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Sample records for absorbed fraction internal irradiation

  1. Specific absorbed fraction for Korean adult voxel phantom from internal photon source

    International Nuclear Information System (INIS)

    Absorbed fraction (AF) and specific absorbed fraction (SAF) are crucial values for the calculation of radionuclide S-values and consequently for internal dose estimates. The formalism of the Medical Internal Radiation Dose (MIRD) committee of the Society of Nuclear Medicine (SNM) has been utilised as a standard in the calculation of individual organ doses for biologically distributed radionuclides and for different types of radiation. Although those quantities are highly sensitive to individual anatomical difference, the SAF dataset calculated by Caucasian-based stylised phantoms have been applied to Korean population until now. This study was intended to calculate the SAFs by using realistic Korean voxel phantom and Monte Carlo transport technique for the first time and compare the results with those of the existing Caucasian-based data and the Korean stylised phantom published recently. The up-to-date realistic Korean voxel phantom, KTMAN-2, which was developed from computed tomography (CT) images of an average Korean adult male, was employed for Monte Carlo calculation using EGSnrc user-code, developed for the purpose of this study. The SAFs for 32 target organs and tissues from the photon source, uniformly deposited in a total of 37 source organs and tissues, were calculated from KTMAN-2. The results were compared with those for an adult phantom of Oak Ridge National Laboratory (ORNL) and Korean adult stylised phantom. Two major reasons of discrepancy were analysed: (1) racial difference between the Korean and the Caucasian and (2) anatomical difference between stylised and voxel phantoms. When the source organ was identical to the target organ, difference in SAF caused by the difference in target-organ mass between the Korean and the Caucasian phantoms was mainly observed. When the source and target organs were not identical, significant difference in SAF was observed which was mainly attributed to the difference in inter-organ distance and organ shape between

  2. Specific absorbed fraction for Korean adult voxel phantom from internal photon source.

    Science.gov (United States)

    Lee, C; Park, S; Lee, J K

    2007-01-01

    Absorbed fraction (AF) and specific absorbed fraction (SAF) are crucial values for the calculation of radionuclide S-values and consequently for internal dose estimates. The formalism of the Medical Internal Radiation Dose (MIRD) committee of the Society of Nuclear Medicine (SNM) has been utilised as a standard in the calculation of individual organ doses for biologically distributed radionuclides and for different types of radiation. Although those quantities are highly sensitive to individual anatomical difference, the SAF dataset calculated by Caucasian-based stylised phantoms have been applied to Korean population until now. This study was intended to calculate the SAFs by using realistic Korean voxel phantom and Monte Carlo transport technique for the first time and compare the results with those of the existing Caucasian-based data and the Korean stylised phantom published recently. The up-to-date realistic Korean voxel phantom, KTMAN-2, which was developed from computed tomography (CT) images of an average Korean adult male, was employed for Monte Carlo calculation using EGSnrc user-code, developed for the purpose of this study. The SAFs for 32 target organs and tissues from the photon source, uniformly deposited in a total of 37 source organs and tissues, were calculated from KTMAN-2. The results were compared with those for an adult phantom of Oak Ridge National Laboratory (ORNL) and Korean adult stylised phantom. Two major reasons of discrepancy were analysed: (1) racial difference between the Korean and the Caucasian and (2) anatomical difference between stylised and voxel phantoms. When the source organ was identical to the target organ, difference in SAF caused by the difference in target-organ mass between the Korean and the Caucasian phantoms was mainly observed. When the source and target organs were not identical, significant difference in SAF was observed which was mainly attributed to the difference in inter-organ distance and organ shape between

  3. Specific absorbed fractions of energy at various ages from internal photon sources: 7, Adult male

    International Nuclear Information System (INIS)

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for an adult male (70-kg Reference Man). These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods at photon energies below 200 keV. 12 refs., 2 tabs

  4. Specific absorbed fractions of energy at various ages from internal photon sources: 1, Methods

    International Nuclear Information System (INIS)

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. This volume outlines various methods used to compute the PHI-values and describes how the ''best'' estimates recommended by us are chosen. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods that Spiers and co-workers developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with the methods at photon energies below 200 keV. 41 refs., 25 figs., 23 tabs

  5. Specific absorbed fractions of energy at various ages from internal photon sources: 2, One-year-old

    International Nuclear Information System (INIS)

    Specific absorbed fractions (PHI's) in various organs of the body (targets organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a one-year old or 9.8-kg person. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission of Radiological Protection recognizes that the endosteal or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods that Spiers and co-workers developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods at photon energies below 200 keV. 12 refs., 2 tabs

  6. Specific absorbed fractions of energy at various ages from internal photon sources: 4, Ten-year-old

    International Nuclear Information System (INIS)

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a ten-year-old or 32-kg person. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods that Spiers and co-workers developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods at photon energies below 200 keV. 12 refs., 2 tabs

  7. Specific absorbed fractions of energy at various ages from internal photon sources: 3, Five-year-old

    International Nuclear Information System (INIS)

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a five-year-old or 19-kg person. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods at photon energies below 200 keV. 12 refs., 2 tabs

  8. Absorbed fractions for electrons in ellipsoidal volumes

    Science.gov (United States)

    Amato, E.; Lizio, D.; Baldari, S.

    2011-01-01

    We applied a Monte Carlo simulation in Geant4 in order to calculate the absorbed fractions for monoenergetic electrons in the energy interval between 10 keV and 2 MeV, uniformly distributed in ellipsoids made from soft tissue. For each volume, we simulated a spherical shape, four oblate and four prolate ellipsoids, and one scalene shape. For each energy and for every geometrical configuration, an analytical relationship between the absorbed fraction and a 'generalized radius' was found, and the dependence of the fit parameters from electron energy is discussed and fitted by proper parametric functions. With the proposed formulation, the absorbed fraction for electrons in the 10-2000 keV energy range can be calculated for all volumes and for every ellipsoidal shape of practical interest. This method can be directly applied to evaluation of the absorbed fraction from the radionuclide emission of monoenergetic electrons, such as Auger or conversion electrons. The average deposited energy per disintegration in the case of extended beta spectra can be evaluated through integration. Two examples of application to a pure beta emitter such as 90Y and to 131I, whose emission include monoenergetic and beta electrons plus gamma photons, are presented. This approach represent a generalization of our previous studies, allowing a comprehensive treatment of absorbed fractions from electron and photon sources uniformly distributed in ellipsoidal volumes of any ellipticity and volume, in the whole range of practical interest for internal dosimetry in nuclear medicine applications, as well as in radiological protection estimations of doses from an internal contamination.

  9. Computational modeling of the mathematical phantoms of the Brazilian woman to internal dosimetry calculations and for comparison of the absorbed fractions with specific reference women

    International Nuclear Information System (INIS)

    The theme of this work is the study of the concept of mathematical dummy - also called phantoms - used in internal dosimetry and radiation protection, from the perspective of computer simulations. In this work he developed the mathematical phantom of the Brazilian woman, to be used as the basis of calculations of Specific Absorbed Fractions (AEDs) in the body's organs and skeleton by virtue of goals with regarding the diagnosis or therapy in nuclear medicine. The phantom now developed is similar, in form, to Snyder phantom making it more realistic for the anthropomorphic conditions of Brazilian women. For so we used the Monte Carlo method of formalism, through computer modeling. As a contribution to the objectives of this study, it was developed and implemented the computer system cFAE - consultation Fraction Specific Absorbed, which makes it versatile for the user's query researcher

  10. Specific absorbed fractions from the image-based VIP-Man body model and EGS4-VLSI Monte Carlo code: internal electron emitters

    Science.gov (United States)

    Chao, T. C.; Xu, X. G.

    2001-04-01

    VIP-Man is a whole-body anatomical model newly developed at Rensselaer from the high-resolution colour images of the National Library of Medicine's Visible Human Project. This paper summarizes the use of VIP-Man and the Monte Carlo method to calculate specific absorbed fractions from internal electron emitters. A specially designed EGS4 user code, named EGS4-VLSI, was developed to use the extremely large number of image data contained in the VIP-Man. Monoenergetic and isotropic electron emitters with energies from 100 keV to 4 MeV are considered to be uniformly distributed in 26 organs. This paper presents, for the first time, results of internal electron exposures based on a realistic whole-body tomographic model. Because VIP-Man has many organs and tissues that were previously not well defined (or not available) in other models, the efforts at Rensselaer and elsewhere bring an unprecedented opportunity to significantly improve the internal dosimetry.

  11. Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetry and ends of comparison of the fractions absorbed specific with the woman reference

    International Nuclear Information System (INIS)

    Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97R computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF - consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several 'look-up' facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them. (author)

  12. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons

    Energy Technology Data Exchange (ETDEWEB)

    Hadid, L; Desbree, A; Franck, D; Blanchardon, E [IRSN, Institute for Radiological Protection and Nuclear Safety, Internal Dosimetry Department, IRSN/DRPH/SDI, BP 17, F-92262 Fontenay-aux-Roses Cedex (France); Schlattl, H; Zankl, M, E-mail: lama.hadid@irsn.f [Institute of Radiation Protection, Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Neuherberg (Germany)

    2010-07-07

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum Muenchen (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  13. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons

    Science.gov (United States)

    Hadid, L.; Desbrée, A.; Schlattl, H.; Franck, D.; Blanchardon, E.; Zankl, M.

    2010-07-01

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  14. Specific absorbed fractions of energy at various ages from internal photon sources: 5, Fifteen-year-old male and adult female

    International Nuclear Information System (INIS)

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. In this volume PHI-values are tabulated for a fifteen-year-old male or an adult female (55 to 58 kg). These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with other methods of Snyder et al. at photon energies below 200 keV. 12 refs., 2 tabs

  15. Absorbed fraction of electrons in human respiratory tract

    International Nuclear Information System (INIS)

    Absorbed fractions of electrons, defined as part of electron energy deposited in the target, were calculated for various combinations of source and targets in HRTM. In that propose source code for PENELOPE was developed while respirator tract was modeled according to ICRP66. Absorbed fractions were fitted with the function presented in the paper

  16. Self-absorption effects on electron absorbed fraction in the anterior nose

    International Nuclear Information System (INIS)

    The electron absorbed fraction in the anterior nose is estimated in the International Commission on Radiological Protection Publication 66 using EGS4 Code and a cylinder model. The electrons are assumed to come from point sources lining the inner surface of the nose. Although the radioactive source particles are carried in dust, self-absorption in the dust is ignored. Consequently, the absorbed fractions published in ICRP 66 cannot represent the correct energy deposition in the basal cell region. In this work we estimate the energy lost by the emitted electrons inside spherical dust particles, which vary in diameter from 1 μm to 100 μm. The absorbed fractions in the basal cell layer are then estimated using the modified electron energy spectrum. To illustrate these effects, modified absorbed fractions for a dust particle radius of 20 μm are compared to the absorbed fractions presented in ICRP 66. Significant differences are noted. (author)

  17. Charged particle equilibrium effects on the electron absorbed fraction in the extra-thoracic airways

    International Nuclear Information System (INIS)

    Estimates of the dose to the extra thoracic airway (nasal vestibule) from inhaled beta-emitting radionuclides, obtained using the respiratory tract model presented in Publication 66 of the International Commission on Radiological Protection, frequently predict that the basal cells in this region are the most highly irradiated tissues of the body. The dose to the basal cells is averaged over a layer of tissue 10 μm thick located at a depth of 40 μm into the airway assuming that charged particle equilibrium exists. Since the target (basal cell layer) is very small and thin (10 cm2 area and 10 μm thickness), charged particle equilibrium does not exist. In this work the effect on the absorbed fraction of the lack of charged particle equilibrium is investigated. (authors)

  18. Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

    Institute of Scientific and Technical Information of China (English)

    WANG Wen; CHENG Meng-Yun; LONG Peng-Cheng; HU Li-Qin

    2015-01-01

    The specific absorbed fractions (SAF) for self-and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides.A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom,which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team.The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians.In this study,the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP.Results were compared with the values from ICRP reference and ORNL models.The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models.The differences were due to the racial and anatomical differences in organ mass and inter-organ distance.The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females.

  19. Specific Absorbed Fractions of Electrons and Photons for Rad-HUMAN Phantom Using Monte Carlo Method

    CERN Document Server

    Wang, Wen; Long, Peng-cheng; Hu, Li-qin

    2014-01-01

    The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photon and electron were calculated using the Rad-HUMAN phantom, a computational voxel phantom of Chinese adult female and created using the color photographic image of the Chinese Visible Human (CVH) data set. The model can represent most of Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10keV to 4MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from Rad-HUMAN have the similar trends but larger than those from the other two models. The differences were due to the racial and anatomical differences in o...

  20. Specific absorbed fraction in bone tissue and bone marrow resulting from photons distributed in the skeleton

    International Nuclear Information System (INIS)

    The computer code 'ALGAM: Monte Carlo Estimation of Internal Dose from Gamma -ray Sources in a Phanton Man' only provides for an average dose to bone marrow resulting from a photon source distributed in the human body. Since there is no realistic model for the separation of these doses in the present phantom, some modifications were performed in the ALGAM code in order to introduce an heterogeneous skeleton and through this new model it was possible to make the estimation of dose in bone marrow. The specific absorbed fraction resulting from running the new program for 12 monoenergetic photon sources distributed in three source organs - skeleton, red marrow and yellow marrow is presented. The results obtained show that for low photon energies, the old model overestimates the specific absorbed fraction in bone marrow up to a factor of 4; while in bone, it underestimates the specific absorbed fractions up to a factor of 1.6. (Author)

  1. Absorbed Dose Distributions in Irradiated Plastic Tubing and Wire Insulation

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1979-01-01

    Plastic tubing and wire insulation were simulated by radiochromic dye dosimeter films having electron absorbing properties similar to the materials of interest (polyethylene and PVC). A 400-keV electron accelerator was used to irradiate from 1, 2, 3 and 4 sides simulating possible industrial...

  2. Specific absorbed fractions and S-factors for calculating absorbed dose to embryo and fetus

    International Nuclear Information System (INIS)

    The variation of specific absorbed fractions from maternal tissues to embryo/fetus is investigated for four different target masses and geometries. S-factors are calculated for selected radionuclides assumed to be distributed uniformly in fetal tissues represented by spheres from 1 mg to 4 kg. As an example, the dose to fetal tissues for iodine-131 and iron-59 is estimated based on human biokinetic data for various stages of pregnancy. 24 references, 4 tables

  3. International Developments of Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P. [Head, Food Preservation Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940`s: discovery of principles of food irradiation; 1950`s: initiation of research in advanced countries; 1960`s: research and development were intensified in some advanced and developing countries; 1970`s: proof of wholesomeness of irradiated foods; 1980`s: establishment of national regulations; 1990`s: commercialization and international trade. (Author)

  4. International Developments of Food Irradiation

    International Nuclear Information System (INIS)

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940's: discovery of principles of food irradiation; 1950's: initiation of research in advanced countries; 1960's: research and development were intensified in some advanced and developing countries; 1970's: proof of wholesomeness of irradiated foods; 1980's: establishment of national regulations; 1990's: commercialization and international trade. (Author)

  5. Specification of absorbed dose for reporting a therapeutic irradiation

    International Nuclear Information System (INIS)

    The problem of dose specification in external beam therapy with photons and electrons has been dealt with in ICRU Report 29 (1978). This problem arises from the fact that the absorbed dose distribution is usually not uniform in the target volume and that for the purpose of treatment reporting a nominal absorbed dose - which will be called target absorbed dose - has to be selected. When comparing the clinical results obtained between radiotherapy centres, the differences in the reported target absorbed doses which can be introduced by differences in the methods of dose specification often are much larger than the differences related to the dosimetric procedures themselves. This shows the importance of the problem. In this paper, some definitions of terms and concepts currently used in radiotherapy are first recalled: tumour volume, target volume, treatment volume, etc. These definitions have been proposed in ICRU Report 29 for photon and electron beams; they can be extended to any kind of irradiation. For external beam therapy with photons and electrons, the target absorbed dose is defined as the absorbed dose at selected point(s) (specification point(s)) having a meaningful relation to the target volume and/or the irradiation beams. Examples are discussed for typical cases. As far as interstitial and intracavitary therapy is concerned, the problem is more complex and no recommendations have so far been made by the ICRU Commission. A major difficulty arises from the sharp dose gradient as a function of the distance to the sources. The particular case of the treatment of cervix carcinoma is considered and some possible methods of specification are discussed: (1) the indication of the sources (in adequate units) and the duration of the application, (2) the absorbed doses at selected reference points (bladder, rectum, bony structures) and (3) the description of the tissue volume (height, width, thickness) encompassed by a given isodose surface (60Gy). (author)

  6. A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions

    International Nuclear Information System (INIS)

    Existing models that allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six, and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs., 2 figs

  7. A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions

    Energy Technology Data Exchange (ETDEWEB)

    Watson, E.E.; Stabin, M.G.

    1986-01-01

    Existing models that allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six, and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs., 2 figs.

  8. Changes of arterial blood pressure, heart rate, internal body temperature, and blood acido-basic balance in the unanaesthetized rabbit following whole-body gamma irradiation at a mean absorbed dose of 250 rads

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, R.; Court, L.

    1973-09-01

    The general effects of whole-body gamma -irradiation at a mean absorbed dose of 250 rads were studied simultaneously in the unanaesthetized rabbit for 48 hours. They occurred early, with the following characteristics: arterial blood pressure decreased steadily as early as the 2nd hour and reached its minimum value on the 5th hour with a decrease of about 14%; it remained low during the following two days. Heart rate increased during the first hour, was the highest by the end of the second hour, and resumed normal value on the 24th hour. Internal body temperature increased during the 1st hour and was maximum by the end of the 2nd hour, with a mean increase of 1.2 deg C; hyperthermia steadily decreased between the 4th and the 6th hours and had completely disappeared by the 24th hour. Respiratory alkalosis is shown in the acido-basic balance by a raise of pH, a decrease of PCO/sub 2/ and arterial blood bicarbonates. These various changes seem to indicate a double origin, both central and peripheral. (FR)

  9. International status of food irradiation

    International Nuclear Information System (INIS)

    Recent international moves that are likely to result in an increasing acceptance of irradiated foods are reviewed. Particular attention is given to the activities of the FAO, WHO, Codex Alimentarius and to attitudes in the United States and the Asian-Pacific region. In 1979, the Codex Alimentarius Commission adopted a Recommended General Standard for Irradiated Food. A resume is given of a revised version of the standard that is presently under consideration. However, remaining barriers to trade in irradiated food are briefly discussed, such as legal and regulatory problems, labelling, public acceptance and economic viability

  10. Patient absorbed radiation doses estimation related to irradiation anatomy

    International Nuclear Information System (INIS)

    Developed a direct equation to estimate the absorbed dose to the patient in x-ray examinations, using electric, geometric parameters and filtering combined with data from irradiated anatomy. To determine the absorbed dose for each examination, the entrance skin dose (ESD) is adjusted to the thickness of the patient's specific anatomy. ESD is calculated from the estimated KERMA greatness in the air. Beer-Lambert equations derived from power data mass absorption coefficients obtained from the NIST / USA, were developed for each tissue: bone, muscle, fat and skin. Skin thickness was set at 2 mm and the bone was estimated in the central ray of the site, in the anteroposterior view. Because they are similar in density and attenuation coefficients, muscle and fat are treated as a single tissue. For evaluation of the full equations, we chose three different anatomies: chest, hand and thigh. Although complex in its shape, the equations simplify direct determination of absorbed dose from the characteristics of the equipment and patient. The input data is inserted at a single time and total absorbed dose (mGy) is calculated instantly. The average error, when compared with available data, is less than 5% in any combination of device data and exams. In calculating the dose for an exam and patient, the operator can choose the variables that will deposit less radiation to the patient through the prior analysis of each combination of variables, using the ALARA principle in routine diagnostic radiology sector

  11. Neutron Absorbing Ability Variation in Neutron Absorbing Material Caused by the Neutron Irradiation in Spent Fuel Storage Facility

    International Nuclear Information System (INIS)

    In spent fuel storage facility like high density spent fuel storage racks and dry storage casks, spent fuels are stored with neutron absorbing materials installed as a part of those facilities, and they are used for absorbing neutrons emitted from spent fuels. Usually structural material with neutron absorbing material of racks and casks are located around spent fuels, so it is irradiated by neutrons for long time. Neutron absorbing ability could be changed by the variation of nuclide composition in neutron absorbing material caused by the irradiation of neutrons. So, neutron absorbing materials are continuously faced with spent fuels with boric acid solution or inert gas environment. Major nuclides in neutron absorbing material are Al27, C12, B11, B10 and they are changed to numerous other ones as radioactive decay or neutron absorption reaction. The B10 content in neutron absorbing material dominates the neutron absorbing ability, so, the variation of nuclide composition including the decrease of B10 content is the critical factor on neutron absorbing ability. In this study, neutron flux in spent fuel, the activation of neutron absorbing material and the variation of nuclide composition are calculated. And, the minimum neutron flux causing the decrease of B10 content is calculated in spent fuel storage facility. Finally, the variation of neutron multiplication factor is identified according to the one of B10 content in neutron absorbing material. The minimum neutron flux to impact the neutron absorbing ability is 1010 order, however, usual neutron flux from spent fuel is 108 order. Therefore, even though neutron absorbing material is irradiated for over 40 years, B10 content is little decreased, so, initial neutron absorbing ability could be kept continuously

  12. Response functions for computing absorbed dose to skeletal tissues from photon irradiation-an update

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Perry B; Bahadori, Amir A [Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Eckerman, Keith F [Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Lee, Choonsik [Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892 (United States); Bolch, Wesley E, E-mail: wbolch@ufl.edu [Nuclear and Radiological/Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2011-04-21

    A comprehensive set of photon fluence-to-dose response functions (DRFs) is presented for two radiosensitive skeletal tissues-active and total shallow marrow-within 15 and 32 bone sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron-absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon micro-CT images of trabecular spongiosa taken from a 40 year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, and a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In this study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma coefficients for active marrow, inactive marrow, trabecular bone and spongiosa at higher energies are calculated using the DRF algorithm setting the electron-absorbed fraction for self-irradiation to unity. By comparing kerma coefficients and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985 Br. J. Radiol. 58 345-56) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R{sup 2} = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites representing the first such derivation for this target tissue.

  13. Specific absorbed fraction of X-ray in tissues from human organs

    International Nuclear Information System (INIS)

    Full text: X- rays are widely used in medical imaging and radiation therapy. The user of radioisotopes must have knowledge about how radiation interacts with matter, especially with the human body, because when photons enter the medium/body, they degrade their energy and build up in the medium, giving rise to secondary radiation. Calculations of the energy absorbed in a medium include not only the contribution of the uncollided photons from the source, but must also include the contributions from collided and secondary photons. In practice, this is done by multiplying the contribution of the uncollided photons by the energy absorption buildup factor. An accurate absorbed dose calculation needs specific absorbed fraction of energy. Geometric progression (GP) fitting method has been used to compute energy absorption build-up factor of Human organs such as brain, breast, eye lens, GI track, heart, kidney, liver, lung, lymph, ovary, pancreas, testis and skeleton-femur. The computed absorption build-up factor is used to estimate specific absorbed fraction of energy. The thickness of the medium up to 10mm and with penetration depth up to 40 mean free paths considered. The dependence of specific absorbed fraction of energy on incident photon energy, penetration and the thickness of the medium have also been studied. The specific absorbed fraction of energy increases up to the Epe and then decreases. Here Epe is the energy value at which the photo electric interaction coefficients matches with Compton interaction coefficients for a given value of effective atomic number (Zeff). The variation of specific absorbed fractions with energy is due to dominance of photoelectric absorption in the lower end and dominance of pair production in the higher photon energy region. In the lower energy end photoelectric absorption is dominant photon interaction process; hence specific absorbed fractions values minimum. As the energy of incident photon increases, Compton scattering overtakes

  14. Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN/MG), Belo Horizonte, MG (Brazil)], e-mail: gas@cdtn.br, e-mail: pls@cdtn.br, e-mail: fcp@cdtn.br, e-mail: lcmb@cdtn.br, e-mail: pabloag@cdtn.br

    2009-07-01

    The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

  15. Absorber Tube with Internal Pin-Fins for Solar Parabolic Trough Collector

    Directory of Open Access Journals (Sweden)

    Kalidasan B.

    2016-01-01

    Full Text Available Solar parabolic trough collectors exploit solar energy for power generation in solar thermal power stations. These systems require long arrays of reflective troughs with absorber tube running along the axis of parabolic dish. A successful attempt to reduce the length of arrays was accomplished by experimentally analysing the modifications done in absorber tube. Two out of three tubes were fabricated and they were employed to obtain the performance parameters through experimentation conducted at VIT University, Vellore, India. Distilled water was used as the working fluid. Maximum efficiency of 39.12% was obtained at 451.6 W/m2 of direct normal irradiance (DNI for absorber tube with internal pin-fins and without glass tube (AFWGt compared to 8.15% obtained at same value of DNI and other conditions for simple absorber tube without glass cover (AWGt. Cylindrical parabolic trough available at the university was utilized, providing the basis for designing and fabrication of the tubes. Plots for varying mass flow rate at interval of 10 minutes were made against instantaneous thermal efficiency and heat utilized, for direct normal irradiance vs. temperature difference across the tubes and instantaneous thermal efficiency. Through the experimentation conducted, better performance was procured compared to earlier works. Thus, the proposal infers that absorber tube with internal fins has good scope for its application, both domestically as well as industrially. It also calls for further research and development of proposed techniques so as to achieve better performance curves.

  16. Calculation of half-value thickness for aluminum absorbers by means of fractional calculus

    International Nuclear Information System (INIS)

    Highlights: • Inconsistency of half-value thickness for Al absorber is corrected by fractional calculus. • Experiments and calculations are performed for Cs-137, Tl-204 and Sr-90/Y-90 beta sources. • Theoretical values are calculated as equivalent with experimental data at same fractional order. • This fractional order is standard for Al absorber. - Abstract: Half-value thickness of aluminum absorbers has been investigated experimentally and theoretically. Cs-137, Tl-204 and Sr-90/Y-90 radio-isotopes were used as beta sources. Inconsistency between experimental measurements and standard theoretical calculations has been removed with the help of fractional calculus. The experimental and theoretical half-thickness values have been found equivalent for fractional derivative order ≈0.3

  17. Paired-organ and other selected absorbed fraction for the Korean Reference Adult Male model

    International Nuclear Information System (INIS)

    The authors have developed a mathematical model for calculating internal radionuclide dosimetry for the Korean Reference Adult Male, and have also derived paired-organ and other selected inter-organ photon-specific absorbed fractions for this model. Each lung, kidney and adrenal gland was set as a separate source region even though each of them shares an identical physiological function with their complementary half. The thyroid gland was also set as a source region. Specific absorbed fractions (SAFs) were then derived by selecting 10 photon energies from 0.02 to 4.0 MeV inclusive. For this purpose the Monte Carlo methodology was used, and the derived SAF was compared with the resulting value of MIRD Pamphlet No. 5 and ORNL TM-8381, both of which were derived on the basis of the ICRP-23 reference man. The comparison showed that MIRD No. 5 and ORNL TM-8381 resulted in a higher absorbed fraction, but the phantom created on the basis of the Korean reference man led to a higher SAF. The weight of the organs of the phantom, and the size and location of the trunk seem to account for the differences. The energy-dependent differences in the SAFs are considered to be related to the distance between the source and target regions, the composition of the intervening tissues, and the photon energies and mean free paths. Also, as a result of deriving SAFs after setting each separate lung, kidney and adrenal gland as a source region, it was found that, although they are of the same physiological function, each individual organ serves as a source region on its own. Differences were noted in SAFs exerted on the source and target organs in accordance with the location of the organs, that is, whether they were located to the left or right of the source organs. The SAF derived in this study can be used for a more accurate internal radionuclide dosimetry for Koreans and other Orientals whose physiology, lifestyle and dietary habits are similar to those of Koreans. (authors)

  18. Effect of Acute and Fractionated Irradiation on Hippocampal Neurogenesis

    Directory of Open Access Journals (Sweden)

    Jin Kyu Kim

    2012-08-01

    Full Text Available Ionizing radiation has become an inevitable health concern emanating from natural sources like space travel and from artificial sources like medical therapies. In general, exposure to ionizing radiation such as γ-rays is one of the methods currently used to stress specific model systems. In this study, we elucidated the long-term effect of acute and fractionated irradiation on DCX-positive cells in hippocampal neurogenesis. Groups of two-month-old C57BL/6 female mice were exposed to whole-body irradiation at acute dose (5 Gy or fractional doses (1 Gy × 5 times and 0.5 Gy × 10 times. Six months after exposure to γ-irradiation, the hippocampus was analyzed. Doublecortin (DCX immunohistochemistry was used to measure changes of neurogenesis in the subgranular zone (SGZ of the hippocampal dentate gyrus (DG. The number of DCX-positive cells was significantly decreased in all acute and fractionally irradiation groups. The long-term changes in DCX-positive cells triggered by radiation exposure showed a very different pattern to the short-term changes which tended to return to the control level in previous studies. Furthermore, the number of DCX-positive cells was relatively lower in the acute irradiation group than the fractional irradiation groups (approximately 3.6-fold, suggesting the biological change on hippocampal neurogenesis was more susceptible to being damaged by acute than fractional irradiation. These results suggest that the exposure to γ-irradiation as a long-term effect can trigger biological responses resulting in the inhibition of hippocampal neurogenesis.

  19. Estimating Solar Irradiation Absorbed by Photovoltaic Panels with Low Concentration Located in Craiova, Romania

    Directory of Open Access Journals (Sweden)

    Ionel L. Alboteanu

    2015-03-01

    Full Text Available Solar irradiation is one of the important parameters that should be taken into consideration for the design and utilization of a photovoltaic system. Usually, the input parameters of a photovoltaic system are solar irradiation, the ambient environment temperature and the wind speed, and as a consequence most photovoltaic systems are equipped with sensors for measuring these parameters. This paper presents several mathematical models for solar irradiation assessment. The starting point is represented by the mathematical model of extraterrestrial irradiation, and resulting finally in the model for solar irradiation, absorbed by a low concentration photovoltaic panel. These estimating models of solar irradiation have been particularized for the Craiova, Romania, and have been verified through numerical simulation. Regarding terrestrial solar irradiation, four mathematical models have been adopted, namely Adnot, Haurwitz, Kasten and Empirical (EIM. Of these, the most appropriate for the Craiova location were the models Adnot and Empirical. Consequently, for the calculation of the solar irradiation absorbed by the photovoltaic (PV panels with low concentration, these models have been taken into consideration. In this study, a comparative analysis was also carried out with respect to the solar irradiation absorbed by the PV panels without concentration and those with collectedness of the solar radiation. This analysis was based on the results of numerical simulation and experimental tests.

  20. Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetry and ends of comparison of the fractions absorbed specific with the woman reference; Modelagem computacional do manequim matematico da mulher brasileira para calculos de dosimetria interna e para fins de comparacao das fracoes absorvidas especificas com a mulher referencia

    Energy Technology Data Exchange (ETDEWEB)

    Ximenes, Edmir

    2006-07-01

    Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97{sup R} computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF - consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several 'look-up' facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them. (author)

  1. Ultrastructural morphometry of parotid acinar cells following fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Grehn, A.-L.; Gustafsson, H.; Franzen, L.; Thornell, L.-E.; Henriksson, R. [Umeaa Univ. (Sweden)

    1997-01-01

    The aim of this study was to evaluate the long term effects on the ultrastructure of parotid glands after fractionated irradiation. The method implemented involved 5 x 6 Gy and 5 x 8 Gy, Monday to Friday 6 MV photons. By unilateral irradiation, the contralateral parotid gland served as a control. Although irradiation diminished the acinar cell density in light microscopic sections from 75 to 32% after 5 x 8 Gy of irradiation, ultrastructural morphometry could not detect any statistically significant differences in acinar cell size, nuclear size, nuclear density, granule area, mean granule size, or granule density. In general, greater differences were seen between rats receiving 30 or 40 Gy, on both the irradiated and the control side, than between the irradiated side and the control side. This was interpreted as due to differences in the nutritional state of the animals. This analysis concluded that individual acinar cells that survive irradiation seem not to be damaged in the long term when evaluated at the ultrastructural level. The study further stresses the importance of adequate sampling sizes and the use of adequate controls. (author).

  2. Mouse skin damages caused by fractionated irradiation with carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K.; Chen, Y.J.; Ohira, C.; Nojima, K.; Ando, S.; Kobayashi, N.; Ohbuchi, T.; Shimizu, W. [Space and Particle Radiation Science Research Group, Chiba (Japan); Koike, S.; Kanai, T. [National Inst. of Radiological Sciences, Chiba (Japan). Div. of Accelerator Physics

    1997-09-01

    We have investigated carbon-dose responses of early and late skin damages after daily fractionations to the mouse leg. Depilated legs were irradiated with 7 different positions within 290 MeV/u carbon beams. Fractionation schedules were 1, 2, 4 and 8 daily fractions. Skin reaction was scored every other day for 32 days. Five highest scores in individual mice were averaged, and used as averaged peak reaction. The isoeffect doses to produce an averaged peak skin reaction of 3.0 (moist desquamation) on dose-response curves were calculated with 95% confidence limit. The isoeffect dose for control gamma rays constantly increased with an increase in the number of fraction. The isoeffect doses in low LET carbon ions of 14- and 20 keV/{mu}m also increased up to 4 fractions, but did not increase when 4 fractions increased to 8 fractions. The saturation of isoeffect dose was more prominently observed for 40 keV/{mu}m in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/{mu}m were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/{mu} steadily increased with an increase in the number of fraction and did not show any saturation up to 8 fractions. Relation between LET and RBE was linear for all fractionation schedules. The slope of regression line in 4 fractions was steepest, and significantly (P<0.05) different from that in 1 fraction. (orig.)

  3. How to improve the irradiation conditions for the International Fusion Materials Irradiation Facility

    CERN Document Server

    Daum, E

    2000-01-01

    The accelerator-based intense D-Li neutron source International Fusion Materials Irradiation Facility (IFMIF) provides very suitable irradiation conditions for fusion materials development with the attractive option of accelerated irradiations. Investigations show that a neutron moderator made of tungsten and placed in the IFMIF test cell can further improve the irradiation conditions. The moderator softens the IFMIF neutron spectrum by enhancing the fraction of low energy neutrons. For displacement damage, the ratio of point defects to cascades is more DEMO relevant and for tritium production in Li-based breeding ceramic materials it leads to a preferred production via the sup 6 Li(n,t) sup 4 He channel as it occurs in a DEMO breeding blanket.

  4. Glycolytic metabolism and tumour response to fractionated irradiation

    International Nuclear Information System (INIS)

    Background and purpose: To study whether pre-therapeutic lactate or pyruvate predict for tumour response to fractionated irradiation and to identify possible coherencies between intermediates of glycolysis and expression levels of selected proteins. Materials and methods: Concentrations of lactate, pyruvate, glucose and ATP were quantified via bioluminescence imaging in tumour xenografts derived from 10 human head and neck squamous cell carcinoma (HNSCC) lines. Tumours were irradiated with 30 fractions within 6 weeks. Expression levels of the selected proteins in tumours were measured at the mRNA and protein level. Tumour-infiltrating leucocytes were quantified after staining for CD45. Results: Lactate but not pyruvate concentrations were significantly correlated with tumour response to fractionated irradiation. Lactate concentrations in vivo did not reflect lactate production rates in vitro. Metabolite concentrations did not correlate with GLUT1, PFK-L or LDH-A at the transcriptional or protein level. CD45-positive cell infiltration was low in the majority of tumours and did not correlate with lactate concentration. Conclusions: Our data support the hypothesis that the antioxidative capacity of lactate may contribute to radioresistance in malignant tumours. Non-invasive imaging of lactate to monitor radiation response and testing inhibitors of glycolysis to improve outcome after fractionated radiotherapy warrant further investigations.

  5. DNA damage induced by radionuclide internal irradiation

    International Nuclear Information System (INIS)

    Objective: To study the DNA damage of peripheral blood mononuclear cell (PBMC) in rats exposed to radionuclide internal irradiation. Methods: The radionuclides were injected into the rats and single cell get electrophoresis (SCGE) was performed to detect the length of DNA migration in the rat PBMC. Results: DNA migration in the rat PBMC increased with accumulative dose or dose-rate. It showed good relationship of dose vs. response and of dose-rate vs. response, both relationship could be described as linear models. Conclusion: Radionuclide internal irradiation could cause DNA damage in rat PBMC. (authors)

  6. Influence of voxel size on specific absorbed fractions and S-values in a mouse voxel phantom.

    Science.gov (United States)

    Mohammadi, A; Kinase, S

    2011-02-01

    Photon and electron specific absorbed fractions (SAFs) and S-values have been evaluated using mouse voxel phantoms. In voxel phantoms, it is important to choose the voxel size carefully since it affects the accuracy of results. In this study, two mouse voxel phantoms were constructed, with cubic voxels, one with 0.1-mm sides and the other with 0.4-mm sides. The sources were considered to be distributed uniformly in the main organs and the radiation transport was simulated using the Monte Carlo code EGS4. It was found that the effect of voxel size on SAFs for self-irradiation was not high (voxel size was investigated on S-values for some beta emitters such as (131)I, (153)Sm, (188)Re and (90)Y.

  7. Traversal of cells by radiation and absorbed fraction estimates for electrons and alpha particles

    International Nuclear Information System (INIS)

    Consideration of the pathlength which radiation traverses in a cell is central to algorithms for estimating energy deposition on a cellular level. Distinct pathlength distributions occur for radionuclides: (1) uniformly distributed in space about the cell (referred to as μ-randomness); (2) uniformly distributed on the surface of the cell (S-randomness); and (3) uniformly distributed within the cell volume (I-randomness). For a spherical cell of diameter d, the mean pathlengths are 2/3d, and 3/4d, respectively, for these distributions. Algorithms for simulating the path of radiation through a cell are presented and the absorbed fraction in the cell and its nucleus are tabulated for low energy electrons and alpha particles emitted on the surface of spherical cells. The algorithms and absorbed fraction data should be of interest to those concerned with the dosimetry of radionuclide-labeled monoclonal antibodies. 8 references, 3 figures, 2 tables

  8. International standards and agreements in food irradiation

    International Nuclear Information System (INIS)

    The economies of both developed and developing countries have been effected by their exported food and agricultural products. Trading policies of food and agricultural products are governed by international agreement as well as national regulations. Trade in food and agricultural commodities may be affected by both principal Agreements within the overall World Trade Organization (WTO) Agreement, though neither specifically refers to irradiation or irradiated foods. The principal Agreements are the Technical Barriers to Trade (TBT) Agreement and the Sanitary and Phyto sanitary (SPS) Agreement. The SPS of the WTO requires governments to harmonize their sanitary and phyto sanitary measures on as wide basis as possible. Related standards, guidelines and recommendations of international standard setting bodies such as the Codex Alimentarius Commission (food safety); the International Plant Protection Convention (IPPC) (plant health and quarantine); and International Office of Epizootic (animal health and zoo noses) should be used in such a harmonization. International Standards for Phyto sanitary Measures (ISPM) no.18 was published under the IPPC by FAO (April 2003, Rome-Italy). ISPM standard provides technical guidance on the specific procedure for the application of ionizing radiation as a phyto sanitary treatment for regulated pests or articles. Moreover, Codex Alimentarius Commission, Codex General Standard for Irradiated Foods (Stand 106-1983) and Recommended International Code of Practice were first published in 1983 and revised in March 2003. Scope of this standard applies to foods processed by ionizing radiation that is used in conjunction with applicable hygienic codes, food standards and transportation codes. It does not apply to foods exposed to doses imparted by measuring instruments used for inspection purposes. Codex documents on Principles and Guidelines for the Import/Export Inspection and Certification of Foods have been prepared to guide international

  9. Comparison of One and Two Fractional Irradiation by X-rays on Fibroblasts

    Institute of Scientific and Technical Information of China (English)

    WangJufang; WeyratherWilma

    2003-01-01

    In order to investigate the fractional effect, normal human fibroblasts GM5758 were irradiated with oneand two fractional X-rays. After irradiation, cell survival was performed by standard methods. Cell terminal differentiation pattern was determined as mitotic fibroblasts (MF) Ⅰ, Ⅱ and Ⅲ, post mitotic fibroblasts (PMF) Ⅳ, Ⅴ and Ⅵ, according to cellular morphology, as described by C. Fournier. As show in Fig.l, the survival fraction of two-fraction irradiation is higher than that of one-fraction irradiation. This result suggests that sub-lethal damage induced by radiation can be repaired efficiently for fractional irradiation. As for differentiation

  10. Food Irradiation. Proceedings of the International Symposium on Food Irradiation

    International Nuclear Information System (INIS)

    For some years research has been done in several countries, with the object of contributing to the world's food supplies, on the application of nuclear methods to food preservation and processing. The importance of food preservation is of particular relevance in certain regions of the world where up to thirty per cent of harvested foodstuffs are being lost because of damage by animal pests and microorganisms. A series of international meetings have been held on this subject; the first, held in 1958 at Harwell, was followed by further meetings in 1960 in Paris and in 1961 in Brussels. The International Symposium on Food Irradiation organized by the International Atomic Energy Agency and the Food and Agriculture Organization of the United Nations through their Joint Division of Atomic Energy in Agriculture, and held at the Karlsruhe Nuclear Research Centre, Karlsruhe, from 6 to 10 June 1966, at the generous invitation of the Government of the Federal Republic of Germany, is the most recent of this series of meetings. It was held for the purpose of exchanging the most up-to-date results of research, of contributing towards co-operative efforts between Member States, and of stimulating trade in the international exchange of irradiated products between nations. Papers describing research over the past fourteen years were given by outstanding authorities; the results point to a breakthrough having been achieved in the use of ionizing radiation in food preservation, notwithstanding some problems still to be solved, such as overcoming changes in colour, flavour, odour or texture. The Symposium was attended by over 200 scientists from 25 countries and four international organizations. Sixty-nine papers were presented. It was shown that a wide variety of foodstuffs exist for which radiation could be used for three different purposes: to produce indefinitely stable products, to rid food of organisms that constitute health hazards, and to extend the normal shelf or market life

  11. Photon and electron specific absorbed fractions for the University of Florida paediatric hybrid computational phantoms

    International Nuclear Information System (INIS)

    The University of Florida has developed a set of computational phantoms which originated from real human anatomy in the form of computed tomography (CT) image sets. The organ shapes, orientation, and placement of the internal anatomy were directly determined from these image sets, imported into a 3D graphics program Rhinoceros, and scaled to ICRP reference values. Rhinoceros employs a method of volume description called non-uniform rational B-spline (NURBS) surfaces. Any given volume is described by the boundary created by these surfaces. The surfaces themselves are easy to manipulate, so non-reference body morphometries are readily modeled. The majority of the gross human anatomy was created using NURBS surfaces, but the skeleton was treated separately due to its complexity. A skeletal model with delineated cortical bone and spongiosa/medullary cavity regions was created and imported into Rhinoceros and left in polygon mesh format. Surfaces are initially in polygon mesh format when imported. They are subsequently converted to NURBS surfaces. The result was a model which combines the anatomic realism of actual human anatomy with the simple deformability of stylized models. This class of phantom was termed the ''hybrid'' phantom. Male and female models were created for the ICRP reference ages of newborn, 1 year, 5 years, 10 years, and 15 years. The process for performing internal dosimetry for non-skeletal anatomy is relatively straight forward. Using MCNPX 2.6, radiation transport is performed, and the energy deposited in any given target organ is tallied and divided by the total energy emitted from any given source organ and the target organ's mass. This calculation yields the specific absorbed fraction or SAF, which contains the critical geometric information needed to perform accurate dose calculations for any nuclear medicine procedure. Coupled with the total number of transformations in the source organ and the radionuclide's radiation energies and yields, a

  12. Study on Fractionated Total Body Irradiation before Hematopoietic Stem Cell Transplantation

    Institute of Scientific and Technical Information of China (English)

    Tong Fang; Bo Liu; Hong Gao

    2009-01-01

    OBJECTIVE To observe the dose and the complications from total body irradiation before hematopoietic stem cell transplantation.METHODS This study involved 312 patients with total body irradiation before hematopoietic stem cell transplantation. They were entered into the treated research from May 1999 to October 2005. All patients had Received the irradiation from 60Co of an absorbed dose rate of (5.2 ± 1.13) cGy/min. The total dose of TBI was 7~12 Gy, 1 f/d × 2 d. A high-dose rate group (≥ 10 Gy) included 139 cases and a low-dose rate group (< 10 Gy) included 173 cases.RESULTS The probability of acute gastrointestinal reactions in the high-dose rate group was more compared with that in the low-dose rate group. The differences for other reactions, such as hematopoietic reconstitution and graft survival rate, between the two groups were insignificant.CONCLUSION Using fractional total body irradiation at a dose rate of 5 cGy/min, with a total dose of 7~12 Gy, 1 f/d x 2 d, with the lung receiving under 7.5 Gy is a safe and effective pretreatment for hematopoietic stem cell transplantation.

  13. NOAA Climate Data Record (CDR) of Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR), Version 4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains gridded daily Leaf Area Index (LAI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) derived from the NOAA Climate Data...

  14. Quality assurance program of a respiratory gating irradiation system based on external and internal fiducial markers

    International Nuclear Information System (INIS)

    Respiratory Gating involves the administration of radiation during treatment delivery within a particular portion of the patients breathing cycle, so the absorbed dose administration with respiratory control techniques requires specific quality control to ensure the correctness of the delivered dose. The establishment of a Quality Control Program (QC) is proposed for the Respiratory Gating based techniques in order to have a better understanding of how this system works and to know its associated dosimetric impact. The influence of the CT acquisition under respiratory motion conditions has been analyzed for the treatment isocenter localization, using internal and external fiducial markers with IGRT techniques that allow the correlation of the isocenter positioning with the phase of the respiratory cycle. Radiation delivery in the presence of intra fraction organ motion causes an averaging or blurring of the static dose distribution over the path of motion increasing the beam penumbra of the radiation field and reducing the therapeutic region when the irradiation is not breath controlled. The feasibility of intensity modulated treatments (IMRT) for both static and dynamic techniques, managed by respiratory control has been tested, demonstrating the possibility of synchronizing the movement of the leaves in the microfluorimeter collimator (mMLC) with the gated beam irradiation. (Author) 45 refs.

  15. Mean Absorbed Dose to the Anal-Sphincter Region and Fecal Leakage among Irradiated Prostate Cancer Survivors

    Energy Technology Data Exchange (ETDEWEB)

    Alsadius, David, E-mail: david.alsadius@oncology.gu.se [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg (Sweden); Hedelin, Maria [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg (Sweden); Division of Clinical Cancer Epidemiology, Department of Oncology-Pathology, Karolinska Institute, Stockholm (Sweden); Lundstedt, Dan [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg (Sweden); Pettersson, Niclas [Department of Radiophysics, Sahlgrenska Academy at University of Gothenburg (Sweden); Wilderaeng, Ulrica [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg (Sweden); Steineck, Gunnar [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg (Sweden); Division of Clinical Cancer Epidemiology, Department of Oncology-Pathology, Karolinska Institute, Stockholm (Sweden)

    2012-10-01

    Purpose: To supplement previous findings that the absorbed dose of ionizing radiation to the anal sphincter or lower rectum affects the occurrence of fecal leakage among irradiated prostate-cancer survivors. We also wanted to determine whether anatomically defining the anal-sphincter region as the organ at risk could increase the degree of evidence underlying clinical guidelines for restriction doses to eliminate this excess risk. Methods and Materials: We identified 985 men irradiated for prostate cancer between 1993 and 2006. In 2008, we assessed long-term gastrointestinal symptoms among these men using a study-specific questionnaire. We restrict the analysis to the 414 men who had been treated with external beam radiation therapy only (no brachytherapy) to a total dose of 70 Gy in 2-Gy daily fractions to the prostate or postoperative prostatic region. On reconstructed original radiation therapy dose plans, we delineated the anal-sphincter region as an organ at risk. Results: We found that the prevalence of long-term fecal leakage at least once per month was strongly correlated with the mean dose to the anal-sphincter region. Examining different dose intervals, we found a large increase at 40 Gy; {>=}40 Gy compared with <40 Gy gave a prevalence ratio of 3.8 (95% confidence interval 1.6-8.6). Conclusions: This long-term study shows that mean absorbed dose to the anal-sphincter region is associated with the occurrence of long-term fecal leakage among irradiated prostate-cancer survivors; delineating the anal-sphincter region separately from the rectum and applying a restriction of a mean dose <40 Gy will, according to our data, reduce the risk considerably.

  16. IRRADIATION TESTING OF THE RERTR FUEL MINIPLATES WITH BURNABLE ABSORBERS IN THE ADVANCED TEST REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    I. Glagolenko; D. Wachs; N. Woolstenhulme; G. Chang; B. Rabin; C. Clark; T. Wiencek

    2010-10-01

    Based on the results of the reactor physics assessment, conversion of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) can be potentially accomplished in two ways, by either using U-10Mo monolithic or U-7Mo dispersion type plates in the ATR fuel element. Both designs, however, would require incorporation of the burnable absorber in several plates of the fuel element to compensate for the excess reactivity and to flatten the radial power profile. Several different types of burnable absorbers were considered initially, but only borated compounds, such as B4C, ZrB2 and Al-B alloys, were selected for testing primarily due to the length of the ATR fuel cycle and fuel manufacturing constraints. To assess and compare irradiation performance of the U-Mo fuels with different burnable absorbers we have designed and manufactured 28 RERTR miniplates (20 fueled and 8 non-fueled) containing fore-mentioned borated compounds. These miniplates will be tested in the ATR as part of the RERTR-13 experiment, which is described in this paper. Detailed plate design, compositions and irradiations conditions are discussed.

  17. FRACTIONAL DIFFUSION EQUATIONS WITH INTERNAL DEGREES OF FREEDOM

    Institute of Scientific and Technical Information of China (English)

    Luis Vázquez

    2003-01-01

    We present a generalization of the linear one-dimensional diffusion equation by combining the fractional derivatives and the internal degrees of freedom. The solutions are constructed from those of the scalar fractional diffusion equation. We analyze the interpolation between the standard diffusion and wave equations defined by the fractional derivatives. Our main result is that we can define a diffusion process depending on the internal degrees of freedom associated to the system.

  18. An international dosimetry exchange for boron neutron capture therapy. Part I: Absorbed dose measurements.

    Science.gov (United States)

    Binns, P J; Riley, K J; Harling, O K; Kiger, W S; Munck af Rosenschöld, P M; Giusti, V; Capala, J; Sköld, K; Auterinen, I; Serén, T; Kotiluoto, P; Uusi-Simola, J; Marek, M; Viererbl, L; Spurny, F

    2005-12-01

    An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 microg g(-1) that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study. PMID:16475772

  19. Absorbed dose assessment in particle-beam irradiated metal-oxide and metal-nonmetal memristors

    Directory of Open Access Journals (Sweden)

    Knežević Ivan D.

    2012-01-01

    Full Text Available Absorbed dose was estimated after Monte Carlo simulation of proton and ion beam irradiation on metal-oxide and metal-nonmetal memristors. A memristive device comprises two electrodes, each of a nanoscale width, and a double-layer active region disposed between and in electrical contact with electrodes. Following materials were considered for the active region: titanium dioxide, zirconium dioxide, hafnium dioxide, strontium titanium trioxide and galium nitride. Obtained results show that significant amount of oxygen ion - oxygen and nonmetal ion - nonmetal vacancy pairs is to be generated. The loss of such vacancies from the device is believed to deteriorate the device performance over time. Estimated absorbed dose values in the memristor for different constituting materials are of the same order of magnitude because of the close values of treshold displacement energies for the investigated materials.

  20. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    OpenAIRE

    Liu, Fangfang; Conghui DU; Linya ZHANG

    2015-01-01

    The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA) as cross linking agent, and (NH4)2S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that...

  1. Response functions for computing absorbed dose to skeletal tissues from neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bahadori, Amir A; Johnson, Perry; Bolch, Wesley E [Department of Biomedical Engineering, University of Florida, Gainesville, FL (United States); Jokisch, Derek W [Department of Physics and Astronomy, Francis Marion University, Florence, SC (United States); Eckerman, Keith F, E-mail: wbolch@ufl.edu [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2011-11-07

    Spongiosa in the adult human skeleton consists of three tissues-active marrow (AM), inactive marrow (IM) and trabecularized mineral bone (TB). AM is considered to be the target tissue for assessment of both long-term leukemia risk and acute marrow toxicity following radiation exposure. The total shallow marrow (TM{sub 50}), defined as all tissues lying within the first 50 {mu}m of the bone surfaces, is considered to be the radiation target tissue of relevance for radiogenic bone cancer induction. For irradiation by sources external to the body, kerma to homogeneous spongiosa has been used as a surrogate for absorbed dose to both of these tissues, as direct dose calculations are not possible using computational phantoms with homogenized spongiosa. Recent micro-CT imaging of a 40 year old male cadaver has allowed for the accurate modeling of the fine microscopic structure of spongiosa in many regions of the adult skeleton (Hough et al 2011 Phys. Med. Biol. 56 2309-46). This microstructure, along with associated masses and tissue compositions, was used to compute specific absorbed fraction (SAF) values for protons originating in axial and appendicular bone sites (Jokisch et al 2011 Phys. Med. Biol. 56 6857-72). These proton SAFs, bone masses, tissue compositions and proton production cross sections, were subsequently used to construct neutron dose-response functions (DRFs) for both AM and TM{sub 50} targets in each bone of the reference adult male. Kerma conditions were assumed for other resultant charged particles. For comparison, AM, TM{sub 50} and spongiosa kerma coefficients were also calculated. At low incident neutron energies, AM kerma coefficients for neutrons correlate well with values of the AM DRF, while total marrow (TM) kerma coefficients correlate well with values of the TM{sub 50} DRF. At high incident neutron energies, all kerma coefficients and DRFs tend to converge as charged-particle equilibrium is established across the bone site. In the range of

  2. Side branch absorber for exhaust manifold of two-stroke internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Ralph E. (San Antonio, TX); Broerman, III, Eugene L. (San Antonio, TX); Bourn, Gary D. (Laramie, WY)

    2011-01-11

    A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.

  3. Comparison of photon and electron absorbed fractions in voxel-based and simplified phantoms for small animals

    International Nuclear Information System (INIS)

    Internal dosimetry on non-human biota is getting more important from the view point of radiation protection of environment. The International Commission on Radiological Protection (ICRP) proposed the Reference Animals and Plants using simplified phantoms, such as ellipsoids and spheres, and assessed absorbed fractions (AFs) for the whole bodies. In this study, photon and electron AFs in whole body of voxel-based frog and mouse phantoms were evaluated and compared with AFs in simplified phantoms. The evaluations were done by Monte Carlo methods for voxel-based and simplified phantoms. The monoenergetic photon or electron source was considered to be distributed uniformly in whole body. There were very small differences (less than 2%) between whole-body AFs in voxel-based and simplified mouse phantoms however the differences were up to 24% for the voxel-based and the Reference Frog phantoms. Whole-body AFs in voxel-based and simplified phantoms demonstrated that not only mass but also shape of whole body effected on AFs significantly. The results of this study suggest the replacement of the Reference Animal phantoms by voxel-based animal phantoms to improve the accuracy of the whole-body AFs. (author)

  4. Role and activities of international consultative group on food irradiation

    International Nuclear Information System (INIS)

    This paper discusses the formation of a consultative group to focus on international cooperation on food irradiation. The functions of the group include studying such items as legislation, wholesomeness of irradiated food, safety, trade and technical training, marketing and labelling and providing an inventory of food irradiation facilities. (U.K.)

  5. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation

    OpenAIRE

    Ganesh Chandra Jagetia; Golgod Krishnamurthy Rajanikant

    2015-01-01

    Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain b...

  6. Recent international developments regarding standardization of food irradiation treatment

    International Nuclear Information System (INIS)

    The recommendations of the Joint Expert Committee on Food Irradiation at its 1976 and 1979 meetings, published by WHO/FAO/IAEA in 1977 and 1980 are discussed in relation to the Recommended Codex International General Standard for Irradiated Food and the Recommended International Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Foods, which are based on them. The texts of these documents are appended. The problem of labelling irradiated foods is discussed

  7. Swelling and phenol absorbing property of Xanthan gum-g-N-vinylpyrrolidone prepared by irradiation

    International Nuclear Information System (INIS)

    Xanthan gum-g-N-vinylpyrrolidone graft copolymer (XG-g-NVP) was prepared by irradiation, and its swelling and phenol absorbing properties were studied. Results showed that the XG-g-NVP had the best swelling property (62.1 g/g) and the best phenol adsorption capacity (0.76 g/g) at the grafting yield of 623%. IR analysis showed that the copolymer was combined with phenol through hydrogen bonds. The data of isotherm were fitted to Freundlich model. At the temperature of 298 K, free energy (ΔG) of the adsorption process was -2.586 kJ/mol. Thus identified that the process was a physical adsorption and spontaneously occurred. Therefore, XG-g-NVP could be used as a highly effective adsorbent for wastewater treatment. (authors)

  8. Results of post-irradiation examinations of the absorber NS 201 (with pellets) of the KNK II first core

    International Nuclear Information System (INIS)

    The absorber NS-201 of the KNK II first core has been unloaded after a residence time of 273 equivalent full-power days, because gap closure between pellet and cladding had to be expected in 24 pins with B4C-pellets. Selected pins of this element underwent post-irradiation examinations in the hot cells of the KfK Karlsruhe. The evaluated and interpreted results of the investigations, which are documented in this report, allow the conclusion that the absorber could have been irradiated for the full core residence time. The good irradiation behaviour of the pellets and the cladding without any visible interaction, lead to the plan for further irradiation of a complete pellet column of one pin in the third core of KNK II

  9. A Comparison of Model Calculation and Measurement of Absorbed Dose for Proton Irradiation. Chapter 5

    Science.gov (United States)

    Zapp, N.; Semones, E.; Saganti, P.; Cucinotta, F.

    2003-01-01

    With the increase in the amount of time spent EVA that is necessary to complete the construction and subsequent maintenance of ISS, it will become increasingly important for ground support personnel to accurately characterize the radiation exposures incurred by EVA crewmembers. Since exposure measurements cannot be taken within the organs of interest, it is necessary to estimate these exposures by calculation. To validate the methods and tools used to develop these estimates, it is necessary to model experiments performed in a controlled environment. This work is such an effort. A human phantom was outfitted with detector equipment and then placed in American EMU and Orlan-M EVA space suits. The suited phantom was irradiated at the LLUPTF with proton beams of known energies. Absorbed dose measurements were made by the spaceflight operational dosimetrist from JSC at multiple sites in the skin, eye, brain, stomach, and small intestine locations in the phantom. These exposures are then modeled using the BRYNTRN radiation transport code developed at the NASA Langley Research Center, and the CAM (computerized anatomical male) human geometry model of Billings and Yucker. Comparisons of absorbed dose calculations with measurements show excellent agreement. This suggests that there is reason to be confident in the ability of both the transport code and the human body model to estimate proton exposure in ground-based laboratory experiments.

  10. Solar Multi-stage Refrigeration Systems on the Basis of Absorber with the Internal Evaporative Cooling

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-08-01

    Full Text Available In the article, the developed schematics are presented for the alternative refrigeration systems and air-conditioning systems, based on the use of absorbing cycle and solar energy for the regeneration of absorbent solution. Multi-stage principle of construction of drying and cool contours of solar systems is used with growth of concentration of absorbent on the stages of cooler. An absorber with internal evaporative cooling, allowing to remove the separate evaporated cooler, usually included after the absorber of the proper stage, is developed. Heat-mass-transfer apparatus of film-type, entering in the complement of drying and cool contours compatible and executed on the basis of multichannel compositions from polymeric materials. The preliminary comparative analysis of possibilities of the solar refrigeration systems and air-conditioning systems is executed.

  11. A model for assessing cognitive impairment after fractionated whole-brain irradiation in nonhuman primates.

    Science.gov (United States)

    Robbins, Mike E; Bourland, J Daniel; Cline, J Mark; Wheeler, Kenneth T; Deadwyler, Sam A

    2011-04-01

    To investigate the effect of fractionated whole-brain irradiation on nonhuman primates, 6-9-year-old male rhesus monkeys were irradiated with 40 Gy delivered as two 5-Gy fractions/week for 4 weeks. Cognitive function was assessed 5 days/week for 4 months prior to fractionated whole-brain irradiation and for 11 months after irradiation using a Delayed-Match-to-Sample (DMS) task at both low and high cognitive loads. Local rates of cerebral glucose metabolism were measured prior to and 9 months after irradiation using [(18)F]-2-deoxy-2-fluoro-d-glucose positron emission tomography. Low cognitive load trials did not reveal a significant reduction in performance until 7 months after irradiation; performance then declined progressively. In high cognitive load trials, the initial impairment was observed ∼1 month after irradiation. This was followed by a transient recovery period over the next 1-2 months, after which performance declined progressively through 11 months after irradiation. Nine months after irradiation, glucose uptake during the DMS task was decreased in the cuneate and prefrontal cortex and was increased in the cerebellum and thalamus compared with the levels prior to irradiation. Results from this pilot study suggest that the radiation-induced changes in cognition and brain metabolism observed in rhesus monkeys may be similar to those observed in brain tumor patients receiving brain irradiation. PMID:21275607

  12. Uncertainties in electron-absorbed fractions and lung doses from inhaled beta-emitters.

    Science.gov (United States)

    Farfán, Eduardo B; Bolch, Wesley E; Huston, Thomas E; Rajon, Didier A; Huh, Chulhaeng; Bolch, W Emmett

    2005-01-01

    The computer code LUDUC (Lung Dose Uncertainty Code), developed at the University of Florida, was originally used to investigate the range of potential doses from the inhalation of either plutonium or uranium oxides. The code employs the ICRP Publication 66 Human Respiratory Tract model; however, rather than using simple point estimates for each of the model parameters associated with particle deposition, clearance, and lung-tissue dosimetry, probability density functions are ascribed to these parameters based upon detailed literature review. These distributions are subsequently sampled within LUDUC using Latin hypercube sampling techniques to generate multiple (e.g., approximately 1,000) sets of input vectors (i.e., trials), each yielding a unique estimate of lung dose. In the present study, the dosimetry component of the ICRP-66 model within LUDUC has been extended to explicitly consider variations in the beta particle absorbed fraction due to corresponding uncertainties and biological variabilities in both source and target tissue depths and thicknesses within the bronchi and bronchioles of the thoracic airways. Example dose distributions are given for the inhalation of absorption Type S compounds of 90Sr (Tmax = 546 keV) and 90Y (Tmax = 2,284 keV) as a function of particle size. Over the particle size range of 0.001 to 1 microm, estimates of total lung dose vary by a factor of 10 for 90Sr particles and by a factor of 4 to 10 for 90Y particles. As the particle size increases to 10 microm, dose uncertainties reach a factor of 100 for both radionuclides. In comparisons to identical exposures scenarios run by the LUDEP 2.0 code, Reference Man doses for inhaled beta-emitters were shown to provide slightly conservative estimates of lung dose compared to those in this study where uncertainties in lung airway histology are considered.

  13. Aluminum levels in convenience and fast foods: in vitro study of the absorbable fraction.

    Science.gov (United States)

    López, Francisco E; Cabrera, Carmen; Lorenzo, M Luisa; López, M Carmen

    2002-12-01

    We evaluated the levels of aluminum in a total of 120 samples of 35 different convenience and fast foods that are widely consumed in Spain. Aluminum was determined in the samples mineralized with HNO3, HClO4 and V2O5, using electrothermal atomic absorption spectrometry as the analytical technique. Reliability of the procedure was checked by statistically comparing the results with those obtained with a previous microwave oven mineralization stage and by analysis of several certified reference materials. No matrix effect was observed and aqueous standard solutions were used for calibration. The detection limit was 4.0 pg and the characteristic mass of 10.0 pg. Aluminum concentrations ranged from 0.85 to 38.10 microg/g, refereed to fresh weight of the edible portion. The presence of this metal was detected in all the samples we analyzed, but the most elevated levels were encountered in pork- and chicken- based foods (mean 8.45 and 13.94 microg/g, respectively). The more elevated Al concentrations were detected in foods with a greater content of spices and aromatic herbs, pasta, certain vegetables and additives, and foods packaged in Al vessels. The absorbable fraction of Al estimated with in vitro assays was between 0.85 and 2.15%. The growing popularity of these products in recent years requires additional data and a periodical control. In addition, the present findings are of potential use to efforts aimed at determining tolerable levels of Al intake from the diet.

  14. Kantian fractionalization predicts the conflict propensity of the international system

    CERN Document Server

    Cranmer, Skyler J; Mucha, Peter J

    2014-01-01

    The study of complex social and political phenomena with the perspective and methods of network science has proven fruitful in a variety of areas, including applications in political science and more narrowly the field of international relations. We propose a new line of research in the study of international conflict by showing that the multiplex fractionalization of the international system (which we label Kantian fractionalization) is a powerful predictor of the propensity for violent interstate conflict, a key indicator of the system's stability. In so doing, we also demonstrate the first use of multislice modularity for community detection in a multiplex network application. Even after controlling for established system-level conflict indicators, we find that Kantian fractionalization contributes more to model fit for violent interstate conflict than previously established measures. Moreover, evaluating the influence of each of the constituent networks shows that joint democracy plays little, if any, rol...

  15. The studies of irradiation hardening of stainless steel reactor internals under proton and xenon irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chaoliang; Zhang, Lu; Qian, Wangjie; Mei, Jinna; Liu, Xiang Bing [Suzhou Nuclear Power Research Institute, Suzuhou (China)

    2016-06-15

    Specimens of stainless steel reactor internals were irradiated with 240 keV protons and 6 MeV Xe ions at room temperature. Nanoindentation constant stiffness measurement tests were carried out to study the hardness variations. An irradiation hardening effect was observed in proton- and Xe-irradiated specimens and more irradiation damage causes a larger hardness increment. The Nix-Gao model was used to extract the bulk-equivalent hardness of irradiation-damaged region and critical indentation depth. A different hardening level under H and Xe irradiation was obtained and the discrepancies of displacement damage rate and ion species may be the probable reasons. It was observed that the hardness of Xe-irradiated specimens saturate at about 2 displacement/atom (dpa), whereas in the case of proton irradiation, the saturation hardness may be more than 7 dpa. This discrepancy may be due to the different damage distributions.

  16. Immunologic changes after loco-regional radiotherapy and fractionated total body irradiation (TBI) in mice

    International Nuclear Information System (INIS)

    The immunologic effects of fractionated irradiation to both hind limbs and the tail of adult mice were investigated. A dose of 34 Gy given in 17 fractions of 2 Gy, 1 fraction per day, 5 days per week, was delivered with a 60Co source. A significant decrease of the total splenocyte count and of the PHA(phytohemagglutinin)-induced proliferation of T cells was found immediately after irradiation. Both parameters normalized within 30 days after irradiation. Immediately after irradiation, the MLC (mixed lymphocyte culture) was supranormal, dropped to 45% 1 week later, and normalized within 1 month after radiotherapy. The NK (natural killer) activity was significantly decreased only the first week after loco-regional irradiation, while the LAK (lymphokine activated killer) activity was not altered at all. The percentage of goat-anti-mouse+ cells (mainly B lymphocytes) was not changed immediately after loco-regional irradiation, but rose to supranormal values (175% of control level) 3 months after irradiation. A persistent decrease of the percentage and the absolute numbers of the Lyt2+ cells (= CD8+ cells, suppressor/cytotoxic phenotype) was observed up to 3 months after irradiation, while the percentage of L3T4+ cells (= CD4+ cells, helper phenotype) remained normal for the total follow-up. No differences in allogeneic skin graft survival could be demonstrated between irradiated and control animals. The observed immunological effects could not be explained by the scatter irradiation to the whole body as total body irradiation (TBI) administered in a dose and dose rate similar to the scatter dose did not result in persistent immunologic changes. No dose-rate effect could be demonstrated in a low dose fractionated total body irradiation schedule. A total body irradiation similar to the scatter dose in humans did not result in significant immunologic changes

  17. Internal friction of cold worked and irradiated copper

    International Nuclear Information System (INIS)

    The internal friction spectrum of cold worked copper is strongly modified, either by increasing the stress or by introducing irradiation point defects. It is shown that, in copper samples containing suitable dislocation lattices, it is possible to develop a Hasiguti-type peak by electron irradiation

  18. Effect of Fractionated Doses of Cerastes Cerastes Crude Venom on Tissues of Irradiated Mice

    International Nuclear Information System (INIS)

    This Work aims to study the effect of fractionated doses of Cerastes cerastes (C. cerastes) crude venom (CCV) on physiological alterations in different tissues of 5.5 Gy γ-irradiated mice. Male mice were grouped into: Control group. CCV group; mice received via inter peritoneum (i.p.) ⅓LD50 CCV in fractionated doses over a period of 2 weeks. Irradiated group; mice whole body exposed to 5.5 Gy γ-rays. Irradiated+ CCV; mice received via i.p ⅓LD50 CCV in fractionated doses over a period of 2 weeks starting 1 h post irradiation. Exposure to 5.5 Gy γ-rays elevated advanced oxidation protein products (AOPP) and malondialdehyde (MDA) levels and decreased glutathione (GSH) content of liver, spleen and kidney. Moreover, γ-irradiation significantly decreased calcium (Ca) and elevated zinc (Zn), and cupper (Cu) in liver, spleen and kidney tissues compared to the control, whereas, iron (Fe) was significantly elevated in liver and spleen and decreased in kidney. In addition, serum urea and creatinine and their ratio were significantly increased. Irradiated mice treated with fractionated CCV showed significant amelioration of oxidative stress and element alterations in the different tissues. It could be concluded that the fractionated doses of CCV (⅓LD50) might have favourable potential against irradiation induced-biochemical injuries.

