquisition, the system contains an onboard computer, a GPS receiver and environmental sensors, all enclosed in a single housing manufactured of fiberglass-reinforced composite material. The data collected during the flight is transmitted in real-time to the ground station via a TETRA radio network. The radiation surveillance unit is an independent module and as such can be used in, for example, airplanes, helicopters and cars. | Interviews with board members and surveys of residents in a Swedish housing cooperative revealed that their choice to partly reject new energy-efficient outdoor lighting for their outdoor environment (retrofit with light emitting diods) was motivated by multiple goal frames. The board weighed the normative goal of perceived safety and the subordinate hedonic goal of the perceived quality of the light against gain goals. The final choice could be attributed to the normative goal of perceived safety for the elderly. This was consistent with the view of the residents who rated all goal frames high, but perceived safety as the most important. Adoption or rejection of new energy-efficient lighting technology is determined by both cost and energy savings, and people's expectations and perceptions of the light and the lit environment. | eng_Latn | 15,521 |
A Simple Mathematical Model to Calculate Dose Distribution of the Co-60 Beam | A general expression for megavoltage central axis depth doses | Dosimetric Factors Used for Thoracic X-Ray Radiotherapy are not Predictive of the Occurrence of Radiation Pneumonitis after Carbon-Ion Radiotherapy | eng_Latn | 15,522 |
Radiation damage effects in far-ultraviolet filters, thin films, and substrates. | Photonics on the mission to Mars | High-speed running performance is largely unaffected by hypoxic reductions in aerobic power | eng_Latn | 15,523 |
High resolution X‐ray diffraction study of single crystal diamond radiators | Plant ionomics: a newer approach to study mineral transport and its regulation | Delayed Reactive Distractor Suppression in Aging Populations | eng_Latn | 15,524 |
Accelerating radiation dose calculation: A multi-FPGA solution | GPU-accelerated Monte Carlo convolution/superposition implementation for dose calculation | Surface of localized pleural plaques quantitated by computed tomography scanning: no relation with cumulative asbestos exposure and no effect on lung function | eng_Latn | 15,525 |
Quality control phantom for flat panel detector X-ray systems. | A cross‐sectional study of the radiation dose and image quality of X‐ray equipment used in IVR | Negative feedback in ants: crowding results in less trail pheromone deposition | eng_Latn | 15,526 |
Medical exposures account, on average, for some 14% of the background ionising radiation exposure in the UK and form the great majority of the non-natural component. In the United States of America, medical exposures comprised over 50% of the total in 2006. This is due primarily to an increase in x-ray computed tomography (CT) and positron emission tomography (PET) procedures. This paper highlights the potential problems in the use of CT scanning to investigate the asymptomatic individual, where the traditional risk/benefit considerations are less clear-cut than in conventional clinical situations. It draws on a recent COMARE report which examined the use of CT for whole body, heart, lung and colon studies. The number of PET facilities is increasing rapidly in the UK and, in addition to considerations of radiation dose to subjects, careful planning is necessary to limit doses to staff. In non-ionising radiation, a topic of keen interest at present is the use of increasingly powerful sunbeds, particularly by those aged under 18. Legislation and regulation vary widely across Europe and the Scottish Parliament has recently introduced the first UK regulation. It is suggested that further research is required into the effects of current UV systems and the reasons why tanning is thought so desirable by Caucasians. Lastly, a number of issues requiring radiobiological and epidemiological input are considered and actions to satisfy these identified. | Background. Although using computed tomography (CT) can be greatly beneficial, the associated relatively high radiation doses have led to growing concerns in relation to potential associations with risk of future cancer. Very little has been published regarding the trends of CT use in young people. Therefore, our objective was to assess temporal and other patterns in CT usage among patients aged under 22 years in Great Britain from 1993 to 2002. Methods. Electronic data were obtained from the Radiology Information Systems of 81 hospital trusts within Great Britain. All included patients were aged under 22 years and examined using CT between 1993 and 2002, with accessible radiology records. Results. The number of CT examinations doubled over the study period. While increases in numbers of recorded examinations were seen across all age groups, the greatest increases were in the older patients, most notably those aged 15–19 years of age. Sixty percent of CT examinations were of the head, with the percentages varying with calendar year and patient age. Conclusions. In contrast to previous data from the North of England, the doubling of CT use was not accompanied by an increase in numbers of multiple examinations to the same individual. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,527 |
The induced colour changing of dyes under the effect of radiation has been sufficiently documented in literature. Most of the reported experimental work has been done on aqueous aerated acidic or alkaline dye solutions. The main objective of this research project is to study the effect of sunlight exposure on natural dye solutions which extracted from Rhizophora Apiculata tree. The Rhizophora Apiculata dye solutions were prepared by soaking the Rhizophora Apiculata bark in an organic solvent for 7 days. The sunlight exposure is carried out at room temperature up to 30 days. The absorbance measurements of the dye solutions were measured by using UV-Vis spectrophotometer (Palo Alto, CA). The Rhizophora Apiculata dye solutions absorbance were found at the absorption band of 665 nm and decrease with increasing of day exposure. | Dosimetric characterisation of aqueous solution of brilliant green has been studied spectrophotometrically for possible applications in low-dose food irradiation dosimetry. Absorption spectra of unirradiated and irradiated solutions were determined which showed two absorption bands with peaks at 427 and 626 nm and a decrease in absorption as the radiation dose is increased. Radiation-induced bleaching of the dye was measured at wavelengths of maximum absorbance (427 and 626 nm) as well as at 550 and 570 nm. At all these wavelengths, the decrease in absorbance of the dosimeter was linear with respect to the absorbed dose from 20 to 120 Gy. However, the upper dose limit was increased to 200 Gy when the negative logarithm of the absorbance ( − log A ) was plotted versus absorbed dose. The stability of dosimetric solution during post-irradiation storage in dark at room temperature showed that after some initial bleaching within the first 5 h of irradiation the response was stable for about 18 days. The effect of different light and temperature conditions to which a dosimeter may be exposed during commercial irradiation has been discussed. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,528 |
PURPOSE ::: To assess correlation between attenuation measurements of incidental findings in abdominal second generation dual-energy computed tomography (CT) on true noncontrast (TNC) and virtual noncontrast (VNC) images. ::: ::: ::: MATERIALS AND METHODS ::: Sixty-three patients underwent arterial dual-energy CT (Somatom Definition Flash, Siemens; pitch factor, 0.75-1.0; gantry rotation time, 0.28 seconds) after endovascular aneurysm repair, consisting of a TNC single energy CT scan (collimation, 128 × 0.6 mm; 120 kVp) and a dual-energy arterial phase scan (collimation, 32 × 0.6 mm, 140 and 100 kVp; blended, 120 kVp data set). Attenuation measurements in Hounsfield units (HU) of liver parenchyma and incidental findings like renal and hepatic cysts and adrenal masses on TNC and VNC images were done by drawing regions of interest. Statistical analysis was performed by paired t test and Pearson correlation. ::: ::: ::: RESULTS ::: Incidental findings were detected in 56 (89%) patients. There was excellent correlation for both renal (n = 40) and hepatic cysts (n = 12) as well as adrenal masses (n = 6) with a Pearson correlation of 0.896, 0.800, and 0.945, respectively, and mean attenuation values on TNC and VNC images of 10.6 HU ± 12.8 versus 5.1 HU ± 17.5 (attenuation value range from -8.8 to 59.1 HU vs -11.8 to 73.4 HU), 6.4 HU ± 5.8 versus 6.3 HU ± 4.6 (attenuation value range from 2.0 to 16.2 HU vs -3.0 to 15.9 HU), and 12.8 HU ± 11.2 versus 12.4 HU ± 10.2 (attenuation value range from -2.3 to 27.5 HU vs -2.2 to 23.6 HU), respectively. As proof of principle, liver parenchyma measurements also showed excellent correlation between TNC and VNC (n = 40) images with a Pearson correlation of 0.839 and mean attenuation values on TNC and VNC images of 47.2 HU ± 10.5 versus 43.8 HU ± 8.7 (attenuation value range from 21.9 to 60.2 HU vs 4.5 to 65.3 HU). ::: ::: ::: CONCLUSIONS ::: In conclusion, attenuation measurements of incidental findings like renal cysts or adrenal masses on TNC and VNC images derived from second generation dual-energy CT scans show excellent correlation providing considerable dose savings, favorable for future application in clinical routine. | The use of additional spectral filtration for dual-energy (DE) imaging using a dual-source CT (DSCT) system was investigated and its effect on the material-specific DE(ratio) was evaluated for several clinically relevant materials. The x-ray spectra, data acquisition, and reconstruction processes for a DSCT system (Siemens Definition) were simulated using information provided by the system manufacturer, resulting in virtual DE images. The factory-installed filtration for the 80 kV spectrum was left unchanged to avoid any further reductions in tube output, and only the filtration for the high-energy spectrum was modified. Only practical single-element filter materials within the atomic number range of 40 < or = Z < or = 83 were evaluated, with the aim of maximizing the separation between the two spectra, while maintaining similar noise levels for high- and low-energy images acquired at the same tube current. The differences between mean energies and the ratio of the 140 and 80 kV detector signals, each integrated below 80 keV, were evaluated. The simulations were performed for three attenuation scenarios: Head, body, and large body. The large body scenario was evaluated for the DE acquisition mode using the 100 and 140 kV spectra. The DE(ratio) for calcium hydroxyapatite (simulating bone or calcifications), iodine, and iron were determined for CT images simulated using the modified and factory-installed filtration. Several filter materials were found to perform well at proper thicknesses, with tin being a good practical choice. When image noise was matched between the low- and high-energy images, the spectral difference in mean absorbed energy using tin was increased from 25.7 to 42.7 keV (head), from 28.6 to 44.1 keV (body), and from 20.2 to 30.2 keV (large body). The overlap of the signal spectra for energies below 80 keV was reduced from 78% to 31% (head), from 93% to 27% (body), and from 106% to 79% (large body). The DE(ratio) for the body attenuation scenario increased from 1.45 to 1.91 (calcium), from 1.84 to 3.39 (iodine), and from 1.73 to 2.93 (iron) with the additional tin filtration compared to the factory filtration. This use of additional filtration for one of the x-ray tubes used in dual-source DECT dramatically increased the difference between material-specific DE ratios, e.g., from 0.39 to 1.48 for calcium and iodine or from 0.28 to 1.02 for calcium and iron. Because the ability to discriminate between different materials in DE imaging depends primarily on the differences in DE ratios, this increase is expected to improve the performance of any material-specific DECT imaging task. Furthermore, for the large patient size and in conjunction with a 100/140 kV acquisition, the use of additional filtration decreased noise in the low-energy images and increased contrast in the DE image relative to that obtained with 80/140 kV and no additional filtration. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 15,529 |
Cerenkov luminescence imaging can image radiopharmaceuticals using a high-sensitivity charge-coupled device camera. However, Cerenkov luminescence emitted from the radiopharmaceuticals is weak and has low penetration depth in biologic tissues, which severely limits the sensitivity and accuracy of Cerenkov luminescence imaging. This study presents 3-dimensional (3D) radiopharmaceutical-excited fluorescence tomography (REFT) using europium oxide (EO) nanoparticles, which enhances the Cerenkov luminescence signal intensity, improves the penetration depth, and obtains more accurate 3D distribution of radiopharmaceuticals. REFT with EO nanoparticles significantly improves accuracy of localization of radiopharmaceuticals and can precisely localize the tumor in vivo. | Cerenkov luminescence imaging (CLI) is a novel imaging modality to study charged particles with optical methods by detecting the Cerenkov luminescence produced in tissue. This paper first describes the physical processes that govern the production and transport in tissue of Cerenkov luminescence. The detectors used for CLI and their most relevant specifications to optimize the acquisition of the Cerenkov signal are then presented, and CLI is compared with the other optical imaging modalities sharing the same data acquisition and processing methods. Finally, the scientific work related to CLI and the applications for which CLI has been proposed are reviewed. The paper ends with some considerations about further perspectives for this novel imaging modality. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 15,530 |
The problem of choosing which collimator to use for imaging a new isotope has been approached by collecting resolution and sensitivity data for a selected group of isotopes. These have been chosen to be readily available and to have generally a single γ-ray only. Resolution and sensitivity plots for a low energy collimator and a high energy collimator are presented and their use with several isotopes of interest is discussed. The interpretation of recommendations in the literature on the choice of collimators for newly introduced isotopes would be considerably simpler if data in this format were commonly available. | Measurements of sensitivity, spatial resolution, dead time, and field uniformity, as well as imaging of phantoms, provide a satisfactory means of evaluating and comparing Anger camera systems. The authors recommend that these parameters be measured periodically to detect deterioration of performance. A clinical evaluation of images depends upon the type of cathode-ray tube display and associated film response. Thus, given an optimized camera system, an appropriate display format is also required for best results. | By using a superluminescent diode as the light source and a depolariser inside the fibre coil, a constant scale factor is achieved without using polarisation control elements. For long-term behaviour an RMS-bias drift of 10 degrees/h is obtained. | eng_Latn | 15,531 |
We examined the relationship between the formation of proliferating cell nuclear antigen (PCNA) complex with DNA and nucleotide excision repair in human fibroblasts following ultraviolet light (uv) irradiation. PCNA complex formation was detected by the immunofluorescence method after methanol fixation and nucleotide excision repair activity was detected as the unscheduled DNA synthesis (UDS) by autoradiography labeled with [3H]thymidine. Quiescent normal cells showed a strong punctuated pattern of PCNA staining 5 min to 3 h and UDS 3 h after 10 J/m2 of uv irradiation, but they no longer showed PCNA staining and UDS 24 h after irradiation. In contrast, xeroderma pigmentosum group A (XP-A) cells, which lack UDS activity, did not show PCNA staining up to 30 min after irradiation; however, unexpectedly, they were stained 3 h and even 24 h after irradiation with their staining pattern being different from that in normal cells. Namely, the fluorescence spots in XP-A cells were larger in size and much smaller in number than those in normal cells. When XP-A cells were fused with normal cells with polyethylene glycol treatment, nuclei of XP-A cells showed a PCNA staining pattern similar to that of normal cells at 30 min, which was no longer detected 24 h after irradiation. These results suggest that there exist two types of PCNA complex formation, nucleotide excision repair-related and -unrelated, in human fibroblasts following uv irradiation. | The subcellular distribution and posttranslational modification of human chromatin assembly factor 1 (CAF-1) have been investigated after UV irradiation of HeLa cells. In an asynchronous cell population only a subfraction of the two large CAF-1 subunits, p150 and p60, were found to exist in a chromatin-associated fraction. This fraction is most abundant during S phase in nonirradiated cells and is much reduced in G2 cells. After UV irradiation, the chromatin-associated form of CAF-1 dramatically increased in all cells irrespective of their position in the cell cycle. Such chromatin recruitment resembles that seen for PCNA, a DNA replication and repair factor. The chromatin-associated fraction of p60 was predominantly hypophosphorylated in nonirradiated G2 cells. UV irradiation resulted in the rapid recruitment to chromatin of phosphorylated forms of the p60 subunit. Furthermore, the amount of the p60 and p150 subunits of CAF-1 associated with chromatin was a function of the dose of UV irradiation. Consistent with these in vivo observations, we found that the amount of CAF-1 required to stimulate nucleosome assembly during the repair of UV photoproducts in vitro depended upon both the number of lesions and the phosphorylation state of CAF-1. The recruitment of CAF-1 to chromatin in response to UV irradiation of human cells described here supports a physiological role for CAF-1 in linking chromatin assembly to DNA repair. | The USACE-Norfolk District (NAO) and the City of Petersburg, VA are working toward restoring the former Appomattox River Federal Navigation Channel. In this effort, ~350,000 cubic yards of deposited sediment will be removed from -14 feet MLLW up to + 6 feet MLLW over a ~1 mile reach of the Appomattox River. Historical industrial uses have resulted in PAH contamination exceeding 500 mg/kg on average, with hotspots detected in excess of 5,000 mg/kg based on USACE 2004 analytical data. To support the NAO with its assessment of contaminant distribution, upland source control measures, dredge sequencing, sediment capping requirements to address residual contaminants and beneficial reuse options for the dredged material have been evaluated. In support of beneficial reuse as agricultural soil, a lab treatability study has been completed to assess biodegradation potential. Total PAH concentrations in three laboratory test pans after 46 weeks of treatment indicated an overall 80% contaminant reduction using an enhanced bioremediation process. The results of this bench-scale study were used as the basis for the design of a pilot field-scale landfarm study demonstration undertaken during July 2007. After five months of treatment, LMW PAHs in landfarm material appear to have degraded first while HMW PAHs are degrading more slowly, a process which generally mimics the results of the laboratory investigation. Conclusions based on the laboratory and landfarm activities as well as the technical and regulatory issues that must be resolved to allow eventual placement of the material at a mine reclamation site for revegetation purposes will be presented. | eng_Latn | 15,532 |
