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Sample records for biokinetic ieubk model

  1. 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.

  2. 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.

  3. 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.

  4. A biokinetic model for manganese

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W., E-mail: rwl@ornl.gov

    2011-09-15

    The International Commission on Radiological Protection (ICRP) is updating its biokinetic models used to derive dose coefficients and assess bioassay data for intake of radionuclides. This paper reviews biokinetic data for manganese and proposes a biokinetic model for systemic manganese in adult humans. The proposed model provides a more detailed and physiologically meaningful description of the behavior of absorbed manganese in the body than the current ICRP model. The proposed model and current ICRP model yield broadly similar estimates of dose per unit activity of inhaled or ingested radio-manganese but differ substantially with regard to interpretation of bioassay data. The model is intended primarily for use in radiation protection but can also serve as a baseline model for evaluation of potentially excessive intakes of stable manganese in occupational settings. - Highlights: {yields} Manganese is an essential trace element but a neurotoxin when inhaled excessively. {yields} Manganese-54 is an important radiation hazard in and around nuclear reactors. {yields} Biokinetic data for manganese are reviewed and a new biokinetic model is developed. {yields} The main purpose is to update the manganese model used in radiation protection. {yields} The model can also be applied in evaluations of manganese as a chemical hazard.

  5. A biokinetic model for manganese

    International Nuclear Information System (INIS)

    Leggett, R.W.

    2011-01-01

    The International Commission on Radiological Protection (ICRP) is updating its biokinetic models used to derive dose coefficients and assess bioassay data for intake of radionuclides. This paper reviews biokinetic data for manganese and proposes a biokinetic model for systemic manganese in adult humans. The proposed model provides a more detailed and physiologically meaningful description of the behavior of absorbed manganese in the body than the current ICRP model. The proposed model and current ICRP model yield broadly similar estimates of dose per unit activity of inhaled or ingested radio-manganese but differ substantially with regard to interpretation of bioassay data. The model is intended primarily for use in radiation protection but can also serve as a baseline model for evaluation of potentially excessive intakes of stable manganese in occupational settings. - Highlights: → Manganese is an essential trace element but a neurotoxin when inhaled excessively. → Manganese-54 is an important radiation hazard in and around nuclear reactors. → Biokinetic data for manganese are reviewed and a new biokinetic model is developed. → The main purpose is to update the manganese model used in radiation protection. → The model can also be applied in evaluations of manganese as a chemical hazard.

  6. Biokinetic models for radionuclides in experimental animals

    International Nuclear Information System (INIS)

    Morcillo, M. A.

    2003-01-01

    The biokinetic models for many radionuclides are, to a large extent, based on data obtained in experimental animals. The methods used in the experimental development of a biokinetic model can be classified in two groups (i) those applied during the experimental work, which include the activity determination of a given radionuclide at different times and in different biological media such as blood, serum, organs/tissues, urine, bile and faeces and (ii) those methods used for the analysis and study of the experimental data, based in mathematical tools. Some of these methods are reviewed,with special emphasis in the whole body macro autoradiography. To conclude, the contribution that this type of studies can have in two fields of radiation protection is discussed, namely optimization of dosimetric evaluations and decorporation of radionuclides. (Author)

  7. 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)

  8. A biokinetic and dosimetric model for ionic indium in humans

    Science.gov (United States)

    Andersson, Martin; Mattsson, Sören; Johansson, Lennart; Leide-Svegborn, Sigrid

    2017-08-01

    This paper reviews biokinetic data for ionic indium, and proposes a biokinetic model for systemic indium in adult humans. The development of parameter values focuses on human data and indium in the form of ionic indium(III), as indium chloride and indium arsenide. The model presented for systemic indium is defined by five different pools: plasma, bone marrow, liver, kidneys and other soft tissues. The model is based on two subsystems: one corresponding to indium bound to transferrin and one where indium is transported back to the plasma, binds to red blood cell transferrin and is then excreted through the kidneys to the urinary bladder. Absorbed doses to several organs and the effective dose are calculated for 111In- and 113mIn-ions. The proposed biokinetic model is compared with previously published biokinetic indium models published by the ICRP. The absorbed doses are calculated using the ICRP/ICRU adult reference phantoms and the effective dose is estimated according to ICRP Publication 103. The effective doses for 111In and 113mIn are 0.25 mSv MBq-1 and 0.013 mSv MBq-1 respectively. The updated biokinetic and dosimetric models presented in this paper take into account human data and new animal data, which represent more detailed and presumably more accurate dosimetric data than that underlying previous models for indium.

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

    International Nuclear Information System (INIS)

    Leggett, Richard Wayne

    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 loss of systemic zinc in excreta have been developed from the derived data. 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 current radiation protection model for zinc yield broadly similar estimates of effective dose from internally deposited radioisotopes of zinc but substantially different dose estimates for several individual tissues, particularly the liver.

  10. Calculating the interindividual geometric standard deviation for use in the integrated exposure uptake biokinetic model for lead in children.

    Science.gov (United States)

    Griffin, S; Marcus, A; Schulz, T; Walker, S

    1999-06-01

    The integrated exposure uptake biokinetic (IEUBK) model, recommended for use by the U.S. Environmental Protection Agency at residential Superfund sites to predict potential risks to children from lead exposure and to establish lead remediation levels, requires an interindividual geometric standard deviation (GSDi) as an essential input parameter. The GSDi quantifies the variability of blood lead concentrations for children exposed to similar environmental concentrations of lead. Estimates of potential risks are directly related to the GSDi, and therefore the GSDi directly impacts the scope of remediation at Superfund sites. Site-specific GSDi can be calculated for sites where blood lead and environmental lead have been measured. This paper uses data from blood and environmental lead studies conducted at the Bingham Creek and Sandy, Utah, Superfund sites to calculate GSDi using regression modeling, box modeling, and structural equation modeling. GSDis were calculated using various methods for treating values below the analytical method detection and quantitation limits. Treatment of nonquantifiable blood lead concentrations affected the GSDi more than the statistical method used to calculate the GSDi. For any given treatment, the different statistical methods produced similar GSDis. Because of the uncertainties associated with data in the blood lead studies, we recommend that a range of GSDis be used when analyzing site-specific risks associated with exposure to environmental lead instead of a single estimate. Because the different statistical methods produce similar GSDis, we recommend a simple procedure to calculate site-specific GSDi from a scientifically sound blood and environmental lead study.

  11. Age and gender specific biokinetic model for strontium in humans

    Energy Technology Data Exchange (ETDEWEB)

    Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2015-03-01

    A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitation for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic model for strontium (Sr-AGe model). The Sr-AGe model has similar structure as the ICRP model for the alkaline earth elements. The following parameters were mainly reevaluated: gastro-intestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0–80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general population exposed to ingested strontium radioisotopes.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

    Information on the biokinetics of the 15 elements of the lanthanide series, {sup 57}La to {sup 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)

  19. Parameter uncertainty analysis of a biokinetic model of caesium

    International Nuclear Information System (INIS)

    Li, W.B.; Oeh, U.; Klein, W.; Blanchardon, E.; Puncher, M.; Leggett, R.W.; Breustedt, B.; Nosske, D.; Lopez, M.A.

    2015-01-01

    Parameter uncertainties for the biokinetic model of caesium (Cs) developed by Leggett et al. were inventoried and evaluated. The methods of parameter uncertainty analysis were used to assess the uncertainties of model predictions with the assumptions of model parameter uncertainties and distributions. Furthermore, the importance of individual model parameters was assessed by means of sensitivity analysis. The calculated uncertainties of model predictions were compared with human data of Cs measured in blood and in the whole body. It was found that propagating the derived uncertainties in model parameter values reproduced the range of bioassay data observed in human subjects at different times after intake. The maximum ranges, expressed as uncertainty factors (UFs) (defined as a square root of ratio between 97.5. and 2.5. percentiles) of blood clearance, whole-body retention and urinary excretion of Cs predicted at earlier time after intake were, respectively: 1.5, 1.0 and 2.5 at the first day; 1.8, 1.1 and 2.4 at Day 10 and 1.8, 2.0 and 1.8 at Day 100; for the late times (1000 d) after intake, the UFs were increased to 43, 24 and 31, respectively. The model parameters of transfer rates between kidneys and blood, muscle and blood and the rate of transfer from kidneys to urinary bladder content are most influential to the blood clearance and to the whole-body retention of Cs. For the urinary excretion, the parameters of transfer rates from urinary bladder content to urine and from kidneys to urinary bladder content impact mostly. The implication and effect on the estimated equivalent and effective doses of the larger uncertainty of 43 in whole-body retention in the later time, say, after Day 500 will be explored in a successive work in the framework of EURADOS. (authors)

  20. Preclinical Biokinetic Modelling of Tc-99m Radiophamaceuticals Obtained from Semi-Automatic Image Processing.

    Science.gov (United States)

    Cornejo-Aragón, Luz G; Santos-Cuevas, Clara L; Ocampo-García, Blanca E; Chairez-Oria, Isaac; Diaz-Nieto, Lorenza; García-Quiroz, Janice

    2017-01-01

    The aim of this study was to develop a semi automatic image processing algorithm (AIPA) based on the simultaneous information provided by X-ray and radioisotopic images to determine the biokinetic models of Tc-99m radiopharmaceuticals from quantification of image radiation activity in murine models. These radioisotopic images were obtained by a CCD (charge couple device) camera coupled to an ultrathin phosphorous screen in a preclinical multimodal imaging system (Xtreme, Bruker). The AIPA consisted of different image processing methods for background, scattering and attenuation correction on the activity quantification. A set of parametric identification algorithms was used to obtain the biokinetic models that characterize the interaction between different tissues and the radiopharmaceuticals considered in the study. The set of biokinetic models corresponded to the Tc-99m biodistribution observed in different ex vivo studies. This fact confirmed the contribution of the semi-automatic image processing technique developed in this study.

  1. 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.)

  2. 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

    ... (POL) products utilized in the current and future combat systems. As part of these efforts, a bio-kinetic model was developed to predict the biodegradability of lubricants including hydraulic fluids...

  3. Lead toxicokinetics. Development of a biokinetic model to understand and predict the outcome of treatment.

    Science.gov (United States)

    de Vries, I; Spaans, E; van Dijk, A; Meulenbelt, J

    1998-01-01

    Quite often physicians contact the Dutch Poisons Control Centre for information on patients with increased lead exposure. The most important questions raised by physicians dealing with these patients are how to estimate the lead exposure and the total lead body burden, how to interpret blood lead concentrations and whether the patient needs treatment. In order to answer these questions we need knowledge of the toxicokinetics of lead in the human body. To achieve insight and to make this knowledge accessible to physicians a biokinetic model for lead metabolism in the human body was developed. A four-compartment model with first-order kinetics, based on the concept of Kneip, was used. A biokinetic model uses a mathematical approach to translate the complex biological and kinetic behaviour of lead. In order to develop this biokinetic model two computer programmes were used. At the moment the model is tested with clinical data from patient treated at the medical toxicology outpatient clinic of the Utrecht University Hospital (this department cooperates very closely with the National Poisons Control Centre). Especially with regard to chelation therapy for elevated blood lead levels due to chronic exposure, the model is very helpful in visualising the toxicokinetics of lead in the human body. Toxicokinetic model might help improve knowledge of lead toxicokinetics, leading to well-considered guidelines for treatment of lead intoxications.

  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. 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

  6. 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...

  7. 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)

  8. 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)

  9. 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)

  10. 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)

  11. 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

  12. Structure of a physiologically based biokinetic model for use in 14C and organically bound tritium dosimetry

    International Nuclear Information System (INIS)

    Whillians, D.W.

    2003-01-01

    Physiologically based biokinetic (PBBK) dosimetry models for beta emitters like 3 H and 14 C must include rapid turnover compartments which, while they may be minor in terms of dose commitment, can dominate bioassay measurements at early times after intake. In this paper a consistent PBBK model structure will be described for use in dose assessments for organic 14 C and organically bound tritium (OBT), and also for 14 CO 2 , based on the literature of human carbon metabolism, and on direct measurements of human excretion. CO 2 /HCO 3 - is a central compartment in carbon metabolism. The 14 CO 2 biokinetic model described in ICRP Publication 80 for the calculation of dose coefficients was found to omit early components of excretion necessary for the accurate interpretation of bioassay results. Recommendations on the requirements on dosimetry models for intakes of 14 C and OBT are made. (author)

  13. 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.

  14. 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

  15. Calibration of Biokinetic and Biological Parameters for a Groundwater Bioremediation Model using Heuristics and Function Approximation Optimization

    Science.gov (United States)

    Mugunthan, P.; Shoemaker, C. A.; Regis, R. G.

    2003-12-01

    Heuristics and function approximation optimization methods were applied in calibrating biological and biokinetic parameters for a computationally expensive groundwater bioremediation model for engineered reductive dechlorination of chlorinated ethenes. Multi-species groundwater bioremediation models that use monod type kinetics are often not amenable to traditional derivative based optimization due to stiff biokinetic equations. The performance of three heuristic methods, Stochastic Greedy Search (GS), Real Genetic Algorithm (RGA), Derandomized Evolution Strategy (DES), and, Function Approximation Optimization based on Radial Basis Function (FA-RBF) were compared on three-dimensional hypothetical and field problems. GS was implemented so as to perform a more global search. Optimization results on hypothetical problem indicated that FA-RBF performed statistically significantly better than heuristic based evolutionary algorithms at a 10% significance level. Further, this particular implementation of GS performed well and proved superior to RGA. These heuristic methods and FA-RBF, with the exception of RGA, were applied to calibrate biological and biokinetic parameters using treatability test data for enhanced bioremediation at a Naval Air Station in Alameda Point, CA. All three methods performed well and identified similar solutions. The approximate simulation times for the hypothetical and real problems were 7 min and 2.5 hours respectively. Calibration of such computationally expensive models by heuristic and function approximation methods appears promising.

  16. 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

  17. Molecular Biomarker-Based Biokinetic Modeling of a PCE-Dechlorinating and Methanogenic Mixed Culture

    Energy Technology Data Exchange (ETDEWEB)

    Heavner, Gretchen L. W.; Rowe, Annette R.; Mansfeldt, Cresten B.; Pan, Ju Khuan; Gossett, James M.; Richardson, Ruth E.

    2013-04-16

    Bioremediation of chlorinated ethenes via anaerobic reductive dechlorination relies upon the activity of specific microbial population-most notably Dehalococcoides (DHC) strains. In the lab and field Dehalococcoides grow most robustly in mixed communities which usually contain both fermenters and methanogens. Recently, researchers have been developing quantitative molecular biomarkers to aid in field site diagnostics and it is hoped that these biomarkers could aid in the modeling of anaerobic reductive dechlorination. A comprehensive biokinetic model of a community containing Dehalococcoides mccartyi (formerly D. ethenogenes) was updated to describe continuously fed reactors with specific biomass levels based on quantitative PCR (qPCR)-based population data (DNA and RNA). The model was calibrated and validated with subsets of chemical and molecular biological data from various continuous feed experiments (n = 24) with different loading rates of the electron acceptor (1.5 to 482 μeeq/L-h), types of electron acceptor (PCE, TCE, cis-DCE) and electron donor to electron acceptor ratios. The resulting model predicted the sum of dechlorination products vinyl chloride (VC) and ethene (ETH) well. However, VC alone was under-predicted and ETH was over predicted. Consequently, competitive inhibition among chlorinated ethenes was examined and then added to the model. Additionally, as 16S rRNA gene copy numbers did not provide accurate model fits in all cases, we examined whether an improved fit could be obtained if mRNA levels for key functional enzymes could be used to infer respiration rates. The resulting empirically derived mRNA “adjustment factors” were added to the model for both DHC and the main methanogen in the culture (a Methanosaeta species) to provide a more nuanced prediction of activity. Results of this study suggest that at higher feeding rates competitive inhibition is important and mRNA provides a more accurate indicator of a population’s instantaneous

  18. A physiologically based biokinetic (PBBK) model for estragole bioactivation and detoxification in rat

    International Nuclear Information System (INIS)

    Punt, Ans; Freidig, Andreas P.; Delatour, Thierry; Scholz, Gabriele; Boersma, Marelle G.; Schilter, Benoit; Bladeren, Peter J. van; Rietjens, Ivonne M.C.M.

    2008-01-01

    The present study defines a physiologically based biokinetic (PBBK) model for the alkenylbenzene estragole in rat based on in vitro metabolic parameters determined using relevant tissue fractions, in silico derived partition coefficients, and physiological parameters derived from the literature. The model consists of eight compartments including liver, lung and kidney as metabolizing compartments, and additional compartments for fat, arterial blood, venous blood, rapidly perfused tissue and slowly perfused tissue. Evaluation of the model was performed by comparing the PBBK predicted dose-dependent formation of the estragole metabolites 4-allylphenol and 1'-hydroxyestragole glucuronide to literature reported levels of these metabolites, which were demonstrated to be in the same order of magnitude. With the model obtained the relative extent of bioactivation and detoxification of estragole at different oral doses was examined. At low doses formation of 4-allylphenol, leading to detoxification, is observed to be the major metabolic pathway, occurring mainly in the lung and kidney due to formation of this metabolite with high affinity in these organs. Saturation of this metabolic pathway in the lung and kidney leads to a relative increase in formation of the proximate carcinogenic metabolite 1'-hydroxyestragole, occurring mainly in the liver. This relative increase in formation of 1'-hydroxyestragole leads to a relative increase in formation of 1'-hydroxyestragole glucuronide and 1'-sulfooxyestragole the latter being the ultimate carcinogenic metabolite of estragole. These results indicate that the relative importance of different metabolic pathways of estragole may vary in a dose-dependent way, leading to a relative increase in bioactiviation of estragole at higher doses

  19. 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

  20. 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.

  1. 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.)

  2. 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)

  3. ICRP 67 Biokinetic Models for AM-241 Applied to Nonhuman Primates.

    Science.gov (United States)

    Alomairy, Nada A; Brey, Richard R; Guilmette, Raymond A

    2017-05-01

    Between 1960 and 1985, Patricia Durbin and colleagues performed studies on the distribution of intravenously and intramuscularly injected Am citrate with dosages ranging from 16 to 32 kBq kg in 30 male and female non-human primates (NHP). Dr. Durbin died unexpectedly in March of 2009, leaving much of the extensive serial blood, bioassay, and autopsy data from these NHP studies unanalyzed. As part of the experimental design, serial blood samples were taken, and urine and feces samples were collected separately for the duration of the study. The measurements of urine, fecal excretion, blood samples, and organ burden data obtained from the animals were used to evaluate the transfer rates of the ICRP 67 biokinetic model for Am. Seven cases, in which the primates were administered Am citrate by intravenous injection, were evaluated using the ICRP 67 systemic model. There were differences ranging from 51.4% underestimated to 102.7% overestimated activity between the predicted intake, which was calculated using IMBA Professional Plus software and based upon the urine bioassay data and the actual activity. The difference between the predicted activity at the time of death in the liver and skeleton using IMBA professional software and the value of the measured activity at the time of death were also compared. Generally, the ratios of predicted activity in the liver and skeleton at the time of death to the measured activity were consistently more than 1. However, the ratios were less than 1 in the skeleton for animals that were sacrificed 2,199 and 973 d post injection. The posterior probability distributions for model parameters derived using WeLMoS method were inconsistent with the ICRP 67 default parameters. The prediction made based on the posterior probability distributions for model parameters derived using WeLMoS gave the best fit to these data; however, the modified parameters overestimated the activity in almost all cases. The difference between the predicted Am

  4. 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

  5. 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

  6. 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

  7. 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.

  8. A simple allometric diffusion-based biokinetic model to predict Cu(II) uptake across gills of freshwater clam Corbicula fluminea.

    Science.gov (United States)

    Chen, W-Y; Lin, C-M; Ju, Y-R; Liao, C-M

    2010-06-01

    The purpose of this study was to link Fick's type mass transfer and biokinetics together with Michaelis-Menten kinetics to arrive at a simple predictive framework for quantifying biouptake mechanisms in gills of freshwater clam Corbicula fluminea exposed to Cu(II). A diffusion-based Cu(II) influx and permeability can be calculated using physiological and allometric-related parameters. Simulations indicate that Cu(II) bioconcentration factor of gills was 42. Estimated steady-state Cu(II) gill uptake influx and permeability were 0.097 nmol cm(-2) s(-1) and 0.48 cm s(-1), respectively. The proposed simple allometric diffusion-based biokinetic model meets the need for describing nonequilibrium aspects of biouptake mechanisms in bivalve gills.

  9. Combining computational fluid dynamics with a biokinetic model for predicting ammonia and phosphate behavior in aeration tanks.

    Science.gov (United States)

    Zima, Piotr; Makinia, Jacek; Swinarski, Marek; Czerwionka, Krzysztof

    2009-11-01

    The aim of this study was to use computational fluid dynamics for predicting the behavior of reactive pollutants (ammonia and phosphate) in the aerobic zone of the bioreactor located at the Wschod wastewater treatment plant in Gdansk, Poland. The one-dimensional advection-dispersion equation was combined with simple biokinetic models incorporating the Monod-type expressions as source terms for the two pollutants. The problem was solved numerically by a multi-step splitting technique algorithm. The dispersion coefficient, E(L), was estimated using a statistical method and numerical optimization based on experimental data from three tracer studies. With the first method, the values of EL varied within the range 1082 to 1860 m2/h and 695 to 1355 m2/h, respectively, in sections 1 and 2 of the aerobic zone. Except for one case, deviations of the corresponding numerically optimized values of E(L) did not exceed 14%. The maximum specific rates of nitrification [r(n,max,20) = 4.6 g N/(kg VSS h)] and phosphate uptake [r(Pupt,max,20) = 13.5 g P/(kg VSS h)] at T = 20 degrees C were determined based on laboratory batch experiments. With minor adjustments of the kinetic parameters, the model was capable of accurately predicting the longitudinal profiles of ammonia and phosphate in the aerobic zone, and the simulation results were presented using the actual horizontal geometry of the bioreactor as a background.