  19. Spinal cord tolerance to single-fraction partial-volume irradiation: a swine model

    NARCIS (Netherlands)

    Medin, P.M.; Foster, R.D.; Kogel, A.J. van der; Sayre, J.W.; McBride, W.H.; Solberg, T.D.

    2011-01-01

    PURPOSE: To determine the spinal cord tolerance to single-fraction, partial-volume irradiation in swine. METHODS AND MATERIALS: A 5-cm-long cervical segment was irradiated in 38-47-week-old Yucatan minipigs using a dedicated, image-guided radiosurgery linear accelerator. The radiation was delivered

  20. Influence of high absorbed irradiation doses on conversion of CO2-H2S mixtures

    International Nuclear Information System (INIS)

    It was investigated the CO2-H2S mixture radiolysis at large absorbed irradiation doses. The observed high yield of final products in this system (Gpr.≥10.0) gives the possibility to consider the radiolytic hydrogen sulphide decomposition as one of the variants of purification of hydrogen sulphide containing residues of natural gas with a simultaneous production of sulphur and synthesis-gas (CO2). It has been show that at dose MGy∼16 % of initial product convert into synthesis-gas and sulfur. The mechanism of radiolytic conversion is discussed and the observed yield of hydrogen made G0(H2)=11.0±0.8 that considerably excesses G0(H2) at radiolysis of pure H2S(G0(H2)=7.5±0.5). Accumulation of carbon monoxide is described with 5 % accuracy with parabola of the second order: [CO] (-0.00082+0.359D-0.0013D2)·1019 mol/cm3 the initial yield of CO production for the given mixture is equal 3.59 which is G0(CO) = 4.5 in recalculation upon pure carbon dioxide. It has been established that the radiolytic reprocessing of acidic components of natural gas (CO2, H2S) gives the possibility to product sulphur and synthesis gas with yield to 30 vol.% (D=10 MGy), and the opportunity of simultaneous decision of ecological problems

  1. Development Manufacturing Method of Highly Functional Kapok Fiber Absorbent Using Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jae Sung; Nho, Young Chang; Kang, Phil Hyun; Baek, Myung Hwa

    2006-01-15

    The hydrophobic characteristic of kapok fibers was changed to hydrophilic property after NaClO2, treatments which is able to break all phenolic units especially lignin. After NaClO2 treatment, NaIO4, applied to kapok fibers for opening hexagonal polysaccharide structure, this step led to produce carbonyl groups(>C=O) on kapok fibers. In the final step, NaClO2, treatments were performed again to provide carboxyl groups(-COOH) on kapok fibers. In addition, kapok fibers after all chemical treatments were retained hollow structure which was observed by scanning electron microscopy(SEM). Kapok fibers which were obtained after chemical treatments would be a good heavy metal absorbent when these fibers applied less than in 10 mg/L standard solution. Moreover, these fibers were not detached heavy metals even added physical forces and used kapok fibers are able to reuse after detached heavy metals under pH 2-3. The degree of grafting increased as the irradiation dose increased, and are in the range 32% to 250% when the concentration of glycidyl methacrylate monomer was 50 vol. %. Based on this result, various functional groups are possible to be attached on kapok fibers used by radiation grafting technique.

  2. Internal radiation absorbed dose estimation in human brain due to technetium-99m and iodine-131

    International Nuclear Information System (INIS)

    Internal dosimetry is a branch of medical physics that deals with the measurement of the internally absorbed dose by an organ after applying isotopes. In this study, internal radiation absorbed dose has been calculated for 99mTc and 131I, which are frequently used for functioning tests and therapeutic treatments of thyroid, respectively in these cases, some amount of isotopes are accumulated in other tissues like brain, which are very soft and cannot be regenerated if they are damaged. Using ionizing radiation inside the body and to ensure the safety of brain, the internal radiation absorbed dose has been calculated applying direct counting measurement. Accumulation of isotopes to target organ has been measured and this target organ is considered as primary target organ; also this organ is considered as source with respect to other organs. These organ counts have, been measured by computer-based scintillation system. The amount of exposure in brain has been measured with the help of the data obtained from the special set-up equipment, including NaI detector, radiation survey meter and water phantoms of various sizes. Absorbed dose in brain for each isotope has been calculated by applying time-activity curve analysis. Finally, these results have been compared with the data in ICRP l Reports 53 and 71. (author)

  3. Tests of equal effect per fraction in microcolony assays of survival after fractionated irradiations

    International Nuclear Information System (INIS)

    H.D Thames, Jr. and H.R. Withers propose a test of an equal effect per fraction in microcolony assays after fractionated radiation, in which the total effect is measured by counting microcolonies derived from surviving cells in a tissue. The factors considered to influence the cytocidal effect per fraction are incomplete repair, repopulation, and synchrony. The statistics used in the method are criticized and conditions are given under which the test should not be used. An alternative method of testing for an equal effect per fraction is proposed. The pros and cons of each test are discussed and compared using some mouse jejunal crypt cell survival data

  4. The studies of irradiation assisted stress corrosion cracking on reactor internals stainless steel under Xe irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rong-shan [Suzhou Nuclear Power Research Institute, Suzhou, Jiangsu Province 215004 (China); Xu, Chao-liang, E-mail: xuchaoliang@cgnpc.com.cn [Suzhou Nuclear Power Research Institute, Suzhou, Jiangsu Province 215004 (China); Liu, Xiang-bing; Huang, Ping [Suzhou Nuclear Power Research Institute, Suzhou, Jiangsu Province 215004 (China); Chen, Yu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing 100049 (China)

    2015-02-15

    Specimens of Chinese domestic reactor internals stainless steel were irradiated with 6 MeV Xe ions for three peak displacement damage of 2, 7 and 15 dpa at room temperature. The slow strain rate tests (SSRT), grazing incidence X-ray diffraction (GIXRD) and nano-indentation tests were carried out to study the IASCC properties, phase transition and nano-hardness variations. The SSRT results indicate that the IASCC susceptibility increases with irradiation damage. Ion irradiation accelerates the stress corrosion cracking (SCC). A new ferrite phase diffraction peak of α(1 1 0) after irradiated to 7 dpa and another two α phase of α(2 0 0) and α(2 1 1) after irradiated to 15 dpa were observed by GIXRD, which may be due to localized deformation. A similar trend of irradiation hardening and IASCC susceptibility was observed, which suggests an essential connection between them.

  5. Stimulation of hematopoietic stem cells by interferon inducer in nonhuman primates receiving fractionated total body irradiation

    International Nuclear Information System (INIS)

    Interferon response and hematopoietic stem cells (spleen colony forming units-CFU-S) were studied in rhesus monkeys subjected to fractionated total body irradiation (FTBI). An interferon inducer, a nuclease resistant complex of polyinosinic-polycytidylic acid with poly-L-lysine and carboxmethylcellulose[-poly(ICLC)] was used. Poly(ICLC) at 3.75 mg/m2 was given I.V. to 7 monkeys, 5 of which, starting 24 hours later, received 50 rad of 4 MV X rays twice a week for 2.5 weeks (total of 250 rad). Another group of 4 monkeys received FTBI only. Although the initial interferon response was similar in both groups treated with poly(ICLC)-800 international units (IU), the animals receiving FTBI showed reduced interferon levels after 100 rad. These animals, however, did not develop the hyporesponsiveness to subsequent poly(ICLC) injections that was observed in non-irradiated monkeys. Stabile interferon response (30-100 IU) in the FTBI group paralleled the prolonged persistence of the drug in their serum. Bone marrow (BM) aspirates from animals receiving FTBI and poly(ICLC) contained more CFU-S per 106 nucleated cells than those treated with poly(ICLC) alone or FTBI alone. FTBI with and without poly(ICLC) led to thrombocytopenia and leukopenia. Lower white blood cell (WBC) count was found in irradiated animals treated with poly(ICLC). Partial alopecia was observed in animals receiving poly(ICLC). Two animals--one in the poly(ICLC) and FTBI group and the other receiving FTBI alone, died with thrombocytopenia and leukopenia

  6. Stimulation of hematopoietic stem cells by interferon inducer in nonhuman primates receiving fractionated total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lvovsky, E.A. (George Washington Univ. Medical Center, Washington, DC); Levine, P.H.; Bengali, Z.; Leiseca, S.A.; Cicmanec, J.L.; Robinson, J.E.; Bautro, N.; Levy, H.B.; Scott, R.M.

    1982-10-01

    Interferon response and hematopoietic stem cells (spleen colony forming units--CFU-S) were studied in rhesus monkeys subjected to fractionated total body irradiation (FTBI). An interferon inducer, a nuclease resistant complex of polyinosinic-polycytidylic acid with poly-L-lysine and carboxmethylcellulose(-poly(ICLC)) was used. Poly(ICLC) at 3.75 mg/m/sup 2/ was given I.V. to 7 monkeys, 5 of which, starting 24 hours later, received 50 rad of 4 MV X rays twice a week at 2.5 weeks (total of 250 rad). Another group of 4 monkeys received FTBI only. Although the initial interferon response was similar in both groups treated wih poly(ICLC)--800 international units (IU), the animals that receiving FTBI showed reduced interferon levels after 100 rad. These animals, however, did not develop the hyporesponsiveness to subsequent poly(ICLC) injections that was observed in non-irradiated monkeys. Stabile interferon response (30-100 IU) in the FTBI group paralleled the prolonged persistence of the drug in their serum. Bone marrow (BM) aspirates from animals receiving FTBI and poly(ICLC) contained more CFU-S per 10/sup 6/ nucleated cells than those treated with poly(ICLC) along or FTBI with and without poly(ICLC) lead to thrombocytopenia and leukopenia. Lower white blood cell (WBC) count was found in irradiated animals treated with poly(ICLC). Partial alopecia was observed in animals receiving poly(ICLC). Two animals--one in the poly(ICLC) and FTBI group and the other receiving FTBI along, died with thrombocytopenia and leukopenia.

  7. Investigation of the bystander effect in MRC5 cells after acute and fractionated irradiation in vitro

    Directory of Open Access Journals (Sweden)

    Shokouhozaman Soleymanifard

    2014-01-01

    Full Text Available Radiation-induced bystander effect (RIBE has been defined as radiation responses observed in nonirradiated cells. It has been the focus of investigators worldwide due to the deleterious effects it induces in nonirradiated cells. The present study was performed to investigate whether acute or fractionated irradiation will evoke a differential bystander response in MRC5 cells. A normal human cell line (MRC5, and a human lung tumor cell line (QU-DB were exposed to 0, 1, 2, and 4Gy of single acute or fractionated irradiation of equal fractions with a gap of 6 h. The MRC5 cells were supplemented with the media of irradiated cells and their micronucleus frequency was determined. The micronucleus frequency after single and fractionated irradiation did not vary significantly in the MRC5 cells conditioned with autologous or QU-DB cell-irradiated media, except for 4Gy where the frequency of micronucleated cells was lower in those MRC5 cells cultured in the media of QU-DB-exposed with a single dose of 4Gy. Our study demonstrates that the radiation-induced bystander effect was almost similar after single acute and fractionated exposure in MRC5 cells.

  8. Histological examination of the effect of differently fractionated irradiations in rat and mouse organs. Pt. 3

    International Nuclear Information System (INIS)

    The spleen of rats was irradiated with 50 Gy dose local X-rays in two different fractionation rhythms, i.e. twice a week given high and daily applied lower fractions of radiation. According to the results of 3H-thymidine autoradiography made after the last irradiation 24 hours later both in the white and the red pulp the labelling index was less on the effect of twice in a week applied high radiation fractions than in case of daily given lower fractions. This indicate in correlation with the results of earlier analogous histological experiments that the damaging effect of rarely given higher fractions of radiation in the spleen is especially obvious. (orig.)

  9. Effect of absorbed dose and storage length on electron paramagnetic resonance (EPR) signal strength in irradiated alfalfa seeds

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A kind of alfalfa seeds was irradiated by 1, 2, 3, 4 and 5 kGy at a dose rate of 6.288 kGy. h-1 in a self-shielded irradiator of 137Cs gamma rays. The EPR spectra, which were measured subsequently between 0.3401and 0.3501 T, showed that there was a direct proportional relationship between the EPR signal strength of free radicals produced by gamma irradiation in the alfalfa seeds and absorbed dose. The first derivative EPR spectra of the alfalfa seeds were very clear and easy to identify. However, the EPR signal strength of the peak-to-peak amplitude decreased rapidly and most of them decayed beyond 50% within 3 days after the seeds were irradiated. It tended to stabilize after half a month since the seeds were irradiated. The differences of the EPR signal strength between the irradiated and unirradiated alfalfa seeds still remained. All seeds were stored at ambient temperature for more than 3months. Therefore, using EPR spectrometry technique to measure free radicals in alfalfa seeds as a means to determine whether the seeds have been irradiated or not is feasible, relatively fast and simple.

  10. Effect of absorbed dose and storage length on electron paramagnetic resonance (EPR) signal strength in irradiated alfalfa seeds

    International Nuclear Information System (INIS)

    A kind of alfalfa seeds was irradiated by 1, 2, 3, 4 and 5 kGy at a dose rate of 6.288 kGy·h-1 in a self-shielded irradiator of 137Cs gamma rays. The EPR spectra, which were measured subsequently between 0.3401 and 0.3501 T, showed that there was a direct proportional relationship between the EPR signal strength of free radicals produced by gamma irradiation in the alfalfa seeds and absorbed dose. The first derivative EPR spectra of the alfalfa seeds were very clear and easy to identify. However, the EPR signal strength of the peak-to-peak amplitude decreased rapidly and most of them decayed beyond 50% within 3 days after the seeds were irradiated. It tended to stabilize after half a month since the seeds were irradiated. the differences of the EPR signal strength between the irradiated and unirradiated alfalfa seeds still remained. All seeds were stored at ambient temperature for more than 3 months. Therefore, using EPR spectrometry technique to measure free radicals in alfalfa seeds as a means to determine whether the seeds have been irradiated or not is feasible, relatively fast and simple. (authors)

  11. Dependence of microwave absorption properties on ferrite volume fraction in MnZn ferrite/rubber radar absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Gama, Adriana M., E-mail: adrianaamg@iae.cta.br [Divisao de Materiais (AMR), Instituto de Aeronautica e Espaco (IAE), Departamento de Ciencia e Tecnologia Aeroespacial - DCTA (Brazil); Rezende, Mirabel C., E-mail: mirabelmcr@iae.cta.br [Divisao de Materiais (AMR), Instituto de Aeronautica e Espaco (IAE), Departamento de Ciencia e Tecnologia Aeroespacial - DCTA (Brazil); Dantas, Christine C., E-mail: christineccd@iae.cta.br [Divisao de Materiais (AMR), Instituto de Aeronautica e Espaco (IAE), Departamento de Ciencia e Tecnologia Aeroespacial - DCTA (Brazil)

    2011-11-15

    We report the analysis of measurements of the complex magnetic permeability ({mu}{sub r}) and dielectric permittivity ({epsilon}{sub r}) spectra of a rubber radar absorbing material (RAM) with various MnZn ferrite volume fractions. The transmission/reflection measurements were carried out in a vector network analyzer. Optimum conditions for the maximum microwave absorption were determined by substituting the complex permeability and permittivity in the impedance matching equation. Both the MnZn ferrite content and the RAM thickness effects on the microwave absorption properties, in the frequency range of 2-18 GHz, were evaluated. The results show that the complex permeability and permittivity spectra of the RAM increase directly with the ferrite volume fraction. Reflection loss calculations by the impedance matching degree (reflection coefficient) show the dependence of this parameter on both thickness and composition of RAM. - Highlights: > Permeability and permittivity spectra of a MnZn ferrite RAM (2-18 GHz) are given. > Higher MnZn volume fraction favors increase of RAM/'s permeability and permittivity. > Minimum RL as a function of frequency, thickness and MnZn volume fraction given. > Higher thicknesses imply better absorption; optimum band shifts to lower frequencies. > For higher volume fractions, smaller thickness might offer better absorption (>10 GHz).

  12. Dietary enhancement of intestinal radioresistance during fractionated irradiation

    International Nuclear Information System (INIS)

    Rats fed laboratory chow or elemental diet 3 were given fractions of 240 rads of 60Co γ radiation abdominally (1200 rads/week) until all animals had died. Changes in appetite, body weight, and mortality were monitored as a function of the cumulative dose received. More radiation was needed in the diet-fed group to achieve both 0 and 100% mortality, a difference of 37% at the mean lethal dose level. Both groups developed similar progressive anorexia but the diet-fed animals lost weight more slowly. Data indicate that basic intestinal radioresistance is enhanced by feeding the elemental diet

  13. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation

    Directory of Open Access Journals (Sweden)

    Ganesh Chandra Jagetia

    2015-01-01

    Full Text Available Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain better therapeutic gains. Curcumin is an antioxidant and a free radical scavenging dietary supplement, commonly used as a flavoring agent in curries. Therefore, the effect of 100 mg/kg body weight curcumin was studied on the antioxidant status of mice skin exposed to a total dose of 10, 20 and 40 Gy γ-radiation below the rib cage delivered as a single fraction of 2 Gy per day for 5, 10 or 20 days. Skin biopsies from both the curcumin treated or untreated irradiated groups were collected for the biochemical estimations at various post-irradiation times. The irradiation of animals caused a dose dependent decline in the glutathione concentration, glutathione peroxidase, and superoxide dismutase activities and increased the lipid peroxidation in the irradiated skin. Curcumin treatment before irradiation resulted in a significant rise in the glutathione concentration and activities of both the glutathione peroxidase and superoxide dismutase enzymes in mouse skin, whereas lipid peroxidation declined significantly. The present study indicates that curcumin treatment increased the antioxidant status of mouse exposed to different doses of fractionated γ-radiation.

  14. Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation.

    Science.gov (United States)

    Jagetia, Ganesh Chandra; Rajanikant, Golgod Krishnamurthy

    2015-01-01

    Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain better therapeutic gains. Curcumin is an antioxidant and a free radical scavenging dietary supplement, commonly used as a flavoring agent in curries. Therefore, the effect of 100 mg/kg body weight curcumin was studied on the antioxidant status of mice skin exposed to a total dose of 10, 20 and 40 Gy γ-radiation below the rib cage delivered as a single fraction of 2 Gy per day for 5, 10 or 20 days. Skin biopsies from both the curcumin treated or untreated irradiated groups were collected for the biochemical estimations at various post-irradiation times. The irradiation of animals caused a dose dependent decline in the glutathione concentration, glutathione peroxidase, and superoxide dismutase activities and increased the lipid peroxidation in the irradiated skin. Curcumin treatment before irradiation resulted in a significant rise in the glutathione concentration and activities of both the glutathione peroxidase and superoxide dismutase enzymes in mouse skin, whereas lipid peroxidation declined significantly. The present study indicates that curcumin treatment increased the antioxidant status of mouse exposed to different doses of fractionated γ-radiation. PMID:26785336

  15. Role of Rad52 in fractionated irradiation induced signaling in A549 lung adenocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Somnath, E-mail: ghosh.barc@gmail.com [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Krishna, Malini, E-mail: malinik00@gmail.com [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2012-01-03

    The effect of fractionated doses of {gamma}-irradiation (2 Gy per fraction over 5 days), as delivered in cancer radiotherapy, was compared with acute doses of 10 and 2 Gy, in A549 cells. A549 cells were found to be relatively more radioresistant if the 10 Gy dose was delivered as a fractionated regimen. Microarray analysis showed upregulation of DNA repair and cell cycle arrest genes in the cells exposed to fractionated irradiation. There was intense activation of DNA repair pathway-associated genes (DNA-PK, ATM, Rad52, MLH1 and BRCA1), efficient DNA repair and phospho-p53 was found to be translocated to the nucleus of A549 cells exposed to fractionated irradiation. MCF-7 cells responded differently in fractionated regimen. Silencing of the Rad52 gene in fractionated group of A549 cells made the cells radiosensitive. The above result indicated increased radioresistance in A549 cells due to the activation of Rad52 gene.

  16. Role of Rad52 in fractionated irradiation induced signaling in A549 lung adenocarcinoma cells.

    Science.gov (United States)

    Ghosh, Somnath; Krishna, Malini

    2012-01-01

    The effect of fractionated doses of γ-irradiation (2Gy per fraction over 5 days), as delivered in cancer radiotherapy, was compared with acute doses of 10 and 2Gy, in A549 cells. A549 cells were found to be relatively more radioresistant if the 10Gy dose was delivered as a fractionated regimen. Microarray analysis showed upregulation of DNA repair and cell cycle arrest genes in the cells exposed to fractionated irradiation. There was intense activation of DNA repair pathway-associated genes (DNA-PK, ATM, Rad52, MLH1 and BRCA1), efficient DNA repair and phospho-p53 was found to be translocated to the nucleus of A549 cells exposed to fractionated irradiation. MCF-7 cells responded differently in fractionated regimen. Silencing of the Rad52 gene in fractionated group of A549 cells made the cells radiosensitive. The above result indicated increased radioresistance in A549 cells due to the activation of Rad52 gene. PMID:22001234

  17. EFFECT OF IRRADIATION TEMPERATURE ON GENERAL EQUATION OF SOL FRACTION-DOSE RELATIONSHIP FOR FLUOROPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wanxi; XU Jun

    1992-01-01

    In this paper, the effect of irradiation temperature on sol fraction-dose relationship of fluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of β value of fluoropolymer , which increases the crosslinking probability of fluoropolymer. The relationship between crosslinking parameter β and irradiation temperature (Ti)of fluoropolymer is established as follows:β=2.2 × 10-3Tg +4×10-4 (Tg-Ti )+0.206.β values of some fluoropolymers calculated from the above expression are in agreement with the experimental values.

  18. The effect of cis-diamminedichloroplatinum (II) on radiation damage in mouse rectum after fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dewit, L.; Oussoren, Y.; Bartelink, H. (Nederlands Kanker Inst. ' Antoni van Leeuwenhoekhuis' , Amsterdam (Netherlands)); Thames, H.D. (Anderson (M.D.) Hospital and Tumor Inst., Houston, TX (USA))

    1989-10-01

    The influence of cis-diamminedichloroplatinum (II) (c-DDP) on radiation injury in the rectum of ice was investigated after single dose and fractionated irradiation. Mice were exposed to single doses, or 2, 4 or 8 fractions of X-rays given daily (or twice a day for the 8 fractions) with or without 8 mg/kg of c-DDP. The incidence of rectal stenosis and of anal discharge were scored and a direct analysis of the data for linear-quadratic dose-dependence of damage was performed with correction for censoring. For each endpoint, c-DDP did not significantly change the dose-response curves after fractionated irradiation. Subtile modifications in the coefficients of the linear-quadratic relationship were observed. The drug appeared to increase the {alpha} term by a factor of 2.3 and the {beta} term by a factor of 1.5, but the differences did not reach statistical significance. For the rectal stenosis endpoint, the {alpha}/{beta} was 4.4 Gy after irradiation alone and 6.9 Gy after combination treatment. Again the differences were not significant. These data suggest that c-DDP did not reduce the repair capacity in the mouse rectum during fractionated irradiation. Combined modality therapy with c-DDP and radiation would therefore not be expected to cause an increas in late damage in the large bowel. (author). 23 refs.; 2 figs.; 1 tab.

  19. Evaluation of absorbed dose in irradiated sugar-containing plant material (peony roots) by an ESR method

    Science.gov (United States)

    Yamaoki, Rumi; Kimura, Shojiro; Ohta, Masatoshi

    2015-12-01

    The relationship between electron spin resonance (ESR) signal intensity of irradiated plant materials and sugar content was investigated by spectral analysis using peony roots. A weak background signal near g=2.005 was observed in the roots. After a 10 kGy irradiation, the ESR line broadened and the intensity increased, and the spectral characteristics were similar to a typical spectrum of irradiated food containing crystalline sugars. The free radical concentration was nearly stable 30 days after irradiation. The spectrum of peony root 30 days after irradiation was simulated using the summation of the intensities of six assumed components: radical signals derived from (a) sucrose, (b) glucose, (c) fructose, (d) cellulose, (e) the background signal near g=2.005 and (f) unidentified component. The simulated spectra using the six components were in agreement with the observed sample spectra. The intensity of sucrose radical signal in irradiated samples increased proportionally up to 20 kGy. In addition, the intensity of sucrose radical signals was strongly correlated with the sucrose contents of the samples. The results showed that the radiation sensitivity of sucrose in peony roots was influenced little by other plant constituents. There was also a good correlation between the total area of the spectra and the sucrose content, because the sucrose content was higher than that of other sugars in the samples. In peony roots, estimation of the absorbed dose from the ESR signal intensity may be possible by a calibration method based on the sucrose content.

  20. Self-shielding and burn-out effects in the irradiation of strongly-neutron-absorbing material

    International Nuclear Information System (INIS)

    Self-shielding and burn-out effects are discussed in the evaluation of radioisotopes formed by neutron irradiation of a strongly-neutron-absorbing material. A method of the evaluation of such effects is developed both for thermal and epithermal neutrons. Gadolinium oxide uniformly mixed with graphite powder was irradiated by reactor-neutrons together with pieces of a Co-Al alloy wire (the content of Co being 0.475%) as the neutron flux monitor. The configuration of the samples and flux monitors in each of two irradiations is illustrated. The yields of activities produced in the irradiated samples were determined by the γ-spectrometry with a Ge(Li) detector of a relative detection efficiency of 8%. Activities at the end of irradiation were estimated by corrections due to pile-up, self-absorption, detection efficiency, branching ratio, and decay of the activity. Results of the calculation are discussed in comparison with the observed yields of 153Gd, 160Tb, and 161Tb for the case of neutron irradiation of disc-shaped targets of gadolinium oxide. (T.G.)

  1. Treatment of displaced radial head fractures by internal fixation with absorbable pins

    Institute of Scientific and Technical Information of China (English)

    HOU Zhen-hai; ZHOU Ji-hong; SHI Jian-guo; SHI Yi-bin; XIA Jun-jie; YAO Jun

    2006-01-01

    Objective: To study the effect of internal fixation with absorbable pins on treatment of displaced radial head fractures.Methods: From May 1999 to May 2004, 16 patients with displaced radial head fractures (Mason types Ⅱ and Ⅲ) were treated with internal fixation by absorbable pins.The duration of follow-up averaged 22.6 months (12-58 months). The outcome was assessed on the basis of elbow motion, radiographic findings and the functional rating score delineated by Broberg and Morrey.Results: All fractures healed within 10 months without avascular necrosis of radial head. The mean elbow flexion loss was 15°(0°-35°), and pronation and supination decreased by 10° (0°-30°) on average compared with those of the contralateral elbow. Five patients had an excellent result, 6 a good result, and 3 a fair result according to the criteria of Borberg and Morrey.Conclusions: Internal fixation with absorbable pins is an effective method in treating displaced radial head fractures. It can maintain the biomechanical stability of forearm, improve the elbow function and avoid second operation.

  2. Fractionated irradiation combined with carbogen breathing and nicotinamide of two human glioblastomas grafted in nude mice

    OpenAIRE

    Sun, Lin-Quan; Buchegger, Franz; Coucke, Philippe; MIRIMANOFF

    2001-01-01

    This study addressed the potential radiosensitizing effect of nicotinamide and/or carbogen on human glioblastoma xenografts in nude mice. U-87MG and LN-Z308 tumors were irradiated with either 20 fractions over 12 days or 5 fractions over 5 days in air-breathing mice, mice injected with nicotinamide, mice breathing carbogen, or mice receiving nicotinamide plus carbogen. The responses to treatment were assessed using local control and moist desquamation. In U-87MG tumors, the enhancement ratios...

  3. NMR analysis of fractionated irradiated {kappa}-carrageenan oligomers as plant growth promoter

    Energy Technology Data Exchange (ETDEWEB)

    Abad, L.V., E-mail: lvabad@pnri.dost.gov.ph [Philippine Nuclear Research Institute, Commonwealth Avenue, Diliman, Quezon City (Philippines); Saiki, S.; Nagasawa, N. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Kudo, H.; Katsumura, Y. [Graduate School of Engineering, The University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); De La Rosa, A.M. [Philippine Nuclear Research Institute, Commonwealth Avenue, Diliman, Quezon City (Philippines)

    2011-09-15

    The optimum plant growth promoting effect in irradiated {kappa}-carrageenan is known to be of Mw<10,000. This is obtained by irradiating {kappa}-carrageenan at a dose of 100 kGy in solid and at 2 kGy in 1% aqueous solution. Kappa carrageenan irradiated at these doses was fractionated at different Mw ranges. The isolated fraction with a Mw of 3-10 kDa was analyzed by NMR. The chemical shifts of {sup 13}C and {sup 1}H spectra indicated that the basic functional structure of {kappa}-carrageenan (alternating D-galactose-4-sulfate and 3,6-anhydro-D-galactose dimer) remains intact at a Mw of 3-10 kDa. No radiolytic products were detected at this range. - Highlights: > Irradiated {kappa}-carrageenan fractions with Mw<3 kDa contained higher carbonyl bonds. > {sup 1}H NMR and {sup 13}C spectra of irradiated {kappa}-carrageenan were similar to references. > {kappa}-Carrageenan oligomers with Mw of 3-10 kDa may be suitable as plant growth promoter.

  4. Response of human lymphocyte chromosomes to fractionated neutron irradiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Sevan' kaev, A.V.; Nasonova, V.A.; Golovinova, G.I. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    A comparative study was made of the yield of chromosome aberrations in a human lymphocyte culture after a single and fractionated exposure to neutron radiation at the beginning of the G/sub 1/ phase and during the S phase of the mitotic cycle. It was shown that the degree of the chromosome affection in both phases does not depend upon the irradiation schedules.

  5. Radiobiological effect of abdominal X-ray hypo-fraction irradiation on Wistar rats liver

    Institute of Scientific and Technical Information of China (English)

    Peng Qi; Yongheng An; Hongsheng Yu; Xinjia He

    2012-01-01

    Objective: The aim of our study was to investigate the impact of abdominal hypo-fraction irradiation on liver dam-age in rats so as to provide a reference for its clinical application. Methods: A total of 100 Wistar rats were equally randomized to five groups as control, 4 Gy, 6 Gy, 8 Gy and 12 Gy group, and the corresponding fractionated doses were offered. Liver functions were examined at the 2nd, 4th, 6th, 8th and 10th week after irradiation. Morphological changes were observed by HE staining. Expressions of Bcl-2 and Bax were examined by immunohistochemical technique. Results: In all irradiation groups, hepatocellular swell, degeneration, necrosis and even hepatic fibrosis could be seen. The differences of the liver coef-ficient, Glutamyl pyruvic transaminase (GPT), Glutamyl oxaloacetic transaminase (GOT) were significant among the groups and different time points (F = 11.833–781.972, F = 20.857–264.692, P < 0.001). Expressions of Bcl-2 and Bax were signifi-cantly different between each group (F = 211.607, 116.577; P < 0. 001), and between each time point (F = 54.083, 68.749; P < 0. 001). Conclusion: Compare with conventional fraction, abdominal hypo-fraction irradiation may cause radiation damage to rat liver, being dose-and-time dependent. Up-regulation of activating apoptosis protein Bax and down-regulation of inhibiting apoptosis protein Bcl-2 may involve in the process.

  6. Estimating Solar Irradiation Absorbed by Photovoltaic Panels with Low Concentration Located in Craiova, Romania

    OpenAIRE

    Ionel L. Alboteanu; Cornelia A. Bulucea; Sonia Degeratu

    2015-01-01

    Solar irradiation is one of the important parameters that should be taken into consideration for the design and utilization of a photovoltaic system. Usually, the input parameters of a photovoltaic system are solar irradiation, the ambient environment temperature and the wind speed, and as a consequence most photovoltaic systems are equipped with sensors for measuring these parameters. This paper presents several mathematical models for solar irradiation assessment. The starting point is repr...

  7. In Vitro and In Vivo Radiosensitizing Effect of Valproic Acid on Fractionated Irradiation

    OpenAIRE

    Chie, Eui Kyu; Shin, Jin Hee; Kim, Jin Ho; Kim, Hak Jae; Kim, In Ah; Kim, Il Han

    2014-01-01

    Purpose This study was conducted in order to validate the radiosensitization effect of valproic acid, a biologically available histone deacetylase inhibitor, for fractionated radiation. Materials and Methods Radiosensitization effect of valproic acid was tested for the A549 cell line and U87MG cell line in vitro. Fractionated irradiation of 12 Gy in four fractions was administered on D2-5 with valproic acid, 150 mg/Kg, ip, bid for six consecutive days (D1-6) to A549 and U87MG tumors implanted...

  8. Post-irradiation-examination results for absorber material irradiation rig AMIR-6. The results of non-destructive examination for capsules

    International Nuclear Information System (INIS)

    Irradiation tests of Absorber Material Irradiation Rig (AMIR) have been continuously conducted, using the experimental fast reactor Joyo. AMIR-6, which was submitted for post-irradiation-examinations (PIE) this time, was irradiated in order to evaluate the limit of failure in control rods and confirm the effect of method for suppression of relocation caused by cracking of boron carbide (B4C) pellets. According to this purpose, gap size between B4C pellet and cladding tube (inner capsule tube), enrichment of 10B, thickness of cladding tube and its material were changed in this test. In addition, thin shroud tube wrapping B4C pellets was used as the method for suppression of relocation. Capsules were loaded in compartments, which had the upper and lower stairs, and irradiation rig AMIR-6 was constructed of seven compartments in total. The irradiation capsule had double tubes, namely inner capsule tube and outer capsule tube. Between these tubes, sodium was filled. AMIR-6 was irradiated at the 6 raw in Joyo Mark-II core up to 106 x 1026 cap/m3 (max. burn-up) and 3.82 x 1026 n/m2 (max, fluence). Irradiation temperatures were evaluated from 530 to 890 degC in design. Extraordinary results were observed for lower capsules by weight measurement performed. So, detailed visual inspection was carried out for these capsules. Consequently, sodium entered from the crack of screwhead attached to the outer tube in three irradiation capsules, whose weight increased. It was recognized that the sodium level between cladding tube and outer tube was lower in six capsules of lower stairs. Cladding crack was found out in three cladding tubes of lower irradiation capsule. It was suggested that the crack become for decrease of strength of cladding tube because those temperature increased at the position where sodium was not filled. The irradiation capsule using a shroud tube showed no diameter increase and ovality in the cladding. It is guessed from the results that the function as the

  9. International co-operation in the field of food irradiation

    International Nuclear Information System (INIS)

    In 1982, the Directors General of FAO, IAEA and WHO took the initiative in forming the International Consultative Group on Food Irradiation, as an independent body composed of government-designated experts (currently 37 member states). It is the successor of the International Project in the Field of Food Irradiation (IFIP), Karlsruhe which terminated in 1983 after successful complation of its tasks. The major functions of ICGFI, as stated in Declaration, are: - To evaluate global developments; - to provide advice to Member States and the three organizations; - to furnish information through the organizations to the JECFI and CAC. ICGFI addresses matters such as safety assurance, legislation, public information, technical and economical feasibility, training and international trade. Under the Auspices of ICGFI Codes of Food Irradiation Practice for eight different food groups were published. ICGFI organizes workshops on different topics, harmonize legislation and regulation in the field of food irradiation, provides information to the general public, records the files on clearances of radiated food and market testing. (orig.)

  10. Patient absorbed radiation doses estimation related to irradiation anatomy; Estimativa de dose absorvida pelo paciente relacionada a anatomia irradiada

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Flavio Augusto Penna; Soares, Amanda Anastacio; Kahl, Gabrielly Gomes, E-mail: prof.flavio@gmail.com, E-mail: amanda-a-soares@hotmail.com, E-mail: gabriellygkahl@gmail.com [Instituto Federal de Eduacao, Ciencia e Tecnologia de Santa Catarina (IFSC), Florianopolis, SC (Brazil)

    2014-07-01

    Developed a direct equation to estimate the absorbed dose to the patient in x-ray examinations, using electric, geometric parameters and filtering combined with data from irradiated anatomy. To determine the absorbed dose for each examination, the entrance skin dose (ESD) is adjusted to the thickness of the patient's specific anatomy. ESD is calculated from the estimated KERMA greatness in the air. Beer-Lambert equations derived from power data mass absorption coefficients obtained from the NIST / USA, were developed for each tissue: bone, muscle, fat and skin. Skin thickness was set at 2 mm and the bone was estimated in the central ray of the site, in the anteroposterior view. Because they are similar in density and attenuation coefficients, muscle and fat are treated as a single tissue. For evaluation of the full equations, we chose three different anatomies: chest, hand and thigh. Although complex in its shape, the equations simplify direct determination of absorbed dose from the characteristics of the equipment and patient. The input data is inserted at a single time and total absorbed dose (mGy) is calculated instantly. The average error, when compared with available data, is less than 5% in any combination of device data and exams. In calculating the dose for an exam and patient, the operator can choose the variables that will deposit less radiation to the patient through the prior analysis of each combination of variables, using the ALARA principle in routine diagnostic radiology sector.

  11. Effect of roentgen, cyclotron neutron, or mixed neutron-photon fractionated irradiation of mice

    International Nuclear Information System (INIS)

    Mice were whole-body-irradiated with 5 fractions of roentgen rays in 5 days, 5 fractions of cycotron neutrons in 5 days, or with mixed neutron-photon fractionated radiation, in the sequence n-n-x-x-x or n-x-x-x-n. The LD50 sub(/) 4 day values were determined. Roentgen rays and neutrons interact in the additive manner in the mixed fractionation schemes: effective dose per fraction is as predicted from the roentgen ray-only and neutron-only experiments. This essentially agrees with HENDRY et coll. (1976). However, no trend was found towards a less-than-additive effect which was observed by those authors and has also been suggested in skin response to mixed schemes (NELSON et coll 1975). (author)

  12. Acute and persisting Th2-1ike immune response after fractionated colorectal γ-irradiation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To investigate if an immune imbalance may ac-count for the development and progression of chronic radiation enteritis. We analyzed the Th1/Th2 immune response profile early and 6 mo after fractionated colorectal irradiation. METHODS: A rat model of fractionated colorectal γ-irradiation (4-Gy fractions, 3 fractions per week) was designed to investigate the effects of cumulative dose on inflammatory mediators (cytokines and chemo-k/nes) and immune response (Th1/Th2 profile and im-munosuppressive mediator It-10) during acute (early) response and 6 mo after the end of fractionated irradia-tion (chronic response). Analyses were performed 1 d after the cumulative doses of 16 Gy and 36 Gy and 1 d, 3 d, and 26 wk after the cumulative dose of 52 Gy. RESULTS: Without causing histological damage, frac-tionated radiation induced elevated expression of IL-1β,TNFα, MCP-1, and iNOS in distal colonic mucosa dur-ing the early post-irradiation phase. At that time, a Th2 profile was confirmed by expression of both the Th2-specific transcription factor GATA-3 and the chemokine receptor CCR4 and by suppression of the Th1 cytokine IFNγ/IP-10 throughout the irradiation protocol. After 6 too, despite the 2-fold reduction of iNOS and MCP-1 levels, the Th2 profile persisted, as shown by a 50% re-duction in the expression of the Th1 transcription factor T-bet, the chemokine receptor CCXCR3, and the IFNy/ STAT1 pathway. At the same time-point, the immuno-suppressive IL-10/STAT3 pathway, known to regulate the Th1/Th2 balance, was expressed, in irradiated rats, at approximately half its level as compared to controls. This suppression was associated with an overexpression of SOCS3, which inhibits the feedback of the Th1 polar-ization and regulates IL-10 production.CONCLUSION: Colorectal irradiation induces Th2 po-larization, defective IL-10/STAT3 pathway activation and sacs3 overexpression. These changes, in turn, main-rain a immunological imbalance that persists in the long term.

  13. Changes in hemopoiesis of dying and surviving mice after fractionated irradiation and repeated bone marrow transplantation

    International Nuclear Information System (INIS)

    Mice received doses of 3 Gy of 60Co-gamma rays total body irradiation at four-day intervals up to a total dose of 24 Gy. After each dose per fraction half of the animals were injected with 106 bone marrow cells. At four- and nine-day intervals evaluations were made of the blood count, bone marrow and spleen cellularities, and spleen mass. In animals subjected only to irradiation the damage of hemopoietic organs was becoming deeper until the end of observation; the majority of these mice died by nine days after the irradiation with the last dose per fraction (by 37 days of the experiment). The authors consider anemia as the main cause of their death. All of the mice that were given bone marrow injections survived; nine days after the last dose of irradiation the mean cellularities of their bone marrows and spleens were 76.8% and 112.3% of the unirradiated controls respectively. In general, regeneration of erythropoiesis was quite successful, the number of thrombocytes was positively influenced, and the number of leukocytes nearly unchanged in bone marrow recipients when compared with the only irradiated mice. We observed two periods of maximum and one of minimum bone marrow and spleen regeneration, which were not synchronized. These results deny an unrepairable damage to the hemopoietic microenvironment in conditions of our experiment. This paper follows up with our preceding work describing results of an experiment which ended on day 24. (orig.)

  14. Effects of single-dose and fractionated cranial irradiation on rat brain accumulation of methotrexate

    International Nuclear Information System (INIS)

    The effects of single-dose and fractionated whole-brain irradiation on brain methotrexate (MTX) has been studied in a rat model. The amount of MTX present in the brain 24 hr after a single i.p. dose (100 mg/kg) was the same whether animals were sham irradiated or given a single dose of 2000 rads 6 or 48 hr prior to the drug (6.9, 8.3, and 6.8 pmol MTX/g, wet weight, respectively). Animals sham irradiated or given 2000 rads in 10 fractions over 11 days and treated with an average dose of 1.2 mg MTX/kg i.p. twice a week for 24 weeks did not differ significantly in their brain MTX concentration (7.9 and 8.3 pmol MTX/g, wet weight, respectively). Chronically MTX-treated animals became folate deficient whether they were irradiated or not (450 and 670 pmol folate/g, wet weight, brain in MTX-treated and control animals). Thus, MTX accumulates in the brain with acute or chronic administration, and this accumulation is not altered by this amount of brain irradiation

  15. Food Preservation by Irradiation. Vol. II. Proceedings of an International Symposium on Food Preservation by Irradiation

    International Nuclear Information System (INIS)

    In the task of alleviating the distress caused by the world-wide food shortage it is essential to preserve what has been grown and harvested in the fields. Clearly all suitable methods for preserving agricultural produce and food should be made use of. In this context treatment with ionizing radiation has proved its value as an environmentally clean, physical method of food preservation which is low in its energy requirement, but the volume of food being processed in this way is still low. The introduction of food irradiation on a global basis poses certain economic, legal, regulatory and health-related questions, the solution of which requires close international collaboration. Such collaboration between many international, intergovernmental and national organizations began over a decade ago. The need for dissemination and discussion of information gained through research and development work on this subject became apparent, and a number of inter-regional meetings were held. The last international symposium on the topic was held jointly by FAO and the IAEA in 1972 in Bombay. To review progress made since then, FAO and the IAEA, together with WHO, convened the present Symposium on 21-25 November 1977. It appeared timely to hold this Symposium for the following reasons: (1) Apart from significant scientific work reported in the literature, progress in other directions between 1972 and 1977 had also been made. For example, the number of food items authorized by governments, with or without restriction, had grown from 19 to 26, and the number of countries accepting one or more irradiated foods for human consumption had increased from 11 to 19. (2) Largely on the basis of the work of the International Project in the Field of Food Irradiation (Karlsruhe), already described at the Bombay Symposium, an international expert committee, jointly convened by FAO, the IAEA and WHO in August-September 1976, had made important statements on the philosophy of wholesomeness studies

  16. Food Preservation by Irradiation. Vol. I. Proceedings of an International Symposium on Food Preservation by Irradiation

    International Nuclear Information System (INIS)

    In the task of alleviating the distress caused by the world-wide food shortage it is essential to preserve what has been grown and harvested in the fields. Clearly all suitable methods for preserving agricultural produce and food should be made use of. In this context treatment with ionizing radiation has proved its value as an environmentally clean, physical method o f food preservation which is low in its energy requirement, but the volume of food being processed in this way is still low. The introduction o f food irradiation on a global basis poses certain economic, legal, regulatory and health-related questions, the solution o f which requires close international collaboration. Such collaboration between many international, intergovernmental and national organizations began over a decade ago. The need for dissemination and discussion o f information gained through research and development work on this subject became apparent, and a number of inter-regional meetings were held. The last international symposium on the topic was held jointly by FAO and the IAEA in 1972 in Bombay. To review progress made since then, FAO and the IAEA, together with WHO, convened the present Symposium on 21-25 November 1977. It appeared timely to hold this Symposium for the following reasons: (1) Apart from significant scientific work reported in the literature, progress in other directions between 1972 and 1977 had also been made. For example, the number of food items authorized by governments, with or without restriction, had grown from 19 to 26, and the number of countries accepting one or more irradiated foods for human consumption had increased from 11 to 19. (2) Largely on the basis of the work of the International Project in the Field of Food Irradiation (Karlsruhe), already described at the Bombay Symposium, an international expert committee, jointly convened by FAO, the IAEA and WHO in August-September 1976, had made important statements on the philosophy of wholesomeness

  17. Effects of modified fractionated irradiation on the growth of sarcoma 180 solid tumor in mouse

    International Nuclear Information System (INIS)

    The present experimental study has been designed and carried out to investigate the effects of various doses and timings of fractionated irradiation of 6 MV X-rays obtained from a linear accelerator on sarcoma 180 solid tumors produced in DDO/Lee mouse. A total of 2700 to approx. 2800 cGy(or rad) was delivered with daily dose of 250/ cGy, 350cGy, and 450cGy every other day to the inoculated site starting on day 2,4,6, and 8 post-inoculation and the tumor size change was observed by measuring a maximum circumference of tumor bearing region. The dose experimentally established in the mouse for one half of animals to produce a solid tumor (TSD50) from ascitic mouse sarcoma 180 was 10/sup 3.87/ cells/ml. The effect of fractionated irradiation on days 2 and 4 post-inoculation was inhibitory to the growth of solid form tumor of experimentally produced sarcoma 180 (p<0.001). The growth of tumor was also inhibited when irradiated on days 6 and 8 post-inoculation but the grade was less. Histologically tumor cells of mouse sarcoma 180 produced in the experimental animal were shown to be destroyed and eradicated by radiation once they were responsive to X-irradiation. The present study suggests that a small or early tumor is benefitted by a small daily dose(e.g. 250 cGy) irradiation whereas a moderately advanced tumor is beneficially treated with a relatively high dose (e.g. 450 cGy) irradiation. A large tumor responded very poorly to irradiation

  18. Fractional Absorption of Active Absorbable Algal Calcium (AAACa and Calcium Carbonate Measured by a Dual Stable-Isotope Method

    Directory of Open Access Journals (Sweden)

    Steven A. Abrams

    2010-07-01

    Full Text Available With the use of stable isotopes, this study aimed to compare the bioavailability of active absorbable algal calcium (AAACa, obtained from oyster shell powder heated to a high temperature, with an additional heated seaweed component (Heated Algal Ingredient, HAI, with that of calcium carbonate. In 10 postmenopausal women volunteers aged 59 to 77 years (mean ± S.D., 67 ± 5.3, the fractional calcium absorption of AAACa and CaCO3 was measured by a dual stable isotope method. 44Ca-enriched CaCO3 and AAACa were administered in all subjects one month apart. After a fixed-menu breakfast and pre-test urine collection (Urine 0, 42Ca-enriched CaCl2 was intravenously injected, followed by oral administration of 44Ca-enriched CaCO3 without carrier 15 minutes later, and complete urine collection for the next 24 hours (Urine 24. The fractional calcium absorption was calculated as the ratio of Augmentation of 44Ca from Urine 0 to Urine 24/ augmentation of 42Ca from Urine 0 to Urine 24. Differences and changes of 44Ca and 42Ca were corrected by comparing each with 43Ca. Fractional absorption of AAACa (mean ± S.D., 23.1 ± 6.4, was distinctly and significantly higher than that of CaCO3 (14.7 ± 6.4; p = 0.0060 by paired t-test. The mean fractional absorption was approximately 1.57-times higher for AAACa than for CaCO3. The serum 25(OH vitamin D level was low (mean ± S.D., 14.2 ± 4.95 ng/ml, as is common in this age group in Japan. Among the parameters of the bone and mineral metabolism measured, none displayed a significant correlation with the fractional absorption of CaCO3 and AAACa. Higher fractional absorption of AAACa compared with CaCO3 supports previous reports on the more beneficial effect of AAACa than CaCO3 for osteoporosis.

  19. Mathematical models and specific absorbed fractions of photon energy in the nonpregnant adult female and at the end of each trimester of pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Stabin, M.G.; Watson, E.E.; Cristy, M.; Ryman, J.C.; Eckerman, K.F. [Oak Ridge National Lab., TN (United States); Davis, J.L. [Tennessee Univ., Chattanooga, TN (United States); Marshall, D. [Florida Univ., Gainesville, FL (United States). Dept. of Nuclear Engineering; Gehlen, M.K. [San Diego State Univ., CA (United States)

    1995-05-08

    Mathematical phantoms representing the adult female at three, six, and nine months of gestation are described. They are modifications of the 15-year-old male/adult female phantom (15-AF phantom) of Cristy and Eckerman (1987). The model of uterine contents includes the fetus, fetal skeleton, and placenta. The model is suitable for dose calculations for the fetus as a whole; individual organs within the fetus (other than the skeleton) are not modeled. A new model for the nonpregnant adult female is also described, comprising (1) the 15-AF phantom; (2) an adjustment to specific absorbed fractions for organ self-dose from photons to better match Reference Woman masses; and (3) computation of specific absorbed fractions with Reference Woman masses from ICRP Publication 23 for both penetrating and nonpenetrating radiations. Specific absorbed fractions for photons emitted from various source regions are tabulated for the new non;pregnant adult female model and the three pregnancy models.

  20. Arrested neuronal proliferation and impaired hippocampal function following fractionated brain irradiation in the adult rat

    DEFF Research Database (Denmark)

    Madsen, Torsten Meldgaard; Kristjansen, P.E.G.; Bolwig, Tom Gert;

    2003-01-01

    The generation of new neurons in the adult mammalian brain has been documented in numerous recent reports. Studies undertaken so far indicate that adult hippocampal neurogenesis is related in a number of ways to hippocampal function.Here, we report that subjecting adult rats to fractionated brain...... days after irradiation, the animals with blocked neurogenesis performed poorer than controls in a hippocampus-dependent place-recognition task, indicating that the presence of newly generated neurons may be necessary for the normal function of this brain area. The animals were never impaired...... irradiation blocked the formation of new neurons in the dentate gyrus of the hippocampus. At different time points after the termination of the irradiation procedure, the animals were tested in two tests of short-term memory that differ with respect to their dependence on hippocampal function. Eight and 21...

  1. Large effect of irradiance on hydrogen isotope fractionation of alkenones in Emiliania huxleyi

    Science.gov (United States)

    van der Meer, Marcel T. J.; Benthien, Albert; French, Katherine L.; Epping, Eric; Zondervan, Ingrid; Reichart, Gert-Jan; Bijma, Jelle; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2015-07-01

    The hydrogen isotopic (δD) composition of long-chain alkenones produced by certain haptophyte algae has been suggested as a potential proxy for reconstructing paleo sea surface salinity. However, environmental parameters other than salinity may also affect the δD of alkenones. We investigated the impact of the level of irradiance on hydrogen isotopic fractionation of alkenones versus growth water by cultivating two strains of the cosmopolitan haptophyte Emiliania huxleyi at different light intensities. The hydrogen isotope fractionation decreased by approximately 40‰ when irradiance was increased from 15 to 200 μmol photons m-2 s-1 above which it was relatively constant. The response is likely a direct effect of photosystem I and II activity as the relationship of the fractionation factor α versus light intensity can be described by an Eilers-Peeters photosynthesis model. This irradiance effect is in agreement with published δD data of alkenones derived from suspended particulate matter collected from different depths in the photic zone of the Gulf of California and the eastern tropical North Pacific. However, haptophyte algae tend to bloom at relatively high light intensities (>500 μmol photons m-2 s-1) occurring at the sea surface, at which hydrogen isotope fractionation is relatively constant and not affected by changes in light intensity. Alkenones accumulating in the sediment are likely mostly derived from these surface water haptophyte blooms, when the largest amount of biomass is produced. Therefore, the observed irradiance effect is unlikely to affect the applicability of the hydrogen isotopic composition of sedimentary long chain alkenones as a proxy for paleosalinity.

  2. Surviving defect fraction in 14-MeV neutron-irradiated copper

    International Nuclear Information System (INIS)

    The fraction of Frenkel defects that survive in isolated or clustered form during room temperature irradiation of copper has been measured as a function of fluence by a combination of electron microscopy (TEM) and electrical resistivity methods. Both methods indicate that the ratio of surviving to created defects decreased from 12 to 4.7% as the fluence of 14-MeV neutrons increased from 1x1020 to 2.9x1021 n/m2. (orig.)

  3. Geant4-based comprehensive study of the absorbed fraction for electrons and gamma-photons using various geometrical models and biological tissues

    OpenAIRE

    Rahman Ziaur; Rehman Shakeel Ur.; Mirza Sikander M.; Arshed Waheed; Mirza Nasir M.

    2013-01-01

    The Geant4-based comprehensive model has been developed to predict absorbed fraction values for both electrons and gamma photons in spherical, ellipsoidal, and cylindrical geometries. Simulations have been carried out for water, ICRP soft-, brain-, lung-, and ICRU bone tissue for electrons in 0.1 MeV-4 MeV and g-photons in the 0.02 MeV-2.75 MeV energy range. Consistent with experimental observations, the Geant4-simulated values of absorbed fractions show a ...

  4. Understanding and predicting the behaviour of silver base neutron absorbers under irradiations; Comprehension et prediction du comportement sous irradiation neutronique d`alliages absorbants a base d`argent

    Energy Technology Data Exchange (ETDEWEB)

    Desgranges, C

    1998-12-31

    The effect of neutron irradiation induced transmutations on the swelling of AgInCd (AIC) alloys used as neutron absorber in the control rods of Pressurized Water Reactors has been studied both experimentally and theoretically. Effective atomic volumes have been determined in synthetic AgCdInSn alloys with various compositions and containing fcc and hc phases, representative of irradiated AIC (Sn is a transmutation product). Swelling is shown to result first from the transmutation of Ag into Cd and of In into Sn, both with larger effective volume than the mother atom, and second from grain boundaries precipitation of s still less dense hc phase when solid solubility of transmuted products is exceeded. For both fcc and hc phases, we have determined profiles at the temperatures in the vicinity of the operating temperature. Unusual characteristics of second phase growth at grain boundaries induced by transmutations are identified on a simple binary alloy model: kinetics is controlled by irradiation temperature which scales diffusivities and flux which scales transmutation rates, as well as by the grain size in the underlying matrix. To address the AgInCdSn alloys, a novel technique is proposed to model diffusion in multicomponent alloys. It is based on a linearization of a simple atomistic model. With a single set of parameters, for each phase, our model well reproduces our interdiffusion measurements in quaternary alloys as well as existing interdiffusion experiments in binary alloys. Finally this diffusion model implemented with a moving interface algorithm is used to model the growth of the second phase induced by transmutation in the AIC under irradiation. (authors) 74 refs.

  5. Degradation and decoloration of textiles wastewater by electron beam irradiation: Effect of energy, current and absorbed dose

    Energy Technology Data Exchange (ETDEWEB)

    Bakar, Khomsaton Abu; Zulkafli,; Hashim, Siti A' aisah [Malaysian Nuclear Agency (Nuclear Malaysia), Bangi 43000 Kajang Selangor (Malaysia); Ahmad, Pauzi [Universiti Kebangsaan Malaysia, 43600 UKM, Bangi Selangor (Malaysia)

    2014-09-03

    In this study, electron beam accelerator (EB) was used to treat textiles wastewater from Rawang Industrial Park, Selangor. The objectives were to determine effective energy, beam current and absorbed dose required for decoloration and degradation of the textiles effluent. The textiles effluent was irradiated in a batch with various energy of 1MeV to 3MeV at constant beam current of 30mA. It was observed that removal of color and COD increases with higher beam energy. The EB energy of 1MeV effectively to removed 58% color and 19% COD. For textile effluent sample irradiated at fix energy of 1MeV and 3Mev but at different beam current 10mA, 20mA and 30mA. It was observed that removal of color and COD increases with the increased of beam current at each energy. However removal of color was significantly better at 1Mev as compared to 3Mev. In the case of textiles effluent, irradiated at doses of 17, 20,25,30, 35, 100 and 200kGy using 30 kW power of EB (1Mev, 30mA), results shows removal of BOD{sub 5}, COD and color were in the range 9%-33%, 14%-38% and 43%-78% respectively.

  6. Study of chromosome aberration repair after acute or fractionated X-irradiation in human peripheral lymphocytes

    International Nuclear Information System (INIS)

    Pure human peripheral blood has been subjected to a single irradiation with the dose of 125 and 250R and by fractions with the doses of 125+125 R in the following periods of the cell cycle: 0, 2, 4, 6, 8, 12, 16, 24, 30, 40 and 45 hrs. The following types of structural chromosome aberrations are counted on metaphase plates with a good chromosome scattering: dicentrics, rings, interstitial deletions, symmetric translocations, chromatide and chromosome fragments. The data on polycentrics and rings prove to be most characteristic: the frequency of these aberrations in the case of single irradiation for all periods of the ''presynthetic'' Gsub(I) period is stable varying in the range of 17-20% in the case of a 125 R dose and 66-73% in the case of a 250 R dose. Their frequency decreased for both doses of irradiation in later periods and reached 1% by the end of the synthetic period. The fractionated effect of two doses 125 R each gives the following values of polycentric and ring formation: second hour - 44,15%, fourth - 50,82%, sixth - 55,15% eighth -58,32% (maximum), twelfth - 55,48%. The descending tendency is preserved till the end of the presynthetic period and in the synthetic period. The statistic processing of results shows statistically authentic differences between fractionated and single irradiation in the output of polycentrics and rings, as well as other types of aberrations and breaks per cell. The data obtained permit to conclude that repair processes are undulatory and are characterized by maximum intensity in the first hours of presynthetic period which weakens to the 8th hour and then strengthens again almost to the end of the synthetic period

  7. Development of in vitro models for investigating spatially fractionated irradiation: physics and biological results

    Science.gov (United States)

    Blockhuys, S; Vanhoecke, B; Paelinck, L; Bracke, M; DeWagter, C

    2009-03-01

    We present different in vitro experimental models which allow us to evaluate the effect of spatially fractionated dose distributions on metabolic activity. We irradiated a monolayer of MCF-7/6 human breast cancer cells with a steep and a smooth 6 MV x-ray dose gradient. In the steep gradient model, we irradiated the cells with three separate small fields. We also developed two smooth gradient models. In the first model, the cells are cultured in a T25 flask and irradiated with a smooth dose gradient over the length of the flask, while in the second one, the cells are cultured in a 96-well plate and also irradiated over the length of the plate. In an attempt to correlate the spatially fractionated dose distributions with metabolic activity, the effect of irradiation was evaluated by means of the MTT assay. This assay is used to determine the metabolic activity by measuring the amount of formazan formed after the conversion of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by cellular dehydrogenases. The results obtained with our different models suggest a dose-specific effect on metabolic activity, characterized by an increased formazan optical density occurring in the dose range 1.0-4.0 Gy in the steep dose gradient model and in the dose ranges 4.2-6.5 Gy and 2.3-5.1 Gy in the two smooth dose gradient models. The corresponding times for maximal formazan accumulation were 5-7 days in the steep dose gradient model and day 9-13 and day 9-11 in the smooth dose gradient models. Altogether, our results suggest that the MTT assay may be used as a biological dose-response meter to monitor the radiotherapeutic effectiveness.

  8. Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun-Jung, E-mail: forejs2@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jun Won, E-mail: JUNWON@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Yoo, Hyun, E-mail: gochunghee@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kwak, Woori, E-mail: asleo02@snu.ac.kr [Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-747 (Korea, Republic of); Choi, Won Hoon, E-mail: wonhoon@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Cho, Seoae, E-mail: seoae@cnkgenomics.com [C& K Genomics, Seoul National University Mt.4-2, Main Bldg. #514, SNU Research Park, NakSeoungDae, Gwanakgu, Seoul 151-919 (Korea, Republic of); Choi, Yu Jeong, E-mail: yunk9275@daum.net [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Lee, Yoon-Jin, E-mail: yjlee8@kirams.re.kr [Division of Radiation Effects, Research Center for Radiotherapy, Korea Institute of Radiological & Medical Sciences, Seoul 139-760 (Korea, Republic of); Cho, Jaeho, E-mail: jjhmd@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of)

    2015-08-14

    We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm{sup 2} fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL

  9. Calculation of the internal radiation absorbed dose of 123I-Annexin V

    International Nuclear Information System (INIS)

    To estimate absorbed doses by 123I-Annexin V in human, 125I-Annexin V was used as a radiotracer for measuring the distribution of radiolabeled Annexin V in mice. The standard Medical Internal Radiation Dose (MIRD) method was used by Mirdose-3 software in dosimetry estimation. The results show that liver and kidney received 2.77 x 10-3 and 2.71 x 10-3 mGy/MBq, respectively. The red marrow received 1.78 x 10-5 mGy/MBq, and the other organs received doses between 1.5 x 10-4 and 10.5 x 10-4 mGy/MBq. The effective dose was estimated at 5.55 x 10-4 mSv/MBq. Human radiation dosimetry can be performed by the mice biodistribution data and important data for clinical safe trial of 123I-Annexin V are provided. (authors)

  10. Experimental and theoretical determination of absorbed microwave dose rate distributions in phantom heads irradiated by an aperture source

    International Nuclear Information System (INIS)

    A thermographic technique is used to determine absorbed microwave energy distribution in phantom monkey and human heads irradiated by an aperture source. The phantom heads are brain equivalent tissue spheres and a bone and brain tissue geometric model of a monkey head. The results of the experiment are compared to patterns obtained from theoretical calculations, indicating good general agreement between experimental and theoretical data. The penetration of microwave energy is less for the phantom human head than for the monkey head. The overall poor penetration of the radiation due to the 2450 MHz aperture source used in this experiment indicates a need for further research using frequency and aperture dimensions as parameters to obtain desired microwave absorption patterns for both biological experiments and therapeutic applications. (author)

  11. Concept of Staged Approach for International Fusion Materials Irradiation Facility

    CERN Document Server

    Sugimoto, M; Takeuchi, H

    2000-01-01

    The intense neutron source for development of fusion materials planned by international collaboration makes a new step to clarify the technical issues for realizing the 40 MeV, 250 mA deuteron beam facility. The baseline concept employs two identical 125 mA linac modules whose beams are combined at the flowing lithium target. Recent work for reducing the cost loading concerns the staged deployment of the full irradiation capability in three steps. The Japanese activity about the design and development study about IFMIF accelerator in this year is presented and the schedule of next several years is overviewed.

  12. A framework for consistent estimation of leaf area index, fraction of absorbed photosynthetically active radiation, and surface albedo from MODIS time-series data

    DEFF Research Database (Denmark)

    Xiao, Zhiqiang; Liang, Shunlin; Wang, Jindi;

    2015-01-01

    model and the MODIS surface reflectance data. The estimated LAI values were then input into the ACRM to calculate the surface albedo and the fraction of absorbed photosynthetically active radiation (FAPAR). For snow-covered areas, the surface albedo was calculated as the underlying vegetation canopy...

  13. Reemergence of apoptotic cells between fractionated doses in irradiated murine tumors

    International Nuclear Information System (INIS)

    The purpose of this investigation was to follow up our previous studies on the development of apoptosis in irradiated murine tumors by testing whether an apoptotic subpopulation of cells reemerges between fractionated exposures. Mice bearing a murine ovarian carcinoma, OCa-I, were treated in vivo with two fractionation protocols: two doses of 12.5 Gy separated by various times out to 5 days and multiple daily fractions of 2.5 Gy. Animals were killed 4 h after the last dose in each protocol, and the percent apoptosis was scored from stained histological sections made from the irradiated tumors according to the specific features characteristic of this mode of cell death. The 12.5+12.5 Gy protocol yielded a net total percent apoptosis of about 45% when the two doses were separated by 5 days (total dose = 25 Gy), whereas the 2.5 Gy per day protocol yielded about 50% net apoptotic cells when given for 5 days (total dose = 12.5 Gy). These values are to be compared to the value of 36% apoptotic cells that is yielded by large single doses (> 25 Gy). Thus, these results indicate that an apoptotic subpopulation of cells reemerged between the fractions in both protocols, but the kinetics appeared to be delayed in the 12.5+12.5 Gy vs. the multiple 2.5 Gy protocol. This reemergence of cells with the propensity for radiation-induced apoptosis between fractionated exposures is consistent with a role for this mode of cell death in the response of tumors to radiotherapy and may represent the priming of a new subpopulation of tumor cells for apoptosis as part of normal tumor homeostasis to counterbalance cell division. 25 refs., 3 figs., 1 tab

  14. Haemopoiesis in murine bone marrow and spleen after fractionated irradiation and repeated bone marrow transplantation. I

    International Nuclear Information System (INIS)

    Erythropoiesis was studied in mice repeatedly exposed to doses of 3 Gy of 60Co γ-rays at 4-day intervals up to a total dose of 24 Gy on the basis of total bone marrow and spleen cellularity follow-up and analysis of myelograms and splenograms. Half the number of the mice received 106 nuclear cells of syngeneic bone marrow after each fractional radiation dose. It was mainly the spleen which was involved in the adaptation and regeneration of erythropoiesis, its contribution to total erythropoiesis in bone marrow recipients having been as high as 73.9% (day 20 of experiment, total dose 15 Gy). In mice only irradiated, the number of nuclear cells of erythroid lineage decreased to zero values sooner in the spleen (day 16 of experiment, total dose 12 Gy) than in the bone marrow (day 24 of experiment, total dose 18 Gy). The analysis of the results of collections made on day 9 after the last irradiation revealed, however, that the hemopoietic microenvironment of the spleen and hemopoietic cells capable of differentiation in the erythroid direction were so resistant to irradiation in mice only irradiated that erythropoiesis in their spleens exhibited signs of regeneration even after the highest total dose of 24 Gy. (author). 2 figs., 3 tabs., 12 refs

  15. Standardized methods to verify absorbed dose in irradiated food for insect control. Proceedings of a final research co-ordination meeting

    International Nuclear Information System (INIS)

    Irradiation to control insect infestation of food is increasingly accepted and applied, especially as a phytosanitary treatment of food as an alternative to fumigation. However, unlike other processes for insect control, irradiation does not always result in immediate insect death. Thus, it is conceivable that fresh and dried fruits and tree nuts, which have been correctly irradiated to meet insect disinfestation/quarantine requirements, may still contain live insects at the time of importation. There is, however, a movement by plant quarantine authorities away from inspecting to ensure the absence of live insects in imported consignments towards examining through administrative procedures that a treatment required by law has been given. Nevertheless, there is a need to provide plant quarantine inspectors with a reliable objective method to verify that a minimum absorbed dose of radiation was given to supplement administrative procedures. Such an objective method is expected to bolster the confidence of the inspectors in clearing the consignment without delay and to facilitate trade in irradiated commodities. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture initiated a co-ordinated research project (CRP) in 1994 to generate data on the verification of absorbed dose of irradiation in fresh, dried fruits and tree nuts for insect disinfestation/quarantine purposes. A standardized label dose indicator available commercially was used to verify the minimum/maximum absorbed dose of the irradiated commodities for these purposes as required by regulations in certain countries. It appears that such a label dose indicator with certain modifications could be made available to assist national authorities and the food industry to verify the absorbed dose of irradiation to facilitate trade in such irradiated commodities. This TECDOC reports on the accomplishments of this co-ordinated research project and includes the papers presented by the participants

  16. Measured Wavelength-Dependent Absorption Enhancement of Internally Mixed Black Carbon with Absorbing and Nonabsorbing Materials.