We study the production of radioisotopes for nuclear medicine in (gamma,gamma') photoexcitation reactions or (gamma,xn + yp) photonuclear reactions for the examples of ^195mPt, ^117mSn and ^44Ti with high flux [(10^13 - 10^15) gamma/s], small beam diameter and small energy band width (Delta E/E ~ 10^-3 -10^-4) gamma beams. In order to realize an optimum gamma-focal spot, a refractive gamma-lens consisting of a stack of many concave micro-lenses will be used. It allows for the production of a high specific activity and the use of enriched isotopes. For photonuclear reactions with a narrow gamma beam, the energy deposition in the target can be reduced by using a stack of thin target wires, hence avoiding direct stopping of the Compton electrons and e^+e^- pairs. The well-defined initial excitation energy of the compound nucleus leads to a small number of reaction channels and enables new combinations of target isotope and final radioisotope. The narrow-bandwidth gamma excitation may make use of collective resonances in gamma-width, leading to increased cross sections. (gamma,gamma') isomer production via specially selected gamma cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. The produced isotopes will open the way for completely new clinical applications of radioisotopes. For example ^195mPt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. In targeted radionuclide therapy the short-range Auger and conversion electrons of ^195mPt and ^117mSn enable a very local treatment. The generator ^44Ti allows for a PET with an additional gamma-quantum (gamma-PET), resulting in a reduced dose or better spatial resolution. | The BR2 reactor is a 100MW(th) high-flux 'materials testing reactor', which produces a wide range of radioisotopes for various applications in nuclear medicine and industry. Tin-117m ((117m)Sn), a promising radionuclide for therapeutic applications, and its production have been validated in the BR2 reactor. In contrast to therapeutic beta emitters, (117m)Sn decays via isomeric transition with the emission of monoenergetic conversion electrons which are effective for metastatic bone pain palliation and radiosynovectomy with lesser damage to the bone marrow and the healthy tissues. Furthermore, the emitted gamma photons are ideal for imaging and dosimetry. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,533 |
Although not yet implemented, the 1996 amendments to the Safe Drinking Water Act instructed the states (or local water suppliers) to address radon concentrations in community water systems (CWS). As an alternative to reducing waterborne radon concentrations in the CWS to the maximum contaminant level (MCL) of 11 Bq L -1 , states (or individual CWS) would be permitted to develop a multimedia mitigation (MMM) program, which allowed a greater concentration (148 Bq L -1 ) of waterborne radon in the CWS, if it could be shown that an equivalent health risk reduction could be achieved by reducing indoor radon concentrations. For a MMM program to be acceptable, the U.S. Environmental Protection Agency required the health-risk reduction attained through mitigations and radon-resistant new construction (RRNC) to offset the increased health risk due to radon in community water systems above the MCL of 11 Bq L -1 . A quantitative assessment indicates that the reduction in health risk currently achieved in New York State through radon mitigations and RRNC exceeded the increase in risk associated with an alternative MCL of 148 Bq L -1 . The implementation of a MMM program in New York would result in an overall reduction in the health risk associated with exposure to radon. | Enhanced thoron (220Rn) concentrations reported in Chinese traditional clay dwellings [18, 21], Japanese traditional mud houses [3, 6], Italian tuff and pozzolana buildings [16, 17] and some other potential high risk areas [19] have caused some attention. The decay products of thoron, both attached and unattached fractions, have high potential alpha energy per activity which contributes to a distinct inhalation exposure [23]. Increasing reports point out that the ratio of effective dose from thoron and its progeny to that from radon, thoron and their progeny in some cases accounts for 20% [26], 38% [18] and 55% [7]. Thereby, the exploration on controlling the thoron decay products has practical significance. There are some existing reports about the mitigation of radon and its decay products [2, 8, 10, 14, 25], while scarce literature on the active mitigating of thoron decay products exists. For radon, there are several techniques to minimize the radon concentration, like sub-slab ventilation, foundation drain suction, crawl space ventilation, heat recovery ventilation, sump and sealing, fan-ion generator [1, 4, 9, 12], etc. On the contrary to radon and its progeny, thoron has a very short half-life (56 s), and its most important decay products have longer half-lives (10.6 h, 1 h) compared to the short-lived radon decay products. The consequence is a different activity size distribution in nucleation and accumulation mode of the thoron decay products [5]. The mitigation approach and its effectiveness might therefore differ. Filtration approach to mitigate indoor thoron progeny concentration Jin Wang, Oliver Meisenberg, Yongheng Chen, Erwin Karg, Jochen Tschiersch | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 15,534 |
The worldwide proliferation of mobile phones raises the question of the effects of 900-MHz electromagnetic fields (EMF) on the brain. Using a head-only exposure device in the rat, we showed that a 15-min exposure to 900-MHz pulsed microwaves at a high brain-averaged power of 6 W/kg induced a strong glial reaction in the brain. This effect, which suggests neuronal damage, was particularly pronounced in the striatum. Moreover, we observed significant and immediate effects on the Kd and Bmax values of N-methyl-D-aspartate (NMDA) and GABA(A) receptors as well as on dopamine transporters. Decrease of the amount of NMDA receptors at the postsynaptic membrane is also reported. Although we showed that the rat general locomotor behavior was not significantly altered on the short term, our results provide the first evidence for rapid cellular and molecular alterations in the rat brain after an acute exposure to high power GSM (Global System for Mobile communication) 900-MHz microwaves. | Worldwide expansion of mobile phones and electromagnetic field (EMF) exposure has raised question of their possible biological effects on the brain and nervous system. Radiofrequency (RF) radiation might alter intracellular signaling pathways through changes in calcium (Ca(2+)) permeability across cell membranes. Changes in the expression of calcium binding proteins (CaBP) like calbindin D28-k (CB) and calretinin (CR) could indicate impaired Ca(2+)homeostasis due to EMF exposure. CB and CR expression were measured with immunohistochemistry in the hippocampus of mice after EMF exposure at 835 MHz for different exposure times and absorption rates, 1 h/day for 5 days at a specific absorption rate (SAR)=1.6 W/kg, 1 h/day for 5 days at SAR=4.0 W/kg, 5 h/day for 1 day at SAR=1.6 W/kg, 5 h/day for 1 day at SAR=4.0 W/kg, daily exposure for 1 month at SAR=1.6 W/kg. Body weights did not change significantly. CB immunoreactivity (IR) displayed moderate staining of cells in the cornu ammonis (CA) areas and prominently stained granule cells. CR IR revealed prominently stained pyramidal cells with dendrites running perpendicularly in the CA area. Exposure for 1 month produced almost complete loss of pyramidal cells in the CA1 area. CaBP differences could cause changes in cellular Ca(2+)levels, which could have deleterious effect on normal hippocampal functions concerned with neuronal connectivity and integration. | The method of anomalous viscosity time dependence (AVTD) was used to study the influence of nonthermal microwaves on the genome conformational state (GCS) of Escherichia coli cells. 20-Gy X-rayed cells were exposed to circularly polarized microwaves at seven frequencies of the 51.62–51.84 GHz band in which linearly polarized electromagnetic radiation (EMR) resonantly inhibits repair of X-ray-induced changes in the GCS. At all the frequencies that were studied, right-handed-polarized microwaves effectively influenced the GCS of X-rayed cells, whereas left-handed polarization was virtually ineffective. And conversely, right-handed polarization was ineffective and the left-handed polarized EMR effectively influenced the GCS when intact cells were exposed to microwaves. The two resonance dependences of millimeter waves' effect on the GCS of E. coli cells (both preliminarily irradiated and unirradiated by X-rays) had the same resonance frequency of 51.76 GHz, and a half–width of the resonance of about 100 MHz.... | eng_Latn | 15,535 |
There are few effective treatment options for radiation-induced dermatitis in breast cancer patients. We conducted a single-arm trial to tested the hypothesis that topical epigallocatechin-3-gallate (EGCG) is effective against radiation-induced dermatitis in breast cancer patients undergoing radiotherapy. Forty-nine patients participated in this study. The patients underwent mastectomy followed by adjuvant radiotherapy. Topical EGCG was applied daily, starting when grade I dermatitis appeared and ending two weeks after radiotherapy. The maximum dermatitis observed during the EGCG treatment was as follows: Grade 1 toxicity, 71.4% (35 patients); grade 2 toxicity, 28.6% (14 patients); there were no patients with grade 3 or 4 toxicity. The majority of the radiation-induced dermatitis was observed 1 week after the end of radiotherapy. EGCG reduced the pain in 85.7% of patients, burning-feeling in 89.8%, itching in 87.8%, pulling in 71.4%, and tenderness in 79.6%. These findings suggest topical EGCG may be an effective treatment for radiation-induced dermatitis and has acceptable toxicity. | Green tea is rich in polyphenols, like catechins, which are thought to contribute to the health benefits of tea. The aim of this study was to evaluate the radioprotective effect of EGCG (epigallocatechin-3-gallate), a green tea catechin on γ-radiation induced cell damage. Under acellular condition of radiation exposure, pBR322 plasmid DNA was protected by EGCG in a concentration dependent manner. Treatment of murine splenocytes with EGCG 2 h prior to radiation (3 Gy), protected the cellular DNA against radiation-induced strand breaks. EGCG also inhibited γ-radiation induced cell death in splenocytes. EGCG pretreatment to the cells decreased the radiation induced lipid peroxidation and membrane damage. The levels of phase II enzymes, glutathione and lactate dehydrogenase were restored with EGCG treatment prior to radiation. Our results show that pretreatment with EGCG offers protection to pBR322 DNA under acellular condition and normal splenocytes under cellular condition, against γ-radiation induced damage and is better radioprotector in comparison to quercetin and vitamin C. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 15,536 |
The effects of radiofrequency electromagnetic field (RF-EMF) exposure on neuronal phenotype maturation have been studied in two different in vitro models: murine SN56 cholinergic cell line and rat primary cortical neurons. The samples were exposed at a dose of 1W/kg at 900 MHz GSM modulated. The phenotype analysis was carried out at 48 and 72 h (24 and 48 h of SN56 cell line differentiation) or at 24, 72, 120 h (2, 4 and 6 days in vitro for cortical neurons) of exposure, on live and immunolabeled neurons, and included the morphological study of neurite emission, outgrowth and branching. Moreover, cortical neurons were studied to detect alterations in the expression pattern of cytoskeleton regulating factors, e.g. beta-thymosin, and of early genes, e.g. c-Fos and c-Jun through real-time PCR on mRNA extracted after 24h exposure to EMF. We found that RF-EMF exposure reduced the number of neurites generated by both cell systems, and this alteration correlates to increased expression of beta-thymosin mRNA. | This study investigated the effects of mobile-phone-type radiation on the cerebral activity of seizure-prone animals. The experimental set-up used in this research for exposure of small animals to radiofrequency standing waves allows direct measurement of the power absorbed by the animal. Essentially, the setup consists of a metallic box containing an antenna and experimental animal immobilized in a methacrylate holder; a signal generator feeding the antenna; and a power meter. In addition, the box can also contain a video camera to record the animal's behavior, and a receiving antenna (connected externally to a power meter and a spectrum analyser) to detect undesired (external) radiation and possible harmonics of the radiating system. The absorbed power measurement trivially allows calculation of whole-body mean SAR from the animal's weight; an assuming local SARs to be proportional to whole-body mean SAR, the latter can be used to adjust organ-specific SAR predictions obtained by simulation using a commercial FDTD program with a numerical phantom. In an experiment the rats were transformed into an experimental model of seizure-proneness by acute subconvulsive doses of picrotoxin were exposed to 2 hours GSM-modulated 900MHz radiation at intensity similar to that emitted by mobile phones. In this study we analyzed -by means of immunochemical testing of relevant anatomical areas- the relationship between the induction of c-fos (neuronal marker) and GFAP (glia marker) in acute experimentally models to establish the effects on the CNS (Central Nervous System) of 72 adult male Sprague-Dawley rats after 60 minutes, 24 hours and 3 days of exposure to EMF radiation. The parameters of radiation absorbed power, incident power, for the calculus of average SAR exp , Peak SAR values calculated for picrotoxin-treated and untreated irradiated rats showed non thermal values. The significance of between-group differences in c-fos positive cell counts was assessed by ANOVA: a) considering all brain regions together, with factors Treatment (picrotoxin, or no picrotoxin) and Radiation (no radiation, modulated radiation) and Time (90 min, 1 day, 3 days); b) considering each brain region separately, with factors Treatment, Radiation, Area and Time (i.e. areas within that region); and c) considering each brain area separately, with factors Treatment and Radiation and Time. Similar studies were carried out for GFAP positive cells but only at time =3 days. Natural logarithm transformations were applied to data to obtain normality and homoscedasticity. Differences between regions and areas were considered significant at P 3 areas (p< 0.001, p= 0.016), but not in remaining areas. The treatment-by-radiation interaction was significant globally and in the entorhinal area (p<=0.001). These results showed that the compensatory mechanism of radiation in brain tissues depends on the time in every neuronal expression of c-fos. But the glia population had a limited response in several areas or regions for same level of radiation. | Eisenia fetida earthworms were exposed to electromagnetic field (EMF) at a mobile phone frequency (900 MHz) and at field levels ranging from 10 to 120 V m-1 for a period of two hours (corresponding to specific absorption rates ranging from 0.13 to 9.33 mW kg-1). Potential effects of longer exposure (four hours), field modulation, and a recovery period of 24 h after two hours of exposure were addressed at the field level of 23 V m-1. All exposure treatments induced significant DNA modifications as assessed by a quantitative random amplified polymorphic DNA-PCR. Even after 24 h of recovery following a two hour-exposure, the number of probe hybridisation sites displayed a significant two-fold decrease as compared to untreated control earthworms, implying a loss of hybridisation sites and a persistent genotoxic effect of EMF. Expression of genes involved in the response to general stress (HSP70 encoding the 70 kDa heat shock protein, and MEKK1 involved in signal transduction), oxidative stress (CAT, encoding catalase), and chemical and immune defence (LYS, encoding lysenin, and MYD, encoding a myeloid differentiation factor) were up-regulated after exposure to 10 and modulated 23 V m-1 field levels. Western blots showing an increased quantity of HSP70 and MTCO1 proteins confirmed this stress response. HSP70 and LYS genes were up-regulated after 24 h of recovery following a two hour-exposure, meaning that the effect of EMF exposure lasted for hours. | eng_Latn | 15,537 |
