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Sample records for biokinetic pbbk modeling

  1. Biokinetic model for 137 Cs

    International Nuclear Information System (INIS)

    Melo, Dunstana Rabelo de

    1995-01-01

    The main objective of this work was to provide a realistic biokinetic model for 137 Cs metabolism. This model was based on the retention of cesium in 57 people contaminated in the Goiania accident, ages 1 to 73 y old, complemented by data obtained in an experiment with beagle dogs, and data taken from the open literature. Cesium is distributed among all tissues and organs of the body. Its main retention site is the skeletal muscle tissue. Mathematically, cesium retention in the body may be described by a sum of three terms exponential equation. The first term represents the fraction which is rapidly eliminated in urine. This fraction is weight dependent (negative correlation). The second term represents the retention of cesium in tissues and organs of the body. For children and adolescents, the second term biological half-life is a function of the weight. For adults, it is correlated with sex. Men present a higher retention of cesium than women. The third term correspond to a retention fraction of the order of 0,1% of the initial body burden. It is characterized by a very long half-life and represents a subcellular retention of cesium in the skeletal muscle tissue. During pregnancy the transfer factor from the mother to the fetus is correlated to the amount of cesium in the blood and it is equal to 1, if the intake of cesium occurs pregnancy. (author)

  2. Consistent biokinetic models for the actinide elements

    International Nuclear Information System (INIS)

    Leggett, R.W.

    2001-01-01

    The biokinetic models for Th, Np, Pu, Am and Cm currently recommended by the International Commission on Radiological Protection (ICRP) were developed within a generic framework that depicts gradual burial of skeletal activity in bone volume, depicts recycling of activity released to blood and links excretion to retention and translocation of activity. For other actinide elements such as Ac, Pa, Bk, Cf and Es, the ICRP still uses simplistic retention models that assign all skeletal activity to bone surface and depicts one-directional flow of activity from blood to long-term depositories to excreta. This mixture of updated and older models in ICRP documents has led to inconsistencies in dose estimates and interpretation of bioassay for radionuclides with reasonably similar biokinetics. This paper proposes new biokinetic models for Ac, Pa, Bk, Cf and Es that are consistent with the updated models for Th, Np, Pu, Am and Cm. The proposed models are developed within the ICRP's generic model framework for bone-surface-seeking radionuclides, and an effort has been made to develop parameter values that are consistent with results of comparative biokinetic data on the different actinide elements. (author)

  3. Development, implementation and quality assurance of biokinetic models within CONRAD

    International Nuclear Information System (INIS)

    Nosske, D.; Birchall, A.; Blanchardon, E.; Breustedt, B.; Giussani, A.; Luciani, A.; Oeh, U.; Lopez, M. A.

    2008-01-01

    The work of the Task Group 5.2 'Research Studies on Biokinetic Models' of the CONRAD project is presented. New biokinetic models have been implemented by several European institutions. Quality assurance procedures included intercomparison of the results as well as quality assurance of model formulation. Additionally, the use of the models was examined leading to proposals of tuning parameters. Stable isotope studies were evaluated with respect to their implications to the new models, and new biokinetic models were proposed on the basis of their results. Furthermore, the development of a biokinetic model describing the effects of decorporation of actinides by diethylenetriaminepentaacetic acid treatment was initiated. (authors)

  4. A biokinetic model for zinc for use in radiation protection

    International Nuclear Information System (INIS)

    Leggett, R.W.

    2012-01-01

    The physiology of the essential trace element zinc has been studied extensively in human subjects using kinetic analysis of time-dependent measurements of administered zinc tracers. A number of biokinetic models describing zinc exchange between plasma and tissues and endogenous excretion of zinc have been derived as fits to data for specific study groups. More rudimentary biokinetic models for zinc have been developed to estimate radiation doses from internally deposited radioisotopes of zinc. The latter models are designed to provide broadly accurate estimates of cumulative decays of zinc radioisotopes in tissues and are not intended as realistic descriptions of the directions of movement of zinc in the body. This paper reviews biokinetic data for zinc and proposes a physiologically meaningful biokinetic model for systemic zinc for use in radiation protection. The proposed model bears some resemblance to zinc models developed in physiological studies but depicts a finer division of systemic zinc and is based on a broader spectrum of data than previous models. The proposed model and the model for zinc currently recommended by the International Commission on Radiological Protection yield reasonably similar estimates of total-body retention and effective dose for internally deposited radioisotopes of zinc but much different systemic distributions of activity and much different dose estimates for some individual tissues, particularly the liver. - Highlights: ► Zinc is an essential trace element with numerous functions in the human body. ► Several biokinetic models for zinc have been developed from tracer studies on humans. ► More rudimentary biokinetic models for zinc have been developed in radiation protection. ► Biokinetic data for zinc are reviewed and a new biokinetic model is proposed for radiation protection. ► The proposed model may also be useful for investigation of zinc physiology and homeostasis.

  5. An optimization strategy for a biokinetic model of inhaled radionuclides

    International Nuclear Information System (INIS)

    Shyr, L.J.; Griffith, W.C.; Boecker, B.B.

    1991-01-01

    Models for material disposition and dosimetry involve predictions of the biokinetics of the material among compartments representing organs and tissues in the body. Because of a lack of human data for most toxicants, many of the basic data are derived by modeling the results obtained from studies using laboratory animals. Such a biomathematical model is usually developed by adjusting the model parameters to make the model predictions match the measured retention and excretion data visually. The fitting process can be very time-consuming for a complicated model, and visual model selections may be subjective and easily biased by the scale or the data used. Due to the development of computerized optimization methods, manual fitting could benefit from an automated process. However, for a complicated model, an automated process without an optimization strategy will not be efficient, and may not produce fruitful results. In this paper, procedures for, and implementation of, an optimization strategy for a complicated mathematical model is demonstrated by optimizing a biokinetic model for 144Ce in fused aluminosilicate particles inhaled by beagle dogs. The optimized results using SimuSolv were compared to manual fitting results obtained previously using the model simulation software GASP. Also, statistical criteria provided by SimuSolv, such as likelihood function values, were used to help or verify visual model selections

  6. Software for biokinetic modeling of the radiopharmaceuticals used in PET

    International Nuclear Information System (INIS)

    Cordeiro, Leanderson P.; Vieira, Igor F.; Lima, Fernando R.A. de; Vieira, Jose W.

    2013-01-01

    In this work will be presented the current state of software in development to estimate the dose from PET images. Will be given the main biokinetic models used in PET, as well as the general features of a tool in development, whose current features allow quantitative analysis of compartmental models. Further, the tool allows display images 2D PET (in DICOM format) and quantify the intensity map of regions of interest in counts per second coincidence events. The next step is to insert in the same tool to estimate the activity concentration for ROI and estimate dose from PET images static and / or dynamic

  7. Biokinetic models for the metabolism of uranium: an overview

    International Nuclear Information System (INIS)

    Bertelli, Luiz; Lipsztein, Joyce L.; Melo, Dunstana R.; Puerta, Anselmo; Wrenn, McDonald E.

    1997-01-01

    This work reviews the main experiments involving uranium injection and inhalation into several animal species and those associated with humans as well. The literature was carefully selected to involve the uranium intake, distribution and excretion in humans and mammals. The available biokinetic models for the uranium metabolism, proposed by ICRP in Publications 2, 30 and 69, were shortly described and tested against the data. Human data which incorporates measurements of urine, autopsy and biopsy samples were also used completing the review of models associated with the systemic part. (author). 21 refs., 4 figs

  8. A recycling model of the biokinetics of systemic tellurium.

    Science.gov (United States)

    Giussani, Augusto

    2014-11-01

    To develop a compartmental model of the systemic biokinetics of tellurium required for calculating the internal dose and interpreting bioassay measurements after incorporation of radioactive tellurium. The compartmental model for tellurium was developed with the software SAAM II v. 2.0 (©The Epsilon Group, Charlottesville, Virginia, USA). Model parameters were determined on the basis of published retention and excretion data in humans and animals. The model consists of two blood compartments, one compartment each for liver, kidneys, thyroid, four compartments for bone tissues and a generic compartment for the soft tissues. The model predicts a rapid urinary excretion of systemic tellurium: 45% in the first 24 h and 84% after 50 d. Faecal excretion amounts to 0.4% after 3 d and 9% after 50 d. Whole body retention is 55% after one day, and 2.8% after 100 d. These values as well as the retained fractions in the single organs are reasonably consistent with the available human and animal data (studies with swine and guinea pigs). The proposed model gives a realistic description of the available biokinetic data for tellurium and will be adopted by the International Commission on Radiological Protection for applications in internal dosimetry.

  9. Identification of nevadensin as an important herb-based constituent inhibiting estragole bioactivation and physiology-based biokinetic modeling of its possible in vivo effect

    International Nuclear Information System (INIS)

    Alhusainy, W.; Paini, A.; Punt, A.; Louisse, J.; Spenkelink, A.; Vervoort, J.; Delatour, T.; Scholz, G.; Schilter, B.; Adams, T.; Bladeren, P.J. van; Rietjens, I.M.C.M.

    2010-01-01

    Estragole is a natural constituent of several herbs and spices including sweet basil. In rodent bioassays, estragole induces hepatomas, an effect ascribed to estragole bioactivation to 1'-sulfooxyestragole resulting in DNA adduct formation. The present paper identifies nevadensin as a basil constituent able to inhibit DNA adduct formation in rat hepatocytes exposed to the proximate carcinogen 1'-hydroxyestragole and nevadensin. This inhibition occurs at the level of sulfotransferase (SULT)-mediated bioactivation of 1'-hydroxyestragole. The Ki for SULT inhibition by nevadensin was 4 nM in male rat and human liver fractions. Furthermore, nevadensin up to 20 μM did not inhibit 1'-hydroxyestragole detoxification by glucuronidation and oxidation. The inhibition of SULT by nevadensin was incorporated into the recently developed physiologically based biokinetic (PBBK) rat and human models for estragole bioactivation and detoxification. The results predict that co-administration of estragole at a level inducing hepatic tumors in vivo (50 mg/kg bw) with nevadensin at a molar ratio of 0.06, representing the ratio of their occurrence in basil, results in almost 100% inhibition of the ultimate carcinogen 1'-sulfooxyestragole when assuming 100% uptake of nevadensin. Assuming 1% uptake, inhibition would still amount to more than 83%. Altogether these data point at a nevadensin-mediated inhibition of the formation of the ultimate carcinogenic metabolite of estragole, without reducing the capacity to detoxify 1'-hydroxyestragole via glucuronidation or oxidation. These data also point at a potential reduction of the cancer risk when estragole exposure occurs within a food matrix containing SULT inhibitors compared to what is observed upon exposure to pure estragole.

  10. A biokinetic and dosimetric model for the metabolism of uranium

    International Nuclear Information System (INIS)

    Wrenn, M.E.; Bertelli, L.; Durbin, P.W.; Eckerman, K.F.; Lipsztein, J.L.; Singh, N.P.

    1995-10-01

    Experiments involving injection and inhalation of uranium compounds into several animal species as well as those associated with humans are described and analyzed. A revised biokinetic and dosimetric model for the metabolism of uranium suitable for bioassay procedures is proposed. The model consists of a systematic part coupled to a model of the respiratory tract. The model has been tested against human data which incorporates in vivo measurements over the chest and measurements of urine, feces, and autopsy and biopsy samples.In particular the lung model of the International Commission on Radiological Protection, Publication 30 ( ICRP-30 ), has been modified in order to provide a model which more nearly predicts urinary excretion in accord with the experiences in humans and animals. We have also tested the data against the new ICRP (LUDEP) lung model. (author). 55 refs., 14 tabs., 33 figs

  11. A case of accidental intake of Molybdenum Radionuclides: analysis of data with a revised biokinetic model

    International Nuclear Information System (INIS)

    Giussani, A.; Cantone, M.C.; Tavola, F.; Lopez, M.A.; Navarro, T.

    2002-01-01

    In recent years, a series of investigations on the biokinetics of molybdenum in humans, conducted using stable isotopes of Mo as tracers, has provided valuable experimental data about the dynamics of relevant processes such as the uptake from the gut walls, the clearance from the systemic circulation and the elimination pathways. The results of these studies are in good agreement with the findings of a group of nutritionist who also performed biokinetic studies with stable tracers. All measurements show several deviations from the predictions of the current ICRP model. On the basis of these data, a preliminary revision of the biokinetic model for Mo was presented. The modified model was thus used as a starting point for a new series of biokinetic investigations, aimed at a better definition of some of its features. In a total of 54 studies conducted in 15 volunteers, the influence of the mass and of the chemical form on intestinal absorption, internal kinetics and urinary excretion was investigated

  12. A generic biokinetic model for predicting the behaviour of the lanthanide elements in the human body

    International Nuclear Information System (INIS)

    Taylor, D.M.; Leggett, R.W.

    2003-01-01

    Information on the biokinetics of the 15 elements of the lanthanide series, 57 La to 71 Lu, is too sparse to permit individual development of meaningful biokinetic models to describe the behaviour of each of the elements in humans. The lanthanides show a regular gradation in chemical properties across the series, and animal studies indicate that this is reflected in regular differences in their deposition in tissues such as the liver and skeleton. These regular differences in chemical and biological behaviour have been utilised to construct a generic lanthanide biokinetic model and to define element-specific parameters for each element in the series. This report describes the use of the available biokinetic data for humans and animals to derive the parameters for each of the elements. (author)

  13. Proposal of a new biokinetic model for niobium

    International Nuclear Information System (INIS)

    Oliveira, Roges

    2006-01-01

    There are two niobium isotopes generated in nuclear power plants: 95 Nb and 94 Nb. Workers and members of the public are subjects to intake these radionuclides in accident situation. For dose calculation purpose, it is very important to develop a model that describes in a more realistic way the kinetics of niobium inside of the human body. Presently the model adopted by ICRP (ICRP, 1989) is based on animal studies and describes the behavior of niobium in human being in a simple manner. The new model proposal describes the kinetics of the niobium from the intake into the blood until the excretion, doing this in a more realistic form and considering not only data from animals but data from human beings as well. For this objective, a workers group of a niobium extraction and processing industry exposed to stable niobium (93 Nb) in oxide insoluble form with associated uranium, was monitored for uranium and niobium determination in urinary and fecal excretion, by mass spectrometry. Based in the ratios of the niobium concentration in urinary and faecal excretion of this workers and animal data study, a new biokinetic model for niobium was proposed, with the followings modifications relative to ICRP model: a new compartment that represents muscular tissue; the fractions which are deposited into the compartment are modified; a third component in the retention equation of the bone tissue; introduction of recirculation between organs and blood. The new model was applied for a case of accidental intake and described adequately the experimental data

  14. Reliability of a new biokinetic model of zirconium in internal dosimetry: part I, parameter uncertainty analysis.

    Science.gov (United States)

    Li, Wei Bo; Greiter, Matthias; Oeh, Uwe; Hoeschen, Christoph

    2011-12-01

    The reliability of biokinetic models is essential in internal dose assessments and radiation risk analysis for the public, occupational workers, and patients exposed to radionuclides. In this paper, a method for assessing the reliability of biokinetic models by means of uncertainty and sensitivity analysis was developed. The paper is divided into two parts. In the first part of the study published here, the uncertainty sources of the model parameters for zirconium (Zr), developed by the International Commission on Radiological Protection (ICRP), were identified and analyzed. Furthermore, the uncertainty of the biokinetic experimental measurement performed at the Helmholtz Zentrum München-German Research Center for Environmental Health (HMGU) for developing a new biokinetic model of Zr was analyzed according to the Guide to the Expression of Uncertainty in Measurement, published by the International Organization for Standardization. The confidence interval and distribution of model parameters of the ICRP and HMGU Zr biokinetic models were evaluated. As a result of computer biokinetic modelings, the mean, standard uncertainty, and confidence interval of model prediction calculated based on the model parameter uncertainty were presented and compared to the plasma clearance and urinary excretion measured after intravenous administration. It was shown that for the most important compartment, the plasma, the uncertainty evaluated for the HMGU model was much smaller than that for the ICRP model; that phenomenon was observed for other organs and tissues as well. The uncertainty of the integral of the radioactivity of Zr up to 50 y calculated by the HMGU model after ingestion by adult members of the public was shown to be smaller by a factor of two than that of the ICRP model. It was also shown that the distribution type of the model parameter strongly influences the model prediction, and the correlation of the model input parameters affects the model prediction to a

  15. Basis for the ICRP's age-specific biokinetic model for uranium

    International Nuclear Information System (INIS)

    Leggett, R.W.

    1994-01-01

    In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is developing age-specific biokinetic models and dose coefficients for environmentally important radionuclides. This paper describes the ICRP's age-specific biokinetic model for uranium. The model is constructed within a physiologically based framework originally developed for application to the alkaline earth elements but sufficiently general to apply to the larger class of bone-volume-seeking elements. Transfer rates for a reference adult are based mainly on: (1) measurements of uranium in blood and excreta of several human subjects who were intravenously injected with uranium; (2) postmortem measurements of uranium in tissues of some of those subjects; (3) postmortem measurements of uranium in tissues of occupationally and non-occupationally exposed subjects; (4) data on baboons, dogs, and smaller laboratory animals exposed to uranium for experimental purposes; and (5) consideration of the physiological processes thought to control retention and translocation of uranium in the body. Transfer rates for the adult are extended to children by application of a set of generic assumptions applied by the ICRP to calcium-like elements. These assumptions were derived mainly from observations of the age-specific biokinetics of the alkaline earth elements and lead in humans and laboratory animals but are consistent with available age-specific biokinetic data on uranium. 82 refs., 17 figs., 8 tabs

  16. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Biokinetics and dosimetry of incorporated radionuclides. Final report

    International Nuclear Information System (INIS)

    Roth, P.; Aubineau-Laniece, I.; Bailly-Despiney, I.

    2000-01-01

    The final report 'Biokinetics and Dosimetry of Incorporated Radionuclides' presented here is one part of the 5 individual reports. The work to be carried out within this project is structured into four Work Packages: Workpackage 1 concentrates on ingested radionuclides, considering doses to the GI tract and radionuclide absorption. A major objective is the development of a new dosimetric model of the GI tract, taking account of most recent data on gut transit and dose to sensitive cells. Workpackage 2 seeks to improve and extend biokinetic and dosimetric models for systemic radionuclides. Existing models for adults and children will be extended to other elements and new models will be developed for the embryo and fetus. Workpackage 3 is to improve assessment of localised distribution of dose within tissues at the cellular level for specific examples of Auger emitters and alpha emitting isotopes, in relation to observed effects. The work will include experimental studies of dose/effect relationship and the development of localisation methods. Workpackage 4 concerns the development of computer codes for the new dosimetric models, quality assurance of the models and the calculation of dose coefficients. Formal sensitivity analysis will be used to identify critical areas of model development and to investigate the effects of variability and incertainty in biokinetic parameters. (orig.)

  17. A quantitative evaluation of multiple biokinetic models using an assembled water phantom: A feasibility study.

    Directory of Open Access Journals (Sweden)

    Da-Ming Yeh

    Full Text Available This study examined the feasibility of quantitatively evaluating multiple biokinetic models and established the validity of the different compartment models using an assembled water phantom. Most commercialized phantoms are made to survey the imaging system since this is essential to increase the diagnostic accuracy for quality assurance. In contrast, few customized phantoms are specifically made to represent multi-compartment biokinetic models. This is because the complicated calculations as defined to solve the biokinetic models and the time-consuming verifications of the obtained solutions are impeded greatly the progress over the past decade. Nevertheless, in this work, five biokinetic models were separately defined by five groups of simultaneous differential equations to obtain the time-dependent radioactive concentration changes inside the water phantom. The water phantom was assembled by seven acrylic boxes in four different sizes, and the boxes were linked to varying combinations of hoses to signify the multiple biokinetic models from the biomedical perspective. The boxes that were connected by hoses were then regarded as a closed water loop with only one infusion and drain. 129.1±24.2 MBq of Tc-99m labeled methylene diphosphonate (MDP solution was thoroughly infused into the water boxes before gamma scanning; then the water was replaced with de-ionized water to simulate the biological removal rate among the boxes. The water was driven by an automatic infusion pump at 6.7 c.c./min, while the biological half-life of the four different-sized boxes (64, 144, 252, and 612 c.c. was 4.8, 10.7, 18.8, and 45.5 min, respectively. The five models of derived time-dependent concentrations for the boxes were estimated either by a self-developed program run in MATLAB or by scanning via a gamma camera facility. Either agreement or disagreement between the practical scanning and the theoretical prediction in five models was thoroughly discussed. The

  18. Surface-seeking radionuclides in the skeleton: current approach and recent developments in biokinetic modelling for humans and beagles

    International Nuclear Information System (INIS)

    Luciani, A.; Polig, E.

    2007-01-01

    In the last decade, the biokinetics of surface-seeking radionuclides in the skeleton has been the object of several studies. Investigations were carried out to determine the kinetics of plutonium and americium in the skeleton of humans and beagles. As a result of these investigations, in recent years the models presented by ICRP in Publication 67 for humans were partially revised, particularly the skeletal part. The aim of the present work is to present recent developments in the biokinetic modelling of surface-seeking radionuclides (plutonium and americium) in beagles and humans. Various assumptions and physiological interpretations of the different approaches to the biokinetic modelling of the skeleton are discussed. Current ICRP concepts and skeleton modelling of plutonium and americium in humans are compared to the latest developments in biokinetic modelling in beagles. (authors)

  19. Uncertainty and sensitivity analysis of biokinetic models for radiopharmaceuticals used in nuclear medicine

    International Nuclear Information System (INIS)

    Li, W. B.; Hoeschen, C.

    2010-01-01

    Mathematical models for kinetics of radiopharmaceuticals in humans were developed and are used to estimate the radiation absorbed dose for patients in nuclear medicine by the International Commission on Radiological Protection and the Medical Internal Radiation Dose (MIRD) Committee. However, due to the fact that the residence times used were derived from different subjects, partially even with different ethnic backgrounds, a large variation in the model parameters propagates to a high uncertainty of the dose estimation. In this work, a method was developed for analysing the uncertainty and sensitivity of biokinetic models that are used to calculate the residence times. The biokinetic model of 18 F-FDG (FDG) developed by the MIRD Committee was analysed by this developed method. The sources of uncertainty of all model parameters were evaluated based on the experiments. The Latin hypercube sampling technique was used to sample the parameters for model input. Kinetic modelling of FDG in humans was performed. Sensitivity of model parameters was indicated by combining the model input and output, using regression and partial correlation analysis. The transfer rate parameter of plasma to other tissue fast is the parameter with the greatest influence on the residence time of plasma. Optimisation of biokinetic data acquisition in the clinical practice by exploitation of the sensitivity of model parameters obtained in this study is discussed. (authors)

  20. Reliability of a new biokinetic model of zirconium in internal dosimetry: part II, parameter sensitivity analysis.

    Science.gov (United States)

    Li, Wei Bo; Greiter, Matthias; Oeh, Uwe; Hoeschen, Christoph

    2011-12-01

    The reliability of biokinetic models is essential for the assessment of internal doses and a radiation risk analysis for the public and occupational workers exposed to radionuclides. In the present study, a method for assessing the reliability of biokinetic models by means of uncertainty and sensitivity analysis was developed. In the first part of the paper, the parameter uncertainty was analyzed for two biokinetic models of zirconium (Zr); one was reported by the International Commission on Radiological Protection (ICRP), and one was developed at the Helmholtz Zentrum München-German Research Center for Environmental Health (HMGU). In the second part of the paper, the parameter uncertainties and distributions of the Zr biokinetic models evaluated in Part I are used as the model inputs for identifying the most influential parameters in the models. Furthermore, the most influential model parameter on the integral of the radioactivity of Zr over 50 y in source organs after ingestion was identified. The results of the systemic HMGU Zr model showed that over the first 10 d, the parameters of transfer rates between blood and other soft tissues have the largest influence on the content of Zr in the blood and the daily urinary excretion; however, after day 1,000, the transfer rate from bone to blood becomes dominant. For the retention in bone, the transfer rate from blood to bone surfaces has the most influence out to the endpoint of the simulation; the transfer rate from blood to the upper larger intestine contributes a lot in the later days; i.e., after day 300. The alimentary tract absorption factor (fA) influences mostly the integral of radioactivity of Zr in most source organs after ingestion.

  1. Strontium biokinetic model for the pregnant woman and fetus: application to Techa River studies

    International Nuclear Information System (INIS)

    Shagina, N B; Tolstykh, E I; Degteva, M O; Fell, T P; Harrison, J D

    2015-01-01

    A biokinetic model for strontium (Sr) for the pregnant woman and fetus (Sr-PWF model) has been developed for use in the quantification of doses from internal radiation exposures following maternal ingestion of Sr radioisotopes before or during pregnancy. The model relates in particular to the population of the Techa River villages exposed to significant amounts of ingested Sr radioisotopes as a result of releases of liquid radioactive wastes from the Mayak plutonium production facility (Russia) in the early 1950s. The biokinetic model for Sr metabolism in the pregnant woman was based on a biokinetic model for the adult female modified to account for changes in mineral metabolism during pregnancy. The model for non-pregnant females of all ages was developed earlier with the use of extensive data on 90 Sr-body measurements in the Techa Riverside residents. To determine changes in model parameter values to take account of changing mineral metabolism during pregnancy, data from longitudinal studies of calcium homeostasis during human pregnancy were analysed and applied. Exchanges between maternal and fetal circulations and retention in fetal skeleton and soft tissues were modelled as adaptations of previously published models, taking account of data on Sr and calcium (Ca) metabolism obtained in Russia (Southern Urals and Moscow) relating to dietary calcium intakes, calcium contents in maternal and fetal skeletons and strontium transfer to the fetus. The model was validated using independent data on 90 Sr in the fetal skeleton from global fallout as well as unique data on 90 Sr-body burden in mothers and their still-born children for Techa River residents. While the Sr-PWF model has been developed specifically for ingestion of Sr isotopes by Techa River residents, it is also more widely applicable to maternal ingestion of Sr radioisotopes at different times before and during pregnancy and different ages of pregnant women in a general population. (paper)

  2. Recent developments in biokinetic models and the calculation of internal dose coefficients

    International Nuclear Information System (INIS)

    Fell, T.P.; Phipps, A.W.; Kendall, G.M.; Stradling, G.N.

    1997-01-01

    In most cases the measurement of radioactivity in an environmental or biological sample will be followed by some estimation of dose and possibly risk, either to a population or an individual. This will normally involve the use of a dose coefficient (dose per unit intake value) taken from a compendium. In recent years the calculation of dose coefficients has seen many developments in both biokinetic modelling and computational capabilities. ICRP has recommended new models for the respiratory tract and for the systemic behavior of many of the more important elements. As well as this, a general age-dependent calculation method has been developed which involves an effectively continuous variation of both biokinetic and dosimetric parameters, facilitating more realistic estimation of doses to young people. These new developments were used in work for recent ICRP, IAEA and CEC compendia of dose coefficients for both members of the public (including children) and workers. This paper presents a general overview of the method of calculation of internal doses with particular reference to the actinides. Some of the implications for dose coefficients of the new models are discussed. For example it is shown that compared with data in ICRP Publications 30 and 54: the new respiratory tract model generally predicts lower deposition in systemic tissues per unit intake; the new biokinetic models for actinides allow for burial of material deposited on bone surfaces; age-dependent models generally feature faster turnover of material in young people. All of these factors can lead to substantially different estimates of dose and examples of the new dose coefficients are given to illustrate these differences. During the development of the new models for actinides, human bioassay data were used to validate the model. Thus, one would expect the new models to give reasonable predictions of bioassay quantities. Some examples of the bioassay applications, e.g., excretion data for the

  3. Critical review of membrane bioreactor models--part 1: biokinetic and filtration models.

    Science.gov (United States)

    Naessens, W; Maere, T; Nopens, I

    2012-10-01

    Membrane bioreactor technology exists for a couple of decades, but has not yet overwhelmed the market due to some serious drawbacks of which operational cost due to fouling is the major contributor. Knowledge buildup and optimisation for such complex systems can significantly benefit from mathematical modelling. In this paper, the vast literature on modelling MBR biokinetics and filtration is critically reviewed. It was found that models cover the wide range of empirical to detailed mechanistic descriptions and have mainly been used for knowledge development and to a lesser extent for system optimisation/control. Moreover, studies are still predominantly performed at lab or pilot scale. Trends are discussed, knowledge gaps identified and interesting routes for further research suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Reliability of Current Biokinetic and Dosimetric Models for Radionuclides: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Meck, Robert A. [U.S. Nuclear Regulatory Commission

    2008-10-01

    This report describes the results of a pilot study of the reliability of the biokinetic and dosimetric models currently used by the U.S. Nuclear Regulatory Commission (NRC) as predictors of dose per unit internal or external exposure to radionuclides. The study examines the feasibility of critically evaluating the accuracy of these models for a comprehensive set of radionuclides of concern to the NRC. Each critical evaluation would include: identification of discrepancies between the models and current databases; characterization of uncertainties in model predictions of dose per unit intake or unit external exposure; characterization of variability in dose per unit intake or unit external exposure; and evaluation of prospects for development of more accurate models. Uncertainty refers here to the level of knowledge of a central value for a population, and variability refers to quantitative differences between different members of a population. This pilot study provides a critical assessment of models for selected radionuclides representing different levels of knowledge of dose per unit exposure. The main conclusions of this study are as follows: (1) To optimize the use of available NRC resources, the full study should focus on radionuclides most frequently encountered in the workplace or environment. A list of 50 radionuclides is proposed. (2) The reliability of a dose coefficient for inhalation or ingestion of a radionuclide (i.e., an estimate of dose per unit intake) may depend strongly on the specific application. Multiple characterizations of the uncertainty in a dose coefficient for inhalation or ingestion of a radionuclide may be needed for different forms of the radionuclide and different levels of information of that form available to the dose analyst. (3) A meaningful characterization of variability in dose per unit intake of a radionuclide requires detailed information on the biokinetics of the radionuclide and hence is not feasible for many infrequently

  5. Improvements in the biokinetic model for strontium with allowance for age and gender differences in bone mineral metabolism

    International Nuclear Information System (INIS)

    Shagina, N.B.; Tolstykh, E.I.; Degteva, M.O.

    2003-01-01

    An age- and gender-dependent biokinetic model for strontium was developed based on the study of a population living along the Techa River exposed to effluents from the Mayak Production Association. To estimate parameters of a new model (Techa biokinetic model, TBM) many data sets have been assembled: our whole-body counter data on long-term retention of 90 Sr in humans, data from studies during the period of global fallout, data resulting from deliberate injections of strontium radionuclides, and non-radiological data regarding bone formation and resorption, mineral content of the body, etc. The model was developed using the basic structure of the ICRP biokinetic model for strontium, but new age- and gender-specific parameters were derived. This paper discusses the approaches applied to develop the new model. (author)

  6. A biokinetic model of inhaled Cm compounds in dogs: Application to human exposure data

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Mewhinney, J.A.

    1989-01-01

    Curium isotopes are major by-products in irradiated nuclear reactor fuel and comprise a significant fraction of the alpha-emitting radionuclide inventory. Although little use is currently being made of purified Cm sources, such usage is possible if reprocessing of spent fuel becomes feasible. Because little information is available on the biokinetics and dosimetry of inhaled Cm compounds, a study was conducted in which adult beagle dogs received a single inhalation exposure to either a monodisperse aerosol of 244Cm2O3 (1.4 micron activity median aerodynamic diameter [AMAD]; sigma g = 1.16) or a polydisperse aerosol of 244Cm (NO3)3 (1.1 micron AMAD; sigma g = 1.74). At times ranging from 4 h to 2 y after exposure, animals were sacrificed and their tissues analyzed for Cm content. The data describing the uptake and retention of 244Cm in the different organs and tissues and the measured rates of excretion of these dogs formed the basis on which a biokinetic model of Cm metabolism was constructed. This Cm model was based on a previously published model of the biokinetics of 241Am that was shown to be applicable to data from human cases of inhalation exposure to 241Am aerosols. This Cm model was found to be adequate to describe the biological distribution of Cm in dogs and was also applied to the sparse data from humans. Reasonable agreement was found between the model predictions for lung retention of Cm and for urinary excretion patterns in humans

  7. A physiological skeletal model for radionuclide and stable element biokinetics in children and adults

    International Nuclear Information System (INIS)

    Richardson, R.B.

    2010-01-01

    A physiological skeletal model (PSM) is described that represents the skeletal uptake, retention and clearance of both bone-surface-seeking and bone-volume-seeking radionuclides and stable elements. A key objective of the PSM is to model the higher skeletal growth and bone turnover in infants and children (compared to adults) in order to to account for their greater uptake and cancer risk from bone-seeking contaminants such as lead and plutonium. The PSM is a compartmental model that allows for the incorporation of organic and inorganic material in the bone volume via quiescent bone surfaces, forming bone surfaces and the lacuno-canaliculi system. The model uniquely incorporates a tertiary phase of mineralization via bone fluids. The PSM's structural concepts and biokinetic parameters - such as realistic mass transfers, organ and tissue masses, and bone remodelling half times - are selected mainly on the basis of physiological and anatomical criteria. For brevity, model parameter values or evaluated for adults only. The PSM is an improvement on existing skeletal models that are based more on compartment structures and pathways that rendered good fits to biokinetic data rather than on being anatomically and physiologically accurate. (author)

  8. Identification of Biokinetic Models Using the Concept of Extents.

    Science.gov (United States)

    Mašić, Alma; Srinivasan, Sriniketh; Billeter, Julien; Bonvin, Dominique; Villez, Kris

    2017-07-05

    The development of a wide array of process technologies to enable the shift from conventional biological wastewater treatment processes to resource recovery systems is matched by an increasing demand for predictive capabilities. Mathematical models are excellent tools to meet this demand. However, obtaining reliable and fit-for-purpose models remains a cumbersome task due to the inherent complexity of biological wastewater treatment processes. In this work, we present a first study in the context of environmental biotechnology that adopts and explores the use of extents as a way to simplify and streamline the dynamic process modeling task. In addition, the extent-based modeling strategy is enhanced by optimal accounting for nonlinear algebraic equilibria and nonlinear measurement equations. Finally, a thorough discussion of our results explains the benefits of extent-based modeling and its potential to turn environmental process modeling into a highly automated task.

  9. Evaluating Alternate Biokinetic Models for Trace Pollutant Cometabolism

    DEFF Research Database (Denmark)

    Liu, Li; Binning, Philip John; Smets, Barth F.

    2015-01-01

    Mathematical models of cometabolic biodegradation kinetics can improve our understanding of the relevant microbial reactions and allow us to design in situ or in-reactor applications of cometabolic bioremediation. A variety of models are available, but their ability to describe experimental data...

  10. Relevance of the ICRP biokinetic model for dietary organically bound tritium

    International Nuclear Information System (INIS)

    Trivedi, A.

    1999-10-01

    Ingested dietary tritium can participate in metabolic processes, and become synthesized into organically bound tritium in the tissues and organs. The distribution and retention of the organically bound tritium throughout the body are much different than tritium in the body water. The International Commission on Radiological Protection (ICRP) Publication 56 (1989) has a biokinetic model to calculate dose from the ingestion of organically bound dietary tritium. The model predicts that the dose from the ingestion of organically bound dietary tritium is about 2.3 times higher than from the ingestion of the same activity of tritiated water. Under steady-state conditions, the calculated dose rate (using the first principle approach) from the ingestion of dietary organically bound tritium can be twice that from the ingestion of tritiated water. For an adult, the upper-bound dose estimate for the ingestion of dietary organically bound tritium is estimated to be close to 2.3 times higher than that of tritiated water. Therefore, given the uncertainty in the dose calculation with respect to the actual relevant dose, the ICRP biokinetic model for organically bound tritium is sufficient for dosimetry for adults. (author)

  11. A physiological biokinetic model for the [7(N)-{sup 3}H]-cholesterol dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Adriano dos Santos; Martins, Joao Francisco Trencher; Velo, Alexandre Franca; Hamada, Margarida M.; Mesquita, Carlos Henrique de, E-mail: adriano_oliveira@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Cardiovascular diseases (CVD) are a major source of deaths worldwide according to WHO (World Health Organization). It is well-known that the change of the level of plasma lipoproteins, which are responsible for the cholesterol transport in the bloodstream, is a main cause of these diseases. For this reason, to know the biokinetic parameters of plasma lipoproteins and quantifies them is important to correct and deepen the understanding of associated diseases. The main objective of this work is to provide a biokinetic model in order to estimate the radiometric dose, due to the intake of [7(N){sup -3}H] –Cholesterol in physiological issues, in metabolic studies. The internal dosimetry is important to know the biological effects of radiation. The model was based on Schwartz et al (2004), using parameters for the plasmatic lipoproteins and ICRP 30 (1979) gastrointestinal tract; the dose in the compartments were calculated using the MIRD methodology and the compartmental analysis by Matlab® software. The coefficients were estimated for an adult phantom with a body mass of 73.3 kg. (author)

  12. A physiological biokinetic model for the [7(N)-3H]-cholesterol dosimetry

    International Nuclear Information System (INIS)

    Oliveira, Adriano dos Santos; Martins, Joao Francisco Trencher; Velo, Alexandre Franca; Hamada, Margarida M.; Mesquita, Carlos Henrique de

    2015-01-01

    Cardiovascular diseases (CVD) are a major source of deaths worldwide according to WHO (World Health Organization). It is well-known that the change of the level of plasma lipoproteins, which are responsible for the cholesterol transport in the bloodstream, is a main cause of these diseases. For this reason, to know the biokinetic parameters of plasma lipoproteins and quantifies them is important to correct and deepen the understanding of associated diseases. The main objective of this work is to provide a biokinetic model in order to estimate the radiometric dose, due to the intake of [7(N) -3 H] –Cholesterol in physiological issues, in metabolic studies. The internal dosimetry is important to know the biological effects of radiation. The model was based on Schwartz et al (2004), using parameters for the plasmatic lipoproteins and ICRP 30 (1979) gastrointestinal tract; the dose in the compartments were calculated using the MIRD methodology and the compartmental analysis by Matlab® software. The coefficients were estimated for an adult phantom with a body mass of 73.3 kg. (author)

  13. A multiple-compartment model for biokinetics studies in plants

    International Nuclear Information System (INIS)

    Garcia, Fermin; Pietrobron, Flavio; Fonseca, Agnes M.F.; Mol, Anderson W.; Rodriguez, Oscar; Guzman, Fernando

    2001-01-01

    In the present work is used the system of linear equations based in the general Assimakopoulos's GMCM model , for the development of a new method that will determine the flow's parameters and transfer coefficients in plants. The need of mathematical models to quantify the penetration of a trace substance in animals and plants, has often been stressed in the literature. Usually, in radiological environment studies, it is used the mean value of contaminant concentrations on whole or edible part plant body, without taking in account vegetable physiology regularities. In this work concepts and mathematical formulation of a Vegetable Multi-compartment Model (VMCM), taking into account the plant's physiology regularities is presented. The model based in general ideas of the GMCM , and statistical Square Minimum Method STATFLUX is proposed to use in inverse sense: the experimental time dependence of concentration in each compartment, should be input, and the parameters should be determined from this data in a statistical approach. The case of Uranium metabolism is discussed. (author)

  14. Bayesian model selection validates a biokinetic model for zirconium processing in humans

    Science.gov (United States)

    2012-01-01

    Background In radiation protection, biokinetic models for zirconium processing are of crucial importance in dose estimation and further risk analysis for humans exposed to this radioactive substance. They provide limiting values of detrimental effects and build the basis for applications in internal dosimetry, the prediction for radioactive zirconium retention in various organs as well as retrospective dosimetry. Multi-compartmental models are the tool of choice for simulating the processing of zirconium. Although easily interpretable, determining the exact compartment structure and interaction mechanisms is generally daunting. In the context of observing the dynamics of multiple compartments, Bayesian methods provide efficient tools for model inference and selection. Results We are the first to apply a Markov chain Monte Carlo approach to compute Bayes factors for the evaluation of two competing models for zirconium processing in the human body after ingestion. Based on in vivo measurements of human plasma and urine levels we were able to show that a recently published model is superior to the standard model of the International Commission on Radiological Protection. The Bayes factors were estimated by means of the numerically stable thermodynamic integration in combination with a recently developed copula-based Metropolis-Hastings sampler. Conclusions In contrast to the standard model the novel model predicts lower accretion of zirconium in bones. This results in lower levels of noxious doses for exposed individuals. Moreover, the Bayesian approach allows for retrospective dose assessment, including credible intervals for the initially ingested zirconium, in a significantly more reliable fashion than previously possible. All methods presented here are readily applicable to many modeling tasks in systems biology. PMID:22863152

  15. Estimation of parameters biokinetics from the resolution of a model compartment for I-131. Application to a patient with thyroid carcinoma hemodialysis

    International Nuclear Information System (INIS)

    Garcia, R.; Jimenez Feltstrom, D.; Luis dimon, F. J.; Sanchez Carmona, G.; Herrador Cordoba, M.

    2013-01-01

    This work aims to define a biokinetic model for the I-131, and solve it for different conditions of the patient or person affected (normal, with cancer of the thyroid or hyperthyroid). Solve the model in the case of a patient treated with I-131 for ablation of thyroid remnants with undergoing renal insufficiency and hemodialysis . Get the parameters Biokinetic this model for different situations. (Author)

  16. INDOSE V2.1.1, Internal Dosimetry Code Using Biokinetics Models

    International Nuclear Information System (INIS)

    Silverman, Ido

    2002-01-01

    A - Description of program or function: InDose is an internal dosimetry code developed to enable dose estimations using the new biokinetic models (presented in ICRP-56 to ICRP71) as well as the old ones. The code is written in FORTRAN90 and uses the ICRP-66 respiratory tract model and the ICRP-30 gastrointestinal tract model as well as the new and old biokinetic models. The code has been written in such a way that the user is able to change any of the parameters of any one of the models without recompiling the code. All the parameters are given in well annotated parameters files that the user may change and the code reads during invocation. As default, these files contains the values listed in ICRP publications. The full InDose code is planed to have three parts: 1) the main part includes the uptake and systemic models and is used to calculate the activities in the body tissues and excretion as a function of time for a given intake. 2) An optimization module for automatic estimation of the intake for a specific exposure case. 3) A module to calculate the dose due to the estimated intake. Currently, the code is able to perform only its main task (part 1) while the other two have to be done externally using other tools. In the future we would like to add these modules in order to provide a complete solution for the people in the laboratory. The code has been tested extensively to verify the accuracy of its results. The verification procedure was divided into three parts: 1) verification of the implementation of each model, 2) verification of the integrity of the whole code, and 3) usability test. The first two parts consisted of comparing results obtained with InDose to published results for the same cases. For example ICRP-78 monitoring data. The last part consisted of participating in the 3. EIE-IDA and assessing some of the scenarios provided in this exercise. These tests where presented in a few publications. It has been found that there is very good agreement

  17. Mathematical solutions to problems in radiological protection involving air sampling and biokinetic modelling

    International Nuclear Information System (INIS)

    Birchall, A.

    1989-04-01

    Intakes of radionuclides are estimated with the personal air sampler (PAS) and by biological monitoring techniques: in the case of plutonium, there are problems with both methods. The statistical variation in activity collected when sampling radioactive aerosols with low number concentrations was investigated. It was shown that the PAS is barely adequate for monitoring plutonium at annual limit of intake (ALI) levels in typical workplace conditions. Two algorithms were developed, enabling non-recycling and recycling compartmental models to be solved. Their accuracy and speed were investigated, and methods of dealing with partitioning, continuous intake, and radioactive progeny were discussed. Analytical, rather than numerical, methods were used. These are faster, and thus ideally suited for implementation on microcomputers. The algorithms enable non-specialists to solve quickly and easily any first order compartmental model, including all the ICRP metabolic models. Non-recycling models with up to 50 compartments can be solved in seconds: recycling models take a little longer. A biokinetic model for plutonium in man following systemic uptake was developed. The proposed ICRP lung model (1989) was represented by a first order compartmental model. These two models were combined, and the recycling algorithm was used to calculate urinary and faecal excretion of plutonium following acute or chronic intake by inhalation. The results indicate much lower urinary excretion than predicted by ICRP Publication 54. (author)

  18. Calibration of hydrodynamic behavior and biokinetics for TOC removal modeling in biofilm reactors under different hydraulic conditions.

    Science.gov (United States)

    Zeng, Ming; Soric, Audrey; Roche, Nicolas

    2013-09-01

    In this study, total organic carbon (TOC) biodegradation was simulated by GPS-X software in biofilm reactors with carriers of plastic rings and glass beads under different hydraulic conditions. Hydrodynamic model by retention time distribution and biokinetic measurement by in-situ batch test served as two significant parts of model calibration. Experimental results showed that TOC removal efficiency was stable in both media due to the enough height of column, although the actual hydraulic volume changed during the variation of hydraulic condition. Simulated TOC removal efficiencies were close to experimental ones with low theil inequality coefficient values (below 0.15). Compared with glass beads, more TOC was removed in the filter with plastic rings due to the larger actual hydraulic volume and lower half saturation coefficient in spite of its lower maximum specific growth rate of biofilm, which highlighted the importance of calibrating hydrodynamic behavior and biokinetics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Intercomparison and biokinetic model validation of radionuclide intake assessment. Report of a co-ordinated research project. 1996-1998

    International Nuclear Information System (INIS)

    1999-03-01

    This TECDOC presents the results of a Co-ordinated Research Project (CRP) on Intercomparison and Biokinetic Model Validation of Radionuclide Intake Assessment, including the conclusions of a Research Co-ordination Meeting held from 6 to 8 July 1998. The present CRP on Intercomparison and Biokinetic Model Validation of Radionuclide Intake Assessment is part of the activities of the IAEA's Occupational Protection programme. The objective of this programme is to promote an internationally harmonized approach for optimizing occupational radiation protection through: the development of guides, within the IAEA's activities for establishing standards for radiation protection, for restricting radiation exposures in the workplace and for applying current occupational radiation protection techniques; and the promotion of application of these guidelines

  20. Quantitative analysis of multiple biokinetic models using a dynamic water phantom: A feasibility study

    Science.gov (United States)

    Chiang, Fu-Tsai; Li, Pei-Jung; Chung, Shih-Ping; Pan, Lung-Fa; Pan, Lung-Kwang

    2016-01-01

    ABSTRACT This study analyzed multiple biokinetic models using a dynamic water phantom. The phantom was custom-made with acrylic materials to model metabolic mechanisms in the human body. It had 4 spherical chambers of different sizes, connected by 8 ditches to form a complex and adjustable water loop. One infusion and drain pole connected the chambers to an auxiliary silicon-based hose, respectively. The radio-active compound solution (TC-99m-MDP labeled) formed a sealed and static water loop inside the phantom. As clean feed water was infused to replace the original solution, the system mimicked metabolic mechanisms for data acquisition. Five cases with different water loop settings were tested and analyzed, with case settings changed by controlling valve poles located in the ditches. The phantom could also be changed from model A to model B by transferring its vertical configuration. The phantom was surveyed with a clinical gamma camera to determine the time-dependent intensity of every chamber. The recorded counts per pixel in each chamber were analyzed and normalized to compare with theoretical estimations from the MATLAB program. Every preset case was represented by uniquely defined, time-dependent, simultaneous differential equations, and a corresponding MATLAB program optimized the solutions by comparing theoretical calculations and practical measurements. A dimensionless agreement (AT) index was recommended to evaluate the comparison in each case. ATs varied from 5.6 to 48.7 over the 5 cases, indicating that this work presented an acceptable feasibility study. PMID:27286096

  1. Modeling Aspects of Activated Sludge Processes Part l l: Mathematical Process Modeling and Biokinetics of Activated Sludge Processes

    Energy Technology Data Exchange (ETDEWEB)

    AbdElHaleem, H S [Cairo Univ.-CivlI Eng. Dept., Giza (Egypt); EI-Ahwany, A H [CairoUlmrsity- Faculty ofEngincering - Chemical Engineering Department, Giza (Egypt); Ibrahim, H I [Helwan University- Faculty of Engineering - Biomedical Engineering Department, Helwan (Egypt); Ibrahim, G [Menofia University- Faculty of Engineering Sbebin EI Kom- Basic Eng. Sc. Dept., Menofia (Egypt)

    2004-07-01

    Mathematical process modeling and biokinetics of activated sludge process were reviewed considering different types of models. It has been evaluated the task group models of ASMI. and 2, and 3 versioned by Henze et al considering the conditions of each model and the different processes of which every model consists. It is revealed that ASMI contains some defects avoided in ASM3. Relied on homogeneity, Models can be classified into homogenous models characterized by taking the activated sludge process as one phase. In this type of models, the internal mass transfer inside the floes was neglected.. Hence, the kinetic parameter produces can be considered inaccurate. The other type of models is the heterogeneous model This type considers the mass transfer operations in addition to the biochemical reaction processes; hence, the resulted kinetic parameters can be considered more accurate than that of homogenous type.

  2. Modeling Aspects of Activated Sludge Processes Part l l: Mathematical Process Modeling and Biokinetics of Activated Sludge Processes

    International Nuclear Information System (INIS)

    AbdElHaleem, H.S.; EI-Ahwany, A. H.; Ibrahim, H.I.; Ibrahim, G.

    2004-01-01

    Mathematical process modeling and biokinetics of activated sludge process were reviewed considering different types of models. It has been evaluated the task group models of ASMI. and 2, and 3 versioned by Henze et al considering the conditions of each model and the different processes of which every model consists. It is revealed that ASMI contains some defects avoided in ASM3. Relied on homogeneity, Models can be classified into homogenous models characterized by taking the activated sludge process as one phase. In this type of models, the internal mass transfer inside the floes was neglected.. Hence, the kinetic parameter produces can be considered inaccurate. The other type of models is the heterogeneous model This type considers the mass transfer operations in addition to the biochemical reaction processes; hence, the resulted kinetic parameters can be considered more accurate than that of homogenous type

  3. Investigation on biokinetics of 134Cs and 241Am radionuclides in three different organisms and a new evaluation by using discrete time model

    International Nuclear Information System (INIS)

    Guengoer, N.

    1999-05-01

    In this study, 134 Cs and 241 Am biokinetic experiments have been observed originally for Black Sea condition with using the gastropod Patella coerulea and the macro algae Enteremorpha linza and the common mussel Mytilus galloprovlncialis as bio indicator organisms. The experiments that have at least three originality, have been carried out very carefully and biokinetic parameters have been calculated by using classical model. The results are compared with the proportionally similar experiments in the literature globally. In this thesis, a new model application has proposed for the biokinetic evaluation for loss experiments of organisms. That is discrete time model. Loss experiments can be evaluated proportionally in a quick and easy way by using this model. Then, it can be observed that the calculated decreasing factor (r) by discrete time model, shows the loss process quality. Moreover, the loss experiments can be stopped when the decreasing factor goes to 1. So, the loss experiment can be evaluated rapidly and quickly with the adequate reliability by using discrete time model. Furthermore, the loss process in the organisms becomes slower and biologic half-lives becomes longer, when the decreasing factor (r) goes to 1. On the other hand, the biological depuration rate (k) goes to nearly zero. So, the proposed discrete time model that is applied in this thesis originally for biokinetic, can be evident that it has an adequate reliability for the biokinetic evaluation

  4. Controlling intake of uranium in the workplace: Applications of biokinetic modeling and occupational monitoring data

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; McGinn, Wilson [ORNL; Meck, Dr. Robert A. [U.S. Nuclear Regulatory Commission

    2012-01-01

    This report provides methods for interpreting and applying occupational uranium monitoring data. The methods are based on current international radiation protection guidance, current information on the chemical toxicity of uranium, and best available biokinetic models for uranium. Emphasis is on air monitoring data and three types of bioassay data: the concentration of uranium in urine; the concentration of uranium in feces; and the externally measured content of uranium in the chest. Primary Reference guidance levels for prevention of chemical effects and limitation of radiation effects are selected based on a review of current scientific data and regulatory principles for setting standards. Generic investigation levels and immediate action levels are then defined in terms of these primary guidance levels. The generic investigation and immediate actions levels are stated in terms of radiation dose and concentration of uranium in the kidneys. These are not directly measurable quantities, but models can be used to relate the generic levels to the concentration of uranium in air, urine, or feces, or the total uranium activity in the chest. Default investigation and immediate action levels for uranium in air, urine, feces, and chest are recommended for situations in which there is little information on the form of uranium taken into the body. Methods are prescribed also for deriving case-specific investigation and immediate action levels for uranium in air, urine, feces, and chest when there is sufficient information on the form of uranium to narrow the range of predictions of accumulation of uranium in the main target organs for uranium: kidneys for chemical effects and lungs for radiological effects. In addition, methods for using the information herein for alternative guidance levels, different from the ones selected for this report, are described.

  5. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Executive summary

    International Nuclear Information System (INIS)

    Jacob, P.; Paretzke, H.G.; Roth, P.

    2000-01-01

    The Association Contract covers a range of research domains that are important to the Radiation Protection Research Action, especially in the areas 'Evaluation of Radiation Risks' and 'Understanding Radiation Mechanisms and Epidemiology'. Three research projects concentrate on radiation dosimetry research and two projects on the modelling of radiation carcinogenesis. The following list gives an overview on the topics and responsible scientific project leaders of the Association Contract: Study of radiation fields and dosimetry at aviation altitudes. Biokinetics and dosimetry of incorporated radionuclides. Dose reconstruction. Biophysical models for the induction of cancer by radiation. Experimental data for the induction of cancer by radiation of different qualities. (orig.)

  6. Strontium biokinetic model for the lactating woman and transfer to breast milk: application to Techa River studies

    International Nuclear Information System (INIS)

    Shagina, N B; Tolstykh, E I; Degteva, M O; Fell, T P; Smith, T J; Harrison, J D

    2015-01-01

    This paper presents a biokinetic model for strontium metabolism in the lactating woman and transfer to breast milk for members of Techa River communities exposed as a result of discharges of liquid radioactive wastes from the Mayak plutonium production facility (Russia) in the early 1950s. This model was based on that developed for the International Commission for Radiological Protection with modifications to account for population specific features of breastfeeding and maternal bone mineral metabolism. The model is based on a biokinetic model for the adult female with allowances made for changes in mineral metabolism during periods of exclusive and partial breast-feeding. The model for females of all ages was developed earlier from extensive data on 90 Sr-body measurements for Techa Riverside residents. Measurements of 90 Sr concentrations in the maternal skeleton and breast milk obtained in the1960s during monitoring of global fallout in the Southern Urals region were used for evaluation of strontium transfer to breast and breast milk. The model was validated with independent data from studies of global fallout in Canada and measurements of 90 Sr body-burden in women living in the Techa River villages who were breastfeeding during maximum 90 Sr-dietary intakes. The model will be used in evaluations of the intake of strontium radioisotopes in breast milk by children born in Techa River villages during the radioactive releases and quantification of 90 Sr retention in the maternal skeleton. (paper)

  7. Uranium: biokinetics and toxicity

    International Nuclear Information System (INIS)

    Menetrier, F.; Renaud-Salis, V.; Flury-Herard, A.

    2000-01-01

    This report was achieved as a part of a collaboration with the Fuel Cycle Direction. Its aim was to give the state of the art about: the behaviour of uranium in the human organism (biokinetics) after ingestion, its toxicity (mainly renal) and the current regulation about its incorporation. Both in the upstream and in the downstream of the fuel cycle, uranium remains, quantitatively, the first element in the cycle which is, at the present time, temporarily disposed or recycled. Such a considerable quantity of uranium sets the problem of its risk on the health. In the long term, the biosphere may be affected and consequently the public may ingest water or food contaminated with uranium. In this way, radiological and chemical toxicity risk may be activated. This report emphasizes: the necessity of confirming some experimental and epidemiological biokinetic data used or not in the ICRP models. Unsolved questions remain about the gastrointestinal absorption according to chemical form (valency state, mixtures...), mass and individual variations (age, disease) further a chronic ingestion of uranium. It is well established that uranium is mainly deposited in the skeleton and the kidney. But the skeleton kinetics following a chronic ingestion and especially in some diseases has to be more elucidated; the necessity of taking into account uranium at first as a chemical toxic, essentially in the kidney and determining the threshold of functional lesion. In this way, it is important to look for some specific markers; the problem of not considering chemical toxicity of uranium in the texts regulating its incorporation

  8. Quantitative biokinetic analysis of radioactively labelled, inhaled Titanium dioxide Nanoparticles in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Kreyling, Wolfgang G.; Wenk, Alexander; Semmler-Behnke, Manuela [Helmholtz Zentrum Muenchen, Deutsches Forschungszentrum fuer Gesundheit und Umwelt GmbH (Germany). Inst. fuer Lungenbiologie und Erkrankungen, Netzwerk Nanopartikel und Gesundheit

    2010-09-15

    The aim of this project was the determination of the biokinetics of TiO{sub 2} nanoparticles (NP) in the whole body of healthy adult rats after NP administration to the respiratory tract - either via inhalation or instillation. We developed an own methodology to freshly synthesize and aerosolize TiO{sub 2}-NP in our lab for the use of inhalation studies. These NP underwent a detailed physical and chemical characterization providing pure polycrystalline anatase TiO{sub 2}-NP of about 20 nm (geometric standard deviation 1.6) and a specific surface area of 270 m{sup 2}/g. In addition, we developed techniques for sufficiently stable radioactive {sup 48}V labelling of the TiO{sub 2} NP. The kinetics of solubility of {sup 48}V was thoroughly determined. The methodology of quantitative biokinetics allows for a quantitative balance of the retained and excreted NP in control of the administered NP dose and provides a much more precise determination of NP fractions and concentrations of NP in organs and tissues of interest as compared to spotting biokinetics studies. Small fractions of TiO{sub 2}-NP translocate across the air-blood-barrier and accumulate in secondary target organs, soft tissue and skeleton. The amount of translocated TiO{sub 2}-NP is approximately 2% of TiO{sub 2}-NP deposited in the lungs. A prominent fraction of these translocated TiO{sub 2}-NP was found in the remainder. Smaller amounts of TiO{sub 2}-NP accumulate in secondary organs following particular kinetics. TiO{sub 2}-NP translocation was grossly accomplished within the first 2-4 hours after inhalation followed by retention in all organs and tissues studied without any detectable clearance of these biopersistent TiO{sub 2}-NP within 28 days. Therefore, our data suggest crossing of the air-blood-barrier of the lungs and subsequent accumulation in secondary organs and tissues depends on the NP material and its physico-chemical properties. Furthermore, we extrapolate that during repeated or chronic

  9. Quantitative biokinetic analysis of radioactively labelled, inhaled Titanium dioxide Nanoparticles in a rat model

    International Nuclear Information System (INIS)

    Kreyling, Wolfgang G.; Wenk, Alexander; Semmler-Behnke, Manuela

    2010-01-01

    The aim of this project was the determination of the biokinetics of TiO 2 nanoparticles (NP) in the whole body of healthy adult rats after NP administration to the respiratory tract - either via inhalation or instillation. We developed an own methodology to freshly synthesize and aerosolize TiO 2 -NP in our lab for the use of inhalation studies. These NP underwent a detailed physical and chemical characterization providing pure polycrystalline anatase TiO 2 -NP of about 20 nm (geometric standard deviation 1.6) and a specific surface area of 270 m 2 /g. In addition, we developed techniques for sufficiently stable radioactive 48 V labelling of the TiO 2 NP. The kinetics of solubility of 48 V was thoroughly determined. The methodology of quantitative biokinetics allows for a quantitative balance of the retained and excreted NP in control of the administered NP dose and provides a much more precise determination of NP fractions and concentrations of NP in organs and tissues of interest as compared to spotting biokinetics studies. Small fractions of TiO 2 -NP translocate across the air-blood-barrier and accumulate in secondary target organs, soft tissue and skeleton. The amount of translocated TiO 2 -NP is approximately 2% of TiO 2 -NP deposited in the lungs. A prominent fraction of these translocated TiO 2 -NP was found in the remainder. Smaller amounts of TiO 2 -NP accumulate in secondary organs following particular kinetics. TiO 2 -NP translocation was grossly accomplished within the first 2-4 hours after inhalation followed by retention in all organs and tissues studied without any detectable clearance of these biopersistent TiO 2 -NP within 28 days. Therefore, our data suggest crossing of the air-blood-barrier of the lungs and subsequent accumulation in secondary organs and tissues depends on the NP material and its physico-chemical properties. Furthermore, we extrapolate that during repeated or chronic exposure to insoluble NP the translocated fraction of NP will

  10. Cadmium bioavailability to Hyalella azteca from a periphyton diet compared to an artificial diet and application of a biokinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Golding, Lisa A., E-mail: lisa.golding@csiro.au [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Borgmann, Uwe [Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada); George Dixon, D. [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2013-01-15

    Differences between the bioavailability of cadmium in a periphyton diet and an artificial laboratory diet (TetraMin{sup Registered-Sign }) have important consequences for predicting bioaccumulation and toxicity in the freshwater amphipod Hyalella azteca. The assimilation efficiency (AE) of Cd was compared between periphyton and TetraMin{sup Registered-Sign} at low (1510 and 358 nmol/g ash-free dry mass respectively) and chronically lethal (31,200 and 2890 nmol/g ash-free dry mass respectively) Cd concentrations and in fresh and dry forms using a {sup 109}Cd radiotracer pulse-chase feeding technique. Assimilation efficiency of Cd from periphyton (AE = 3-14%) was lower than that for TetraMin{sup Registered-Sign} (AE = 44-86%) regardless of Cd concentration or food form. Ingestion rate (IR) was lower for dry than fresh forms of periphyton (0.042 and 0.16 g AFDM/g H. azteca/day respectively) and TetraMin{sup Registered-Sign} (0.19 and 0.87 AFDM/g H. azteca/day respectively) and depuration rate (k{sub e}) did not differ statistically with food type, form or Cd concentration (0.032-0.094 d{sup -1}). Biokinetic models with parameters of AE, IR and k{sub e} were used to estimate bioaccumulation from the separate food types. These estimates were compared to those from an independent chronic Cd saturation bioaccumulation model. While the model estimates did not concur, a sensitivity analysis indicated that AE and IR were the most influential biokinetic model parameters for Cd in periphyton and TetraMin{sup Registered-Sign} respectively. It was hypothesized that AE was underestimated for Cd in periphyton due to a non-adapted gut enzyme system and IR was overestimated for Cd in TetraMin{sup Registered-Sign} due to an initial rapid ingestion phase in H. azteca's feeding habits. This research demonstrated the importance of using ecologically relevant food types in laboratory experiments and verifying acute biokinetic model predictions of dietary metal contribution with

  11. Proposal of a new biokinetic model for niobium; Proposta de um novo modelo biocinetico para o niobio

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Roges

    2006-07-01

    There are two niobium isotopes generated in nuclear power plants: 95 Nb and 94 Nb. Workers and members of the public are subjects to intake these radionuclides in accident situation. For dose calculation purpose, it is very important to develop a model that describes in a more realistic way the kinetics of niobium inside of the human body. Presently the model adopted by ICRP (ICRP, 1989) is based on animal studies and describes the behavior of niobium in human being in a simple manner. The new model proposal describes the kinetics of the niobium from the intake into the blood until the excretion, doing this in a more realistic form and considering not only data from animals but data from human beings as well. For this objective, a workers group of a niobium extraction and processing industry exposed to stable niobium (93 Nb) in oxide insoluble form with associated uranium, was monitored for uranium and niobium determination in urinary and fecal excretion, by mass spectrometry. Based in the ratios of the niobium concentration in urinary and faecal excretion of this workers and animal data study, a new biokinetic model for niobium was proposed, with the followings modifications relative to ICRP model: a new compartment that represents muscular tissue; the fractions which are deposited into the compartment are modified; a third component in the retention equation of the bone tissue; introduction of recirculation between organs and blood. The new model was applied for a case of accidental intake and described adequately the experimental data.

  12. Biokinetics of radiolabeled Iodophenylpentadecanoic acid (I-123-IPPA) and thallium-201 in a rabbit model of chronic myocardial infarction measured using a series of thermoluminescent dosimeters

    Science.gov (United States)

    Medich, David Christopher

    1997-09-01

    The biokinetics of Iodophenylpentadecanoic acid (123I-IPPA) during a chronic period of myocardial infarction were determined and compared to 201Tl. IPPA was assessed as a perfusion and metabolic tracer in the scintigraphic diagnosis of coronary artery disease. The myocardial clearance kinetics were measured by placing a series of thermoluminescent dosimeters (TLDs) on normal and infarcted tissue to measure the local myocardial activity content over time. The arterial blood pool activity was fit to a bi-exponential function for 201Tl and a tri-exponential function for 123I-IPPA to estimate the left ventricle contribution to TLD response. At equilibrium, the blood pool contribution was estimated experimentally to be less than 5% of the total TLD response. The method was unable to resolve the initial uptake of the imaging agent due in part to the 2 minute TLD response integration time and in part to the 30 second lag time for the first TLD placement. A noticeable disparity was observed between the tracer concentrations of IPPA in normal and ischemic tissue of approximately 2:1. The fitting parameters (representing the biokinetic eigenvalue rate constants) were related to the fundamental rate constants of a recycling biokinetic model. The myocardial IPPA content within normal tissue was elevated after approximately 130 minutes post injection. This phenomenon was observed in all but one (950215) of the IPPA TLD kinetics curves.

  13. Application of the new ICRP respiratory tract model to inhaled plutonium nitrate using experimental biokinetic data

    Energy Technology Data Exchange (ETDEWEB)

    Birchall, A.; Bailey, M.R.; Jarvis, N.S. [National Radiological Protection Board, Chilton (United Kingdom)

    1995-12-31

    This paper describes the new ICRP respiratory tract model with particular reference to inhaled plutonium nitrate. The model is used to determine the absorption rates to blood for plutonium nitrate which when combined with the plutonium excretion functions were used to predict urinary excretion in man. The implications of the new model for radiological protection are discussed. (UK).

  14. Biokinetic of plutonium in human beings. Analysis and modification of ICRP 67 model

    International Nuclear Information System (INIS)

    Luciani, A.; Castellani, C. M.