    Science.gov (United States)

    You, Rian; Radney, James G; Zachariah, Michael R; Zangmeister, Christopher D

    2016-08-01

    Optical absorption spectra of laboratory generated aerosols consisting of black carbon (BC) internally mixed with nonabsorbing materials (ammonium sulfate, AS, and sodium chloride, NaCl) and BC with a weakly absorbing brown carbon surrogate derived from humic acid (HA) were measured across the visible to near-IR (550 to 840 nm). Spectra were measured in situ using a photoacoustic spectrometer and step-scanning a supercontinuum laser source with a tunable wavelength and bandwidth filter. BC had a mass-specific absorption cross section (MAC) of 7.89 ± 0.25 m(2) g(-1) at λ = 550 nm and an absorption Ångström exponent (AAE) of 1.03 ± 0.09 (2σ). For internally mixed BC, the ratio of BC mass to the total mass of the mixture was chosen as 0.13 to mimic particles observed in the terrestrial atmosphere. The manner in which BC mixed with each material was determined from transmission electron microscopy (TEM). AS/BC and HA/BC particles were fully internally mixed, and the BC was both internally and externally mixed for NaCl/BC particles. The AS/BC, NaCl/BC, and HA/BC particles had AAEs of 1.43 ± 0.05, 1.34 ± 0.06, and 1.91 ± 0.05, respectively. The observed absorption enhancement of mixed BC relative to the pure BC was wavelength dependent for AS/BC and decreased from 1.5 at λ = 550 nm with increasing wavelength while the NaCl/BC enhancement was essentially wavelength independent. For HA/BC, the enhancement ranged from 2 to 3 and was strongly wavelength dependent. Removal of the HA absorption contribution to enhancement revealed that the enhancement was ≈1.5 and independent of wavelength. PMID:27359341

  17. Response of human tumor cell lines in vitro to fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, J.H.; Meeker, B.E.; Chapman, J.D.

    1989-01-01

    The surviving fraction of human tumor cell lines after 2 Gy (SF2) varies between 0.1 and 0.8. It has been postulated that differences in inherent radiosensitivity of tumor cells are a major determinant of radiation response in vivo. Assays of inherent radiosensitivity based on acute survival are being developed as predictors of tumor response which often assume that the same inherent radiosensitivity persists throughout a fractionated treatment. We have investigated the response of 2 human tumor cell lines (A549 and MCF7) with different inherent radiosensitivities to in vitro fractionated irradiation. A549 cells had an SF2 of 0.62 and a mean inactivation dose (D) of 3.07 Gy whereas MCF7 cells had an SF2 of 0.30 and a D of 1.52 Gy. Split dose repair capacity (at equal survival levels) was less for A549 than for MCF7 cells and recovery kinetics for both cell lines were substantially longer than those of rodent cell lines. Survival after 5 fractions of 2 Gy given 12 hr apart at 37 degrees C was near to that predicted from the acute survival curve, assuming complete repair and no proliferation. Acute survival of A549 cells which survived 5 fractions of 2 Gy given 12 hr apart was similar to the acute survival of unirradiated cells. When A549 cells were incubated at 22 degrees C between 5 fractions of 2 Gy given 12 hr apart, proliferation and split dose repair were substantially inhibited. These studies support the proposals to use in vitro inherent radiosensitivity assays for the prediction of in vivo response of tumors to fractionated treatment.

  18. Response of human tumor cell lines in vitro to fractionated irradiation.

    Science.gov (United States)

    Matthews, J H; Meeker, B E; Chapman, J D

    1989-01-01

    The surviving fraction of human tumor cell lines after 2 Gy (SF2) varies between 0.1 and 0.8. It has been postulated that differences in inherent radiosensitivity of tumor cells are a major determinant of radiation response in vivo. Assays of inherent radiosensitivity based on acute survival are being developed as predictors of tumor response which often assume that the same inherent radiosensitivity persists throughout a fractionated treatment. We have investigated the response of 2 human tumor cell lines (A549 and MCF7) with different inherent radiosensitivities to in vitro fractionated irradiation. A549 cells had an SF2 of 0.62 and a mean inactivation dose (D) of 3.07 Gy whereas MCF7 cells had an SF2 of 0.30 and a D of 1.52 Gy. Split dose repair capacity (at equal survival levels) was less for A549 than for MCF7 cells and recovery kinetics for both cell lines were substantially longer than those of rodent cell lines. Survival after 5 fractions of 2 Gy given 12 hr apart at 37 degrees C was near to that predicted from the acute survival curve, assuming complete repair and no proliferation. Acute survival of A549 cells which survived 5 fractions of 2 Gy given 12 hr apart was similar to the acute survival of unirradiated cells. When A549 cells were incubated at 22 degrees C between 5 fractions of 2 Gy given 12 hr apart, proliferation and split dose repair were substantially inhibited. These studies support the proposals to use in vitro inherent radiosensitivity assays for the prediction of in vivo response of tumors to fractionated treatment. PMID:2912934

  19. The Effect of 60Co Gamma Irradiation on Various Fractions of Human Blood-Plasma Proteins

    International Nuclear Information System (INIS)

    The potential usefulness of employing ionizing radiation to cold-sterilize biomedical products has stimulated interest in characterizing the radiation sensitivity of various biologicals like vitamins, antibiotics, enzymes, antibodies and blood plasma fractions. This report presents findings on the sensitivity of haemagglutinin activity in human sera exposed to cobalt-60 gamma radiation. At doses tested between 0.2 and 5.0 Mrad, α-isohaemagglutinins were found to be more readily inactivated than ß-isohaemagglutinins, but neither was completely inactivated in this range. Sterility, clotting and antihaemophilic activity were also assessed on irradiated and freeze-dried preparations of human plasma with no significant differences in response detected. (author)

  20. Radiation tolerance dose of the spinal cord following conventionally fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Shogo; Hoshi, Akihiko; Takai, Yoshihiro; Hoshino, Fumiya; Mochizuki, Yukio; Kanehira, Chihiro; Kaneta, Koichi.

    1987-08-01

    409 patients whose spinal cord were irradiated over 30 Gy with conentionally fractionated method were surveied to study the colleration between the dose of spinal cord and the incidence of radiation myelitis. Radiation myelitis was observed in 26 cases including 3 transverse myelitis ones. 5 year incidences of transverse myelitis calculated with life table method were approximately 0 % at 40 Gy, 5 % at 50 Gy, 10 % at 60 Gy and 20 % at 70 Gy. The radiation tolerance dose of the spinal cord was considered to be 50 Gy.

  1. Radiation tolerance dose of the spinal cord following conventionally fractionated irradiation

    International Nuclear Information System (INIS)

    409 patients whose spinal cord were irradiated over 30 Gy with conentionally fractionated method were surveied to study the colleration between the dose of spinal cord and the incidence of radiation myelitis. Radiation myelitis was observed in 26 cases including 3 transverse myelitis ones. 5 year incidences of transverse myelitis calculated with life table method were approximately 0 % at 40 Gy, 5 % at 50 Gy, 10 % at 60 Gy and 20 % at 70 Gy. The radiation tolerance dose of the spinal cord was considered to be 50 Gy. (author)

  2. Effects of irradiation with conventional and multiple daily fractionation on serum amylase activity

    International Nuclear Information System (INIS)

    The behaviour of serum α-amylase activity was determined in patients with head and neck cancer treated by radiation therapy. The levels of serum α-analyse activity during conventional and multiple daily fractionation were compared. Starting from the second day of treatment an increase of serum α-amylase activity was observed. The increase and its duration depended on the total daily dose: after the first day of treatment a linear correlation between serum levels and total daily dose could be observed. The size of the amylase increase correlated to the proportion of salivary gland tissue included in the irradiated volume. (orig.)

  3. Incompatible SLA bone marrow graft in the pig after fractionated irradiation and administration of cyclosporin A

    International Nuclear Information System (INIS)

    A series of fractionated partial irradiations which consisted of either 3 gray x 6 times or 3 gray x 4 times, combined with pharmacological immunosuppression (Cyclosporin A: Cs-A) ensure a SLA semidifferent bone marrow graft in the pig. Bone marrow and peripheral blood lymphocytes chimerism was readily detectable. No graft versus host disease (GVHD) symptoms were noticed as long as Cs-A was given at a sufficient dose. However when Cs-A treatment was stopped GVHD or rejection of the graft developed rapidly

  4. Facts about food irradiation. A series of fact sheets from the International Consultative Group on Food Irradiation

    International Nuclear Information System (INIS)

    The safety and benefits of foods processed by ionizing radiation are well documented. In an effort to provide governments, especially those of developing countries, with scientifically accurate information on issues of general interest to the public, the International Consultative Group on Food Irradiation (ICGFI), which was established under the aegis of the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the IAEA, decided at its 7th Annual Meeting in Rome, Italy, on October 1990, to issue a series of ''Fact Sheets'' on the subject. ICGFI, an inter-governmental body with a membership of 37 governments, has as one of its mandates the function to provide information to Member States of the FAO, WHO, and IAEA and to the three organizations themselves on the safe and proper use of food irradiation technology. The Fact Sheets included here cover issues relating to: status and trends; scientific and technical terms; food irradiation and radioactivity; chemical changes in irradiated food; nutritional quality of irradiated foods; genetic studies; microbiological safety of irradiated food; irradiation and food safety; irradiation and food additives and residues; packaging of irradiated foods; safety of irradiation facilities; controlling the process; food irradiation costs; and irradiated foods and the consumer. The Fact Sheets have been separately indexed and included in the INIS Database under Reference Numbers 23011206-23011217, 23011319 and 23012743. The Fact Sheets were first issued by the ICGFI Secretariat (Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Vienna, Austria) in May 1991

  5. Retrieval of Leaf Area Index (LAI and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR from VIIRS Time-Series Data

    Directory of Open Access Journals (Sweden)

    Zhiqiang Xiao

    2016-04-01

    Full Text Available Long-term high-quality global leaf area index (LAI and fraction of absorbed photosynthetically active radiation (FAPAR products are urgently needed for the study of global change, climate modeling, and many other problems. As the successor of the Moderate Resolution Imaging Spectroradiometer (MODIS sensor, the Visible Infrared Imaging Radiometer Suite (VIIRS will continue to provide global environmental measurements. This paper aims to generate longer time series Global LAnd Surface Satellite (GLASS LAI and FAPAR products after the era of the MODIS sensor. To ensure spatial and temporal consistencies between GLASS LAI/FAPAR values retrieved from different satellite observations, the GLASS LAI/FAPAR retrieval algorithms were adapted in this study to retrieve LAI and FAPAR values from VIIRS surface reflectance time-series data. After reprocessing of the VIIRS surface reflectance to remove remaining effects of cloud contamination and other factors, a database generated from the GLASS LAI product and the reprocessed VIIRS surface reflectance for all Benchmark Land Multisite Analysis and Intercomparison of Products (BELMANIP sites was used to train general regression neural networks (GRNNs. The reprocessed VIIRS surface reflectance data from an entire year were entered into the trained GRNNs to estimate the one-year LAI values, which were then used to calculate FAPAR values. A cross-comparison indicates that the LAI and FAPAR values retrieved from VIIRS surface reflectance were generally consistent with the GLASS, MODIS and Geoland2/BioPar version 1 (GEOV1 LAI/FAPAR values in their spatial patterns. The LAI/FAPAR values retrieved from VIIRS surface reflectance achieved good agreement with the GLASS LAI/FAPAR values (R2 = 0.8972 and RMSE = 0.3054; and R2 = 0.9067 and RMSE = 0.0529, respectively. However, validation of the LAI and FAPAR values derived from VIIRS reflectance data is now limited by the scarcity of LAI/FAPAR ground measurements.

  6. Combination Processes in Food Irradiation. Proceedings of an International Symposium on Combination Processes in Food Irradiation

    International Nuclear Information System (INIS)

    Processes in Food Irradiation was held by the IAEA and FAO at the Bandaranaike Memorial International Conference Hall in Colombo on 24-28 November 1980, and the present volume contains the proceedings. One of the most effective means demonstrated of increasing the efficacy of irradiation in the control of food spoilage is the combination of a low irradiation dose with a mild heat treatment. Promising results were reported for the shelf-life extension of mangoes and papayas, and the disinfestation of dried dates. Commercial application of the heat-irradiation treatment for some fruits is expected to follow soon. The Symposium covered other topics, such as the mechanisms of sensitization of microorganisms by physical and chemical agents, improvement of the microbiological quality of foods by combination processes, and the aspects of the wholesomeness and legislation of the food irradiation process. A key issue in the general discussion was the recommendation on the acceptability of food irradiated up to an overall average dose of 10 kGy. This important recommendation had been achieved at a recently convened Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Foods (27 October — 3 November 1980, Geneva). The breakthrough on the toxicological acceptability constitutes a firm basis for going ahead speedily with the development of practical applications of food irradiation, which should take its rightful place among other food preservation methods in helping to provide more and better food to a world in need. The sponsoring organizations hope that the publication of these proceedings will encourage further research and development of food irradiation to the benefit of mankind

  7. Nd:YAG laser irradiation on temporary teeth carious tissue using 12% diamine silver fluoride as a photo-absorber - a morphological study

    International Nuclear Information System (INIS)

    Since Nd:YAG laser radiation was first introduced in Dentistry various photo-absorbers were employed with the intent of improving its efficacy when used on dental carious tissue. The purpose of the present study was to analyze the influence of this radiation using Scanning and Optical microscopy over carious tissue of primary teeth using two photo-absorbers. 15 primary human teeth were used and, in each one, 3 cavity preparations were performed. Specimens were then submitted to an in vitro demineralizing environment during 18 days. Two of the cavities of each specimen were laser irradiated using the Nd:YAG laser with 60 mJ of energy per pulse, 10 Hz and average power of 0,6 W. The 12% diamine silver fluoride or the mineral coal were used as photo-absorbers. The third cavity of the specimens was used as a control and received no laser irradiation. Samples were transversally cut and the section analyzed by SEM and OM. Results showed that the 12% diamine silver fluoride is an efficient photo-absorber and, when used it the Nd:YAG laser, leading to melting and resolidification of the carious tissue. It can be concluded that the 12% diammine silver fluoride presents advantages over the mineral coal as a photo absorber when used in primary teeth as it promotes and improves the efficacy of laser irradiation. This substance also works as a barrier on the carie progression in deeper areas such as the infected and necrotic zones. (author)

  8. Comparison of US and FRG post-irradiation examination procedures to measure statistically significant failure fractions of irradiated coated-particle fuels. [HTGR

    Energy Technology Data Exchange (ETDEWEB)

    Kania, M.J.; Homan, F.J.; Mehner, A.W.

    1982-08-01

    Two methods for measuring failure fraction on irradiated coated-particle fuels have been developed, one in the United States (the IMGA system - Irradiated-Microsphere Gamma Analyzer) and one in the Federal Republic of Germany (FRG) (the PIAA procedure - Postirradiation Annealing and Beta Autoradiography). A comparison of the two methods on two standardized sets of irradiated particles was undertaken to evaluate the accuracy, operational procedures, and expense of each method in obtaining statistically significant results. From the comparison, the postirradiation examination method employing the IMGA system was found to be superior to the PIAA procedure for measuring statistically significant failure fractions. Both methods require that the irradiated fuel be in the form of loose particles, each requires extensive remote hot-cell facilities, and each is capable of physically separating failed particles from unfailed particles. Important differences noted in the comparison are described.

  9. Comparison of US and FRG post-irradiation examination procedures to measure statistically significant failure fractions of irradiated coated-particle fuels

    International Nuclear Information System (INIS)

    Two methods for measuring failure fraction on irradiated coated-particle fuels have been developed, one in the United States (the IMGA system - Irradiated-Microsphere Gamma Analyzer) and one in the Federal Republic of Germany (FRG) (the PIAA procedure - Postirradiation Annealing and Beta Autoradiography). A comparison of the two methods on two standardized sets of irradiated particles was undertaken to evaluate the accuracy, operational procedures, and expense of each method in obtaining statistically significant results. From the comparison, the postirradiation examination method employing the IMGA system was found to be superior to the PIAA procedure for measuring statistically significant failure fractions. Both methods require that the irradiated fuel be in the form of loose particles, each requires extensive remote hot-cell facilities, and each is capable of physically separating failed particles from unfailed particles. Important differences noted in the comparison are described

  10. Skin toxicity during hypo fractionated breast irradiation in patient with early breast cancer

    International Nuclear Information System (INIS)

    Radiotherapy is an important component in the treatment of breast cancer. (1) Many women with an early stage of breast cancer are candidates for a breast conservation therapy, which combines both conservative surgery and radiotherapy. (2) According to the data from some series, an estimated 90% of the patients treated with radiotherapy for breast cancer will develop a degree of radiation-induced dermatitis. (3) The severity of the skin reactions during and following the breast irradiation is influenced by both treatment-related and patient-related factors. The treatment - related factors include the fraction size (the dose delivered with each treatment), the total dose delivered, the volume of tissue treated, the type of radiation (4) and the addition of chemotherapy. (5) The patient-related factors include breast size, smoking, axillary lymphocele drainage before treatment, age, and infection of the surgical wound. (6) A hypo fractionation radiotherapy is alternative for a standard fractionation radiotherapy for women with early stage of breast cancer after conservative surgery. The aim of the study was to analyse the acute skin reactions during a hypo fractionated radiotherapy in patients with early breast cancer at our institution. Materials and methods: Twenty patients with early stage of breast cancer (Stadium I and II) and conservative surgery (quadrantectomy of breast with ipsilateral axillary dissection) were analysed. The patients were treated with 6MV x rays on LINAC, using tangential fields with 2.65Gy per fraction and the total dose prescribed to target volume was 42,4 Gy. These patients were observed for acute skin toxicity during the second week and at the end of the treatment. We evaluated dryness, epilation, pigmentation, changes and eritema, dry desquamation (clinically characterized by scaling and pruritus) and moist desquamation (characterized by serious oozing and exposure of the dermis). By using the radiation therapy oncology group’s (RTOG

  11. Fractionated half body irradiation for palliation of multiple symptomatic bone metastases from solid tumors

    International Nuclear Information System (INIS)

    This was a phase I-II nonrandomized study that explored the toxicity and response of fractionated half-body irradiation (F-HBI) in patients with multiple symptomatic osseous metastases. The patients had no premedication and received 10 Gy in 5 fractions with a dose rate of 15 cGy/min. At the Cancer Institute Hospital, 9 patients were treated by this technique (1 upper and lower F-HBI, 6 upper F-HBI, 2 lower F-HBI). All patients were female and had adenocarcinomas (8 breast and 1 lung). Adverse effects were myelosuppression, vomiting and partial alopecia. But hematologic toxicity was treated with blood transfusion or G-CSF. All toxicity was transient, and no pneumonitis nor radiation-related deaths occurred. When given as palliation, F-HBI was found to relieve pain in 80% of the patients. In 10% of the patients the pain relief was complete. The mean time to achieve pain relief in responders after F-HBI was 9 days. The pain relief was long-lasting and continued without need of reirradiation for 40% of the remaining patient's life. This treatment modality appears to be well tolerated and effective in patients with multiple symptomatic osseous metastases. The optimal indications, dose and fractionation for F-HBI should be further explored in randomized trials. (author)

  12. Fractionated half body irradiation for palliation of multiple symptomatic bone metastases from solid tumors

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, Kenji; Hayashi, Shinya; Sunagawa, Yoshimitsu; Sougawa, Mitsuharu; Nakazawa, Masanori; Yamashita, Takashi (Japanese Foundation for Cancer Research, Tokyo (Japan). Hospital)

    1992-06-01

    This was a phase I-II nonrandomized study that explored the toxicity and response of fractionated half-body irradiation (F-HBI) in patients with multiple symptomatic osseous metastases. The patients had no premedication and received 10 Gy in 5 fractions with a dose rate of 15 cGy/min. At the Cancer Institute Hospital, 9 patients were treated by this technique (1 upper and lower F-HBI, 6 upper F-HBI, 2 lower F-HBI). All patients were female and had adenocarcinomas (8 breast and 1 lung). Adverse effects were myelosuppression, vomiting and partial alopecia. But hematologic toxicity was treated with blood transfusion or G-CSF. All toxicity was transient, and no pneumonitis nor radiation-related deaths occurred. When given as palliation, F-HBI was found to relieve pain in 80% of the patients. In 10% of the patients the pain relief was complete. The mean time to achieve pain relief in responders after F-HBI was 9 days. The pain relief was long-lasting and continued without need of reirradiation for 40% of the remaining patient's life. This treatment modality appears to be well tolerated and effective in patients with multiple symptomatic osseous metastases. The optimal indications, dose and fractionation for F-HBI should be further explored in randomized trials. (author).

  13. Enrofloxacin and marbofloxacin in horses: comparison of pharmacokinetic parameters, use of urinary and metabolite data to estimate first-pass effect and absorbed fraction.

    Science.gov (United States)

    Peyrou, M; Bousquet-Melou, A; Laroute, V; Vrins, A; Doucet, M Y

    2006-10-01

    Enrofloxacin and marbofloxacin are two veterinary fluoroquinolones used to treat severe bacterial infections in horses. A repeated measures study has been designed to compare their pharmacokinetic parameters, to investigate their bioavailability and to estimate their absorbed fraction and first-pass effect by using plasma, urinary and metabolite data collected from five healthy mares. Clearance and V(d(ss)) were greater for enrofloxacin (mean +/- SD = 6.34 +/- 1.5 mL/min/kg and 2.32 +/- 0.32 L/kg, respectively) than for marbofloxacin (4.62 +/- 0.67 mL/min/kg and 1.6 +/- 0.25 L/kg, respectively). Variance of the AUC(0-inf) of marbofloxacin was lower than that for enrofloxacin, with, respectively, a CV = 15% and 26% intravenously and a CV = 31% and 55% after oral administration. Mean oral bioavailability was not significantly different between marbofloxacin (59%) and enrofloxacin (55%). The mean percentage of the dose eliminated unchanged in urine was significantly higher for marbofloxacin (39.7%) than that for enrofloxacin (3.4%). Absorbed fraction and first-pass effect were only determinable for enrofloxacin, whereas the percentage of the dose absorbed in the portal circulation was estimated to be 78% and the fraction not extracted during the first pass through the liver was 65%. Consequently, the moderate observed bioavailability of enrofloxacin appears to be mainly caused by hepatic first-pass effect.

  14. International Cooperation to Establish Standard Operating Procedure (SOP) for Quarantine Management of Irradiated Foods in International Trade

    International Nuclear Information System (INIS)

    · Development of SOPs through various research activities such as building international cooperation, and analysing current status of food irradiation in domestic and international markets, export and import, international market size, and of R and D - Analysis of examples for quarantine management in agricultural product exporting countries and use of irradiation technology for agricultural product quarantine, and changes in international quarantine management - Analysis of SOPs for food irradiation quarantine in international organization (CODEX, IPPC, WHO). U.S, EU, China, India, and Australia. - Collaborative researches of India/Korea and China/Korea entered into an agreement for market trials · Publishment of irradiation quarantine management SOPs agreed to CODEX standards - Collaborative researches for quarantine management, avoiding Technical Barrier to Trade (TBT), and Sanitary Phytosanitary Measures were conducted, and advanced SOPs agreed with WTO/FTA system were published

  15. Allogeneic bone marrow transplantation in adults after fractionated body irradiation and high dose cyclophosphamide

    International Nuclear Information System (INIS)

    The authors present short and long-term results of allogeneic bone marrow transplantation after hyper-fractionated total body irradiation and high dose cyclophosphamide in ten patients treated for leukaemia during th period 1985-89. Three patients died from complications connected to the transplantation, while seven are living free from leukaemia 18 to 59 months after transplantation. Two patients need treatment for chronic graft versus host disease. Allogeneic bone marrow transplantation is expensive and risky. Close cooperation between clinicians and laboratory specialists is essential. The treatment increases long term survival and probably cures certain patients with leukaemia. Some of the patients will need treatment for chronic graft versus host disease and other late sequelae. 19 refs., 2 tabs

  16. Electron absorbed fractions of energy and S-values in an adult human skeleton based on {mu}CT images of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, R; Cassola, V F; Khoury, H J; De O Lira, C A B [Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire, 1000, CEP 50740-540, Recife (Brazil); Richardson, R B [Radiation Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J 1J0 (Canada); Vieira, J W [Federal Institute of Education, Science and Technology of Pernambuco, Recife (Brazil); Brown, K Robson, E-mail: rkramer@uol.com.br [Imaging Laboratory, Department of Archaeology and Anthropology, University of Bristol, Bristol (United Kingdom)

    2011-03-21

    When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on {mu}CT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 {mu}m thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters {sup 14}C, {sup 59}Fe, {sup 131}I, {sup 89}Sr, {sup 32}P and {sup 90}Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 {mu}m endosteum and the previously recommended 10 {mu}m endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by {approx}20% when the beta emitters are in marrow.

  17. New specific absorbed fractions for annihilation radiation as a step towards a more individual dosimetry in nuclear diagnostics

    International Nuclear Information System (INIS)

    In order to establish a more individual dosimetry for treatments involving radiopharmaceuticals like nuclear diagnostics and targeted radionuclide therapy, this project aims to calculate Specific Absorbed Fractions (SAFs) for annihilation radiation over a broad range of physiognomies. For the estimation of the SAFs varying with different physiognomic parameters, the study uses the Monte Carlo N-Particle Transport Code (MCNP) which during the last decades proved to be a powerful and reliable tool for dose calculations in human tissue. The human phantoms are generated from an additional software called The Body Builder which enables the user to generate a phantom according to his specifications. The phantoms generated by The Body Builder are based on the Christy/Eckermann phantoms with a first interpolation made on their coefficients and a subsequent transformation into the equivalent MCNP surface representation. The spectrum of age groups ranges from 1 to 21 years, covering both sexes. As source organs we chose the biokinetical compartments of 18 F-fluorodeoxyglucose (FDG) used in the model of Hays and Segall. A homogeneous distribution of the activity within the source organ is assumed, which means that the annihilation photons of 511 keV are considered to be emitted from an isotropic and homogenous volume source. In order to get good statistics the number of photons simulated ranged between 2 and 20 million, depending on size and distance between source and target organs. Results. Considering all possible combinations between source and target organs, representing 21 age groups of both sexes, one gets more than 30 000 SAFs. The work is still in progress during the preparation of this paper, but first results are already presented here. The relative error of the Monte Carlo simulation for every SAF mentioned below does not exceed 1,1%. An additional uncertainty factor of approximately 0,5% is introduced by using the p-mode of MCNP. The results of the different age

  18. Irradiation-assisted stress corrosion cracking behavior of austenitic stainless steels applicable to LWR core internals.

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. M.; Shack, W. J.; Energy Technology

    2006-01-31

    This report summarizes work performed at Argonne National Laboratory on irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels that were irradiated in the Halden reactor in simulation of irradiation-induced degradation of boiling water reactor (BWR) core internal components. Slow-strain-rate tensile tests in BWR-like oxidizing water were conducted on 27 austenitic stainless steel alloys that were irradiated at 288 C in helium to 0.4, 1.3, and 3.0 dpa. Fractographic analysis was conducted to determine the fracture surface morphology. Microchemical analysis by Auger electron spectroscopy was performed on BWR neutron absorber tubes to characterize grain-boundary segregation of important elements under BWR conditions. At 0.4 and 1.4 dpa, transgranular fracture was mixed with intergranular fracture. At 3 dpa, transgranular cracking was negligible, and fracture surface was either dominantly intergranular, as in field-cracked core internals, or dominantly ductile or mixed. This behavior indicates that percent intergranular stress corrosion cracking determined at {approx}3 dpa is a good measure of IASCC susceptibility. At {approx}1.4 dpa, a beneficial effect of a high concentration of Si (0.8-1.5 wt.%) was observed. At {approx}3 dpa, however, such effect was obscured by a deleterious effect of S. Excellent resistance to IASCC was observed up to {approx}3 dpa for eight heats of Types 304, 316, and 348 steel that contain very low concentrations of S. Susceptibility of Types 304 and 316 steels that contain >0.003 wt.% S increased drastically. This indicates that a sulfur related critical phenomenon plays an important role in IASCC. A sulfur content of <0.002 wt.% is the primary material factor necessary to ensure good resistance to IASCC. However, for Types 304L and 316L steel and their high-purity counterparts, a sulfur content of <0.002 wt.% alone is not a sufficient condition to ensure good resistance to IASCC. This is in distinct contrast to

  19. Identification and absorbed dose determination in irradiated kiwi by electron paramagnetic resonance; Identificacao e medida de dose absorvida em kiwi irradiado utilizando ressonancia paramagnetica eletronica

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Edgar F.O. de; Lopes, Ricardo T. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Rossi, Alexandre M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1997-12-01

    A methodology for identification and absorbed dose determination in irradiated Kiwi with doses between 200 and 1000 Gy is present. Measurement are performed by Electron Paramagetic Resonance (ESR) in the flesh of the fruit after alcohol extration that removes water and soluble substances. The signal used is the radial produced in cellulose by radiation that shows to be stable during the usefull life of the fruit and that is not present in non-irradiated samples. Reference samples are not necessary to dose determination and the results shows that 85% of the calculated values are found to be within {+-} 15% of the applied initial dose. (author). 9 refs., 5 figs., 2 tabs.

  20. Benefits of online in vivo dosimetry for single-fraction total body irradiation.

    Science.gov (United States)

    Eaton, David J; Warry, Alison J; Trimble, Rachel E; Vilarino-Varela, Maria J; Collis, Christopher H

    2014-01-01

    Use of a patient test dose before single-fraction total body irradiation (TBI) allows review of in vivo dosimetry and modification of the main treatment setup. However, use of computed tomography (CT) planning and online in vivo dosimetry may reduce the need for this additional step. Patients were treated using a supine CT-planned extended source-to-surface distance (SSD) technique with lead compensators and bolus. In vivo dosimetry was performed using thermoluminescent dosimeters (TLDs) and diodes at 10 representative anatomical locations, for both a 0.1-Gy test dose and the treatment dose. In total, 28 patients were treated between April 2007 and July 2013, with changes made in 10 cases (36%) following test dose results. Overall, 98.1% of measured in vivo treatment doses were within 10% of the prescribed dose, compared with 97.0% of test dose readings. Changes made following the test dose could have been applied during the single-fraction treatment itself, assuming that the dose was delivered in subportions and online in vivo dosimetry was available for all clinically important anatomical sites. This alleviates the need for a test dose, saving considerable time and resources.

  1. Benefits of online in vivo dosimetry for single-fraction total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, David J., E-mail: davideaton@nhs.net [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom); Warry, Alison J. [Department of Radiotherapy Physics, University College London Hospital, London (United Kingdom); Trimble, Rachel E.; Vilarino-Varela, Maria J.; Collis, Christopher H. [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom)

    2014-01-01

    Use of a patient test dose before single-fraction total body irradiation (TBI) allows review of in vivo dosimetry and modification of the main treatment setup. However, use of computed tomography (CT) planning and online in vivo dosimetry may reduce the need for this additional step. Patients were treated using a supine CT-planned extended source-to-surface distance (SSD) technique with lead compensators and bolus. In vivo dosimetry was performed using thermoluminescent dosimeters (TLDs) and diodes at 10 representative anatomical locations, for both a 0.1-Gy test dose and the treatment dose. In total, 28 patients were treated between April 2007 and July 2013, with changes made in 10 cases (36%) following test dose results. Overall, 98.1% of measured in vivo treatment doses were within 10% of the prescribed dose, compared with 97.0% of test dose readings. Changes made following the test dose could have been applied during the single-fraction treatment itself, assuming that the dose was delivered in subportions and online in vivo dosimetry was available for all clinically important anatomical sites. This alleviates the need for a test dose, saving considerable time and resources.

  2. Dose Calculation Evolution for Internal Organ Irradiation in Humans

    International Nuclear Information System (INIS)

    The International Commission of Radiation Units (ICRU) has established through the years, a discrimination system regarding the security levels on the prescription and administration of doses in radiation treatments (Radiotherapy, Brach therapy, Nuclear Medicine). The first level is concerned with the prescription and posterior assurance of dose administration to a point of interest (POI), commonly located at the geometrical center of the region to be treated. In this, the effects of radiation around that POI, is not a priority. The second level refers to the dose specifications in a particular plane inside the patient, mostly the middle plane of the lesion. The dose is calculated to all the structures in that plane regardless if they are tumor or healthy tissue. In this case, the dose is not represented by a point value, but by level curves called 'isodoses' as in a topographic map, so you can assure the level of doses to this particular plane, but it also leave with no information about how this values go thru adjacent planes. This is why the third level is referred to the volumetrical description of doses so these isodoses construct now a volume (named 'cloud') that give us better assurance about tissue irradiation around the volume of the lesion and its margin (sub clinical spread or microscopic illness). This work shows how this evolution has resulted, not only in healthy tissue protection improvement but in a rise of tumor control, quality of life, better treatment tolerance and minimum permanent secuelae

  3. Modern Hypofractionation Schedules for Tangential Whole Breast Irradiation Decrease the Fraction Size-corrected Dose to the Heart

    DEFF Research Database (Denmark)

    Appelt, Ane L; Vogelius, Ivan R; Bentzen, Søren M

    2013-01-01

    as calculated from the EQD(2) dose distributions, were compared between schedules. Results: For alpha/beta = 3 Gy, V-40(Gy)EQD2 favours hypofractionation for 40 Gy/15 fractions, 39 Gy/13 fractions and 42.5 Gy/16 fractions, but not for 41.6 Gy/13 fractions. All of the hypofractionation schedules result in lower...... D-mean(EQD2) compared with normofractionation. These results hold as long as alpha/beta greater than or similar to 1.5 Gy. If the heart is blocked from the treatment beam, the fraction size-corrected dose is lower for the first three hypofractionation schedules, compared with normofractionation......, even for alpha/beta = similar to 1 Gy. Conclusion: For standard tangential field whole breast irradiation, most of the examined hypofractionation schedules are estimated to spare the heart when compared with normofractionation. The dose to the heart, adjusted for fraction size using the linear...

  4. In vivo dosimetry of high-dose fractionated irradiation in an experimental set-up with rats

    Energy Technology Data Exchange (ETDEWEB)

    Fortan, L.; Van Hecke, H.; Van Duyse, B.; De Neve, W.; De Meerleer, B. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Pattyn, P.; Van Renthergem, K. [Ghent University (Belgium). Dept. of Surgery

    1995-12-01

    The feasibility to irradiate a limited section of a rat abdomen with well-defined edges was assessed. Because of the relative small volume involved, in vivo dosimetry with TLDs was necessary in providing us information about the accuracy of the irradiation method. Three to five days prior to the start of the radiotherapy treatment, two plastic strips - each containing a TLD-dosimeter (Harshaw TLD10 LiF rods, 1 mm dia x 6 mm) sealed in polyethylene tubing, and a lead bean - were implanted in the rat abdomen. The plastic strips made a closed loop around the bowel, through the mesenterium, and were fixed with a single stitch on the inner abdominal wall. One loop was made in the hepatic area; another was made in the lower abdomen, around the rectosigmoid. Conscious animals were irradiated using a purpose-build plexi-holder, with rear legs immobilised to avoid longitudinal movements. The implanted lead beans enabled us to simulate the rat prior to each radiation session. This way, the radiation field could be set up individually for each rat, in such way that the rectosigmoid area received full dose and the hepatic area received no irradiation dose at all. Irradiation was carried out, using 5 MV photons of a linear accelerator. Fifteen animals per group were irradiated according a conventional (2.0 Gy / fraction; 5 fractions / week) or a hyperfractionated (1.6 Gy / fraction; 2 daily fractions; 5 days / week) schedule, with different total doses. Prior to implantation, TLDs were individually calibrated and checked for stability. After removal from the abdomen . TLDs were tested again for accuracy. TLDs with an unacceptable read-out curve were rejected (about 2 to 4 TLDs per group of 15). The obtained accumulated doses - as determined by TLD read-outs-were comparable to the theoretical doses, indicating that fractionated radiation of small fields, with well defined mark off, in rats is feasible.

  5. Spinal cord response to altered fractionation and re-irradiation: Radiobiological considerations and role of bioeffect models

    Directory of Open Access Journals (Sweden)

    Supe Sanjay

    2006-01-01

    Full Text Available The aim of radiation oncologist is to implement an uncomplicated loco regional control of cancer by radiation therapy. The bioeffect of a physical dose depends on the nature of the tissue, fractionation scheme, dose rate and treatment time. The transformation of absorbed dose into a bioeffect dose is controlled by treatment variables and the radiobiological characteristics of the relevant tissue. Various bioeffect models have been proposed to predict the biological effect of radiotherapy treatments. Dale has proposed extrapolated response dose (ERD equations for external beam therapy, intracavitary brachytherapy and interstitial brachytherapy. Within the context of the LQ model, the parameter which quantifies the overall biological effect on a given tissue is the biologically effective dose (BED which is obtained by applying repopulation correction to ERD (Orton,. Thames proposed the total effect (TE concept based on the incomplete repair LQ model which accounts for the biological effect of a fractionated course of radiotherapy. Spinal cord myelitis limits the dose to tumours in the head and neck, thoracic and upper abdominal regions resulting in reduction of tumour control probability. Radiation myelopathy is one of the most devastating complications of clinical radiotherapy. Treatment techniques that are designed to minimize the risk of spinal cord injury are likely to underdose the tumour consequent failure to control the disease. Since radiation myelopathy results in severe and irreversible morbidity, it is important to establish the tolerance dose of the spinal cord. A number of patients have recently been reported to have developed radiation myelopathy following hyperfractionated accelerated radiotherapy. As the survival rates of patients increase, radiation oncologists are more frequently faced with the problem of treatment of late recurrence or second tumours situated within or close to previously treated site. A rationale for taking a

  6. Characterization of gamma irradiated plasticized carboxymethyl cellulose (CMC)/gum arabic (GA) polymer blends as absorbents for dyestuffs

    Indian Academy of Sciences (India)

    Sayeda M Ibrahim; Issa M Mousaa; Mervat S Ibrahim

    2014-05-01

    Polymer blends based on carboxymethylcellulose (CMC) and gum arabic (GA) were prepared by solution casting method. Glycerol was added to the polymer blend solution as a plasticizer with different ratios (2.5, 5, 10 and 20%). Then, the plasticized blends were exposed to gamma irradiation at different doses (5, 10 and 20 kGy). The physical properties of the plasticized polymer blends were investigated in terms of gel fraction (%) and swelling percent (%). Thermal properties were investigated by TGA. Also, the structure of the plasticized polymer blends was characterized by Fourier transform infrared spectroscopy. Scanning electron microscope was investigated in order to examine the compatibility between two polymers in the blend and also between polymer blend and plasticizer. The prepared plasticized polymer blends were used as an adsorbent for different dyestuffs. The sorption of dyestuffs by the plasticized polymer blend was determined by a method based on spectroscopic analysis. The results showed that the plasticized polymer blend has a high affinity for basic, acid, reactive and direct dyes. The obtained results showed that using glycerol as plasticizer improved the swellability of polymer blend and also the dye uptake (%).

  7. Clinical and experimental study of the radioprotective effect of riboxine in the case of low dose rate fractionated irradiation

    International Nuclear Information System (INIS)

    In experiments with dogs (fractionated gamma-irradiation, accumulated dose 1 Gy) as well as in clinical testing of the group of men, recieved 0.25 Gy being engaged in the Chernobyl NPS disaster repairment, the positive influence of riboxin (purine nucleoside0 course treatment on parameters of peripheral blood and non-specific ressitance system has been shown

  8. VARIATIONS IN RADIATION SENSITIVITY AND REPAIR AMONG DIFFERENT HEMATOPOIETIC STEM-CELL SUBSETS FOLLOWING FRACTIONATED-IRRADIATION

    NARCIS (Netherlands)

    DOWN, JD; BOUDEWIJN, A; VANOS, R; THAMES, HD; PLOEMACHER, RE

    1995-01-01

    The radiation dose-survival of various hematopoietic cell subsets in murine bone marrow (BM) was determined in the cobblestone area forming cell (CAFC) assay under conditions of single-, split-, and multiple-dose irradiation. A greater recovery in cell survival with decreasing dose per fraction, or

  9. Proton irradiation in a single fraction for hepatocellular carcinoma patients with uncontrollable ascites. Technical considerations and results

    Energy Technology Data Exchange (ETDEWEB)

    Hata, Masaharu [Tsukuba Univ., Ibaraki (Japan). Proton Medical Research Center; Tsukuba Univ., Ibaraki (Japan). Dept. of Radiation Oncology; Yokohama City Univ. Graduate School of Medicine, Kanagawa (Japan). Dept. of Radiology; Tokuuye, Koichi; Fukumitsu, Nobuyoshi; Hashimoto, Takayuki; Akine, Yasuyuki [Tsukuba Univ., Ibaraki (Japan). Proton Medical Research Center; Tsukuba Univ., Ibaraki (Japan). Dept. of Radiation Oncology; Sugahara, Shinji; Ohnishi, Kayoko; Nemoto, Keiko; Ohara, Kiyoshi [Tsukuba Univ., Ibaraki (Japan). Dept. of Radiation Oncology; Tohno, Eriko [Tsukuba Univ., Ibaraki (Japan). Dept. of Radiology; Sakae, Takeji [Tsukuba Univ., Ibaraki (Japan). Proton Medical Research Center

    2007-08-15

    Purpose: To present technical considerations and results of proton irradiation in a single fraction for hepatocellular carcinoma (HCC) patients with uncontrollable ascites. Patients and Methods: Three HCC patients with uncontrollable ascites underwent proton irradiation of 24 Gy in a single fraction. Hepatic tumors were solitary in two patients, and multiple in one, and tumor sizes were 30, 30, and 33 mm in maximum diameter. No patient had lymph node or distant metastases. The center position of radiation fields was determined and the beam range was adjusted, using CT data taken immediately before irradiation to compensate for changes in the volume of ascites. Adjustment of the beam range was within 6 mm in water-equivalent thickness. Results: All irradiated tumors showed objective responses, and were controlled during the follow-up period. Of the three patients, two were alive with no evidence of disease at 13 and 30 months, respectively, after treatment. The remaining patient died of ruptured esophageal varices 6 months after treatment. No therapy-related toxicity of grade 3 or more was observed. Conclusion: Proton beams were successfully adjusted immediately before irradiation. Single-dose irradiation with precisely adjusted proton beams may be tolerable for HCC patients with uncontrollable ascites. (orig.)

  10. Fractionation for Whole Breast Irradiation: An American Society for Radiation Oncology (ASTRO) Evidence-Based Guideline

    International Nuclear Information System (INIS)

    Purpose: In patients with early-stage breast cancer treated with breast-conserving surgery, randomized trials have found little difference in local control and survival outcomes between patients treated with conventionally fractionated (CF-) whole breast irradiation (WBI) and those receiving hypofractionated (HF)-WBI. However, it remains controversial whether these results apply to all subgroups of patients. We therefore developed an evidence-based guideline to provide direction for clinical practice. Methods and Materials: A task force authorized by the American Society for Radiation Oncology weighed evidence from a systematic literature review and produced the recommendations contained herein. Results: The majority of patients in randomized trials were aged 50 years or older, had disease Stage pT1-2 pN0, did not receive chemotherapy, and were treated with a radiation dose homogeneity within ±7% in the central axis plane. Such patients experienced equivalent outcomes with either HF-WBI or CF-WBI. Patients not meeting these criteria were relatively underrepresented, and few of the trials reported subgroup analyses. For patients not receiving a radiation boost, the task force favored a dose schedule of 42.5 Gy in 16 fractions when HF-WBI is planned. The task force also recommended that the heart should be excluded from the primary treatment fields (when HF-WBI is used) due to lingering uncertainty regarding late effects of HF-WBI on cardiac function. The task force could not agree on the appropriateness of a tumor bed boost in patients treated with HF-WBI. Conclusion: Data were sufficient to support the use of HF-WBI for patients with early-stage breast cancer who met all the aforementioned criteria. For other patients, the task force could not reach agreement either for or against the use of HF-WBI, which nevertheless should not be interpreted as a contraindication to its use.

  11. Electron Spin Resonance in Nitrogen-Vacancy Centers in Diamond and Ionization Fraction vs. Electron Irradiation Dose

    CERN Document Server

    Kim, C; Bauch, E; Budker, D; Hemmer, P R

    2009-01-01

    A high-nitrogen-concentration diamond sample was subject to electron irradiation using a transmission-electron microscope. The optical and spin-resonance properties of the nitrogen-vacancy (NV) color centers were investigated as a function of the irradiation dose. The electron spin transition frequency of the NV- center is found to shift by up to 0.7% (18 MHz) and broaden with increasing electron-irradiation dose up to 6.39x1021e-/cm2. An increase in the fraction of the neutral NV0 centers is also observed with increasing irradiation dose, reaching more than 50% NV0 before the background fluorescence obscures the NV signal.

  12. Inhibiting the Aurora B Kinase Potently Suppresses Repopulation During Fractionated Irradiation of Human Lung Cancer Cell Lines

    International Nuclear Information System (INIS)

    Purpose: The use of molecular-targeted agents during radiotherapy of non-small-cell lung cancer (NSCLC) is a promising strategy to inhibit repopulation, thereby improving therapeutic outcome. We assessed the combined effectiveness of inhibiting Aurora B kinase and irradiation on human NSCLC cell lines in vitro. Methods and Materials: NSCLC cell lines were exposed to concentrations of AZD1152-hydroxyquinazoline pyrazol anilide (AZD1152-HQPA) inhibiting colony formation by 50% (IC50clone) in combination with single dose irradiation or different fractionation schedules using multiple 2-Gy fractions per day up to total doses of 4–40 Gy. The total irradiation dose required to control growth of 50% of the plaque monolayers (TCD50) was determined. Apoptosis, G2/M progression, and polyploidization were also analyzed. Results: TCD50 values after single dose irradiation were similar for the H460 and H661 cell lines with 11.4 ± 0.2 Gy and 10.7 ± 0.3 Gy, respectively. Fractionated irradiation using 3 × 2 Gy/day, 2 × 2 Gy/day, and 1 × 2 Gy/day schedules significantly increased TCD50 values for both cell lines grown as plaque monolayers with increasing radiation treatment time. This could be explained by a repopulation effect per day that counteracts 75 ± 8% and 27 ± 6% of the effect of a 2-Gy fraction in H460 and H661 cells, respectively. AZD1152-HQPA treatment concomitant to radiotherapy significantly decreased the daily repopulation effect (H460: 28 ± 5%, H661: 10 ± 4% of a 2-Gy fraction per day). Treatment with IC50clone AZD1152-HPQA did not induce apoptosis, prolong radiation-induced G2 arrest, or delay cell cycle progression before the spindle check point. However, polyploidization was detected, especially in cell lines without functional p53. Conclusions: Inhibition of Aurora B kinase with low AZD1152-HQPA concentrations during irradiation of NSCLC cell lines affects repopulation during radiotherapy. Thus, concomitant Aurora B kinase inhibition and irradiation

  13. Inhibiting the Aurora B Kinase Potently Suppresses Repopulation During Fractionated Irradiation of Human Lung Cancer Cell Lines

    Energy Technology Data Exchange (ETDEWEB)

    Sak, Ali, E-mail: ali.sak@uni-due.de [Department of Radiotherapy, West German Cancer Centre (WTZ), University Hospital Essen, University Duisburg-Essen, Essen (Germany); Stuschke, Martin; Groneberg, Michael; Kuebler, Dennis; Poettgen, Christoph [Department of Radiotherapy, West German Cancer Centre (WTZ), University Hospital Essen, University Duisburg-Essen, Essen (Germany); Eberhardt, Wilfried E.E. [Department of Medicine (Cancer Research), West German Cancer Centre (WTZ), University Hospital Essen, University Duisburg-Essen, Essen (Germany)

    2012-10-01

    Purpose: The use of molecular-targeted agents during radiotherapy of non-small-cell lung cancer (NSCLC) is a promising strategy to inhibit repopulation, thereby improving therapeutic outcome. We assessed the combined effectiveness of inhibiting Aurora B kinase and irradiation on human NSCLC cell lines in vitro. Methods and Materials: NSCLC cell lines were exposed to concentrations of AZD1152-hydroxyquinazoline pyrazol anilide (AZD1152-HQPA) inhibiting colony formation by 50% (IC50{sub clone}) in combination with single dose irradiation or different fractionation schedules using multiple 2-Gy fractions per day up to total doses of 4-40 Gy. The total irradiation dose required to control growth of 50% of the plaque monolayers (TCD50) was determined. Apoptosis, G2/M progression, and polyploidization were also analyzed. Results: TCD50 values after single dose irradiation were similar for the H460 and H661 cell lines with 11.4 {+-} 0.2 Gy and 10.7 {+-} 0.3 Gy, respectively. Fractionated irradiation using 3 Multiplication-Sign 2 Gy/day, 2 Multiplication-Sign 2 Gy/day, and 1 Multiplication-Sign 2 Gy/day schedules significantly increased TCD50 values for both cell lines grown as plaque monolayers with increasing radiation treatment time. This could be explained by a repopulation effect per day that counteracts 75 {+-} 8% and 27 {+-} 6% of the effect of a 2-Gy fraction in H460 and H661 cells, respectively. AZD1152-HQPA treatment concomitant to radiotherapy significantly decreased the daily repopulation effect (H460: 28 {+-} 5%, H661: 10 {+-} 4% of a 2-Gy fraction per day). Treatment with IC50{sub clone} AZD1152-HPQA did not induce apoptosis, prolong radiation-induced G2 arrest, or delay cell cycle progression before the spindle check point. However, polyploidization was detected, especially in cell lines without functional p53. Conclusions: Inhibition of Aurora B kinase with low AZD1152-HQPA concentrations during irradiation of NSCLC cell lines affects repopulation during

  14. Haemopoiesis in murine bone marrow and spleen after fractionated irradiation and repeated bone marrow transplantation. II

    International Nuclear Information System (INIS)

    Granulopoiesis was studied in mice repeatedly exposed to doses of 3 Gy of 60Co γ-rays at 4-day intervals up to a total dose of 24 Gy on the basis of total bone marrow cellularity follow-up and analysis of myelograms and splenograms. Half the number of the mice received lO6 nuclear cells of syngeneic bone marrow after each fractional radiation dose. After an initial steep decrease, the number of granuloid cells in the spleen increased about 30-fold between days 12 and 16 of the experiment (total dose 9 and 12 Gy, respectively). This increase was temporary and between days 20 and 24 (total dose 15 and 18 Gy, respectively) a steep decrease again occurred. At a low level (below 10% of the control value) the granuloid cells remained in the spleens of bone marrow recipients until the end of the experiment (day 37, total dose 24 Gy). The behavior of the granuloid compartment of hemopoiesis thus contrasts with findings in the erythroid compartment (Hofer et al., 1989) when high numbers of erythroid nuclear cells remained in the spleens of bone marrow recipients until the end of the experiment. On the whole, the influence of repeated bone marrow transplantation on granulopoiesis in the bone marrow and spleen is positive. Of the 22 comparisons made between bone marrow recipients and mice only irradiated, 14 differences are statistically significant, always in favor of bone marrow recipients. (author)

  15. Fractionated irradiation-induced EMT-like phenotype conferred radioresistance in esophageal squamous cell carcinoma

    Science.gov (United States)

    Zhang, Hongfang; Luo, Honglei; Jiang, Zhenzhen; Yue, Jing; Hou, Qiang; Xie, Ruifei; Wu, Shixiu

    2016-01-01

    The efficacy of radiotherapy, one major treatment modality for esophageal squamous cell carcinoma (ESCC) is severely attenuated by radioresistance. Epithelial-to-mesenchymal transition (EMT) is a cellular process that determines therapy response and tumor progression. However, whether EMT is induced by ionizing radiation and involved in tumor radioresistance has been less studied in ESCC. Using multiple fractionated irradiation, the radioresistant esophageal squamous cancer cell line KYSE-150R had been established from its parental cell line KYSE-150. We found KYSE-150R displayed a significant EMT phenotype with an elongated spindle shape and down-regulated epithelial marker E-cadherin and up-regulated mesenchymal marker N-cadherin in comparison with KYSE-150. Furthermore, KYSE-150R also possessed some stemness-like properties characterized by density-dependent growth promotion and strong capability for sphere formation and tumorigenesis in NOD-SCID mice. Mechanical studies have revealed that WISP1, a secreted matricellular protein, is highly expressed in KYSE-150R and mediates EMT-associated radioresistance both in ESCC cells and in xenograft tumor models. Moreover, WISP1 has been demonstrated to be closely associated with the EMT phenotype observed in ESCC patients and to be an independent prognosis factor of ESCC patients treated with radiotherapy. Our study highlighted WISP1 as an attractive target to reverse EMT-associated radioresistance in ESCC and can be used as an independent prognostic factor of patients treated with radiotherapy. PMID:27125498

  16. Glycolysis-related gene induction and ATP reduction during fractionated irradiation. Markers for radiation responsiveness of human tumor xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Goetze, K.; Meyer, S.S.; Mueller-Klieser, W. [University Medical Center Mainz Univ. (Germany). Inst. of Physiology and Pathophysiology; Yaromina, A. [Technical Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Zips, D. [University Hospital Tuebingen (Germany). Dept. of Radiation Oncology; Baumann, M. [Technical Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; University Hospital Dresden Technical Univ. Dresden (Germany). Dept. of Radiation Oncology

    2013-09-15

    Background and purpose: Lactate was previously shown to be a prognostic but not a predictive pre-therapeutic marker for radiation response of tumor xenografts. We hypothesize that metabolic changes during fractionated irradiation may restrict the predictiveness of lactate regarding tumor radiosensitivity. Materials and methods: Tumor xenografts were generated in nude mice by implanting 4 head and neck squamous cell carcinoma lines with different sensitivities to fractionated irradiation. Tumors were irradiated with up to 15 fractions of 2 Gy over a period of 3 weeks, and ATP and lactate levels were measured in vital tumor areas with induced metabolic bioluminescence imaging. Corresponding changes in mRNA expression of glycolysis-related genes were determined by quantitative RT-PCR. Results: Lactate content decreased significantly in 3 out of 4 cell lines in the course of irradiation showing no correlation with cell line-specific radiosensitivity. Radiation-induced changes in ATP levels and glycolysis-related mRNA expression, however, only occurred in radiosensitive or intermediately radioresistant xenografts, whereas these parameters remained unchanged in radioresistant tumors. Conclusion: Sensitivity-related differences in the transcriptional response of tumors to radiotherapy may be exploited in the clinic for better individualization of tumor treatment. (orig.)

  17. Hypo-fractionated whole breast irradiation: Pro and cons; Irradiation hypofractionnee dans le cancer du sein: pour ou contre?

    Energy Technology Data Exchange (ETDEWEB)

    Cutuli, B. [Institut du cancer Courlancy, 38, rue de Courlancy, 51100 Reims (France); Fourquet, A. [Institut Curie, 26, rue d' Ulm, 75005 Paris (France)

    2011-10-15

    The continuous increase of breast cancer (BC) incidence, the logistic constraints of the protracted standard 5-week radiations regimen have led to test short hypo-fractionated whole breast radiation therapy schemes. Three prospective randomized trials and a pilot trial have been published. Large numbers of patients were included, with follow-up duration ranging from 5 to 12 years. The conclusions of these trials were similar, showing local control and toxicity equivalent to those of the standard regimen, and supporting the use of three schemes: 42.5 Gy/16 fractions/3 weeks, 40 Gy/15 fractions/3 weeks or 41.6 Gy/13 fractions/5 weeks. However, the patients in these trials had favourable prognostic factors, were treated to the breast only and the boost dose, when indicated, was delivered with a standard fractionation. Hypo-fractionated treatment can only be recommended in patients treated to the breast only, without nodal involvement, with grade < 3 tumours and who are not candidate to chemotherapy. If a boost is to be given, a standard fractionation should be used. Particular care should be taken to avoid heterogeneities leading to high fractional doses to organs at risk (lung and heart). (authors)

  18. Impact of anemia prevention by recombinant human erythropoietin on the sensitivity of xenografted glioblastomas to fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Stueben, G.; Poettgen, C.; Knuehmann, K.; Sack, H.; Stuschke, M. [West German Tumor Center, Dept. of Radiotherapy, Univ. Hospital Essen (Germany); Thews, O.; Vaupel, P. [Inst. of Physiology and Pathophysiology, Univ. of Mainz (Germany)

    2003-09-01

    Background: Pronounced oxygen deficiency in tumors which might be caused by a diminished oxygen transport capacity of the blood (e.g., in anemia) reduces the efficacy of ionizing radiation. The aim of this study was to analyze whether anemia prevention by recombinant human erythropoietin (rHuEPO) affects the radiosensitivity of human glioblastoma xenografts during fractionated irradiation. Material and Methods: Anemia was induced by total body irradiation (TBI, 2 x 4 Gy) of mice prior to tumor implantation into the subcutis of the hind leg. In one experimental group, the development of anemia was prevented by rHuEPO (750 U/kg s.c.) given three times weekly starting 10 days prior to TBI. 13 days after tumor implantation (tumor volume approx. 40 mm{sup 3}), fractionated irradiation (4 x 7 Gy, one daily fraction) of the glioblastomas was performed resulting in a growth delay with subsequent regrowth of the tumors. Results: Compared to nonanemic control animals (hemoglobin concentration cHb = 14.7 g/dl), the growth delay in anemic mice (cHb = 9.9 g/dl) was significantly shorter (49 {+-} 5 days vs. 79 {+-} 4 days to reach four times the initial tumor volume) upon fractionated radiation. The prevention of anemia by rHuEPO treatment (cHb = 13.3 g/dl) resulted in a significantly prolonged growth delay (61 {+-} 5 days) compared to the anemia group, even though the growth inhibition found in control animals was not completely achieved. Conclusions: These data indicate that moderate anemia significantly reduces the efficacy of radiotherapy. Prevention of anemia with rHuEPO partially restores the radiosensitivity of xenografted glioblastomas to fractionated irradiation. (orig.)

  19. The Suitability of Absorbable Mesh Insertion for Oncoplastic Breast Surgery in Patients with Breast Cancer Scheduled to Be Irradiated

    OpenAIRE

    Kim, Taehyun; Cho, Heunglae

    2013-01-01

    Purpose The objective of this study was to investigate the influence of radiotherapy on the cosmetic outcome after immediate breast reconstruction using an absorbable mesh in breast cancer. Methods From July 2008 to July 2009, 35 breast cancer patients who received immediate breast reconstruction with absorbable mesh insertion at the time of breast conserving surgery followed by radiotherapy were retrospectively studied. Results In 91% of cases there was an excellent or good cosmetic outcome ...

  20. Quality assurance program of a respiratory gating irradiation system based on external and internal fiducial markers; Programa de garantia de calidad de un sistema de irradiacion con control respiratorio basado en marcadores fiduciales externos e internos

    Energy Technology Data Exchange (ETDEWEB)

    Zucca Aparicio, D.; Perez Moreno, J. M.; Fernandez Leton, P.; Garcia Ruiz-Zorrilla, J.; Minambres Moro, A.

    2011-07-01

    Respiratory Gating involves the administration of radiation during treatment delivery within a particular portion of the patients breathing cycle, so the absorbed dose administration with respiratory control techniques requires specific quality control to ensure the correctness of the delivered dose. The establishment of a Quality Control Program (QC) is proposed for the Respiratory Gating based techniques in order to have a better understanding of how this system works and to know its associated dosimetric impact. The influence of the CT acquisition under respiratory motion conditions has been analyzed for the treatment isocenter localization, using internal and external fiducial markers with IGRT techniques that allow the correlation of the isocenter positioning with the phase of the respiratory cycle. Radiation delivery in the presence of intra fraction organ motion causes an averaging or blurring of the static dose distribution over the path of motion increasing the beam penumbra of the radiation field and reducing the therapeutic region when the irradiation is not breath controlled. The feasibility of intensity modulated treatments (IMRT) for both static and dynamic techniques, managed by respiratory control has been tested, demonstrating the possibility of synchronizing the movement of the leaves in the microfluorimeter collimator (mMLC) with the gated beam irradiation. (Author) 45 refs.

  1. Impact of fractionated local irradiation on lung metastasis in H22-bearing mice and exploration of its mechanism

    International Nuclear Information System (INIS)

    Objective: To study the impact of local fractionated irradiation on lung metastasis in H22-bearing ice, and to explore its mechanism involved. Methods: Subcutaneous transplantation tumor model bearing with H22 was established. Mice were divided into three groups as healthy control, tumor control and irradiation groups. The size of subcutaneous tumors was measured and lung metastasis was observed. The expressions of PCNA, VEGF and MVD were detected immunohistochemically. The plasma levels of CD4 and CD8 were determined by using flow cytometry. Results: The tumor size in irradiated group was smaller than that in tumor control group. The tumor inhibition rate in irradiated group was 30%. Lung metastasis in irradiated group was more severe than that in tumor control group (χ2=8.31, 4.48, 9.60, P<0.05). The expressions of PCNA, VEGF and MVD in two groups were statistically different (t=23.78, -2.47, -6.43, P<0.05). The levels of CD4 and CD8 in irradiated group were statistically different compared to healthy control group (t=4.72 and 3.31, P<0.05). Conclusions: For the H22 model, radiation might inhibit the local transplantation tumor, but increase the risk of lung metastasis. (authors)

  2. CMSAF products Cloud Fraction Coverage and Cloud Type used for solar global irradiance estimation

    Science.gov (United States)

    Badescu, Viorel; Dumitrescu, Alexandru

    2016-08-01

    Two products provided by the climate monitoring satellite application facility (CMSAF) are the instantaneous Cloud Fractional Coverage (iCFC) and the instantaneous Cloud Type (iCTY) products. Previous studies based on the iCFC product show that the simple solar radiation models belonging to the cloudiness index class n CFC = 0.1-1.0 have rRMSE values ranging between 68 and 71 %. The products iCFC and iCTY are used here to develop simple models providing hourly estimates for solar global irradiance. Measurements performed at five weather stations of Romania (South-Eastern Europe) are used. Two three-class characterizations of the state-of-the-sky, based on the iCTY product, are defined. In case of the first new sky state classification, which is roughly related with cloud altitude, the solar radiation models proposed here perform worst for the iCTY class 4-15, with rRMSE values ranging between 46 and 57 %. The spreading error of the simple models is lower than that of the MAGIC model for the iCTY classes 1-4 and 15-19, but larger for iCTY classes 4-15. In case of the second new sky state classification, which takes into account in a weighted manner the chance for the sun to be covered by different types of clouds, the solar radiation models proposed here perform worst for the cloudiness index class n CTY = 0.7-0.1, with rRMSE values ranging between 51 and 66 %. Therefore, the two new sky state classifications based on the iCTY product are useful in increasing the accuracy of solar radiation models.

  3. Fractionated irradiation and early changes in noradrenaline induced potassium efflux ([sup 86]Rb[sup +]) in rat parotid gland

    Energy Technology Data Exchange (ETDEWEB)

    Franzen, L.; Littbrand, B.; Henriksson, R. (Univ. Hospital, Dept. of Oncology, Umeaa (Sweden)); Sundstroem, S. (Univ. Hospital, Dept. of Histology and Cell Biology, Umeaa (Sweden)); Karlsson, M. (Univ. Hospital, Dept. of Radiation Physics, Umeaa (Sweden)); Gustafsson, H. (Univ. Hospital, Dept. of Oto-Laryngology, Umeaa (Sweden))

    1992-01-01

    The effects of fractionated irradiation on the electrolyte fluid secretion from rat parotid gland were studied. Secretion was measured as noradrenaline stimulated potassium efflux in vitro with [sup 86]Rb[sup +] as tracer for potassium. The irradiation was delivered either as a five-day schedule (total dose 20, 25, 30, 35, 40, 45 Gy) or a two-day schedule (total dose 24, 32 Gy). The noradrenaline stimulated efflux was decreased in comparison with contralateral controls 10 days after the last irradiation. The effect was dose-dependent. Based on the data available, [alpha]/[beta] ratio of the used system was calculated to about 20 Gy, which corresponds to other results regarding early radiation effects. (orig.).

  4. Decoloration and mineralization of reactive dyes using electron beam irradiation, Part I: Effect of the dye structure, concentration and absorbed dose (single, binary and ternary systems)

    Science.gov (United States)

    Vahdat, Ali; Bahrami, S. Hajir; Arami, M.; Bahjat, A.; Tabakh, F.; Khairkhah, M.

    2012-07-01

    In this study, three different reactive dyes (C.I. Reactive Red 4, C.I. Reactive Blue 2 and C.I. Reactive Yellow 4) and their blend solutions were irradiated with 10 MeV electron beam. Effect of absorbed dose, dye structure and primary solution concentrations on the pH value changes, degree of decoloration and chemical oxygen demand (COD) removal of solutions were investigated. Results show that this method is effective in decomposition and decoloration of the dyes solutions. This method can be applied in mineralization of wastewater containing different dyes.

  5. Fractionated irradiation and late changes in rat parotid gland: effects on the number of acinar cells, potassium efflux, and amylase secretion

    Energy Technology Data Exchange (ETDEWEB)

    Franzen, L.; Gustafsson, H.; Sundstroem, S.; Karlsson, M.; Littbrand, B.; Henriksson, R. (Umeaa Univ. Hospital (Sweden). Dept. of Oncology, Otorhinolaryngology, Histology and Cell Biology)

    1993-07-01

    The authors used different in vitro secretory models and quantitative morphological characterization of rat parotid gland following fractionated unilateral irradiation to one gland on a 5-day fraction schedule with 6 MV photons (total dose 30, 35, 40 and 45 Gy) or a two-fractions regimen in 5 days with total dose of 24 and 32 Gy. The contralateral shielded gland served as control, and parallel analyses of irradiated and control glands were performed 180 days following the last irradiation. The relative noradrenaline stimulated electrolyte secretion ([sup 86]rubidium tracer for potassium) was decreased in the irradiated compared with control glands. The noradrenaline-stimulated exocytotic amylase release was not significantly affected by irradiation, but the gland content of amylase was decreased dose-dependently. The quantitative morphological analysis revealed a dose-dependent decline in the number of acinar cells; the other parenchymal cells were unaffected by irradiation compared with controls. (author).

  6. Fractionated irradiation and late changes in rat parotid gland: effects on the number of acinar cells, potassium efflux, and amylase secretion

    International Nuclear Information System (INIS)

    The authors used different in vitro secretory models and quantitative morphological characterization of rat parotid gland following fractionated unilateral irradiation to one gland on a 5-day fraction schedule with 6 MV photons (total dose 30, 35, 40 and 45 Gy) or a two-fractions regimen in 5 days with total dose of 24 and 32 Gy. The contralateral shielded gland served as control, and parallel analyses of irradiated and control glands were performed 180 days following the last irradiation. The relative noradrenaline stimulated electrolyte secretion (86rubidium tracer for potassium) was decreased in the irradiated compared with control glands. The noradrenaline-stimulated exocytotic amylase release was not significantly affected by irradiation, but the gland content of amylase was decreased dose-dependently. The quantitative morphological analysis revealed a dose-dependent decline in the number of acinar cells; the other parenchymal cells were unaffected by irradiation compared with controls. (author)

  7. Internal irradiation of the carcinoma of the prostate

    International Nuclear Information System (INIS)

    A procedure for the radiologic treatment of the carcinoma of the prostate has recently been developed by clinicians of the 'Charite' and Berlin University Hospital at Steglitz. In this procedure, access to the carcinoma for spiking with tags and subsequent irradiation using the afterloading method is gained from the perineum. (orig.)

  8. The international protocol for the dosimetry of external radiotherapy beams based on standards of absorbed dose to water

    International Nuclear Information System (INIS)

    An International Code of Practice (CoP, or dosimetry protocol) for external beam radiotherapy dosimetry based on standards of absorbed dose to water has been published by the IAEA on behalf of IAEA, WHO, PAHO and ESTRO. The CoP provides a systematic and internationally unified approach for the determination of the absorbed dose to water in reference conditions with radiotherapy beams. The development of absorbed-dose-to-water standards for high-energy photons and electrons offers the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. Many laboratories already provide calibrations at the radiation quality of 60Co gamma-rays and some have extended calibrations to high-energy photon and electron beams. The dosimetry of kilovoltage x-rays, as well as that of proton and ion beams can also be based on these standards. Thus, a coherent dosimetry system based on the same formalism is achieved for practically all radiotherapy beams. The practical use of the CoP as simple. The document is formed by a set of different CoPs for each radiation type, which include detailed procedures and worksheets. All CoPs are based on ND,w chamber calibrations at a reference beam quality Qo, together with radiation beam quality correction factors kQ preferably measured directly for the user's chamber in a standards laboratory. Calculated values of kQ are provided together with their uncertainty estimates. Beam quality specifiers are 60Co, TPR20,10 (high-energy photons), R50 (electrons), HVL and kV (x-rays) and Rres (protons and ions)

  9. The content and UV-Vis absorbances of bog peat organic matter fractions (Divčivare, Serbia

    Directory of Open Access Journals (Sweden)

    Petrović Petar G.

    2015-01-01

    Full Text Available This paper presents peat soil organic matter characteristics at Divčibare Mountain (950 m a.s.l, mountain climate. Excessive wetting is caused by groundwater and floods, and plant litter originates from hydrophilic vegetation. An investigation was aimed at determining the correlation between organic matter characteristics (humification degree, stability and bioavailability with factors of soil formation and the most important physico-chemical characteristics of peat. Peat is mild acid and has a low base saturation. The content of organic matter is higher than 60% at depth of 40−80 cm, and higher than 40% at depths of 0−40 and 80−105 cm, respectively. Investigated peat had sapric characteristics. A content of humic acids in total organic matter indicates its unequal humification degree within profile, moderate to high at depth of 0−40 cm, low at 40−80-cm depth, and very low beneath 80 cm. A value of Ch/Cf ratio indicates high humus stability up to 80 cm where it has humate-type humus, while below 80 cm humus is the humatefulvate type. A low content of fractions separated with 0.1N cold H2SO4, and cold and hot water, points out a low bioavailability of organic matter through whole soil profile. UV-Vis indices indicate a low humification degree of humic acids (increased to 80-cm depth, and a very low humification degree of fulvic acids (variable, the highest at 60−80-cm depth. Overall results indicate that particle size of mineral fraction, soil reaction, and cation exchange capacity had no significant impact on organic matter characteristics. Soil moisture content, that is alterations of oxido-reductive conditions throughout soil profile had the crucial impact on peat organic matter characteristics.