A neutron track etch detector for electron linear accelerators in radiotherapy Background. Electron linear accelerators in medical radiotherapy have replaced cobalt and caesium sources of radiation. However, medical accelerators with photon energies over 10 MeV generate undesired fast neutron contamination in a therapeutic X-ray photon beam. Photons with energies above 10 MeV can interact with the atomic nucleus of a high-Z material, of which the target and the head of an accelerator consist, and lead to the neutron ejection. Results and conclusions. Our neutron dosimeter, composed of the LR-115 track etch detector and boron foil BN-1 converter, was calibrated on thermal neutrons generated in the nuclear reactor of the Josef Stefan Institute (Slovenia), and applied to dosimetry of undesirable neutrons in photon radiotherapy by the linear accelerator 15 MV Siemens Mevatron. Having considered a high dependence of a cross-section between neutron and boron on neutron energy, and broad neutron spectrum in a photon beam, as well as outside the entrance door to maze of the Mevatron, we developed a method for determining the effective neutron detector response. A neutron dose rate in the photon beam was measured to be 1.96 Sv/h. Outside the Mevatron room the neutron dose rate was 0.62 μSv/h. PACS: 87.52. Ga; 87.53.St; 29.40.Wk. | Medical accelerators with photon energies over 10 MeV generate an undesired fast neutron contamination in the therapeutic beam. In this work, the Monte Carlo code MCNP was used to simulate the transport of these photoneutrons across the head of various medical accelerators of high energy. The average and most probable neutron energies were obtained from these spectra, before and after crossing the accelerator shielding. The degradation of these spectra, when they cross concrete barriers with thickness which vary between 25 and 100 cm, was also studied. | The reduction of proline by Clostridium sporogenes NCIB8053 is coupled to transmembrane proton translocation in an uncoupler-sensitive fashion (and might therefore conserve free energy). This finding serves to explain the increase in the growth yield of this organism when proline is added to a defined growth medium containing glucose as the catabolic substrate. | eng_Latn | 15,538 |
A fundamental problem in cell biology is the cause of aging. The solution to this problem has not yet been obtained because, (l) until recently, it was not possible to image living cells directly. The use of low-energy (soft) X rays has made such imaging possible, perhaps thereby allowing the aging process to be understood and possibly overcome (a result that may well generate further social, moral, and ethical problems). Fortun ately this is not the only aspect of cell biology amenable to soft X-ray imaging, and it is envisaged that many less controversial studies--such as investigations of the detailed differences between healthy and diseased or malignant cells (in their natural states) and processes of cell division and growth-will be made possible. The use of soft X rays is not limited to biological studies-many applications are possible in, for example, fusion research, materials science, and astronomy. Such studies have only recently begun in earnest because several difficulties had to be overcome, major among these being the lack (for some purposes) of sufficiently intense sources, and the technological difficulties associated with making efficient optical systems. As is well known, the advent of dedicated synchrotron radiation sources, in particular, has alleviated the first of these difficulties, not just for the soft X-ray region. It is the purpose of this book to consider progress in the second." | The strong chromatic behavior associated with a conventional diffractive lens is fully exploited to propose a novel optical device for pulse shaping in the femtosecond regime. This device consists of two optical elements: a spatially patterned circularly symmetric mask and a kinoform diffractive lens, which are facing each other. The system performs a mapping between the spatial position of the masking function expressed in the squared radial coordinate and the temporal position in the output waveform. This space-to-time conversion occurs at the chromatic focus of the diffractive lens, and makes it possible to tailor the output central wavelength along the axial location of the output point. Inspection of the validity of our device is performed by means of computer simulations involving the generation of femtosecond optical packets. | A fundamental problem in cell biology is the cause of aging. The solution to this problem has not yet been obtained because, (l) until recently, it was not possible to image living cells directly. The use of low-energy (soft) X rays has made such imaging possible, perhaps thereby allowing the aging process to be understood and possibly overcome (a result that may well generate further social, moral, and ethical problems). Fortun ately this is not the only aspect of cell biology amenable to soft X-ray imaging, and it is envisaged that many less controversial studies--such as investigations of the detailed differences between healthy and diseased or malignant cells (in their natural states) and processes of cell division and growth-will be made possible. The use of soft X rays is not limited to biological studies-many applications are possible in, for example, fusion research, materials science, and astronomy. Such studies have only recently begun in earnest because several difficulties had to be overcome, major among these being the lack (for some purposes) of sufficiently intense sources, and the technological difficulties associated with making efficient optical systems. As is well known, the advent of dedicated synchrotron radiation sources, in particular, has alleviated the first of these difficulties, not just for the soft X-ray region. It is the purpose of this book to consider progress in the second." | eng_Latn | 15,539 |
The effect of gamma irradiation on the alpha-particle track response of CR-39 is investigated. The effects are dramatic above doses of 500Krad. The alpha-particle tracks in highly dosed plastic exhibit a ‘threshold’ residual range below which the track etching appears to saturate. The effects can be simulated by the use of a suitable V T (R) vs range curve and is therefore not a ‘skin’ effect. The effects appear to be due to the addition of the two doses, the effects being present for alpha dose + gamma dose and gamma dose + alpha dose. The average track etch rates V T /V B , remain constant up to 500Krad but then exhibit a fall-off at higher doses. The observations have relevance for neutron spectrometry and dosimetry measurements where large gamma fields may be present. The bulk etching behaviour is also investigated. The change in bulk etching rate is too small to be of any value in a gamma dosemeter for doses below 100Krad. | The present work shows the induced modification of the structural, optical, chemical etching and electrochemical etching parameters of CR-39 irradiated with alpha-particles. CR-39 polymer track detectors were irradiated with different fluences (1.62 × 106, 2.72 × 106, 3.82 × 106 and 5.21 × 106 particles/cm2) of alpha-particles using 241Am source. The structural and optical properties were measured by FT-IR spectroscopy, X-ray diffraction and UV/Vis spectroscopy, respectively. The FT-IR spectra reveal that no major changes in the typical functional groups of irradiated polymer detectors. The X-ray diffraction patterns show that a broad band in the region of 12° < 2θ > 27°, which refers to the presence of the combination of amorphous and crystalline phases. UV/Vis responses of irradiated polymer track detectors exhibit a single absorption band in the range of 254-352 nm that is correlated to the occurrence of electronic transition. Also, the changes in the chemical and electrochemical parameters due to alpha-irradiation are examined and thoroughly discussed. | A major scientific goal of the Lunar Prospector (LP) gamma-ray and neutron spectrometers is to classify all lunar terranes according to composition. A preliminary analysis of early data indicates this goal will be met for the major rock-forming elements on a spatial scale of about 200 km. The low-altitude phase of LP now in progress should allow reduction of this scale by about a factor of 10 for those elements that have sufficiently high measurable fluxes relative to their backgrounds. Most promising are the flux intensities of thermal, epithermal, and fast neutrons (which each average about 300 counts per 50 km of ground track) and 2.6 MeV gamma rays from thorium (which averages about 50 counts per 50 km of ground track). The authors therefore explore the information content of these measurables to classify the various lunar terrane types. | eng_Latn | 15,540 |
An accurate knowledge of selected nuclear decay data is critical to a wide range of processes involving radionuclides. An IAEA publication in 1991 was dedicated to the evaluation of half-lives and specific gamma-ray emission probabilities for 39 selected radionuclides considered to be important for detector efficiency calibrations. A new exercise was initiated in December 1998 to update this previous evaluation and to include a number of new radionuclides of interest; 62 radionuclides were considered along with specific parent-daughter combinations (to give a total of 64 radionuclides). That work is now being completed and a new set of recommended data is being prepared for publication. A critical comparison of the 1991 and 2003 half-life data suggests that there has not been any significant improvement in the accuracy of the recommended data. The possible reasons for this situation are discussed together with the evaluation procedure and the quality of the available data. Proposals are made for concerted actions that could lead to a significant improvement in these recommended half-life data. | Additional large animal models for the acute radiation syndrome (ARS) would facilitate countermeasure development. We demonstrate here that Gottingen minipigs develop hematopoietic ARS symptoms similar to those observed in canines, non-human primates (NHPs) and humans. Dosimetry for whole-body γ irradiation (0.6 Gy/min) was performed using electronic paramagnetic resonance (EPR) with alanine; National Institute of Standards and Technology (NIST)-calibrated alanine pellets and water-filled Plexiglas phantoms were used. After irradiations of 1.6–2.0 Gy, blood pancytopenia was observed for several weeks, accompanied by the characteristic ARS stages: prodromal symptoms, latent period, illness and recovery or morbidity. Morbidity occurred between days 14 and 27, with a preliminary LD50/30 estimate between 1.7 and 1.9 Gy. The criterion of whether platelet counts were <200 × 103/µl 7 days postirradiation predicted whether animals would survive in 18 out of 20 cases. The degree of granulocytosis 3 h post... | We report enhancement of the mechanical stability of graphene through a one-step method to disperse gold nanoparticles on the pristine graphene without any added agent. | eng_Latn | 15,541 |
BACKGROUND: Compared to ISBT128 code labels, radiofrequency identification (RFID) tags have incomparable advantages and gradually applied in blood management system. However, there is no global standard for the uses of RFID frequency. Even though ISBT recommended high-frequency RFID with 13.56 MHz, 820- to 960-MHz ultrahigh frequency (UHF) RFID technology in many ways has even more advantages. For this reason, we studied the effect of UHF RFID tags with 820- to 960-MHz exposure on storage quality of red blood cells (RBCs) and platelets (PLTs). ::: ::: ::: ::: STUDY DESIGN AND METHODS: Thirty units of collected and prepared suspended RBCs (sRBCs) and PLTs were divided into two bags, one each for the test and control groups. The sRBCs were stored in 4 ± 2°C refrigerator and the PLTs in a 22 ± 2°C rocking box. The test groups were exposed to RF reader continuously during storage. Sampling at different time points and biologic changes were tested. ::: ::: ::: ::: RESULTS: As the extension of storage and the pH and chlorine levels in the supernatant of sRBCs were reduced, free hemoglobin, potassium, and sodium increased, but were not significant between test and control groups (p > 0.05). During the storage period, the pH levels, PLT count, and PLT aggregation rate were decreased in both test and control groups, but were not significant (p > 0.05). ::: ::: ::: ::: CONCLUSION: When exposed to 820- to 960-MHz RF, the biologic and biochemical indexes are not found to be exacerbated during 35 days of storage for sRBCs and 5 days for PLTs, respectively. | In this paper, the effects of UHF electromagnetic fields produced by a RFID reader on a blood bag are evaluated numerically in several configurations. The results of the simulation, field level and distribution, specific absorption rate (SAR), and heating time show that an exposure to a typical reader field leads to a temperature increase smaller than 0.1 C and to a SAR smaller than 1 W/kg. As a consequence, no adverse biological effects occur during a typical UHF RFID reading cycle on a blood bag. Therefore, the blood contained in a bag traced using UHF-RFID is as safe as those traced using barcodes. The proposed analysis supports the use of UHF RFID in the blood transfusion supply chain. | Novel circular polarization (CP) design of planar broadband antenna with square slot for UHF RFID system is proposed and experimentally studied. By insetting the arc-shaped strip into the square slot, the proposed CP design can easily be achieved with the impedance bandwidth (RL -10 dB) of about 142 MHz (15.3% @ 931 MHz) and the 3 dB axial-ratio (AR) bandwidth of about 166 MHz (17.7 % @ 940 MHz) for UHF RFID applications. The measured peak gain and radiation efficiency are about 6.8 dBic and 98% across the operating band, respectively, with nearly bidirectional pattern in the XZ- and YZ-plane. | eng_Latn | 15,542 |
Advances in accelerator technology, which have enabled conforming radiotherapy with charged hadronic species, have brought benefits as well as potential new risks to patients. To better understand the effects of ionizing radiation on tumor and surrounding tissue, it is important to investigate and quantify the relationship between energy deposition at the nanometric scale and the initial biological events. Monte Carlo track structure simulation codes provide a powerful tool for investigating this relationship; however, their success and reliability are dependent on their improvement and development accordingly to the dedicated biological data to which they are challenged. For this aim, a microbeam facility that allows for fluence control, down to one ion per cell nucleus, was used to evaluate relative frequencies of DNA damage after interaction between the incoming ion and DNA according to radiation quality. Primary human cells were exposed to alpha particles of three different energies with respective linear energy transfers (LETs) of approximately 36, 85 or 170 keV·µm–1 at the cells' center position, or to protons (19 keV·µm–1). Statistical evaluation of nuclear foci formation (53BP1/γ-H2AX), observed using immunofluorescence and related to a particle traversal, was undertaken in a large population of cell nuclei. The biological results were adjusted to consider the factors that drive the experimental uncertainties, then challenged with results using Geant4-DNA code modeling of the ionizing particle interactions on a virtual phantom of the cell nucleus with the same mean geometry and DNA density as the cells used in our experiments. Both results showed an increase of relative frequencies of foci (or simulated DNA damage) in cell nuclei as a function of increasing LET of the traversing particles, reaching a quasi-plateau when the LET exceeded 80–90 keV·µm–1. For the LET of an alpha particle ranging from 80–90 to 170 keV·µm–1, 10–30% of the particle hits did not lead to DNA damage inducing 53BP1 or γ-H2AX foci formation. | The Geant4-DNA project proposes to develop an open-source simulation software based and fully included in the general-purpose Geant4 Monte-Carlo simulation toolkit. The main objective of this software is to simulate biological damages induced by ionizing radiations at the cellular and sub-cellular scale. This project was originally initiated by the European Space Agency for the prediction of the deleterious effects of radiations that may affect astronauts during future long duration space exploration missions. In this paper, the Geant4-DNA collaboration presents an overview of the whole on-going project, including its most recent developments that are available in the Geant4 toolkit since December 2009 (release 9.3), as well as an illustration example simulating the direct irradiation of a biological chromatin fiber. Expected extensions involving several research domains, such as particle physics, chemistry and cellular and molecular biology, within a fully interdisciplinary activity of the Geant4 collaboration are also discussed. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,543 |
The Radiological Environment Modeling System (REMS) quantifies dose to humans working in radiological environments using the IGRIP (Interactive Graphical Robot Instruction Program) and Deneb/ERGO simulation software. These commercially available products are augmented with custom C code to provide radiation exposure information to, and collect radiation dose information from, workcell simulations. Through the use of any radiation transport code or measured data, a radiation exposure input database may be formulated. User-specified IGRIP simulations utilize these databases to compute and accumulate dose to programmable human models operating around radiation sources. Timing, distances, shielding, and human activity may be modeled accurately in the simulations. The accumulated dose is recorded in output files, and the user is able to process and view this output. The entire REMS capability can be operated from a single graphical user interface. | An optimization of a dismantling process should be at the beginning of a study for an evaluation of the radioactivity inventory and the safety of the workers. Many countries have been studied an optimization to achieve a shortened dismantling schedule, a reduction of an amount of waste, and cut down on the decommissioning by using computer graphics such as animation, simulation, and virtual reality. In this article, we provided methods for identifying an existence of radioactivity which is contained in the dismantling objects and for estimating a worker's dose through a simulation. To estimate a worker's external dose under a virtual dismantling environment which was produced by computer graphics, the shape of the thermal column by 3D CAD was created and the radiation dose surrounding the object was calculated by using MCNP. An animation that can demonstrate a dismantling procedure according to a dismantling scenario was produced. For matching the radiation dose which was calculated by MCNP-4C with an area where workers are dismantling a door on the animation, a simulation module which can show a worker's external dose in a real-time was developed. The result from the distribution of the radioactivity enables us to distinguish where the most contaminated part of the dismantling objects was. In the animation, a virtual worker demonstrated a dismantling activities procedure as a chosen scenario. In the simulation, a worker's exposure dose rate in a real-time as an intended in the design stage has been evaluated. | Blunt trauma abdomen rarely leads to gastrointestinal injury in children and isolated gastric rupture is even rarer presentation. We are reporting a case of isolated gastric rupture after fall from height in a three year old male child. | eng_Latn | 15,544 |