  10. Implementation of iodine biokinetic model for interpreting I-131 contamination in breast milk after the Fukushima nuclear disaster

    Science.gov (United States)

    Tani, Kotaro; Kurihara, Osamu; Kim, Eunjoo; Yoshida, Satoshi; Sakai, Kazuo; Akashi, Makoto

    2015-07-01

    After the accident at the Fukushima Daiichi Nuclear Power Plant run by Tokyo Electric Power Company in 2011, breast milk samples obtained from volunteers living in Fukushima and neighboring prefectures were examined and small amounts of I-131 (2.2-36.3 Bq/kg) were detected in some samples. In this work, the I-131 concentrations in breast milk from nursing mothers in Ibaraki prefecture were calculated based on the iodine biokinetic model during lactation together with time-variable intake scenarios by inhalation of ambient air and ingestion of tap water, using the authors’ code. The calculated I-131 concentrations in breast milk generally agreed with those measured for the volunteers. Based on the results, thyroid equivalent doses to breast-fed infants were estimated for each place of residence of the volunteers on the assumption that these infants consumed 800 ml of breast milk every day, resulting in 10-11 mSv for Mito and Kasama cities and 1.1-1.8 mSv for Tsukuba and Moriya cities. It was suggested that breast milk consumption could be a major contributor to internal dose of breast-fed infants in areas with mild I-131 pollution; however, further studies considering personal behavior surveys would be necessary to estimate individual doses.

  11. How well-mixed is well mixed? Hydrodynamic-biokinetic model integration in an aerated tank of a full-scale water resource recovery facility.

    Science.gov (United States)

    Rehman, Usman; Audenaert, Wim; Amerlinck, Youri; Maere, Thomas; Arnaldos, Marina; Nopens, Ingmar

    2017-10-01

    Current water resource recovery facility (WRRF) models only consider local concentration variations caused by inadequate mixing to a very limited extent, which often leads to a need for (rigorous) calibration. The main objective of this study is to visualize local impacts of mixing by developing an integrated hydrodynamic-biokinetic model for an aeration compartment of a full-scale WRRF. Such a model is able to predict local variations in concentrations and thus allows judging their importance at a process level. In order to achieve this, full-scale hydrodynamics have been simulated using computational fluid dynamics (CFD) through a detailed description of the gas and liquid phases and validated experimentally. In a second step, full ASM1 biokinetic model was integrated with the CFD model to account for the impact of mixing at the process level. The integrated model was subsequently used to evaluate effects of changing influent and aeration flows on process performance. Regions of poor mixing resulting in non-uniform substrate distributions were observed even in areas commonly assumed to be well-mixed. The concept of concentration distribution plots was introduced to quantify and clearly present spatial variations in local process concentrations. Moreover, the results of the CFD-biokinetic model were concisely compared with a conventional tanks-in-series (TIS) approach. It was found that TIS model needs calibration and a single parameter set does not suffice to describe the system under both dry and wet weather conditions. Finally, it was concluded that local mixing conditions have significant consequences in terms of optimal sensor location, control system design and process evaluation.

  12. 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

  13. 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)

  14. 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

  15. Estimation of parameters biokinetics from the resolution of a model compartment for I-131. Application to a patient with thyroid carcinoma hemodialysis; Estimacion de parametros bioceniticos a partir de la resolucion de un modelo compartimental para I-131. Aplicacion a un paciente hemodializado con carcinoma de torioides

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

    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. 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.)

  17. 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.)

  18. 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

  19. 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)

  20. 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.

  1. 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.

  2. 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

    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...... 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...

  3. 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

  4. 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.)

  5. 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

  6. Modeling and monitoring of the acclimatization of conventional activated sludge to a biohydrogen producing culture by biokinetic control

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Morales, F.J.; Villasenor, J.; Infantes, D. [University of Castilla-La Mancha, ITQUIMA, Chemical Engineering Department, Avenida Camilo Jose Cela S/N. 13071 Ciudad Real (Spain)

    2010-10-15

    The purpose of this work was to study the acclimatization of activated sludge as it evolved into an acidogenic culture capable of producing volatile fatty acids and hydrogen from glucose. The experiments were conducted in a Sequential Batch Reactor with a pH of 5, a temperature of 35 C and in the absence of oxygen. Biomass, substrate and product concentrations were monitored during the experiment. The presence of aerobic, facultative and acidogenic microorganisms was determined for the initial seed, and their main kinetic and stoichiometric properties were determined. For the acidogenic microorganisms, {mu}{sub max}, b and Y{sub x} increased during the acclimatization process, reaching final values of 0.125 h{sup -1}, 0.025 h{sup -1}, 0.025 g mmol{sup -1}, respectively. However, for the facultative microorganisms, {mu}{sub max} and b decreased, whereas Y{sub x} remained constant during the acclimatization process, reaching final values of 0.032 h{sup -1}, 0.007 h{sup -1}, 0.017 g mmol{sup -1}, respectively. The evolution of the facultative organisms was significantly related to lactic acid production, whereas the evolution of the acidogenic microorganisms was related to hydrogen, acetic acid and butyric acid production. The biomass concentration of each group was estimated by modeling the experimental data. (author)

  7. 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

  8. 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

  9. 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.)

  10. 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)

  11. Evolution of the profession of biokinetics | Ellapen | South African ...

    African Journals Online (AJOL)

    The profession of Biokinetics has been undergoing significant evolution over the last decades. This paper provides an overview of the history of Biokinetics and the progressive changes to the professional bodies regulating the profession. These changes include the formulation of the Professional Board of Physiotherapy, ...

  12. 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

  13. 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)

  14. 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

  15. Physiologically based biokinetic (PBBK) modeling and validation of dose-, species-, interindividual- and matrix dependent effects on the bioactivation and detoxification of safrole

    NARCIS (Netherlands)

    Martati, E.

    2013-01-01

    Keywords: safrole, PBBK model, DNA adduct, mace  Safrole has been demonstrated to be carcinogenic in rodent studies at high doses of the pure compound. The use of pure safrole in foodshas already been prohibited. As a result, the main

  16. 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.

  17. 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

  18. 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.

  19. Biokinetics and effects of barium sulfate nanoparticles.

    Science.gov (United States)

    Konduru, Nagarjun; Keller, Jana; Ma-Hock, Lan; Gröters, Sibylle; Landsiedel, Robert; Donaghey, Thomas C; Brain, Joseph D; Wohlleben, Wendel; Molina, Ramon M

    2014-10-21

    Nanoparticulate barium sulfate has potential novel applications and wide use in the polymer and paint industries. A short-term inhalation study on barium sulfate nanoparticles (BaSO₄ NPs) was previously published [Part Fibre Toxicol 11:16, 2014]. We performed comprehensive biokinetic studies of ¹³¹BaSO₄ NPs administered via different routes and of acute and subchronic pulmonary responses to instilled or inhaled BaSO₄ in rats. We compared the tissue distribution of ¹³¹Ba over 28 days after intratracheal (IT) instillation, and over 7 days after gavage and intravenous (IV) injection of ¹³¹BaSO₄. Rats were exposed to 50 mg/m³ BaSO₄ aerosol for 4 or 13 weeks (6 h/day, 5 consecutive days/week), and then gross and histopathologic, blood and bronchoalveolar lavage (BAL) fluid analyses were performed. BAL fluid from instilled rats was also analyzed. Inhaled BaSO₄ NPs showed no toxicity after 4-week exposure, but a slight neutrophil increase in BAL after 13-week exposure was observed. Lung burden of inhaled BaSO₄ NPs after 4-week exposure (0.84 ± 0.18 mg/lung) decreased by 95% over 34 days. Instilled BaSO₄ NPs caused dose-dependent inflammatory responses in the lungs. Instilled BaSO₄ NPs (0.28 mg/lung) was cleared with a half-life of ≈ 9.6 days. Translocated ¹³¹Ba from the lungs was predominantly found in the bone (29%). Only 0.15% of gavaged dose was detected in all organs at 7 days. IV-injected ¹³¹BaSO₄ NPs were predominantly localized in the liver, spleen, lungs and bone at 2 hours, but redistributed from the liver to bone over time. Fecal excretion was the dominant elimination pathway for all three routes of exposure. Pulmonary exposure to instilled BaSO₄ NPs caused dose-dependent lung injury and inflammation. Four-week and 13-week inhalation exposures to a high concentration (50 mg/m³) of BaSO₄ NPs elicited minimal pulmonary response and no systemic effects. Instilled and inhaled BaSO₄ NPs were cleared quickly yet

  20. 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 ...

  1. 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)

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. Nuclear analytical techniques applied to the research on biokinetics of incorporated radionuclides for internal dosimetry

    International Nuclear Information System (INIS)

    Cantone, M.C.

    2005-01-01

    Full text: The presentation intends to discuss the contribution that techniques of analysis, based on activation analysis or mass spectrometry, can give to a very selected item of the protection against ionizing radiation: the biokinetics of relevant elements. The assessment of radiation dose to body tissues, following intakes of radionuclides in occupational, accidental exposures and environmental exposure in case of dispersion in the environment of radio contaminants of potential concerns, is essential to evaluate and manage the the related radiological risk, including the decisions and actions to be undertake. Internal dose is not directly measurable and the International Commission on Radiological Protection ICRP has developed models which describes the behavior of the substances in the human body, following their entry ways by inhalation or ingestion. Generally, all the available sources of information contribute in the modeling process, including studies on animals, use of chemical analogues and, obviously direct information on humans, which is definitely the preferred source on which a biokinetic model can be based. Biokinetic data on human are available for most of the biological essential elements (Fe, Zn, Cu, Se) and for some elements the metabolic behavior is well know due to their use in clinical application (I, Sr, Tc), moreover research is in progress for non-essential alpha emitters. However, for a number of element, including elements with radionuclide of radiological significance in case of environmental contamination (Ru, Zr, Ce, Te and Mo), human data are poor or missing and biokinetic parameters are essentially extrapolated from data on animals. The use of stable isotopes is a publicly well acceptable and ethically justifiable method, compared to the use of radioisotopes, when volunteer subjects are considered in the investigations. The design of the investigation is based on the double tracer approach: one isotope is given orally and a second

  12. 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

  13. 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.

  14. 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

  15. Biokinetic study for SRC-I wastewater

    Energy Technology Data Exchange (ETDEWEB)

    1984-06-01

    Biooxidation is an important part of the overall wastewater treatment system for the proposed SRC-I Demonstration Plant in Newman, Kentucky. After the completion of a Baseline Design for the plant in April 1982, various refinements were evaluated. One of these was the inclusion of a process for phenol recovery from four sour-water streams. As part of this evaluation, an extensive laboratory treatability study was conducted on wastewaters both with and without this phenol recovery step. The purpose of the study was to compare the results of different treatment schemes on different wastewaters and did not include the development of the kinetic coefficients that govern the biooxidation process. Additional treatability testing documented herein, has been performed to establish the kinetic coefficients for biooxidation of the SRC-I wastewaters. This will provide a rational basis for any subsequent changes in design. The wastewater feed used in this study was process recycle water from the Fort Lewis, Washington, pilot plant. Prior to biooxidation, it was pretreated by solvent extraction for removal of phenolics and by steam stripping for removal of ammonia and hydrogen sulfide. Two, 2-stage bench scale bioreactors were operated for approximately eight months, during which time they were stabilized at various steady-state conditions. Kinetic coefficients were evaluated according to the Lawrence and McCarty model, based on BOD, COD, and TOC. Nitrification, oxygen utilization, and solids settling velocities were also studied. The results showed that BOD is a poor basis for the model mainly because almost all BOD/sub 5/ was removed at all steady-state conditions. Also, the model was more accurate for steady-state conditions of lower solids retention times. The bulk of both organic and ammonia reductions occurred in the first stage reactors.

  16. 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)

  17. 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

  18. An integrated methodology for assessing the impact of food matrix and gastrointestinal effects on the biokinetics and cellular toxicity of ingested engineered nanomaterials.

    Science.gov (United States)

    DeLoid, Glen M; Wang, Yanli; Kapronezai, Klara; Lorente, Laura Rubio; Zhang, Roujie; Pyrgiotakis, Georgios; Konduru, Nagarjun V; Ericsson, Maria; White, Jason C; De La Torre-Roche, Roberto; Xiao, Hang; McClements, David Julian; Demokritou, Philip

    2017-10-13

    Engineered nanomaterials (ENMs) are increasingly added to foods to improve their quality, sensory appeal, safety and shelf-life. Human exposure to these ingested ENMs (iENMS) is inevitable, yet little is known of their hazards. To assess potential hazards, efficient in vitro methodologies are needed to evaluate particle biokinetics and toxicity. These methodologies must account for interactions and transformations of iENMs in foods (food matrix effect) and in the gastrointestinal tract (GIT) that are likely to determine nano-biointeractions. Here we report the development and application of an integrated methodology consisting of three interconnected stages: 1) assessment of iENM-food interactions (food matrix effect) using model foods; 2) assessment of gastrointestinal transformations of the nano-enabled model foods using a three-stage GIT simulator; 3) assessment of iENMs biokinetics and cellular toxicity after exposure to simulated GIT conditions using a triculture cell model. As a case study, a model food (corn oil-in-water emulsion) was infused with Fe 2 O 3 (Iron(III) oxide or ferric oxide) ENMs and processed using this three-stage integrated platform to study the impact of food matrix and GIT effects on nanoparticle biokinetics and cytotoxicity . A corn oil in phosphate buffer emulsion was prepared using a high speed blender and high pressure homogenizer. Iron oxide ENM was dispersed in water by sonication and combined with the food model. The resulting nano-enabled food was passed through a three stage (mouth, stomach and small intestine) GIT simulator. Size distributions of nano-enabled food model and digestae at each stage were analyzed by DLS and laser diffraction. TEM and confocal imaging were used to assess morphology of digestae at each phase. Dissolution of Fe2O3 ENM along the GIT was assessed by ICP-MS analysis of supernatants and pellets following centrifugation of digestae. An in vitro transwell triculture epithelial model was used to assess

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

    Energy Technology Data Exchange (ETDEWEB)

    Ferro F, G.; Torres G, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Gonzalez V, A. [UAEM, Facultad de Medicina, Toluca (Mexico); Murphy, C.A. de [INCMNSZ, Mexico D.F. (Mexico)

    2006-07-01

    Molecular imaging techniques directly or indirectly monitor and record the spatiotemporal distribution of molecular or cellular processes for biochemical, biologic, diagnostic or therapeutic applications. {sup 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 {sup 99m}Tc-HYNlC-TOC and {sup 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 {sup 99m}Tc-HYNlC-TOC or {sup 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. {sup 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 {sup 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)

  20. 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)

  1. Biokinetics and dosimetry of Depleted Uranium (DU) in rats implanted with DU fragments

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A. [Los Alamos National Lab., Los Alamos, NM (United States); Hahn, F.F. [Lovelace Respiratory Research Inst., Albuquerque, NM (United States); Durbin, P.W. [Lawrence Berkeley National Lab., Berkeley, CA (United States)

    2005-07-01

    As part of a lifespan cancer study done in rats (Hahn et al. 2003), four square (5 mm x 5 mm) DU wafers were implanted in the leg muscles of rats for biokinetic studies. Twenty-four hour urine samples were collected periodically, and DU was analyzed in these samples, kidneys and eviscerated carcass. The daily DU urinary excretion rate increased steeply during the first 30 d after implantation, peaking at 60-90 d at 3-10 x 10{sup -3}%/d. During the first 150 d, the average excretion rate was 2.4 x 10{sup -3}%/d, decreasing thereafter to about 1 x 10{sup -3}%/d. Serial radiographs made of the wound sites showed that, as early as 1 w after implantation, surface corrosion and small, dense bodies were present near the original implant, presumably DU, which continued to increase with time. During this 3-mo period, connective tissue capsules also formed around the implants, and are hypothesized to have reduced the access of DU to tissue fluids by limiting the diffusion rate of dissolved chemical forms of DU from the wound site. Using a model of wound-site retention being developed by a committee of the U. S. NCRP, the DU wound retention could be described by a two-component exponential function in which 0.5% of the DU was retained with a half time of 80 d and the remainder with a half time of about 300 y. (orig.)

  2. Capstone depleted uranium aerosol biokinetics, concentrations, and doses.

    Science.gov (United States)

    Guilmette, Raymond A; Miller, Guthrie; Parkhurst, Mary Ann

    2009-03-01

    One of the principal goals of the Capstone Depleted Uranium (DU) Aerosol Study was to quantify and characterize DU aerosols generated inside armored vehicles by perforation with a DU penetrator. This study consequently produced a database in which the DU aerosol source terms were specified both physically and chemically for a variety of penetrator-impact geometries and conditions. These source terms were used to calculate radiation doses and uranium concentrations for various scenarios as part of the Capstone Human Health Risk Assessment (HHRA). This paper describes the scenario-related biokinetics of uranium, and summarizes intakes, chemical concentrations to the organs, and E(50) and HT(50) for organs and tissues based on exposure scenarios for personnel in vehicles at the time of perforation as well as for first responders. For a given exposure scenario (duration time and breathing rates), the range of DU intakes among the target vehicles and shots was not large, about a factor of 10, with the lowest being for a ventilated operational Abrams tank and the highest being for an unventilated Abrams with DU penetrator perforating DU armor. The ranges of committed effective doses were more scenario-dependent than were intakes. For example, the largest range, a factor of 20, was shown for scenario A, a 1 min exposure, whereas, the range was only a factor of two for the first-responder scenario (E). In general, the committed effective doses were found to be in the tens of mSv. The risks ascribed to these doses are discussed separately.

  3. 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.

  4. 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

  5. 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.

  6. 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 ...

  7. 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.

  8. 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)], E-mail: laura.melendez@unipd.it; 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.

  9. Quantitative biokinetics of titanium dioxide nanoparticles after intravenous injection in rats: Part 1.

    Science.gov (United States)

    Kreyling, Wolfgang G; Holzwarth, Uwe; Haberl, Nadine; Kozempel, Ján; Hirn, Stephanie; Wenk, Alexander; Schleh, Carsten; Schäffler, Martin; Lipka, Jens; Semmler-Behnke, Manuela; Gibson, Neil

    2017-05-01

    Submicrometer TiO 2 particles, including nanoparticulate fractions, are used in an increasing variety of consumer products, as food additives and also drug delivery applications are envisaged. Beyond exposure of occupational groups, this entails an exposure risk to the public. However, nanoparticle translocation from the organ of intake and potential accumulation in secondary organs are poorly understood and in many investigations excessive doses are applied. The present study investigates the biokinetics and clearance of a low single dose (typically 40-400 μg/kg BW) of 48 V-radiolabeled, pure TiO 2 anatase nanoparticles ([ 48 V]TiO 2 NP) with a median aggregate/agglomerate size of 70 nm in aqueous suspension after intravenous (IV) injection into female Wistar rats. Biokinetics and clearance were followed from one-hour to 4-weeks. The use of radiolabeled nanoparticles allowed a quantitative [ 48 V]TiO 2 NP balancing of all organs, tissues, carcass and excretions of each rat without having to account for chemical background levels possibly caused by dietary or environmental titanium exposure. Highest [ 48 V]TiO 2 NP accumulations were found in liver (95.5%ID after one day), followed by spleen (2.5%), carcass (1%), skeleton (0.7%) and blood (0.4%). Detectable nanoparticle levels were found in all other organs. The [ 48 V]TiO 2 NP content in blood decreased rapidly after 24 h while the distribution in other organs and tissues remained rather constant until day-28. The present biokinetics study is part 1 of a series of studies comparing biokinetics after three classical routes of intake (IV injection (part 1), ingestion (part 2), intratracheal instillation (part 3)) under identical laboratory conditions, in order to test the common hypothesis that IV-injection is a suitable predictor for the biokinetics fate of nanoparticles administered by different routes. This hypothesis is disproved by this series of studies.

  10. 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.

  11. 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

  12. Quantitative biokinetics of titanium dioxide nanoparticles after oral application in rats: Part 2.

    Science.gov (United States)

    Kreyling, Wolfgang G; Holzwarth, Uwe; Schleh, Carsten; Kozempel, Ján; Wenk, Alexander; Haberl, Nadine; Hirn, Stephanie; Schäffler, Martin; Lipka, Jens; Semmler-Behnke, Manuela; Gibson, Neil

    2017-05-01

    The biokinetics of a size-selected fraction (70 nm median size) of commercially available and 48 V-radiolabeled [ 48 V]TiO 2 nanoparticles has been investigated in female Wistar-Kyoto rats at retention timepoints 1 h, 4 h, 24 h and 7 days after oral application of a single dose of an aqueous [ 48 V]TiO 2 -nanoparticle suspension by intra-esophageal instillation. A completely balanced quantitative body clearance and biokinetics in all organs and tissues was obtained by applying typical [ 48 V]TiO 2 -nanoparticle doses in the range of 30-80 μg•kg -1 bodyweight, making use of the high sensitivity of the radiotracer technique. The [ 48 V]TiO 2 -nanoparticle content was corrected for nanoparticles in the residual blood retained in organs and tissue after exsanguination and for 48 V-ions not bound to TiO 2 -nanoparticles. Beyond predominant fecal excretion about 0.6% of the administered dose passed the gastro-intestinal-barrier after one hour and about 0.05% were still distributed in the body after 7 days, with quantifiable [ 48 V]TiO 2 -nanoparticle organ concentrations present in liver (0.09 ng•g -1 ), lungs (0.10 ng•g -1 ), kidneys (0.29 ng•g -1 ), brain (0.36 ng•g -1 ), spleen (0.45 ng•g -1 ), uterus (0.55 ng•g -1 ) and skeleton (0.98 ng•g -1 ). Since chronic, oral uptake of TiO 2 particles (including a nano-fraction) by consumers has continuously increased in the past decades, the possibility of chronic accumulation of such biopersistent nanoparticles in secondary organs and the skeleton raises questions about the responsiveness of their defense capacities, and whether these could be leading to adverse health effects in the population at large. After normalizing the fractions of retained [ 48 V]TiO 2 -nanoparticles to the fraction that passed the gastro-intestinal-barrier and reached systemic circulation, the biokinetics was compared to the biokinetics determined after IV-injection (Part 1). Since the biokinetics patterns

  13. 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)

  14. 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)

  15. Biokinetic characterization of the acceleration phase in autotrophic ammonia oxidation.

    Science.gov (United States)

    Chandran, Kartik; Smets, Barth F

    2008-08-01

    Batch autotrophic ammonia oxidation tracked through oxygen uptake measurements displays a preliminary acceleration phase. Failure to recognize the acceleration phase and fitting batch ammonia oxidation profiles with standard Monod-type mathematical models can result in meaningless kinetic parameter estimates. The objectives of this study were to examine the factors controlling the acceleration phase and to derive and test empirical and metabolic models for its description. Because of possible sustained reducing power limitation during batch ammonia oxidation, the extent of the acceleration phase (1) increased with increasing initial ammonia concentration, (2) did not systematically vary with initial biomass concentrations, and (3) increased in response to starvation. Concurrent hydroxylamine oxidation significantly reduced the acceleration phase potentially by relieving reducing power limitation. A nonlinear empirical model described the acceleration phase more accurately than a linear empirical model. The metabolic model also captured experimental trends exceedingly well, but required determination of additional parameters and variables.