    2001-01-01

    A preliminary research of the available data and empirical functions for the plutonium excretion after injection was carried out. The ICRP model presented in the Publication no. 67 was then analyzed comparing its predictions for the activity in urine and, at a lesser extent, in feces and blood, with the collected data and empirical curves. The model was modified and an optimized age-related compartmental model was developed. A new skeletal model recently developed was also introduced and age depending bone remodelling rates were assumed on the basis of the ICRP Publication 70. This model provides a better agreement with measured urinary excretion data than the current ICRP 67 model, avoiding unphysiological assumptions such as the transfer of activity from soft tissue to urinary bladder, that were part of the ICRP model. The new optimized model predictions of the activity in faeces and in blood after an injection are also closer to the available data than the ICRP 67 estimations. A good agreement with the partitioning factor of plutonium between skeleton and liver obtained from different autopsy studies was also observed [it

  15. Evaluation of the various biokinetic models of liberation from characteristic deposition fraction of brazilian population sample

    International Nuclear Information System (INIS)

    Reis, Arlene A. dos; Cardoso, Joaquim C.S.; Lourenco, Maria Cristina

    2005-01-01

    The Publication 66 of International Commission of Radiological Protection (ICRP, 1994) presented the Human Respiratory tract Model that simulates the deposition and translocation of radioactive material in the air that penetrates in the body by inhalation. The main objective of this study is to evaluate the variation in fractional activity absorbed into blood when physiological and morphological parameters from Brazilian population are applied in the deposition model. The clearance model was implemented in the software Excel (version 2000) using a system of differential equations to solve simultaneous process of translocation and absorption of material deposited. After implementation were applied in the model fractional deposition calculated by deposition model using physiological and morphological parameters from Brazilian population. The results show that the variation in the clearance model depends on the material dissolution. For materials of rapid absorption, the variations calculated are not significant. Materials of moderate and slow absorption, presented variation greater than 20% in fractional activity absorbed into blood, depending on levels of exercise. (author)

  16. Biokinetic modelling development and analysis of arsenic dissolution into the gastrointestinal tract using SAAM II

    Science.gov (United States)

    Perama, Yasmin Mohd Idris; Siong, Khoo Kok

    2018-04-01

    A mathematical model comprising 8 compartments were designed to describe the kinetic dissolution of arsenic (As) from water leach purification (WLP) waste samples ingested into the gastrointestinal system. A totally reengineered software system named Simulation, Analysis and Modelling II (SAAM II) was employed to aid in the experimental design and data analysis. As a powerful tool that creates, simulate and analyze data accurately and rapidly, SAAM II computationally creates a system of ordinary differential equations according to the specified compartmental model structure and simulates the solutions based upon the parameter and model inputs provided. The experimental design of in vitro DIN approach was applied to create an artificial gastric and gastrointestinal fluids. These synthetic fluids assay were produced to determine the concentrations of As ingested into the gastrointestinal tract. The model outputs were created based upon the experimental inputs and the recommended fractional transfer rates parameter. As a result, the measured and predicted As concentrations in gastric fluids were much similar against the time of study. In contrast, the concentrations of As in the gastrointestinal fluids were only similar during the first hour and eventually started decreasing until the fifth hours of study between the measured and predicted values. This is due to the loss of As through the fractional transfer rates of q2 compartment to corresponding compartments of q3 and q5 which are involved with excretion and distribution to the whole body, respectively. The model outputs obtained after best fit to the data were influenced significantly by the fractional transfer rates between each compartment. Therefore, a series of compartmental model created with the association of fractional transfer rates parameter with the aid of SAAM II provides better estimation that simulate the kinetic behavior of As ingested into the gastrointestinal system.

  17. A physiologically based biokinetic model for cesium in the human body

    International Nuclear Information System (INIS)

    Leggett, R.W.; Williams, L.R.; Melo, D.R.; Lipsztein, J.L.

    2003-01-01

    A physiologically descriptive model of the biological behavior of cesium in the human body has been constructed around a detailed blood flow model. The rate of transfer from plasma into a tissue is determined by the blood perfusion rate and the tissue-specific extraction fraction of Cs during passage from arterial to venous plasma. Information on tissue-specific extraction of Cs is supplemented with information on the Cs analogues, K and Rb, and known patterns of discrimination between these metals by tissues. The rate of return from a tissue to plasma is estimated from the relative contents of Cs in plasma and the tissue at equilibrium as estimated from environmental studies. Transfers of Cs other than exchange between plasma and tissues (e.g. secretions into the gastrointestinal tract) are based on a combination of physiological considerations and empirical data on Cs or related elements. Model predictions are consistent with the sizable database on the time-dependent distribution and retention of radiocesium in the human body

  18. Comparative biokinetics of radiogallium and radioindium in mice

    International Nuclear Information System (INIS)

    Tsui, B.M.W.; Lathrop, K.A.

    1978-01-01

    The biokinetics of radiogallium and radioindium in normal mice are compared using the compartmental modelling analysis. The rate constants obtained provide useful information in understanding the physiological and biochemical kinetics of radionuclides in the intact object. A comparison of the compartmental models for gallium and indium reveals the similarities and differences between the biokinetics of the two radionuclides. Furthermore, the results provide valuable information and guidance for human studies and clinical use

  19. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996 - 1999. Mid-term reports for the period 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, P; Paretzke, H G; Roth, P [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Michael, B D [Mount Vernon Hospital, Northwood (United Kingdom). Gray Lab.; O` Sullivan, D [Dublin Inst. for Advanced Studies (Ireland)

    1999-12-31

    The main objectives of the first dosimetry project are the measurement of neutron and charged particle flux and energy spectra at altitudes in civil aviation, the determination of response characteristics for detectors, the investigation of calibration procedures, and the evaluation of exposures of aircrews. The overall objective of the second dosimetry project is to improve estimates of dose following the intake of radionuclides by adults and children. The work includes the development of biokinetic and dosimetric models, including models of the gastrointestinal tract, for the systemic behaviour of radionuclides, and for the developing embryo and foetus. Further subjects are target cell dosimetry for short-range particles and the development of computational tools for sensitivity and uncertainty analysis models. The third dosimetry project encompasses the study of different methods for retrospective dose assessments for individuals or groups of individuals accidentally exposed to increased levels of radiation. The methods investigated include electron paramagnetic resonance (EPR) of tooth enamel and chromosome painting (FISH) for lymphocytes in peripheral blood for individual retrospective dose assessments, luminescence techniques on materials in inhabited environment (ceramics, bricks) and model calculations using environmental data as input. (orig.)

  20. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996 - 1999. Mid-term reports for the period 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, P.; Paretzke, H.G.; Roth, P. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Michael, B.D. [Mount Vernon Hospital, Northwood (United Kingdom). Gray Lab.; O`Sullivan, D. [Dublin Inst. for Advanced Studies (Ireland)

    1998-12-31

    The main objectives of the first dosimetry project are the measurement of neutron and charged particle flux and energy spectra at altitudes in civil aviation, the determination of response characteristics for detectors, the investigation of calibration procedures, and the evaluation of exposures of aircrews. The overall objective of the second dosimetry project is to improve estimates of dose following the intake of radionuclides by adults and children. The work includes the development of biokinetic and dosimetric models, including models of the gastrointestinal tract, for the systemic behaviour of radionuclides, and for the developing embryo and foetus. Further subjects are target cell dosimetry for short-range particles and the development of computational tools for sensitivity and uncertainty analysis models. The third dosimetry project encompasses the study of different methods for retrospective dose assessments for individuals or groups of individuals accidentally exposed to increased levels of radiation. The methods investigated include electron paramagnetic resonance (EPR) of tooth enamel and chromosome painting (FISH) for lymphocytes in peripheral blood for individual retrospective dose assessments, luminescence techniques on materials in inhabited environment (ceramics, bricks) and model calculations using environmental data as input. (orig.)

  1. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996 - 1999. Mid-term reports for the period 1996-1997

    International Nuclear Information System (INIS)

    Jacob, P.; Paretzke, H.G.; Roth, P.

    1998-01-01

    The main objectives of the first dosimetry project are the measurement of neutron and charged particle flux and energy spectra at altitudes in civil aviation, the determination of response characteristics for detectors, the investigation of calibration procedures, and the evaluation of exposures of aircrews. The overall objective of the second dosimetry project is to improve estimates of dose following the intake of radionuclides by adults and children. The work includes the development of biokinetic and dosimetric models, including models of the gastrointestinal tract, for the systemic behaviour of radionuclides, and for the developing embryo and foetus. Further subjects are target cell dosimetry for short-range particles and the development of computational tools for sensitivity and uncertainty analysis models. The third dosimetry project encompasses the study of different methods for retrospective dose assessments for individuals or groups of individuals accidentally exposed to increased levels of radiation. The methods investigated include electron paramagnetic resonance (EPR) of tooth enamel and chromosome painting (FISH) for lymphocytes in peripheral blood for individual retrospective dose assessments, luminescence techniques on materials in inhabited environment (ceramics, bricks) and model calculations using environmental data as input. (orig.)

  2. Biokinetics and dosimetry of a hybrid formulation of 9mTc-BN and 99mTc-RGD2 starting from optic images in a murine model

    International Nuclear Information System (INIS)

    Cornejo A, L. G.

    2015-01-01

    This work has the purpose of evaluate the biokinetics and absorbed dose of radiation of hybrid formulation 99m Tc-BN / 99m Tc-RGD 2 in a murine model by optical imaging techniques using the multimodal preclinical in vivo image system Xtreme. The used method were the 99m Tc-BN, 99m Tc-RGD 2 and 99m Tc-BN/ 99m Tc-RGD 2 formulas, with specific recognition for GRPr and the integrin s α(v)β(3) and α(v)β(5) respectively, was injected in the vein tail of three nude mousses with induce breast cancer tumors (cell line T-47-D), by the preclinical multimodal imaging system Xtreme (Bruker), optical images in different times was acquired (5, 10, 20 min, 2 and 24 h), using Images Processing Toolbox of MATLAB these images was transform from RGB format to gray scales and sectioned in five independent images corresponding to heart, kidneys, bladder and tumor areas. The intensity of each images was computed in counts per pixel, then those intensities was corrected for background, attenuation and scattering, using different factors for each phenomena previously calculated. Finally the activity values quantified vs time was fitted into a biokinetic model to obtain the disintegrations number and cumulate activities in each organ. With these data the radiation absorbed dose were calculated using MIRD methodology. Results: The number of disintegration and absorbed dose calculated in MBq h/MBq and mGy/MBq, of injected mouse with the 99m Tc-BN/ 99m Tc-RGD 2 formulation, was: 0.035 ± 0.65 E-02, 0.25 x 10 -5 ± 0.46 E-07; 0.393 ± 0.51 E-1, 2.85 E-05 ± 3.7 E-06; 0.306 ± 0.21 E-01, 2.11 E-05 ± 1.45 E-06 and 0.151 ± 0.19 E-01, 1.09 E-05 ± 1.42 E-06 , in heart, kidneys, bladder and tumor, respectively. The number of disintegration obtained in kidneys is comparable to those reported for Trinidad B. 2014 Conclusions: Our results demonstrated that using optical images and a code for image analyses development in MATLAB, could achieve comparable quantitative results as the conventional

  3. Stable tracer investigations in humans for assessing the biokinetics of ruthenium and zirconium radionuclides

    International Nuclear Information System (INIS)

    Veronese, I.; Cantone, M.C.; Giussani, A.; Maggioni, T.; Birattari, C.; Bondardi, M.; Groppi, F.; Garlaschelli, I.; Werner, E.; Roth, P.; Hoellriegl, V.; Louvat, P.; Felgenhauer, N.; Zilker, Th.

    2003-01-01

    The interest in the biokinetics of ruthenium and zirconium in humans is justified by the potential radiological risk represented by their radionuclides. Only a few data related to the biokinetics of ruthenium and zirconium in humans are available and, accordingly, the biokinetic models currently recommended by the ICRP for these elements are mainly based on data from animal experiments. The use of stable isotopes as tracers, coupled with a proper analytical technique (nuclear activation analysis with protons) for their determination in biological samples, represents an ethically acceptable methodology for biokinetic investigations, being free from any radiation risk for the volunteer subjects. In this work, the results obtained in eight biokinetic investigations for ruthenium, conducted on a total of three healthy volunteers, and six for zirconium, performed on a total of three subjects, are presented and compared to the predictions of the ICRP models. (author)

  4. The biokinetics of ruthenium in the human body

    International Nuclear Information System (INIS)

    Leggett, Richard Wayne

    2011-01-01

    The biokinetics of ruthenium (Ru) in the human body is of interest due mainly to the potential for occupational or environmental exposure to 106Ru (T1/2 = 373.6 d) and 103Ru (T1/2 = 39.3 d), which typically represent a significant portion of the fission products in a reactor inventory. During reactor operations or nuclear fuel reprocessing these ruthenium isotopes may be present as ruthenium tetroxide (RuO4) vapor, a highly mobile form of ruthenium that has been involved in a number of cases of accidental exposure to 106Ru or 103Ru. This paper summarizes the biokinetic database for ruthenium and proposes a new respiratory model for inhaled RuO4 vapor, a new biokinetic for systemic (absorbed) ruthenium, and material-specific gastrointestinal absorption fractions for ruthenium. The proposed respiratory model for RuO4 differs from the current ICRP model mainly in that it depicts slower clearance of deposited activity from the respiratory tract and lower absorption to blood than depicted in the current ICRP model. The proposed systemic biokinetic model depicts more realistic paths of movement of absorbed ruthenium in the body than the current ICRP model and, in contrast to the present model, a less uniform distribution of systemic activity. Implications of the proposed models with regard to inhalation and ingestion dose coefficients for 106Ru are examined.

  5. The biokinetic of incorporates radionuclides; Die Biokinetik von inkorporierten Radionukliden

    Energy Technology Data Exchange (ETDEWEB)

    Breustedt, Bastian [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Strahlenforschung; Giussani, Augusto [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Arbeitsgruppe ' ' Externe und interne Dosimetrie, Biokinetik' '

    2017-08-01

    Incorporated radionuclides from nuclear accidents, fission product releases or nuclear medical administration are distributed in the human body in organs and tissue, absorbed 9or excreted. The interpretation of incorporation monitoring results and the estimation of the internal doses that cannot be measured directly need mathematical methods and the formulation of biokinetic models.

  6. Towards a consensus-based biokinetic model for green microalgae - The ASM-A.

    Science.gov (United States)

    Wágner, Dorottya S; Valverde-Pérez, Borja; Sæbø, Mariann; Bregua de la Sotilla, Marta; Van Wagenen, Jonathan; Smets, Barth F; Plósz, Benedek Gy

    2016-10-15

    Cultivation of microalgae in open ponds and closed photobioreactors (PBRs) using wastewater resources offers an opportunity for biochemical nutrient recovery. Effective reactor system design and process control of PBRs requires process models. Several models with different complexities have been developed to predict microalgal growth. However, none of these models can effectively describe all the relevant processes when microalgal growth is coupled with nutrient removal and recovery from wastewaters. Here, we present a mathematical model developed to simulate green microalgal growth (ASM-A) using the systematic approach of the activated sludge modelling (ASM) framework. The process model - identified based on a literature review and using new experimental data - accounts for factors influencing photoautotrophic and heterotrophic microalgal growth, nutrient uptake and storage (i.e. Droop model) and decay of microalgae. Model parameters were estimated using laboratory-scale batch and sequenced batch experiments using the novel Latin Hypercube Sampling based Simplex (LHSS) method. The model was evaluated using independent data obtained in a 24-L PBR operated in sequenced batch mode. Identifiability of the model was assessed. The model can effectively describe microalgal biomass growth, ammonia and phosphate concentrations as well as the phosphorus storage using a set of average parameter values estimated with the experimental data. A statistical analysis of simulation and measured data suggests that culture history and substrate availability can introduce significant variability on parameter values for predicting the reaction rates for bulk nitrate and the intracellularly stored nitrogen state-variables, thereby requiring scenario specific model calibration. ASM-A was identified using standard cultivation medium and it can provide a platform for extensions accounting for factors influencing algal growth and nutrient storage using wastewater resources. Copyright

  7. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Dose reconstruction. Final report

    International Nuclear Information System (INIS)

    Jacob, P.; Aragno, D.; Bailiff, I.K.

    2000-01-01

    The project Dose Reconstruction was conducted within the five work packages: - EPR with teeth, - Chromosome painting (FISH) in lymphocytes, - Luminescence methods, - Modelling, and - Evaluation. (orig.)

  8. Towards a consensus-based biokinetic model for green microalgae – The ASM-A

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta; Valverde Pérez, Borja; Sæbø, Mariann

    2016-01-01

    developed to predict microalgal growth. However, none of these models can effectively describe all the relevant processes when microalgal growth is coupled with nutrient removal and recovery from wastewaters. Here, we present a mathematical model developed to simulate green microalgal growth (ASM-A) using...... and substrate availability can introduce significant variability on parameter values for predicting the reaction rates for bulk nitrate and the intracellularly stored nitrogen state-variables, thereby requiring scenario specific model calibration. ASM-A was identified using standard cultivation medium...

  9. The STATFLUX code: a statistical method for calculation of flow and set of parameters, based on the Multiple-Compartment Biokinetical Model

    Science.gov (United States)

    Garcia, F.; Mesa, J.; Arruda-Neto, J. D. T.; Helene, O.; Vanin, V.; Milian, F.; Deppman, A.; Rodrigues, T. E.; Rodriguez, O.

    2007-03-01

    radioactive substances, through environmental pathways, is very important for radiological protection of populations. One such pathway, associated with the food chain, is the grass-animal-man sequence. The distribution of trace elements in humans and laboratory animals has been intensively studied over the past 60 years [R.C. Pendlenton, C.W. Mays, R.D. Lloyd, A.L. Brooks, Differential accumulation of iodine-131 from local fallout in people and milk, Health Phys. 9 (1963) 1253-1262]. In addition, investigations on the incidence of cancer in humans, and a possible causal relationship to radioactive fallout, have been undertaken [E.S. Weiss, M.L. Rallison, W.T. London, W.T. Carlyle Thompson, Thyroid nodularity in southwestern Utah school children exposed to fallout radiation, Amer. J. Public Health 61 (1971) 241-249; M.L. Rallison, B.M. Dobyns, F.R. Keating, J.E. Rall, F.H. Tyler, Thyroid diseases in children, Amer. J. Med. 56 (1974) 457-463; J.L. Lyon, M.R. Klauber, J.W. Gardner, K.S. Udall, Childhood leukemia associated with fallout from nuclear testing, N. Engl. J. Med. 300 (1979) 397-402]. From the pathways of entry of radionuclides in the human (or animal) body, ingestion is the most important because it is closely related to life-long alimentary (or dietary) habits. Those radionuclides which are able to enter the living cells by either metabolic or other processes give rise to localized doses which can be very high. The evaluation of these internally localized doses is of paramount importance for the assessment of radiobiological risks and radiological protection. The time behavior of trace concentration in organs is the principal input for prediction of internal doses after acute or chronic exposure. The General Multiple-Compartment Model (GMCM) is the powerful and more accepted method for biokinetical studies, which allows the calculation of concentration of trace elements in organs as a function of time, when the flow parameters of the model are known. However, few

  10. The biokinetics of uranium migrating from embedded DU fragments

    International Nuclear Information System (INIS)

    Leggett, R.W.; Pellmar, T.C.

    2003-01-01

    Military uses of depleted uranium (DU) munitions have resulted in casualties with embedded DU fragments. Assessment of radiological or chemical health risks from these fragments requires a model relating urinary U to the rate of migration of U from the fragments, and its accumulation in systemic tissues. A detailed biokinetic model for U has been published by the International Commission on Radiological Protection (ICRP), but its applicability to U migrating from embedded DU fragments is uncertain. Recently, ) conducted a study at the Armed Forces Radiobiology Research Institute (AFRRI) on the redistribution and toxicology of U in rats with implanted DU pellets, simulating embedded fragments. This paper compares the biokinetic data from that study with the behavior of commonly studied forms of U in rats (e.g., intravenously injected U nitrate). The comparisons indicate that the biokinetics of U migrating from embedded DU is similar to that of commonly studied forms of U with regard to long-term accumulation in kidneys, bone, and liver. The results provide limited support for the application of the ICRP's model to persons with embedded DU fragments. Additional information is needed with regard to the short-term behavior of migrating U and its accumulation in lymph nodes, brain, testicles, and other infrequently studied U repositories

  11. The biokinetics of Rhuthenium and Zirconium radionuclides in humans studied with stable tracers

    International Nuclear Information System (INIS)

    Veronese, I.; Cantone, M.C.; Giussani, A.

    2002-01-01

    The assessment of the internal radiation dose delivered by radionuclides incorporated in the human body after accidental release into the environment requires the use of suitable biokinetic models. These models describe the absorption of radionuclides into the blood circulation, their distribution and retention in various organs and tissues, and the excretion routes. Biokinetic models are also employed for interpreting bioassay measurements in exposed subjects, like activity concentration measurements in body fluids (e.g. urine, blood), in order to estimate the incorporated amount of radioactive substances. The reliability of a biokinetic model is closely linked to the available experimental data used to develop the model itself. Biokinetic data for human subjects are available for most essential elements, as well as for some important non-essential elements such as caesium, lead, radium, uranium, americium and plutonium. For many other radionuclides, either very little or no information is available from human studies, and the respective models must be derived from other sources. These may include results from studies in animals, comparative data on the behaviour of similar radionuclides or chemical analogues in vitro. Biokinetic models developed from such a variety of data sources can be applied to humans only with a limited degree of confidence. The availability of data directly obtained on human subjects is therefore fundamental to set up more reliable and realistic models. Ruthenium and zirconium are among the elements characterised by a serious lack of reliable data in humans

  12. Biokinetics of radiotellurium in rats

    International Nuclear Information System (INIS)

    Nishimura, Y.; Sahoo, S.K.; Kim, S.; Homma-Takeda, S.; Watanabe, Y.; Inaba, J.

    2003-01-01

    Radiotellurium is present in the environment primarily due to its release during nuclear reactor accidents. Little is known of tellurium metabolism in juveniles, although the element is relatively abundant and has a number of industrial uses. A biokinetic study of radiotellurium in rats was done using gamma-ray counting. Wistar strain rats were used to determine the uptake of H 2 123 Te m O 3 by the whole-body retention of juvenile rats and the conceptus in relation to its gestational stages, by measurements in the placenta, fetal membranes, fetal fluid, and fetus. The whole-body retention of 123 Te m in juvenile rats was higher than that of adult rats. The relative concentration in the placenta and fetal membranes was higher than in the fetus. No activity was observed in the fetal fluid. These results indicate that the placenta and fetal membranes play significant roles as barriers to the transfer of 123 Te m into the fetus. The ratio, relative concentration in fetus/relative concentration in mother (C F /C M ), was calculated. The C F /C M ratio was dependent on the stage of gestation and ranged from 0.2 to 0.5. A little 123 Te m was transferred to the suckling rats through the mother's milk when the isotope was administered intravenously to the mother. (author)

  13. Biokinetics and internal dosimetry of inhaled metal tritide particles

    Science.gov (United States)

    Wang, Yansheng

    1998-12-01

    Metal tritides (MT), stable chemical compounds of tritium, are widely used in nuclear engineering facilities. MT particles can be released as aerosols. Inhaling MT particles is a potential occupational radiation hazard. Little information is available on their dissolution behavior, biokinetics, and dosimetry. The objectives of present dissertation are to estimate dissolution rates, to develop biokinetic models, to improve internal dosimetric considerations, and to classify MT materials. This study consisted of three phases: In vitro dissolution in a simulated lung fluid, In vivo rat experiments on retention and clearance, and biokinetic modeling and dosimetric evaluation. There was a supporting study on self- absorption of tritium beta in MT particles. MT materials used in this study were titanium (Ti) and zirconium (Zr) tritides. Results shows considerable self-absorption of beta particles and their energy, even for respirable MT particles smaller than 5 μm. The self-absorption factors should be required for counting MT particle samples and for estimating absorbed dose to tissues. In vitro and in vivo dissolution data indicate that Ti and Zr tritides are poorly soluble materials. Ti tritide belongs to the W class or M type while Zr tritide can be classified as Y class or S type. Due to long retention time of the MT particles, tritium betas directly from the particles contribute over 90% of the absorbed dose to lung. The lung dose contributes most of the effective dose to the whole body. Dissolved tritium including tritiated water (HTO) and organically bound tritium (OBT) has less effect on the lung dose and effective dose. Results on the annual limit on intake (ALI) indicate that the current radiation protection guideline based on HTO is not adequate for inhalation exposure to MT particles and needs to be modified. The biokinetic models developed in this study have predictive powers to estimate the consequences of a human inhalation exposure to MT aerosols. The

  14. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Biophysical models for the induction of cancer by radiation. Final report

    International Nuclear Information System (INIS)

    Paretzke, H.G.; Ballarini, F.; Brugmans, M.

    2000-01-01

    The overall project is organised into seven work packages. WP1 concentrates on the development of mechanistic, quantitative models for radiation oncogenesis using selected data sets from radiation epidemiology and from experimental animal studies. WP2 concentrates on the development of mechanistic, mathematical models for the induction of chromosome aberrations. WP3 develops mechanistic models for radiation mutagenesis, particularly using the HPRT-mutation as a paradigm. WP4 will develop mechanistic models for damage and repair of DNA, and compare these with experimentally derived data. WP5 concentrates on the improvement of our knowledge on the chemical reaction pathways of initial radiation chemical species in particular those that migrate to react with the DNA and on their simulation in track structure codes. WP6 models by track structure simulation codes the production of initial physical and chemical species, within DNA, water and other components of mammalian cells, in the tracks of charged particles following the physical processes of energy transfer, migration, absorption, and decay of excited states. WP7 concentrates on the determination of the start spectra of those tracks considered in WP6 for different impinging radiation fields and different irradiated biological objects. (orig.)

  15. Performance analysis of numeric solutions applied to biokinetics of radionuclides

    International Nuclear Information System (INIS)

    Mingatos, Danielle dos Santos; Bevilacqua, Joyce da Silva

    2013-01-01

    Biokinetics models for radionuclides applied to dosimetry problems are constantly reviewed by ICRP. The radionuclide trajectory could be represented by compartmental models, assuming constant transfer rates between compartments. A better understanding of physiological or biochemical phenomena, improve the comprehension of radionuclide behavior in the human body and, in general, more complex compartmental models are proposed, increasing the difficulty of obtaining the analytical solution for the system of first order differential equations. Even with constant transfer rates numerical solutions must be carefully implemented because of almost singular characteristic of the matrix of coefficients. In this work we compare numerical methods with different strategies for ICRP-78 models for Thorium-228 and Uranium-234. The impact of uncertainty in the parameters of the equations is also estimated for local and global truncation errors. (author)

  16. Biokinetics and dosimetry of radioactively labelled organic C-14 compounds

    International Nuclear Information System (INIS)

    Krins, A.; Sahre, P.; Schoenmuth, T.

    2003-12-01

    The report starts with summarising research work and the resulting scientific information in connection with the dosimetry of C-14 labelled organic compounds. Biokinetic models are developed for compounds such as benzene, phenol, aniline, nitrobenzene, and a selection of pharmaceuticals, in order to show the radioactivity distribution after administration of the C-14 labelled substances. Based on the those models, dose coefficients and excretion rates are derived. The following synoptic view of the available data library leads on to a discussion of various aspects, as eg. the question of whether and how monitoring for detection of incorporation of C-14 administered with labelled organic compounds is possible. None of the questions and aspects arising in connection with this subject can be adequately dealt with in the present document, but concepts and methods are presented which permit an interpretation of radioactivity excretion data measured after incorporation of C-14 labelled organic substances. (orig./CB) [de

  17. Empleo de isótopos radiactivos en estudios biocinéticos con animales de experimentación Use of radioisotopes in biokinetic models with experimental animals

    Directory of Open Access Journals (Sweden)

    F. R. Martín Martín

    2002-06-01

    Full Text Available En el presente trabajo se pretende realizar una revisión de las diferentes técnicas radioisotópicas que se utilizan con animales de experimentación a la hora de desarrollar modelos biocinéticos tanto de sustancias como de elementos químicos presentes en el medio ambiente. Dicha experimentación permite relacionar la exposición externa a un xenobiótico con la medida interna de la dosis en el organismo y, consecuentemente, sus posibles efectos tóxicos, todo ello con vistas a evaluar los efectos adversos que pudieran existir sobre la salud humana. Se hace hincapié en la macroautorradiografía de animal completo, técnica que permite la detección, localización y cuantificación del radionucleido de interés en diferentes órganos/tejidos del organismo y, por tanto, contribuye a la estimación de la dosis interna y al conocimiento del comportamiento biocinético del compuesto/elemento objeto de estudio. Se presentan algunos ejemplos de la utilidad de esta técnica en estudios biocinéticos con animales de experimentación de interés en diferentes áreas relacionadas con la Salud y el Medio Ambiente. Se destaca la utilidad que presenta esta experimentación a la hora de extrapolar el comportamiento metabólico de contaminantes de máxima radiotoxicidad en personas expuestas a la radiación ionizante, con el objeto de optimizar las evaluaciones dosimétricas y los protocolos de vigilancia que ayudan a conocer con más exactitud los daños de la exposición interna sobre la salud humana.Biokinetic models are useful tools to relate external exposures to internal measures of dose. The knowledge of internal dose and factors that influence absorption, distribution, metabolism, and elimination in experimental animals provide a scientific rationale for estimating low-dose human risk. A bioanalytical procedure to support biokinetic studies is the use of radiolabeled compounds, so that mass balance, autoradiography, and preliminary metabolism

  18. Biokinetic study of 131I following ablation dose administration

    International Nuclear Information System (INIS)

    Nascimento, A.C.H.; Lipsztein, J.L.; Lucena, E.A.; Dantas, B.M.; Rebelo, A.M.O.; Mello, R.C.

    2002-01-01

    Aim: The aim of this investigation is to study biokinetics from internally 131 I deposited for thyroid cancer patients during radioiodine therapy (2 to 3 days), after ablation dose administration (3.7 GBq). These data will help in the elaboration of a metabolic model, which will permit absorbed dose assessment for this specific case, since the biokinetic models for iodine available in scientific literature can not be applied to thyroidectomized patient's studies. Material and Methods: Four females patients, between 22 and 50 years old, without metastases, between 1.9 to 6% of remnant thyroid tissue uptake, agreed to contribute to this study. For the in vivo bioassay, periodical measurements were performed along internment time (2 to 3 days), just after Na 131 I dose administration (3.7 GBq). For this, we used the counting system for Nuclear Medicine model 13S002, IEN/CNEN- Brazil, which was adapted with lead filters, in order to allow the work with high rate counting. The measurements were performed in two geometries: thyroid region and thigh. Results: For each patient, we have done approximately 26 measurements for both geometries, starting at the first hour following dose administration until the release from hospital of patient. The results of counting rate (cps) were plotted against time (h). The measurements suggest a relation between remnant thyroid tissue uptake values and the time where counting rates start decreasing. In addition, it was observed a correlation between remnant thyroid tissue radioactive burdens and the circulating iodine through time. Conclusion: It is necessary to follow-up a greater number of patients aiming to confirm the observed correlations and with a greater number of measurements during the first 24 hours, in other to delimit the time range of increasing and decreasing counting rate

  19. Transuranic biokinetic parameters for marine invertebrates--a review.

    Science.gov (United States)

    Ryan, T P

    2002-04-01

    A catalogue of biokinetic parameters for the transuranic elements plutonium, americium, curium, neptunium, and californium in marine invertebrates is presented. The parameters considered are: the seawater-animal concentration factor (CF); the sediment-animal concentration ratio (CR); transuranic assimilation efficiency; transuranic tissue distribution and transuranic elimination rates. With respect to the seawater-animal CF, authors differ considerably on how they define this parameter and a seven-point reporting system is suggested. Transuranic uptake from sediment by animals is characterised by low CRs. The assimilation efficiencies of transuranic elements in marine invertebrates are high compared to vertebrates and mammals in general and the distribution of transuranics within the body tissue of an animal is dependent on the uptake path. The elimination of transuranics from most species examined conformed to a standard biphasic exponential model though some examples with three elimination phases were identified.

  20. Biokinetics of radionuclides and treatment of accidental intakes

    International Nuclear Information System (INIS)

    Taylor, D.M.; Stradling, G.N.; Menetrier, F.

    2003-01-01

    This paper describes the objectives and reviews the progress of EULEP Working Party 5, convened under the auspices of the European Union's Fifth Framework Programme, to 'cluster' two EU-supported contracts, Biokinetics and Dosimetry of Internal Contamination (BIODOS (EU Contract FIS5-1999-00214)) and Radionuclide Biokinetics Database (EULEP) ( RBDATA-EULEP (Concerted Action Contract FIS5-1999-00218), and two non-EU funded projects, Biokinetics of Radionuclides in Human Volunteers (RNHV (non-EU Funded Project) and Treatment of Accidental Intakes of Radionuclides (TAIR (part-funded by EULEP)). (author)

  1. Biokinetic of plutonium in human beings. Analysis and modification of ICRP 67 model; Biocinetica del plutonio nell'organismo umano. Analisi e modifica del modello ICRP 67

    Energy Technology Data Exchange (ETDEWEB)

    Luciani, A.; Castellani, C.M. [ENEA, Divisione Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche Ezio Clementel, Bologna (Italy)

    2001-07-01

    A preliminary research of the available data and empirical functions for the plutonium excretion after injection was carried out. The ICRP model presented in the Publication no. 67 was then analyzed comparing its predictions for the activity in urine and, at a lesser extent, in feces and blood, with the collected data and empirical curves. The model was modified and an optimized age-related compartmental model was developed. A new skeletal model recently developed was also introduced and age depending bone remodelling rates were assumed on the basis of the ICRP Publication 70. This model provides a better agreement with measured urinary excretion data than the current ICRP 67 model, avoiding unphysiological assumptions such as the transfer of activity from soft tissue to urinary bladder, that were part of the ICRP model. The new optimized model predictions of the activity in faeces and in blood after an injection are also closer to the available data than the ICRP 67 estimations. A good agreement with the partitioning factor of plutonium between skeleton and liver obtained from different autopsy studies was also observed. [Italian] E' stata effettuata preliminarmente una ricerca bibliografica dei dati e delle funzioni di escrezione del plutonio attualmente disponibili in letteratura. Sulla base dei risultati di tale ricerca e' stato verificato il modello proposto dall'ICRP nella Pubblicazione n. 67. Tale modello e' stato quindi modificato al fine non solo di avere una piu' realistica descrizione dei valori predetti per l'escrezione urinaria, ma anche di modellare la cinetica del plutonio evitando quelle assunzioni introdotte appositamente nel modello dell'ICRP per correggere le previsini del modello ma che mancano di una chiara spiegazione di carattere fisiologico. Esso fornisce valutazioni piu' realistiche anche per l'attivita' nelle feci e nel sangue. Il modello sviluppato comprende un modello scheletrico

  2. Biokinetic model-based multi-objective optimization of Dunaliella tertiolecta cultivation using elitist non-dominated sorting genetic algorithm with inheritance.

    Science.gov (United States)

    Sinha, Snehal K; Kumar, Mithilesh; Guria, Chandan; Kumar, Anup; Banerjee, Chiranjib

    2017-10-01

    Algal model based multi-objective optimization using elitist non-dominated sorting genetic algorithm with inheritance was carried out for batch cultivation of Dunaliella tertiolecta using NPK-fertilizer. Optimization problems involving two- and three-objective functions were solved simultaneously. The objective functions are: maximization of algae-biomass and lipid productivity with minimization of cultivation time and cost. Time variant light intensity and temperature including NPK-fertilizer, NaCl and NaHCO 3 loadings are the important decision variables. Algal model involving Monod/Andrews adsorption kinetics and Droop model with internal nutrient cell quota was used for optimization studies. Sets of non-dominated (equally good) Pareto optimal solutions were obtained for the problems studied. It was observed that time variant optimal light intensity and temperature trajectories, including optimum NPK fertilizer, NaCl and NaHCO 3 concentration has significant influence to improve biomass and lipid productivity under minimum cultivation time and cost. Proposed optimization studies may be helpful to implement the control strategy in scale-up operation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. An empirical multivariate log-normal distribution representing uncertainty of biokinetic parameters for 137Cs

    International Nuclear Information System (INIS)

    Miller, G.; Martz, H.; Bertelli, L.; Melo, D.

    2008-01-01

    A simplified biokinetic model for 137 Cs has six parameters representing transfer of material to and from various compartments. Using a Bayesian analysis, the joint probability distribution of these six parameters is determined empirically for two cases with quite a lot of bioassay data. The distribution is found to be a multivariate log-normal. Correlations between different parameters are obtained. The method utilises a fairly large number of pre-determined forward biokinetic calculations, whose results are stored in interpolation tables. Four different methods to sample the multidimensional parameter space with a limited number of samples are investigated: random, stratified, Latin Hypercube sampling with a uniform distribution of parameters and importance sampling using a lognormal distribution that approximates the posterior distribution. The importance sampling method gives much smaller sampling uncertainty. No sampling method-dependent differences are perceptible for the uniform distribution methods. (authors)

  4. Laboratory-scale in situ bioremediation in heterogeneous porous media: biokinetics-limited scenario.

    Science.gov (United States)

    Song, Xin; Hong, Eunyoung; Seagren, Eric A

    2014-03-01

    Subsurface heterogeneities influence interfacial mass-transfer processes and affect the application of in situ bioremediation by impacting the availability of substrates to the microorganisms. However, for difficult-to-degrade compounds, and/or cases with inhibitory biodegradation conditions, slow biokinetics may also limit the overall bioremediation rate, or be as limiting as mass-transfer processes. In this work, a quantitative framework based on a set of dimensionless coefficients was used to capture the effects of the competing interfacial and biokinetic processes and define the overall rate-limiting process. An integrated numerical modeling and experimental approach was used to evaluate application of the quantitative framework for a scenario in which slow-biokinetics limited the overall bioremediation rate of a polycyclic aromatic hydrocarbon (naphthalene). Numerical modeling was conducted to simulate the groundwater flow and naphthalene transport and verify the system parameters, which were used in the quantitative framework application. The experiments examined the movement and biodegradation of naphthalene in a saturated, heterogeneous intermediate-scale flow cell with two layers of contrasting hydraulic conductivities. These experiments were conducted in two phases: Phase I, simulating an inhibited slow biodegradation; and Phase II, simulating an engineered bioremediation, with system perturbations selected to enhance the slow biodegradation rate. In Phase II, two engineered perturbations to the system were selected to examine their ability to enhance in situ biodegradation. In the first perturbation, nitrogen and phosphorus in excess of the required stoichiometric amounts were spiked into the influent solution to mimic a common remedial action taken in the field. The results showed that this perturbation had a moderate positive impact, consistent with slow biokinetics being the overall rate-limiting process. However, the second perturbation, which was to

  5. Biokinetics – the development of a health profession from physical ...

    African Journals Online (AJOL)

    Biokinetics – the development of a health profession from physical education - a historical perspective. ... In this respect some medical aid funds supported this philosophy of health promotion, as the curative treatment of health problems are becoming increasingly expensive and are burdening health-care costs. At present ...

  6. Comparison of predicted with observed biokinetics of inhaled plutonium nitrate and gadolinium oxide in humans

    International Nuclear Information System (INIS)

    Hodgson, A.; Shutt, A.L.; Etherington, G.; Hodgson, S.A.; Rance, E.; Stradling, G.N.; Youngman, M.J.; Ziesenis, A.; Kreyling, W.G.

    2003-01-01

    The absorption kinetics to blood of plutonium and gadolinium after inhalation as nitrate and oxide in humans and animals has been studied. For each material, values describing the time dependence of absorption were derived from the studies in animals and used with the ICRP human respiratory tract model to predict lung retention and cumulative amounts to blood for the volunteers inhaling the same materials. Comparison with the observed behaviour in the volunteers suggests that absorption of plutonium and gadolinium is reasonably species independent, and that data obtained from animal studies can be used to assess their biokinetic behaviour in humans. (author)

  7. 99mTc-UBI Biokinetics: A Specific Peptide for Infection Detection

    Science.gov (United States)

    Rodríguez-Cortés, J.; Meléndez-Alafort, L.; Herrera-Rodríguez, R.; Ferro-Flores, G.; Mitsoura, E.; Martínez-Duncker, C.

    2003-09-01

    Recently, antimicrobial peptides have been proposed as new agents to distinguish between bacterial infections and sterile inflammatory processes. Based on these considerations, Ubiquicidin peptide 29-41 (UBI) has been labeled with 99mTc using a new direct method showing a radiochemical purity > 97 %, high stability in human serum, and low protein binding. In addition 99mTc-UBI showed a specific in vitro and in vivo binding to bacteria. However its biokinetic parameters have not been evaluated since it is one of the new generation radiopharmaceuticals based on peptide structures. Therefore the aim of this project was to establish the biokinetic model for 99mTc-UBI. An activity from 74 to 148 MBq was injected to patients with bone infection and 5 whole body scans were taken at 1, 30, 120, 240 min and 24 h after radiopharmaceutical administration, with a dual head scanner. Urine was collected for 24 h. An antropomorphic phantom was previously used to calculate the effect of attenuation and scattered radiation on the gamma camera acquisition images. ROIs of the selected organs in patients (kidney, liver, heart, bone, soft tissue and lesion) were drawn, and attenuation and scatter corrected. The % urine elimination at 24 h and time integrated ROIs (cpm/pixel/ROIs) were used to obtain the residence time (τ) in each tissue and to establish the biokinetic model. Pharmacokinetic data show that blood clearance is biexponential with a mean residence time in the central compartment of 0.52 h. The images showed non-accumulation in metabolic organs. More than 75 % of the injected activity was eliminated by renal clearance 4 h after 99mTc-UBI administration. The mean radiation dose calculated according to the MIRD formalism was 0.130 mGy/MBq for kidney and the effective dose was 4.29 × 10-3 mSv/MBq.

  8. Biokinetics aand dosimetry of inhaled 238PuO2 in the beagle dog: An update

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Griffith, W.C.; Diel, J.H.

    1994-01-01

    The temporal and spatial distributions of 238 Pu have been measured during the course of a dose-response study of the biological effects of inhaled 238 PuO 2 in Beagle dogs. These measurements were done on the dose-response study animals, as well as a separate group of dogs exposed to similar aerosols and killed serially out to 4 y after exposure. The data from this latter group provided the basis for the development of a biokinetic/dosimetric model for 238 PuO 2 in dogs. Since the publication of this model, several important findings have been made that affected the dosimetric evaluations. The first involved the discovery of significant quantities of natural uranium (U) in the feces samples. The U was measured with the plutonium (Pu), which inflated the values for purported Pu in feces. The second finding involved the addition of Pu biokinetics data from the dose-response dogs, which increased the period of observation from 4 y to 15 y; these later data were not consistent with the earlier model predictions. The purpose of this investigation was (1) to remove the analytical bias in the 238 Pu radiochemical data due to the U and (2) to modify the original model of Mewhinney and Diel, taking into account all data from both studies

  9. Different biokinetics of nanomedicines linking to their toxicity; an overview

    Directory of Open Access Journals (Sweden)

    Abdollahi Mohammad

    2013-02-01

    Full Text Available Abstract In spite of the extreme rise to the knowledge of nanotechnology in pharmaceutical sciences, there are currently limited experimental works studying the interactions between nanoparticles (NPs and the biological system. Adjustment of size and surface area plays the main role in the reaction between NPs and cells leading to their increased entrance into cells through skin, gastrointestinal and respiratory system. Moreover, change in physicochemical reactivity of NPs causes them to interact with circulatory and cellular proteins differentially leading to the altered parameters of their biokinetics, including adsorption, distribution, translocation, transformation, and elimination. A direct relationship between the surface area, reactive oxygen species generating capability, and proinflammatory effects of NPs have been found in respiratory tract toxicity. Additionally, complement-mediated hypersensitivity reactions to liposomes and other lipid-based nanodrugs have been well defined. Inhalation studies of some NPs have confirmed the translocation of inhaled materials to extra pulmonary organs such as central nervous system (CNS via olfactory neurons and induction of inflammatory response. Injectable uncoated NPs have a tendency to remain on the injection site while the poly ethanol glycol (PEG-coated NPs can be notably drained from the injection site to get as far as the lymph nodes where they accumulate. This confirms the existence of channels within the extracellular matrix for NPs to move along. Furthermore, induction of DNA strand breaks and formation of micronuclei have been recorded for exposure to some NPs such as single-walled carbon nanotubes. In the recent years, most of the studies have simply outlined better efficacy of nanodrugs, but few discussed their possible toxic reactions specially if used chronically. Therefore, we emphasize that this part of the nanoscience must not be undermined and toxicologists must be sensitive to

  10. Biokinetics and bacterial communities of propionate oxidizing bacteria in phased anaerobic sludge digestion systems.

    Science.gov (United States)

    Zamanzadeh, Mirzaman; Parker, Wayne J; Verastegui, Yris; Neufeld, Josh D

    2013-03-15

    Phased anaerobic digestion is a promising technology and may be a potential source of bio-energy production. Anaerobic digesters are widely used for sewage sludge stabilization and thus a better understanding of the microbial process and kinetics may allow increased volatile solids reduction and methane production through robust process operation. In this study, we analyzed the impact of phase separation and operational conditions on the bio-kinetic characteristics and communities of bacteria associated with four phased anaerobic digestion systems. In addition to significant differences between bacterial communities associated with different digester operating temperatures, our results also revealed that bacterial communities in the phased anaerobic digestion systems differed between the 1st and 2nd phase digesters and we identified strong community composition correlations with several measured physicochemical parameters. The maximum specific growth rates of propionate oxidizing bacteria (POB) in the mesophilic and thermophilic 1st phases were 11 and 23.7 mgCOD mgCOD(-1) d(-1), respectively, while those of the mesophilic and thermophilic 2nd-phase digesters were 6.7 and 18.6 mgCOD mgCOD(-1) d(-1), respectively. Hence, the biokinetic characteristics of the POB population were dependent on the digester loading. In addition, we observed that the temperature dependency factor (θ) values were higher for the less heavily loaded digesters as compared to the values obtained for the 1st-phase digesters. Our results suggested the appropriate application of two sets of POB bio-kinetic that reflect the differing growth responses as a function of propionate concentration (and/or organic loading rates). Also, modeling acetogenesis in phased anaerobic sludge digestion systems will be improved considering a population shift in separate phases. On the basis of the bio-kinetic values estimated in various digesters, high levels of propionate in the thermophilic digesters may be

  11. Biokinetics and dosimetry of a hybrid formulation of {sup 9{sup m}}Tc-BN and {sup 99m}Tc-RGD{sub 2} starting from optic images in a murine model; Biocinetica y dosimetria de una formulacion hibrida de {sup 99m}Tc-BN y {sup 99m}Tc-RGD{sub 2} a partir de imagenes opticas en un modelo murino

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo A, L. G.

    2015-07-01

    This work has the purpose of evaluate the biokinetics and absorbed dose of radiation of hybrid formulation {sup 99m}Tc-BN /{sup 99m}Tc-RGD{sub 2} in a murine model by optical imaging techniques using the multimodal preclinical in vivo image system Xtreme. The used method were the {sup 99m}Tc-BN, {sup 99m}Tc-RGD{sub 2} and {sup 99m}Tc-BN/{sup 99m}Tc-RGD{sub 2} formulas, with specific recognition for GRPr and the integrin s α(v)β(3) and α(v)β(5) respectively, was injected in the vein tail of three nude mousses with induce breast cancer tumors (cell line T-47-D), by the preclinical multimodal imaging system Xtreme (Bruker), optical images in different times was acquired (5, 10, 20 min, 2 and 24 h), using Images Processing Toolbox of MATLAB these images was transform from RGB format to gray scales and sectioned in five independent images corresponding to heart, kidneys, bladder and tumor areas. The intensity of each images was computed in counts per pixel, then those intensities was corrected for background, attenuation and scattering, using different factors for each phenomena previously calculated. Finally the activity values quantified vs time was fitted into a biokinetic model to obtain the disintegrations number and cumulate activities in each organ. With these data the radiation absorbed dose were calculated using MIRD methodology. Results: The number of disintegration and absorbed dose calculated in MBq h/MBq and mGy/MBq, of injected mouse with the {sup 99m}Tc-BN/{sup 99m}Tc-RGD{sub 2} formulation, was: 0.035 ± 0.65 E-02, 0.25 x 10{sub -5} ± 0.46 E-07; 0.393 ± 0.51 E-1, 2.85 E-05 ± 3.7 E-06; 0.306 ± 0.21 E-01, 2.11 E-05 ± 1.45 E-06 and 0.151 ± 0.19 E-01, 1.09 E-05 ± 1.42 E-06 , in heart, kidneys, bladder and tumor, respectively. The number of disintegration obtained in kidneys is comparable to those reported for Trinidad B. 2014 Conclusions: Our results demonstrated that using optical images and a code for image analyses development in MATLAB, could

  12. Uranium: biokinetics and toxicity; Biocinetique et toxicite de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Menetrier, F.; Renaud-Salis, V.; Flury-Herard, A

    2000-07-01

    This report was achieved as a part of a collaboration with the Fuel Cycle Direction. Its aim was to give the state of the art about: the behaviour of uranium in the human organism (biokinetics) after ingestion, its toxicity (mainly renal) and the current regulation about its incorporation. Both in the upstream and in the downstream of the fuel cycle, uranium remains, quantitatively, the first element in the cycle which is, at the present time, temporarily disposed or recycled. Such a considerable quantity of uranium sets the problem of its risk on the health. In the long term, the biosphere may be affected and consequently the public may ingest water or food contaminated with uranium. In this way, radiological and chemical toxicity risk may be activated. This report emphasizes: the necessity of confirming some experimental and epidemiological biokinetic data used or not in the ICRP models. Unsolved questions remain about the gastrointestinal absorption according to chemical form (valency state, mixtures...), mass and individual variations (age, disease) further a chronic ingestion of uranium. It is well established that uranium is mainly deposited in the skeleton and the kidney. But the skeleton kinetics following a chronic ingestion and especially in some diseases has to be more elucidated; the necessity of taking into account uranium at first as a chemical toxic, essentially in the kidney and determining the threshold of functional lesion. In this way, it is important to look for some specific markers; the problem of not considering chemical toxicity of uranium in the texts regulating its incorporation.

  13. Radiation exposure of the patient in diagnostic nuclear medicine. Experimental studies of the biokinetics of 111In-DTPA-D-Phe1-octreotide, 99mTc-MIBI, 14C-triolein and 14C-urea, and development of dosimetric models

    International Nuclear Information System (INIS)

    Leide Svegborn, S.

    1999-03-01

    Biokinetic and dosimetric models for a number of clinically used radiopharmaceuticals, for which information on the radiation dosimetry is scarce, have been produced. On patients undergoing investigations with 111 In-DTPA-D-Phe 1 -octreotide (for diagnosis of neuroendocrine tumours) and 99m Tc-MIBI (for myocardial perfusion imaging), whole body gamma camera scanning was performed several times after administration of the radiopharmaceutical. Total body and organ activity content was determined using the geometric mean of the number of counts in two 180 deg opposed planar images. A thorough investigation of sources influencing the accuracy of the quantification of activity was carried out, showing an overall uncertainty varying from 10% to 30% for organs with a significant uptake and 5% for the whole body. The activity in blood and urine was also measured. 111 In-DTPA-D-Phe 1 -octreotide was predominantly excreted via the kidney-bladder system and a typical investigation with 1200 MBq resulted in an effective dose of 8.4 mSv (0.076 mSv/MBq). 99m Tc-MIBI was to a great extent excreted via the gastrointestinal tract and an investigation with 1200 MBq resulted in an effective dose of 13 mSv (0.011 mSv/MBq). Accelerator mass spectrometry (AMS) was used to investigate the possibility to measure ultra-low activity concentrations of 14 CO 2 , in exhaled air from patients undergoing 14 C-breath tests, with special application to 14 C-triolein (for study of fat malabsorption). AMS was proven to be a useful technique for long-term retention studies of 14 C, and was used together with liquid scintillation counting in an investigation of the biokinetics of 14 C-urea in adult and paediatric patients (for diagnosis of Helicobacter pylori infection in the upper gastrointestinal tract). The effective dose for 14 C-urea was 0.019 mSv/MBq for adults and from 0.041 to 0.019 mSv/MBq for seven- to fourteen -year-old children, resulting in an effective dose of approximately 0.002 mSv per

  14. Radiation exposure of the patient in diagnostic nuclear medicine. Experimental studies of the biokinetics of {sup 111}In-DTPA-D-Phe{sup 1}-octreotide, {sup 99m}Tc-MIBI, {sup 14}C-triolein and {sup 14}C-urea, and development of dosimetric models

    Energy Technology Data Exchange (ETDEWEB)

    Leide Svegborn, S

    1999-03-01

    Biokinetic and dosimetric models for a number of clinically used radiopharmaceuticals, for which information on the radiation dosimetry is scarce, have been produced. On patients undergoing investigations with {sup 111}In-DTPA-D-Phe{sup 1}-octreotide (for diagnosis of neuroendocrine tumours) and {sup 99m}Tc-MIBI (for myocardial perfusion imaging), whole body gamma camera scanning was performed several times after administration of the radiopharmaceutical. Total body and organ activity content was determined using the geometric mean of the number of counts in two 180 deg opposed planar images. A thorough investigation of sources influencing the accuracy of the quantification of activity was carried out, showing an overall uncertainty varying from 10% to 30% for organs with a significant uptake and 5% for the whole body. The activity in blood and urine was also measured. {sup 111}In-DTPA-D-Phe{sup 1}-octreotide was predominantly excreted via the kidney-bladder system and a typical investigation with 1200 MBq resulted in an effective dose of 8.4 mSv (0.076 mSv/MBq). {sup 99m}Tc-MIBI was to a great extent excreted via the gastrointestinal tract and an investigation with 1200 MBq resulted in an effective dose of 13 mSv (0.011 mSv/MBq). Accelerator mass spectrometry (AMS) was used to investigate the possibility to measure ultra-low activity concentrations of {sup 14}CO{sub 2}, in exhaled air from patients undergoing {sup 14}C-breath tests, with special application to {sup 14}C-triolein (for study of fat malabsorption). AMS was proven to be a useful technique for long-term retention studies of {sup 14}C, and was used together with liquid scintillation counting in an investigation of the biokinetics of {sup 14}C-urea in adult and paediatric patients (for diagnosis of Helicobacter pylori infection in the upper gastrointestinal tract). The effective dose for {sup 14}C-urea was 0.019 mSv/MBq for adults and from 0.041 to 0.019 mSv/MBq for seven- to fourteen -year-old children

  15. Biokinetics and dosimetric studies about 99mTc(V)DMSA distribution

    International Nuclear Information System (INIS)

    Correia, M.B.L.; Magnata, S.S.L.P.; Silva, I.M.S.; Lima, F.F.; Catanho, M.T.J.A.

    2008-01-01

    Research for radiodiagnostic agents should considerate biological critical parameters as half-life effective, target/not target uptake ratio and metabolites that together will determinate the biokinetic. Each parameter give own contribution in the absorbed dose. The dimercaptosuccinic acid (DMSA) labeled with 99m Tc(VN) is a radiopharmaceutical which has well established role in medullar thyroid carcinoma and has been proposed in complementary evaluation of bone metastasis. The aim of this work was study the biokinetics and dosimetry of 99m Tc(V)-DMSA by animal model. The 99m Tc(V)-DMSA was prepared by (III)DMSA kit alkalized. The methodology used mice, 70 days old, both males and females. The animals (n=5) received 99m Tc(V)DMSA administered IV (tail vein). After determinate times (30 min, 1h, 5h and 12h) the animals were sacrificed, the organs (blood, lungs, kidneys, muscle and bone) were excised and the activities were measured by a gamma counter. The results were evaluated based on %activity/g and the absorbed dose was estimated by extrapolation of data from animal to human, using the residence time to each organ in the MIRDOSE 3.0 program. The results show that the majority of organs reaches the top uptake at 30 min, the kidney has the greatest uptake in this time, (4.81 ± 1.38) % activity per gram, while the bone presents its highest uptake at 1h (5.49 ± 0.47)% activity per gram, after 1h all the organs had activity exponential decrease. About the absorbed dose estimated to human scale, the preliminary results showed higher value to bone, being the soft tissue dose relatively low. These dose values, however, are submitted to biological implications which are under studying yet. The biokinetic profile of 99m Tc(V)-DMSA, prepared from a DMSA kit by IPEN, was well established, allowing quantifying of residence time, while the dosimetric model presented preliminary data which directs to new analyzes

  16. Study of the influence of radionuclide biokinetics on in vivo counting using voxel phantoms

    International Nuclear Information System (INIS)

    Lamart, St.

    2008-10-01

    The in vivo measurement is an efficient method to estimate the retention of activity in case of internal contamination. However, it is currently limited by the use of physical phantoms for the calibration, not enabling to reproduce neither the morphology of the measured person nor the actual distribution of the contamination. The current method of calibration therefore leads to significant systematic uncertainties on the quantification of the contamination. To improve the in vivo measurement, the Laboratory of Internal Dose Assessment (LEDI, IRSN) has developed an original numerical calibration method with the OEDIPE software. It is based on voxel phantoms created from the medical images of persons, and associated with the MCNPX Monte Carlo code of particle transport. The first version of this software enabled to model simple homogeneous sources and to better estimate the systematic uncertainties in the lung counting of actinides due to the detector position and to the heterogeneous distribution of activity inside the lungs. However, it was not possible to take into account the dynamic feature, and often heterogeneous distribution between body organs and tissues of the activity. Still, the efficiency of the detection system depends on the distribution of the source of activity. The main purpose of the thesis work is to answer to the question: what is the influence of the biokinetics of the radionuclides on the in vivo counting? To answer it, it was necessary to deeply modify OEDIPE. This new development enabled to model the source of activity more realistically from the reference biokinetic models defined by the ICRP. The first part of the work consisted in developing the numerical tools needed to integrate the biokinetics in OEDIPE. Then, a methodology was developed to quantify its influence on the in vivo counting from the results of simulations. This method was carried out and validated on the model of the in vivo counting system of the LEDI. Finally, the

  17. Biokinetic behavior of Tc in the red abalone, Haliotis rufescens: a reassessment

    International Nuclear Information System (INIS)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

    1981-01-01

    The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments on other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalone exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by the abalone following a single feeding of labeled macroalga, Nereocystis pyrifera, is high (approx. 45%) and loss kinetics are similar to those observed following direct uptake from seawater

  18. Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J. (Oregon State Univ., Newport (USA). Marine Science Center)

    1982-10-01

    The biokinetic behavior of sup(95m)Tc in the red abalone, haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of sup(95m)Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, approximately equal to 45% and loss kinetics are similar to those observed following direct uptake from seawater.

  19. Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

    1982-10-01

    The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labelled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, is approximately 45% and loss kinetics are similar to those observed following direct uptake from seawater.

  20. Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

    International Nuclear Information System (INIS)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

    1982-01-01

    The biokinetic behavior of sup(95m)Tc in the red abalone, haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of sup(95m)Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, approximately equal to 45% and loss kinetics are similar to those observed following direct uptake from seawater. (author)

  1. Compared biokinetic and biological studies of chronic and acute inhalations of uranium compounds in the rat

    International Nuclear Information System (INIS)

    Monleau, M.

    2005-12-01

    Uranium is a natural, radioactive heavy metal, widely used in the nuclear industry in various chemical and isotopic forms. Its use in the fuel cycle involves the risk of radiological exposure for the workers, mainly via the inhalation of uranium particles. According to the workplace configuration, uranium contaminations can be acute or repeated, involve various chemical forms and different levels of enrichment, as well as involving one or several components. The dosimetric concepts and models available for workers' radiological protection, as well as most of the studies of the biological effects, correspond to acute exposure situations. Moreover the processes leading to pathological effects are little known in vivo. In this context, the main question is to know whether exposures due to repeated inhalation by rats induce the element kinetics and toxicity, which may be different from those observed after an acute exposure. In this study, comparison of the experimental and theoretical biokinetics of an insoluble uranium repeatedly inhaled over three weeks shows that a chronic contamination is correctly modelled, except for bone retention, by the sum of acute, successive and independent incorporations. Moreover, the kinetics of a soluble uranium inhaled irregularly can be modified by previous repeated exposure to an insoluble uranium. In certain cases therefore, exposure to uranium could modify its biokinetics during later exposures. At a toxicological level, the study demonstrates that the uranium particles inhaled repeatedly induce behavioural disruptions and genotoxic effects resulting in various sorts of DNA damage, in several cell types and certainly depending on the quantity inhaled. Exposures involving several uraniferous components produce a synergy effect. Moreover, repeated inhalations worsen the genotoxic effects in comparison to an acute exposure. This work demonstrates the importance of not ignoring the effects of the repetition of uranium exposure. It

  2. A biokinetic study of {sup 209}Po in man

    Energy Technology Data Exchange (ETDEWEB)

    Henricsson, C.F.; Ranebo, Y. [Department of Medical Radiation Physics, Clinical Sciences in Lund, Lund University, Skane University Hospital in Lund (Sweden); Hansson, M. [Medical Radiation Physics, Department of Clinical Sciences in Malmoe, Lund University, Skane University Hospital in Malmoe (Sweden); Raeaef, C.L., E-mail: Christopher.Raaf@med.lu.se [Medical Radiation Physics, Department of Clinical Sciences in Malmoe, Lund University, Skane University Hospital in Malmoe (Sweden); Holm, E. [Norwegian Radiation Protection Authority, Osteras (Norway)

    2012-10-15

    Five adult volunteers participated in a biokinetic study of radioactive polonium. Portions of about 10 Bq of {sup 209}Po were orally administrated to four of the volunteers in a single ingestion. The fifth volunteer ingested a daily amount of 53 mBq of 209Po for 243 d to study the time to achieve equilibrium between intake and excretion for protracted intakes. For the subjects ingesting single intakes of {sup 209}Po complete sampling of urine and feces was subsequently collected the first few days upon the ingestion. The samples were processed with radiochemical extraction and analyzed with alpha spectrometry. In the study, the maximum daily excretion rates in feces were 18-50% of the ingested activity, observed within 3 d after intake. Regarding the urine excretion, the daily excretion peaked, on average, at 0.15-1% of the ingested activity within two days upon intake. These results indicate an average gastro-intestinal uptake fraction of 0.46 {+-} 0.08, which agrees well with earlier biokinetic studies of polonium in man. -- Highlights: Black-Right-Pointing-Pointer Human metabolism of an oral intake of polonium. Black-Right-Pointing-Pointer 4 individuals were administrated about 10 Bq polonium-209. Black-Right-Pointing-Pointer Gastro-intestinal uptake fraction, if orally administrated polonium-209 was investigated. Black-Right-Pointing-Pointer The biological half-time of polonium in human body was studied.

  3. Biokinetics of 131I in human organism

    International Nuclear Information System (INIS)

    Hermanska, J.; Nemec, J.; Karny, M.; Guy, T.V.; Jirsa, L.; Blazek, T.

    1995-01-01

    Time evolution of the cumulated activity in human body is one of the key characteristics determining medical impacts of ionizing radiation. In nuclear medicine, so called effective half-life is mostly used for the evolution description. This quantity is usually estimated by fitting a straight line in semi-logarithmic coordinates. Its novel Bayesian estimate was also proposed and its advantageous properties were verified. During extensive tests, it was found that the effective half-live has limited use as the underlying deterministic relationship time - activity can hardly be taken as (mono)exponential. It stimulated the research for a better and still simple model. A quadratic dependence of ln(activity) on ln(time) was found as an adequate candidate. Preliminary experiments on a restricted set of real data were promising enough to justify its further elaboration. (authors) 1 tab., 19 refs

  4. Accuracy of internal dose calculations with special consideration of radiopharmaceutical biokinetics

    International Nuclear Information System (INIS)

    Roedler, H.D.

    1981-01-01

    The individual steps of internal dose calculation, including the models and data used, as well as error considerations, are analysed following a short synopsis on the formalism of absorbed dose calculation. The mean dose in a target tissue depends on the administered activity, the residence time of the activity in the source tissues and the mean absorbed dose in the target tissue per transformation in a source tissue. Usually, a standard dosage is applied in radionuclide studies except in children. Actually administered and nomial activities generally differ by less than 10%. For the purpose of internal dose calculation, the biokinetics of a radiopharmaceutical are reflected in the residence times for the individual source tissues. The methods and the evaluation of measurements of biodistribution and retention data are discussed. The extrapolation of animal data to man is treated in some detail, including a survey of the methods used, as well as an attempt for validating these methods. None of these seem to yield more convincing results than the direct transfer of the residence times from animal to man, at least for the two radiopharmaceuticals discussed. The minimum period of measurement to derive residence times for the purpose of dose calculation has been determined as about one physical half-time. Some problems of the dose per transformation to a phantom are presented, including the age- or size-dependence of the internal dose. Organ doses to the phantom, calculated from different apparently reliable sets of biokinetic data, are generally compatible within a factor of 2 to 3, and somatically effective doses are generally compatible within a factor of less than 2

  5. Amiodarone biokinetics, the formation of its major oxidative metabolite and neurotoxicity after acute and repeated exposure of brain cell cultures.

    Science.gov (United States)

    Pomponio, Giuliana; Zurich, Marie-Gabrielle; Schultz, Luise; Weiss, Dieter G; Romanelli, Luca; Gramowski-Voss, Alexandra; Di Consiglio, Emma; Testai, Emanuela

    2015-12-25

    The difficulty in mimicking nervous system complexity and cell-cell interactions as well as the lack of kinetics information has limited the use of in vitro neurotoxicity data. Here, we assessed the biokinetic profile as well as the neurotoxicity of Amiodarone after acute and repeated exposure in two advanced rodent brain cell culture models, consisting of both neurons and glial cells organized in 2 or 3 dimensions to mimic the brain histiotypic structure and function. A strategy was applied to evidence the abiotic processes possibly affecting Amiodarone in vitro bioavailability, showing its ability to adsorb to the plastic devices. At clinically relevant Amiodarone concentrations, known to induce neurotoxicity in some patients during therapeutic treatment, a complete uptake was observed in both models in 24 h, after single exposure. After repeated treatments, bioaccumulation was observed, especially in the 3D cell model, together with a greater alteration of neurotoxicity markers. After 14 days, Amiodarone major oxidative metabolite (mono-N-desethylamiodarone) was detected at limited levels, indicating the presence of active drug metabolism enzymes (i.e. cytochrome P450) in both models. The assessment of biokinetics provides useful information on the relevance of in vitro toxicity data and should be considered in the design of an Integrated Testing Strategy aimed to identify specific neurotoxic alerts, and to improve the neurotoxicity assay predictivity for human acute and repeated exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The biokinetics and radiotoxicology of curium: A comparison with americium

    Energy Technology Data Exchange (ETDEWEB)

    Menetrier, F. [CEA, Fontenay-aux-Roses (France); Taylor, D.M. [School of Chemistry, Cardiff University, Cardiff CF10 3AT (United Kingdom)], E-mail: davtay@btinternet.com; Comte, A. [CEA, Fontenay-aux-Roses (France)

    2008-05-15

    The human and animal data on the biokinetics of {sup 242}Cm and {sup 244}Cm are reviewed and shown to be very similar to those for {sup 241}Am. Liver and skeleton are the main organs of deposition and the retention of curium in the skeleton is very prolonged in all the species examined. Retention of both curium and americium in the liver appears to be species-dependent, being relatively rapidly removed from the liver of rats, and probably humans, but being tenaciously retained in dogs and some other species. The radiotoxicity of curium is also reviewed and it is shown that, as with {sup 241}Am, lung and bone tumour induction are the major hazards from inhaled and systemically deposited {sup 244}Cm. The use of chelating agents for the treatment of accidental contamination of the human body with {sup 242,244}Cm is also discussed.