Introduction: Although travertine is now widely used as a building material, the effects of its radiological hazards to public health should be a matter of concern. Therefore, this study aimed to determine its radiological parameters with regard to human health. Material and Methods: In this research 10 travertine samples were collected from exploitation zone in Haji Abad Mine in Mahallat, Iran. Specific radionuclide activities were determined by gamma spectrometry using a high purity germanium detector. In addition, radiological parameters, such as radium equivalent, air doses, internal and external risk factors (Hin, Hex), yearly gonadal dose equivalent (AGDE), and additional cancer risk (ELCR) throughout life were calculated. Results: The specific activities of 226Ra, 232Th, and 40K radionuclides ranged within 3.08-9.16, 1.22-6.45, and 20.15-91.04 Bq/kg, respectively. The obtained means of internal and external annual effective dose of samples were 0.03 and 0.007 mSv/y. External and internal hazard indices for samples were within the range of 0.003-0.01 and 0.01-0.03, respectively. Conclusion: The results of this study show that the amount of radionuclides in travertine rocks is very small compared to its global average in soil and rock. Therefore, it is suggested to use travertine as a building material, which is not a threat to public health. | Using gamma spectrometry, the activity concentrations of natural radionuclides (226Ra, 232Th and 40K) were measured in phosphate rock samples collected from phosphate mines located in El-Sibaiya (Nile valley) and Red Sea coast, Egypt. The average activity concentrations of 226Ra, 232Th and 40K (Bqkg−1) in phosphate rocks were 512 ± 26, 41 ± 2 and 428 ± 21 Bq kg−1 for El-Sibaiya and 422 ± 21, 37 ± 2 and 324 ± 16 Bq kg−1 Red Sea coast, respectively. The radiological hazards to the occupational workers and public caused by γ-radiation have been determined. | The oxidative polymorphism of debrisoquine (DBQ) has been determined in 89 patients with colo-rectal cancer and in 556 normal control subjects. Four patients and 34 controls, with a metabolic ratio >12.6, were classified as poor metabolisers of DBQ (n.s.). | eng_Latn | 15,545 |
A high precision patient dosimetry method has been developed, based on the use of p-type diodes. First, entrance as well as exit dose calibration factors have to be determined under reference irradiation conditions. Secondly, a set of correction factors must be added for situations deviating from the reference conditions, i.e. for different source-skin distances, phantom (patient) thicknesses, field sizes or for insertion of a wedge into the photon beam. Finally some other detector characteristics such as the temperature dependence of the response have to be taken into account. For most irradiation conditions this procedure is sufficiently accurate to allow entrance as well as exist dose determinations with a diode to be in good agreement with dose values measured by an ionization chamber. The main factors effecting the value of the correction factors, the dependence of the diode sensitivity on the energy and the dose per pulse, have been investigated to explain some of the observed phenomena. Despite a strong energy dependence of the sensitivity, the correction factors are, for a particular type of diode, the same for 4 and 8 MV x-ray beams. The variation in the values for the correction factors with integrated dose received by the diode is small. These findings indicate that the correction factors, once available, can be applied under a number of circumstances. Due to the difference in behaviour of various diodes, even from the same batch, it is, however, necessary to determine the characteristics for each diode individually. | In this study, we use the quadratic calibration method (QCM), in which an EPID image is converted into a matrix of equivalent path lengths (EPLs) and, therefore, exit doses, so as to model doses in conformal and enhanced dynamic wedge (EDW) fields. The QCM involves acquiring series of EPID images at a reference field size for different thicknesses of homogeneous solid water blocks. From these, a set of coefficients is established that is used to compute the EPL of any other irradiated material. To determine the EPL, the irradiated area must be known in order to establish the appropriate scatter correction. A method was devised for the automatic calculation of areas from the EPID image that facilitated the calculation of EPL for any field and exit dose. For EDW fields, the fitting coefficients were modified by utilizing the linac manufacturer's golden segmented treatment tables (GSTT) methodology and MU fraction model. The nonlinear response of the EPL with lower monitor units (MUs) was investigated and slight modification of the algorithm performed to account for this. The method permits 2D dose distributions at the exit of phantom or patient to be generated by relating the EPL with an appropriate depth dose table. The results indicate that the inclusion of MU correction improved the EPL determination. The irradiated field areas can be accurately determined from EPID images to within ± 1% uncertainty. Cross-plane profiles and 2D dose distributions of EPID predicted doses were compared with those calculated with the Eclipse treatment planning system (TPS) and those measured directly with MapCHECK 2 device. Comparison of the 2D EPID dose maps to those from TPS and MapCHECK shows that more than 90% of all points passed the gamma index acceptance criteria of 3% dose difference and 3 mm distance to agreement (DTA), for both conformal and EDW study cases. We conclude that the EPID QCM is an accurate and convenient method for in vivo dosimetry and may, therefore, complement existing techniques. | By using a superluminescent diode as the light source and a depolariser inside the fibre coil, a constant scale factor is achieved without using polarisation control elements. For long-term behaviour an RMS-bias drift of 10 degrees/h is obtained. | eng_Latn | 15,546 |
The Waste Inspection Tomography (WIT) mobile trailer was developed and is operated by the Waste Inspection Technology Company (WITCO). WIT is designed for the unique characterization of transuranic (TRU) waste drums by performing high-energy 2 MV x-ray NonDestructive Examination (NDE) and gamma NonDestructive Assay (NDA). WIT provides for drum characterization through x-ray inspection of drum content and gamma assay determination of entrained radioactive isotopes using active and passive tomographic principles for all waste matrices. In the summer of 1998, WIT was deployed at the U.S. Department of Energy Nevada Test Site (DOE NTS) to perform its first commercial TRU drum characterization service for the DOE. The road to WIT commercialization involved an 8-year effort focused on supplying services to the DOE with the new WIT technology. This paper describes the path taken to achieve WIT commercialization with the DOE. This effort started in 1990 with a DOE Small Business Innovative Research (SBIR) grant designed to determine the feasibility of using Computed Tomography (CT) to inspect nuclear waste drums. The SBIR grant results were used in a proposal to the DOE Environmental Management Office of Science and Technology (EM-50) for the adaptation of existing medical x-ray CT technology from the proposer, Bio-Imaging Research, Inc. (BIR) and included the technology transfer of LLNL developed CT gamma assay techniques. Two EM-50 cost shared support contracts resulted in WIT trailer development and field-testing. These contracts were designed to develop BIR into a privatized commercial source for the DOE required services. The DOE SBIR and both EM-50 contracts with BIR all originated from competitively bid solicitations. WIT developed practical field experience with deployments at 3 DOE sites and one commercial site including LLNL, RFETS, INEEL, and B&W. WIT successfully participated in a number of DOE sponsored inter-comparison performance test programs including the RCI, CEP, and PDP. WIT performance was verified through a competitively bid cooperative agreement from a Rapid Commercialization Initiative (RCI). The RCI team of verifiers included the DOE, EPA, Army Corps of Engineers, and numerous state environmental regulators who prepared a verification statement. BIR won the SBA Tibbitts award for WIT innovation and economic development as an Illinois company. WIT participated in another competitively bid cooperative agreement for a DOE mobile vendor approval program designed to achieve quality assurance through audits to meet the DOE requirements for TRU waste drum disposal at WIPP. Recently, WITCO joined a commercial team of companies, “ the TRUtech team”. TRUtech and WITCO supply DOE with all of the required TRU drum WIPP certification technologies which resulted in the competitively bid NTS characterization services contract which included DOE “approvals” of WIT NDE and NDA technologies. | This paper describes the progress of a multi-modality (three detector type) system for x-rays and gamma-rays developed for the waste inspection tomography (WIT) program. WIT provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Without opening waste drums, WIT inspects and characterizes radioactive waste, including low level (LLW), transuranic (TRU), and mixed waste. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in 2D and 3D space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in 2D and 3D space, identify gamma emitting isotopic species, identify gamma emitting isotopic species, identify the extermal activity approximations, and provide the data needed for waste classification as LLW or TRU. | This paper describes the progress of a multi-modality (three detector type) system for x-rays and gamma-rays developed for the waste inspection tomography (WIT) program. WIT provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Without opening waste drums, WIT inspects and characterizes radioactive waste, including low level (LLW), transuranic (TRU), and mixed waste. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in 2D and 3D space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in 2D and 3D space, identify gamma emitting isotopic species, identify gamma emitting isotopic species, identify the extermal activity approximations, and provide the data needed for waste classification as LLW or TRU. | eng_Latn | 15,547 |
A seven step series of whole body irradiations beginning with 1,872 R and ending with 20,000 R showed that 10,000 R is not sufficient to block posterior regeneration from the fiftieth segment in the barnyard earthworm, Eisenia foetida but that 20,000 R is completely effective. ::: ::: ::: ::: With partial body irradiation at 20,000 or 30,000 R, if the five segments adjacent to the cut surface are exposed and the rest of the body shielded, there is no regeneration by the end of four weeks when controls have regenerated a mean of 34 segments and a minimum of 23 and stopped forming new ones. At the end of seven or more weeks all the partially irradiated worms had recovered and regenerated up to means of 17.3, 20.0, and even 26.3 segments. ::: ::: ::: ::: An abscopal effect was clearly evident in worms in which the first 40 segments were irradiated and the rest of the body, including the ten segments adjacent to the cut surface, shielded. All such worms regenerated without appreciable delay but markedly fewer segments than the controls. The question then arises as to why regenerating blastemas which are fully competent to regenerate a mean of 25 segments do not continue to proliferate until they have formed about 35 like the controls. | Significance: Radiation therapy (from external beams to unsealed and sealed radionuclide sources) takes advantage of the detrimental effects of the clustered production of radicals and rea... | An electronically steerable parasitic array radiator antenna is presented. The antenna has only a single element connected to a receiver or a transmitter. This active element is surrounded by parasitic elements loaded with variable reactors (varactors). The loaded reactance and the length of the parasitic radiators are designed so that each of the parasitic elements plays its role of director or reflector depending on its bias voltage on the loaded reactance. This design guarantees that the radiation pattern can be controlled by changing the bias voltages on the varactors. For omnipattern forming, a voltage vector is obtained such that the received power is maximised under the assumption that each component of the voltage vector is equal. An experiment yields an omnipattern with an average −0.83 dBi gain over the angles [0°, 360°). For sector pattern forming, a single-source power maximisation technique is proposed to optimise the voltage vector such that the received signal power is as large as possible in the direction of the source. Experiments yield twelve sector patterns at every 30°. The average gain is 5.5 dBi in the patterns' beam directions. The average 3 dB beamwidth is 72.4° for the sector patterns in the directions 0°, 60°, 120°, 180°, 240°, and 300°, while the average value is 90.1° for the remaining patterns. | eng_Latn | 15,548 |
The RVG-4 permits automatic exposure compensation (AEC). The purpose of this investigation was to determine the effects of AEC on image contrast. Images were made either with or without a dental QA jaw phantom using a fixed image projection geometry. Exposures were 6.3 through 27.3 μC/kg using an X-ray generator operated at 70 kVp. Region of interest pixel value distributions were measured at tissue thicknesses in this phantom, and the average pixel values and signal-to-noise ratios (SNR) were calculated. The use of AEC without an object in place resulted in a disproportionate relationship between pixel value and exposure with a marked reduction in SNR. The use of AEC on under- and over-exposed images of the phantom simultaneously enhanced image contrast and reduced SNR. Thus, AEC provides a convenient and quick method for achieving high-contrast images with sub-optimal exposures, however, this could lead to inappropriate patient dosages if the function is used for over-exposed images. AEC reduces the SNR and produces disproportionate pixel values relative to exposure. | The Sens-A-Ray system for direct digital intraoral radiography may be used with any computer compatible with an IBM PC/AT. The system relies on a charge-coupled device designed for direct conversion of x-ray energy to an electronic signal. It is the first such device for direct acquisition of radiographs. Technical properties of charge-coupled device detectors when exposed to radiation energies in the range of x-rays used in dental radiography have been studied. Even in the absence of light or x-radiation there is a spontaneous generation of charge within a charge-coupled device detector that gives rise to a background signal, a dark current. It was found that the dark current is a linear function of exposure time. The dose response of the charge-coupled device detector was determined at nominal kilovoltages that range from 50 to 90 kVp. The dose response was shown to be a linear function of exposure. The functions for all kVp settings were practically identical. The charge-coupled device detector is more sensitive to x-radiation than conventional dental films and, consequently, its exposure range is more narrow. The signal-to-noise ratio was calculated from the digital radiographs used for the dose response test. The ratio is above 10 for exposures higher than about 2 microC/kg. The line spread function was determined from test radiographs of a 10 microns wide slit in a test object of 1.5 mm thick tantalum. After curve fitting, the line spread function could be expressed as the sum of a Gaussian and an exponential function. Presampling modulation transfer functions valid at the detector plane and at an object plane were calculated from fitted data on the line spread function. It is concluded that the Sens-A-Ray system has such technical properties that it may replace conventional film-based systems. | Connected vehicles provide advanced transformations and attractive business opportunities in the automotive industry. Presently, IEEE 802.11p and evolving 5G are the mainstream radio access technologies in the vehicular industry, but neither of them can meet all requirements of vehicle communication. In order to provide low-latency and high-reliability communication, an SDN-enabled network architecture assisted by MEC, which integrates different types of access technologies, is proposed. MEC technology with its on-premises feature can decrease data transmission time and enhance quality of user experience in latency-sensitive applications. Therefore, MEC plays as important a role in the proposed architecture as SDN technology. The proposed architecture was validated by a practical use case, and the obtained results have shown that it meets application- specific requirements and maintains good scalability and responsiveness. | eng_Latn | 15,549 |
