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Sample records for absorbed fraction internal irradiation

  1. An analytical model to calculate absorbed fractions for internal dosimetry with alpha, beta and gamma emitters

    Ernesto Amato

    2014-03-01

    Full Text Available We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'generalized radius', calculated as 3V/S, where V is the ellipsoid volume and S its surface. Radiation-specific parametric functions were obtained in order to calculate the absorbed fraction of a given radiation in a generic ellipsoidal volume. The dose from a generic radionuclide can be calculated through a process of summation and integration over the whole radionuclide emission spectrum, profitably implemented in an electronic spreadsheet. We compared the results of our analytical calculation approach with those obtained from the OLINDA/EXM computer software, finding a good agreement in a wide range of sphere radii, for the high-energy pure beta emitter 90Y, the commonly employed beta-gamma emitter 131I, and the pure alpha emitter 213Po. The generality of our approach makes it useful an easy to implement in clinical dosimetry calculations as well as in radiation safety estimations when doses from internal radionuclide uptake are to be taken into account.

  2. Calculation of absorbed dose of anchorage-dependent cells from internal beta-rays irradiation

    Objective: To elicit the formula of internal dosimetry in anchorage-dependent cells by beta-emitting radionuclides from uniformly distributed volume sources. Methods: By means of the definition of absorbed dose and the MIRD (Medical International Radiation Dose) scheme the formula of internal dosimetry was reasonably deduced. Firstly, studying the systems of suspension culture cells. Then, taking account of the speciality of the systems of the anchorage-dependent cells and the directions of irradiation, the absorbed dose of anchorage -dependent cells was calculated by the accumulated radioactivity, beta-ray energy, and the volume of the cultured systems. Results: The formula of internal dosimetry of suspension culture cells and anchorage-dependent cells were achieved. At the same time, the formula of internal dosimetry of suspension culture cells was compared with that of MIRD and was confirmed accurate. Conclusion: The formula of internal dosimetry is concise, reliable and accurate

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

    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

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

    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

  5. Specific absorbed fractions of energy at various ages from internal photon sources: 6, Newborn

    Specific absorbed fraction (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 newborn or 3.4-kg person. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target 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

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

    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

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

    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

  8. Internal photomechanical fracture of spatially limited absorbers irradiated by short laser pulses

    Paltauf, Guenther; Schmidt-Kloiber, Heinz

    1998-05-01

    A photomechanical damage mechanism in abosrbing regions or particles surrounded by a non-abosrbing medium after irradiation with a short laser pulse is investigated experimentally and theoretically. In tissue, such absorbers are for example melanosomes, blood vessels or tatoo pigments. It follows from theoretical considerations that the photoacoustic wave caused by irradiation of a spatially limited volume contains both compressive and tensile stress. Experiments were performed to test whether these tensile stresses cause cavitation in absorbers of spherical or cylindrical shape. High-speed video images of liquid spheres or gelatin cylinders (diameters 200 to 300 micrometer) suspended in oil showed that cavitation occurs at the center of the spheres or on the cylinder axis, respectively, shortly after irradiation with a light pulse (6 ns duration) from an optical parametric oscillator. The cavitation effect was observed at maximum temperatures below and above the boiling point and at ratios of the absorber size on the absorption length larger and smaller than one. The experimental findings are supported by theoretical calculations, from which strong tensile stresses are predicted in the interior of the absorbers, even if the values of acoustic impedance inside and outside the absorbing volume are equal. The reported effect is believed to cause damage to absorbers if the pulse duration is short enough to provide stress confinement, that is if the time an acoustic wave needs to cross the abosrbing region is longer than the pulse duration. For small absorbers such as melanosomes with a size of about 1 micrometer this requires a laser pulse duration in the picosecond regime.

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

    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

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

    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

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

    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

  12. Absorbed fractions for electrons in ellipsoidal volumes

    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.