  7. The Effect of Body Size in Mercury Accumulation Biokinetic of Cockle Shell (Anadara Granosa)

    International Nuclear Information System (INIS)

    Wahyu Retno Prihatiningsih

    2007-01-01

    Accumulation of mercury biokinetic in cockle shell (Anadara granosa) through water pathway has been investigated under laboratory condition. The objective of research is to find the effect of body size in mercury biokinetic of Anadara granosa and to find bioindicator based on biokinetic parameter. The research shows that body size of Anadara granosa give an effect to concentration factor and could barrier mercury contaminant. Concentration factor for size 1.9, 2.5 and 3.9 cm of biota moving high and reach steady state condition after 24 days. Concentration factor of Anadara granosa in size 1.9, 2.5 and 3.9 is 0.1476, 0.1645 and 0.2573 day. Based on mechanism of mercury biokinetic process, it was proof that Anadara granosa is an ideal invertebrate for bioindicator. (author)

  8. Biokinetics of zinc oxide nanoparticles: toxicokinetics, biological fates, and protein interaction

    Directory of Open Access Journals (Sweden)

    Choi SJ

    2014-12-01

    Full Text Available Soo-Jin Choi,1 Jin-Ho Choy2 1Department of Food Science and Technology, Seoul Women's University, 2Center for Intelligent Nano Bio Materials (CINBM, Department of Bioinspired Science and Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, South Korea Abstract: Biokinetic studies of zinc oxide (ZnO nanoparticles involve systematic and quantitative analyses of absorption, distribution, metabolism, and excretion in plasma and tissues of whole animals after exposure. A full understanding of the biokinetics provides basic information about nanoparticle entry into systemic circulation, target organs of accumulation and toxicity, and elimination time, which is important for predicting the long-term toxic potential of nanoparticles. Biokinetic behaviors can be dependent on physicochemical properties, dissolution property in biological fluids, and nanoparticle–protein interaction. Moreover, the determination of biological fates of ZnO nanoparticles in the systemic circulation and tissues is critical in interpreting biokinetic behaviors and predicting toxicity potential as well as mechanism. This review focuses on physicochemical factors affecting the biokinetics of ZnO nanoparticles, in concert with understanding bioavailable fates and their interaction with proteins. Keywords: ZnO nanoparticles, biokinetics, distribution, excretion, fate, interaction

  9. Biokinetics and dosimetry with 177Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

    Science.gov (United States)

    Rodríguez-Cortés, J.; de Murphy, C. Arteaga; Ferro-Flores, Ge; Pedraza-López, M.; Murphy-Stack, E.

    Malignant pancreatic tumours induced in athymic mice are a good model for peptide receptor targeted radiotherapy. The objective of this research was to determine biokinetic parameters in mice, in order to estimate the induced pancreatic tumour absorbed doses and to evaluate an `in house' 177Lu-DOTA-TATE radiopharmaceutical as part of preclinical studies for targeted therapy in humans. AR42J murine pancreas cancer cells expressing somatostatin receptors, were implanted in athymic mice (nD22) to obtain biokinetic and dosimetric data of 177Lu-DOTA-TATE. The mean tumour uptake 2 h post injection was 14.76±1.9% I.A./g; kidney and pancreas uptake, at the same time, were 7.27±1.1% I.A./g (1.71±0.90%/organ) and 4.20±0.98% I.A./g (0.42±0.03%/organ), respectively. The mean absorbed dose to tumour, kidney and pancreas was 0.58±0.02 Gy/MBq; 0.23±0.01 Gy/MBq and 0.14±0.01 Gy/MBq, respectively. These studies justify further dosimetric estimations to ensure that 177Lu-DOTA-TATE will act as expected in humans.

  10. Biokinetics and dosimetry of target-specific radiopharmaceuticals for molecular imaging and therapy

    International Nuclear Information System (INIS)

    Ferro F, G.; Torres G, E.; Gonzalez V, A.; Murphy, C.A. de

    2006-01-01

    Molecular imaging techniques directly or indirectly monitor and record the spatiotemporal distribution of molecular or cellular processes for biochemical, biologic, diagnostic or therapeutic applications. 99m Tc-HYNlC-TOC has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. Therapies using radiolabeled anti-CD20 have demonstrated their efficacy in patients with B-cell non Hodgkin's Iymphoma (NHL). The aim of this study was to establish biokinetic models for 99m Tc-HYNlC-TOC and 188 Re-anti-CD20 prepared from Iyophilized kits, and to evaluate their dosimetry as target-specific radiopharmaceuticals. Whole-body images were acquired at different times after 99m Tc-HYNlC-TOC or 188 Re-anti-CD20 administration obtained from instant freeze-dried kit formulations with radiochemical purities > 95 %. Regions of interest (ROls) were drawn around source organs on each time frame. The cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate time-activity curves in each organ, to adjust the biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. 99m Tc-HYNlC-TOC images showed an average tumor/blood (heart) ratio of 4.3 ± 0.7 in receptor-positive tumors at 1 h and the mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv. Results showed that after administration of 7 GBq of 188 Re-anti-CD20 the absorbed dose to whole body would be 0.7 Gy (0.1 mGy/MBq) which is the indicated dose for non Hodgkin's Iymphome therapies. (Author)

  11. Multigenerational cadmium acclimation and biokinetics in Daphnia magna

    International Nuclear Information System (INIS)

    Guan Rui; Wang Wenxiong

    2006-01-01

    A Cd exposure (3 μg L -1 ) experiment was conducted for six successive generations to investigate the responses to chronic Cd stress in Daphnia magna. We observed a biphasic accumulation of Cd in the six generations and suggested a similar pattern with respect to daphnids' tolerance. Cd assimilation efficiencies, daphnid growth, and reproduction corresponded to the changes of tolerance, which was partially accounted for by metallothionein induction. When maternally exposed neonates grew in Cd-free water for one or two generations, their growth, MT concentration and biokinetic parameters partially or totally recovered. The rapid recovery suggests the high potential for ecological restoration from Cd pollution. Our results indicate that the tolerance of sensitive D. magna clones to Cd was dependent on long-term or multigenerational exposure. The tolerance developed within the first several generations might not be maintained, and the animals may become even more sensitive to Cd stress in subsequent generations. - Tolerance of sensitive Daphnia magna clones to cadmium was dependent on long-term or multigenerational exposure

  12. The computation of ICRP dose coefficients for intakes of radionuclides with PLEIADES: biokinetic aspects.

    Science.gov (United States)

    Fell, T P

    2007-01-01

    The ICRP has published dose coefficients for the ingestion or inhalation of radionuclides in a series of reports covering intakes by workers and members of the public including children and pregnant or lactating women. The calculation of these coefficients conveniently divides into two distinct parts--the biokinetic and dosimetric. This paper gives a brief summary of the methods used to solve the biokinetic problem in the generation of dose coefficients on behalf of the ICRP, as implemented in the Health Protection Agency's internal dosimetry code PLEIADES.

  13. The computation of ICRP dose coefficients for intakes of radionuclides with PLEIADES: biokinetic aspects

    International Nuclear Information System (INIS)

    Fell, T.P.

    2007-01-01

    The ICRP has published dose coefficients for the ingestion or inhalation of radionuclides in a series of reports covering intakes by workers and members of the public including children and pregnant or lactating women. The calculation of these coefficients conveniently divides into two distinct parts - the biokinetic and dosimetric. This paper gives a brief summary of the methods used to solve the biokinetic problem in the generation of dose coefficients on behalf of the ICRP, as implemented in the Health Protection Agency's internal dosimetry code PLEIADES. (author)

  14. Biokinetics and dosimetry in patients of 99mTc-EDDA/HYNIC-Tyr3-octreotide prepared from lyophilized kits.

    Science.gov (United States)

    González-Vázquez, Armando; Ferro-Flores, Guillermina; Arteaga de Murphy, Consuelo; Gutiérrez-García, Zohar

    2006-07-01

    99mTc-EDDA/HYNIC-Tyr3-octreotide (99mTc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for 99mTc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients were acquired at 5, 60, 90, 180 min and 24 h after 99mTc-HYNIC-TOC administration obtained from instant freeze-dried kit formulations with radiochemical purities >95%. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all eight scans and the count per minute (cpm) of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99mTc-HYNIC-TOC time-activity curves in each organ, to adjust a biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed an average tumor/blood (heart) ratio of 4.3+/-0.7 in receptor-positive tumors at 1 h. The mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv.

  15. Distribution and biokinetic analysis of {sup 210}Pb and {sup 210}Po in poultry due to ingestion of dicalcium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Casacuberta, N., E-mail: Nuria.Casacuberta@uab.es [Departament de Fisica and Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Traversa, F.L. [Departament d' Electronica, Escola Tecnica Superior d' Enginyeria, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Masque, P.; Garcia-Orellana, J. [Departament de Fisica and Institut de Ciencia i Tecnologia Ambientals, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Anguita, M.; Gasa, J. [Departament de Ciencia Animal i dels Aliments, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Garcia-Tenorio, R. [Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012 Sevilla (Spain)

    2010-09-15

    Dicalcium phosphate (DCP) is used as a calcium supplement for food producing animals (i.e., cattle, poultry and pig). When DCP is produced via wet acid digestion of the phosphate rock and depending on the acid used in the industrial process, the final product can result in enhanced {sup 210}Pb and {sup 210}Po specific activities ({approx} 2000 Bq.kg{sup -1}). Both {sup 210}Pb and {sup 210}Po are of great interest because their contribution to the dose received by ingestion is potentially large. The aims of this work are to examine the accumulation of {sup 210}Pb and {sup 210}Po in chicken tissues during the first 42 days of life and to build a suitable single-compartment biokinetic model to understand the behavior of both radionuclides within the entire animal using the experimental results. Three commercial corn-soybean-based diets containing different amounts and sources of DCP were fed to broilers during a period of 42 days. The results show that diets containing enhanced concentrations of {sup 210}Pb and {sup 210}Po lead to larger specific accumulation in broiler tissues compared to the blank diet. Radionuclides do not accumulate homogeneously within the animal body: {sup 210}Pb follows the calcium pathways to some extent and accumulates largely in bones, while {sup 210}Po accumulates to a large extent in liver and kidneys. However, the total amount of radionuclide accumulation in tissues is small compared to the amounts excreted in feces. The single-compartment non-linear biokinetic model proposed here for {sup 210}Pb and {sup 210}Po in the whole animal takes into account the size evolution and is self-consistent in that no fitting parameterization of intake and excretions rates is required.

  16. Biokinetics and dosimetry in patients of 99mTc-EDDA/HYNIC-Tyr3-octreotide prepared from lyophilized kits

    International Nuclear Information System (INIS)

    Gonzalez-Vazquez, Armando; Ferro-Flores, Guillermina; Arteaga de Murphy, Consuelo; Gutierrez-Garcia, Zohar

    2006-01-01

    99m Tc-EDDA/HYNIC-Tyr 3 -octreotide ( 99m Tc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for 99m Tc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients were acquired at 5, 60, 90, 180 min and 24 h after 99m Tc-HYNIC-TOC administration obtained from instant freeze-dried kit formulations with radiochemical purities >95%. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all eight scans and the count per minute (cpm) of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-TOC time-activity curves in each organ, to adjust a biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed an average tumor/blood (heart) ratio of 4.3±0.7 in receptor-positive tumors at 1 h. The mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv

  17. Biokinetics of 13C in the human body after oral administration of 13C-labeled glucose as an index for the biokinetics of 14C.

    Science.gov (United States)

    Masuda, Tsuyoshi; Tako, Yasuhiro; Matsushita, Kensaku; Takeda, Hiroshi; Endo, Masahiro; Nakamura, Yuji; Hisamatsu, Shun'ichi

    2016-09-01

    The retention of 13 C in the human body after oral administration of 13 C-labeled glucose was studied in three healthy volunteer subjects to estimate the 50 year cumulative body burden for 13 C as an index of the committed dose of the radioisotope 14 C. After administration of 13 C-labeled glucose, the volunteers ingested controlled diets with a fixed number of calories for 112 d. Samples of breath and urine were collected up to 112 d after administration. Samples of feces were collected up to 14 d after administration. Hair samples were obtained at 119 d after administration and analyzed as a representative index of the rate of excretion of organic 13 C via pathways such as skin cell exfoliation and mucus secretion. All samples were analyzed for 13 C/ 12 C atomic ratio to determine the rate of excretion via each pathway. We then constructed a metabolic model with a total of four pathways (breath, urine, feces, and other) comprising seven compartments. We determined the values of the biokinetic parameters in the model by using the obtained excretion data. From 74% to 94% of the 13 C administered was excreted in breath, whereas    0.1). In addition, the dataset for one of the three subjects was markedly different from those of the other two. When we estimated the 50 year cumulative body burden for 13 C by using our model and we included non-statistically significant parameters, a considerable cumulative body burden was found in the compartments excreting to the other pathway. Although our results on the cumulative body burden of 13 C from orally administered carbon as glucose were inconclusive, we found that the compartments excreting to the other pathway had a markedly long residence time and therefore should be studied further to clarify the fate of carbon in the human body. In addition to excreta, data for serum and blood cell samples were also collected from the subjects to examine the metabolism of 13 C in human body.

  18. A profile of Biokinetics service provided by the University of Kwa ...

    African Journals Online (AJOL)

    Biokinetics can be viewed as an emerging member of the South African health professions in comparison to the longstanding professions of physiotherapy, chiropractics and occupational therapy which were established in 1924, 1939 and 1945, respectively. The aim of this investigation was to determine the profile of the ...

  19. Effect of wastewater treatment on bio-kinetics of dissolved oxygen in Ravi river

    International Nuclear Information System (INIS)

    Haider, H.; Ali, W.

    2010-01-01

    Waste management studies are usually done using calibrated and verified water quality models. Ravi River located in Lahore, Pakistan is receiving untreated wastewater from number of out falls and . Surfaced rains and thus model calibration and verification are done using the data under the prevailing conditions. The water quality objectives can only be met with wastewater treatment wherein the model rate coefficients may change. The objective of this paper is to study the changes that may occur in these coefficients as a result of wastewater treatment. For this purpose, long-term BOD analyses have been carried out using river water and wastewater after different degrees of treatment. A laboratory scale biological reactor was used to study the effect of biological treatment on rate coefficients at 3, 6 and 10 days detention times. The study results show that CBOD biokinetic rate coefficient (K) reduces significantly from 0.25 day/sup -1/ for raw waste water to 0.1 day for the wastewater treatment for 3 days detention time in the biological reactor. Further reductions in the value of K to 0.07 day/sup -1 and 0.05 day/sup -1/ occurred for a treatment level corresponding to 6 and 10 days detention times, respectively. The NBOD rate coefficient (K/sub n/ was found to be 0.08 day/sup -1/ for 3 days detention time and 0.06 day/sup -1/ after treatment in the biological reactor at 6 and 10 days detention times. (author)

  20. Biokinetic and dosimetric studies of 188Re-hyaluronic acid: a new radiopharmaceutical for treatment of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Melendez-Alafort, Laura; Nadali, Anna; Zangoni, Elena; Banzato, Alessandra; Rondina, Maria; Rosato, Antonio; Mazzi, Ulderico

    2009-01-01

    Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has very limited therapeutic options. Recently, it has been found that hyaluronic acid (HA) shows selective binding to CD44 receptors expressed in most cancer histotypes. Since the trend in cancer treatment is the use of targeted radionuclide therapy, the aim of this research was to label HA with rhenium-188 and to evaluate its potential use as a hepatocarcinoma therapeutic radiopharmaceutical. Methods: 188 Re-HA was prepared by a direct labelling method to produce a ReO(O-COO) 2 -type coordination complex. 188 Re-HA protein binding and its stability in saline, phosphate buffer, human serum and cysteine solutions were determined. Biokinetic and dosimetric data were estimated in healthy mice (n=60) using the Medical Internal Radiation Dose methodology and mouse model beta-absorbed fractions. To evaluate liver toxicity, alanine aminotranferase (AST) and aspartate aminotranferase (ALT) levels in mice were assessed and the liver maximum tolerated dose (MTD) of 188 Re-HA was determined. Results: A stable complex of 188 Re-HA was obtained with high radiochemical purity (>90%) and low serum protein binding (2%). Biokinetic studies showed a rapid blood clearance (T 1/2 α=21 min). Four hours after administration, 188 Re-HA was almost totally removed from the blood by the liver due to the selective uptake via HA-specific receptors (73.47±5.11% of the injected dose). The liver MTD in mice was ∼40 Gy after 7.4 MBq of 188 Re-HA injection. Conclusions: 188 Re-HA complex showed good stability, pharmacokinetic and dosimetric characteristics that confirm its potential as a new agent for HCC radiation therapy.

  1. Biokinetic and dosimetric studies of {sup 188}Re-hyaluronic acid: a new radiopharmaceutical for treatment of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Melendez-Alafort, Laura [Dipartimento di Scienze Farmaceutiche, Universita degli Studi di Padova, 35131 Padua (Italy); Nadali, Anna; Zangoni, Elena [Dipartimento di Scienze Farmaceutiche, Universita degli Studi di Padova, 35131 Padua (Italy); Banzato, Alessandra; Rondina, Maria [Dipartimento di Scienze Oncologiche e Chirurgiche, Universita degli Studi di Padova, Padua (Italy); Rosato, Antonio [Dipartimento di Scienze Oncologiche e Chirurgiche, Universita degli Studi di Padova, Padua (Italy); Istituto Oncologico Veneto, IOV, Padova, Padua (Italy); Mazzi, Ulderico [Dipartimento di Scienze Farmaceutiche, Universita degli Studi di Padova, 35131 Padua (Italy)

    2009-08-15

    Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has very limited therapeutic options. Recently, it has been found that hyaluronic acid (HA) shows selective binding to CD44 receptors expressed in most cancer histotypes. Since the trend in cancer treatment is the use of targeted radionuclide therapy, the aim of this research was to label HA with rhenium-188 and to evaluate its potential use as a hepatocarcinoma therapeutic radiopharmaceutical. Methods: {sup 188}Re-HA was prepared by a direct labelling method to produce a ReO(O-COO){sub 2}-type coordination complex. {sup 188}Re-HA protein binding and its stability in saline, phosphate buffer, human serum and cysteine solutions were determined. Biokinetic and dosimetric data were estimated in healthy mice (n=60) using the Medical Internal Radiation Dose methodology and mouse model beta-absorbed fractions. To evaluate liver toxicity, alanine aminotranferase (AST) and aspartate aminotranferase (ALT) levels in mice were assessed and the liver maximum tolerated dose (MTD) of {sup 188}Re-HA was determined. Results: A stable complex of {sup 188}Re-HA was obtained with high radiochemical purity (>90%) and low serum protein binding (2%). Biokinetic studies showed a rapid blood clearance (T{sub 1/2}{alpha}=21 min). Four hours after administration, {sup 188}Re-HA was almost totally removed from the blood by the liver due to the selective uptake via HA-specific receptors (73.47{+-}5.11% of the injected dose). The liver MTD in mice was {approx}40 Gy after 7.4 MBq of {sup 188}Re-HA injection. Conclusions: {sup 188}Re-HA complex showed good stability, pharmacokinetic and dosimetric characteristics that confirm its potential as a new agent for HCC radiation therapy.

  2. Radionuclide decorporation: matching the biokinetics of actinides by transdermal delivery of pro-chelators.

    Science.gov (United States)

    Zhang, Yong; Sadgrove, Matthew P; Mumper, Russell J; Jay, Michael

    2013-10-01

    The threat of nuclear terrorism by the deliberate detonation of a nuclear weapon or radiological dispersion device ("dirty bomb") has made emergency response planning a priority. The only FDA-approved treatments for contamination with isotopes of the transuranic elements Am, Pu, and Cm are the Ca and Zn salts of diethylenetriaminepentaacetic acid (DTPA). These injectable products are not well suited for use in a mass contamination scenario as they require skilled professionals for their administration and are rapidly cleared from the circulation. To overcome the mismatch in the pharmacokinetics of the DTPA and the biokinetics of these transuranic elements, which are slowly released from contamination sites, the penta-ethyl ester of DTPA (C2E5) was prepared and formulated in a nonaqueous gel for transdermal administration. When gels comprised of 40% C2E5, 40-45% Miglyol® 840, and 15-20% ethyl cellulose were spiked with [(14)C]-C2E5 and applied to rat skin; over 60% of the applied dose was absorbed within a 24-h period. Radioactivity was observed in urinary and fecal excretions for over 3 days after removal of the gel. Using an (241)Am wound contamination model, transdermal C2E5 gels were able to enhance total body elimination and reduce the liver and skeletal burden of (241)Am in a dose-dependent manner. The efficacy achieved by a single 1,000 mg/kg dose to contaminated rats was statistically comparable to intravenous Ca-DTPA at 14 mg/kg. The effectiveness of this treatment, favorable sustained release profile of pro-chelators, and ease of administration support its use following radiological emergencies and for its inclusion in the Strategic National Stockpile.

  3. 99mTc-exendin(9-39)/octreotide: biokinetics and radiation dosimetry in healthy individuals.

    Science.gov (United States)

    Ocampo-García, Blanca E; Santos-Cuevas, Clara L; Luna-Gutiérrez, Myrna A; Ignacio-Alvarez, Eleazar; Pedraza-López, Martha; Manzano-Mayoral, Cesar

    2017-11-01

    About 90% of insulinomas are benign and 5-15% are malignant. Benign insulinomas express the glucagon-like peptide-1 receptor (GLP-1R, which recognizes exendin-4 and low levels of the somatostatin receptor (SSTR, which recognizes octreotide), whereas malignant insulinomas overexpress SSTR and low levels of GLP-1R. Recently, Lys(Tc-EDDA/HYNIC)-exendin(9-39)/Tc-EDDA/HYNIC-Tyr-octreotide was formulated to detect 100% of insulinomas. The aim of this study was to estimate the biokinetics and dosimetry of Tc-exendin(9-39)/octreotide in four healthy individuals. Tc-exendin(9-39)/octreotide was obtained from a lyophilized formulation with radiochemical purities of more than 97%, determined by reversed-phase high-performance liquid chromatography. Whole-body images from four healthy individuals were acquired at 20 min, 2, 6, and 24 h after Tc-exendin(9-39)/octreotide administration. Regions of interest were drawn around the source organs on each time frame. Each region of interest was corrected by background, attenuation, scattered radiation, and physical decay. The image sequence was used to extrapolate the Tc-exendin(9-39)/octreotide time-activity curves of each organ to adjust the biokinetic model and calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation doses. Furthermore, in a patient suspicious of harboring an insulinoma, whole-body single-photon emission computed tomography/computed tomography images were obtained at 3 h. For four healthy individuals, the blood activity showed a half-life value of 1.20 min for the fast component (T1/2 α=ln 2/34.71), 8.7 min for the first slow component (T1/2 β=ln 2/4.76), and 1.7 h for the second slow component (T1/2 γ=ln 2/0.401). The average equivalent doses calculated for a study using 555 MBq were 15.10, 4.13, 3.08, 2.61, and 1.90 mSv for the kidneys, upper large intestinal wall, lower large

  4. Mechanism of cisplatin proximal tubule toxicity revealed by integrating transcriptomics, proteomics, metabolomics and biokinetics.

    Science.gov (United States)

    Wilmes, Anja; Bielow, Chris; Ranninger, Christina; Bellwon, Patricia; Aschauer, Lydia; Limonciel, Alice; Chassaigne, Hubert; Kristl, Theresa; Aiche, Stephan; Huber, Christian G; Guillou, Claude; Hewitt, Philipp; Leonard, Martin O; Dekant, Wolfgang; Bois, Frederic; Jennings, Paul

    2015-12-25

    Cisplatin is one of the most widely used chemotherapeutic agents for the treatment of solid tumours. The major dose-limiting factor is nephrotoxicity, in particular in the proximal tubule. Here, we use an integrated omics approach, including transcriptomics, proteomics and metabolomics coupled to biokinetics to identify cell stress response pathways induced by cisplatin. The human renal proximal tubular cell line RPTEC/TERT1 was treated with sub-cytotoxic concentrations of cisplatin (0.5 and 2 μM) in a daily repeat dose treating regime for up to 14 days. Biokinetic analysis showed that cisplatin was taken up from the basolateral compartment, transported to the apical compartment, and accumulated in cells over time. This is in line with basolateral uptake of cisplatin via organic cation transporter 2 and bioactivation via gamma-glutamyl transpeptidase located on the apical side of proximal tubular cells. Cisplatin affected several pathways including, p53 signalling, Nrf2 mediated oxidative stress response, mitochondrial processes, mTOR and AMPK signalling. In addition, we identified novel pathways changed by cisplatin, including eIF2 signalling, actin nucleation via the ARP/WASP complex and regulation of cell polarization. In conclusion, using an integrated omic approach together with biokinetics we have identified both novel and established mechanisms of cisplatin toxicity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Performance analysis of numeric solutions applied to biokinetics of radionuclides; Analise de desempenho de solucoes numericas aplicadas a biocinetica de radionuclideos

    Energy Technology Data Exchange (ETDEWEB)

    Mingatos, Danielle dos Santos; Bevilacqua, Joyce da Silva, E-mail: dani@ime.usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (IME/USP), SP (Brazil). Instituto de Matematica e Estatistica; Todo, Alberto Saburo; Rodrigues Junior, Orlando, E-mail: astodo@ipen.br, E-mail: rodrijr@ipen.br [Instituto de Pesquisas Energeticas Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Biokinetics models for radionuclides applied to dosimetry problems are constantly reviewed by ICRP. The radionuclide trajectory could be represented by compartmental models, assuming constant transfer rates between compartments. A better understanding of physiological or biochemical phenomena, improve the comprehension of radionuclide behavior in the human body and, in general, more complex compartmental models are proposed, increasing the difficulty of obtaining the analytical solution for the system of first order differential equations. Even with constant transfer rates numerical solutions must be carefully implemented because of almost singular characteristic of the matrix of coefficients. In this work we compare numerical methods with different strategies for ICRP-78 models for Thorium-228 and Uranium-234. The impact of uncertainty in the parameters of the equations is also estimated for local and global truncation errors. (author)

  6. Physiologically based pharmacokinetics model for estimating urinary excretion of short half-life nuclides in nuclear medicine

    International Nuclear Information System (INIS)

    Akahane, K.; Kai, M.; Konishi, E.; Kusama, T.; Aoki, Y.

    1995-01-01

    The biokinetic model in ICRP 53 is used for calculating absorbed dose to each organ of a patient in nuclear medicine. The ICRP model is a simple compartment model based on human data; however, the model cannot produce the biokinetics of radiopharmaceuticals under various physiological conditions. On the other hand, a physiologically based pharmacokinetics model (PBPK model) can describe the flow of radiopharmaceuticals as a compartment model for any physiological conditions theoretically. The PBPK model was applied especially for the kidney-bladder dynamics, and similar results obtained compared with the ICRP model. This suggests the possibility of the PBPK model for predicting the biokinetics of radiopharmaceuticals under various physiological conditions. (Author)

  7. Biokinetics and dosimetry in patients of {sup 99m}Tc-EDDA/HYNIC-Tyr{sup 3}-octreotide prepared from lyophilized kits

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Vazquez, Armando [Departamento de Medicina Nuclear, Hospital Militar (Mexico); Facultad de Medicina, Universidad Autonoma del Estado de Mexico (Mexico); Ferro-Flores, Guillermina [Departamento de Materiales Radiactivos, Gerencia de Aplicaciones Nucleares en la Salud, Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carretera Mexico-Toluca, Ocoyoacac, Estado de Mexico, C.P. 52045 (Mexico)]. E-mail: gff@nuclear.inin.mx; Arteaga de Murphy, Consuelo [Departamento de Medicina Nuclear, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran (Mexico); Gutierrez-Garcia, Zohar [Departamento de Medicina Nuclear, Hospital Militar (Mexico)

    2006-07-15

    {sup 99m}Tc-EDDA/HYNIC-Tyr{sup 3}-octreotide ({sup 99m}Tc-HYNIC-TOC) has shown high in vitro and in vivo stability, rapid background clearance and rapid detection of somatostatin receptor-positive tumors. The aim of this study was to establish a biokinetic model for {sup 99m}Tc-HYNIC-TOC prepared from lyophilized kits, and to evaluate its dosimetry as a tumor imaging agent in patients with histologically confirmed neuroendocrine tumors. Whole-body images from eight patients were acquired at 5, 60, 90, 180 min and 24 h after {sup 99m}Tc-HYNIC-TOC administration obtained from instant freeze-dried kit formulations with radiochemical purities >95%. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all eight scans and the count per minute (cpm) of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-HYNIC-TOC time-activity curves in each organ, to adjust a biokinetic model using the SAAM software, and to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed an average tumor/blood (heart) ratio of 4.3{+-}0.7 in receptor-positive tumors at 1 h. The mean radiation absorbed dose calculated for a study using 740 MBq was 24, 21.5, 5.5 and 1.0 mSv for spleen, kidneys, liver and bone marrow respectively and the effective dose was 4.4 mSv.

  8. Biokinetic study of plutonium and americium associated to the particulates of soil

    International Nuclear Information System (INIS)

    Espinosa, A.; Aragon, A.; Martinez, J.; Iranzo, C.E.

    1996-01-01

    The object of this study is to determine the biokinetic parameters of different Plutonium isotopes and Americium inhaled in the state in which they are found in the environment as a result of their deposition in the soil, from an aviation accident that generated different plutonium oxides. to achieve this objective, two lines of work planned. One was the determination of the mineralogical composition and associations that plutonium and americium present in that soil 22 years after the nuclear accident. Other studies were directed to determine the biokinetic of the plutonium isotopes and americium (contained in the dust) deposited tracheally and inhaled by laboratory animals (rats) and in vitro experiments by pulmonary leaching simulation. The in vivo tests have been developed in NRPB (U.K.) and the in vitro experiment, geochemical associations studies, assessment of internal doses to humans resulting from intake of plutonium and americium bearing dusts present in the contaminated area and establishment of ALIs for inhalation, were carried out in CIEMAT (Spain). In this work only determinations and experiments carried out by CIEMAT are includes as a part of the EU Project ''INHALATION AND INGESTION OF RADIONUCLIDES'' contract: FI3P-CT920064a. (Author) 10 refs

  9. Acquisition of biokinetic data for internal dose calculations for some novel radiopharmaceuticals

    International Nuclear Information System (INIS)

    Smith, T.; Zanelli, G.D.; Crawley, C.W.

    1986-01-01

    Estimation of radiation dose commitment, expresses as an effective dose equivalent, is a prior requisite to the application for a license to administer radiopharmaceuticals and, therefore, in the case of novel radiopharmaceuticals is leading to an increasing awareness of the need for dosimetry-orientated studies. In this laboratory potential new radiopharmaceuticals are investigated initially by animal studies to assess the possible distribution in man, and subsequently in controlled volunteer studies designed to obtain the maximum possible amount of biokinetic data to allow accurate estimation of radiation dose. A variety of techniques are used for this purpose, including profile counting, partial and whole-body scanning by LFOV gamma camera and whole-body counting, in addition to the analysis of radioactivity in blood and excreta. The use of these techniques is illustrated for the acquisition of biokinetic data and subsequent dosimetry of three novel radiopharmaceuticals: 77 Br-p-bromospiperone (quantification of dopamine receptors in the brain). 99 Tc/sup m/-porphyrins and 99 Tc/sup m/ DEPE (a possible novel blood pool marker for MUGA studies). 14 references, 14 figures, 2 tables

  10. Comparison between two clones of Daphnia magna: effects of multigenerational cadmium exposure on toxicity, individual fitness, and biokinetics.

    Science.gov (United States)

    Guan, Rui; Wang, Wen-Xiong

    2006-03-10

    We investigated the effects of genotype (two different clones) and multigenerational Cd-exposure history on Cd toxicity, individual fitness, and biokinetics in populations of a freshwater cladoceran Daphnia magna. The adults of the tolerant (T) clone had longer mean-survival-time than the sensitive (S) clone in both control groups (without Cd-exposure) and continuous Cd-exposure groups, but the two clones showed comparable resistances to acute Cd stress in the recovery groups. The body concentration of metallothionein (MT) played a critical role in handling Cd stress, which mainly accounted for the significant difference between the two clones in terms of survival distribution. High comparability of these two clones in individual fitness parameters and biokinetics suggested that these parameters are unlikely driven by genetic variation. For each specific clone, continuous Cd-exposure inhibited the animal growth, elevated the MT induction, and increased the Cd uptake rate (ingestion rate, assimilation efficiency from dietary phase, and uptake rate from dissolved phase), all of which enhanced the weight-specific Cd accumulation in daphnids' bodies. The strong dependence of biokinetic parameters on environmental factors (e.g., food concentrations, pH, dissolved or dietary metal concentration, and metal exposure histories) rather than on genotypes implied the great potential of using biokinetics in inter-lab comparisons and environmental risk assessments.

  11. Comparison between two clones of Daphnia magna: Effects of multigenerational cadmium exposure on toxicity, individual fitness, and biokinetics

    International Nuclear Information System (INIS)

    Guan Rui; Wang Wenxiong

    2006-01-01

    We investigated the effects of genotype (two different clones) and multigenerational Cd-exposure history on Cd toxicity, individual fitness, and biokinetics in populations of a freshwater cladoceran Daphnia magna. The adults of the tolerant (T) clone had longer mean-survival-time than the sensitive (S) clone in both control groups (without Cd-exposure) and continuous Cd-exposure groups, but the two clones showed comparable resistances to acute Cd stress in the recovery groups. The body concentration of metallothionein (MT) played a critical role in handling Cd stress, which mainly accounted for the significant difference between the two clones in terms of survival distribution. High comparability of these two clones in individual fitness parameters and biokinetics suggested that these parameters are unlikely driven by genetic variation. For each specific clone, continuous Cd-exposure inhibited the animal growth, elevated the MT induction, and increased the Cd uptake rate (ingestion rate, assimilation efficiency from dietary phase, and uptake rate from dissolved phase), all of which enhanced the weight-specific Cd accumulation in daphnids' bodies. The strong dependence of biokinetic parameters on environmental factors (e.g., food concentrations, pH, dissolved or dietary metal concentration, and metal exposure histories) rather than on genotypes implied the great potential of using biokinetics in inter-lab comparisons and environmental risk assessments

  12. The in vitro biokinetics of chlorpromazine and diazepam in aggregating rat brain cell cultures after repeated exposure

    NARCIS (Netherlands)

    Broeders, Jessica J W; Hermens, Joop L M; Blaauboer, Bas J; Zurich, Marie-Gabrielle

    2015-01-01

    Neurotoxic effects of compounds can be tested in vitro using cell systems. One example is aggregating rat brain cell cultures. For the extrapolation of in vitro data to the in vivo situation, it is important to take the biokinetics of the test compound into account. In addition, the exposure in vivo

  13. A novel bench-scale column assay to investigate site-specific nitrification biokinetics in biological rapid sand filters

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2013-01-01

    A bench-scale assay was developed to obtain site-specific nitrification biokinetic information from biological rapid sand filters employed in groundwater treatment. The experimental set-up uses granular material subsampled from a full-scale filter, packed in a column, and operated with controlled...

  14. Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2016-01-01

    The biokinetic behavior of NH4 + removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4 + loadings in a continuous...

  15. Biokinetics of {sup 131}I in human organism

    Energy Technology Data Exchange (ETDEWEB)

    Hermanska, J; Nemec, J [Faculty Hospital Motol, Prague (Czech Republic). Clinic of Nuclear Madecine; Karny, M; Guy, T V [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Ist. of Information Theory and Automation; Jirsa, L; Blazek, T [Charles Univ., Prague (Czech Republic). 2nd Medical Faculty

    1996-12-31

    Time evolution of the cumulated activity in human body is one of the key characteristics determining medical impacts of ionizing radiation. In nuclear medicine, so called effective half-life is mostly used for the evolution description. This quantity is usually estimated by fitting a straight line in semi-logarithmic coordinates. Its novel Bayesian estimate was also proposed and its advantageous properties were verified. During extensive tests, it was found that the effective half-live has limited use as the underlying deterministic relationship time - activity can hardly be taken as (mono)exponential. It stimulated the research for a better and still simple model. A quadratic dependence of ln(activity) on ln(time) was found as an adequate candidate. Preliminary experiments on a restricted set of real data were promising enough to justify its further elaboration. (authors) 1 tab., 19 refs.

  16. Investigations on the biokinetics of carbon 14 in algae cultures

    International Nuclear Information System (INIS)

    Leister, W.

    1981-01-01

    The uptake of 14 C by Scenedesmus quadricauda is quantitatively investigated by simulation models of radio ecological relevance. Due to the complexing of the procedures in the natural ecosystem, it was only possible to consider idealized conditions. The batch culture ressembles the conditons of still waters or relatively still waters without notable water exchange. The effect of the 14 C enrichment, as well as the drastic carbon reduction in the substrate as a result of algae growth, was avoided in the modified batch culture under conditions of simultaneous substrate diffusion by means of a permeation system. The 14 C and 12 C uptake of the cells thus took place solely under the conditions of constant concentration in the culture medium. The consequences for flowing water resulting from a nuclear power plant accident are to be simulated for the extent of the 14 C uptake by green algae using the continuous culture model with dynamic 14 C exposure. The continuous infusion of 14 C in the continuous culture corresponds to the possible cases where 14 C escapes into a flowing water at a constant rate over a long period of time, whether this may be via chronical release from a nuclear power plant or by 'fallout' resulting from nuclear arms testing. The results shown lead to the conclusion that the emission of 14 C to the environment, which according to prognoses will be considerably higher after the year 2000, presents a serious radioactivity potential which man and environment will have to live with should these developments continue and the prognoses come true. (orig./MG) [de

  17. Biokinetic aspects of tissue-bound tritium in algae

    International Nuclear Information System (INIS)

    Strack, S.; Kistner, G.

    1978-01-01

    For the estimate of the radiation exposure of man and for the calculation of the risk of artificial tritium from nuclear power plants, organic tissue-bound tritium is of decisive importance. In model experiments, a tritium incorporation of 61 to 71% was found from tritiated water (HTO) into organic matter of planctonic algae under reproducible conditions and this was related to the theoretical value. In further experiments the tritium release from these high tritiated algae was of interest. Kept in darkness in tritium-free, non-sterile river water, so that autolytic processes and bacterial decomposition could occur, the concentration of HTO was measured over a period of three weeks. A relatively long half-life of tissue-bound tritium was found under various temperature conditions. Therefore it must be considered that a significant retention of tritium in biological matter has to be taken into account in a natural ecosystem. In streams into which the cooling water of a nuclear reactor is released all conditions are found already for a long turnover and cycling of artificial tritium in living organisms as well as the conditions for a favourable transport of tritium by food chains to man. (Auth.)

  18. Nanomaterial translocation - the biokinetics, tissue accumulation, toxicity and fate of materials in secondary organs

    DEFF Research Database (Denmark)

    Kermanizadeh, Ali; Balharry, Dominique; Wallin, Håkan

    2015-01-01

    into the toxicity posed by the NMs in these secondary organs is expanding due to the realisation that some materials may reach and accumulate in these target sites. The translocation to secondary organs includes, but is not limited to, the hepatic, central nervous, cardiovascular and renal systems. Current data...... dioxide and quantum dots) or fast (e.g. zinc oxide) solubility. The translocation of NMs following intratracheal, intranasal and pharyngeal aspiration is higher (up to 10% of administered dose), however the relevance of these routes for risk assessment is questionable. Uptake of the materials from....... For toxicological and risk evaluation, further information on the toxicokinetics and persistence of NMs is crucial. The overall aim of this review is to outline the data currently available in the literature on the biokinetics, accumulation, toxicity and eventual fate of NMs in order to assess the potential risks...

  19. Biokinetics of carbohydrate and lipid matabolism in normal laying hen; pt. 3

    International Nuclear Information System (INIS)

    Chiang, Y.H.; Riis, P.M.

    1979-01-01

    The radiochemical purity of sup(14)C(U)-glucose solution to be injected to normal laying hen was investigated for studying biokinetics of carbohydrate and lipid metabolism. The liquid scintillation counter was employed for determining the activity of carbon-14. The barium hydroxide and zinc sulfate were adopted to precipitate the protein in the solution. The glucose content in the solution was observed as 0.912 mg per ml. applying Hultman's method. The specific activity of sup(14)C(U)-glucose solution was known as 31.3 nCi/mg glucose. The glucose pentaacetate was synthesized to isolate the pure glucose from the solution. The specific activity of pure glucose was measured as 28.5 nCi/mg glucose. Therefore, it was known that the radiochemical purity of the solution was 82.7%. (Author)

  20. Selenium-75 and technetium-95m biokinetics in rats at different physiological states

    International Nuclear Information System (INIS)

    Archimbaud, Yves; Grillon, Gerard; Poncy, Jean-Luc; Masse, Roland

    1992-06-01

    Selenium 79 ( 79 Se) and technetium ( 99 Tc), beta emitters, components of nuclear wastes, may increase the dose equivalent to members of the public. Data used by ICRP show that there is relatively little information on Te and Se biokinetics at different physiologic stages. Retention was almost equivalent for young, male adult and pregnant rat. Selenium was concentrated in the testis, the kidneys, the liver and the spleen as technetium was in the skin, the thyroid and the kidneys. The biological half-time for Se and Te was respectively 20 and 41 days for pregnant rats, 33 and 15 days for young rats. Placental transfer per one fetus was 0.56% of the initial activity for Te and 1.27% for Se. These data point out the eventually high doses delivered to the skin for Te and to the testis for Se. They may be taken into consideration in estimating risk by humans at different stages of life [fr

  1. A review of contributions of human tissue studies to biokinetics, bio-effects and dosimetry of plutonium in man

    International Nuclear Information System (INIS)

    Kathren, R. L.

    2004-01-01

    This paper briefly reviews the contributions made by human tissue studies to improved understanding of the biokinetics, dosimetry and potential bio-effects of plutonium in man. It includes consideration of tissue donations from both environmental and occupational populations, along with a brief history of human experience with plutonium and consideration of the bio-ethical aspects of post-mortem human tissue sampling. (authors)

  2. Bioavailability and Biokinetics of Anthocyanins From Red Grape Juice and Red Wine

    Directory of Open Access Journals (Sweden)

    Roland Bitsch

    2004-01-01

    Full Text Available In a comparative study, 9 healthy volunteers ingested a single oral dose of 400 mL red grape juice or red wine with dose-adjusted anthocyanin content (283.5 mg or 279.6 mg, resp. in crossover. The content of anthocyanin glucosides was detected in plasma and urinary excretion. Additionally, the plasmatic antioxidant activity was assessed after intake. Based on the plasma content, biokinetic criteria of the single anthocyanins were calculated, such as AUC, cmax, tmax, and the elimination rate t1/2. The urinary excretion of total anthocyanins differed significantly and amounted to 0.18% (red wine and 0.23% (red grape juice of the administered dose. Additionally, the plasmatic antioxidant activity increased to higher levels after juice ingestion compared to wine. The intestinal absorption of the anthocyanins of red grape juice seemed to be improved compared to red wine, suggesting a possible synergistic effect of the glucose content of the juice. The improved absorption resulted in an enhanced plasmatic bioactivity.

  3. Uniquely high turnover of nickel in contaminated oysters Crassostrea hongkongensis: Biokinetics and subcellular distribution.

    Science.gov (United States)

    Yin, Qijun; Wang, Wen-Xiong

    2018-01-01

    Despite the environmental concerns regarding nickel (Ni) especially in China, it has received little attention in aquatic animals due to its comparatively weak toxicity. In the present study, we explored the bioaccumulation, biokinetics, and subcellular distribution of Ni in an estuarine oyster Crassostrea hongkongensis. We demonstrated that Ni represented a new pattern of bioaccumulation in oysters characterized by rapid elimination and low dissolved uptake. The waterborne uptake rate constant and dietary assimilation efficiency were 0.036L/g/h and 28%, respectively, and dissolved uptake was the predominant exposure route. The efflux rate constant was positively related to tissue Ni concentration, with the highest efflux of 0.155d -1 . Such high elimination resulted in a high Ni turnover and steady-state condition reached rapidly, as shown with a 4-week waterborne exposure experiment at different Ni concentrations. Ni in oysters was mainly sequestered in metallothionein-like protein (MTLP), metal-rich granule, and cellular debris. MTLP was the most important binding fraction during accumulation and depuration, and played a dynamic role leading to rapid Ni elimination. Pre-exposure to Ni significantly reduced the dissolved uptake, probably accompanied by depressed filtration activity. Overall, the high turnover and regulation of Ni in oysters were achieved by enhanced efflux, suppressed uptake, and sequestration of most Ni into the detoxified pool. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Decoupling of cadmium biokinetics and metallothionein turnover in a marine polychaete after metal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Tania Y.-T. [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Rainbow, Philip S. [Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Amiard-Triquet, Claude; Amiard, Jean-Claude [Universite de Nantes, Faculte de Pharmacie, MMS EA2160, Service d' ecotoxicologie, F-44000 Nantes (France); Wang Wenxiong [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China)], E-mail: wwang@ust.hk

    2008-08-11

    This study investigated the kinetics of Cd bioaccumulation, detoxification, subcellular distribution, and efflux in the nereid polychaete Perinereis aibuhitensis after Cd pre-exposure. Cd pre-exposure increased the Cd body burden in the worms, but did not affect the overall Cd uptake and efflux rates and metallothionein-like protein (MTLP) concentrations. During short-term exposure to dissolved Cd, Cd in the cytosolic fraction increased after Cd pre-exposure, and this fraction also increased during the Cd efflux period, indicating that the insoluble fraction of Cd was presumably lost at a faster rate than the loss of cytosolic Cd. Even though the MTLP concentration remained comparable after Cd pre-exposure, both the MTLP synthesis rate and the degradation rate increased, thus leading to a high MTLP turnover in the Cd-exposed worms. However, Cd uptake and efflux into different protein size fractions did not follow the patterns of MTLP synthesis and degradation, strongly suggesting that Cd kinetics is decoupled from the MTLP kinetics in the worms. Our study adds to an increasing body of evidence on the complicated relationship between metal biokinetics and MTLP kinetics in different groups of marine invertebrates which have strong contrasts in their metal handling strategies.

  5. Decoupling of cadmium biokinetics and metallothionein turnover in a marine polychaete after metal exposure

    International Nuclear Information System (INIS)

    Ng, Tania Y.-T.; Rainbow, Philip S.; Amiard-Triquet, Claude; Amiard, Jean-Claude; Wang Wenxiong

    2008-01-01

    This study investigated the kinetics of Cd bioaccumulation, detoxification, subcellular distribution, and efflux in the nereid polychaete Perinereis aibuhitensis after Cd pre-exposure. Cd pre-exposure increased the Cd body burden in the worms, but did not affect the overall Cd uptake and efflux rates and metallothionein-like protein (MTLP) concentrations. During short-term exposure to dissolved Cd, Cd in the cytosolic fraction increased after Cd pre-exposure, and this fraction also increased during the Cd efflux period, indicating that the insoluble fraction of Cd was presumably lost at a faster rate than the loss of cytosolic Cd. Even though the MTLP concentration remained comparable after Cd pre-exposure, both the MTLP synthesis rate and the degradation rate increased, thus leading to a high MTLP turnover in the Cd-exposed worms. However, Cd uptake and efflux into different protein size fractions did not follow the patterns of MTLP synthesis and degradation, strongly suggesting that Cd kinetics is decoupled from the MTLP kinetics in the worms. Our study adds to an increasing body of evidence on the complicated relationship between metal biokinetics and MTLP kinetics in different groups of marine invertebrates which have strong contrasts in their metal handling strategies

  6. 99mTc-labeled PSMA inhibitor: Biokinetics and radiation dosimetry in healthy subjects and imaging of prostate cancer tumors in patients.

    Science.gov (United States)

    Santos-Cuevas, Clara; Davanzo, Jenny; Ferro-Flores, Guillermina; García-Pérez, Francisco O; Ocampo-García, Blanca; Ignacio-Alvarez, Eleazar; Gómez-Argumosa, Edgar; Pedraza-López, Martha

    2017-09-01

    The prostate-specific membrane antigen (PSMA) is expressed in epithelial cells of the prostate and highly overexpressed in 95% of advanced prostate cancers. The aims of this study was to estimate the biokinetics and dosimetry of 99m Tc-EDDA/HYNIC-iPSMA ( 99m Tc-labeled PSMA inhibitor) in eight healthy subjects and evaluate its usefulness as a tumor-imaging agent in eight prostate cancer patients. 99m Tc-EDDA/HYNIC-iPSMA was obtained from a lyophilized formulation with radiochemical purities >98%, determined by reversed-phase HPLC and ITLC-SG analyses. Whole-body images from eight healthy subjects were acquired at 20min, and at 2, 6 and 24h after 99m Tc-EDDA/HYNIC-iPSMA administration. Regions of interest (ROIs) were drawn around the source organs on each time frame. Each ROI was corrected by background, attenuation, scattered radiation and physical decay. The image sequence was used to extrapolate the 99m Tc-EDDA/HYNIC-iPSMA time-activity curves of each organ to adjust the biokinetic model and calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation doses. In eight prostate cancer patients with histologically confirmed cancer, whole-body SPECT/CT images were obtained at 3h. The blood activity showed a half-life value of 4.98min for the fast component (T 1/2 α=ln2/8.34), 2.49h for the first slow component (T 1/2 β=ln2/0.278), and 9.24h for the second slow component (T 1/2 γ=ln2/0.076). Images from patients showed an average tumor/background ratio of 8.99±3.27 at 3h. The average equivalent doses calculated for a study using 740MBq were 3.80, 7.06, 9.69, 10.70, and 28.80mSv for the breast, spleen, salivary glands, liver, and kidneys respectively, with an effective dose of 3.42±0.78mSv. All the absorbed doses were comparable to those known for most of the 99m Tc studies. 99m Tc-EDDA/HYNIC-iPSMA obtained from kit formulations showed high tumor uptake in

  7. Energy use and carbon footprints differ dramatically for diverse wastewater-derived carbonaceous substrates: An integrated exploration of biokinetics and life-cycle assessment.

    Science.gov (United States)

    Li, Yanbo; Wang, Xu; Butler, David; Liu, Junxin; Qu, Jiuhui

    2017-03-21

    Energy neutrality and reduction of carbon emissions are significant challenges to the enhanced sustainability of wastewater treatment plants (WWTPs). Harvesting energy from wastewater carbonaceous substrates can offset energy demands and enable net power generation; yet, there is limited research about how carbonaceous substrates influence energy and carbon implications of WWTPs with integrated energy recovery at systems-level. Consequently, this research uses biokinetics modelling and life cycle assessment philology to explore this notion, by tracing and assessing the quantitative flows of energy embodied or captured, and by exploring the carbon footprint throughout an energy-intensive activated sludge process with integrated energy recovery facilities. The results indicate that energy use and carbon footprint per cubic meter of wastewater treated, varies markedly with the carbon substrate. Compared with systems driven with proteins, carbohydrates or other short-chain fatty acids, systems fed with acetic acid realized energy neutrality with maximal net gain of power from methane combustion (0.198 kWh) and incineration of residual biosolids (0.153 kWh); and also achieved a negative carbon footprint (72.6 g CO 2 ). The findings from this work help us to better understand and develop new technical schemes for improving the energy efficiency of WWTPs by repurposing the stream of carbon substrates across systems.

  8. Maza and Ojo (16)

    African Journals Online (AJOL)

    DELL

    intake was high, the brain was quite susceptible to mercury intoxication, even at low doses. Keyword: Human PBBK Models, Binary Mixtures, Mercury/Selenium, Lead/Selenium. ABSTRACT .... the published work of these authors, however,.

  9. From Technique of Tattooing to Biokinetics and Toxicology of Injected Tattoo Ink Particles and Chemicals.

    Science.gov (United States)

    Serup, Jørgen

    2017-01-01

    Tattoo colourants are colourful nano- and microparticles, which are practically insoluble and thus permanent once installed in the dermis by the tattooist. Tattoo ink also has soluble ingredients and contaminants. Pigments can distribute via the lymph and possibly also directly to the blood, and a minute fraction may over time undergo metabolic breakdown and as hapten(s) induce allergic reactions of red tattoos. Carbon black of black tattoos has a tendency to agglomerate and form larger bodies that can elicit foreign body reactions in black tattoos and even granuloma formation with overlap to sarcoidosis in the clinic. Very little is known about the biokinetics and safety profile of the many tattoo pigments in use, and no specific pigment-related chemical of tattoo ink causing identified adverse reactions in humans has been depicted. Inks have many ingredients and contaminants. Insoluble and soluble ingredients of inks supposedly have very different characteristics of absorption, distribution, metabolism, and excretion, with pigments being extremely slowly excreted, contrasting soluble ingredients with fast elimination. Tattoos are a single-dose exposure. Controlling the safety of tattoo inks by banning potentially critical chemicals hitherto has been unsuccessful due to lacking documentation of clinical and epidemiological relevance and because the tattoo industry is already internationally established, free, and in the ownership of the people. Doctors treating patients with tattoo complications consequently have a key role in identifying risk situations and local outbreaks, which needs clarification, therapy, and the intervention of authorities. In the treatment of complications, as seen in general practice and in other specialties, basic insight into the fate of tattoo pigments in the body is necessary. Tattoo complications are complicated and facetted with many entities and disease mechanisms; they are a new subspecialty in medicine and dermatology. © 2017 S

  10. Parametric study of a thorium model

    International Nuclear Information System (INIS)

    Lourenco, M.C.; Lipsztein, J.L.; Szwarcwald, C.L.

    2002-01-01

    Models for radionuclides distribution in the human body and dosimetry involve assumptions on the biokinetic behavior of the material among compartments representing organs and tissues in the body. One of the most important problem in biokinetic modeling is the assignment of transfer coefficients and biological half-lives to body compartments. In Brazil there are many areas of high natural radioactivity, where the population is chronically exposed to radionuclides of the thorium series. The uncertainties of the thorium biokinetic model are a major cause of uncertainty in the estimates of the committed dose equivalent of the population living in high background areas. The purpose of this study is to discuss the variability in the thorium activities accumulated in the body compartments in relation to the variations in the transfer coefficients and compartments biological half-lives of a thorium-recycling model for continuous exposure. Multiple regression analysis methods were applied to analyze the results. (author)

  11. Compared biokinetic and biological studies of chronic and acute inhalations of uranium compounds in the rat; Etudes biocinetique et biologique comparees d'inhalations chroniques et aigues de composes uraniferes chez le rat

    Energy Technology Data Exchange (ETDEWEB)

    Monleau, M

    2005-12-15

    Uranium is a natural, radioactive heavy metal, widely used in the nuclear industry in various chemical and isotopic forms. Its use in the fuel cycle involves the risk of radiological exposure for the workers, mainly via the inhalation of uranium particles. According to the workplace configuration, uranium contaminations can be acute or repeated, involve various chemical forms and different levels of enrichment, as well as involving one or several components. The dosimetric concepts and models available for workers' radiological protection, as well as most of the studies of the biological effects, correspond to acute exposure situations. Moreover the processes leading to pathological effects are little known in vivo. In this context, the main question is to know whether exposures due to repeated inhalation by rats induce the element kinetics and toxicity, which may be different from those observed after an acute exposure. In this study, comparison of the experimental and theoretical biokinetics of an insoluble uranium repeatedly inhaled over three weeks shows that a chronic contamination is correctly modelled, except for bone retention, by the sum of acute, successive and independent incorporations. Moreover, the kinetics of a soluble uranium inhaled irregularly can be modified by previous repeated exposure to an insoluble uranium. In certain cases therefore, exposure to uranium could modify its biokinetics during later exposures. At a toxicological level, the study demonstrates that the uranium particles inhaled repeatedly induce behavioural disruptions and genotoxic effects resulting in various sorts of DNA damage, in several cell types and certainly depending on the quantity inhaled. Exposures involving several uraniferous components produce a synergy effect. Moreover, repeated inhalations worsen the genotoxic effects in comparison to an acute exposure. This work demonstrates the importance of not ignoring the effects of the repetition of uranium exposure. It

  12. Compared biokinetic and biological studies of chronic and acute inhalations of uranium compounds in the rat; Etudes biocinetique et biologique comparees d'inhalations chroniques et aigues de composes uraniferes chez le rat

    Energy Technology Data Exchange (ETDEWEB)

    Monleau, M

    2005-12-15

    Uranium is a natural, radioactive heavy metal, widely used in the nuclear industry in various chemical and isotopic forms. Its use in the fuel cycle involves the risk of radiological exposure for the workers, mainly via the inhalation of uranium particles. According to the workplace configuration, uranium contaminations can be acute or repeated, involve various chemical forms and different levels of enrichment, as well as involving one or several components. The dosimetric concepts and models available for workers' radiological protection, as well as most of the studies of the biological effects, correspond to acute exposure situations. Moreover the processes leading to pathological effects are little known in vivo. In this context, the main question is to know whether exposures due to repeated inhalation by rats induce the element kinetics and toxicity, which may be different from those observed after an acute exposure. In this study, comparison of the experimental and theoretical biokinetics of an insoluble uranium repeatedly inhaled over three weeks shows that a chronic contamination is correctly modelled, except for bone retention, by the sum of acute, successive and independent incorporations. Moreover, the kinetics of a soluble uranium inhaled irregularly can be modified by previous repeated exposure to an insoluble uranium. In certain cases therefore, exposure to uranium could modify its biokinetics during later exposures. At a toxicological level, the study demonstrates that the uranium particles inhaled repeatedly induce behavioural disruptions and genotoxic effects resulting in various sorts of DNA damage, in several cell types and certainly depending on the quantity inhaled. Exposures involving several uraniferous components produce a synergy effect. Moreover, repeated inhalations worsen the genotoxic effects in comparison to an acute exposure. This work demonstrates the importance of not ignoring the effects of the repetition of uranium exposure

  13. On the incorporation of biokinetic and mechanistic data in modeling for risk assessment

    NARCIS (Netherlands)

    Clewell, H.J.

    2007-01-01

    The goal of the studies described in this thesis was to foster the increased use of emerging scientific information and innovative methods in chemical risk assessments, in order to assure the protection of public health while limiting the economic and social consequences of over-regulation. The

  14. Biokinetic data of various radioactive cationic molecules. An attempt at evaluation of significant chemical properties of myotropic agents

    International Nuclear Information System (INIS)

    Munze, R.; Kretzschmar, M.; Syhre, R.; Kampf, G.; Klotzer, D.; Guthert, I.; Bergmann, R.

    1986-01-01

    Research on lipophilic cationic radiopharmaceuticals has been established as an important field of modern radiopharmacology and experimental nuclear medicine. The present state is best demonstrated by scintigrams obtained with Tc-TBI (TBI = tertiary butylisocyanide). These images clearly reveal the advantage of these compounds, namely high information density, which resulted in an excellent delineation of activity accumulations, as well as the lasting drawback represented by partial overlapping of the right lobe of the liver in a certain region of the inferior wall of the heart. Current research is mainly focused on overcoming this disadvantage by synthesizing appropriate compounds with higher heart/liver uptake in man. A more sophisticated rationale than cationic charge and lipophilicity would be much appreciated. This paper deals with possible correlations between the biodistribution and biokinetics of such compounds, though not exclusively for technetium cations, and their important chemical properties such as composition, size, and polar regions within the lipophilic molecule, which are considered significant parameters

  15. Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2016-01-01

    The biokinetic behavior of NH4 + removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4 + loadings in a continuous......-flow lab-scale assay. NH4 + removal capacity, estimated from short term loading up-shifts, was at least 10 times higher in the top than in the middle and bottom filter layers, consistent with the stratification of Ammonium Oxidizing Bacteria (AOB). AOB density increased consistently with the NH4 + removal...... rate, indicating their primarily role in nitrification under the imposed experimental conditions. The maximum AOB cell specific NH4 + removal rate observed at the bottom was at least 3 times lower compared to the top and middle layers. Additionally, a significant up-shift capacity (4.6 and 3.5 times...

  16. Dosimetric evaluation in organs of the Tc99m, I123 bio-kinetics to estimate dose in thyroid children 1 and 5 years

    International Nuclear Information System (INIS)

    Vasquez, A. M.; Quispe, R.; Vasquez, D. J.; Rocha, M. D.; Morales, N. R.; Marin, R. K.; Zelada, A. L.

    2012-10-01

    Using the formalism MIRD and the representation of Cristy-Eckerman for the thyroid in children of 1 and 5 years, is demonstrated that the dosimetric contribution of the organs of I 123 (iodure) bio-kinetics is not significant in the dose estimate. The total dose absorbed by the gland is its auto dose. The dosimetric contribution of the organs source of the Tc 99m (pertechnetate) bio-kinetics in the gland is significant in the dose estimate like to be ignored. The reported results for the iodure are not significantly different to the found for the Marinelli scheme (auto-dose) for thyroid represented by a sphere of 1,78 and 3,45 grams. (Author)

  17. Influence of zinc on the biokinetics of Zn-65 and hepatic trace elements of ethanol treated rats

    International Nuclear Information System (INIS)

    Dhawan, D.K.; Pathak, A.; Pathak, R.; Mahmood, A.

    2002-01-01

    Influence of zinc on the biokinetics of 65 Zn and hepatic trace elements of ethanol treated rats. The effect of zinc on the biokinetics of 65 Zn in liver and whole body and its relation to the hepatic levels of different elements was evaluated in male wistar rats under alcoholic conditions. The rats were segregated into four treatment groups viz., normal control, ethanol treated, zinc treated and combined zinc+ethanol treated. Animals were fed 3ml of 30% ethanol orally daily and zinc in the form of zinc sulfate (ZnSo 4 7H 2 O) was administrated to rats at a dose level of 227mg/L mixed in their drinking water for a total duration of 2 months. Whole body counting studies indicated that the Tb 1 i.e., the faster elimination of the radiotracer. On the contrary, Tb 2 i.e., the slower component was increased significantly following ethanol treatment. Percent uptake values of 65 Zn were found to be increased in liver, intestine, muscle and kidney and decreased in bone under alcoholic conditions. A significant elevation was noticed in in vitro uptake 65 Zn in ethanol treated animals. In the above said conditions, the values were reverted back to within normal limits upon zinc supplementation to these ethanol intoxicated animals, except in the case of in vitro 65 Zn uptake in liver where the uptake was further increased upon combined treatment. A significant decrease in zinc contents was noticed in ethanol treated rats, which however were raised to normal levels upon zinc supplementation. Copper levels, on the other hand, were found to be significantly enhanced in both ethanol fed and combined ethanol+zinc supplemented animals. Calcium levels were found to e significantly decreased in both ethanol and zinc treated rats, which however were further reduced upon zinc supplementation to ethanol fed rats. However, no significant change was observed in the concentrations of sodium and potassium in any of the treatment groups. Therefore, zinc appears to play a protective role by

  18. Investigations by gamma spectrometry and histoaudiography of the biokinetics of colloidal 232ThO2 ('Thorotrast')

    International Nuclear Information System (INIS)

    Foell, U.

    1978-01-01

    Experiments were carried out in mice in order to determine activity ratios and distribution kinetics of ThO 2 and its decay products. The data will be used as a basic for dose calculations. In supplementary investigations, the microdistribution, localisation, and quantitative enrichment of thorotrast were determined in order to provide a basis for microdosimetric evaluation of late thorotrast lesions. The radioactive colloid was injected intravenously into the tail vein of the animals (25 to 250 μl). Whole-body activity was measured at regular intervals. The animals were killed at different times after incorporation, and their livers, spleens, and skeleton without bone marrow were investigated by gammy spectrometry and histoautoradiography. With the findings obtained for the macroscopic distribution of colloid 232 ThO 2 and its decay products on the cellular level as a function of the duration of thorotrast storage, the mean radiation exposure of RHS organs can be determined and at least the order of magnitude of the local dose can be estimated. It will require long-term animal experiments to determine the biological effects of thorotrast incorporation and correlate them with the results of these dose calculations on the basis of the studies on thorotrast biokinetics. (orig./MG) [de

  19. Lead Bioaccumulation Factor of Cockle Shell (Anadara granosa) Base on Biokinetic Study that Used Radiotracer 210Pb

    International Nuclear Information System (INIS)

    Heru Umbara; Heny Suseno

    2007-01-01

    Lead is kind of hazardous heavy metal to human health and the concentration in the coastal environment should be monitored continuously because lead could be accumulated by marine biota. One of the monitoring techniques is bio indicator. Anadara granosa is a marine biota which spread in almost all Indonesian coastal, life in the bottom and mud sandy environment in the depth of until 4 meter and relatively still. Base on the book of environmental equilibrium balance DKI Jakarta, Anadara granosa is a macrozobenthos in Jakarta bay which have second highest density after Donax or with density of 14 individual per meter square. Base on the environmental equilibrium balance from 26 locations, 22 locations can be found Anadara granosa so this mollusk could be used for bio indicator. The objective of research for bioaccumulation that use 210 Pb as a tracer is to find bio indicator base on biokinetic process which include concentration factor, uptake and depuration processes and biology half life. The result shows that Anadara granosa could be use as a lead bio indicator in Jakarta bay. (author)

  20. Kit preparation and biokinetics in women of 99mTc-EDDA/HYNIC-E-[c(RGDfK)]2 for breast cancer imaging.

    Science.gov (United States)

    Ortiz-Arzate, Zareth; Santos-Cuevas, Clara L; Ocampo-García, Blanca E; Ferro-Flores, Guillermina; García-Becerra, Rocío; Estrada, Gisela; Gómez-Argumosa, Edgar; Izquierdo-Sánchez, Vanessa

    2014-04-01

    In breast cancer, α(ν)β(3) and/or α(ν)β(5) integrins are overexpressed in both endothelial and tumour cells. Radiolabelled peptides based on the Arg-Gly-Asp (RGD) sequence are radiopharmaceuticals with high affinity and selectivity for these integrins. The RGD-dimer peptide (E-[c(RGDfK)]2) radiolabelled with (99m)Tc has been reported as a radiopharmaceutical with a 10-fold higher affinity for the α(ν)β(3) integrin compared with the RGD-monomer. Ethylenediamine-N,N'-diacetic acid (EDDA) is a hydrophilic molecule that may favour renal excretion when used as coligand in the (99m)Tc labelling of hydrazinonicotinamide (HYNIC) peptides and can easily be formulated in a lyophilized kit. The aim of this study was to establish a biokinetic model for (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 prepared from lyophilized kits and evaluate its dosimetry as a tumour-imaging agent in seven healthy women and three breast cancer patients. (99m)Tc labelling was performed by adding sodium pertechnetate solution and 0.2 mol/l phosphate buffer (pH 7.0) to a lyophilized formulation containing E-[c(RGDfK)]2, EDDA, tricine, mannitol and stannous chloride. The radiochemical purity was evaluated using reverse-phase high-performance liquid chromatography and instant thin-layer chromatography on silica gel analyses. Stability studies in human serum were carried out using size-exclusion high-performance liquid chromatography. In-vitro cell uptake was tested using breast cancer cells (MCF7, T47D and MDA-MB-231) with blocked and nonblocked receptors. Biodistribution and tumour uptake were determined in MCF7 tumour-bearing nude mice with blocked and nonblocked receptors, and images were obtained using a micro-SPECT/PET/CT. Whole-body images from seven healthy women were acquired at 0.5, 1, 3, 6 and 24 h after (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 administration with radiochemical purities greater than 94%. Regions of interest were drawn around the source organs at each time frame. Each region of

  1. Dosimetric contribution of the organs of the I123, I124 and I131 bio-kinetics in the dose estimate for euthyroid adults

    International Nuclear Information System (INIS)

    Vasquez, A. M.; Rojas, A. R.; Castillo, D. C.; Idrogo, C. J.; Flores, U. H.