  16. 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.

  17. 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.

  18. 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...

  19. 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

  20. 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.)

  1. 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)

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

    DEFF Research Database (Denmark)

    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...

  3. 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

  4. Prediction of blood lead levels in children before and after remediation of soil samples in the upper Meza Valley, Slovenia.

    Science.gov (United States)

    Jez, Erika; Lestan, Domen

    2015-10-15

    The Meza Valley, Slovenia, has been contaminated by Pb smelting, resulting in an epidemic of lead poisoning in childhood. The potential of remediation with EDTA soil washing to mitigate the risk from Pb poisoning was investigated by applying the Integrated Exposure Uptake Bio-kinetic (IEUBK) model. Soils from 79 locations were collected and the total and bio-accessible Pb concentrations were determined before and after extraction with 60 mmol kg(-1) EDTA. Extraction reduced the soil Pb concentration in towns of Mezica, Zerjav and Crna by 53, 67 and 62%, respectively, and the concentration of in vitro bio-accessible Pb in the simulated human gastric phase by 2.6-, 3.2- and 2.9-times, respectively. The predictions of the IEUBK model based on Pb contamination data were verified with data on blood Pb levels in children. The IEUBK model predicted that, after soil remediation, the number of locations at which the expected blood Pb level in children was higher than the stipulated 10 μg d L(-1) would decrease by 90, 38 and 91% in the towns of Mezica, Zerjav and Crna, respectively. The results confirmed the feasibility of soil washing with EDTA as an efficient remediation measure in Mezica and Crna and advice for soil capping/removal for the most polluted town of Zerjav. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Quantitative biokinetics of titanium dioxide nanoparticles after intratracheal instillation in rats: Part 3.

    Science.gov (United States)

    Kreyling, Wolfgang G; Holzwarth, Uwe; Haberl, Nadine; Kozempel, Ján; Wenk, Alexander; Hirn, Stephanie; Schleh, Carsten; Schäffler, Martin; Lipka, Jens; Semmler-Behnke, Manuela; Gibson, Neil

    2017-05-01

    The biokinetics of a size-selected fraction (70 nm median size) of commercially available and 48 V-radiolabeled [ 48 V]TiO 2 nanoparticles has been investigated in healthy adult female Wistar-Kyoto rats at retention time-points of 1 h, 4 h, 24 h, 7 d and 28 d after intratracheal instillation of a single dose of an aqueous [ 48 V]TiO 2 -nanoparticle suspension. A completely balanced quantitative biodistribution in all organs and tissues was obtained by applying typical [ 48 V]TiO 2 -nanoparticle doses in the range of 40-240 μg·kg -1 bodyweight and making use of the high sensitivity of the radiotracer technique. The [ 48 V]TiO 2 -nanoparticle content was corrected for residual blood retained in organs and tissues after exsanguination and for 48 V-ions not bound to TiO 2 -nanoparticles. About 4% of the initial peripheral lung dose passed through the air-blood-barrier after 1 h and were retained mainly in the carcass (4%); 0.3% after 28 d. Highest organ fractions of [ 48 V]TiO 2 -nanoparticles present in liver and kidneys remained constant (0.03%). [ 48 V]TiO 2 -nanoparticles which entered across the gut epithelium following fast and long-term clearance from the lungs via larynx increased from 5 to 20% of all translocated/absorbed [ 48 V]TiO 2 -nanoparticles. This contribution may account for 1/5 of the nanoparticle retention in some organs. After normalizing the fractions of retained [ 48 V]TiO 2 -nanoparticles to the fraction that reached systemic circulation, the biodistribution was compared with the biodistributions determined after IV-injection (Part 1) and gavage (GAV) (Part 2). The biokinetics patterns after IT-instillation and GAV were similar but both were distinctly different from the pattern after intravenous injection disproving the latter to be a suitable surrogate of the former applications. Considering that chronic occupational inhalation of relatively biopersistent TiO 2 -particles (including nanoparticles) and accumulation in

  6. 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.

  7. 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.

  8. 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.

  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. Investigation of biokinetics of cadmium in the mussel in various environmental conditions

    International Nuclear Information System (INIS)

    Erdener, B.

    1982-01-01

    The biokinetics of cadmium were investigated under different environmental conditions in mussel (M. galloprovincialis) using sup(115m)Cd as tracer. The accumulation experiment was followed from water for 34 days and observed concentration factor 68 was obtained. On the other hand, it is observed that between the concentrations used in the experiment, the accumulation increased proportionally with the stable cadmium concentration in water. During depuration, more than one compartment has been observed on the loss curves carried out under different temperature and salinity. The results showed that mussels under 22-1 0 C lost cadmium more rapidly at the beginning compared with the ones under 15-1 0 C, which were kept in the same salinity, 0.21%. At the same time, the loss rates were found significantly different under different salinities. For example, the biological half-lives were 407.6 and 866.2 at the salinities 0.21% and 0.7% S respectively. The loss rate of cadmium was also followed under field condition. It is concluded that the results obtained in the field and the laboratory cannot be comparable; for example, the biological half-lives for the slow components in these two experiments were 350 and 612 days respectively. The relative distribution of cadmium in different organs and tissues are examined, it is observed that cadmium both after accumulation and loss periods, is localized in stomach hepatopancreas, gills and mantle. At the end of the accumulation experiment the highest relative percentage of cadmium was 30% in stomach, 22.7% in hepatopancreas. Likely at the end of loss periods the highest percentages of retained cadmium were 42% in stomach and 32% in hepatopancreas. (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

  12. 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)

  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. 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...... and continuous hydraulic and ammonium loading. Flowrates and flow recirculation around the column are chosen to mimic full-scale hydrodynamic conditions, and minimize axial gradients. A reference ammonium loading rate is calculated based on the average loading experienced in the active zone of the full......-scale filter. Effluent concentrations of ammonium are analyzed when the bench-scale column is subject to reference loading, from which removal rates are calculated. Subsequently, removal rates above the reference loading are measured by imposing short-term loading variations. A critical loading rate...

  16. Intratherapeutic biokinetic measurements, dosimetry parameter estimates, and monitoring of treatment efficacy using cerenkov luminescence imaging in preclinical radionuclide therapy.

    Science.gov (United States)

    Timmermand, Oskar Vilhelmsson; Tran, Thuy A; Strand, Sven-Erik; Axelsson, Johan

    2015-03-01

    In recent years, there has been increasing interest in noninvasive Cerenkov luminescence imaging (CLI) of in vivo radionuclide distribution in small animals, a method proven to be a high-throughput modality for confirmation of tracer uptake. 11B6 is an IgG1 monoclonal antibody that is specific to free human kallikrein-related peptidase 2, an antigen abundant in malignant prostatic tissue. Free human kallikrein-related peptidase 2 was targeted in prostate cancer xenografts using (177)Lu-labeled 11B6 in either murine or humanized forms for radionuclide therapy. In this setting, CLI was investigated as a tool for providing parameters of dosimetric importance during radionuclide therapy. First, longitudinal imaging of biokinetics using CLI and SPECT was compared. Second, the CLI signal was correlated to quantitative ex vivo tumor activity measurements. Finally, CLI was used to monitor the radionuclide treatment, and the integrated CLI radiance was found to correlate well with subject-specific tumor volume reduction. 11B6 was radiolabeled with (177)Lu through the CHX-A″-DTPA chelator. In vivo CLI and SPECT imaging of (177)Lu-DTPA-11B6 uptake was performed on NMRI and BALB/c nude mice with subcutaneous LNCaP xenografts up to 14 d after injection. Tumor size was measured to assess response to radionuclide therapy. CLI correlated well with SPECT imaging and could be applied up to 14 d after injection of 20 MBq with the specific tracer used. Through integration of the CLI radiance as a function of time, a dose metric for the tumors could be formed that correlated exponentially with tumor volume reduction. CLI provided valuable intratherapeutic biokinetic measurements for treatment monitoring and could be used as a tool for subject-specific absorbed dose estimation. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  17. 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)

  18. 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

  19. In vitro and in vivo interactions of selected nanoparticles with rodent serum proteins and their consequences in biokinetics

    Directory of Open Access Journals (Sweden)

    Wolfgang G. Kreyling

    2014-10-01

    Full Text Available When particles incorporated within a mammalian organism come into contact with body fluids they will bind to soluble proteins or those within cellular membranes forming what is called a protein corona. This binding process is very complex and highly dynamic due to the plethora of proteins with different affinities and fractions in different body fluids and the large variation of compounds and structures of the particle surface. Interestingly, in the case of nanoparticles (NP this protein corona is well suited to provide a guiding vehicle of translocation within body fluids and across membranes. This NP translocation may subsequently lead to accumulation in various organs and tissues and their respective cell types that are not expected to accumulate such tiny foreign bodies. Because of this unprecedented NP accumulation, potentially adverse biological responses in tissues and cells cannot be neglected a priori but require thorough investigations. Therefore, we studied the interactions and protein binding kinetics of blood serum proteins with a number of engineered NP as a function of their physicochemical properties. Here we show by in vitro incubation tests that the binding capacity of different engineered NP (polystyrene, elemental carbon for selected serum proteins depends strongly on the NP size and the properties of engineered surface modifications. In the following attempt, we studied systematically the effect of the size (5, 15, 80 nm of gold spheres (AuNP, surface-modified with the same ionic ligand; as well as 5 nm AuNP with five different surface modifications on the binding to serum proteins by using proteomics analyses. We found that the binding of numerous serum proteins depended strongly on the physicochemical properties of the AuNP. These in vitro results helped us substantially in the interpretation of our numerous in vivo biokinetics studies performed in rodents using the same NP. These had shown that not only the

  20. Integration of the predictions of two models with dose measurements in a case study of children exposed to the emissions of a lead smelter

    Energy Technology Data Exchange (ETDEWEB)

    Bonnard, R.; McKone, T.E.

    2009-03-01

    The predictions of two source-to-dose models are systematically evaluated with observed data collected in a village polluted by a currently operating secondary lead smelter. Both models were built up from several sub-models linked together and run using Monte-Carlo simulation, to calculate the distribution children's blood lead levels attributable to the emissions from the facility. The first model system is composed of the CalTOX model linked to a recoded version of the IEUBK model. This system provides the distribution of the media-specific lead concentrations (air, soil, fruit, vegetables and blood) in the whole area investigated. The second model consists of a statistical model to estimate the lead deposition on the ground, a modified version of the model HHRAP and the same recoded version of the IEUBK model. This system provides an estimate of the concentration of exposure of specific individuals living in the study area. The predictions of the first model system were improved in terms of accuracy and precision by performing a sensitivity analysis and using field data to correct the default value provided for the leaf wet density. However, in this case study, the first model system tends to overestimate the exposure due to exposed vegetables. The second model was tested for nine children with contrasting exposure conditions. It managed to capture the blood levels for eight of them. In the last case, the exposure of the child by pathways not considered in the model may explain the failure of the model. The interest of this integrated model is to provide outputs with lower variance than the first model system, but at the moment further tests are necessary to conclude about its accuracy.

  1. 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)

  2. 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

  3. 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)

  4. 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.)

  5. 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)

  6. 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.)

  7. 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)

  8. 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)

  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. 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.

  11. Development of a mechanistic biokinetic model for hepatic bile acid handling to predict possible cholestatic effects of drugs

    NARCIS (Netherlands)

    Notenboom, Sylvia; Weigand, Karl M; Proost, Johannes H; van Lipzig, Marola M H; van de Steeg, Evita; van den Broek, Petra H H; Greupink, Rick; Russel, Frans G M; Groothuis, Geny M M

    2018-01-01

    Drug-induced liver injury (DILI) is a common reason for drug withdrawal from the market. An important cause of DILI is drug-induced cholestasis. One of the major players involved in drug-induced cholestasis is the bile salt efflux pump (BSEP; ABCB11). Inhibition of BSEP by drugs potentially leads to

  12. 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

  13. 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

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

    Directory of Open Access Journals (Sweden)

    José Willegaignon

    2016-06-01

    Full Text Available Abstract Objective: To compare the probe detection method with the image quantification method when estimating 131I 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 131I to each individual. Whole-body scans and probe measurements were performed at 4, 24, 48, 72, and 96 h after 131I administration in order to estimate the effective half-life (Teff and residence time of 131I in the body. Results: The mean values for Teff 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 Teff (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 131I administration (p > 0.914. Conclusion: There is full agreement as to the feasibility of using probe detection and image quantification when estimating 131I biokinetics and red-marrow/whole-body doses. However, because the probe detection method is inefficacious in identifying tumor sites and critical organs during radionuclide therapy and therefore liable to skew adjustment of the amount of 131I to be administered to patients under such therapy, it should be used with caution.

  15. 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

  16. 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)

  17. 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...

  18. ASM1-based activated sludge model with biopolymer kinetics for integrated simulation of membrane bioreactors for wastewater treatment

    OpenAIRE

    Janus, Tomasz; Ulanicki, Bogumil

    2015-01-01

    This paper presents an activated sludge model suitable for modelling membrane bioreactors (MBRs) for wastewater treatment. The model, later referred to as combined EPS and SMP production ASM1-based model (CES-ASM1), extends Activated Sludge Model No. 1 (ASM1) with biokinetics of two types of bacterial biopolymers: soluble microbial products (SMP) and extracellular polymeric substances (EPS). The biopolymer kinetics in CES-ASM1 are, in their majority, borrowed from Laspidou and Rittmann[1] ...

  19. Biogeochemical characterization of municipal compost to support urban agriculture and limit childhood lead exposure from resuspended urban soils

    Directory of Open Access Journals (Sweden)

    Maia G. Fitzstevens

    2017-09-01

    Full Text Available Chronic low-level lead exposure among low-income minority children is an urgent environmental justice issue. Addressing this ubiquitous urban public health crisis requires a new transdisciplinary paradigm. The primary goals of this work are to inform best practices for urban gardeners working in lead contaminated soils and to reimagine urban organic waste management schemes to produce compost, which when covering or mixed with urban soil, could minimize lead exposure. We investigate bulk and bioaccessible lead from five types of compost used in urban gardens in Boston, MA. We categorized them by feedstock and measured bulk elemental concentrations and physical characteristics. Our results show that different feedstocks exhibit unique geochemical fingerprints. While bulk lead concentrations in compost are a fraction of what is typical for urban soils, the bioaccessible lead fraction in compost is greater than the default parameters for the Integrated Exposure Uptake Biokinetic (IEUBK model. The lack of geochemical differences across feedstocks for lead sorption to carbon indicates a similar sorption mechanism for all compost. This suggests that municipal compost would be suitable for capping lead contaminated urban soils. Risk assessment models should consider lead bioaccessibility, to prevent the underprediction of exposure risk, and should include compost along with soils as urban matrices. Based on the observed bioaccessibility in our compost samples, 170 mg/kg total lead in compost will yield the same bioaccessible lead as the IEUBK model predicts for the 400 mg/kg EPA soil lead benchmark. Local logistical challenges remain for interdisciplinary teams of city planners, exposure scientists, and urban agricultural communities to design organic waste collection practices to produce compost that will support urban agriculture and primary lead exposure prevention.

  20. Population balance models: a useful complementary modelling framework for future WWTP modelling

    DEFF Research Database (Denmark)

    Nopens, Ingmar; Torfs, Elena; Ducoste, Joel

    2015-01-01

    efforts of several current and future unit processes in wastewater treatment plants could potentially benefit from this framework, especially when distributed dynamics have a significant impact on the overall unit process performance. In these cases, current models that rely on average properties cannot...... capability. Hence, PBMs should be regarded as a complementary modelling framework to biokinetic models. This paper provides an overview of current applications, future potential and limitations of PBMs in the field of wastewater treatment modelling, thereby looking over the fence to other scientific...

  1. 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

  2. Biokinetics of ultrafine gold nanoparticles (AuNPs) relating to redistribution and urinary excretion: a long-term in vivo study.

    Science.gov (United States)

    Naz, Farhat; Koul, Veena; Srivastava, Amita; Gupta, Yogendra Kumar; Dinda, Amit Kumar

    2016-09-01

    Gold nanoparticles (AuNPs) of ultrafine size have drawn attention for their use in drug delivery systems. Tissue toxicity may be an issue when AuNPs are used for such applications. We investigated the long-term biokinetics (90 d), redistribution, and urinary excretion of three different-sized (2 ± 0.5 nm, 5 ± 1 nm, and 10 ± 2 nm) AuNPs after a single intravenous (i.v.) administration of 1250 µg/kg dose in mice. ICP-AES analysis of lungs, liver, spleen, heart, kidney, brain, blood, and urine revealed highest accumulation of gold in spleen around 15 d after injection. A low concentration was detected in brain after 1 d without any residual AuNPs after 30 d. Ultrastructural study of brain tissue also showed few AuNPs in lysosome with no changes in cellular architecture. Renal retention of AuNPs was limited indicating low nephrotoxic potential. AuNPs were detectable in urine till 30 d after single injection indicating slow excretion from the body. No evidence of significant toxicity was observed in hemogram, serum biochemistry, and tissue histology. No mortality, changes in behavior, hair color, weight, and food intake was observed as compared to control mice. Therefore, we conclude that the ultrafine AuNPs are predominantly excreted in urine without any systemic toxicity following i.v. administration and are hence safe for use in drug delivery systems.

  3. 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)

  4. Kinetic Modeling of Dye Effluent Biodegradation by Pseudomonas Stutzeri

    Directory of Open Access Journals (Sweden)

    N. Rajamohan

    2013-04-01

    Full Text Available Dye industry waste water is difficult to treat because of the presence of dyes with complex aromatic structure. In this research study, the biodegradation studies of dye effluent were performed utilizing Pseudomonas stutzeri in a controlled laboratory environment under anoxic conditions. The effects of operational parameters like initial pH of the effluent and initial Chemical Oxygen Demand (COD of the effluent on percentage COD removal were studied. A biokinetic model is established giving the dependence of percentage COD removal on biomass concentration and initial COD of the effluent. The biokinetics of the COD removal was found to be first order with respect to both the microbial concentration and initial COD of the effluent. The optimal pH for better bacterial degradation was found to be 8.The specific degradation rate was found to be 0.1417 l/g Dry Cell Mass (DCM h, at 320 C.

  5. A physiological systems model for iodine for use in radiation protection

    International Nuclear Information System (INIS)

    Leggett, Richard Wayne

    2010-01-01

    This paper summarizes the biokinetic database for iodine in the human body and proposes a biokinetic model for use in dose assessments for radioiodine. The model unifies and extends existing physiological systems models describing three subsystems of the iodine cycle in the body: circulating (extrathyroidal) inorganic iodide; thyroidal iodine (trapping and organic binding of iodide, and synthesis, storage, and secretion of thyroid hormones); and extrathyroidal organic iodine. Thyroidal uptake of iodide is described as a function of daily stable iodine intake and requirements for thyroid hormones. Baseline parameter values are developed for adults with typical iodine intakes and hormone requirements. Estimated thyroid doses derived from the baseline parameter values and reference thyroid weights are higher than values predicted by the current model of the International Commission on Radiological Protection (ICRP) for adults for intake of iodine isotopes with half-lives up to a few hours but consistent with ICRP predictions for longer-lived isotopes. For nearly all iodine isotopes, the proposed model yields order-of-magnitude differences from the ICRP's current iodine model for adults for stomach wall, salivary gland, and kidneys. Dose estimates for intravenously injected 131I-labeled thyroid hormones based on the present model differ substantially from current ICRP values for adult patients for some organs, including the thyroid. Subsequent studies will address age-specific biokinetics of iodine, reduction of doses from radioiodine due to thyroid blocking, and effects of dietary iodine levels and thyroid hormone requirements on thyroid doses from radioiodine.

  6. A physiological systems model for iodine for use in radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL

    2010-01-01

    This paper summarizes the biokinetic database for iodine in the human body and proposes a biokinetic model for use in dose assessments for radioiodine. The model unifies and extends existing physiological systems models describing three subsystems of the iodine cycle in the body: circulating (extrathyroidal) inorganic iodide; thyroidal iodine (trapping and organic binding of iodide, and synthesis, storage, and secretion of thyroid hormones); and extrathyroidal organic iodine. Thyroidal uptake of iodide is described as a function of daily stable iodine intake and requirements for thyroid hormones. Baseline parameter values are developed for adults with typical iodine intakes and hormone requirements. Estimated thyroid doses derived from the baseline parameter values and reference thyroid weights are higher than values predicted by the current model of the International Commission on Radiological Protection (ICRP) for adults for intake of iodine isotopes with half-lives up to a few hours but consistent with ICRP predictions for longer-lived isotopes. For nearly all iodine isotopes, the proposed model yields order-of-magnitude differences from the ICRP s current iodine model for adults for stomach wall, salivary gland, and kidneys. Dose estimates for intravenously injected 131I-labeled thyroid hormones based on the present model differ substantially from current ICRP values for adult patients for some organs, including the thyroid. Subsequent studies will address age-specific biokinetics of iodine, reduction of doses from radioiodine due to thyroid blocking, and effects of dietary iodine levels and thyroid hormone requirements on thyroid doses from radioiodine.

  7. 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.

  8. Sentinel lymph node diagnostic in prostate carcinoma. Part II. Biokinetics and dosimetry of 99mTc-nanocolloid after intraprostatic injection

    International Nuclear Information System (INIS)

    Wengenmair, H.; Kopp, J.; Vogt, H.; Groeber, S.; Dorn, R.; Heidenreich, P.; Wawroschek, F.