  13. 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

    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

  14. 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

    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)

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

    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

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

    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

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

    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

  18. Absorbed fraction of electrons in human respiratory tract

    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

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

    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)

  20. Comparison of internal doses calculated using the specific absorbed fractions of the average adult Japanese male phantom with those of the reference computational phantom-adult male of ICRP publication 110

    In order to study the effects of body sizes and masses of organs and tissues on internal dose assessment, the values corresponding to effective dose coefficients for intakes of radionuclides were calculated using the specific absorbed fractions (SAFs) of two phantoms: the average adult Japanese male phantom (JM-103) and the reference computational phantom-adult male (RCP-AM) of the International Commission on Radiological Protection. SAFs were evaluated using the phantoms and Monte Carlo radiation transport code MCNPX or were taken from published data. As a result of a comparison for 2894 cases of 923 radionuclides, the maximum discrepancy in the effective dose coefficients between the JM-103 and RCP-AM was about 40%. However, the discrepancies were smaller than 10% in 97% of all cases. (paper)

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

    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)

  2. Taking into account absorbed doses in tooth enamel due to internal irradiation of human body by radioactive cesium isotopes at analysis EPR dosimetry data: Calculation by Monte-Carlo method

    Borysheva, N. [Medical Radiological Research Center, Korolyov str., 4, Obninsk 249020 (Russian Federation); Ivannikov, A. [Medical Radiological Research Center, Korolyov str., 4, Obninsk 249020 (Russian Federation)], E-mail: Ivannikov-Alexander@yandex.ru; Tikunov, D.; Orlenko, S.; Skvortsov, V.; Stepanenko, V. [Medical Radiological Research Center, Korolyov str., 4, Obninsk 249020 (Russian Federation); Hoshi, M. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553 (Japan)

    2007-07-15

    By Monte-Carlo simulation of ionizing particles transport, for a realistic mathematical phantom of a man supplemented by a dental region, absorbed doses in teeth enamel and whole body doses are calculated for cases of internal irradiation by {sup 137}Cs and {sup 134}Cs isotopes incorporated in the human body resulted from staying in radioactive contaminated territory. It is shown that dose in enamel constitutes (40{+-}4)% and (59{+-}6)% of whole body dose resulted from the decay of {sup 137}Cs and {sup 134}Cs isotopes, respectively. The results of calculations may be used for conversion of absorbed dose in enamel obtained by the tooth enamel EPR spectroscopy method to whole body dose for dosimetric investigation of population of territories contaminated by the radioactive cesium, which is specific for the Chernobyl accident.

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

    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.

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

    Wang, Wen; Cheng, Meng-Yun; Long, Peng-Cheng; Hu, Li-Qin

    2015-07-01

    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. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03040000), National Natural Science Foundation of China (910266004, 11305205, 11305203) and National Special Program for ITER (2014GB112001)

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

    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)

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

    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...

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

    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

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

    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

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

    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.

  10. Absorbed dose estimation and prediction irradiation effects in tumor-bearing mice under radionuclide therapy

    Full text: As the sizes of mouse organ are comparable with the range of the high-energy beta particles emitted by the radionuclides commonly used in radionuclide therapy a significant amount of beta radiation emitted could be imparted to the adjacent tissues. The often assumption that beta particles are fully-absorbed at the emission site is not satisfied and cross-irradiation should be included into the dose estimation formulas. Keeping in mind that the radiation effects are correlated with the absorbed dose in the target the inclusion of cross-irradiation in the dose estimation must be evaluated. The MIRD's formulation was used to perform absorbed dose calculation in mice using absorbed fractions previously reported for 131I, 90Y and 177Lu. Two approaches were considered: a) cross irradiation when a fraction of beta particles emitted can escape from the organ source and, b) full self- irradiation when the beta particles are considered fully absorbed at the emission site. The formulation of linear-quadratic model was readapted to be used in the radionuclide therapy. Treatment with a single administration in mice was simulated and radiation effects on tumor, bone marrow and kidneys under the assumption of cross-irradiation were predicted. A biphasic repair kinetics was considered in the calculation of irradiation effects on kidneys. Typical published biokinetic data for radiopharmaceutical assayed in mice and radiobiological parameters were used in the calculations. The influence of cross irradiation condition was diverse for the tissues analyzed here. The absorbed dose values in kidneys calculated for both methods were no significantly different for low energies, but variations around to 40-50% (over or under-estimation) in absorbed dose were obtained for high energies. Approximately a 30% of the beta radiation emitted from bone will cross irradiates the bone marrow. For injected activities values higher than 10MBq (300μCi), as a single injection, the