  10. Five years' experience of the International Facility for Food Irradiation Technology

    International Nuclear Information System (INIS)

    The International Facility for Food Irradiation Technology (IFFIT) is an international project, jointly established by the IAEA, the FAO and the Ministry of Agriculture and Fisheries of The Netherlands, to speed up progress in the practical introduction of the process of food irradiation in developing countries. The project is hosted by the Pilot Plant for Food Irradiation and the State Institute for Quality Control of Agricultural Products, Wageningen, The Netherlands. The purpose of IFFIT is: 1) to offer training and assist in international co-ordination of development and research in the fields of technology, economics and implementation of food irradiation; 2) to assist national and international agencies in their assessment of the feasibility of applying radiation preservation techniques to foods; 3) to develop and facilitate the dissemination of information on the above topics without proprietary restrictions. The paper summarizes IFFIT's activities of its first five years of active existence, including training courses, long-term applied research training, feasibility studies, evaluation of trial shipments of irradiated commodities, irradiation services, and information activities. (author)

  11. Effects of bone marrow or mesenchymal stem cell transplantation on oral mucositis (mouse) induced by fractionated irradiation

    International Nuclear Information System (INIS)

    Oral mucositis is a severe and dose limiting early side effect of radiotherapy for head-and-neck tumors. This study was initiated to determine the effect of bone marrow- and mesenchymal stem cell transplantation on oral mucositis (mouse tongue model) induced by fractionated irradiation. Daily fractionated irradiation (5 x 3 Gy/week) was given over 1 (days 0-4) or 3 weeks (days 0-4, 7-11, 14-18). Each protocol was terminated (day 7 or 21) by graded test doses (5 dose groups, 10 animals each) in order to generate complete dose-effect curves. The incidence of mucosal ulceration, corresponding to confluent mucositis grade 3 (RTOG/EORTC), was analyzed as the primary, clinically relevant endpoint. Bone marrow or mesenchymal stem cells were transplanted intravenously at various time points within these fractionation protocols. Transplantation of 6 x 106, but not of 3 x 106 bone marrow stem cells on day -1, +4, +8, +11 or +15 significantly increased the ED50 values (dose, at which an ulcer is expected in 50% of the mice); transplantation on day +2, in contrast, was ineffective. Mesenchymal stem cell transplantation on day -1, 2 or +8 significantly, and on day +4 marginally increased the ED50 values. Transplantation of bone marrow or mesenchymal stem cells has the potential to modulate radiation-induced oral mucositis during fractionated radiotherapy. The effect is dependent on the timing of the transplantation. The mechanisms require further investigation. (orig.)

  12. Effects of bone marrow or mesenchymal stem cell transplantation on oral mucositis (mouse) induced by fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, M. [Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Department of Radiotherapy and Radiation Oncology, OncoRay - National Center for Radiation Research in Oncology, Dresden (Germany); German Cancer Consortium (DKTK), Dresden (Germany); German Cancer Research Center (DKFZ), Heidelberg (Germany); Haagen, J.; Noack, R.; Siegemund, A.; Gabriel, P. [Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Department of Radiotherapy and Radiation Oncology, OncoRay - National Center for Radiation Research in Oncology, Dresden (Germany); Doerr, W. [Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Department of Radiotherapy and Radiation Oncology, OncoRay - National Center for Radiation Research in Oncology, Dresden (Germany); Comprehensive Cancer Center, Medical University/AKH Vienna, Dept. of Radiation Oncology/Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Vienna (Austria)

    2014-04-15

    Oral mucositis is a severe and dose limiting early side effect of radiotherapy for head-and-neck tumors. This study was initiated to determine the effect of bone marrow- and mesenchymal stem cell transplantation on oral mucositis (mouse tongue model) induced by fractionated irradiation. Daily fractionated irradiation (5 x 3 Gy/week) was given over 1 (days 0-4) or 3 weeks (days 0-4, 7-11, 14-18). Each protocol was terminated (day 7 or 21) by graded test doses (5 dose groups, 10 animals each) in order to generate complete dose-effect curves. The incidence of mucosal ulceration, corresponding to confluent mucositis grade 3 (RTOG/EORTC), was analyzed as the primary, clinically relevant endpoint. Bone marrow or mesenchymal stem cells were transplanted intravenously at various time points within these fractionation protocols. Transplantation of 6 x 10{sup 6}, but not of 3 x 10{sup 6} bone marrow stem cells on day -1, +4, +8, +11 or +15 significantly increased the ED{sub 50} values (dose, at which an ulcer is expected in 50% of the mice); transplantation on day +2, in contrast, was ineffective. Mesenchymal stem cell transplantation on day -1, 2 or +8 significantly, and on day +4 marginally increased the ED{sub 50} values. Transplantation of bone marrow or mesenchymal stem cells has the potential to modulate radiation-induced oral mucositis during fractionated radiotherapy. The effect is dependent on the timing of the transplantation. The mechanisms require further investigation. (orig.)

  13. International Project on the Irradiation of Fruit and Fruit Juices

    International Nuclear Information System (INIS)

    To extend the application of irradiation to food preservation in a more general way, and to obtain the best conditions for this new technique, more fundamental research is needed. The main problem is to reduce the dose as much as possible. Reducing to the minimum the degradation due to radiation of the constituents of food assures organoleptic quality and wholesomeness and renders the product economic. Fruit juice was selected as a model substance for fundamental studies for the following reasons: (a) The components are representative for most foods; (b) The components can be easily separated; (c) The microorganism spoiling the fruit juice is mainly yeast, on which extended research work has been done; and (d) The item has economic value. The programme includes the following lines of research; Fundamental research. This has dealt mainly with the radiosensitization of microorganisms, that is, yeast in the case of fruit juice and, to a certain extent, mould. Technological studies. Based on the results of the basic research, studies on technological feasibility have been undertaken, including organoleptic and microbiological analysis of volatile and non-volatile substances. The results on apple juice are promising. Wholesomeness tests. Animal feeding studies on rats, mice and pigs started with tests of the amount of apples and apple juice which can be tolerated by the animals. Tissue cultures have been cultivated for the biological screening of degradation products. Irradiation facility. An irradiation plant of a new design for about 30 to 40 000 Ci and 10 000 Ci 60Co is under construction. (author)

  14. Tumor Induction in Mice After Localized Single- or Fractionated-Dose Irradiation: Differences in Tumor Histotype and Genetic Susceptibility Based on Dose Scheduling

    International Nuclear Information System (INIS)

    Purpose: To investigate differences in tumor histotype, incidence, latency, and strain susceptibility in mice exposed to single-dose or clinically relevant, fractioned-dose γ-ray radiation. Methods and Materials: C3Hf/Kam and C57BL/6J mice were locally irradiated to the right hindlimb with either single large doses between 10 and 70 Gy or fractionated doses totaling 40 to 80 Gy delivered at 2-Gy/d fractions, 5 d/wk, for 4 to 8 weeks. The mice were closely evaluated for tumor development in the irradiated field for 800 days after irradiation, and all tumors were characterized histologically. Results: A total of 210 tumors were induced within the radiation field in 788 mice. An overall decrease in tumor incidence was observed after fractionated irradiation (16.4%) in comparison with single-dose irradiation (36.1%). Sarcomas were the predominant postirradiation tumor observed (n=201), with carcinomas occurring less frequently (n=9). The proportion of mice developing tumors increased significantly with total dose for both single-dose and fractionated schedules, and latencies were significantly decreased in mice exposed to larger total doses. C3Hf/Kam mice were more susceptible to tumor induction than C57BL/6J mice after single-dose irradiation; however, significant differences in tumor susceptibilities after fractionated radiation were not observed. For both strains of mice, osteosarcomas and hemangiosarcomas were significantly more common after fractionated irradiation, whereas fibrosarcomas and malignant fibrous histiocytomas were significantly more common after single-dose irradiation. Conclusions: This study investigated the tumorigenic effect of acute large doses in comparison with fractionated radiation in which both the dose and delivery schedule were similar to those used in clinical radiation therapy. Differences in tumor histotype after single-dose or fractionated radiation exposures provide novel in vivo evidence for differences in tumor

  15. The occurrence of recruitment supported from the finding of an increase in radiosensitivity of quiescent cells in solid tumors after fractionated irradiation with X-rays

    International Nuclear Information System (INIS)

    We examined the behavior of quiescent cells in solid tumors irradiated twice at various intervals with X-rays, using our recently developed method for selectively detecting the response of quiescent cells in solid tumors. To determine the labeling indices of tumors at the second irradiation, each mouse group included mice that were continuously administered BrdU until just before the second irradiation using mini-osmotic pumps which had been implanted before the first irradiation. Radiosensitivity of total tumor cells at the second irradiation decreased in proportion to the increase in interval time. However, radiosensitivity of quiescent cells was raised with increase in the interval time. In addition, the labeling index at the second irradiation was higher than that at the first irradiation. These findings supported the occurrence of recruitment from quiescent to proliferating state during fractionated irradiation. (author)

  16. The aims and achievements of the international project in the field of food irradiation

    International Nuclear Information System (INIS)

    By the end of the 1960's a large number of food items were being considered for irradiation treatment. Because of the potential importance of the process, the cost of biological tests and the danger of unnecessary duplication, international collaboration became desirable. The International Food Irradiation Project (IFIP) was established in 1970. Membership at the present time numbers 25 countries. Objectives of the Project: The basic function has been to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. It is not concerned with promoting the use of the process or with assessing or improving its economical feasibility. (a) Wholesomeness Testing: Studies were initiated on irradiated potatoes, wheat and wheat products. Additional foodstuffs were chosen on the basis of certain factors. Products chosen included fish, rice, spices, mangoes, dates and onions. In none of these studies was any significant effect observed which could be attributed to the feeding of irradiated food. (b) Methology Research: IFIP has devoted considerable attention to reviewing and up-dating its testing procedures. A continuous study of the scientific literature and the publications of regulatory bodies has been linked with practical research work in IFIP's laboratory and consultation with many experts in toxicology. (c) Information Activities: The results of scientific investigations sponsored by IFIP, as well as information of more general interest, are published. (d) Assistance to National and International Authorities: IFIP does not judge the acceptability of irradiated foods. However, when requested by regulatory bodies responsible for such decisions, IFIP is willing to provide information and advice

  17. Electron absorbed fractions in skeletal soft tissues based on red bone marrow segmentation at runtime in muCT images of human trabecular bone;Fracoes absorvidas de eletrons em tecidos moles do esqueleto avaliadas com base na segmentacao em tempo de execucao da medula ossea vermelha contida em imagens muCT do osso trabecular humano

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, J.W. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco, Recife, PE (Brazil); Kramer, R. [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Khoury, H.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Robson-Brown, K. [University of Bristol, Bristol (United Kingdom). Dept. of Archaeology and Anthropology

    2009-07-01

    Skeletal dosimetry determines equivalent dose or absorbed fractions in the red bone marrow (RBM) and the osteogenic cells on bone surfaces (BSC). Following a method used earlier for the BSC, RBM and yellow bone marrow (YBM) have been segmented in the marrow cavities of muCT images of human spongiosa at runtime, i.e. during the execution of the Monte Carlo calculation, which avoids the necessity to segment RBM and YBM externally in muCT images for many different cellularities and to store the data. Using this internal RBM/YBM segmentation, this study presents electron absorbed fractions for the RBM and the BSC as a function of the voxel resolution and also compares the results with data from other investigations. (author)

  18. Tuning algorithms for fractional order internal model controllers for time delay processes

    Science.gov (United States)

    Muresan, Cristina I.; Dutta, Abhishek; Dulf, Eva H.; Pinar, Zehra; Maxim, Anca; Ionescu, Clara M.

    2016-03-01

    This paper presents two tuning algorithms for fractional-order internal model control (IMC) controllers for time delay processes. The two tuning algorithms are based on two specific closed-loop control configurations: the IMC control structure and the Smith predictor structure. In the latter, the equivalency between IMC and Smith predictor control structures is used to tune a fractional-order IMC controller as the primary controller of the Smith predictor structure. Fractional-order IMC controllers are designed in both cases in order to enhance the closed-loop performance and robustness of classical integer order IMC controllers. The tuning procedures are exemplified for both single-input-single-output as well as multivariable processes, described by first-order and second-order transfer functions with time delays. Different numerical examples are provided, including a general multivariable time delay process. Integer order IMC controllers are designed in each case, as well as fractional-order IMC controllers. The simulation results show that the proposed fractional-order IMC controller ensures an increased robustness to modelling uncertainties. Experimental results are also provided, for the design of a multivariable fractional-order IMC controller in a Smith predictor structure for a quadruple-tank system.

  19. Low-dose X-irradiation of adjuvant-induced arthritis in rats. Efficacy of different fractionation schedules

    Energy Technology Data Exchange (ETDEWEB)

    Liebmann, A.; Hindemith, M.; Jahns, J.; Kamprad, F.; Hildebrandt, G. [Dept. of Radiotherapy and Radiooncology, Univ. of Leipzig (Germany); Madaj-Sterba, P.; Weisheit, S. [Medical-Experimental Center, Univ. of Leipzig (Germany)

    2004-03-01

    Background and purpose: low-dose radiotherapy is widely accepted as a very effective treatment option for inflammatory symptoms associated with painful degenerative joint disorders. Radiation doses and fractionation schedules in practical use are empirical and mainly based on clinical observations. Experimental data are rare. The efficacy of low-dose X-irradiation on adjuvant induced arthritis in rats using different fractionation schemes was investigated in vivo, in order to explore whether there is a dose and fractionation dependence. Material and methods: adjuvant arthritis in female lewis rats (n = 128) was induced by intradermal injection of heat-inactivated Mycobacterium tuberculosis on day 0. Both arthritic hind paws were sham-irradiated (group 1: days 10-14; group 2: days 15-19; group 3: days 22-26) or X-irradiated with either 5 x 1.0 Gy (group 4: days 10-14; group 6: days 15-19; group 8: days 22-26; group 10: days 10, 12, 14, 16, and 18) or 5 x 0.5 Gy (group 5: days 10-14; group 7: days 15-19; group 9: days 22-26; group 11: days 10, 12, 14, 16, and 18; group 12: days 10-14 and 22-26). The clinical parameters arthritis score (AS), hind paw volume (HPV), and body weight were determined. Results: a significant decrease of the clinical arthritis parameters was observed following 5 x 0.5 Gy or 5 x 1.0 Gy during the acute maximum of the inflammatory response (days 15-19). The most pronounced treatment effect was reached after two daily fractionated series of 5 x 0.5 Gy with an early treatment onset (days 10-14) and repetition in interval (days 22-26). After the application of 5 x 1.0 Gy on days 10-14 or in a protracted scheme (days 10, 12, 14, 16, and 18), only a nonsignificant positive trend could be detected. Daily fractionated X-irradiation in the chronic phase of adjuvant arthritis (days 22-26) did not show any positive clinical effect. Conclusion: low-dose radiotherapy is able to prevent a full-blown arthritic reaction if given during the florid phase of

  20. Low-dose X-irradiation of adjuvant-induced arthritis in rats. Efficacy of different fractionation schedules

    International Nuclear Information System (INIS)

    Background and purpose: low-dose radiotherapy is widely accepted as a very effective treatment option for inflammatory symptoms associated with painful degenerative joint disorders. Radiation doses and fractionation schedules in practical use are empirical and mainly based on clinical observations. Experimental data are rare. The efficacy of low-dose X-irradiation on adjuvant induced arthritis in rats using different fractionation schemes was investigated in vivo, in order to explore whether there is a dose and fractionation dependence. Material and methods: adjuvant arthritis in female lewis rats (n = 128) was induced by intradermal injection of heat-inactivated Mycobacterium tuberculosis on day 0. Both arthritic hind paws were sham-irradiated (group 1: days 10-14; group 2: days 15-19; group 3: days 22-26) or X-irradiated with either 5 x 1.0 Gy (group 4: days 10-14; group 6: days 15-19; group 8: days 22-26; group 10: days 10, 12, 14, 16, and 18) or 5 x 0.5 Gy (group 5: days 10-14; group 7: days 15-19; group 9: days 22-26; group 11: days 10, 12, 14, 16, and 18; group 12: days 10-14 and 22-26). The clinical parameters arthritis score (AS), hind paw volume (HPV), and body weight were determined. Results: a significant decrease of the clinical arthritis parameters was observed following 5 x 0.5 Gy or 5 x 1.0 Gy during the acute maximum of the inflammatory response (days 15-19). The most pronounced treatment effect was reached after two daily fractionated series of 5 x 0.5 Gy with an early treatment onset (days 10-14) and repetition in interval (days 22-26). After the application of 5 x 1.0 Gy on days 10-14 or in a protracted scheme (days 10, 12, 14, 16, and 18), only a nonsignificant positive trend could be detected. Daily fractionated X-irradiation in the chronic phase of adjuvant arthritis (days 22-26) did not show any positive clinical effect. Conclusion: low-dose radiotherapy is able to prevent a full-blown arthritic reaction if given during the florid phase of

  1. No evidence for a different magnitude of the time factor for continuously fractionated irradiation and protocols including gaps in two human squamous cell carcinoma in nude mice

    International Nuclear Information System (INIS)

    Background and purpose: To study whether the magnitude of the time factor is different for continuously fractionated irradiation and for fractionation protocols including gaps. Materials and methods: Two human head and neck squamous cell carcinomas (SCCs), FaDu and GL, were transplanted subcutaneously into the right hindleg of NMRI (nu/nu) mice and irradiated with 30 fractions under ambient conditions within 2, 6 and 10 weeks. Irradiations within 6 and 10 weeks were given either as a continuous course or with a mid-course gap of 3 weeks. The end-point of the experiments was local tumor control at day 120 (FaDu) or day 180 (GL) after the end of treatment. Results: In FaDu tumors, two experimental cohorts (A, B) yielded significantly different results and were analyzed separately. In cohort A, the tumor control dose 50% (TCD50) increased from 37 to 89 Gy when the treatment time of continuous fractionated irradiation was extended from 2 to 10 weeks. The recovered dose/day (Dr) was 0.98 Gy (95% confidence interval, 0.72; 1.27). In cohort B, the TCD50 increased from 35 to 63 Gy, and the Dr was 0.51 Gy (0.24; 0.75). In GL tumors, the TCD50 for continuously fractionated irradiation increased from 41 to 48 Gy. This increase was not significant, and the Dr was 0.15 Gy (0; 0.30). None of the TCD50 and Dr values obtained in both tumor models for continuous irradiation vs. irradiation with a gap were significantly different. Conclusions: Prolongation of the overall treatment time of fractionated irradiation resulted in a pronounced decrease of local control in human FaDu SCC and little decrease of local control in human GL SCC. No evidence was found that the magnitude of the time factor in these tumors is different for continuous fractionation or fractionation protocols including gaps

  2. Action of prolonged treatment with cod liver oil on certain biochemical changes in rats exposed to fractionated gamma irradiation

    International Nuclear Information System (INIS)

    The effect of prolonged treatment of rats with cod liver oil in modifying the radiation induced changes in the level of glucose, pyruvic acid, lactic acid and the activity of lactate dehydrogenase (LDH) in serum of irradiated rats were studied. Emulsion of liver oil was orally administered every day for a period of 4 weeks. The daily administered dose was 1ml emulsion containing 857 ng vitamin A, 7.2 ng vitamin D and 875 ng vitamin E/100 g body weight. The rats were whole body gamma irradiated at fractionated doses up to Gy (4 equal fractions, 2 Gy weekly) and the first radiation fraction was given to rats at the end of the first week of treatment with cod liver oil. The data obtained revealed that treatment of normal rats with cod liver oil did not induce any significant changes in the levels of the parameters studied (glucose, pyruvic acid and lactic acid) as well as in the activity of LDH during all the experimental time periods (1, 7, 14 and 30 days post treatment)

  3. Variations of salivary amylase as a test of internal irradiation in man

    Energy Technology Data Exchange (ETDEWEB)

    Zamfirescu-Gheorghiu, M.; Cheta, N.; Funduc, I.; Ciobanu, F.

    1975-01-01

    The hypothesis of the parotid gland radiosensitivity has suggested to the authors to follow up the effect of therapeutic internal irradiation on the serum, urine and salivary ..cap alpha..-amylasee activity in man. The assay and visualization of ..cap alpha..-amylase isoenzymes on agar gel zymograms by using the ''Phadebas amylase test'' tablets has demonstrated in some cases increases of salivary ..cap alpha..-amylase activity expressed by the ratio of the optical density after internal irradiation to that before administration of radioisotopes.

  4. The reaction of lymphatic component of hemopoiesis to fractionated irradiation and repeated bone marrow transplantation

    International Nuclear Information System (INIS)

    Mice were repeatedly subjected to individual doses of 60Co-gamma rays at intervals of four days up to total doses of 3, 6, 9, 12, 15, 18, 21 and 24 Gy. Under these conditions, signs of partial adaptation of the lymphatic component of hemopoiesis to conditions of repeated irradiations were found in mice which were given transplants of 106 nuclear cells of syngenetic bone marrow after each irradiation. Systematic findings of statistically significant differences in the values of the lymphatic hemopoietic component parameters studied between bone marrow recipients and animals subjected only to repeated irradiations were recorded after 24th day of experiment in mice which received total doses of 21 and 24 Gy. A positive influence of repeated transplantations in bone marrow recipients became manifested in these experimental groups already upon withdrawals made on day 4 after the last irradiation. A quite pronounced increase in the values of the bone marrow recipients' lymphatic hemopoietic component studied was then recorded upon withdrawals made on day 9 after the last irradiation. (orig.)

  5. Low-dose fractionated whole-body irradiation in the treatment of advanced non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Thirty-nine patients with advanced non-Hodgkin's lymphoma (38 patients with lymphocytic lymphoma and 1 patient with mixed lymphocytic and histiocytic lymphoma) were treated by fractionated low dose whole body irradiation (WBI) with a minimum follow-up of 8 months. Twenty-eight patients had no previous treatment and the other 11 patients were in relapse after previous chemotherapy or regional radiotherapy. There were 20 and 19 patients in stages III and IV groups, respectively. The majority of patients (31) had nodular histology; diffuse lymphocytic lymphoma was present in 8 patients (Rappaport criteria) (9). Constitutional symptoms were present in 10 patients. Thirty-three (85%) attained complete remission (CR) with median duration of remission 24 months. Actuarial survival was 78% and 74% at 3 and 4 years. However, relapse free survival was 26% at 3 and 4 years. A prospective randomized trial to compare 10 vs. 15 rad per fraction of fractionated WBI schedules (the same total dose 150 rad) demonstrated no difference in response rate, response duration, and median nadir platelet or WBC counts between the two schedules. Supplement radiotherapy to bulky tumor site prevented local recurrence, but did not influence survival or duration or remission. Major toxicity was thrombocytopenia with median nadir platelet counts 77,000/mm3 (11,000 to 170,000/mm3). Five of 6 patients with diffuse lymphocytic poorly differentiated lymphoma attained CR. However, their median survival was 30 months which is much shorter than that of nodular lymphoma. Constitutional symptoms and advanced stage (stage IV) were associated with shorter duration of remission. Response of patients in relapse after WBI to subsequent chemotherapy +- local radiotherapy was CR in 50% and PR in 40%. Fractionated whole body irradiation is an excellent systemic induction agent for advanced lymphocytic and mixed lymphoma

  6. Vertebral compression fractures after spine irradiation using conventional fractionation in patients with metastatic colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ree, Woo Joong; Kim, Kyung Hwan; Chang, Jee Suk; Kim, Hyun Ju; Choi, Seo Hee; Koom, Woong Sub [Dept.of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul (Korea, Republic of)

    2014-12-15

    To evaluate the risk of vertebral compression fracture (VCF) after conventional radiotherapy (RT) for colorectal cancer (CRC) with spine metastasis and to identify risk factors for VCF in metastatic and non-metastatic irradiated spines. We retrospectively reviewed 68 spinal segments in 16 patients who received conventional RT between 2009 and 2012. Fracture was defined as a newly developed VCF or progression of an existing fracture. The target volume included all metastatic spinal segments and one additional non-metastatic vertebra adjacent to the tumor-involved spines. The median follow-up was 7.8 months. Among all 68 spinal segments, there were six fracture events (8.8%) including three new VCFs and three fracture progressions. Observed VCF rates in vertebral segments with prior irradiation or pre-existing compression fracture were 30.0% and 75.0% respectively, compared with 5.2% and 4.7% for segments without prior irradiation or pre-existing compression fracture, respectively (both p < 0.05). The 1-year fracture-free probability was 87.8% (95% CI, 78.2-97.4). On multivariate analysis, prior irradiation (HR, 7.30; 95% CI, 1.31-40.86) and pre-existing compression fracture (HR, 18.45; 95% CI, 3.42-99.52) were independent risk factors for VCF. The incidence of VCF following conventional RT to the spine is not particularly high, regardless of metastatic tumor involvement. Spines that received irradiation and/or have pre-existing compression fracture before RT have an increased risk of VCF and require close observation.

  7. Effect of irradiation point defects on the internal friction peaks of cold worked copper

    International Nuclear Information System (INIS)

    In cold worked copper the internal friction is decreased by electron irradiation between 20-140K and increased between 140-280K. In a copper specimen containing a convenient dislocation network, it is possible to develop Hasiguti type peaks

  8. A contribution to the study of damage and regeneration of hemopoiesis during fractionated irradiation and repeated bone marrow transplantation

    International Nuclear Information System (INIS)

    The experiment was aimed at studying two contradictory actions: damage to hemopoietic organs during application of radiation doses per fraction and regenerative efforts of the organism support by repeated bone marrow transplantation. The mice received doses of 3 Gy or 60Co-gamma rays total body irradiation at four-day intervals up to a total dose of 18 Gy. After each dose per fraction half of the animals were injected with 106 bone marrow cells. At four-day intervals evaluations were made of the blood count, bone marrow and spleen cellularities, and spleen mass. In animals subjected only to irradiation the damage to hemopoietic organs was becoming deeper until the end of observation. In bone marrow recipients the decrease in bone marrow cellularity and the number of leukocytes stopped after day 16, and there was a steep growth of splenic cellularity and mass; the decrease in erythrocyte count stopped on day 20. Obviously a certain recovery of hemopoiesis occurred after the total dose of 12 Gy between days 12 and 16. The lodging of injected hemopoietic stem cells and their proliferation had to be preceeded by a regeneration of the hemopoietic microenvironment. (orig.)

  9. A pilot study to evaluate the cost-effectiveness of ondansetron and granisetron in fractionated total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, S.J.; Cassoni, A.M. [Middlesex Hospital, London (United Kingdom)

    1996-11-01

    The duration of the antiemetic effect of granisetron was examined in a pilot study of patients (n = 26) undergoing a standard emetogenic stimulus in the form of total body irradiation fractionated over 3-4 days, in a randomized comparison with twice-daily ondansetron. A single intravenous dose of granisetron at the onset of therapy was effective over the entire follow-up period in 50% (6/12) of patients, compared with 77% (10/13) prescribed twice-daily oral ondansetron for 3 or 4 days. The response rate within the first 24 hours from the start of irradiation was 67% (8/12) for granisetron and 77% (10/13) for ondansetron. Granisetron and ondansetron was therefore of similar efficacy within the first 24-hour period, but granisetron was less efficaceous more than 24 hours after the onset of therapy. Patients who required a second dose of granisetron did so at intervals of 12, 42, 47 and 48 hours following the first fraction of radiotherapy. The cost per patient in this study was 48 for granisetron and {sub 1}54 for ondanestron, but the dose scheduling we used cannot be recommended in view of the lower effectiveness of granisetron. (author).

  10. Fractionated irradiation induced radio-resistant esophageal cancer EC109 cells seem to be more sensitive to chemotherapeutic drugs

    Directory of Open Access Journals (Sweden)

    Wang Xingwu

    2009-05-01

    Full Text Available Abstract Background Chemo-radiotherapy, a combination of chemotherapy and radiotherapy, is the most frequent treatment for patients with esophageal cancer. In the process of radiotherapy, the radiosensitive cancer will become a radio-resistant one. Methods In order to detect the chemotherapeutic drug sensitivity in radio-resistant cancer cells and improve the therapy efficiency, we firstly established a radio-resistant esophageal cancer cell model (referred to as EC109/R from the human esophageal squamous cell carcinoma cell line EC109 through fractionated irradiation using X-rays. The radio-sensitivity of EC109/R cells was measured by clonogenic assay. To detect the drug sensitivity for EC109/R compared to its parent cells, we employed MTT method to screen the effectiveness of five different drugs commonly used in clinical therapy. The ratio of apoptosis was examined by flow cytometry. Results EC109/R cells were more sensitive to 5-fluorouracil, doxorubicin, paclitaxel and etoposide, but tolerant to cisplatin compared to its original cells. Conclusion Our study implies that fractionated irradiation induced radio-resistant esophageal cancer cell is more sensitive to certain kind of chemotherapeutic drugs. It provides evidence for choosing the sequence of radiotherapy and chemotherapy in esophageal cancer.

  11. Release of monocyte migration signals by breast cancer cell lines after ablative and fractionated γ-irradiation

    International Nuclear Information System (INIS)

    Radiotherapy, administered in fractionated as well as ablative settings, is an essential treatment component for breast cancer. Besides the direct tumor cell death inducing effects, there is growing evidence that immune mechanisms contribute - at least in part - to its therapeutic success. The present study was designed to characterize the type and the extent of cell death induced by fractionated and ablative radiotherapy as well as its impact on the release of monocyte migration stimulating factors by dying breast cancer cells. Cell death and senescence assays were employed to characterize the response of a panel of breast cancer cell lines with different receptor and p53 status towards γ-irradiation applied in a fractionated (daily doses of 2 Gy) or ablative setting (single dose of 20 Gy). Cell-free culture supernatants were examined for their monocyte migration stimulating potential in transwell migration and 2D chemotaxis/chemokinesis assays. Irradiation-induced transcriptional responses were analyzed by qRT-PCR, and CD39 surface expression was measured by flow cytometry. Fast proliferating, hormone receptor negative breast cancer cell lines with defective p53 predominantly underwent primary necrosis in response to γ-irradiation when applied at a single, ablative dose of 20 Gy, whereas hormone receptor positive, p53 wildtype cells revealed a combination of apoptosis, primary, and secondary (post-apoptotic) necrosis. During necrosis the dying tumor cells released apyrase-sensitive nucleotides, which effectively stimulated monocyte migration and chemokinesis. In hormone receptor positive cells with functional p53 this was hampered by irradiation-induced surface expression of the ectonucleotidase CD39. Our study shows that ablative radiotherapy potently induces necrosis in fast proliferating, hormone receptor negative breast cancer cell lines with mutant p53, which in turn release monocyte migration and chemokinesis stimulating nucleotides. Future studies have

  12. The different biological effects of single, fractionated and continuous low dose rate irradiation on CL187 colorectal cancer cells

    International Nuclear Information System (INIS)

    To determine the biological effectiveness of single, fractionated and continuous low dose rate irradiation on the human colorectal cancer cell line CL187 in vitro and explore the cellular mechanisms. The CL187 cells were exposed to radiation of 6 MV X-ray at a high dose rate of 4Gy/min and 125I seed at a low dose rate of 2.77 cGy/h. Three groups were employed: single dose radiation group (SDR), fractionated dose radiation group (FDR) by 2Gy/f and continuous low dose rate radiation group (CLDR). Four radiation doses 2, 4, 6 and 8Gy were chosen and cells without irradiation as the control. The responses of CL187 cells to distinct modes of radiation were evaluated by the colony-forming assay, cell cycle progression as well as apoptosis analysis. In addition, we detected the expression patterns of DNA-PKcs, Ku70 and Ku80 by Western blotting. The relative biological effect for 125I seeds compared with 6 MV X-ray was 1.42. 48 hrs after 4Gy irradiation, the difference between proportions of cells at G2/M phase of SDR and CLDR groups were statistically significant (p = 0.026), so as the FDR and CLDR groups (p = 0.005). 48 hrs after 4Gy irradiation, the early apoptotic rate of CLDR group was remarkably higher than SDR and FDR groups (CLDR vs. SDR, p = 0.001; CLDR vs. FDR, p = 0.02), whereas the late apoptotic rate of CLDR group increased significantly compared with SDR and FDR group (CLDR vs. SDR, p = 0.004; CLDR vs. FDR, p = 0.007). Moreover, DNA-PKcs and Ku70 expression levels in CLDR-treated cells decreased compared with SDR and FDR groups. Compared with the X-ray high dose rate irradiation, 125I seeds CLDR showed more effective induction of cell apoptosis and G2/M cell cycle arrest. Furthermore, 125I seeds CLDR could impair the DNA repair capability by down-regulating DNA-PKcs and Ku70 expression

  13. Systemic Effects of Fractionated, Whole-Brain Irradiation in Young Adult and Aging Rats

    OpenAIRE

    Forbes, M. E.; Paitsel, M.; Bourland, J. D.; Riddle, D. R.

    2013-01-01

    Cranial irradiation is a critical and effective treatment for primary brain tumors and metastases. Unfortunately, most patients who are treated and survive for more than a few months develop neural and cognitive problems as the result of radiation-induced normal tissue injury. The neurobiological mechanisms underlying these cognitive deficits remain largely unknown and there are no validated treatments to prevent or ameliorate them; thus, there is a significant and continuing need for preclin...

  14. On the definition of absorbed dose

    International Nuclear Information System (INIS)

    Purpose: The quantity absorbed dose is used extensively in all areas concerning the interaction of ionizing radiation with biological organisms, as well as with matter in general. The most recent and authoritative definition of absorbed dose is given by the International Commission on Radiation Units and Measurements (ICRU) in ICRU Report 85. However, that definition is incomplete. The purpose of the present work is to give a rigorous definition of absorbed dose. Methods: Absorbed dose is defined in terms of the random variable specific energy imparted. A random variable is a mathematical function, and it cannot be defined without specifying its domain of definition which is a probability space. This is not done in report 85 by the ICRU, mentioned above. Results: In the present work a definition of a suitable probability space is given, so that a rigorous definition of absorbed dose is possible. This necessarily includes the specification of the experiment which the probability space describes. In this case this is an irradiation, which is specified by the initial particles released and by the material objects which can interact with the radiation. Some consequences are discussed. Specific energy imparted is defined for a volume, and the definition of absorbed dose as a point function involves the specific energy imparted for a small mass contained in a volume surrounding the point. A possible more precise definition of this volume is suggested and discussed. Conclusions: The importance of absorbed dose motivates a proper definition, and one is given in the present work. No rigorous definition has been presented before. - Highlights: • A stringent definition of absorbed dose is given. • This requires the definition of an irradiation and a suitable probability space. • A stringent definition is important for an understanding of the concept absorbed dose

  15. A 3D Monte Carlo Method for Estimation of Patient-specific Internal Organs Absorbed Dose for (99m)Tc-hynic-Tyr(3)-octreotide Imaging.

    Science.gov (United States)

    Momennezhad, Mehdi; Nasseri, Shahrokh; Zakavi, Seyed Rasoul; Parach, Ali Asghar; Ghorbani, Mahdi; Asl, Ruhollah Ghahraman

    2016-01-01

    Single-photon emission computed tomography (SPECT)-based tracers are easily available and more widely used than positron emission tomography (PET)-based tracers, and SPECT imaging still remains the most prevalent nuclear medicine imaging modality worldwide. The aim of this study is to implement an image-based Monte Carlo method for patient-specific three-dimensional (3D) absorbed dose calculation in patients after injection of (99m)Tc-hydrazinonicotinamide (hynic)-Tyr(3)-octreotide as a SPECT radiotracer. (99m)Tc patient-specific S values and the absorbed doses were calculated with GATE code for each source-target organ pair in four patients who were imaged for suspected neuroendocrine tumors. Each patient underwent multiple whole-body planar scans as well as SPECT imaging over a period of 1-24 h after intravenous injection of (99m)hynic-Tyr(3)-octreotide. The patient-specific S values calculated by GATE Monte Carlo code and the corresponding S values obtained by MIRDOSE program differed within 4.3% on an average for self-irradiation, and differed within 69.6% on an average for cross-irradiation. However, the agreement between total organ doses calculated by GATE code and MIRDOSE program for all patients was reasonably well (percentage difference was about 4.6% on an average). Normal and tumor absorbed doses calculated with GATE were slightly higher than those calculated with MIRDOSE program. The average ratio of GATE absorbed doses to MIRDOSE was 1.07 ± 0.11 (ranging from 0.94 to 1.36). According to the results, it is proposed that when cross-organ irradiation is dominant, a comprehensive approach such as GATE Monte Carlo dosimetry be used since it provides more reliable dosimetric results. PMID:27134562

  16. International Workshop on “Generalized Concavity, Fractional Programming and Economic Applications”

    CERN Document Server

    Castagnoli, Erio; Martein, Laura; Mazzoleni, Piera; Schaible, Siegfried

    1990-01-01

    Generalizations of convex functions have been used in a variety of fields such as economics. business administration. engineering. statistics and applied sciences.· In 1949 de Finetti introduced one of the fundamental of generalized convex functions characterized by convex level sets which are now known as quasiconvex functions. Since then numerous types of generalized convex functions have been defined in accordance with the need of particular applications.· In each case such functions preserve soine of the valuable properties of a convex function. In addition to generalized convex functions this volume deals with fractional programs. These are constrained optimization problems which in the objective function involve one or several ratios. Such functions are often generalized convex. Fractional programs arise in management science. economics and numerical mathematics for example. In order to promote the circulation and development of research in this field. an international workshop on "Generalized Concavi...

  17. Measurement of absorbed doses near metal and dental material interfaces irradiated by x- and gamma-ray therapy beams

    International Nuclear Information System (INIS)

    Soft-tissue damage adjacent to dental restorations is a deleterious side effect of radiation therapy associated with low-energy electron scatter from dental materials of high electron density. This study was designed to investigate the enhancement of dose to soft tissue (or water) close to high electron-density materials and to measure the detailed lateral and depth-dose profiles in soft-tissue-simulating polymer adjacent to planar interfaces of several higher atomic-number materials: 18-carat gold dental casting alloy; Ag-Hg dental amalgam alloy; Ni-Cr dental casting alloy; and natural human tooth structure. Results indicate that the dose-enhancement in 'tissue' is as great as a factor of 2 on the backscatter side adjacent to gold and a factor of 1.2 adjacent to tooth tissue, but is insignificant on the forward-scatter side because of the predominant effect of attenuation by the high-density, high atomic-number absorbing material. (author)

  18. Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

    Indian Academy of Sciences (India)

    S Panda; B K Panda

    2010-09-01

    Chemical potential and internal energy of a noninteracting Fermi gas at low temperature are evaluated using the Sommerfeld method in the fractional-dimensional space. When temperature increases, the chemical potential decreases below the Fermi energy for any dimension equal to 2 and above due to the small entropy, while it increases above the Fermi energy for dimensions below 2 as a result of high entropy. The ranges of validity of the truncated series expansions of these quantities are extended from low to intermediate temperature regime as well as from high to relatively low density regime by using the Pad ́e approximant technique.

  19. Repair and biochemical protection in life shortening of mice exposed to fractionated X-irradiation

    International Nuclear Information System (INIS)

    Male mice of the BALB/c+ strain were exposed to X-rays at fractionation intervals of 7, 15, 30, and 60 days. One group received a mixture of radioprotectors, another only AET (only 30 days fractionation), a third one served as control. The doses ranged, dependent on the treatment, from 300-1,500 R. When survival was corrected for acute death, the control and AET treated animals died after an accumulated dose of about 2,000 R whereas those treated with a mixture of radioprotectors died after about 4,000 R. Bone marrow failure and lung damage is the main cause of death within the initial 200 days after start of the exposure. At later times, fibrotic changes and in particular glomerulosclerosis are observed. (orig.)

  20. Cataracts after bone marrow transplantation: long-term follow-up of adults treated with fractionated total body irradiation

    International Nuclear Information System (INIS)

    Purpose: To determine the risk of, and risk factors for, developing cataracts after bone marrow transplantation.Methods and Materials: Four hundred and ninety-two adults who underwent bone marrow transplantation in Seattle were followed for 2 to 18 (median, 6) years. Before transplantation, patients received a preparative regimen of chemotherapy plus total body irradiation (TBI) (n = 407) or chemotherapy alone, without TBI (n = 85). TBI was administered in a single dose of 10 Gy (n = 74) or in fractionated doses totaling 12-15.75 Gy (n = 333). The risk of cataracts was determined for groups of patients with respect to the type of preparative regimen received and other pretransplant and posttransplant variables. Results: One hundred and fifty-nine patients (32%) developed cataracts between 0.5 to 11 (median, 2.3) years after transplantation. The probability of cataracts at 11 years after transplantation was 85%, 50%, 34%, and 19% for patients receiving 10 Gy of single-dose TBI, >12 Gy fractionated TBI, 12 Gy fractionated TBI, and no TBI, respectively (p 12 Gy fractionated TBI, 12 Gy fractionated TBI, or no TBI (33%, 22% and 23%, respectively). Patients given corticosteroids after transplant had a higher probability of cataracts (45%) than those without steroids (38%)(p <0.0001). In a proportional hazards regression model, the variables that were correlated with an increased probability of cataracts were single-dose TBI (relative risk (RR) = 2.46) and steroid therapy (RR = 2.34), while a decreased probability of cataracts was correlated with a nonTBI preparative regimen (RR = 0.41). The yearly hazard of developing cataracts in recipients of single-dose TBI was highest during the third year after transplantation, while in recipients of fractionated TBI, the hazard was distributed among years one through seven. The probability of cataracts in all groups reached a plateau at 7 years after transplantation, after which the development of cataracts was extremely unlikely

  1. First international comparison of primary absorbed dose to water standards in the medium-energy X-ray range

    Science.gov (United States)

    Büermann, Ludwig; Guerra, Antonio Stefano; Pimpinella, Maria; Pinto, Massimo; de Pooter, Jacco; de Prez, Leon; Jansen, Bartel; Denoziere, Marc; Rapp, Benjamin

    2016-01-01

    This report presents the results of the first international comparison of primary measurement standards of absorbed dose to water for the medium-energy X-ray range. Three of the participants (VSL, PTB, LNE-LNHB) used their existing water calorimeter based standards and one participant (ENEA) recently developed a new standard based on a water-graphite calorimeter. The participants calibrated three transfer chambers of the same type in terms of absorbed dose to water (NDw) and in addition in terms of air kerma (NK) using the CCRI radiation qualities in the range 100 kV to 250 kV. The additional NK values were intended to be used for a physical analysis of the ratios NDw/NK. All participants had previously participated in the BIPM.RI(I)-K3 key comparison of air kerma standards. Ratios of pairs of NMI's NK results of the current comparison were found to be consistent with the corresponding key comparison results within the expanded uncertainties of 0.6 % - 1 %. The NDw results were analysed in terms of the degrees of equivalence with the comparison reference values which were calculated for each beam quality as the weighted means of all results. The participant's results were consistent with the reference value within the expanded uncertainties. However, these expanded uncertainties varied significantly and ranged between about 1-1.8 % for the water calorimeter based standards and were estimated at 3.7 % for the water-graphite calorimeter. It was shown previously that the ratios NDw/NK for the type of ionization chamber used as transfer chamber in this comparison were very close (within less than 1 %) to the calculated values of (bar muen/ρ)w,ad, the mean values of the water-to-air ratio of the mass-energy-absorption coefficients at the depth d in water. Some of the participant's results deviated significantly from the expected behavior. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of

  2. Effect of gamma irradiation on the activity of alanine and aspartate transaminases in subcellular fractions of the brain and heart in white rats

    Energy Technology Data Exchange (ETDEWEB)

    Plenin, A.E.

    1973-01-01

    In experiments on rats, the activity of alanine (I) and aspartate transaminases (II) was studied in homogenates and subcellular fractions of the brain and myocardium under normal conditions and for 30 days after ..gamma.. irradiation at 40 rads. The activity of II in brain homogenates increased 1 hour after irradiation but decreased by 20 percent on day 3; it decreased again on days 7 and 15. The activity of brain I increased after 1 hour and 3 days but then returned to normal. The activity of I in heart homogenates increased in all the periods after irradiation. The subcellular fractions exhibited phase changes in the activity of the enzymes. These changes were different in nature from those observed after X and ..gamma.. irradiation at the same dose.

  3. Accelerated partial breast irradiation using once-daily fractionation: analysis of 312 cases with four years median follow-up

    Directory of Open Access Journals (Sweden)

    Shaikh Arif Y

    2012-02-01

    Full Text Available Abstract Background There are limited data on accelerated partial breast irradiation (APBI using external beam techniques. Moreover, there are recent reports of increased fibrosis and unacceptable cosmesis with APBI using external beam with BID fractionation. We adopted a once daily regimen of APBI with fractionation similar to that shown to be effective in a Canadian randomized trial of whole breast irradiation. It is unclear whether patients with DCIS or invasive lobular carcinoma (ILC are suitable for APBI. Methods The retrospective cohort included 310 patients with 312 tumors of T1-T2N0-N1micM0 invasive ductal carcinoma (IDC, ILC, or Tis (DCIS treated with APBI via external beam. Most patients were treated using IMRT with 16 daily fractions of 270 cGy to a dose of 4320 cGy. The target volume included the lumpectomy cavity plus 1.0 cm to account for microscopic disease and an additional 0.5 to 1.0 cm for setup uncertainty and breathing motion. Ipsilateral breast failure (IBF was pathologically confirmed as a local failure (LF or an elsewhere failure (EF. Results Median follow-up was 49 months. Among the 312 cases, 213 were IDC, 31 ILC, and 68 DCIS. Median tumor size was 1.0 cm. There were 9 IBFs (2.9% including 5 LFs and 4 EFs. The IBF rates among patients with IDC, ILC, and DCIS were 2.4%, 3.2%, and 4.4%, respectively, with no significant difference between histologies. When patients were analyzed by the ASTRO APBI consensus statement risk groups, 32% of treated cases were considered suitable, 50% cautionary, and 18% unsuitable. The IBF rates among suitable, cautionary, and unsuitable patients were 4.0%, 2.6%, and 1.8%, respectively, with no significant difference between risk groups. Acute skin reactions were rare and long-term cosmetic outcome was very good to excellent. Conclusions External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not

  4. Biodosimetry Based on γ-H2AX Quantification and Cytogenetics after Partial- and Total-Body Irradiation during Fractionated Radiotherapy.

    Science.gov (United States)

    Zahnreich, Sebastian; Ebersberger, Anne; Kaina, Bernd; Schmidberger, Heinz

    2015-04-01

    The aim of this current study was to quantitatively describe radiation-induced DNA damage and its distribution in leukocytes of cancer patients after fractionated partial- or total-body radiotherapy. Specifically, the impact of exposed anatomic region and administered dose was investigated in breast and prostate cancer patients receiving partial-body radiotherapy. DNA double-strand breaks (DSBs) were quantified by γ-H2AX immunostaining. The frequency of unstable chromosomal aberrations in stimulated lymphocytes was also determined and compared with the frequency of DNA DSBs in the same samples. The frequency of radiation-induced DNA damage was converted into dose, using ex vivo generated calibration curves, and was then compared with the administered physical dose. This study showed that 0.5 h after partial-body radiotherapy the quantity of radiation-induced γ-H2AX foci increased linearly with the administered equivalent whole-body dose for both tumor entities. Foci frequencies dropped 1 day thereafter but proportionality to the equivalent whole-body dose was maintained. Conversely, the frequency of radiation-induced cytogenetic damage increased from 0.5 h to 1 day after the first partial-body exposure with a linear dependence on the administered equivalent whole-body dose, for prostate cancer patients only. Only γ-H2AX foci assessment immediately after partial-body radiotherapy was a reliable measure of the expected equivalent whole-body dose. Local tumor doses could be approximated with both assays after one day. After total-body radiotherapy satisfactory dose estimates were achieved with both assays up to 8 h after exposure. In conclusion, the quantification of radiation-induced γ-H2AX foci, but not cytogenetic damage in peripheral leukocytes was a sensitive and rapid biodosimeter after acute heterogeneous irradiation of partial body volumes that was able to primarily assess the absorbed equivalent whole-body dose.

  5. Fractionated afterloading irradiation as a new therapy method for inoperable cerebral tumors

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, H.; Scheffler, A.; Oppel, F.; Brock, M.; Brust, V.; Bauer, R.; Pannek, H.W.

    1986-07-01

    A method is shown for fractionated afterloading therapy of inoperable cerebral tumors. A 3 mm thick, tube-form applicator of noble metal which is closed at the front side is implanted into the tumor by a stereotaxic technique and firmly screwed together with the osseous calotte. It remains there up to two weeks, giving full mobility to the patient. The afterloading therapy with a moving iridium source is performed one or two times per day with individual doses of 2 Gray. Thus, the chronological and - to a certain extent - also the spatial dose distribution is variable when applying this method.

  6. Irradiation experiments on materials for core internals, pressure vessel and fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Materials degradation due to the aging phenomena is one of the key issues for the life assessment and extension of the light water reactors (LWRs). This presentation introduces JAERI`s activities in the field of LWR material researches which utilize the research and testing reactors for irradiation experiments. The activities are including the material studies for the core internals, pressure vessel and fuel cladding. These materials are exposed to the neutron/gamma radiation and high temperature water environments so that it is worth reviewing their degradation phenomena as the continuum. Three topics are presented; For the core internal materials, the irradiation assisted stress corrosion cracking (IASCC) of austenitic stainless steels is the present major concern. At JAERI the effects of alloying elements on IASCC have been investigated through the post-irradiation stress corrosion cracking tests in high-temperature water. The radiation embrittlement of pressure vessel steels is still a significant issue for LWR safety, and at JAERI some factors affecting the embrittlement behavior such as a dose rate have been investigated. Waterside corrosion of Zircaloy fuel cladding is one of the limiting factors in fuel rod performance and an in-situ measurement of the corrosion rate in high-temperature water was performed in JMTR. To improve the reliability of experiments and to extent the applicability of experimental techniques, a mutual utilization of the technical achievements in those irradiation experiments is desired. (author)

  7. Radiosensitivity of Nicotiana protoplasts. Action on cell; cycle effects of low dose and fractionated irradiations; biological repair

    International Nuclear Information System (INIS)

    Leaf protoplasts of Nicotiana plumbaginifolia and Nicotiana sylvestris demonstrate five main qualities: they can be maintained as haploid lines; they constitute starting populations with a remarkable cytological homogeneity; they show a transient initial lag-phase; they yield very high plating efficiencies and retain permanently a complete differentiation capacity; being derived of a cell wall, they appear well adapted for fusion experiments or enzymatic dosages. The resumption of mitotic activity was followed by cytophotometric measurements, labelling experiments, nuclear sizing and enzymatic assays. The action of 5 Gy gamma-ray irradiations delayed entrance in the S-phase, provoked an otherwise not verified dependency between transcription, translation and protein synthesis, increased nuclear volumes in the G2-phase, and slightly stimulated the activity of a repair enzyme. The plating efficiency was a sensitive end-point which allowed the evaluation of the biological effectiveness of low to medium radiation-doses after gamma-ray and fast neutron irradiations. The neutron dose-RBE relationship increased from 3 to 25 when the dose decreased from 5 Gy to 5 mGy. When fractionated into low single doses only, a neutron dose of 300 mGy markedly increased its biological effectiveness: this phenomenon could not be explained by cell progression, and necessitated additional hypotheses involving other mechanisms in the specific action of low radiation doses. Radiation-induced UDS was measured in presence of aphidicolin. A beta-like DNA-polymerase was shown to be definitely involved in nuclear repair synthesis

  8. A generalization of the clonal survival models: equations for the families of curves obtained with fractionated irradiation

    International Nuclear Information System (INIS)

    The survival curves obtained when cellular recovery follows various first radiation dose deliveries DI seem, when semi-logarithmically plotted, to be translated from the part of the curve corresponding to an unfractionated irradiation beyond a dose DR. A possible assumption consistent with such experimental observations is proposed which allows the generalization of any survival model S=f(D). The derived equation S=f(DR+D-DI)f(DI)/f(DR) is convenient for the whole family of experimental survival curves involving cellular damage repairs when the first radiation doses vary. All the parameters of the family equation can be simultaneously fitted so that their reliability is increased. The generalized equations are given for the four following models: two-hits targets, Chadwick and Leenhouts, Green and Burki, Wideroee. As an example, the Chadwick and Leenhouts generalized model parameters are fitted to a family of experimental survical curves concerning Chlorella cells exposed to fractionated and continuous gamma irradiation. The fittings are presented with their confidence limits and are briefly discussed. (orig.)

  9. Phototropism of Arabidopsis thaliana in microgravity and fractional gravity on the International Space Station.

    Science.gov (United States)

    Kiss, John Z; Millar, Katherine D L; Edelmann, Richard E

    2012-08-01

    While there is a great deal of knowledge regarding plant growth and development in microgravity aboard orbiting spacecraft, there is little information available about these parameters in reduced or fractional gravity conditions (less than the nominal 1g on Earth). Thus, in these experiments using the European Modular Cultivation System on the International Space Station, we studied the interaction between phototropism and gravitropism in the WT and mutants of phytochrome A and B of Arabidopis thaliana. Fractional gravity and the 1 g control were provided by centrifuges in the spaceflight hardware, and unidirectional red and blue illumination followed a white light growth period in the time line of the space experiments. The existence of red-light-based positive phototropism in hypocotyls of seedlings that is mediated by phytochrome was confirmed in these microgravity experiments. Fractional gravity studies showed an attenuation of red-light-based phototropism in both roots and hypocotyls of seedlings occurring due to gravitational accelerations ranging from 0.l to 0.3 g. In contrast, blue-light negative phototropism in roots, which was enhanced in microgravity compared with the 1g control, showed a significant attenuation at 0.3 g. In addition, our studies suggest that the well-known red-light enhancement of blue-light-induced phototropism in hypocotyls is likely due to an indirect effect by the attenuation of gravitropism. However, red-light enhancement of root blue-light-based phototropism may occur via a more direct effect on the phototropism system itself, most likely through the phytochrome photoreceptors. To our knowledge, these experiments represent the first to examine the behavior of flowering plants in fractional or reduced gravity conditions.

  10. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Final report

    International Nuclear Information System (INIS)

    This report documents the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member

  11. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Martone, M. [ENEA, Centro Ricerche Frascati, Rome (Italy)

    1997-01-01

    This report documents the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member.

  12. Internal stress distribution for generating closure domains in laser-irradiated Fe–3%Si(110) steels

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Keiji, E-mail: iwata.24h.keiji@jp.nssmc.com [Advanced Technology Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, Futtsu, Chiba 293-8511 (Japan); Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai 980-8577 (Japan); Imafuku, Muneyuki; Orihara, Hideto; Sakai, Yusuke; Ohya, Shin-Ichi [Department of Mechanical Systems Engineering, Tokyo City University, Tokyo, 158-0087 (Japan); Suzuki, Tamaki [Advanced Technology Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, Futtsu, Chiba 293-8511 (Japan); Shobu, Takahisa [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148 (Japan); Akita, Koichi [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Naka, Ibaraki 319-1195 (Japan); Ishiyama, Kazushi [Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai 980-8577 (Japan)

    2015-05-07

    Internal stress distribution for generating closure domains occurring in laser-irradiated Fe–3%Si(110) steels was investigated using high-energy X-ray analysis and domain theory based on the variational principle. The measured triaxial stresses inside the specimen were compressive and the stress in the rolling direction became more dominant than stresses in the other directions. The calculations based on the variational principle of magnetic energy for closure domains showed that the measured triaxial stresses made the closure domains more stable than the basic domain without closure domains. The experimental and calculation results reveal that the laser-introduced internal stresses result in the occurrence of the closure domains.

  13. An experimental investigation of fractionation by sputter deposition. [application to solar wind irradiation of lunar soil

    Science.gov (United States)

    Paruso, D. M.; Cassidy, W. A.; Hapke, B. W.

    1978-01-01

    Artificial glass targets composed of elements varying widely in atomic weight were irradiated at an angle of incidence of 45 deg by 2-keV hydrogen ions at a current density of .33 mA/sq cm, and sputtered atoms were caught on a molybdenum film. Analyses of the sputter-deposited films and unsputtered target glasses were carried out by electron microprobe. The backward-sputtered component was found to be enriched in elements of low atomic weight, while the forward-sputtered component was enriched in heavy atoms. These results indicate that at the lunar surface lighter elements and isotopes would tend to be ejected in backward directions, escaping directly through the openings which admit bombarding ions without first striking an adjacent grain surface; heavy elements and isotopes would be forward-sputtered deeper into the soil and be preferentially retained, contributing to the reported enrichments of heavy elements and isotopes. Additional results show that the binding energy of an element in its oxide form influences the sticking coefficient of a sputtered atom; elements of low binding energy are likely to desorb, while elements of high binding energy tend to stick to the first bounce surface.

  14. Phase I trial of panobinostat and fractionated stereotactic re-irradiation therapy for recurrent high grade gliomas.

    Science.gov (United States)

    Shi, Wenyin; Palmer, Joshua D; Werner-Wasik, Maria; Andrews, David W; Evans, James J; Glass, Jon; Kim, Lyndon; Bar-Ad, Voichita; Judy, Kevin; Farrell, Christopher; Simone, Nicole; Liu, Haisong; Dicker, Adam P; Lawrence, Yaacov R

    2016-05-01

    Panobinostat is an oral HDAC inhibitor with radiosensitizing activity. We investigated the safety, tolerability and preliminary efficacy of panobinostat combined with fractionated stereotactic re-irradiation therapy (FSRT) for recurrent high grade gliomas. Patients with recurrent high grade gliomas were enrolled in a 3 + 3 dose escalation study to determine dose limiting toxicities (DLTs), maximum tolerated dose (MTD), safety, tolerability, and preliminary efficacy. FSRT was prescribed to 30-35 Gy delivered in 10 fractions. Panobinostat was administrated concurrently with radiotherapy. Of 12 evaluable patients, 8 had recurrent GBM, and 4 had recurrent anaplastic astrocytoma. There were three grade 3 or higher toxicities in each the 10 and 30 mg cohorts. In the 30 mg cohort, there was one DLT; grade 4 neutropenia. One patient developed late grade 3 radionecrosis. The median follow up was 18.8 months. The PFS6 was 67, 33, and 83 % for 10, 20, and 30 mg cohorts, respectively. The median OS was 7.8, 6.1 and 16.1 months for the 10, 20 and 30 mg cohorts, respectively. Panobinostat administrated with FSRT is well tolerated at 30 mg. A phase II trial is warranted to assess the efficacy of panobinostat plus FSRT for recurrent glioma. PMID:26821711

  15. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E., E-mail: claudia.ruebe@uks.eu

    2015-08-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.

  16. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age

    International Nuclear Information System (INIS)

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author)

  17. Comparative evaluation of changes in the absorbed doses of neutron radiation and chromosome aberration frequency in human blood lymphocytes by a water phantom depth during irradiation with a medico-biological beam at the BR-10 reactor

    International Nuclear Information System (INIS)

    Distribution of the chromosome aberration frequency in human blood lymphocyte samples and absorbed doses have been compared by the water phantom depth during irradiation with 1.5 Gy neutrons (mean energy of 0.85 MeV). There is a good concordance of their depth distribution. The half-fall layer of the absorbed dose within the tissue-equivalent medium is similar (∼ 5 cm) with both measurements done. The aberration frequency in the biological samples placed outside the radiation field in the phantom increases which indicates that the neutron beem bounds are indistinct upon passing the tissue-equivalent medium

  18. The effect of the overall treatment time of fractionated irradiation on the tumor control probability of a human soft tissue sarcoma xenograft in nude mice

    International Nuclear Information System (INIS)

    Purpose: To study the impact of the overall treatment time of fractionated irradiation on the tumor control probability (TCP) of a human soft tissue sarcoma xenograft growing in nude mice, as well as to compare the pretreatment potential doubling time (Tpot) of this tumor to the effective doubling time (Teff) derived from three different schedules of irradiation using the same total number of fractions with different overall treatment times. Methods and Materials: The TCP was assessed using the TCD50 value (the 50% tumor control dose) as an end point. A total of 240 male nude mice, 7-8 weeks old were used in three experimental groups that received the same total number of fractions (30 fractions) with different overall treatment times. In group 1, the animals received three equal fractions/day for 10 consecutive days, in group 2 they received two equal fractions/day for 15 consecutive days, and in group 3 one fraction/day for 30 consecutive days. All irradiations were given under normal blood flow conditions to air breathing animals. The mean tumor diameter at the start of irradiation was 7-8 mm. The mean interfraction intervals were from 8-24 h. The Tpot was measured using Iododeoxyuridine (IudR) labeling and flow cytometry and was compared to Teff. Results: The TCD50 values of the three different treatment schedules were 58.8 Gy, 63.2 Gy, and 75.6 Gy for groups 1, 2, and 3, respectively. This difference in TCD50 values was significant (p pot (2.4 days) was longer than the calculated Teff in groups 2 and 3 (1.35 days). Conclusion: Our data show a significant loss in TCP with prolongation of the overall treatment time. This is most probably due to an accelerated repopulation of tumor clonogens. The pretreatment Tpot of this tumor model does not reflect the actual doubling of the clonogens in a protracted regimen

  19. Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine

    International Nuclear Information System (INIS)

    The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. α/β coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction α/β for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). α/β coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method α/β for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of α/β coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (Fr) was much bigger for photons. For X-rays it was 50% for early and 63% for late effects. In case of

  20. Nuclear data needs for neutron spectrum tailoring at International Fusion Materials Irradiation Facility (IFMIF)

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    International Fusion Materials Irradiation Facility (IFMIF) is a proposal of D-Li intense neutron source to cover all aspects of the fusion materials development in the framework of IEA collaboration. The new activity has been started to qualifying the important technical issues called Key Element technology Phase since 2000. Although the neutron spectrum can be adjusted by changing the incident beam energy, it is favorable to be carried out many irradiation tasks at the same time under the unique beam condition. For designing the tailored neutron spectrum, neutron nuclear data for the moderator-reflector materials up to 50 MeV are required. The data for estimating the induced radioactivity is also required to keep the radiation level low enough at maintenance time. The candidate materials and the required accuracy of nuclear data are summarized. (author)

  1. IFMIF - International Fusion Materials Irradiation Facility Conceptual Design Activity/Interim Report

    Energy Technology Data Exchange (ETDEWEB)

    Rennich, M.J.

    1995-12-01

    Environmental acceptability, safety, and economic viability win ultimately be the keys to the widespread introduction of fusion power. This will entail the development of radiation- resistant and low- activation materials. These low-activation materials must also survive exposure to damage from neutrons having an energy spectrum peaked near 14 MeV with annual radiation doses in the range of 20 displacements per atom (dpa). Testing of candidate materials, therefore, requires a high-flux source of high energy neutrons. The problem is that there is currently no high-flux source of neutrons in the energy range above a few MeV. The goal, is therefore, to provide an irradiation facility for use by fusion material scientists in the search for low-activation and damage-resistant materials. An accellerator-based neutron source has been established through a number of international studies and workshops` as an essential step for materials development and testing. The mission of the International Fusion Materials Irradiation Facility (IFMIF) is to provide an accelerator-based, deuterium-lithium (D-Li) neutron source to produce high energy neutrons at sufficient intensity and irradiation volume to test samples of candidate materials up to about a full lifetime of anticipated use in fusion energy reactors. would also provide calibration and validation of data from fission reactor and other accelerator-based irradiation tests. It would generate material- specific activation and radiological properties data, and support the analysis of materials for use in safety, maintenance, recycling, decommissioning, and waste disposal systems.

  2. Synergistic antitumor effect between gefitinib and fractionated irradiation in anaplastic oligodendrogliomas cannot be predicted by the Egfr signaling activity.

    Directory of Open Access Journals (Sweden)

    Sophie Pinel

    Full Text Available In high-grade gliomas, the identification of patients that could benefit from EGFR inhibitors remains a challenge, hindering the use of these agents. Using xenografts models, we evaluated the antitumor effect of the combined treatment "gefitinib + radiotherapy" and aimed to identify the profile of responsive tumors. Expression of phosphorylated proteins involved in the EGFR-dependent signaling pathways was analyzed in 10 glioma models. We focused on three models of anaplastic oligodendrogliomas (TCG2, TCG3 and TCG4 harboring high levels of phospho-EGFR, phospho-AKT and phospho-MEK1. They were treated with gefitinib (GEF 75 mg/kg/day x 5 days/week, for 2 weeks and/or fractionated radiotherapy (RT: 5x2Gy/week for 2 weeks. Our results showed that GEF and/or RT induced significant tumor growth delays. However, only the TCG3 xenografts were highly responsive to the combination GEF+RT, with ∼50% of tumor cure. Phosphoproteins analysis five days after treatment onset demonstrated in TCG3 xenografts, but not in TCG2 model, that the EGFR-dependent pathways were inhibited after GEF treatment. Moreover, TCG3-bearing mice receiving GEF monotherapy exhibited a transient beneficial therapeutic response, rapidly followed by tumor regrowth, along with a major vascular remodeling. Taken together, our data evoked an "EGFR-addictive" behavior for TCG3 tumors. This study confirms that combination of gefitinib with fractionated irradiation could be a potent therapeutic strategy for anaplastic oligodendrogliomas harboring EGFR abnormalities but this treatment seems mainly beneficial for "EGFR-addictive" tumors. Unfortunately, neither the usual molecular markers (EGFR amplification, PTEN loss nor the basal overexpression of phosphoproteins were useful to distinguish this responsive tumor. Evaluating the impact of TKIs on the EGFR-dependent pathways during the treatment might be more relevant, and requires further validation.

  3. RBE values and repair characteristics for colo-rectal injury after caesium 137 gamma-ray and neutron irradiation. II. Fractionation up to ten doses.

    Science.gov (United States)

    Terry, N H; Denekamp, J

    1984-07-01

    Early and late colo-rectal damage in mice have been assessed after 137Cs gamma irradiation and 3 MeV neutrons given as 1,2,5 or 10 fractions. Damage was measured by early changes in body weight, the late production of short faecal pellets and the pattern of lethality after irradiation. The data have been analysed in terms of the time course of expression of damage, fractionation effects and the RBE for neutrons over a wide range of doses per fraction (0.5-12.5 Gy neutrons, 3.5-33.5 Gy gamma rays). An initial epithelial denudation led to an early loss of weight, maximal at 11-17 days after irradiation. A dose-dependent weight reduction persisted over the animals' life-time. Deaths after localised pelvic gamma irradiation were progressive with no sharp demarcation between early or late phases of injury. The time course for lethality was qualitatively similar after neutrons. Beyond six months the rectum became constricted by fibrosis and a higher proportion of small faecal pellets was observed. At 6-15 months relatively shallow dose-response curves were obtained for this change. The sparing effect of fractionation was marked for the gamma-irradiated mice and almost absent after neutrons. A very high repair increment (11 Gy) was seen with two gamma-ray fractions of 20 Gy. At lower doses per fraction the proportion of each gamma-ray fraction recovered was 50-69% for all assays, i.e., similar to that for other normal tissues. There was a slight enhancement in the sparing effect for the late compared with the early assays over the lower dose range. The RBE was strongly dependent on dose per fraction because of the lack of reparable damage after neutrons. The RBE for both early and late effects was 5.0 at a neutron dose per fraction of 1 Gy. Extrapolation of the RBE data to lower doses, using the linear quadratic model, predicts a higher RBE for late (7.4-12.7) than for early damage (5.7-8.5) if gamma-ray doses below 5 Gy are used.

  4. Oxidative quality of commercial fried nuts: evaluation of a surface and an internal lipid fraction

    Directory of Open Access Journals (Sweden)

    Dobarganes, M. C.