    2002-01-01

    Aim: To visualise the sentinel lymph nodes (SLNs) of the prostate we injected the radiotracer into the parenchyma of the prostate. The activity was deposited in liver, spleen, bone marrow, urinary bladder and regional lymphatic system. The aim of this work is to determine biokinetical data and to estimate radiation doses to the patient. Methods: The patients with prostate cancer received a sonographically controlled, transrectal administration of 99m Tc-Nanocoll trademark, injected directly into both prostate lobes. In 10 randomly selected patients radionuclide distribution and its time course was determined via regions of interest (ROIs) over prostate, urinary bladder, liver, spleen and the lymph nodes. The uptake in the SLNs was estimated from gamma probe measurements at the surgically removed nodes. To compare tumour positive with tumour free lymph nodes according to SLN-uptake and SLN-localisation we evaluated 108 lymph nodes out of 24 patients with tumour positive SLN. For calculating the effective dose according to ICRP 60 of the patients we used the MIRD-method and the Mirdose 3.1 software. Results: The average uptake of separate organs was: bladder content 24%, liver 25.5%, spleen 2%, sum of SLN 0.5%. An average of 9% of the applied activity remained in the prostate. The residual activity was mainly accumulated in bone marrow and blood. Occasionally a weak activity enrichment in intestinal tract and kidneys could be recognized. The effective dose to the patient was estimated to 7.6 μSv/MBq. The radioactivity uptake of the SLN varied in several orders of magnitude between 0.006% and 0.6%. The probability of SLN-metastasis was found to be independent from tracer uptake in the lymph node. The radioactivity uptake of the SLNs in distinct lymph node regions showed no significant differences. Conclusion: The radiotracer is transferred out of the prostate via blood flow, by direct transfer via the urethra into the bladder and by lymphatic transport. Injecting a

  9. 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)

  10. 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)

  11. Mathematical Modeling of Hollow-Fiber Membrane System in Biological Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Jian PENG

    2006-02-01

    Full Text Available A set of mathematical models were derived based on the bio-kinetics and material balance principles to describe the performance of membrane system in this research. A synthetic wastewater and a meat packing wastewater were processed through a lab-scale membrane bioreactor system to generate experimental data for calibration and verification of the derived models. For the synthetic wastewater treatment, a high and stable Total Organic Carbon (TOC removal was achieved with volumetric organic loading from 0.2 to 24.2 kg TOC/m3ƒ(d. It was found that the derived system models fit the experimental data well. The bio-kinetic coefficients of k, Ks, Y and kd in the models were found to be 0.16 d-1, 1.0 mg/L, 1.75 mg Mixed Liquor Volatile Suspended Solids (MLVSS/mg TOC and 0.11 d-1, respectively. For the meat packing wastewater treatment, the bio-kinetic coefficients of k, Ks, Y and kd were found to be 0.48 d-1, 56.3 mg/L, 0.53 mg MLVSS/mg COD and 0.04 d-1, respectively. F/M ratio of 0.08 was found to be the proper operating condition for the system. Based on the proposed system models, the optimum MLSS concentration and F/M ratio can be computed to yield minimum cost of a membrane bioreactor system without excess biomass production.

  12. 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

  13. 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)

  14. 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)

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

    DEFF Research Database (Denmark)

    Plósz, Benedek; De Clercq, Jeriffa; Nopens, Ingmar

    2011-01-01

    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 Taka´ cs...... 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...

  16. 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

  17. 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.,

  18. 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

  19. 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.

  20. 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

  1. 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)

  2. 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)

  3. A systematic approach for model verification: application on seven published activated sludge models.

    Science.gov (United States)

    Hauduc, H; Rieger, L; Takács, I; Héduit, A; Vanrolleghem, P A; Gillot, S

    2010-01-01

    The quality of simulation results can be significantly affected by errors in the published model (typing, inconsistencies, gaps or conceptual errors) and/or in the underlying numerical model description. Seven of the most commonly used activated sludge models have been investigated to point out the typing errors, inconsistencies and gaps in the model publications: ASM1; ASM2d; ASM3; ASM3 + Bio-P; ASM2d + TUD; New General; UCTPHO+. A systematic approach to verify models by tracking typing errors and inconsistencies in model development and software implementation is proposed. Then, stoichiometry and kinetic rate expressions are checked for each model and the errors found are reported in detail. An attached spreadsheet (see http://www.iwaponline.com/wst/06104/0898.pdf) provides corrected matrices with the calculations of all stoichiometric coefficients for the discussed biokinetic models and gives an example of proper continuity checks.

  4. 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

  5. Good modelling practice in applying computational fluid dynamics for WWTP modelling.

    Science.gov (United States)

    Wicklein, Edward; Batstone, Damien J; Ducoste, Joel; Laurent, Julien; Griborio, Alonso; Wicks, Jim; Saunders, Stephen; Samstag, Randal; Potier, Olivier; Nopens, Ingmar

    2016-01-01

    Computational fluid dynamics (CFD) modelling in the wastewater treatment (WWT) field is continuing to grow and be used to solve increasingly complex problems. However, the future of CFD models and their value to the wastewater field are a function of their proper application and knowledge of their limits. As has been established for other types of wastewater modelling (i.e. biokinetic models), it is timely to define a good modelling practice (GMP) for wastewater CFD applications. An International Water Association (IWA) working group has been formed to investigate a variety of issues and challenges related to CFD modelling in water and WWT. This paper summarizes the recommendations for GMP of the IWA working group on CFD. The paper provides an overview of GMP and, though it is written for the wastewater application, is based on general CFD procedures. A forthcoming companion paper to provide specific details on modelling of individual wastewater components forms the next step of the working group.

  6. 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)

  7. 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)

  8. Physiologically based pharmacokinetic modeling of 18F-SiFAlin-Asp3-PEG1-TATE in AR42J tumor bearing mice

    International Nuclear Information System (INIS)

    Maaß, Christian; Rivas, Jose Ricardo Avelar; Attarwala, Ali Asgar; Hardiansyah, Deni; Niedermoser, Sabrina; Litau, Shanna; Wängler, Carmen; Wängler, Björn; Glatting, Gerhard

    2016-01-01

    Purpose: Peptide receptor radionuclide therapy (PRRT) is commonly performed in the treatment of neuroendocrine tumors (NET), where somatostatin analogs (DOTATATE) are radiolabeled with 90 Y, 68 Ga or 111 In for pre-therapeutic and therapeutic purposes. Quantitative evaluation of the biokinetic data can be performed by using physiologically based pharmacokinetic (PBPK) models. Knowledge about the biodistribution in a pre-clinical setting would allow optimizing the translation from bench to bedside. The aim of this study was to develop a PBPK model to describe the biodistribution of a novel sst2-targeting radiotracer. Methods: Biokinetic data of six mice after injection of 18 F-SiFAlin-Asp 3 -PEG 1 -TATE were investigated using two PBPK models. The PBPK models describe the biodistribution of the tracer in the tumor, kidneys, liver, remainder and whole body via blood flow to these organs via absorption, distribution, metabolism and excretion. A recently published sst2 PBPK model for humans (model 1) was used to describe the data. Physiological information in this model was adapted to that of a mouse. Model 1 was further modified by implementing receptor-mediated endocytosis (model 2). Model parameters were fitted to the biokinetic data of each mouse. Model selection was performed by calculating Akaike weights w i using the corrected Akaike Information Criterion (AICc). Results: The implementation of receptor-mediated endocytosis considerably improved the description of the biodistribution (Akaike weights w 1 = 0% and w 2 = 100% for model 1 and 2, respectively). The resulting time-integrated activity coefficients determined by model 2 were for tumor (0.05 ± 0.02) h, kidneys (0.11 ± 0.01) h and liver (0.02 ± 0.01) h. Conclusion: Simply downscaling a human PBPK model does not allow for an accurate description of 18 F-SiFAlin-Asp 3 -PEG 1 -TATE in mice. Biokinetics of this tracer can be accurately and adequately described using a physiologically based pharmacokinetic

  9. 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)

  10. 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.

  11. 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

  12. 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)

  13. 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)

  14. Optimization of GATE simulations for whole-body planar scintigraphic acquisitions using the XCAT male phantom with177Lu-DOTATATE biokinetics in a Siemens Symbia T2.

    Science.gov (United States)

    Costa, G C A; Bonifácio, D A B; Sarrut, D; Cajgfinger, T; Bardiès, M

    2017-10-01

    Simulations of planar whole body acquisitions in therapeutic procedures are often extensively time-consuming and therefore rarely used. However, optimising tools and variance reduction techniques can be employed to overcome this problem. In this paper, a variety of features available in GATE are explored and their capabilities to reduce simulation time are evaluated. For this purpose, the male XCAT phantom was used as a virtual patient with 177 Lu-DOTATATE pharmacokinetic for whole body planar acquisition simulations in a Siemens Symbia T2 model. Activity distribution was divided into 8 compartments that were simulated separately. GATE optimization techniques included reducing the amount of time spent in both voxel and detector tracking. Some acceleration techniques led to a decrease of CPU-time by a factor of 167, while image statistics were kept constant. In that context, the simulation of therapeutic procedure imaging would still require 46days on a single CPU, but this could be reduced to hours on a dedicated cluster. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. Use of simulated epithelial lung fluid in assessing the human health risk of Pb in urban street dust.

    Science.gov (United States)

    Dean, John R; Elom, Nwabueze I; Entwistle, Jane A

    2017-02-01

    In many urban contexts, non-dietary Pb exposure from street dusts may add to the overall exposure burden, and the presence of high total Pb content is well documented in urban street dust from across the globe. Given the increasing recognition of the potential adverse health effects from both the quantity and the chemical and physical composition of the inhaled fraction, and the recognition that it is the soluble fraction rather than the total element content that has more direct links to health effects, attention has focused in this study on the human health risks via this exposure pathway. In order to investigate the environmental exposure to Pb from the inhalation of urban street dusts, a newly developed in vitro simulated epithelium lung fluid (SELF) has been applied to the <10μm fraction of urban street dusts. In this context, 21 urban street dust samples, across five UK cities, were selected based on their high pseudo-total Pb content. The work revealed that inhalation bioaccessibility, and hence inhalation dose, varied across the cities but was generally found to be low (<10%). Indeed, the lung bioaccessibility was far lower (% lung bioaccessibility ranged from 1.2 to 8.8) than is currently applied in two of the most commonly employed risk assessment models i.e. the Integrated Exposure Uptake Biokinetic model (IEUBK, USA) and the Contaminated Land Exposure Assessment model (CLEA, UK). The estimated inhalation dose (for adults) calculated from the PM10 bioaccessibility ranged from 7ngkg -1 BW day -1 (Edinburgh) to 1.3ngkg -1 BW day -1 (Liverpool). The results indicate a low potential inhalation bioaccessibility for Pb in these urban street dust samples when modelled using the neutral pH conditions of the SELF. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Biokinetics and Biodynamics of Nanomaterial Interactions

    Science.gov (United States)

    2009-09-30

    onspecific interactions between the Ag NP ncrease in absorbance at the highest dosing P. The unwashed 20nm (Figure 5a), 50nm significant increase in...the molecular interactions of the probe compounds with the surface of the nanoparticle. The competitive adsorption of the diverse compounds reveals the...MNM) and its interaction with biological systems, very complicated adsorption mechanisms could be involved (e.g. competitive probe adsorption

  17. 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......, 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...... a different optimum parameter selection for the calibration of WWTP models when either of the 1-D SST models is used. Using first-order models, the calibration should give equal importance to the adjustment of the hindered settling and slow settling parameter values. The adjusted hindered settling parameters...

  18. 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

  19. Bioaccessibility of Pb from ammunition in game meat is affected by cooking treatment.

    Science.gov (United States)

    Mateo, Rafael; Baos, Ana R; Vidal, Dolors; Camarero, Pablo R; Martinez-Haro, Monica; Taggart, Mark A

    2011-01-14

    The presence of lead (Pb) ammunition residues in game meat has been widely documented, yet little information exists regarding the bioaccessibility of this Pb contamination. We study how cooking treatment (recipe) can affect Pb bioaccessibility in meat of animals hunted with Pb ammunition. We used an in vitro gastrointestinal simulation to study bioaccessibility. The simulation was applied to meat from red-legged partridge (Alectoris rufa) hunted with Pb shot pellets and cooked using various traditional Spanish game recipes involving wine or vinegar. Total Pb concentrations in the meat were higher in samples with visible Pb ammunition by X-ray (mean±SE: 3.29±1.12 µg/g w.w.) than in samples without this evidence (1.28±0.61 µg/g). The percentage of Pb that was bioaccessible within the simulated intestine phase was far higher in meat cooked with vinegar (6.75%) and wine (4.51%) than in uncooked meat (0.7%). Risk assessment simulations using our results transformed to bioavailability and the Integrated Exposure Uptake Biokinetic model (IEUBK; US EPA) show that the use of wine instead of vinegar in cooking recipes may reduce the percentage of children that would be expected to have >10 µg/dl of Pb in blood from 2.08% to 0.26% when game meat represents 50% of the meat in diet. Lead from ammunition in game meat is more bioaccessible after cooking, especially when using highly acidic recipes. These results are important because existing theoretical models regarding Pb uptake and subsequent risk in humans should take such factors into account.

  20. A plant wide aqueous phase chemistry model describing pH variations and ion speciation/pairing in wastewater treatment process models

    DEFF Research Database (Denmark)

    Flores-Alsina, X.; Mbamba, C. Kazadi; Solon, K.

    /pairing is presented and interfaced with industry standard models. The module involves extensive consideration of non-ideality by 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......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 (Batstone et al., 2012). Indeed, future modelling needs, such as a plant-wide phosphorus (P) description...... 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 of the most frequently used WWTP process simulation models. Finally, it is shown how traditional wastewater modelling studies can...

  1. 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

  2. Biofilm carrier migration model describes reactor performance.

    Science.gov (United States)

    Boltz, Joshua P; Johnson, Bruce R; Takács, Imre; Daigger, Glen T; Morgenroth, Eberhard; Brockmann, Doris; Kovács, Róbert; Calhoun, Jason M; Choubert, Jean-Marc; Derlon, Nicolas

    2017-06-01

    The accuracy of a biofilm reactor model depends on the extent to which physical system conditions (particularly bulk-liquid hydrodynamics and their influence on biofilm dynamics) deviate from the ideal conditions upon which the model is based. It follows that an improved capacity to model a biofilm reactor does not necessarily rely on an improved biofilm model, but does rely on an improved mathematical description of the biofilm reactor and its components. Existing biofilm reactor models typically include a one-dimensional biofilm model, a process (biokinetic and stoichiometric) model, and a continuous flow stirred tank reactor (CFSTR) mass balance that [when organizing CFSTRs in series] creates a pseudo two-dimensional (2-D) model of bulk-liquid hydrodynamics approaching plug flow. In such a biofilm reactor model, the user-defined biofilm area is specified for each CFSTR; thereby, X carrier does not exit the boundaries of the CFSTR to which they are assigned or exchange boundaries with other CFSTRs in the series. The error introduced by this pseudo 2-D biofilm reactor modeling approach may adversely affect model results and limit model-user capacity to accurately calibrate a model. This paper presents a new sub-model that describes the migration of X carrier and associated biofilms, and evaluates the impact that X carrier migration and axial dispersion has on simulated system performance. Relevance of the new biofilm reactor model to engineering situations is discussed by applying it to known biofilm reactor types and operational conditions.

  3. Population balance models: a useful complementary modelling framework for future WWTP modelling.

    Science.gov (United States)

    Nopens, Ingmar; Torfs, Elena; Ducoste, Joel; Vanrolleghem, Peter A; Gernaey, Krist V

    2015-01-01

    Population balance models (PBMs) represent a powerful modelling framework for the description of the dynamics of properties that are characterised by distributions. This distribution of properties under transient conditions has been demonstrated in many chemical engineering applications. Modelling efforts of several current and future unit processes in wastewater treatment plants could potentially benefit from this framework, especially when distributed dynamics have a significant impact on the overall unit process performance. In these cases, current models that rely on average properties cannot sufficiently capture the true behaviour and even lead to completely wrong conclusions. Examples of distributed properties are bubble size, floc size, crystal size or granule size. In these cases, PBMs can be used to develop new knowledge that can be embedded in our current models to improve their predictive capability. Hence, PBMs should be regarded as a complementary modelling framework to biokinetic models. This paper provides an overview of current applications, future potential and limitations of PBMs in the field of wastewater treatment modelling, thereby looking over the fence to other scientific disciplines.

  4. 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...... 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....... The outcome of this study contributes to a better understanding of uncertainty in WWTPs, and explicitly demonstrates the significance of secondary settling processes that are crucial elements of model prediction under dry and wet-weather loading conditions....

  5. 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.

  6. 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).

  7. Computer modelling of the chemical speciation of lanthanide and actinide elements in the human gastrointestinal tract

    International Nuclear Information System (INIS)

    Webb, L.M.; Taylor, D.M.; Williams, D.R.

    1998-01-01

    Joint expert speciation system (JESS) computer modelling is used to produce biokinetic models of the gastrointestinal tract, for the radiation dose from internally deposited radionuclides to be calculated. Preliminary estimations of the interactions of Gd and Cm with all the metal binding species present in the small intestine, i.e. bile and pancreatic fluid, over a pH range of pH 5.0-9.0, have been made. The development of the models and these initial validation results for the use of Gd as a surrogate for Cm, will be presented and discussed. From these aqueous studies it appears that the use of Gd as a surrogate for Cm in bile or pancreatic fluid is doubtful. However, further speciation modelling, incorporating solids, is in process to confirm these findings. (orig.)

  8. 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

  9. 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.

  10. 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.

  11. 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)

  12. 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

  13. 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

    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...... 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...... 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...

  14. A plant-wide aqueous phase chemistry module describing pH variations and ion speciation/pairing in wastewater treatment process models

    DEFF Research Database (Denmark)

    Flores Alsina, Xavier; Kazadi Mbamba, Christian; Solon, Kimberly

    2015-01-01

    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......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...... 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 of the most frequently used WWTP process simulation models. Finally, it is shown how traditional wastewater modelling...

  15. Models and phantoms for internal dose assessment

    International Nuclear Information System (INIS)

    Giussani, Augusto

    2015-01-01

    Radiation doses delivered by incorporated radionuclides cannot be directly measured, and they are assessed by means of biokinetic and dosimetric models and computational phantoms. For emitters of short-range radiation like alpha-particles or Auger electrons, the doses at organ levels, as they are usually defined in internal dosimetry, are no longer relevant. Modelling the inter- and intra-cellular radiation transport and the local patterns of deposition at molecular or cellular levels are the challenging tasks of micro- and nano-dosimetry. With time, the physiological and anatomical realism of the models and phantoms have increased. However, not always the information is available that would be required to characterise the greater complexity of the recent models. Uncertainty studies in internal dose assessment provide here a valuable contribution for testing the significance of the new dose estimates and of the discrepancies from the previous values. Some of the challenges, limitations and future perspectives of the use of models and phantoms in internal dosimetry are discussed in the present manuscript. (authors)

  16. {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)

  17. 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)

  18. {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)

  19. 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)

  20. 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.)

  1. Characterization and modeling of nutrient-deficient tomato-processing wastewater treatment using an anaerobic/aerobic system.

    Science.gov (United States)

    Xu, Zhongda; Nakhla, George; Patel, Jignesh

    2006-11-01

    Tomato-processing wastewaters are typical of slowly biodegradable high strength wastewaters generated from the food canning industry. Three different samples of influent and three samples of anaerobic effluents corresponding to the three influents collected from an on-site pilot-scale anaerobic/aerobic system were characterized using respirometric methods. Respirometric studies demonstrated that the pretreatment in the anaerobic reactor of the pilot-scale system increased the readily biodegradable fraction from an average of 40% of the SCOD in the influent to 50% of the SCOD in the anaerobic effluent, improved kinetics from an average micro(max) of 1.5d(-1) in the influent to 3.5d(-1) in the anaerobic effluent, and eliminated nutrient deficiency. Furthermore, the system was calibrated and simulated by application of wastewater characterization and biokinetic data derived form respirometric tests of influent and anaerobic effluent in Activated Sludge Model no.1 (ASM1).

  2. Automated workflows for modelling chemical fate, kinetics and toxicity.

    Science.gov (United States)

    Sala Benito, J V; Paini, Alicia; Richarz, Andrea-Nicole; Meinl, Thorsten; Berthold, Michael R; Cronin, Mark T D; Worth, Andrew P

    2017-12-01

    Automation is universal in today's society, from operating equipment such as machinery, in factory processes, to self-parking automobile systems. While these examples show the efficiency and effectiveness of automated mechanical processes, automated procedures that support the chemical risk assessment process are still in their infancy. Future human safety assessments will rely increasingly on the use of automated models, such as physiologically based kinetic (PBK) and dynamic models and the virtual cell based assay (VCBA). These biologically-based models will be coupled with chemistry-based prediction models that also automate the generation of key input parameters such as physicochemical properties. The development of automated software tools is an important step in harmonising and expediting the chemical safety assessment process. In this study, we illustrate how the KNIME Analytics Platform can be used to provide a user-friendly graphical interface for these biokinetic models, such as PBK models and VCBA, which simulates the fate of chemicals in vivo within the body and in vitro test systems respectively. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. A comprehensive approach to age-dependent dosimetric modeling

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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

  5. 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

  6. Study of the biokinetic behavior of {sup 99m}Tc-DMSA in renal scintigraphy of pediatric patients; Estudo de comportamento biocinetico do {sup 99m}Tc-DMSA em cintilografia renal de pacientes pediatricos

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Felipe Simas dos

    2013-07-01

    In Brazil, renal studies with {sup 99m}Tc{sub D}TPA and {sup 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 {sup 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 {sup 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 {sup 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{sub 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

  7. Bioavailability of Lead in Small Arms Range Soils

    Science.gov (United States)

    2007-09-01

    regardless of the end use. The IEUBK model, which is currently undergoing revision so that it can be used for all ages, rather than just children ...the oral absorption fraction ( AFo ). Relative bioavailability (RBA) is the ratio of the absolute bioavailability of lead present in some test...absorption for children over adults, a distinction with which we agree, since children absorb more lead than adults, and are also more vulnerable to

  8. 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.

  9. 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

  10. 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.

  11. 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)

  12. 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...