  11. Specification of absorbed dose for reporting a therapeutic irradiation

    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)

  12. International Developments of Food Irradiation

    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)

  13. International Developments of Food Irradiation

    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)

  14. International status of food irradiation

    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

  15. Patient absorbed radiation doses estimation related to irradiation anatomy

    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

  16. Irradiation performances of the Superphenix type absorber element

    Several aspects of irradiation behaviour of the SUPERPHENIX type absorber element are presented in this paper. A large programme of irradiation tests was performed in PHENIX to assess and to improve the absorber pin design whose main characteristics for the first load are a sodium bonded and vented pin with high density (96% TD) and highly enriched (up to 90 at % of boron 10) B4C pellets. We present and discuss the main post-irradiation results obtained by this program which concerns the behaviour of both B4C pellets (fragmentation, swelling, helium release, thermal conductivity evolution) and stainless steel clad (embrittlement by carburization, mechanical interaction). It appears that the residence time of the first load of SUPERPHENIX control rods is clearly limited by mechanical interaction between B4C and the clad, and particularly by relocating of small fragments of B4C at beginning of life of the first gap. The irradiation performed in PHENIX led to fix the residence time of the first load of control rods to 240 e.f.p.d. The analyses of the effects limiting the residence time have enabled us to propose an extension of this time by two measures. The first one is reduction of the capture rate in boron carbide. The measure was brought into operation by mean of lowering at 48 at % the boron 10 enrichment of the B4C pellets in the lower part of the pin. The second measure is preventing the fragment relocation by adoption of a thin stainless shroud enclosing the pellet stack. The efficiency of these measures was proved in several irradiation tests (ANTIMAG experiments) in PHENIX. A burn-up of 220 x 1020 capt/cm3 was achieved without any dimensional change of the pin diameter. The shroud failed but could nevertheless prevent any pellet cladding deformation. Thus, these results have enabled us to fix a residence time of 640 e.f.p.d. for the third load of the SUPERPHENIX control rods. The achievement in the future of lifetime up to 1000 e.f.p.d. will require the

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

    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

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

    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

  19. An international intercomparison of absorbed dose measurements for radiation therapy

    Dose intercomparison on an international basis has become an important component of quality assurance measurement i.e. to check the performance of absorbed dose measurements in radiation therapy. The absorbed dose to water measurements for radiation therapy at the SSDL, MINT have been regularly compared through international intercomparison programmes organised by the IAEA Dosimetry Laboratory, Seibersdorf, Austria such as IAEA/WHO TLD postal dose quality audits and the Intercomparison of therapy level ionisation chamber calibration factors in terms of air kerma and absorbed dose to water calibration factors. The results of these intercomparison in terms of percentage deviations for Cobalt 60 gamma radiation and megavoltage x-ray from medical linear accelerators participated by the SSDL-MINT during the year 1985-2001 are within the acceptance limit. (Author)

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

    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

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

    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)

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

    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)

  3. Influence of caffeine on fractionated irradiation in wheat and barley

    Fractionated irradiation is one of the important methods studying repair of radiation damage. Some authors reported that caffeine, a repair inhibitor, had no effects on fractionated irradiation in human cell, animal cell and Vicia faba. And they concluded that caffeine inhibited the repair of potentially lethal damage (PLD), but did not inhibit the repair of sub-lethal damage (SLD). In this study, the effect of caffeine on the repair of PLD and SLD were reexamined in wheat and barley systems. The germinating seeds of wheat of barley were pre-irradiation treated 3 h with 5 x 10-3 mol/L caffeine, then they were irradiated by single or fractionated X-ray doses. The results showed that after caffeine treatment the effect of fractionated irradiation was disappeared. In this case, caffeine not only inhibited the repair of PLD but also inhibited the repair SLD. In previous fracttionated radiation experiments, the repairs during interval were discussed in detail, but the repairs after whole irradiation were neglected. According to the resuls of this experiment and some early reported about fractionated irradiation, the repair efficiency during interval and the repair function after whole irradiation were discussed