    2006-09-01

    Full Text Available The oxidative quality of commercial fried nuts was evaluated by independent analyses of two lipid fractions, the surface oil, and the internal lipid fraction. The nuts studied were 6 samples of almonds, 10 samples of peanuts, 4 samples of sunflower seeds and 2 samples of cashew nuts. The oil content, peroxide value, polymer content, and fatty acid composition were analyzed. The results showed two lipid fractions with different oxidation status. Higher oxidation levels were normally found in the oil fraction more exposed  to air, although considerably higher oxidation status in the internal oil was also detected in various samples. Oxidative quality was also evaluated in selected samples of each nut after 1 year of storage at room temperature, in the dark . Only the almonds and cashew nuts exhibited acceptable oxidative quality after storage. In addition, a study on the changes due to frying and the contribution of the frying oil to the lipids in the final product showed that the composition of the surface oil can be changed by the incorporation of substantial contents of the frying fat. Consequently, the frying fat may exert some effect on the oxidative quality and oxidative stability of the surface oil.En este estudio se evalúa la calidad oxidativa de muestras comerciales de frutos secos fritos mediante el análisis independiente de dos fracciones lipídicas, el aceite superficial, fácilmente extraíble con disolventes orgánicos, y la fracción de lípidos internos. Las muestras estudiadas fueron 6 muestras de almendras, 10 muestras de cacahuetes, 4 muestras de pipas de girasol y 2 muestras de anacardos. Se analizaron el contenido de aceite, el índice de peróxidos, el contenido de polímeros y la composición de ácidos grasos. Los resultados mostraron dos fracciones lipídicas con diferente estado de oxidación. Mayores niveles de oxidación fueron normalmente encontrados en la fracción más expuesta al aire, aunque estados de oxidaci

  5. Pretransplant pulmonary function tests predict risk of mortality following fractionated total body irradiation and allogeneic peripheral blood stem cell transplant

    International Nuclear Information System (INIS)

    Purpose: To determine the value of pulmonary function tests (PFTs) done before peripheral blood stem cell transplant (PBSCT) in predicting mortality after total body irradiation (TBI) performed with or without dose reduction to the lung. Methods and Materials: From 1997 to 2004, 146 consecutive patients with hematologic malignancies received fractionated TBI before PBSCT. With regimen A (n = 85), patients were treated without lung dose reduction to 13.6 gray (Gy). In regimen B (n = 35), total body dose was decreased to 12 Gy (1.5 Gy twice per day for 4 days) and lung dose was limited to 9 Gy by use of lung shielding. In regimen C (n = 26), lung dose was reduced to 6 Gy. All patients received PFTs before treatment, 90 days after treatment, and annually. Results: Median follow-up was 44 months (range, 12-90 months). Sixty-one patients had combined ventilation/diffusion capacity deficits defined as both a forced expiratory volume in the first second (FEV1) and a diffusion capacity of carbon dioxide (DLCO) <100% predicted. In this group, there was a 20% improvement in one-year overall survival with lung dose reduction (70 vs. 50%, log-rank test p = 0.042). Conclusion: Among those with combined ventilation/diffusion capacity deficits, lung dose reduction during TBI significantly improved survival

  6. IFMIF (International Fusion Materials Irradiation Facility) key element technology phase interim report

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hiroo; Ida, Mizuho; Sugimoto, Masayoshi; Takeuchi, Hiroshi; Yutani, Toshiaki (eds.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-03-01

    Activities of International Fusion Materials Irradiation Facility (IFMIF) have been performed under an IEA collaboration since 1995. IFMIF is an accelerator-based deuteron (D{sup +})-lithium (Li) neutron source designed to produce an intense neutron field (2 MW/m{sup 2}, 20 dpa/year for Fe) in a volume of 500 cm{sup 3} for testing candidate fusion materials. In 2000, a 3 year Key Element technology Phase (KEP) of IFMIF was started to reduce the key technology risk factors. This interim report summarizes the KEP activities until mid 2001 in the major project work-breakdown areas of accelerator, target, test facilities and design integration. (author)

  7. IFMIF (International Fusion Materials Irradiation Facility) key element technology phase interim report

    International Nuclear Information System (INIS)

    Activities of International Fusion Materials Irradiation Facility (IFMIF) have been performed under an IEA collaboration since 1995. IFMIF is an accelerator-based deuteron (D+)-lithium (Li) neutron source designed to produce an intense neutron field (2 MW/m2, 20 dpa/year for Fe) in a volume of 500 cm3 for testing candidate fusion materials. In 2000, a 3 year Key Element technology Phase (KEP) of IFMIF was started to reduce the key technology risk factors. This interim report summarizes the KEP activities until mid 2001 in the major project work-breakdown areas of accelerator, target, test facilities and design integration. (author)

  8. The Solar Spectral Irradiance Measured on Board the International Space Station and the Picard Spacecraft

    Science.gov (United States)

    Thuillier, G. O.; Bolsee, D.; Schmidtke, G.; Schmutz, W. K.

    2011-12-01

    On board the International Space Station, the spectrometers SOL-ACES and SOLSPEC measure the solar spectrum irradiance from 17 to 150 nm and 170 to 2900 nm, respectively. On board PICARD launched on 15 June 2010, the PREMOS instrument consists in a radiometer and several sunphotometers operated at several fixed wavelengths. We shall present spectra at different solar activity levels as well as their quoted accuracy. Comparison with similar data from other missions presently running in space will be shown incorporating the PREMOS measurements. Some special solar events will be also presented and interpreted.

  9. Effect of the lipid fraction of Listeria monocytogenes cells on the immune response of irradiated mice. Pt. 2. Effect of lipids administered after irradiation

    International Nuclear Information System (INIS)

    Lipids from Listeria monocytegenes were tested for their effect on the process of recovery of the immune reactivity in mice irradiated with 250 and 500 R. The recovery was evaluated by determining cellular and humoral immune response to sheep erythrocytes given as antigen 15 and 30 days after irradiation. The administration of lipids was shown to accelerate the recovery of the immune mechanisms impaired by irradiation. The effect was greatly dependent upon the lipid dose and time of its administration. The effect was highest when the lipid was given 10 days after irradiation, the optimal dose being 0.25 mg. (author)

  10. Promotive effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on recovery from neutropenia induced by fractionated irradiation in mice

    International Nuclear Information System (INIS)

    The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the recovery from neutropenia induced by fractionated whole-body irradiation was investigated in mice. Male 7-week old C3H/HeN mice received a total of ten exposures of 0.25 Gy/day from day 1 to 5 and from day 8 to 12. Peripheral neutropenia with a nadir on day 17 was caused by the fractionated irradiation. Daily subcutaneous injections of rhG-CSF at 0.25 and 2.5 μg/body/day from day from day 1 to 21 promoted the recovery of neutrophils in a dose-dependent manner. The kinetics of morphologically identifiable bone marrow cells were studied to clarify the mechanism behind the promotive effect of this factor. A slight decrease in mitotic immature granulocytes, such as myeloblasts, promyelocytes and myelocytes on day 5, and a drastic decrease in metamyelocytes and marrow neutrophils on days 5, 9, and 17 were seen in the femur of irradiated mice. Treatment using rhG-CSF caused an increase in immature granulocytes of all differential stages in the femur. Microscopic findings of the femurs and spleens also reveals an increase in immature granulocytes in these organs in mice injected with rhG-CSF. These results indicate that rhG-CSF accelerates granulopoiesis in the femur and spleen, thereby promoting recovery from neutropenia induced by fractionated irradiation. (author)

  11. Irradiation of dehydrated vegetables

    International Nuclear Information System (INIS)

    The reason for radurization was to decreased the microbial count of dehydrated vegetables. The average absorbed irradiation dose range between 2kGy and 15kGy. The product catagories include a) Green vegetables b) White vegetables c) Powders of a) and b). The microbiological aspects were: Declining curves for the different products of T.P.C., Coliforms, E. Coli, Stap. areus, Yeast + Mold at different doses. The organoleptical aspects were: change in taste, flavour, texture, colour and moisture. The aim is the marketing of irradiated dehydrated vegetables national and international basis

  12. Internal hydriding in irradiated defected Zircaloy fuel rods: A review (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, J C

    1987-10-01

    Although not a problem in recent commercial power reactors, including the Shippingport Light Water Breeder Reactor, internal hydriding of Zircaloy cladding was a persistent cause of gross cladding failures during the 1960s. It occurred in the fuel rods of water-cooled nuclear power reactors that had a small cladding defect. This report summarizes the experimental findings, causes, mechanisms, and methods of minimizing internal hydriding in defected Zircaloy-clad fuel rods. Irradiation test data on the different types of defected fuel rods, intentionally fabricated defected and in-pile operationally defected rods, are compared. Significant factors affecting internal hydriding in defected Zircaloy-clad fuel rods (defect hole size, internal and external sources of hydrogen, Zircaloy cladding surface properties, nickel alloy contamination of Zircaloy, the effect of heat flux and fluence) are discussed. Pertinent in-pile and out-of-pile test results from Bettis and other laboratories are used as a data base in constructing a qualitative model which explains hydrogen generation and distribution in Zircaloy cladding of defected water-cooled reactor fuel rods. Techniques for minimizing internal hydride failures in Zircaloy-clad fuel rods are evaluated.

  13. Internal hydriding in irradiated defected Zircaloy fuel rods: A review (LWBR Development Program)

    International Nuclear Information System (INIS)

    Although not a problem in recent commercial power reactors, including the Shippingport Light Water Breeder Reactor, internal hydriding of Zircaloy cladding was a persistent cause of gross cladding failures during the 1960s. It occurred in the fuel rods of water-cooled nuclear power reactors that had a small cladding defect. This report summarizes the experimental findings, causes, mechanisms, and methods of minimizing internal hydriding in defected Zircaloy-clad fuel rods. Irradiation test data on the different types of defected fuel rods, intentionally fabricated defected and in-pile operationally defected rods, are compared. Significant factors affecting internal hydriding in defected Zircaloy-clad fuel rods (defect hole size, internal and external sources of hydrogen, Zircaloy cladding surface properties, nickel alloy contamination of Zircaloy, the effect of heat flux and fluence) are discussed. Pertinent in-pile and out-of-pile test results from Bettis and other laboratories are used as a data base in constructing a qualitative model which explains hydrogen generation and distribution in Zircaloy cladding of defected water-cooled reactor fuel rods. Techniques for minimizing internal hydride failures in Zircaloy-clad fuel rods are evaluated

  14. Surface and internal microstructure damage of He-ion-irradiated CLAM steel studied by cross-sectional transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, P.P. [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhan, Q., E-mail: qzhan@mater.ustb.edu.cn [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Fu, Z.Y.; Wei, Y.P. [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Y.M. [Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Wang, F.M. [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Ohnuki, S. [Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Wan, F.R. [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-11-15

    Good understanding of blistering and embrittlement mechanism depends on good investigation of surface and internal microstructure damage of gas-ion-irradiated materials. Internal and surface microstructure of He{sup +} ion irradiated CLAM steel were examined by cross-sectional transmission electron microscopy combining focused ion beam. Variation of helium bubble density and size distribution versus depth in CLAM steel after high dose helium irradiation at room temperature was investigated. The average size of helium bubble increased within 100–400 nm but decreased near the non-irradiated matrix with the increase of depth, while the density followed a reverse trend. The formation and growth mechanism of helium bubble is different at different irradiation depth. The formation of a zone of large bubbles under the surface is the main reason of surface blistering and flaking. Helium induced irradiation swelling and surface blistering at low temperature were also discussed. - Highlights: • Microstructure of helium irradiated CLAM steel was investigated by FIB and TEM. • The nucleation of helium bubble was controlled by both different mechanisms. • The substructure of surface blisters has been analyzed in detail by XTEM. • Helium induced surface blistering and irradiation swelling have been discussed.

  15. Surface and internal microstructure damage of He-ion-irradiated CLAM steel studied by cross-sectional transmission electron microscopy

    International Nuclear Information System (INIS)

    Good understanding of blistering and embrittlement mechanism depends on good investigation of surface and internal microstructure damage of gas-ion-irradiated materials. Internal and surface microstructure of He+ ion irradiated CLAM steel were examined by cross-sectional transmission electron microscopy combining focused ion beam. Variation of helium bubble density and size distribution versus depth in CLAM steel after high dose helium irradiation at room temperature was investigated. The average size of helium bubble increased within 100–400 nm but decreased near the non-irradiated matrix with the increase of depth, while the density followed a reverse trend. The formation and growth mechanism of helium bubble is different at different irradiation depth. The formation of a zone of large bubbles under the surface is the main reason of surface blistering and flaking. Helium induced irradiation swelling and surface blistering at low temperature were also discussed. - Highlights: • Microstructure of helium irradiated CLAM steel was investigated by FIB and TEM. • The nucleation of helium bubble was controlled by both different mechanisms. • The substructure of surface blisters has been analyzed in detail by XTEM. • Helium induced surface blistering and irradiation swelling have been discussed

  16. IAEA international studies on irradiation embrittlement of reactor pressure vessel steels

    Energy Technology Data Exchange (ETDEWEB)

    Brumovsky, M. [Nuclear Research Institute Rez plc (Czech Republic); Steele, L.E. [Chief Scientific Investigator of the Programme, Springfield, VA (United States)

    1997-02-01

    In last 25 years, three phases a Co-operative Research Programme on Irradiation Embrittlement of Reactor Pressure Vessel Steels has been organized by the International Atomic Energy Agency. This programme started with eight countries in 1971 and finally 16 countries took part in phase III of the Programme in 1983. Several main efforts were put into preparation of the programme, but the principal task was concentrated on an international comparison of radiation damage characterization by different laboratories for steels of {open_quotes}old{close_quotes} (with high impurity contents) and {open_quotes}advanced{close_quotes} (with low impurity contents) types as well as on development of small scale fracture mechanics procedures applicable to reactor pressure vessel surveillance programmes. This year, a new programme has been opened, concentrated mostly on small scale fracture mechanics testing.

  17. IAEA international studies on irradiation embrittlement of reactor pressure vessel steels

    International Nuclear Information System (INIS)

    In last 25 years, three phases a Co-operative Research Programme on Irradiation Embrittlement of Reactor Pressure Vessel Steels has been organized by the International Atomic Energy Agency. This programme started with eight countries in 1971 and finally 16 countries took part in phase III of the Programme in 1983. Several main efforts were put into preparation of the programme, but the principal task was concentrated on an international comparison of radiation damage characterization by different laboratories for steels of open-quotes oldclose quotes (with high impurity contents) and open-quotes advancedclose quotes (with low impurity contents) types as well as on development of small scale fracture mechanics procedures applicable to reactor pressure vessel surveillance programmes. This year, a new programme has been opened, concentrated mostly on small scale fracture mechanics testing

  18. Microstructural characterization and model of hardening for the irradiated austenitic stainless steels of the internals of pressurized water reactors; Caracterisation microstructurale et modelisation du durcissement des aciers austenitiques irradies des structures internes des reacteurs a eau pressurisee

    Energy Technology Data Exchange (ETDEWEB)

    Pokor, C

    2003-07-01

    The core internals of Pressurized Water Reactors (PWR) are composed of SA 304 stainless steel plates and CW 316 stainless steel bolts. These internals undergo a neutron flux at a temperature between 280 deg C and 380 deg C which modifies their mechanical properties. These modifications are due to the changes in the microstructure of these materials under irradiation which depend on flux, dose and irradiation temperature. We have studied, by Transmission Electron Microscopy, the microstructure of stainless steels SA 304, CW 316 and CW 316Ti irradiated in a mixed flux reactor (OSIRIS at 330 deg C between 0,8 dpa et 3,4 dpa) and in a fast breeder reactor at 330 deg C (BOR-60) up to doses of 40 dpa. Moreover, samples have been irradiated at 375 deg C in a fast breeder reactor (EBR-II) up to doses of 10 dpa. The microstructure of the irradiated stainless steels consists in faulted Frank dislocation loops in the [111] planes of austenitic, with a Burgers vector of [111]. It is possible to find some voids in the solution annealed samples irradiated at 375 deg C. The evolution of the dislocations loops and voids has been simulated with a 'cluster dynamic' model. The fit of the model parameters has allowed us to have a quantitative description of our experimental results. This description of the microstructure after irradiation was coupled together with a hardening model by Frank loops that has permitted us to make a quantitative description of the hardening of SA 304, CW 316 and CW 316Ti stainless steels after irradiation at a certain dose, flux and temperature. The irradiation doses studied grow up to 90 dpa, dose of the end of life of PWR internals. (author)

  19. RBE values and repair characteristics for colo-rectal injury after caesium 137 gamma-ray and neutron irradiation. 2. Fractionation up to ten doses

    Energy Technology Data Exchange (ETDEWEB)

    Terry, N.H.A.; Denekamp, J. (Mount Vernon Hospital, Northwood (UK). Gray Lab.)

    1984-07-01

    Early and late colo-rectal damage in mice have been assessed after /sup 137/Cs ..gamma.. irradiation and 3 MeV neutrons given as 1, 2, 5 or 10 fractions. Damage was measured by early changes in body weight, the late production of short faecal pellets and the pattern of lethality after irradiation. The data have been analysed in terms of the time course of expression of damage, fractionation effects and the RBE for neutrons over a wide range of doses per fraction (0.5-12.5 Gy neutrons, 3.5-33.5 Gy ..gamma.. rays). The RBE was strongly dependent on dose per fraction because of the lack of reparable damage after neutrons. The RBE for both early and late effects was 5.0 at a neutron dose per fraction of 1 Gy. Extrapolation of the RBE data to lower doses, using the linear quadratic model, predicts a higher RBE for late (7.4-12.7) than for early damage (5.7-8.5) if ..gamma..-ray doses below 5 Gy are used.

  20. High-dose total-body irradiation and autologous marrow reconstitution in dogs: dose-rate-related acute toxicity and fractionation-dependent long-term survival

    International Nuclear Information System (INIS)

    Beagle dogs treated by total-body irradiation (TBI) were given autologous marrow grafts in order to avoid death from marrow toxicity. Acute and delayed non-marrow toxicities of high single-dose (27 dogs) and fractionated TBI (20 dogs) delivered at 0.05 or 0.1 Gy/min were compared. Fractionated TBI was given in increments of 2 Gy every 6 hr for three increments per day. Acute toxicity and early mortality (<1 month) at identical total irradiation doses were comparable for dogs given fractionated or single-dose TBI. With single-dose TBI, 14, 16, and 18 Gy, respectively, given at 0.05 Gy/min, 0/5, 5/5, and 2/2 dogs died from acute toxicity; with 10, 12, and 14 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 5/5 dogs died acutely. With fractionated TBI, 14 and 16 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 2/2 dogs died auctely. Early deaths were due to radiation enteritis with or without associated septicemia (29 dogs; less than or equal to Day 10). Three dogs given 10 Gy of TBI at 0.1 Gy/min died from bacterial pneumonia; one (Day 18) had been given fractionated and two (Days 14, 22) single-dose TBI. Fifteen dogs survived beyond 1 month; eight of these had single-dose TBI (10-14 Gy) and all died within 7 months of irradiation from a syndrome consisting of hepatic damage, pancreatic fibrosis, malnutrition, wasting, and anemia. Seven of the 15 had fractionated TBI, and only one (14 Gy) died on Day 33 from hepatic failure, whereas 6 (10-14 Gy) are alive and well 250 to 500 days after irradiation. In conclusion, fractionated TBI did not offer advantages over single-dose TBI with regard to acute toxicity and early mortality; rather, these were dependent upon the total dose of TBI. The total acutely tolerated dose was dependent upon the exposure rate; however, only dogs given fractionated TBI became healthy long-term survivors

  1. High Dose-Per-Fraction Irradiation of Limited Lung Volumes Using an Image-Guided, Highly Focused Irradiator: Simulating Stereotactic Body Radiotherapy Regimens in a Small-Animal Model

    International Nuclear Information System (INIS)

    Purpose: To investigate the underlying biology associated with stereotactic body radiotherapy (SBRT), both in vivo models and image-guided, highly focal irradiation systems are necessary. Here, we describe such an irradiation system and use it to examine normal tissue toxicity in a small-animal model at lung volumes similar to those associated with human therapy. Methods and Materials: High-dose radiation was delivered to a small volume of the left lung of C3H/HeJCr mice using a small-animal stereotactic irradiator. The irradiator has a collimation mechanism to produce focal radiation beams, an imaging subsystem consisting of a fluorescent screen coupled to a charge-coupled device camera, and a manual positioning stage. Histopathologic examination and micro-CT were used to evaluate the radiation response. Results: Focal obliteration of the alveoli by fibrous connective tissue, hyperplasia of the bronchiolar epithelium, and presence of a small number of inflammatory cells are the main reactions to low-volume/high-dose irradiation of the mouse lung. The tissue response suggested a radiation dose threshold for early phase fibrosis lying between 40 and 100 Gy. The irradiation system satisfied our requirements of high-dose-rate, small beam diameter, and precise localization and verification. Conclusions: We have established an experimental model and image-guided animal irradiation system for the study of high dose per fraction irradiations such as those used with SBRT at volumes analogous to those used in human beings. It will also allow the targeting of specific anatomical structures of the thorax or ultimately, orthotopic tumors of the lung.

  2. Suitability and feasibility of the International Fusion Materials Irradiation Facility (IFMIF) for fusion materials studies

    International Nuclear Information System (INIS)

    There is a global consensus among materials scientists and engineers that the qualification of materials in an appropriate test environment is indispensable for the design, construction and safe operation of demonstration fusion reactors as well as for the calibration of data generated from fission reactor and accelerator irradiations. In an evaluation process based on a series of technical workshops it was concluded that an accelerator driven D-Li stripping source would be the best choice to fulfil the requirements within a realistic time frame. In response to this need, an international design team with members from the European Union, Japan, the United States of America and the Russian Federation has developed, under the auspices of the International Energy Agency during a conceptual design activity phase (1994-1996), a suitable and feasible concept for an accelerator driven D-Li stripping source. This reference design for the International Fusion Materials Irradiation Facility (IFMIF) is based on conservative linac technology and two parallel operating 125 mA, 40 MeV deuteron beams that are focused onto a common liquid Li target with a beam footprint of 50 mm by 200 mm. The materials testing volume behind the Li target is subdivided into different flux regions: the high flux test region (0.5 L, 20-55 dpa/full power year), the medium flux test region (6 L, 1-20 dpa/full power year), and the low flux test region ( > 100 L, < 1 dpa/full power year). The design developed was the basis for the conceptual design evaluation phase (1997-1998) and for subsequent engineering oriented activities. On the basis of comprehensive neutron transport calculations, an evaluation of the irradiation parameters and the available testing volumes has shown that the users' requirements can be fulfilled. Major engineering efforts have been undertaken to establish an IFMIF design that is based on available and already proven technologies. The design developed is based on extensive

  3. On the definition of absorbed dose

    Science.gov (United States)

    Grusell, Erik

    2015-02-01

    Purpose: The quantity absorbed dose is used extensively in all areas concerning the interaction of ionizing radiation with biological organisms, as well as with matter in general. The most recent and authoritative definition of absorbed dose is given by the International Commission on Radiation Units and Measurements (ICRU) in ICRU Report 85. However, that definition is incomplete. The purpose of the present work is to give a rigorous definition of absorbed dose. Methods: Absorbed dose is defined in terms of the random variable specific energy imparted. A random variable is a mathematical function, and it cannot be defined without specifying its domain of definition which is a probability space. This is not done in report 85 by the ICRU, mentioned above. Results: In the present work a definition of a suitable probability space is given, so that a rigorous definition of absorbed dose is possible. This necessarily includes the specification of the experiment which the probability space describes. In this case this is an irradiation, which is specified by the initial particles released and by the material objects which can interact with the radiation. Some consequences are discussed. Specific energy imparted is defined for a volume, and the definition of absorbed dose as a point function involves the specific energy imparted for a small mass contained in a volume surrounding the point. A possible more precise definition of this volume is suggested and discussed. Conclusions: The importance of absorbed dose motivates a proper definition, and one is given in the present work. No rigorous definition has been presented before.

  4. Early micro-rheological consequences of single fraction total body low-dose photon irradiation in mice.

    Science.gov (United States)

    Szluha, Kornelia; Lazanyi, Kornelia; Furka, Andrea; Kiss, Ferenc; Szabo, Imre; Pintye, Eva; Miko, Iren; Nemeth, Norbert

    2014-01-01

    Despite of the studies on widespread biological effects of irradiation, surprisingly only little number of papers can be found dealing with its in vivo hemorheological impact. Furthermore, other studies suggested that low-dose irradiation might differ from high-dose in more than linear ways. On Balb/c Jackson female adult mice hematological and hemorheological impacts of total body irradiation were investigated 1 hour following 0.002, 0.005, 0.01, 0.02, 0.05 and 0.1 Gy dose irradiation. In case of 0.01 Gy further groups were analyzed 30 minutes, 2, 4, 6, 24 and 48 h after irradiation. According to the results, it seems that the dose-dependent changes of blood micro-rheological parameters are not linear. The irradiation dose of 0.01 Gy acted as a point of 'inflexion', because by this dose we found the most expressed changes in hematological parameters, as well as in red blood cell aggregation, deformability and osmoscan data. The time-dependent changes showed progressive decrease in pH, rise in lactate concentration, further decrease in erythrocyte aggregation index and deformability, with moderate shifting of the optimal osmolarity point and modulation in membrane stability. As conclusion, low-dose total body irradiation may cause micro-rheological changes, being non-linearly correlated with the irradiation dose.

  5. Post-irradiation effects in polyethylenes irradiated under various atmospheres

    International Nuclear Information System (INIS)

    If a large amount of polymer free radicals remain trapped after irradiation of polymers, the post-irradiation effects may result in a significant alteration of physical properties during long-term shelf storage and use. In the case of polyethylenes (PEs) some failures are attributed to the post-irradiation oxidative degradation initiated by the reaction of residual free radicals (mainly trapped in crystal phase) with oxygen. Oxidation products such as carbonyl groups act as deep traps and introduce changes in carrier mobility and significant deterioration in the PEs electrical insulating properties. The post-irradiation behaviour of three different PEs, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) was studied; previously, the post-irradiation behaviour of the PEs was investigated after the irradiation in air (Suljovrujic, 2010). In this paper, in order to investigate the influence of different irradiation media on the post-irradiation behaviour, the samples were irradiated in air and nitrogen gas, to an absorbed dose of 300 kGy. The annealing treatment of irradiated PEs, which can substantially reduce the concentration of free radicals, is used in this study, too. Dielectric relaxation behaviour is related to the difference in the initial structure of PEs (such as branching, crystallinity etc.), to the changes induced by irradiation in different media and to the post-irradiation changes induced by storage of the samples in air. Electron spin resonance (ESR), differential scanning calorimetry (DSC), infra-red (IR) spectroscopy and gel measurements were used to determine the changes in the free radical concentration, crystal fraction, oxidation and degree of network formation, respectively. - Highlights: • The post-irradiation behaviour of three different PEs, LDPE, LLDPE and HDPE, was studied. • In order to investigate influence of different irradiation media on post-irradiation behaviour, samples

  6. Pulmonary connective tissue modifications induced by internal α-irradiation. II. Alterations of collagen and non collagen proteins biosynthesis following inhalation of plutonium 239 dioxide aerosol in rat

    International Nuclear Information System (INIS)

    Preliminary studies have shown that internal α irradiation following inhalation of plutonium 239 dioxide in rat increased collagen content in the lung. Effect was maximal at 200 days with the highest dose. This increase was found transient and collagen dropped back to control values after 400 days in rats with the same initial lung burden or the same total dose. A new increase was observed later on, largely related to oncoming death. Here, we have studied, simultaneously, content and biosynthesis of collagen and non collagen proteins, 200 d and 400 d after 239PuO2 inhalation (100-150 nCi ILB). The results confirmed a biphasic effect of inhaled 239PuO2 on the pulmonary connective tissue: a/ A significant increase (p < 0.01) of soluble non-collagen proteins correlated to a decrease of the insoluble fraction was observed 200 d after inhalation. Similar parameters were not significantly different in controls on irradiated rats after 400 days. b/ Soluble and non-soluble collagen contents increased by a factor of 3 and 1.5 respectively 200 d after inhalation. No effect after 400 d. c/ Biosynthesis of non-collagen connective tissue components were 2 to 5 lower than in controls at 400d. d/collagen biosynthesis was decreased by a factor between 4 and 6 for the soluble and insoluble fractions at 200 d but normal at 400 d

  7. Influence of ion irradiation on internal residual stress in DLC films

    Energy Technology Data Exchange (ETDEWEB)

    Karaseov, Platon A., E-mail: platon.karaseov@rphf.spbstu.r [St. Petersburg State Polytechnic University, Polytechnicheskaya St. 29, 195251 St. Petersburg (Russian Federation); Podsvirov, Oleg A.; Karabeshkin, Konstantin V. [St. Petersburg State Polytechnic University, Polytechnicheskaya St. 29, 195251 St. Petersburg (Russian Federation); Vinogradov, Andrei Ya. [Ioffe Physicotechnical Institute RAS, Polytechnicheskaya 26, 195252 St. Petersburg (Russian Federation); Azarov, Alexander Yu. [St. Petersburg State Polytechnic University, Polytechnicheskaya St. 29, 195251 St. Petersburg (Russian Federation); Karasev, Nikita N. [State University of Information Technologies, Mechanics and Optics, Sablinskaya Str. 14, 197101 St. Petersburg (Russian Federation); Titov, Andrei I.; Smirnov, Alexander S. [St. Petersburg State Polytechnic University, Polytechnicheskaya St. 29, 195251 St. Petersburg (Russian Federation)

    2010-10-01

    The dependence of internal residual stress in thin diamond-like carbon films grown on Si substrate by PECVD technique on most important growth parameters, namely RF-power, DC bias voltage and substrate temperature, is described. Results show that compressive stress reaches the highest value of 2.7 GPa at low RF-power and DC bias. Increase of substrate temperature from 250 to 350 {sup o}C leads to nonlinear increase of stress value. Inhomogeneity of residual stress along the film surface disappears when film is deposited at temperatures above 275 {sup o}C. Post-growth film irradiation by P{sup +} and In{sup +} ions cause decrease of compressive stress followed by its inversion to tensile. For all ion energy combinations used residual stress changes linearly with normalized fluence up to 0.2 DPA with slope (8.7 {+-} 1.3) GPa/DPA.

  8. General design of the International Fusion Materials Irradiation Facility deuteron injector: Source and beam line

    International Nuclear Information System (INIS)

    In the framework of the International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities (IFMIF-EVEDA) project, CEA/IRFU is in charge of the design and realization of the 140 mA cw deuteron Injector. The electron cyclotron resonance ion source operates at 2.45 GHz and a 4 electrode extraction system has been chosen. A 2 solenoid beam line, together with a high space charge compensation have been optimized for a proper beam injection in the 175 MHz radio frequency quadrupole. The injector will be tested with proton and deuteron beam production either in pulsed mode or in cw mode on the CEA-Saclay site before to be shipped to Japan. Special attention was paid to neutron emission due to (d,D) reaction. In this paper, the general IFMIF Injector design is reported, pointing out beam dynamics, radioprotection, diagnostics, and mechanical aspects.

  9. IFMIF-KEP. International fusion materials irradiation facility key element technology phase report

    International Nuclear Information System (INIS)

    The International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based D-Li neutron source designed to produce an intense neutron field that will simulate the neutron environment of a D-T fusion reactor. IFMIF will provide a neutron flux equivalent to 2 MW/m2, 20 dpa/y in Fe, in a volume of 500 cm3 and will be used in the development and qualification of materials for fusion systems. The design activities of IFMIF are performed under an IEA collaboration which began in 1995. In 2000, a three-year Key Element Technology Phase (KEP) of IFMIF was undertaken to reduce the key technology risk factors. This KEP report describes the results of the three-year KEP activities in the major project areas of accelerator, target, test facilities and design integration. (author)

  10. Installation and first operation of the International Fusion Materials Irradiation Facility injector at the Rokkasho site

    Energy Technology Data Exchange (ETDEWEB)

    Gobin, Raphael, E-mail: rjgobin@cea.fr; Bogard, Daniel; Bolzon, Benoit; Bourdelle, Gilles; Chauvin, Nicolas; Chel, Stéphane; Girardot, Patrick; Gomes, Adelino; Guiho, Patrice; Harrault, Francis; Loiseau, Denis; Lussignol, Yves; Misiara, Nicolas; Roger, Arnaud; Senée, Franck; Valette, Matthieu [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France); Cara, Philippe; Duglué, Daniel; Gex, Dominique [Fusion for Energy, BFD Department, Garching (Germany); Okumura, Yoshikazu [IFMIF/EVEDA Project Team, Obuchi-Omotedate, 2-166, Rokkasho, Aomori (Japan); and others

    2016-02-15

    The International Fusion Materials Irradiation Facility (IFMIF) linear IFMIF prototype accelerator injector dedicated to high intensity deuteron beam production has been designed, built, and tested at CEA/Saclay between 2008 and 2012. After the completion of the acceptance tests at Saclay, the injector has been fully sent to Japan. The re-assembly of the injector has been performed between March and May 2014. Then after the check-out phase, the production of the first proton beam occurred in November 2014. Hydrogen and deuteron beam commissioning is now in progress after having proceeded with the final tests on the entire injector equipment including high power diagnostics. This article reports the different phases of the injector installation pointing out the safety and security needs, as well as the first beam production results in Japan and chopper tests. Detailed operation and commissioning results (with H{sup +} and D{sup +} 100 keV beams) are reported in a second article.

  11. IFMIF-KEP. International fusion materials irradiation facility key element technology phase report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    The International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based D-Li neutron source designed to produce an intense neutron field that will simulate the neutron environment of a D-T fusion reactor. IFMIF will provide a neutron flux equivalent to 2 MW/m{sup 2}, 20 dpa/y in Fe, in a volume of 500 cm{sup 3} and will be used in the development and qualification of materials for fusion systems. The design activities of IFMIF are performed under an IEA collaboration which began in 1995. In 2000, a three-year Key Element Technology Phase (KEP) of IFMIF was undertaken to reduce the key technology risk factors. This KEP report describes the results of the three-year KEP activities in the major project areas of accelerator, target, test facilities and design integration. (author)

  12. Installation and first operation of the International Fusion Materials Irradiation Facility injector at the Rokkasho site

    Science.gov (United States)

    Gobin, Raphael; Bogard, Daniel; Bolzon, Benoit; Bourdelle, Gilles; Chauvin, Nicolas; Chel, Stéphane; Girardot, Patrick; Gomes, Adelino; Guiho, Patrice; Harrault, Francis; Loiseau, Denis; Lussignol, Yves; Misiara, Nicolas; Roger, Arnaud; Senée, Franck; Valette, Matthieu; Cara, Philippe; Duglué, Daniel; Gex, Dominique; Okumura, Yoshikazu; Marcos Ayala, Juan; Knaster, Juan; Marqueta, Alvaro; Kasugai, Atsushi; O'Hira, Shigeru; Shinto, Katsuhiro; Takahashi, Hiroki

    2016-02-01

    The International Fusion Materials Irradiation Facility (IFMIF) linear IFMIF prototype accelerator injector dedicated to high intensity deuteron beam production has been designed, built, and tested at CEA/Saclay between 2008 and 2012. After the completion of the acceptance tests at Saclay, the injector has been fully sent to Japan. The re-assembly of the injector has been performed between March and May 2014. Then after the check-out phase, the production of the first proton beam occurred in November 2014. Hydrogen and deuteron beam commissioning is now in progress after having proceeded with the final tests on the entire injector equipment including high power diagnostics. This article reports the different phases of the injector installation pointing out the safety and security needs, as well as the first beam production results in Japan and chopper tests. Detailed operation and commissioning results (with H+ and D+ 100 keV beams) are reported in a second article.

  13. Influence of ion irradiation on internal residual stress in DLC films

    International Nuclear Information System (INIS)

    The dependence of internal residual stress in thin diamond-like carbon films grown on Si substrate by PECVD technique on most important growth parameters, namely RF-power, DC bias voltage and substrate temperature, is described. Results show that compressive stress reaches the highest value of 2.7 GPa at low RF-power and DC bias. Increase of substrate temperature from 250 to 350 oC leads to nonlinear increase of stress value. Inhomogeneity of residual stress along the film surface disappears when film is deposited at temperatures above 275 oC. Post-growth film irradiation by P+ and In+ ions cause decrease of compressive stress followed by its inversion to tensile. For all ion energy combinations used residual stress changes linearly with normalized fluence up to 0.2 DPA with slope (8.7 ± 1.3) GPa/DPA.

  14. Effect of weight fraction of carbon black and number of plies of E-glass fiber to reflection loss of E-glass/ripoxy composite for radar absorbing structure (RAS)

    Science.gov (United States)

    Widyastuti, Ramadhan, Rizal; Ardhyananta, Hosta; Zainuri, Mochamad

    2013-09-01

    Nowadays, studies on investigating radar absorbing structure (RAS) using fiber reinforced polymeric (FRP) composite materials are becoming popular research field because the electromagnetic properties of FRP composites can be tailored effectively by just adding some electromagnetic powders, such as carbon black, ferrite, carbonyl iron, and etc., to the matrix of composites. The RAS works not only as a load bearing structure to hold the antenna system, but also has the important function of absorbing the in-band electromagnetic wave coming from the electromagnetic energy of tracking systems. In this study, E-glass fiber reinforced ripoxy resin composite was fabricated by blending the conductive carbon black (Ketjenblack EC300J) with the binder matrix of the composite material and maximizing the coefficient of absorption more than 90% (more than -10 dB) within the X-band frequency (8 - 12 GHz). It was measured by electrical conductivity (LCR meter) and vector network analyzer (VNA). Finally, the composite RAS with 0.02 weight fraction of carbon black and 4 plies of E-glass fiber showed thickness of 2.1 mm, electrical conductivity of 8.33 × 10-6 S/m, and maximum reflection loss of -27.123 dB, which can absorb more than 90% of incident EM wave throughout the entire X-band frequency range, has been developed.

  15. Microstructural characterization and modeling of the hardening of irradiated austenitic steels from the internal structures of PWRs; Caracterisation microstructurale et modelisation du durcissement des aciers austenitiques irradies des structures internes des reacteurs a eau pressurisee

    Energy Technology Data Exchange (ETDEWEB)

    Pokor, C.; Dubuisson, P. [CEA Saclay, DMN/SRMA, 91 - Gif-sur-Yvette (France); Massoud, J.P. [Electricite de France (EDF/MMC), 78 - Saint Moret sur Loing (France); Brechet, Y. [Institut Polytechnique de Grenoble, Lab. de Thermodynamique et de Physico Chimie Metallurgiques, CNRS, 38 (France); Barbu, A. [Ecole Polytechnique, Lab. des Solides Irradies, CEA / CNRS, 91 - Palaiseau (France)

    2002-07-01

    The screws and bolts of the lower internal structures of PWRs made of 316L cold-drawn austenitic steels is submitted to a neutron flux at a temperature comprised between 280 deg. C and 380 deg. C, which modifies their operation properties. These modifications of the mechanical properties are the consequence of the modifications of the microstructure of this steel which depends on the flux, fluence, reactor spectrum and irradiation temperature. Samples of 316L cold-drawn steels irradiated in a mixed flux reactor (Osiris at 330 deg. C between 0.8 dpa and 3.4 dpa) and in fast breeder reactors (Bor-60 at 330 deg. C up to 40 dpa and EBR-II at 375 deg. C up to 10 dpa) have been observed in transmission electron microscopy. Irradiation defects are Frank dislocation loops and the presence of cavities has been evidenced in materials irradiated at 375 deg. C. The evolution of the irradiation loops population has been modeled using an 'accumulation dynamics'-type simulation. The adjustment of the parameters of the model has permitted to describe quantitatively the experimental results. This description of the irradiation microstructure has been coupled with a Frank loops hardening model which has permitted to describe the observed hardening. The range of explored doses goes up to 40 dpa and is representative of the irradiation dose corresponding to the half life of the reactors design. (J.S.)

  16. Effect of the lipid fraction of Listeria monocytogenes cells on the immune response of irradiated mice. Pt. 1. Effect of lipids administered prior to irradiation

    International Nuclear Information System (INIS)

    Stimulation of the immune mechanisms by Listeria monocytogenes lipides, given prior to irradiation, was tested for its effect on the rate of the immune response of mice to sheep erythrocytes given as the antigen. Cellular and humoral response was evaluated each time on the fourth day after immunization, which was performed 5, 15, and 30 days after exposure to X rays in doses of 250 or 500 R. The administration of lipids prior to irradiation was found to decrease in some measure the immuno-suppresive effect of X rays. The observed protective effect was greatly related to the lipid dose given, as well as to time interval between the lipid administration and irradiation. (author)

  17. Use of studies with laboratory animals to assess the potential early health effects of combined internal alpha and beta irradiation

    International Nuclear Information System (INIS)

    The potential health impacts of radionuclides released in nuclear accidents are of major concern to the public and to regulatory and other governmental agencies. One mode of potential exposure is by inhalation of airborne radionuclides, which could lead to combined internal irradiation by high (alpha) and low (beta) linear energy transfer (LET) radiations. Epidemiological data for health effects of human inhalation exposure are too limited to derive reliable estimates of risks of potential health effects. However, results of studies in which beagle dogs were exposed by inhalation to insoluble radioactive aerosols can be used to estimate expected effects in humans. Data for mortality from radiation pneumonitis and pulmonary fibrosis caused by internal irradiation of dog lungs by alpha or beta radiations are used to derive the relative biological effectiveness (RBE) of alpha irradiation compared to beta irradiation; predict the expected combined effects of alpha and beta irradiation of dog lungs; and extrapolate the results to humans. The extrapolation to humans assumed that, for similar ages at exposure, dog and human lungs have similar sensitivities to lung irradiation. Results of theoretical calculations related to mortality from early effects indicated that the synergistic effects of high- and low-LET radiations should depend on the percentages of the total dose contributed by high- and low-LET radiations, and for very low or very high doses, synergistic effects should be negligible. 23 refs., 8 figs

  18. 辐照包装箱吸收剂量的检测方法及剂量计的评价%METHODS TO VERIFY ABSORBED DOSE OF IRRADIATED ORANGE CONTAINERS AND EVALUATION OF DOSIMETERS

    Institute of Scientific and Technical Information of China (English)

    高美须; 王传耀; 唐掌雄; 李淑荣

    1998-01-01

    The research on dose distribution on irradiated food containers and evaluation of several methods to verify absorbed dose were carried out. The minimum absorbed dose of treated five orange containers was in the top of the highest or in the bottom of lowest container in a commercial 60Co facility.Dmax/Dmin in this study was 1.45 . The density of orange containers was 0.391g/cm3. The evaluation of dosimeters showed that the PMMA-YL and clear PMMA dosimeters have line relationship with dose response, and the word NOT in STERIN-125 and STERIN-300 indicators were covered completely at the dosage of 125 and 300 Gy, respectively.

  19. Fractionated irradiation and early changes in salivary glands. Different effects on potassium efflux, exocytotic amylase release and gland morphology

    International Nuclear Information System (INIS)

    Irradiation is a potent treatment modality of head and neck cancer. However, the irradiation is usually associated with an influence on salivary glands with ensuing dryness and discomfort for the patients. In the present study we used different in vitro secretory models and morphologic characterization of rat parotid gland. Radiation was given to one gland on a 5-day schedule with 6 MV photons (total dose 20, 30, 35, 40, 45 Gy). The contralateral gland served as control, and the analysis of glands were performed 10 days after the last irradiation treatment. The noradrenaline stimulated electrolyte secretion (86rubidium tracer for potassium) was decreased in relation to the irradiation dose and in comparison to contralateral control glands. Noradrenaline stimulated exocytotic amylase release was not affected by irradiation and, there were no signs of obvious quantitative morphologic alterations after irradiation compared with controls. The results suggest that there are differences in the sensitivity to radiation for the two different secretory processes in salivary glands, and, thus, the structures regulating electrolyte and fluid secretion seem to be more vulnerable to irradiation than the process of exocytosis. The results, however, do not allow discrimination between temporary cellular impairment and irreversible damage leading to cell death

  20. Ionizing radiation and autoimmunity: Induction of autoimmune disease in mice by high dose fractionated total lymphoid irradiation and its prevention by inoculating normal T cells

    International Nuclear Information System (INIS)

    Ionizing radiation can functionally alter the immune system and break self-tolerance. High dose (42.5 Gy), fractionated (2.5 Gy 17 times) total lymphoid irradiation (TLI) on mice caused various organ-specific autoimmune diseases, such as gastritis, thyroiditis, and orchitis, depending on the radiation dosages, the extent of lymphoid irradiation, and the genetic background of the mouse strains. Radiation-induced tissue damage is not the primary cause of the autoimmune disease because irradiation of the target organs alone failed to elicit the autoimmunity and shielding of the organs from irradiation was unable to prevent it. In contrast, irradiation of both the thymus and the peripheral lymphoid organs/tissues was required for efficient induction of autoimmune disease by TLI. TLI eliminated the majority of mature thymocytes and the peripheral T cells for 1 mo, and inoculation of spleen cell, thymocyte, or bone marrow cell suspensions (prepared from syngeneic nonirradiated mice) within 2 wk after TLI effectively prevented the autoimmune development. Depletion of T cells from the inocula abrogated the preventive activity. CD4+ T cells mediated the autoimmune prevention but CD8+ T cells did not. CD4+ T cells also appeared to mediate the TLI-induced autoimmune disease because CD4+ T cells from disease-bearing TLI mice adoptively transferred the autoimmune disease to syngeneic naive mice. Taken together, these results indicate that high dose, fractionated ionizing radiation on the lymphoid organs/tissues can cause autoimmune disease by affecting the T cell immune system, rather than the target self-Ags, presumably by altering T cell-dependent control of self-reactive T cells. 62 refs., 9 figs., 2 tabs

  1. Results from the CDE phase activity on neutron dosimetry for the international fusion materials irradiation facility test cell

    CERN Document Server

    Esposito, B; Maruccia, G; Petrizzi, L; Bignon, G; Blandin, C; Chauffriat, S; Lebrun, A; Recroix, H; Trapp, J P; Kaschuck, Y

    2000-01-01

    The international fusion materials irradiation facility (IFMIF) project deals with the study of an accelerator-based, deuterium-lithium source, producing high energy neutrons at sufficient intensity and irradiation volume to test samples of candidate materials for fusion energy reactors. IFMIF would also provide calibration and validation of data from fission reactor and other accelerator based irradiation tests. This paper describes the activity on neutron/gamma dosimetry (necessary for the characterization of the specimens' irradiation) performed in the frame of the IFMIF conceptual design evaluation (CDE) neutronics tasks. During the previous phase (conceptual design activity (CDA)) the multifoil activation method was proposed for the measurement of the neutron fluence and spectrum and a set of suitable foils was defined. The cross section variances and covariances of this set of foils have now been used for tests on the sensitivity of the IFMIF neutron spectrum determination to cross section uncertainties...

  2. Microstructural characterization and modeling of the hardening of irradiated austenitic steels from the internal structures of PWRs

    International Nuclear Information System (INIS)

    The screws and bolts of the lower internal structures of PWRs made of 316L cold-drawn austenitic steels is submitted to a neutron flux at a temperature comprised between 280 deg. C and 380 deg. C, which modifies their operation properties. These modifications of the mechanical properties are the consequence of the modifications of the microstructure of this steel which depends on the flux, fluence, reactor spectrum and irradiation temperature. Samples of 316L cold-drawn steels irradiated in a mixed flux reactor (Osiris at 330 deg. C between 0.8 dpa and 3.4 dpa) and in fast breeder reactors (Bor-60 at 330 deg. C up to 40 dpa and EBR-II at 375 deg. C up to 10 dpa) have been observed in transmission electron microscopy. Irradiation defects are Frank dislocation loops and the presence of cavities has been evidenced in materials irradiated at 375 deg. C. The evolution of the irradiation loops population has been modeled using an 'accumulation dynamics'-type simulation. The adjustment of the parameters of the model has permitted to describe quantitatively the experimental results. This description of the irradiation microstructure has been coupled with a Frank loops hardening model which has permitted to describe the observed hardening. The range of explored doses goes up to 40 dpa and is representative of the irradiation dose corresponding to the half life of the reactors design. (J.S.)

  3. Recovery capacity of glial progenitors after in vivo fission-neutron or X irradiation: age dependence, fractionation and low-dose-rate irradiations.

    NARCIS (Netherlands)

    Philippo, H.; Winter, E.A.M.; Kogel, A.J. van der; Huiskamp, R.

    2005-01-01

    Previous experiments on the radiosensitivity of O-2A glial progenitors determined for single-dose fission-neutron and X irradiation showed log-linear survival curves, suggesting a lack of accumulation of recovery of sublethal damage. In the present study, we addressed this question and further chara

  4. A study on the constitutive model of irradiated austenitic stainless steel for the functionality analysis of nuclear internals

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Il Sup [Yeungnam University, Gyeongsan (Korea, Republic of)

    2016-04-15

    The internal components of nuclear reactor are exposed to the neutron irradiation environment. The constituent materials of the components are susceptible to remarkable changes in the mechanical properties such as elastic modulus, strength, ductility and toughness. The mechanical and thermal deformations are accompanied with the void swelling and the irradiation creep in the environment. The functionality analysis which evaluates the structural integrity of the aged internals needs to take the degradation characteristics of the material into account. In this paper, a constitutive model of austenitic stainless steel developed by EPRI is studied and implemented into numerical analysis vehicles. The mechanical properties of irradiated 304 stainless steel are presented and the deformation behaviors are simulated. The criteria and methodology for the functionality analysis are also discussed and illustrated.

  5. Effects of chronic internal alpha irradiation on physiology, growth and reproductive success of Daphnia magna

    International Nuclear Information System (INIS)

    Daphnids were chronically exposed to waterborne Am-241, an alpha-emitting radionuclide, ranging in concentration from 0.4 to 40 Bq ml-1. Am-241 amounts were monitored in the medium, daphnid tissues and cuticles. Corresponding average dose rates of 0.02, 0.11 and 0.99 mGy h-1 were calculated for whole organisms with internal α-radiation contributing 99% of total dose rates. Effects of internal alpha irradiation on respiration and ingestion rates, adult, egg and neonate individual dry masses, fecundity and larval resistance to starvation were examined in 23-day experiments. Daphnids showed increased respiratory demand after 23 days at the highest dose rate, suggesting increased metabolic cost of maintenance due to coping with alpha radiological stress. Although no effect was detected on ingestion rates between contaminated and control daphnids, exposure to dose rates of 0.11 mGy h-1 or higher, resulted in a significant 15% reduction in body mass. Fecundity remained unchanged over the 23-day period, but individual masses of eggs and neonates were significantly smaller compared to the control. This suggested that increased metabolic expenditure in chronically alpha-radiated daphnids came at the expense of their energy investment per offspring. As a consequence, neonates showed significantly reduced resistance to starvation at every dose rate compared to the control. Our observations are discussed in comparison with literature results reported for cadmium, a chemical toxicant which affects feeding activity and strongly reduces individual energy uptake

  6. Radiation cross-linked carboxymethyl sago pulp hydrogels loaded with ciprofloxacin: Influence of irradiation on gel fraction, entrapped drug and in vitro release

    International Nuclear Information System (INIS)

    Carboxymethyl sago pulp (CMSP) with 0.4 DS, viscosity 184 dl/g and molecular weight 76,000 g/mol was synthesized from sago waste. 10 and 20% w/v solutions of CMSP were irradiated at 10–30 kGy to form hydrogels and were characterized by % gel fraction (GF). Irradiation of 20% CMSP using 25 kGy has produced stable hydrogels with the highest % GF and hence loaded with ciprofloxacin HCl. Drug-loaded hydrogels were produced by irradiating the mixture of drug and 20% CMSP solution at 25 kGy. After irradiation, the hydrogels were cut into circular discs with a diameter of 6±1 mm and evaluated for physicochemical properties as well as drug release kinetics. The ciprofloxacin loading in the disc was 14.7%±1 w/w with an entrapment efficiency of 73.5% w/w. The low standard deviation of drug-loaded discs indicated uniform thickness (1.5±0.3 mm). The unloaded discs were thinner (1±0.4 mm) and more brittle than the drug-loaded discs. FESEM, FT-IR, XRD, DSC and TGA analysis revealed the absence of polymer–drug interaction and transformation of crystalline to amorphous form of ciprofloxacin in the discs. The disc sustained the drug release in phosphate buffer pH 7.4 over 36 h in a first-order manner. The mechanism of the drug release was found to be swelling controlled diffusion and matrix erosion. The anti-bacterial effect of ciprofloxacin was retained after irradiation and CMSP disc could be a promising device for ocular drug delivery. - Highlights: • Carboxymethyl sago pulp (CMSP) with ciprofloxacin is irradiated to form hydrogels. • 20% CMSP at 25 kGy has produced stable hydrogels with the highest gel fraction. • Crystalline ciprofloxacin converted as amorphous during hydrogel formation. • Hydrogel in disc form sustained the drug release drug up to 36 h. • Irradiation cross-linked polymeric chain of CMSP resulted in controlled swelling

  7. Proceedings of the international workshop on irradiated fuel storage: operating experience and development programs

    International Nuclear Information System (INIS)

    Irradiated fuel storage was discussed under the following major topic headings: irradiated fuel management strategies, water pool storage, dry storage technology and engineering studies, dry storage economics, standards and licensing, dry storage - fuel behaviour, and dry storage - the future

  8. Autologous stem cell transplantation following high-dose whole-body irradiation of dogs - influence of cell number and fractionation regimes

    International Nuclear Information System (INIS)

    The acute radiation syndrome after a single dose of 1600 R (approx. 12-14 Gy in body midline) and after fractionated irradiation with 2400 R (approx. 18-20 Gy) was studied with regard to fractionation time and to the number of bone marrow cells infused. The acute radiation syndrome consisted of damage to the alimentary tract and of damage to the hemopoietic system. Damage of hemopoiesis was reversible in dogs which had been given a sufficient amount of hemopoietic cells. Furthermore changes in skin and in the mucous membranes occurred. Hemopoietic recovery following infusion of various amounts of bone marrow was investigated in dogs which were irradiated with 2400 R within 7 days. Repopulation of bone marrow as well as rise of leukocyte and platelet counts in the peripheral blood was taken as evidence of complete hemopoietic reconstitution. The results indicate that the acute radiation syndrom following 2400 R TBI and autologous BMT can be controlled by fractionation of this dose within 5 or 7 days. The acute gastrointestinal syndrome is aggravated by infusion of a lesser amount of hemopoietic cells. However, TBI with 2400 R does not require greater numbers of hemopoietic cells for restoration of hemopoiesis. Thus, the hemopoiesis supporting tissue can not be damage by this radiation dose to an essential degree. Longterm observations have not revealed serious late defects which could represent a contraindication to the treatment of malignent diseases with 2400 R of TBI. (orig./MG)

  9. Suitability and feasibility of the International Fusion Materials Irradiation Facility (IFMIF) for fusion materials studies

    International Nuclear Information System (INIS)

    There is a global consensus among materials scientists and engineers that the qualification of materials in an appropriate test environment is inevitable for design, construction and safe operation of DEMOnstration fusion reactors as well as for calibration of data generated from fission reactor and accelerators irradiations. In an evaluation process based on a series of technical workshops it was concluded that an accelerator driven D-Li stripping source would be the best choice to fulfill the requirements within a realistic time frame. In response to this need, an international design team with members from Europe, Japan, USA and Russia has developed under the auspices of the IEA during a Conceptual Design Activity Phase (1994-96) a suitable and feasible concept for an accelerator driven D-Li stripping source. This IFMIF reference design is based on conservative linac technology and two parallel operating 125-mA, 40-MeV deuteron beams that are focused onto a common liquid lithium target with a beam footprint of 50 mm by 200 mm. The materials testing volume downstream the Li-target is subdivided into different flux regions: The high flux test region (0.5 liter, 20-55 dpa/full power year), the medium flux test region (6 liter, 1-20 dpa/fpy), and low flux test regions (> 100 liter, < 1 dpa/fpy). The developed design was the basis fore the present Conceptual Design Evaluation Phase (1997-98) and for subsequent engineering oriented activities. Based on comprehensive neutron transport calculations, an evaluation of the irradiation parameters and the available test volumes has shown that the users requirements can be fulfilled. Major engineering efforts have been undertaken to establish an IFMIF design that is based on available and already proven technologies. The developed design includes extensive reliability, availability, maintainability as well as safety studies and is conceived for long-term operation with a total annual facility availability of at least 70

  10. Suitability and feasibility of the international fusion materials irradiation facility (IFMIF) for fusion materials studies

    International Nuclear Information System (INIS)

    There is a global consensus among materials scientists and engineers that the qualification of materials in an appropriate test environment is inevitable for design, construction and safe operation of DEMOnstration fusion reactors as well as for calibration of data generated from fission reactor and accelerators irradiations. In an evaluation process based on a series of technical workshops it was concluded that an accelerator driven D-Li stripping source would be the best choice to fulfill the requirements within a realistic time frame. In response to this need, an international design team with members from Europe, Japan, USA and Russia has developed under the auspices of the IEA during a Conceptual Design Activity Phase (1994-96) a suitable and feasible concept for an accelerator driven D-Li stripping source. This IFMIF reference design is based on conservative linac technology and two parallel operating 125-mA, 40-MeV deuteron beams that are focused onto a common liquid lithium target with a beam footprint of 50 mm by 200 mm. The materials testing volume downstream the Li-target is subdivided into different flux regions: The high flux test region (0.5 liter, 20-55 dpa/full power year), the medium flux test region (6 liter, 1-20 dpa/fpy), and low flux test regions (>100 liter, < 1 dpa/fpy). The developed design was the basis fore the present Conceptual Design Evaluation Phase (1997-98) and for subsequent engineering oriented activities. Based on comprehensive neutron transport calculations, an evaluation of the irradiation parameters and the available test volumes has shown that the users requirements can be fulfilled. Major engineering efforts have been undertaken to establish an IFMIF design that is based on available and already proven technologies. The developed design includes extensive reliability, availability, maintainability as well as safety studies and is conceived for long-term operation with a total annual facility availability of at least 70

  11. Biological studies of the effect of a venom fraction isolated from the scorpion,androctonus amoreuxi on irradiated rats

    International Nuclear Information System (INIS)

    scorpion venom of androctonus amoreuxi contains a strong bradykinin potentiating factor (BPF) that augments bradykinin effect through enhancing its release . cytoprotective ability of BPF has been documented. the possible carcinogenicity that can be induced by BPF isolated from the scorpion, androctonus amoreuxi venom was evaluated in the presence of isologous bone marrow transplantation (BMT) and/or radiation protection. the examined parameters included serum alpha feto protein, carcino embryonic antigen, B2-microglobulin, total cholesterol, triglycerides, total and direct bilirubin levels besides histopathological examination of the liver, kidney and testis.a group of rats (70 gm) received isologous BMT (75x106 cells ) was performed 3 hours post irradiation , while the other group received i.p. injection of 8 doses of BPF each of 1μg /gm body wt (one dose /week). irradiation was performed at a dose level of 5 Gy. all animals were examined after an investigation period of 60 days. either biological agents or their combination was performed together with irradiation , the results pointed out that irradiation discerned a significant elevation in the level of each of B2-microglobulin (p≤0.05), cholesterol, triglycerides and bilirubin after a period of 60 days. neither BPF repeated injection nor BMT solely or combined induced any carcinogenicity after irradiation application as indicated by the examined tumor markers which was confirmed by histological examination

  12. Sound Absorbers

    Science.gov (United States)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  13. Relationship between chromosomal aberration of bone marrow cells and dosage of irradiation after 46Sc internal pollution and external low dose X-irradiation in mice

    International Nuclear Information System (INIS)

    The relationship between chromosomal aberration of bone marrow cells and dosage in mice 24 h after 46Sc internal pollution combined with external low dose whole body X-irradiation was quantiatively studied. The results showed that the relationship between chromosomal aberration and dosage was expressed in a linear regression equation. The chromosomal aberration rate was lower in the combined exposure than that of the sum of internal and external exposures, but higher than that of either the internal or external exposure singly. The relationship between chromosomal aberration and time was expressed in the following three phase exponential function: Y(t) = 2.9078 exp0.27668t + 2.9371 exp-0.0778t + 2.3786-0.01788t. By means of fit test, there was no significant difference between the determined and the theoretical values. The 90% theoretical values got from all the equations distributed over the determined values

  14. Absorbed Dose Distributions in Small Copper Wire Insulation due to Multiple-Sided Irradiations by 0.4 MeV Electrons

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.; Pedersen, Walther Batsberg;

    1979-01-01

    When scanned electron beams are used to crosslink polymeric insulation of wire and cable, an important goal is to achieve optimum uniformity of absorbed dose distributions. Accurate measurements of dose distributions in a plastic dosimeter simulating a typical insulating material (polyethylene) s...

  15. Irradiated stainless steel material constitutive model for use in the performance evaluation of PWR pressure vessel internals

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, J.Y.; Dunham, R.S. [ANATECH (United States); Demma, A. [Electric Power Research Institute - EPRI (United States)

    2011-07-01

    Demonstration of component functionality requires analytical simulations of reactor internals behavior. Towards that aim, EPRI has undertaken the development of irradiated material constitutive model and damage criteria for use in global and local finite-element based functionality analysis methodology. The constitutive behavioral regimes of irradiated stainless steel types 316 and 304 materials included in the model consist of: elastic-plastic material response considering irradiation hardening of the stress-strain curve, irradiation creep, stress relaxation, and void swelling. IASCC and degradation of ductility with irradiation are the primary damage mechanisms considered in the model. The material behavior model development consists of two parts: the first part is a user-material subroutine that can interface with a general-purpose finite element computer program to adapt it to the special-purpose of functionality analysis of reactor internals. The second part is a user utility in the form of Excel Spread sheets that permit users to extract a given property, e.g. the elastic-plastic stress-strain curve, creep curve, or void-swelling curve, as function of the relevant independent variables. The development of the model takes full advantage of the significant work that has been undertaken within EPRI's Material Reliability Program (MRP) to improve the knowledge of the material properties of irradiated stainless steels. Data from EPRI's MRP database have been utilized to develop equations that characterize the yield strength, ultimate tensile strength, uniform elongation, total elongation, reduction in area, void swelling and irradiation creep of stainless steels in a PWR environment. It is noted that, while the development of the model's equations has been statistically faithful to the material database, approximations were introduced in the model to ensure appropriate conservatism in the model's application consistently with accepted

  16. Ten-Year Survival Results of a Randomized Trial of Irradiation of Internal Mammary Nodes After Mastectomy

    Energy Technology Data Exchange (ETDEWEB)

    Hennequin, Christophe, E-mail: christophe.hennequin@sls.aphp.fr [Hôpital Saint-Louis, AP-HP et Université de Paris VII (France); Bossard, Nadine [Hospices Civils de Lyon, Service de Biostatistique, Université Lyon 1, Lyon, and CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biotatistique-Santé, Villeurbanne (France); Servagi-Vernat, Stéphanie [Centre hospitalier Universitaire de Besançon (France); Maingon, Philippe [Centre François Leclerc, Dijon (France); Dubois, Jean-Bernard [Centre Val d' Aurelle, Montpellier (France); Datchary, Jean [Centre Hospitalier d' Annecy (France); Carrie, Christian [Centre Léon Bérard, Lyon (France); Roullet, Bernard [Centre Hospitalier Universitaire de Limoges (France); Suchaud, Jean-Philippe [Centre Hospitalier de Roanne (France); Teissier, Eric [Centre de Radiothérapie de Mougins (France); Lucardi, Audrey [Hospices Civils de Lyon (France); Gerard, Jean-Pierre [Centre Antoine Lacassagne, Nice (France); Belot, Aurélien [Hospices Civils de Lyon, Service de Biostatistique, Université Lyon 1, Lyon, and CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biotatistique-Santé, Villeurbanne (France); Institut de Veille Sanitaire, Département des Maladies Chroniques et des Traumatismes, Saint-Maurice (France); and others

    2013-08-01

    Purpose: To evaluate the efficacy of irradiation of internal mammary nodes (IMN) on 10-year overall survival in breast cancer patients after mastectomy. Methods and Patients: This multicenter phase 3 study enrolled patients with positive axillary nodes (pN+) or central/medial tumors with or without pN+. Other inclusion criteria were age <75 and a Karnofsky index ≥70. All patients received postoperative irradiation of the chest wall and supraclavicular nodes and were randomly assigned to receive IMN irradiation or not. Randomization was stratified by tumor location (medial/central or lateral), axillary lymph node status, and adjuvant therapy (chemotherapy vs no chemotherapy). The prescribed dose of irradiation to the target volumes was 50 Gy or equivalent. The first 5 intercostal spaces were included in the IMN target volume, and two-thirds of the dose (31.5 Gy) was given by electrons. The primary outcome was overall survival at 10 years. Disease-free survival and toxicity were secondary outcomes. Results: T total of 1334 patients were analyzed after a median follow-up of 11.3 years among the survivors. No benefit of IMN irradiation on the overall survival could be demonstrated: the 10-year overall survival was 59.3% in the IMN-nonirradiated group versus 62.6% in the IMN-irradiated group (P=.8). According to stratification factors, we defined 6 subgroups (medial/central or lateral tumor, pN0 [only for medial/central] or pN+, and chemotherapy or not). In all these subgroups, IMN irradiation did not significantly improve overall survival. Conclusions: In patients treated with 2-dimensional techniques, we failed to demonstrate a survival benefit for IMN irradiation. This study cannot rule out a moderate benefit, especially with more modern, conformal techniques applied to a higher risk population.

  17. Compatibility of the Linear-Quadratic Formalism and Biologically Effective Dose Concept to High-Dose-Per-Fraction Irradiation in a Murine Tumor

    International Nuclear Information System (INIS)

    Purpose: To evaluate the compliance of linear-quadratic (LQ) model calculations in the high-dose range as used in stereotactic irradiation in a murine tumor model. Methods and Materials: Female 10-week-old Balb/c mice bearing 1-cm-diameter EMT6 tumors in the hind legs were used. Single doses of 10–25 Gy were compared with 2–5 fractions of 4–13 Gy given at 4-hour intervals. Cell survival after irradiation was determined by an in vivo–in vitro assay. Using an α/β ratio determined for in vitro EMT6 cells and the LQ formalism, equivalent single doses for the hypofractionated doses were calculated. They were then compared with actually measured equivalent single doses for the hypofractionated doses. These fractionation schedules were also compared simultaneously to investigate the concordance/divergence of dose–survival curves plotted against actual radiation doses and biologically effective doses (BED). Results: Equivalent single doses for hypofractionated doses calculated from LQ formalism were lower than actually measured doses by 21%–31% in the 2- or 3-fraction experiments and by 27%–42% in the 4- or 5-fraction experiments. The differences were all significant. When a higher α/β ratio was assumed, the discrepancy became smaller. In direct comparison of the 2- to 5-fraction schedules, respective dose–response curves almost overlapped when cell survival was plotted against actual radiation doses. However, the curves tended to shift downward by increasing the fraction number when cell survival was plotted against BED calculated using an α/β ratio of 3.5 Gy for in vitro EMT6 cells. Conclusion: Conversion of hypofractionated radiation doses to single doses using the LQ formalism underestimated the in vivo effect of hypofractionated radiation by approximately 20%–40%. The discrepancy appeared to be larger than that seen in the previous in vitro study and tended to increase with the fraction number. BED appeared to be an unreliable measure of tumor

  18. Can a Satellite-Derived Estimate of the Fraction of PAR Absorbed by Chlorophyll (FAPAR(sub chl)) Improve Predictions of Light-Use Efficiency and Ecosystem Photosynthesis for a Boreal Aspen Forest?

    Science.gov (United States)

    Zhang, Qingyuan; Middleton, Elizabeth M.; Margolis, Hank A.; Drolet, Guillaume G.; Barr, Alan A.; Black, T. Andrew

    2009-01-01

    Gross primary production (GPP) is a key terrestrial ecophysiological process that links atmospheric composition and vegetation processes. Study of GPP is important to global carbon cycles and global warming. One of the most important of these processes, plant photosynthesis, requires solar radiation in the 0.4-0.7 micron range (also known as photosynthetically active radiation or PAR), water, carbon dioxide (CO2), and nutrients. A vegetation canopy is composed primarily of photosynthetically active vegetation (PAV) and non-photosynthetic vegetation (NPV; e.g., senescent foliage, branches and stems). A green leaf is composed of chlorophyll and various proportions of nonphotosynthetic components (e.g., other pigments in the leaf, primary/secondary/tertiary veins, and cell walls). The fraction of PAR absorbed by whole vegetation canopy (FAPAR(sub canopy)) has been widely used in satellite-based Production Efficiency Models to estimate GPP (as a product of FAPAR(sub canopy)x PAR x LUE(sub canopy), where LUE(sub canopy) is light use efficiency at canopy level). However, only the PAR absorbed by chlorophyll (a product of FAPAR(sub chl) x PAR) is used for photosynthesis. Therefore, remote sensing driven biogeochemical models that use FAPAR(sub chl) in estimating GPP (as a product of FAPAR(sub chl x PAR x LUE(sub chl) are more likely to be consistent with plant photosynthesis processes.

  19. Segmented Ge detector rejection of internal beta activity produced by neutron irradiation

    Science.gov (United States)

    Varnell, L. S.; Callas, J. L.; Mahoney, W. A.; Pehl, R. H.; Landis, D. A.

    1991-01-01

    Future Ge spectrometers flown in space to observe cosmic gamma-ray sources will incorporate segmented detectors to reduce the background from radioactivity produced by energetic particle reactions. To demonstrate the effectiveness of a segmented Ge detector in rejecting background events due to the beta decay of internal radioactivity, a laboratory experiment has been carried out in which radioactivity was produced in the detector by neutron irradiation. A Cf-252 source of neutrons was used to produce, by neutron capture on Ge-74 (36.5 percent of natural Ge) in the detector itself, Ge-75 (t sub 1/2 = 82.78 min), which decays by beta emission with a maximum electron kinetic energy of 1188 keV. By requiring that an ionizing event deposit energy in two or more of the five segments of the detector, each about 1-cm thick, the beta particles, which have a range of about 1-mm, are rejected, while most external gamma rays incident on the detector are counted. Analysis of this experiment indicates that over 85 percent of the beta events from the decay of Ge-75 are rejected, which is in good agreement with Monte Carlo calculations.