    2011-10-01

    Using the formalism MIRD and the representation of Crysty-Eckerman for the thyroid adult, is demonstrated that the dosimetric contributions of source organs of the biokinetics of the radiopharmaceuticals I 123 , I 124 and I 131 (iodine) are not significant in the dose estimate. Therefore, the total absorbed dose by the gland is its auto-dose. Equally, the reported results do not present significant differences to the results found by the Marinelli scheme (auto-dose) for the thyroid represented by a sphere of 20 grams. (Author)

  2. CFD simulation of fluid dynamic and biokinetic processes within activated sludge reactors under intermittent aeration regime.

    Science.gov (United States)

    Sánchez, F; Rey, H; Viedma, A; Nicolás-Pérez, F; Kaiser, A S; Martínez, M

    2018-08-01

    Due to the aeration system, biological reactors are the most energy-consuming facilities of convectional WWTPs. Many biological reactors work under intermittent aeration regime; the optimization of the aeration process (air diffuser layout, air flow rate per diffuser, aeration length …) is necessary to ensure an efficient performance; satisfying the effluent requirements with the minimum energy consumption. This work develops a CFD modelling of an activated sludge reactor (ASR) which works under intermittent aeration regime. The model considers the fluid dynamic and biological processes within the ASR. The biological simulation, which is transient, takes into account the intermittent aeration regime. The CFD modelling is employed for the selection of the aeration system of an ASR. Two different aeration configurations are simulated. The model evaluates the aeration power consumption necessary to satisfy the effluent requirements. An improvement of 2.8% in terms of energy consumption is achieved by modifying the air diffuser layout. An analysis of the influence of the air flow rate per diffuser on the ASR performance is carried out. The results show a reduction of 14.5% in the energy consumption of the aeration system when the air flow rate per diffuser is reduced. The model provides an insight into the aeration inefficiencies produced within ASRs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Reliability of the ICRP's dose coefficients for members of the public: IV. Basis of the human alimentary tract model and uncertainties in model predictions

    International Nuclear Information System (INIS)

    Leggett, R.; Harrison, J.; Phipps, A.

    2007-01-01

    The biokinetic and dosimetric model of the gastrointestinal (GI) tract applied in current documents of the International Commission on Radiological Protection (ICRP) was developed in the mid-1960's. The model was based on features of a reference adult male and was first used by the ICRP in Publication 30, Limits for Intakes of Radionuclides by Workers (Part 1, 1979). In the late 1990's an ICRP task group was appointed to develop a biokinetic and dosimetric model of the alimentary tract that reflects updated information and addresses current needs in radiation protection. The new age-specific and gender-specific model, called the Human Alimentary Tract Model (HATM), has been completed and will replace the GI model of Publication 30 in upcoming ICRP documents. This paper discusses the basis for the structure and parameter values of the HATM, summarises the uncertainties associated with selected features and types of predictions of the HATM and examines the sensitivity of dose estimates to these uncertainties for selected radionuclides. Emphasis is on generic biokinetic features of the HATM, particularly transit times through the lumen of the alimentary tract, but key dosimetric features of the model are outlined, and the sensitivity of tissue dose estimates to uncertainties in dosimetric as well as biokinetic features of the HATM are examined for selected radionuclides. (authors)

  4. Biokinetics and dosimetry of {sup 111}In-DOTA-NOC-ATE compared with {sup 111}In-DTPA-octreotide

    Energy Technology Data Exchange (ETDEWEB)

    Boubaker, Ariane; Prior, John O.; Champendal, Melanie; Bischof Delaloye, Angelika [Lausanne University Hospital, CHUV, Department of Nuclear Medicine, Lausanne (Switzerland); Willi, Jean-Pierre [University Hospital of Geneva, Department of Nuclear Medicine, Geneva 14 (Switzerland); Kosinski, Marek; Baechler, Sebastien [Lausanne University Hospital, Institute of Radiation Physics, Lausanne (Switzerland); Maecke, Helmut R. [University Hospital of Freiburg, Department of Nuclear Medicine, Freiburg (Germany); Ginj, Mihaela [University Health Network, Joint Department of Medical Imaging, Toronto, ON (Canada); Buchegger, Franz [Lausanne University Hospital, CHUV, Department of Nuclear Medicine, Lausanne (Switzerland); University Hospital of Geneva, Department of Nuclear Medicine, Geneva 14 (Switzerland)

    2012-12-15

    The biokinetics and dosimetry of {sup 111}In-DOTA-NOC-ATE (NOCATE), a high-affinity ligand of SSTR-2 and SSTR-5, and {sup 111}In-DTPA-octreotide (Octreoscan trademark, OCTREO) were compared in the same patients. Seventeen patients (10 men, 7 women; mean age 60 years), referred for an OCTREO scan for imaging of a neuroendocrine tumour (15), thymoma (1) or medullary thyroid carcinoma (1), agreed to undergo a second study with NOCATE. Whole-body anterior-posterior scans were recorded 0.5 (100 % reference scan), 4, 24 and 48 h (17 patients) and 120 h (5 patients) after injection. In 16 patients the OCTREO scan (178 {+-} 15 MBq) was performed 16 {+-} 5 days before the NOCATE scan (108 {+-} 14 MBq) with identical timing; 1 patient had the NOCATE scan before the OCTREO scan. Blood samples were obtained from 14 patients 5 min to 48 h after injection. Activities expressed as percent of the initial (reference) activity in the whole body, lung, kidney, liver, spleen and blood were fitted to biexponential or single exponential functions. Dosimetry was performed using OLINDA/EXM. Initial whole-body, lung and kidney activities were similar, but retention of NOCATE was higher than that of OCTREO. Liver and spleen uptakes of NOCATE were higher from the start (p < 0.001) and remained so over time. Whole-body activity showed similar {alpha} and {beta} half-lives, but the {beta} fraction of NOCATE was double that of OCTREO. Blood T{sub 1/2}{beta} for NOCATE was longer (19 vs. 6 h). As a result, the effective dose of NOCATE (105 {mu}Sv/MBq) exceeded that of OCTREO (52 {mu}Sv/MBq), and the latter result was similar to the ICRP 106 value of 54 {mu}Sv/MBq. Differential activity measurement in blood cells and plasma showed an average of <5 % of NOCATE and OCTREO attached to globular blood components. NOCATE showed a slower clearance from normal tissues and its effective dose was roughly double that of OCTREO. (orig.)

  5. Excretion of radionuclides in human breast milk after nuclear medicine examinations. Biokinetic and dosimetric data and recommendations on breastfeeding interruption

    Energy Technology Data Exchange (ETDEWEB)

    Leide-Svegborn, Sigrid; Ahlgren, Lars; Mattsson, Soeren [Lund University, Department of Medical Radiation Physics, Skaane University Hospital, Malmoe (Sweden); Johansson, Lennart [Umeaa University, Department of Radiation Sciences, Umeaa (Sweden)

    2016-05-15

    To review early recommendations and propose guidelines for breastfeeding interruption after administration of radiopharmaceuticals, based on additional biokinetic and dosimetric data. Activity concentrations in breast milk from 53 breastfeeding patients were determined. The milk was collected at various times after administration of 16 different radiopharmaceuticals. The fraction of the activity administered to the mother excreted in the breast milk, the absorbed doses to various organs and tissues and the effective dose to the infant were estimated. The fraction of the administered activity excreted per millilitre of milk varied widely from 10{sup -10} to 10{sup -3} MBq/MBq administered. For {sup 99m}Tc-labelled radiopharmaceuticals, the total fraction of the administered activity excreted in the milk varied from 0.0057 % for {sup 99m}Tc-labelled red blood cells (RBC) to 19 % for {sup 99m}Tc-pertechnetate. The effective dose to an infant per unit activity administered to the mother ranged from 6.7 x 10{sup -6} mSv/MBq for {sup 99m}Tc-labelled RBC to 3.6 x 10{sup -2} mSv/MBq for {sup 99m}Tc-pertechnetate. For the other radiopharmaceuticals, the total fraction of administered activity excreted in the milk varied from 0.018 % ({sup 51}Cr-EDTA) to 48 % ({sup 131}I-NaI). The effective dose ranged from 5.6 x 10{sup -5} mSv{sub infant}/MBq{sub mother} ({sup 51}Cr-EDTA) to 106 mSv{sub infant}/MBq{sub mother} ({sup 131}I-NaI). Based on an effective dose limit of 1 mSv to the infant and a typical administered activity, we recommend cessation of breastfeeding for {sup 131}I-NaI and interruption of feeding for 12 h for {sup 125}I-iodohippurate, {sup 131}I-iodohippurate, {sup 99m}Tc-pertechnetate and {sup 99m}Tc-MAA. During this 12-h period all breast milk should be expressed at least three times and discarded. For the other radiopharmaceuticals included in this study, no interruption of breastfeeding is necessary. (orig.)

  6. Biokinetics of copper in black-banded rainbowfish (Melanotaenia nigrans) tolerant to elevated copper concentrations, using the radioisotope 64Cu

    International Nuclear Information System (INIS)

    Gale, S.; Jeffree, R.; Smith, S.; Lim, R.

    2000-01-01

    Full text: For over 40 years black-banded rainbowfish (Melanotaenia nigrans) living in the East Branch of the Finniss River, Northern Territory have been exposed to elevated copper concentrations due to mine waste from the Rum Jungle uranium/copper mine. In the 1970s prior to remediation of the mine, fish kills were observed along the length of the East Branch. While copper concentrations remain comparatively high (up to 2000 μg/L) in the East Branch since remediation of the mine site, M. nigrans have been observed in the area. It was, therefore, hypothesised that due to selective pressure of lethal exposure, the population of black-banded rainbowfish in the East Branch have developed a tolerance to elevated copper concentrations. This project aimed to demonstrate copper tolerance and evaluate possible mechanism(s). In May 2000, fish were collected from the East Branch (exposed fish) and from a catchment previously unexposed to elevated metal concentrations (reference fish). The 96-hour EC 50 , fish imbalance (i.e. the concentration of copper that affects 50% of fish over 96 hours) for the exposed fish was over 8 times higher than the reference fish. Using the radioisotope, 64 Cu, the biokinetics of newly accumulated copper was traced in exposed and reference fish at low and elevated copper concentrations. The uptake rate, and therefore body burden, were significantly (p=0.000) lower in exposed fish, at both low and elevated copper concentrations compared to reference fish. Possible mechanisms of reducing copper uptake will be discussed. Tolerance was not lost when fish were maintained in relatively low copper concentrations in the laboratory. Also, the two populations of fish were genetically dissimilar based on allozyme analysis, which suggests that the mechanism is genetically mediated. The outcome of this project will be important in assisting accurate risk assessment and the development of environmental management strategies for the conservation of biota. The

  7. Biokinetics and dosimetry of 99m Tc-EDDA/HYNIC-[Lys3]-bombesin in humans: imaging of GRP receptors

    International Nuclear Information System (INIS)

    Santos C, C.L.; Ferro F, G.; Murphy, C.A de; Cardena, E.; Pichardo R, P.

    2007-01-01

    Full text: Bombesin (BN) receptor subtype 2 (GRP-r) is over-expressed on various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently we reported the 99- mTc-EDDA/HYNIC-[Lys 3 ]-Bombesin ( 99m Tc-HYNIC-BN) complex as a new radiopharmaceutical with high stability in human serum, specific cell GRP-receptor binding and rapid internalization. The aim of this study was to evaluate the 99m Tc-HYNIC-BN biokinetics and dosimetry in 5-healthy and 3-breast cancer women. Whole-body images were acquired at 20, 90, 180 min and 24 h after 99m Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source' organs on each time frame. The same set of ROIs was used for all 8 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-BN time activity curves in each organ, to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed a rapid radiopharmaceutical blood clearance with predominantly renal excretion and minimal hepatobiliary elimination. 99m Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in breast cancer lesions and well differentiated from GRP-r expression in lungs and airways with normal GRP-r density (ratio 3:1). The equivalent doses for a study using 370 MBq were 7.38±1.68, 0.59±0.08, 2.07±0.60, 0.58±0.1, 0.75±0.09 and 0.43±0.07 mSv for kidneys, liver, lungs, ovaries, pancreas and red marrow respectively. The effective dose was 1.64±0.25 mSv which is comparable with the doses known for most of the 99m Tc radiopharmaceutical studies in nuclear medicine. (Author)

  8. Lead remediation and changes in human lead exposure: some physiological and biokinetic dimensions.

    Science.gov (United States)

    Mushak, Paul

    2003-02-15

    This paper presents a qualitative and quantitative analysis of the various aspects of lead remediation effectiveness with particular reference to human health risk assessment. One of the key elements of lead remediation efforts at such sites as those under the Superfund program deals with populations at elevated exposure and toxicity risk in the proximity of, or at, the site of remediation, especially remediation workers, workers at other tasks on sites that were remediated down to some action level of lead concentration in soils, and groups at risk in nearby communities. A second element has to do with how one measures or models lead exposure changes with special reference to baseline and post-remediation conditions. Various biomarkers of lead exposure can be employed, but their use requires detailed knowledge of what results using each means. The most commonly used approach is measurement of blood lead (Pb-B). Recognized limitations in the use of Pb-B has led to the use of predictive Pb exposure models, which are less vulnerable to the many behavioral, physiological, and environmental parameters that can distort isolated or 'single shot' Pb-B testings. A third aspect covered in this paper presents various physiological factors that affect the methods by which one evaluates Pb remediation effectiveness. Finally, this article offers an integrated look at how lead remediation actions directed at one lead source or pathway affect the total lead exposure picture for human populations at elevated lead exposure and toxicity risk.

  9. Application for internal dosimetry using biokinetic distribution of photons based on nuclear medicine images.

    Science.gov (United States)

    Leal Neto, Viriato; Vieira, José Wilson; Lima, Fernando Roberto de Andrade

    2014-01-01

    This article presents a way to obtain estimates of dose in patients submitted to radiotherapy with basis on the analysis of regions of interest on nuclear medicine images. A software called DoRadIo (Dosimetria das Radiações Ionizantes [Ionizing Radiation Dosimetry]) was developed to receive information about source organs and target organs, generating graphical and numerical results. The nuclear medicine images utilized in the present study were obtained from catalogs provided by medical physicists. The simulations were performed with computational exposure models consisting of voxel phantoms coupled with the Monte Carlo EGSnrc code. The software was developed with the Microsoft Visual Studio 2010 Service Pack and the project template Windows Presentation Foundation for C# programming language. With the mentioned tools, the authors obtained the file for optimization of Monte Carlo simulations using the EGSnrc; organization and compaction of dosimetry results with all radioactive sources; selection of regions of interest; evaluation of grayscale intensity in regions of interest; the file of weighted sources; and, finally, all the charts and numerical results. The user interface may be adapted for use in clinical nuclear medicine as a computer-aided tool to estimate the administered activity.

  10. Application for internal dosimetry using biokinetic distribution of photons based on nuclear medicine images*

    Science.gov (United States)

    Leal Neto, Viriato; Vieira, José Wilson; Lima, Fernando Roberto de Andrade

    2014-01-01

    Objective This article presents a way to obtain estimates of dose in patients submitted to radiotherapy with basis on the analysis of regions of interest on nuclear medicine images. Materials and Methods A software called DoRadIo (Dosimetria das Radiações Ionizantes [Ionizing Radiation Dosimetry]) was developed to receive information about source organs and target organs, generating graphical and numerical results. The nuclear medicine images utilized in the present study were obtained from catalogs provided by medical physicists. The simulations were performed with computational exposure models consisting of voxel phantoms coupled with the Monte Carlo EGSnrc code. The software was developed with the Microsoft Visual Studio 2010 Service Pack and the project template Windows Presentation Foundation for C# programming language. Results With the mentioned tools, the authors obtained the file for optimization of Monte Carlo simulations using the EGSnrc; organization and compaction of dosimetry results with all radioactive sources; selection of regions of interest; evaluation of grayscale intensity in regions of interest; the file of weighted sources; and, finally, all the charts and numerical results. Conclusion The user interface may be adapted for use in clinical nuclear medicine as a computer-aided tool to estimate the administered activity. PMID:25741101

  11. Application for internal dosimetry using biokinetic distribution of photons based on nuclear medicine images

    International Nuclear Information System (INIS)

    Leal Neto, Viriato; Vieira, Jose Wilson; Lima, Fernando Roberto de Andrade

    2014-01-01

    Objective: this article presents a way to obtain estimates of dose in patients submitted to radiotherapy with basis on the analysis of regions of interest on nuclear medicine images. Materials and methods: a software called DoRadIo (Dosimetria das Radiacoes Ionizantes [Ionizing Radiation Dosimetry]) was developed to receive information about source organs and target organs, generating graphical and numerical results. The nuclear medicine images utilized in the present study were obtained from catalogs provided by medical physicists. The simulations were performed with computational exposure models consisting of voxel phantoms coupled with the Monte Carlo EGSnrc code. The software was developed with the Microsoft Visual Studio 2010 Service Pack and the project template Windows Presentation Foundation for C ⧣ programming language. Results: with the mentioned tools, the authors obtained the file for optimization of Monte Carlo simulations using the EGSnrc; organization and compaction of dosimetry results with all radioactive sources; selection of regions of interest; evaluation of grayscale intensity in regions of interest; the file of weighted sources; and, finally, all the charts and numerical results. Conclusion: the user interface may be adapted for use in clinical nuclear medicine as a computer-aided tool to estimate the administered activity. (author)

  12. Application for internal dosimetry using biokinetic distribution of photons based on nuclear medicine images

    Energy Technology Data Exchange (ETDEWEB)

    Leal Neto, Viriato, E-mail: viriatoleal@yahoo.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Vieira, Jose Wilson [Universidade Federal de Pernambuco (UPE), Recife, PE (Brazil); Lima, Fernando Roberto de Andrade [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2014-09-15

    Objective: this article presents a way to obtain estimates of dose in patients submitted to radiotherapy with basis on the analysis of regions of interest on nuclear medicine images. Materials and methods: a software called DoRadIo (Dosimetria das Radiacoes Ionizantes [Ionizing Radiation Dosimetry]) was developed to receive information about source organs and target organs, generating graphical and numerical results. The nuclear medicine images utilized in the present study were obtained from catalogs provided by medical physicists. The simulations were performed with computational exposure models consisting of voxel phantoms coupled with the Monte Carlo EGSnrc code. The software was developed with the Microsoft Visual Studio 2010 Service Pack and the project template Windows Presentation Foundation for C ⧣ programming language. Results: with the mentioned tools, the authors obtained the file for optimization of Monte Carlo simulations using the EGSnrc; organization and compaction of dosimetry results with all radioactive sources; selection of regions of interest; evaluation of grayscale intensity in regions of interest; the file of weighted sources; and, finally, all the charts and numerical results. Conclusion: the user interface may be adapted for use in clinical nuclear medicine as a computer-aided tool to estimate the administered activity. (author)

  13. Dosimetric contribution of organs of biokinetics of {sup 99m}Tc and {sup 123}I to estimate radiation doses in thyroids of children of 1 and 5 years; Contribucion dosimetrica de organos de la biocinetica del {sup 99m}Tc y {sup 123}I para estimar dosis en tiroides de ninos de 1 y 5 anos

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.V.; Castillo, C.E.; Abanto, D.M.; Rocha, D.; Garcia, W.H.; Marin, K., E-mail: marvva@hotmail.com [Universidad Nacional de Trujillo (UNT), Trujillo (Peru); Quispe, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, UNAM, Mexico (Mexico)

    2015-07-01

    The absorbed doses by thyroids during uptake studies through biokinetics of radiopharmaceuticals containing {sup 123}I (iodine) or {sup 99m}Tc (pertechnetate) are estimated. Using the MIRD scheme and the representation of Cristy-Eckerman for thyroids in children of 1 and 5 years, the objective of the study was to determine whether the dosimetric biokinetic contributions of the organs of {sup 123}I (iodide) and {sup 99m}Tc (pertechnetate) biokinetic are significant in the estimated of the absorbed dose for thyroid uptake studies.

  14. Bioaccumulation of Trace Metals in Bloody Cockle (Anadara senilis) from Ghana: Biokinetics and Human Bioaccessibility Studies

    International Nuclear Information System (INIS)

    Kuranchie-Mensah, Harriet

    2016-07-01

    A series of experimental studies has been carried out to study the kinetic of accumulation and human exposure to trace metals using the bloody cockle (Anadara senilis) as a model organism. This species is of ecological and economic importance in Ghana and other parts of Western Africa where they are commonly found. Trace metals mainly Mn, Co, Zn, Ag and Cd were studied using both laboratory mesocosm and field investigations. The laboratory experiments were carried out through the use of radiotracers: "5"4Mn, "5"7Co, "6"5Zn, "1"1"0"mAg and "1"0"9Cd, to study the kinetics of metal accumulation in the cockle through 2 different exposure pathways. The variability of metal bioaccumulation in the bloody cockle as a function of environmental and physiological conditions was also investigated. Metal subcellular fractionation, tissue distribution and simulating human digestion through the use of in vitro methodology were incorporated to understand the processes governing metal accumulation and human health risk assessment from the consumption of contaminated shellfish. Following a 2-hour single feeding and a 28-day depuration period, metals ingested with food (Isochrysis galbana or Skeletonema costatum) were moderate to highly assimilated in the cockle (11 to 72%), although, the degree of assimilation was dependant on the type of phytoplankton strain, the studied metals and the size of the cockle. Retention of assimilated metals was metal dependant being described as weak for Ag (T_b_1_/_2 of 2 to 6 days), moderate for Mn, Co and Zn (T_b_1_/_2 of 13 to 47 days) and strong for Cd (T_b_1_/_2 ≥ 97 days). Over a 28-day dissolved exposure period, bioconcentration kinetics of metals in two size classes of bloody cockles studied under different exposure conditions (high and low salinity) generally were best described by a saturation model assuming an apparent steady state concentration. The results showed strong variability on the kinetics of metal uptake among different size

  15. Development of a New Bio-Kinetic Model for Assessing the Environmental Property of Military Hydraulic Fluids

    National Research Council Canada - National Science Library

    Rhee, In-Sik

    2006-01-01

    The U.S. Army Tank-Automotive Research. Development and Engineering Center (TARDEC) is actively developing biodegradation technologies that can be used to minimize waste stream of Petroleum, Oils, and Lubricant...

  16. Whole body MR-PET: a new internal dosimetry method for radiation transport calculation from biokinetic model data

    International Nuclear Information System (INIS)

    Nunes, Ana; Alves, Francisco; Patrício, Miguel

    2014-01-01

    In order to ensure the safe usage of new radiopharmaceuticals in Positron Emission Tomography (PET), it is necessary to quantify the doses delivered to the organs and tissues within the patients’ bodies. A framework that allows estimating the dose delivered by PET has been established by the MIRD Committee [1, 2] and ICRP []. Although this covers the most important terms and concepts in Internal Radiation Dosimetry (IRD), it does not provide a detailed guide to assist in the development of a full dosimetric study. We discuss the development, implementation, assessment and validation of an accurate method for IRD studies of PET radiotracers.

  17. Plutonium biokinetics in humans

    International Nuclear Information System (INIS)

    Popplewell, D.; Ham, G.; McCarthy, W.; Lands, C.

    1994-01-01

    By using an 'unusual' isotope it is possible to carry out experiments with plutonium in volunteers at minimal radiation dose levels. Measurements have been made of the gut transfer factor and the urinary excretion of plutonium after intravenous injection. (author)

  18. Parametric study of a thorium model

    International Nuclear Information System (INIS)

    Lourenco, M.C.; Lipztein, J.L.; Szwarcwald, C.L.

    1997-01-01

    Full text. Models for radionuclides distribution in the human body and dosimetry involve assumptions on the biokinetic behaviour of the material among compartments representing organs and tissues in the body. The lack of knowledge about the metabolic behaviour of a radionuclide represents a factor of uncertainty in estimates of committed dose equivalent. An important problem in biokinetic modeling is the correct assignment of transfer coefficients and biological half-lives to body compartments. The purpose of this study is to analyze the variability in the activities of the body compartments in relation to the variations in the transfer coefficients and compartments biological half-lives in a certain model. A thorium specific recycling model for continuous exposure was used. Multiple regression analysis methods were applied to analyze the results

  19. Biokinetics and dosimetry in patients of 99mTc-HYNIC-Lys3-Bombesin: images of GRP receptors

    International Nuclear Information System (INIS)

    Santos C, C. L.

    2007-01-01

    The bombesin (BN) receptor subtype 2 (GRP-r) is expressed in several normal human tissues and is over-expressed in various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently [ 99m Tc]EDDA/HYNIC-Lys 3 -bombesin ( 99m Tc-HYNIC-BN) was reported as a radiopharmaceutical with high stability in human serum, specific cell GRP-r binding and rapid cell internalization. The aim of this study was to evaluate the feasibility of using 99m Tc-HYNIC-BN to image GRP-r and to assess the radiopharmaceutical biokinetics and dosimetry in 4 breast cancer patients and in 7 healthy women. Methods: Whole-body images were acquired at 20, 90, 180 min and 24 h after 99m Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all 11 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-HYNIC-BN time-activity curves in each organ in order to calculate the total number of disintegrations (N) that occurred in the source regions, according with MIRD methodology. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Results: Images showed a rapid radiopharmaceutical blood clearance with renal excretion as predominant route. 99m Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in cancer mammary glands and well differentiated from the ubiquitous GRP-r expression in normal breast, lungs and airways. There was no statistically significant difference (p > 0.05) in the radiation absorbed doses between cancer patients and healthy women. The average equivalent doses (n=11) for a study using 740 MBq were 24.8 +- 8.8 mSv (kidneys), 7.3 +- 1.8 mSv (lungs), 6.5 +- 4.0 mSv (breast) 2.0 +- 0.3 mSv (pancreas), 1.6 +- 0.3 mSv (liver), 1.2 +- 0.2 mSv (ovaries) and 1.0 +- 0.2 mSv (red marrow). The mean effective dose

  20. Blood doses and remnant biokinetics after thyroid ablation therapy of differentiated thyroid cancer: withdrawal vs. rh TSH

    International Nuclear Information System (INIS)

    Lassmann, Michael; Haenscheid, Heribert; Luster, Markus; Reiners, Christoph; Ablation, Trial Study Group

    2005-01-01

    Full text: An international randomized multicenter trial (9 sites; North America: 5, Europe: 4) was carried out investigating the effectiveness of ablation therapy with 3.7 GBq 131 I in differentiated thyroid cancer. We present the results of the trial dosimetry assessments. 63 patients were randomized after thyroidectomy to either hypothyroidism (THW) or euthyroidism in combination with rh TSH (0.9 mg q d x 2, Thyrogen). The biokinetics and residence times (RT) of the remnants were assessed from 3 neck scans starting 48 h after administration. The blood doses (a surrogate for the bone marrow dose) were calculated from activity concentrations in blood samples and 131 I whole body retention measurements between 2 and 168 h after 131 I administration. The overall dosimetry results were calculated centrally (Wuerzberg) in an externally audited standardized data evaluation procedure. The patient ablation rate was 100%. The 48 h 131 I uptake was lower in the remnant tissue of the rh TSH group: 0.5 ± 0.7%; THW group: 0.9 ±1.0% (p=0.1), the effective half life showed smaller values for the THW group (48.0 ± 52.6 h vs. 67.6 ± 48.9 h, p=0.0116). The mean RT in the remnant tissue was shorter in the rh TSH group: 0.9 ± 1.3 h; THW group: 1.4 ± 1.5 h (p=0.1). A greater decrease in the mean percentage of administered activity in the blood at 48 h, and a lower mean residence time was seen in the rh TSH group: 0.8%, RT: 2.3 ± 0.7 h; THW group: 1.8% (p=0.0011), RT: 3.5 ± 1.63 h (p=0.0004). The mean specific blood dose was significantly lower (p<0.0001) in the rh TSH group (0.072 ± 0.017 mGy/MBq, blood vessel radius (VR):0.2 mm; 0.104 ± 0.025 mGy/MBq, VR: 5 mm) than in the Hypothyroid group (0.106 ± 0.037 mGy/MBq, VR: 0.2 mm; 0.158 ± 0.059 mGy/MBq, VR: 5 mm). Conclusion: Although the remnant RT tended to be lower in the rh TSH group the ablation rates in the 2 study arms were comparable. The radiation dose to the blood was significantly lower in the rh TSH group. This

  1. Biokinetics of radioiodine (125I) during pre and post-natal development and the interference with the induction of developmental effects in the mouse brain

    International Nuclear Information System (INIS)

    Konermann, G.

    1992-01-01

    On day 13 post-conception, pregnant mice were injected with equal activities of either 125 I-sodium iodide or 5-( 125 I)-iodo-2-deoxyuridine in order to study the biokinetic behaviour in relation to the induction of developmental long-term damage to the brain. Brain weight, cortex diameters and alignment of cortical neurons were more affected by 125 I-IUdR (37-231 kBq.g -1 ) than by 125 I-NaI, consistent with decay sites within the DNA or mainly extranuclear sites, respectively. Dose calculations according to the MIRD scheme gave underestimates of the radiotoxicity, especially for the DNA bound 125 I. This is consistent with pronounced RBE effects derived from in vitro studies. The transfer of these RBE effects to the developing brain is, however, limited by the complex interference between the manifestation and compensation of damage within the prolonged response chains. (author)

  2. Biokinetics of radioiodine ( sup 125 I) during pre and post-natal development and the interference with the induction of developmental effects in the mouse brain

    Energy Technology Data Exchange (ETDEWEB)

    Konermann, G. (Freiburg Univ. (Germany). Inst. fuer Biophysik und Strahlenbiologie)

    1992-01-01

    On day 13 post-conception, pregnant mice were injected with equal activities of either {sup 125}I-sodium iodide or 5-({sup 125}I)-iodo-2-deoxyuridine in order to study the biokinetic behaviour in relation to the induction of developmental long-term damage to the brain. Brain weight, cortex diameters and alignment of cortical neurons were more affected by {sup 125}I-IUdR (37-231 kBq.g{sup -1}) than by {sup 125}I-NaI, consistent with decay sites within the DNA or mainly extranuclear sites, respectively. Dose calculations according to the MIRD scheme gave underestimates of the radiotoxicity, especially for the DNA bound {sup 125}I. This is consistent with pronounced RBE effects derived from in vitro studies. The transfer of these RBE effects to the developing brain is, however, limited by the complex interference between the manifestation and compensation of damage within the prolonged response chains. (author).

  3. Plutonium 238/239 Decorporation Model

    Science.gov (United States)

    2014-10-01

    4. Transfer Coefficients for the DTPA Biokinetic Model (Breustedt 2009) ...................... 25 Table 5. Decay Properties of Pu-238 and Pu-239...volume 2), cesium-137 (volume 3), F. tularensis (volume 4), sulfur mustard (volume 5), americium-241 (volume 6), Y. pestis (volume 7), botulinum ... toxin (volume 8), plutonium-238/239 (volume 9) and vesicants (volume 10, an expansion on volume 5). This paper presents an inhalation exposure model for

  4. Influence of selecting secondary settling tank sub-models on the calibration of WWTP models – A global sensitivity analysis using BSM2

    DEFF Research Database (Denmark)

    Ramin, Elham; Flores Alsina, Xavier; Sin, Gürkan

    2014-01-01

    This study investigates the sensitivity of wastewater treatment plant (WWTP) model performance to the selection of one-dimensional secondary settling tanks (1-D SST) models with first-order and second-order mathematical structures. We performed a global sensitivity analysis (GSA) on the benchmark...... simulation model No.2 with the input uncertainty associated to the biokinetic parameters in the activated sludge model No. 1 (ASM1), a fractionation parameter in the primary clarifier, and the settling parameters in the SST model. Based on the parameter sensitivity rankings obtained in this study......, the settling parameters were found to be as influential as the biokinetic parameters on the uncertainty of WWTP model predictions, particularly for biogas production and treated water quality. However, the sensitivity measures were found to be dependent on the 1-D SST models selected. Accordingly, we suggest...

  5. Prediction of iodine-131 biokinetics and radiation doses from therapy on the basis of tracer studies: an important question for therapy planning in nuclear medicine.

    Science.gov (United States)

    Willegaignon, José; Pelissoni, Rogério A; Lima, Beatriz C G D; Sapienza, Marcelo T; Coura-Filho, George B; Buchpiguel, Carlos A

    2016-05-01

    This study aimed to present a comparison of iodine-131 (I) biokinetics and radiation doses to red-marrow (rm) and whole-body (wb), following the administration of tracer and therapeutic activities, as a means of confirming whether I clearance and radiation doses for therapy procedures can be predicted by tracer activities. Eleven differentiated thyroid cancer patients were followed after receiving tracer and therapeutic I activity. Whole-body I clearance was estimated using radiation detectors and OLINDA/EXM software was used to calculate radiation doses to rm and wb. Tracer I activity of 86 (±14) MBq and therapeutic activity of 8.04 (±1.18) GBq were administered to patients, thereby producing an average wb I effective half-time and residence time of, respectively, 13.51 (±4.05) and 23.13 (±5.98) h for tracer activities and 13.32 (±3.38) and 19.63 (±4.77) h for therapy. Radiation doses to rm and wb were, respectively, 0.0467 (±0.0208) and 0.0589 (±0.0207) mGy/MBq in tracer studies and 0.0396 (±0.0169) and 0.0500 (±0.0163) mGy/MBq in therapy. Although the differences were not considered statistically significant between averages, those between the values of effective half-times (P=0.906), residence times (P=0.145), and radiation doses to rm (P=0.393) and to wb (P=0.272), from tracer and therapy procedures, large differences of up to 80% in wb I clearance, and up to 50% in radiation doses were observed when patients were analyzed individually, thus impacting on the total amount of I activity calculated to be safe for application in individual therapy. I biokinetics and radiation doses to rm and wb in therapy procedures are well predicted by diagnostic activities when average values of a group of patients are compared. Nonetheless, when patients are analyzed individually, significant differences may be encountered, thus implying that nuclear medicine therapy-planning requires due consideration of changes in individual patient-body status from

  6. Estimating {sup 131}I biokinetics and radiation doses to the red marrow and whole body in thyroid cancer patients: probe detection versus image quantification

    Energy Technology Data Exchange (ETDEWEB)

    Willegaignon, Jose; Pelissoni, Rogerio Alexandre; Lima, Beatriz Christine de Godoy Diniz; Coura-Filho, George Barberio; Queiroz, Marcelo Araujo, E-mail: j.willegaignon@gmail.com [Instituto do Cancer do Estado de Sao Paulo Octavio Frias de Oliveira (ICESP), Sao Paulo, SP (Brazil); Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Departamento de Radiologia

    2016-05-15

    Objective: to compare the probe detection method with the image quantification method when estimating {sup 131}I biokinetics and radiation doses to the red marrow and whole body in the treatment of thyroid cancer patients. Materials and methods: fourteen patients with metastatic thyroid cancer, without metastatic bone involvement, were submitted to therapy planning in order to tailor the therapeutic amount of {sup 131}I to each individual. Whole-body scans and probe measurements were performed at 4, 24, 48, 72, and 96 h after {sup 131}I administration in order to estimate the effective half-life (T{sub eff}) and residence time of {sup 131}I in the body. Results: the mean values for T{sub eff} and residence time, respectively, were 19 ± 9 h and 28 ± 12 h for probe detection, compared with 20 ± 13 h and 29 ± 18 h for image quantification. The average dose to the red marrow and whole body, respectively, was 0.061 ± 0.041 mGy/MBq and 0.073 ± 0.040 mGy/MBq for probe detection, compared with 0.066 ± 0.055 mGy/MBq and 0.078 ± 0.056 mGy/MBq for image quantification. Statistical analysis proved that there were no significant differences between the two methods for estimating the T{sub eff} (p = 0.801), residence time (p = 0.801), dose to the red marrow (p = 0.708), and dose to the whole body (p = 0.811), even when we considered an optimized approach for calculating doses only at 4 h and 96 h after {sup 131}I administration (p > 0.914). Conclusion: there is full agreement as to the feasibility of using probe detection and image quantification when estimating {sup 131}I biokinetics and red-marrow/whole-body doses. However, because the probe detection method is ineffective in identifying tumor sites and critical organs during radionuclide therapy and therefore liable to skew adjustment of the amount of {sup 131}I to be administered to patients under such therapy, it should be used with caution. (author)

  7. Modelling of green microalgal growth and algal storage processes using wastewater resources

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta; Plósz, Benedek G.; Valverde Pérez, Borja

    2017-01-01

    Recent research focuses on the recovery of nutrients, water and energy from wastewater. Microalgal cultivation on wastewater resources is considered as a more sustainable means to produce fertilizers or biofuels. Innovative systems that incorporate microalgal cultivation into conventional wastewa...... have been developed according to the activated sludge modelling (ASM) framework to facilitate the integration with existing modelling frameworks in water treatment. This chapter presents in detail the recently developed ASM-A biokinetic green microalgal process model. The model includes...

  8. Influence on dose coefficients for workers of the new metabolic models

    International Nuclear Information System (INIS)

    Gomez Parada, I.M.; Rojo, A.M.

    1998-01-01

    The International Commission on Radiological Protection (ICRP) has recently reviewed the biokinetic models used in the internal contamination dose assessment. ICRP has adopted a new model for the human respiratory tract and has updated, in ICRP Publications 56, 67 and 69, some of the biokinetic models of ICRP Publication 30. In this paper, the dose coefficients for some selected radionuclides issued in ICRP Publication 68 are compared with those obtained using the software LUPED (LUng Dose Evaluation Program). The former were calculated using the new systemic models, while the latter are based on the old metabolic models. The aim is to know to what extent the new models for systematic retention influence the dose coefficients for workers. (author) [es

  9. Browse Title Index

    African Journals Online (AJOL)

    Items 151 - 200 of 524 ... Vol 18, No 4 (2016), Development of human PBBK models for mixtures: Binary ... study of an iron and steel smelting industry, Lagos, Nigeria, Abstract PDF ... Vol 16, No 3 (2014), Effect of selected factors on the current flow and voltage ... Vol 14, No 2 (2012), Effects of nutrient and light stress on some ...

  10. Effect of bacteria density and accumulated inert solids on the effluent pollutant concentrations predicted by the constructed wetlands model BIO_PORE

    OpenAIRE

    Samsó Campà, Roger; Blazquez, Jordi; Agullo Chaler, Nuria; Grau Barceló, Joan; Torres Cámara, Ricardo; García Serrano, Joan

    2015-01-01

    Constructed wetlands are a widely adopted technology for the treatment of wastewater in small communities. The understanding of their internal functioning has increased at an unprecedented pace over recent years, in part thanks to the use of mathematical models. BIO_PORE model is one of the most recent models developed for constructed wetlands. This model was built in the COMSOL Multiphysics (TM) software and implements the biokinetic expressions of Constructed Wetlands Model 1 (CWM1) to desc...

  11. Dimer of the peptide cycle (Ar-Gly-Asp-D-Phe-Lys) radiolabeled with 99mTc for the integrin s over-expression image: formulation, biokinetics and dosimetry

    International Nuclear Information System (INIS)

    Ortiz A, Z.

    2013-01-01

    In breast cancer, α(v)β(3) and/or α(v)β(5) integrin s are over-expressed in both endothelial and tumour cells. Radiolabeled peptides based on the RGD (Arg-Gly-Asp) sequence are radiopharmaceuticals with high affinity and selectivity for those integrin s. The RGD-dimer peptide (E-[c(RGDfK)] 2 ) radiolabeled with 99m Tc has been reported as a radiopharmaceutical with 10-fold higher affinity for the α(v)β(3) integrin as compared to the RGD-monomer. EDDA (Ethylenediamine-N,N-diacetic acid) is a hydrophilic molecule that may favours renal excretion when used as coligand in the 99m Tc labelling of HYNIC-peptides and can easily be formulated in a lyophilized kit. Aim: Establish a biokinetic model for 99m Tc-EDDA/HYNIC-E-[c(RGDfK)] 2 prepared from lyophilized kits and evaluate the dosimetry as breast cancer imaging agent. Methods: 99m Tc labelling was performed by addition of sodium pertechnetate solution and 0.2 M phosphate buffer ph 7.0 to a lyophilized formulation containing E-[c(RGDfK)] 2 , EDDA, tricine, mannitol and stannous chloride. Radiochemical purity was evaluated by reversed phase HPLC and ITLC-SG analyses. Stability studies in human serum were carried out by size-exclusion HPLC. In-vitro cell uptake was tested using breast cancer cells (MCF7, T47D and MDA-MB-231) with blocked and non-blocked receptors. Biodistribution and tumour uptake were determined in MCF7 tumour-bearing nude mice with blocked and non-blocked receptors, and images were obtained using a micro-SPECT/CT. Whole-body images from seven healthy women were acquired at 1, 3, 6 and 24 h after 99m Tc-EDDA/HYNIC-E-[c(RGDfK)] 2 administration obtained with radiochemical purities of >94 %. Regions of interest (ROIs) were drawn around source organs on each time frame. Each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate 99m Tc-EDDA/HYNIC-E-[c(RGDfK)] 2 time-activity curves in each organ in order to adjust the biokinetic model and to

  12. Biokinetics and radiation dosimetry of 14C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Gunnarsson, Mikael

    2002-08-01

    14 C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used 14 C-breath tests: 14 C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low 14 C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform 14 C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of 14 C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: 14 C-glycocholic acid - 0.4 mSv/MBq, 14 C-triolein - 0.3 mSv/MBq, 14 C-xylose - 0.1 mSv/MBq and 14 C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the 14 C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  13. Biokinetics of a transuranic (238PU) and a rare earth element (152Eu) in the lobster (Homarus gammarus): transfer mechanisms (accumulation and detoxification) in organs and at the cellular level

    International Nuclear Information System (INIS)

    Tocquet, N.

    1995-01-01

    The work presented here is an experimental investigation of the biokinetics of transfer of a transuranic and a rare earth element ( 238 Pu and 152 Eu) in the lobster Homarus gammarus. The study of 238 Pu biokinetics forms part of a wider framework of research concerning the transfer of transuranic elements in marine species, while the study of 152 Eu is carried out with a view to supporting the analogy between the behaviour of transuranics and rare earths in living organisms. Exactly the same experimental protocol, based on techniques from various disciplines (biology, biochemistry and metrology), was used to Investigate the biokinetics of transfer of these two radionuclides. The Individual lobsters were radiolabelled by means of one-shot or chronic ingestion of spiked meals. As the first approach, the kinetics and transfer mechanisms were studied In whole animal samples and in different organs distinct series of pathways through the different organs were identified in the case of both radionuclides, being mainly linked to digestive processes induced by the meal as well as the transport function of hemo-lymph in this way, the Important role of the digestive gland was picked out, with two of four cellular types displaying a successive involvement In the fixation and then the retention of the studied radionuclides. As a corroborative approach, the digestive gland was subjected to a more detailed investigation with the aim of describing the mechanisms of Incorporation and elucidating transfer processes at the cellular and molecular levels. 238 Pu is preferentially partitioned into the cytosol, where it is associated with various constituents such as ferritin (iron-storing protein). 152 Eu is more diffusely distributed in the hepato-pancreatic cells, while the lysosomes appear to play a more important role during transfer. The results obtained in this study, both on the macroscopic scale (i.e. the whole animal and different organs) as well as the cellular and molecular

  14. DETERMINATION OF ACTIVATED SLUDGE MODEL ASDM PARAMETERS FOR WASTE WATER TREATMENT PLANT OPERATING IN THE SEQUENTIAL–FLOW TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik

    2015-01-01

    Full Text Available This paper presents a method for calibration of activated sludge model with the use of computer program BioWin. Computer scheme has been developed on the basis of waste water treatment plant operating in the sequential – flow technology. For calibration of the activated sludge model data of influent and treated effluent from the existing object were used. As a result of conducted analysis was a change in biokinetic model and kinetic parameters parameters of wastewater treatment facilities. The presented method of study of the selected parameters impact on the activated sludge biokinetic model (including autotrophs maximum growth rate, the share of organic slurry in suspension general operational, efficiency secondary settling tanks can be used for conducting simulation studies of other treatment plants.

  15. Targeted imaging of gastrin-releasing peptide receptors with 99mTc-EDDA/HYNIC-[Lys3]-bombesin: biokinetics and dosimetry in women.

    Science.gov (United States)

    Santos-Cuevas, Clara L; Ferro-Flores, Guillermina; Arteaga de Murphy, Consuelo; Pichardo-Romero, Pablo A

    2008-08-01

    The gastrin-releasing peptide receptor (GRP-R) is expressed in several normal human tissues and is overexpressed in various human tumors including breast, prostate, small-cell lung cancer and pancreatic cancer. Recently, 99mTc-EDDA/HYNIC-[Lys]-bombesin (99mTc-HYNIC-BN) was reported as a radiopharmaceutical with high stability in human serum, specific cell GRP-R binding and rapid cell internalization. The aim of this study was to determine the biokinetics and dosimetry of 99mTc-HYNIC-BN and the feasibility of using this radiopharmaceutical to image GRP-R in four early breast cancer patients and seven healthy women. Whole-body images were acquired at 20, 90, 180 min, and 24 h after 99mTc-HYNIC-BN administration. The same regions of interest were drawn around source organs on each time frame and regions of interest were converted to activity (conjugate view counting method). The image sequence was used to extrapolate 99mTc-HYNIC-BN time-activity curves in each organ to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. 99mTc-HYNIC-BN had a rapid blood clearance with mainly renal excretion. No statistically significant differences (P>0.05) in the radiation-absorbed doses among cancer patients and healthy women were observed. The average equivalent doses (n=11) were 24.8+/-8.8 mSv (kidneys), 7.3+/-1.8 mSv (lungs), 6.5+/-4.0 mSv (breast), 2.0+/-0.3 mSv (pancreas), 1.6+/-0.3 mSv (liver), 1.2+/-0.2 mSv (ovaries), and 1.0+/-0.2 mSv (red marrow). The effective dose was 3.3+/-0.6 mSv. The images showed well-differentiated concentration of 99mTc-HYNIC-BN in cancer mammary tissue. All the absorbed doses were comparable with those known for most of the 99mTc studies. 99mTc-HYNIC-BN shows high tumor uptake in breasts with malignant tumors so it is a promising imaging radiopharmaceutical to target site-specific early breast cancer. The results obtained

  16. Biokinetics and dosimetry of {sup 99m} Tc-EDDA/HYNIC-[Lys{sup 3}]-bombesin in humans: imaging of GRP receptors

    Energy Technology Data Exchange (ETDEWEB)

    Santos C, C.L.; Ferro F, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Murphy, C.A de [INCMNSZ, 14000 Mexico D.F. (Mexico); Cardena, E.; Pichardo R, P. [Departamento de Medicina Nuclear, Oncologia Centro Medico Siglo XXI, Mexico D.F. (Mexico)

    2007-07-01

    Full text: Bombesin (BN) receptor subtype 2 (GRP-r) is over-expressed on various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently we reported the {sup 99-}mTc-EDDA/HYNIC-[Lys{sup 3}]-Bombesin ({sup 99m}Tc-HYNIC-BN) complex as a new radiopharmaceutical with high stability in human serum, specific cell GRP-receptor binding and rapid internalization. The aim of this study was to evaluate the {sup 99m}Tc-HYNIC-BN biokinetics and dosimetry in 5-healthy and 3-breast cancer women. Whole-body images were acquired at 20, 90, 180 min and 24 h after {sup 99m}Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source' organs on each time frame. The same set of ROIs was used for all 8 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-HYNIC-BN time activity curves in each organ, to calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Images showed a rapid radiopharmaceutical blood clearance with predominantly renal excretion and minimal hepatobiliary elimination. {sup 99m}Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in breast cancer lesions and well differentiated from GRP-r expression in lungs and airways with normal GRP-r density (ratio 3:1). The equivalent doses for a study using 370 MBq were 7.38{+-}1.68, 0.59{+-}0.08, 2.07{+-}0.60, 0.58{+-}0.1, 0.75{+-}0.09 and 0.43{+-}0.07 mSv for kidneys, liver, lungs, ovaries, pancreas and red marrow respectively. The effective dose was 1.64{+-}0.25 mSv which is comparable with the doses known for most of the {sup 99m}Tc radiopharmaceutical studies in nuclear medicine. (Author)

  17. Experimental studies on the biokinetics of Cs-134 and Cd-109 in the blood cockle (Anadara granosa)

    International Nuclear Information System (INIS)

    Norfaizal Mohamed; Nita Salina Abu Bakar; Zal Uyun Wan Mahmood; Nur Hidaya Dmuliany Mohd Sidek; Zaharudin Ahmad

    2010-01-01

    Bioaccumulation and depuration study under controlled laboratory conditions of Cs and Cd in Anadara granosa collected at coastal Kapar, Selangor was carried out using respective radiotracer, Cs-134 and Cd-109. The radioactivity of Cs-134 and Cd-109 were determined using high resolution hyper germanium detector. Our results demonstrate that Cd-109 was accumulated efficiently by this species, except Cs-134. The steady state concentration factor (CF) for accumulation of Cs-134 and Cd-109 from seawater was estimated to be about 5.86 and 51.31, respectively. For the depuration stage, loss kinetics of Cs-134 and Cd-109 was best described by 2-compartment exponential model. Results shown that A. granosa exposed to Cs-134 have a total loss of 69% in compared to 19 % of Cd-109. Results gained in this experiment are a baseline data to evaluate future released of radioactive material from nuclear power programme facilities within this region. (author)

  18. Biokinetic and dosimetry of 99mTc-14F7-monoclonal antibody in patients with breast cancer

    International Nuclear Information System (INIS)

    Gonzalez, Joaquin; Calderon, Carlos; Pimentel, Gilmara; Oliva, Juan P.; Casaco, Angel

    2008-01-01

    19h. The distribution volume was similar to physiological volume in normal subject. A low urinary excretion was observed. The biodistribution shows a high retention of radiotracer in whole-body. A high uptake and retention was observed in bone marrow, kidneys and liver. The highest absorbed dose per MBq was observed in liver and kidneys. The 99m Tc-14F7 shows a rapid tumor uptake (<2.5h) with a delayed biological elimination half time (>4.5 days). In most cases, the maximum activity uptake in tumor (<1%/100g of tumor) was observed at 24 hours after injection. The pharmacokinetic data observed for 99m Tc-14F7 MAb behaves as a monoexponential model showing a slow clearance from plasma and a low urinary excretion. (author)

  19. Study of the biokinetic behavior of 99mTc-DMSA in renal scintigraphy of pediatric patients

    International Nuclear Information System (INIS)

    Santos, Felipe Simas dos

    2013-01-01

    In Brazil, renal studies with 99m Tc D TPA and 99m Tc-DMSA constitute about 18% of pediatric diagnostic procedures. A retrospective non-randomized study was conducted in 2010, for absolute quantification of kidney activities. In 2010,51 patients underwent renal studies in the Hospital of the Rio de Janeiro State University - HUPE-UERJ/ RJ, Brazil. 19 of them with 9±4 years of age and body mass of 31.8±20.8 kg showed relative uptake of 99m Tc-DMSA between 45% and 55%. Still images (AP, PA and posterior oblique abdomen incidences) were acquired 4 h after intravenous administration of 115.69±42.31 MBq of 99m Tc-DMSA using gamma camera (Siemens E-Cam), LEHR collimator, matrix of 256x256 and 5min imaging. In 2012, 3 patients (9.3±2.1 years, 31.97±10.75 kg) in the previous study were followed in a prospective study. All urinary excretions samples were collected from administration of 99m Tc-DMSA to 6 h after, while simultaneously images were acquired AP and PA abdominal region with Philips model Picker Prism 2000XP. Aliquots of each urine sample were measured in gamma counter shaft GenesysTM Gamma 1 with Nal (TI) detector. For whole body, the biological half-life estimate was 11.0±2.0 h, and the residence time was found to be 5.6±0.4 h while the literature suggests 4.l±0.5 h for age range studied. Residence time for kidney was found to be 0.7±0.4 h, while the literature shows, 3.07 h and 1.4 h for patients with normal and renal pathologies, respectively. This difference may be attributed to the methodology because while the images were taken during the first 6 h, SMITH et aI. (1996) performed images of the kidneys and whole body 30 h after administration of 99mTc D MSA, incorporating the slow term of biological half-life. For liver, it was found the average residence time of 3.0±0.4 min, whereas the literature indicates 20.8 min and 25.1 min, respectively according to SMITH et. ai (1996) and ICRP (1998). The fact that the administered activity was higher than

  20. Biokinetic and dosimetry of {sup 99m}Tc-14F7-monoclonal antibody in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Joaquin; Calderon, Carlos; Pimentel, Gilmara; Oliva, Juan P., E-mail: jgg@infomed.sld.cu [Departmento de Medicina Nuclear, Instituto de Oncologia y Radiobiologia, Cidad Habana (Cuba); Casaco, Angel [Division de Ensayos Clinicos, Centro de Inmunologia Molecular, Reparto Siboney, Ciudad Habana (Cuba)

    2008-07-01

    ranged in 15h and 19h. The distribution volume was similar to physiological volume in normal subject. A low urinary excretion was observed. The biodistribution shows a high retention of radiotracer in whole-body. A high uptake and retention was observed in bone marrow, kidneys and liver. The highest absorbed dose per MBq was observed in liver and kidneys. The {sup 99m}Tc-14F7 shows a rapid tumor uptake (<2.5h) with a delayed biological elimination half time (>4.5 days). In most cases, the maximum activity uptake in tumor (<1%/100g of tumor) was observed at 24 hours after injection. The pharmacokinetic data observed for {sup 99m}Tc-14F7 MAb behaves as a monoexponential model showing a slow clearance from plasma and a low urinary excretion. (author)

  1. Bibliographic study on molybdenum biokinetics

    International Nuclear Information System (INIS)

    Erzberger, A.

    1988-05-01

    This bibliographical study compiles and analyzes findings about the metabolism and resorption of molybdenum. Besides including studies on the physiology of molybdenum 99, a general survey is given on molybdenum in the environment and on its physiological behaviour. In particular, information on the dependence of molybdenum resorption on various factors, such as the chemical form, antagonisms etc., are gathered from literature. These factors have to be considered for sensibly carrying out necessary experiments. (orig./MG) [de

  2. DOSE210, A Semi-empirical Model for Prediction of Organ Distribution and Radiation Doses from Long Term Exposure to 210Pb and 210Po

    International Nuclear Information System (INIS)

    Salmon, P.L.; Bondarenko, O.A.; Henshaw, D.L.

    1999-01-01

    The DOSE210 model is an internal dosimetric model for 210 Pb and 210 Po which is based on current ICRP generic models. It is constrained and validated by reference to up-to-date published biokinetic data for both nuclides. The model has been validated primarily in regard to the relation between levels of chronic lifetime intake and organ concentrations of 210 Pb and 210 Po. To this end some adjustments to current ICRP biokinetic parameters have been made. The most substantial changes have been made to bone surface biokinetics of 210 Pb and 210 Po to reflect recent experimental studies on the microdistribution and radioactive equilibrium of these nuclides in bone, as well as measurements in biopsied human red bone marrow. An important dosimetric prediction of DOSE210 is a substantially lower dose to skeletal tissues from internal 210 Pb and 210 Po than that predicted by the current ICRP model. The most significant dose component predicted from lifetime environmental exposure to 210 Pb and 210 Po is the alpha dose to liver and kidney in infancy. Recycling of historic intakes of 210 Pb in the adult, principally from bone, is calculated to account for 22% of 210 Pb present in the plasma. (author)

  3. Age-specific models for evaluating dose and risk from internal exposures to radionuclides: Report of current work of the Metabolism and Dosimetry Research Group, July 1, 1985-June 30, 1987

    International Nuclear Information System (INIS)

    Leggett, R.W.; Warren, B.P.

    1987-09-01

    A projection of the health risk to a population internally exposed to a radionuclide requires explicit or implicit use of demographic, biokinetic, dosimetric, and dose-response models. Exposure guidelines have been based on models for a reference adult with a fixed life span. In this report, we describe recent efforts to develop a comprehensive methodology for estimation of radiogenic risk to individuals and to heterogeneous populations. Emphasis is on age-dependent biokinetics and dosimetry for internal emitters, but consideration also is given to conversion of age-specific doses to estimates of risk using realistic, site-specific demographic models and best available age-specific dose-response functions. We discuss how the methods described here may also improve estimates for the reference adult usually considered in radiation protection. 159 refs

  4. Age-specific models for evaluating dose and risk from internal exposures to radionuclides: Report of current work of the Metabolism and Dosimetry Research Group, July 1, 1985-June 30, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W.; Warren, B.P. (eds.)

    1987-09-01

    A projection of the health risk to a population internally exposed to a radionuclide requires explicit or implicit use of demographic, biokinetic, dosimetric, and dose-response models. Exposure guidelines have been based on models for a reference adult with a fixed life span. In this report, we describe recent efforts to develop a comprehensive methodology for estimation of radiogenic risk to individuals and to heterogeneous populations. Emphasis is on age-dependent biokinetics and dosimetry for internal emitters, but consideration also is given to conversion of age-specific doses to estimates of risk using realistic, site-specific demographic models and best available age-specific dose-response functions. We discuss how the methods described here may also improve estimates for the reference adult usually considered in radiation protection. 159 refs.

  5. Matrix modulation of the toxicity of alkenylbenzenes, studied by an integrated approach using in vitro, in vivo, and physiologically based biokinetic models

    NARCIS (Netherlands)

    Al-Husainy, W.A.A.M.

    2013-01-01

    Alkenylbenzenes such as estragole and methyleugenol are common components of spices and herbs such as tarragon, basil, fennel, mace, allspice, star anise and anise and their essential oils (Smithet al., 2002). There is an interest in the safety evaluation of alkenylbenzenes because

  6. Dosimetric evaluation in organs of the Tc{sup 99m}, I{sup 123} bio-kinetics to estimate dose in thyroid children 1 and 5 years; Evaluacion dosimetrica en organos de la biocinetica del Tc{sup 99m}, I{sup 123} para estimar dosis en tiroides ninos 1 y 5 anos

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, A. M.; Quispe, R.; Vasquez, D. J.; Rocha, M. D.; Morales, N. R.; Marin, R. K. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Ciudad Universitaria, Trujillo (Peru); Zelada, A. L., E-mail: marvva@hotmail.com [Universidad Cesar Vallejo, Grupo de Fisica Medica, Av. Larco s/n, Trujillo (Peru)

    2012-10-15

    Using the formalism MIRD and the representation of Cristy-Eckerman for the thyroid in children of 1 and 5 years, is demonstrated that the dosimetric contribution of the organs of I{sup 123} (iodure) bio-kinetics is not significant in the dose estimate. The total dose absorbed by the gland is its auto dose. The dosimetric contribution of the organs source of the Tc{sup 99m} (pertechnetate) bio-kinetics in the gland is significant in the dose estimate like to be ignored. The reported results for the iodure are not significantly different to the found for the Marinelli scheme (auto-dose) for thyroid represented by a sphere of 1,78 and 3,45 grams. (Author)

  7. The models of internal dose calculation in ICRP

    International Nuclear Information System (INIS)

    Nakano, Takashi

    1995-01-01

    There are a lot discussions about internal dose calculation in ICRP. Many efforts are devoted to improvement in models and parameters. In this report, we discuss what kind of models and parameters are used in ICRP. Models are divided into two parts, the dosimetric model and biokinetic model. The former is a mathematical phantom model, and it is mainly developed in ORNL. The results are used in many researchers. The latter is a compartment model and it has a difficulty to decide the parameter values. They are not easy to estimate because of their age dependency. ICRP officially sets values at ages of 3 month, 1 year, 5 year, 10 year, 15 year and adult, and recommends to get values among ages by linear age interpolate. But it is very difficult to solve the basic equation with these values, so we calculate by use of computers. However, it has complex shame and needs long CPU time. We should make approximated equations. The parameter values include much uncertainty because of less experimental data, especially for a child. And these models and parameter values are for Caucasian. We should inquire whether they could correctly describe other than Caucasian. The body size affects the values of calculated SAF, and the differences of metabolism change the biokinetic pattern. (author)

  8. Modelling the effect of continuous infusion DTPA therapy on the retention and dosimetry of inhaled actinides

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Muggenburg, B.A.

    1989-01-01

    A biokinetic model of the treatment of dogs that inhaled 241 AmO 2 aerosols with continuously infused DTPA has been adapted from a previously published model by Mewhinney and Griffith. This model was parameterised to simulate both the tissue retention and the excretion of 241 Am, and was used to estimate the cumulative radiation doses to tissues at risk from the α radiation of 241 Am. The results showed that at 64 days after exposure, the liver dose of the DTPA-treated animals was 3% that of the corresponding controls, the skeleton dose was 2%, the kidney dose was 4% and the lung dose was 67% of controls. (author)

  9. LUDEP 1. 0, a personal computer program to implement the new ICRP respiratory tract model

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, N.S.; Birchall, A. (National Radiological Protection Board, Chilton (United Kingdom))

    1994-01-01

    The International Commission on Radiological Protection has recently approved a new model of the human respiratory tract. This model has been designed to represent realistically the deposition and biokinetic behaviour of inhaled radionuclides, and to calculate doses to the respiratory tract. In order to examine the practical application and radiological implications of the new model, a Personal Computer program has been developed. LUDEP 1.0 is a user-friendly program for the IBM-compatible PC which enables the user to calculate doses to the respiratory tract and to other organs. (author).

  10. Dimer of the peptide cycle (Ar-Gly-Asp-D-Phe-Lys) radiolabeled with {sup 99m}Tc for the integrin s over-expression image: formulation, biokinetics and dosimetry; Dimero del peptido ciclo(Arg-Gly-Asp-D-Phe-Lys) radiomarcado con {sup 99m}Tc para la imagen de sobre-expresion de integrinas: formulacion, biocinetica y dosimetria

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz A, Z.

    2013-07-01

    In breast cancer, α(v)β(3) and/or α(v)β(5) integrin s are over-expressed in both endothelial and tumour cells. Radiolabeled peptides based on the RGD (Arg-Gly-Asp) sequence are radiopharmaceuticals with high affinity and selectivity for those integrin s. The RGD-dimer peptide (E-[c(RGDfK)]{sub 2}) radiolabeled with {sup 99m}Tc has been reported as a radiopharmaceutical with 10-fold higher affinity for the α(v)β(3) integrin as compared to the RGD-monomer. EDDA (Ethylenediamine-N,N-diacetic acid) is a hydrophilic molecule that may favours renal excretion when used as coligand in the {sup 99m}Tc labelling of HYNIC-peptides and can easily be formulated in a lyophilized kit. Aim: Establish a biokinetic model for {sup 99m}Tc-EDDA/HYNIC-E-[c(RGDfK)]{sub 2} prepared from lyophilized kits and evaluate the dosimetry as breast cancer imaging agent. Methods: {sup 99m}Tc labelling was performed by addition of sodium pertechnetate solution and 0.2 M phosphate buffer ph 7.0 to a lyophilized formulation containing E-[c(RGDfK)]{sub 2}, EDDA, tricine, mannitol and stannous chloride. Radiochemical purity was evaluated by reversed phase HPLC and ITLC-SG analyses. Stability studies in human serum were carried out by size-exclusion HPLC. In-vitro cell uptake was tested using breast cancer cells (MCF7, T47D and MDA-MB-231) with blocked and non-blocked receptors. Biodistribution and tumour uptake were determined in MCF7 tumour-bearing nude mice with blocked and non-blocked receptors, and images were obtained using a micro-SPECT/CT. Whole-body images from seven healthy women were acquired at 1, 3, 6 and 24 h after {sup 99m}Tc-EDDA/HYNIC-E-[c(RGDfK)]{sub 2} administration obtained with radiochemical purities of >94 %. Regions of interest (ROIs) were drawn around source organs on each time frame. Each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-EDDA/HYNIC-E-[c(RGDfK)]{sub 2} time-activity curves in each

  11. Biokinetics and radiation dosimetry of {sup 14}C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, Mikael

    2002-08-01

    {sup 14}C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used {sup 14}C-breath tests: {sup 14}C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low {sup 14}C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform {sup 14}C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of {sup 14}C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: {sup 14}C-glycocholic acid - 0.4 mSv/MBq, {sup 14}C-triolein - 0.3 mSv/MBq, {sup 14}C-xylose - 0.1 mSv/MBq and {sup 14}C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the {sup 14}C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  12. Dosimetric contribution of the organs of the I{sup 123}, I{sup 124} and I{sup 131} bio-kinetics in the dose estimate for euthyroid adults; Contribucion dosimetrica de los organos de la biocinetica de I{sup 123}, I{sup 124} y I{sup 131} en el estimado de dosis para adultos eutiroideos

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, A. M.; Rojas, A. R.; Castillo, D. C.; Idrogo, C. J.; Flores, U. H., E-mail: marvva@hotmail.com [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Ciudad Universitaria, Trujillo (Peru)

    2011-10-15

    Using the formalism MIRD and the representation of Crysty-Eckerman for the thyroid adult, is demonstrated that the dosimetric contributions of source organs of the biokinetics of the radiopharmaceuticals I{sup 123}, I{sup 124} and I{sup 131} (iodine) are not significant in the dose estimate. Therefore, the total absorbed dose by the gland is its auto-dose. Equally, the reported results do not present significant differences to the results found by the Marinelli scheme (auto-dose) for the thyroid represented by a sphere of 20 grams. (Author)

  13. Modeling the effect of continuous infusion DTPA therapy on the retention and dosimetry of inhaled actinides

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Muggenburg, B.A.

    1988-01-01

    A biokinetic model of the treatment of dogs that inhaled 241 AmO 2 aerosols with continuously infused DTPA has been adapted from a model previously published by Mewhinney and Griffith. This model simulated both the tissue retention and excretion of 241 Am, and was used to estimate the cumulative radiation doses to tissues at risk from 241 Am alpha radiation. The results showed that at 64 days after exposure, the liver dose of the DTPA-treated animals was 3% that of the corresponding controls, the skeletal dose was 2%, the kidney dose was 4%, and the lung dose was 67% of controls. This paper describes a biokinetic and dosimetric model that was adapted from a previously published model. It was developed to provide a means of estimating radiation doses for cases where continuously infused DTPA therapy is used to reduce radiation dose. The model was formulated for the case of 241 Am0 2 inhalation, a physicochemical form of Am that is moderately soluble in vivo, and one to which people have been exposed. Because adequate human data, particularly tissue data, are not available from cases of accidental human exposure to 241 Am, two published data sets from experiments in which Beagle dogs inhaled 241 Am0 2 aerosols have been used to obtain parameter estimates for the model. The model simulations were then used to provide dose estimates with and without infused-DTPA therapy. (author)

  14. BK/TD models for analyzing in vitro impedance data on cytotoxicity.

    Science.gov (United States)

    Teng, S; Barcellini-Couget, S; Beaudouin, R; Brochot, C; Desousa, G; Rahmani, R; Pery, A R R

    2015-06-01

    The ban of animal testing has enhanced the development of new in vitro technologies for cosmetics safety assessment. Impedance metrics is one such technology which enables monitoring of cell viability in real time. However, analyzing real time data requires moving from static to dynamic toxicity assessment. In the present study, we built mechanistic biokinetic/toxicodynamic (BK/TD) models to analyze the time course of cell viability in cytotoxicity assay using impedance. These models account for the fate of the tested compounds during the assay. BK/TD models were applied to analyze HepaRG cell viability, after single (48 h) and repeated (4 weeks) exposures to three hepatotoxic compounds (coumarin, isoeugenol and benzophenone-2). The BK/TD models properly fit the data used for their calibration that was obtained for single or repeated exposure. Only for one out of the three compounds, the models calibrated with a single exposure were able to predict repeated exposure data. We therefore recommend the use of long-term exposure in vitro data in order to adequately account for chronic hepatotoxic effects. The models we propose here are capable of being coupled with human biokinetic models in order to relate dose exposure and human hepatotoxicity. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  15. Bone and marrow dose modeling

    International Nuclear Information System (INIS)

    Stabin, Michael G.