  4. A mathematical model for the kidney and estimative of the specific absorbed fractions by Monte Carlo method

    Presently, the estimates of specific absorbed fractions in various organs of a heterogeneous phantom are based on Monte Carlo calculation for monoenergetic photons uniformly distributed in the organs of an adult phantom. But, it is known that the kidney and some other organs (for example the skeleton) do not retain the radionuclides in an uniform manner in its internal region. So, we developed a model for the kidney including the cortex, medulla and collecting region. This model was utilized to estimate the specific absorbed fractions, for monoenergetic photons or electrons, in various organs of a heterogeneous phantom, when sources were uniformly distributed in each region of the kidney. All results obtained in this work were compared with those using a homogeneous model for the kidney as presented in ORNL-5000. (Author)

  5. 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

    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)

  6. Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

    The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

  7. Dynamic dose-shaping by gravity-oriented absorbers for total lymph node irradiation

    Rotational therapy with gravity-oriented absorbers is proposed for better total lymph node irradiation (TLI). Two metal semicylinders are joined coaxially (face to face) to form a radiation absorber that is centrally suspended in the beam. During rotation this absorber is kept parallel to itself by gravity, like the riders of a Ferris wheel. The vertebrae remain continuously protected under the absorber's shadow. The circular full-dose region, achieved by ordinary rotation, is now transformed into a horse-shoe region embracing the spine anteriorly. The abdominal lymph nodes are thus irradiated while the spine and most of the normal tissue around the spine are protected. A similar technique is applied for the selective irradiation of the pelvic lymph nodes, which are confined in the two legs of an inverted V region

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

    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.

  9. Estimation of the absorbed dose in gamma irradiated food containing bone by electron spin resonance spectroscopy

    The use of electron spin resonance (ESR) spectroscopy to accurately evaluate the absorbed dose to radiationprocessed bones (and thus meats) is examined. The exposure of foodstuffs containing bone to a dose of ionizing radiation results in the formation of long lived free radicals which give rise to characteristics ESR signals. The yield of radicals was found to be proportional to absorbed dose. Additive re-irradiation of previously irradiated bone was used to estimate the absorbed dose in the irradiated chicken bone. Simple non-linear rational equation was found to fit to the data and yields good dose estimates for irradiated bone in the range of doses (1.0 - 5.0 kGy). Decay of the ESR signal intensity was monitored at different dose levels (2.0 and 7.0 kGy) up to 22 days. The absorbed dose in irradiated chicken (2.Om 3.0 and 6.0 kGy) was assessed at 2, 6 and 12 days after irradiation. Relatively good results were obtained when measurements were made within the following days (up to 12 days) after irradiation. The ability of the dose additive method to provide accurate dose assessments is tested here

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

    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

  11. Storage tank with internal neutron absorbers for fissile materials

    The advantages of the new storage tank design with internal neutron absorbers for fissile materials compared to the traditional slab tank design are as follows: The available volume of this vessel design has a value of more than 80%. The tank does not require neutron absorbers to be spaced between adjacent tanks as with the case with slab tanks. This results in a saving in cost and space. The tank is smaller in height and breadth and thus requires less room space for the same amount of storage capacity. Costs are reduced in manufacturing material and room space. The outer surface area of the tank is roughly 7 times smaller than the outer surface area of the slab tank and in less area for heat transfer in case of fire - improved safety. The tank manufacturing will require less welding points to be done and the type of welding required can be automated by machinery. The welding method required, is similar to the welding method that is used to weld the fuel rods for conventional HWR nuclear reactors and thus the technology is known, automated and proven. The tube bundle can be easily removed and more space is available inside the tank for inspection and maintenance of the vessel due to the circular geometry. The vessel design is similar to pressure vessel design which is a proven and well documented method.