  20. IFMIF (International Fusion Materials Irradiation Facility) conceptual design activity reduced cost report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    This report describes the results of a preliminary reevaluation of the design and cost of the International Fusion Materials Irradiation Facility (IFMIF) Project in response to the request from the 28th FPCC meeting in January 1999. Two major ideas have been considered: 1) reduction of the total construction cost through elimination of the previously planned facility upgrade and 2) a facility deployment in 3 stages with capabilities for limited experiments in the first stage. As a result, the size and complexity of the facility could be significantly reduced, leading to substantial cost savings. In addition to these two ideas, this study also included a critical review of the original CDA specification with the objective of elimination of nonessential items. For example, the number of lithium targets was reduced from two to one. As a result of these changes in addition to the elimination of the upgrade, the total cost estimate was very substantially reduced from 797.2 MICF to 487.8 MICF, where 1 MICF = 1 Million of the IFMIF Conversion Units (approximately $1M US January, 1996). (author)

  1. IFMIF, International Fusion Materials Irradiation Facility conceptual design activity cost report

    International Nuclear Information System (INIS)

    This report documents the cost estimate for the International Fusion Materials Irradiation Facility (IFMIF) at the completion of the Conceptual Design Activity (CDA). The estimate corresponds to the design documented in the Final IFMIF CDA Report. In order to effectively involve all the collaborating parties in the development of the estimate, a preparatory meeting was held at Oak Ridge National Laboratory in March 1996 to jointly establish guidelines to insure that the estimate was uniformly prepared while still permitting each country to use customary costing techniques. These guidelines are described in Section 4. A preliminary cost estimate was issued in July 1996 based on the results of the Second Design Integration Meeting, May 20--27, 1996 at JAERI, Tokai, Japan. This document served as the basis for the final costing and review efforts culminating in a final review during the Third IFMIF Design Integration Meeting, October 14--25, 1996, ENEA, Frascati, Italy. The present estimate is a baseline cost estimate which does not apply to a specific site. A revised cost estimate will be prepared following the assignment of both the site and all the facility responsibilities

  2. IFMIF, International Fusion Materials Irradiation Facility conceptual design activity cost report

    Energy Technology Data Exchange (ETDEWEB)

    Rennich, M.J. [comp.

    1996-12-01

    This report documents the cost estimate for the International Fusion Materials Irradiation Facility (IFMIF) at the completion of the Conceptual Design Activity (CDA). The estimate corresponds to the design documented in the Final IFMIF CDA Report. In order to effectively involve all the collaborating parties in the development of the estimate, a preparatory meeting was held at Oak Ridge National Laboratory in March 1996 to jointly establish guidelines to insure that the estimate was uniformly prepared while still permitting each country to use customary costing techniques. These guidelines are described in Section 4. A preliminary cost estimate was issued in July 1996 based on the results of the Second Design Integration Meeting, May 20--27, 1996 at JAERI, Tokai, Japan. This document served as the basis for the final costing and review efforts culminating in a final review during the Third IFMIF Design Integration Meeting, October 14--25, 1996, ENEA, Frascati, Italy. The present estimate is a baseline cost estimate which does not apply to a specific site. A revised cost estimate will be prepared following the assignment of both the site and all the facility responsibilities.

  3. Characterization of Complex Fractionated Atrial Electrograms by Sample Entropy: An International Multi-Center Study

    Directory of Open Access Journals (Sweden)

    Eva Cirugeda–Roldán

    2015-10-01

    Full Text Available Atrial fibrillation (AF is the most commonly clinically-encountered arrhythmia. Catheter ablation of AF is mainly based on trigger elimination and modification of the AF substrate. Substrate mapping ablation of complex fractionated atrial electrograms (CFAEs has emerged to be a promising technique. To improve substrate mapping based on CFAE analysis, automatic detection algorithms need to be developed in order to simplify and accelerate the ablation procedures. According to the latest studies, the level of fractionation has been shown to be promisingly well estimated from CFAE measured during radio frequency (RF ablation of AF. The nature of CFAE is generally nonlinear and nonstationary, so the use of complexity measures is considered to be the appropriate technique for the analysis of AF records. This work proposes the use of sample entropy (SampEn, not only as a way to discern between non-fractionated and fractionated atrial electrograms (A-EGM, Entropy 2015, 17 7494 but also as a tool for characterizing the degree of A-EGM regularity, which is linked to changes in the AF substrate and to heart tissue damage. The use of SampEn combined with a blind parameter estimation optimization process enables the classification between CFAE and non-CFAE with statistical significance (p < 0:001, 0.89 area under the ROC, 86% specificity and 77% sensitivity over a mixed database of A-EGM combined from two independent CFAE signal databases, recorded during RF ablation of AF in two EU countries (542 signals in total. On the basis of the results obtained in this study, it can be suggested that the use of SampEn is suitable for real-time support during navigation of RF ablation of AF, as only 1.5 seconds of signal segments need to be analyzed.

  4. Large-fraction preoperative irradiation in combination with organ-sparing surgery for first- or second-stage breast cancer

    International Nuclear Information System (INIS)

    A method of combined organ-sparing treatment for first-or second-stage breast cancer has been developed. It includes large-fraction preoperative radiation (28.5 Gy in 5 daily fractions) and segmental mastectomy with axillary lymphadenectomy. The method has been used in 25 patients. Mean follow-up time is 23 months. No local or regional relapses have been recorded. Total relapse-free survival is 92%. The cosmetic and functional effect is satisfactory

  5. Effect of chronic fractionated low-dose gamma irradiation on division potential of human embryonic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami; Suzuki, Masao; Suzuki, Keiji; Watanabe, Kimiko (Yokohama City Univ. (Japan). Faculty of Medicine); Nakano, Kazushiro

    1991-12-01

    We investigated the in vitro phenotypic transformation of human embryo (HE) cells that were repeatedly irradiated (7.5 cGy once a week) throughout their life-span. Irradiation was repeated until the cells had accumulated 195 cGy (equivalent to the 26th passage). Samples of cells were assayed for survival by colony formation, as well as for mutation at the hypoxanthine guanine phosphoribosyl transferase (HGPRT) locus and for transformation by focus formation. The life-span (mean number of population doublings) of multiply irradiated cells with a total dose of 97.5 cGy was slightly but significantly prolonged over that of controls. After HE cells had accumulated 195 cGy, the maximum number of divisions increased to 130-160% of the number in non-irradiated control cells. Transformed foci were not observed until cells had accumulated 97.5 cGy, and then increased with the increasing accumulation of radiation. However, no cells showed immortality or expressed a malignant phenotype in vitro. (author).

  6. High Levels of Dietary Supplement Vitamins A, C and E are Absorbed in the Small Intestine and Protect Nutrient Transport Against Chronic Gamma Irradiation.

    Science.gov (United States)

    Roche, Marjolaine; Neti, Prasad V S V; Kemp, Francis W; Azzam, Edouard I; Ferraris, Ronaldo P; Howell, Roger W

    2015-11-01

    We examined nutrient transport in the intestines of mice exposed to chronic low-LET 137Cs gamma rays. The mice were whole-body irradiated for 3 days at dose rates of 0, 0.13 and 0.20 Gy/h, for total dose delivery of 0, 9.6 or 14.4 Gy, respectively. The mice were fed either a control diet or a diet supplemented with high levels of vitamins A, C and E. Our results showed that nutrient transport was perturbed by the chronic irradiation conditions. However, no apparent alteration of the macroscopic intestinal structures of the small intestine were observed up to day 10 after initiating irradiation. Jejunal fructose uptake measured in vitro was strongly affected by the chronic irradiation, whereas uptake of proline, carnosine and the bile acid taurocholate in the ileum was less affected. D-glucose transport did not appear to be inhibited significantly by either 9.6 or 14.4 Gy exposure. In the 14.4 Gy irradiated groups, the diet supplemented with high levels of vitamins A, C and E increased intestinal transport of fructose compared to the control diet (day 10; t test, P = 0.032), which correlated with elevated levels of vitamins A, C and E in the plasma and jejunal enterocytes. Our earlier studies with mice exposed acutely to 137Cs gamma rays demonstrated significant protection for transport of fructose, glucose, proline and carnosine. Taken together, these results suggest that high levels of vitamins A, C and E dietary supplements help preserve intestinal nutrient transport when intestines are irradiated chronically or acutely with low-LET gamma rays. PMID:26484399

  7. High Levels of Dietary Supplement Vitamins A, C and E are Absorbed in the Small Intestine and Protect Nutrient Transport Against Chronic Gamma Irradiation.

    Science.gov (United States)

    Roche, Marjolaine; Neti, Prasad V S V; Kemp, Francis W; Azzam, Edouard I; Ferraris, Ronaldo P; Howell, Roger W

    2015-11-01

    We examined nutrient transport in the intestines of mice exposed to chronic low-LET 137Cs gamma rays. The mice were whole-body irradiated for 3 days at dose rates of 0, 0.13 and 0.20 Gy/h, for total dose delivery of 0, 9.6 or 14.4 Gy, respectively. The mice were fed either a control diet or a diet supplemented with high levels of vitamins A, C and E. Our results showed that nutrient transport was perturbed by the chronic irradiation conditions. However, no apparent alteration of the macroscopic intestinal structures of the small intestine were observed up to day 10 after initiating irradiation. Jejunal fructose uptake measured in vitro was strongly affected by the chronic irradiation, whereas uptake of proline, carnosine and the bile acid taurocholate in the ileum was less affected. D-glucose transport did not appear to be inhibited significantly by either 9.6 or 14.4 Gy exposure. In the 14.4 Gy irradiated groups, the diet supplemented with high levels of vitamins A, C and E increased intestinal transport of fructose compared to the control diet (day 10; t test, P = 0.032), which correlated with elevated levels of vitamins A, C and E in the plasma and jejunal enterocytes. Our earlier studies with mice exposed acutely to 137Cs gamma rays demonstrated significant protection for transport of fructose, glucose, proline and carnosine. Taken together, these results suggest that high levels of vitamins A, C and E dietary supplements help preserve intestinal nutrient transport when intestines are irradiated chronically or acutely with low-LET gamma rays.

  8. QUANTITATIVE DETECTION OF ABSORBED DOSE OF IRRADIATED DRIED FRUIT BY ESR SPECTROSCOPY METHOD%ESR法定量检测干果类辐照食品

    Institute of Scientific and Technical Information of China (English)

    李伟明; 哈益明; 赵永富; 张彦立

    2011-01-01

    以葵花籽、核桃、开心果和榛子为试验材料,研究在0、1.0、3.0、5.0和10.0kGy剂量范围内4种样品辐照剂量与信号强度的关系以及相关性.结果表明:4种样品在辐照前后ESR波谱有明显区别,其信号强度与辐照剂量均呈正相关.辐照后样品的ESR强度和谱形都发生变化,应用ESR法能够鉴定4种食品是否经过辐照.其中核桃和开心果的ESR谱线中心信号左右两侧出现的2个对称小峰证明了纤维素自由基的存在.研究得出核桃的最低检出剂量接近1kGy,其余3种样品的检出剂量更低.本研究证明,应用ESR法能够定量检测干果类食品的吸收剂量.%Sunflower seeds, walnuts, pistachios, and hazelnuts were used as experimental materials which were irradiated at 1.0, 3.0, 5.0 and 10. 0kGy, respectively. The relationships and correlations between ESR signal intensity and irradiation dosages were studied. The results showed that ESR spectra of irradiated samples were obviously different from that of CK, and the ESR signal intensity was positively related with the irradiation dose. After irradiation, the ESR intensity and spectrum shapes all changed, and all four samples were clearly identified irradiated or unirradiated. The appearances of the two weak satellite lines which situated left and right to the intense singlet line in walnuts and pistachios proved the existence of cellulose radical. The detection dose limit of irradiated walnut was 1 kGy, and the detection limits of the other three samples were lower than 1 kGy. In conclusion, the ESR method could be used to irradiated.

  9. Liquid metal reactor absorber technology

    International Nuclear Information System (INIS)

    This paper reports that the selection of boron carbide as the reference liquid metal reactor absorber material is supported by results presented for irradiation performance, reactivity worth, compatibility, and benign failure consequences. Scram response requirements are met easily with current control rod configurations. The trend in absorber design development is toward larger sized pins with fewer pins per bundle, providing economic savings and improved hydraulic characteristics. Very long-life absorber designs appear to be attainable with the application of vented pin and sodium-bonded concepts

  10. Synthesis of poly (acrylamide-co-metacrylic acid) hydrogels By means of gamma irradiation techniques: influence of Absorbed dose on the swelling process

    International Nuclear Information System (INIS)

    In this report gamma radiation techniques were performed a double function of proceeding the processes of polymerization and crosslinking with the advantage of avoid the uses of chemicals crosslinks. The influence of absorbed dose on the swelling ratio as a function of pH have been presented. For these hydrogels, swelling studies indicated that swelling decrease with the increase of the absorbed dose from 10 to 50 kGy. It was confirmed that at the firsts stages (100-150 min) the diffusion studies were in accordance with Fickian behavior and the diffusion coefficients were obtained, whereas the latest stages were in good agreement with second-order diffusion kinetics proposed by Schott 1 .These news hydrogels exhibit a higher degree of swelling, a factor that, a priori, assures high biocompatibility because it increases the similarity with living tissues

  11. Dosimetry of total body irradiation

    International Nuclear Information System (INIS)

    In the treatment of disseminated malignancies an improvement in the curability and reduction of complication rates require high precision total body irradiation (TBI) and correct reporting of relevant treatment parameters. Optimal TBI dosimetry is the basis. Radiooncological and radiobiological requirements as well as the special physical situation have to be considered. To review the efforts of medical physicists, highlights from TBI workshops and publications are summarized. Additionally, dosimetric data from 34 European radiooncological centres contributing to the recent ESTRO inquiry on TBI are analysed. The topics are: absorbed dose and dose monitor calibration, determination of absolute and relative doses, dose ratios, attenuation data and heterogeneity corrections; TBI dose calculation methods regarding patient position, beam incidence, body shape and thickness, lung size and density; methods of TBI treatment planning including calculated dose modification and of TBI quality assurance. In conclusion, the following recommendations can be given: TBI dosimetry shall be performed under TBI conditions, close to the real treatment situation. The absorbed dose to water must be determined. The dose monitor should be calibrated against dose measurements at the centre of a water equivalent phantom of TBI equivalent size and typical thickness. Photon fluence profiles have to be measured with small phantoms. Influences on the local dose must be investigated systematically. A reproducible AP/PA TBI technique should be used. The TBI dose shall be specified to mid-abdomen and reported in units of gray. The single and total dose and the dose rate to the lungs, the number of fractions and the treatment time schedule must be stated. In vivo dosimetry is required if non-reliable TBI techniques are used. An international TBI dosimetry intercomparison could assist these efforts to improve the treatment of acute leukaemia. (author). 89 refs, 3 figs, 13 tabs

  12. Status of international benchmark experiment for effective delayed neutron fraction ({beta}eff)

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, S.; Sakurai, T.; Mukaiyama, T. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To improve the prediction accuracy of the {beta}eff, the program of the international benchmark experiment (Beta Effect Reactor Experiment for a New International Collaborative Evaluation: BERNICE) was planned. This program composed of two parts; BERNICE-MASURCA and BERNICE-FCA. The former one was carried out in the fast critical facility MASURCA of CEA, FRANCE between 1993 and 1994. The latter one started in the FCA, JAERI in 1995 and still is going. In these benchmark experiments, various experimental techniques have been applied for in-pile measurements of the {beta}eff. The accuracy of the measurements was better than 3%. (author)

  13. International Fusion Materials Irradiation Facility injector acceptance tests at CEA/Saclay: 140 mA/100 keV deuteron beam characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gobin, R., E-mail: rjgobin@cea.fr; Bogard, D.; Chauvin, N.; Chel, S.; Delferrière, O.; Harrault, F.; Mattei, P.; Senée, F. [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France); Cara, P. [Fusion for Energy, BFD Department, Garching (Germany); Mosnier, A. [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France); Fusion for Energy, BFD Department, Garching (Germany); Shidara, H. [IFMIF/EVEDA Project Team, Obuchi-Omotedate 2-166, Rokkasho, Aomori (Japan); Okumura, Y. [JAEA, Division of Rokkasho BA Project, Obuchi-Omotedate 2-166, Rokkasho, Aomori (Japan)

    2014-02-15

    In the framework of the ITER broader approach, the International Fusion Materials Irradiation Facility (IFMIF) deuteron accelerator (2 × 125 mA at 40 MeV) is an irradiation tool dedicated to high neutron flux production for future nuclear plant material studies. During the validation phase, the Linear IFMIF Prototype Accelerator (LIPAc) machine will be tested on the Rokkasho site in Japan. This demonstrator aims to produce 125 mA/9 MeV deuteron beam. Involved in the LIPAc project for several years, specialists from CEA/Saclay designed the injector based on a SILHI type ECR source operating at 2.45 GHz and a 2 solenoid low energy beam line to produce such high intensity beam. The whole injector, equipped with its dedicated diagnostics, has been then installed and tested on the Saclay site. Before shipment from Europe to Japan, acceptance tests have been performed in November 2012 with 100 keV deuteron beam and intensity as high as 140 mA in continuous and pulsed mode. In this paper, the emittance measurements done for different duty cycles and different beam intensities will be presented as well as beam species fraction analysis. Then the reinstallation in Japan and commissioning plan on site will be reported.

  14. Distribution of vitamin E among tissues and subcellular fractions in sublethally irradiated mice. [X radiation, /sup 3/H tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Lussier, D.M.; Roy, R.M.

    1977-04-01

    The distribution of /sup 3/H-activity among blood plasma, lung, spleen, liver and gut as well as among nuclear, mitochondrial, microsomal, and soluble fractions of the liver has been measured at 48 hr following intraperitoneal injection of 10 ..mu..Ci of (/sup 3/H)d-..cap alpha..-tocopherol. Lung and spleen were the most highly labeled tissues and nuclei, mitochondria and microsomes were more highly labeled than the soluble supernatant. Immediately following exposure to 500 R of 260 kVp x-radiation, the specific activity of plasma, lung, and spleen were significantly reduced. In addition, liver nuclear fraction was also reduced. The distribution of label administered 24 hr postirradiation was significantly altered, insofar as increased label was detected in gut and liver. In liver, microsomal, and soluble supernatant fractions were also greatly increased.

  15. The Text of an Agreement for Collaboration in an International Programme on Irradiation of Fruit and Fruit Juices

    International Nuclear Information System (INIS)

    The text of the Agreement between the Agency, the Osterreichische Studiengesellschaft fuer Atomenergie GmbH and the Organisation for Economic Co-operation and Development for Collaboration in an International Programme on Irradiation of Fruit and Fruit Juices, which was signed on 16 September 1964 and entered into force on 1 January 1965, is reproduced in this document for the information of all Members of the Agency,

  16. Three-year outcomes of a once daily fractionation scheme for accelerated partial breast irradiation (APBI) using 3-D conformal radiotherapy (3D-CRT)

    International Nuclear Information System (INIS)

    The aim of this study was to report 3-year outcomes of toxicity, cosmesis, and local control using a once daily fractionation scheme (49.95 Gy in 3.33 Gy once daily fractions) for accelerated partial breast irradiation (APBI) using three-dimensional conformal radiotherapy (3D-CRT). Between July 2008 and August 2010, women aged ≥40 years with ductal carcinoma in situ or node-negative invasive breast cancer ≤3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study. Women were treated with APBI using 3–5 photon beams, delivering 49.95 Gy over 15 once daily fractions over 3 weeks. Patients were assessed for toxicities, cosmesis, and local control rates before APBI and at specified time points. Thirty-four patients (mean age 60 years) with Tis 0 (n = 9) and T1N0 (n = 25) breast cancer were treated and followed up for an average of 39 months. Only 3% (1/34) patients experienced a grade 3 subcutaneous fibrosis and breast edema and 97% of the patients had good/excellent cosmetic outcome at 3 years. The 3-year rate of ipsilateral breast tumor recurrence (IBTR) was 0% while the rate of contralateral breast events was 6%. The 3-year disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS) was 94%, 100%, and 100%, respectively. Our novel accelerated partial breast fractionation scheme of 15 once daily fractions of 3.33 Gy (49.95 Gy total) is a remarkably well-tolerated regimen of 3D-CRT-based APBI. A larger cohort of patients is needed to further ascertain the toxicity of this accelerated partial breast regimen

  17. A practical alpha particle irradiator for studying internal alpha particle exposure.

    Science.gov (United States)

    Lee, Ki-Man; Lee, Ui-Seob; Kim, Eun-Hee

    2016-09-01

    An alpha particle irradiator has been built in the Radiation Bioengineering Laboratory at Seoul National University (SNU) to investigate the cellular responses to alpha emissions from radon and the progeny. This irradiator is designed to have the energy of alpha particles entering target cells similar to that of alpha emissions from the radon progeny Po-218 and Po-214 residing in the human respiratory tract. For the SNU alpha particle irradiator, an irradiation system is equipped with cell dishes of 4µm thick Mylar bottom and a special setup of cells on slide for gamma-H2AX assay. Dose calibration for the alpha particle irradiator was performed by dual approaches, detection and computer simulation, in consideration of the source-to-target distance (STD) and the size of a cell dish. The uniformity of dose among cells in a dish is achieved by keeping the STD and the size of cell dish in certain ranges. The performance of the SNU alpha particle irradiator has been proven to be reliable through the gamma-H2AX assay with the human lung epithelial cells irradiated. PMID:27475622

  18. The CORONIS Trial. International study of caesarean section surgical techniques: a randomised fractional, factorial trial

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available Abstract Background Caesarean section is one of the most commonly performed operations on women throughout the world. Rates have increased in recent years – about 20–25% in many developed countries. Rates in other parts of the world vary widely. A variety of surgical techniques for all elements of the caesarean section operation are in use. Many have not yet been rigorously evaluated in randomised controlled trials, and it is not known whether any are associated with better outcomes for women and babies. Because huge numbers of women undergo caesarean section, even small differences in post-operative morbidity rates between techniques could translate into improved health for substantial numbers of women, and significant cost savings. Design CORONIS is a multicentre, fractional, factorial randomised controlled trial and will be conducted in centres in Argentina, Ghana, India, Kenya, Pakistan and Sudan. Women are eligible if they are undergoing their first or second caesarean section through a transverse abdominal incision. Five comparisons will be carried out in one trial, using a 2 × 2 × 2 × 2 × 2 fractional factorial design. This design has rarely been used, but is appropriate for the evaluation of several procedures which will be used together in clinical practice. The interventions are: • Blunt versus sharp abdominal entry • Exteriorisation of the uterus for repair versus intra-abdominal repair • Single versus double layer closure of the uterus • Closure versus non-closure of the peritoneum (pelvic and parietal • Chromic catgut versus Polyglactin-910 for uterine repair The primary outcome is death or maternal infectious morbidity (one or more of the following: antibiotic use for maternal febrile morbidity during postnatal hospital stay, antibiotic use for endometritis, wound infection or peritonitis or further operative procedures; or blood transfusion. The sample size required is 15,000 women in total; at least 7,586 women

  19. Modeling international stock market contagion using multivariate fractionally integrated APARCH approach

    Directory of Open Access Journals (Sweden)

    Zouheir Mighri

    2014-12-01

    Full Text Available The aim of this article is to examine how the dynamics of correlations between two emerging countries (Brazil and Mexico and the US evolved from January 2003 to December 2013. The main contribution of this study is to explore whether the plunging stock market in the US, in the aftermath of global financial crisis (2007–2009, exerts contagion effects on emerging stock markets. To this end, we rely on a multivariate fractionally integrated asymmetric power autoregressive conditional heteroskedasticity dynamic conditional correlation framework, which accounts for long memory, power effects, leverage terms, and time-varying correlations. The empirical analysis shows a contagion effect for Brazil and Mexico during the early stages of the global financial crisis, indicating signs of “recoupling.” Nevertheless, linkages show a general pattern of “decoupling” after the Lehman Brothers collapse. Furthermore, correlations between Brazil and the US are decreased from early 2009 onwards, implying that their dependence is larger in bearish than in bullish markets.

  20. Measurement of absorbed radiation doses during whole body irradiation for bone marrow transplants using thermoluminescent dosimeters; Verificacao das doses de radiacao absorvidas durante a tecnica de irradiacao de corpo inteiro nos transplantes de medula ossea, por meio de dosimetros termoluminescentes

    Energy Technology Data Exchange (ETDEWEB)

    Giordani, Adelmo Jose; Segreto, Helena Cristina Comodo; Segreto, Roberto Araujo; Medeiros, Regina Bitelli; Oliveira, Jose Salvador R. de [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Setor de Radioterapia]. E-mail: adelmogiordani@ig.com.br

    2004-10-01

    The objective was to evaluate the precision of the absorbed radiation doses in bone marrow transplant therapy during whole body irradiation. Two-hundred CaSO{sub 4}:Dy + teflon tablets were calibrated in air and in 'phantom'. These tablets were randomly selected and divided in groups of five in the patients' body. The dosimetric readings were obtained using a Harshaw 4000A reader. Nine patients had their entire bodies irradiated in parallel and opposite laterals in a cobalt-60 Alcion II model, with a dose rate of 0.80 Gy/min at 80.5 cm, {l_brace}(10 ? 10) cm{sup 2} field. The dosimetry of this unit was performed using a Victoreen 500 dosimeter. For the determination of the mean dose at each point evaluated, the individual values of the tablets calibrated in air or 'phantom' were used, resulting in a build up of 2 mm to superficialize the dose at a distance of 300 cm. In 70% of the patients a variation of less than 5% in the dose was obtained. In 30% of the patients this variation was less than 10%, when values obtained were compared to the values calculated at each point. A mean absorption of 14% was seen in the head, and an increase of 2% of the administered dose was seen in the lungs. In patients with latero-lateral distance greater than 35 cm the variation between the calculated doses and the measured doses reached 30% of the desired dose, without the use of compensation filters. The measured values of the absorbed doses at the various anatomic points compared to the desired doses (theoretic) presented a tolerance of {+-} 10%, considering the existent anatomical differences and when using the individual calibration factors of the tablets. (author)

  1. Irradiation Induced Microstructure Evolution in Nanostructured Materials: A Review

    Directory of Open Access Journals (Sweden)

    Wenbo Liu

    2016-02-01

    Full Text Available Nanostructured (NS materials may have different irradiation resistance from their coarse-grained (CG counterparts. In this review, we focus on the effect of grain boundaries (GBs/interfaces on irradiation induced microstructure evolution and the irradiation tolerance of NS materials under irradiation. The features of void denuded zones (VDZs and the unusual behavior of void formation near GBs/interfaces in metals due to the interactions between GBs/interfaces and irradiation-produced point defects are systematically reviewed. Some experimental results and calculation results show that NS materials have enhanced irradiation resistance, due to their extremely small grain sizes and large volume fractions of GBs/interfaces, which could absorb and annihilate the mobile defects produced during irradiation. However, there is also literature reporting reduced irradiation resistance or even amorphization of NS materials at a lower irradiation dose compared with their bulk counterparts, since the GBs are also characterized by excess energy (compared to that of single crystal materials which could provide a shift in the total free energy that will lead to the amorphization process. The competition of these two effects leads to the different irradiation tolerance of NS materials. The irradiation-induced grain growth is dominated by irradiation temperature, dose, ion flux, character of GBs/interface and nanoprecipitates, although the decrease of grain sizes under irradiation is also observed in some experiments.

  2. [Effect of low-power laser irradiation on the structure and properties of protein molecules under non-specific energy absorbance].

    Science.gov (United States)

    Romodanova, E O; Diubko, T S; Morozova, T F; Roshal', O D; Distanov, V B; Hurkalenko, Iu O

    2003-01-01

    The influence of the helium-neon laser emission on HSA was investigated at present work by means of the fluorescent probe MNBIS (4-morpholino-7-oxy-7-H-benzo-[de]-benzo-[4,5]-imidazo-[2,1-a]- izoquinolin-5-sulfonic acid) sensitive to protein conformational changes using. Fluorescence spectra parameters of the probe and kinetics of probe interaction with protein molecules were analyzed. Possible mechanisms of the helium-neon laser irradiation on water-protein solution structure are discussed.

  3. A New Approach for Studying Nonlinear Dynamic Response of a Thin Plate with Internal Resonance in a Fractional Viscoelastic Medium

    Directory of Open Access Journals (Sweden)

    Yury A. Rossikhin

    2015-01-01

    Full Text Available In the previous analysis, the dynamic behaviour of a nonlinear plate embedded into a fractional derivative viscoelastic medium has been studied by the method of multiple time scales under the conditions of the internal resonances two-to-one and one-to-one, as well as the internal combinational resonances for the case when the linear parts of nonlinear equations of motion occur to be coupled. A new approach proposed in this paper allows one to uncouple the linear parts of equations of motion of the plate, while the same method, the method of multiple time scales, has been utilized for solving nonlinear equations. The influence of viscosity on the energy exchange mechanism between interacting nonlinear modes has been analyzed. It has been shown that for some internal resonances there exist such particular cases when it is possible to obtain two first integrals, namely, the energy integral and the stream function, which allows one to reduce the problem to the calculation of elliptic integrals. The new approach enables one to solve the problems of vibrations of thin bodies more efficiently.

  4. Photocatalytic CO2 reduction over B4C/C3N4 with internal electric field under visible light irradiation.

    Science.gov (United States)

    Zhang, Xiaojie; Wang, Lei; Du, Quanchao; Wang, Zhiyong; Ma, Shuguo; Yu, Miao

    2016-02-15

    Boron carbide/graphitic carbon nitride (B4C/g-C3N4) p-n hetero-junction photocatalyst with an internal electric field was synthesized by a facile solvent evaporation method and characterized by field emission scanning electron microscope (FESEM), UV-Vis diffuse reflectance spectra (UV-Vis DRS), photoluminescence spectra (PL), etc. Photocatalytic activity of the composite B4C/g-C3N4 loaded with Pt co-catalyst was evaluated using CO2 conversion to CH4 with H2 as the hydrogen source and reductant under visible light irradiation. The coupling of p-type B4C with n-type g-C3N4 significantly improved the performance of photocatalytic CO2 reduction; with the optimum B4C mass fraction of 1/6, the composite photocatalyst showed approximately 6 and 8 times higher CH4 generation rate than g-C3N4 and B4C, respectively. The enhancement was attributed to efficient photo-excited electron/hole separation due to the formation of internal electric field at the p-B4C/n-C3N4 interface.

  5. Irradiation-induced sensitization and stress corrosion cracking of Type 304 stainless steel core-internal components

    International Nuclear Information System (INIS)

    High- and commercial-purity heats of Type 304 stainless steel, obtained from neutron absorber tubes after irradiation to fluence levels of up to 2 x 1021 n·cm-2 (E > 1 MeV) in two boiling water reactors, were examined by Auger electron spectroscopy to characterize irradiation-induced grain- boundary segregation and depletion of alloying and impurity elements. Segregation of Si, P, Ni, and an unidentified element or compound that gives rise to an Auger energy peak at 59 eV was observed in the commercial-purity heat. Such segregation was negligible in high-purity material, except for Ni. No evidence of S segregation was observed in either material. Cr depletion was more pronounced in the high-purity material than in the commercial-purity material. These observations suggest a synergism between the significant level of impurities and Cr depletion in the commercial-purity heat. In the absence of such synergism, Cr depletion appears more pronounced in the high-purity heat. Initial results of constant-extension-rate tests conducted on the two heats in air an in simulated BWR water were correlated with the results from analysis by Auger electron spectroscopy. 15 refs., 10 figs

  6. Changes in the phospholipid fraction of intramuscular fat from pork loin (fresh and marinated) with different irradiation and packaging during storage

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Marquez, I.; Narvaez-Rivas, M.; Gallardo, E.; Cabeza, C. M.; Leon-Camacho, M.

    2013-05-01

    A study on the effect of E-beam (1 and 2 kGy) on the phospholipid classes of fresh and marinated pork loin stored at 4 degree centigrade and 8 degree centigrade under different atmospheres (air, vacuum and carbon dioxide enriched atmospheres) has been conducted. This is the first time that a study of this kind has been carried out on these types of samples. The combined statistical treatment of the distinct variables shows that minor changes (cardiol pin and sphingomyelin between both types of loin, cardiolipin vs storage temperatures and phosphatidylethanolamine vs the modified atmospheres) are produced in the individual phospholipids subjected to the different selected conditions. The more relevant result was that no effect of the irradiation doses on the phospholipids classes was found, so the E-beam can be considered a useful tool to extend the shelf-life of fresh meat without changes in the phospholipid fraction. (Author) 24 refs.

  7. Radiobiological restrictions and tolerance doses of repeated single-fraction hdr-irradiation of intersecting small liver volumes for recurrent hepatic metastases

    Directory of Open Access Journals (Sweden)

    Wust Peter

    2010-05-01

    Full Text Available Abstract Background To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice. Methods Twenty patients with liver metastases were treated repeatedly (2 - 4 times at identical or intersecting locations by CT-guided interstitial brachytherapy with varying time intervals. Magnetic resonance imaging using the hepatocyte selective contrast media Gd-BOPTA was performed before and after treatment to determine the volume of hepatocyte function loss (called pseudolesion, and the last acquired MRI data set was merged with the dose distributions of all administered brachytherapies. We calculated the BED (biologically equivalent dose for a single dose d = 2 Gy for different α/β values (2, 3, 10, 20, 100 based on the linear-quadratic model and estimated the tolerance dose for liver parenchyma D90 as the BED exposing 90% of the pseudolesion in MRI. Results The tolerance doses D90 after repeated brachytherapy sessions were found between 22 - 24 Gy and proved only slightly dependent on α/β in the clinically relevant range of α/β = 2 - 10 Gy. Variance analysis showed a significant dependency of D90 with respect to the intervals between the first irradiation and the MRI control (p 90 and the pseudolesion's volume. No symptoms of liver dysfunction or other toxic effects such as abscess formation occurred during the follow-up time, neither acute nor on the long-term. Conclusions Inactivation of liver parenchyma occurs at a BED of approx. 22 - 24 Gy corresponding to a single dose of ~10 Gy (α/β ~ 5 Gy. This tolerance dose is consistent with the large potential to treat oligotopic and/or recurrent liver metastases by CT-guided HDR brachytherapy without radiation-induced liver disease (RILD. Repeated small volume irradiation may be applied safely within the limits of this study.

  8. Hypofractionated Prostate Radiotherapy with or without Conventionally Fractionated Nodal Irradiation: Clinical Toxicity Observations and Retrospective Daily Dosimetry

    Directory of Open Access Journals (Sweden)

    Andrew M. McDonald

    2012-01-01

    Methods and Materials. Fifty-seven patients received pelvic image-guided IMRT to 50.4 Gy in 28 fractions with a hypofractionated simultaneous boost to the prostate to 70 Gy. Thirty-one patients received prostate-only treatment to 70 Gy in 28 fractions. Results. Median followup was 41.1 months. Early grade ≥2 urinary toxicity rates were 49% (28 of 57 for patients receiving ENI and 58% (18 of 31 for those not (P=0.61. Early grade ≥2 rectal toxicity rates were 40% (23 of 57 and 23% (7 of 31, respectively (P=0.09. The addition of ENI resulted in a 21% actuarial rate of late grade ≥2 rectal toxicity at 4 years, compared to 0% for patients treated to the prostate only (P=0.02. Retrospective daily dosimetry of patients experiencing late rectal toxicity revealed an average increase of 2.67% of the rectal volume receiving 70 Gy compared to the original plan. Conclusions. The addition of ENI resulted in an increased risk of late rectal toxicity. Grade ≥2 late rectal toxicity was associated with worse daily rectal dosimetry compared to the treatment plan.

  9. Synergistic antitumor effect between gefitinib and fractionated irradiation in anaplastic oligodendrogliomas cannot be predicted by the Egfr signaling activity.

    OpenAIRE

    Sophie Pinel; Jihane Mriouah; Marc Vandamme; Alicia Chateau; François Plénat; Eric Guérin; Luc Taillandier; Valérie Bernier-Chastagner; Jean-Louis Merlin; Pascal Chastagner

    2013-01-01

    International audience In high-grade gliomas, the identification of patients that could benefit from EGFR inhibitors remains a challenge, hindering the use of these agents. Using xenografts models, we evaluated the antitumor effect of the combined treatment "gefitinib + radiotherapy" and aimed to identify the profile of responsive tumors. Expression of phosphorylated proteins involved in the EGFR-dependent signaling pathways was analyzed in 10 glioma models. We focused on three models of a...

  10. HemoHIM ameliorates the persistent down-regulation of Th1-like immune responses in fractionated γ-irradiated mice by modulating the IL-12p70-STAT4 signaling pathway.

    Science.gov (United States)

    Park, Hae-Ran; Jo, Sung-Kee; Choi, Nam-Hee; Jung, Uhee

    2012-05-01

    Whole body irradiated mice appear to experience a down-regulation of the helper T (Th)1-like immune response, and maintain a persistent immunological imbalance. In the current study, we evaluated the effect of HemoHIM (an herbal product made from Angelica Radix, Cnidium officinale , and Paeonia japonica cultivated in Korea) to ameliorate the immunological imbalance induce in fractionated γ-irradiated mice. The mice were exposed to γ rays twice a week (0.5 Gy fractions) for a total dose of 5 Gy, and HemoHIM was administrated orally from 1 week before the first irradiation to 1 week before the final analysis. All experiments were performed 4 and 6 months after their first exposure. HemoHIM ameliorated the Th1- and Th2-related immune responses normally occur in irradiated mice with or without dinitrophenylated keyhole limpet hemocyanin immunization. HemoHIM also restored the natural killer cell activities without changing the percentage of natural killer cells in irradiated mice. Furthermore, the administration of HemoHIM prevented the reduction in levels of interleukin-12p70 in irradiated mice. Finally, we found that HemoHIM enhanced the phosphorylation of signal transducer and activator of transcription (STAT) 4 that was reduced in irradiated mice. Our findings suggest that HemoHIM ameliorates the persistent down-regulation of Th1-like immune responses by modulating the IL-12p70/pSTAT4 signaling pathway. PMID:22439601

  11. HemoHIM ameliorates the persistent down-regulation of Th1-like immune responses in fractionated γ-irradiated mice by modulating the IL-12p70-STAT4 signaling pathway.

    Science.gov (United States)

    Park, Hae-Ran; Jo, Sung-Kee; Choi, Nam-Hee; Jung, Uhee

    2012-05-01

    Whole body irradiated mice appear to experience a down-regulation of the helper T (Th)1-like immune response, and maintain a persistent immunological imbalance. In the current study, we evaluated the effect of HemoHIM (an herbal product made from Angelica Radix, Cnidium officinale , and Paeonia japonica cultivated in Korea) to ameliorate the immunological imbalance induce in fractionated γ-irradiated mice. The mice were exposed to γ rays twice a week (0.5 Gy fractions) for a total dose of 5 Gy, and HemoHIM was administrated orally from 1 week before the first irradiation to 1 week before the final analysis. All experiments were performed 4 and 6 months after their first exposure. HemoHIM ameliorated the Th1- and Th2-related immune responses normally occur in irradiated mice with or without dinitrophenylated keyhole limpet hemocyanin immunization. HemoHIM also restored the natural killer cell activities without changing the percentage of natural killer cells in irradiated mice. Furthermore, the administration of HemoHIM prevented the reduction in levels of interleukin-12p70 in irradiated mice. Finally, we found that HemoHIM enhanced the phosphorylation of signal transducer and activator of transcription (STAT) 4 that was reduced in irradiated mice. Our findings suggest that HemoHIM ameliorates the persistent down-regulation of Th1-like immune responses by modulating the IL-12p70/pSTAT4 signaling pathway.

  12. Phase 2 Trial of Accelerated, Hypofractionated Whole-Breast Irradiation of 39 Gy in 13 Fractions Followed by a Tumor Bed Boost Sequentially Delivering 9 Gy in 3 Fractions in Early-Stage Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ja Young [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Jung, So-Youn; Lee, Seeyoun; Kang, Han-Sung; Lee, Eun Sook; Park, In Hae; Lee, Keun Seok; Ro, Jungsil [Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Lee, Nam Kwon [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Radiation Oncology, Korea University Medical Center, Collage of Medicine, Seoul (Korea, Republic of); Shin, Kyung Hwan, E-mail: radiat@ncc.re.kr [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Radiation Oncology, Korea University Medical Center, Collage of Medicine, Seoul (Korea, Republic of)

    2013-12-01

    Purpose: To report a phase 2 trial of accelerated, hypofractionated whole-breast irradiation (AH-WBI) delivered as a daily dose of 3 Gy to the whole breast followed by a tumor bed boost. Methods and Materials: Two hundred seventy-six patients diagnosed with breast cancer (pT1-2 and pN0-1a) who had undergone breast-conserving surgery in which the operative margins were negative were treated with AH-WBI delivered as 39 Gy in 13 fractions of 3 Gy to the whole breast once daily over 5 consecutive working days, and 9 Gy in 3 sequential fractions of 3 Gy to a lumpectomy cavity, all within 3.2 weeks. Results: After a median follow-up period of 57 months (range: 27-75 months), the rate of 5-year locoregional recurrence was 1.4% (n=4), whereas that of disease-free survival was 97.4%. No grade 3 skin toxicity was reported during the follow-up period. Qualitative physician cosmetic assessments of good or excellent were noted in 82% of the patients at 2 months after the completion of AH-WBI. The global cosmetic outcome did not worsen over time, and a good or excellent cosmetic outcome was reported in 82% of the patients at 3 years. The mean pretreatment percentage breast retraction assessment was 12.00 (95% confidence interval [CI]: 11.14-12.86). The mean value of percentage breast retraction assessment increased to 13.99 (95% CI: 12.17-15.96) after 1 year and decreased to 13.54 (95% CI: 11.84-15.46) after 3 years but was not significant (P>.05). Conclusions: AH-WBI consisting of 39 Gy in 13 fractions followed by a tumor bed boost sequentially delivering 9 Gy in 3 fractions can be delivered with excellent disease control and tolerable skin toxicity in patients with early-stage breast cancer after breast-conserving surgery.

  13. Phase 2 Trial of Accelerated, Hypofractionated Whole-Breast Irradiation of 39 Gy in 13 Fractions Followed by a Tumor Bed Boost Sequentially Delivering 9 Gy in 3 Fractions in Early-Stage Breast Cancer

    International Nuclear Information System (INIS)

    Purpose: To report a phase 2 trial of accelerated, hypofractionated whole-breast irradiation (AH-WBI) delivered as a daily dose of 3 Gy to the whole breast followed by a tumor bed boost. Methods and Materials: Two hundred seventy-six patients diagnosed with breast cancer (pT1-2 and pN0-1a) who had undergone breast-conserving surgery in which the operative margins were negative were treated with AH-WBI delivered as 39 Gy in 13 fractions of 3 Gy to the whole breast once daily over 5 consecutive working days, and 9 Gy in 3 sequential fractions of 3 Gy to a lumpectomy cavity, all within 3.2 weeks. Results: After a median follow-up period of 57 months (range: 27-75 months), the rate of 5-year locoregional recurrence was 1.4% (n=4), whereas that of disease-free survival was 97.4%. No grade 3 skin toxicity was reported during the follow-up period. Qualitative physician cosmetic assessments of good or excellent were noted in 82% of the patients at 2 months after the completion of AH-WBI. The global cosmetic outcome did not worsen over time, and a good or excellent cosmetic outcome was reported in 82% of the patients at 3 years. The mean pretreatment percentage breast retraction assessment was 12.00 (95% confidence interval [CI]: 11.14-12.86). The mean value of percentage breast retraction assessment increased to 13.99 (95% CI: 12.17-15.96) after 1 year and decreased to 13.54 (95% CI: 11.84-15.46) after 3 years but was not significant (P>.05). Conclusions: AH-WBI consisting of 39 Gy in 13 fractions followed by a tumor bed boost sequentially delivering 9 Gy in 3 fractions can be delivered with excellent disease control and tolerable skin toxicity in patients with early-stage breast cancer after breast-conserving surgery

  14. Improvement of colour strength and colourfastness properties of gamma irradiated cotton using reactive black-5

    Science.gov (United States)

    Ahmad Bhatti, Ijaz; Adeel, Shahid; Nadeem, Raziya; Asghar, Toheed

    2012-03-01

    The dyeing behaviour of gamma irradiated cotton fabric using Reactive Black-5 dye powder has been investigated. The mercerized, bleached and plain weaved cotton fabric was irradiated to different absorbed doses of 100, 200, 300, 400, 500 and 600 Gy using Co-60 gamma irradiator. Dyeing was performed using irradiated and un-irradiated cotton with dye solutions. The dyeing parameters such as temperature of dyeing, time of dyeing and pH of dyeing solutions were optimised. The colour strength values of dyed fabrics were evaluated by comparing irradiated and un-irradiated cotton in CIE Lab system using Spectra flash SF650. Methods suggested by International Standard Organisation (ISO) were employed to study the effect of gamma irradiation on the colourfastness properties of dyed fabric. It is found that gamma irradiated cotton dyed with Reactive Black-5 has not only improved the colour strength but also enhanced the rating of fastness properties.

  15. Nd:YAG laser irradiation on temporary teeth carious tissue using 12% diamine silver fluoride as a photo-absorber - a morphological study; Estudo comparativo morfologico da acao do laser de Nd:YAG em dentina cariada de dentes deciduos in vitro, condicionados com diamino fluoreto de prata a 12% e carvao mineral

    Energy Technology Data Exchange (ETDEWEB)

    Calmon, Andrea de Avillez

    2001-07-01

    Since Nd:YAG laser radiation was first introduced in Dentistry various photo-absorbers were employed with the intent of improving its efficacy when used on dental carious tissue. The purpose of the present study was to analyze the influence of this radiation using Scanning and Optical microscopy over carious tissue of primary teeth using two photo-absorbers. 15 primary human teeth were used and, in each one, 3 cavity preparations were performed. Specimens were then submitted to an in vitro demineralizing environment during 18 days. Two of the cavities of each specimen were laser irradiated using the Nd:YAG laser with 60 mJ of energy per pulse, 10 Hz and average power of 0,6 W. The 12% diamine silver fluoride or the mineral coal were used as photo-absorbers. The third cavity of the specimens was used as a control and received no laser irradiation. Samples were transversally cut and the section analyzed by SEM and OM. Results showed that the 12% diamine silver fluoride is an efficient photo-absorber and, when used it the Nd:YAG laser, leading to melting and resolidification of the carious tissue. It can be concluded that the 12% diammine silver fluoride presents advantages over the mineral coal as a photo absorber when used in primary teeth as it promotes and improves the efficacy of laser irradiation. This substance also works as a barrier on the carie progression in deeper areas such as the infected and necrotic zones. (author)

  16. Characterization and clonality of prelymphoma cells of B10 mice treated with fractionated X-irradiation (FX)

    International Nuclear Information System (INIS)

    With a combined use of cell separation by cell sorter and intrathymic injection assay, it was shown that prelymphoma cells existed in the subpopulation of thymocytes expressing TL-2 antigen which is not expressed on normal thymocytes of B10. Thy 1.2 or B10. Thy 1.1 mice. We then addressed a question whether all TL-2+ cells undergo neoplastic initiation or pre-neoplastic cells develop infrequently from TL-2+ cells. To investigate this problem and to examine the clonality of prelymphoma cells, thymocytes from individual B10. Thy 1.1 mice at various times after FX were stained with anti TL-2 mAb and the content of TL-2+ cells was evaluated. A graded amount of TL-2+ thymocytes from individual mice was injected into the thymuses of B10. Thy 1.2 mice. Although various numbers of TL-2+ cells appeared in the thymus of individual mice 14 - 28 days after FX, the donor type T cell lymphomas developed when 102 - 105 of TL-2+ cells from 7 individuals out of 20 mice were injected into the recipient mice. On the other hand, injection of TL-2+ cells from other mice (13 out of 20) did not develop donor type T cell lymphoma in spite of TL-2+ cells appearing in the thymus. These results indicate that all TL-2+ cells did not always undergo neoplastic initiation, and prelymphoma cells might develop infrequently from TL-2+ cells. To evaluate the clonality of prelymphoma cells, high molecular weight DNAs were isolated from the donor-derived T cell lymphomas and the rearrangement of T cell receptors examined by Southern blot analysis. The nucleotide sequences of V-J junctions were also determined by polymerase chain reaction techniques. The results indicated that after irradiation neoplastic initiation might occur oligoclonally in some of the TL-2+ cells. (author)

  17. Protective Effect of the Ethyl Acetate Fraction of Sargassum muticum against Ultraviolet B–Irradiated Damage in Human Keratinocytes

    Directory of Open Access Journals (Sweden)

    Jin Won Hyun

    2011-11-01

    Full Text Available The aim of this study was to investigate the cytoprotective properties of the ethyl acetate fraction of Sargassum muticum (SME against ultraviolet B (UVB-induced cell damage in human keratinocytes (HaCaT cells. SME exhibited scavenging activity toward the 1,1-diphenyl-2-picrylhydrazyl radicals and hydrogen peroxide (H2O2 and UVB-induced intracellular reactive oxygen species (ROS. SME also scavenged the hydroxyl radicals generated by the Fenton reaction (FeSO4 + H2O2, which was detected using electron spin resonance spectrometry. In addition, SME decreased the level of lipid peroxidation that was increased by UVB radiation, and restored the level of protein expression and the activities of antioxidant enzymes that were decreased by UVB radiation. Furthermore, SME reduced UVB-induced apoptosis as shown by decreased DNA fragmentation and numbers of apoptotic bodies. These results suggest that SME protects human keratinocytes against UVB-induced oxidative stress by enhancing antioxidant activity in cells, thereby inhibiting apoptosis.

  18. Comparison between absorbed dose to water standards established by water calorimetry at the LNE-LNHB and by application of international air-kerma based protocols for kilovoltage medium energy x-rays.

    Science.gov (United States)

    Perichon, N; Rapp, B; Denoziere, M; Daures, J; Ostrowsky, A; Bordy, J-M

    2013-05-01

    Nowadays, the absorbed dose to water for kilovoltage x-ray beams is determined from standards in terms of air-kerma by application of international dosimetry protocols. New standards in terms of absorbed dose to water has just been established for these beams at the LNE-LNHB, using water calorimetry, at a depth of 2 cm in water in accordance with protocols. The aim of this study is to compare these new standards in terms of absorbed dose to water, to the dose values calculated from the application of four international protocols based on air-kerma standards (IAEA TRS-277, AAPM TG-61, IPEMB and NCS-10). The acceleration potentials of the six beams studied are between 80 and 300 kV with half-value layers between 3.01 mm of aluminum and 3.40 mm of copper. A difference between the two methods smaller than 2.1% was reported. The standard uncertainty of water calorimetry being below 0.8%, and the one associated with the values from protocols being around 2.5%, the results are in good agreement. The calibration coefficients of some ionization chambers in terms of absorbed dose to water, established by application of calorimetry and air-kerma based dosimetry protocols, were also compared. The best agreement with the calibration coefficients established by water calorimetry was found for those established with the AAPM TG-61 protocol.

  19. Internal mammary chain irradiation in breast cancer: State of the art

    International Nuclear Information System (INIS)

    Radiation therapy has a major role in the management of infiltrative breast cancers. However, there is no consensus for the prophylactic treatment of the internal mammary chain (IMC), with strategies that show strong differences according to centers and physicians. Indications for internal mammary chain radiotherapy are debated, since this treatment significantly increases the dose delivered to the heart and leads to potential technical difficulties. Important prospective data recently suggested that internal mammary chain radiotherapy would not be necessary, even in cases of internal or central tumor locations, or in patients with positive axillary lymph nodes. Although these data warrant confirmation by two other prospective trials, there is evidence that the indications for internal mammary chain radiotherapy should be careful and that high quality techniques should be used for decreasing the dose delivered to the heart. This review of literature presents the state of art on the radiotherapy of internal mammary chain, with special focus on the indications, techniques, and potential toxicity. (authors)

  20. Comparative analysis of acute leukemia hematopoietic stem cell transplantation in single body irradiation and fractionated total body irradiation mode%急性白血病造血干细胞移植前单次全身照射与分次全身照射模式的对比分析

    Institute of Scientific and Technical Information of China (English)

    赵奇; 马骁; 周菊英; 秦颂兵

    2015-01-01

    目的 对比单次全身照射(single total body irradiation,STBI)8 Gy和分次全身照射(fractionated total body irradiation,FTBI) 12 Gy两种不同的全身照射模式,探讨合适的造血干细胞移植前全身照射(total body irradiation,TBI)方案.方法 回顾性分析苏州大学附属第一医院2003-04-05-2010-07-10确诊的160例急性白血病患者资料,所有患者均接受移植前TBI预处理,70例患者进行STBI 8 Gy照射,90例患者行FTBI 12 Gy照射,2次/d,2 Gy/次,连续照射3d,2次间隔6h,比较不同方案的急性期毒副作用、造血重建时间、移植存活率、间质性肺炎(interstitial pneumonia,IP)和急性移植物抗宿主病(acute graft-versus host disease,aGVHD)的发生情况.结果 STBI 8 Gy照射组和FTBI 12 Gy照射组胃肠道反应(恶心、呕吐)发生率分别为61.4%(43/70)和40.0%(36/90),x2=7.223,P=0.006;口腔黏膜炎分别为71.4%(50/70)和45.6%(41/90),x2=10.746,P=0.001;腮腺炎分别为64.3%(45/70)和48.9%(44/90),x2=3.782,P=0.037.两组上述毒副作用相比差异有统计学意义.STBI 8 Gy组中性粒细胞造血重建时间、血小板造血重建时间、移植存活率和Ⅲ~Ⅳ度aGVHD的发生率分别为13.84士3.84、16.69±4.70、95.7%(67/70)和14.3%(10/70),FTBI12 Gy组分别为14.31±3.79、17.43±5.26、95.6%(86/90)和16.7%(15/90),两组相比差异无统计学意义.IP发生率FTBI 12 Gy照射组为4.4%(4/90),STBI 8 Gy照射组为14.3%(10/70).多因素Logistic回归分析显示,IP的发生与照射方案和剂量率有关,与性别、年龄、干细胞来源和腮腺炎无关.结论 FTBI 12 Gy方案与STBI 8 Gy方案相比可减轻急性期毒副作用,减轻肺部放射损伤,而造血重建时间、移植存活率和aGVHD的发生两种方案相比差异无统计学意义.采用FTBI 12 Gy方案,吸收剂量率控制在4~6 cGy/min,肺中位剂量控制在<8 Gy,对比STBI 8 Gy方案是安全、有效的造血干细胞移植预处理方案.%OBJECTIVE To

  1. Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine; Ocena zaleznosci pomiedzy sposobem frakcjonowania dawki fotonow i neutronow a nasileniem popromiennego odczynu jelita grubego myszy

    Energy Technology Data Exchange (ETDEWEB)

    Gasinska, A. [Oncology Center, Cracow (Poland)

    1995-12-31

    The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. {alpha}/{beta} coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction {alpha}/{beta} for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). {alpha}/{beta} coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method {alpha}/{beta} for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of {alpha}/{beta} coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (F{sub r}) was much bigger for photons. For X-rays it was 50

  2. Current Role of Selective Internal Irradiation With Yttrium-90 Microspheres in the Management of Hepatocellular Carcinoma: A Systematic Review

    International Nuclear Information System (INIS)

    Purpose: This article reviews the role of selective internal irradiation (SIR) with yttrium-90 (90Y) microspheres for hepatocellular carcinoma (HCC). Methods and Materials: Studies were identified by searching Medline and PubMed databases for articles from 1990 to 2009 using the keywords 'selective internal irradiation,' 'hepatocellular carcinoma,' 'therapeutic embolization,' and 'yttrium-90.' Results: 90Y microspheres are a safe and well-tolerated therapy for unresectable HCC (median survival range, 7 -21.6 months). The evidence was limited to cohort studies and comparative studies with historical control. 90Y microspheres have been reported to downstage unresectable HCC to allow for salvage treatments with curative intent, act as a bridging therapy before liver transplantation, and treat HCC with curative intent for patients who are not surgical candidates because of comorbidities. Conclusions: 90Y microsphere is recommended as an option of palliative therapy for large or multifocal HCC without major portal vein invasion or extrahepatic spread. It can also be used for recurrent unresectable HCC, as a bridging therapy before liver transplantation, as a tumor downstaging treatment, and as a curative treatment for patients with associated comorbidities who are not candidates for surgery.

  3. Using EO-1 Hyperion to Simulate HyspIRI Products for a Coniferous Forest: The Fraction of PAR Absorbed by Chlorophyll (fAPAR(sub chl)) and Leaf Water Content(LWC)

    Science.gov (United States)

    Zhang, Qingyuan; Middleton, Elizabeth M.; Gao, Bo-Cai; Cheng, Yen-Ben

    2012-01-01

    This paper presents development of prototype products for terrestrial ecosystems in preparation for the future imaging spectrometer planned for the Hyperspectral Infrared Imager (HyspIRI) mission. We present a successful demonstration example in a coniferous forest of two product prototypes: fraction of photosynthetically active radiation (PAR) absorbed by chlorophyll of a canopy (fAPARchl) and leaf water content (LWC), for future HyspIRI implementation at 60-m spatial resolution. For this, we used existing 30-m resolution imaging spectrometer data available from the Earth Observing One (EO-1) Hyperion satellite to simulate and prototype the level one radiometrically corrected radiance (L1R) images expected from the HyspIRI visible through shortwave infrared spectrometer. The HyspIRIlike images were atmospherically corrected to obtain surface reflectance and spectrally resampled to produce 60-m reflectance images for wavelength regions that were comparable to all seven of the MODerate resolution Imaging Spectroradiometer (MODIS) land bands. Thus, we developed MODIS-like surface reflectance in seven spectral bands at the HyspIRI-like spatial scale, which was utilized to derive fAPARchl and LWC with a coupled canopy-leaf radiative transfer model (PROSAIL2) for the coniferous forest. With this paper, we provide additional evidence that the fAPARchl product is more realistic in describing the physiologically active canopy than the traditional fAPAR parameter for the whole canopy (fAPARcanopy), and thus, it should replace it in ecosystem process models to reduce uncertainties in terrestrial carbon cycle and ecosystem studies.

  4. Understanding Trends Associated with Clouds in Irradiated Exoplanets

    CERN Document Server

    Heng, Kevin

    2013-01-01

    Unlike previously explored relationships between the properties of hot Jovian atmospheres, the geometric albedo and the incident stellar flux do not exhibit a clear correlation, as revealed by our re-analysis of Q0 to Q14 Kepler data. If the albedo is primarily associated with the presence of clouds in these irradiated atmospheres, a holistic modeling approach needs to relate the following properties: the strength of stellar irradiation (and hence the strength and depth of atmospheric circulation), the geometric albedo (which controls both the fraction of starlight absorbed and the pressure level at which it is predominantly absorbed) and the properties of the embedded cloud particles (which determine the albedo). The anticipated diversity in cloud properties renders any correlation between the geometric albedo and the stellar flux to be weak and characterized by considerable scatter. In the limit of vertically uniform populations of scatterers and absorbers, we use an analytical model and scaling relations t...

  5. Research in radiobiology. Annual report of work in progress in the internal irradiation program

    International Nuclear Information System (INIS)

    Research progress on studies of the effects of internally deposited radionuclides in dogs, mice, and humans is reported. The studies include toxicity of plutonium 239, radium 226, and radium 224, the kinetics of actinides in beagles, and dosimetry of internal emitters

  6. Food irradiation

    International Nuclear Information System (INIS)

    Food irradiation is a promising technology in which food products are exposed to a controlled amount of radiant energy to eliminate disease-causing bacteria. The process can also control parasites and insects, reduce spoilage and inhibit ripening and sprouting. Food irradiation is endorsed by the most important health organisations (WHO, CDC, USDA, FDA, EFSA, etc.) and allowed in nearly 40 Countries. It is to remember that irradiation is not a substitute either for comprehensive food safety programs or for good food-handling practices. Irradiated foods must be labelled with either the statement treated with radiation or treated by irradiation and the international symbol for irradiation, the radura. Some consumer associations suppose negative aspects of irradiation, such as increase of the number of free radicals in food and decrease of antioxidant vitamins that neutralize them

  7. Anomalous Diffusion with Absorbing Boundary

    OpenAIRE

    Kantor, Yacov; Kardar, Mehran

    2007-01-01

    In a very long Gaussian polymer on time scales shorter that the maximal relaxation time, the mean squared distance travelled by a tagged monomer grows as ~t^{1/2}. We analyze such sub-diffusive behavior in the presence of one or two absorbing boundaries and demonstrate the differences between this process and the sub-diffusion described by the fractional Fokker-Planck equation. In particular, we show that the mean absorption time of diffuser between two absorbing boundaries is finite. Our res...

  8. Determination of neutron absorbed doses in lithium aluminates.

    Science.gov (United States)

    Delfín Loya, A; Carrera, L M; Ureña-Núñez, F; Palacios, O; Bosch, P

    2003-04-01

    Lithium-based ceramics have been proposed as tritium breeders for fusion reactors. The lithium aluminate (gamma phase) seems to be thermally and structurally stable, the damages produced by neutron irradiation depend on the absorbed dose. A method based on the measurement of neutron activation of foils through neutron capture has been developed to obtain the neutron absorbed dose in lithium aluminates irradiated in the thermal column facility and in the fixed irradiation system of a Triga Mark III Nuclear Reactor. PMID:12672632

  9. Effect of mercerization and gamma irradiation on the dyeing behaviour of cotton using stilbene based direct dye

    Science.gov (United States)

    Bhatti, Ijaz Ahmad; Adeel, Shahid; Fazal-ur-Rehman; Irshad, Misbah; Abbas, Muhammad

    2012-07-01

    The dyeing behaviour of mercerized and gamma irradiated cotton fabric using stilbene based direct dye has been investigated. The fabric was treated with different concentrations of alkali to optimize the mercerization. The optimum mercerized cotton fabric was irradiated to absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. Dyeing was performed using irradiated and un-irradiated cotton with dye solutions. The dyeing parameters such as temperature, time of dyeing, pH of dyeing solutions and salt concentration were optimized. The colour strength values of dyed fabrics were evaluated by comparing irradiated and un-irradiated cotton in CIE Lab system using Spectra flash SF650. Methods suggested by International Standard Organization (ISO) were employed to study the effect of gamma irradiation on the colourfastness properties of dyed fabric. It was found that mercerized and irradiated cotton have not only improved the colour strength but enhanced the rating of fastness properties also.

  10. International Fusion Material Irradiation Facility (IFMIF) neutron source term simulation and neutronics analyses of the high flux test module

    CERN Document Server

    Simakov, S P; Heinzel, V; Moellendorff, U V

    2002-01-01

    The report describes the new results of the development work performed at Forschungszentrum Karlsruhe on the neutronics of the International Fusion Materials Irradiation Facility (IFMIF). An important step forward has been done in the simulation of neutron production of the deuteron-lithium source using the Li(d,xn) reaction cross sections from evaluated data files. The developed Monte Carlo routine and d-Li reaction data newly evaluated at INPE Obninsk have been verified against available experimental data on the differential neutron yield from deuteron-bombarded thick lithium targets. With the modified neutron source three-dimensional distributions of neutron and photon fluxes, displacement and gas production rates and nuclear heating inside the high flux test module (HFTM) were calculated. In order to estimate the uncertainty resulting from the evaluated data, two independent libraries, recently released by INPE and LANL, have been used in the transport calculations. The proposal to use a reflector around ...

  11. Absorber materials in CANDU PHWRs

    International Nuclear Information System (INIS)

    In a CANDU reactor the fuel channels are arranged on a square lattice in a calandria filled with heavy water moderator. This arrangement allows five types of tubular neutron absorber devices to be located in the relatively benign environment of low pressure, low temperature heavy water between neighbouring rows or columns of fuel channels. This paper will describe the roles of the devices and outline the design requirements of the absorber component from a reactor physics viewpoint. Nuclear heating and activation problems associated with the different absorbers will be briefly discussed. The design and manufacture of the devices will be also discussed. The control rod absorbers and shut off materials are cadmium and stainless steel. In the tubular arrangement, the cadmium is sandwiched between stainless steel tubes. This type of device has functioned well, but there is now concern over the availability and expense of cadmium which is used in two types of CANDU control devices. There are also concerns about the toxicity of cadmium during the fabrication of the absorbers. These concerns are prompting AECL to study alternatives. To minimize design changes, pure boron-10 alloyed in stainless steel is a favoured option. Work is underway to confirm the suitability of the boron-loaded steel and identify other encapsulated absorber materials for practical application. Because the reactivity devices or their guide tubes span the calandria vessel, the long slender components must be sufficiently rigid to resist operational vibration and also be seismically stable. Some of these components are made of Zircaloy to minimize neutron absorption. Slow irradiation growth and creep can reduce the spring tension, and periodic adjustments to the springs are required. Experience with the control absorber devices has generally been good. In one instance liquid zone controllers had a problem of vibration induced fretting but a redesigned back-fit resolved the problem. (author). 3 refs, 8

  12. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates

    Science.gov (United States)

    Fournier, P.; Crosbie, J. C.; Cornelius, I.; Berkvens, P.; Donzelli, M.; Clavel, A. H.; Rosenfeld, A. B.; Petasecca, M.; Lerch, M. L. F.; Bräuer-Krisch, E.

    2016-07-01

    Microbeam radiation therapy (MRT) is a new radiation treatment modality in the pre-clinical stage of development at the ID17 Biomedical Beamline of the European synchrotron radiation facility (ESRF) in Grenoble, France. MRT exploits the dose volume effect that is made possible through the spatial fractionation of the high dose rate synchrotron-generated x-ray beam into an array of microbeams. As an important step towards the development of a dosimetry protocol for MRT, we have applied the International Atomic Energy Agency’s TRS 398 absorbed dose-to-water protocol to the synchrotron x-ray beam in the case of the broad beam irradiation geometry (i.e. prior to spatial fractionation into microbeams). The very high dose rates observed here mean the ion recombination correction factor, k s , is the most challenging to quantify of all the necessary corrections to apply for ionization chamber based absolute dosimetry. In the course of this study, we have developed a new method, the so called ‘current ramping’ method, to determine k s for the specific irradiation and filtering conditions typically utilized throughout the development of MRT. Using the new approach we deduced an ion recombination correction factor of 1.047 for the maximum ESRF storage ring current (200 mA) under typical beam spectral filtering conditions in MRT. MRT trials are currently underway with veterinary patients at the ESRF that require additional filtering, and we have estimated a correction factor of 1.025 for these filtration conditions for the same ESRF storage ring current. The protocol described herein provides reference dosimetry data for the associated Treatment Planning System utilized in the current veterinary trials and anticipated future human clinical trials.

  13. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates.

    Science.gov (United States)

    Fournier, P; Crosbie, J C; Cornelius, I; Berkvens, P; Donzelli, M; Clavel, A H; Rosenfeld, A B; Petasecca, M; Lerch, M L F; Bräuer-Krisch, E

    2016-07-21

    Microbeam radiation therapy (MRT) is a new radiation treatment modality in the pre-clinical stage of development at the ID17 Biomedical Beamline of the European synchrotron radiation facility (ESRF) in Grenoble, France. MRT exploits the dose volume effect that is made possible through the spatial fractionation of the high dose rate synchrotron-generated x-ray beam into an array of microbeams. As an important step towards the development of a dosimetry protocol for MRT, we have applied the International Atomic Energy Agency's TRS 398 absorbed dose-to-water protocol to the synchrotron x-ray beam in the case of the broad beam irradiation geometry (i.e. prior to spatial fractionation into microbeams). The very high dose rates observed here mean the ion recombination correction factor, k s , is the most challenging to quantify of all the necessary corrections to apply for ionization chamber based absolute dosimetry. In the course of this study, we have developed a new method, the so called 'current ramping' method, to determine k s for the specific irradiation and filtering conditions typically utilized throughout the development of MRT. Using the new approach we deduced an ion recombination correction factor of 1.047 for the maximum ESRF storage ring current (200 mA) under typical beam spectral filtering conditions in MRT. MRT trials are currently underway with veterinary patients at the ESRF that require additional filtering, and we have estimated a correction factor of 1.025 for these filtration conditions for the same ESRF storage ring current. The protocol described herein provides reference dosimetry data for the associated Treatment Planning System utilized in the current veterinary trials and anticipated future human clinical trials. PMID:27366861

  14. Mortality theory used to predict the life-span shortening caused by chronic internal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Panteleev, L.I.; Shvedov, V.L. (Institut Biofiziki, Moscow (USSR))

    In experiments on albino rats received strontium 90 in daily doses of 1.85 to 185 kBq/day the regularities of death were studied. It was shown that death of animals exposed to chronic internal radiation followed the Gomperz B. mortality law.