    2004-01-01

    Nuclear medicine therapy is being used increasingly in the treatment of cancer (thyroid, leukemia/lymphoma with RIT, primary and secondary bone malignancies, and neuroblastomas). In all cases it is marrow toxicity that limits the amount of treatment that can be administered safely. Marrow dose calculations are more difficult than for many major organs because of the intricate association of bone and soft tissue elements. In RIT, there appears to be no consensus on how to calculate that dose accurately, or of individual patients ability to tolerate planned therapy. Available dose models are designed after an idealized average, healthy individual. Patient-specific methods are applied in evaluation of biokinetic data, and need to be developed for treatment of the physical data (dose conversion factors) as well: age, prior patient therapy, disease status. Contributors to marrow dose: electrons and photons

  16. A computational code for resolution of general compartment models applied to internal dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Claro, Thiago R.; Todo, Alberto S., E-mail: claro@usp.br, E-mail: astodo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The dose resulting from internal contamination can be estimated with the use of biokinetic models combined with experimental results obtained from bio analysis and the knowledge of the incorporation time. The biokinetics models can be represented by a set of compartments expressing the transportation, retention and elimination of radionuclides from the body. The ICRP publications, number 66, 78 and 100, present compartmental models for the respiratory tract, gastrointestinal tract and for systemic distribution for an array of radionuclides of interest for the radiological protection. The objective of this work is to develop a computational code for designing, visualization and resolution of compartmental models of any nature. There are available four different techniques for the resolution of system of differential equations, including semi-analytical and numerical methods. The software was developed in C{ne} programming, using a Microsoft Access database and XML standards for file exchange with other applications. Compartmental models for uranium, thorium and iodine radionuclides were generated for the validation of the CBT software. The models were subsequently solved by SSID software and the results compared with the values published in the issue 78 of ICRP. In all cases the system is in accordance with the values published by ICRP. (author)

  17. A computational code for resolution of general compartment models applied to internal dosimetry

    International Nuclear Information System (INIS)

    Claro, Thiago R.; Todo, Alberto S.

    2011-01-01

    The dose resulting from internal contamination can be estimated with the use of biokinetic models combined with experimental results obtained from bio analysis and the knowledge of the incorporation time. The biokinetics models can be represented by a set of compartments expressing the transportation, retention and elimination of radionuclides from the body. The ICRP publications, number 66, 78 and 100, present compartmental models for the respiratory tract, gastrointestinal tract and for systemic distribution for an array of radionuclides of interest for the radiological protection. The objective of this work is to develop a computational code for designing, visualization and resolution of compartmental models of any nature. There are available four different techniques for the resolution of system of differential equations, including semi-analytical and numerical methods. The software was developed in C≠ programming, using a Microsoft Access database and XML standards for file exchange with other applications. Compartmental models for uranium, thorium and iodine radionuclides were generated for the validation of the CBT software. The models were subsequently solved by SSID software and the results compared with the values published in the issue 78 of ICRP. In all cases the system is in accordance with the values published by ICRP. (author)

  18. Developing a physiologically based approach for modeling plutonium decorporation therapy with DTPA.

    Science.gov (United States)

    Kastl, Manuel; Giussani, Augusto; Blanchardon, Eric; Breustedt, Bastian; Fritsch, Paul; Hoeschen, Christoph; Lopez, Maria Antonia

    2014-11-01

    To develop a physiologically based compartmental approach for modeling plutonium decorporation therapy with the chelating agent Diethylenetriaminepentaacetic acid (Ca-DTPA/Zn-DTPA). Model calculations were performed using the software package SAAM II (©The Epsilon Group, Charlottesville, Virginia, USA). The Luciani/Polig compartmental model with age-dependent description of the bone recycling processes was used for the biokinetics of plutonium. The Luciani/Polig model was slightly modified in order to account for the speciation of plutonium in blood and for the different affinities for DTPA of the present chemical species. The introduction of two separate blood compartments, describing low-molecular-weight complexes of plutonium (Pu-LW) and transferrin-bound plutonium (Pu-Tf), respectively, and one additional compartment describing plutonium in the interstitial fluids was performed successfully. The next step of the work is the modeling of the chelation process, coupling the physiologically modified structure with the biokinetic model for DTPA. RESULTS of animal studies performed under controlled conditions will enable to better understand the principles of the involved mechanisms.

  19. New framework for standardized notation in wastewater treatment modelling

    DEFF Research Database (Denmark)

    Corominas, L.; Rieger, L.; Takacs, I.

    2010-01-01

    Many unit process models are available in the field of wastewater treatment. All of these models use their own notation, causing problems for documentation, implementation and connection of different models (using different sets of state variables). The main goal of this paper is to propose a new...... is a framework that can be used in whole plant modelling, which consists of different fields such as activated sludge, anaerobic digestion, sidestream treatment, membrane bioreactors, metabolic approaches, fate of micropollutants and biofilm processes. The main objective of this consensus building paper...... notational framework which allows unique and systematic naming of state variables and parameters of biokinetic models in the wastewater treatment field. The symbols are based on one main letter that gives a general description of the state variable or parameter and several subscript levels that provide...

  20. Biokinetics and dosimetry in patients administered with 111In-DOTA-Tyr3-octreotide: implications for internal radiotherapy with 90Y-DOTATOC

    International Nuclear Information System (INIS)

    Cremonesi, M.; Ferrari, M.; Maecke, H.R.; Tosi, G.; Zoboli, S.; Chinol, M.; Fiorenza, M.; Paganelli, G.; Stabin, M.G.; Orsi, F.O.; Jermann, E.; Robertson, C.

    1999-01-01

    Recent advances in receptor-mediated tumour imaging have resulted in the development of a new somatostatin analogue, DOTA-dPhe 1 -Tyr 3 -octreotide. This new compound, named DOTATOC, has shown high affinity for somatostatin receptors, ease of labelling and stability with yttrium-90 and favourable biodistribution in animal models. The aim of this work was to evaluate the biodistribution and dosimetry of DOTATOC radiolabelled with indium-111, in anticipation of therapy trials with 90 Y-DOTATOC in patients. Eighteen patients were injected with DOTATOC (10 μg), labelled with 150-185 MBq of 111 In. Blood and urine samples were collected throughout the duration of the study (0-2 days). Planar and single-photon emission tomography images were acquired at 0.5, 3-4, 24 and 48 h and time-activity curves were obtained for organs and tumours. A compartmental model was used to determine the kinetic parameters for each organ. Dose calculations were performed according to the MIRD formalism. Specific activities of >37 GBq/ μmol were routinely achieved. Patients showed no acute or delayed adverse reactions. The residence time for 111 In-DOTATOC in blood was 0.9±0.4 h. The injected activity excreted in the urine in the first 24 h was 73%±11%. The agent localized primarily in spleen, kidneys and liver. The residence times in source organs were: 2.2±1.8 h in spleen, 1.7±1.2 h in kidneys, 2.4±1.9 h in liver, 1.5±0.3 h in urinary bladder and 9.4±5.5 h in the remainder of the body; the mean residence time in tumour was 0.47 h (range: 0.03-6.50 h). Based on our findings, the predicted absorbed doses for 90 Y-DOTATOC would be 7.6±6.3 (spleen), 3.3±2.2 (kidneys), 0.7±0.6 (liver), 2.2±0.3 (bladder), 0.03±0.01 (red marrow) and 10.1 (range: 1.4-31.0) (tumour) mGy/MBq. These results indicate that high activities of 90 Y-DOTATOC can be administered with low risk of myelotoxicity, although with potentially high radiation doses to the spleen and kidneys. Tumour doses were high

  1. Biokinetics and dosimetry in patients administered with {sup 111}In-DOTA-Tyr{sup 3}-octreotide: implications for internal radiotherapy with {sup 90}Y-DOTATOC

    Energy Technology Data Exchange (ETDEWEB)

    Cremonesi, M.; Ferrari, M.; Maecke, H.R.; Tosi, G. [Department of Health Physics, European Institute of Oncology, Milan (Italy); Zoboli, S.; Chinol, M.; Fiorenza, M.; Paganelli, G. [Division of Nuclear Medicine, European Institute of Oncology, via Ripamonti, 435, I-20141-Milan (Italy); Stabin, M.G. [Nuclear Energy Department, Recife, Pernambuco (Brazil); Orsi, F.O. [Department of Radiology, European Institute of Oncology, Milan (Italy); Jermann, E. [Nuclear Medicine Department, University of Basel (Switzerland); Robertson, C. [Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan (Italy)

    1999-08-01

    Recent advances in receptor-mediated tumour imaging have resulted in the development of a new somatostatin analogue, DOTA-dPhe{sup 1}-Tyr{sup 3}-octreotide. This new compound, named DOTATOC, has shown high affinity for somatostatin receptors, ease of labelling and stability with yttrium-90 and favourable biodistribution in animal models. The aim of this work was to evaluate the biodistribution and dosimetry of DOTATOC radiolabelled with indium-111, in anticipation of therapy trials with {sup 90}Y-DOTATOC in patients. Eighteen patients were injected with DOTATOC (10 {mu}g), labelled with 150-185 MBq of {sup 111}In. Blood and urine samples were collected throughout the duration of the study (0-2 days). Planar and single-photon emission tomography images were acquired at 0.5, 3-4, 24 and 48 h and time-activity curves were obtained for organs and tumours. A compartmental model was used to determine the kinetic parameters for each organ. Dose calculations were performed according to the MIRD formalism. Specific activities of >37 GBq/ {mu}mol were routinely achieved. Patients showed no acute or delayed adverse reactions. The residence time for {sup 111}In-DOTATOC in blood was 0.9{+-}0.4 h. The injected activity excreted in the urine in the first 24 h was 73%{+-}11%. The agent localized primarily in spleen, kidneys and liver. The residence times in source organs were: 2.2{+-}1.8 h in spleen, 1.7{+-}1.2 h in kidneys, 2.4{+-}1.9 h in liver, 1.5{+-}0.3 h in urinary bladder and 9.4{+-}5.5 h in the remainder of the body; the mean residence time in tumour was 0.47 h (range: 0.03-6.50 h). Based on our findings, the predicted absorbed doses for {sup 90}Y-DOTATOC would be 7.6{+-}6.3 (spleen), 3.3{+-}2.2 (kidneys), 0.7{+-}0.6 (liver), 2.2{+-}0.3 (bladder), 0.03{+-}0.01 (red marrow) and 10.1 (range: 1.4-31.0) (tumour) mGy/MBq. These results indicate that high activities of {sup 90}Y-DOTATOC can be administered with low risk of myelotoxicity, although with potentially high radiation

  2. Biokinetics and dosimetry in patients administered with [sup 111]In-DOTA-Tyr[sup 3]-octreotide: implications for internal radiotherapy with [sup 90]Y-DOTATOC

    Energy Technology Data Exchange (ETDEWEB)

    Cremonesi, M.; Ferrari, M.; Maecke, H.R.; Tosi, G. (Department of Health Physics, European Institute of Oncology, Milan (Italy)); Zoboli, S.; Chinol, M.; Fiorenza, M.; Paganelli, G. (Division of Nuclear Medicine, European Institute of Oncology, via Ripamonti, 435, I-20141-Milan (Italy)); Stabin, M.G. (Nuclear Energy Department, Recife, Pernambuco (Brazil)); Orsi, F.O. (Department of Radiology, European Institute of Oncology, Milan (Italy)); Jermann, E. (Nuclear Medicine Department, University of Basel (Switzerland)); Robertson, C. (Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan (Italy))

    1999-08-01

    Recent advances in receptor-mediated tumour imaging have resulted in the development of a new somatostatin analogue, DOTA-dPhe[sup 1]-Tyr[sup 3]-octreotide. This new compound, named DOTATOC, has shown high affinity for somatostatin receptors, ease of labelling and stability with yttrium-90 and favourable biodistribution in animal models. The aim of this work was to evaluate the biodistribution and dosimetry of DOTATOC radiolabelled with indium-111, in anticipation of therapy trials with [sup 90]Y-DOTATOC in patients. Eighteen patients were injected with DOTATOC (10 [mu]g), labelled with 150-185 MBq of [sup 111]In. Blood and urine samples were collected throughout the duration of the study (0-2 days). Planar and single-photon emission tomography images were acquired at 0.5, 3-4, 24 and 48 h and time-activity curves were obtained for organs and tumours. A compartmental model was used to determine the kinetic parameters for each organ. Dose calculations were performed according to the MIRD formalism. Specific activities of >37 GBq/ [mu]mol were routinely achieved. Patients showed no acute or delayed adverse reactions. The residence time for [sup 111]In-DOTATOC in blood was 0.9[+-]0.4 h. The injected activity excreted in the urine in the first 24 h was 73%[+-]11%. The agent localized primarily in spleen, kidneys and liver. The residence times in source organs were: 2.2[+-]1.8 h in spleen, 1.7[+-]1.2 h in kidneys, 2.4[+-]1.9 h in liver, 1.5[+-]0.3 h in urinary bladder and 9.4[+-]5.5 h in the remainder of the body; the mean residence time in tumour was 0.47 h (range: 0.03-6.50 h). Based on our findings, the predicted absorbed doses for [sup 90]Y-DOTATOC would be 7.6[+-]6.3 (spleen), 3.3[+-]2.2 (kidneys), 0.7[+-]0.6 (liver), 2.2[+-]0.3 (bladder), 0.03[+-]0.01 (red marrow) and 10.1 (range: 1.4-31.0) (tumour) mGy/MBq. These results indicate that high activities of [sup 90]Y-DOTATOC can be administered with low risk of myelotoxicity, although with potentially high radiation

  3. Significance of uncertainties derived from settling tank model structure and parameters on predicting WWTP performance - A global sensitivity analysis study

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen

    2011-01-01

    Uncertainty derived from one of the process models – such as one-dimensional secondary settling tank (SST) models – can impact the output of the other process models, e.g., biokinetic (ASM1), as well as the integrated wastewater treatment plant (WWTP) models. The model structure and parameter...... and from the last aerobic bioreactor upstream to the SST (Garrett/hydraulic method). For model structure uncertainty, two one-dimensional secondary settling tank (1-D SST) models are assessed, including a first-order model (the widely used Takács-model), in which the feasibility of using measured...... uncertainty of settler models can therefore propagate, and add to the uncertainties in prediction of any plant performance criteria. Here we present an assessment of the relative significance of secondary settling model performance in WWTP simulations. We perform a global sensitivity analysis (GSA) based...

  4. Exposure implications for uranium aerosols formed at a new laser enrichment facility: application of the ICRP Respiratory Tract and Systemic Model

    Energy Technology Data Exchange (ETDEWEB)

    Ansorbolo, E.; Hodgson, A.; Stradling, G.N.; Hodgson, S.; Metivier, H.; Henge-Napoli, M.H.; Jarvis, N.S.; Birchall, A

    1998-07-01

    A pilot enrichment facility developed in France employs laser technology. The development of this process has resulted in three different types of aerosols identified as variable mixtures of U{sub metal}+ UO{sub 2} and U{sub 3}O{sub 8}. A procedure is described for assessing intakes and doses after inhalation of these dusts using site and material specific data in conjunction with the most recent ICRP biokinetic models. It is concluded that exposure control could be based on either radiotoxicity or chemical toxicity and that chest monitoring and urine assay could be useful, provided that measurements are made soon after a known acute intake. (author)

  5. Mixing characterisation of full-scale membrane bioreactors: CFD modelling with experimental validation.

    Science.gov (United States)

    Brannock, M; Wang, Y; Leslie, G

    2010-05-01

    Membrane Bioreactors (MBRs) have been successfully used in aerobic biological wastewater treatment to solve the perennial problem of effective solids-liquid separation. The optimisation of MBRs requires knowledge of the membrane fouling, biokinetics and mixing. However, research has mainly concentrated on the fouling and biokinetics (Ng and Kim, 2007). Current methods of design for a desired flow regime within MBRs are largely based on assumptions (e.g. complete mixing of tanks) and empirical techniques (e.g. specific mixing energy). However, it is difficult to predict how sludge rheology and vessel design in full-scale installations affects hydrodynamics, hence overall performance. Computational Fluid Dynamics (CFD) provides a method for prediction of how vessel features and mixing energy usage affect the hydrodynamics. In this study, a CFD model was developed which accounts for aeration, sludge rheology and geometry (i.e. bioreactor and membrane module). This MBR CFD model was then applied to two full-scale MBRs and was successfully validated against experimental results. The effect of sludge settling and rheology was found to have a minimal impact on the bulk mixing (i.e. the residence time distribution).

  6. Biokinetics and Biodynamics of Nanomaterial Interactions

    Science.gov (United States)

    2009-09-30

    HEK viability. The medium from each treatment set of the dosed cells was removed, pooled into a microfuge tube , and quickly frozen to -80ºC until...Trump’s fixative at 4ºC. The cells were rinsed in 0.1M phosphate buffer (pH 7.2), pelleted in a microfuge tube , resuspended, and quickly pelleted in 3...formulation on in vitro human skin localized NP in the upper stratum corneum with minimal penetration (Cross et al., 2007) and microfine zinc oxide with a

  7. the Sweet Hearts biokinetics pilot study

    African Journals Online (AJOL)

    Kathryn van Boom

    2Department of Sport Management, Faculty of Business and Management. Sciences ... (DoH) - outlines three main public health strategies: 1) prevent. NCDs and ... physical activity and healthy nutritional habits in those who participated.

  8. Biokinetics and dosimetry in patients of {sup 99m}Tc-HYNIC-Lys{sup 3}-Bombesin: images of GRP receptors; Biocinetica y dosimetria en humanos de {sup 99m}Tc-HYNIC-Lys{sup 3}-Bombesina: imagenes de receptores GRP

    Energy Technology Data Exchange (ETDEWEB)

    Santos C, C L [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2007-07-01

    The bombesin (BN) receptor subtype 2 (GRP-r) is expressed in several normal human tissues and is over-expressed in various human tumors including breast, prostate, small cell lung and pancreatic cancer. Recently [{sup 99m}Tc]EDDA/HYNIC-Lys{sup 3}-bombesin ({sup 99m}Tc-HYNIC-BN) was reported as a radiopharmaceutical with high stability in human serum, specific cell GRP-r binding and rapid cell internalization. The aim of this study was to evaluate the feasibility of using {sup 99m}Tc-HYNIC-BN to image GRP-r and to assess the radiopharmaceutical biokinetics and dosimetry in 4 breast cancer patients and in 7 healthy women. Methods: Whole-body images were acquired at 20, 90, 180 min and 24 h after {sup 99m}Tc-HYNIC-BN administration. Regions of interest (ROIs) were drawn around source organs on each time frame. The same set of ROIs was used for all 11 scans and the cpm of each ROI was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate {sup 99m}Tc-HYNIC-BN time-activity curves in each organ in order to calculate the total number of disintegrations (N) that occurred in the source regions, according with MIRD methodology. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. Results: Images showed a rapid radiopharmaceutical blood clearance with renal excretion as predominant route. {sup 99m}Tc-HYNIC-BN exhibited high in vivo affinity for GRP-r over-expression successfully visualized in cancer mammary glands and well differentiated from the ubiquitous GRP-r expression in normal breast, lungs and airways. There was no statistically significant difference (p > 0.05) in the radiation absorbed doses between cancer patients and healthy women. The average equivalent doses (n=11) for a study using 740 MBq were 24.8 +- 8.8 mSv (kidneys), 7.3 +- 1.8 mSv (lungs), 6.5 +- 4.0 mSv (breast) 2.0 +- 0.3 mSv (pancreas), 1.6 +- 0.3 mSv (liver), 1.2 +- 0.2 mSv (ovaries) and 1.0 +- 0.2 mSv (red

  9. Biokinetics of a transuranic ({sup 238}PU) and a rare earth element ({sup 152}Eu) in the lobster (Homarus gammarus): transfer mechanisms (accumulation and detoxification) in organs and at the cellular level; Biocinetiques d'un element transuranien, le {sup 238}PU, et d'une terre rare, le {sup 152}EU, chez le homard homarus gammarus (organes et niveau cellulaire) modalites des transferts (accumulation et detoxication)

    Energy Technology Data Exchange (ETDEWEB)

    Tocquet, N

    1995-07-01

    The work presented here is an experimental investigation of the biokinetics of transfer of a transuranic and a rare earth element ({sup 238}Pu and {sup 152}Eu) in the lobster Homarus gammarus. The study of {sup 238}Pu biokinetics forms part of a wider framework of research concerning the transfer of transuranic elements in marine species, while the study of {sup 152}Eu is carried out with a view to supporting the analogy between the behaviour of transuranics and rare earths in living organisms. Exactly the same experimental protocol, based on techniques from various disciplines (biology, biochemistry and metrology), was used to Investigate the biokinetics of transfer of these two radionuclides. The Individual lobsters were radiolabelled by means of one-shot or chronic ingestion of spiked meals. As the first approach, the kinetics and transfer mechanisms were studied In whole animal samples and in different organs distinct series of pathways through the different organs were identified in the case of both radionuclides, being mainly linked to digestive processes induced by the meal as well as the transport function of hemo-lymph in this way, the Important role of the digestive gland was picked out, with two of four cellular types displaying a successive involvement In the fixation and then the retention of the studied radionuclides. As a corroborative approach, the digestive gland was subjected to a more detailed investigation with the aim of describing the mechanisms of Incorporation and elucidating transfer processes at the cellular and molecular levels. {sup 238}Pu is preferentially partitioned into the cytosol, where it is associated with various constituents such as ferritin (iron-storing protein). {sup 152}Eu is more diffusely distributed in the hepato-pancreatic cells, while the lysosomes appear to play a more important role during transfer. The results obtained in this study, both on the macroscopic scale (i.e. the whole animal and different organs) as well

  10. Biokinetics of a transuranic ({sup 238}PU) and a rare earth element ({sup 152}Eu) in the lobster (Homarus gammarus): transfer mechanisms (accumulation and detoxification) in organs and at the cellular level; Biocinetiques d'un element transuranien, le {sup 238}PU, et d'une terre rare, le {sup 152}EU, chez le homard homarus gammarus (organes et niveau cellulaire) modalites des transferts (accumulation et detoxication)

    Energy Technology Data Exchange (ETDEWEB)

    Tocquet, N

    1995-07-01

    The work presented here is an experimental investigation of the biokinetics of transfer of a transuranic and a rare earth element ({sup 238}Pu and {sup 152}Eu) in the lobster Homarus gammarus. The study of {sup 238}Pu biokinetics forms part of a wider framework of research concerning the transfer of transuranic elements in marine species, while the study of {sup 152}Eu is carried out with a view to supporting the analogy between the behaviour of transuranics and rare earths in living organisms. Exactly the same experimental protocol, based on techniques from various disciplines (biology, biochemistry and metrology), was used to Investigate the biokinetics of transfer of these two radionuclides. The Individual lobsters were radiolabelled by means of one-shot or chronic ingestion of spiked meals. As the first approach, the kinetics and transfer mechanisms were studied In whole animal samples and in different organs distinct series of pathways through the different organs were identified in the case of both radionuclides, being mainly linked to digestive processes induced by the meal as well as the transport function of hemo-lymph in this way, the Important role of the digestive gland was picked out, with two of four cellular types displaying a successive involvement In the fixation and then the retention of the studied radionuclides. As a corroborative approach, the digestive gland was subjected to a more detailed investigation with the aim of describing the mechanisms of Incorporation and elucidating transfer processes at the cellular and molecular levels. {sup 238}Pu is preferentially partitioned into the cytosol, where it is associated with various constituents such as ferritin (iron-storing protein). {sup 152}Eu is more diffusely distributed in the hepato-pancreatic cells, while the lysosomes appear to play a more important role during transfer. The results obtained in this study, both on the macroscopic scale (i.e. the whole animal and different organs) as well

  11. Speciation and internal dosimetry: from chemical species to dosimetric models

    International Nuclear Information System (INIS)

    Paquet, F.; Frelon, S.; Cote, G.; Madic, C.

    2004-01-01

    Speciation studies refer to the distribution of species in a particular sample or matrix. These studies are necessary to improve the description, understanding and prediction of trace element kinetics and toxicity. In case of internal contamination with radionuclides, speciation studies could help to improve both the biokinetic and dosimetric models for radionuclides. There are different methods to approach the speciation of radionuclide in a biological system, depending on the degree of accuracy needed and the level of uncertainties accepted. Among them, computer modelling and experimental determination are complementary approaches. This paper describes what is known about speciation of actinides in blood, GI-tract, liver and skeleton and of their consequences in terms of internal dosimetry. The conclusion is that such studies provide very valuable data and should be targeted in the future on some specific tissues and biomolecules. (authors)

  12. Models for high cell density bioreactors must consider biomass volume fraction: Cell recycle example.

    Science.gov (United States)

    Monbouquette, H G

    1987-06-01

    Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity.

  13. Models for high cell density bioreactors must consider biomass volume fraction: cell recycle example

    Energy Technology Data Exchange (ETDEWEB)

    Monbouquette, H.G.

    1987-06-01

    Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity. (Refs. 14).

  14. Dynamic model for the assessment of radiological exposure to marine biota

    Energy Technology Data Exchange (ETDEWEB)

    Vives i Batlle, J. [Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)], E-mail: jordi.vives@westlakes.ac.uk; Wilson, R.C.; Watts, S.J.; Jones, S.R.; McDonald, P.; Vives-Lynch, S. [Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)

    2008-11-15

    A generic approach has been developed to simulate dynamically the uptake and turnover of radionuclides by marine biota. The approach incorporates a three-compartment biokinetic model based on first order linear kinetics, with interchange rates between the organism and its surrounding environment. Model rate constants are deduced as a function of known parameters: biological half-lives of elimination, concentration factors and a sample point of the retention curve, allowing for the representation of multi-component release. The new methodology has been tested and validated in respect of non-dynamic assessment models developed for regulatory purposes. The approach has also been successfully tested against research dynamic models developed to represent the uptake of technetium and radioiodine by lobsters and winkles. Assessments conducted on two realistic test scenarios demonstrated the importance of simulating time-dependency for ecosystems in which environmental levels of radionuclides are not in equilibrium.

  15. A Development of Domestic Food Chain Model Data for Chronic Effect Estimation of Off-site Consequence Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seok-Jung; KEUM, Dong-Kwon; Jang, Seung-Cheol [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The FCM includes complex transport phenomena of radiation materials on a biokinetic system of contaminated environments. An estimation of chronic health effects is a key part of the level 3 PSA (Probabilistic Safety Assessment), which depends on the FCM estimation from contaminated foods ingestion. A cultural ingestion habit of a local region and agricultural productions are different to the general features over worldwide scale or case by case. This is a reason to develop a domestic FCM data for the level 3 PSA. However, a generation of the specific FCM data is a complex process and under a large degree of uncertainty due to inherent biokinetic models. As a preliminary study, the present study focuses on an infrastructure development to generation of a specific FCM data. During this process, the features of FCM data to generate a domestic FCM data were investigated. Based on the insights obtained from this process, a specific domestic FCM data was developed. The present study was developed a domestic FCM data to estimate the chronic health effects of off-site consequence analysis. From this study, an insight was obtained, that a domestic FCM data is roughly 20 times higher than the MACCS2 defaults data. Based on this observation, it is clear that the specific chronic health effects of a domestic plant site should be considered in the off-site consequence analysis.

  16. A Development of Domestic Food Chain Model Data for Chronic Effect Estimation of Off-site Consequence Analysis

    International Nuclear Information System (INIS)

    Han, Seok-Jung; KEUM, Dong-Kwon; Jang, Seung-Cheol

    2015-01-01

    The FCM includes complex transport phenomena of radiation materials on a biokinetic system of contaminated environments. An estimation of chronic health effects is a key part of the level 3 PSA (Probabilistic Safety Assessment), which depends on the FCM estimation from contaminated foods ingestion. A cultural ingestion habit of a local region and agricultural productions are different to the general features over worldwide scale or case by case. This is a reason to develop a domestic FCM data for the level 3 PSA. However, a generation of the specific FCM data is a complex process and under a large degree of uncertainty due to inherent biokinetic models. As a preliminary study, the present study focuses on an infrastructure development to generation of a specific FCM data. During this process, the features of FCM data to generate a domestic FCM data were investigated. Based on the insights obtained from this process, a specific domestic FCM data was developed. The present study was developed a domestic FCM data to estimate the chronic health effects of off-site consequence analysis. From this study, an insight was obtained, that a domestic FCM data is roughly 20 times higher than the MACCS2 defaults data. Based on this observation, it is clear that the specific chronic health effects of a domestic plant site should be considered in the off-site consequence analysis

  17. A model for the bioaccumulation of {sup 99}Tc in lobsters (Homarus gammarus) from the West Cumbrian coast

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Y.S.; Vives i Batlle, J. E-mail: jordi.vives@westlakes.ac.uk

    2003-07-01

    A biokinetic model is presented that simulates the uptake and release of {sup 99}Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for {sup 99}Tc. The model is designed to represent annually averaged {sup 99}Tc concentrations in lobsters from the Cumbrian coast, where significant levels of {sup 99}Tc have been released under authorisation by the nuclear fuel reprocessing plant at BNFL Sellafield. This paper describes the construction of the model, how it was calibrated using data from published literature, and preliminary results indicating that model output agrees well with the available monitoring data. Given that this model successfully combines laboratory and field data, this research could potentially make a significant contribution to the field, as, to date, it has been difficult to predict and explain concentrations of {sup 99}Tc in lobsters.

  18. A model for the bioaccumulation of 99Tc in lobsters (Homarus gammarus) from the West Cumbrian coast

    International Nuclear Information System (INIS)

    Olsen, Y.S.; Vives i Batlle, J.

    2003-01-01

    A biokinetic model is presented that simulates the uptake and release of 99 Tc by the European lobster (Homarus gammarus). This organism is of significant radioecological interest since lobsters, in contrast to most other organisms, have a high affinity for 99 Tc. The model is designed to represent annually averaged 99 Tc concentrations in lobsters from the Cumbrian coast, where significant levels of 99 Tc have been released under authorisation by the nuclear fuel reprocessing plant at BNFL Sellafield. This paper describes the construction of the model, how it was calibrated using data from published literature, and preliminary results indicating that model output agrees well with the available monitoring data. Given that this model successfully combines laboratory and field data, this research could potentially make a significant contribution to the field, as, to date, it has been difficult to predict and explain concentrations of 99 Tc in lobsters

  19. Biodegradation of phenol with chromium(VI) reduction in an anaerobic fixed-biofilm process-Kinetic model and reactor performance

    International Nuclear Information System (INIS)

    Lin, Yen-Hui; Wu, Chih-Lung; Hsu, Chih-Hao; Li, Hsin-Lung

    2009-01-01

    A mathematical model system was derived to describe the simultaneous removal of phenol biodegradation with chromium(VI) reduction in an anaerobic fixed-biofilm reactor. The model system incorporates diffusive mass transport and double Monod kinetics. The model was solved using a combination of the orthogonal collocation method and Gear's method. A laboratory-scale column reactor was employed to validate the kinetic model system. Batch kinetic tests were conducted independently to evaluate the biokinetic parameters used in the model simulation. The removal efficiencies of phenol and chromium(VI) in an anaerobic fixed-biofilm process were approximately 980 mg/g and 910 mg/g, respectively, under a steady-state condition. In the steady state, model-predicted biofilm thickness reached up to 350 μm and suspended cells in the effluent were 85 mg cell/l. The experimental results agree closely with the results of the model simulations.

  20. Role of bio-effect models in improving radiotherapy of cancer

    International Nuclear Information System (INIS)

    Rao, B.S.

    2013-01-01

    Application of linear quadratic model of cell survival in radiotherapy has enabled to successfully predict the response of both the normal tissues and tumours. Even the simplest form of BED (biological effective dose) equation for fractionated radiotherapy could precisely predict the late normal tissue complications resulting from large dose per fraction. These observations have led to the development MFD (multiple fractions daily) protocol, with the specific objective of reducing late normal tissue morbidity. Protraction of treatment and consequent loss of BED and tumour control; multiple fractions delivered without adequate intervals resulting in incomplete repair of sub-lethal damage and consequent normal tissue complications, have been explained successfully by the LQ model. In the recent past LDR (low dose rate) brachytherapy is mostly replaced by HDR (high dose rate) technique. A series of calculations based on tumour bio-kinetics parameters, as well as the geometric sparing provides a sound rationale for replacing LDR technique by HDR technique. Some of the calculations relevant to this will be presented during this talk. Bio-effect models can also provide insight in to the rationale of RIT (radio-immunotherapy). With an adequate knowledge of biological half-life of antibodies in the tumour/critical organs, and biological uptake half-time in the tumour, it is possible to evaluate the efficacy of a number of radio-nuclides in RIT. Calculations based on LQ models suggest that longer lived isotopes such as 32 P, 86 Rb, 144m In may have an advantage over the shorter lived radio-nuclides. A clear knowledge of the various parameters like/values, potentially doubling time of tumour and other bio-kinetic parameters may hold the key for successful application of bio-effect models in predicting the response to radiotherapy. Feedback from the clinics will further help in refining and validating the existing models. (author)

  1. Uncertainty analysis in WWTP model applications: a critical discussion using an example from design

    DEFF Research Database (Denmark)

    Sin, Gürkan; Gernaey, Krist; Neumann, Marc B.

    2009-01-01

    of design performance criteria differs significantly. The implication for the practical applications of uncertainty analysis in the wastewater industry is profound: (i) as the uncertainty analysis results are specific to the framing used, the results must be interpreted within the context of that framing......This study focuses on uncertainty analysis of WWTP models and analyzes the issue of framing and how it affects the interpretation of uncertainty analysis results. As a case study, the prediction of uncertainty involved in model-based design of a wastewater treatment plant is studied. The Monte...... to stoichiometric, biokinetic and influent parameters; (2) uncertainty due to hydraulic behaviour of the plant and mass transfer parameters; (3) uncertainty due to the combination of (1) and (2). The results demonstrate that depending on the way the uncertainty analysis is framed, the estimated uncertainty...

  2. Shall we upgrade one-dimensional secondary settler models used in WWTP simulators? - An assessment of model structure uncertainty and its propagation.

    Science.gov (United States)

    Plósz, Benedek Gy; De Clercq, Jeriffa; Nopens, Ingmar; Benedetti, Lorenzo; Vanrolleghem, Peter A

    2011-01-01

    In WWTP models, the accurate assessment of solids inventory in bioreactors equipped with solid-liquid separators, mostly described using one-dimensional (1-D) secondary settling tank (SST) models, is the most fundamental requirement of any calibration procedure. Scientific knowledge on characterising particulate organics in wastewater and on bacteria growth is well-established, whereas 1-D SST models and their impact on biomass concentration predictions are still poorly understood. A rigorous assessment of two 1-DSST models is thus presented: one based on hyperbolic (the widely used Takács-model) and one based on parabolic (the more recently presented Plósz-model) partial differential equations. The former model, using numerical approximation to yield realistic behaviour, is currently the most widely used by wastewater treatment process modellers. The latter is a convection-dispersion model that is solved in a numerically sound way. First, the explicit dispersion in the convection-dispersion model and the numerical dispersion for both SST models are calculated. Second, simulation results of effluent suspended solids concentration (XTSS,Eff), sludge recirculation stream (XTSS,RAS) and sludge blanket height (SBH) are used to demonstrate the distinct behaviour of the models. A thorough scenario analysis is carried out using SST feed flow rate, solids concentration, and overflow rate as degrees of freedom, spanning a broad loading spectrum. A comparison between the measurements and the simulation results demonstrates a considerably improved 1-D model realism using the convection-dispersion model in terms of SBH, XTSS,RAS and XTSS,Eff. Third, to assess the propagation of uncertainty derived from settler model structure to the biokinetic model, the impact of the SST model as sub-model in a plant-wide model on the general model performance is evaluated. A long-term simulation of a bulking event is conducted that spans temperature evolution throughout a summer

  3. 131I-SPGP internal dosimetry: animal model and human extrapolation

    International Nuclear Information System (INIS)

    Andrade, Henrique Martins de; Ferreira, Andrea Vidal; Soprani, Juliana; Santos, Raquel Gouvea dos; Figueiredo, Suely Gomes de

    2009-01-01

    Scorpaena plumieri is commonly called moreia-ati or manganga and is the most venomous and one of the most abundant fish species of the Brazilian coast. Soprani 2006, demonstrated that SPGP - an isolated protein from S. plumieri fish- possess high antitumoral activity against malignant tumours and can be a source of template molecules for the development (design) of antitumoral drugs. In the present work, Soprani's 125 ISPGP biokinetic data were treated by MIRD formalism to perform Internal Dosimetry studies. Absorbed doses due to the 131 I-SPGP uptake were determinate in several organs of mice, as well as in the implanted tumor. Doses obtained for animal model were extrapolated to humans assuming a similar ratio for various mouse and human tissues. For the extrapolation, it was used human organ masses from Cristy/Eckerman phantom. Both penetrating and non-penetrating radiation from 131 I were considered. (author)

  4. {sup 131}I-CRTX internal dosimetry: animal model and human extrapolation

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Henrique Martins de; Ferreira, Andrea Vidal; Soares, Marcella Araugio; Silveira, Marina Bicalho; Santos, Raquel Gouvea dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: hma@cdtn.br

    2009-07-01

    Snake venoms molecules have been shown to play a role not only in the survival and proliferation of tumor cells but also in the processes of tumor cell adhesion, migration and angiogenesis. {sup 125}I-Crtx, a radiolabeled version of a peptide derived from Crotalus durissus terrificus snake venom, specifically binds to tumor and triggers apoptotic signalling. At the present work, {sup 125}I-Crtx biokinetic data (evaluated in mice bearing Erlich tumor) were treated by MIRD formalism to perform Internal Dosimetry studies. Doses in several organs of mice were determinate, as well as in implanted tumor, for {sup 131}I-Crtx. Doses results obtained for animal model were extrapolated to humans assuming a similar concentration ratio among various tissues between mouse and human. In the extrapolation, it was used human organ masses from Cristy/Eckerman phantom. Both penetrating and non-penetrating radiation from {sup 131}I in the tissue were considered in dose calculations. (author)

  5. {sup 131}I-SPGP internal dosimetry: animal model and human extrapolation

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Henrique Martins de; Ferreira, Andrea Vidal; Soprani, Juliana; Santos, Raquel Gouvea dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: hma@cdtn.br; Figueiredo, Suely Gomes de [Universidade Federal do Espirito Santo, (UFES), Vitoria, ES (Brazil). Dept. de Ciencias Fisiologicas. Lab. de Quimica de Proteinas

    2009-07-01

    Scorpaena plumieri is commonly called moreia-ati or manganga and is the most venomous and one of the most abundant fish species of the Brazilian coast. Soprani 2006, demonstrated that SPGP - an isolated protein from S. plumieri fish- possess high antitumoral activity against malignant tumours and can be a source of template molecules for the development (design) of antitumoral drugs. In the present work, Soprani's {sup 125}ISPGP biokinetic data were treated by MIRD formalism to perform Internal Dosimetry studies. Absorbed doses due to the {sup 131}I-SPGP uptake were determinate in several organs of mice, as well as in the implanted tumor. Doses obtained for animal model were extrapolated to humans assuming a similar ratio for various mouse and human tissues. For the extrapolation, it was used human organ masses from Cristy/Eckerman phantom. Both penetrating and non-penetrating radiation from {sup 131}I were considered. (author)

  6. 131I-CRTX internal dosimetry: animal model and human extrapolation

    International Nuclear Information System (INIS)

    Andrade, Henrique Martins de; Ferreira, Andrea Vidal; Soares, Marcella Araugio; Silveira, Marina Bicalho; Santos, Raquel Gouvea dos

    2009-01-01

    Snake venoms molecules have been shown to play a role not only in the survival and proliferation of tumor cells but also in the processes of tumor cell adhesion, migration and angiogenesis. 125 I-Crtx, a radiolabeled version of a peptide derived from Crotalus durissus terrificus snake venom, specifically binds to tumor and triggers apoptotic signalling. At the present work, 125 I-Crtx biokinetic data (evaluated in mice bearing Erlich tumor) were treated by MIRD formalism to perform Internal Dosimetry studies. Doses in several organs of mice were determinate, as well as in implanted tumor, for 131 I-Crtx. Doses results obtained for animal model were extrapolated to humans assuming a similar concentration ratio among various tissues between mouse and human. In the extrapolation, it was used human organ masses from Cristy/Eckerman phantom. Both penetrating and non-penetrating radiation from 131 I in the tissue were considered in dose calculations. (author)

  7. The application of equilibrium models to incidence situations using the example of the exposure pathway human milk

    International Nuclear Information System (INIS)

    Steiner, Martin; Karcher, Klaus; Nosske, Dietmar

    2012-01-01

    The radiation exposure after a short-term release of radioactive substances is often calculated assuming equilibrium conditions. An example is that of the German Incident Calculation Bases for nuclear power plants with pressurized water reactors. Here, the contamination of human milk is calculated using transfer factors. Applying this equilibrium model to incident situations raises the question whether baby's radiation exposure is adequately assessed. This contribution shows that compliance with the relevant dose limits of paragraph 49 of the German Radiation Protection Ordinance is ensured for design basis accidents on the assumption that the hypothetical breastfeeding period starts at the beginning of the activity release. Comparative analyses were performed against the biokinetic models applied by ICRP for radiation protection purposes, taking the reference nuclides 137 Cs, 90 Sr, 131 I, 241 Am and long-lived plutonium isotopes as examples. (orig.)

  8. The application of equilibrium models to incidence situations using the example of the exposure pathway human milk

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, Martin; Karcher, Klaus; Nosske, Dietmar [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany)

    2012-06-15

    The radiation exposure after a short-term release of radioactive substances is often calculated assuming equilibrium conditions. An example is that of the German Incident Calculation Bases for nuclear power plants with pressurized water reactors. Here, the contamination of human milk is calculated using transfer factors. Applying this equilibrium model to incident situations raises the question whether baby's radiation exposure is adequately assessed. This contribution shows that compliance with the relevant dose limits of paragraph 49 of the German Radiation Protection Ordinance is ensured for design basis accidents on the assumption that the hypothetical breastfeeding period starts at the beginning of the activity release. Comparative analyses were performed against the biokinetic models applied by ICRP for radiation protection purposes, taking the reference nuclides {sup 137}Cs, {sup 90}Sr, {sup 131}I, {sup 241}Am and long-lived plutonium isotopes as examples. (orig.)

  9. Assessing internal exposure in the absence of an appropriate model: two cases involving an incidental inhalation of transuranic elements

    International Nuclear Information System (INIS)

    Blanchin, N.; Grappin, L.; Guillermin, A.M.; Lafon, P.; Miele, A.; Berard, P.; Blanchardon, E.; Fottorino, R.

    2008-01-01

    Two incidents involving internal exposure by inhalation of transuranic compounds are presented herein. The results of the measurements of urinary and faecal excretions of the two individuals involved do not concur with the values predicted by the ICRP models that should be applied by default, according to the circumstances of the incidents and the chemical form of the products involved: oxide in the first case and nitrate in the second. These cases are remarkable in the similarity of their biokinetic behaviour even though they occurred in different situations and involved different chemical compounds. Both situations provide an illustration of the management of internal contamination events. The precautions to be taken and the questions that the physician should ask himself in the estimation of the internal dose are listed as follows: What type of examinations should be prescribed and at what frequency? What analysis results should be used in assessing the dose? How can the effect of the Ca-DTPA treatment be assessed? How long is it necessary to perform radio toxicological exams before assessing the dose? What should be done if the ICRP model corresponding to the initial circumstances does not fit the measurement data? Finally, our selected hypotheses, used to explain specific biokinetic behaviour and to estimate its intake in both cases, are detailed. These incidental contaminations suggest that further studies should be carried out to develop a new model for inhalation of transuranic compounds that would follow neither the S nor the M absorption type of the respiratory tract model of ICRP publication 66. (authors)

  10. Assessing internal exposure in the absence of an appropriate model: two cases involving an incidental inhalation of transuranic elements

    International Nuclear Information System (INIS)

    Blanchin, Nicolas; Fottorino, Robert; Grappin, Louise; Guillermin, Anne-Marie; Lafon, Philippe; Miele, Alain; Berard, Philippe; Blanchardon, Eric

    2008-01-01

    Two incidents involving internal exposure by inhalation of transuranic compounds are presented herein. The results of the measurements of urinary and faecal excretions of the two individuals involved do not concur with the values predicted by the ICRP models that should be applied by default, according to the circumstances of the incidents and the chemical form of the products involved: oxide in the first case and nitrate in the second. These cases are remarkable in the similarity of their biokinetic behaviour even though they occurred in different situations and involved different chemical compounds. Both situations provide an illustration of the management of internal contamination events. The precautions to be taken and the questions that the physician should ask himself in the estimation of the internal dose are listed as follows: a) What type of examinations should be prescribed and at what frequency?; b) What analysis results should be used in assessing the dose?; c) How can the effect of the Ca-DTPA treatment be assessed?; d) How long is it necessary to perform radio toxicological exams before assessing the dose?; e) What should be done if the ICRP model corresponding to the initial circumstances does not fit the measurement data? Finally, our selected hypotheses, used to explain specific biokinetic behaviour and to estimate its intake in both cases, are detailed. These incidental contaminations suggest that further studies should be carried out to develop a new model for inhalation of transuranic compounds that would follow neither the S nor the M absorption type of the respiratory tract model of ICRP publication 66. (author)

  11. Time-integrated activity coefficient estimation for radionuclide therapy using PET and a pharmacokinetic model: A simulation study on the effect of sampling schedule and noise

    Energy Technology Data Exchange (ETDEWEB)

    Hardiansyah, Deni [Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167, Germany and Department of Radiation Oncology, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167 (Germany); Guo, Wei; Glatting, Gerhard, E-mail: gerhard.glatting@medma.uni-heidelberg.de [Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim 68167 (Germany); Kletting, Peter [Department of Nuclear Medicine, Ulm University, Ulm 89081 (Germany); Mottaghy, Felix M. [Department of Nuclear Medicine, University Hospital, RWTH Aachen University, Aachen 52074, Germany and Department of Nuclear Medicine, Maastricht University Medical Center MUMC+, Maastricht 6229 (Netherlands)

    2016-09-15

    Purpose: The aim of this study was to investigate the accuracy of PET-based treatment planning for predicting the time-integrated activity coefficients (TIACs). Methods: The parameters of a physiologically based pharmacokinetic (PBPK) model were fitted to the biokinetic data of 15 patients to derive assumed true parameters and were used to construct true mathematical patient phantoms (MPPs). Biokinetics of 150 MBq {sup 68}Ga-DOTATATE-PET was simulated with different noise levels [fractional standard deviation (FSD) 10%, 1%, 0.1%, and 0.01%], and seven combinations of measurements at 30 min, 1 h, and 4 h p.i. PBPK model parameters were fitted to the simulated noisy PET data using population-based Bayesian parameters to construct predicted MPPs. Therapy simulations were performed as 30 min infusion of {sup 90}Y-DOTATATE of 3.3 GBq in both true and predicted MPPs. Prediction accuracy was then calculated as relative variability v{sub organ} between TIACs from both MPPs. Results: Large variability values of one time-point protocols [e.g., FSD = 1%, 240 min p.i., v{sub kidneys} = (9 ± 6)%, and v{sub tumor} = (27 ± 26)%] show inaccurate prediction. Accurate TIAC prediction of the kidneys was obtained for the case of two measurements (1 and 4 h p.i.), e.g., FSD = 1%, v{sub kidneys} = (7 ± 3)%, and v{sub tumor} = (22 ± 10)%, or three measurements, e.g., FSD = 1%, v{sub kidneys} = (7 ± 3)%, and v{sub tumor} = (22 ± 9)%. Conclusions: {sup 68}Ga-DOTATATE-PET measurements could possibly be used to predict the TIACs of {sup 90}Y-DOTATATE when using a PBPK model and population-based Bayesian parameters. The two time-point measurement at 1 and 4 h p.i. with a noise up to FSD = 1% allows an accurate prediction of the TIACs in kidneys.

  12. A comprehensive approach to age-dependent dosimetric modeling

    International Nuclear Information System (INIS)

    Leggett, R.W.; Cristy, M.; Eckerman, K.F.

    1986-01-01

    In the absence of age-specific biokinetic models, current retention models of the International Commission on Radiological Protection (ICRP) frequently are used as a point of departure for evaluation of exposures to the general population. These models were designed and intended for estimation of long-term integrated doses to the adult worker. Their format and empirical basis preclude incorporation of much valuable physiological information and physiologically reasonable assumptions that could be used in characterizing the age-specific behavior of radioelements in humans. In this paper we discuss a comprehensive approach to age-dependent dosimetric modeling in which consideration is given not only to changes with age in masses and relative geometries of body organs and tissues but also to best available physiological and radiobiological information relating to the age-specific biobehavior of radionuclides. This approach is useful in obtaining more accurate estimates of long-term dose commitments as a function of age at intake, but it may be particularly valuable in establishing more accurate estimates of dose rate as a function of age. Age-specific dose rates are needed for a proper analysis of the potential effects on estimates or risk of elevated dose rates per unit intake in certain stages of life, elevated response per unit dose received during some stages of life, and age-specific non-radiogenic competing risks

  13. A comprehensive approach to age-dependent dosimetric modeling

    International Nuclear Information System (INIS)

    Leggett, R.W.; Cristy, M.; Eckerman, K.F.

    1987-01-01

    In the absence of age-specific biokinetic models, current retention models of the International Commission of Radiological Protection (ICRP) frequently are used as a point of departure for evaluation of exposures to the general population. These models were designed and intended for estimation of long-term integrated doses to the adult worker. Their format and empirical basis preclude incorporation of much valuable physiological information and physiologically reasonable assumptions that could be used in characterizing the age-specific behavior of radioelements in humans. In this paper a comprehensive approach to age-dependent dosimetric modeling is discussed in which consideration is given not only to changes with age in masses and relative geometries of body organs and tissues but also to best available physiological and radiobiological information relating to the age-specific biobehavior of radionuclides. This approach is useful in obtaining more accurate estimates of long-term dose commitments as a function of age at intake, but it may be particularly valuable in establishing more accurate estimates of dose rate as a function of age. Age-specific dose rates are needed for a proper analysis of the potential effects on estimates of risk of elevated dose rates per unit intake in certain stages of life, elevated response per unit dose received during some stages of life, and age-specific non-radiogenic competing risks. 16 refs.; 3 figs.; 1 table

  14. Predicting patient exposure to nickel released from cardiovascular devices using multi-scale modeling.

    Science.gov (United States)

    Saylor, David M; Craven, Brent A; Chandrasekar, Vaishnavi; Simon, David D; Brown, Ronald P; Sussman, Eric M

    2018-04-01

    Many cardiovascular device alloys contain nickel, which if released in sufficient quantities, can lead to adverse health effects. However, in-vivo nickel release from implanted devices and subsequent biodistribution of nickel ions to local tissues and systemic circulation are not well understood. To address this uncertainty, we have developed a multi-scale (material, tissue, and system) biokinetic model. The model links nickel release from an implanted cardiovascular device to concentrations in peri-implant tissue, as well as in serum and urine, which can be readily monitored. The model was parameterized for a specific cardiovascular implant, nitinol septal occluders, using in-vitro nickel release test results, studies of ex-vivo uptake into heart tissue, and in-vivo and clinical measurements from the literature. Our results show that the model accurately predicts nickel concentrations in peri-implant tissue in an animal model and in serum and urine of septal occluder patients. The congruity of the model with these data suggests it may provide useful insight to establish nickel exposure limits and interpret biomonitoring data. Finally, we use the model to predict local and systemic nickel exposure due to passive release from nitinol devices produced using a wide range of manufacturing processes, as well as general relationships between release rate and exposure. These relationships suggest that peri-implant tissue and serum levels of nickel will remain below 5 μg/g and 10 μg/l, respectively, in patients who have received implanted nitinol cardiovascular devices provided the rate of nickel release per device surface area does not exceed 0.074 μg/(cm 2  d) and is less than 32 μg/d in total. The uncertainty in whether in-vitro tests used to evaluate metal ion release from medical products are representative of clinical environments is one of the largest roadblocks to establishing the associated patient risk. We have developed and validated a multi

  15. Inter-comparison of dynamic models for radionuclide transfer to marine biota in a Fukushima accident scenario

    Energy Technology Data Exchange (ETDEWEB)

    Vives i Batlle, J.; Beresford, N. A.; Beaugelin-Seiller, K.; Bezhenar, R.; Brown, J.; Cheng, J. -J.; Ćujić, M.; Dragović, S.; Duffa, C.; Fiévet, B.; Hosseini, A.; Jung, K. T.; Kamboj, S.; Keum, D. -K.; Kryshev, A.; LePoire, D.; Maderich, V.; Min, B. -I.; Periáñez, R.; Sazykina, T.; Suh, K. -S.; Yu, C.; Wang, C.; Heling, R.

    2016-03-01

    We report an inter-comparison of eight models designed to predict the radiological exposure of radionuclides in marine biota. The models were required to simulate dynamically the uptake and turnover of radionuclides by marine organisms. Model predictions of radionuclide uptake and turnover using kinetic calculations based on biological half-life (TB1/2) and/or more complex metabolic modelling approaches were used to predict activity concentrations and, consequently, dose rates of 90Sr, 131I and 137Cs to fish, crustaceans, macroalgae and molluscs under circumstances where the water concentrations are changing with time. For comparison, the ERICA Tool, a model commonly used in environmental assessment, and which uses equilibrium concentration ratios, was also used. As input to the models we used hydrodynamic forecasts of water and sediment activity concentrations using a simulated scenario reflecting the Fukushima accident releases. Although model variability is important, the intercomparison gives logical results, in that the dynamic models predict consistently a pattern of delayed rise of activity concentration in biota and slow decline instead of the instantaneous equilibrium with the activity concentration in seawater predicted by the ERICA Tool. The differences between ERICA and the dynamic models increase the shorter the TB1/2 becomes; however, there is significant variability between models, underpinned by parameter and methodological differences between them. The need to validate the dynamic models used in this intercomparison has been highlighted, particularly in regards to optimisation of the model biokinetic parameters.

  16. Development of an Age- and Gender-specific Model for Strontium Metabolism in Humans

    International Nuclear Information System (INIS)

    Shagina, N. B.; Degteva, M. O.; Tolstykh, E. I.

    2004-01-01

    This paper presents a development of a new biokinetic model for strontium, which accounts for age and gender differences of metabolism in humans. This model was developed based on the long-term follow-up of the residents living on the banks of the Techa River (Southern Urals, Russia) contaminated with 89,90Sr in 1950-1956. The new model uses the structure of ICRP model for strontium but model parameters have been estimated to account for age, gender and population differences in strontium retention and elimination. Estimates of age- and gender-specific model parameters were derived from (a) the results of long-term measurements of 90Sr-body burden for the Techa River population; (b) experimental studies of calcium and strontium metabolism in humans and (c) non-radiological data regarding bone metabolism (mineral content of the body, bone turnover, etc). As a result, the new model satisfactorily describes data on long-term retention of 90Sr in residents of the Techa River settlements of all ages and both genders and also data from studies during the period of global fallout in the UK and the USA and experimental data on strontium retention in humans. The new model can be used to calculate dose from 89,90Sr for the Techa River residents and also for other populations with similar parameters of skeletal maturation and also for other populations with similar parameters of skeletal maturation and involution. (Author) 27 refs

  17. Retention of tritium in reference persons: a metabolic model. Derivation of parameters and application of the model to the general public and to workers

    International Nuclear Information System (INIS)

    Galeriu, D; Melintescu, A

    2010-01-01

    Tritium ( 3 H) is a radioactive isotope of hydrogen that is ubiquitous in environmental and biological systems. Following debate on the human health risk from exposure to tritium, there have been claims that the current biokinetic model recommended by the International Commission on Radiological Protection (ICRP) may underestimate tritium doses. A new generic model for tritium in mammals, based on energy metabolism and body composition, together with all its input data, has been described in a recent paper and successfully tested for farm and laboratory mammals. That model considers only dietary intake of tritium and was extended to humans. This paper presents the latest development of the human model with explicit consideration of brain energy metabolism. Model testing with human experimental data on organically bound tritium (OBT) in urine after tritiated water (HTO) or OBT intakes is presented. Predicted absorbed doses show a moderate increase for OBT intakes compared with doses recommended by the ICRP. Infants have higher tritium retention-a factor of 2 longer than the ICRP estimate. The highest tritium concentration is in adipose tissue, which has a very low radiobiological sensitivity. The ranges of uncertainty in retention and doses are investigated. The advantage of the new model is its ability to be applied to the interpretation of bioassay data.

  18. Retention of tritium in reference persons: a metabolic model. Derivation of parameters and application of the model to the general public and to workers

    Energy Technology Data Exchange (ETDEWEB)

    Galeriu, D; Melintescu, A, E-mail: galdan@ifin.nipne.r, E-mail: dangaler@yahoo.co [' Horia Hulubei' National Institute for Physics and Nuclear Engineering, Department of Life and Environmental Physics, 407 Atomistilor Street, Bucharest-Magurele, POB MG-6, RO-077125 (Romania)

    2010-09-15

    Tritium ({sup 3}H) is a radioactive isotope of hydrogen that is ubiquitous in environmental and biological systems. Following debate on the human health risk from exposure to tritium, there have been claims that the current biokinetic model recommended by the International Commission on Radiological Protection (ICRP) may underestimate tritium doses. A new generic model for tritium in mammals, based on energy metabolism and body composition, together with all its input data, has been described in a recent paper and successfully tested for farm and laboratory mammals. That model considers only dietary intake of tritium and was extended to humans. This paper presents the latest development of the human model with explicit consideration of brain energy metabolism. Model testing with human experimental data on organically bound tritium (OBT) in urine after tritiated water (HTO) or OBT intakes is presented. Predicted absorbed doses show a moderate increase for OBT intakes compared with doses recommended by the ICRP. Infants have higher tritium retention-a factor of 2 longer than the ICRP estimate. The highest tritium concentration is in adipose tissue, which has a very low radiobiological sensitivity. The ranges of uncertainty in retention and doses are investigated. The advantage of the new model is its ability to be applied to the interpretation of bioassay data.

  19. Bibliographic study on molybdenum biokinetics. Literaturstudie zur Biokinetik von Molybdaen

    Energy Technology Data Exchange (ETDEWEB)

    Erzberger, A.

    1988-05-01

    This bibliographical study compiles and analyzes findings about the metabolism and resorption of molybdenum. Besides including studies on the physiology of molybdenum 99, a general survey is given on molybdenum in the environment and on its physiological behaviour. In particular, information on the dependence of molybdenum resorption on various factors, such as the chemical form, antagonisms etc., are gathered from literature. These factors have to be considered for sensibly carrying out necessary experiments.

  20. Biokinetics of 237Np in mussels and shrimp

    International Nuclear Information System (INIS)

    Guary, J.C.; Fowler, S.W.

    1977-01-01

    Neptunium-237 kinetics were studied in marine shrimp and mussels using a thick source alpha counting technique. Bioaccumulation of 237 Np from water was relatively slow in both species, reaching whole body concentration factors of only 15 to 20 after three months. Surface adsorption was implicated in the initial uptake. Both uptake and loss of the radioisotope were not significantly affected by temperature; this may be a reflection of the physical nature of the uptake. By virtue of the large amounts of accumulated 237 Np associated with the exoskeleton of shrimp, molting will play an important role in the biogeochemical cycling of this transuranic in the marine environment. Rapid growth of organisms like mussels acts to reduce the 237 Np concentration in tissues during a period of decontamination

  1. Nitrification biokinetics in rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Tatari, Karolina

    Danmarks drikkevandsforsyning er udelukkende baseret på grundvand – og mere end 2500 vandværker behandler hver dag vand til de danske forbrugere. Selv om denne vandbehandling betegnes som simpel, er den i virkeligheden baseret på komplicerede mikrobielle processer, som vi hidtil har vidst relativ...

  2. Biokinetics of 237Np in two marine benthic invertebrates

    International Nuclear Information System (INIS)

    Guary, J.C.; Fowler, S.W.

    1976-01-01

    The long-lived alpha-emitting actinide 237 Np (T 1/2 = 2.2 x 10 6 y) enters the aquatic environment directly from nuclear testing and reprocessing plant wastes as well as indirectly by in situ generation from 241 Am. Earlier studies on 239 Np in the Columbia river ecosystem demonstrated that neptunium accumulated in aquatic species such as algae, sponges and insect larvae but was not detectable in higher trophic level organisms. Based on these findings and the fact that neptunium is chemically similar to the rare earth elements, it has been suggested that this actinide would not easily become incorporated into aquatic biota

  3. Biokinetic studies on 14C-chitosan in rats

    International Nuclear Information System (INIS)

    Jia Minghong; Nishimura, Y.; Watanabe, Y.; Yukawa, M.

    1998-05-01

    The absorption and the basic metabolism of chitosan in rats are investigated. The results indicated that 14 C-chitosan from gastrointestinal tract was absorbed, metabolized and excreted quickly without re-bioavailability. The radioactive compounds perhaps with specifically chemical forms in serum, liver and the contents of small intestines were separated on GPC column and measured by radioactivity counting. A big pile of peaks with the retention volume almost same as that of standard 14 C-chitosan and another sharp one with the retention volume in the range of higher molecular weight same as that of BSA were discovered in analysis respectively for contents of intestine and serum or liver. The sharp peak would disappear if the proteins contained in the serum or liver were removed. In addition, and interesting tail peak, followed with the pile ones and eluted with the retention volume of lower molecular weight range same as that of chitooligosaccharides was also found in each of the 3 samples, ignoring the protein removal or not. These results suggested that most of 14 C-chitosan was not to be digested in intestine. On the other hand, a small amount of 14 C-chitosan was likely to be absorbed directly or after degraded to small molecular compounds into blood, liver and other tissues, and then connected with the proteins. Perhaps it is these trace materials that were playing important roles in reduction of the bioavailability of radiostrontium in rats

  4. Micro-dosing for early biokinetic studies in humans

    International Nuclear Information System (INIS)

    Stenstroem, K.; Sydoff, M.; Mattsson, S.

    2010-01-01

    Micro-dosing is a new concept in drug development that-if implemented in the pharmaceutical industry-would mean that new drugs can be tested earlier in humans than done today. The human micro-dosing concept-or 'Phase 0'-may offer improved candidate selection, reduced failure rates in the drug development line and a reduction in the use of laboratory animals in early drug development, factors which will help to speed up drug development and also reduce the costs. Micro-dosing utilises sub-pharmacological amounts of the substance to open opportunities for early studies in man. Three technologies are used for micro-dosing: accelerator mass spectrometry (AMS), positron emission tomography and liquid chromatography-tandem mass spectrometry. This paper focuses on the principle of AMS and discusses the current status of micro-dosing with AMS. (authors)

  5. Bio-kinetic energy harvesting using electroactive polymers

    Science.gov (United States)

    Slade, Jeremiah R.; Bowman, Jeremy; Kornbluh, Roy

    2012-06-01

    In hybrid vehicles, electric motors are used on each wheel to not only propel the car but also to decelerate the car by acting as generators. In the case of the human body, muscles spend about half of their time acting as a brake, absorbing energy, or doing what is known as negative work. Using dielectric elastomers it is possible to use the "braking" phases of walking to generate power without restricting or fatiguing the Warfighter. Infoscitex and SRI have developed and demonstrated methods for using electroactive polymers (EAPs) to tap into the negative work generated at the knee during the deceleration phase of the human gait cycle and convert it into electrical power that can be used to support wearable information systems, including display and communication technologies. The specific class of EAP that has been selected for these applications is termed dielectric elastomers. Because dielectric elastomers dissipate very little mechanical energy into heat, greater amounts of energy can be converted into electricity than by any other method. The long term vision of this concept is to have EAP energy harvesting cells located in components of the Warfighter ensemble, such as the boot uppers, knee pads and eventually even the clothing itself. By properly locating EAPs at these sites it will be possible to not only harvest power from the negative work phase but to actually reduce the amount of work done by the Warfighter's muscles during this phase, thereby reducing fatigue and minimizing the forces transmitted to the joints.

  6. Modelling

    CERN Document Server

    Spädtke, P

    2013-01-01

    Modeling of technical machines became a standard technique since computer became powerful enough to handle the amount of data relevant to the specific system. Simulation of an existing physical device requires the knowledge of all relevant quantities. Electric fields given by the surrounding boundary as well as magnetic fields caused by coils or permanent magnets have to be known. Internal sources for both fields are sometimes taken into account, such as space charge forces or the internal magnetic field of a moving bunch of charged particles. Used solver routines are briefly described and some bench-marking is shown to estimate necessary computing times for different problems. Different types of charged particle sources will be shown together with a suitable model to describe the physical model. Electron guns are covered as well as different ion sources (volume ion sources, laser ion sources, Penning ion sources, electron resonance ion sources, and H$^-$-sources) together with some remarks on beam transport.

  7. Modeling arsenite oxidation by chemoautotrophic Thiomonas arsenivorans strain b6 in a packed-bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Dastidar, Aniruddha, E-mail: andy.dastidar@ky.gov [USEPA Research Participant, Division of Water, Frankfort, KY 40601 (United States); Wang, Yi-Tin, E-mail: ywang@engr.uky.edu [Department of Civil Engineering, University of Kentucky, Lexington (United States)

    2012-08-15

    Arsenic is a major toxic pollutant of concern for the human health. Biological treatment of arsenic contaminated water is an alternative strategy to the prevalent conventional treatments. The biological treatment involves a pre-oxidation step transforming the most toxic form of arsenic, As (III), to the least toxic form, As (V), respectively. This intermediate process improves the overall efficiency of total arsenic removal from the contaminated water. As (III) oxidation by the chemoautotrophic bacterium Thiomonas arsenivorans strain b6 was investigated in a fixed-film reactor under variable influent As (III) concentrations (500-4000 mg/L) and hydraulic residence times (HRTs) (0.2-1 day) for a duration of 137 days. During the entire operation, seven steady-state conditions were obtained with As (III) oxidation efficiency ranging from 48.2% to 99.3%. The strong resilience of the culture was exhibited by the recovery of the bioreactor from an As (III) overloading of 5300 {+-} 400 mg As (III)/L day operated at a HRT of 0.2 day. An arsenic mass balance revealed that As (III) was mainly oxidized to As (V) with unaccounted arsenic ({<=} 4%) well within the analytical error of measurement. A modified Monod flux expression was used to determine the biokinetic parameters by fitting the model against the observed steady-state flux data obtained from operating the bioreactor under a range of HRTs (0.2-1 day) and a constant influent As (III) concentration of 500 mg/L. Model parameters, k = 0.71 {+-} 0.1 mg As (III)/mg cells h, and K{sub s} = 13.2 {+-} 2.8 mg As (III)/L were obtained using a non-linear estimation routine and employing the Marquardt-Levenberg algorithm. Sensitivity analysis revealed k to be more sensitive to model simulations of As (III) oxidation under steady-state conditions than parameter K{sub s}. -- Highlights: Black-Right-Pointing-Pointer As (III) oxidation. Black-Right-Pointing-Pointer Biokinetic parameters. Black-Right-Pointing-Pointer Model validation

  8. A Common Decision of Compartmental Models on the Base of Laplace Transform and Retain Function Concept

    International Nuclear Information System (INIS)

    Dimitrov, L.; Tzvetkova, A.; Nikolov, A.