  13. 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

  14. Upon biodistribution and biokinetics of radioiodine-labelled diethylstilbestroldiphosphate

    International Nuclear Information System (INIS)

    Mende, T.; Wollny, G.; Gens, J.; Franke, W.G.; Schubert, J.; Kelly, L.U.

    1983-01-01

    Radioiodine-labelled ( 131 I, 125 I, 123 I) diethylstilbestroldiphosphate (DES) was investigated with respect to measuring radio-labelled hormone derivatives in animals and men. DES was injected intravenously in Wistar rats and mammatumor-bearing mice (Carcinoma solidum simplex), and activities were measured in several organs between 10 minutes and 7 days, p.inj. The liver showed strong activity concentration and long-lasting retention, smaller concentrations were found in kidneys, adrenals, blood, abdominal wall and prostate. The tumor concentration between 10 minutes and 15 hours p.inj. was below the blood concentrations and later on up to 7 days in the order of the blood concentrations, however, always significantly exceeding muscle tissue concentrations. Respective measurements were done in men using tissue cylinders from the prostate gained by puncture-biopsy or other tissue specimens gained during surgery. Activity concentration in the liver is high, therefore the scintigraphic visualization of the liver is possible immediately after injection up to 13 days later. Potentially it is a receptor-sensitive scintigraphy of the liver. (orig.) [de

  15. 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.

  16. 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.

  17. Modelling of hybrid moving bed biofilm reactors: a pilot plant experiment.

    Science.gov (United States)

    Mannina, G; Di Trapani, D; Torregrossa, M; Viviani, G

    2007-01-01

    In recent years there has been an increasing interest in the development of hybrid biofilm reactors, especially in the upgrading of existing WWTP that are no longer able to respect concentration limits. In fact, today's challenge is the achievement of a good aquatic state for the receiving water bodies according to the Water Framework Directive requirements, which indeed limit even more the continuous emissions, i.e. coming from WWTP. This paper presents the setting up of a mathematical model for the simulation of a hybrid MBBR system; the model calibration/validation has been carried out considering a field gathering campaign on an experimental pilot plant. The main goal is to gain insight about MBBR processes attempting to overcome main shortcomings in particular referring to the modelling aspects. The model is made up of two connected sub-models for the simulation of the suspended and attached biomass. The model is mainly based on the concepts of the activated sludge model No. 1 (ASM1) for the description of the biokinetic process both for the suspended and for the attached biomass. The results show a good agreement between predicted and observed values both for the attached and for the suspended biomass moreover they are encouraging for further researches.

  18. MODELING OF MIXED LIQUOR VOLATILE SUSPENDED SOLIDS AND PERFORMANCE EVALUATION FOR A SEQUENCING BATCH REACTOR

    Directory of Open Access Journals (Sweden)

    S.A. Mirbagheri

    2015-01-01

    Full Text Available This study examined carbon, nitrogen and phosphorous removal from municipal wastewater in a sequencing batch reactor and biokinetic coefficients were evaluated according to results of BOD and COD. Furthermore, the MLVSS in the aeration reactor was modeled by using multilayer perceptron and radial basis function artificial neural networks (MLPANN and RBFANN. The experiments were performed so that the cell retention time, filling time and intensity of aeration were (5, 10 and 15 d, (1, 2 and 3 h and (weak, medium and strong respectively. The result indicated that with cell retention time of 15 d, filling time of 1 h, aeration time of 6 h and settling time of 3 h the HRT is optimized at 10 h. The BOD5, COD, TP, TN and NH4  N removal efficiencies were 97.13%, 94.58%, 94.27%, 89.7% and 92.75% respectively. The yield coefficient (Y, decay coefficient (Kd, maximum specific growth rate (K and saturation constant (Ks were 6.22 mgVSS/mgCOD, 0.002 1/d, 0.029 1/d and 20 mg COD/L according to COD experimental data. The values of the biokinetic coefficients were found to be as follows: Y = 10.45 mgVSS/mgBOD, Kd = 0.01 1/d, 0.014 1/d and 3.38 mgBOD/L according to BOD5 experimental data. The training procedures for simulation of MLVSS were highly collaborated for both RBFANN and MLPANN. The train and test models for both MLPANN and RBFANN demonstrated perfectly matched results between the experimental and the simulated values of MLVSS. The values of RMSE for train and test (verification models obtained by MLPANN were 31.82 and 40.25 mg/L respectively, and the value of R2 was 0.99 for both models. The values of RMSE for train and test models obtained by RBFANN were 69.04 and 43.87 mg/L respectively, and the value of R2 was 0.99 for both models. It was observed that the MLPANN has stronger approximation and generalization ability than the RBFANN with regard to our experimental data for MLVSS.

  19. 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.

  20. 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.

  1. Integration of kinetic modeling and desirability function approach for multi-objective optimization of UASB reactor treating poultry manure wastewater.

    Science.gov (United States)

    Yetilmezsoy, Kaan

    2012-08-01

    An integrated multi-objective optimization approach within the framework of nonlinear regression-based kinetic modeling and desirability function was proposed to optimize an up-flow anaerobic sludge blanket (UASB) reactor treating poultry manure wastewater (PMW). Chen-Hashimoto and modified Stover-Kincannon models were applied to the UASB reactor for determination of bio-kinetic coefficients. A new empirical formulation of volumetric organic loading rate was derived for the first time for PMW to estimate the dimensionless kinetic parameter (K) in the Chen-Hashimoto model. Maximum substrate utilization rate constant and saturation constant were predicted as 11.83 g COD/L/day and 13.02 g COD/L/day, respectively, for the modified Stover-Kincannon model. Based on four process-related variables, three objective functions including a detailed bio-economic model were derived and optimized by using a LOQO/AMPL algorithm, with a maximum overall desirability of 0.896. The proposed optimization scheme demonstrated a useful tool for the UASB reactor to optimize several responses simultaneously. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. 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.

  3. Adsorption and biodegradation of 2-chlorophenol by mixed culture using activated carbon as a supporting medium-reactor performance and model verification

    Science.gov (United States)

    Lin, Yen-Hui

    2017-11-01

    A non-steady-state mathematical model system for the kinetics of adsorption and biodegradation of 2-chlorophenol (2-CP) by attached and suspended biomass on activated carbon process was derived. The mechanisms in the model system included 2-CP adsorption by activated carbon, 2-CP mass transport diffusion in biofilm, and biodegradation by attached and suspended biomass. Batch kinetic tests were performed to determine surface diffusivity of 2-CP, adsorption parameters for 2-CP, and biokinetic parameters of biomass. Experiments were conducted using a biological activated carbon (BAC) reactor system with high recycled rate to approximate a completely mixed flow reactor for model verification. Concentration profiles of 2-CP by model predictions indicated that biofilm bioregenerated the activated carbon by lowering the 2-CP concentration at the biofilm-activated carbon interface as the biofilm grew thicker. The removal efficiency of 2-CP by biomass was approximately 98.5% when 2-CP concentration in the influent was around 190.5 mg L-1 at a steady-state condition. The concentration of suspended biomass reached up to about 25.3 mg L-1 while the thickness of attached biomass was estimated to be 636 μm at a steady-state condition by model prediction. The experimental results agree closely with the results of the model predictions.

  4. Modeling of carbon dioxide mass transfer behavior in attached cultivation photobioreactor using the analysis of the pH profiles.

    Science.gov (United States)

    Ji, Chunli; Wang, Junfeng; Li, Runzhi; Liu, Tianzhong

    2017-07-01

    The CO 2 mass transfer model associated with growth kinetics of microalgal biofilm in attached cultivation photobioreactor was developed and verified by using the analysis of pH profiles which were in equilibrium with inorganic carbon components concentrations (CO 2 , H 2 CO 3 , HCO 3 - and CO 3 2- ) in medium. Model simulation results showed that the model well presented the biofilm growth process. The overall volumetric mass transfer coefficient of CO 2 was more influenced by CO 2 concentration in aerated gas but less by gas aeration rate and medium circulation rate. Other bio-kinetic parameters related with the microalgal biofilm such as CO 2 diffusion coefficient in biofilm, Monod maximum utilization rate of CO 2 , lag phase duration of biofilm and half-saturation CO 2 concentration in the biofilm were independent on operational conditions. The pH profiles provided a way to monitor the variations of inorganic carbon concentrations of medium and to regulate the cultivation of attached microalgal biofilm by CO 2 supplement.

  5. 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.

  6. 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

  7. 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)

  8. 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

  9. 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

  10. A physiologically based biodynamic (PBBD) model for estragole DNA binding in rat liver based on in vitro kinetic data and estragole DNA adduct formation in primary hepatocytes

    International Nuclear Information System (INIS)

    Paini, Alicia; Punt, Ans; Viton, Florian; Scholz, Gabriele; Delatour, Thierry; Marin-Kuan, Maricel; Schilter, Benoit; Bladeren, Peter J. van; Rietjens, Ivonne M.C.M.

    2010-01-01

    Estragole has been shown to be hepatocarcinogenic in rodent species at high-dose levels. Translation of these results into the likelihood of formation of DNA adducts, mutation, and ultimately cancer upon more realistic low-dose exposures remains a challenge. Recently we have developed physiologically based biokinetic (PBBK) models for rat and human predicting bioactivation of estragole. These PBBK models, however, predict only kinetic characteristics. The present study describes the extension of the PBBK model to a so-called physiologically based biodynamic (PBBD) model predicting in vivo DNA adduct formation of estragole in rat liver. This PBBD model was developed using in vitro data on DNA adduct formation in rat primary hepatocytes exposed to 1'-hydroxyestragole. The model was extended by linking the area under the curve for 1'-hydroxyestragole formation predicted by the PBBK model to the area under the curve for 1'-hydroxyestragole in the in vitro experiments. The outcome of the PBBD model revealed a linear increase in DNA adduct formation with increasing estragole doses up to 100 mg/kg bw. Although DNA adduct formation of genotoxic carcinogens is generally seen as a biomarker of exposure rather than a biomarker of response, the PBBD model now developed is one step closer to the ultimate toxic effect of estragole than the PBBK model described previously. Comparison of the PBBD model outcome to available data showed that the model adequately predicts the dose-dependent level of DNA adduct formation. The PBBD model predicts DNA adduct formation at low levels of exposure up to a dose level showing to cause cancer in rodent bioassays, providing a proof of principle for modeling a toxicodynamic in vivo endpoint on the basis of solely in vitro experimental data.

  11. 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)

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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

  2. 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

  3. Biokinetics and dose estimation of {sup 65}Zn in the salivary gland and male reproductive organs

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, M. [Research Center for Radiation Emergency Medicine, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan); Homma-Takeda, S. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan); Nishimura, Y. [Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)

    2007-07-01

    ICRP is revising its recommendations for radiological protection and has added salivary and secretory glands as new target organs. However, little information is available on the distributions of radionuclides in the salivary gland, secretory glands and male reproductive organs. This study deals with the distribution of {sup 65}Zn in the salivary gland and male reproductive organs as a function of time after a single intravenous and oral administration. For the study, 64 Wistar strain male rats, eight weeks of age were used. The rats were periodically sacrificed, the liver, kidney, spleen, pancreas, thymus, salivary gland, testis, epididymitis and prostate gland sampled and the radioactivity of these organs measured with an NaI scintillation counter. The relative concentration of {sup 65}Zn was highest in the prostate gland. We estimated the radiation dose in humans using rat data for the salivary and secretory glands as well as reproductive organs after intake of {sup 65}Zn. (authors)

  4. 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)

  5. Absorption and biokinetics of U in rats following an oral administration of uranyl nitrate solution

    Energy Technology Data Exchange (ETDEWEB)

    La Touche, Y.D.; Willis, D.L.; Dawydiak, O.I.

    1987-08-01

    The absorption of U within the male Wistar rat was determined following oral gavage with uranyl nitrate solutions at seven different dosages. Gavage levels ranged from 0.003 to 45 mg U per kilogram body weight. Uranium tissue burdens were determined at 0.25, 0.5, 1, 2, 4, 8, 24, 48, 96 and 240 h following gavage. Blood, kidney, liver and bone were analyzed for U content using neutron activation followed by delayed neutron counting. Uranium rapidly localized in the kidneys and bone following ingestion. Bone was found to be the primary tissue of deposition. Skeletal and kidney burdens closely paralleled each other from 15 min to 10 d after oral gavage. Uranium burdens in the blood reached a maximum within 30 min but declined rapidly thereafter. Burdens of all tissues were well correlated with each other and with dosage at all dose levels. Equations relating body burdens with blood levels were developed and found to be useful for predicting body burdens for the initial 8 h following gavage. Gastrointestinal absorption (f1) was 0.6-2.8% over the range of U administered. Movement of U through the GI tract was assessed at two dosages. The transit time of U through the GI tract was approximately 48 h. Uranium loss from the stomach was described as a power function of time. The maximum value in the small intestine was attained within 2 h, and thereafter its rapid loss was linear up to 8 h. A minor residual loss component from the small intestine was evident beyond 8 h post-gavage.

  6. 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)

  7. Biokinetics of different-shaped copper oxide nanoparticles in the freshwater gastropod, Potamopyrgus antipodarum

    DEFF Research Database (Denmark)

    Ramskov, Tina; Croteau, Marie-Noelle; Forbes, Valery E

    2015-01-01

    Sediment is recognized as a major environmental sink for contaminants, including engineered nanoparticles (NPs). Consequently, sediment-living organisms are likely to be exposed to NPs. There is evidence that both accumulation and toxicity of metal NPs to sediment-dwellers increase with decreasing...... particle size, although NP size does not always predict effects. In contrast, not much is known about the influence of particle shape on bioaccumulation and toxicity. Here, we examined the influence of copper oxide (CuO) NP shape (rods, spheres, and platelets) on their bioaccumulation kinetics and toxicity...

  8. Biokinetics of Radiocobalt in the Asteroid Asterias rubens (Echinodermata): Sea Water and Food Exposures

    Energy Technology Data Exchange (ETDEWEB)

    Warnau, Michel; Fowler, Scott W.; Teyssie, Jean-Louis

    1999-01-01

    Uptake and loss of cobalt-57 were investigated in the starfish Asterias rubens, in order to assess its value as a sentinel organism for nearshore radionuclide contamination. Whole-body uptake from sea water was linear over a 32-day exposure period and reached wet weight concentration factor (CF) of 23 {+-} 5. Bioaccumulation of {sup 57}Co was dependent upon body compartment, the aboral part of the body wall concentrating cobalt to the greatest degree (wet weight CF: 77 {+-} 16). After restoration of uncontaminated conditions, radiocobalt was released following an exponential loss kinetics characterized by a biological half-life (T{sub b1/2}) of 27 {+-} 6 day. Dietary radiocobalt (taken up during a short-term feeding for 24 h on radiolabelled mussels) showed a much more rapid turnover time (T{sub b1/2}: 14 {+-} 4 d), suggesting that A. rubens accumulates this radionuclide predominantly from sea water. A. rubens, and more particularly the aboral part of its body wall, would readily reveal the presence of an environmental contamination by radiocobalt and could preserve this information over a period of few months.

  9. Biokinetics of Radiocobalt in the Asteroid Asterias rubens (Echinodermata): Sea Water and Food Exposures

    International Nuclear Information System (INIS)

    Warnau, Michel; Fowler, Scott W.; Teyssie, Jean-Louis

    1999-01-01

    Uptake and loss of cobalt-57 were investigated in the starfish Asterias rubens, in order to assess its value as a sentinel organism for nearshore radionuclide contamination. Whole-body uptake from sea water was linear over a 32-day exposure period and reached wet weight concentration factor (CF) of 23 ± 5. Bioaccumulation of 57 Co was dependent upon body compartment, the aboral part of the body wall concentrating cobalt to the greatest degree (wet weight CF: 77 ± 16). After restoration of uncontaminated conditions, radiocobalt was released following an exponential loss kinetics characterized by a biological half-life (T b1/2 ) of 27 ± 6 day. Dietary radiocobalt (taken up during a short-term feeding for 24 h on radiolabelled mussels) showed a much more rapid turnover time (T b1/2 : 14 ± 4 d), suggesting that A. rubens accumulates this radionuclide predominantly from sea water. A. rubens, and more particularly the aboral part of its body wall, would readily reveal the presence of an environmental contamination by radiocobalt and could preserve this information over a period of few months

  10. Biokinetics of different-shaped copper oxide nanoparticles in the freshwater gastropod, Potamopyrgus antipodarum

    Science.gov (United States)

    Ramskov, Tina; Croteau, Marie-Noele; Forbes, Valery E.; Selck, Henriette

    2015-01-01

    Sediment is recognized as a major environmental sink for contaminants, including engineered nanoparticles (NPs). Consequently, sediment-living organisms are likely to be exposed to NPs. There is evidence that both accumulation and toxicity of metal NPs to sediment-dwellers increase with decreasing particle size, although NP size does not always predict effects. In contrast, not much is known about the influence of particle shape on bioaccumulation and toxicity. Here, we examined the influence of copper oxide (CuO) NP shape (rods, spheres, and platelets) on their bioaccumulation kinetics and toxicity to the sediment-dwelling gastropod, Potamopyrgus antipodarum. The influence of Cu added as CuCl2 (i.e., aqueous Cu treatment) was also examined. Exposure to sediment mixed with aqueous Cu or with different-shaped CuO NPs at an average measured exposure concentration of 207 μg Cu per g dry weight sediment for 14 days did not significantly affect snail mortality. However, growth decreased for snails exposed to sediment amended with CuO NP spheres and platelets. P. antipodarum accumulated Cu from all Cu forms/shapes in significant amounts compared to control snails. In addition, once accumulated, Cu was efficiently retained (i.e., elimination rate constants were generally not significantly different from zero). Consequently, snails are likely to concentrate Cu over time, from both aqueous and NP sources, resulting in a high potential for toxicity.

  11. 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

    indicates that pulmonary exposure is associated with low (inhalation route-0.00001-1% of total applied dose-24 h) translocation of virtually insoluble NMs such as iridium, carbon black, gold and polystyrene, while slightly higher translocation has been observed for NMs with either slow (e.g. silver, cerium...

  12. Radionuclide Decorporation: Matching the Biokinetics of Actinides by Transdermal Delivery of Pro-chelators

    OpenAIRE

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

    2013-01-01

    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 admin...

  13. Modelling the Effect of Different Substrates and Temperature on the Growth and Lactic Acid Production by Lactobacillus amylovorus DSM 20531T in Batch Process

    Directory of Open Access Journals (Sweden)

    Antonija Trontel

    2010-01-01

    Full Text Available Amylolytic lactic acid bacterium Lactobacillus amylovorus DSM 20531T utilised glucose, sucrose and starch as a sole carbon and energy source. The three substrates were completely depleted from MRS medium during batch cultivations carried out in a laboratory scale stirred tank bioreactor at constant temperature (40 °C and pH value (5.5. Under the tested conditions, the bacterium was capable of conducting simultaneously starch hydrolysis and fermentation. A mixture of two stereoisomers, D-(–- and L-(+-lactic acid, was produced in all cases by highly efficient homofermentative bioprocess with 0.93 to 1 g of lactate produced per g of total (consumed substrate. The effect of temperature on the kinetics of cell growth and lactic acid production by the amylolytic strain in the starch-containing medium was also investigated. Efficient simultaneous saccharification and fermentation (SSF was obtained at 35, 40 and 45 °C with completely degraded complex carbohydrate in 8 to 12 h and the product yield coefficient in the range from 0.91 to 0.93 g/g. Maximum values for substrate consumption rate (0.89 h^–1, maximum specific growth rate (0.87 h^–1, product formation rate (2.01 h^–1, and productivity of lactic acid (1.45 g/(L·h were obtained at 45 °C, while maximum biomass concentration (4.38 g/L was attained at 40 °C. The ratio of the two stereoisomeric forms of produced lactic acid was strongly affected by the temperature. Unstructured kinetic model was used to describe the consumption of the three substrates, bacterial biomass formation and lactic acid production by L. amylovorus DSM 20531T. The dependence of biokinetic parameters on temperature was described by cardinal temperature model. The applied models successfully predicted all experimental data.

  14. Comparing the effects of various fuel alcohols on the natural attenuation of benzene plumes using a general substrate interaction model.

    Science.gov (United States)

    Gomez, Diego E; Alvarez, Pedro J J

    2010-04-01

    The effects of five fuel alcohols (methanol, ethanol, 1-propanol, iso-butanol and n-butanol) on the natural attenuation of benzene were compared using a previously developed numerical model (General Substrate Interaction Module--GSIM) and a probabilistic sensitivity analysis. Simulations with a 30 gal dissolving LNAPL (light non-aqueous phase liquid) source consisting of a range of gasoline blends (10% and 85% v:v alcohol content) suggest that all fuel alcohols can hinder the natural attenuation of benzene, due mainly to accelerated depletion of dissolved oxygen and a decrease in the specific degradation rate for benzene (due to catabolite repression and metabolic flux dilution). Simulations for blends with 10% alcohol, assuming a homogeneous sandy aquifer, inferred maximum benzene plume elongations (relative to a regular gasoline release) of 26% for ethanol, 47% for iso-butanol, 147% for methanol, 188% for 1-propanol, and 265% for n-butanol. The corresponding elongation percentages for blends with 85% alcohol were generally smaller (i.e., 25%, 54%, 135%, 163%, and 181%, respectively), reflecting a lower content of benzene in the simulated release. Benzene plume elongation and longevity were more pronounced in the presence of alcohols that biodegrade slower (e.g., propanol and n-butanol), forming longer and more persistent alcohol plumes. Conversely, ethanol and iso-butanol exhibited the lowest potential to hinder the natural attenuation of benzene, illustrating the significant effect that a small difference in chemical structure (e.g., isomers) can have on biodegradation. Overall, simulations were highly sensitive to site-specific biokinetic coefficients for alcohol degradation, which forewarns against generalizations about the level of impact of specific fuel alcohols on benzene plume dynamics. 2010 Elsevier B.V. All rights reserved.

  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

    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

  16. Underbody Blast Models of TBI Caused by Hyper-Acceleration and Secondary Head Impact

    Science.gov (United States)

    2016-02-01

    pixels in the selected area. Final PCI helmet selection was based on several criteria including elastic modulus, load transfer char - acteristics and the...Biokinetics of Impacts (IRCOBI), San Diego, California, October 17–19, 1983. 17Hong, Y., and R. Bartlett. Routledge handbook of bio - mechanics and human...Kochanek PM, Dixon CE, Shellington DK, Shin SS, Bayır H, Jackson EK, Kagan VE, Yan HQ, Swauger PV, Parks SA, et al. Screening of bio - chemical and molecular

  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. EURADOS coordinated action on research, quality assurance and training of internal dose assessments.