  15. Characterization and quantification of the cholesterol oxidation product fraction of the intramuscular fat from pork loin (fresh and marinated with different irradiation and packaging during storage

    Directory of Open Access Journals (Sweden)

    García-Márquez, I.

    2014-12-01

    Full Text Available A study of the effect of E-beam (1 and 2 kGy on the cholesterol oxidation product (COP composition of fresh and marinated pork loin stored at 4 and 8 °C under different atmospheres (air, vacuum and carbon dioxide enriched has been carried out for the first time. The combined statistical treatment of the distinct variables showed that minor differences were found in some cholesterol oxidation products of fresh loin due to storage temperature, packaging method and storage time. No effect of irradiation (up to 2 KGy on the COP amount was found, concluding that E-beam can be a useful tool to extend the shelf-life of fresh and marinated loin without changes in the COP fraction.Se ha realizado un estudio sobre el efecto de la radiación de electrones (E-beam (1 y 2 kGy sobre los compuestos de oxidación del colesterol (COPs del lomo de cerdo almacenado a 4 y 8 °C bajo diferentes atmósferas (aire, vacío y dióxido de carbono. Este tipo de estudio ha sido llevado a cabo por primera vez en este tipo de muestras. El tratamiento estadístico combinado de distintas variables muestra que se producen cambios menores en algunos COPs en el lomo fresco debido a la temperatura de almacenamiento al método de empaquetado y al tiempo de almacenamiento. No hubo efecto de la dosis de radiación (hasta 2 KGy en los COPs, por lo que la radiación E-beam puede ser una herramienta útil para prolongar la vida útil del lomo fresco y adobado sin producir cambios en la composición de los COPs.

  16. External Beam Accelerated Partial-Breast Irradiation Using 32 Gy in 8 Twice-Daily Fractions: 5-Year Results of a Prospective Study

    Energy Technology Data Exchange (ETDEWEB)

    Pashtan, Itai M. [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Recht, Abram [Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts (United States); Ancukiewicz, Marek [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Brachtel, Elena [Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts (United States); Abi-Raad, Rita F. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); D' Alessandro, Helen A. [Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts (United States); Levy, Antonin; Wo, Jennifer Y. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Hirsch, Ariel E. [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts (United States); Kachnic, Lisa A. [Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Goldberg, Saveli [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Specht, Michelle; Gadd, Michelle; Smith, Barbara L. [Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Powell, Simon N. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Taghian, Alphonse G., E-mail: ataghian@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2012-11-01

    Purpose: External beam accelerated partial breast irradiation (APBI) is an increasingly popular technique for treatment of patients with early stage breast cancer following breast-conserving surgery. Here we present 5-year results of a prospective trial. Methods and Materials: From October 2003 through November 2005, 98 evaluable patients with stage I breast cancer were enrolled in the first dose step (32 Gy delivered in 8 twice-daily fractions) of a prospective, multi-institutional, dose escalation clinical trial of 3-dimensional conformal external beam APBI (3D-APBI). Median age was 61 years; median tumor size was 0.8 cm; 89% of tumors were estrogen receptor positive; 10% had a triple-negative phenotype; and 1% had a HER-2-positive subtype. Median follow-up was 71 months (range, 2-88 months; interquartile range, 64-75 months). Results: Five patients developed ipsilateral breast tumor recurrence (IBTR), for a 5-year actuarial IBTR rate of 5% (95% confidence interval [CI], 1%-10%). Three of these cases occurred in patients with triple-negative disease and 2 in non-triple-negative patients, for 5-year actuarial IBTR rates of 33% (95% CI, 0%-57%) and 2% (95% CI, 0%-6%; P<.0001), respectively. On multivariable analysis, triple-negative phenotype was the only predictor of IBTR, with borderline statistical significance after adjusting for tumor grade (P=.0537). Conclusions: Overall outcomes were excellent, particularly for patients with estrogen receptor-positive disease. Patients in this study with triple-negative breast cancer had a significantly higher IBTR rate than patients with other receptor phenotypes when treated with 3D-APBI. Larger, prospective 3D-APBI clinical trials should continue to evaluate the effect of hormone receptor phenotype on IBTR rates.

  17. Mycosis Fungoides electron beam absorbed dose distribution using Fricke xylenol gel dosimetry

    Science.gov (United States)

    da Silveira, Michely C.; Sampaio, Francisco G. A.; Petchevist, Paulo C. D.; de Oliveira, André L.; Almeida, Adelaide de

    2011-12-01

    Radiotherapy uses ionizing radiation to destroy tumor cells. The absorbed dose control in the target volume is realized through radiation sensors, such as Fricke dosimeters and radiochromic film, which permit to realize bi-dimensional evaluations at once and because of that, they will be used in this study as well. Among the several types of cancer suitable for ionizing radiation treatment, the Mycosis Fungoides, a lymphoma that spreads on the skin surface and depth, requires for its treatment total body irradiation by high-energy electrons. In this work the Fricke xylenol gel (FXG) was used in order to obtain information about the absorbed dose distribution induced by the electron interactions with the irradiated tissues and to control this type of treatment. FXG can be considered as an alternative dosimeter, since up to now only films have been used. FXG sample cuvettes, simulating two selected tomos (cranium and abdomen) of the Rando anthropomorphic phantom, were positioned along with radiochromic films for comparison. The phantom was subjected to Stanford total body irradiation using 6 MeV electrons. Tomographic images were acquired for both dosimeters and evaluated through horizontal and vertical profiles along the tomographic centers. These profiles were obtained through a Matlab routine developed for this purpose. From the obtained results, one could infer that, for a superficial and internal patient irradiation, the FXG dosimeter showed an absorbed dose distribution similar to the one of the film. These results can validate the FXG dosimeter as an alternative dosimeter for the Mycosis Fungoides treatment planning.

  18. Mycosis Fungoides electron beam absorbed dose distribution using Fricke xylenol gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Michely C. da [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Sampaio, Francisco G.A., E-mail: francisampaio@pg.ffclrp.usp.br [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Petchevist, Paulo C.D., E-mail: petchevist12@yahoo.com.br [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Instituto de Radioterapia e Megavoltagem, Ribeirao Preto, Sao Paulo (Brazil); Oliveira, Andre L. de [Servico de Radioterapia do Hospital das Clinicas da Unicamp, Campinas, Sao Paulo (Brazil); Almeida, Adelaide de, E-mail: dalmeida@ffclrp.usp.br [FFCLRP, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil)

    2011-12-15

    Radiotherapy uses ionizing radiation to destroy tumor cells. The absorbed dose control in the target volume is realized through radiation sensors, such as Fricke dosimeters and radiochromic film, which permit to realize bi-dimensional evaluations at once and because of that, they will be used in this study as well. Among the several types of cancer suitable for ionizing radiation treatment, the Mycosis Fungoides, a lymphoma that spreads on the skin surface and depth, requires for its treatment total body irradiation by high-energy electrons. In this work the Fricke xylenol gel (FXG) was used in order to obtain information about the absorbed dose distribution induced by the electron interactions with the irradiated tissues and to control this type of treatment. FXG can be considered as an alternative dosimeter, since up to now only films have been used. FXG sample cuvettes, simulating two selected tomos (cranium and abdomen) of the Rando anthropomorphic phantom, were positioned along with radiochromic films for comparison. The phantom was subjected to Stanford total body irradiation using 6 MeV electrons. Tomographic images were acquired for both dosimeters and evaluated through horizontal and vertical profiles along the tomographic centers. These profiles were obtained through a Matlab routine developed for this purpose. From the obtained results, one could infer that, for a superficial and internal patient irradiation, the FXG dosimeter showed an absorbed dose distribution similar to the one of the film. These results can validate the FXG dosimeter as an alternative dosimeter for the Mycosis Fungoides treatment planning.

  19. Analyse of the international recommendations on the calculation of absorbed dose in the biota; Analise das recomendacoes internacionais sobre calculo de dose absorvida na biota

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de S.; Py Junior, Delcy de A., E-mail: wspereira@inb.gov.b, E-mail: delcy@inb.gov.b [Industrias Nucleares do Brasil (UTM/INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerios; Universidade Federal Fluminense (LARARA/UFF), Niteroi, RJ (Brazil). Lab. de Radiobiologia e Radiometria; Kelecom, Alphonse [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-Graduacao em Ciencia Ambiental

    2011-10-26

    This paper evaluates the recommendations of ICRP which has as objective the environmental radioprotection. It was analysed the recommendations 26, 60, 91, 103 and 108 of the ICRP. The ICRP-103 defined the concept of animal and plant of reference (APR) to be used in the RAP based on the calculation of absorbed dose based on APR concept. This last view allows to build a legal framework of environmental protection with a etic, moral and scientific visualization, more defensible than the anthropomorphic concept

  20. Effects of cyclic deformation and irradiation at low temperature on the internal friction of pure aluminium

    International Nuclear Information System (INIS)

    The spectrum of internal friction (measurement frequency of about 2.5 Hz) as a function of temperature obtained with a sample of 99.999 % Al after cyclic deformation presents a peak at about 260 K. This peak is almost nonexistent after cold-working. The evolution of the spectra with annealing temperature and annealing time is described. The results are interpreted by the presence and the thermally activated migration of dislocation loops and impurities. (author)

  1. Optimum thickness of Mossbauer absorber

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    If recoilless fraction fa is available, the optimum absorber thickness dopt can be calculated by maximizing the signal to noise ratio or Q factor. In this work,an approach presented is to get experimental Qexp as a function of the thickness, and then fitting Qexp by its theoretical expression gives fa value. At last the dopt value is deduced from a maximum on the fitted curve. In such a way, thicknesses of six specimens with quadrupole or magnetic hyperfine splitting were optimized.

  2. [The assessment of accumulated internal irradiation doses of the inhabitants of the populated areas in Republik Belarus after Chernobyl accident].

    Science.gov (United States)

    Chunikhin, L A; Drozdov, D N

    2012-01-01

    A new system of evaluation methods has been developed for the assessment of the accumulated internal irradiation doses in the inhabitants of the populated areas of the Republic of Belarus that were contaminated by the Chernobyl radionuclides. The system is based on the results of WBC measurements. The model is based on the WBC-results of the State Dosimetric Register for the period of 1987-2010. The dose assessment model is based on the classification of the populated areas, on the regional features of the soils through which 137Cs can enter into the locally grown and produced foods. The model is also based on building the regressive correlations of accumulated internal doses to the contamination density of the territory of a populated area. Such regressive correlations are made for each region. The influence of indirect factors of dose forming was taken into consideration in the dose assessment. Among these factors are the population of the area, and the amount of forested territory around it, which were taken as correction coefficients. The coefficients were determined from the regressive correlation of the correction coefficients to a specific area of forest for each region. So called "countermeasure factor" was used for specification of other model results.

  3. Can absorb frame nail in multiple frame analysis the analysis of internal fixation%可吸收肋骨钉在多发性肋骨析内固定的分析

    Institute of Scientific and Technical Information of China (English)

    姜毅

    2012-01-01

      objective:discuss absorbability frame nail in multiple fractured ribs of internal fixation effect. Methods:select 15 cases of multiple frame fracture patients, divided into the observation group and the control group and observation group the absorbability soft fixed internal fixation, the comparison group USES the steel plate internal fixation, compared with two groups of curative effect. As a result, observation group than in the control group total effective rate in patients with high, infection rates low, shorter hospitalization time. Conclusion: the absorbability frame nail treatment of multiple fractured ribs is a new method, safe and reliable, the pain is small, it is suggested that clinical promotion.%  目的:讨论可吸收性肋骨钉在多发性肋骨骨折中的内固定作用。方法:选择15例多发性肋骨骨折患者,分为观察组和对照组,观察组采用可吸收性软固定内固定,对照组采用钢板内固定,比较两组的疗效。结果:观察组比对照组患者总有效率高,感染率低,住院时间短。结论:可吸收性肋骨钉是治疗多发性肋骨骨折的新方法,安全可靠,痛苦小,建议临床推广。

  4. Influence of the fractioned irradiation energy in the phototherapy with low intensity laser on the growth of human dental pulp fibroblasts

    Science.gov (United States)

    Meneguzzo, D. T.; Eduardo, C. P.; Ribeiro, M. S.; Marques, M. M.

    2008-03-01

    Laser phototherapy has proven to improve treatment of several pathologies in dentistry. The aim of the present study was to analyze the low power laser phototherapy effects comparing multiple irradiations with the same total energy at once. This in vitro study focuses on the biostimulation of cellular growth of pulp fibroblasts (FP5 cell lineage). The cells were grown in Dulbecco's Modified Eagle's (DME) medium with either 5% (nutritional deficit) or 10% fetal bovine serum (FBS). Laser irradiation was carried out with diode lasers with the following parameters: 685 nm, 40 mW, spot size 0.019 cm2. The groups were: G1(6.3J/cm2, 3 s, 0.12J), G2 (12.6J/cm2, 6 s, 0.24J), G3 (18.9J/cm2, 9 s, 0.36J), G4 (2 irradiations of 6.3J/cm2, 0.24J), G5 (3 irradiations of 6.3J/cm2, 0.36J), G6 (5% SFB, negative control, without irradiation), and G7 (10% SFB, positive control, without irradiation). On groups G4 and G5 the irradiation was performed with 6h-intervals. For growth analysis, the MTT test was used 24 hours after the last irradiation. The data from spectrophotometer were analyzed by ANOVA followed by the Tukey's test. The groups submitted to multiple irradiations presented significantly higher cell growth than the groups with single irradiation. This cell growth was similar to that of positive control group. The laser phototherapy with multiple irradiations is more effective on cellular growth.

  5. Operation and commissioning of IFMIF (International Fusion Materials Irradiation Facility) LIPAc injector

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, Y., E-mail: okumura.yoshikazu@jaea.go.jp, E-mail: rjgobin@cea.fr; Knaster, J.; Ayala, J.-M.; Marqueta, A.; Perez, M.; Pruneri, G.; Scantamburlo, F. [IFMIF/EVEDA Project Team, Obuchi-Omotedate, 039-3212 Rokkasho, Aomori (Japan); Gobin, R., E-mail: okumura.yoshikazu@jaea.go.jp, E-mail: rjgobin@cea.fr; Bolzon, B.; Chauvin, N.; Chel, S.; Harrault, F.; Senée, F.; Valette, M. [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France); Heidinger, R.; Cara, P.; Gex, D.; Phillips, G. [F4E, Fusion for Energy, BFD Department, D-85748 Garching (Germany); Ichimiya, R.; Ihara, A. [JAEA, Division of Rokkasho BA Project, Obuchi-Omotedate, 039-3212 Rokkasho, Aomori (Japan); and others

    2016-02-15

    The objective of linear IFMIF prototype accelerator is to demonstrate 125 mA/CW deuterium ion beam acceleration up to 9 MeV. The injector has been developed in CEA Saclay and already demonstrated 140 mA/100 keV deuterium beam [R. Gobin et al., Rev. Sci. Instrum. 85, 02A918 (2014)]. The injector was disassembled and delivered to the International Fusion Energy Research Center in Rokkasho, Japan. After reassembling the injector, commissioning has started in 2014. Up to now, 100 keV/120 mA/CW hydrogen and 100 keV/90 mA/CW deuterium ion beams have been produced stably from a 10 mm diameter extraction aperture with a low beam emittance of 0.21 π mm mrad (rms, normalized). Neutron production by D-D reaction up to 2.4 × 10{sup 9} n/s has been observed in the deuterium operation.

  6. The 90Sr +90Y kinetics investigation exchange and absorbed doses formation after acute internal irradiation of the rats in model experiment

    International Nuclear Information System (INIS)

    The possibility of the camera model theory application for the description of metabolic processes in the living organisms has been analyzed. The type of transport matrix of the model has been determined according to physical and biological limits for the system. It has been shown that camera model is stable. It is able to describe uniquely the processes in the living organisms. Model of 10 cameral has been proposed in order to describe 90Sr + 90Y exchange in the laboratory rats organism. The functions of isotope retention and kinetic constants needed for the practical application of the camera model theory have been determined for each camera. The doses of exposure of the experimental animals' organs ant tissues have been calculated

  7. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age; Etude bibliographique des parametres radiobiologiques du cesium-137 necessaires a l'evaluation des doses d'irradiation interne en fonction de l'age

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, A. [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author) [French] Ce document rassemble les informations publiees dans la litterature scientifique, concernant les parametres radiobiologiqueo du cesium-137, necessaires a l'evaluation des doses d'irradiation interne de l'homme en fonction de l'age. Ces donnees sont completees par une revue commentee des modeles mathematiques proposes en vue de l'evaluation des doses d'irradiation a partir des quantites de cesium ingerees et des parametres biologiques. (auteur)

  8. Optimization of the fractionated irradiation scheme considering physical doses to tumor and organ at risk based on dose–volume histograms

    Energy Technology Data Exchange (ETDEWEB)

    Sugano, Yasutaka [Graduate School of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Mizuta, Masahiro [Laboratory of Advanced Data Science, Information Initiative Center, Hokkaido University, Kita-11, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0811 (Japan); Takao, Seishin; Shirato, Hiroki; Sutherland, Kenneth L. [Department of Radiation Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Date, Hiroyuki, E-mail: date@hs.hokudai.ac.jp [Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan)

    2015-11-15

    Purpose: Radiotherapy of solid tumors has been performed with various fractionation regimens such as multi- and hypofractionations. However, the ability to optimize the fractionation regimen considering the physical dose distribution remains insufficient. This study aims to optimize the fractionation regimen, in which the authors propose a graphical method for selecting the optimal number of fractions (n) and dose per fraction (d) based on dose–volume histograms for tumor and normal tissues of organs around the tumor. Methods: Modified linear-quadratic models were employed to estimate the radiation effects on the tumor and an organ at risk (OAR), where the repopulation of the tumor cells and the linearity of the dose-response curve in the high dose range of the surviving fraction were considered. The minimization problem for the damage effect on the OAR was solved under the constraint that the radiation effect on the tumor is fixed by a graphical method. Here, the damage effect on the OAR was estimated based on the dose–volume histogram. Results: It was found that the optimization of fractionation scheme incorporating the dose–volume histogram is possible by employing appropriate cell surviving models. The graphical method considering the repopulation of tumor cells and a rectilinear response in the high dose range enables them to derive the optimal number of fractions and dose per fraction. For example, in the treatment of prostate cancer, the optimal fractionation was suggested to lie in the range of 8–32 fractions with a daily dose of 2.2–6.3 Gy. Conclusions: It is possible to optimize the number of fractions and dose per fraction based on the physical dose distribution (i.e., dose–volume histogram) by the graphical method considering the effects on tumor and OARs around the tumor. This method may stipulate a new guideline to optimize the fractionation regimen for physics-guided fractionation.

  9. Changes in the phospholipid fraction of intramuscular fat from pork loin (fresh and marinated with different irradiation and packaging during storage

    Directory of Open Access Journals (Sweden)

    García-Márquez, I.

    2013-03-01

    Full Text Available A study on the effect of E-beam (1 and 2 kGy on the phospholipid classes of fresh and marinated pork loin stored at 4 °C and 8 °C under different atmospheres (air, vacuum and carbon dioxide enriched atmospheres has been conducted. This is the first time that a study of this kind has been carried out on these types of samples. The combined statistical treatment of the distinct variables shows that minor changes (cardiolpin and sphingomyelin between both types of loin, cardiolipin vs storage temperatures and phosphatidylethanolamine vs the modified atmospheres are produced in the individual phospholipids subjected to the different selected conditions. The more relevant result was that no effect of the irradiation doses on the phospholipids classes was found, so the E-beam can be considered a useful tool to extend the shelf-life of fresh meat without changes in the phospholipid fraction.

    Se ha realizado un estudio sobre el efecto de la radiación de electrones (E-beam (1 y 2 kGy en las clases de fosfolípidos del lomo de cerdo almacenado a 4 y 8 °C bajo diferentes atmósferas ( aire, vacío y dióxido de carbono. Este tipo de estudio ha sido llevado a cabo por primera vez en este tipo de muestras. El tratamiento estadístico combinado de distintas variables muestran que se producen cambios menores en los fosfolípidos individuales sujetos a las diferentes condiciones seleccionadas (la cardiolipina y la esfingomielina se ven afectadas por el tipo de lomo, la cardiolipina por la temperatura de almacenamiento y la fosfatidiletanolamina por las atmósferas modificadas. El resultado más relevante fue que no hubo efecto de la dosis de radiación en las diferentes clases de fosfolípidos, por lo que la radiación E-beam se convierte en una herramienta útil para prolongar la vida útil de la carne fresca sin producir cambios en la fracción de fosfolípidos de ésta.

  10. [The effect of chronic internal irradiation from incorporated radionuclides on liver function].

    Science.gov (United States)

    Dedenko, I K; Zakharash, M P; Ganich, O N; Siksaĭ, L T; Shnitser, R I; Sofienko, G I; Bytsaĭ, N N; Zemskov, V S; Trunov, V I; Bukanov, V N

    1990-01-01

    On chronic supply to the body of a mixture of nuclear division products lanthanum-140, barium-140, tellurium-132, neodymium-147, neptunium-239, zirconium-95, niobium-95, iodine-131, cerium-141, -144, cesium-134, -137, and ruthenium-103 are detectable in liver tissue within the first months. In the 2 to 4 years following the disaster, liver tissue primarily accumulates cerium-144, radium-226, thorium-228, -232, ruthenium-106, antimony-125, and europium-154. Within the first periods the liver radionuclide content was 19 to 31% higher than that in the blood, and in the following years it was 24 to 38% higher. The radionuclides indicated were actively excreted with the bile into the gastrointestinal lumen. Within the first months after the chronic internal radiation the functional liver disorders were detectable in 30 to 40% of the patients. Later on diverse acute and chronic diseases of the liver, gallbladder and pancreas were detectable in 20 to 30% of the patients. The radionuclide content in the body was found to be in parallel with functional liver disorders. Acceleration of radionuclide excretion from the body results in liver function improvement.

  11. Research in radiobiology: Annual report of work in progress in the internal irradiation program

    International Nuclear Information System (INIS)

    In the early 1950's the Atomic Energy Commission established at the University of Utah a large, long-term study designed to investigate the toxicity of internally deposited radionuclides in beagles. The first animals were injected on December 1, 1952 and thus began an odyssey unusual in modern science both for its duration and continued scientific interest and relevance. The original dogs were injected with 239Pu and 226Ra. Later, studies were initiated with 241Am, 249Cf, 252Cf, 253Es, 224Ra, 228Ra, 90Sr, and 228Th. These studies were unique and have and will continue to contribute valuable scientific information on the behavior and effects of these substances in biological systems. We feel that the data collected from these studies will be useful for many decades to come as we ask more demanding questions relative to radionuclides and environmental, biological and health issues. While this publication will be the last of our series Research in Radiobiology, the lifespan carcinogenesis studies are continuing under a collaborative arrangement with the I.T.R.I. Beginning in 1988, the colony status tables of dogs in the Utah studies and reports of research by the Radiobiology faculty will be included in the annual I.T.R.I. report. Under our new collaborative arrangements with the I.T.R.I. for the conduct of the lifespan carcinogenesis studies, we expect a continued high level of scientific productivity from our faculty

  12. Weekly bi-fractionated 40 Gy three-dimensional conformational accelerated partial irradiation of breast: results of a phase II French pilot study; Irradiation partielle acceleree du sein tridimensionnelle conformationnelle de 40Gy bifractionnee hebdomadaire: resultats d'une etude pilote francaise de phase II

    Energy Technology Data Exchange (ETDEWEB)

    Bourgier, C.; Pichenot, C.; Verstraet, R.; Heymann, S.; Biron, B.; Delaloge, S.; Garbay, J.R.; Marsiglia, H.; Bourhis, J. [Intitut Gustave-Roussy, 94 - Villejuif (France); Taghian, A. [Massachusetts General Hospital-Harvard, Boston (United States); Marsiglia, H. [Universite Florence (Italy)

    2010-10-15

    The authors report the first French experience of three-dimensional conformational and accelerated partial irradiation of breast. Twenty five patients have been concerned by this phase II trial. The prescribed total dose was 40 Gy, was delivered over 5 days in two daily fractions. Irradiation was performed with two 6 MV tangential mini-beams and a 6-22 MeV front electron beams. The planning target volume coverage was very good. Toxicity has been assessed. Healthy tissues (heart, lungs) are considerably protected. The acute and late toxicity is correct. Short communication

  13. Safety of Long Term Treatment with Venom Fraction Isolated from the Scorpion Androctonus amoreuxi to Irradiated Rats Receiving Bone Marrow Transplantation

    International Nuclear Information System (INIS)

    Scorpion Venom of Androctonus amoreuxi contains a strong bradykinin potentiating factor (BPF) that augments bradykinin effect through enhancing its release. Cytoprotective ability of BPF has been documented, but its stimulation to cellular proliferation and differentiation could induce possible carcinogenicity, so this study aims to assure its safe use. BPF and isologous bone marrow transplantation (BMT) has been investigated in irradiated rats. The examined parameters included serum alpha fetoprotein, carcinoembryonic antigen, β2-microglobulin, total cholesterol, triglycerides and bilirubin beside liver histopathology. A group of rats received isologous BMT (75 x 106 ±5 cells) performed 3 h post irradiation, another group received i.p. injection of 8 doses of BPF each of 1 μg/ g body wt (one dose/ week). Irradiation was performed at the dose level of 5 Gy. All animals were examined after an investigation period of 60 days. Either biological agent was performed solely or together with irradiation, as well as their combination. The results pointed out that irradiation induced a significant elevation in the level of serum β2-microglobulin (P< 0.05), cholesterol, triglycerides and bilirubin after a period of 60 days. Neither BPF repeated injection nor BMT solely or combined with irradiation induced any carcinogenicity as indicated by tumour markers and confirmed by histo-pathological examination. Both treatments with irradiation significantly depressed cholesterol, triglycerides and bilirubin compared to the irradiated group. Regeneration in liver cells is observed 60 days post irradiation and treatment with both agents as well as an increase in hepatic cells, nuclear size and maintained cytoplasm. Results clarify the safe use of BPF as a biological treatment comparable to BMT

  14. Technology and assessment of neutron absorbing materials

    International Nuclear Information System (INIS)

    The present review assesses more recent developments in the technology and application of those absorber materials which are considered to be established or to have shown potential in reactor control. Emphasis is placed on physical, chemical and metallurgical properties and upon irradiation behaviour. (author)

  15. The ALICE absorbers

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Weighing more than 400 tonnes, the ALICE absorbers and the surrounding support structures have been installed and aligned with a precision of 1-2 mm, hardly an easy task but a very important one. The ALICE absorbers are made of three parts: the front absorber, a 35-tonne cone-shaped structure, and two small-angle absorbers, long straight cylinder sections weighing 18 and 40 tonnes. The three pieces lined up have a total length of about 17 m.

  16. Changes in the Lipid Fraction of Eel Gills after Ionizing Irradiation in Vivo and a Shift from Fresh to Sea Water

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max

    1975-01-01

    Sixteen eels were adapted to tap water for a week. Then eight of them were irradiated with 1000 R γ-radiation and four of the irradiated group and four of the nonirradiated control group were transferred to sea water. The rest remained in tap water. Three days later all were incubated with 14 C-l...... been irradiated and transferred to sea water. By measuring lipid biosynthesis in gill tissue it was thus possible to show an interaction between the effect of ionizing irradiation and the salinity of the environment, in agreement with previous biological findings.......Sixteen eels were adapted to tap water for a week. Then eight of them were irradiated with 1000 R γ-radiation and four of the irradiated group and four of the nonirradiated control group were transferred to sea water. The rest remained in tap water. Three days later all were incubated with 14 C......-labeled acetate and 32 P-labeled phosphate added to the water in the aquariums. Lipids from the gills were separated by tlc and the individual fatty acids were assayed by paper chromatography. Results showed an enhanced incorporation of 14 C activity into sterol esters in sea water. This was further intensified...

  17. Comparison of the guinea pig's physiological and cellular response to the respirable fraction of untreated, heat treated, microwave irradiated and ethylene oxide treated DB 1/88 bulk cotton dust

    International Nuclear Information System (INIS)

    A study was conducted to determine whether bulk cotton dust could be treated in order to reduce the biological activity of the respirable fraction of the dust. Four groups of guinea-pigs were exposed to respirable DB 1/88 bulk cotton dust aerosol which had been untreated, heat treated (to 190 degrees-C for 2 hours), microwave irradiated (for 3 minutes at 700 watts and a frequency of 2450 megahertz), and ethylene-oxide treated (for 48 hours) and a control group which was held in a chamber with filtered air. Animals exposed to the respirable fraction of untreated DB 1.88 bulk dust had the greatest breathing rate response while the minimum breathing rate response occurred in the group of animals exposed to the respirable fraction of heat treated DB 1.88 bulk cotton dust. Lymphocyte and granulocyte infiltration was greatest in animals exposed to the respirable fraction of the untreated DB 1.88 bulk cotton dust and the smallest in animals exposed to the respirable fraction of heated DB 1.88 bulk cotton dust. The results indicated that treating bulk cotton dust to alter bacteria viability and bacteria byproducts was effective in reducing the response of the guinea-pig model to the respirable dust

  18. Bladder preservation by internal iliac arterial infusion chemotherapy and irradiation in T3 bladder carcinoma patients over the age of 70 years

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Senji; Shintaku, Ichiro; Suzuki, Ken-ichi; Takahashi, Toshiko; Kaihou, Yasuhiro; Ishidoya, Shigeto; Namima, Takashige; Ohyama, Chikara; Orikasa, Seiichi [Tohoku Univ., Sendai (Japan). School of Medicine

    2000-12-01

    Treatment by internal iliac arterial infusion chemotherapy (IA) combined with pelvic irradiation has proved to be effective for locally invasive bladder. Eight male patients, median age of 78 years (range 73-81) were enrolled. Pretreatment CT and whole layer core biopsy revealed T3a or T3b. Pelvic CT or fine needle aspiration biopsy following bipedal lymphography revealed N0 in 4 cases, N2 in 2 and N3 in 2, respectively. Three to 7 cycles of cisplatin (CDDP) 30-50 mg/m{sup 2}, methotrexate 20 mg/m{sup 2} and tetrahydropymnyl-adriamycin 20 mg/m{sup 2} every 3 week was administered combined with 40-50 Gy of whole pelvis irradiation. In 4 renal function impaired patients, 100 mg/m{sup 2} of carboplatin was administered instead of CDDP. All patients obtained complete response and the bladders were preserved. Observation periods were from 9 to 75 months (median 37 months). One N2 patient died with metastatic disease and two died without carcinoma. Two patients developed invasive bladder cancer on the side opposite to the primary tumors. Both were successfully treated by IA and irradiation. Bladders of all except one patient functioned for a long period. Side effects of IA and irradiation were not significant. IA combined with pelvic irradiation is effective and safe for elderly patients with bladder carcinoma. (author)

  19. Initial increase, ''peaking effect'', in the internal friction of copper following pulsed neutron and electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, H.M.; Parkin, D.M.; Goldstone, J.A.; Hemsky, J.W.

    1985-01-01

    Under certain experimental conditions the internal friction in metals can first increase and following prolonged irradiation decrease. Many models have been proposed to account for this ''peaking effect''; however, in many of the cases, no effort is made to distinguish between the influence of interstitials and/or vacancies. To determine the nature of the point defect responsible for the peaking effect in high purity copper, we have performed a series of pulsed irradiations using neutrons and electrons. In all of the experiments an initial very rapid rise in the internal friction and Young's modulus was observed. These data show that a fast diffusing defect is responsible for the peaking effect: i.e. the interstitial.

  20. 四物汤不同部位对辐射小鼠外周血象的影响%Effect of Different Fractions of Siwu Decoction on Hematopoietic Cells of Irradiated Mice

    Institute of Scientific and Technical Information of China (English)

    肖成荣; 马增春; 梁乾德; 谭洪玲; 王宇光; 汤响林; 赵永红; 高月; 刘曙晨

    2014-01-01

    目的:观察四物汤不同分离部位对3.5 Gy照射小鼠外周血象的影响,发现四物汤补血作用的活性部位。方法60只小鼠常规饲养适应环境后,采用60 Co-γ射线3.5 Gy全身一次照射,照射后立即给予四物汤不同分离部位,连续给药7 d,在照射后1、3、5、7、9、11、13、15、17、19 d检测其对外周血象的影响。结果与模型对照组相比,四物汤不同洗脱分离部位在不同时间点可以升高辐射致血虚证小鼠外周血白细胞、红细胞和血小板,其中水洗脱部分对辐射致血虚证小鼠补血效果较佳。结论四物汤补血作用的主要物质为多糖、单糖等大极性成分。%Objective To observe the effect of different fractions of Siwu decoction by evaluating the recov-ery of peripheral blood hematology of irradiated mice in order to screen hematopoietic constituents. Methods Sixty mice were irradiated at a dose of 3. 5 Gy using cobalt-60 gamma resources. Following irradiation,different elution fractions of Siwu decoction were administered intragastrically for 7 consecutive days. Blood samples were collected from the tail end and the number of peripheral blood cells was counted on days 1 ,3 ,5 ,7 ,9 ,11 ,13 ,15 ,17 and 19 using a microcell counter. Results Compared with the control group,white blood cells,red blood cells,platelets were all increased in drug treated group. The water eluted fraction of the supernatant of 60% alcohol is the most ef-fective constituent to increase peripheral white blood cells. Conclusion The fraction of polysaccharide and monosac-charide in Siwu decoction is the most effective constituent to stimulate the recovery of peripheral blood hematology of irradiated mice.

  1. Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)

    Science.gov (United States)

    Rehman, Fazal-ur; Adeel, Shahid; Qaiser, Summia; Ahmad Bhatti, Ijaz; Shahid, Muhammad; Zuber, Mohammad

    2012-11-01

    Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash -SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.

  2. Results of electron beam irradiation for tongue cancer

    International Nuclear Information System (INIS)

    From 1967 through 1988 183 previously untreated patients with squamous-cell carcinoma of the tongue were treated with electron beam irradiation. The patients were restaged as stage I (38 patients), stage II (64), stage III (58), and stage IV (28). For evaluable patients treated with intra-oral cone irradiation (IOC) alone (n=53) or combined with external irradiation (n=120), the two-year local control rate was 85% for T1, 73% for T2, and 58% for T3. According to clinical features, it was 80% for tumorous type, 68% for small ulceration type, and 53% for large ulceration type. In comparing uneven and even fractionated irradiation procedures, there was no significant difference in two-year local control rate (68% for uneven fractionated irradiation vs. 61% for even fractionated irradiation). When restricting to T2 and T3 patients, it was significantly higher for uneven fractionated irradiation (77% and 63%) than even fractionated irradiation (56% and 40%). In comparing T3 patients categorized as having >1000 mm2 (I) with those as having ≤1000 mm2 (II). the two-year local control rate was 48% for category I and 72% for category II. For T3 patients, it was 43% when associated with ulcer, as compared with 74% without it. The actuarial five-year survival rate was 92% for stage I, 72% for stage II, 67% for stage III, and 12% for stage IV. Delayed radiation ulcer and bone exposure were seen in 22 and 7 patients, respectively. In conclusion, IOC is comparable to internal irradiation and is clinically effective for T1 through T3 (in smaller size) tongue cancer. (N.K.)

  3. Research on porous sound-absorbing materials by the secondary cracking fraction of cracked residue of waste silicone rubbers%废硅橡胶二次裂解渣制多孔吸声材料的研究

    Institute of Scientific and Technical Information of China (English)

    吕春丽; 范磊; 王明贤

    2011-01-01

    采用吸声材料是吸声、降噪、改善声环境的有效手段.本文研究用废旧硅橡胶二次裂解渣和粘结剂为主要原料,采用压制成型的工艺,在常温下制成一种多孔吸声材料.主要考虑残渣里的硅烷类油份和所用发泡剂对试件吸声性能的影响.试验结果表明:所制吸声材料能达到一定的吸声性能,具有对环境无污染,施工方便等优点;且分离出硅烷类油份的灰渣所制试件比原废旧硅橡胶裂解残渣的吸声效果好很多,尤其在共振频率1250Hz下达到吸声峰值0.87.FP - 186植物性水泥发泡剂相比FP- 180动物性水泥发泡剂对试件吸声性能有所改善,使吸声特性曲线向低频方向移动.%With the development of the economic and society in our country, people's living standards are increasing. People demand higher quality of life environment in city, and draw attention on the noise reduction and the improvement of the acoustic environment, increasingly. Sound-absorbing material is an effective means of sound absorption and improving the acoustic environment. In this paper, the porous absorbing material were made by press forming technique at room temperature incorporatly with binder and the secondary cracked residue of waste silicone rubbers. The influences of oil portion of silanes and foaming agent on sound absorption of the porous absorbing material were investigated. The material showed the characteristics of low cost of preparation and non-pollution to the environment. The results showed that the sound absorbing effect of the specimens made by ash and slag, separated from oil portion of silanes was better than the specimens made by cracked residue of waste silicone rubbers, especially when the resonant frequency was 1250Hz,product sound absorption coefficient could be 0. 87. The specimens adding FP - 186 botanical cement foaming agent showed a good improvement of the sound absorbing effect than FP -180 animalic cement foaming agent

  4. Methods for absorbing neutrons

    Science.gov (United States)

    Guillen, Donna P.; Longhurst, Glen R.; Porter, Douglas L.; Parry, James R.

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  5. Control of good irradiation practices and the role of the ICGFI guidelines and codes

    International Nuclear Information System (INIS)

    Considerable guidance is available to managers of an irradiator plant on ways and means to produce safe, wholesome, quality irradiated foods. The foundation for good manufacturing practices (GMPs), which apply to all food processes, is the Codex General Principles of Food Hygiene. These principles provide good common sense procedures in the handling of food for human consumption in order to ensure safe, wholesome quality products. The GMPs cover the growing, harvesting, preparation, processing, packaging, storage, transport, distribution and sale of food. They provide good check lists for safety and quality. More detailed guidelines specifically aimed at food irradiation are found in the Codex Code of Practice for the Operation of Irradiation Facilities and in the Codes of Good Irradiation Practice (GIPs) developed by the International Consultative Group on Food Irradiation. GIPs are available for eight commodity groups. They provide guidance on pre-irradiation handling (including microbiological guidelines), packaging, pre-irradiation storage and transport, irradiation facilities and absorbed doses, post-irradiation storage and handling, final product specifications, labelling, re-irradiation and the quality of irradiated products. In order to apply GIPs effectively, it recommended that the Hazard Analysis Critical Control Point concept (HACCP) be implemented. The HACCP concept emphasizes prevention of, rather than detection of defects. The HACCP concept has been adopted by the Codex Alimentarius Commission and is being applied to Codex Codes of Practice. (author). 7 refs

  6. Food irradiation and sterilization

    International Nuclear Information System (INIS)

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25 to 70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning in achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70 to 800C (bacon to 530C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurrence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-400C to -200C). Radappertized foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for 'wholesomeness' (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effects of radappertization on the 'wholesomeness' characteristics of these foods. (author)

  7. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  8. Quality control in the process and in the irradiated food

    International Nuclear Information System (INIS)

    In the irradiation process, absorbed dose is the key parameter that must be controlled. In general, the minimum absorbed dose needed to accomplish a desired effect, such as insect disinfestation or pathogen reduction, is already known from previous research, and is often prescribed by government regulations. The irradiation process is effective, however, only if the food can tolerate this dose without experiencing unwanted changes in flavor or appearance. The dose that food can tolerate often depends on such things as the variety of the fruit or vegetable, where it was grown, the season in which it was harvested and the length of time between harvesting and irradiation. Once the minimum and maximum doses are established, the irradiator operator must make sure that these dose limits are not exceeded. First, a dose mapping using many dosimeters must be undertaken to determine the locations of the minimum and maximum dose in the overall process load. From then on, the process load must always be the same, and, as a key step in the overall process control, dosimeters need to be placed from time to time only at the minimum or maximum locations. The dosimeters must be calibrated and directly trackable to national or international standards, and a fool-proof method of labelling and segregating irradiated from unirradiated product must be used. Radiation sensitive indicators that may help identify irradiated from unirradiated food should not be relied upon, and are not a substitute fro proper dosimetry. (Author)

  9. Quality control in the process and in the irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Farrar IV, H. [Chairman, ASTM Subcommittee E10.01 `Dosimetry for Radiation Processing`, 18 Flintlock Lane, Bell Canyon, California 91307-1127 (United States)

    1997-12-31

    In the irradiation process, absorbed dose is the key parameter that must be controlled. In general, the minimum absorbed dose needed to accomplish a desired effect, such as insect disinfestation or pathogen reduction, is already known from previous research, and is often prescribed by government regulations. The irradiation process is effective, however, only if the food can tolerate this dose without experiencing unwanted changes in flavor or appearance. The dose that food can tolerate often depends on such things as the variety of the fruit or vegetable, where it was grown, the season in which it was harvested and the length of time between harvesting and irradiation. Once the minimum and maximum doses are established, the irradiator operator must make sure that these dose limits are not exceeded. First, a dose mapping using many dosimeters must be undertaken to determine the locations of the minimum and maximum dose in the overall process load. From then on, the process load must always be the same, and, as a key step in the overall process control, dosimeters need to be placed from time to time only at the minimum or maximum locations. The dosimeters must be calibrated and directly trackable to national or international standards, and a fool-proof method of labelling and segregating irradiated from unirradiated product must be used. Radiation sensitive indicators that may help identify irradiated from unirradiated food should not be relied upon, and are not a substitute fro proper dosimetry. (Author)

  10. An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Louise G [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Tobin, S. J. [Los Alamos National Laboratory; Boyer, B. D. [Los Alamos National Laboratory; Menlove, H. O. [Los Alamos National Laboratory; Schear, M. A. [Los Alamos National Laboratory; Worrall, Andrew [U.K., NNL

    2010-11-24

    Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

  11. An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Louise G [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Tobin, S. J. [Los Alamos National Laboratory; Menlove, H. O. [Los Alamos National Laboratory; Schear, M. A. [Los Alamos National Laboratory; Worrall, Andrew [U.K. NNL

    2011-01-13

    Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/ or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

  12. Optimizing the schedules of fractionated irradiation in subclinical tumors of malignant glioma%恶性脑胶质瘤亚临床肿瘤分割照射方案优化的实验研究

    Institute of Scientific and Technical Information of China (English)

    许新; 杨伟志; 高黎; 盖雪; 石惠珍; 宋丽京

    2012-01-01

    目的 观察比较不同分割方案对人脑胶质瘤裸小鼠移植瘤亚临床肿瘤的剂量效应关系,筛选分割照射的优化方案.方法 采用人脑胶质母细胞瘤裸小鼠移植瘤亚临床肿瘤为实验模型进行不同总剂量(40、60 Gy)、不同分割方案(200 cGy5次/周、160 cGy2次/d、300 cGy5次/周和400cGy3次/周)及靶向药泰欣生联合常规分割照射.观察指标为成瘤率、肿瘤复发时间及肿瘤基底最大径,总观察时间为24周.结果 总剂量40 Gy时大分割组近期疗效较好(400 cGy3次/周疗程结束时成瘤率为0),无论采用何种分割方案均未能阻断肿瘤持续生长.总剂量60 Gy时常规分割的控制效果最差(成瘤率为100%),超分割方案的效果相对最好(远期控制为25%),其次为300 cGy5次/周(远期控制为12.5%),400 cGy3次/周相对较差(近期控制较远期好).靶向药泰欣生联合常规分割60 Gy照射无改善作用.结论 对控制恶性脑胶质瘤亚临床肿瘤常规分割模式尚不是一个优化方案,超分割160 cGy2次/d和300 cGy5次/周是相对优化方案.%Objective To study dose-response relationship and screen the optimized fractionated irradiation schedules in subclinical tumors of malignant glioma.Methods Balb/c-nude mice bearing human malignant glioma xenograft were assigned randomly into control group,fractionated irradiation schedules group and nimotuzumab-conventional fraction group.The fractionated schedules were 200 cGy x 5f/w,300 cGy ×5f/w,160 cGy ×2f/d x5 d and 400 cGy ×3f/w with total dose of 40 Gy and 60 Gy,respectively.Measurement indexes were tumor-forming rate,average recurrence time and maximum diameter of the tumor bottom.The observation lasted 24 weeks.Results With the total dose of 40 Gy,none of the significant long-term tumor regression were detected in any fractionated irradiation schedules; 400 cGy x 3f/w with complete tumor response at the end of treatment showed a better short-term curative effect

  13. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  14. Isoeffective dose: a concept for biological weighting of absorbed dose in proton and heavier-ion therapies

    CERN Document Server

    Wambersie, A; Menzel, H G; Gahbauer, R; DeLuca, P M; Hendry, J H; Jones, D T L

    2011-01-01

    When reporting radiation therapy procedures, International Commission on Radiation Units and Measurements (ICRU) recommends specifying absorbed dose at/in all clinically relevant points and/or volumes. In addition, treatment conditions should be reported as completely as possible in order to allow full understanding and interpretation of the treatment prescription. However, the clinical outcome does not only depend on absorbed dose but also on a number of other factors such as dose per fraction, overall treatment time and radiation quality radiation biology effectiveness (RBE). Therefore, weighting factors have to be applied when different types of treatments are to be compared or to be combined. This had led to the concept of `isoeffective absorbed dose', introduced by ICRU and International Atomic Energy Agency (IAEA). The isoeffective dose D(IsoE) is the dose of a treatment carried out under reference conditions producing the same clinical effects on the target volume as those of the actual treatment. It i...

  15. Quality control in the commerce of irradiated foods

    International Nuclear Information System (INIS)

    In spite of an irradiated food is innocuous for health and that the irradiation process offers great advantages as conservation and hygiene method and it has been recognised by the Agriculture and Health International organizations and although the adequate equipment exists to make this treatment in the majority of countries, an international trade of irradiated foods has not been established and it is that it has to be required that the quality control of the treatment should be regulated by the corresponding authorities and it also should be harmonized with other countries for the commercial interchange. Owing to up to present an identification method of irradiated foods which is validated, the unique quality control for irradiated foods is realized in the irradiation plant, measuring the absorbed dose in products, using dosimetric systems justly calibrated and standardized to be used the adequate for the type of product and dose level which is wanted to be measured for foods mainly for quarantine treatment which is very important to determine that any part of the irradiation system has reached the minimum dose to obtain the technical effect which is desired and that it does not exceed the maximum dose for that the product quality not to be altered. (Author)

  16. Absorbable internal fixation materials in the repair of patellar transverse fractures%可吸收内固定材料修复髌骨横断性骨折

    Institute of Scientific and Technical Information of China (English)

    王峰; 贾金领

    2016-01-01

    BACKGROUND: In recent years, al kinds of absorbable internal fixation materials have been used in the clinical treatment of patel ar transverse fractures. OBJECTIVE: To investigate the repairing effect of absorbable internal fixation materials on patel ar transverse fractures. METHODS: Total y 102 cases of fresh patel ar transverse fractures were included 62 males and 40 females cases, with a mean age of (41.85±11.15) years, and according to treatment methods, they were divided into two groups: observation group (n=52) using absorbable screws for reconstruction and control group (n=50) using Kirschner wire repair. At 12 months after repair, Lysholm knee function score were measured and evaluated, and the occurrence of adverse events was recorded. RESULTS AND CONCLUSION: The knee function score and excel ent rate of the observation group were significantly higher than those of the control group (both P < 0.05). In the observation group, there were four cases of fracture displacement, but no skin irritation and other adverse events occurred; in the control group, there were two cases of nonunion and five cases of skin irritation or internal fixation loosening and slippage. Therefore, there was a higher incidence of adverse events in the control group compared with the observation group (P < 0.05). These experimental results show that the use of absorbable screws in the repair of patel ar transverse fracture can promote the functional recovery of the knee joint, with good biocompatibility.%背景:近几年来,各种可吸收内固定材料开始被积极应用于各种髌骨横断性骨折的临床治疗中。目的:探讨可吸收内固定材料修复髌骨横断性骨折的效果。方法:纳入102例新鲜髌骨横断性骨折患者,其中男62例,女40例,年龄(41.85±11.15)岁,按治疗方法分为2组,观察组(n=52)采用可吸收螺钉修复,对照组(n=50)采用改良张力带钢丝内固定修复。修复后12个月,进行 Lysholm

  17. Absorbing Outflows in AGN

    Science.gov (United States)

    Mathur, Smita

    2002-01-01

    The goal of this program was a comprehensive multiwavelength study of absorption phenomena in active galactic nuclei (AGN). These include a variety of associated absorption systems: X-ray warm absorbers, X-ray cold absorbers. UV absorbers with high ionization lines, MgII absorbers, red quasars and BALQSOs. The aim is to determine the physical conditions in the absorbing outflows, study their inter-relations and their role in AGN. We designed several observing programs to achieve this goal: X-ray spectroscopy, UV spectroscopy, FLAY spectroscopy and X-ray imaging. We were very successful towards achieving the goal over the five year period as shown through following observing programs and papers. Copies of a few papers are attached with this report.

  18. Materials response to irradiation

    International Nuclear Information System (INIS)

    Radiation-induced changes in the mechanical properties of metals, e.g. due to the embrittlement necessitate irradiation experiments with HTR-specific neutron spectra. These experiments help to determine materials behaviour and establish basic data for design and safety testing, especially with a view to the high fluence and temperature loads on absorber cans. The experiments are carried out up to maximum operational fluence (>= 1022nsub(th)/cm2). Results so far have shown the importance of the materials structure for assurance of sufficient residual ductility after irradiation. Secondary experiments, e.g. on He implantation and radiation response of the absorber material B4C, are mentioned. (orig.)

  19. Use of electron accelerators in food irradiation

    International Nuclear Information System (INIS)

    Preservation of food by ionizing radiations involves controlled application of energy of radiation to agricultural commodities, foods and food ingredients, for improving storage life, hygiene and safety. Insects and microbes cause major economic losses to stored crops. Many of our food products are contaminated with diseases causing germs and toxin producing molds. Without improvement in microbial quality and getting properly treated to overcome quarantine barriers our agricultural products cannot get international markets. In this respect electron accelerators have immense potential in commercial radiation processing of foods. Both low and high dose applications with increased process rates can be achieved using accelerators to cover a wide spectrum of food commodities approved for commercial radiation processing as per the recent gazette notification under Atomic Energy (Radiation Processing of Food and Allied Products) Rule, 2012. The effectiveness of processing of food by ionizing radiation depends on proper delivery of absorbed dose and its reliable measurement. For food destined for international trade, it is important that the dosimetry used for dose determination is carried out accurately and that the process is monitored in accordance with the internationally accepted procedures. Experiments using alanine-EPR system were carried out to optimize the process parameters of 10 MeV electron beam for commercial irradiation of food. Different food commodities namely, mango, potato and rawa (semolina) were irradiated to measure the absorbed dose distribution. The actual depth dose profile in food products and useful scan width of the electron beam were determined for commercial radiation processing of food using electron beam. (author)

  20. On-Going International Research Program on Irradiated Concrete Conducted by DOE, EPRI and Japan Research Institutions. Roadmap, Achievements and Path Forward

    International Nuclear Information System (INIS)

    The Joint Department of Energy (DOE)-Electric Power Research Institute (EPRI) Program (Light Water Reactor Sustainability (LWRS) Program Material Pathway Concrete and Long-Term Operation (LTO) Program) and US Nuclear Regulatory Commission (NRC) research studies aim at understanding the most prominent degradation modes and their effects on the long-term operation of concrete structures to nuclear power generation. Based on the results of the Expanded Materials Degradation Analysis (EMDA), (NUREG/CR-7153, ORNL/TM-2011/545), irradiated concrete and alkali-silica reaction (ASR)-affected concrete structures are the two prioritized topics of on-going research. This report focuses specifically on the topic of irradiated concrete and summarizes the main accomplishments obtained by this joint program, but also provides an overview of current relevant activities domestically and internationally. Possible paths forward are also suggested to help near-future orientation of this program.

  1. On-Going International Research Program on Irradiated Concrete Conducted by DOE, EPRI and Japan Research Institutions. Roadmap, Achievements and Path Forward

    Energy Technology Data Exchange (ETDEWEB)

    Le Pape, Yann [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rosseel, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-01

    The Joint Department of Energy (DOE)-Electric Power Research Institute (EPRI) Program (Light Water Reactor Sustainability (LWRS) Program–Material Pathway–Concrete and Long-Term Operation (LTO) Program) and US Nuclear Regulatory Commission (NRC) research studies aim at understanding the most prominent degradation modes and their effects on the long-term operation of concrete structures to nuclear power generation. Based on the results of the Expanded Materials Degradation Analysis (EMDA), (NUREG/CR-7153, ORNL/TM-2011/545), irradiated concrete and alkali-silica reaction (ASR)-affected concrete structures are the two prioritized topics of on-going research. This report focuses specifically on the topic of irradiated concrete and summarizes the main accomplishments obtained by this joint program, but also provides an overview of current relevant activities domestically and internationally. Possible paths forward are also suggested to help near-future orientation of this program.

  2. Internal irradiation of the carcinoma of the prostate. Interview with Prof. Dr. S. Loening. Interne Bestrahlung des Prostatakarzinoms. Nachgefragt bei Prof. Dr. S. Loening

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-01-01

    A procedure for the radiologic treatment of the carcinoma of the prostate has recently been developed by clinicians of the 'Charite' and Berlin University Hospital at Steglitz. In this procedure, access to the carcinoma for spiking with tags and subsequent irradiation using the afterloading method is gained from the perineum. (orig.).

  3. The effect of E-beam irradiation on the sterilization for calcium lactate

    International Nuclear Information System (INIS)

    The sterilization of calcium lactate as food additive was performed by electron beam. The quality, numbers of colony, gather mold and yeasts were determined before and after irradiation. It was found that the mortality of microbes significantly decreased with the increment of absorbed doses and the D10 value of colony number was determined to be 4.38 kGy. And the quality of calcium lactate satisfied the food standard though its mass fraction decreased a little after irradiation with electron beam of 10 kGy. (authors)

  4. Higher toxicity with 42 Gy in 10 fractions as a total dose for 3D-conformal accelerated partial breast irradiation: results from a dose escalation phase II trial

    International Nuclear Information System (INIS)

    Recent recommendations regarding indications of accelerated partial breast irradiation (APBI) have been put forward for selected breast cancer (BC) patients. However, some treatment planning parameters, such as total dose, are not yet well defined. The Institut Gustave Roussy has initiated a dose escalation trial at the 40 Gy/10 fractions/5 days and at a further step of total dose (TD) of 42 Gy/10 fractions/ 5 days. Here, we report early results of the latest step compared with the 40 Gy dose level. From October 2007 to March 2010, a total of 48 pT1N0 BC patients were enrolled within this clinical trial: 17 patients at a TD of 42 Gy/10f/5d and 31 at a TD of 40 Gy/10f/5d. Median follow-up was 19 months (min-max, 12–26). All the patients were treated by APBI using a technique with 2 minitangents and an “enface” electrons delivering 20% of the total dose. Toxicities were systematically assessed at 1; 2; 6 months and then every 6 months. Patients’ recruitment of 42 Gy step was ended owing to persistent grade 3 toxicity 6 months after APBI completion (n = 1). Early toxicities were statistically higher after a total dose of 42 Gy regarding grade ≥2 dry (p = 0.01) and moist (p = 0.05) skin desquamation. Breast pain was also statistically higher in the 42 Gy step compared to 40 Gy step (p = 0.02). Other late toxicities (grade ≥2 fibrosis and telangectasia) were not statistically different between 42 Gy and 40 Gy. Early toxicities were more severe and higher rates of late toxicities were observed after 42 Gy/10 fractions/5 days when compared to 40 Gy/10 fractions/5 days. This data suggest that 40 Gy/10 fractions/ 5 days could potentially be the maximum tolerance for PBI although longer follow-up is warranted to better assess late toxicities

  5. Storage, transportation, test marketing and consumer acceptance of irradiated potatoes, onions, garlic and fruit

    International Nuclear Information System (INIS)

    The Shanghai Irradiation Center irradiated 830 tonnes of garlic 395 tonnes of potatoes 620 tonnes of onions and 50 tonnes of apples from 1990 to 1993 for test marketing. A consumer trial on irradiated apples was conducted. The results showed that 90% of consumers liked irradiated fruit and would be willing to buy them again. SIC established technological standards for the irradiation of garlic, potatoes and onions based on the codes of good irradiation practices recommended by the International Consultative Group on Food Irradiation. These standards were followed during the conduct of the research studies reported in this paper. A cost-benefit analysis of irradiated apples and garlic was performed. It was observed that irradiated apples would provide a profit of 52% and irradiated garlic 100% compared to unirradiated products. Data from an economic benefits study showed that products requiring a low absorbed dose have a higher profit margin. Therefore, the irradiation of garlic, potatoes and apples would be more profitable than radiation treatment of medical supplies and industrial products. (author). 7 refs, 3 figs, 10 tabs

  6. Internal mammary chain irradiation in breast cancer: State of the art; Radiotherapie de la chaine mammaire interne dans les cancers du sein: etat des lieux

    Energy Technology Data Exchange (ETDEWEB)

    Auberdiac, P.; Cartier, L.; Hau Desbat, N.H.; De Laroche, G.; Magne, N. [Unite de curietherapie, departement de radiotherapie, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France); Chargari, C. [Service d' oncologie radiotherapie, hopital d' instruction des armees du Val-de-Grace, 74, boulevard Port-Royal, 75230 Paris cedex 5 (France); Zioueche, A. [Service de radiotherapie, CHU Dupuytren, 2, avenue Martin-Luther-King, 87000 Limoges (France); Melis, A. [Departement d' oncologie medicale, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, 42271 Saint-Priest-en-Jarez cedex (France); Kirova, Y.M. [Service de radiotherapie oncologique, institut Curie, 26, rue d' Ulm, 75005 Paris (France)

    2011-04-15

    Radiation therapy has a major role in the management of infiltrative breast cancers. However, there is no consensus for the prophylactic treatment of the internal mammary chain (IMC), with strategies that show strong differences according to centers and physicians. Indications for internal mammary chain radiotherapy are debated, since this treatment significantly increases the dose delivered to the heart and leads to potential technical difficulties. Important prospective data recently suggested that internal mammary chain radiotherapy would not be necessary, even in cases of internal or central tumor locations, or in patients with positive axillary lymph nodes. Although these data warrant confirmation by two other prospective trials, there is evidence that the indications for internal mammary chain radiotherapy should be careful and that high quality techniques should be used for decreasing the dose delivered to the heart. This review of literature presents the state of art on the radiotherapy of internal mammary chain, with special focus on the indications, techniques, and potential toxicity. (authors)

  7. Report 1. An experiment model. Radiation loading in animals living in conditions of external and internal irradiation within the zone of Chernobyl accident

    International Nuclear Information System (INIS)

    Irradiation conditions in which laboratory animals were kept in experimental laboratories of Chernobyl and Kiev after the accident APS are described. The data are presented on the spectral structure and activity of radionuclides in the diet as well as in the organs and tissues of the animals. The radition loads have been estimated with regard to an external gamma-component and the internal one contributed by the incorporated radionuclides. It has been shown that radiation doses received by the animals during their lifetime due to these contributions do not exceed units of cGy

  8. Late radiation damage in bone, bone marrow and brain vasculature, with particular emphasis upon fractionation models

    International Nuclear Information System (INIS)

    X-ray induced changes in rat and human bone and bone marrow vasculature and in rat brain vasculature were measured as a function of time after irradiation and absorbed dose. The absorbed dose in the organ varied from 5 to 25 Gy for single dose irradiations and from 19 to 58 Gy for fractionated irradiations.The number of fractions varied from 3 to 10 for the rats and from 12 to 25 for the human. Blood flow changes were measured using an ''1''2''5I antipyrine or ''8''6RbCl extraction technique. The red blood cell (RBC) volume was examined by ''5''1Cr labelled red cells. Different fractionation models have been compared. Radiation induced reduction of bone and bone marrow blood flow were both time and dose dependent. Reduced blood flow 3 months after irradiation would seem to be an important factor in the subsequent atrophy of bones. With a single dose of 10 Gy the bone marrow blood flow returned to the control level by 7 months after irradiation. In the irradiated bone the RBC volume was about same as that in the control side but in bone marrow the reduction was from 32 to 59%. The dose levels predicted by the nominal standard dose (NSD) formula produced about the same damage to the rat femur seven months after irradiation when the extraction of ''8''6Rb chloride and the dry weight were concerned as the end points. However, the results suggest that the NSB formula underestimates the late radiation damage in bone marrow when a small number of large fractions are used. In the irradiated brains of the rats the blood flow was on average 20.4% higher compared to that in the control group. There was no significant difference in brain blood flow between different fractionation schemes. The value of 0.42 for the exponent of N corresponds to the average value for central nervous system tolerance in the literature. The model used may be sufficiently accurate for clinical work provided the treatment schemes used do not depart too radically from standard practice

  9. TOMS Absorbing Aerosol Index

    Data.gov (United States)

    Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

  10. Multiband terahertz metamaterial absorber

    Institute of Scientific and Technical Information of China (English)

    Gu Chao; Qu Shao-Bo; Pei Zhi-Bin; Xu Zhuo; Liu Jia; Gu Wei

    2011-01-01

    This paper reports the design of a multiband metamaterial (MM) absorber in the terahertz region. Theoretical and simulated results show that the absorber has four distinct and strong absorption points at 1.69, 2.76, 3.41 and that the impedance of MM could be tuned to match approximately the impedance of the free space to minimise the reflectance at absorption frequencies and large power loss exists at absorption frequencies. The distribution of the power loss indicates that the absorber is an excellent electromagnetic wave collector: the wave is first trapped and reinforced in certain specific locations and then consumed. This multiband absorber has applications in the detection of explosives and materials characterisation.

  11. Metasurface Broadband Solar Absorber

    OpenAIRE

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Milan Sykora; Nina R. Weisse-Bernstein; Luk, Ting S.; Antoinette J. Taylor; Dalvit, Diego A. R.; Hou-Tong Chen

    2016-01-01

    We demonstrate a broadband, polarization independent, omnidirectional absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low emissivity at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experiment...

  12. The MIRD method of estimating absorbed dose

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D.A.

    1991-01-01

    The estimate of absorbed radiation dose from internal emitters provides the information required to assess the radiation risk associated with the administration of radiopharmaceuticals for medical applications. The MIRD (Medical Internal Radiation Dose) system of dose calculation provides a systematic approach to combining the biologic distribution data and clearance data of radiopharmaceuticals and the physical properties of radionuclides to obtain dose estimates. This tutorial presents a review of the MIRD schema, the derivation of the equations used to calculate absorbed dose, and shows how the MIRD schema can be applied to estimate dose from radiopharmaceuticals used in nuclear medicine.

  13. Laser Assisted Cancer Immunotherapy: Surface Irradiation

    Science.gov (United States)

    Wilson, Joshua; Chen, Hsin-Wei; Bandyopadhyay, Pradip

    2006-03-01

    Experiments in our laboratory incorporate a non-invasive approach to treat superficial tumors in animal models. Based on the concept of Laser Assisted Cancer Immunotherapy, surface irradiation provides good information to compare to invasive alternatives. The procedure involves injecting an immunoadjuvant (Glycated Chitosan) as well as a light absorbing dye (Indocyanine Green) directly into the tumor (5 to 7 mm in diameter). The temperature of the tumor is raised using an infrared diode laser operating at 804 nm, with a silica fiber tip placed a set distance away from the surface of the tumor. We monitor the surface temperature using non-invasive (infrared detector probe) as well as the internal temperature of the tumor using invasive (micro thermocouples) methods. This study aims at the success of the surface irradiation mode to treat solid tumors. * This work is supported by a grant from The National Institute of Health.

  14. Clinical application of a OneDose(TM) MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Kinhikar, Rajesh A [Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai 400 012 (India); Sharma, Pramod K [Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai 400 012 (India); Tambe, Chandrashekhar M [Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai 400 012 (India); Mahantshetty, Umesh M [Department of Radiation Oncology, Tata Memorial Hospital, Parel, Mumbai 400 012 (India); Sarin, Rajiv [Advanced Centre for Training Research and Education in Cancer, Kharghar, Navi Mumbai (India); Deshpande, Deepak D [Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai 400 012 (India); Shrivastava, Shyam K [Department of Radiation Oncology, Tata Memorial Hospital, Parel, Mumbai 400 012 (India)

    2006-07-21

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose(TM) in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs. (note)

  15. Sperm parameters in rats after low-dose irradiation of sex cells in male parents during two cycles of gametogenesis

    International Nuclear Information System (INIS)

    Chronic combined (internal and external) irradiation in low doses (absorbed doses 0.4 - 3.6 cGy) during two cycles of gametogenesis results in defective stimulation of spermatogenesis in male rats and provokes genotoxic action. The offspring from fathers with 0.7 and 3.6 cGy irradiation have decreased viability and oligozoospermia in mature age. The offsprings from the father with 3.6 cGy have increased sensitivity to weak irradiation and react by increases oligozoospermia. The data are accord with the idea about more pronounced genetic radioresistance of premeiosis cells during gametogenesis

  16. Fractionated irradiation of meningiomas of the optic nerve: the average ocular dose is a predictive factor of the visual function future

    International Nuclear Information System (INIS)

    As radiotherapy is efficient in terms of tumour growth control in the case of optic nerve meningiomas and allows a stabilization of visual acuity, but as radio-induced toxicity may threaten the functional benefit, the authors report a study which aimed at identifying predictive factors of a pejorative evolution of the visual function for patients submitted to radiotherapy for an optic nerve meningioma. Files of ten patients have been analyzed in terms clinical, radiological and dosimetric aspects. Visual acuity and visual field before and after conformational radiotherapy have been compared by means of the Wilcoxon Rank test. It appears that the visual function future can be threatened by irradiation side effects. Short communication

  17. A germination test: an easy approach to know the irradiation

    International Nuclear Information System (INIS)

    Food irradiation is an evolving preserving technique that provides a shield against the spoilage and might have a potential to ensure the food safety and security world wide. In the present study, feasibility to apply germination test to distinguish an un-irradiated and irradiated samples of wheat, maize, chickpea and black eye beans was checked. Samples were irradiated to the absorbed doses ranging from 0-10 kGy using Co-60 gamma irradiator and were germinated in plant growth chamber. Root and shoot lengths were measured at 7th day after gamma radiation treatment. In all the irradiated samples root and shoot lengths were decreased with the increase in radiation absorbed doses. The seeds irradiated to the absorbed doses more than 2 kGy were not germinated. Germination test proved as an easy and simple method to detect irradiation in wheat, maize, chickpea and black eye beans irradiated even at low absorbed doses. (author)

  18. IMRT dose fractionation for head and neck cancer: Variation in current approaches will make standardisation difficult

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Kean F. (Academic Dept. of Radiation Oncology, Univ. of Manchester, Manchester (United Kingdom)); Fowler, Jack F. (Dept. of Human Oncology and Medical Physics, Univ. of Wisconsin, Wisconsin (United States)); Sykes, Andrew J.; Yap, Beng K.; Lee, Lip W.; Slevin, Nick J. (Dept. of Clinical Oncology, Christie Hospital NHS Foundation Trust, Manchester (United Kingdom))

    2009-04-15

    Introduction. Altered fractionation has demonstrated clinical benefits compared to the conventional 2 Gy/day standard of 70 Gy. When using synchronous chemotherapy, there is uncertainty about optimum fractionation. IMRT with its potential for Simultaneous Integrated Boost (SIB) adds further to this uncertainty. This survey will examine international practice of IMRT fractionation and suggest possible reasons for diversity in approach. Material and methods. Fourteen international cancer centres were surveyed for IMRT dose/fractionation practised in each centre. Results. Twelve different types of dose fractionation were reported. Conventional 70-72 Gy (daily 2 Gy/fraction) was used in 3/14 centres with concurrent chemotherapy while 11/14 centres used altered fractionation. Two centres used >1 schedule. Reported schedules and number of centres included 6 fractions/week DAHANCA regime (3), modest hypofractionation (=2.2 Gy/fraction) (3), dose-escalated hypofractionation (=2.3 Gy/fraction) (4), hyperfractionation (1), continuous acceleration (1) and concomitant boost (1). Reasons for dose fractionation variability include (i) dose escalation; (ii) total irradiated volume; (iii) number of target volumes; (iv) synchronous systemic treatment; (v) shorter overall treatment time; (vi) resources availability; (vii) longer time on treatment couch; (viii) variable GTV margins; (ix) confidence in treatment setup; (x) late tissue toxicity and (xi) use of lower neck anterior fields. Conclusions. This variability in IMRT fractionation makes any meaningful comparison of treatment results difficult. Some standardization is needed particularly for design of multi-centre randomized clinical trials.