Glasses are of special interest nowadays mainly because of the large applications that they span. Raman spectroscopy is an experimental technique appropriate for providing information about the structure of local arrangements of the atoms in glasses. The influence of CaO content on the structure of borate glasses was investigated by Raman spectroscopy. At low calcium oxide content the structure of calcium borate glass consists mainly of boroxol groups and a smaller number of pentaborate groups. In the vitreous network there are few diborate groups, chain type metaborate groups and pyroborate groups. At high calcium oxide content, pentaborate, orthoborate and metaborate groups appear. The increase of calcium oxide content yields an increase in number of non-bridging oxygen ions. Therefore, we conclude that calcium ions act as network modifiers in borate glasses. | A three-oxide sodium borosilicate glass was irradiated with 2.3 MeV electrons up to 0.15 GGy and 4.6 GGy, and subsequently with 96 MeV Xe ions. The irradiated samples were characterised using Raman spectroscopy, ToF-SIMS, microhardness and surface profilometry. Electron irradiation of the pristine glasses resulted in different structural modifications at the sample surface and in the bulk of the glass, whereas, ion irradiation of either the pristine or bulk of the electron pre-irradiated glasses induced same structural, physical and mechanical property changes. Furthermore, sample surfaces showed a different behaviour than that of the bulk upon subsequent ion irradiation. These results show that the radiation sensitivity of surfaces can significantly vary depending on the type of the irradiation. Therefore, detailed studies aimed at understanding the response of the surfaces to mono and electron-ion double-beam irradiations should be undertaken to address the long-term evolution of the nuclear waste glass matrix surfaces. | Background ::: Serum calcium (Ca) and inorganic phosphate (Pi) concentrations and calcium-phosphate product (CPP) levels are positively associated with worse outcomes in patients with chronic kidney disease, but there are few data for Pi or Ca and none for CPP in patients with chronic heart failure (CHF). | eng_Latn | 15,550 |
Large anterior electron fields are sometimes used to irradiate the neck when treating head & neck tumors. To offer a degree of spinal cord shielding, wax bolus, approximately the width of the vertebral bodies, is placed on the immobilization shell. The thickness of the bolus is adjusted so that the radiological depth of the anterior edge of the vertebral bodies is equal to the R80 depth for the energy used. This approach ignores electron scattering. Using a CT study of a thyroid cancer patient, neck contours were generated at 0.5 cm intervals and entered into the Alberta Treatment Planning system. Internal contours for the trachea and vertebral bodies were added and CT information was used for treatment planning purposes. The bolus outline was added as described above, and the dose calculated using a 3D implementation of the M.D. Anderson (Hogstrom) algorithm. The calculation shows that the simple bolus technique described above is inappropriate. The spinal cord is adequately shielded, but the target volume is not covered by the 80% isodose line. Qualitatively, the results can be explained by the lateral scatter non-equilibrium introduced by the bolus. By iteratively adjusting the shape and thickness of the wax bolus and recalculating the dose distribution, we were able to better fulfill the dose prescription. Comparison with measured data shows reasonable, but not perfect agreement. In conclusion, electron beam treatments must be examined closely to ensure that the treatment goals are met. In some cases, treatment integrity may be compromised by incorrect assumptions regarding the nature of the electron transport and dose deposition. | The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American ::: Association of Physicists in Medicine (AAPM) was to provide a methodology and set of ::: procedures for a medical physicist performing clinical electron beam ::: dosimetry in the ::: nominal energy range of 5–25 MeV. Specifically, the task group recommended procedures for ::: acquiring basic information required for acceptance testing and treatment planning of new ::: accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant ::: advances have taken place in the field of electron beam ::: dosimetry, the ::: most significant being that primary standards laboratories around the world have shifted ::: from calibration ::: standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has ::: published a new calibration protocol, TG-51, for the calibration of high-energy ::: photon and ::: electron beams. ::: The formalism and dosimetry procedures recommended in this protocol are based on the ::: absorbed dose to ::: water calibration ::: coefficient of an ionization ::: chamber at ::: C ::: 60 ::: o ::: energy, ::: N ::: D ::: , ::: w ::: 60 ::: Co ::: , together with the theoretical beam quality conversion ::: coefficient ::: k ::: Q ::: for the determination of absorbed dose to water in high-energy ::: photon and ::: electron beams. ::: Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring ::: them into alignment with report TG-51 and to recommend new methodologies and procedures ::: that would allow the practicing medical physicist to initiate and continue a high quality ::: program in clinical electron ::: beam ::: dosimetry. This ::: TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by ::: including new topics and topics that were not covered in depth in the TG-25 report. These ::: topics include procedures for obtaining data to commission a treatment planning computer, ::: determining dose ::: in irregularly shaped electron fields, and commissioning of sophisticated special ::: procedures using high-energy electron beams. The use of radiochromic film for electrons is ::: addressed, and radiographic film that is no longer available has been replaced by film ::: that is available. Realistic stopping-power data are incorporated when appropriate along ::: with enhanced tables of electron fluence data. A larger list of clinical applications of ::: electron beams ::: is included in the full TG-70 report available at http://www.aapm.org/pubs/reports. ::: Descriptions of the techniques in the clinical sections are not exhaustive but do describe ::: key elements of the procedures and how to initiate these programs in the clinic. There ::: have been no major changes since the TG-25 report relating to flatness and symmetry, ::: surface dose, use ::: of thermoluminescent dosimeters or diodes, virtual source position designation, air gap ::: corrections, oblique incidence, or corrections for inhomogeneities. Thus these topics are ::: not addressed in the TG-70 report. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 15,551 |
A graphic analysis is presented for the measurement of S period in asynchronously growing cell populations by double labeling with 3 H and 14 C- thymidine. It is applicable to growth characteristics anywhere between an exponential and a near steady state. Measurements made on Ehrlich ascites tumors of two different ages agree well with the values obtained by the labeled mitoses technique. | In vitro labeling and gold activation autoradiography were used to determine the [3H]thymidine ([3H]TdR)-labeling indices and DNA synthesis times for C3H/He spontaneous mammary tumors. Three variations of the [3H]TdR, [14C]thymidine ([14C]TdR) double-labeling method, together with double-emulsion autoradiography, were used to determine the DNA synthesis times (TS). Tumors labeled totally in vivo (in vivo-in vivo method) and tumors labeled with [3H]TdR in vivo and subsequently labeled with [14C]TdR in vitro showed similar TS values. DNA synthesis times for tumors determined totally in vitro by double labeling (in vitro-in vitro method) were significantly longer than those observed in vivo; however, identical samples subjected to Hypaque-Ficoll gradient separation after double labeling showed TS's similar to those found in vivo. Furthermore, the interval between [3H]TdR and [14C]TdR administration had no effect on TS estimates in vitro. Gold activation autoradiography was used in the present experiments to reduce autoradiographic exposure times. This method, together with in vitro labeling, permits [3H]TdR labeling index and TS determinations after 6-hr and 7-day exposures, respectively. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 15,552 |
Problems in Performance Testing of Fluorocarbon Coatings of Metallic Wall Screen and Conntermeasares | With a view to the problems in the performance testing of fluorocarbon coatings of metallic wall screen, including verification of the resin systems used in vanishesand top-coats, determination of content of polyvinylidene fluoride ( PVDF) , and arbitration of color variation of coatings with angles, efforts were made to modify currently available methodsspecified in relevant national standards for performance tes-ting of coatings. At the same time, qualitative analysis of the varnishesand top-coats by Fourier transformation infrared (FT-IR) spectrometry and quantitative analysis of the content of PVDF by differential scanning colorimetry were conducted. And the variationin the color of the coatings was examined using a 5-angle spectrophotometer. This would be helpful to resolving the above-mentioned problems concerning the performance testing of the flu-orocarbon coatings of metallic wall screen. | In this study, the neutron emission rate from neutron sources using prompt gamma rays in hydrogen was determined, and several improvements were applied. Using Monte Carlo calculations, the best positions for the source, moderator and detector relative to each other were selected. For (241)Am-Be and (252)Cf sources, the sizes for polyethylene spheres with the highest efficiency were 12- and 10-inch, respectively. In addition, a new shielding cone was designed to account for scattered neutrons and gamma rays. The newly designed shielding cone, which is 45 cm in length, provided suitable attenuation for the source radiation. | eng_Latn | 15,553 |
Radiation Exposure and Health Risks for Orthopaedic Surgeons | Orthopaedic surgeons are routinely exposed to intraoperative radiation and, therefore, follow the principle of "as low as reasonably achievable" with regard to occupational safety. However, standardized education on the long-term health effects of radiation and the basis for current radiation exposure limits is limited in the field of orthopaedics. Much of orthopaedic surgeons' understanding of radiation exposure limits is extrapolated from studies of survivors of the atomic bombings in Hiroshima and Nagasaki, Japan. Epidemiologic studies on cancer risk in surgeons and interventional proceduralists and dosimetry studies on true radiation exposure during trauma and spine surgery recently have been conducted. Orthopaedic surgeons should understand the basics and basis of radiation exposure limits, be familiar with the current literature on the incidence of solid tumors and cataracts in orthopaedic surgeons, and understand the evidence behind current intraoperative fluoroscopy safety recommendations. | Abstract : These abstracts provide a synopsis of research projects conducted by dental officers enrolled in the first, second, and third year residency programs at the National Naval Dental Center, Bethesda, Maryland, during the academic year 1977-1978. The projects were completed in partial fulfillment of the requirements of the programs. (Author) | eng_Latn | 15,554 |
Contamination prevention system, lithographic apparatus, radiation source, and method for manufacturing a device | A contamination prevention system is constructed and arranged to prevent material from propagating with radiation into a lithographic apparatus. The contamination prevention system includes a rotatable carrier provided with a plurality of generally radially outwardly extending blades. The blades are constructed and arranged to absorb or deflect the material. The system also includes a stationary shaft, and a bearing constructed and arranged to rotate the rotatable carrier and the blades around the shaft. The rotatable carrier is provided with a space for at least partially receiving a portion of the shaft. | The behaviour of swelling and collapsible soils would be better understood by taking into account available data from distribution of moisture and void ratio in the media. A laboratory computerised gamma-ray tomography (CT) has been applied to measure those variables and their spatial distribution on soil media. CT consists basically of scanning a soil sample with gamma-ray and measuring the attenuation coefficients of the soil. The obtained measurements are used to plot an image of soil properties. Some applications of CT to non saturated soils such as the water and unit weight distribution inside soil sample are shown. (A) For the covering abstract see IRRD 881647. | eng_Latn | 15,555 |
Using Gamma-Ray to Determine the Homogeneity of Some Building Materials | In this paper, we use a narrow collimated beam of mono- energetic gamma rays emitted from the radioactive source 137 Cs (662 keV) and the system of measuring gamma rays UCS-20 associated with the sodium iodide detector NaI (Tl) to determine the homogeneity of the building materials, Granite, Marble, Cement, Ceramic and Bricks. The homogeneity test was determined from the percentage difference between the transmitted intensity of gamma-rays and the linear attenuation coefficient at different positions for each sample of the material then the percentage of standard deviation was checked. | Abstract The paper commences with a discussion of the assumptions embodied in the normal method of presenting results of environmental stress-rupture tests. Results are presented from two test programmes on glass fibre-reinforced polyesters: a chopped strand mat laminate in air; and a mixed woven rovings/chopped strand mat laminate in aqueous environments, revealing very large experimental scatter. The author then describes methods which have been employed in an attempt to extract from the data predictions of the long term behaviour of the composites and indications of the environment upon them. | eng_Latn | 15,556 |
Compton scatter with polychromatic sources for lung densitometry. | A mobile lung densitometer using conventional x-ray tubes, NaI detectors, and principles of two-source, two-detector Compton scattered densitometry, is described. The device is capable of one to two per second density measurements from a 45-cm3 volume with a precision of 5%. The expected in vivo accuracy (2%-3%) is determined by using an anthropomorphic phantom with replaceable lung inserts. The unintentional detection of multiple-scattered x rays results in a small density-dependent error. This error is predictable and relatively insensitive to differences in surrounding absorbers such as the chest wall. With this device, dynamic in vivo densitometry of the lung in the clinical laboratory and intensive care unit will be possible. | e18068Background: One method of therapy deintensification in locally advanced (LA) HPVOPC is to reduce total radiation dose during concomitant chemoradiation (CRT) in a sequential therapy plan. We ... | eng_Latn | 15,557 |
Development of a soft X-ray pulse height analyzer on the J-TEXT tokamak | Abstract A soft X-ray pulse height analyzer has been designed and installed on the J-TEXT tokamak for measuring the electron temperature and possibly for monitoring the impurity content and concentration. A multi-channel analyzer, a set of amplifiers, and three silicon drift detectors constitute the detection system. An off-line analysis code was developed to analyze the raw data recorded by the system. The system can measure a minimum electron temperature of 400 eV, and its routine operation provides electron temperature measurements at three different positions with a temporal resolution of 60 ms and channel separation of 18 cm. Line radiation from some moderate and high Z impurities are observable by the system. The results show that the intensity of line radiation from heavy impurity ions is inversely proportional to the plasma density under similar discharge conditions. | AbstractTo understand how cells respond to the nanoscale extracellular environment in vivo, cells from various sources have been cultured on nanoscale patterns fabricated using bottom-up and top-down techniques. Human fetal osteoblasts (hFOBs) and stem cells are some of them and they are known to be overtly responsive to nanoscale topographies – allowing us to investigate the hows and whys of the response in vitro. Information gathered from these in vitro studies could be used to control the cells, i.e. make the stem cells differentiate or retain their characteristics without the use of medium supplements. In this review, hFOB and stem cell responses to nanotopographies are summarized and discussed to shed some light on the influence of patterns on the reactions. Although both types of cells are responsive to nanoscale topographies, the responses are found to be unique to topographical dimension, shape, orientation and the types of cells used. This implies that cellular responses are influenced by multitu... | eng_Latn | 15,558 |
Radioactive Tracers in Chemistry | THE scientific programme of this year's anniversary meeting of the Chemical Society was arranged in collaboration with the Chemistry Division of the Government's Atomic Energy Research Establishment. During March 28–30 a symposium on "The Chemistry of the Heavy Elements"and on "Radioactive Tracers "took place in Oxford, and on April 1 a discussion was held in London on "The Use of Radioactive Tracers in Chemistry". The Oxford meeting has already been reported in Nature of June 18 and 25. | The paper provides a view of the results obtained in Norway with regard to use of multispectral satellite images for mapping and monitoring cultural heritage sites on the basis of soil chemistry as ground-truthing. | eng_Latn | 15,559 |
Modelling the long-term dynamics of radionuclides in rivers | A model describing the long-term dynamics of radioactive contamination of rivers was developed. The radionuclide activity concentration in river water is assumed to be directly proportional to the content of the radionuclide exchangeable form in the surface layer of soil on the river catchment. The model input parameter values can be determined independently or estimated using results of the short-term observations. The modelled and measured 137 Cs activity concentrations in rivers contaminated as a result of the Chernobyl accident are in good agreement. | A healthy tissue tolerance study1,2 with Beagle dogs was carried out at the Finnish BNCT facility FiR 1 during February-March 1998. Three dose groups of dogs without boron carrier, each comprising five Beagles, and one dose group with BPA-F infusion were irradiated. Individual dose plans1 were done for each dog. The absorbed doses, which were actually delivered to healthy tissues, were monitored in vivo by placing the dosimeters on the shaved skin of the dogs or in the accessible cavities. In this study, absorbed gamma doses were monitored with thermoluminescent (TL) dosimeters, and neutron fluences were determined with activation foils. The obtained results were compared to the calculated values. | eng_Latn | 15,560 |