    Science.gov (United States)

    Lopez, M A; Balásházy, I; Bérard, P; Blanchardon, E; Breustedt, B; Broggio, D; Castellani, C M; Franck, D; Giussani, A; Hurtgen, C; James, A C; Klein, W; Kramer, G H; Li, W B; Marsh, J W; Malatova, I; Nosske, D; Oeh, U; Pan, G; Puncher, M; Peixoto Telles, P; Teixoto Telles, P; Schimmelpfeng, J; Vrba, T

    2011-03-01

    EURADOS working group on 'Internal Dosimetry (WG7)' represents a frame to develop activities in the field of internal exposures as coordinated actions on quality assurance (QA), research and training. The main tasks to carry out are the update of the IDEAS Guidelines as a reference document for the internal dosimetry community, the implementation and QA of new ICRP biokinetic models, the assessment of uncertainties related to internal dosimetry models and their application, the development of physiology-based models for biokinetics of radionuclides, stable isotope studies, biokinetic modelling of diethylene triamine pentaacetic acid decorporation therapy and Monte-Carlo applications to in vivo assessment of intakes. The working group is entirely supported by EURADOS; links are established with institutions such as IAEA, US Transuranium and Uranium Registries (USA) and CEA (France) for joint collaboration actions.

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. Cognitive modeling

    OpenAIRE

    Zandbelt, Bram

    2017-01-01

    Introductory presentation on cognitive modeling for the course ‘Cognitive control’ of the MSc program Cognitive Neuroscience at Radboud University. It addresses basic questions, such as 'What is a model?', 'Why use models?', and 'How to use models?'

  8. 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

  9. Prostate lymphoscintigraphy for sentinel lymph node identification in canines: reproducibility, uptake, and biokinetics depending on different injection strategies.

    Science.gov (United States)

    Wawroschek, Friedhelm; Wengenmair, Hermann; Senekowitsch-Schmidtke, Reingard; Hamm, Michael; Henke, Julia; Schönberger, Tanja; Hauser, Andrea; Erhardt, Wolf; Harzmann, Rolf

    2003-07-01

    At present there are neither clinical nor experimental data available on the influence of technical details on the quality and reproducibility of prostate lymphoscintigraphy. Six adult fox hounds received repeated transrectal ultrasound guided intraprostatic injections of a technetium 99m labeled nanocolloid to prove the influence of different techniques of injection (one central injection in both prostate lobes vs two peripheral injections in both lobes) on tracer accumulation in sentinel lymph nodes (SLN) and other organs. The reproducibility of the favored technique was examined and in a last step it was subject to scrutiny following a reduction of the injected volume to 1% of the prostate volume. The number of scintigraphically visualized SLN varied between four and seven. They were located in the region of the internal and external iliac vessels, presacrally, paravesically, and directly paraprostatically. In five of six cases, the localization was reproducible both with the central application of an identical volume as well as with the volume reduced central injection. Tracer accumulation of SLNs and other organs varied enormously. We expect that with the combination of both injection techniques, even with the reduced injection volume, an optimized prostate lymphoscintigraphy will be the outcome.

  10. Determination of biokinetic coefficients for an adsorption/bio-oxidation process on municipal wastewater in pilot-scale

    Directory of Open Access Journals (Sweden)

    Mostafa Hadei

    2015-01-01

    Conclusions: All coefficients were in the range of activated sludge coefficients that are mentioned in the literature, except μmax and K S of B-stage. However, K S value of B-stage was close to the desired range. Sensitivity analysis showed that μmax and K S have the most influence on effluent substrate concentration (sCOD.

  11. 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.

  12. 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.

  13. 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 &...

  14. 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...... years of experience is providing in directing the reader in their activities.Traps and pitfalls are discussed and strategies also given to improve model development towards “fit-for-purpose” models. The emphasis in this chapter is the adoption and exercise of a modelling methodology that has proven very...

  15. Development of mathematical models for insitu bioremediation of Cr(VI) contaminated Aquifers

    Science.gov (United States)

    Vairavan, S.; Philip, L.; Bhallamudi, M. S.

    2009-12-01

    Hexavalent Chromium (Cr(VI)) is a contaminant of significant concern due to its carcinogenic and mutagenic property in mammals. Cr(VI) abatement in aquifers can be achieved by reducing chromium from its hexavalent state to trivalent state because Cr(III) is less toxic, insoluble and immobile compared to Cr(VI). Reduction of Cr(VI) by Fe(II)/S2- present in mineral deposits followed by precipitation as hydroxides and/or sulfides and adsorption of Cr(VI) over mineral deposits in the geological formations are predominant mechanisms which account for the natural attenuation of Cr(VI) inside an aquifer. Once the Cr(VI) concentration goes beyond the carrying capacity of the aquifer, it can be cleaned by constructing a Permeable Reactive Barrier (PRB) perpendicular to the direction of the flow of groundwater or by introducing Injection Wells (IW) along the direction of flow. In both the above mentioned cases addition of chemical reductants results in high costs. On the other hand, bacterial biotransformation of Cr(VI) in presence of organic matter seems to be a viable and eco friendly option for remediation of chromium contaminated aquifers. Enhancement of biotransformation of hexavalent chromium is expected in the presence of soil microbes such as Sulfate Reducing Bacteria (SRB) and Iron Reducing Bacteria (IRB) along with Chromium Reducing Bacteria (CRB). Groundwater usually contains sulfate and iron (dissolution from the mineral deposits) which can act as electron acceptor for IRB and SRB metabolism and yield biogenic reductants such as Fe2+, and S2- which abiotically reduce Cr(VI) to Cr(III). The objective of the present work is to understand the effect of different electron acceptors on Cr(VI) reduction and to model the fate and transport of Cr(VI) in an aquifer. Batch studies were conducted to estimate biokinetic parameters such as maximum specific growth rate (µmax), half saturation constant (Ks), yield coefficient (YT) and inhibition constant (Ki). Transformation

  16. 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, ...

  17. STRUCTURAL MODELLING

    Directory of Open Access Journals (Sweden)

    Tea Ya. Danelyan

    2014-01-01

    Full Text Available The article states the general principles of structural modeling in aspect of the theory of systems and gives the interrelation with other types of modeling to adjust them to the main directions of modeling. Mathematical methods of structural modeling, in particular method of expert evaluations are considered.

  18. (HEV) Model

    African Journals Online (AJOL)

    Moatez Billah HARIDA

    The use of the simulator “Hybrid Electrical Vehicle Model Balances Fidelity and. Speed (HEVMBFS)” and the global control strategy make it possible to achieve encouraging results. Key words: Series parallel hybrid vehicle - nonlinear model - linear model - Diesel engine - Engine modelling -. HEV simulator - Predictive ...

  19. Constitutive Models

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Piccolo, Chiara; Heitzig, Martina

    2011-01-01

    This chapter presents various types of constitutive models and their applications. There are 3 aspects dealt with in this chapter, namely: creation and solution of property models, the application of parameter estimation and finally application examples of constitutive models. A systematic...... procedure is introduced for the analysis and solution of property models. Models that capture and represent the temperature dependent behaviour of physical properties are introduced, as well as equation of state models (EOS) such as the SRK EOS. Modelling of liquid phase activity coefficients are also...

  20. 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

  1. 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

  2. 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...

  3. 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

  4. 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

  5. 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

  6. 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

  7. Turbulence modelling

    International Nuclear Information System (INIS)

    Laurence, D.

    1997-01-01

    This paper is an introduction course in modelling turbulent thermohydraulics, aimed at computational fluid dynamics users. No specific knowledge other than the Navier Stokes equations is required beforehand. Chapter I (which those who are not beginners can skip) provides basic ideas on turbulence physics and is taken up in a textbook prepared by the teaching team of the ENPC (Benque, Viollet). Chapter II describes turbulent viscosity type modelling and the 2k-ε two equations model. It provides details of the channel flow case and the boundary conditions. Chapter III describes the 'standard' (R ij -ε) Reynolds tensions transport model and introduces more recent models called 'feasible'. A second paper deals with heat transfer and the effects of gravity, and returns to the Reynolds stress transport model. (author)

  8. 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.

  9. Modelling Overview

    DEFF Research Database (Denmark)

    Larsen, Lars Bjørn; Vesterager, Johan

    sharing many of the characteristics of a virtual enterprise. This extended enterprise will have the following characteristics: The extended enterprise is focused on satisfying the current customer requirement so that it has a limited life expectancy, but should be capable of being recreated to deal....... One or more units from beyond the network may complement the extended enterprise. The common reference model for this extended enterprise will utilise GERAM (Generalised Enterprise Reference Architecture and Methodology) to provide an architectural framework for the modelling carried out within......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...

  10. Mathematical modelling

    DEFF Research Database (Denmark)

    Blomhøj, Morten

    2004-01-01

    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......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...

  11. 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...... be characterized by their occurrence times and the participating books and borrowers. When we characterize events as information objects we focus on concepts like information structures. When viewed as change agents events are phenomena that trigger change. For example, when borrow event occurs books are moved...

  12. 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 ...

  13. Spherical models

    CERN Document Server

    Wenninger, Magnus J

    2012-01-01

    Well-illustrated, practical approach to creating star-faced spherical forms that can serve as basic structures for geodesic domes. Complete instructions for making models from circular bands of paper with just a ruler and compass. Discusses tessellation, or tiling, and how to make spherical models of the semiregular solids and concludes with a discussion of the relationship of polyhedra to geodesic domes and directions for building models of domes. "". . . very pleasant reading."" - Science. 1979 edition.

  14. 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.

  15. 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...... to construct this approach in mathematics education research....

  16. Virtual modeling

    NARCIS (Netherlands)

    Flores, J.; Kiss, S.; Cano, P.; Nijholt, Antinus; Zwiers, Jakob

    2003-01-01

    We concentrate our efforts on building virtual modelling environments where the content creator uses controls (widgets) as an interactive adjustment modality for the properties of the edited objects. Besides the advantage of being an on-line modelling approach (visualised just like any other on-line

  17. 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...

  18. 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

  19. Modeling Sunspots

    Science.gov (United States)

    Oh, Phil Seok; Oh, Sung Jin

    2013-01-01

    Modeling in science has been studied by education researchers for decades and is now being applied broadly in school. It is among the scientific practices featured in the "Next Generation Science Standards" ("NGSS") (Achieve Inc. 2013). This article describes modeling activities in an extracurricular science club in a high…

  20. 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,

  1. 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

  2. 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...

  3. OSPREY Model

    Energy Technology Data Exchange (ETDEWEB)

    Veronica J. Rutledge

    2013-01-01

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed within Multi-physics Object Oriented Simulation Environment (MOOSE) developed at the Idaho National Laboratory (INL). Off-gas Separation and REcoverY (OSPREY) models the adsorption of off-gas constituents for dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions. Inputs to the model include gas, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. The simulation outputs component concentrations along the column length as a function of time from which breakthrough data is obtained. The breakthrough data can be used to determine bed capacity, which in turn can be used to size columns. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data and parameters were input into the adsorption model to develop models specific for krypton adsorption. The same can be done for iodine, xenon, and tritium. The model will be validated with experimental breakthrough curves. Customers will be given access to

  4. Modeling Applications.

    Science.gov (United States)

    McMEEKIN, Thomas A; Ross, Thomas

    1996-12-01

    The concept of predictive microbiology has developed rapidly through the initial phases of experimental design and model development and the subsequent phase of model validation. A fully validated model represents a general rule which may be brought to bear on particular cases. For some microorganism/food combinations, sufficient confidence now exists to indicate substantial benefits to the food industry from use of predictive models. Several types of devices are available to monitor and record environmental conditions (particularly temperature). These "environmental histories" can be interpreted, using predictive models, in terms of microbial proliferation. The current challenge is to provide systems for the collection and interpretation of environmental information which combine ease of use, reliability, and security, providing the industrial user with the ability to make informed and precise decisions regarding the quality and safety of foods. Many specific applications for predictive modeling can be developed from a basis of understanding the inherent qualities of a fully validated model. These include increased precision and confidence in predictions based on accumulation of quantitative data, objective and rapid assessment of the effect of environmental conditions on microbial proliferation, and flexibility in monitoring the relative contribution of component parts of processing, distribution, and storage systems for assurance of shelf life and safety.

  5. A Model for Math Modeling

    Science.gov (United States)

    Lin, Tony; Erfan, Sasan

    2016-01-01

    Mathematical modeling is an open-ended research subject where no definite answers exist for any problem. Math modeling enables thinking outside the box to connect different fields of studies together including statistics, algebra, calculus, matrices, programming and scientific writing. As an integral part of society, it is the foundation for many…

  6. 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.

  7. RNICE Model

    DEFF Research Database (Denmark)

    Pedersen, Mogens Jin; Stritch, Justin Michael

    2018-01-01

    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...... 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...... of the model using two previously published replication studies as examples....

  8. Correct Models

    OpenAIRE

    Blacher, René

    2010-01-01

    Ce rapport complete les deux rapports précédents et apporte une explication plus simple aux résultats précédents : à savoir la preuve que les suites obtenues sont aléatoires.; In previous reports, we have show how to transform a text $y_n$ in a random sequence by using functions of Fibonacci $T_q$. Now, in this report, we obtain a clearer result by proving that $T_q(y_n)$ has the IID model as correct model. But, it is necessary to define correctly a correct model. Then, we study also this pro...

  9. 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...

  10. Anchor Modeling

    Science.gov (United States)

    Regardt, Olle; Rönnbäck, Lars; Bergholtz, Maria; Johannesson, Paul; Wohed, Petia

    Maintaining and evolving data warehouses is a complex, error prone, and time consuming activity. The main reason for this state of affairs is that the environment of a data warehouse is in constant change, while the warehouse itself needs to provide a stable and consistent interface to information spanning extended periods of time. In this paper, we propose a modeling technique for data warehousing, called anchor modeling, that offers non-destructive extensibility mechanisms, thereby enabling robust and flexible management of changes in source systems. A key benefit of anchor modeling is that changes in a data warehouse environment only require extensions, not modifications, to the data warehouse. This ensures that existing data warehouse applications will remain unaffected by the evolution of the data warehouse, i.e. existing views and functions will not have to be modified as a result of changes in the warehouse model.

  11. 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.

  12. Environmental Modeling

    Science.gov (United States)

    EPA's modeling community is working to gain insights into certain parts of a physical, biological, economic, or social system by conducting environmental assessments for Agency decision making to complex environmental issues.

  13. Quark models

    International Nuclear Information System (INIS)

    Rosner, J.L.

    1981-01-01

    This paper invites experimenters to consider the wide variety of tests suggested by the new aspects of quark models since the discovery of charm and beauty, and nonrelativistic models. Colors and flavours are counted and combined into hadrons. The current quark zoo is summarized. Models and theoretical background are studied under: qualitative QCD: strings and bags, potential models, relativistic effects, electromagnetic transitions, gluon emissions, and single quark transition descriptions. Hadrons containing quarks known before 1974 (i.e. that can be made of ''light'' quarks u, d, and s) are treated in Section III, while those containing charmed quarks and beauty (b) quarks are discussed in Section IV. Unfolding the properties of the sixth quark from information on its hadrons is seen as a future application of the methods used in this study

  14. 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.

  15. Numerical models

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Manoj, N.T.

    developed most of the above models. This is a good approximation to simulate horizontal distribution of active and passive variables. The future challenge lies in developing capability to simulate the distribution in the vertical....

  16. Composite models

    International Nuclear Information System (INIS)

    Peccei, R.D.

    If quarks and leptons are composite, it should be possible eventually to calculate their mass spectrum and understand the reasons for the observed family replications, questions which lie beyond the standard model. Alas, all experimental evidence to date points towards quark and lepton elemenarity with the typical momentum scale Λsub(comp), beyond which effects of inner structure may be seen, probably being greater than ITeV. One supersymmetric preon model explained provides a new dynamical alternative for obtaining light fermions which is that these states are quasi Goldstone fermions. This, and similar models are discussed. Although quasi Goldstone fermions provide an answer to the 0sup(th)-order question of composite models the questions of how masses and families are generated remain unanswered. (U.K.)

  17. 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.

  18. Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan; Vatrapu, Ravi

    2016-01-01

    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....

  19. Accelerated life models modeling and statistical analysis

    CERN Document Server

    Bagdonavicius, Vilijandas

    2001-01-01

    Failure Time DistributionsIntroductionParametric Classes of Failure Time DistributionsAccelerated Life ModelsIntroductionGeneralized Sedyakin's ModelAccelerated Failure Time ModelProportional Hazards ModelGeneralized Proportional Hazards ModelsGeneralized Additive and Additive-Multiplicative Hazards ModelsChanging Shape and Scale ModelsGeneralizationsModels Including Switch-Up and Cycling EffectsHeredity HypothesisSummaryAccelerated Degradation ModelsIntroductionDegradation ModelsModeling the Influence of Explanatory Varia

  20. 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

  1. Mechanistic models

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, S.B.

    1990-09-01

    Several models and theories are reviewed that incorporate the idea of radiation-induced lesions (repairable and/or irreparable) that can be related to molecular lesions in the DNA molecule. Usually the DNA double-strand or chromatin break is suggested as the critical lesion. In the models, the shoulder on the low-LET survival curve is hypothesized as being due to one (or more) of the following three mechanisms: (1) ``interaction`` of lesions produced by statistically independent particle tracks; (2) nonlinear (i.e., linear-quadratic) increase in the yield of initial lesions, and (3) saturation of repair processes at high dose. Comparisons are made between the various approaches. Several significant advances in model development are discussed; in particular, a description of the matrix formulation of the Markov versions of the RMR and LPL models is given. The more advanced theories have incorporated statistical fluctuations in various aspects of the energy-loss and lesion-formation process. An important direction is the inclusion of physical and chemical processes into the formulations by incorporating relevant track structure theory (Monte Carlo track simulations) and chemical reactions of radiation-induced radicals. At the biological end, identification of repair genes and how they operate as well as a better understanding of how DNA misjoinings lead to lethal chromosome aberrations are needed for appropriate inclusion into the theories. More effort is necessary to model the complex end point of radiation-induced carcinogenesis.

  2. Mechanistic models

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, S.B.

    1990-09-01

    Several models and theories are reviewed that incorporate the idea of radiation-induced lesions (repairable and/or irreparable) that can be related to molecular lesions in the DNA molecule. Usually the DNA double-strand or chromatin break is suggested as the critical lesion. In the models, the shoulder on the low-LET survival curve is hypothesized as being due to one (or more) of the following three mechanisms: (1) interaction'' of lesions produced by statistically independent particle tracks; (2) nonlinear (i.e., linear-quadratic) increase in the yield of initial lesions, and (3) saturation of repair processes at high dose. Comparisons are made between the various approaches. Several significant advances in model development are discussed; in particular, a description of the matrix formulation of the Markov versions of the RMR and LPL models is given. The more advanced theories have incorporated statistical fluctuations in various aspects of the energy-loss and lesion-formation process. An important direction is the inclusion of physical and chemical processes into the formulations by incorporating relevant track structure theory (Monte Carlo track simulations) and chemical reactions of radiation-induced radicals. At the biological end, identification of repair genes and how they operate as well as a better understanding of how DNA misjoinings lead to lethal chromosome aberrations are needed for appropriate inclusion into the theories. More effort is necessary to model the complex end point of radiation-induced carcinogenesis.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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...... to land. The paper advances the position that cadastral modeling has to include not only the physical objects, agents, and information sets of the domain, but also the objectives or requirements of cadastral systems....

  9. (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 ...

  10. 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...

  11. Markov model

    Indian Academy of Sciences (India)

    pattern of the watershed LULC, leading to an accretive linear growth of agricultural and settlement areas. The annual rate of ... thereby advocates for better agricultural practices with additional energy subsidy to arrest further forest loss and LULC ...... automaton model and GIS: Long-term urban growth pre- diction for San ...

  12. 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 ...

  13. 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…

  14. 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....

  15. Model Checking

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 7. Model Checking - Automated Verification of Computational Systems. Madhavan Mukund. General Article Volume 14 Issue 7 July 2009 pp 667-681. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. 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.

  17. 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:

  18. 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...

  19. Model-reduced inverse modeling

    NARCIS (Netherlands)

    Vermeulen, P.T.M.

    2006-01-01

    Although faster computers have been developed in recent years, they tend to be used to solve even more detailed problems. In many cases this will yield enormous models that can not be solved within acceptable time constraints. Therefore, there is a need for alternative methods that simulate such

  20. 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...

  1. 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.

  2. 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.

  3. 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...

  4. Persistent Modelling

    DEFF Research Database (Denmark)

    2012-01-01

    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......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...... characteristic of architectural practice. But the persistence in persistent modelling can also be understood to apply in other ways, reflecting and anticipating extended roles for representation. This book identifies three principle areas in which these extensions are becoming apparent within contemporary...

  5. Persistent Modelling

    DEFF Research Database (Denmark)

    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......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...... characteristic of architectural practice. But the persistence in persistent modelling can also be understood to apply in other ways, reflecting and anticipating extended roles for representation. This book identifies three principle areas in which these extensions are becoming apparent within contemporary...

  6. Modeling Minds

    DEFF Research Database (Denmark)

    Michael, John

    others' minds. Then (2), in order to bring to light some possible justifications, as well as hazards and criticisms of the methodology of looking time tests, I will take a closer look at the concept of folk psychology and will focus on the idea that folk psychology involves using oneself as a model...... of other people in order to predict and understand their behavior. Finally (3), I will discuss the historical location and significance of the emergence of looking time tests...

  7. Hydroballistics Modeling

    Science.gov (United States)

    1975-01-01

    detailed rendered visible in his photographs by streams of photographs of spheres entering the water small bubbles from electrolysis . So far as is...of the cavity is opaque or, brined wihile the sphere wats still in the oil. At if translucent, the contrast between thle jet and about the time the...and brass, for example) should be so model velocity scale according to Equation 1.18, selected that electrolysis is not a problem. the addition of

  8. 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...