  19. IMRT dose fractionation for head and neck cancer: Variation in current approaches will make standardisation difficult

    International Nuclear Information System (INIS)

    Introduction. Altered fractionation has demonstrated clinical benefits compared to the conventional 2 Gy/day standard of 70 Gy. When using synchronous chemotherapy, there is uncertainty about optimum fractionation. IMRT with its potential for Simultaneous Integrated Boost (SIB) adds further to this uncertainty. This survey will examine international practice of IMRT fractionation and suggest possible reasons for diversity in approach. Material and methods. Fourteen international cancer centres were surveyed for IMRT dose/fractionation practised in each centre. Results. Twelve different types of dose fractionation were reported. Conventional 70-72 Gy (daily 2 Gy/fraction) was used in 3/14 centres with concurrent chemotherapy while 11/14 centres used altered fractionation. Two centres used >1 schedule. Reported schedules and number of centres included 6 fractions/week DAHANCA regime (3), modest hypofractionation (=2.2 Gy/fraction) (3), dose-escalated hypofractionation (=2.3 Gy/fraction) (4), hyperfractionation (1), continuous acceleration (1) and concomitant boost (1). Reasons for dose fractionation variability include (i) dose escalation; (ii) total irradiated volume; (iii) number of target volumes; (iv) synchronous systemic treatment; (v) shorter overall treatment time; (vi) resources availability; (vii) longer time on treatment couch; (viii) variable GTV margins; (ix) confidence in treatment setup; (x) late tissue toxicity and (xi) use of lower neck anterior fields. Conclusions. This variability in IMRT fractionation makes any meaningful comparison of treatment results difficult. Some standardization is needed particularly for design of multi-centre randomized clinical trials

  20. Solar Irradiance Variation and the Response of the Upper Atmosphere - A Review of Recent Progress in the International TIGER Program

    Science.gov (United States)

    Solomon, Stanley

    Solar irradiance in the ultraviolet, extreme-ultraviolet, and X-ray spectral regions are a key determinant of the state and variation of upper atmosphere and ionosphere parameters, including densities, temperatures, composition, photoelectron fluxes, airglow emission processes, and magnetosphere-ionosphere coupling. The Thermosphere-Ionosphere-Geosphere Research (TIGER) program was established in 1998 with the objective of obtaining a better quantitative understanding of variations in solar irradiance and the effects on the upper atmosphere. The TIGER program has contributed to progress in this area through an ongoing series of conferences, workshops, publications, and data exchange. Advances in measurement and modeling of the solar spectrum have led to improved understanding of the atmosphere/ionosphere response, and to closure between models and measurements in several areas. In this paper, a brief overview of recent results is provided, some critical outstanding questions are identified, and the prospects for new solar and terrestrial observational programs are described.

  1. Food irradiation seminar: Asia and the Pacific

    International Nuclear Information System (INIS)

    The report covers the Seminar for Asia and the Pacific on the practical application of food irradiation. The seminar assessed the practical application of food irradiation processes, commercial utilisation and international trade of irradiated food

  2. Topical or systemic 16,16 dm prostaglandin E2 or WR-2721 (WR-1065) protects mice from alopecia after fractionated irradiation

    International Nuclear Information System (INIS)

    Previous studies in mice demonstrated that systemic or topical 16,16 dm PGE2 protected against single dose radiation-induced hair loss. The authors have now investigated prostaglandin, or WR-2721, protection against murine alopecia produced by varying doses and schedules of fractionated radiation. In some studies with the radioprotectors given systematically, WR-2721 afforded slightly greater radioprotection than 16,16 dm PGE2. The two compounds were essentially equally radioprotective in the topical application studies. Since both systemic and topical applications of the agents tested enhanced hair regrowth following radiation, the authors conclude that clinical use of these compounds may provide some protection of hair follicles, and perhaps other tissues, lying within a radiation therapy field. (author)

  3. Topical or systemic 16,16 dm prostaglandin E sub 2 or WR-2721 (WR-1065) protects mice from alopecia after fractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Geng, L.; Malkinson, F.D. (Rush-Presbyterian-St. Luke' s Medical Center, Chicago, IL (United States)); Hanson, W.R. (Hines VA Medical Center, IL (United States))

    1992-04-01

    Previous studies in mice demonstrated that systemic or topical 16,16 dm PGE{sub 2} protected against single dose radiation-induced hair loss. The authors have now investigated prostaglandin, or WR-2721, protection against murine alopecia produced by varying doses and schedules of fractionated radiation. In some studies with the radioprotectors given systematically, WR-2721 afforded slightly greater radioprotection than 16,16 dm PGE{sub 2}. The two compounds were essentially equally radioprotective in the topical application studies. Since both systemic and topical applications of the agents tested enhanced hair regrowth following radiation, the authors conclude that clinical use of these compounds may provide some protection of hair follicles, and perhaps other tissues, lying within a radiation therapy field. (author).

  4. Unidirectional perfect absorber

    Science.gov (United States)

    Jin, L.; Wang, P.; Song, Z.

    2016-09-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices.

  5. Metasurface Broadband Solar Absorber

    CERN Document Server

    Azad, A K; Sykora, M; Weisse-Bernstein, N R; Luk, T S; Taylor, A J; Dalvit, D A R; Chen, H -T

    2015-01-01

    We demonstrate a broadband, polarization independent, omnidirectional absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low emissivity at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. Furthermore, we discuss the potential use of our metasurface absorber design in solar thermophotovoltaics by exploiting refractory plasmonic materials.

  6. Unidirectional perfect absorber.

    Science.gov (United States)

    Jin, L; Wang, P; Song, Z

    2016-01-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices. PMID:27615125

  7. Regulatory aspect of food irradiation

    International Nuclear Information System (INIS)

    Interest in the process of food irradiation is reviewed once again internationally. Although food irradiation has been thoroughly investigated, global acceptance is still lacking. Factors which impede the progress of the technology are discussed here. (author)

  8. Antifungal impact of volatile fractions of Peumus boldus and Lippia turbinata on Aspergillus section Flavi and residual levels of these oils in irradiated peanut.

    Science.gov (United States)

    Passone, María Alejandra; Etcheverry, Miriam

    2014-01-01

    To investigate the antifungal properties of essential oil (EO) vapors from boldo and poleo on Aspergillus section Flavi and the residual levels of the oils in peanut, irradiated peanuts conditioned at three water activities (0.98, 0.95, 0.93) were treated with 2 and 3 μL/g of boldo and 3 and 5 μL/g of poleo. EO treatments produced the greatest impact on fungal growth parameters, followed by oil concentrations and aW levels. The three main components in peanut exposed to oil vapors were piperitone oxide, α-terpinene and eucalyptol for boldo and β-caryophyllene epoxide, limonene and piperitenone for poleo. Residues of boldo and poleo EO were significantly decreased from 24.7 to 100% and from 26.6 to 99.7% at the end of the incubation period, respectively. The application of nontoxic boldo oil as fumigant in the control of Aspergillus section Flavi may represent a potential alternative antifungal treatment, without significant residues after 35 days. PMID:24211775

  9. Anti-wrinkle effects of Sargassum muticum ethyl acetate fraction on ultraviolet B-irradiated hairless mouse skin and mechanistic evaluation in the human HaCaT keratinocyte cell line.

    Science.gov (United States)

    Song, Jae Hyoung; Piao, Mei Jing; Han, Xia; Kang, Kyoung Ah; Kang, Hee Kyoung; Yoon, Weon Jong; Ko, Mi Hee; Lee, Nam Ho; Lee, Mi Young; Chae, Sungwook; Hyun, Jin Won

    2016-10-01

    The present study investigated the photoprotective properties of the ethyl acetate fraction of Sargassum muticum (SME) against ultraviolet B (UVB)‑induced skin damage and photoaging in a mouse model. HR‑1 strain hairless male mice were divided into three groups: An untreated control group, a UVB‑irradiated vehicle group and a UVB‑irradiated SME group. The UVB‑irradiated mice in the SME group were orally administered with SME (100 mg/kg body weight in 0.1 ml water per day) and then exposed to radiation at a dose of 60‑120 mJ/cm2. Wrinkle formation and skin damage were evaluated by analysis of skin replicas, epidermal thickness and collagen fiber integrity in the dermal connective tissue. The mechanism underlying the action of SME was also investigated in the human HaCaT keratinocyte cell line following exposure of the cells to UVB at a dose of 30 mJ/cm2. The protein expression levels and activity of matrix metalloproteinase‑1 (MMP‑1), and the binding of activator protein‑1 (AP‑1) to the MMP‑1 promoter were assessed in the HaCaT cells using western blot analysis, an MMP‑1 fluorescent assay and a chromatin immune‑precipitation assay, respectively. The results showed that the mean length and depth of the wrinkles in the UVB‑exposed hairless mice were significantly improved by oral administration of SME, which also prevented the increase in epidermal thickness triggered by UVB irradiation. Furthermore, a marked increase in collagen bundle formation was observed in the UVB‑treated mice with SME administration. SME pretreatment also significantly inhibited the UVB‑induced upregulation in the expression and activity of MMP‑1 in the cultured HaCaT keratinocytes, and the UVB‑enhanced association of AP‑1 with the MMP‑1 promoter. These results suggested that SME may be useful as an anti-photoaging resource for the skin. PMID:27573915

  10. Effects of dose fractionation on the response of alanine dosimetry

    International Nuclear Information System (INIS)

    Alanine dosimetry is well established as a transfer standard and is becoming more prevalently used in routine dosimetry systems for radiation processing. Many routine measurement applications in radiation processing involve absorbed dose measurements resulting from fractioned exposures to ionizing radiation. Fractioning of absorbed dose is identified as an influence quantity (ISO/ASTM, 2013). This paper reports on study results of absorbed dose fractioning characteristics of alanine for gamma and high energy electron beam radiation sources. The results of this study indicate a radiation response difference due to absorbed dose fractioning in response can be observed after four fractionations for high-energy electron beams and no difference up to seven fractions for gamma rays using an ANOVA evaluation method. - Highlights: • Fractioning effects signaled in electron beam using an ANOVA at 6 equal increments. • Fractioning effects not signaled in gamma using an ANOVA up to 7 equal increments. • Insensitivity of alanine to dose fractioning indicates nominal impact on calibration

  11. Naval Reactors Prime Contractor Team (NRPCT) Experiences and Considerations With Irradiation Test Performance in an International Environment

    Energy Technology Data Exchange (ETDEWEB)

    MH Lane

    2006-02-15

    This letter forwards a compilation of knowledge gained regarding international interactions and issues associated with Project Prometheus. The following topics are discussed herein: (1) Assessment of international fast reactor capability and availability; (2) Japanese fast reactor (JOYO) contracting strategy; (3) NRPCT/Program Office international contract follow; (4) Completion of the Japan Atomic Energy Agency (JAEA)/Pacific Northwest National Laboratory (PNNL) contract for manufacture of reactor test components; (5) US/Japanese Departmental interactions and required Treaties and Agreements; and (6) Non-technical details--interactions and considerations.

  12. Naval Reactors Prime Contractor Team (NRPCT) Experiences and Considerations With Irradiation Test Performance in an International Environment

    International Nuclear Information System (INIS)

    This letter forwards a compilation of knowledge gained regarding international interactions and issues associated with Project Prometheus. The following topics are discussed herein: (1) Assessment of international fast reactor capability and availability; (2) Japanese fast reactor (JOYO) contracting strategy; (3) NRPCT/Program Office international contract follow; (4) Completion of the Japan Atomic Energy Agency (JAEA)/Pacific Northwest National Laboratory (PNNL) contract for manufacture of reactor test components; (5) US/Japanese Departmental interactions and required Treaties and Agreements; and (6) Non-technical details--interactions and considerations

  13. A comparison of single-dose and fractionated total-body irradiation on the development of pneumonitis following bone marrow transplantation

    International Nuclear Information System (INIS)

    Purpose: A review of 132 consecutive patients who received bone marrow transplant for various malignancies was conducted to determine factors associated with increased risk in developing interstitial pneumonitis (IP) as the result of total body irradiation (TBI). Twenty-four patients were excluded because 22 did not receive TBI and two had insufficient records. Methods and Materials: Patients were conditioned with TBI and various drug regimens. Eighteen patients received a single 6.0 Gy dose of x-rays. The remaining 90 were treated with three doses of 3.33 Gy separated by 24 h. All patients were followed for at least 18 months for the purposes of determining the IP incidence. Results: Twenty-seven of there 108 (25%) patients developed IP; 19 (17.6%) died. The 2-year estimated incidence of IP was 24 and 18.6% for fatal IP. The etiology was determined to be idiopathic in 12 patients, the result of cytomegalovirus in 6 patients, and caused by a variety of other infectious organisms in 9 patients. We were unable to demonstrate a statistically significant increase in IP with age (adults vs. children), dose regimen, use of methotrexate for graft-vs.-host disease prophylaxis, the presence of acute graft-vs.-host disease, time from diagnosis to transplant, or transplant type (allogeneic vs. autologous). Conclusions: The incidence of fatal IP reported here is similar to that reported by other institutions utilizing hyperfractionated TBI protocols. Our data do not support the need for hyperfractionation to reduce the risk of IP

  14. Busulfan, cyclophosphamide and fractionated total body irradiation as a conditioning regimen for allogeneic bone marrow transplantation in patients with non-lymphocytic hematopoietic malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroshi [Jikei Univ., Tokyo (Japan). School of Medicine

    1996-11-01

    Allogeneic bone marrow transplantation (BMT) with the conditioning regimen of 8 mg/kg of busulfan (BUS), 120 mg/kg of cyclophosphamide (CPM) and 10 Gy of total body irradiation (TBI) was evaluated in the patients with non-lymphocytic hematopoietic malignancies. The disease distribution of the 22 patients was as follows; 14 in the standard risk group (SRG), 8 in the high risk group (HRG). SRG included the patients with acute myeloid leukemia (AML) in the first complete remission, chronic myelogenous leukemia (CML) in chronic phase and myelodysplastic syndrome with refractory anemia, while HRG included the patients with refractory AML and CML in blastic phase. The median age of patients was 33 years old (y.o.), and the median observation period was 34.5 months No relapse occurred, but 8 patients (36%) died of various complications. Ail the patients who died of interstitial pneumonitis (4 cases) were 40 y.o. and more. Acute graft-versus-host disease (GvHD) and chronic GvHD were clinically controllable. The probability of disease-free survival rate at 5 years (5y-DFS) was 50.0% in overall patients. The 5y-DFS was 57.1% in HRG (7 cases), while 54.3% in SRG (13 cases) donated from the HLA identical siblings (20 cases). In these 13 patients in SRG, the 5y-DFS was 100% in patients under 40 y.o. (6 cases), while the probability of disease-free survival rate at 3 years was 68.6% and the 5y-DFS was 0% in patients over 40 y.o. (7 cases). Our data indicate that the conditioning regimen combining BUS, CPM and TBI for allogeneic BMT is promising for the treatment of the patients of HRG and the patients under 40 y.o. in SRG. (author)

  15. Solar concentrator/absorber

    Science.gov (United States)

    Von Tiesenhausen, G. F.

    1976-01-01

    Collector/energy converter, consisting of dual-slope optical concentrator and counterflow thermal energy absorber, is attached to multiaxis support structure. Efficient over wide range of illumination levels, device may be used to generate high temperature steam, serve as solar powered dryer, or power absorption cycle cooler.

  16. Establishment of an animal model of internal exposure to radioactive iodine

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, Y.; Hoshi, M. [Research Institute for Radiation Biology and Medicine, Hiroshima (Japan); Endo, S. [Hiroshima Univ., Hiroshima (Japan)

    2002-07-01

    Age is a potent modifier of the thyroid cancer risk at internal as well as external exposure. The short latency for the development of thyroid cancer in the post-Chernobyl cases proposes us to make sure the thyroid susceptibility to internal exposure at young ages. At the beginning of a large-scale carcinogenesis experiment for the induction of thyroid cancer by the internal exposure of 131 I into rats, we established the way to estimate absorbed doses in the thyroid and total body of rats at different ages: newborn, puberty and adult. Female rats of the Fischer 344 strain were exposed to {sub 131} I at the age of 1, 4 and 9 weeks, and have been kept for 16 days (twice of the {sub 131} I-half life) to draw kinetic curves of the isotope in the thyroid and total body. We drew the standard curve to estimate absorbed fraction of radioactivity from {beta} - and {gamma} -rays from the {sub 131} I in the thyroids of different sizes, because the thyroid size differs depending on age. Then we drew the standard curve to estimate absorbed doses in the thyroid and total body from the injected activities. Irradiation at 1 week of age caused heavier exposure than at 4 and 9 weeks of ages by 8 times in the thyroid. We tested the acute effects of radiation on the thyroid epithelium at the three ages. Radiation-induced apoptosis and post apoptotic cell proliferation of the thyroid epithelium were investigated. Apoptosis was not obvious in all the three age groups. Labeling index of the proliferating cell nuclear antigen (PCNA) increased in the 4 weeks old groups of both SD and IDD treatment. While in the 9 weeks old groups, it increased only by the treatment of IDD. One-week-old rats did not show any increase in the cell proliferation activity by{sub 60} Co {gamma} -irradiation, and did show small increase in the Sodium- {sub 131} I ( {sub 131} I)-injected IDD group.

  17. Negative impedance shunted electromagnetic absorber for broadband absorbing: experimental investigation

    International Nuclear Information System (INIS)

    The traditional tuned mass absorber is widely employed to control the vibration of a primary structure by transferring the vibrating energy to the absorber. However, the working band of the absorber is very narrow, which limits the application of broadband vibration control. This study presents a novel broadband electromagnetic absorber by first introducing two negative impedance shunts to improve broadband damping of the absorber. The electromagnetic absorber is modeled, and the corresponding electromagnetic coupling coefficient is tested. A cantilever beam is employed to verify the broadband vibration absorption of the negative resistance (NR) shunted electromagnetic absorber (NR absorber) and the negative inductance NR shunted electromagnetic absorber (NINR absorber). The governing equations of the beam with two absorbers are derived, and the experiments are set up. The results point out that the NR and NINR absorbers can attenuate the broadband vibration. The proposed absorbers do not need the feedback system and the real-time controller compared to the active absorber; hence, they have great application potential in aerospace and in submarine applications, as well as in civil and mechanical engineering. (paper)

  18. Conformal radiotherapy made easy through gravity oriented absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Proimos, B.S. [Patras Univ. (Greece). Dept. of Medical Physics

    1995-12-01

    In the 50`s and the 60`s simple techniques modulating the beam intensity in synchronism with the rotation, either of the vertical patient or of the machine around the horizontal patient were developed. An absorber, which is similar in shape to a vital organ, intercepts the beam, casting its protective `shade` over the organ, for all positions of rotation. In this way, the organ is protected during the irradiation time. On any transverse cross, any point outside of the organ`s cross-section is protected for only a fraction of T, which is decreasing with the distance of that point from the organ. Consequently, the dose to the protected organ is smaller than (a) the dose it would absorb without protection (b) the dose to the surrounding (less vital) healthy tissue and (c), the dose to the neighbouring tumour. Consider a plane perpendicular to the principal plane and passing through the source. It cuts the organ and its protector in two cross-sections, which remain always homiotheta, with centre of homiothesis the source. In this way, the protector`s cross-section is projected by the beam on the organ`s cross-section for all positions of rotation. The larger the cross-section of the organ and the smaller the required protection, the smaller must be the attenuation coefficient of the material the protector is made of. The dose distributions in a series of actual cases, such as head tumours with eyes protection, neck or chest tumours with spinal cord protection, cervix tumours with rectum and bladder protection, are discussed. In most cases, if the vital organs are not overprotected, the 90% or 80% isodose surface fits to or conforms with the surface of the Planning Target Volume (PTV) no matter how irregular (convex and concave) it is.

  19. Solar absorber material stability under high solar flux

    Science.gov (United States)

    Ignatiev, A.; Zajac, G.; Smith, G. B.

    1982-04-01

    Solar absorbing Black Chrome coatings have been exposed to high temperatures (350-400 C) under high solar fluxes (0.4 to 2.0 MW/sq m) to test for their stability under actual operating conditions. Field tests at the White Sands Solar Furnace have shown higher stability than expected from oven tested samples. Laboratory studies utilizing spectrally selective concentrated solar simulated radiation have indicated that the cause of the higher stability under solar irradiation is photo-stimulated desorption of oxygen bearing species at the absorber surface and resultant reduced oxidation of the absorber.

  20. Accelerated partial breast irradiation: Bi-fractionated 40 Gy in one week. A French pilot phase II study; Etude pilote francaise de phase 2 d'irradiation partielle acceleree du sein conformationnelle tridimensionnelle bi-fractionnee hebdomadaire de 40 Gy

    Energy Technology Data Exchange (ETDEWEB)

    Bourgier, C.; Heymann, S.; Bourhis, J.; Marsiglia, H. [Departement d' oncologie-radiotherapie, institut Gustave-Roussy, 94 - Villejuif (France); Pichenot, C.; Verstraet, R.; Biron, B. [Departement de physique, institut Gustave-Roussy, 94 - Villejuif (France); Balleyguier, C. [Departement de radiologie, institut Gustave-Roussy, 94 - Villejuif (France); Delalogen, S. [Departement d' oncologie medicale, institut Gustave-Roussy, 94 - Villejuif (France); Mathieu, M.C. [Departement d' anatomie-pathologie, institut Gustave-Roussy, 94 - Villejuif (France); Uzan, C.; Garbay, J.R.; Marsiglia, H. [Departement de chirurgie-senologie, institut Gustave-Roussy, 94 - Villejuif (France); Taghian, A. [Departement d' oncologie-radiotherapie, Massachusetts General Hospital, Harvard Medical School, Massachusetts (United States); Bourgier, C.; Pichenot, C.; Verstraet, R.; Heymann, S.; Biron, B.; Balleyguier, C.; Delalogen, S.; Mathieu, M.C.; Uzan, C.; Garbay, J.R.; Bourhis, J.; Taghian, A.; Marsiglia, H. [Universite de Florence, Firenze (Italy)

    2010-12-15

    Purpose: Since 2009, accelerated partial breast irradiation (APBI) in North America has been allowed to be used for selected group of patients outside a clinical trial according to the ASTRO consensus statement. In France, accelerated partial breast irradiation is still considered investigational, several clinical trials have been conducted using either intraoperative (Montpellier) or Mammosite{sup R} (Lille) or brachytherapy modality (PAC GERICO/FNCLCC). Here, we report the original dosimetric results of this technique. Patients and methods: Since October 2007, Institut Gustave-Roussy has initiated a phase II trial using 3D-conformal accelerated partial breast irradiation (40 Gy in 10 fractions BID in 1 week). Twenty-five patients with pT1N0 breast cancer were enrolled and were treated by two mini-tangent photons beams (6 MV) and an 'en face' electron beam (6-22 MeV). Results: The mean clinical target volume and planning target volume were respectively 15.1 cm{sup 3} (range: 5.2-28.7 cm{sup 3}) and 117 cm{sup 3} (range: 52-185 cm{sup 3}). The planning target volume coverage was adequate with at least a mean of 99% of the volume encompassed by the isodose 40 Gy. The mean dose to the planning target volume was 41.8 Gy (range: 41-42.4 Gy). Dose inhomogeneity did not exceed 5%. Mean doses to the ipsilateral lung and heart were 1.6 Gy (range: 1.0-2.3 Gy) and 1.2 Gy (range: 1.0-1.6 Gy), respectively. Conclusion: The 3D conformal accelerated partial breast irradiation using two mini-tangent and 'en face' electron beams using a total dose of 40 Gy in 10 fractions BID over 5 days achieves appropriate planning target volume coverage and offers significant normal-tissue sparing (heart, lung). Longer follow-up is needed to evaluate the tissue tolerance to this radiation dose. (authors)

  1. Artificial and enhanced humification of soil organic matter using microwave irradiation.

    Science.gov (United States)

    Kim, Min Chan; Kim, Han S

    2013-04-01

    Microwave (MW) irradiation, a less energy-intensive irradiation technique, was employed to promote the changes in physicochemical properties of soil organic matter (SOM). MW was irradiated to forest soils for 10 min. Then, the physical and chemical properties of the SOM were analyzed with UV absorbance spectroscopy, Fourier transform infrared spectroscopy, elemental analysis, and size exclusion chromatography. Also, the SOM was fractionated into biopolymer, fulvic acid, and humic acid, and each fraction was analyzed quantitatively. These analyses revealed that the SOM became more aromatic and nonpolar, highly condensed, and macromolecular organic substances that possess a higher amount of functional groups found in highly humified substances than the original SOM as a result of the MW irradiation. The humification-like alteration of SOM property was attributable to the thermal cracking and to the radical reaction, particularly when the MW was irradiated along with activated carbon under the aerobic condition. The results of this study suggest that the artificial and enhanced property changes of SOM can be accomplished by MW irradiation on an engineering time scale, which can contribute to the successful soil and groundwater remediation practice. PMID:22895631

  2. Nitrogen-atom endohedral fullerene synthesis with high efficiency by controlling plasma-ion irradiation energy and C{sub 60} internal energy

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Soon Cheon; Kaneko, Toshiro, E-mail: kaneko@ecei.tohoku.ac.jp; Ishida, Hiroyasu; Hatakeyama, Rikizo [Department of Electronic Engineering, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2015-03-28

    The nitrogen-atom endohedral fullerene (N@C{sub 60}) has been synthesized by controlling the plasma ion irradiation energy (E{sub i}) and fullerene (C{sub 60}) behavior in the sublimation phase. We examined the relationship between the synthesis purity of N@C{sub 60} [molar concentration ratio of N@C{sub 60} to pristine fullerene (C{sub 60})] and E{sub i}, which was controlled by changing the substrate bias voltages (V{sub sub}) and gas pressure (P{sub N2}) during the plasma irradiation process. High-density nitrogen-molecular ions (N{sub 2}{sup +}) with a suitable E{sub i} near 80 eV are confirmed to be the optimum condition of the nitrogen plasma for the synthesis of high-purity N@C{sub 60}. In addition, high sublimation of C{sub 60} contributes to a higher yield due to the high internal energy of C{sub 60} and the related cage defects that are present under these conditions. As a result, a purity of 0.83% is realized for the first time, which is almost two orders of magnitude higher than that using other methods.

  3. Low-grade astrocytomas: treatment with unconventionally fractionated external beam stereotactic radiation therapy

    International Nuclear Information System (INIS)

    Fourteen patients with nonoperable low-grade astrocytomas were treated with unconventionally fractionated stereotactic radiation therapy. The target volume was defined with computed tomography (CT) performed under stereotactic conditions. The treatment was carried out with a technique producing multiple noncoplanar arc irradiation, with the center of the target volume placed at the isocenter of the linear accelerator. A total dose of 16-50 Gy was administered in either one fraction or two fractions 8 days apart. The concentration of dose within the target volume allowed reduction of dose absorbed by adjacent critical structures of the intact brain. Patients were followed up for 11-48 months. Twelve of 14 patients had a partial or complete response to treatment, as demonstrated by CT. Stereotactic radiation therapy appears to be effective in the control of small radioresistant cerebral neoplasms, without damaging surrounding healthy tissues

  4. Low-grade astrocytomas: treatment with unconventionally fractionated external beam stereotactic radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pozza, F.; Colombo, F.; Chierego, G.; Avanzo, R.C.; Marchetti, C.; Benedetti, A.; Casentini, L.; Danieli, D.

    1989-05-01

    Fourteen patients with nonoperable low-grade astrocytomas were treated with unconventionally fractionated stereotactic radiation therapy. The target volume was defined with computed tomography (CT) performed under stereotactic conditions. The treatment was carried out with a technique producing multiple noncoplanar arc irradiation, with the center of the target volume placed at the isocenter of the linear accelerator. A total dose of 16-50 Gy was administered in either one fraction or two fractions 8 days apart. The concentration of dose within the target volume allowed reduction of dose absorbed by adjacent critical structures of the intact brain. Patients were followed up for 11-48 months. Twelve of 14 patients had a partial or complete response to treatment, as demonstrated by CT. Stereotactic radiation therapy appears to be effective in the control of small radioresistant cerebral neoplasms, without damaging surrounding healthy tissues.

  5. Fractional Echoes

    CERN Document Server

    Karras, G; Billard, F; Lavorel, B; Siour, G; Hartmann, J -M; Faucher, O; Gershnabel, Erez; Prior, Yehiam; Averbukh, Ilya Sh

    2016-01-01

    We report the observation of fractional echoes in a double-pulse excited nonlinear system. Unlike standard echoes which appear periodically at delays which are integer multiple of the delay between the two exciting pulses, the fractional echoes appear at rational fractions of this delay. We discuss the mechanism leading to this phenomenon, and provide the first experimental demonstration of fractional echoes by measuring third harmonic generation in a thermal gas of CO2 molecules excited by a pair of femtosecond laser pulses.

  6. Chalk effect on PVC cross-linking under irradiation

    International Nuclear Information System (INIS)

    Effect of nonmodified and modified chalk on curing degree of polymer matrix was studied under-irradiation of PVC-compositions. Films of the compositions (100 mass part 7 PVC, 0-100 mas.part of chalk, 2.5 - lead sulfate, 1.5 - lead stearate and 0.3 - glycerin) were irradiated up to absorbed dose 0.1 MGy in an inert medium. Content of gel-fraction after boiling in THF was determined with use of IR spectroscopy. It was established, that intensive dehydrochlorination and polymer curing took place on chalk particle surface. Network fixed strongly chalk particles. However, chalk inhibited processes of dehydrochlorination and PVC curing, increasing amount of noncured PVC in polymer matrix

  7. Measurement of ion species in high current ECR H{sup +}/D{sup +} ion source for IFMIF (International Fusion Materials Irradiation Facility)

    Energy Technology Data Exchange (ETDEWEB)

    Shinto, K., E-mail: shinto.katsuhiro@jaea.go.jp; Ichimiya, R.; Ihara, A.; Ikeda, Y.; Kasugai, A.; Kitano, T.; Kondo, K.; Takahashi, H. [Rokkasho Fusion Institute, Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Senée, F.; Bolzon, B.; Chauvin, N.; Gobin, R.; Valette, M. [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France); Ayala, J.-M.; Marqueta, A.; Okumura, Y. [IFMIF/EVEDA Project Team, Rokkasho, Aomori 039-3212 (Japan)

    2016-02-15

    Ion species ratio of high current positive hydrogen/deuterium ion beams extracted from an electron-cyclotron-resonance ion source for International Fusion Materials Irradiation Facility accelerator was measured by the Doppler shift Balmer-α line spectroscopy. The proton (H{sup +}) ratio at the middle of the low energy beam transport reached 80% at the hydrogen ion beam extraction of 100 keV/160 mA and the deuteron (D{sup +}) ratio reached 75% at the deuterium ion beam extraction of 100 keV/113 mA. It is found that the H{sup +} ratio measured by the spectroscopy gives lower than that derived from the phase-space diagram measured by an Allison scanner type emittance monitor. The H{sup +}/D{sup +} ratio estimated by the emittance monitor was more than 90% at those extraction currents.

  8. Fractional randomness

    Science.gov (United States)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  9. Comparison of piezoelectronic networks acting as distributed vibration absorbers

    OpenAIRE

    Maurini, Corrado; Dell'Isola, Francesco; Del Vescovo, Dionisio

    2004-01-01

    International audience Electric vibration absorbers made of distributed piezoelectric devices for the control of beam vibrations are studied. The absorbers are obtained by interconnecting an array of piezoelectric transducers uniformly distributed on a beam with different modular electric networks. Five different topologies are considered and their damping performance is analysed and compared.

  10. [Application of the Gompertz mortality law to the prognosis of lifespan shortening due to chronic internal irradiation].

    Science.gov (United States)

    Panteleev, L I; Shvedov, V L

    1984-01-01

    In experiments on albino rats received strontium 90 in daily doses of 1.85 to 185 kBq/day the regularities of death were studied. It was shown that death of animals exposed to chronic internal radiation followed the Gomperz B. mortality law.

  11. Metasurface Broadband Solar Absorber

    Science.gov (United States)

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-02-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure.

  12. Optimal Sound Absorbing Structures

    CERN Document Server

    Yang, Min; Fu, Caixing; Sheng, Ping

    2016-01-01

    Causal nature of the acoustic response, for any materials or structures, dictates an inequality that relates the absorption spectrum of the sample to its thickness. We present a general recipe for constructing sound-absorbing structures that can attain near-equality for the causal relation with very high absorption performance; such structures are denoted optimal. Our strategy involves using carefully designed acoustic metamaterials as backing to a thin layer of conventional sound absorbing material, e.g., acoustic sponge. By using this design approach, we have realized a 12 cm-thick structure that exhibits broadband, near-perfect flat absorption spectrum starting at around 400 Hz. From the causal relation, the calculated minimum sample thickness is 11.5 cm for the observed absorption spectrum. We present the theory that underlies such absorption performance, involving the evanescent waves and their interaction with a dissipative medium, and show the excellent agreement with the experiment.

  13. Universal metamaterial absorbe

    CERN Document Server

    Smaali, Rafik; Moreau, Antoine; Taliercio, Thierry; Centeno, Emmanuel

    2016-01-01

    We propose a design for an universal absorber, characterized by a resonance frequency that can be tuned from visible to microwave frequencies independently of the choice of the metal and the dielectrics involved. An almost resonant perfect absorption up to 99.8 % is demonstrated at resonance for all polarization states of light and for a very wide angular aperture. These properties originate from a magnetic Fabry-Perot mode that is confined in a dielectric spacer of $\\lambda/100$ thickness by a metamaterial layer and a mirror. An extraordinary large funneling through nano-slits explains how light can be trapped in the structure. Simple scaling laws can be used as a recipe to design ultra-thin perfect absorbers whatever the materials and the desired resonance wavelength, making our design truly universal.

  14. Metasurface Broadband Solar Absorber.

    Science.gov (United States)

    Azad, Abul K; Kort-Kamp, Wilton J M; Sykora, Milan; Weisse-Bernstein, Nina R; Luk, Ting S; Taylor, Antoinette J; Dalvit, Diego A R; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  15. Ionized Absorbers in AGN

    Science.gov (United States)

    Mathur, S.

    1999-01-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  16. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  17. Burnable neutron absorbers

    International Nuclear Information System (INIS)

    This patent deals with the fabrication of pellets for neutron absorber rods. Such a pellet includes a matrix of a refractory material which may be aluminum or zirconium oxide, and a burnable poison distributed throughout the matrix. The neutron absorber material may consist of one or more elements or compounds of the metals boron, gadolinium, samarium, cadmium, europium, hafnium, dysprosium and indium. The method of fabricating pellets of these materials outlined in this patent is designed to produce pores or voids in the pellets that can be used to take up the expansion of the burnable poison and to absorb the helium gas generated. In the practice of this invention a slurry of Al2O3 is produced. A hard binder is added and the slurry and binder are spray dried. This powder is mixed with dry B4C powder, forming a homogeneous mixture. This mixture is pressed into green tubes which are then sintered. During sintering the binder volatilizes leaving a ceramic with nearly spherical high-density regions of

  18. Fractional thermoelasticity

    CERN Document Server

    Povstenko, Yuriy

    2015-01-01

    This book is devoted to fractional thermoelasticity, i.e. thermoelasticity based on the heat conduction equation with differential operators of fractional order. Readers will discover how time-fractional differential operators describe memory effects and space-fractional differential operators deal with the long-range interaction. Fractional calculus, generalized Fourier law, axisymmetric and central symmetric problems and many relevant equations are featured in the book. The latest developments in the field are included and the reader is brought up to date with current research.  The book contains a large number of figures, to show the characteristic features of temperature and stress distributions and to represent the whole spectrum of order of fractional operators.  This work presents a picture of the state-of-the-art of fractional thermoelasticity and is suitable for specialists in applied mathematics, physics, geophysics, elasticity, thermoelasticity and engineering sciences. Corresponding sections of ...

  19. The second international intercomparison on EPR tooth dosimetry

    International Nuclear Information System (INIS)

    Eighteen international EPR laboratories participated in the second intercomparison programme. Each participant had to prepare enamel samples and evaluate the absorbed dose from molars that were irradiated in vitro in the range 0-1000 mGy. The objective of the programme was to bring together all methods which are currently applied by different laboratories for EPR dose reconstruction and to demonstrate the present state of dosimetry. An overview of the essential features of the different methods is presented. The current accuracy of EPR tooth enamel dosimetry under defined conditions of irradiation is evaluated

  20. BAY 87–2243, a novel inhibitor of hypoxia-induced gene activation, improves local tumor control after fractionated irradiation in a schedule-dependent manner in head and neck human xenografts

    International Nuclear Information System (INIS)

    The transcription factor hypoxia-inducible factor-1 (HIF-1) pathway plays an important role in tumor response to cytotoxic treatments. We investigated the effects of a novel small molecule inhibitor of mitochondrial complex I and hypoxia-induced HIF-1 activity BAY-87-2243, on tumor microenvironment and response of human squamous cell carcinoma (hSCC) to clinically relevant fractionated radiotherapy (RT) with and without concomitant chemotherapy. When UT-SCC-5 hSCC xenografts in nude mice reached 6 mm in diameter BAY-87-2243 or carrier was administered before and/or during RT or radiochemotherapy with concomitant cisplatin (RCT). Local tumor control was evaluated 150 days after irradiation and the doses to control 50% of tumors (TCD50) were compared between treatment arms. Tumors were excised at different time points during BAY-87-2243 or carrier treatment for western blot and immunohistological investigations. BAY-87-2243 markedly decreased nuclear HIF-1α expression and pimonidazole hypoxic fraction already after 3 days of drug treatment. BAY-87-2243 prior to RT significantly reduced TCD50 from 123 to 100 Gy (p=0.037). Additional BAY-87-2243 application during RT did not decrease TCD50. BAY-87-2243 before and during radiochemotherapy did not improve local tumor control. Pronounced reduction of tumor hypoxia by application of BAY-87-2243 prior to RT improved local tumor control. The results demonstrate that radiosensitizing effect importantly depends on treatment schedule. The data support further investigations of HIF-1 pathway inhibitors for radiotherapy and of predictive tests to select patients who will benefit from this combined treatment

  1. Cell survival and iso-effect contours in irradiated tissues

    International Nuclear Information System (INIS)

    Cell population kinetic parameters derived from radiobiological experiments and analysis of clinical data can be used to compute cellular surviving fractions in irradiated tumours and normal tissues. A three-component model of cellular radiation lethality, capable of simulating irreparable lethal events, reversible or sublethal effects and tissue repopulation processes, has proved adequate for clinical purposes. On this basis, computer programs have been developed for generating iso-effect (iso-survival) functions for various fractionation intervals in several tissues and tumours; for determining surviving fractions, equivalent single doses, and probabilities of response with specified fractionation schemes; and for optimizing treatment by identifying the procedure giving the highest probability of uncomplicated cure for a given tumour type growing in a specified location. If the relevant parameters for each of the tissues traversed by the beam, the physical dose absorbed at each point of interest, and the size, number and sequence of fractional doses reaching that point are known, then a series of computations of cellular surviving fractions can be made and used to draw iso-effect contours as a supplement to the physical isodose distribution in the same region. Procedures for both physical and biological optimization of the whole treatment plan are suggested. (author)

  2. Absorber for terahertz radiation management

    Science.gov (United States)

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  3. Characterization of low molecular weight fragments from gamma irradiated κ-carrageenan used as plant growth promoter

    Science.gov (United States)

    Abad, Lucille V.; Aurigue, Fernando B.; Relleve, Lorna S.; Montefalcon, Djowel Recto V.; Lopez, Girlie Eunice P.

    2016-01-01

    Radiation degraded κ-carrageenan (1% solution at absorbed doses of 20 kGy and 30 kGy) were tested for its plant growth promoter (PGP) effect on pechay plants under hydroponics condition. Results revealed that higher PGP effects were found in κ-carrageenan irradiated at an absorbed dose of 30 kGy. Mw of irradiated κ-carrageenan as measured by GPC were determined to be 7362 Da and 6762 Da for 20 kGy and 30 kGy, respectively. Fractionation of the irradiated κ-carrageenan (30 kGy) was done to separate different Mw fractions using Mw cut-off filters of 1 kDa, 3 kDa, and 5 kDa. The PGP effect of the different retentates showed that biological activity in plants followed the order of 5 kDa>3 kDa>1 kDa using hydroponics condition but the reverse was observed in the order of 1 kDa>3 kDa>5 kDa when absorbed in plants by foliar spraying. GPC chromatogram indicated at least three (3) low molecular weight (LMW) fragments from radiation modified κ-carrageenan solution with an Mw<2000 Da. A fragment has also been identified with an Mw of as low as 160 Da which was produced under acidic (un-neutralized) condition. This may be attributed to the formation of 5-hydroxymethylfurfural (5-HMF).

  4. Characterization of low molecular weight fragments from gamma irradiated κ-carrageenan used as plant growth promoter

    Science.gov (United States)

    Abad, Lucille V.; Aurigue, Fernando B.; Relleve, Lorna S.; Montefalcon, Djowel Recto V.; Lopez, Girlie Eunice P.

    2016-01-01

    Radiation degraded κ-carrageenan (1% solution at absorbed doses of 20 kGy and 30 kGy) were tested for its plant growth promoter (PGP) effect on pechay plants under hydroponics condition. Results revealed that higher PGP effects were found in κ-carrageenan irradiated at an absorbed dose of 30 kGy. Mw of irradiated κ-carrageenan as measured by GPC were determined to be 7362 Da and 6762 Da for 20 kGy and 30 kGy, respectively. Fractionation of the irradiated κ-carrageenan (30 kGy) was done to separate different Mw fractions using Mw cut-off filters of 1 kDa, 3 kDa, and 5 kDa. The PGP effect of the different retentates showed that biological activity in plants followed the order of 5 kDa>3 kDa>1 kDa using hydroponics condition but the reverse was observed in the order of 1 kDa>3 kDa>5 kDa when absorbed in plants by foliar spraying. GPC chromatogram indicated at least three (3) low molecular weight (LMW) fragments from radiation modified κ-carrageenan solution with an Mwhydroxymethylfurfural (5-HMF).

  5. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan; Farmer, Joseph C.; Lee, Chuck K.; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  6. XIIth international meeting on radiation processing Avignon 25-30 March 2001 (Polymer irradiation: past-present and future)

    Science.gov (United States)

    Chapiro, Adolphe

    2002-03-01

    Radiations are used efficiently and economically for the production of new or modified polymers. The following processes are considered: Radiation curing; Radiation cross-linking; Radiation grafting. These processes are commonly used today in industry and provide a broad range of new potential applications in various fields. The history of their development is briefly reported. The chemical reactions underlying these processes are described. (1) Radiation curing is used commercially on a large scale for the production of improved coatings, lacquers and inks. The process can be conducted at very high speeds. Curing of magnetic formulations leads to particularly stable products, which compete favourably with more conventional materials. (2) Radiation cross-linking is an established technology in the wire and cable industry. It emparts to the modified insulators improved resistance to solvents, to ageing and to elevated temperatures. The resulting cross-linked network also reduces the migration of fillers and thereby stabilizes in time any message imprinted with magnetic or colored pigments dispersed in a polymer. (3) Radiation grafting is a powerful method for modifying more profoundly the properties of a polymer and for creating numerous, entirely new materials. The chemical modification can be applied at will into the bulk of the material or limited to a surface zone of any desired depth. This method can be used for instance, for introducing polar groups in the bulk or on the surface of non-polar polymers, for increasing or reducing the wettability of a polymer, for imparting a better compatibility of a polymer to a specific coating and the like. The irradiation of water-soluble polymers in aqueous solutions, with or without the addition of another monomer gives rise to a variety of cross-linked gels which find useful applications in the biomedical field. Other promising applications will be considered.

  7. Fourth international radiopharmaceutical dosimetry symposium

    International Nuclear Information System (INIS)

    The focus of the Fourth International Radiopharmaceutical Dosimetry Symposium was to explore the impact of current developments in nuclear medicine on absorbed dose calculations. This book contains the proceedings of the meeting including the edited discussion that followed the presentations. Topics that were addressed included the dosimetry associated with radiolabeled monoclonal antibodies and blood elements, ultrashort-lived radionuclides, and positron emitters. Some specific areas of discussion were variations in absorbed dose as a result of alterations in the kinetics, the influence of radioactive contaminants on dose, dose in children and in the fetus, available instrumentation and techniques for collecting the kinetic data needed for dose calculation, dosimetry requirements for the review and approval of new radiopharmaceuticals, and a comparison of the effect on the thyroid of internal versus external irradiation. New models for the urinary blader, skeleton including the active marrow, and the blood were presented. Several papers dealt with the validity of traditional ''average-organ'' dose estimates to express the dose from particulate radiation that has a short range in tissue. These problems are particularly important in the use of monoclonal antibodies and agents used to measure intracellular functions. These proceedings have been published to provide a resource volume for anyone interested in the calculation of absorbed radiation dose

  8. Sensing with THz metamaterial absorbers

    CERN Document Server

    Cong, Longqing

    2014-01-01

    Metamaterial perfect absorbers from microwaves to optical part of the electromagnetic spectrum has been intensely studied for its ability to absorb electromagnetic radiation. Perfect absorption of light by metamaterials have opened up new opportunities for application oriented functionalities such as efficient sensors and emitters. We present an absorber based sensing scheme at the terahertz frequencies and discuss optimized designs to achieve high frequency and amplitude sensitivities. The major advantage of a perfect metamaterial absorber as a sensor is the sensitive shift in the absorber resonance frequency along with the sharp change in the amplitude of the resonance due to strong interaction of the analyte with the electric and the magnetic fields at resonant perfect absorption frequency. We compare the sensing performance of the perfect metamaterial absorber with its complementary structural design and planar metasurface with identical structure. The best FoM values obtained for the absorber sensor here...

  9. International

    International Nuclear Information System (INIS)

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  10. First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV.

    Science.gov (United States)

    Aguilar, M; Alberti, G; Alpat, B; Alvino, A; Ambrosi, G; Andeen, K; Anderhub, H; Arruda, L; Azzarello, P; Bachlechner, A; Barao, F; Baret, B; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Basili, A; Batalha, L; Bates, J; Battiston, R; Bazo, J; Becker, R; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Berges, P; Bertucci, B; Bigongiari, G; Biland, A; Bindi, V; Bizzaglia, S; Boella, G; de Boer, W; Bollweg, K; Bolmont, J; Borgia, B; Borsini, S; Boschini, M J; Boudoul, G; Bourquin, M; Brun, P; Buénerd, M; Burger, J; Burger, W; Cadoux, F; Cai, X D; Capell, M; Casadei, D; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, C R; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chernoplyiokov, N; Chikanian, A; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Commichau, V; Consolandi, C; Contin, A; Corti, C; Costado Dios, M T; Coste, B; Crespo, D; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirkoz, B; Dennett, P; Derome, L; Di Falco, S; Diao, X H; Diago, A; Djambazov, L; Díaz, C; von Doetinchem, P; Du, W J; Dubois, J M; Duperay, R; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eppling, F J; Eronen, T; van Es, J; Esser, H; Falvard, A; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Flood, K; Foglio, R; Fohey, M; Fopp, S; Fouque, N; Galaktionov, Y; Gallilee, M; Gallin-Martel, L; Gallucci, G; García, B; García, J; García-López, R; García-Tabares, L; Gargiulo, C; Gast, H; Gebauer, I; Gentile, S; Gervasi, M; Gillard, W; Giovacchini, F; Girard, L; Goglov, P; Gong, J; Goy-Henningsen, C; Grandi, D; Graziani, M; Grechko, A; Gross, A; Guerri, I; de la Guía, C; Guo, K H; Habiby, M; Haino, S; Hauler, F; He, Z H; Heil, M; Heilig, J; Hermel, R; Hofer, H; Huang, Z C; Hungerford, W; Incagli, M; Ionica, M; Jacholkowska, A; Jang, W Y; Jinchi, H; Jongmanns, M; Journet, L; Jungermann, L; Karpinski, W; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Koulemzine, A; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Laudi, E; Laurenti, G; Lauritzen, C; Lebedev, A; Lee, M W; Lee, S C; Leluc, C; León Vargas, H; Lepareur, V; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Lipari, P; Lin, C H; Liu, D; Liu, H; Lomtadze, T; Lu, Y S; Lucidi, S; Lübelsmeyer, K; Luo, J Z; Lustermann, W; Lv, S; Madsen, J; Majka, R; Malinin, A; Mañá, C; Marín, J; Martin, T; Martínez, G; Masciocchi, F; Masi, N; Maurin, D; McInturff, A; McIntyre, P; Menchaca-Rocha, A; Meng, Q; Menichelli, M; Mereu, I; Millinger, M; Mo, D C; Molina, M; Mott, P; Mujunen, A; Natale, S; Nemeth, P; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oh, S; Oliva, A; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Park, W H; Pauluzzi, M; Pauss, F; Pauw, A; Pedreschi, E; Pensotti, S; Pereira, R; Perrin, E; Pessina, G; Pierschel, G; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pochon, J; Pohl, M; Poireau, V; Porter, S; Pouxe, J; Putze, A; Quadrani, L; Qi, X N; Rancoita, P G; Rapin, D; Ren, Z L; Ricol, J S; Riihonen, E; Rodríguez, I; Roeser, U; Rosier-Lees, S; Rossi, L; Rozhkov, A; Rozza, D; Sabellek, A; Sagdeev, R; Sandweiss, J; Santos, B; Saouter, P; Sarchioni, M; Schael, S; Schinzel, D; Schmanau, M; Schwering, G; Schulz von Dratzig, A; Scolieri, G; Seo, E S; Shan, B S; Shi, J Y; Shi, Y M; Siedenburg, T; Siedling, R; Son, D; Spada, F; Spinella, F; Steuer, M; Stiff, K; Sun, W; Sun, W H; Sun, X H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tassan-Viol, J; Ting, Samuel C C; Ting, S M; Titus, C; Tomassetti, N; Toral, F; Torsti, J; Tsai, J R; Tutt, J C; Ulbricht, J; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vargas Trevino, M; Vaurynovich, S; Vecchi, M; Vergain, M; Verlaat, B; Vescovi, C; Vialle, J P; Viertel, G; Volpini, G; Wang, D; Wang, N H; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Wallraff, W; Weng, Z L; Willenbrock, M; Wlochal, M; Wu, H; Wu, K Y; Wu, Z S; Xiao, W J; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J G; Zhang, Z; Zhang, M M; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zuccon, P; Zurbach, C

    2013-04-01

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena. PMID:25166975

  11. First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV.

    Science.gov (United States)

    Aguilar, M; Alberti, G; Alpat, B; Alvino, A; Ambrosi, G; Andeen, K; Anderhub, H; Arruda, L; Azzarello, P; Bachlechner, A; Barao, F; Baret, B; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Basili, A; Batalha, L; Bates, J; Battiston, R; Bazo, J; Becker, R; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Berges, P; Bertucci, B; Bigongiari, G; Biland, A; Bindi, V; Bizzaglia, S; Boella, G; de Boer, W; Bollweg, K; Bolmont, J; Borgia, B; Borsini, S; Boschini, M J; Boudoul, G; Bourquin, M; Brun, P; Buénerd, M; Burger, J; Burger, W; Cadoux, F; Cai, X D; Capell, M; Casadei, D; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, C R; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chernoplyiokov, N; Chikanian, A; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Commichau, V; Consolandi, C; Contin, A; Corti, C; Costado Dios, M T; Coste, B; Crespo, D; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirkoz, B; Dennett, P; Derome, L; Di Falco, S; Diao, X H; Diago, A; Djambazov, L; Díaz, C; von Doetinchem, P; Du, W J; Dubois, J M; Duperay, R; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eppling, F J; Eronen, T; van Es, J; Esser, H; Falvard, A; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Flood, K; Foglio, R; Fohey, M; Fopp, S; Fouque, N; Galaktionov, Y; Gallilee, M; Gallin-Martel, L; Gallucci, G; García, B; García, J; García-López, R; García-Tabares, L; Gargiulo, C; Gast, H; Gebauer, I; Gentile, S; Gervasi, M; Gillard, W; Giovacchini, F; Girard, L; Goglov, P; Gong, J; Goy-Henningsen, C; Grandi, D; Graziani, M; Grechko, A; Gross, A; Guerri, I; de la Guía, C; Guo, K H; Habiby, M; Haino, S; Hauler, F; He, Z H; Heil, M; Heilig, J; Hermel, R; Hofer, H; Huang, Z C; Hungerford, W; Incagli, M; Ionica, M; Jacholkowska, A; Jang, W Y; Jinchi, H; Jongmanns, M; Journet, L; Jungermann, L; Karpinski, W; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Koulemzine, A; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Laudi, E; Laurenti, G; Lauritzen, C; Lebedev, A; Lee, M W; Lee, S C; Leluc, C; León Vargas, H; Lepareur, V; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Lipari, P; Lin, C H; Liu, D; Liu, H; Lomtadze, T; Lu, Y S; Lucidi, S; Lübelsmeyer, K; Luo, J Z; Lustermann, W; Lv, S; Madsen, J; Majka, R; Malinin, A; Mañá, C; Marín, J; Martin, T; Martínez, G; Masciocchi, F; Masi, N; Maurin, D; McInturff, A; McIntyre, P; Menchaca-Rocha, A; Meng, Q; Menichelli, M; Mereu, I; Millinger, M; Mo, D C; Molina, M; Mott, P; Mujunen, A; Natale, S; Nemeth, P; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oh, S; Oliva, A; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Park, W H; Pauluzzi, M; Pauss, F; Pauw, A; Pedreschi, E; Pensotti, S; Pereira, R; Perrin, E; Pessina, G; Pierschel, G; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pochon, J; Pohl, M; Poireau, V; Porter, S; Pouxe, J; Putze, A; Quadrani, L; Qi, X N; Rancoita, P G; Rapin, D; Ren, Z L; Ricol, J S; Riihonen, E; Rodríguez, I; Roeser, U; Rosier-Lees, S; Rossi, L; Rozhkov, A; Rozza, D; Sabellek, A; Sagdeev, R; Sandweiss, J; Santos, B; Saouter, P; Sarchioni, M; Schael, S; Schinzel, D; Schmanau, M; Schwering, G; Schulz von Dratzig, A; Scolieri, G; Seo, E S; Shan, B S; Shi, J Y; Shi, Y M; Siedenburg, T; Siedling, R; Son, D; Spada, F; Spinella, F; Steuer, M; Stiff, K; Sun, W; Sun, W H; Sun, X H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tassan-Viol, J; Ting, Samuel C C; Ting, S M; Titus, C; Tomassetti, N; Toral, F; Torsti, J; Tsai, J R; Tutt, J C; Ulbricht, J; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vargas Trevino, M; Vaurynovich, S; Vecchi, M; Vergain, M; Verlaat, B; Vescovi, C; Vialle, J P; Viertel, G; Volpini, G; Wang, D; Wang, N H; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Wallraff, W; Weng, Z L; Willenbrock, M; Wlochal, M; Wu, H; Wu, K Y; Wu, Z S; Xiao, W J; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J G; Zhang, Z; Zhang, M M; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zuccon, P; Zurbach, C

    2013-04-01

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

  12. Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

    1998-05-01

    The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

  13. Improving intra-fractional target position accuracy using a 3D surface surrogate for left breast irradiation using the respiratory-gated deep-inspiration breath-hold technique.

    Directory of Open Access Journals (Sweden)

    Yi Rong

    Full Text Available PURPOSE: To evaluate the use of 3D optical surface imaging as a surrogate for respiratory gated deep-inspiration breath-hold (DIBH for left breast irradiation. MATERIAL AND METHODS: Patients with left-sided breast cancer treated with lumpectomy or mastectomy were selected as candidates for DIBH treatment for their external beam radiation therapy. Treatment plans were created on both free breathing (FB and DIBH computed tomography (CT simulation scans to determine dosimetric benefits from DIBH. The Real-time Position Management (RPM system was used to acquire patient's breathing trace during DIBH CT acquisition and treatment delivery. The reference 3D surface models from FB and DIBH CT scans were generated and transferred to the "AlignRT" system for patient positioning and real-time treatment monitoring. MV Cine images were acquired during treatment for each beam as quality assurance for intra-fractional position verification. The chest wall excursions measured on these images were used to define the actual target position during treatment, and to investigate the accuracy and reproducibility of RPM and AlignRT. RESULTS: Reduction in heart dose can be achieved using DIBH for left breast/chest wall radiation. RPM was shown to have inferior correlation with the actual target position, as determined by the MV Cine imaging. Therefore, RPM alone may not be an adequate surrogate in defining the breath-hold level. Alternatively, the AlignRT surface imaging demonstrated a superior correlation with the actual target positioning during DIBH. Both the vertical and magnitude real-time deltas (RTDs reported by AlignRT can be used as the gating parameter, with a recommended threshold of ±3 mm and 5 mm, respectively. CONCLUSION: The RPM system alone may not be sufficient for the required level of accuracy in left-sided breast/CW DIBH treatments. The 3D surface imaging can be used to ensure patient setup and monitor inter- and intra- fractional motions

  14. UNDERSTANDING TRENDS ASSOCIATED WITH CLOUDS IN IRRADIATED EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Heng, Kevin [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Demory, Brice-Olivier, E-mail: kevin.heng@csh.unibe.ch, E-mail: demory@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2013-11-10

    Unlike previously explored relationships between the properties of hot Jovian atmospheres, the geometric albedo and the incident stellar flux do not exhibit a clear correlation, as revealed by our re-analysis of Q0-Q14 Kepler data. If the albedo is primarily associated with the presence of clouds in these irradiated atmospheres, a holistic modeling approach needs to relate the following properties: the strength of stellar irradiation (and hence the strength and depth of atmospheric circulation), the geometric albedo (which controls both the fraction of starlight absorbed and the pressure level at which it is predominantly absorbed), and the properties of the embedded cloud particles (which determine the albedo). The anticipated diversity in cloud properties renders any correlation between the geometric albedo and the stellar flux weak and characterized by considerable scatter. In the limit of vertically uniform populations of scatterers and absorbers, we use an analytical model and scaling relations to relate the temperature-pressure profile of an irradiated atmosphere and the photon deposition layer and to estimate whether a cloud particle will be lofted by atmospheric circulation. We derive an analytical formula for computing the albedo spectrum in terms of the cloud properties, which we compare to the measured albedo spectrum of HD 189733b by Evans et al. Furthermore, we show that whether an optical phase curve is flat or sinusoidal depends on whether the particles are small or large as defined by the Knudsen number. This may be an explanation for why Kepler-7b exhibits evidence for the longitudinal variation in abundance of condensates, while Kepler-12b shows no evidence for the presence of condensates despite the incident stellar flux being similar for both exoplanets. We include an 'observer's cookbook' for deciphering various scenarios associated with the optical phase curve, the peak offset of the infrared phase curve, and the geometric

  15. Food irradiation 2009

    International Nuclear Information System (INIS)

    Food irradiation principles; its main applications, advantages and limitations; wholesomeness, present activities at Ezeiza Atomic Centre; research coordinated by the International Atomic Energy Agency; capacity building; and some aspects on national and international regulations, standards and commercialization are briefly described. At present 56 countries authorize the consumption of varied irradiated foods; trade is performed in 32 countries, with about 200 irradiation facilities. Argentina pioneered nuclear energy knowledge and applications in Latin America, food irradiation included. A steady growth of food industrial volumes treated in two gamma facilities can be observed. Food industry and producers show interest towards new facilities construction. However, a 15 years standstill in incorporating new approvals in the Argentine Alimentary Code, in spite of consecutive request performed either by CNEA or some food industries restricts, a wider industrial implementation, which constitute a drawback to future regional commercialization in areas such as MERCOSUR, where Brazil since 2000 freely authorize food irradiation. Besides, important chances in international trade with developed countries will be missed, like the high fresh fruits and vegetables requirements United States has in counter-season, leading to convenient sale prices. The Argentine food irradiation facilities have been designed and built in the country. Argentina produces Cobalt-60. These capacities, unusual in the world and particularly in Latin America, should be protected and enhanced. Being the irradiation facilities scarce and concentrated nearby Buenos Aires city, the possibilities of commercial application and even research and development are strongly limited for most of the country regions. (author)

  16. Polymer fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Hadermann, A. F.

    1985-04-09

    Soluble polymers are fractionated according to molecular weight by cryogenically comminuting the polymer and introducing the polymer particles, while still in the active state induced by cryogenic grinding, into a liquid having a solvent power selected to produce a coacervate fraction containing high molecular weight polymer species and a dilute polymer solution containing lower molecular weight polymer species. The coacervate may be physically separated from the solution and finds use in the production of antimisting jet fuels and the like.

  17. Irradiation of onions, pulses and dried fish: Process control, storage, test marketing and economic analysis of the process

    International Nuclear Information System (INIS)

    Scaled up irradiation and storage of onions, pulses and dried fish were undertaken to determine technical suitability and economic benefits of irradiation processing with emphasis on process control and consumer acceptance to facilitate commercial application of the technology. Two storage trials of each product were carried out involving 20 MT onions, 6 MT pulses and 3 MT dried fish during 1990-93. In selecting products for experimental purposes, post-harvest quality, hygiene and associated standards were considered as embodied in the Codex General Standard for Irradiated Foods. Each food Item were considered as embodied in the Codex General Standard for Irradiated Foods. Each food item was suitably packaged and appropriate product inventory control was ensured. Products were irradiated to specified doses of gamma radiation. Source handling and operation was done by trained operators and designated personnel. Good Irradiation Practices and the Recommended International Code of Practice for the Operation of Irradiation Facilities were strictly adhered to while irradiating the products. Measurement of absorbed doses in various positions within the product package and monitoring of the physical parameters of the process were routinely made to determine dose uniformity ratio and overall average absorbed doses. Post irradiation storage of the products at ambient conditions was done appropriately. Test marketing of the irradiated products was successfully undertaken with favourable response from consumers because of superior overall quality of the products. Economic benefits have been studied keeping in mind the technical success achieved under local conditions. The process appeared to be economically feasible. 12 refs, 3 figs, 14 tabs

  18. Liquid Hydrogen Absorber for MICE

    Energy Technology Data Exchange (ETDEWEB)

    Ishimoto, S.; Suzuki, S.; Yoshida, M.; Green, Michael A.; Kuno, Y.; Lau, Wing

    2010-05-30

    Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with {approx}2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

  19. Energy-absorbing effectiveness factor

    OpenAIRE

    Jones, Norman

    2010-01-01

    Abstract A study is reported on the energy-absorbing effectiveness factor which was introduced recently. The factor is defined as the quotient of the total energy, which can be absorbed in a system, to the maximum energy up to failure in a normal tensile specimen, which is made from the same volume of material. This dimensionless parameter allows comparisons to be made of the effectiveness of various geometrical shapes and of energy-absorbers made from different materials. The infl...

  20. Contributions of the food irradiation technology to the nutritional and alimentary safety

    International Nuclear Information System (INIS)

    This work is a bibliographic review about the contributions of the food irradiation technology on nutritional and alimentary safety. Subjected to research and development for more than 60 years, these technology was approved by a jointly FAO/WHO/IAEA Expert Committees in 1980 with the conclusion that the irradiation of food up to an overall average dose of 10 kGy present no toxicological hazard and introduce no special nutritional or microbiological problems. Following these conclusions general standards and practices for food irradiation were adopted by the Codex Alimentarium Commission in 1983, opening the possibilities for internal applications and international commerce of irradiated food in many countries. Radiation from radioisotopes sources, electron accelerators or X-ray generators can be applied to food in order to reduce the microbial load, insect disinfestation, improving the shelf life extension of the products. Absorbed doses up to 10 kGy level do not introduce significant alterations in the macro or micro nutrients contents or in the sensorial characteristic of irradiated food. Although food safety can be related with many other important topics, irradiation technology improving food quality, reducing food spoilage during preservation and preventing problems related with food borne disease present a good potential to contribute with the foment and guaranty of the nutritional and alimentary safety. (author)

  1. Time-dose relationship of erythema in high energy photon irradiation therapy

    International Nuclear Information System (INIS)

    Skin doses of 100 patients who were treated with high energy ionizing irradiation during conventional irradiation therapy were measured by thermoluminescence dosimeter (TLD). In 87 of the 100 patients, acute hyperemic change of the skin (erythema) of the irradiated region was observed. In the other 13 patients, alopetia of the scalp was observed. The following conclusions were reached. The time-dose relationship was linear when erythema tolerance was used as an index, but not when alopecia was used. The tolerance dose for erythema was lower than previously reported. The slope of the isoeffect curve on the log-log plot of total absorbed skin dose against total number of days after the first irradiation was 0.68 when erythema was used as an index. This number is larger than previously reported results. We considered that erythema is significantly influenced by fraction size and that hyperfractionation is a promising method of irradiation, especially in Japan. Combined use of chemotherapeutic agents, such as 5-FU, accelerated erythema. The slope of combined treatment was 0.86. Observing acute hyperemic change of skin is considered to be a useful method of investigating the combined effects of chemotherapeutic agents on irradiation. (author)

  2. Study on the Microstructure of Polyester Polyurethane Irradiated in Air and Water

    Directory of Open Access Journals (Sweden)

    Qiang Tian

    2015-09-01

    Full Text Available The gamma irradiation induced aging of thermoplastic polymer Estane 5703 in air and water environments was studied by small-angle neutron scattering (SANS, Fourier transform infrared spectroscopy (FTIR, gel permeation chromatography (GPC, and X-ray diffraction (XRD. The degree of phase mixing was increased after irradiation, accompanied by the increase of domain distance and decrease of domain size. The hard domain distance increased from 9.8 to 11.2 nm and 14.4 nm for the samples irradiated in air and water with a dose up to 500 kGy, respectively. The GPC results indicated progressive formation of larger linked structures with very high molar mass with increasing absorbed doses. The samples irradiated in water exhibited a stronger aging effect than those irradiated in air. The FTIR results suggested that the cross-linking occurred among the secondary alkyl radicals, and the interactions in hard domains weakened because of the loss of inter-urethane H-bonds. The volume fraction of well-ordered soft segments in Estane increased upon irradiation.

  3. Time-dose relationship of erythema in high energy photon irradiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hidetoshi (Gifu Prefectural Tajimi Hospital (Japan)); Sakuma, Sadayuki

    1992-01-01

    Skin doses of 100 patients who were treated with high energy ionizing irradiation during conventional irradiation therapy were measured by thermoluminescence dosimeter (TLD). In 87 of the 100 patients, acute hyperemic change of the skin (erythema) of the irradiated region was observed. In the other 13 patients, alopetia of the scalp was observed. The following conclusions were reached. The time-dose relationship was linear when erythema tolerance was used as an index, but not when alopecia was used. The tolerance dose for erythema was lower than previously reported. The slope of the isoeffect curve on the log-log plot of total absorbed skin dose against total number of days after the first irradiation was 0.68 when erythema was used as an index. This number is larger than previously reported results. We considered that erythema is significantly influenced by fraction size and that hyperfractionation is a promising method of irradiation, especially in Japan. Combined use of chemotherapeutic agents, such as 5-FU, accelerated erythema. The slope of combined treatment was 0.86. Observing acute hyperemic change of skin is considered to be a useful method of investigating the combined effects of chemotherapeutic agents on irradiation. (author).

  4. New Technology in Hydrogen Absorbers for Muon Cooling Channels

    CERN Document Server

    Cummings, M A C

    2005-01-01

    Ionization cooling is the only technique fast enough to cool and focus muons for neutrino factories and muon colliders, and hydrogen is the optimal material for maximum cooling and minimal multiple scattering. Liquid hydrogen absorber R&D for the Muon Collaboration has proceeded on parallel and complementary fronts. The continuing LH2 absorber engineering and technical developments by the MuCool group conducted by ICAR* institutions (NIU, IIT and UIUC), the University of Mississippi and Oxford University, in cooperation with Fermilab, will be summarized, including results from the first hydrogen absorber tests at the newly constructed FNAL Mucool Test Area (MTA). The program includes designs for the high-powered test of an absorber prototype (external heat exchange) at the MTA which are nearing completion to be installed by summer 2005, an alternative absorber design (internal heat exchange) being finalized for the approved cooling experiment (MICE) at Rutherford-Appleton Laboratory, and a novel idea for ...

  5. Issues in food irradiation

    International Nuclear Information System (INIS)

    This discussion paper has two goals: first, to raise public awareness of food irradiation, an emerging technology in which Canada has the potential to build a new industry, mainly oriented to promising overseas markets; and second, to help build consensus among government and private sector decision makers about what has to be done to realize the domestic and export potential. The following pages discuss the potential of food irradiation; indicate how food is irradiated; outline the uses of food irradiation; examine questions of the safety of the equipment and both the safety and nutritional value of irradiated food; look at international commercial developments; assess the current and emerging domestic scene; and finally, draw some conclusions and offer suggestions for action

  6. Quality control in the commerce of irradiated foods; Control de calidad en el comercio de alimentos irradiados

    Energy Technology Data Exchange (ETDEWEB)

    Bustos R, M.E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    In spite of an irradiated food is innocuous for health and that the irradiation process offers great advantages as conservation and hygiene method and it has been recognised by the Agriculture and Health International organizations and although the adequate equipment exists to make this treatment in the majority of countries, an international trade of irradiated foods has not been established and it is that it has to be required that the quality control of the treatment should be regulated by the corresponding authorities and it also should be harmonized with other countries for the commercial interchange. Owing to up to present an identification method of irradiated foods which is validated, the unique quality control for irradiated foods is realized in the irradiation plant, measuring the absorbed dose in products, using dosimetric systems justly calibrated and standardized to be used the adequate for the type of product and dose level which is wanted to be measured for foods mainly for quarantine treatment which is very important to determine that any part of the irradiation system has reached the minimum dose to obtain the technical effect which is desired and that it does not exceed the maximum d