Effect of naloxon on expression of c-fos mRNA in rat cerebral cortex | To investigate relationship between naloxon woke up anaesthetic rat by XFM and c-fos gene,by study on effect of naloxon on the expression of c-fos mRNA in the rat cerebral cortex,78 SD rats were divided randomly into blank control group,XFM group,XFM add naloxon group,XFM add saline group.The contents of c-fos mRNA was measured by RT-PCR in cerebral cortex.The contents of c-fos mRNA was obviously increased in the XFM anesthesia group as compared with blank control group(P0.01).The contents of c-fos mRNA was significantly decreased after naloxon administrated as compared with XFM group(P0.05 or P0.01).The results indicated that naloxon palinesthesia action was concerned with c-fos gene in cerebral cortex.Naloxon attenuates expression of c-fos gene in the rat cerebral cortex may be an important mechanism that naloxon woke up anaesthetic rat by XFM. | Twenty-five rhesus monkeys were randomly assigned to one of five mouth irradiation treatment schedules: control group, no irradiation; $sup 60$Co $gamma$ five times weekly; $sup 60$Co twice weekly; 16-MeV/sub d$Yields$Be/ neutrons twice weekly. Although the acute reactions of the oral mucosa were similar in the four irradiated groups, the late sequelae were more severe in the animals irradiated twice weekly with $sup 60$Co $gamma$ or neutrons. All of the animals irradiated with $sup 60$Co $gamma$ twice weekly or with 16 MeV/sub d$Yields$Be/ neutrons exhibited oromucosal necrosis, whereas none of those irradiated five times weekly with $sup 60$Co $gamma$ did. The difference in the effect of photon fractionation on early and late radiation sequelae may be related to different patterns of redistribution of surviving cells through the division cycle in tissues responsible for early and late damage. (auth) | eng_Latn | 15,561 |
AN ANALYSIS OF THE ROTATIONAL STRUCTURE OF THE $b ^{3}\Sigma^{+} - a ^{3}\pi$ BAND SYSTEM OF AlCl | $^{1}$ D. Sharma, Astrophys, J., 113, 210 (1950) $^{2}$R. Contolini, Ph.D. thesis, The Ohio State University (1981) $^{3}$J. M. Brown, I, Kopp, C. Malmberg, and B. Rydh, Phys. Scripta, 17, 55 (1978) | A software system that facilities the calibration of X‐ray measuring instruments used in medical applications is presented. The Secondary Standard Dosimetry Laboratory (SSDL) of the Nuclear Research National Institute in Mexico (ININ in Spanish), supports activities concerning with ionizing radiations in medical area. One of these activities is the calibration of X‐ray measuring instruments, in terms of air kerma or exposure by substitution method in an X‐ray beam at a point where the rate has been determined by means of a standard ionization chamber. To automatize this process, a software system has been developed, the calibration system is composed by an X‐ray unit, a Dynalizer IIIU X‐ray meter by RADCAL, a commercial data acquisition card, the software system and the units to be tested and calibrated. A quality control plan has been applied in the development of the software system, ensuring that quality assurance procedures and standards are being followed. | yue_Hant | 15,562 |
The effect of iron deficiency and iron overload on the evolution of chagas disease produced by three strains of trypanosoma cruzi in cfw mice | 1. CFW mice were fed either on control diet or on iron-deficient diet. 2. After 5 months the mice were infected with CL, Y or YuYu strain of Trypanosoma cruzi. 3. On the fifth day after the infection, the mice on control diet were divided in three groups: one group remained as controls, two groups were injected either with desferrioxamine or iron-dextran. 4. The severity of the disease was evaluated by parasitemia and mortality. 5. The experimental groups were compared with the infected group fed on the control diet. 6. In mice fed on the iron-deficient diet, the disease was more severe for CL strain and less severe for Y and YuYu strains. 7. Treatment with desferrioxamine produced a less severe disease with YuYu strain and no difference with the other strains. 8. On Treatment with iron-dextran, the disease became more severe with Y and CL strains; no effect was observed with YuYu strain. 9. These findings may be due to intraspecific differences among the strains. | Twenty-five rhesus monkeys were randomly assigned to one of five mouth irradiation treatment schedules: control group, no irradiation; $sup 60$Co $gamma$ five times weekly; $sup 60$Co twice weekly; 16-MeV/sub d$Yields$Be/ neutrons twice weekly. Although the acute reactions of the oral mucosa were similar in the four irradiated groups, the late sequelae were more severe in the animals irradiated twice weekly with $sup 60$Co $gamma$ or neutrons. All of the animals irradiated with $sup 60$Co $gamma$ twice weekly or with 16 MeV/sub d$Yields$Be/ neutrons exhibited oromucosal necrosis, whereas none of those irradiated five times weekly with $sup 60$Co $gamma$ did. The difference in the effect of photon fractionation on early and late radiation sequelae may be related to different patterns of redistribution of surviving cells through the division cycle in tissues responsible for early and late damage. (auth) | eng_Latn | 15,563 |
RADIOACTIVE FALLOUT IN AUSTRALIA FROM OPERATION BUFFALO | Atomic weapoas tests of the Buffalo series were held in Australia in 1956. Fall-out measurements were made at a network of 86 stations throughout Australia. Data are tabulated. (C.H.) | I have chosen to publish this paper as a reminder to be aware of postradiation ulceration. If this occurs, think malignancy. Biopsy should be done and, if positive, there should be wide resection and repair with well-vascularized tissue, muscle flap, and simple skin reconstruction—skin graft. Follow-up should be frequent, and any suspicious region should be biopsied. This seems very elementary, but unfortunately these simple rules are not always obeyed. | yue_Hant | 15,564 |
Detection of rust resistance in selected Zimbabwean and ICARDA bread wheat (Triticum aestivum) germplasm using conventional and molecular techniques | Host resistance is the most effective and economical method to minimise yield losses caused by rusts. The aim of this study was to detect the presence of resistance in 75 wheat genotypes. The presence of the genes Sr2, Sr24, Lr34, Lr37, Lr46 and Lr68 was investigated using simple sequence repeat and sequence tagged site markers. Quantitative aspects of resistance to leaf rust were assessed through infection response, disease severity, coefficient of infection (CI), disease incidence (DI), leaf tip necrosis (Ltn) and area under disease progress curve (AUDPC) under natural epidemics. Highly significant (p ≤ 0.001) differences were observed among the genotypes for CI, DI, AUDPC and relative AUDPC (rAUDPC). Twenty genotypes exhibited high levels of adult-plant resistance, showing CI less than 20% and AUDPC less than 300%, with moderately susceptible to susceptible reactions. The most frequently occurring gene was Lr46 (21%), followed by Lr68 (20%), Lr34 (19%), Lr37 (11%), and Sr24 (0%). Selection for Lr34 and... | SummaryThe synthesis of DNA, RNA and protein, and the rejoining of DNA strand-breaks and DNA breakdown were studied in cells of Bacillus subtilis γ-irradiated in the presence of iodoacetic acid (I. CH2. COOH), potassium iodide (KI) or potassium iodate (KIO3). Observations on incorporation of radioactive precursors into bacteria mildly radiosensitized by the above reagents indicated that synthesis of DNA was generally more sensitive than that of protein or RNA. A cellular radiosensitizing effect cannot be explained by increase of radiation-induced in situ damage in DNA, because a drug effect was not found on radiation inactivation of transforming DNA. Also, the number of radiation-induced breaks in DNA strand studied by means of alkaline-sucrose gradient centrifugation was very similar in the absence or presence of reagent at the time of irradiation.Studies with KIO3 have shown that the presence of the reagent during irradiation of bacteria considerably reduced rejoining of DNA strand-breaks during subsequ... | eng_Latn | 15,565 |
[Combinations of scan parameters and image quality at C-arm CT for abdominal imaging]. | We measured the contrast-to-noise ratio (CNR) and evaluated low-contrast images and streak artifacts to optimize abdominal C-arm CT imaging, and we investigated the view number, acquisition matrix, and pixel depth. To measure CNR, we filled 0.125-1.0-inch cavities in an American Association of Physicists in Medicine (AAPM) CT performance phantom with a sodium chloride solution. Five radiological technologists visually evaluated the noise, signal conspicuity at low-and high-signal density, and the overall image quality using paired comparisons based on Thurstone's law. In a given acquisition matrix, the total view number had the greatest effect on the image noise, artifacts, and signal detectability on C-arm CT images. For a given incident dose per view on the flat-panel detector (FPD), fewer images with noise and streak artifacts resulted when a larger view number was selected. | Sony ICX 259AL CCD matrices were irradiated by proton and neutron beams of a synchrocyclotron of the Petersburg Nuclear Physics Institute. The data on production cross sections, as well as the spatial and time distributions of pixels of the irradiated matrices with high dark current, are presented. The experimental data are compared with the calculation results. | eng_Latn | 15,566 |
gamma-Ray-induced mutations in male germ cells of a recombination-defective strain (c3G) of Drosophila melanogaster. | The gamma-ray (60Co) induction of the dumpy and Minute mutations, and the hyperploid exceptions during spermatogenesis was investigated by using a recombination-defective strain of Drosophila melanogaster, c3G and its wild-type strain, Oregon-R (c3G+). The results show that: (1) no essential difference exists in the response patterns for the dumpy and Minute mutations between these two strains; (2) however, a striking difference exists in the response pattern for the hyperploid exceptions. This is mainly due to an extraordinarily high sensitivity of the early spermatocytes of the c3G males to gamma-ray induction of these mutations. These findings possibly suggest that c3G gene may have some kind of role in the production of large structural changes by ionizing radiation, but not in the production of gene mutations. | In this paper, a Rotman lens with Ridge Gap Waveguide technology (RGW) is proposed as an alternative for beam scanning in millimeter wave applications. To facilitate the design and measurements, a first prototype at 38 GHz will be designed and built; afterwards a final device at 60 GHz will be designed. | eng_Latn | 15,567 |
2-DE protein expression in endometrial carcinoma | The objective of this study was to explore the protein expression pattern in normal endometrial mucosa (n = 5) and endometrial carcinoma (n = 15) of low (diploid) and high (aneuploid) malignancy potential by two-dimensional gel electrophoresis (2-DE). The specimens were evaluated for histopathologic subtype, stage and grade in relation to DNA ploidy. A match-set consisting of five samples from normal endometrium, eight diploid and seven aneuploid tumours was created. All the diploid and three of the aneuploid tumours were of endometrioid subtype, while the remaining four were of uterine seropapillary type. There were 192 protein spots differentiating diploid tumours from normal endometrium and 238 protein spots were separating aneuploid tumours from normal endometrium (p < 0.01). A cluster analysis based on 52 significantly deviating protein spots within the groups showed clustering and separation of the normal endometrium, diploid and aneuploid tumours. In conclusion this study showed significant differe... | Abstract The processes occurring during electron irradiation of cis-polybutadiene have been investigated. The concentration of unsaturated bonds decays during irradiation with the formation of intermolecular crosslinks, intramolecular cyclic structures and polyene groups. The decay processes can be described by equations which approximate to first order kinetics. Rate constants for the decay processes have been estimated from the experimental data. | eng_Latn | 15,568 |
[The development of the ionization chamber and the researching of its characteristics for automatic exposure controlling in the X-ray diagnosis machine]. | An ionization chamber for automatic exposure controlling used in X ray diagnosis machine was developped, and its characteristics were measured and researched. The electrodes of measuring field were made of carbon, such couldn't leave it's imaging on the film. In order to increase the ionization efficiency and decrease the thickness and electric capacity between electrodes, the chamber was constructed in multilayers. The chamber we developed can be fixed in different x ray machines convenientlly, there is a fine linearity between it's signal output and the exposures, the beam quality response is uniform and output-timing response is also good. | Invention in Barok Era and The Development of Piano Lesson. In piano lesson, one material of parts towhich had been given is polyphony, which is an Invention from J.S. Invention is a basic fi nger-skill for pianist.Invention develops in the Baroque period. The baroque ideology is not only called as the reaction of Renaissance,but also as the continuing development from Renaissance. Invention is known in two forms. First is as a pianocomposition and second is as a piano play which can push a pianist to understand more about an arrangement thathe played and expressed. | eng_Latn | 15,569 |
A computed tomography apparatus and the rotor of a gantry of a computed tomography device | The computed tomography device according to the invention and the rotor according to the invention (1) are characterized in that the rotor at least in sections from a reinforced with particles (2) composite material is made with a metal matrix. Parikel (2) reinforced composite materials with a polymer matrix have high specific strength characteristics and stiffness characteristic values with low use of material, so that high rotation speeds of the rotor (1) without affecting the image quality can be realized in generated tompgraphischen images. | Dust containing radioactive materials dispersed following the Fukushima nuclear power plant accident in March 2011. Gamma-rays are emitted in the process when unstable nuclei in the materials decay. Based on the technology of Si/CdTe Compton Camera, we have manufactured a quick prototype model for the use in the field. The camera, now called a "Ultra-Wide-Angle Compton Camera" was successfully applied to visualize the distribution of radio-active substances in the Fukushima area. | eng_Latn | 15,570 |
[Case report of pulmonary histoplasmosis]. | A case of pulmonary histoplasmosis in Beijing was reported Patient's CT scan showed naly patchy consolidation partly with small cavitations and hilar silhouette enlarged in both lungs. On pathologic examination, Histoplasma Capsutatums were found in the lung tissures by percutaneous lung biopsy. Skin rash had developed in the course. After treated by fluconaxole, most of the lung lesions and skin rash disappeared. | This report covers holdup measurements of uranium residue in the cooling hut HEPA bank of the 321-M facility. This report discusses the methodology, non-destructive assay measurements, assumptions, and results of the uranium holdup in this item. | eng_Latn | 15,571 |
Review of Reactor-Based Neutron Beam Development for Bnct Applications | The revival over the last decade of BNCT as a potentially successful form of radiotherapy, especially for the treatment of otherwise untreatable, deep-seated tumours such as glioma, has led to a variety of neutron beam designs becoming available and being proposed at a number of nuclear research centres throughout the world. Present designs focus on producing beams of predominately epithermal neutrons which can penetrate healthy tissue to give the tumour at depth lethal doses whilst leaving the healthy tissue relatively unscathed. As well as the established design route using nuclear research reactors1,2,3,4, recent work is also looking at accelerators (see Yanch, Shefer, these proceedings) and radioisotope sources (see Kim, these proceedings). Despite this proliferation of designs for epithermal neutron beams, BNCT is performed currently, albeit in Japan only, using thermal neutron beams5,6. Epithermal neutron beams have therefore, as yet, still not been used for the treatment of patients. | The problem of scaling down the size of the transmitting antenna of a solar power satellite is briefly discussed. It is shown that a multibeam Power Relay Satellite leads to smaller ground receiver stations which will improve the market penetration of power satellites. (WHK) | eng_Latn | 15,572 |
Modification of Radiation Effects in Bacteria | Radiobiological studies in bacteria began in 1877 when Downes and Blunt published their observations of the killing of bacteria by sunlight. A voluminous literature has been accumulated since that date, and in a short discussion it is impossible to accomplish more than to mention briefly some aspects of the subject which, hopefully, are of interest. | A healthy tissue tolerance study1,2 with Beagle dogs was carried out at the Finnish BNCT facility FiR 1 during February-March 1998. Three dose groups of dogs without boron carrier, each comprising five Beagles, and one dose group with BPA-F infusion were irradiated. Individual dose plans1 were done for each dog. The absorbed doses, which were actually delivered to healthy tissues, were monitored in vivo by placing the dosimeters on the shaved skin of the dogs or in the accessible cavities. In this study, absorbed gamma doses were monitored with thermoluminescent (TL) dosimeters, and neutron fluences were determined with activation foils. The obtained results were compared to the calculated values. | eng_Latn | 15,573 |