  12. Electron beam dosimetry for a thin-layer absorber irradiated by 300-keV electrons

    Depth-dose distributions in thin-layer absorbers were measured for 300-keV electrons from a scanning-type irradiation system, the electrons having penetrated through a Ti-window and an air gap. Irradiations of stacks of cellulose triacetate(CTA) film were carried out using either a conveyor (i.e. dynamic irradiation) or fixed (i.e. static) irradiation. The sample was irradiated using various angles of incidence of electrons, in order to examine the effect of obliqueness of electron incidence at low-energy representative of routine radiation curing of thin polymeric or resin layers. Dynamic irradiation gives broader and shallower depth-dose distributions than static irradiation. Greater obliqueness of incident electrons gives results that can be explained in terms of broader and shallower depth-dose distributions. The back-scattering of incident electrons by a metal(Sn) backing material enhances the absorbed dose in a polymeric layer and changes the overall distribution. It is suggested that any theoretical estimations of the absorbed dose in thin layers irradiated in electron beam curing must be accomplished and supported by experimental data such as that provided by this investigation. (Author)

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

    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/μm 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/μm in such that the isoeffect doses did not change among 2, 4 and 8 fractions. The isoeffect doses for LET higher than 50 keV/μm were smaller than those for lower LET. However, the isoeffect doses for 50-, 60-, 80- and 100 keV/μ 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.)

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

    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.)

  15. Absorbed dose distribution analyses in irradiation with adjacent fields

    Because the special irradiation technique with adjacent fields is the most used in the case of medulloblastoma treatment, we consider very important to specify some general information about medulloblastoma. This malignant disease has a large incidence in children with age between 5-7 years. This tumor usually originates in the cerebellum and is referred to as primitive undifferentiated tumor. It may spread contiguously to the cerebellar peduncle, floor of the fourth ventricle, into the cervical spine. In addition, it may spread via the cerebrospinal fluid intracranially and/or to the spinal cord. For this purpose it is necessary to perform a treatment technique with cranial tangential fields combined with adjacent fields for the entire spinal cord to achieve a perfect coverage of the zones with malignant cells. The treatment in this case is an association between surgery-radio-chemotherapy, where the radiotherapy has a very important roll and a curative purpose. This is due to the fact that the migration of malignant cells in the body can't be controlled by surgery. Because of this special irradiation technique used in medulloblastoma treatment, we chase to describe in this paper this complex type of irradiation where the implications of the beams divergence in doses distribution are essentials

  16. Glycolytic metabolism and tumour response to fractionated irradiation

    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.

  17. Spheroid control of malignant glioma cell lines after fractionated irradiation

    Spheroid control doses (SCD50) were determined for ten human glioma lines after fractionated irradiation under oxic conditions. In addition, SF2 values and colony forming efficiencies (CFE) were measured in a soft agarose clonogenic assay. A significant relationship existed between the SCD50 values and the SF2CFE data pairs (p=0.01) but the SCD50 values were higher than expected from the SF2 and CFE values. This comparison shows the influence of environmental factors (different in both model systems) on reproductive tumour cell death after irradiation. (author). figs., tab

  18. Assessment of specific absorbed fractions for photons and electrons using average adult Japanese male phantom

    The International Commission on Radiological Protection (ICRP) is revising dose coefficients, which are effective and equivalent doses per unit intake of radionuclides, based on the 2007 Recommendations. Specific absorbed fractions (SAFs) of voxel phantoms having standard physiques and organ masses (physical characteristics) of Caucasian are used for calculation of the new dose coefficients. SAFs depend on physical characteristics of a phantom used for assessment of the SAFs. Therefore, the SAFs and the dose coefficients developed by ICRP reflect physical characteristics of Caucasian. On the other hand, physiques of adult Japanese are generally smaller than those of adult Caucasian, and organ masses are also different from each other. Consequently, it is expected that SAFs and dose coefficients with physical characteristics of adult Japanese are different from those of ICRP. It is important to understand the influence of the differences in physical characteristics between both races on SAFs and dose coefficients when using the SAFs and dose coefficients of ICRP for radiation protection for Japanese. In order to evaluate internal doses considering the physical characteristics of adult Japanese, the Japan Atomic Energy Agency plans to develop a comprehensive data set of SAFs for photons, electrons, alpha particles and neutrons using average adult Japanese male and female phantoms (male: JM-103, female: JF-103). This report presents a data set of photon and electron SAFs for JM-103. JM-103 was incorporated into the general purpose radiation transport code, MCNPX 2.6.0, and the SAFs were calculated by the MCNPX 2.6.0 for 25 energies from 10 keV to 10 MeV and for combinations of 67 source regions and 41 target organs. Influences of differences in physical characteristics between adult Japanese and Caucasian on SAFs was also examined by comparison between the calculated SAFs in this study and the SAFs of the reference adult male phantom of ICRP. The photon and electron