    1997-01-01

    The compartmental models have a variety of applications in the analysis of the transport of radioactive and non-radioactive material in complex systems as atmosphere, hydrosphere, food chains, human body. The analysis of the biokinetic behaviour of the radioactive material into a human body gives a possibility for correct assessment of the dose from internal irradiation. Skrable has given a decision of non-cyclic linear compartmental models in case of a single intake of material in the compartments as an initial condition. The main purpose of our article is to write down a procedure for analysis of a general compartmental model in case of continuous intake of material into the compartments. This procedure is related to retain function concept and had developed on the base of Laplace transform. On the base on the proposed procedure a non-cyclic linear compartmental model decisions are given in case of both a single and a continuous intake. The Laplace images of cyclic and circular linear compartmental model decisions and their originals in some cases are given too. (author)

  9. Activated sludge model (ASM) based modelling of membrane bioreactor (MBR) processes: a critical review with special regard to MBR specificities.

    Science.gov (United States)

    Fenu, A; Guglielmi, G; Jimenez, J; Spèrandio, M; Saroj, D; Lesjean, B; Brepols, C; Thoeye, C; Nopens, I

    2010-08-01

    Membrane bioreactors (MBRs) have been increasingly employed for municipal and industrial wastewater treatment in the last decade. The efforts for modelling of such wastewater treatment systems have always targeted either the biological processes (treatment quality target) as well as the various aspects of engineering (cost effective design and operation). The development of Activated Sludge Models (ASM) was an important evolution in the modelling of Conventional Activated Sludge (CAS) processes and their use is now very well established. However, although they were initially developed to describe CAS processes, they have simply been transferred and applied to MBR processes. Recent studies on MBR biological processes have reported several crucial specificities: medium to very high sludge retention times, high mixed liquor concentration, accumulation of soluble microbial products (SMP) rejected by the membrane filtration step, and high aeration rates for scouring purposes. These aspects raise the question as to what extent the ASM framework is applicable to MBR processes. Several studies highlighting some of the aforementioned issues are scattered through the literature. Hence, through a concise and structured overview of the past developments and current state-of-the-art in biological modelling of MBR, this review explores ASM-based modelling applied to MBR processes. The work aims to synthesize previous studies and differentiates between unmodified and modified applications of ASM to MBR. Particular emphasis is placed on influent fractionation, biokinetics, and soluble microbial products (SMPs)/exo-polymeric substances (EPS) modelling, and suggestions are put forward as to good modelling practice with regard to MBR modelling both for end-users and academia. A last section highlights shortcomings and future needs for improved biological modelling of MBR processes. (c) 2010 Elsevier Ltd. All rights reserved.

  10. A model for the transfer of alkaline earth elements to the fetus

    International Nuclear Information System (INIS)

    Fell, T.P.; Harrison, J.D.; Leggett, R.W.

    2001-01-01

    A biokinetic model has been developed for the transfer of calcium, strontium, barium and radium to the human fetus. For the mother, ICRP models were adapted for pregnancy to include increases in gastrointestinal absorption, urinary excretion and bone turnover rates. The fetus was modelled with blood, soft tissue and bone compartments. Fetal requirements for Ca were determined by skeletal calcification, and recycling between fetal and maternal blood was included. Daily transfer of Sr, Ba and Ra to the fetus was taken to be lower than for Ca by factors of 0.6 for Sr and 0.4 for Ba and Ra. For acute intakes in late pregnancy at 35 weeks after conception, when maximum transfer occurs, the model predicts whole-body fetus:mother concentration ratios (C F :C M ) of 18 for Ca, 8 for Sr and 2 for Ba and Ra, respectively. Estimates of committed equivalent doses to the red bone marrow of offspring, including in utero and postnatal dose, after maternal ingestion in late pregnancy, were greater than corresponding doses in adults by factors of 20-30 for 45 Ca, 2-3 for 90 Sr and 3-4 for 226 Ra but slightly lower (0.8-0.9) for 133 Ba. (author)

  11. Assessing the reliability of dose coefficients for exposure to radioiodine by members of the public, accounting for dosimetric and risk model uncertainties.

    Science.gov (United States)

    Puncher, M; Zhang, W; Harrison, J D; Wakeford, R

    2017-06-26

    Assessments of risk to a specific population group resulting from internal exposure to a particular radionuclide can be used to assess the reliability of the appropriate International Commission on Radiological Protection (ICRP) dose coefficients used as a radiation protection device for the specified exposure pathway. An estimate of the uncertainty on the associated risk is important for informing judgments on reliability; a derived uncertainty factor, UF, is an estimate of the 95% probable geometric difference between the best risk estimate and the nominal risk and is a useful tool for making this assessment. This paper describes the application of parameter uncertainty analysis to quantify uncertainties resulting from internal exposures to radioiodine by members of the public, specifically 1, 10 and 20-year old females from the population of England and Wales. Best estimates of thyroid cancer incidence risk (lifetime attributable risk) are calculated for ingestion or inhalation of 129 I and 131 I, accounting for uncertainties in biokinetic model and cancer risk model parameter values. These estimates are compared with the equivalent ICRP derived nominal age-, sex- and population-averaged estimates of excess thyroid cancer incidence to obtain UFs. Derived UF values for ingestion or inhalation of 131 I for 1 year, 10-year and 20-year olds are around 28, 12 and 6, respectively, when compared with ICRP Publication 103 nominal values, and 9, 7 and 14, respectively, when compared with ICRP Publication 60 values. Broadly similar results were obtained for 129 I. The uncertainties on risk estimates are largely determined by uncertainties on risk model parameters rather than uncertainties on biokinetic model parameters. An examination of the sensitivity of the results to the risk models and populations used in the calculations show variations in the central estimates of risk of a factor of around 2-3. It is assumed that the direct proportionality of excess thyroid cancer

  12. Implementation of the NCRP wound model for interpretation of bioassay data for intake of radionuclides through contaminated wounds

    International Nuclear Information System (INIS)

    Ishigure, Nobuhito

    2009-01-01

    Emergency response preparedness for radiological accidents involving wound contamination has become more important, considering the current extending tendency in the nuclear industry related to the nuclear fuel cycle. The US National Council on Radiation Protection and Measurements (NCRP) proposed a biokinetic and dosimetric model for the intake of radionuclides through contaminated wounds in 2007. The present paper describes the implementation of this NCRP wound model for the prediction of systemic behaviour of some important radioactive elements encountered in workplaces related to the nuclear industry. The NCRP wound model was linked to the current ICRP systemic model at each blood compartment and simultaneous differential equations for the content of radioactivity in each compartment and excreta were solved with the Runge-Kutta method. The results of the calculation of wound, whole-body or specific organ retention and daily urinary or faecal excretion rate of some selected elements will be useful for the interpretation of bioassay data and dose assessment for cases of wound contamination. (author)

  13. Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects

    Science.gov (United States)

    Buchwalter, D.B.; Cain, D.J.; Clements, W.H.; Luoma, S.N.

    2007-01-01

    Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. ?? 2007 American Chemical Society.

  14. Uncertainty and sensitivity analysis of control strategies using the benchmark simulation model No1 (BSM1).

    Science.gov (United States)

    Flores-Alsina, Xavier; Rodriguez-Roda, Ignasi; Sin, Gürkan; Gernaey, Krist V

    2009-01-01

    The objective of this paper is to perform an uncertainty and sensitivity analysis of the predictions of the Benchmark Simulation Model (BSM) No. 1, when comparing four activated sludge control strategies. The Monte Carlo simulation technique is used to evaluate the uncertainty in the BSM1 predictions, considering the ASM1 bio-kinetic parameters and influent fractions as input uncertainties while the Effluent Quality Index (EQI) and the Operating Cost Index (OCI) are focused on as model outputs. The resulting Monte Carlo simulations are presented using descriptive statistics indicating the degree of uncertainty in the predicted EQI and OCI. Next, the Standard Regression Coefficients (SRC) method is used for sensitivity analysis to identify which input parameters influence the uncertainty in the EQI predictions the most. The results show that control strategies including an ammonium (S(NH)) controller reduce uncertainty in both overall pollution removal and effluent total Kjeldahl nitrogen. Also, control strategies with an external carbon source reduce the effluent nitrate (S(NO)) uncertainty increasing both their economical cost and variability as a trade-off. Finally, the maximum specific autotrophic growth rate (micro(A)) causes most of the variance in the effluent for all the evaluated control strategies. The influence of denitrification related parameters, e.g. eta(g) (anoxic growth rate correction factor) and eta(h) (anoxic hydrolysis rate correction factor), becomes less important when a S(NO) controller manipulating an external carbon source addition is implemented.

  15. Estimates of potential childhood lead exposure from contaminated soil using the US EPA IEUBK Model in Sydney, Australia.

    Science.gov (United States)

    Laidlaw, Mark A S; Mohmmad, Shaike M; Gulson, Brian L; Taylor, Mark P; Kristensen, Louise J; Birch, Gavin

    2017-07-01

    Surface soils in portions of the Sydney (New South Wales, Australia) urban area are contaminated with lead (Pb) primarily from past use of Pb in gasoline, the deterioration of exterior lead-based paints, and industrial activities. Surface soil samples (n=341) were collected from a depth of 0-2.5cm at a density of approximately one sample per square kilometre within the Sydney estuary catchment and analysed for lead. The bioaccessibility of soil Pb was analysed in 18 samples. The blood lead level (BLL) of a hypothetical 24 month old child was predicted at soil sampling sites in residential and open land use using the United States Environmental Protection Agency (US EPA) Integrated Exposure Uptake and Biokinetic (IEUBK) model. Other environmental exposures used the Australian National Environmental Protection Measure (NEPM) default values. The IEUBK model predicted a geometric mean BLL of 2.0±2.1µg/dL using measured soil lead bioavailability measurements (bioavailability =34%) and 2.4±2.8µg/dL using the Australian NEPM default assumption (bioavailability =50%). Assuming children were present and residing at the sampling locations, the IEUBK model incorporating soil Pb bioavailability predicted that 5.6% of the children at the sampling locations could potentially have BLLs exceeding 5µg/dL and 2.1% potentially could have BLLs exceeding 10µg/dL. These estimations are consistent with BLLs previously measured in children in Sydney. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Application of a canine 238Pu dosimetry model to human bioassay data

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, Jr., A. W. [Florida Univ., Gainesville, FL (United States)

    1991-08-01

    Associated with the use of 2238Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to 238Pu, primarily by inhalation. In the event of human internal exposure, a means is needed for assessing the level of intake and calculating radiation doses. Several bioassay/dosimetry models have been developed for 239Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of 238Pu are significantly different from those for 239Pu. A canine model accounting for these differences has been applied in this work to urinary excretion data from seven humans occupationally exposed to low levels of an insoluble 238Pu compound. The modified model provides a good description of the urinary excretion kinetics observed in the exposed humans. The modified model was also used to provide estimates of the initial intakes of 238Pu for the seven individuals; these estimates ranged from 4.5 nCi (170 Bq) to 87 nCi (3200 Bq). Autopsy data on the amount and distribution of 238Pu retained in the organs may be used in the future to validate or refute both these estimates and the assumptions used to formulate the human model. Modification of the human model to simulate an injection exposure to 239Pu gave patterns of retention in the organs and urinary excretion comparable to those seen previously in humans; further modification of the model using fecal data (unavailable for the subjects of this study) is indicated.

  17. The 10th international congress of IRPA. The development of models for internal dosimetry

    International Nuclear Information System (INIS)

    Stather, J.W.

    2000-01-01

    In the past ten years a series of Publications have been issued by Committee 2 of the International Commission on Radiological Protection (ICRP) giving dose coefficients for intakes of radionuclides by inhalation and ingestion for both members of the public and workers. The biokinetic and dosimetric models used in the calculation of dose coefficients have been based largely on the model structure adopted in ICRP Publication 30 although new, physiologically-based models, involving recycling of radionuclides have been developed for both the alkaline earth and actinide elements. In addition, a new model for the human respiratory tract (HRTM) has been developed. A comprehensive series of dose coefficients have also been published by ICRP on CD-ROM. The series of reports giving dose coefficients for members of the public of various ages is to be completed with the issue of two further reports. The first will give dose coefficients for the embryo, fetus and newborn child following intakes of radionuclides by the mother either before or during pregnancy. Models for infants and children can generally be based on those for adults, with modifications to parameter values, but in the case of the embryo and fetus, fundamentally new models have had to be developed. Models are also being developed for calculating radiation doses to the offspring as a result of the intake of radionuclides in breast milk. The HRTM used for calculating inhalation dose coefficients was developed to allow the use of material specific data. To date, however, it has only been applied using default model parameters. A technical report is being developed that will give guidance on the practical application of the HRTM in circumstances which require the use of data on the deposition and solubility characteristics of specific inhaled materials. The present model used for assessing doses from ingestion of radionuclides was prepared in 1966. An improved model for the human alimentary tract is being developed

  18. Biological behaviour of plutonium inhaled by baboons as plutonium n-tributylphosphate complex. Comparison with ICRP models

    International Nuclear Information System (INIS)

    Metivier, H.; Duserre, C.; Rateau, G.; Legendre, N.; Masse, R.; Piechowski, J.; Menoux, B.

    1989-01-01

    In order to devise a model capable of calculating committed doses for workers contaminated by inhalation of plutonium tributylphosphate complex during reprocessing, we investigated the biokinetics of plutonium in baboons after inhalation of this chemical form. The animals were killed 0.6, 3, 15, 30, 90 and 365 days post inhalation. Urine and faeces were collected daily. After killing, the main organs were collected for chemical analysis. In order to improve our knowledge of the behaviour of systemic plutonium, three baboons were given an intravenous injection of Pu-TBP and were respectively killed 2, 30 and 365 days post injection. We observed that Pu-TBP could be classified as a W compound, with a half-time for lung clearance of 150 days. Urinary Pu excretion was 3 times higher than was expected from Durbin's model, suggesting that Pu introduced as Pu-TBP, is extremely mobile, and that the complex formed with blood proteins differs from the one formed after inhalation of plutonium nitrate. (author)

  19. Advanced computational modeling for in vitro nanomaterial dosimetry.

    Science.gov (United States)

    DeLoid, Glen M; Cohen, Joel M; Pyrgiotakis, Georgios; Pirela, Sandra V; Pal, Anoop; Liu, Jiying; Srebric, Jelena; Demokritou, Philip

    2015-10-24

    Accurate and meaningful dose metrics are a basic requirement for in vitro screening to assess potential health risks of engineered nanomaterials (ENMs). Correctly and consistently quantifying what cells "see," during an in vitro exposure requires standardized preparation of stable ENM suspensions, accurate characterizatoin of agglomerate sizes and effective densities, and predictive modeling of mass transport. Earlier transport models provided a marked improvement over administered concentration or total mass, but included assumptions that could produce sizable inaccuracies, most notably that all particles at the bottom of the well are adsorbed or taken up by cells, which would drive transport downward, resulting in overestimation of deposition. Here we present development, validation and results of two robust computational transport models. Both three-dimensional computational fluid dynamics (CFD) and a newly-developed one-dimensional Distorted Grid (DG) model were used to estimate delivered dose metrics for industry-relevant metal oxide ENMs suspended in culture media. Both models allow simultaneous modeling of full size distributions for polydisperse ENM suspensions, and provide deposition metrics as well as concentration metrics over the extent of the well. The DG model also emulates the biokinetics at the particle-cell interface using a Langmuir isotherm, governed by a user-defined dissociation constant, K(D), and allows modeling of ENM dissolution over time. Dose metrics predicted by the two models were in remarkably close agreement. The DG model was also validated by quantitative analysis of flash-frozen, cryosectioned columns of ENM suspensions. Results of simulations based on agglomerate size distributions differed substantially from those obtained using mean sizes. The effect of cellular adsorption on delivered dose was negligible for K(D) values consistent with non-specific binding (> 1 nM), whereas smaller values (≤ 1 nM) typical of specific high

  20. Measurement and modelling in anthropo-radiometry

    International Nuclear Information System (INIS)

    Carlan, Loic de

    2011-01-01

    In this HDR (Accreditation to supervise researches) report, the author gives an overview of his research activities, gives a summary of his research thesis (feasibility study of an actinide measurement system in the case of lungs), and proposes a research report on the different aspects of anthropo-radiometric measurement: context (principles, significance, sampling phantoms), development of digital phantoms (software presentation and validation), interface development and validation, application to actinide measurement in lung, taking biokinetic data into account for anthropo-radiometric measurement

  1. Biodistribution dosimetric study of radiopharmaceutical 99mTc Ixolaris in mice for melanoma diagnosis by molecular image and translational model for human beings

    International Nuclear Information System (INIS)

    Soriano, Sarah Canuto Silva

    2015-01-01

    The labeling of Ixolaris with 99m Tc was developed by Barboza et.al. (2013) aiming its use primarily in glioblastoma and after in melanoma diagnosis, a less common but very aggressive cancer and with high mortality rate. Preliminary tests on animals have proven its effectiveness of labeling but a dosimetric study to human clinical trials should be performed. This study aimed to: (1) determine the biokinetic model for the radiotracer 99m Tc-Ixolaris in mice by imaging dosimetry method; and (2) estimate the absorbed and effective dose resulting from the use of a new radiopharmaceutical for melanoma and metastases diagnosis in human beings, since a dosimetric study of new radiopharmaceuticals in animals is necessary to test them subsequently in humans and apply for registration in ANVISA. According to SPECT images, was found a latency period of 15 to 21 days for the development of lung metastasis in mice. Three C57BL6 mice, one control animal, and two animals with induced cell line B16-F10 murine melanoma were tested. The 99m Tc-Ixolaris radiopharmaceutical was administered intravenously in a caudal vein, and SPECT images were acquired 0.5 h, 1.5 h, 2.5 h, 3.5 h and 24 h post-administration for analysis and biodistribution quantification. The biokinetic model was determined and thus, obtained cumulative activity in order to estimate the absorbed dose in each organ. The mass and metabolic differences between mice and humans were considered and used to extrapolate the data acquired at different scales. Based on dose factors provided by the software MIRDOSE and Olinda (S factor), absorbed doses in irradiated target organs were calculated for the source organs, and finally the effective dose was estimated. The results indicate that for diagnostic exams conducted in human melanoma patients by administering approximately 25.7 MBq the estimated effective dose was 4.3 mSv. Comparing with effective doses obtained in other diagnostic techniques with 99m Tc, a range of effective

  2. The Mayak Worker Dosimetry System (MWDS-2013): a comparison of intakes based on urine versus autopsy data from Mayak workers using the Leggett systemic model for plutonium

    International Nuclear Information System (INIS)

    Birchall, A.; Dorrian, M.-D.; Suslova, K. G.; Sokolova, A. B.

    2017-01-01

    The Mayak Worker Dosimetry System-2013 (MWDS-2013) uses a model developed by Leggett and colleagues to represent the biokinetic behaviour of plutonium after uptake to blood. Of particular importance, with regard to estimating intakes (and doses), is the distribution of activity between urine and body organs (particularly liver and skeleton). In this study, measurement data (urine and autopsy) from around 500 Mayak workers have been used to validate use of this model. A robust method has been developed and used to estimate intakes from both urine and autopsy data separately, and the ratio of these estimates has been calculated for each worker. The geometric mean ratio has been shown to lie within a range of 0.92-1.14, depending on assumptions made. Since this range includes 1, the hypothesis that the model is unbiased with regard to estimating intakes either with urine or autopsy data cannot be rejected on the basis of these data. This lends weight to the argument for increasing the MWDS-2013 cohort to include an additional 500 workers for whom only autopsy data are available, and who have previously been excluded from the cohort. Future directions in which this work could be extended are also suggested. (authors)

  3. Dosimetric Significance of the ICRP's Updated Guidance and Models, 1989-2003, and Implications for U.S. Federal Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W.

    2003-09-10

    Over the past two decades the U.S. Environmental Protection Agency (EPA) has issued a series of Federal guidance documents for the purpose of providing the Federal and State agencies with technical information to assist their implementation of radiation protection programs. Currently recommended dose conversion factors, annual limits on intake, and derived air concentrations for intake of radionuclides are tabulated in Federal Guidance Report No. 11 (FGR 11), published in 1988. The tabulations in FGR 11 were based on dosimetric quantities and biokinetic and dosimetric models of the International Commission on Radiological Protection (ICRP) developed for application to occupational exposures. Since the publication of FGR 11 the ICRP has revised some of its dosimetric quantities and its models for workers and has also developed age-specific models and dose conversion factors for intake of radionuclides by members of the public. This report examines the extent of the changes in the inhalation and ingestion dose coefficients of FGR 11 implied by the updated recommendations of the ICRP, both for workers and members of the public.

  4. Computational fluid dynamics modeling of Bacillus anthracis spore deposition in rabbit and human respiratory airways

    Energy Technology Data Exchange (ETDEWEB)

    Kabilan, S.; Suffield, S. R.; Recknagle, K. P.; Jacob, R. E.; Einstein, D. R.; Kuprat, A. P.; Carson, J. P.; Colby, S. M.; Saunders, J. H.; Hines, S. A.; Teeguarden, J. G.; Straub, T. M.; Moe, M.; Taft, S. C.; Corley, R. A.

    2016-09-01

    Three-dimensional computational fluid dynamics and Lagrangian particle deposition models were developed to compare the deposition of aerosolized Bacillus anthracis spores in the respiratory airways of a human with that of the rabbit, a species commonly used in the study of anthrax disease. The respiratory airway geometries for each species were derived respectively from computed tomography (CT) and µCT images. Both models encompassed airways that extended from the external nose to the lung with a total of 272 outlets in the human model and 2878 outlets in the rabbit model. All simulations of spore deposition were conducted under transient, inhalation–exhalation breathing conditions using average species-specific minute volumes. Two different exposure scenarios were modeled in the rabbit based upon experimental inhalation studies. For comparison, human simulations were conducted at the highest exposure concentration used during the rabbit experimental exposures. Results demonstrated that regional spore deposition patterns were sensitive to airway geometry and ventilation profiles. Due to the complex airway geometries in the rabbit nose, higher spore deposition efficiency was predicted in the nasal sinus compared to the human at the same air concentration of anthrax spores. In contrast, higher spore deposition was predicted in the lower conducting airways of the human compared to the rabbit lung due to differences in airway branching pattern. This information can be used to refine published and ongoing biokinetic models of inhalation anthrax spore exposures, which currently estimate deposited spore concentrations based solely upon exposure concentrations and inhaled doses that do not factor in species-specific anatomy and physiology for deposition.

  5. Computational Fluid Dynamics Modeling of Bacillus anthracis Spore Deposition in Rabbit and Human Respiratory Airways

    Energy Technology Data Exchange (ETDEWEB)

    Kabilan, Senthil; Suffield, Sarah R.; Recknagle, Kurtis P.; Jacob, Rick E.; Einstein, Daniel R.; Kuprat, Andrew P.; Carson, James P.; Colby, Sean M.; Saunders, James H.; Hines, Stephanie; Teeguarden, Justin G.; Straub, Tim M.; Moe, M.; Taft, Sarah; Corley, Richard A.

    2016-09-30

    Three-dimensional computational fluid dynamics and Lagrangian particle deposition models were developed to compare the deposition of aerosolized Bacillus anthracis spores in the respiratory airways of a human with that of the rabbit, a species commonly used in the study of anthrax disease. The respiratory airway geometries for each species were derived from computed tomography (CT) or µCT images. Both models encompassed airways that extended from the external nose to the lung with a total of 272 outlets in the human model and 2878 outlets in the rabbit model. All simulations of spore deposition were conducted under transient, inhalation-exhalation breathing conditions using average species-specific minute volumes. The highest exposure concentration was modeled in the rabbit based upon prior acute inhalation studies. For comparison, human simulation was also conducted at the same concentration. Results demonstrated that regional spore deposition patterns were sensitive to airway geometry and ventilation profiles. Due to the complex airway geometries in the rabbit nose, higher spore deposition efficiency was predicted in the upper conducting airways compared to the human at the same air concentration of anthrax spores. As a result, higher particle deposition was predicted in the conducting airways and deep lung of the human compared to the rabbit lung due to differences in airway branching pattern. This information can be used to refine published and ongoing biokinetic models of inhalation anthrax spore exposures, which currently estimate deposited spore concentrations based solely upon exposure concentrations and inhaled doses that do not factor in species-specific anatomy and physiology.

  6. Children's Lead Exposure: A Multimedia Modeling Analysis to Guide Public Health Decision-Making.

    Science.gov (United States)

    Zartarian, Valerie; Xue, Jianping; Tornero-Velez, Rogelio; Brown, James

    2017-09-12

    Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)'s National Drinking Water Advisory Council (NDWAC) recommended establishment of a "health-based, household action level" for lead in drinking water based on children's exposure. The primary objective was to develop a coupled exposure-dose modeling approach that can be used to determine what drinking water lead concentrations keep children's blood lead levels (BLLs) below specified values, considering exposures from water, soil, dust, food, and air. Related objectives were to evaluate the coupled model estimates using real-world blood lead data, to quantify relative contributions by the various media, and to identify key model inputs. A modeling approach using the EPA's Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia and Integrated Exposure Uptake and Biokinetic (IEUBK) models was developed using available data. This analysis for the U.S. population of young children probabilistically simulated multimedia exposures and estimated relative contributions of media to BLLs across all population percentiles for several age groups. Modeled BLLs compared well with nationally representative BLLs (0-23% relative error). Analyses revealed relative importance of soil and dust ingestion exposure pathways and associated Pb intake rates; water ingestion was also a main pathway, especially for infants. This methodology advances scientific understanding of the relationship between lead concentrations in drinking water and BLLs in children. It can guide national health-based benchmarks for lead and related community public health decisions. https://doi.org/10.1289/EHP1605.

  7. Mathematical model for carbon dioxide evolution from the thermophilic composting of synthetic food wastes made of dog food

    International Nuclear Information System (INIS)

    Chang, J.I.; Tsai, J.J.; Wu, K.H.

    2005-01-01

    The impacts of the aeration and the agitation on the composting process of synthetic food wastes made of dog food were studied in a laboratory-scale reactor. Two major peaks of CO 2 evolution rate were observed. Each peak represented an independent stage of composting associated with the activities of thermophilic bacteria. CO 2 evolutions known to correlate well with microbial activities and reactor temperatures were fitted successfully to a modified Gompertz equation, which incorporated three biokinetic parameters, namely, CO 2 evolution potential, specific CO 2 evolution rate, and lag phase time. No parameters that describe the impact of operating variables are involved. The model is only valid for the specified experimental conditions and may look different with others. The effects of operating parameters such as aeration and agitation were studied statistically with multivariate regression technique. Contour plots were constructed using regression equations for the examination of the dependence of CO 2 evolution potentials on aeration and agitation. In the first stage, a maximum CO 2 evolution potential was found when the aeration rate and the agitation parameter were set at 1.75 l/kg solids-min and 0.35, respectively. In the second stage, a maximum existed when the aeration rate and the agitation parameter were set at 1.8 l/kg solids-min and 0.5, respectively. The methods presented here can also be applied for the optimization of large-scale composting facilities that are operated differently and take longer time

  8. Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models.

    Science.gov (United States)

    Teng, S; Tebby, C; Barcellini-Couget, S; De Sousa, G; Brochot, C; Rahmani, R; Pery, A R R

    2016-08-15

    Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro - in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models

    International Nuclear Information System (INIS)

    Teng, S.; Tebby, C.; Barcellini-Couget, S.; De Sousa, G.; Brochot, C.; Rahmani, R.; Pery, A.R.R.

    2016-01-01

    Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro – in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. - Highlights: • We could predict cell response over repeated exposure to mixtures of cosmetics. • Compounds acted independently on the cells. • Metabolic interactions impacted exposure concentrations to the compounds.

  10. Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models

    Energy Technology Data Exchange (ETDEWEB)

    Teng, S.; Tebby, C. [Models for Toxicology and Ecotoxicology Unit, INERIS, Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Barcellini-Couget, S. [ODESIA Neosciences, Sophia Antipolis, 400 route des chappes, 06903 Sophia Antipolis (France); De Sousa, G. [INRA, ToxAlim, 400 route des Chappes, BP, 167 06903 Sophia Antipolis, Cedex (France); Brochot, C. [Models for Toxicology and Ecotoxicology Unit, INERIS, Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Rahmani, R. [INRA, ToxAlim, 400 route des Chappes, BP, 167 06903 Sophia Antipolis, Cedex (France); Pery, A.R.R., E-mail: alexandre.pery@agroparistech.fr [AgroParisTech, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thiverval Grignon (France); INRA, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thiverval Grignon (France)

    2016-08-15

    Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro – in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. - Highlights: • We could predict cell response over repeated exposure to mixtures of cosmetics. • Compounds acted independently on the cells. • Metabolic interactions impacted exposure concentrations to the compounds.

  11. The measurement of thoron (220Rn) concentration in indoor air continuously using pylon model WLx

    International Nuclear Information System (INIS)

    Hasnel Sofyan

    2011-01-01

    The concentration of thoron ( 220 Rn) in particular location can be higher than radon ( 220 Rn), however, its presence is always neglected. This might be due to the difficulties in calibration and discrimination between radon and thoron. From biokinetic and dosimetric model, it has been known that the dominant contribution of thoron to the effective dose is in the lungs. UNSCEAR estimates the doses contribution of thoron and its progenies is between 5-10% of the annual dose received by the general public and the risk level is 4.4 times greater than radon and progenies. Therefore, it is necessary to study the thoron concentration in indoor air and workplaces. Radon-thoron concentration in indoor air can be determined by direct methods using Pylon Model WLx device and passive methods using Solid State Nuclear Track Detector (SSNTDs). In this research the measurement of thoron was carried out continuously using Pylon Model WLx equipment that is sensitive to radon for 24, 65, 72, 116 and 154 hours in different rooms. The measurement result showed that the mean value of thoron working level (WL) concentration obtained in room-1 was 2.53 ± 0.67 Bq/m 3 with maximum and minimum of thoron concentrations were 3.37 and 2.22 Bq/m 3 respectively. From the measurement in different locations, it was obtained that the largest and smallest average concentrations of thoron progenies were 0.83 ± 0.23 Bq/m 3 and 0.29 ± 0.64 Bq/m 3 , while the maximum and minimum concentration values were 7.80 Bq/m 3 and 0.01 Bq/m 3 respectively. Pylon Model WLx device is not enables to be used for longer and large scale survey area concurrently, so the SSNTDs which is sensitive to the emission of alpha particles and can measure cumulative thoron concentrations is required. (author)

  12. Application of IEUBK model in lead risk assessment of children aged 61–84 months old in central China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanyan [MOE Key Lab of Environment and Health, Institute of Environmental Medicine, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Hu, Jia [Suzhou Center for Disease Prevention and Control, Suzhou, Jiangsu (China); Wu, Wei [MOE Key Lab of Environment and Health, Institute of Environmental Medicine, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Liu, Shuyun [Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Li, Mei [Hanyang Center for Disease Prevention and Control, Wuhan, Hubei (China); Yao, Na; Chen, Jianwei [MOE Key Lab of Environment and Health, Institute of Environmental Medicine, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Ye, Linxiang [Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Wang, Qi, E-mail: lwq95@126.com [MOE Key Lab of Environment and Health, Institute of Environmental Medicine, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China); Zhou, Yikai, E-mail: zhouyk@mails.tjmu.edu.cn [MOE Key Lab of Environment and Health, Institute of Environmental Medicine, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, Hubei (China)

    2016-01-15

    Few studies have focused on the accuracy of using the Integrated Exposure Uptake Biokinetic (IEUBK) model in Chinese children with site- and age-specific exposure data. This study aimed to validate the accuracy and sensitivity of the IEUBK model in lead risk assessment of Chinese children aged 61–84 months old. A total of 760 children were enrolled from two respective counties in Central China by using random cluster sampling method. Blood lead levels (BLLs) of all subjects were determined using graphite furnace atomic absorption spectrometry, as well as that in the environmental media, such as air, drinking water, soil, dust and food. Age- and site-specific time-activity patterns and water consumption were evaluated by using questionnaires for children. Exposure parameters including outdoor and indoor activity time, ventilation rate and water consumption in this study were different from the default values of the IEUBK model. Statistical analysis revealed no significant differences between the predicted and observed BLLs. Diet and soil/dust lead intake contributed approximately 83.39% (57.40%–93.84% range) and 15.18% (3.25%–41.60% range) of total lead intake, respectively. These findings showed that the IEUBK model is suitable for lead risk assessment of Chinese children aged 61–84 months old and diet acts as an important lead source. - Highlights: • The first time to fit and discuss the IEUBK model in China based on comprehensive local children exposure parameters. • Two different exposure scenarios to apply the IEUBK model in different conditions. • The first time to report the ventilation rate in Chinese children aged 61 to 84 months. • Highlight the role of dietary to lead intake for Chinese children.

  13. Application of IEUBK model in lead risk assessment of children aged 61–84 months old in central China

    International Nuclear Information System (INIS)

    Li, Yanyan; Hu, Jia; Wu, Wei; Liu, Shuyun; Li, Mei; Yao, Na; Chen, Jianwei; Ye, Linxiang; Wang, Qi; Zhou, Yikai

    2016-01-01

    Few studies have focused on the accuracy of using the Integrated Exposure Uptake Biokinetic (IEUBK) model in Chinese children with site- and age-specific exposure data. This study aimed to validate the accuracy and sensitivity of the IEUBK model in lead risk assessment of Chinese children aged 61–84 months old. A total of 760 children were enrolled from two respective counties in Central China by using random cluster sampling method. Blood lead levels (BLLs) of all subjects were determined using graphite furnace atomic absorption spectrometry, as well as that in the environmental media, such as air, drinking water, soil, dust and food. Age- and site-specific time-activity patterns and water consumption were evaluated by using questionnaires for children. Exposure parameters including outdoor and indoor activity time, ventilation rate and water consumption in this study were different from the default values of the IEUBK model. Statistical analysis revealed no significant differences between the predicted and observed BLLs. Diet and soil/dust lead intake contributed approximately 83.39% (57.40%–93.84% range) and 15.18% (3.25%–41.60% range) of total lead intake, respectively. These findings showed that the IEUBK model is suitable for lead risk assessment of Chinese children aged 61–84 months old and diet acts as an important lead source. - Highlights: • The first time to fit and discuss the IEUBK model in China based on comprehensive local children exposure parameters. • Two different exposure scenarios to apply the IEUBK model in different conditions. • The first time to report the ventilation rate in Chinese children aged 61 to 84 months. • Highlight the role of dietary to lead intake for Chinese children.

  14. Modeling metal bioaccumulation in the invasive mussels Dreissena polymorpha and Dreissena rostriformis bugensis in the rivers Rhine and Meuse.

    Science.gov (United States)

    Le, T T Yen; Leuven, Rob S E W; Hendriks, A Jan

    2011-12-01

    The metal-specific covalent index and the species-specific size-based filtration rate were integrated into a biokinetic model estimating metal bioaccumulation in mussels from the dissolved phase and phytoplankton. The model was validated for zebra (Dreissena polymorpha) and quagga (Dreissena rostriformis bugensis) mussels in the rivers Rhine and Meuse, the Netherlands. The model performed well in predicting tissue concentrations in different-sized zebra mussels from various sampling sites for (55) Mn, (56) Fe, (59) Co, (60) Ni, (82) Se, (111) Cd, (118) Sn, and (208) Pb (r(2) =0.71-0.99). Performance for (52) Cr, (63) Cu, (66) Zn, (68) Zn, and (112) Cd was moderate (r(2) quagga mussels, approximately 73 to 94% of the variability in concentrations of (82) Se, (111) Cd, (112) Cd, and (208) Pb was explained by the model (r(2) =0.73-0.94), followed by (52) Cr, (55) Mn, (56) Fe, (60) Ni, and (63) Cu (r(2) =0.48-0.61). Additionally, in both zebra and quagga mussels, average modeled concentrations were within approximately one order of magnitude of the measured values. In particular, in zebra mussels, estimations of (60) Ni and (82) Se concentrations were equal to 51 and 76% of the measurements, respectively. Higher deviations were observed for (52) Cr, (59) Co, (55) Mn, (56) Fe, (111) Cd, (63) Cu, and (112) Cd (underestimation), and (66) Zn, (68) Zn, (208) Pb, and (118) Sn (overestimation). For quagga mussels, modeled concentrations of (66) Zn and (68) Zn differed approximately 14% from the measured levels. Differences between predictions and measurements were higher for other metals. Copyright © 2011 SETAC.

  15. Kinetic modelling and characterization of microbial community present in a full-scale UASB reactor treating brewery effluent.

    Science.gov (United States)

    Enitan, Abimbola M; Kumari, Sheena; Swalaha, Feroz M; Adeyemo, J; Ramdhani, Nishani; Bux, Faizal

    2014-02-01

    The performance of a full-scale upflow anaerobic sludge blanket (UASB) reactor treating brewery wastewater was investigated by microbial analysis and kinetic modelling. The microbial community present in the granular sludge was detected using fluorescent in situ hybridization (FISH) and further confirmed using polymerase chain reaction. A group of 16S rRNA based fluorescent probes and primers targeting Archaea and Eubacteria were selected for microbial analysis. FISH results indicated the presence and dominance of a significant amount of Eubacteria and diverse group of methanogenic Archaea belonging to the order Methanococcales, Methanobacteriales, and Methanomicrobiales within in the UASB reactor. The influent brewery wastewater had a relatively high amount of volatile fatty acids chemical oxygen demand (COD), 2005 mg/l and the final COD concentration of the reactor was 457 mg/l. The biogas analysis showed 60-69% of methane, confirming the presence and activities of methanogens within the reactor. Biokinetics of the degradable organic substrate present in the brewery wastewater was further explored using Stover and Kincannon kinetic model, with the aim of predicting the final effluent quality. The maximum utilization rate constant U max and the saturation constant (K(B)) in the model were estimated as 18.51 and 13.64 g/l/day, respectively. The model showed an excellent fit between the predicted and the observed effluent COD concentrations. Applicability of this model to predict the effluent quality of the UASB reactor treating brewery wastewater was evident from the regression analysis (R(2) = 0.957) which could be used for optimizing the reactor performance.

  16. High Throughput PBPK: Evaluating EPA's Open-Source Data and Tools for Dosimetry and Exposure Reconstruction (SOT)

    Science.gov (United States)

    To address this need, new tools have been created for characterizing, simulating, and evaluating chemical biokinetics. Physiologically-based pharmacokinetic (PBPK) models provide estimates of chemical exposures that produce potentially hazardous tissue concentrations, while tissu...

  17. Ab initio chemical safety assessment: A workflow based on exposure considerations and non-animal methods

    OpenAIRE

    Berggren, Elisabet; White, Andrew; Ouedraogo, Gladys; Paini, Alicia; Richarz, Andrea-Nicole; Bois, Frederic Y.; Exner, Thomas; Leite, Sofia; Grunsven, Leo A. van; Worth, Andrew; Mahony, Catherine

    2017-01-01

    Highlights • A workflow for an exposure driven chemical safety assessment to avoid animal testing. • Hypothesis based on existing data, in silico modelling and biokinetic considerations. • A tool to inform targeted and toxicologically relevant in vitro testing.

  18. Root uptake of uranium by a higher plant model (Phaseolus vulgaris) bioavailability from soil solution

    Energy Technology Data Exchange (ETDEWEB)

    Laroche, L.; Henner, P.; Camilleri, V.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Uranium behaviour in soils is controlled by actions and interactions between physicochemical and biological processes that also determine its bioavailability. In soil solution, uranium(+VI) aqueous speciation undergoes tremendous changes mainly depending on pH, carbonates, phosphates and organic matter. In a first approach to identify bioavailable species of U to plants, cultures were performed using hydroponics, to allow an easy control of the composition of the exposure media. The latter, here an artificial soil solution, was designed to control the uranium species in solution. The geochemical speciation code JCHESS using a database compiled from the OECD/NEA thermochemical database project and verified was used to perform the solution speciation calculations. On this theoretical basis, three domains were defined for short-duration well-defined laboratory experiments in simplified conditions: pH 4.9, 5.8 and 7 where predicted dominant species are uranyl ions, hydroxyl complexes and carbonates respectively. For these domains, biokinetics and characterization of transmembrane transport according to a classical Michaelis Menten approach were investigated. The Free Ion Model (or its derived Biotic Ligand Model) was tested to determine if U uptake is governed by the free uranyl species or if other metal complexes can be assimilated. The effect of different variables on root assimilation efficiency and phyto-toxicity was explored: presence of ligands such as phosphates or carbonates and competitive ions such as Ca{sup 2+} at the 3 pH. According to previous experiments, uranium was principally located in roots whatever the pH and no difference in uranium uptake was evidenced between the main growth stages of the plant. Within the 3 studied chemical domains, results from short-term kinetics evidenced a linear correlation between total uranium concentration in bean roots and that in exposure media, suggesting that total uranium in soil solution could be a good predictor

  19. Root uptake of uranium by a higher plant model (Phaseolus vulgaris) bioavailability from soil solution

    International Nuclear Information System (INIS)

    Laroche, L.; Henner, P.; Camilleri, V.; Garnier-Laplace, J.

    2004-01-01

    Uranium behaviour in soils is controlled by actions and interactions between physicochemical and biological processes that also determine its bioavailability. In soil solution, uranium(+VI) aqueous speciation undergoes tremendous changes mainly depending on pH, carbonates, phosphates and organic matter. In a first approach to identify bioavailable species of U to plants, cultures were performed using hydroponics, to allow an easy control of the composition of the exposure media. The latter, here an artificial soil solution, was designed to control the uranium species in solution. The geochemical speciation code JCHESS using a database compiled from the OECD/NEA thermochemical database project and verified was used to perform the solution speciation calculations. On this theoretical basis, three domains were defined for short-duration well-defined laboratory experiments in simplified conditions: pH 4.9, 5.8 and 7 where predicted dominant species are uranyl ions, hydroxyl complexes and carbonates respectively. For these domains, biokinetics and characterization of transmembrane transport according to a classical Michaelis Menten approach were investigated. The Free Ion Model (or its derived Biotic Ligand Model) was tested to determine if U uptake is governed by the free uranyl species or if other metal complexes can be assimilated. The effect of different variables on root assimilation efficiency and phyto-toxicity was explored: presence of ligands such as phosphates or carbonates and competitive ions such as Ca 2+ at the 3 pH. According to previous experiments, uranium was principally located in roots whatever the pH and no difference in uranium uptake was evidenced between the main growth stages of the plant. Within the 3 studied chemical domains, results from short-term kinetics evidenced a linear correlation between total uranium concentration in bean roots and that in exposure media, suggesting that total uranium in soil solution could be a good predictor for

  20. Biodistribution dosimetric study of radiopharmaceutical {sup 99mT}c Ixolaris in mice for melanoma diagnosis by molecular image and translational model for human beings; Estudo dosimetrico da biodistribuicao do radiofarmaco Ixolaris-{sup 99m}Tc em camundongos para diagnostico de melanoma atraves de imagem molecular e modelo translacional para humanos

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Sarah Canuto Silva

    2015-07-01

    The labeling of Ixolaris with {sup 99m}Tc was developed by Barboza et.al. (2013) aiming its use primarily in glioblastoma and after in melanoma diagnosis, a less common but very aggressive cancer and with high mortality rate. Preliminary tests on animals have proven its effectiveness of labeling but a dosimetric study to human clinical trials should be performed. This study aimed to: (1) determine the biokinetic model for the radiotracer {sup 99m}Tc-Ixolaris in mice by imaging dosimetry method; and (2) estimate the absorbed and effective dose resulting from the use of a new radiopharmaceutical for melanoma and metastases diagnosis in human beings, since a dosimetric study of new radiopharmaceuticals in animals is necessary to test them subsequently in humans and apply for registration in ANVISA. According to SPECT images, was found a latency period of 15 to 21 days for the development of lung metastasis in mice. Three C57BL6 mice, one control animal, and two animals with induced cell line B16-F10 murine melanoma were tested. The {sup 99m}Tc-Ixolaris radiopharmaceutical was administered intravenously in a caudal vein, and SPECT images were acquired 0.5 h, 1.5 h, 2.5 h, 3.5 h and 24 h post-administration for analysis and biodistribution quantification. The biokinetic model was determined and thus, obtained cumulative activity in order to estimate the absorbed dose in each organ. The mass and metabolic differences between mice and humans were considered and used to extrapolate the data acquired at different scales. Based on dose factors provided by the software MIRDOSE and Olinda (S factor), absorbed doses in irradiated target organs were calculated for the source organs, and finally the effective dose was estimated. The results indicate that for diagnostic exams conducted in human melanoma patients by administering approximately 25.7 MBq the estimated effective dose was 4.3 mSv. Comparing with effective doses obtained in other diagnostic techniques with {sup 99m

  1. Prediction of time-integrated activity coefficients in PRRT using simulated dynamic PET and a pharmacokinetic model.

    Science.gov (United States)

    Hardiansyah, Deni; Attarwala, Ali Asgar; Kletting, Peter; Mottaghy, Felix M; Glatting, Gerhard

    2017-10-01

    To investigate the accuracy of predicted time-integrated activity coefficients (TIACs) in peptide-receptor radionuclide therapy (PRRT) using simulated dynamic PET data and a physiologically based pharmacokinetic (PBPK) model. PBPK parameters were estimated using biokinetic data of 15 patients after injection of (152±15)MBq of 111 In-DTPAOC (total peptide amount (5.78±0.25)nmol). True mathematical phantoms of patients (MPPs) were the PBPK model with the estimated parameters. Dynamic PET measurements were simulated as being done after bolus injection of 150MBq 68 Ga-DOTATATE using the true MPPs. Dynamic PET scans around 35min p.i. (P 1 ), 4h p.i. (P 2 ) and the combination of P 1 and P 2 (P 3 ) were simulated. Each measurement was simulated with four frames of 5min each and 2 bed positions. PBPK parameters were fitted to the PET data to derive the PET-predicted MPPs. Therapy was simulated assuming an infusion of 5.1GBq of 90 Y-DOTATATE over 30min in both true and PET-predicted MPPs. TIACs of simulated therapy were calculated, true MPPs (true TIACs) and predicted MPPs (predicted TIACs) followed by the calculation of variabilities v. For P 1 and P 2 the population variabilities of kidneys, liver and spleen were acceptable (v10%). Treatment planning of PRRT based on dynamic PET data seems possible for the kidneys, liver and spleen using a PBPK model and patient specific information. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  2. Copper complex N(4)-ortho-toluyl-2-acetylpyridine thiosemicarbazone - ({sup 64}Cu)(H2Ac4oT)Cl - internal dosimetry: animal model and human extrapolation

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Josianne L.; Silva, Paulo R.O.; Santos, Raquel G.; Ferreira, Andrea V., E-mail: jlr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Thiosemicarbazones have attracted great pharmacological interest because of their biological properties, such as cytotoxic activity against multiple strains of human tumors. Due to the excellent properties of {sup 64}Cu, the copper complex N(4)-ortho-toluyl-2-acetylpyridine thiosemicarbazone (({sup 64}Cu)(H2Ac4oT)Cl) was developed for tumor detection by positron emission tomography. The radiopharmaceuticals were produced in the nuclear reactor TRIGA-IPR-R1 from CDTN. At the present work, ({sup 64}Cu)(H2Ac4oT)Cl biokinetic data (evaluated in mice bearing Ehrlich tumor) were treated by MIRD formalism to perform Internal Dosimetry studies. Doses in several organs of mice were determinate, as well as in implanted tumor, for ({sup 64}Cu)(H2Ac4oT)Cl. Doses results obtained for animal model were extrapolated to humans assuming a similar concentration ratio among various tissues between mouse and human. In the extrapolation, it was used human organ masses from Cristy/Eckerman phantom. Both penetrating and non-penetrating radiation from {sup 64}Cu in the tissue were considered in dose calculations. (author)

  3. Application of the IEUBK model for linking Children's blood lead with environmental exposure in a mining site, south China

    International Nuclear Information System (INIS)

    Zhang, Xin-Ying; Carpenter, David O.; Song, Yong-Jin; Chen, Ping; Qin, Yaoming; Wei, Ni-Yu; Lin, Shan-Chun

    2017-01-01

    This study consisted of a site- and age-specific investigation linking children's blood lead level (BLL) to environmental exposures in a historic mining site in south China. A total of 151 children, aged 3–7 years, were included in this study. The geometric mean (GM) BLL was 8.22 μg/dl, indicating an elevated BLL. The Integrated Exposure Uptake Bio-Kinetic (IEUBK) model has proven useful at many sites for study of routes of exposure. Application of the IEUBK model to these children indicated that the GM difference between observed and predicted BLL levels was only 1.07 μg/dl. It was found that the key environmental exposure pathway was soil/dust intake, which contributed 86.3% to the total risk. Younger children had higher BLL than did older children. Therefore, of the various low risk-high benefit solutions, interventions for the children living near the site should be focused on the dust removal and soil remediation. Implementation of the China Eco-village Construction Plan and China New Rural Reconstruction Movement of the government may be a better solution. - Highlights: • BLLs were measured in 151 children aged 3–7 years in a Chinese mining town. • Pb was measured in soil, dust, air, drinking water, home grown vegetables and meat. • IEUBK model predicted BLL was 9.29 μg/dL and observed BLL was 8.22 μg/dL. • Most important exposure pathway was soil/dust which contributed 86.3% of the risk. • Soil and dust remediation is recommended to reduce children's BLLs.

  4. Modeling The Skeleton Weight of an Adult Caucasian Man.

    Science.gov (United States)

    Avtandilashvili, Maia; Tolmachev, Sergei Y

    2018-05-17

    biokinetic modeling of U.S. Transuranium and Uranium Registries partial-body donation cases.

  5. Experimental studies on the biokinetics of plutonium and americium in the cephalopod Octopus vulgaris

    International Nuclear Information System (INIS)

    Guary, J.C.; Fowler, S.W.

    1982-01-01

    Radiotracer experiments using the photon-emitters 237 Pu and 241 Am were performed to examine uptake, tissue distribution and retention of plutonium and americium in the cephalopod Octopus vulgaris Cuvier. A 2 wk exposure in contaminated sea water resulted in twice as much 237 Pu being taken up by whole octopus as 241 Am. Immediately following uptake approximately 41% and 73% of the 237 Pu and 241 Am respectively were located in the branchial hearts. Depuration rates for both radionuclides were identical; approximately 46% of both radionuclides initially incorporated were associated with a long-lived compartment which turned over very slowly (Tbsub(1/2) = 1.5 yr). Longer exposures to 241 Am resulted in an increase in the size of the slowly exchanging 241 Am pool in the octopus. After 2 mo depuration, the majority of the residual activity of both radionuclides was in the branchial hearts. On average 33% of the 241 Am ingested with food was assimilated into tissues, primarily the hepatopancreas. Different whole-body 241 Am excretion rates were observed at different times following assimilation and were related to transfer processes taking place within internal tissues, most notably between hepatopancreas and the branchial hearts. Relationships between circulatory and excretory functions of these 2 organs are discussed and a physiological mechanism is proposed to explain the observed patterns of 241 Am excretion in O. vulgaris. (orig.)

  6. Experimental studies on the biokinetics of plutonium and americium in the cephalopod Octopus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Guary, J.C.; Fowler, S.W.

    1982-03-05

    Radiotracer experiments using the photon-emitters /sup 237/Pu and /sup 241/Am were performed to examine uptake, tissue distribution and retention of plutonium and americium in the cephalopod Octopus vulgaris Cuvier. A 2 wk exposure in contaminated sea water resulted in twice as much /sup 237/Pu being taken up by whole octopus as /sup 241/Am. Immediately following uptake approximately 41% and 73% of the /sup 237/Pu and /sup 241/Am respectively were located in the branchial hearts. Depuration rates for both radionuclides were identical; approximately 46% of both radionuclides initially incorporated were associated with a long-lived compartment which turned over very slowly (Tbsub(1/2) = 1.5 yr). Longer exposures to /sup 241/Am resulted in an increase in the size of the slowly exchanging /sup 241/Am pool in the octopus. After 2 mo depuration, the majority of the residual activity of both radionuclides was in the branchial hearts. On average 33% of the /sup 241/Am ingested with food was assimilated into tissues, primarily the hepatopancreas. Different whole-body /sup 241/Am excretion rates were observed at different times following assimilation and were related to transfer processes taking place within internal tissues, most notably between hepatopancreas and the branchial hearts. Relationships between circulatory and excretory functions of these 2 organs are discussed and a physiological mechanism is proposed to explain the observed patterns of /sup 241/Am excretion in O. vulgaris.

  7. From Technique of Tattooing to Biokinetics and Toxicology of Injected Tattoo Ink Particles and Chemicals

    DEFF Research Database (Denmark)

    Serup, Jørgen

    2017-01-01

    by banning potentially critical chemicals hitherto has been unsuccessful due to lacking documentation of clinical and epidemiological relevance and because the tattoo industry is already internationally established, free, and in the ownership of the people. Doctors treating patients with tattoo complications...

  8. Review of biokinetic and biological transport of transuranic radionuclides in the marine environment

    International Nuclear Information System (INIS)

    Beasley, T.M.; Cross, F.A.

    1980-01-01

    Present understanding of the uptake, retention, and loss of transuranic radionuclides by marine biota is limited. Laboratory experiments have demonstrated that for certain species assimilation of plutonium and americium from labeled food is an efficient process and that direct uptake from seawater is important in the bioaccumulation of all transuranic radionuclides studied to date. Organisms appear to play an important role in the vertical transport of these radioelements from the surface layers of the ocean to greater depths

  9. Biokinetics of indium-111 labeled platelets after cryotherapy of hepatic metastases

    International Nuclear Information System (INIS)

    Alexander, C.; Kirsch, C.-M.; Pistorius, G.; Feifel, G.

    2002-01-01

    Full text: The present investigation was performed to evaluate mean platelet live-span and the proportion of platelet disposal in different organs in patients after hepatic cryotherapy. Seven patients with advanced colorectal cancer and liver metastases were included. Directly before the surgical procedure a blood specimen was drawn and an in vitro labeling of patients platelets with 18 MBq Indium-111 oxime was performed. Reinjection was done intraoperatively just before cryotherapy. Blood specimen were drawn at 1, 2, 3, 24 und 48 h p.i.. Whole-body scintigraphy was acquired on day two alter operation. The evaluation comprised the calculation of mean platelet live-span and of organ activities as percentage of whole-body activity. The local disposal of platelets at the site of cryotherapy ranged from 0 to 35.2 percent, the mean value was 16,2 ± 12,2 percent (mean ± SD). The mean half-time of time-activity curve gave 0.6 to 2.4 days (mean ± SD: 1.6 ± 0.6 d; normal value: 3.5-6 d), the mean platelet life-span was between 2.1 and 5.2 days corresponding to a mean value of 3.4 ± 1.0 days (normal value: 7-11 d). The evaluation of SPECT slices of large liver metastases demonstrated that platelet disposal takes place at the border zone of the metastases just around the necrotic center. We conclude that the enhanced local platelet trapping is a major cause for cryothermia-induced systemic thrombocytopenia. (author)

  10. Biokinetic and therapeutic use of 131I-MIBG in nude mice hosting human neuroblastoma xenografts

    International Nuclear Information System (INIS)

    Laubenbacher, C.; Kriegel, H.; Moellenstaedt, S.; Senekowitsch, R.; Technische Univ. Muenchen

    1988-01-01

    The biological halflife of 131 I-MIBG in nude mice with xenotransplanted human neuroblastoma derived from the SK-N-SH cell line comes to 6 h. The adrenal gland and the neuroblastoma show the highest uptake of MIBG. Based on these datas it could be calculated that 185 MBq would be necessary to get 60 Gy radiation absorbed dose in the tumor. 15-20 days after injection of this activity the tumors could no longer be palpated and they remained missing over the whole observation period. 92.5 MBq weren't enough getting a stable remission. Eleven days p.i. neuroblastoma started growing again. For the first time it could be shown that only high activity of 131 I-MIBG is able to restrain neuroblastoma totally. (orig.)

  11. Mechanism of cisplatin proximal tubule toxicity revealed by integrating transcriptomics, proteomics, metabolomics and biokinetics

    NARCIS (Netherlands)

    Wilmes, Anja; Bielow, Chris; Ranninger, Christina; Bellwon, Patricia; Aschauer, Lydia; Limonciel, Alice; Chassaigne, Hubert; Kristl, Theresa; Aiche, Stephan; Huber, Christian G; Guillou, Claude; Hewitt, Philipp; Leonard, Martin O; Dekant, Wolfgang; Bois, Frederic Y; Jennings, Paul

    2015-01-01

    Cisplatin is one of the most widely used chemotherapeutic agents for the treatment of solid tumours. The major dose-limiting factor is nephrotoxicity, in particular in the proximal tubule. Here, we use an integrated omics approach, including transcriptomics, proteomics and metabolomics coupled to

  12. Synthesis, labeling with 99mTc and biokinetics of brains scintigraphy diaminodithiol perfusion radiopharmaceuticals

    International Nuclear Information System (INIS)

    Goncalves, Marcos Moises

    1999-01-01

    The recent tomography status using radiopharmaceuticals have been contributing greatly with the 'age of certainty' in the diagnosis examination of syndromes, pathologies and clinical signs, because they can evidence some phenomena occurring in a molecular manner. The purpose of this work have had the development of new diaminodithiol (DADT) perfusion radiopharmaceuticals to be used in brain diagnosis using S.P.E.T. (Single Photon Emission Tomography). Initially, the rational planning had been performed with the new DADT molecular structures as radiopharmaceutical candidates. Using of Q.S.A.R. (Quantitative Structure Activity Relationship) techniques, the molecular descriptors such as partition coefficient and effective polarizability, have been studied in order to increase the blood brain barrier transport and the brain uptake respectively. Applying the Q.S.P.R. (Quantitative Structure Property Relationship) concepts to perform drug latentiation, based on bio-labile functional groups, the congener DADT derivative has been transformed into a pro-drug that works as a DADT moiety carrier, allowing the increasing of brain radiopharmaceutical uptake. Later on, synthetic routes and chemical purifications have been developed allowing the creation of the proposed chemical structure. Each new DADT derivative has been synthesized and analyzed in terms of elemental analysis, infrared and NMR spectra, in order to confirm its proposed chemical structure. Then, the new derivative has been labeled with 99m Tc, radiochemically purified, intravenously injected in Swiss mice, allowing its biodistribution to evidence its brain transport and uptake. The rational planning studies have been re-evaluated after each biodistribution had been performed, to see what kind of molecular descriptor was responsible for causing a stronger optimization in the brain perfusion characteristics and then, new DADT derivatives have been prepared. Three new DADT derivatives have been obtained by using QSAR: DADT-PR, DADT-DIPA, DADT-DIB. In terms of absolute values, expressed as % dose/organ, the DADT-DIPA showed the biggest brain uptake, because it has got the partition coefficient closest to the ideal and a high effective polarizability value. DADT - DIPA proved that the partition coefficient is the most important molecular descriptor in the optimization of the DADT derivatives because in the case of DADT-DIB, even possessing the most effective polarizability, but a non-ideal partition coefficient value , it was showed a significantly smaller brain uptake. The DADT -DIPA derivative is potentially a brain perfusion radiopharmaceutical to be explored in details. The DADT - BUT , developed by QSPR despite the fact of having a low brain uptake expressed in terms of % dose/organ, presented pro-drug behaviour, because even 30 minutes after its administration, the radiopharmaceutical strikingly still retained 62% of the 5 minutes brain uptake. This DADT derivative has proved to possess low cerebral clearance, creating the possibility of becoming a good brain perfusion agent, once its structure assumes the closest to ideal partition coefficient value by adequate molecular modification. (author)

  13. Uranium incorporation biokinetics in poultry bones as function of phytase doses

    International Nuclear Information System (INIS)

    Arruda-Neto, J.D.T.; Cestari, A.C.; Zamboni, C.B.; Saiki, M.; Nogueira, G.P.; Fonseca, L.E.C.; Manso-Guevara, M.V.; Deppman, A.; Likhachev, V.P.; Mesa, J.

    2005-01-01

    Neutron activation analysis has been used to study uranium incorporation in poultry bones as function of chow doped with: (a) uranium (20 ppm); (b) U-doped food (20 ppm) plus phytase (120 ppm) and (c) U-doped food (20 ppm) plus phytase (180 ppm). To investigate this situation experiments involving several groups of Cobb broilers was performed. Two animals per group were sacrificed weekly up to their adultness and uranium concentration in the tibia was measured. It was observed that the concentration of uranium (μg U/g bone) is decreasing all along the animal life spanning period of 14-42 days. This behavior suggests that the skeleton mass is growing faster than the corresponding accumulation of uranium. The administration of phytase seems not to alter this scenario. (author)

  14. Revised dose limits and new respiratory tract model and their implications for annual limits of intake of radioactive materials - A review of recent ICRP publications

    International Nuclear Information System (INIS)

    Schlesinger, T.; Silverman, I.; Shapira, M.

    1996-01-01

    Ionizing radiation may cause immediate and/or delayed biological damages to the body of the exposed person and/or his/her progeny. The exposure may be caused by an external source or may arise due to internal contamination by a radioactive material. In order to prevent such exposure, or to reduce the probability that it will occur, national authorities and international organizations that are engaged in radiation safety and protection have set limits for the exposure to ionizing radiation from either source. The sensitivity of the body to ionizing radiation usually decreases with age. For this reason and due to the limited possibilities to control the exposure of the general public, different limits have been set for for occupational exposure and for the exposure of members of the public of different age groups. The general principles of these limits and guidelines for their calculations are set by the International Commission on Radiological Protection (ICRP) and published in the Annals of the ICRP. The basic philosophy of the Commission, which includes the principles of justification, optimization and dose limits, the basic radiobiological models, and the distinction between stochastic and non-stochastic effects has been presented in its publication no. 26 . Based on this philosophy, the Commission issued between 1979 and 1988 a series of publications followed by annexes and addenda known as publication no. 30 . This series presented models describing the metabolism of radioactive materials which enter the body by inhalation and ingestion, the transfer of such materials from the respiratory tract and the gastrointestinal tract to the blood, and from there to the body organs and the excretion of the material from the body. This series presented also values for biokinetic parameters of these systems and transfer paths, and methods for calculating limits on intake which ensure that the exposure from internal contamination will not exceed the dose limits set by the

  15. Revised dose limits and new respiratory tract model and their implications for annual limits of intake of radioactive materials - A review of recent ICRP publications

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, T; Silverman, I; Shapira, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1996-12-01

    Ionizing radiation may cause immediate and/or delayed biological damages to the body of the exposed person and/or his/her progeny. The exposure may be caused by an external source or may arise due to internal contamination by a radioactive material. To prevent such exposure, or to reduce the probability that it will occur, national authorities and international organizations engaged in radiation safety and protection have set limits for the exposure to ionizing radiation from either source. The sensitivity of the body to ionizing radiation usually decreases with age. For this reason and due to the limited possibilities to control the exposure of the general public, different limits have been set for for occupational exposure and for the exposure of members of the public of different age groups. The general principles of these limits and guidelines for their calculations are set by the International Commission on Radiological Protection (ICRP) and published in the Annals of the ICRP. The basic philosophy of the Commission, which includes the principles of justification, optimization and dose limits, the basic radiobiological models, and the distinction between stochastic and non-stochastic effects has been presented in its publication no. 26. Based on this philosophy, the Commission issued between 1979 and 1988 a series of publications followed by annexes and addenda known as publication no. 30. This series presented models describing the metabolism of radioactive materials which enter the body by inhalation and ingestion, the transfer of such materials from the respiratory tract and the gastrointestinal tract to the blood, and from there to the body organs and the excretion of the material from the body. This series presented also values for biokinetic parameters of these systems and transfer paths, and methods for calculating limits on intake which ensure that the exposure from internal contamination will not exceed the dose limits set.

  16. Modelling the relationship between zooplankton biomass and environmental variations in the distribution of 210Po during a one year cycle in northwestern Mediterranean coastal waters.

    Science.gov (United States)

    Färber Lorda, Jaime; Tateda, Yutaka; Fowler, Scott W

    2017-08-01

    To clarify the relationship between zooplankton biomass and the environmental kinetics of the natural radionuclide 210 Po during a one-year period (October 1995 to November 1996) in northwestern Mediterranean coastal waters, a modelling analysis was applied. Using 210 Po concentrations in seawater and zooplankton, the 210 Po uptake rate constant from food for zooplankton was evaluated using a biokinetics calculation involving the uptake and the excretion rate constants between seawater and zooplankton. Using the transfer constants obtained, the 210 Po concentrations in zooplankton were reconstructed and validated by observed concentrations. The simulation results were in good agreement with the measured 210 Po concentrations in zooplankton. Assuming that 210 Po fecal excretion represents the majority of the excretion of 210 Po from zooplankton, the fecal matter associated 210 Po vertical flux was calculated, and compared with the observed vertical fluxes of 210 Po measured in sediment traps. The modelling evaluation showed that fecal pellet vertical transport could not fully explain the observed sinking fluxes of particulate organic matter at 150 m depth, suggesting that other sinking biodetrital aggregates are also important components of the plankton-derived vertical flux of 210 Po. The relationship between 210 Po concentration in seawater and that in rain and dry fallout and their potential effect on 210 Po concentrations in zooplankton at this location were also examined. A similar, but diphased trend between 210 Po in zooplankton and 210 Po in rain and dry fallout deposition rate was demonstrated. 210 Po concentrations in the dissolved phase of seawater tended to diminish as mean daily rainfall increased suggesting that rain inputs serve as a 210 Po dilution mechanism in seawater at this location. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Adaptation of the ICRP models for the Techa River populations to estimate in utero and postnatal haemopoietic tissue doses from ingested strontium isotopes

    International Nuclear Information System (INIS)

    Shagina, Natalia; Tolstykh, Evgenia; Degteva, Marina; Fell, Tim; Harrison, John

    2008-01-01

    Full text: Reliable estimation of tissue doses for exposed individuals is very important in epidemiological studies. Long-term cohort studies of the Techa River populations exposed in the early 1950s due to releases of liquid radioactive wastes from the Mayak plutonium production facility (Southern Urals, Russia) are unique in allowing the quantification of risks from low-level chronic exposure of the general population and providing information on risks for persons exposed in utero. Strontium isotopes were the most important contributors to haemopoietic tissue doses for people living in the riverside settlements. Large-scale monitoring of the exposed population has provided a comprehensive database, including post mortem and in vivo measurements of 90 Sr in bones and whole body, for use in the estimation of doses. The International Commission on Radiological Protection (ICRP) has published biokinetic and dosimetric models for the calculation of doses to members of the public, including doses from in utero exposures and from intakes with breast milk. However, the ICRP models as applied to Sr required modification to provide best estimates of doses to Techa River residents. Adaptations were made to the ICRP model for Sr in children and adults to take account of population-specific features relating to bone mineral turnover and to model age and gender differences in strontium retention. Refinements in the ICRP model for Sr uptake and retention in the fetus were made to improve the treatment of discrimination against Sr, relative to Ca, in transfer from maternal to foetal blood and to take account of population-specific data on the calcium content of the maternal and fetal skeleton. Modification of the ICRP model for Sr transfer in breast-milk included adaptations relating to changes in maternal mineral metabolism during lactation and consideration of population-specific features of breast feeding in the rural population. The improved models were successfully

  18. A plant-wide aqueous phase chemistry module describing pH variations and ion speciation/pairing in wastewater treatment process models.

