The possible inductions of bone cancer and leukemia are the two health effects of primary concern in the irradiation of the skeleton. The relevant target tissues to consider in the dosimetric evaluation have been the cells on or near endosteal surfaces of bone, from which osteosarcomas are thought to arise, and hematopoietic bone marrow, which is associated with leukemia. The ...

The possible inductions of bone cancer and leukemia are the two health effects of primary concern in the irradiation of the skeleton. The relevant target tissues to consider in the dosimetric evaluation have been the cells on or near endosteal surfaces of bone, from which osteosarcomas are thought to arise, and hematopoietic bone marrow, which is associated with leukemia. The ...

Current knowledge of the fraction of ingested actinide absorbed from the gastrointestinal (GI) tract, and of factors influencing that fraction absorbed, is probably adequate for the establishment of safe limits for the exposure of workers. Uncertainties n...

Irradiation of trabecular bone regions is an important area within internal dosimetry considering the role these bone sites play in both the skeletal and hematopoietic systems. Since bone marrow is located within trabecular bone regions, radiation incident upon bone is likely to also cause damage to the marrow. Radionuclides that localize in bone, ...

We developed a Monte Carlo simulation in Geant4 to calculate the absorbed fractions for electrons emitted by 199Au, 177Lu, 131I, 153Sm, 186Re and 90Y, characterized by average energies ranging from 86 keV to 949 keV, uniformly distributed in ellipsoidal volumes of soft tissue. Code validation results with respect to reference data for doses, ranges and ...

... fraction method of radiation absorbed dose calculation (eg, system set forth by Medical Internal Radiation Dose Committee of the Society of Nuclear Medicine or ...

Internal heat flow from radioactive decay in Triton's interior along with absorbed thermal energy from Neptune total 5 to 20 percent of the insolation absorbed by Triton, thus comprising a significant fraction of Triton's surface energy balance. These add...

Parylene disks supported on glass stalks were irradiated with 1.06 $mu$m wavelength laser light pulses focused to flux intensities in the range from 10$sup 15$ to 10$sup 17$ W/cm$sup 2$. According to photodiode measurements the fraction of laser light absorbed, 25 to 50 percent, increased slightly as the laser intensity was ...

X-ray induced changes in rat and human bone and bone marrow vasculature and in rat brain vasculature were measured as a function of time after irradiation and absorbed dose. The absorbed dose in the organ varied from 5 to 25 Gy for single dose irradiation...

This paper presents the calorimetric measurement of the inward-flowing fraction of absorbed solar radiation for a venetian blind at various blind slat angles. The general methodology used for this study followed that originally used by Klems and Kelley (1996). By conducting controlled experiments with an electrically heated blind (to simulate the effects ...

The fraction, of photosynthetically active radiation absorbed by vegetation, F sub ipar, is an important requirement for estimating vegetation biomass productivity and related quantities. This was an integral part of a large international effort; the Firs...

The current dose coefficients for internal dose assessment of occupationally exposed persons and the general public were derived using the methodology of the International Commission on Radiological Protection (ICRP), which is similar to the Medical Internal Radiation Dose (MIRD)-type methodology. One component of this methodology is ...

rates from internal and external exposures. Internal dose rates are calculated using organism- and nuclide-specific bioaccumulation factors and absorbed energy fractions. External dose rates are calculated the outside the body are called external exposures; calculated dose equivalents. Thus, the presented exposures

Reactor pressure vessel (RPV) reference steel samples submitted to neutron irradiations followed by thermal annealing were investigated by X-ray absorption fine structure (XAFS) spectroscopy. Several studies revealed that Cu and Ni impurities can form nanoclusters. In the unirradiated sample and in the only-irradiated sample no significant clustering is ...

Several therapeutic and diagnostic techniques involve injection of radioactive material into the peritoneal cavity. Estimation of the radiation dose to the surface of the peritoneum or to surrounding organs is hampered by the lack of a suitable source region in the phantom commonly used for such calculations. We have modified the Fisher-Snyder phantom to include a region representing the ...

Several therapeutic and diagnostic techniques involve injection of radioactive material into the peritoneal cavity. Estimation of the radiation dose to the surface of the peritoneum or to surrounding organs is hampered by the lack of a suitable source region in the phantom commonly used for such calculations. We have modified the Fisher-Snyder phantom to include a region representing the ...

We discuss a study of the radiation transport of monoenergetic photons within a mathematical phantom of the pregnant female at the end of the first trimester. This phantom was developed from the adult female member of the ORNL phantom series with modifications reflecting anatomical changes at this stage of pregnancy. This geometry was incorporated into the ALGAMP Monte Carlo radiation transport ...