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

    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

  20. The characteristics and mechanism of apoptosis induced by internal irradiation

    Apoptosis in tumor cells induced by radionuclides is likely the most effective way to cure cancer. In order to explore the possibility in clinic application, the characteristics and mechanism of apoptosis induced by internal irradiation were investigated. The apoptosis and expressions of bcl-2mRNA, bcl-2 and bax of K562 cells following internal exposure with different accumulated absorbed doses of strontium-89 were studied. 6 h after irradiation, the characteristics of apoptosis and necrosis appeared in K562 cells. The apoptosis and necrosis enhanced with the prolongation of internally contaminated time at 6 h, 9 h, 12 h, 24 h and 48 h. The expressions of bcl-2mRNA decreased at 12 h, most remarkably at 24 h. The expressions of bcl-2 decreased after irradiation whereas bax had no obvious changes. The results suggest that the apoptosis induced by internal exposure may be regulated by lower expressions of bcl-2mRNA and bcl-2, lower bcl-2/bax value

  1. Analytical formulae in fractionated irradiation of normal tissue

    The new conception of the modeling of the cell tissue kinetics after fractionated irradiation is proposed. The formulae given earlier are compared with experimental data on various normal tissues and further adjustments are considered. The tissues are shown to exhibit several general patterns of behaviour. The repopulation, if it takes place, seems to start after some time, independently of fractionation in first approximation and can be treated as simple autogenesis. The results are compared with the commonly used NSD conception and the well-known Cohen cell tissue kinetic model

  2. DNA damage induced by radionuclide internal irradiation

    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)

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

    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. Effects of carbogen plus fractionated irradiation on KHT tumor oxygenation

    Background and purpose: Numerous studies have demonstrated improvements in the oxygenation of tumor cells following both irradiation and carbogen breathing. The current studies were initiated to measure the combined effects of carbogen inhalation plus single and multi-dose irradiation on tumor oxygen availability, to better define the underlying physiological relationships. Materials and methods: Using KHT murine sarcomas, radiation was delivered to the tumor-bearing legs of non-anesthetized mice. Tumors were quick-frozen prior to or following single or multifraction irradiation and carbogen breathing, and intravascular HbO2 saturation profiles were determined cryospectrophotometrically. Results: HbO2 levels for blood vessels located near the tumor surface initially decreased following 10 Gy irradiation, then increased and remained elevated. Interior HbO2 levels remained unchanged. Following 2.5 Gy, HbO2 changes were minimal. At 24 h following 10 Gy, HbO2 levels were significantly increased compared to non-irradiated controls, and carbogen breathing produced no additional benefit. At 24 h following five fractions of 2 Gy, HbO2 levels throughout the tumor volume were significantly higher in carbogen breathing animals than in air breathing controls. Conclusions: Although peripheral blood vessels demonstrated substantial improvements in oxygenation following irradiation, oxygen availability nearer the tumor center remained at very low levels. The utility of carbogen in enhancing tumor oxygen availability was maintained following five clinically relevant fractions. At higher doses, radiation-induced enhancements in HbO2 levels overshadowed the carbogen effect. For either air or carbogen breathing, a decrease in the percentage of vessels with very low oxygen content did not appear to be a major factor in the reoxygenation of the KHT tumor

  5. International standards and agreements in food irradiation

    Full text: 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

  6. International standards and agreements in food irradiation

    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

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

    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...

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

    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

  9. Postirradiation examination of JOYO MK-II control rods. Irradiation performance of absorber pins

    Postirradiation examinations of JOYO MK-II control rods have been carried out since 1983, where 16 subassemblies with total 110 absorber pins of initial load to the fifth reload control rods have been subjected to a number of both non-destructive and destructive examinations. In the course of postirradiation examinations, a cracking of cladding tube was found in the total 15 absorber pins in five control assemblies. This paper indicates the results of postirradiation examinations and analysis of absorber pin performance using CORAL code to elucidate the cause of absorber pin cracking in JOYO MK-II control rods. The cause of cladding failure was attributed to the ACMI where the gap closure due to relocation of B4C pellet took place from early times of irradiation. The code analysis by CORAL indicated that the cladding strain due to ACMI was not fully absorbed by the irradiation creep and that the plastic strain became large enough to make a fracture of absorber pins with an increasing burnup. (J.P.N.)