    Science.gov (United States)

    Flores-Alsina, Xavier; Kazadi Mbamba, Christian; Solon, Kimberly; Vrecko, Darko; Tait, Stephan; Batstone, Damien J; Jeppsson, Ulf; Gernaey, Krist V

    2015-11-15

    There is a growing interest within the Wastewater Treatment Plant (WWTP) modelling community to correctly describe physico-chemical processes after many years of mainly focusing on biokinetics. Indeed, future modelling needs, such as a plant-wide phosphorus (P) description, require a major, but unavoidable, additional degree of complexity when representing cationic/anionic behaviour in Activated Sludge (AS)/Anaerobic Digestion (AD) systems. In this paper, a plant-wide aqueous phase chemistry module describing pH variations plus ion speciation/pairing is presented and interfaced with industry standard models. The module accounts for extensive consideration of non-ideality, including ion activities instead of molar concentrations and complex ion pairing. The general equilibria are formulated as a set of Differential Algebraic Equations (DAEs) instead of Ordinary Differential Equations (ODEs) in order to reduce the overall stiffness of the system, thereby enhancing simulation speed. Additionally, a multi-dimensional version of the Newton-Raphson algorithm is applied to handle the existing multiple algebraic inter-dependencies. The latter is reinforced with the Simulated Annealing method to increase the robustness of the solver making the system not so dependent of the initial conditions. Simulation results show pH predictions when describing Biological Nutrient Removal (BNR) by the activated sludge models (ASM) 1, 2d and 3 comparing the performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) treatment plant configuration under different anaerobic/anoxic/aerobic conditions. The same framework is implemented in the Benchmark Simulation Model No. 2 (BSM2) version of the Anaerobic Digestion Model No. 1 (ADM1) (WWTP3) as well, predicting pH values at different cationic/anionic loads. In this way, the general applicability/flexibility of the proposed approach is demonstrated, by implementing the aqueous phase chemistry module in some

  19. A saturable repair model for radionuclide therapy using low LET radiation emitters

    International Nuclear Information System (INIS)

    Calderon, Carlos F.; Joaquin Gonzalez; Guido Martin

    2004-01-01

    Purpose: In conventional radiotherapy doses of about 60Gy are necessary to achieve the tumor control or eradication. For systemic applications in radionuclide radiotherapy (RT) 0.1-0.5cGy/min and total dose 15-20 Gy could be reached with effective irradiation times of few days. The dose rate in tumor change exponentially as a time function where an uptake phase well differentiated from an elimination phase-will- appear both determined by the effective uptake and elimination times respectively. The biological response in RT will be determined not only by the total dose, but also by initial dose rate, the length of irradiation time (effective half-life) and biological factors, like radiosensitivity, repair and doubling times. Most quantitative models of radiation action on cells make the assumption that cell repair mechanisms are relevant in the response and it proceed in a dose-dependent way. The cell proliferation will influence too the response when the overall irradiation is comparable or greater than cell population doubling time. Many proposal had been made to apply radiobiological model for the prediction of the treatment response in RN. Saturable repair models are able, in principle, to explain the usual data base of radiobiological phenomena including which where other biophysical model does not work good. It is presented here an analytical expression to calculate the survival fraction in a cell population after irradiation based on a saturable repair radiobiological model proposed by Sanchez-Reyes [Sanchez-Reyes A. Radiact. Res., 1992;130:139-147] as function of radiobiological and biokinetics parameters which could be used in RN. The original radiobiological model consider a cell population where the DNA repair mechanisms are saturable and it could be affected by radiation action. The contribution of cell proliferation were considered keeping in mind that cell population grow up exponentially at constant rate. The dose rate was considered uniformly

  20. Determination and reliability of dose coefficients for radiopharmaceuticals; Ermittlung der Zuverlaessigkeit von Dosiskoeffizienten fuer Radiopharmaka

    Energy Technology Data Exchange (ETDEWEB)

    Spielmann, V.; Li, W.B.; Zankl, M.; Oeh, U.

    2015-11-15

    The dose coefficients used in nuclear medicine for dose calculations of radiopharmaceuticals are based on recommendations by ICRP (International Commission on radiological protection) and the MIRD (Medical Internal Radiation Dose Committee) using mathematical models for the temporal activity distributions in organs and tissues (biokinetic models) and mathematical models of the human body. These models using an idealized human body do not include uncertainty estimations. The research project is aimed to determine the uncertainties and thus the reliability of the dose coefficients for radiopharmaceuticals and to identify the biokinetic and dosimetric parameters that contribute most of the uncertainties.

  1. Modelling Practice

    DEFF Research Database (Denmark)

    Cameron, Ian; Gani, Rafiqul

    2011-01-01

    This chapter deals with the practicalities of building, testing, deploying and maintaining models. It gives specific advice for each phase of the modelling cycle. To do this, a modelling framework is introduced which covers: problem and model definition; model conceptualization; model data...... requirements; model construction; model solution; model verification; model validation and finally model deployment and maintenance. Within the adopted methodology, each step is discussedthrough the consideration of key issues and questions relevant to the modelling activity. Practical advice, based on many...

  2. Leadership Models.

    Science.gov (United States)

    Freeman, Thomas J.

    This paper discusses six different models of organizational structure and leadership, including the scalar chain or pyramid model, the continuum model, the grid model, the linking pin model, the contingency model, and the circle or democratic model. Each model is examined in a separate section that describes the model and its development, lists…

  3. Models and role models.

    Science.gov (United States)

    ten Cate, Jacob M

    2015-01-01

    Developing experimental models to understand dental caries has been the theme in our research group. Our first, the pH-cycling model, was developed to investigate the chemical reactions in enamel or dentine, which lead to dental caries. It aimed to leverage our understanding of the fluoride mode of action and was also utilized for the formulation of oral care products. In addition, we made use of intra-oral (in situ) models to study other features of the oral environment that drive the de/remineralization balance in individual patients. This model addressed basic questions, such as how enamel and dentine are affected by challenges in the oral cavity, as well as practical issues related to fluoride toothpaste efficacy. The observation that perhaps fluoride is not sufficiently potent to reduce dental caries in the present-day society triggered us to expand our knowledge in the bacterial aetiology of dental caries. For this we developed the Amsterdam Active Attachment biofilm model. Different from studies on planktonic ('single') bacteria, this biofilm model captures bacteria in a habitat similar to dental plaque. With data from the combination of these models, it should be possible to study separate processes which together may lead to dental caries. Also products and novel agents could be evaluated that interfere with either of the processes. Having these separate models in place, a suggestion is made to design computer models to encompass the available information. Models but also role models are of the utmost importance in bringing and guiding research and researchers. 2015 S. Karger AG, Basel

  4. Model(ing) Law

    DEFF Research Database (Denmark)

    Carlson, Kerstin

    The International Criminal Tribunal for the former Yugoslavia (ICTY) was the first and most celebrated of a wave of international criminal tribunals (ICTs) built in the 1990s designed to advance liberalism through international criminal law. Model(ing) Justice examines the case law of the ICTY...

  5. Models and role models

    NARCIS (Netherlands)

    ten Cate, J.M.

    2015-01-01

    Developing experimental models to understand dental caries has been the theme in our research group. Our first, the pH-cycling model, was developed to investigate the chemical reactions in enamel or dentine, which lead to dental caries. It aimed to leverage our understanding of the fluoride mode of

  6. Experimental and theoretical study of the transport of silver nanoparticles at their prolonged administration into a mammal organism

    Science.gov (United States)

    Antsiferova, A. A.; Buzulukov, Yu. P.; Kashkarov, P. K.; Kovalchuk, M. V.

    2016-11-01

    The transport of silver nanoparticles in the organism of laboratory animals has been investigated. A mathematical model of the biokinetics of prolonged administration of nonmetabolizable and nonaglomerating pharmaceutical preparations is proposed, and its analytical solution is found. Based on the experimental data on the prolonged introduction and excretion of colloidal silver nanoparticles and the numerical approximation of the solutions to the equations for the proposed model, time dependences of the silver mass content in brain and blood are obtained and some other important biokinetic parameters are determined. It is concluded that both chronic1 and subchronic2 peroral application of these nanoparticles as an biologically active additive or antiseptic is potentially dangerous.

  7. Evaluation of the absorbed dose to the lungs due to Xe{sup 133} and Tc{sup 99m} (MAA); Evaluacion de la dosis absorbida en los pulmones debido al Xe{sup 133} y Tc{sup 99m} (MAA)

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez A, M.; Murillo C, F.; Castillo D, C.; Sifuentes D, Y.; Sanchez S, P. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Trujillo (Peru); Rojas P, E. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima (Peru); Marquez P, F., E-mail: marvva@hotmail.com [Instituto Nacional de Enfermedades Neoplasicas, Av. Angamos 2520, Lima (Peru)

    2015-10-15

    The absorbed dose in lungs of an adult patient has been evaluated using the biokinetics of radiopharmaceuticals containing Xe{sup 133} or Tc{sup 99m} (MAA). The absorbed dose was calculated using the MIRD formalism, and the Cristy-and Eckerman lungs model. The absorbed dose in the lungs due to {sup 133}Xe is 0.00104 mGy/MBq. Here, the absorbed dose due to remaining tissue, included in the {sup 133}Xe biokinetics is not significant. The absorbed dose in the lungs, due Tc{sup 99m} (MAA), is 0.065 mGy/MBq. Approximately, 4.6% of the absorbed dose is due to organs like liver, kidneys, bladder, and the rest of tissues, included in the Tc{sup 99m} biokinetics. Here, the absorbed dose is very significant to be overlooked. The dose contribution is mainly due to photons emitted by the liver. (Author)

  8. Dose absorbed in adults and children thyroid due to the I123 using the dosimetry MIRD and Marinelli

    International Nuclear Information System (INIS)

    Vasquez, M.; Castillo, C.; Cabrera, C.; Sarachaga, R.; Castaneda, J.; Diaz, E.

    2014-08-01

    Using the dosimetry MIRD, and representation Cristy-Eckerman in the thyroid gland and organs of their bio-kinetics when I 123 (Iodine) is used, the study demonstrates that the absorbed dose by the gland of an adult, children, and newly born, is their auto-dose, independent of the compartments number of their bio-kinetics. The dosimetric contributions of the organs of their bio-kinetics are insignificant. Their results are not significantly different to those obtained by the formalism MARINELLI (auto-dose) when it uses a sphere like glandular representation. In consequence, the kinetic model corresponding to the glandular representation decreases to a compartment, where the gland can also be represented like a sphere. (Author)

  9. Evaluation of the absorbed dose to the lungs due to Xe133 and Tc99m (MAA)

    International Nuclear Information System (INIS)

    Vazquez A, M.; Murillo C, F.; Castillo D, C.; Sifuentes D, Y.; Sanchez S, P.; Rojas P, E.; Marquez P, F.

    2015-10-01

    The absorbed dose in lungs of an adult patient has been evaluated using the biokinetics of radiopharmaceuticals containing Xe 133 or Tc 99m (MAA). The absorbed dose was calculated using the MIRD formalism, and the Cristy-and Eckerman lungs model. The absorbed dose in the lungs due to 133 Xe is 0.00104 mGy/MBq. Here, the absorbed dose due to remaining tissue, included in the 133 Xe biokinetics is not significant. The absorbed dose in the lungs, due Tc 99m (MAA), is 0.065 mGy/MBq. Approximately, 4.6% of the absorbed dose is due to organs like liver, kidneys, bladder, and the rest of tissues, included in the Tc 99m biokinetics. Here, the absorbed dose is very significant to be overlooked. The dose contribution is mainly due to photons emitted by the liver. (Author)

  10. Dose absorbed in adults and children thyroid due to the I{sup 123} using the dosimetry MIRD and Marinelli; Dosis absorbida en tiroides de adultos y ninos debido al I{sup 123} utilizando las dosimetrias MIRD y Marinelli

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Castillo, C.; Cabrera, C.; Sarachaga, R.; Castaneda, J. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Ciudad Universitaria, Trujillo (Peru); Diaz, E., E-mail: marvva@hotmail.com [Universidade Federal do Rio Grande do Sul, Av. Paulo Gamma 110, Bairro Farropilhas, Porto Alegre, RS 90040-060 (Brazil)

    2014-08-15

    Using the dosimetry MIRD, and representation Cristy-Eckerman in the thyroid gland and organs of their bio-kinetics when I{sup 123} (Iodine) is used, the study demonstrates that the absorbed dose by the gland of an adult, children, and newly born, is their auto-dose, independent of the compartments number of their bio-kinetics. The dosimetric contributions of the organs of their bio-kinetics are insignificant. Their results are not significantly different to those obtained by the formalism MARINELLI (auto-dose) when it uses a sphere like glandular representation. In consequence, the kinetic model corresponding to the glandular representation decreases to a compartment, where the gland can also be represented like a sphere. (Author)

  11. Modelling SDL, Modelling Languages

    Directory of Open Access Journals (Sweden)

    Michael Piefel

    2007-02-01

    Full Text Available Today's software systems are too complex to implement them and model them using only one language. As a result, modern software engineering uses different languages for different levels of abstraction and different system aspects. Thus to handle an increasing number of related or integrated languages is the most challenging task in the development of tools. We use object oriented metamodelling to describe languages. Object orientation allows us to derive abstract reusable concept definitions (concept classes from existing languages. This language definition technique concentrates on semantic abstractions rather than syntactical peculiarities. We present a set of common concept classes that describe structure, behaviour, and data aspects of high-level modelling languages. Our models contain syntax modelling using the OMG MOF as well as static semantic constraints written in OMG OCL. We derive metamodels for subsets of SDL and UML from these common concepts, and we show for parts of these languages that they can be modelled and related to each other through the same abstract concepts.

  12. Internal dosimetry contamination: update of revision of the dose coefficients for intakes of radionuclides by workers

    International Nuclear Information System (INIS)

    Gomez Parada, I.; Rojo, A.M.; Sanguineti, R.

    1995-01-01

    ICRP publication 60 introduces new biological information related to the detriment associated with radiation exposures. The International Commission on Radiological Protection has also issued, in publications 57, 67 y 69, new biokinetic models for selected radionuclides since the issue of publication 30. In publication 66 the new human respiratory tract model for radiological protection is described. The aim of the present paper is to compare values of dose coefficients for workers calculated using the new tissue weighting factors, biokinetic models and lung model with those given in publication 30.The software package LUPED 1.1 was used to calculate dose coefficients for inhalation and ingestion. When possible, some changes in the biokinetic models were made trying to incorporate new parameters. The following radionuclides were analysed: 60 Co, 90 Sr, 99m Tc, 131 I, 137 Cs, 239 Pu y 241 Am. Most of the inhalation dose coefficients calculated with the new assumptions are within a factor of three of those calculated using the ICRP 30 lung and biokinetic models. Generally, the inhalation dose coefficients calculated with the new respiratory tract model and assuming a 5μm AMAD are lower than those calculated using the ICRP 30 model and parameters. The inhalation dose coefficients are generally within 10-90 % of the corresponding Publication 61 values, the difference tending to increase for relative insoluble compounds. (author). 10 refs., 4 tabs

  13. Modelling growth of Penicillium expansum and Aspergillus niger at constant and fluctuating temperature conditions.

    Science.gov (United States)

    Gougouli, Maria; Koutsoumanis, Konstantinos P

    2010-06-15

    The growth of Penicillium expansum and Aspergillus niger, isolated from yogurt production environment, was investigated on malt extract agar with pH=4.2 and a(w)=0.997, simulating yogurt, at isothermal conditions ranging from -1.3 to 35 degrees C and from 5 to 42.3 degrees C, respectively. The growth rate (mu) and (apparent) lag time (lambda) of the mycelium growth were modelled as a function of temperature using a Cardinal Model with Inflection (CMI). The results showed that the CMI can describe successfully the effect of temperature on fungal growth within the entire biokinetic range for both isolates. The estimated values of the CMI for mu were T(min)=-5.74 degrees C, T(max)=30.97 degrees C, T(opt)=22.08 degrees C and mu(opt)=0.221 mm/h for P. expansum and T(min)=10.13 degrees C, T(max)=43.13 degrees C, T(opt)=31.44 degrees C, and mu(opt)=0.840 mm/h for A. niger. The cardinal values for lambda were very close to the respective values for mu indicating similar temperature dependence of the growth rate and the lag time of the mycelium growth. The developed models were further validated under fluctuating temperature conditions using various dynamic temperature scenarios. The time-temperature conditions studied included single temperature shifts before or after the end of the lag time and continuous periodic temperature fluctuations. The prediction of growth at changing temperature was based on the assumption that after a temperature shift the growth rate is adopted instantaneously to the new temperature, while the lag time was predicted using a cumulative lag approach. The results showed that when the temperature shifts occurred before the end of the lag, they did not cause any significant additional lag and the observed total lag was very close to the cumulative lag predicted by the model. In experiments with temperature shifts after the end of the lag time, accurate predictions were obtained when the temperature profile included temperatures which were inside the

  14. Modelling the models

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    By analysing the production of mesons in the forward region of LHC proton-proton collisions, the LHCf collaboration has provided key information needed to calibrate extremely high-energy cosmic ray models.   Average transverse momentum (pT) as a function of rapidity loss ∆y. Black dots represent LHCf data and the red diamonds represent SPS experiment UA7 results. The predictions of hadronic interaction models are shown by open boxes (sibyll 2.1), open circles (qgsjet II-03) and open triangles (epos 1.99). Among these models, epos 1.99 shows the best overall agreement with the LHCf data. LHCf is dedicated to the measurement of neutral particles emitted at extremely small angles in the very forward region of LHC collisions. Two imaging calorimeters – Arm1 and Arm2 – take data 140 m either side of the ATLAS interaction point. “The physics goal of this type of analysis is to provide data for calibrating the hadron interaction models – the well-known &...

  15. Labelling study of galacturonic acid with Tc-99m and investigation of the biokinetic behaviour in experimental animals

    International Nuclear Information System (INIS)

    1988-01-01

    The main criterion in the selection of a proper ligand to be labelled with Technetium is to match the requirement of a radiopharmaceutical of good biological specificity, where the target organ-to-background ratio is considerably high. Perliminary study on experimental animals has shown, that galacturonic acid is among those ligands of high renal specificity after complexing with Tc-99. In this communication we describe for the first time the labelling of galacturonic acid with Tc-99, using stannous chloride as a reducing agent for pertechnetate. The radioanalytical results assessed by gelchromatography column scanning (GCS) method, reveal that, the labelling efficiency of (Tc)99-galacturonate complex is promoted by raising the pH of the reaction mixture to a value higher than 7 using tris (hydroxymethyl) aminomethane buffer. The optimal amounts of the reactants to obtain a high labelled and stable complex with high kidney uptake, were found to be not less than 50 mg galacturonic acid and not more than 200 Mg SnCl2.H2O in the preparation

  16. Biokinetics of osteotropic radiopharmaceuticals in metabolic osteopathies - comparison of 47Ca and sup(99m)Tc-MDP

    International Nuclear Information System (INIS)

    Knop, J.; Montz, R.

    1983-01-01

    Plasma clearance and osseous accumulation rates of sup(99m)Tc methylene diphosphonate (MDP) in the lumbar spine were measured in 11 patients with osteoporosis (OP), 7 patients with hyperparathyroidism (HPT), 4 patients with osteomalacia (OM) and in 3 patients (N) who were studied to exclude metabolic bone disease. The findings in 19 patients were compared with the results of 47 Ca kinetics. The plasma elimination of sup(99m)Tc-MDP during the first hour after application was normal in almost all the patients. The sup(99m)Tc-MDP accumulation rates in the lumbar spine were raised in patients with HPT and OM (p 0,05). 47 Ca kinetics were disturbed in most of the patients with metabolic bone disease, with minimal deviations in OP. The comparison of sup(99m)Tc-MDP accumulation rates with the results of 47 Ca kinetics revealed significant correlations with exchangeable bone and soft tissue calcium. The correlations with total calcium turnover and calcium accretion were poor. Only half of the patients had equal results of sup(99m)Tc-MDP accumulation rates and bone calcium accretion rates. It is concluded that the sup(99m)Tc-MDP uptake by bone is an index of bone metabolism presumably of the organic matrix, whereas 47 Ca kinetics represent the mineral metabolism of bone. (orig.) [de

  17. Variation of solubility, biokinetics and dose coefficient of industrial uranium oxides according to the specific surface area

    International Nuclear Information System (INIS)

    Chazel, V.; Houpert, P.; Ansorbolo, E.; Henge-Napoli, M.H.; Paquet, F.

    2000-01-01

    The in vitro solubility, absorption to blood, lung retention and dose coefficient of industrial UO 2 samples were studied as a function of the specific surface area (SSA) of the particles. An in vitro study has been carried out on two samples of industrial UO 4 to compare the results with those obtained with UO 2 . Ten UO 2 samples supplied by different fuel factories or research laboratories, presented specific surface areas from 1.00 to 4.45 m 2 .g -1 . The wide range of values of SSA was due to the different conditions of fabrication. Dissolution tests in cell culture medium made on these ten samples have shown that the solubility increased 2.5-fold when the SSA increased 1.7-fold. The same tendency has been found for UO 4 , a soluble compound, and for U 3 O 8 , a moderately soluble compound. Four in vivo experiments carried out on rats by intratracheal instillation of dust suspensions of UO 2 , have highlighted the decrease in lung retention and the increase of absorption to blood with the SSA. The experimental absorption parameters calculated from the in vivo data allowed specific dose coefficients to be obtained which decreased from 6.6 to 4.3 μSv.Bq -1 when the SSA increased from 1.60 to 3.08 m 2 .g -1 . Thus, the medical monitoring of workers at the workplace has to take into account any change in the fabrication process of the uranium compound which can affect the physiochemical properties and consequently the dose coefficient. (author)

  18. Excretion of radionuclides in human breast milk after nuclear medicine examinations. Biokinetic and dosimetric data and recommendations on breastfeeding interruption

    Energy Technology Data Exchange (ETDEWEB)

    Liepe, K. [GH Hospital Frankfurt/Oder, Department of Nuclear Medicine, Frankfurt an der Oder (Germany); Becker, A. [GH Hospital Frankfurt/Oder, Department of Internal Medicine, Frankfurt an der Oder (Germany)

    2016-05-15

    Since the 1990s the advantages of breastfeeding have been emphasized and the number of women who nurse their infant has increased significantly. Although women in this population are generally healthy and relatively rarely need radionuclide imaging or radionuclide therapies, the issue of radiation protection of breastfed children arises because of their higher radiosensitivity. Approximately 55 papers on excretion of radionuclides in human breast milk after radionuclide imaging or therapy have been published. Unfortunately, most of them are case reports or include only a small number of cases. In 1955 the first report was published about a breastfeeding woman after radioiodine treatment of thyrotoxicosis. This early study showed a higher concentration of radioiodine in breast milk than in plasma and investigated the risk to the infant, especially to the thyroid gland.

  19. Biokinetics of Hg and Pb accumulation in the encapsulated egg of the common cuttlefish Sepia officinalis: Radiotracer experiments

    International Nuclear Information System (INIS)

    Lacoue-Labarthe, T.; Warnau, M.; Metian, M.; Oberhaensli, F.; Rouleau, C.; Bustamante, P.

    2009-01-01

    Uptake and depuration kinetics of dissolved 203 Hg and 210 Pb were determined during the entire embryonic development of the eggs of the cuttlefish, Sepia officinalis (50 d at 17 o C). 203 Hg and 210 Pb were accumulated continuously by the eggs all along the development time reaching load/concentration ratio (LCR) of 467 ± 43 and 1301 ± 126 g, respectively. During the first month, most of the 203 Hg and 210 Pb remained associated with the eggshell indicating that the latter acted as an efficient shield against metal penetration. From this time onwards, 203 Hg accumulated in the embryo, indicating that it passed through the eggshell, whereas 210 Pb did not cross the chorion during the whole exposure time. It also demonstrated that translocation of Hg associated with the inner layers of the eggshell is a significant source of exposure for the embryo. This study highlighted that the maturing embryo could be subjected to the toxic effects of Hg in the coastal waters where the embryonic development is taking place.

  20. Biokinetics of Hg and Pb accumulation in the encapsulated egg of the common cuttlefish Sepia officinalis: Radiotracer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lacoue-Labarthe, T., E-mail: tlacouel@gmail.com [Littoral, Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17042 La Rochelle Cedex 01 (France); Warnau, M., E-mail: warnaumichel@yahoo.com [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine Ier, MC-98000 (Monaco); Metian, M. [Littoral, Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17042 La Rochelle Cedex 01 (France); International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine Ier, MC-98000 (Monaco); Oberhaensli, F. [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine Ier, MC-98000 (Monaco); Rouleau, C. [Institut Maurice-Lamontagne, 850 Route de la Mer, C.P. 1000, Mont-Joli, Quebec (Canada); Bustamante, P., E-mail: pbustama@univ-lr.fr [Littoral, Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17042 La Rochelle Cedex 01 (France)

    2009-12-01

    Uptake and depuration kinetics of dissolved {sup 203}Hg and {sup 210}Pb were determined during the entire embryonic development of the eggs of the cuttlefish, Sepia officinalis (50 d at 17 {sup o}C). {sup 203}Hg and {sup 210}Pb were accumulated continuously by the eggs all along the development time reaching load/concentration ratio (LCR) of 467 {+-} 43 and 1301 {+-} 126 g, respectively. During the first month, most of the {sup 203}Hg and {sup 210}Pb remained associated with the eggshell indicating that the latter acted as an efficient shield against metal penetration. From this time onwards, {sup 203}Hg accumulated in the embryo, indicating that it passed through the eggshell, whereas {sup 210}Pb did not cross the chorion during the whole exposure time. It also demonstrated that translocation of Hg associated with the inner layers of the eggshell is a significant source of exposure for the embryo. This study highlighted that the maturing embryo could be subjected to the toxic effects of Hg in the coastal waters where the embryonic development is taking place.

  1. Biokinetic Analysis and Metabolic Fate of 2,4-D in 2,4-D-Resistant Soybean (Glycine max).

    Science.gov (United States)

    Skelton, Joshua J; Simpson, David M; Peterson, Mark A; Riechers, Dean E

    2017-07-26

    The Enlist weed control system allows the use of 2,4-D in soybean but slight necrosis in treated leaves may be observed in the field. The objectives of this research were to measure and compare uptake, translocation, and metabolism of 2,4-D in Enlist (E, resistant) and non-AAD-12 transformed (NT, sensitive) soybeans. The adjuvant from the Enlist Duo herbicide formulation (ADJ) increased 2,4-D uptake (36%) and displayed the fastest rate of uptake (U 50 = 0.2 h) among treatments. E soybean demonstrated a faster rate of 2,4-D metabolism (M 50 = 0.2 h) compared to NT soybean, but glyphosate did not affect 2,4-D metabolism. Metabolites of 2,4-D in E soybean were qualitatively different than NT. Applying 2,4-D-ethylhexyl ester instead of 2,4-D choline (a quaternary ammonium salt) eliminated visual injury to E soybean, likely due to the time required for initial de-esterification and bioactivation. Excessive 2,4-D acid concentrations in E soybean resulting from ADJ-increased uptake may significantly contribute to foliar injury.

  2. Effects of hemodialysis on iodine-131 biokinetics in thyroid carcinoma patients with end-stage chronic renal failure.

    Science.gov (United States)

    Yeyin, Nami; Cavdar, Iffet; Uslu, Lebriz; Abuqbeitah, Mohammad; Demir, Mustafa

    2016-03-01

    Radioiodine therapy could be challenging in chronic renal failure patients requiring hemodialysis. The aim of this study was to establish the effects of hemodialysis on elimination of radioiodine from the body in thyroid carcinoma patients with end-stage chronic renal failure and to determine its effects on environmental radiation dose. Three end-stage chronic renal failure patients (four cases) diagnosed with differentiated thyroid carcinoma requiring radioiodine therapy were included in our study. Each patient was given 50-75 mCi (1850-2775 MBq) iodine-131 with 50% dose reduction. Dose rate measurement was performed at the 2nd, 24th, and 48th hour (immediately before and after hemodialysis) after radioiodine administration. The Geiger-Müller probe was held at 1 m distance at the level of the midpoint of the thorax for the dose rate measurement. The effective half-life of iodine-131 for three patients was found to be 44 h. In conclusion, the amount of radioiodine excreted per hemodialysis session was calculated to be 51.25%.

  3. Biokinetics of osteotropic radiopharmaceuticals in metabolic osteopathies - comparison of /sup 47/Ca and sup(99m)Tc-MDP

    Energy Technology Data Exchange (ETDEWEB)

    Knop, J.; Montz, R.

    1983-10-01

    Plasma clearance and osseous accumulation rates of sup(99m)Tc methylene diphosphonate (MDP) in the lumbar spine were measured in 11 patients with osteoporosis (OP), 7 patients with hyperparathyroidism (HPT), 4 patients with osteomalacia (OM) and in 3 patients (N) who were studied to exclude metabolic bone disease. The findings in 19 patients were compared with the results of /sup 47/Ca kinetics. The plasma elimination of sup(99m)Tc-MDP during the first hour after application was normal in almost all the patients. The sup(99m)Tc-MDP accumulation rates in the lumbar spine were raised in patients with HPT and OM (p<=0,01) and normal in patients with OP and N (p>0,05). /sup 47/Ca kinetics were disturbed in most of the patients with metabolic bone disease, with minimal deviations in OP. The comparison of sup(99m)Tc-MDP accumulation rates with the results of /sup 47/Ca kinetics revealed significant correlations with exchangeable bone and soft tissue calcium. The correlations with total calcium turnover and calcium accretion were poor. Only half of the patients had equal results of sup(99m)Tc-MDP accumulation rates and bone calcium accretion rates. It is concluded that the sup(99m)Tc-MDP uptake by bone is an index of bone metabolism presumably of the organic matrix, whereas /sup 47/Ca kinetics represent the mineral metabolism of bone.

  4. Binary mixtures of mercury/ selenium, and lead/selenium

    African Journals Online (AJOL)

    Physiologically-based biokinetic models have been developed for predicting simultaneously the Absorption, Distribution, Metabolism and Elimination (ADME) properties of lead (Pb) and selenium (Se), and mercury (Hg) and selenium in a number of target tissues of humans. This was done for three population groups, ...

  5. Modelling Overview

    DEFF Research Database (Denmark)

    Larsen, Lars Bjørn; Vesterager, Johan

    This report provides an overview of the existing models of global manufacturing, describes the required modelling views and associated methods and identifies tools, which can provide support for this modelling activity.The model adopted for global manufacturing is that of an extended enterprise s...

  6. Document Models

    Directory of Open Access Journals (Sweden)

    A.A. Malykh

    2017-08-01

    Full Text Available In this paper, the concept of locally simple models is considered. Locally simple models are arbitrarily complex models built from relatively simple components. A lot of practically important domains of discourse can be described as locally simple models, for example, business models of enterprises and companies. Up to now, research in human reasoning automation has been mainly concentrated around the most intellectually intensive activities, such as automated theorem proving. On the other hand, the retailer business model is formed from ”jobs”, and each ”job” can be modelled and automated more or less easily. At the same time, the whole retailer model as an integrated system is extremely complex. In this paper, we offer a variant of the mathematical definition of a locally simple model. This definition is intended for modelling a wide range of domains. Therefore, we also must take into account the perceptual and psychological issues. Logic is elitist, and if we want to attract to our models as many people as possible, we need to hide this elitism behind some metaphor, to which ’ordinary’ people are accustomed. As such a metaphor, we use the concept of a document, so our locally simple models are called document models. Document models are built in the paradigm of semantic programming. This allows us to achieve another important goal - to make the documentary models executable. Executable models are models that can act as practical information systems in the described domain of discourse. Thus, if our model is executable, then programming becomes redundant. The direct use of a model, instead of its programming coding, brings important advantages, for example, a drastic cost reduction for development and maintenance. Moreover, since the model is well and sound, and not dissolved within programming modules, we can directly apply AI tools, in particular, machine learning. This significantly expands the possibilities for automation and

  7. Model theory

    CERN Document Server

    Chang, CC

    2012-01-01

    Model theory deals with a branch of mathematical logic showing connections between a formal language and its interpretations or models. This is the first and most successful textbook in logical model theory. Extensively updated and corrected in 1990 to accommodate developments in model theoretic methods - including classification theory and nonstandard analysis - the third edition added entirely new sections, exercises, and references. Each chapter introduces an individual method and discusses specific applications. Basic methods of constructing models include constants, elementary chains, Sko

  8. Modeling Methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    Simulation models are widely used in all types of hydrologic studies, and many of these models can be used to estimate recharge. Models can provide important insight into the functioning of hydrologic systems by identifying factors that influence recharge. The predictive capability of models can be used to evaluate how changes in climate, water use, land use, and other factors may affect recharge rates. Most hydrological simulation models, including watershed models and groundwater-flow models, are based on some form of water-budget equation, so the material in this chapter is closely linked to that in Chapter 2. Empirical models that are not based on a water-budget equation have also been used for estimating recharge; these models generally take the form of simple estimation equations that define annual recharge as a function of precipitation and possibly other climatic data or watershed characteristics.Model complexity varies greatly. Some models are simple accounting models; others attempt to accurately represent the physics of water movement through each compartment of the hydrologic system. Some models provide estimates of recharge explicitly; for example, a model based on the Richards equation can simulate water movement from the soil surface through the unsaturated zone to the water table. Recharge estimates can be obtained indirectly from other models. For example, recharge is a parameter in groundwater-flow models that solve for hydraulic head (i.e. groundwater level). Recharge estimates can be obtained through a model calibration process in which recharge and other model parameter values are adjusted so that simulated water levels agree with measured water levels. The simulation that provides the closest agreement is called the best fit, and the recharge value used in that simulation is the model-generated estimate of recharge.

  9. Galactic models

    International Nuclear Information System (INIS)

    Buchler, J.R.; Gottesman, S.T.; Hunter, J.H. Jr.

    1990-01-01

    Various papers on galactic models are presented. Individual topics addressed include: observations relating to galactic mass distributions; the structure of the Galaxy; mass distribution in spiral galaxies; rotation curves of spiral galaxies in clusters; grand design, multiple arm, and flocculent spiral galaxies; observations of barred spirals; ringed galaxies; elliptical galaxies; the modal approach to models of galaxies; self-consistent models of spiral galaxies; dynamical models of spiral galaxies; N-body models. Also discussed are: two-component models of galaxies; simulations of cloudy, gaseous galactic disks; numerical experiments on the stability of hot stellar systems; instabilities of slowly rotating galaxies; spiral structure as a recurrent instability; model gas flows in selected barred spiral galaxies; bar shapes and orbital stochasticity; three-dimensional models; polar ring galaxies; dynamical models of polar rings

  10. Model-model Perencanaan Strategik

    OpenAIRE

    Amirin, Tatang M

    2005-01-01

    The process of strategic planning, used to be called as long-term planning, consists of several components, including strategic analysis, setting strategic direction (covering of mission, vision, and values), and action planning. Many writers develop models representing the steps of the strategic planning process, i.e. basic planning model, problem-based planning model, scenario model, and organic or self-organizing model.

  11. Data file on retention and excretion of inhaled radionuclides calculated using ICRP dosimetric models

    International Nuclear Information System (INIS)

    Ishigure, Nobuhito; Nakano, Takashi; Enomoto, Hiroko; Shimo, Michikuni; Inaba, Jiro

    2000-01-01

    The authors have computed whole-body or a specific organ content and the daily urinary and faecal excretion rate of some selected radionuclides following acute intake by inhalation and ingestion, where the ICRP new respiratory tract model (ICRP Publication 66) and the latest ICRP biokinetic models were applied. The results were compiled in a file of MS Excel. The file was tentatively called MONDAI for reference. MONDAI contains the data for all radionuclides in ICRP Publications 54 and 78 and, in addition, some other radionuclides which are important from the viewpoint of occupational exposure in nuclear industry, research and medicine. They are H-3, P-32, Cr-51, Mn-54, Fe-59, Co-57, Co-58, Co-60, Zn-65, Rb-86, Sr-85, Sr-89, Sr-90, Zr-95, Ru-106, Ag-110m, Sb-124, Sb-125, I-125, I-129, I-131, Cs-134, Cs-137, Ba-140, Ce-141, Ce-144, Hg-203, Ra-226, Ra-228, Th-228, Th-232, U-234, U-235, U-238, Np-237, Pu-238, Pu-239, Pu-240, Am-241, Cm-242, Cm-244 and Cf-252. The day-by-day data up to 1000 days and the data at every 10 days up to 10000 days are presented. The following ICRP default values for the physical characteristics of the radioactive aerosols were used: AMAD=5 micron, geometric SD=2.5, particle density = 3 g/cm 3 , particle shape factor = 1.5. The subject exposed to the aerosols is the ICRP reference worker doing light work: light exercise with the ventilation rate of 1.5 m 3 /h for 5.5 h + sitting with the ventilation rate of 0.54 m 3 /h for 2.5 h. MONDAI was originally made by Version 7.0 of MS Excel for Windows 95, but the file was saved in the form of Ver. 4.0 as well as Ver. 7.0. Therefore, if the user has Ver. 4.0 or an upper version, he can open the file and operate it. With the graph-wizard of MS Excel the user can easily make a diagram for the retention or daily excretion of a radionuclide of interest. The dose coefficient (Sv/Bq intake) of each radionuclide for each absorption type given in ICRP Publication 68 was also written in each sheet. Therefore

  12. Event Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2001-01-01

    The purpose of this chapter is to discuss conceptual event modeling within a context of information modeling. Traditionally, information modeling has been concerned with the modeling of a universe of discourse in terms of information structures. However, most interesting universes of discourse...... are dynamic and we present a modeling approach that can be used to model such dynamics.We characterize events as both information objects and change agents (Bækgaard 1997). When viewed as information objects events are phenomena that can be observed and described. For example, borrow events in a library can...

  13. Modelling survival

    DEFF Research Database (Denmark)

    Ashauer, Roman; Albert, Carlo; Augustine, Starrlight

    2016-01-01

    The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test...

  14. Constitutive Models

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Piccolo, Chiara; Heitzig, Martina

    2011-01-01

    covered, illustrating several models such as the Wilson equation and NRTL equation, along with their solution strategies. A section shows how to use experimental data to regress the property model parameters using a least squares approach. A full model analysis is applied in each example that discusses...... the degrees of freedom, dependent and independent variables and solution strategy. Vapour-liquid and solid-liquid equilibrium is covered, and applications to droplet evaporation and kinetic models are given....

  15. Interface models

    DEFF Research Database (Denmark)

    Ravn, Anders P.; Staunstrup, Jørgen

    1994-01-01

    This paper proposes a model for specifying interfaces between concurrently executing modules of a computing system. The model does not prescribe a particular type of communication protocol and is aimed at describing interfaces between both software and hardware modules or a combination of the two....... The model describes both functional and timing properties of an interface...

  16. Lead exposure in young children over a 5-year period from urban environments using alternative exposure measures with the US EPA IEUBK model - A trial.

    Science.gov (United States)

    Gulson, Brian; Taylor, Alan; Stifelman, Marc

    2018-02-01

    The US Environmental Protection Agency (EPA) Integrated Exposure Uptake Biokinetic (IEUBK) model has been widely used to predict blood lead (PbB) levels in children especially around industrial sites. Exposure variables have strongly focussed on the major contribution of lead (Pb) in soil and interior dust to total intake and, in many studies, site-specific data for air, water, diet and measured PbB were not available. We have applied the IEUBK model to a comprehensive data set, including measured PbB, for 108 children monitored over a 5-year period in Sydney, New South Wales, Australia. To use this data set, we have substituted available data (with or without modification) for standard inputs as needed. For example, as an alternative measure for soil Pb concentration (μg/g), we have substituted exterior dust sweepings Pb concentration (μg/g). As alternative measures for interior dust Pb concentration (μg/g) we have used 1) 30-day cumulative petri dish deposition data (PDD) (as µg Pb/m 2 /30days), or 2) hand wipe data (as μg Pb/hand). For comparison, simulations were also undertaken with estimates of dust Pb concentration derived from a prior regression of dust Pb concentration (μg/g) on dust Pb loading (μg/ft 2 ) as concentration is the unit specified for the Model. Simulations for each subject using observed data aggregated over the 5-year interval of the study, the most usual application of the IEUBK model, showed using Wilcoxon tests that there was a significant difference between the observed values and the values predicted by the Model containing soil with hand wipes (p < 0.001), and soil and PDD (p = 0.026) but not those for the other two sets of predictors, based on sweepings and PDD or sweepings and wipes. Overall, simulations of the Model using alternative exposure measures of petri dish dust (and possibly hand wipes) instead of vacuum cleaner dust and dust sweepings instead of soil provide predicted PbB which are generally consistent with each

  17. Hydrological models are mediating models

    Science.gov (United States)

    Babel, L. V.; Karssenberg, D.

    2013-08-01

    Despite the increasing role of models in hydrological research and decision-making processes, only few accounts of the nature and function of models exist in hydrology. Earlier considerations have traditionally been conducted while making a clear distinction between physically-based and conceptual models. A new philosophical account, primarily based on the fields of physics and economics, transcends classes of models and scientific disciplines by considering models as "mediators" between theory and observations. The core of this approach lies in identifying models as (1) being only partially dependent on theory and observations, (2) integrating non-deductive elements in their construction, and (3) carrying the role of instruments of scientific enquiry about both theory and the world. The applicability of this approach to hydrology is evaluated in the present article. Three widely used hydrological models, each showing a different degree of apparent physicality, are confronted to the main characteristics of the "mediating models" concept. We argue that irrespective of their kind, hydrological models depend on both theory and observations, rather than merely on one of these two domains. Their construction is additionally involving a large number of miscellaneous, external ingredients, such as past experiences, model objectives, knowledge and preferences of the modeller, as well as hardware and software resources. We show that hydrological models convey the role of instruments in scientific practice by mediating between theory and the world. It results from these considerations that the traditional distinction between physically-based and conceptual models is necessarily too simplistic and refers at best to the stage at which theory and observations are steering model construction. The large variety of ingredients involved in model construction would deserve closer attention, for being rarely explicitly presented in peer-reviewed literature. We believe that devoting

  18. ICRF modelling

    International Nuclear Information System (INIS)

    Phillips, C.K.

    1985-12-01

    This lecture provides a survey of the methods used to model fast magnetosonic wave coupling, propagation, and absorption in tokamaks. The validity and limitations of three distinct types of modelling codes, which will be contrasted, include discrete models which utilize ray tracing techniques, approximate continuous field models based on a parabolic approximation of the wave equation, and full field models derived using finite difference techniques. Inclusion of mode conversion effects in these models and modification of the minority distribution function will also be discussed. The lecture will conclude with a presentation of time-dependent global transport simulations of ICRF-heated tokamak discharges obtained in conjunction with the ICRF modelling codes. 52 refs., 15 figs

  19. Modelling in Business Model design

    NARCIS (Netherlands)

    Simonse, W.L.

    2013-01-01

    It appears that business model design might not always produce a design or model as the expected result. However when designers are involved, a visual model or artefact is produced. To assist strategic managers in thinking about how they can act, the designers challenge is to combine strategy and

  20. Eclipse models

    International Nuclear Information System (INIS)

    Michel, F.C.

    1989-01-01

    Three existing eclipse models for the PSR 1957 + 20 pulsar are discussed in terms of their requirements and the information they yield about the pulsar wind: the interacting wind from a companion model, the magnetosphere model, and the occulting disk model. It is shown out that the wind model requires an MHD wind from the pulsar, with enough particles that the Poynting flux of the wind can be thermalized; in this model, a large flux of energetic radiation from the pulsar is required to accompany the wind and drive the wind off the companion. The magnetosphere model requires an EM wind, which is Poynting flux dominated; the advantage of this model over the wind model is that the plasma density inside the magnetosphere can be orders of magnitude larger than in a magnetospheric tail blown back by wind interaction. The occulting disk model also requires an EM wind so that the interaction would be pushed down onto the companion surface, minimizing direct interaction of the wind with the orbiting macroscopic particles

  1. Ventilation Model

    International Nuclear Information System (INIS)

    Yang, H.

    1999-01-01

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future

  2. Mathematical modelling

    DEFF Research Database (Denmark)

    Blomhøj, Morten

    2004-01-01

    Developing competences for setting up, analysing and criticising mathematical models are normally seen as relevant only from and above upper secondary level. The general belief among teachers is that modelling activities presuppose conceptual understanding of the mathematics involved. Mathematical...... roots for the construction of important mathematical concepts. In addition competences for setting up, analysing and criticising modelling processes and the possible use of models is a formative aim in this own right for mathematics teaching in general education. The paper presents a theoretical...... modelling, however, can be seen as a practice of teaching that place the relation between real life and mathematics into the centre of teaching and learning mathematics, and this is relevant at all levels. Modelling activities may motivate the learning process and help the learner to establish cognitive...

  3. Mathematical modelling

    CERN Document Server

    2016-01-01

    This book provides a thorough introduction to the challenge of applying mathematics in real-world scenarios. Modelling tasks rarely involve well-defined categories, and they often require multidisciplinary input from mathematics, physics, computer sciences, or engineering. In keeping with this spirit of modelling, the book includes a wealth of cross-references between the chapters and frequently points to the real-world context. The book combines classical approaches to modelling with novel areas such as soft computing methods, inverse problems, and model uncertainty. Attention is also paid to the interaction between models, data and the use of mathematical software. The reader will find a broad selection of theoretical tools for practicing industrial mathematics, including the analysis of continuum models, probabilistic and discrete phenomena, and asymptotic and sensitivity analysis.

  4. Model : making

    OpenAIRE

    Bottle, Neil

    2013-01-01

    The Model : making exhibition was curated by Brian Kennedy in collaboration with Allies & Morrison in September 2013. For the London Design Festival, the Model : making exhibition looked at the increased use of new technologies by both craft-makers and architectural model makers. In both practices traditional ways of making by hand are increasingly being combined with the latest technologies of digital imaging, laser cutting, CNC machining and 3D printing. This exhibition focussed on ...

  5. Model building

    International Nuclear Information System (INIS)

    Frampton, Paul H.

    1998-01-01

    In this talk I begin with some general discussion of model building in particle theory, emphasizing the need for motivation and testability. Three illustrative examples are then described. The first is the Left-Right model which provides an explanation for the chirality of quarks and leptons. The second is the 331-model which offers a first step to understanding the three generations of quarks and leptons. Third and last is the SU(15) model which can accommodate the light leptoquarks possibly seen at HERA

  6. Model building

    International Nuclear Information System (INIS)

    Frampton, P.H.

    1998-01-01

    In this talk I begin with some general discussion of model building in particle theory, emphasizing the need for motivation and testability. Three illustrative examples are then described. The first is the Left-Right model which provides an explanation for the chirality of quarks and leptons. The second is the 331-model which offers a first step to understanding the three generations of quarks and leptons. Third and last is the SU(15) model which can accommodate the light leptoquarks possibly seen at HERA. copyright 1998 American Institute of Physics

  7. Modeling Documents with Event Model

    Directory of Open Access Journals (Sweden)

    Longhui Wang

    2015-08-01

    Full Text Available Currently deep learning has made great breakthroughs in visual and speech processing, mainly because it draws lessons from the hierarchical mode that brain deals with images and speech. In the field of NLP, a topic model is one of the important ways for modeling documents. Topic models are built on a generative model that clearly does not match the way humans write. In this paper, we propose Event Model, which is unsupervised and based on the language processing mechanism of neurolinguistics, to model documents. In Event Model, documents are descriptions of concrete or abstract events seen, heard, or sensed by people and words are objects in the events. Event Model has two stages: word learning and dimensionality reduction. Word learning is to learn semantics of words based on deep learning. Dimensionality reduction is the process that representing a document as a low dimensional vector by a linear mode that is completely different from topic models. Event Model achieves state-of-the-art results on document retrieval tasks.

  8. Animal models

    DEFF Research Database (Denmark)

    Gøtze, Jens Peter; Krentz, Andrew

    2014-01-01

    In this issue of Cardiovascular Endocrinology, we are proud to present a broad and dedicated spectrum of reviews on animal models in cardiovascular disease. The reviews cover most aspects of animal models in science from basic differences and similarities between small animals and the human...

  9. Battery Modeling

    NARCIS (Netherlands)

    Jongerden, M.R.; Haverkort, Boudewijn R.H.M.

    2008-01-01

    The use of mobile devices is often limited by the capacity of the employed batteries. The battery lifetime determines how long one can use a device. Battery modeling can help to predict, and possibly extend this lifetime. Many different battery models have been developed over the years. However,

  10. Didactical modelling

    DEFF Research Database (Denmark)

    Højgaard, Tomas; Hansen, Rune

    The purpose of this paper is to introduce Didactical Modelling as a research methodology in mathematics education. We compare the methodology with other approaches and argue that Didactical Modelling has its own specificity. We discuss the methodological “why” and explain why we find it useful...

  11. Design modelling

    NARCIS (Netherlands)

    Kempen, van A.; Kok, H.; Wagter, H.

    1992-01-01

    In Computer Aided Drafting three groups of three-dimensional geometric modelling can be recognized: wire frame, surface and solid modelling. One of the methods to describe a solid is by using a boundary based representation. The topology of the surface of a solid is the adjacency information between

  12. Education models

    NARCIS (Netherlands)

    Poortman, Sybilla; Sloep, Peter

    2006-01-01

    Educational models describes a case study on a complex learning object. Possibilities are investigated for using this learning object, which is based on a particular educational model, outside of its original context. Furthermore, this study provides advice that might lead to an increase in

  13. VENTILATION MODEL

    International Nuclear Information System (INIS)

    V. Chipman

    2002-01-01

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses

  14. Modelling Constructs

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2009-01-01

    , these notations have been extended in order to increase expressiveness and to be more competitive. This resulted in an increasing number of notations and formalisms for modelling business processes and in an increase of the different modelling constructs provided by modelling notations, which makes it difficult......There are many different notations and formalisms for modelling business processes and workflows. These notations and formalisms have been introduced with different purposes and objectives. Later, influenced by other notations, comparisons with other tools, or by standardization efforts...... to compare modelling notations and to make transformations between them. One of the reasons is that, in each notation, the new concepts are introduced in a different way by extending the already existing constructs. In this chapter, we go the opposite direction: We show that it is possible to add most...

  15. STEREOMETRIC MODELLING

    Directory of Open Access Journals (Sweden)

    P. Grimaldi

    2012-07-01

    Full Text Available These mandatory guidelines are provided for preparation of papers accepted for publication in the series of Volumes of The The stereometric modelling means modelling achieved with : – the use of a pair of virtual cameras, with parallel axes and positioned at a mutual distance average of 1/10 of the distance camera-object (in practice the realization and use of a stereometric camera in the modeling program; – the shot visualization in two distinct windows – the stereoscopic viewing of the shot while modelling. Since the definition of "3D vision" is inaccurately referred to as the simple perspective of an object, it is required to add the word stereo so that "3D stereo vision " shall stand for "three-dimensional view" and ,therefore, measure the width, height and depth of the surveyed image. Thanks to the development of a stereo metric model , either real or virtual, through the "materialization", either real or virtual, of the optical-stereo metric model made visible with a stereoscope. It is feasible a continuous on line updating of the cultural heritage with the help of photogrammetry and stereometric modelling. The catalogue of the Architectonic Photogrammetry Laboratory of Politecnico di Bari is available on line at: http://rappresentazione.stereofot.it:591/StereoFot/FMPro?-db=StereoFot.fp5&-lay=Scheda&-format=cerca.htm&-view

  16. Modeling complexes of modeled proteins.

    Science.gov (United States)

    Anishchenko, Ivan; Kundrotas, Petras J; Vakser, Ilya A

    2017-03-01

    Structural characterization of proteins is essential for understanding life processes at the molecular level. However, only a fraction of known proteins have experimentally determined structures. This fraction is even smaller for protein-protein complexes. Thus, structural modeling of protein-protein interactions (docking) primarily has to rely on modeled structures of the individual proteins, which typically are less accurate than the experimentally determined ones. Such "double" modeling is the Grand Challenge of structural reconstruction of the interactome. Yet it remains so far largely untested in a systematic way. We present a comprehensive validation of template-based and free docking on a set of 165 complexes, where each protein model has six levels of structural accuracy, from 1 to 6 Å C α RMSD. Many template-based docking predictions fall into acceptable quality category, according to the CAPRI criteria, even for highly inaccurate proteins (5-6 Å RMSD), although the number of such models (and, consequently, the docking success rate) drops significantly for models with RMSD > 4 Å. The results show that the existing docking methodologies can be successfully applied to protein models with a broad range of structural accuracy, and the template-based docking is much less sensitive to inaccuracies of protein models than the free docking. Proteins 2017; 85:470-478. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Graphical Rasch models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    Rasch models; Partial Credit models; Rating Scale models; Item bias; Differential item functioning; Local independence; Graphical models......Rasch models; Partial Credit models; Rating Scale models; Item bias; Differential item functioning; Local independence; Graphical models...

  18. Supernova models

    International Nuclear Information System (INIS)

    Woosley, S.E.; California, University, Livermore, CA); Weaver, T.A.

    1981-01-01

    Recent progress in understanding the observed properties of type I supernovae as a consequence of the thermonuclear detonation of white dwarf stars and the ensuing decay of the Ni-56 produced therein is reviewed. The expected nucleosynthesis and gamma-line spectra for this model of type I explosions and a model for type II explosions are presented. Finally, a qualitatively new approach to the problem of massive star death and type II supernovae based upon a combination of rotation and thermonuclear burning is discussed. While the theoretical results of existing models are predicated upon the assumption of a successful core bounce calculation and the neglect of such two-dimensional effects as rotation and magnetic fields the new model suggests an entirely different scenario in which a considerable portion of the energy carried by an equatorially ejected blob is deposited in the red giant envelope overlying the mantle of the star

  19. Model theory

    CERN Document Server

    Hodges, Wilfrid

    1993-01-01

    An up-to-date and integrated introduction to model theory, designed to be used for graduate courses (for students who are familiar with first-order logic), and as a reference for more experienced logicians and mathematicians.

  20. Markov model

    Indian Academy of Sciences (India)

    2School of Water Resources, Indian Institute of Technology,. Kharagpur ... the most accepted method for modelling LULCC using current .... We used UTM coordinate system with zone 45 .... need to develop criteria for making decision about.

  1. Paleoclimate Modeling

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Computer simulations of past climate. Variables provided as model output are described by parameter keyword. In some cases the parameter keywords are a subset of all...

  2. Energy Models

    Science.gov (United States)

    Energy models characterize the energy system, its evolution, and its interactions with the broader economy. The energy system consists of primary resources, including both fossil fuels and renewables; power plants, refineries, and other technologies to process and convert these r...

  3. Linear Models

    CERN Document Server

    Searle, Shayle R

    2012-01-01

    This 1971 classic on linear models is once again available--as a Wiley Classics Library Edition. It features material that can be understood by any statistician who understands matrix algebra and basic statistical methods.

  4. Ventilation models

    Science.gov (United States)

    Skaaret, Eimund

    Calculation procedures, used in the design of ventilating systems, which are especially suited for displacement ventilation in addition to linking it to mixing ventilation, are addressed. The two zone flow model is considered and the steady state and transient solutions are addressed. Different methods of supplying air are discussed, and different types of air flow are considered: piston flow, plane flow and radial flow. An evaluation model for ventilation systems is presented.

  5. Model uncertainty: Probabilities for models?

    International Nuclear Information System (INIS)

    Winkler, R.L.

    1994-01-01

    Like any other type of uncertainty, model uncertainty should be treated in terms of probabilities. The question is how to do this. The most commonly-used approach has a drawback related to the interpretation of the probabilities assigned to the models. If we step back and look at the big picture, asking what the appropriate focus of the model uncertainty question should be in the context of risk and decision analysis, we see that a different probabilistic approach makes more sense, although it raise some implementation questions. Current work that is underway to address these questions looks very promising

  6. Thermocouple modeling

    International Nuclear Information System (INIS)

    Fryer, M.O.

    1984-01-01

    The temperature measurements provided by thermocouples (TCs) are important for the operation of pressurized water reactors. During severe inadequate core cooling incidents, extreme temperatures may cause type K thermocouples (TCs) used for core exit temperature monitoring to perform poorly. A model of TC electrical behavior has been developed to determine how TCs react under extreme temperatures. The model predicts the voltage output of the TC and its impedance. A series of experiments were conducted on a length of type K thermocouple to validate the model. Impedance was measured at several temperatures between 22 0 C and 1100 0 C and at frequencies between dc and 10 MHz. The model was able to accurately predict impedance over this wide range of conditions. The average percentage difference between experimental data and the model was less than 6.5%. Experimental accuracy was +-2.5%. There is a sriking difference between impedance versus frequency plots at 300 0 C and at higher temperatures. This may be useful in validating TC data during accident conditions

  7. Photoionization Modeling

    Science.gov (United States)

    Kallman, T.

    2010-01-01

    Warm absorber spectra are characterized by the many lines from partially ionized intermediate-Z elements, and iron, detected with the grating instruments on Chandra and XMM-Newton. If these ions are formed in a gas which is in photoionization equilibrium, they correspond to a broad range of ionization parameters, although there is evidence for certain preferred values. A test for any dynamical model for these outflows is to reproduce these properties, at some level of detail. In this paper we present a statistical analysis of the ionization distribution which can be applied both the observed spectra and to theoretical models. As an example, we apply it to our dynamical models for warm absorber outflows, based on evaporation from the molecular torus.

  8. Reflectance Modeling

    Science.gov (United States)

    Smith, J. A.; Cooper, K.; Randolph, M.

    1984-01-01

    A classical description of the one dimensional radiative transfer treatment of vegetation canopies was completed and the results were tested against measured prairie (blue grama) and agricultural canopies (soybean). Phase functions are calculated in terms of directly measurable biophysical characteristics of the canopy medium. While the phase functions tend to exhibit backscattering anisotropy, their exact behavior is somewhat more complex and wavelength dependent. A Monte Carlo model was developed that treats soil surfaces with large periodic variations in three dimensions. A photon-ray tracing technology is used. Currently, the rough soil surface is described by analytic functions and appropriate geometric calculations performed. A bidirectional reflectance distribution function is calculated and, hence, available for other atmospheric or canopy reflectance models as a lower boundary condition. This technique is used together with an adding model to calculate several cases where Lambertian leaves possessing anisotropic leaf angle distributions yield non-Lambertian reflectance; similar behavior is exhibited for simulated soil surfaces.

  9. Mathematical modeling

    CERN Document Server

    Eck, Christof; Knabner, Peter

    2017-01-01

    Mathematical models are the decisive tool to explain and predict phenomena in the natural and engineering sciences. With this book readers will learn to derive mathematical models which help to understand real world phenomena. At the same time a wealth of important examples for the abstract concepts treated in the curriculum of mathematics degrees are given. An essential feature of this book is that mathematical structures are used as an ordering principle and not the fields of application. Methods from linear algebra, analysis and the theory of ordinary and partial differential equations are thoroughly introduced and applied in the modeling process. Examples of applications in the fields electrical networks, chemical reaction dynamics, population dynamics, fluid dynamics, elasticity theory and crystal growth are treated comprehensively.

  10. Modelling language

    CERN Document Server

    Cardey, Sylviane

    2013-01-01

    In response to the need for reliable results from natural language processing, this book presents an original way of decomposing a language(s) in a microscopic manner by means of intra/inter‑language norms and divergences, going progressively from languages as systems to the linguistic, mathematical and computational models, which being based on a constructive approach are inherently traceable. Languages are described with their elements aggregating or repelling each other to form viable interrelated micro‑systems. The abstract model, which contrary to the current state of the art works in int

  11. Molecular modeling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-01-01

    Full Text Available The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and the exponential growth of the knowledge of protein structures have made it possible for organic compounds to be tailored to decrease the harmful side effects and increase the potency. This article provides a detailed description of the techniques employed in molecular modeling. Molecular modeling is a rapidly developing discipline, and has been supported by the dramatic improvements in computer hardware and software in recent years.

  12. Supernova models

    International Nuclear Information System (INIS)

    Woosley, S.E.; Weaver, T.A.

    1980-01-01

    Recent progress in understanding the observed properties of Type I supernovae as a consequence of the thermonuclear detonation of white dwarf stars and the ensuing decay of the 56 Ni produced therein is reviewed. Within the context of this model for Type I explosions and the 1978 model for Type II explosions, the expected nucleosynthesis and gamma-line spectra from both kinds of supernovae are presented. Finally, a qualitatively new approach to the problem of massive star death and Type II supernovae based upon a combination of rotation and thermonuclear burning is discussed

  13. Painting models

    Science.gov (United States)

    Baart, F.; Donchyts, G.; van Dam, A.; Plieger, M.

    2015-12-01

    The emergence of interactive art has blurred the line between electronic, computer graphics and art. Here we apply this art form to numerical models. Here we show how the transformation of a numerical model into an interactive painting can both provide insights and solve real world problems. The cases that are used as an example include forensic reconstructions, dredging optimization, barrier design. The system can be fed using any source of time varying vector fields, such as hydrodynamic models. The cases used here, the Indian Ocean (HYCOM), the Wadden Sea (Delft3D Curvilinear), San Francisco Bay (3Di subgrid and Delft3D Flexible Mesh), show that the method used is suitable for different time and spatial scales. High resolution numerical models become interactive paintings by exchanging their velocity fields with a high resolution (>=1M cells) image based flow visualization that runs in a html5 compatible web browser. The image based flow visualization combines three images into a new image: the current image, a drawing, and a uv + mask field. The advection scheme that computes the resultant image is executed in the graphics card using WebGL, allowing for 1M grid cells at 60Hz performance on mediocre graphic cards. The software is provided as open source software. By using different sources for a drawing one can gain insight into several aspects of the velocity fields. These aspects include not only the commonly represented magnitude and direction, but also divergence, topology and turbulence .

  14. Entrepreneurship Models.

    Science.gov (United States)

    Finger Lakes Regional Education Center for Economic Development, Mount Morris, NY.

    This guide describes seven model programs that were developed by the Finger Lakes Regional Center for Economic Development (New York) to meet the training needs of female and minority entrepreneurs to help their businesses survive and grow and to assist disabled and dislocated workers and youth in beginning small businesses. The first three models…

  15. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil...

  16. Eclipse models

    International Nuclear Information System (INIS)

    Michel, F.C.

    1989-01-01

    This paper addresses the question of, if one overlooks their idiosyncratic difficulties, what could be learned from the various models about the pulsar wind? The wind model requires an MHD wind from the pulsar, namely, one with enough particles that the Poynting flux of the wind can be thermalized. Otherwise, there is no shock and the pulsar wind simply reflects like a flashlight beam. Additionally, a large flux of energetic radiation from the pulsar is required to accompany the wind and drive the wind off the companion. The magnetosphere model probably requires an EM wind, which is Poynting flux dominated. Reflection in this case would arguably minimize the intimate interaction between the two flows that leads to tail formation and thereby permit a weakly magnetized tail. The occulting disk model also would point to an EM wind so that the interaction would be pushed down onto the companion surface (to form the neutral fountain) and so as to also minimize direct interaction of the wind with the orbiting macroscopic particles

  17. (SSE) model

    African Journals Online (AJOL)

    Simple analytic polynomials have been proposed for estimating solar radiation in the traditional Northern, Central and Southern regions of Malawi. There is a strong agreement between the polynomials and the SSE model with R2 values of 0.988, 0.989 and 0.989 and root mean square errors of 0.061, 0.057 and 0.062 ...

  18. Successful modeling?

    Science.gov (United States)

    Lomnitz, Cinna

    Tichelaar and Ruff [1989] propose to “estimate model variance in complicated geophysical problems,” including the determination of focal depth in earthquakes, by means of unconventional statistical methods such as bootstrapping. They are successful insofar as they are able to duplicate the results from more conventional procedures.

  19. Defect modelling

    International Nuclear Information System (INIS)

    Norgett, M.J.

    1980-01-01

    Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK)

  20. Cadastral Modeling

    DEFF Research Database (Denmark)

    Stubkjær, Erik

    2005-01-01

    to the modeling of an industrial sector, as it aims at rendering the basic concepts that relate to the domain of real estate and the pertinent human activities. The palpable objects are pieces of land and buildings, documents, data stores and archives, as well as persons in their diverse roles as owners, holders...

  1. The Model

    DEFF Research Database (Denmark)

    About the reconstruction of Palle Nielsen's (f. 1942) work The Model from 1968: a gigantic playground for children in the museum, where they can freely romp about, climb in ropes, crawl on wooden structures, work with tools, jump in foam rubber, paint with finger paints and dress up in costumes....

  2. Biotran model

    International Nuclear Information System (INIS)

    Wenzel, W.J.; Gallegos, A.F.; Rodgers, J.C.

    1985-01-01

    The BIOTRAN model was developed at Los Alamos to help predict short- and long-term consequences to man from releases of radionuclides into the environment. It is a dynamic model that simulates on a daily and yearly basis the flux of biomass, water, and radionuclides through terrestrial and aquatic ecosystems. Biomass, water, and radionuclides are driven within the ecosystems by climate variables stochastically generated by BIOTRAN each simulation day. The climate variables influence soil hydraulics, plant growth, evapotranspiration, and particle suspension and deposition. BIOTRAN has 22 different plant growth strategies for simulating various grasses, shrubs, trees, and crops. Ruminants and humans are also dynamically simulated by using the simulated crops and forage as intake for user-specified diets. BIOTRAN has been used at Los Alamos for long-term prediction of health effects to populations following potential accidental releases of uranium and plutonium. Newly developed subroutines are described: a human dynamic physiological and metabolic model; a soil hydrology and irrigation model; limnetic nutrient and radionuclide cycling in fresh-water lakes. 7 references

  3. Turbulence Model

    DEFF Research Database (Denmark)

    Nielsen, Mogens Peter; Shui, Wan; Johansson, Jens

    2011-01-01

    term with stresses depending linearly on the strain rates. This term takes into account the transfer of linear momentum from one part of the fluid to another. Besides there is another term, which takes into account the transfer of angular momentum. Thus the model implies a new definition of turbulence...