Underwater Imaging with Acoustic Lenses: Image Processing and Visualization, | Abstract : This report discusses image processing, scene reconstruction, and visualization techniques used for underwater acoustic images taken with lens-based systems from a stationary platform. These systems are designed for high-resolution imaging of objects from distances of a few meters. The acoustic lenses used for beamforming in the imaging systems are made of crystal polystyrene and are cut in cylindrical or spherical shapes. The cylindrical lens has a fan-shaped beam pattern and produces a 2D intensity image or shadowgram, while the spherical lens with a cone-shaped beam produces a 3D intensity image. Test images obtained by the spherical lens contain a remarkable degree of detail. | In fundamental solvent extraction research at Oak Ridge National Laboratory a large number of systems have been discovered that are selective for one or a few elements. Some of these have been adapted to analytical separation and assay. To serve our own need for highly reproducible and accurate analysis of samples containing ..cap alpha.. and ..beta..-emitting nuclides, we have turned to liquid scintillation in both its familiar ..beta..-liquid scintillation (..beta..-LS) form and in a less-familiar development called Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS) spectrometry. ..beta.. counting by the former and ..cap alpha.. counting by the latter combined with appropriate separation method result in powerful tools for radioassay of a wide range of sample types. 15 refs. | eng_Latn | 15,574 |
Trojan Horse Method experiments with radioactive ion beams | The Trojan Horse Method (THM) is an indirect method that allows to get information about a two body reaction cross-section even at very low energy, avoiding the suppression effects due to the presence of the Coulomb barrier. The method requires a very accurate measurement of a three body reaction in order to reconstruct the whole kinematics and discriminate among different reaction mechanisms that can populate the same final state. These requirements hardly match with the typical low intensity and large divergence of radioactive ion beams (RIBs), and experimental improvements are mandatory for the applicability of the method. The first reaction induced by a radio activeion beam studied by applying the THM was the 18 F(p,α)15 O. Two experiments were performed in two different laboratories and using different experimental set-ups. The two experiments will be discussed and some results will be presented. | Purpose ::: Radiation therapy (RT) is often recommended in the treatment of pelvic cancers. Following RT, a high prevalence of pelvic floor dysfunctions (urinary incontinence, dyspareunia, and fecal incontinence) is reported. However, changes in pelvic floor muscles (PFMs) after RT remain unclear. The purpose of this review was to systematically document the effects of RT on the PFM structure and function in patients with cancer in the pelvic area. | eng_Latn | 15,575 |
[Hyperfractionated radiotherapy in 56 patients with tumors of the head and neck (author's transl)]. | A new method of irradiation known as hyperfractionated radiotherapy was studied in 56 patients with cancers in the region of the ear, nose, and throat. The dose was 72 grays given during 80 sessions over a period of 28 days, with a rest period of two weeks at the half-way point. Each session lasted 2 hours. The results (complications and survival rate) were compared with those obtained in a control group treated with 70 grays in 35 sessions over a period of 7 weeks. The complication rate was 21% in the series treated with hyperfractionated radiotherapy, against 19% in those given classical treatment (results not significant). The survival rate was better, however, (63% against 33% after 18 months), for the patients treated with this new method of irradiation. | Positronium-formation cross sections from positron-hydrogen collisions are calculated by solving a set of close-coupled, time-dependent partial differential equations. These cross sections are determined by propagating a time-evolving wave packet on a two-dimensional radial lattice and then projecting the wave function onto the stationary states of the atom. Calculations are performed through L58 and are extrapolated for L>9 at energies of 30, 40, and 50 eV. Using distorted-wave calculations to determine ionization cross sections at these higher energies, we are able to extract approximate positronium-formation cross sections from the transfer ionization cross sections. Comparisons are made with experiment. @S1050-2947~98!02702-4# | eng_Latn | 15,576 |
[In vitro repair of gamma-irradiated transforming Bacillus subtilis DNA by extracts of blue-green algae]. | A cell-free extract from blue-green alga Anacystis nidulans contains enzymes which repair in vitro the transforming activity of gamma-irradiated Bacillus subtilis DNA. The level of restoration of the transforming activity depends on the protein concentration in the reaction mixture, the duration of incubation and on the dose of irradiation. The repair of gamma-induced lesions is most efficient in the presence of magnesium ions, NAD and ATP. The present data indicate that the repair of transforming DNA is performed with the participation of DNA polymerase and polynucleotide ligase which function in the cell-free extract of algae. | Approximately 130M L of sludge/supernate high-level radioactive waste is currently stored in underground carbon steel tanks at the Savannah River Site in Aiken, South Carolina. The Defense Waste Processing Facility (DWPF) began immobilizing these wastes in borosilicate glass in 1996. Currently, the radioactive glass is being produced as a sludge-only composition by combining washed high-level sludge with glass frit and melting. The glass is poured into stainless steel canisters that will eventually be disposed of in a permanent geological repository. The focus of this report is on frit development activities conducted solely on the basis of predictions generated by DWPF's PCCS glass property-composition models. | eng_Latn | 15,577 |
Software System for the Calibration of X-Ray Measuring Instruments | A software system that facilities the calibration of X‐ray measuring instruments used in medical applications is presented. The Secondary Standard Dosimetry Laboratory (SSDL) of the Nuclear Research National Institute in Mexico (ININ in Spanish), supports activities concerning with ionizing radiations in medical area. One of these activities is the calibration of X‐ray measuring instruments, in terms of air kerma or exposure by substitution method in an X‐ray beam at a point where the rate has been determined by means of a standard ionization chamber. To automatize this process, a software system has been developed, the calibration system is composed by an X‐ray unit, a Dynalizer IIIU X‐ray meter by RADCAL, a commercial data acquisition card, the software system and the units to be tested and calibrated. A quality control plan has been applied in the development of the software system, ensuring that quality assurance procedures and standards are being followed. | Some problems will be encountered when publishing and exploring multimedia CAI course wares developed with Authorware. We propose some methods to overcome the above problems with the examples of the analytical chemistry experiment multimedia CAI courseware. | eng_Latn | 15,578 |
Mononuclear Blood Cell Magnesium in Older Subjects: Evaluation of its Use in Clinical Practice | Serum and mononuclear blood cell (MBC) magnesium were measured in 24 healthy community subjects, average age 76 years (67–93), and in 21 ill hospitalized subjects, average age 79 years (65–90). MBC magnesium, expressed asμmol/mg protein, was significantly lower in the in-patient group (P<0·001), but tended to be higher in the same group when expressed as fmol/cell (not significant). Further samples from community subjects on the same day, and again at 7 days, revealed coefficients of variation for intrasubject analysis of 12% and 22%, respectively (fmol/cell). The equivalent intrasubject values for serum were 2·8% on the same day and 4% at 1 week. MBC magnesium values for inpatients were probably distorted by changes in cell size and cell protein content caused by illness. Biological variability and the effects of illness on the composition and size of cells seem to limit the usefulness of MBC magnesium measurement as a clinical tool for assessment of body magnesium status. | Nondestructive measurements of x-ray and gamma-ray emissions can be used to analyze a sample for plutonium. This report describes the methods and algorithms we have developed for analyzing gamma-ray spectra obtained by using a germanium detector system to accurately determine the relative abundances of various actinide isotopes in a sample. Our methodology requires no calibrations and can be used to measure virtually any size and type of plutonium sample. Measurement times can be as short as a few minutes; measurements are frequently accurate to within 1%. Our methods have been programmed into a computerized analysis code called MGA (Multi-Group Analysis). Our current versions can be run on personal computers (IBM type) and on the DEC VAX microcomputer. Spectral analysis times are usually far less than a minute. 28 refs., 26 figs., 1 tab. | eng_Latn | 15,579 |
miR-155 Inhibits Nucleus Pulposus Cells' Degeneration through Targeting ERK 1/2 | We first investigated the difference in microRNA expression between normal NP cells and degenerative NP cells using gene chip. We have found that the expression of ERK1/2 was decreased with overexpression of miR-155 in normal nucleus pulposus cell. Expression of ERK1/2 was increased with inhibition of miR-155. Overexpression or inhibition of miR-155 had no effects on the expression level of mRNA ERK1/2 in nucleus pulposus cell, which showed that miR-155 affected the expression of pERK1/2 after transcription of ERK1/2 mRNA indicating that ERK1/2 was a new target protein regulated by miR-155. In the degeneration of intervertebral disc, inhibited miR-155 decreased the expressions of extracellular main matrix collagen II and glycosaminoglycan and increased expression of ERK1/2. Taken together, our data suggested that miR-155 was the identified miRNA which regulated NP cells degenerated through directly targeting ERK1/2. | Abstract In the application of some polymers as track detectors, the attention should be paid to the fact that the track recording properties of these polymers are changed under the influence of certain parameters, such as the electromagnetic radiations and environmental conditions. In this work the etching effects of 60Co gamma irradiated CR-39 polycarbonate have been studied. For deeper study of the structural changes in CR-39, the FTIR and UV–visible spectra have been analyzed. The FTIR spectra shows considerable changes due to the gamma exposure. The contribution of degradation mechanism is discussed. | eng_Latn | 15,580 |
[G[P] type profiles of group A human rotavirus and their distribution in Nizhni Novgorod and Dzerzhinsk in 1997-2005]. | RT-PCR was used to determine G (VP7) and P (VP4) genotypes of group A rotavirus found in 2454 children with diarrhea in 1997-2005. Eight G[P] combinations, including G1-4 serotypes and P[4, 6, 8, 9] genotypes, were identified. The P[8] genotype was presented by the subtypes P[8]-1 and P[8]-2. In 1997-2005, the spectrum and distribution of G[P] types were as follows: G1P[8]-1 (10%), G1P[8]-2 (67%), G1P[6] (3%), G2P[4] (9%), G3P[8]-2 (5%), G3P[6] (1%), G3P[9] (1%), G4P[8]-2 (3%), G9 (0%), G?P[?] (1%). Five G[P] types of rotavirus were identified in the 2004-2005 season. The G2P[4] type was prevalent (37%), the GI P[8]-2 type was detected in 25% of cases; G3P[8]-2 in 22%; G4P[8]-2 in 12%; G3P in 2%), G[?]P[?] in 2%. The P[8]-1 subgemotype was not found. The spectrum of the G1P[8] types of rotavirus and their distribution should be taken into account while developing a vaccine prophylaxis program against rotavirus gastroenteritis in Russia. | Reminiscences are given out of the early stages of the development in x-ray crystallography, both in Japan and abroad. Activities in Prof. Ewald's school in Germany, those of Prof. Bragg's in England, Prof. Terada's and Nishikawa's in Japan are described.Prof. Nishikawa's contribution concerning the space group theory in the structure analysis is brought to attention. Early works of Prof. Nitta on organic crystals are also described.Some x-ray photographs taken by Prof. Nishikawa and Prof. Nitta in the early period from 1913 to 1925 are reproduced. (abstract by the editor) | eng_Latn | 15,581 |
Use of sugammadex in a patient with progressive muscular atrophy and in a patient with amyotrophic lateral sclerosis: Case report | INTRODUCTION ::: We herein present 2 cases involving the combination of rocuronium and sugammadex in patients with motor neuron disease. The patients were a 54-year-old man with progressive muscular atrophy who underwent removal of internal fixators in the arm and leg, and a 66-year-old woman with amyotrophic lateral sclerosis who underwent skin grafting in the left lower leg. General anesthesia was induced with propofol, rocuronium, and remifentanil and maintained with desflurane and remifentanil. At the end of the surgical procedure, we administered sugammadex. Three or 4 minutes after administration of sugammadex, the patients began to breathe spontaneously and were extubated without complications. ::: ::: ::: CONCLUSION ::: Sugammadex can be used successfully to reverse neuromuscular blockade in patients with motor neuron disease. | Abstract Man-made long-lived radioisotopes have been produced as a result of different nuclear technologies. The study of accidental spillages and the determination of radioisotope concentrations in nuclear waste prior to final storage in a repository are subjects of great interest in connection with this activity. The accelerator mass spectrometry (AMS) technique is a powerful tool to measure long-lived isotopes at abundance ratios as low as 10 −12 –10 −15 in small samples. Applications to the Argentine nuclear program like those mentioned above, as well as applications to archaeology, hydrology and biomedical research, are considered in an AMS program using the TANDAR 20 UD electrostatic accelerator at Buenos Aires. In this work we present the status of the program and a description of the facility. | eng_Latn | 15,582 |
New methods of separation and assay of some radionuclides of environmental interest | In fundamental solvent extraction research at Oak Ridge National Laboratory a large number of systems have been discovered that are selective for one or a few elements. Some of these have been adapted to analytical separation and assay. To serve our own need for highly reproducible and accurate analysis of samples containing ..cap alpha.. and ..beta..-emitting nuclides, we have turned to liquid scintillation in both its familiar ..beta..-liquid scintillation (..beta..-LS) form and in a less-familiar development called Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS) spectrometry. ..beta.. counting by the former and ..cap alpha.. counting by the latter combined with appropriate separation method result in powerful tools for radioassay of a wide range of sample types. 15 refs. | The paper provides a view of the results obtained in Norway with regard to use of multispectral satellite images for mapping and monitoring cultural heritage sites on the basis of soil chemistry as ground-truthing. | eng_Latn | 15,583 |
Effect of the position of the laser beam focal point on a capillary flow-through cell on the signal-to-noise ratio for a fluorimetric detector in capillary column liquid chromatography | Abstract The use of a high-sensitivity laser-induced fluorescence detector with a capillary flow-through cell (100 μm I.D.) in capillary column liquid chromatography was studied. To reduce the background noise from scattering of the laser light from the cell walls by reflection and refraction, the geometric position of the focal point of the laser beam on the capillary cell is very important. By moving the focusing lens of the laser beam, the best position of the laser on the capillary cell was examined. The use of a video camera was also helpful in setting the laser beam on the capillary cell. With the optimum geometric arrangement, 1.3 fmol of the 4-bromomethyl-7-methoxycoumarine derivative of caproid acid ( k ′ = 3) was detected at a signal-to-noise ratio of 5. | Detailed information, classified by manufacturer and model, is given on the imaging characteristics of collimators for rectilinear scanners and scintillation cameras. Clinicians and physicists will find this useful information. Research workers and designers will be aided in assessing the merits of current collimators, and in designing new ones. Information on line spread function (LSF), modulation transfer function (MTF), and sensitivity is given. Further detailed information on scanner collimators (HEW Publication (FDA) 79-8077 Supplement) is available on request from the Bureau of Radiological Health. | eng_Latn | 15,584 |
Radiographic Imaging of Osteoarthritis | Radiography is the easiest way to identify the anatomical changes in joint structure that confirm the existence of osteoarthritis (OA), with joint space narrowing, corresponding to cartilage loss [1, 2]; subchondral sclerosis and osteophyte formation, the joint’s bony response to the increased mechanical load consequent upon cartilage degeneration and loss [3]. The ease of radiography in detecting these characteristic features, together with the ready availability and ease of interpretation of radiographs, has led to its use as the principal method for imaging OA joints. | Sony ICX 259AL CCD matrices were irradiated by proton and neutron beams of a synchrocyclotron of the Petersburg Nuclear Physics Institute. The data on production cross sections, as well as the spatial and time distributions of pixels of the irradiated matrices with high dark current, are presented. The experimental data are compared with the calculation results. | eng_Latn | 15,585 |