  9. Modelling Behaviour

    DEFF Research Database (Denmark)

    This book reflects and expands on the current trend in the building industry to understand, simulate and ultimately design buildings by taking into consideration the interlinked elements and forces that act on them. This approach overcomes the traditional, exclusive focus on building tasks, while....... The chapter authors were invited speakers at the 5th Symposium "Modelling Behaviour", which took place at the CITA in Copenhagen in September 2015....

  10. Combustor Modelling

    Science.gov (United States)

    1980-02-01

    a teuto 014aceo 0-oiuato 4 ajj 210- I 14 *Experiments l~~lamCID - l2 C15 model+ Aida ditane &Gray medium K .2 a Experiments hont target n-IO a0 deawa...possibilita di valutazione dello scambio termico in focolai di caldaie per ricaldamento"I Atti E Rassegna Tecnica Societa ingegneri e arc~hitetti in Torino

  11. Persistent Modelling

    DEFF Research Database (Denmark)

    practice: the duration of active influence that representation can hold in relation to the represented; the means, methods and media through which representations are constructed and used; and what it is that is being represented. Featuring contributions from some of the world’s most advanced thinkers....... 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....

  12. 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

  13. 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.

  14. Object Modeling and Building Information Modeling

    OpenAIRE

    Auråen, Hege; Gjemdal, Hanne

    2016-01-01

    The main part of this thesis is an online course (Small Private Online Course) entitled "Introduction to Object Modeling and Building Information Modeling". This supplementary report clarifies the choices made in the process of developing the course. The course examines the basic concepts of object modeling, modeling techniques and a modeling language ​​(UML). Further, building information modeling (BIM) is presented as a modeling process, and the object modeling concepts in the BIM softw...

  15. 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

  16. 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

  17. DTN Modeling in OPNET Modeler

    Directory of Open Access Journals (Sweden)

    PAPAJ Jan

    2014-05-01

    Full Text Available Traditional wireless networks use the concept of the point-to-point forwarding inherited from reliable wired networks which seems to be not ideal for wireless environment. New emerging applications and networks operate mostly disconnected. So-called Delay-Tolerant networks (DTNs are receiving increasing attentions from both academia and industry. DTNs introduced a store-carry-and-forward concept solving the problem of intermittent connectivity. Behavior of such networks is verified by real models, computer simulation or combination of the both approaches. Computer simulation has become the primary and cost effective tool for evaluating the performance of the DTNs. OPNET modeler is our target simulation tool and we wanted to spread OPNET’s simulation opportunity towards DTN. We implemented bundle protocol to OPNET modeler allowing simulate cases based on bundle concept as epidemic forwarding which relies on flooding the network with messages and the forwarding algorithm based on the history of past encounters (PRoPHET. The implementation details will be provided in article.

  18. 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...

  19. Model Checking Algorithms for Markov Reward Models

    NARCIS (Netherlands)

    Cloth, Lucia; Cloth, L.

    2006-01-01

    Model checking Markov reward models unites two different approaches of model-based system validation. On the one hand, Markov reward models have a long tradition in model-based performance and dependability evaluation. On the other hand, a formal method like model checking allows for the precise

  20. Modelling Defiguration

    DEFF Research Database (Denmark)

    Bork Petersen, Franziska

    2013-01-01

    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...... catwalks. Vibskov’s catwalk induces what the dance scholar Gabriele Brandstetter has labelled a ‘defigurative choregoraphy’: a straying from definitions, which exist in ballet as in other movement-based genres, of how a figure should move and appear (1998). The catwalk scenography in this instance...

  1. Students' Models of Curve Fitting: A Models and Modeling Perspective

    Science.gov (United States)

    Gupta, Shweta

    2010-01-01

    The Models and Modeling Perspectives (MMP) has evolved out of research that began 26 years ago. MMP researchers use Model Eliciting Activities (MEAs) to elicit students' mental models. In this study MMP was used as the conceptual framework to investigate the nature of students' models of curve fitting in a problem-solving environment consisting of…

  2. Understanding the effects of bulk mixing on the determination of the affinity index: consequences for process operation and design.

    Science.gov (United States)

    Arnaldos, Marina; Rehman, Usman; Naessens, Wouter; Amerlinck, Youri; Nopens, Ingmar

    2018-02-01

    The main objective of this study is to demonstrate the importance of mixing conditions as a source of inconsistencies between half-saturation indices in comparable systems (e.g. conventional activated sludge, membrane bioreactor) when operated at different conditions or different scales. As proof-of-principle, an exemplary system consisting of the second vessel of a hybrid respirometer has been studied. The system has been modeled both using an integrated computational fluid dynamics (CFD)-biokinetic model (assumed to represent the physical system) and a tanks-in-series, completely stirred tank reactor biokinetic model (representing the applied model). The results show that different mixing conditions cause deviations in the half-saturation indices calculated when matching the applied model to the physical system performance. Additionally, sensor location has been shown to impact the calculation of half-saturation indices in the respirometric system. This will only become more pronounced at larger scales. Thus, mixing conditions clearly affect operation and design of wastewater treatment reactors operated at low substrate concentrations. Both operation and design can be improved with the development and application of integrated CFD-biokinetic or compartmental models.

  3. 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.

  4. 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

  5. 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

  6. 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.)

  7. 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

  8. 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

  9. 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

  10. 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)

  11. Biokinetic studies and scintigraphic imaging of human pancreatic carcinoma xenografts with iodine 131-labeled F(ab')2-fragments of monoclonal antibodies

    International Nuclear Information System (INIS)

    Senekowitsch, R.; Moellenstaedt, S.; Kriegel, H.; Baum, R.P.; Maul, F.D.; Hoer, G.; Wenisch, H.J.C.

    1985-01-01

    Biodistribution and tumor uptake of I-131 labeled F(ab') 2 -fragments of monoclonal antibodies to CA 125, CA 19-9 and CEA were investigated in nuce mice with human pancreatic carcinoma xenografts. To assess the immunological specificity of these antibody fragments their tumor uptake was compared with that of unspecific IgG F(ab') 2 . Additionally serum levels of CA 125 and CA 19-9 were determined in tumor bearing mice by radioimmunoassay and the expression of CA 125 and CA 19-9 in pancreatic carcinoma was demonstrated by immunhistochemicals studies. The rapid blood clearance of the antibody fragments leads to increasing tumor-to-blood ratios with time after injection for all antibody fragments. The highest ratios were found for OC 125 at all time points p.i., with mean values of 9.6 at 48 h p.i. and 11.8 at 96 h p.i. On scintigraphic images tumors with a weight of 100 mg could be localized between 24 and 48 h after injection of iodinated OC 125 F(ab') 2 . The serum levels of CA 125 and CA 19-9 were elevated only in some animals and no correlation between the antigen serum levels and the antigen expression in the tumor shown by immunhistochemical staining could be determined. (orig.) [de

  12. 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)

  13. Dosimetry of radioiodine for embryo and fetus

    Energy Technology Data Exchange (ETDEWEB)

    Berkovski, V.; Eckerman, K.F.; Phipps, A.W.; Nosske, D

    2003-07-01

    This paper discusses the biokinetic and dosimetric models adopted in ICRP Publication 88 for the evaluation of fetal doses resulting from maternal intakes of radioiodine. The biokinetic model is used to simulate the behaviour of iodine in both the mother and the fetus. Such simulations provide the basis for the estimation of the dose to the embryo and determine the distribution of maternal iodine at the beginning of the fetal period. The model considers iodine to accumulate in the fetal thyroid from the 11th week. The dose to the fetus delivered following birth is evaluated with the biokinetic and dosimetric models described in ICRP Publication 67. Although a substantial fraction of the emitted energy of electrons and photons is less than 10 keV, conventionally assumed to be non-penetrating radiation, these emissions can escape the small fetal thyroid. Absorbed fractions for both self-dose and crossfire were evaluated for the requirements of radioiodine dosimetry in ICRP Publication 88. (author)

  14. DOSE ASSESSMENT FOR INTAKE OF TRITIATED WATER IN HUMANS: ROLE OF TRITIUM INCORPORATION IN ORGANIC MATTER

    OpenAIRE

    M. I. Balonov; L. A. Chipiga

    2016-01-01

    Tritium is one of the factors of internal exposure of the humans both in occupational and public environments. It enters the body mainly as tritiated water through inhalation, with food, drinks and through the skin; part of tritium gradually transforms into the metabolised organically bound tritium as a result of biochemical reactions. The purpose of this study was to evaluate organically bound tritium contribution to the effective dose of an adult using the biokinetic model and real dosimetr...

  15. 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.)

  16. Building Mental Models by Dissecting Physical Models

    Science.gov (United States)

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to…

  17. 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

  18. Atmospheric Models/Global Atmospheric Modeling

    Science.gov (United States)

    1998-09-30

    Atmospheric Models /Global Atmospheric Modeling Timothy F. Hogan Naval Research Laboratory Monterey, CA 93943-5502 phone: (831) 656-4705 fax: (831...to 00-00-1998 4. TITLE AND SUBTITLE Atmospheric Models /Global Atmospheric Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...initialization of increments, improved cloud prediction, and improved surface fluxes) have been transition to 6.4 (Global Atmospheric Models , PE 0603207N, X-0513

  19. 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...

  20. 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

  1. Wake Expansion Models

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    Different models of wake expansion are presented in this chapter: the 1D momentum theory model, the cylinder analog model and Theodorsen’s model. Far wake models such as the ones from Frandsen or Rathmann or only briefly mentioned. The different models are compared to each other. Results from...

  2. Model Manipulation for End-User Modelers

    DEFF Research Database (Denmark)

    Acretoaie, Vlad

    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...... of these proposals. To achieve its first goal, the thesis presents the findings of a Systematic Mapping Study showing that human factors topics are scarcely and relatively poorly addressed in model transformation research. Motivated by these findings, the thesis explores the requirements of end-user modelers......, 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...

  3. 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.

  4. 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...

  5. 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

  6. 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 ...

  7. 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.

  8. Wake modelling combining mesoscale and microscale models

    DEFF Research Database (Denmark)

    Badger, Jake; Volker, Patrick; Prospathospoulos, J.

    2013-01-01

    parameterizations are demonstrated in theWeather Research and Forecasting mesoscale model (WRF) in an idealized atmospheric flow. The model framework is the Horns Rev I wind farm experiencing an 7.97 m/s wind from 269.4o. Three of the four parameterizations use thrust output from the CRESflow-NS microscale model......In this paper the basis for introducing thrust information from microscale wake models into mesocale model wake parameterizations will be described. A classification system for the different types of mesoscale wake parameterizations is suggested and outlined. Four different mesoscale wake....... The characteristics of the mesoscale wake that developed from the four parameterizations are examined. In addition the mesoscale model wakes are compared to measurement data from Horns Rev I. Overall it is seen as an advantage to incorporate microscale model data in mesocale model wake parameterizations....

  9. 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.

  10. Molecular Models: Construction of Models with Magnets

    Directory of Open Access Journals (Sweden)

    Kalinovčić P.

    2015-07-01

    Full Text Available Molecular models are indispensable tools in teaching chemistry. Beside their high price, commercially available models are generally too small for classroom demonstration. This paper suggests how to make space-filling (callote models from Styrofoam with magnetic balls as connectors and disc magnets for showing molecular polarity

  11. Target Scattering Metrics: Model-Model and Model Data comparisons

    Science.gov (United States)

    2017-12-13

    be suitable for input to classification schemes. The investigated metrics are then applied to model-data comparisons. INTRODUCTION Metrics for...stainless steel replica of artillery shell Table 7. Targets used in the TIER simulations for the metrics study. C. Four Potential Metrics: Four...Four metrics were investigated. The metric, based on 2D cross-correlation, is typically used in classification algorithms. Model-model comparisons

  12. 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...

  13. 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...

  14. Automated data model evaluation

    International Nuclear Information System (INIS)

    Kazi, Zoltan; Kazi, Ljubica; Radulovic, Biljana

    2012-01-01

    Modeling process is essential phase within information systems development and implementation. This paper presents methods and techniques for analysis and evaluation of data model correctness. Recent methodologies and development results regarding automation of the process of model correctness analysis and relations with ontology tools has been presented. Key words: Database modeling, Data model correctness, Evaluation

  15. Elastic Appearance Models

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Fagertun, Jens; Larsen, Rasmus

    2011-01-01

    This paper presents a fusion of the active appearance model (AAM) and the Riemannian elasticity framework which yields a non-linear shape model and a linear texture model – the active elastic appearance model (EAM). The non-linear elasticity shape model is more flexible than the usual linear subs...

  16. 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...

  17. "Bohr's Atomic Model."

    Science.gov (United States)

    Willden, Jeff

    2001-01-01

    "Bohr's Atomic Model" is a small interactive multimedia program that introduces the viewer to a simplified model of the atom. This interactive simulation lets students build an atom using an atomic construction set. The underlying design methodology for "Bohr's Atomic Model" is model-centered instruction, which means the central model of the…

  18. From Numeric Models to Granular System Modeling

    Directory of Open Access Journals (Sweden)

    Witold Pedrycz

    2015-03-01

    To make this study self-contained, we briefly recall the key concepts of granular computing and demonstrate how this conceptual framework and its algorithmic fundamentals give rise to granular models. We discuss several representative formal setups used in describing and processing information granules including fuzzy sets, rough sets, and interval calculus. Key architectures of models dwell upon relationships among information granules. We demonstrate how information granularity and its optimization can be regarded as an important design asset to be exploited in system modeling and giving rise to granular models. With this regard, an important category of rule-based models along with their granular enrichments is studied in detail.

  19. 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

  20. 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

  1. 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...

  2. 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...

  3. 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...

  4. N-Gram models

    NARCIS (Netherlands)

    Hiemstra, Djoerd; Liu, Ling; Tamer Özsu, M.

    2017-01-01

    In language modeling, n-gram models are probabilistic models of text that use some limited amount of history, or word dependencies, where n refers to the number of words that participate in the dependence relation.

  5. Business Model Canvas

    OpenAIRE

    Souza, D', 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.

  6. 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...

  7. 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...

  8. 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...

  9. Quintessence Model Building

    OpenAIRE

    Brax, P.; Martin, J.; Riazuelo, A.

    2001-01-01

    A short review of some of the aspects of quintessence model building is presented. We emphasize the role of tracking models and their possible supersymmetric origin. A short review of some of the aspects of quintessence model building is presented. We emphasize the role of tracking models and their possible supersymmetric origin. A short review of some of the aspects of quintessence model building is presented. We emphasize the role of tracking models and their possible supersymmetric o...

  10. 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

  11. Overuse Injury Assessment Model

    National Research Council Canada - National Science Library

    Stuhmiller, James H; Shen, Weixin; Sih, Bryant

    2005-01-01

    .... Previously, we developed a preliminary model that predicted the stress fracture rate and used biomechanical modeling, nonlinear optimization for muscle force, and bone structural analysis to estimate...

  12. 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

  13. 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)

  14. Validated dynamic flow model

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2011-01-01

    model structure suggested by University of Lund the WP4 leader. This particular model structure has the advantages that it fits better into the control design frame work used by WP3-4 compared to the model structures previously developed in WP2. The different model structures are first summarised....... Then issues dealing with optimal experimental design is considered. Finally the parameters are estimated in the chosen static and dynamic models and a validation is performed. Two of the static models, one of them the additive model, explains the data well. In case of dynamic models the suggested additive...

  15. 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...

  16. 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...

  17. Regularized Structural Equation Modeling

    Science.gov (United States)

    Jacobucci, Ross; Grimm, Kevin J.; McArdle, John J.

    2016-01-01

    A new method is proposed that extends the use of regularization in both lasso and ridge regression to structural equation models. The method is termed regularized structural equation modeling (RegSEM). RegSEM penalizes specific parameters in structural equation models, with the goal of creating easier to understand and simpler models. Although regularization has gained wide adoption in regression, very little has transferred to models with latent variables. By adding penalties to specific parameters in a structural equation model, researchers have a high level of flexibility in reducing model complexity, overcoming poor fitting models, and the creation of models that are more likely to generalize to new samples. The proposed method was evaluated through a simulation study, two illustrative examples involving a measurement model, and one empirical example involving the structural part of the model to demonstrate RegSEM’s utility. PMID:27398019

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Biosphere Model Report

    International Nuclear Information System (INIS)

    M. A. Wasiolek

    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)

  3. 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).

  4. 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).

  5. Lumped Thermal Household Model

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Stoustrup, Jakob

    2013-01-01

    a lumped model approach as an alternative to the individual models. In the lumped model, the portfolio is seen as baseline consumption superimposed with an ideal storage of limited power and energy capacity. The benefit of such a lumped model is that the computational effort of flexibility optimization...

  6. The Moody Mask Model

    DEFF Research Database (Denmark)

    Larsen, Bjarke Alexander; Andkjær, Kasper Ingdahl; Schoenau-Fog, Henrik

    2015-01-01

    This paper proposes a new relation model, called "The Moody Mask model", for Interactive Digital Storytelling (IDS), based on Franceso Osborne's "Mask Model" from 2011. This, mixed with some elements from Chris Crawford's Personality Models, is a system designed for dynamic interaction between ch...

  7. The Model Confidence Set

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Nason, James M.

    The paper introduces the model confidence set (MCS) and applies it to the selection of models. A MCS is a set of models that is constructed such that it will contain the best model with a given level of confidence. The MCS is in this sense analogous to a confidence interval for a parameter. The MCS...

  8. 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].

  9. Numerical Modelling of Streams

    DEFF Research Database (Denmark)

    Vestergaard, Kristian

    In recent years there has been a sharp increase in the use of numerical water quality models. Numeric water quality modeling can be divided into three steps: Hydrodynamic modeling for the determination of stream flow and water levels. Modelling of transport and dispersion of a conservative...

  10. 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...

  11. Generic Market Models

    NARCIS (Netherlands)

    R. Pietersz (Raoul); M. van Regenmortel

    2005-01-01

    textabstractCurrently, there are two market models for valuation and risk management of interest rate derivatives, the LIBOR and swap market models. In this paper, we introduce arbitrage-free constant maturity swap (CMS) market models and generic market models featuring forward rates that span

  12. Modeling the Accidental Deaths

    Directory of Open Access Journals (Sweden)

    Mariyam Hafeez

    2008-01-01

    Full Text Available The model for accidental deaths in the city of Lahore has been developed by using a class of Generalized Linear Models. Various link functions have been used in developing the model. The diagnostic checks have been carried out to see the validity of the fitted model.

  13. Cultural Resource Predictive Modeling

    Science.gov (United States)

    2017-10-01

    refining formal, inductive predictive models is the quality of the archaeological and environmental data. To build models efficiently, relevant...geomorphology, and historic information . Lessons Learned: The original model was focused on the identification of prehistoric resources. This...system but uses predictive modeling informally . For example, there is no probability for buried archaeological deposits on the Burton Mesa, but there is

  14. Modelling Railway Interlocking Systems

    DEFF Research Database (Denmark)

    Lindegaard, Morten Peter; Viuf, P.; Haxthausen, Anne Elisabeth

    2000-01-01

    In this report we present a model of interlocking systems, and describe how the model may be validated by simulation. Station topologies are modelled by graphs in which the nodes denote track segments, and the edges denote connectivity for train traÆc. Points and signals are modelled by annotatio...

  15. Lumped-parameter models

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.

    2006-12-15

    A lumped-parameter model represents the frequency dependent soil-structure interaction of a massless foundation placed on or embedded into an unbounded soil domain. In this technical report the steps of establishing a lumped-parameter model are presented. Following sections are included in this report: Static and dynamic formulation, Simple lumped-parameter models and Advanced lumped-parameter models. (au)

  16. Comparing Active Vision Models

    NARCIS (Netherlands)

    Croon, G.C.H.E. de; Sprinkhuizen-Kuyper, I.G.; Postma, E.O.

    2009-01-01

    Active vision models can simplify visual tasks, provided that they can select sensible actions given incoming sensory inputs. Many active vision models have been proposed, but a comparative evaluation of these models is lacking. We present a comparison of active vision models from two different

  17. Comparing active vision models

    NARCIS (Netherlands)

    Croon, G.C.H.E. de; Sprinkhuizen-Kuyper, I.G.; Postma, E.O.

    2009-01-01

    Active vision models can simplify visual tasks, provided that they can select sensible actions given incoming sensory inputs. Many active vision models have been proposed, but a comparative evaluation of these models is lacking. We present a comparison of active vision models from two different

  18. White Paper on Modelling

    NARCIS (Netherlands)

    Van Bloemendaal, Karen; Dijkema, Gerard P.J.; Woerdman, Edwin; Jong, Mattheus

    2015-01-01

    This White Paper provides an overview of the modelling approaches adopted by the project partners in the EDGaR project 'Understanding Gas Sector Intra- and Inter- Market interactions' (UGSIIMI). The paper addresses three types of models: complementarity modelling, agent-based modelling and property

  19. 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...... of design. Three distinctions are drawn through which to develop this discussion of models in an architectural context. An examination of these distinctions serves to nuance particular characteristics and roles of models, the modelling activity itself and those engaged in it....

  20. Wastewater treatment models

    DEFF Research Database (Denmark)

    Gernaey, Krist; Sin, Gürkan

    2011-01-01

    The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...... of WWTP modeling by linking the wastewater treatment line with the sludge handling line in one modeling platform. Application of WWTP models is currently rather time consuming and thus expensive due to the high model complexity, and requires a great deal of process knowledge and modeling expertise...

  1. Wastewater Treatment Models

    DEFF Research Database (Denmark)

    Gernaey, Krist; Sin, Gürkan

    2008-01-01

    The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...... the practice of WWTP modeling by linking the wastewater treatment line with the sludge handling line in one modeling platform. Application of WWTP models is currently rather time consuming and thus expensive due to the high model complexity, and requires a great deal of process knowledge and modeling expertise...

  2. Applied stochastic modelling

    CERN Document Server

    Morgan, Byron JT; Tanner, Martin Abba; Carlin, Bradley P

    2008-01-01

    Introduction and Examples Introduction Examples of data sets Basic Model Fitting Introduction Maximum-likelihood estimation for a geometric model Maximum-likelihood for the beta-geometric model Modelling polyspermy Which model? What is a model for? Mechanistic models Function Optimisation Introduction MATLAB: graphs and finite differences Deterministic search methods Stochastic search methods Accuracy and a hybrid approach Basic Likelihood ToolsIntroduction Estimating standard errors and correlations Looking at surfaces: profile log-likelihoods Confidence regions from profiles Hypothesis testing in model selectionScore and Wald tests Classical goodness of fit Model selection biasGeneral Principles Introduction Parameterisation Parameter redundancy Boundary estimates Regression and influence The EM algorithm Alternative methods of model fitting Non-regular problemsSimulation Techniques Introduction Simulating random variables Integral estimation Verification Monte Carlo inference Estimating sampling distributi...