The author studied the electron-microscopic picture of the light fraction of centrifuged liver and spleen homogenates of control and irradiated rats and mice. The external irradiation was conducted with Co/sup 60/ gamma-rays (800 r), and internal Po/sup 210/ alpha rays (0.2 mc/kg). Upon ...

Electron-specific absorbed fractions were calculated for selected organs and regions of the mathematical reference man. The organs or regions considered were those with high surface-to-volume ratio, organs with walls, and organs that have subdivisions. The calculated specific absorbed fractions for electrons are a ...

We studied through Monte Carlo simulation in Geant4 the absorbed fractions for photons, characterized by energies ranging from 10 keV to 1000 keV, which can be emitted by gamma radionuclides uniformly distributed in ellipsoidal volumes of soft tissue. The same analytical relationship between absorbed fraction and ...

Monte Carlo calculations of the absorbed dose delivered by point source gamma emitters to tissue equivalent phantoms were performed and the results are presented in tables that include that fraction of the emitted energy absorbed by the phantom. The use of these tables makes it possible to calculate gamma dose- rate in a ...

Specific absorbed fractions (SAF) in various 'target' organs of the body originated from monoenergetic photons in various other 'source' organs were obtained by using voxel anthropomorphic phantoms of a 7-year-old child and a 8-week old baby (CHILD, BABY)...

Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for an adult male (70-kg Reference Man)....

Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a fifteen-year-old male or an adult ...

Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a five-year-old or 19-kg person. The...

Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. This volume outlines various methods used to compute the PHI-values and describe...

Styrene butadiene styrene copolymer (SBS) of different configuration and block ratio were irradiated by 60Co ?-rays at 20 �C and 120 �C. The gel fraction and thermal properties before and after irradiation were discussed. The gel fraction increased with both absorbed doses and temperature. ...

The photocatalytic removal of humic acid (HA) using TiO2 under UVA irradiation was examined by monitoring changes in the UV(254) absorbance, dissolved organic carbon (DOC) concentration, apparent molecular weight distribution, and trihalomethane formation potentials (THMFPs) over treatment time. A resin fractionation technique in which ...

The extent of absorption of sulfanilamide, bretylium tosylate, sulfisohazole acetyl, and riboflavin was determined in rats exposed to 850 rad of cobalt-60 gamma-radiation of sham irradiated. The drugs were administered orally at 1 or 5 days postirradiation, and the amount of drugs excreted in the urine was used as the measure of absorption. Following intravenous drug ...

Blue light-induced absorbance changes were measured from differentially centrifuged membrane fractions from dark-grown coleoptiles of Zea mays L., and mycelia from an albino mutant of Neurospora crassa. Actinic irradiation caused changes in absorbance consistent with a flavinmediated reduction of a b-type ...

The dose absorbed fraction of rat thyroid by internal deposit of 131I has been calculated as a function of effective diameter of thyroid. The calculations were done using two types of Monte Carlo simulations: one was by a simple energy-loss calculation in spherical volume according to the electron stopping power, and another by a more ...

The fraction of radiation absorbed in the canopy depends on the amount and angular distribution of the solar irradiance reaching the top of the canopy as well as the fraction of this irradiance that is transmitted through the canopy gaps and reflected back to the vegetation by the background. ...

Parylene disks supported on glass stalks were irradiated with 1.06 mu m wavelength laser light pulses focused to flux intensities in the range from 10 exp 15 to 10 exp 17 W/cm exp 2 . According to photodiode measurements the fraction of laser light absorb...

Existing models that allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregn...

Mathematical phantoms of the human body at various ages are employed with Monte Carlo radiation transport codes for calculation of photon specific absorbed fractions. The author has developed a pediatric phantom series based on the design of the adult pha...

The standard method outlines a procedure for calculating the absorbed dose in a material given the material composition, the neutron fluence, and threshold-foil data related to the neutron spectrum. The method is applicable to fast-pulsed reactors of the Godiva or TRIGA type, where a substantial fraction of the neutron fluence exceeds epithermal energies ...

The authors studied the rate of regeneration of the locally irradiated liver of mice in different conditions of dose fractionation. Regeneration was induced by a partial hepatectomy, conducted on the 4th day upon the termination of irradiation. Increment in wet and dry weight served as the criteria of intensity of ...

Bone-seeking alpha-particle emitting radionuclides are common health physics hazards. Additionally, they are under consideration as an option for therapeutic molecular radiotherapy applications. Current dose models do not account for energy or bone-site dependence as shown by alpha-particle absorbed fractions given in ICRP Publication 30. Energy-dependent, ...