Present and future optics challenges at CHESS and for proposed energy recovery linac source of synchrotron radiation | We present recent test results and discuss design challenges on x-ray optical components for the wiggler sources at CHESS and for the proposed energy recovery linac (ERL) source at Cornell. For the existing wiggler sources, a new white-beam collimating mirror has been installed and tested at F-line and some preliminary test results are presented. For the proposed ERL, three types of x-ray optical components are identified and considered: (1) high-heat-load capable optics for high-power and high-power-density insertion-device sources, (2) brilliance preserving optics that can provide high transverse coherence, and (3) optics used to manipulate, preserve and produce short x-ray pulses. | In fundamental solvent extraction research at Oak Ridge National Laboratory a large number of systems have been discovered that are selective for one or a few elements. Some of these have been adapted to analytical separation and assay. To serve our own need for highly reproducible and accurate analysis of samples containing ..cap alpha.. and ..beta..-emitting nuclides, we have turned to liquid scintillation in both its familiar ..beta..-liquid scintillation (..beta..-LS) form and in a less-familiar development called Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS) spectrometry. ..beta.. counting by the former and ..cap alpha.. counting by the latter combined with appropriate separation method result in powerful tools for radioassay of a wide range of sample types. 15 refs. | eng_Latn | 15,586 |
Coal-series hard kaolinite stripping method capable of keeping crystal form of kaolinite | The invention discloses a coal-series hard kaolinite stripping method. The method comprises the following steps of: crushing the coal-series hard kaolinite, mixing the crushed coal-series hard kaolinite with water and an intercalator to obtain intercalated compound pulp, striping the intercalated compound pulp by using medium spheres of three types grain sizes, and performing filtration washing and spray-drying to obtain the finished product. By the method, the hexagonal sheet-shaped crystal form of the kaolinite is kept relatively complete, and the content of hexagonal sheet-shaped kaolinite crystals is 30 to 60 percent. | Abstract Laser ablation (1064 nm) Fourier transform mass spectrometry has been used to study the sodium ion-exchanged LTA (Na-A) and MOR (Na-M) zeolites and the potassium ion-exchanged LTL (K-L) zeolite. When the ion-exchanged element is taken into account, the positive-ion and negative-ion laser ablation Fourier transform mass spectra from all three zeolites are similar and apparently independent of the zeolite structure. With the exception of small atomic and diatomic ions, the anions detected from the laser ablation of the zeolites are of the form M(SiO 2 ) x O − (where M=H, Na, K, AlO and x = 1–5). The laser ablation mass spectra show a strong dependence on laser power, with the higher Si Al ratio zeolite, mordenite, exhibiting the highest stability under 1064 nm laser irradiation. | eng_Latn | 15,587 |
IAEA activities related to radiation biology and health effects of radiation | The IAEA is involved in capacity building with regard to the radiobiological sciences in its member states through its technical cooperation programme. Research projects/programmes are normally carried out within the framework of coordinated research projects (CRPs). Under this programme, two CRPs have been approved which are relevant to nuclear/radiation accidents: (1)?stem cell therapeutics to modify radiation-induced damage to normal tissue, and (2)?strengthening biological dosimetry in IAEA member states. | we examine motivations for, and costs/benefits of, participation in three interviews across a one-year period among women recently exposed to intimate partner abuse (IPA). Recruited from publicly accessible police reports, women were not informed that the study focused on IPA in recruiting materials or when they scheduled the first interview. Women ' s ratings on the Response to Research Participation Questionnaire (RRPQ) indicated a positive benefit-to-cost ratio across all three interviews. Negative responses to participation as well as severity of IPA and PTSD symptoms did not predict retention at the next interview. These data dem - onstrate that studies asking about IPA experiences, even when survivors do not know in advance that IPA will be the focus of study, can be implemented within a stable benefit-to-cost ratio over time. | eng_Latn | 15,588 |
The ‘Cosmic’ Connection: Nuclear Astrophysics and Onwards into the Stars | Recently, a large number of new links between nuclear physics and astrophysics have been made. A totally new discipline has emerged at the intersection of these research fields. It goes under the name of nuclear astrophysics. | SUMMARY: In this second article, we continue the review of current health care economics as it relates to radiologists, specifically framed by topics defined by the Accreditation Council for Graduate Medical Education in the evaluation of neuroradiology fellows. The discussion in this article is focused on topics pertaining to levels 4 and 5, which are the more advanced levels of competency defined by the Accreditation Council for Graduate Medical Education Neuroradiology Milestones on Health Care Economics and System Based Practice. | eng_Latn | 15,589 |
Quality control of the gamma camera system at Korle-Bu Teaching Hospital | A thesis submitted to the College of Science in partial fulfilment of the requirements for the degree of Master of Science in Physics, 1993 | SUMMARY: In this second article, we continue the review of current health care economics as it relates to radiologists, specifically framed by topics defined by the Accreditation Council for Graduate Medical Education in the evaluation of neuroradiology fellows. The discussion in this article is focused on topics pertaining to levels 4 and 5, which are the more advanced levels of competency defined by the Accreditation Council for Graduate Medical Education Neuroradiology Milestones on Health Care Economics and System Based Practice. | eng_Latn | 15,590 |
EFFECT OF GAMMA RAYS ON CRYSTALLINE MATERIALS DURING IRRADIATION IN A REACTOR | The article presents and discusses the results of experiments to determine the effect of gamma rays on the change in the properties of diamond, graphite, and structural steel. The materials were irradiated in a VVER type reactor. For diamonds, the effect on the annealing of defects was investigated. As gamma ray intensity increased, the crystal lattice expansion and defect concentration increased. Graphite lattice expansion and the mechanical properties of structural steel were also examined. Graphite lattice expansion increased with increased neutron flux and decreased irradiation temperature. Changes in the impact toughness of structural steel correlated precisely to the gamma ray flux in the experiments. 6 refs., 3 figs. | Abstract Mature, Sprague-Dawley and Holtzman rats were injected intraperitoneally with varying doses of fenfluramine (1.0–31.6mg/kg), reserpine (5mg/kg), methamphetamine (10mg/kg) and p -chloroamphetamine (10 mg/kg). Midbrain sections were studied using two different histologie techniques. Hyperchromatic and argyrophilic (dark) neurons were seen in all treated animals as well as in salinetreated controls. These changes were seen less frequently in frozen sections and were not associated with neuronal loss or with glial reaction except in a few rats treated with p -chloroamphetamine. This supports the current concept that dark neurons are artifacts and are not indicative of pathologic change. | yue_Hant | 15,591 |
Q&A: Mobile phone safety | European research has shown radiation from mobile phones can damage human DNA, reigniting the debate over whether they can harm human health. | MONDAY, Dec. 6 (HealthDayNews) -- Toy safety should be at the top of your list when you select Christmas presents for children. | eng_Latn | 15,592 |
Neuroradiologic evaluation of craniocerebral trauma | Modern imaging techniques have greatly aided our ability to diagnose the effects of craniocerebral trauma. Computed tomography (CT), introduced in 1973, revolutionized the evaluation of changes related to trauma, allowing accurate diagnosis of intracerebral and extracerebral areas of blood accumulation. It became readily apparent that in most cases CT was the only exam necessary prior to surgical treatment. CT also accurately evaluates facial bone trauma. Magnetic resonance (MR), widely introduced in 1983, has also aided in diagnosis and is most accurate in cases of subacute and chronic injury, particularly cases involving shearing injuries. Skull films continue to be useful for linear skull fractures. | A bibliography containing 109 references is presented on the non- destructive analysis of irradiated and unirradiated reactor fuel assemblies. A description of the theory of each method, the equipment utilized, and estimates of the precision obtainable are cortained. Problems presented by variations in enrichment, alloying, cladding, geometrical arrangement, etc., are discussed. (C.J.G.) | eng_Latn | 15,593 |
Cloud reflectance variations in channel-3 | Abstract Using photographic terminology for channel 3 pictures in sunshine, one notes that most ice clouds appear black and that cloud shadows are equally dark, but water droplet clouds appear in all shades. These shades also vary greatly with the direction of sunshine relative to the line of sight because scatter is almost entirely by diffraction. Droplets and ice crystals larger than about 10 fan absorb the incident radiation almost completely and it does not penetrate through clouds unless there exist plenty of unobstructed ray paths through the clouds. The reflection from a water surface is almost metallic in intensity so that glint completely saturates the radiometer. There is no evidence of comparable reflection from ice. All snow-covered surfaces, including sea ice, appear black. Stratus cloud shows large variations in reflectance depending on the state of the convection in it which brings very small droplets to the surface. Small particle size causes some contrails and orographic cirrus to appear ... | Abstract De Ruyck, K., Wilding, C. S., Van Eijkeren, M., Morthier, R., Tawn, E. J. and Thierens, H. Microsatellite Polymorphisms in DNA Repair Genes XRCC1, XRCC3 and XRCC5 in Patients with Gynecological Tumors: Association with Late Clinical Radiosensitivity and Cancer Incidence. Radiat. Res. 164, 237–244 (2005). This study investigates the association of microsatellite polymorphisms in XRCC1, XRCC3 and XRCC5 with the development of late radiation-induced radiotherapy reactions and examines the correlation between these microsatellites and cancer incidence. Sixty-two women with cervical or endometrial cancer treated with radiotherapy were included in the study. According to the CTCAEv3.0 scale, 22 patients showed late adverse radiotherapy reactions (grade 2 or more). PCR on lymphocyte DNA followed by automated fragment analysis was performed to examine the number of tandem repeat units at each locus. No significant association was found between the repeat length at any of the microsatellites in XRCC1, XRC... | eng_Latn | 15,594 |
[The circadian evolution of the karyometric indices of the inner hair cells. A statistical analysis]. | We have realized a statistic study about "Karyometric Index" in the hair cells of the Corti organ of the albino Wistar rat [correction of guinea pig] in thirty of these animals; after in vivo fixation. The Karyometric Index variations are a good indicator of the cellular basic functional activity. Therefore we tried to clarify if the their cells are or not resembling to other cellular types with the functional circadian circles as well as if they present it or not in their basic functionalism, as they are also included in the "Endocrine Difusse System" and the "Paraneuron" concepts. | Risk estimation in radiation carcinogenesis depends primarily on epidemiological data and hazard rate models. The A-bomb survivors follow-up provides information on the complexity of this process. Several hazard rate models are briefly discussed and illustrated using the A-bomb experience. | eng_Latn | 15,595 |
Use of Radiography to Identify the Gangue | The article presents a method of detecting undesirable objects on a conveyor belt. In this paper problem of distinguishing coal from gangue is described. The method which is presented in this article is based on the x-ray phenomenon. The tested objects will be distinguished on the basis of the density difference. This method is very important for mining industry because a stone or another undesirable object which gets to belt conveyor can damage it, and output transport will have stopped. | Objective To prospectively assess the nutritional risk in patients with esophageal cancer,and compare the feasibility and results of nutritional risk screening 2002(NRS 2002) and subjective globe assessment(SGA).Methods Fifty four patients with esophageal cancer were selected for nutritional status survey including human body measurement,blood biochemical index, subjective global assessment(SGA),and nutritional risk screening 2002(NRS 2002).Results All patients completed both NRS 2002 and SGA.The incidences of undernutrition,overweight,and obesity judged by Chinese standard of body mass index(BMI) were 7.4%,18.5%and 5.6%. respectively.The incidences of nutritional risk or undernutrition screened by NRS2002 and SGA were 79.6%and 81.5%,respectively.No significant difference was observed between the results of these two screening tools(P = 0.723).Conclusion Both NRS 2002 and SGA were feasible in screening undernutrition in esophageal cancer patients. | eng_Latn | 15,596 |
Ovarian cancer screening in the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial: Findings from the initial screen of a randomized trial | Objective Ovarian cancer screening with transvaginal ultrasound (TVU) and CA-125 was evaluated in the Prostate, Lung, Colorectal and Ovarian (PLCO) Trial. Study design This was a randomized controlled trial of screening versus usual care. Baseline screening results are reported. Results Of 39,115 women randomized to receive screening, 28,816 received at least 1 test. Abnormal TVU was found in 1338 (4.7%), and abnormal CA-125 in 402 (1.4%). Twenty-nine neoplasms were identified (26 ovarian, 2 fallopian, and 1 primary peritoneal neoplasm). Nine were tumors of low malignant potential and 20 were invasive. The positive predictive value for invasive cancer was 3.7% for an abnormal CA-125, 1.0% for an abnormal TVU, and 23.5% if both tests were abnormal. Conclusion The effect of screening on ovarian cancer mortality in the PLCO cohort has yet to be evaluated and will require longer follow-up. Screening identified both early- and late-stage neoplasms, and the predictive value of both tests was relatively low. | Transporting radioactive material onsite (intrasite transfers) via truck or train must be performed in a safe manner. Adequate safety is assured for each transfer, as documented in the corresponding Onsite Safety Assessment (OSA). One aspect of the OSA is to show that the package to be used for the transfer meets onsite acceptance criteria. The activity being analyzed in this report is the movement of plutonium solution with greater than 20 curies, all reasonable mitigative controls will be implemented to minimize the likelihood of an accidental release, and a probabilistic analysis will be used to evaluate the risk associated with the move. The purpose of this report is to document the evaluation of risk due to vehicle accident associated with transporting plutonium solution from H-area to F-area. Included in the report is a list of the required mitigative controls which reduce the predicted accident and release frequencies to those reported in the summary. | eng_Latn | 15,597 |
Analytic Methods for Biochemical Indicators of Radiation Injury | Since the development of biochemical indicators of radiation injury has been hampered often by the lack of simple and rapid methods of determination, techniques for the measurement of 30 urinary compounds are presented. These methods have been in part taken from the literature, in part they have been modified or developed by us. They represent a compromise between speed and simplicity of execution and specificity of assay. | I have chosen to publish this paper as a reminder to be aware of postradiation ulceration. If this occurs, think malignancy. Biopsy should be done and, if positive, there should be wide resection and repair with well-vascularized tissue, muscle flap, and simple skin reconstruction—skin graft. Follow-up should be frequent, and any suspicious region should be biopsied. This seems very elementary, but unfortunately these simple rules are not always obeyed. | eng_Latn | 15,598 |
Absence of expression of the FMR-1 gene in fragile X syndrome | We previously reported the isolation of a gene (FMR-1) expressed in brain at the fragile X locus. One exon of this gene lies within an EcoRI fragment that exhibits length variation in fragile X patients. This exon also contains the CGG repeat within the CpG island hypermethylated in fragile X patients. To study the involvement of the FMR-1 gene in the fragile X syndrome, its expression was studied in lymphoblastoid cell lines and leukocytes derived from patients and normal controls. FMR-1 mRNA was absent in the majority of male fragile X patients, suggesting a close involvement of this gene in development of the syndrome. Normal individuals and carriers all show expression. The methylation status of the BssHII site at the CpG island was also studied by Southern blot analysis of DNA from patients, carriers, and controls. The minority of fragile X affected males that show expression of FMR-1 demonstrated an associated incomplete methylation of the BssHII site. | Using 907A steel plate specimens with V type gap,the tensile fatigue test was completed and the rule of fatigue crack propagation was researched.Based on singular element method stress intensity factor of plate specimens was calculated,the relation between crack propagation rate and △K was given according to Paris rule.The fatigue crack propagation model was offered for analyzing and predicting crack propagation situation and the remaining life assessment of damaged warship in waves.The reasonability of the method was demonstrated by the calculation example of some warship. | eng_Latn | 15,599 |
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