  3. The Hospitable Meal Model

    DEFF Research Database (Denmark)

    Justesen, Lise; Overgaard, Svend Skafte

    2017-01-01

    -ended approach towards meal experiences. The underlying purpose of The Hospitable Meal Model is to provide the basis for creating value for the individuals involved in institutional meal services. The Hospitable Meal Model was developed on the basis of an empirical study on hospital meal experiences explored......This article presents an analytical model that aims to conceptualize how meal experiences are framed when taking into account a dynamic understanding of hospitality: the meal model is named The Hospitable Meal Model. The idea behind The Hospitable Meal Model is to present a conceptual model...... that can serve as a frame for developing hospitable meal competencies among professionals working within the area of institutional foodservices as well as a conceptual model for analysing meal experiences. The Hospitable Meal Model transcends and transforms existing meal models by presenting a more open...

  4. Calibrated Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Ahlers; H. Liu

    2000-03-12

    The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the ''AMR Development Plan for U0035 Calibrated Properties Model REV00. These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.

  5. Calibrated Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C.F. Ahlers, H.H. Liu

    2001-12-18

    The purpose of this Analysis/Model Report (AMR) is to document the Calibrated Properties Model that provides calibrated parameter sets for unsaturated zone (UZ) flow and transport process models for the Yucca Mountain Site Characterization Project (YMP). This work was performed in accordance with the AMR Development Plan for U0035 Calibrated Properties Model REV00 (CRWMS M&O 1999c). These calibrated property sets include matrix and fracture parameters for the UZ Flow and Transport Model (UZ Model), drift seepage models, drift-scale and mountain-scale coupled-processes models, and Total System Performance Assessment (TSPA) models as well as Performance Assessment (PA) and other participating national laboratories and government agencies. These process models provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic and thermal-loading conditions.

  6. The Hospitable Meal Model

    DEFF Research Database (Denmark)

    Justesen, Lise; Overgaard, Svend Skafte

    2017-01-01

    This article presents an analytical model that aims to conceptualize how meal experiences are framed when taking into account a dynamic understanding of hospitality: the meal model is named The Hospitable Meal Model. The idea behind The Hospitable Meal Model is to present a conceptual model...... that can serve as a frame for developing hospitable meal competencies among professionals working within the area of institutional foodservices as well as a conceptual model for analysing meal experiences. The Hospitable Meal Model transcends and transforms existing meal models by presenting a more open......-ended approach towards meal experiences. The underlying purpose of The Hospitable Meal Model is to provide the basis for creating value for the individuals involved in institutional meal services. The Hospitable Meal Model was developed on the basis of an empirical study on hospital meal experiences explored...

  7. MulensModel: Microlensing light curves modeling

    Science.gov (United States)

    Poleski, Radoslaw; Yee, Jennifer

    2018-03-01

    MulensModel calculates light curves of microlensing events. Both single and binary lens events are modeled and various higher-order effects can be included: extended source (with limb-darkening), annual microlensing parallax, and satellite microlensing parallax. The code is object-oriented and written in Python3, and requires AstroPy (ascl:1304.002).

  8. Business Models and Business Model Innovation

    DEFF Research Database (Denmark)

    Foss, Nicolai J.; Saebi, Tina

    2018-01-01

    While research on business models and business model innovation continue to exhibit growth, the field is still, even after more than two decades of research, characterized by a striking lack of cumulative theorizing and an opportunistic borrowing of more or less related ideas from neighbouring...

  9. EMC Simulation and Modeling

    Science.gov (United States)

    Takahashi, Takehiro; Schibuya, Noboru

    The EMC simulation is now widely used in design stage of electronic equipment to reduce electromagnetic noise. As the calculated electromagnetic behaviors of the EMC simulator depends on the inputted EMC model of the equipment, the modeling technique is important to obtain effective results. In this paper, simple outline of the EMC simulator and EMC model are described. Some modeling techniques of EMC simulation are also described with an example of the EMC model which is shield box with aperture.

  10. Phenomenology of inflationary models

    Science.gov (United States)

    Olyaei, Abbas

    2018-01-01

    There are many inflationary models compatible with observational data. One can investigate inflationary models by looking at their general features, which are common in most of the models. Here we have investigated some of the single-field models without considering their origin in order to find the phenomenology of them. We have shown how to adjust the simple harmonic oscillator model in order to be in good agreement with observational data.

  11. Multilevel statistical models

    CERN Document Server

    Goldstein, Harvey

    2011-01-01

    This book provides a clear introduction to this important area of statistics. The author provides a wide of coverage of different kinds of multilevel models, and how to interpret different statistical methodologies and algorithms applied to such models. This 4th edition reflects the growth and interest in this area and is updated to include new chapters on multilevel models with mixed response types, smoothing and multilevel data, models with correlated random effects and modeling with variance.

  12. Latent classification models

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre

    2005-01-01

    parametric family ofdistributions.  In this paper we propose a new set of models forclassification in continuous domains, termed latent classificationmodels. The latent classification model can roughly be seen ascombining the \\NB model with a mixture of factor analyzers,thereby relaxing the assumptions...... classification model, and wedemonstrate empirically that the accuracy of the proposed model issignificantly higher than the accuracy of other probabilisticclassifiers....

  13. Geochemistry Model Validation Report: External Accumulation Model

    Energy Technology Data Exchange (ETDEWEB)

    K. Zarrabi

    2001-09-27

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  14. Geochemistry Model Validation Report: External Accumulation Model

    International Nuclear Information System (INIS)

    Zarrabi, K.

    2001-01-01

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  15. Crop rotation modelling - A European model intercomparison

    DEFF Research Database (Denmark)

    Kollas, Chris; Kersebaum, Kurt C; Nendel, Claas

    2015-01-01

    crop growth simulation models to predict yields in crop rotations at five sites across Europe under minimal calibration. Crop rotations encompassed 301 seasons of ten crop types common to European agriculture and a diverse set of treatments (irrigation, fertilisation, CO2 concentration, soil types...... accurately than main crops (cereals). The majority of models performed better for the treatments of increased CO2 and nitrogen fertilisation than for irrigation and soil-related treatments. The yield simulation of the multi-model ensemble reduced the error compared to single-model simulations. The low degree...... representation of crop rotations, further research is required to synthesise existing knowledge of the physiology of intermediate crops and of carry-over effects from the preceding to the following crop, and to implement/improve the modelling of processes that condition these effects....

  16. Modelling of an homogeneous equilibrium mixture model

    International Nuclear Information System (INIS)

    Bernard-Champmartin, A.; Poujade, O.; Mathiaud, J.; Mathiaud, J.; Ghidaglia, J.M.

    2014-01-01

    We present here a model for two phase flows which is simpler than the 6-equations models (with two densities, two velocities, two temperatures) but more accurate than the standard mixture models with 4 equations (with two densities, one velocity and one temperature). We are interested in the case when the two-phases have been interacting long enough for the drag force to be small but still not negligible. The so-called Homogeneous Equilibrium Mixture Model (HEM) that we present is dealing with both mixture and relative quantities, allowing in particular to follow both a mixture velocity and a relative velocity. This relative velocity is not tracked by a conservation law but by a closure law (drift relation), whose expression is related to the drag force terms of the two-phase flow. After the derivation of the model, a stability analysis and numerical experiments are presented. (authors)

  17. Model Reduction in Groundwater Modeling and Management

    Science.gov (United States)

    Siade, A. J.; Kendall, D. R.; Putti, M.; Yeh, W. W.

    2008-12-01

    Groundwater management requires the development and implementation of mathematical models that, through simulation, evaluate the effects of anthropogenic impacts on an aquifer system. To obtain high levels of accuracy, one must incorporate high levels of complexity, resulting in computationally demanding models. This study provides a methodology for solving groundwater management problems with reduced computational effort by replacing the large, complex numerical model with a significantly smaller, simpler approximation. This is achieved via Proper Orthogonal Decomposition (POD), where the goal is to project the larger model solution space onto a smaller or reduced subspace in which the management problem will be solved, achieving reductions in computation time of up to three orders of magnitude. Once the solution is obtained in the reduced space with acceptable accuracy, it is then projected back to the full model space. A major challenge when using this method is the definition of the reduced solution subspace. In POD, this subspace is defined based on samples or snapshots taken at specific times from the solution of the full model. In this work we determine when snapshots should be taken on the basis of the exponential behavior of the governing partial differential equation. This selection strategy is then generalized for any groundwater model by obtaining and using the optimal snapshot selection for a simplified, dimensionless model. Protocols are developed to allow the snapshot selection results of the simplified, dimensionless model to be transferred to that of a complex, heterogeneous model with any geometry. The proposed methodology is finally applied to a basin in the Oristano Plain located in the Sardinia Island, Italy.

  18. Model Validation Status Review

    International Nuclear Information System (INIS)

    E.L. Hardin

    2001-01-01

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M and O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  19. Model Validation Status Review

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2001-11-28

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M&O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  20. Modeling for Battery Prognostics

    Science.gov (United States)

    Kulkarni, Chetan S.; Goebel, Kai; Khasin, Michael; Hogge, Edward; Quach, Patrick

    2017-01-01

    For any battery-powered vehicles (be it unmanned aerial vehicles, small passenger aircraft, or assets in exoplanetary operations) to operate at maximum efficiency and reliability, it is critical to monitor battery health as well performance and to predict end of discharge (EOD) and end of useful life (EOL). To fulfil these needs, it is important to capture the battery's inherent characteristics as well as operational knowledge in the form of models that can be used by monitoring, diagnostic, and prognostic algorithms. Several battery modeling methodologies have been developed in last few years as the understanding of underlying electrochemical mechanics has been advancing. The models can generally be classified as empirical models, electrochemical engineering models, multi-physics models, and molecular/atomist. Empirical models are based on fitting certain functions to past experimental data, without making use of any physicochemical principles. Electrical circuit equivalent models are an example of such empirical models. Electrochemical engineering models are typically continuum models that include electrochemical kinetics and transport phenomena. Each model has its advantages and disadvantages. The former type of model has the advantage of being computationally efficient, but has limited accuracy and robustness, due to the approximations used in developed model, and as a result of such approximations, cannot represent aging well. The latter type of model has the advantage of being very accurate, but is often computationally inefficient, having to solve complex sets of partial differential equations, and thus not suited well for online prognostic applications. In addition both multi-physics and atomist models are computationally expensive hence are even less suited to online application An electrochemistry-based model of Li-ion batteries has been developed, that captures crucial electrochemical processes, captures effects of aging, is computationally efficient

  1. Dimension of linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    1996-01-01

    Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four of these cri......Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....

  2. Product and Process Modelling

    DEFF Research Database (Denmark)

    Cameron, Ian T.; Gani, Rafiqul

    This book covers the area of product and process modelling via a case study approach. It addresses a wide range of modelling applications with emphasis on modelling methodology and the subsequent in-depth analysis of mathematical models to gain insight via structural aspects of the models....... These approaches are put into the context of life cycle modelling, where multiscale and multiform modelling is increasingly prevalent in the 21st century. The book commences with a discussion of modern product and process modelling theory and practice followed by a series of case studies drawn from a variety...... to biotechnology applications, food, polymer and human health application areas. The book highlights to important nature of modern product and process modelling in the decision making processes across the life cycle. As such it provides an important resource for students, researchers and industrial practitioners....

  3. Modeling volatility using state space models.

    Science.gov (United States)

    Timmer, J; Weigend, A S

    1997-08-01

    In time series problems, noise can be divided into two categories: dynamic noise which drives the process, and observational noise which is added in the measurement process, but does not influence future values of the system. In this framework, we show that empirical volatilities (the squared relative returns of prices) exhibit a significant amount of observational noise. To model and predict their time evolution adequately, we estimate state space models that explicitly include observational noise. We obtain relaxation times for shocks in the logarithm of volatility ranging from three weeks (for foreign exchange) to three to five months (for stock indices). In most cases, a two-dimensional hidden state is required to yield residuals that are consistent with white noise. We compare these results with ordinary autoregressive models (without a hidden state) and find that autoregressive models underestimate the relaxation times by about two orders of magnitude since they do not distinguish between observational and dynamic noise. This new interpretation of the dynamics of volatility in terms of relaxators in a state space model carries over to stochastic volatility models and to GARCH models, and is useful for several problems in finance, including risk management and the pricing of derivative securities. Data sets used: Olsen & Associates high frequency DEM/USD foreign exchange rates (8 years). Nikkei 225 index (40 years). Dow Jones Industrial Average (25 years).

  4. Empirical Model Building Data, Models, and Reality

    CERN Document Server

    Thompson, James R

    2011-01-01

    Praise for the First Edition "This...novel and highly stimulating book, which emphasizes solving real problems...should be widely read. It will have a positive and lasting effect on the teaching of modeling and statistics in general." - Short Book Reviews This new edition features developments and real-world examples that showcase essential empirical modeling techniques Successful empirical model building is founded on the relationship between data and approximate representations of the real systems that generated that data. As a result, it is essential for researchers who construct these m

  5. Zephyr - the prediction models

    DEFF Research Database (Denmark)

    Nielsen, Torben Skov; Madsen, Henrik; Nielsen, Henrik Aalborg

    2001-01-01

    utilities as partners and users. The new models are evaluated for five wind farms in Denmark as well as one wind farm in Spain. It is shown that the predictions based on conditional parametric models are superior to the predictions obatined by state-of-the-art parametric models.......This paper briefly describes new models and methods for predicationg the wind power output from wind farms. The system is being developed in a project which has the research organization Risø and the department of Informatics and Mathematical Modelling (IMM) as the modelling team and all the Danish...

  6. Models of light nuclei

    International Nuclear Information System (INIS)

    Harvey, M.; Khanna, F.C.

    1975-01-01

    The general problem of what constitutes a physical model and what is known about the free nucleon-nucleon interaction are considered. A time independent formulation of the basic equations is chosen. Construction of the average field in which particles move in a general independent particle model is developed, concentrating on problems of defining the average spherical single particle field for any given nucleus, and methods for construction of effective residual interactions and other physical operators. Deformed shell models and both spherical and deformed harmonic oscillator models are discussed in detail, and connections between spherical and deformed shell models are analyzed. A section on cluster models is included. 11 tables, 21 figures

  7. Building Thermal Models

    Science.gov (United States)

    Peabody, Hume L.

    2017-01-01

    This presentation is meant to be an overview of the model building process It is based on typical techniques (Monte Carlo Ray Tracing for radiation exchange, Lumped Parameter, Finite Difference for thermal solution) used by the aerospace industry This is not intended to be a "How to Use ThermalDesktop" course. It is intended to be a "How to Build Thermal Models" course and the techniques will be demonstrated using the capabilities of ThermalDesktop (TD). Other codes may or may not have similar capabilities. The General Model Building Process can be broken into four top level steps: 1. Build Model; 2. Check Model; 3. Execute Model; 4. Verify Results.

  8. Microsoft tabular modeling cookbook

    CERN Document Server

    Braak, Paul te

    2013-01-01

    This book follows a cookbook style with recipes explaining the steps for developing analytic data using Business Intelligence Semantic Models.This book is designed for developers who wish to develop powerful and dynamic models for users as well as those who are responsible for the administration of models in corporate environments. It is also targeted at analysts and users of Excel who wish to advance their knowledge of Excel through the development of tabular models or who wish to analyze data through tabular modeling techniques. We assume no prior knowledge of tabular modeling

  9. Five models of capitalism

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Bresser-Pereira

    2012-03-01

    Full Text Available Besides analyzing capitalist societies historically and thinking of them in terms of phases or stages, we may compare different models or varieties of capitalism. In this paper I survey the literature on this subject, and distinguish the classification that has a production or business approach from those that use a mainly political criterion. I identify five forms of capitalism: among the rich countries, the liberal democratic or Anglo-Saxon model, the social or European model, and the endogenous social integration or Japanese model; among developing countries, I distinguish the Asian developmental model from the liberal-dependent model that characterizes most other developing countries, including Brazil.

  10. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  11. Biosphere Model Report

    Energy Technology Data Exchange (ETDEWEB)

    D.W. Wu; A.J. Smith

    2004-11-08

    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), TSPA-LA. The ERMYN 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) (Section 6.2), the reference biosphere (Section 6.1.1), the human receptor (Section 6.1.2), and approximations (Sections 6.3.1.4 and 6.3.2.4); (3) Building a mathematical model using the biosphere conceptual model (Section 6.3) 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 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 by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

  12. Biosphere Model Report

    International Nuclear Information System (INIS)

    D.W. Wu; A.J. Smith

    2004-01-01

    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), TSPA-LA. The ERMYN 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) (Section 6.2), the reference biosphere (Section 6.1.1), the human receptor (Section 6.1.2), and approximations (Sections 6.3.1.4 and 6.3.2.4); (3) Building a mathematical model using the biosphere conceptual model (Section 6.3) 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 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 by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7)

  13. Modelling of Innovation Diffusion

    Directory of Open Access Journals (Sweden)

    Arkadiusz Kijek

    2010-01-01

    Full Text Available Since the publication of the Bass model in 1969, research on the modelling of the diffusion of innovation resulted in a vast body of scientific literature consisting of articles, books, and studies of real-world applications of this model. The main objective of the diffusion model is to describe a pattern of spread of innovation among potential adopters in terms of a mathematical function of time. This paper assesses the state-of-the-art in mathematical models of innovation diffusion and procedures for estimating their parameters. Moreover, theoretical issues related to the models presented are supplemented with empirical research. The purpose of the research is to explore the extent to which the diffusion of broadband Internet users in 29 OECD countries can be adequately described by three diffusion models, i.e. the Bass model, logistic model and dynamic model. The results of this research are ambiguous and do not indicate which model best describes the diffusion pattern of broadband Internet users but in terms of the results presented, in most cases the dynamic model is inappropriate for describing the diffusion pattern. Issues related to the further development of innovation diffusion models are discussed and some recommendations are given. (original abstract

  14. Lie Markov models.

    Science.gov (United States)

    Sumner, J G; Fernández-Sánchez, J; Jarvis, P D

    2012-04-07

    Recent work has discussed the importance of multiplicative closure for the Markov models used in phylogenetics. For continuous-time Markov chains, a sufficient condition for multiplicative closure of a model class is ensured by demanding that the set of rate-matrices belonging to the model class form a Lie algebra. It is the case that some well-known Markov models do form Lie algebras and we refer to such models as "Lie Markov models". However it is also the case that some other well-known Markov models unequivocally do not form Lie algebras (GTR being the most conspicuous example). In this paper, we will discuss how to generate Lie Markov models by demanding that the models have certain symmetries under nucleotide permutations. We show that the Lie Markov models include, and hence provide a unifying concept for, "group-based" and "equivariant" models. For each of two and four character states, the full list of Lie Markov models with maximal symmetry is presented and shown to include interesting examples that are neither group-based nor equivariant. We also argue that our scheme is pleasing in the context of applied phylogenetics, as, for a given symmetry of nucleotide substitution, it provides a natural hierarchy of models with increasing number of parameters. We also note that our methods are applicable to any application of continuous-time Markov chains beyond the initial motivations we take from phylogenetics. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  15. Integrated Medical Model – Chest Injury Model

    Data.gov (United States)

    National Aeronautics and Space Administration — The Exploration Medical Capability (ExMC) Element of NASA's Human Research Program (HRP) developed the Integrated Medical Model (IMM) to forecast the resources...

  16. Traffic & safety statewide model and GIS modeling.

    Science.gov (United States)

    2012-07-01

    Several steps have been taken over the past two years to advance the Utah Department of Transportation (UDOT) safety initiative. Previous research projects began the development of a hierarchical Bayesian model to analyze crashes on Utah roadways. De...

  17. Nonlinear Modeling by Assembling Piecewise Linear Models

    Science.gov (United States)

    Yao, Weigang; Liou, Meng-Sing

    2013-01-01

    To preserve nonlinearity of a full order system over a parameters range of interest, we propose a simple modeling approach by assembling a set of piecewise local solutions, including the first-order Taylor series terms expanded about some sampling states. The work by Rewienski and White inspired our use of piecewise linear local solutions. The assembly of these local approximations is accomplished by assigning nonlinear weights, through radial basis functions in this study. The efficacy of the proposed procedure is validated for a two-dimensional airfoil moving at different Mach numbers and pitching motions, under which the flow exhibits prominent nonlinear behaviors. All results confirm that our nonlinear model is accurate and stable for predicting not only aerodynamic forces but also detailed flowfields. Moreover, the model is robustness-accurate for inputs considerably different from the base trajectory in form and magnitude. This modeling preserves nonlinearity of the problems considered in a rather simple and accurate manner.

  18. Solid Waste Projection Model: Model user's guide

    International Nuclear Information System (INIS)

    Stiles, D.L.; Crow, V.L.

    1990-08-01

    The Solid Waste Projection Model (SWPM) system is an analytical tool developed by Pacific Northwest Laboratory (PNL) for Westinghouse Hanford company (WHC) specifically to address solid waste management issues at the Hanford Central Waste Complex (HCWC). This document, one of six documents supporting the SWPM system, contains a description of the system and instructions for preparing to use SWPM and operating Version 1 of the model. 4 figs., 1 tab

  19. Modeling of System Families

    National Research Council Canada - National Science Library

    Feiler, Peter

    2007-01-01

    .... The Society of Automotive Engineers (SAE) Architecture Analysis & Design Language (AADL) is an industry-standard, architecture-modeling notation specifically designed to support a component- based approach to modeling embedded systems...

  20. 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......-efficiency project, this thesis presents an analysis of the central practices that materialised representative physical modelling and implemented operational regulation models. In order to show how the project’s representative modelling and technology development connected physical theory with concrete problems...... theoretical outset, the existing literature on simulation models, and the study’s methodological and empirical approach. The purpose of this thesis is to describe the central practices that developed regulation technology for industrial production processes and to analyse how mathematical modelling...