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

    Doroshenko A.V.; Kirillov V.H.; Antonova A.R.; Liudnicky K.V.

    2015-01-01

    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 ...

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

    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

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

    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. Identification and absorbed dose determination in irradiated kiwi by electron paramagnetic resonance

    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

  14. Methods to verify absorbed dose of irradiated containers and evaluation of dosimeters

    The research on dose distribution in 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. Dmax/Dmin in this study was 1.45 irradiated in a commercial 60Co facility. The density of orange containers was about 0.391g/cm3. The evaluation of dosimeters showed that the PMMA-YL and clear PMMA dosimeters have linear 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. (author)

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

    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

  16. SOLAR REFRIGERATION SYSTEMS BASED ON THE ABSORBER WITH INTERNAL EVAPORATIVE COOLING

    Дорошенко, O.В.; Людницький, К.В.

    2015-01-01

    The paper presents the developed schematics for alternative refrigeration systems and air conditioning systems based on the use of heat-absorption cycle and solar energy for regeneration (recovery) of the absorbent solution. Cascade principle of construction of the drying and cooling circuits with absorbent concentration increasing on the steps of the cascade is used. The absorber with internal evaporative cooling that eliminates a separate evaporative cooler, typically comprised after the co...

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

    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.

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

    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)

  19. Determination of absorbed dose in the experimental animal irradiated on the Leksell gamma knife

    The purpose of this study was to evaluate and quantify inaccuracy of Leksell GammaPlan relative and absolute dose calculations for the experimental animal and to determine necessary corrections that must be applied. Both TLD and semiconductor detectors appeared to be suitable for measurement of absorbed dose in the rat brain irradiated on the Leksell gamma knife. Both detectors, due to their size, measured mean doses, nay doses to maximum. The Leksell GammaPlan treatment planning system can be employed for the calculation of absorbed doses even in such an extreme condition like irradiation of experimental animals. However, in our concrete case, it was necessary to apply correction factor of 1.0779 for the absolute absorbed dose to obtain reliable results. Comparison of dose profiles in all three axis calculated by the treatment planning system and measured ones by polymer gel dosimeter showed acceptable agreement. Results presented in this study are strictly related to the Leksell GammaPlan treatment planning system and the special fixation device developed in Na Homolce Hospital. (authors)

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

    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.

  1. International standards, Agreements and Policy of food Irradiation

    There are few internationally recognised standards and agreements related to irradiated foods. Codex Alimentarius has its General standard for Irradiated foods. This sets standards for the production of irradiated foods that are safe and nutritionally adequate. Guidelines for the proper processing of foods by irradiation are covered in the Codex Recommended International Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Food. For irradiation as a quarantine treatment for fruit, vegetables and other plants, the relevant international organization is the International Plant Protection Convention (IPPC), IPPC has no standards or guidelines for irradiation treatments. However, regional organizations within IPPC are moving towards recognition of irradiation as a technically viable and effective method of insect disinfestation. Especially notable are actions within the North American Plant Protection Organisation (NAPPO). NAPPO has endorsed a standard on the use of irradiation as a quarantine treatment. Other speakers have provided considerable detail on the Codex standard and on the situation with regard to quarantine issues. In this talk I will concentrate on irradiated foods as commodities that will be traded internationally in increasing amounts as we approach the next century. International trade is governed by bilateral arrangements. However, these arrangements should be consistent with the overarching multilateral agreements of the World trade Organization (WTO). The WTO Agreements do not refer directly to irradiation or irradiated foods. However, in this talk I will try to interpret the implications of the Agreements for trade in irradiated food. (Author)

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

    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...

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

    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...

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

    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.