  4. Hydroballistics Modeling

    Science.gov (United States)

    1975-01-01

    thai h’liathe0in antd is finaull’ %IIIrd alt %tramlit And drohlttle. Mike aplpars Ito inua•,e upward in outler a rei and dowoi. ward it %iunr areli, Oil...fiducial marks should be constant and the edges phobic nor hydrophilic is better for routine sharpl ) defined. model testing. Before each launching in

  5. Molecular Modeling

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 5. Molecular Modeling: A Powerful Tool for Drug Design and Molecular Docking. Rama Rao Nadendla. General Article Volume 9 Issue 5 May 2004 pp 51-60. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Criticality Model

    International Nuclear Information System (INIS)

    Alsaed, A.

    2004-01-01

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of this analysis is to document the criticality computational method. The criticality

  7. Building Models and Building Modelling

    DEFF Research Database (Denmark)

    Jørgensen, Kaj; Skauge, Jørn

    2008-01-01

    I rapportens indledende kapitel beskrives de primære begreber vedrørende bygningsmodeller og nogle fundamentale forhold vedrørende computerbaseret modulering bliver opstillet. Desuden bliver forskellen mellem tegneprogrammer og bygnings­model­lerings­programmer beskrevet. Vigtige aspekter om comp...

  8. Persistent Modelling

    DEFF Research Database (Denmark)

    2012-01-01

    The relationship between representation and the represented is examined here through the notion of persistent modelling. This notion is not novel to the activity of architectural design if it is considered as describing a continued active and iterative engagement with design concerns – an evident....... It also provides critical insight into the use of contemporary modelling tools and methods, together with an examination of the implications their use has within the territories of architectural design, realisation and experience....... on this subject, this book makes essential reading for anyone considering new ways of thinking about architecture. In drawing upon both historical and contemporary perspectives this book provides evidence of the ways in which relations between representation and the represented continue to be reconsidered...

  9. Persistent Modelling

    DEFF Research Database (Denmark)

    The relationship between representation and the represented is examined here through the notion of persistent modelling. This notion is not novel to the activity of architectural design if it is considered as describing a continued active and iterative engagement with design concerns – an evident....... It also provides critical insight into the use of contemporary modelling tools and methods, together with an examination of the implications their use has within the territories of architectural design, realisation and experience....... on this subject, this book makes essential reading for anyone considering new ways of thinking about architecture. In drawing upon both historical and contemporary perspectives this book provides evidence of the ways in which relations between representation and the represented continue to be reconsidered...

  10. Acyclic models

    CERN Document Server

    Barr, Michael

    2002-01-01

    Acyclic models is a method heavily used to analyze and compare various homology and cohomology theories appearing in topology and algebra. This book is the first attempt to put together in a concise form this important technique and to include all the necessary background. It presents a brief introduction to category theory and homological algebra. The author then gives the background of the theory of differential modules and chain complexes over an abelian category to state the main acyclic models theorem, generalizing and systemizing the earlier material. This is then applied to various cohomology theories in algebra and topology. The volume could be used as a text for a course that combines homological algebra and algebraic topology. Required background includes a standard course in abstract algebra and some knowledge of topology. The volume contains many exercises. It is also suitable as a reference work for researchers.

  11. Molecular Modelling

    Directory of Open Access Journals (Sweden)

    Aarti Sharma

    2009-12-01

    Full Text Available

    The use of computational chemistry in the development of novel pharmaceuticals is becoming an increasingly important
    tool. In the past, drugs were simply screened for effectiveness. The recent advances in computing power and
    the exponential growth of the knowledge of protein structures have made it possible for organic compounds to tailored to
    decrease harmful side effects and increase the potency. This article provides a detailed description of the techniques
    employed in molecular modeling. Molecular modelling is a rapidly developing discipline, and has been supported from
    the dramatic improvements in computer hardware and software in recent years.

  12. RNICE Model

    DEFF Research Database (Denmark)

    Pedersen, Mogens Jin; Stritch, Justin Michael

    2018-01-01

    Replication studies relate to the scientific principle of replicability and serve the significant purpose of providing supporting (or contradicting) evidence regarding the existence of a phenomenon. However, replication has never been an integral part of public administration and management...... research. Recently, scholars have issued calls for more replication, but academic reflections on when replication adds substantive value to public administration and management research are needed. This concise article presents a conceptual model, RNICE, for assessing when and how a replication study...... contributes knowledge about a social phenomenon and advances knowledge in the public administration and management literatures. The RNICE model provides a vehicle for researchers who seek to evaluate or demonstrate the value of a replication study systematically. We illustrate the practical application...

  13. Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan; Vatrapu, Ravi

    2016-01-01

    Recent advancements in set theory and readily available software have enabled social science researchers to bridge the variable-centered quantitative and case-based qualitative methodological paradigms in order to analyze multi-dimensional associations beyond the linearity assumptions, aggregate...... effects, unicausal reduction, and case specificity. Based on the developments in set theoretical thinking in social sciences and employing methods like Qualitative Comparative Analysis (QCA), Necessary Condition Analysis (NCA), and set visualization techniques, in this position paper, we propose...... and demonstrate a new approach to maturity models in the domain of Information Systems. This position paper describes the set-theoretical approach to maturity models, presents current results and outlines future research work....

  14. Modelling Defiguration

    DEFF Research Database (Denmark)

    Bork Petersen, Franziska

    2013-01-01

    advantageous manner. Stepping on the catwalk’s sloping, moving surfaces decelerates the models’ walk and makes it cautious, hesitant and shaky: suddenly the models lack exactly the affirmative, staccato, striving quality of motion, and the condescending expression that they perform on most contemporary......For the presentation of his autumn/winter 2012 collection in Paris and subsequently in Copenhagen, Danish designer Henrik Vibskov installed a mobile catwalk. The article investigates the choreographic impact of this scenography on those who move through it. Drawing on Dance Studies, the analytical...... focus centres on how the catwalk scenography evokes a ‘defiguration’ of the walking models and to what effect. Vibskov’s mobile catwalk draws attention to the walk, which is a key element of models’ performance but which usually functions in fashion shows merely to present clothes in the most...

  15. Cheating models

    DEFF Research Database (Denmark)

    Arnoldi, Jakob

    The article discusses the use of algorithmic models for so-called High Frequency Trading (HFT) in finance. HFT is controversial yet widespread in modern financial markets. It is a form of automated trading technology which critics among other things claim can lead to market manipulation. Drawing....... The article analyses these challenges and argues that we witness a new post-social form of human-technology interaction that will lead to a reconfiguration of professional codes for financial trading....

  16. Biomimetic modelling.

    OpenAIRE

    Vincent, Julian F V

    2003-01-01

    Biomimetics is seen as a path from biology to engineering. The only path from engineering to biology in current use is the application of engineering concepts and models to biological systems. However, there is another pathway: the verification of biological mechanisms by manufacture, leading to an iterative process between biology and engineering in which the new understanding that the engineering implementation of a biological system can bring is fed back into biology, allowing a more compl...

  17. Ozone modeling

    Energy Technology Data Exchange (ETDEWEB)

    McIllvaine, C M

    1994-07-01

    Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO{sub 2}), nitric oxide (NO), particulate matter, hydrocarbon compounds and trace metals. Estimated emissions from the operation of a hypothetical 500 MW coal-fired power plant are given. Ozone is considered a secondary pollutant, since it is not emitted directly into the atmosphere but is formed from other air pollutants, specifically, nitrogen oxides (NO), and non-methane organic compounds (NMOQ) in the presence of sunlight. (NMOC are sometimes referred to as hydrocarbons, HC, or volatile organic compounds, VOC, and they may or may not include methane). Additionally, ozone formation Alternative is a function of the ratio of NMOC concentrations to NO{sub x} concentrations. A typical ozone isopleth is shown, generated with the Empirical Kinetic Modeling Approach (EKMA) option of the Environmental Protection Agency's (EPA) Ozone Isopleth Plotting Mechanism (OZIPM-4) model. Ozone isopleth diagrams, originally generated with smog chamber data, are more commonly generated with photochemical reaction mechanisms and tested against smog chamber data. The shape of the isopleth curves is a function of the region (i.e. background conditions) where ozone concentrations are simulated. The location of an ozone concentration on the isopleth diagram is defined by the ratio of NMOC and NO{sub x} coordinates of the point, known as the NMOC/NO{sub x} ratio. Results obtained by the described model are presented.

  18. Ozone modeling

    International Nuclear Information System (INIS)

    McIllvaine, C.M.

    1994-01-01

    Exhaust gases from power plants that burn fossil fuels contain concentrations of sulfur dioxide (SO 2 ), nitric oxide (NO), particulate matter, hydrocarbon compounds and trace metals. Estimated emissions from the operation of a hypothetical 500 MW coal-fired power plant are given. Ozone is considered a secondary pollutant, since it is not emitted directly into the atmosphere but is formed from other air pollutants, specifically, nitrogen oxides (NO), and non-methane organic compounds (NMOQ) in the presence of sunlight. (NMOC are sometimes referred to as hydrocarbons, HC, or volatile organic compounds, VOC, and they may or may not include methane). Additionally, ozone formation Alternative is a function of the ratio of NMOC concentrations to NO x concentrations. A typical ozone isopleth is shown, generated with the Empirical Kinetic Modeling Approach (EKMA) option of the Environmental Protection Agency's (EPA) Ozone Isopleth Plotting Mechanism (OZIPM-4) model. Ozone isopleth diagrams, originally generated with smog chamber data, are more commonly generated with photochemical reaction mechanisms and tested against smog chamber data. The shape of the isopleth curves is a function of the region (i.e. background conditions) where ozone concentrations are simulated. The location of an ozone concentration on the isopleth diagram is defined by the ratio of NMOC and NO x coordinates of the point, known as the NMOC/NO x ratio. Results obtained by the described model are presented

  19. Animal models.

    Science.gov (United States)

    Walker, Ellen A

    2010-01-01

    As clinical studies reveal that chemotherapeutic agents may impair several different cognitive domains in humans, the development of preclinical animal models is critical to assess the degree of chemotherapy-induced learning and memory deficits and to understand the underlying neural mechanisms. In this chapter, the effects of various cancer chemotherapeutic agents in rodents on sensory processing, conditioned taste aversion, conditioned emotional response, passive avoidance, spatial learning, cued memory, discrimination learning, delayed-matching-to-sample, novel-object recognition, electrophysiological recordings and autoshaping is reviewed. It appears at first glance that the effects of the cancer chemotherapy agents in these many different models are inconsistent. However, a literature is emerging that reveals subtle or unique changes in sensory processing, acquisition, consolidation and retrieval that are dose- and time-dependent. As more studies examine cancer chemotherapeutic agents alone and in combination during repeated treatment regimens, the animal models will become more predictive tools for the assessment of these impairments and the underlying neural mechanisms. The eventual goal is to collect enough data to enable physicians to make informed choices about therapeutic regimens for their patients and discover new avenues of alternative or complementary therapies that reduce or eliminate chemotherapy-induced cognitive deficits.

  20. Modeling biomembranes.

    Energy Technology Data Exchange (ETDEWEB)

    Plimpton, Steven James; Heffernan, Julieanne; Sasaki, Darryl Yoshio; Frischknecht, Amalie Lucile; Stevens, Mark Jackson; Frink, Laura J. Douglas

    2005-11-01

    Understanding the properties and behavior of biomembranes is fundamental to many biological processes and technologies. Microdomains in biomembranes or ''lipid rafts'' are now known to be an integral part of cell signaling, vesicle formation, fusion processes, protein trafficking, and viral and toxin infection processes. Understanding how microdomains form, how they depend on membrane constituents, and how they act not only has biological implications, but also will impact Sandia's effort in development of membranes that structurally adapt to their environment in a controlled manner. To provide such understanding, we created physically-based models of biomembranes. Molecular dynamics (MD) simulations and classical density functional theory (DFT) calculations using these models were applied to phenomena such as microdomain formation, membrane fusion, pattern formation, and protein insertion. Because lipid dynamics and self-organization in membranes occur on length and time scales beyond atomistic MD, we used coarse-grained models of double tail lipid molecules that spontaneously self-assemble into bilayers. DFT provided equilibrium information on membrane structure. Experimental work was performed to further help elucidate the fundamental membrane organization principles.

  1. The work of Committee 2 of ICRP in developing dose coefficients for the embryo and fetus following intakes of radionuclides by the mother

    International Nuclear Information System (INIS)

    Stather, J.W.; Phipps, A.W.

    1999-01-01

    Committee 2 of the International Commission on Radiological Protection has the responsibility for calculating radiation doses from intakes of radionuclides for all age groups in the population. This includes the development of models for calculating doses to the embryo and fetus following intakes of radionuclides by the mother. The development of both biokinetic and dosimetric models are reviewed and the results of preliminary dose calculations presented. (orig.) [de

  2. Energy Metabolism and Human Dosimetry of Tritium

    International Nuclear Information System (INIS)

    Galeriu, D.; Takeda, H.; Melintescu, A.; Trivedi, A.

    2005-01-01

    In the frame of current revision of human dosimetry of 14 C and tritium, undertaken by the International Commission of Radiological Protection, we propose a novel approach based on energy metabolism and a simple biokinetic model for the dynamics of dietary intake (organic 14 C, tritiated water and Organically Bound Tritium-OBT). The model predicts increased doses for HTO and OBT comparing to ICRP recommendations, supporting recent findings

  3. Model visionary

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, Graham

    2011-03-15

    Ken Dedeluk is the president and CEO of Computer Modeling Group (CMG). Dedeluk started his career with Gulf Oil in 1972, worked in computer assisted design; then joined Imperial Esso and Shell, where he became international operations' VP; and finally joined CMG in 1998. CMG made a decision that turned out to be the company's turning point: they decided to provide intensive support and service to their customer to better use their technology. Thanks to this service, their customers' satisfaction grew as well as their revenues.

  4. Model integration and a theory of models

    OpenAIRE

    Dolk, Daniel R.; Kottemann, Jeffrey E.

    1993-01-01

    Model integration extends the scope of model management to include the dimension of manipulation as well. This invariably leads to comparisons with database theory. Model integration is viewed from four perspectives: Organizational, definitional, procedural, and implementational. Strategic modeling is discussed as the organizational motivation for model integration. Schema and process integration are examined as the logical and manipulation counterparts of model integr...

  5. Microdistribution of uranium in kidney using alpha radiography of body animal

    International Nuclear Information System (INIS)

    Cebrian, D.; Morcillo, M. A.

    2006-01-01

    The radiation dose estimation after an internal contamination by a radionuclide requires the use of biokinetic and dosimetric models, which provide the tools for its calculation. The detailed knowledge of the biokinetic behaviour of the corresponding radionuclide is needed in order to build these models. Laboratory animals are employed to get this knowledge. In this context, the use of appropriate radioactivity measurement techniques is important to follow the distribution of the radionuclide within the organism. In this study an animal model of rat treated with uranyl citrate has been used. Sections of the whole animal are made at different times post-administration, and alpha autoradiography is performed with the slices in order to study the microdistribution of the uranium in the kidney. the utility of the alpha autoradiography whole body animal sections for the detailed study of the alpha emitters biodistribution is shown. (Author) 16 refs

  6. ALEPH model

    CERN Multimedia

    1989-01-01

    A wooden model of the ALEPH experiment and its cavern. ALEPH was one of 4 experiments at CERN's 27km Large Electron Positron collider (LEP) that ran from 1989 to 2000. During 11 years of research, LEP's experiments provided a detailed study of the electroweak interaction. Measurements performed at LEP also proved that there are three – and only three – generations of particles of matter. LEP was closed down on 2 November 2000 to make way for the construction of the Large Hadron Collider in the same tunnel. The cavern and detector are in separate locations - the cavern is stored at CERN and the detector is temporarily on display in Glasgow physics department. Both are available for loan.

  7. modelling distances

    Directory of Open Access Journals (Sweden)

    Robert F. Love

    2001-01-01

    Full Text Available Distance predicting functions may be used in a variety of applications for estimating travel distances between points. To evaluate the accuracy of a distance predicting function and to determine its parameters, a goodness-of-fit criteria is employed. AD (Absolute Deviations, SD (Squared Deviations and NAD (Normalized Absolute Deviations are the three criteria that are mostly employed in practice. In the literature some assumptions have been made about the properties of each criterion. In this paper, we present statistical analyses performed to compare the three criteria from different perspectives. For this purpose, we employ the ℓkpθ-norm as the distance predicting function, and statistically compare the three criteria by using normalized absolute prediction error distributions in seventeen geographical regions. We find that there exist no significant differences between the criteria. However, since the criterion SD has desirable properties in terms of distance modelling procedures, we suggest its use in practice.

  8. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  9. Comparison: Binomial model and Black Scholes model

    Directory of Open Access Journals (Sweden)

    Amir Ahmad Dar

    2018-03-01

    Full Text Available The Binomial Model and the Black Scholes Model are the popular methods that are used to solve the option pricing problems. Binomial Model is a simple statistical method and Black Scholes model requires a solution of a stochastic differential equation. Pricing of European call and a put option is a very difficult method used by actuaries. The main goal of this study is to differentiate the Binominal model and the Black Scholes model by using two statistical model - t-test and Tukey model at one period. Finally, the result showed that there is no significant difference between the means of the European options by using the above two models.

  10. Implications of human tissue studies for radiation protection

    International Nuclear Information System (INIS)

    Kathren, R.L.

    1988-01-01

    Through radiochemical analysis of voluntary tissue donations, the U.S. Transuranium and Uranium Registries (USTR) are gaining improved understanding of the distribution and biokinetics of actinide elements in occupationally exposed persons. Evaluation of the first two whole-body contributions to the USTR revealed an inverse proportionality between actinide concentration and bone ash. The analysis of a whole body with significant 241 Am deposition indicated a significantly shorter half-time in liver and a greater fraction resident in the skeleton than predicted by existing models. Other studies with tissues obtained at autopsy suggest that existing biokinetic models for 238 Pu and 241 Am and the currently accepted models and limits on intake, which use these models as their basis, may be inaccurately implying that revisions of existing safety standards may be necessary. Other studies of the registries are designed to evaluate in-vivo estimates of actinide deposition with those derived from postmortem tissue analysis, to compare results of animal experiments with human data, and to review histopathologic slides for tissue changes that might be attributable to exposure to transuranic elements. The implications of these recent findings and other work of the registries is discussed from the standpoint of this potential effect on biokinetic modeling, internal dose assessment, and safety standards and operational health physics practices

  11. Implications of human tissue studies for radiation protection.

    Science.gov (United States)

    Kathren, R L

    1988-08-01

    Through radiochemical analysis of voluntary tissue donations, the U.S. Transuranium and Uranium Registries (USTR) are gaining improved understanding of the distribution and biokinetics of actinide elements in occupationally exposed persons. Evaluation of the first two whole-body contributions to the USTR revealed an inverse proportionality between actinide concentration and bone ash. The analysis of a whole body with significant 241Am deposition indicated a significantly shorter half-time in liver and a greater fraction resident in the skeleton than predicted by existing models. Other studies with tissues obtained at autopsy suggest that existing biokinetic models for 238Pu and 241Am and the currently accepted models and limits on intake, which use these models as their basis, may be inaccurately implying that revisions of existing safety standards may be necessary. Other studies of the registries are designed to evaluate in-vivo estimates of actinide deposition with those derived from postmortem tissue analysis, to compare results of animal experiments with human data, and to review histopathologic slides for tissue changes that might be attributable to exposure to transuranic elements. The implications of these recent findings and other work of the registries is discussed from the standpoint of this potential effect on biokinetic modeling, internal dose assessment, and safety standards and operational health physics practices.

  12. Computational Modeling | Bioenergy | NREL

    Science.gov (United States)

    cell walls and are the source of biofuels and biomaterials. Our modeling investigates their properties . Quantum Mechanical Models NREL studies chemical and electronic properties and processes to reduce barriers Computational Modeling Computational Modeling NREL uses computational modeling to increase the

  13. Dosimetry and effects of fetal irradiation from incorporated radionuclides

    International Nuclear Information System (INIS)

    Harrison, J.D.; Coffigny, H.; Henshaw, D.L.

    1993-01-01

    An important aspect of the assessment of risks from incorporated radionuclides is the possibility of intakes by pregnant women and in utero exposure of the developing fetus. The overall objective of the project is to provide experimental data for the development of dosimetric models and assessment of risk. Studies include measurements of 210 Po and 239/240 Pu in human fetal tissues and placentae, animal studies of the biokinetics of radionuclide transfer and effects. Animal biokinetic studies concentrate on comparing the uptake and distribution of Po-210, Pu-238 and Am-241 in rats and guinea pigs for different exposure conditions. The data are used, together with the human data, to develop dosimetric models. Objectives and results of the three contributions to the project for the reporting period are presented. (R.P.) 4 figs., 1 tab

  14. Age-dependent dosimetry and metabolism

    International Nuclear Information System (INIS)

    Taylor, D.M.

    1992-01-01

    The release of radionuclides into the environment following the Chernobyl disaster in 1986 created an urgent need for internationally acceptable dose coefficients for calculating the doses delivered to all members of the public, from conception to old age. Organ masses and the kinetics of distribution and retention of elements in humans generally vary with age and often not in simple linear relationship to body weight. Unless variations are considered calculated radiation doses to children may be seriously underestimated. The International Commission on Radiological Protection created in 1987 a Task Group on Age-dependent Doses to Members of the Public from Intake of Radionuclides (AGDOS). The work of AGDOS and the general problems encountered in deriving age-dependent dose coefficients will be discussed in this paper. The first two AGDOS reports, ICRP Publication 56 Parts 1 and 2, provide dose coefficients for the ages 3 months, 1, 5, 10, 15 years and for adults for the 21 elements considered to be of most immediate importance for radiation protection. To develop these dose coefficients, the ICRP Publication 30 dosimetric and biokinetic models were reevaluated and extended. The basic dosimetric model is retained but equivalent dose is now integrated from age at intake to 70 years and the new ICRP Publication 60 tissue weighting factors are incorporated. The development of age-dependent biokinetic models is complicated by the lack of age-related human, or even animal data for the majority of the elements. Thus in formulating the models it has been necessary to use all the available information, biokinetic, physiological chemical and biochemical, and to adopt a number of new approaches including the development of generic biokinetic models for chemically related families of elements such as the actinides and the alkaline earth elements. (author)

  15. Essays on model uncertainty in financial models

    NARCIS (Netherlands)

    Li, Jing

    2018-01-01

    This dissertation studies model uncertainty, particularly in financial models. It consists of two empirical chapters and one theoretical chapter. The first empirical chapter (Chapter 2) classifies model uncertainty into parameter uncertainty and misspecification uncertainty. It investigates the

  16. Vector models and generalized SYK models

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Cheng [Department of Physics, Brown University,Providence RI 02912 (United States)

    2017-05-23

    We consider the relation between SYK-like models and vector models by studying a toy model where a tensor field is coupled with a vector field. By integrating out the tensor field, the toy model reduces to the Gross-Neveu model in 1 dimension. On the other hand, a certain perturbation can be turned on and the toy model flows to an SYK-like model at low energy. A chaotic-nonchaotic phase transition occurs as the sign of the perturbation is altered. We further study similar models that possess chaos and enhanced reparameterization symmetries.

  17. Age-dependent doses to members of the public from intake of radionuclides: Pt. 5. Compilation of ingestion and inhalation dose coefficients

    International Nuclear Information System (INIS)

    1996-01-01

    The present report is a compilation of age-dependent committed effective dose coefficients for ingestion and inhalation of radionuclides of the 31 elements covered in previous CRP Publications. The biokinetic models for adults given in ICRP Publication 30 are applied to calculate these dose coefficients, except that age-specific excretion rates are used and increased gastrointestinal absorption in infants is assurred. Changes in body mass, and tissue geometry in children are also taken into account. (UK)

  18. Determination of the biodistribution and biokinetics of radiopharmaca like 166Ho-ferric-hydroxide or 153Sm-EDTMP used for therapeutic treatment by energy dispersive measurements

    International Nuclear Information System (INIS)

    Fischer, H.; Poljanc, K.; Aiginger, H.; Pruefert, U.; Granegger, S.; Ofluoglu, S.; Pirich, Ch.; Sinzinger, H.; Dudczak, R.; Steger, F.

    2003-01-01

    The activity distribution of beta-emitting radionuclides in the human body and the respective therapeutic dose distribution in the target and the unwanted leakage in the other organs was determined by measurement of corresponding gamma-lines. The measurement was done by scanning in a whole-body counter in the General Hospital Vienna. It is possible to localize activity and dose distribution by means of the detected activity profiles of the four detectors. Two typical treatments are reported: the treatment of synovitis using radiation of 166 Ho-Ferric-Hydroxide (characteristic gamma-line: 81 keV) and radionuclide therapy focused at the palliative treatment of bone metastases with 153 Sm-EDTMP, a bone seeking beta-emitting radionuclide (characteristic gamma-line: 103 keV). For the determination of the applied dose, the leakage and the quality assurance spectroscopic data of a clinical whole-body counter can be a useful tool for controlling and monitoring in health care. (authors)

  19. Biokinetics of cadmium, selenium, and zinc in freshwater alga Scenedesmus obliquus under different phosphorus and nitrogen conditions and metal transfer to Daphnia magna

    International Nuclear Information System (INIS)

    Yu Riqing; Wang Wenxiong

    2004-01-01

    The uptake of Cd, Se(IV) and Zn by the freshwater alga Scenedesmus obliquus and the subsequent transfer and release budget in Daphnia magna were investigated under different nutrient additions and cell incubation conditions. An increase in ambient phosphate concentrations from 0.5 μmol l -1 to 50 μmol l -1 significantly increased the intracellular accumulation of Cd (by 18x) and Zn (by 5x), but decreased the accumulation of Se (by 126x) in the alga. The percentage of these metals distributing in the intracellular pool of algae also increased substantially with increasing ambient P concentrations. Nitrate addition from 5.0 to 200 μmol l -1 did not influence the uptake of any of the three metals, although a significant decrease in the intracellular Se distribution was observed. Radiolabeled algae under different nutrient manipulations (semi-continuous culture, starvation, and P-pulse treatments) were used to measure trophic transfer assimilation efficiency (AE) in Daphnia. When the algal cells were grown in a semi-continuous culture, starved for N and P, or were treated with P-pulse, the AEs of Cd and Zn were generally independent of the nutritional conditions, but the Se AE was significantly affected by different P levels. The efflux rate constants, determined during 10 d depuration following 7 days of dietary uptake, decreased significantly for Cd and Zn, but were relatively constant for Se with increasing P concentration. N-addition caused no effect on the metal efflux rate constants. P- or N-additions did not influence the release budget (including molting, neonates, excretion and feces) for all three elements in Daphnia. Our study indicated that phosphate enrichment may substantially increase metal uptake in green alga S. obliquus. Responses of trophic transfer in Daphnia to nutrient enrichment were metal specific. P-enrichment can possibly lead to considerable decrease on Se transfer from algae to zooplankton. - Phosphorous enrichment influences metal uptake by algae, but not transfer to a zooplankton grazer

  20. The estimation of daily intake and organ content of Cs, I, Sr, Th and U in Indian population: Application to the study of their biokinetics

    International Nuclear Information System (INIS)

    Dang, H.S.; Jaiswal, D.D.; Pullat, V.R.; Parameswaran, M.; Krishnamony, S.

    1998-01-01

    The analytical methods involving both instrumental and radiochemical neutron activation techniques (INAA and RNAA) are being standardised for the determination of the elements Cs, I, Sr, Th and U in various kinds of biological samples. The sampling method proposed to be adopted for the estimation of the daily dietary intake, of the above elements is described. Also reported in this paper are the preliminary results on the concentrations of these elements in the food ingredients which form important components of the diet of Indian population. (author)

  1. Biokinetics of cadmium, selenium, and zinc in freshwater alga Scenedesmus obliquus under different phosphorus and nitrogen conditions and metal transfer to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Yu Riqing; Wang Wenxiong

    2004-06-01

    The uptake of Cd, Se(IV) and Zn by the freshwater alga Scenedesmus obliquus and the subsequent transfer and release budget in Daphnia magna were investigated under different nutrient additions and cell incubation conditions. An increase in ambient phosphate concentrations from 0.5 {mu}mol l{sup -1} to 50 {mu}mol l{sup -1} significantly increased the intracellular accumulation of Cd (by 18x) and Zn (by 5x), but decreased the accumulation of Se (by 126x) in the alga. The percentage of these metals distributing in the intracellular pool of algae also increased substantially with increasing ambient P concentrations. Nitrate addition from 5.0 to 200 {mu}mol l{sup -1} did not influence the uptake of any of the three metals, although a significant decrease in the intracellular Se distribution was observed. Radiolabeled algae under different nutrient manipulations (semi-continuous culture, starvation, and P-pulse treatments) were used to measure trophic transfer assimilation efficiency (AE) in Daphnia. When the algal cells were grown in a semi-continuous culture, starved for N and P, or were treated with P-pulse, the AEs of Cd and Zn were generally independent of the nutritional conditions, but the Se AE was significantly affected by different P levels. The efflux rate constants, determined during 10 d depuration following 7 days of dietary uptake, decreased significantly for Cd and Zn, but were relatively constant for Se with increasing P concentration. N-addition caused no effect on the metal efflux rate constants. P- or N-additions did not influence the release budget (including molting, neonates, excretion and feces) for all three elements in Daphnia. Our study indicated that phosphate enrichment may substantially increase metal uptake in green alga S. obliquus. Responses of trophic transfer in Daphnia to nutrient enrichment were metal specific. P-enrichment can possibly lead to considerable decrease on Se transfer from algae to zooplankton. - Phosphorous enrichment influences metal uptake by algae, but not transfer to a zooplankton grazer.

  2. Experimental study of Americium-241 biokinetics in Homarus Gammarus lobster. Analysis of the accumulation and detoxication mechanisms at the sub-cellular level

    International Nuclear Information System (INIS)

    Paquet, F.

    1991-12-01

    The Americium 241 radioelement accumulation and elimination rate and mechanisms in the lobster organism have been experimentally studied; incorporation and detoxification capacities of each organ are evaluated. The existence of various biological compartments is shown; the major role of the digestive gland in accumulation of the radioelement, its distribution towards the various organs, and its resorption is comprehensively described, with an analysis at the subcellular and molecular levels. 401 p., 65 fig., 43 tab., 428 ref

  3. An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level

    International Nuclear Information System (INIS)

    Paquet, F.

    1993-01-01

    An experimental study of americium-241 kinetics has been conducted in the lobster Homarus gammmarus. The investigations were conducted at all the levels from the whole body to the subcellular and molecular levels. The animals were contaminated by a single or chronic ingestion of 241 Am labelled mussels. Assessments of accumulation, elimination and distribution of the radionuclide were established on organisms kept in the laboratory; they made it possible to demonstrate the importance of the digestive gland in the radionuclide transfer pathways. The preliminary results led to structural then ultrastructural investigations of the digestive gland in association with radioautographic studies and cellular extractions methods. Four cellular types were demonstrated, only two of them being implied in the radionuclide retention, the former being responsible for americium intake and the latter for its long-term retention. By means of biochemical techniques, subcellular accumulation was studied and the organelles implied in the nuclide retention were specified. Finally, a method of cellular nuclei dissociation was developed; it made it possible to analyse the molecular nature of americium ligands and to demonstrate the function of the protein nuclear matrix in the nuclide retention

  4. DEVELOPMENT OF BIOAVAILABILITY AND BIOKINETICS DETERMINATION METHODS FOR ORGANIC POLLUTANTS IN SOIL TO ENHANCE IN-SITU AND ON-SITE BIOREMEDIATION

    Science.gov (United States)

    Determination of biodegradation rates of organics in soil slurry and compacted soil systems is essential for evaluating the efficacy of bioremediation for treatment of contaminated soils. In this paper, a systematic protocol has been developed for evaluating bioknetic and transp...

  5. PROTOCOL FOR DETERMINING BIOAVAILABILITY AND BIOKINETICS OF ORGANIC POLLUTANTS IN DISPERSED, COMPACTED AND INTACT SOIL SYSTEMS TO ENHANCE IN SITU BIOREMEDIATION

    Science.gov (United States)

    The development of effective in situ and on-site bioremediation technologies can facilitate the cleanup of chemically-contaminated soil sites. Knowledge of biodegradation kinetics and bioavailability of organic pollutants can facilitate decisions on the efficacy of in situ and o...

  6. Evaluation of the Enantiomer Specific Biokinetics and Radiation Doses of [18F]Fluspidine—A New Tracer in Clinical Translation for Imaging of σ1 Receptors

    Directory of Open Access Journals (Sweden)

    Mathias Kranz

    2016-09-01

    Full Text Available The enantiomers of [18F]fluspidine, recently developed for imaging of σ1 receptors, possess distinct pharmacokinetics facilitating their use in different clinical settings. To support their translational potential, we estimated the human radiation dose of (S-(−-[18F]fluspidine and (R-(+-[18F]fluspidine from ex vivo biodistribution and PET/MRI data in mice after extrapolation to the human scale. In addition, we validated the preclinical results by performing a first-in-human PET/CT study using (S-(−-[18F]fluspidine. Based on the respective time-activity curves, we calculated using OLINDA the particular organ doses (ODs and effective doses (EDs. The ED values of (S-(−-[18F]fluspidine and (R-(+-[18F]fluspidine differed significantly with image-derived values obtained in mice with 12.9 μSv/MBq and 14.0 μSv/MBq (p < 0.025, respectively. A comparable ratio was estimated from the biodistribution data. In the human study, the ED of (S-(−-[18F]fluspidine was calculated as 21.0 μSv/MBq. Altogether, the ED values for both [18F]fluspidine enantiomers determined from the preclinical studies are comparable with other 18F-labeled PET imaging agents. In addition, the first-in-human study confirmed that the radiation risk of (S-(−-[18F]fluspidine imaging is within acceptable limits. However, as already shown for other PET tracers, the actual ED of (S-(−-[18F]fluspidine in humans was underestimated by preclinical imaging which needs to be considered in other first-in-human studies.

  7. In vivo biokinetic and metabolic characterization of the {sup 68}Ga-labelled α5β1-selective peptidomimetic FR366

    Energy Technology Data Exchange (ETDEWEB)

    D' Alessandria, Calogero; Pohle, Karolin; Schwaiger, Markus [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Rechenmacher, Florian; Neubauer, Stefanie; Kessler, Horst [Technische Universitaet Muenchen, Institute for Advanced Study (IAS) and Center of Integrated Protein Science (CIPSM), Department Chemie, Garching (Germany); Notni, Johannes; Wester, Hans-Juergen [Technische Universitaet Muenchen, Lehrstuhl fuer Pharmazeutische Radiochemie, Garching (Germany); Beer, Ambros J. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Ulm University, Department of Nuclear Medicine, Ulm (Germany)

    2016-05-15

    Integrins are transmembrane receptors responsible for cell-cell adhesion and cell-extracellular matrix binding and play an important role in angiogenesis and tumour metastasis. For this reason, integrins are increasingly used as targets for molecular imaging. Up to now interest has mostly been focused on the integrin subtype αvβ3. However, targeting of other subtypes such as the integrin α5β1 is also of high interest due to its central role in colonization of metastatic cells, resistance of tumour cells to chemotherapy and ionizing radiation, and tumour aggressiveness. Recently, a highly active antagonist ligand (2,2'-(7-(1-carboxy-4-((6-((3-(4-(((S)-1-carboxy-2-(2- (3-guanidinobenzamido)acet amido)ethyl)carbamoyl)-3,5-dimethylphenoxy) propyl)amino)-6-oxohexyl)amino)-4-oxo butyl)-1,4,7-triazonane-1,4-diyl)diacetic acid, FR366) for the integrin subtype α5β1 with high selectivity versus αvβ3, has been developed and tested successfully in preliminary in vitro and in vivo experiments. Here, we present our results of an investigation of the use of {sup 68}Ga-labelled α5β1 ligand in PET imaging. The free α5β1 peptidomimetic ligand was functionalized with a spacer (6-aminohexanoic acid) and the bifunctional chelator 1-((1,3-dicarboxy)propyl) -4,7-(carboxymethyl)-1,4,7-triazacyclononane (NODAGA) to yield FR366 and labelled with {sup 68}Ga. To confirm selective in vivo targeting of α5β1, female BALB/c nude mice xenografted with α5β1-expressing RKO cells in the right shoulder and α5β1/αvβ3-expressing M21 cells in the left shoulder were subjected to PET/CT scans and biodistribution experiments. Specificity of tracer uptake was proven by blocking studies. Metabolic stability of the injected tracer was measured in urine and in plasma. MicroPET/CT scans with radiolabelled FR366 showed a good tumour-to-normal tissue ratio with low uptake in the liver (0.32 ± 0.14 %ID/g) and good retention of {sup 68}Ga-NODAGA-FR366 in the tumour (0.71 ± 0.20 %ID/g and 0.40 ± 0.12 %ID/g for RKO and M21 tumours, respectively, at 90 min after injection). Biodistribution experiments showed uptake in the α5β1-expressing RKO tumour of 1.05 ± 0.23 %ID/g at 90 min after injection. Specificity of tracer uptake was demonstrated by injection of 5 mg/kg unlabelled ligand 10 min prior to tracer injection, resulting in a 67 % reduction in uptake in the RKO tumour. The tracer was found to be metabolically stable in urine and plasma 30 min after injection. Our results show that PET imaging of α5β1 expression with the {sup 68}Ga-labelled α5β1-specific ligand is feasible with good image quality. Thus, FR366 is a promising new tool for investigating the role of α5β1 in angiogenesis and the influence of this integrin subtype on cancer aggressiveness and metastatic potential. (orig.)

  8. Modeling styles in business process modeling

    NARCIS (Netherlands)

    Pinggera, J.; Soffer, P.; Zugal, S.; Weber, B.; Weidlich, M.; Fahland, D.; Reijers, H.A.; Mendling, J.; Bider, I.; Halpin, T.; Krogstie, J.; Nurcan, S.; Proper, E.; Schmidt, R.; Soffer, P.; Wrycza, S.

    2012-01-01

    Research on quality issues of business process models has recently begun to explore the process of creating process models. As a consequence, the question arises whether different ways of creating process models exist. In this vein, we observed 115 students engaged in the act of modeling, recording

  9. The IMACLIM model; Le modele IMACLIM

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document provides annexes to the IMACLIM model which propose an actualized description of IMACLIM, model allowing the design of an evaluation tool of the greenhouse gases reduction policies. The model is described in a version coupled with the POLES, technical and economical model of the energy industry. Notations, equations, sources, processing and specifications are proposed and detailed. (A.L.B.)

  10. From Product Models to Product State Models

    DEFF Research Database (Denmark)

    Larsen, Michael Holm

    1999-01-01

    A well-known technology designed to handle product data is Product Models. Product Models are in their current form not able to handle all types of product state information. Hence, the concept of a Product State Model (PSM) is proposed. The PSM and in particular how to model a PSM is the Research...

  11. Studies on the excretion ratio of U for a group of occupationally exposed subjects

    International Nuclear Information System (INIS)

    Pullat, V.R.; Dang, H.S.

    1999-01-01

    The ICRP biokinetic model of uranium was validated by using the site specific and population specific Indian data on uranium. The daily urinary excretion of uranium and its concentration in blood serum were simultaneously measured in forty occupational workers of uranium oxide processing plant (Y class). In view of the extremely low concentration of uranium in blood serum (<1.0 ppb), a highly sensitive analytical method using radiochemical neutron activation analysis technique (RNAA) was developed, standardised and applied to determine the concentration of uranium in blood serum and urine samples. The results of the estimation showed a statistically significant linear correlation (p<0.01) between the serum burden and the corresponding daily urinary excretion. The median excretion ratio obtained for the forty occupational workers was estimated to be 92% in comparison to 98% expected on the basis of ICRP biokinetic model of uranium. The study indicates that the ICRP biokinetic model can be effectively employed for the internal dose assessment of occupational workers by using bioassay monitoring. (author)

  12. Radiation exposure by Tc-99m-methyldiphosphonate - development and use of a biophysical model for the determination of the local dose distribution in growth zones of a child's skeleton

    International Nuclear Information System (INIS)

    Petrausch, G.

    1984-01-01

    For the determination of the data necessary for dose calculations of an intraveneous application of Tc-99m-MDP in children, ages 3 months to 7 years, test data for the biokinetics of MDP in the whole body as well as in body areas with and without radioactive concentrations was determined by the use of a whole body activity counter and a gamma camera. These investigations were supplemented by laboratory data on the radioactive decay of Tc-99m-MDP in blood serum and on the urinary excretion of MDP. For the determination of the target volume of epiphyseal growth areas with radioactive concentrations distortion corrected measurements of the patient from the bone scintographs were compared to the biological data taken from our X-ray images. The radiation exposure of these growth areas was calculated with consideration of results from animal investigations as well as under the assumption that larger target volumes could be present in the patients. In the animal investigations the organ distribution of the MDP at various times after application, along with the biokinetic data of MDP in the whole body was ascertained as well as the distribution along long hollow bones. The calcium distribution was activationally analytically ascertained along long hollow bones in a young and an adult dog. It was attempted in the animal investigations to autoradiographically present the microdistribution of MDP in border regions epiphyseal cartilage/epiphyseal center and epiphyseal cartilage/metaphyseal growth plate. (orig./MG) [de

  13. The effect of isotope on the dosimetry of inhaled plutonium oxide

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Griffith, W.C.

    1991-01-01

    Results of experimental studies in which animals inhaled 238 PuO 2 or 239 PuO 2 aerosols have shown that the biokinetics and associated radiation dose patterns for these two isotopes differ significantly due to differences in in-vivo solubility caused by the 260-fold difference in specific activity between 238 PuO 2 and 239 PuO 2 . We have adapted a biokinetics and dosimetry model derived from results of the ITRI dog studies to humans and have calculated dose commitments and annual limits on intake (ALI) for both Pu isotopes. Our results show that the ALI calculated in this study is one-third that for class Y 238 Pu from ICRP 30, and one-half or equal to that for class Y 239 Pu, depending on how activity in the thoracic lymph nodes is treated dosimetrically

  14. Modelling live forensic acquisition

    CSIR Research Space (South Africa)

    Grobler, MM

    2009-06-01

    Full Text Available This paper discusses the development of a South African model for Live Forensic Acquisition - Liforac. The Liforac model is a comprehensive model that presents a range of aspects related to Live Forensic Acquisition. The model provides forensic...

  15. Models in architectural design

    OpenAIRE

    Pauwels, Pieter

    2017-01-01

    Whereas architects and construction specialists used to rely mainly on sketches and physical models as representations of their own cognitive design models, they rely now more and more on computer models. Parametric models, generative models, as-built models, building information models (BIM), and so forth, they are used daily by any practitioner in architectural design and construction. Although processes of abstraction and the actual architectural model-based reasoning itself of course rema...

  16. Rotating universe models

    International Nuclear Information System (INIS)

    Tozini, A.V.

    1984-01-01

    A review is made of some properties of the rotating Universe models. Godel's model is identified as a generalized filted model. Some properties of new solutions of the Einstein's equations, which are rotating non-stationary Universe models, are presented and analyzed. These models have the Godel's model as a particular case. Non-stationary cosmological models are found which are a generalization of the Godel's metrics in an analogous way in which Friedmann is to the Einstein's model. (L.C.) [pt

  17. Concept Modeling vs. Data modeling in Practice

    DEFF Research Database (Denmark)

    Madsen, Bodil Nistrup; Erdman Thomsen, Hanne

    2015-01-01

    This chapter shows the usefulness of terminological concept modeling as a first step in data modeling. First, we introduce terminological concept modeling with terminological ontologies, i.e. concept systems enriched with characteristics modeled as feature specifications. This enables a formal...... account of the inheritance of characteristics and allows us to introduce a number of principles and constraints which render concept modeling more coherent than earlier approaches. Second, we explain how terminological ontologies can be used as the basis for developing conceptual and logical data models....... We also show how to map from the various elements in the terminological ontology to elements in the data models, and explain the differences between the models. Finally the usefulness of terminological ontologies as a prerequisite for IT development and data modeling is illustrated with examples from...

  18. Model-to-model interface for multiscale materials modeling

    Energy Technology Data Exchange (ETDEWEB)

    Antonelli, Perry Edward [Iowa State Univ., Ames, IA (United States)

    2017-12-17

    A low-level model-to-model interface is presented that will enable independent models to be linked into an integrated system of models. The interface is based on a standard set of functions that contain appropriate export and import schemas that enable models to be linked with no changes to the models themselves. These ideas are presented in the context of a specific multiscale material problem that couples atomistic-based molecular dynamics calculations to continuum calculations of fluid ow. These simulations will be used to examine the influence of interactions of the fluid with an adjacent solid on the fluid ow. The interface will also be examined by adding it to an already existing modeling code, Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) and comparing it with our own molecular dynamics code.

  19. Cognitive models embedded in system simulation models

    International Nuclear Information System (INIS)

    Siegel, A.I.; Wolf, J.J.

    1982-01-01

    If we are to discuss and consider cognitive models, we must first come to grips with two questions: (1) What is cognition; (2) What is a model. Presumably, the answers to these questions can provide a basis for defining a cognitive model. Accordingly, this paper first places these two questions into perspective. Then, cognitive models are set within the context of computer simulation models and a number of computer simulations of cognitive processes are described. Finally, pervasive issues are discussed vis-a-vis cognitive modeling in the computer simulation context

  20. Model Manipulation for End-User Modelers

    DEFF Research Database (Denmark)

    Acretoaie, Vlad

    , and transformations using their modeling notation and editor of choice. The VM* languages are implemented via a single execution engine, the VM* Runtime, built on top of the Henshin graph-based transformation engine. This approach combines the benefits of flexibility, maturity, and formality. To simplify model editor......End-user modelers are domain experts who create and use models as part of their work. They are typically not Software Engineers, and have little or no programming and meta-modeling experience. However, using model manipulation languages developed in the context of Model-Driven Engineering often...... requires such experience. These languages are therefore only used by a small subset of the modelers that could, in theory, benefit from them. The goals of this thesis are to substantiate this observation, introduce the concepts and tools required to overcome it, and provide empirical evidence in support...

  1. Air Quality Dispersion Modeling - Alternative Models

    Science.gov (United States)

    Models, not listed in Appendix W, that can be used in regulatory applications with case-by-case justification to the Reviewing Authority as noted in Section 3.2, Use of Alternative Models, in Appendix W.

  2. Topological massive sigma models

    International Nuclear Information System (INIS)

    Lambert, N.D.

    1995-01-01

    In this paper we construct topological sigma models which include a potential and are related to twisted massive supersymmetric sigma models. Contrary to a previous construction these models have no central charge and do not require the manifold to admit a Killing vector. We use the topological massive sigma model constructed here to simplify the calculation of the observables. Lastly it is noted that this model can be viewed as interpolating between topological massless sigma models and topological Landau-Ginzburg models. ((orig.))

  3. Business Model Innovation

    OpenAIRE

    Dodgson, Mark; Gann, David; Phillips, Nelson; Massa, Lorenzo; Tucci, Christopher

    2014-01-01

    The chapter offers a broad review of the literature at the nexus between Business Models and innovation studies, and examines the notion of Business Model Innovation in three different situations: Business Model Design in newly formed organizations, Business Model Reconfiguration in incumbent firms, and Business Model Innovation in the broad context of sustainability. Tools and perspectives to make sense of Business Models and support managers and entrepreneurs in dealing with Business Model ...

  4. [Bone remodeling and modeling/mini-modeling.

    Science.gov (United States)

    Hasegawa, Tomoka; Amizuka, Norio

    Modeling, adapting structures to loading by changing bone size and shapes, often takes place in bone of the fetal and developmental stages, while bone remodeling-replacement of old bone into new bone-is predominant in the adult stage. Modeling can be divided into macro-modeling(macroscopic modeling)and mini-modeling(microscopic modeling). In the cellular process of mini-modeling, unlike bone remodeling, bone lining cells, i.e., resting flattened osteoblasts covering bone surfaces will become active form of osteoblasts, and then, deposit new bone onto the old bone without mediating osteoclastic bone resorption. Among the drugs for osteoporotic treatment, eldecalcitol(a vitamin D3 analog)and teriparatide(human PTH[1-34])could show mini-modeling based bone formation. Histologically, mature, active form of osteoblasts are localized on the new bone induced by mini-modeling, however, only a few cell layer of preosteoblasts are formed over the newly-formed bone, and accordingly, few osteoclasts are present in the region of mini-modeling. In this review, histological characteristics of bone remodeling and modeling including mini-modeling will be introduced.

  5. A Model of Trusted Measurement Model

    OpenAIRE

    Ma Zhili; Wang Zhihao; Dai Liang; Zhu Xiaoqin

    2017-01-01

    A model of Trusted Measurement supporting behavior measurement based on trusted connection architecture (TCA) with three entities and three levels is proposed, and a frame to illustrate the model is given. The model synthesizes three trusted measurement dimensions including trusted identity, trusted status and trusted behavior, satisfies the essential requirements of trusted measurement, and unified the TCA with three entities and three levels.

  6. Modelling binary data

    CERN Document Server

    Collett, David

    2002-01-01

    INTRODUCTION Some Examples The Scope of this Book Use of Statistical Software STATISTICAL INFERENCE FOR BINARY DATA The Binomial Distribution Inference about the Success Probability Comparison of Two Proportions Comparison of Two or More Proportions MODELS FOR BINARY AND BINOMIAL DATA Statistical Modelling Linear Models Methods of Estimation Fitting Linear Models to Binomial Data Models for Binomial Response Data The Linear Logistic Model Fitting the Linear Logistic Model to Binomial Data Goodness of Fit of a Linear Logistic Model Comparing Linear Logistic Models Linear Trend in Proportions Comparing Stimulus-Response Relationships Non-Convergence and Overfitting Some other Goodness of Fit Statistics Strategy for Model Selection Predicting a Binary Response Probability BIOASSAY AND SOME OTHER APPLICATIONS The Tolerance Distribution Estimating an Effective Dose Relative Potency Natural Response Non-Linear Logistic Regression Models Applications of the Complementary Log-Log Model MODEL CHECKING Definition of Re...

  7. Modelling freight transport

    NARCIS (Netherlands)

    Tavasszy, L.A.; Jong, G. de

    2014-01-01

    Freight Transport Modelling is a unique new reference book that provides insight into the state-of-the-art of freight modelling. Focusing on models used to support public transport policy analysis, Freight Transport Modelling systematically introduces the latest freight transport modelling

  8. Semantic Business Process Modeling

    OpenAIRE

    Markovic, Ivan

    2010-01-01

    This book presents a process-oriented business modeling framework based on semantic technologies. The framework consists of modeling languages, methods, and tools that allow for semantic modeling of business motivation, business policies and rules, and business processes. Quality of the proposed modeling framework is evaluated based on the modeling content of SAP Solution Composer and several real-world business scenarios.

  9. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  10. Model-Independent Diffs

    DEFF Research Database (Denmark)

    Könemann, Patrick

    just contain a list of strings, one for each line, whereas the structure of models is defined by their meta models. There are tools available which are able to compute the diff between two models, e.g. RSA or EMF Compare. However, their diff is not model-independent, i.e. it refers to the models...

  11. Forest-fire models

    Science.gov (United States)

    Haiganoush Preisler; Alan Ager

    2013-01-01

    For applied mathematicians forest fire models refer mainly to a non-linear dynamic system often used to simulate spread of fire. For forest managers forest fire models may pertain to any of the three phases of fire management: prefire planning (fire risk models), fire suppression (fire behavior models), and postfire evaluation (fire effects and economic models). In...

  12. Environmental Satellite Models for a Macroeconomic Model

    International Nuclear Information System (INIS)

    Moeller, F.; Grinderslev, D.; Werner, M.

    2003-01-01

    To support national environmental policy, it is desirable to forecast and analyse environmental indicators consistently with economic variables. However, environmental indicators are physical measures linked to physical activities that are not specified in economic models. One way to deal with this is to develop environmental satellite models linked to economic models. The system of models presented gives a frame of reference where emissions of greenhouse gases, acid gases, and leaching of nutrients to the aquatic environment are analysed in line with - and consistently with - macroeconomic variables. This paper gives an overview of the data and the satellite models. Finally, the results of applying the model system to calculate the impacts on emissions and the economy are reviewed in a few illustrative examples. The models have been developed for Denmark; however, most of the environmental data used are from the CORINAIR system implemented in numerous countries

  13. Geologic Framework Model Analysis Model Report

    Energy Technology Data Exchange (ETDEWEB)

    R. Clayton

    2000-12-19

    The purpose of this report is to document the Geologic Framework Model (GFM), Version 3.1 (GFM3.1) with regard to data input, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, qualification status of the model, and the differences between Version 3.1 and previous versions. The GFM represents a three-dimensional interpretation of the stratigraphy and structural features of the location of the potential Yucca Mountain radioactive waste repository. The GFM encompasses an area of 65 square miles (170 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the GFM were chosen to encompass the most widely distributed set of exploratory boreholes (the Water Table or WT series) and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The GFM was constructed from geologic map and borehole data. Additional information from measured stratigraphy sections, gravity profiles, and seismic profiles was also considered. This interim change notice (ICN) was prepared in accordance with the Technical Work Plan for the Integrated Site Model Process Model Report Revision 01 (CRWMS M&O 2000). The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The GFM is one component of the Integrated Site Model (ISM) (Figure l), which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1) Geologic Framework Model (GFM); (2) Rock Properties Model (RPM); and (3) Mineralogic Model (MM). The ISM merges the detailed project stratigraphy into model stratigraphic units that are most useful for the primary downstream models and the

  14. Geologic Framework Model Analysis Model Report

    International Nuclear Information System (INIS)

    Clayton, R.

    2000-01-01

    The purpose of this report is to document the Geologic Framework Model (GFM), Version 3.1 (GFM3.1) with regard to data input, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, qualification status of the model, and the differences between Version 3.1 and previous versions. The GFM represents a three-dimensional interpretation of the stratigraphy and structural features of the location of the potential Yucca Mountain radioactive waste repository. The GFM encompasses an area of 65 square miles (170 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the GFM were chosen to encompass the most widely distributed set of exploratory boreholes (the Water Table or WT series) and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The GFM was constructed from geologic map and borehole data. Additional information from measured stratigraphy sections, gravity profiles, and seismic profiles was also considered. This interim change notice (ICN) was prepared in accordance with the Technical Work Plan for the Integrated Site Model Process Model Report Revision 01 (CRWMS M and O 2000). The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The GFM is one component of the Integrated Site Model (ISM) (Figure l), which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1) Geologic Framework Model (GFM); (2) Rock Properties Model (RPM); and (3) Mineralogic Model (MM). The ISM merges the detailed project stratigraphy into model stratigraphic units that are most useful for the primary downstream models and

  15. Lapse rate modeling

    DEFF Research Database (Denmark)

    De Giovanni, Domenico

    2010-01-01

    prepayment models for mortgage backed securities, this paper builds a Rational Expectation (RE) model describing the policyholders' behavior in lapsing the contract. A market model with stochastic interest rates is considered, and the pricing is carried out through numerical approximation...

  16. Lapse Rate Modeling

    DEFF Research Database (Denmark)

    De Giovanni, Domenico

    prepayment models for mortgage backed securities, this paper builds a Rational Expectation (RE) model describing the policyholders' behavior in lapsing the contract. A market model with stochastic interest rates is considered, and the pricing is carried out through numerical approximation...

  17. Multivariate GARCH models

    DEFF Research Database (Denmark)

    Silvennoinen, Annastiina; Teräsvirta, Timo

    This article contains a review of multivariate GARCH models. Most common GARCH models are presented and their properties considered. This also includes nonparametric and semiparametric models. Existing specification and misspecification tests are discussed. Finally, there is an empirical example...

  18. Collaborative networks: Reference modeling

    NARCIS (Netherlands)

    Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    Collaborative Networks: Reference Modeling works to establish a theoretical foundation for Collaborative Networks. Particular emphasis is put on modeling multiple facets of collaborative networks and establishing a comprehensive modeling framework that captures and structures diverse perspectives of

  19. Models in Action

    DEFF Research Database (Denmark)

    Juhl, Joakim

    This thesis is about mathematical modelling and technology development. While mathematical modelling has become widely deployed within a broad range of scientific practices, it has also gained a central position within technology development. The intersection of mathematical modelling and technol...

  20. Business Model Canvas

    NARCIS (Netherlands)

    D'Souza, Austin

    2013-01-01

    Presentatie gegeven op 13 mei 2013 op de bijeenkomst "Business Model Canvas Challenge Assen".
    Het Business Model Canvas is ontworpen door Alex Osterwalder. Het model werkt zeer overzichtelijk en bestaat uit negen bouwstenen.

  1. Energy modelling software

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available The construction industry has turned to energy modelling in order to assist them in reducing the amount of energy consumed by buildings. However, while the energy loads of buildings can be accurately modelled, energy models often under...

  2. Wildfire Risk Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The model combines three modeled fire behavior parameters (rate of spread, flame length, crown fire potential) and one modeled ecological health measure (fire regime...

  3. Mathematical Modeling Using MATLAB

    National Research Council Canada - National Science Library

    Phillips, Donovan

    1998-01-01

    .... Mathematical Modeling Using MA MATLAB acts as a companion resource to A First Course in Mathematical Modeling with the goal of guiding the reader to a fuller understanding of the modeling process...

  4. Analytic Modeling of Insurgencies

    Science.gov (United States)

    2014-08-01

    Counterinsurgency, Situational Awareness, Civilians, Lanchester 1. Introduction Combat modeling is one of the oldest areas of operations research, dating...Army. The ground-breaking work of Lanchester in 1916 [1] marks the beginning of formal models of conflicts, where mathematical formulas and, later...Warfare model [3], which is a Lanchester - based mathematical model (see more details about this model later on), and McCormick’s Magic Diamond model [4

  5. Computational neurogenetic modeling

    CERN Document Server

    Benuskova, Lubica

    2010-01-01

    Computational Neurogenetic Modeling is a student text, introducing the scope and problems of a new scientific discipline - Computational Neurogenetic Modeling (CNGM). CNGM is concerned with the study and development of dynamic neuronal models for modeling brain functions with respect to genes and dynamic interactions between genes. These include neural network models and their integration with gene network models. This new area brings together knowledge from various scientific disciplines, such as computer and information science, neuroscience and cognitive science, genetics and molecular biol

  6. Environmental Modeling Center

    Data.gov (United States)

    Federal Laboratory Consortium — The Environmental Modeling Center provides the computational tools to perform geostatistical analysis, to model ground water and atmospheric releases for comparison...

  7. Multilevel modeling using R

    CERN Document Server

    Finch, W Holmes; Kelley, Ken

    2014-01-01

    A powerful tool for analyzing nested designs in a variety of fields, multilevel/hierarchical modeling allows researchers to account for data collected at multiple levels. Multilevel Modeling Using R provides you with a helpful guide to conducting multilevel data modeling using the R software environment.After reviewing standard linear models, the authors present the basics of multilevel models and explain how to fit these models using R. They then show how to employ multilevel modeling with longitudinal data and demonstrate the valuable graphical options in R. The book also describes models fo

  8. Cosmological models without singularities

    International Nuclear Information System (INIS)

    Petry, W.

    1981-01-01

    A previously studied theory of gravitation in flat space-time is applied to homogeneous and isotropic cosmological models. There exist two different classes of models without singularities: (i) ever-expanding models, (ii) oscillating models. The first class contains models with hot big bang. For these models there exist at the beginning of the universe-in contrast to Einstein's theory-very high but finite densities of matter and radiation with a big bang of very short duration. After short time these models pass into the homogeneous and isotropic models of Einstein's theory with spatial curvature equal to zero and cosmological constant ALPHA >= O. (author)

  9. TRACKING CLIMATE MODELS

    Data.gov (United States)

    National Aeronautics and Space Administration — CLAIRE MONTELEONI*, GAVIN SCHMIDT, AND SHAILESH SAROHA* Climate models are complex mathematical models designed by meteorologists, geophysicists, and climate...

  10. ROCK PROPERTIES MODEL ANALYSIS MODEL REPORT

    International Nuclear Information System (INIS)

    Clinton Lum

    2002-01-01

    The purpose of this Analysis and Model Report (AMR) is to document Rock Properties Model (RPM) 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties models are intended principally for use as input to numerical physical-process modeling, such as of ground-water flow and/or radionuclide transport. The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. This work was conducted in accordance with the following planning documents: WA-0344, ''3-D Rock Properties Modeling for FY 1998'' (SNL 1997, WA-0358), ''3-D Rock Properties Modeling for FY 1999'' (SNL 1999), and the technical development plan, Rock Properties Model Version 3.1, (CRWMS MandO 1999c). The Interim Change Notice (ICNs), ICN 02 and ICN 03, of this AMR were prepared as part of activities being conducted under the Technical Work Plan, TWP-NBS-GS-000003, ''Technical Work Plan for the Integrated Site Model, Process Model Report, Revision 01'' (CRWMS MandO 2000b). The purpose of ICN 03 is to record changes in data input status due to data qualification and verification activities. These work plans describe the scope, objectives, tasks, methodology, and implementing procedures for model construction. The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The work scope for this activity consists of the following: (1) Conversion of the input data (laboratory measured porosity data, x-ray diffraction mineralogy, petrophysical calculations of bound water, and petrophysical calculations of porosity) for each borehole into stratigraphic coordinates; (2) Re-sampling and merging of data sets; (3) Development of geostatistical simulations of porosity; (4

  11. Integrated Site Model Process Model Report

    International Nuclear Information System (INIS)

    Booth, T.

    2000-01-01

    The Integrated Site Model (ISM) provides a framework for discussing the geologic features and properties of Yucca Mountain, which is being evaluated as a potential site for a geologic repository for the disposal of nuclear waste. The ISM is important to the evaluation of the site because it provides 3-D portrayals of site geologic, rock property, and mineralogic characteristics and their spatial variabilities. The ISM is not a single discrete model; rather, it is a set of static representations that provide three-dimensional (3-D), computer representations of site geology, selected hydrologic and rock properties, and mineralogic-characteristics data. These representations are manifested in three separate model components of the ISM: the Geologic Framework Model (GFM), the Rock Properties Model (RPM), and the Mineralogic Model (MM). The GFM provides a representation of the 3-D stratigraphy and geologic structure. Based on the framework provided by the GFM, the RPM and MM provide spatial simulations of the rock and hydrologic properties, and mineralogy, respectively. Functional summaries of the component models and their respective output are provided in Section 1.4. Each of the component models of the ISM considers different specific aspects of the site geologic setting. Each model was developed using unique methodologies and inputs, and the determination of the modeled units for each of the components is dependent on the requirements of that component. Therefore, while the ISM represents the integration of the rock properties and mineralogy into a geologic framework, the discussion of ISM construction and results is most appropriately presented in terms of the three separate components. This Process Model Report (PMR) summarizes the individual component models of the ISM (the GFM, RPM, and MM) and describes how the three components are constructed and combined to form the ISM

  12. ECONOMIC MODELING STOCKS CONTROL SYSTEM: SIMULATION MODEL

    OpenAIRE

    Климак, М.С.; Войтко, С.В.

    2016-01-01

    Considered theoretical and applied aspects of the development of simulation models to predictthe optimal development and production systems that create tangible products andservices. It isproved that theprocessof inventory control needs of economicandmathematical modeling in viewof thecomplexity of theoretical studies. A simulation model of stocks control that allows make managementdecisions with production logistics

  13. Modelling bankruptcy prediction models in Slovak companies

    Directory of Open Access Journals (Sweden)

    Kovacova Maria

    2017-01-01

    Full Text Available An intensive research from academics and practitioners has been provided regarding models for bankruptcy prediction and credit risk management. In spite of numerous researches focusing on forecasting bankruptcy using traditional statistics techniques (e.g. discriminant analysis and logistic regression and early artificial intelligence models (e.g. artificial neural networks, there is a trend for transition to machine learning models (support vector machines, bagging, boosting, and random forest to predict bankruptcy one year prior to the event. Comparing the performance of this with unconventional approach with results obtained by discriminant analysis, logistic regression, and neural networks application, it has been found that bagging, boosting, and random forest models outperform the others techniques, and that all prediction accuracy in the testing sample improves when the additional variables are included. On the other side the prediction accuracy of old and well known bankruptcy prediction models is quiet high. Therefore, we aim to analyse these in some way old models on the dataset of Slovak companies to validate their prediction ability in specific conditions. Furthermore, these models will be modelled according to new trends by calculating the influence of elimination of selected variables on the overall prediction ability of these models.

  14. Better models are more effectively connected models

    Science.gov (United States)

    Nunes, João Pedro; Bielders, Charles; Darboux, Frederic; Fiener, Peter; Finger, David; Turnbull-Lloyd, Laura; Wainwright, John

    2016-04-01

    The concept of hydrologic and geomorphologic connectivity describes the processes and pathways which link sources (e.g. rainfall, snow and ice melt, springs, eroded areas and barren lands) to accumulation areas (e.g. foot slopes, streams, aquifers, reservoirs), and the spatial variations thereof. There are many examples of hydrological and sediment connectivity on a watershed scale; in consequence, a process-based understanding of connectivity is crucial to help managers understand their systems and adopt adequate measures for flood prevention, pollution mitigation and soil protection, among others. Modelling is often used as a tool to understand and predict fluxes within a catchment by complementing observations with model results. Catchment models should therefore be able to reproduce the linkages, and thus the connectivity of water and sediment fluxes within the systems under simulation. In modelling, a high level of spatial and temporal detail is desirable to ensure taking into account a maximum number of components, which then enables connectivity to emerge from the simulated structures and functions. However, computational constraints and, in many cases, lack of data prevent the representation of all relevant processes and spatial/temporal variability in most models. In most cases, therefore, the level of detail selected for modelling is too coarse to represent the system in a way in which connectivity can emerge; a problem which can be circumvented by representing fine-scale structures and processes within coarser scale models using a variety of approaches. This poster focuses on the results of ongoing discussions on modelling connectivity held during several workshops within COST Action Connecteur. It assesses the current state of the art of incorporating the concept of connectivity in hydrological and sediment models, as well as the attitudes of modellers towards this issue. The discussion will focus on the different approaches through which connectivity

  15. Generalized latent variable modeling multilevel, longitudinal, and structural equation models

    CERN Document Server

    Skrondal, Anders; Rabe-Hesketh, Sophia

    2004-01-01

    This book unifies and extends latent variable models, including multilevel or generalized linear mixed models, longitudinal or panel models, item response or factor models, latent class or finite mixture models, and structural equation models.

  16. Biosphere Model Report

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Wu

    2003-07-16

    The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); and (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

  17. Biosphere Model Report

    Energy Technology Data Exchange (ETDEWEB)

    M. A. Wasiolek

    2003-10-27

    The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); and (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

  18. Biosphere Model Report

    International Nuclear Information System (INIS)

    D. W. Wu

    2003-01-01

    The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); and (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7)

  19. AIDS Epidemiological models

    Science.gov (United States)

    Rahmani, Fouad Lazhar

    2010-11-01

    The aim of this paper is to present mathematical modelling of the spread of infection in the context of the transmission of the human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS). These models are based in part on the models suggested in the field of th AIDS mathematical modelling as reported by ISHAM [6].

  20. A Model for Conversation

    DEFF Research Database (Denmark)

    Ayres, Phil

    2012-01-01

    This essay discusses models. It examines what models are, the roles models perform and suggests various intentions that underlie their construction and use. It discusses how models act as a conversational partner, and how they support various forms of conversation within the conversational activity...