Mathematical phantoms of the human body at various ages are employed with Monte Carlo radiation transport codes for calculation of photon specific absorbed fractions. The author has developed a pediatric phantom series based on the design of the adult phantom, but with explicit equations for each organ so that organ sizes and marrow distributions could be ...

A Monte Carlo simulation of multiple trabecular bone cavities in adult bone was developed and the absorbed radiation dose factors evaluated for 3H and 14C. The model was developed to assess the dose from radionuclide uptake in quiescent bone, but also the effects of temporal changes in bone turnover by incorporating bone-modelling units (BMU). Absorbed ...

Tumour control probability (TCP) is the probability of destroying every clonogen in a tumour as a result of a Radiation Therapy treatment. Assuming absorbed dose homogeneity throughout the tumour volume, TCP can be easily derived from a cell survival model. If absorbed dose is non homogeneous, its distribution has to be taken into account, because survival ...

Four patient with nearly normal physiologic condition received five courses of total-body irradiation of calculated absorbe doses from 50 to 150 r at midplane, and one of the patients also received internal irradiation from sodium- 24. Physiological alterations resulting from irradiation ...

Atmospheric aerosols scatter and absorb solar radiation leading to variable effects on Earth's radiative balance. Aerosols individually comprising mixtures of different components ("internally mixed") interact differently with light than mixtures of aerosols, each comprising a different single component ("externally mixed"), even if the relative ...

Rats have been widely used in radiopharmaceutics researches, making it reasonable to develop fine structured computational models for rat internal dose investigation. In this work, we developed three existing types of computational phantoms based on the same data set of rat, simulated photon and electron particles transport using Monte Carlo method and calculated ...

Dose integration properties were investigated for normoxic polymer gels based on methacrylic acid (nMAG) and acrylamide/N, N'-methylenebisacrylamide (nPAG). The effect of sequential irradiation was studied for different fractionation schemes and varying amounts of methacrylic acid for the nMAG gels. Magnetic resonance imaging (MRI) was used for read out of ...

In 131-J treatment as in other forms of internal radiotherapy using biologically distributed radionuclides it is important to differentiate between projected and obtained internal radiation doses which may differ considerably because of a change in the kinetics during and because of the irradiation by radioiodine. The clinical result ...

Rodent species are widely used in the testing and approval of new radiopharmaceuticals, necessitating murine phantom models. As more therapy applications are being tested in animal models, calculating accurate dose estimates for the animals themselves becomes important to explain and control potential radiation toxicity or treatment efficacy. Historically, stylized and mathematically based models ...

Effects of gamma -irradiation on the amimo-carbonyl reaction were investigated with the medel system of various sugar-glycine solutions. The mixed solutions of sugar and glycine were irradiatnd at 20 deg C with gamma rays from a /sup 60/Co source under the presence and absence of oxygen. The browning, the increase in absorbance at 420 nm of ...

In this study tissue culture methods were used to investigate the effects of ionizing irradiation on bone and cartilage of calvaria and radii of 18-day-old embryonic rats (resp. mice). The radii were studied histologically after 2 days of culture following the irradiation. A number of changes were observed. Decrease in growth of the bone collar and of the ...

Measurements of the absorbed radiation dose fractions were made in a representation of an adult human. The primary purpose of this research was to investigate the effect of source organ size on the absorbed fractions in many target organs in the body. For...

... and absorbed photon fractions by the first layers (see the Materials and Methods) TABLE 1 Photoabsorption Cross Section of Constituent Atoms for each Molecule at 538 eV Cited byAkinari ... ...

in global temperature change until 2040: temperature trends along not enough. Why? High sensitivity models have more initial ... earth albedo and therefore fraction of solar irradiance absorbed. .... Given climate variability, 15 to 20 years is required to detect cloud .... CLARREO will likely play a key role. ...

Purified deoxygenated sperm whale myoglobin solutions were exposed to gamma irradiation at levels up to 500 krad. Following irradiation the solutions could be resolved by Sephadex chromatography into three fractions: monomer (molecular weight, M. W., estimate 17,000); dimer (M. W. 38,000); and polymers (M. W. 60,000 and ...

... Accession Number : ADD427491. Title : Effect of Sterilization Irradiation on Fraction and Wear of Ultrahigh-Molecular-Weight Polyethylene,. ...

Industrial areas in proximity to the Vodny settlement in the Komi Republic, Russia, have been contaminated by uranium mill tailings and radium production wastes. These areas, exhibiting high activity concentrations of naturally occurring radionuclides in soils, constitute a field laboratory where the effects of combined chronic exposures to alpha-, beta- and gamma-emitting radionuclides on natural ...