  5. Development of fluorescent, oscillometric and photometric methods to determine absorbed dose in irradiated fruits and nuts

    To ensure suitable quality control at food irradiation technologies and for quarantine authorities, simple routine dosimetry methods are needed for absorbed dose control. Taking into account the requirements at quarantine locations these methods would require nondestructive analysis for repeated measurements. Different dosimetry systems with different analytical evaluation methods have been tested and/or developed for absorbed dose measurements in the dose range of 0.1-10 kGy. In order to use the well accepted ethanolmonochlorobenzene dosimeter solution and the recently developed aqueous alanine solution in small volume sealed vials, a new portable, digital, and programmable oscillometric reader was developed. To make use of the availability of the very sensitive fluorimetric evaluation method, liquid and solid inorganic and organic dosimetry systems were developed for dose control using a new routine, portable, and computer controlled fluorimeter. Absorption or transmission photometric methods were also applied for dose measurements of solid or liquid phase dosimeter systems containing radiochromic dye agents, which change colour upon irradiation. (author)

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

    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...

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

    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.)

  8. About some aspects of absorbed and effective ionizing radiation dose computation of population under external and internal radiation influence

    The purpose of the investigation is to develop methods of dose assessment, absorbed by individual human organs, or effective dose of population, as well as to study factors effecting on uncertainties in their computation. The dose assessment for the Thyroid or other organ is based on retrospective information obtained from radioecological monitoring and according to the information about radioactive fallout's on the surface after each nuclear test, as well as the information about concrete living conditions of local population. The main parameter in proposed algorithms is gamma-radiation dose rate at open area, which is a result of direct measurements. When assessing internal radiation dose, in the course of inhalation, the whole period of local fallout's is taken into consideration. The developed method allows obtaining a systematic information describing irradiation of people by means of the radioactive traces, as well as tabulated information for model computations of internal and external radiation dose

  9. Recent international developments regarding standardization of food irradiation treatment

    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

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

    Gama, Adriana M.; Mirabel C. Rezende; Dantas, Christine C.

    2011-01-01

    We report the analysis of measurements of the complex magnetic permeability ($\\mu_r$) and dielectric permittivity ($\\epsilon_r$) 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 ferri...

  11. Understanding and predicting the behaviour of silver base neutron absorbers under irradiations

    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)

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

    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)

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

    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.

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

    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

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

    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)

  16. Study of the spatial distribution of the absorbed dose in blood volumes irradiated using a teletherapy unit

    Blood irradiation can be performed using a dedicated blood irradiator or a teletherapy unit. A thermal device providing appropriate storage conditions during blood components irradiation with a teletherapy unit has been recently proposed. However, the most appropriated volume of the thermal device was not indicated. The goal of this study was to indicate the most appropriated blood volume for irradiation using a teletherapy unit in order to minimize both the dose heterogeneity in the volume and the blood irradiation time using these equipments. Theoretical and experimental methods were used to study the dose distribution in the blood volume irradiated using a linear accelerator and a cobalt-60 therapy machine. The calculation of absorbed doses in the middle plane of cylindrical acrylic volumes was accomplished by a treatment planning system. Experimentally, we also used cylindrical acrylic phantoms and thermoluminescent dosimeters to confirm the calculated doses. The data obtained were represented by isodose curves. We observed that an irradiation volume should have a height of 28 cm and a diameter of 28 cm and a height of 35 cm and a diameter of 35 cm, when the irradiation is to be performed by a linear accelerator and a cobalt-60 teletherapy unit, respectively. Calculated values of relative doses varied from 93% to 100% in the smaller volume, and from 66% to 100% in the largest one. A difference of 5.0%, approximately, was observed between calculated and experimental data. The size of these volumes permits the irradiation of blood bags in only one bath without compromising the homogeneity of the absorbed dose over the irradiated volume. Thus, these irradiation volumes can be recommend to minimize the irradiation time when a teletherapy unit is used to irradiate blood.

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

    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

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

    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

  19. Secondary absorbed doses from light ion irradiation in anthropomorphic phantoms representing an adult male and a 10 year old child

    Secondary organ absorbed doses were calculated by Monte Carlo simulations with the SHIELD-HIT07 code coupled with the mathematical anthropomorphic phantoms CHILD-HIT and ADAM-HIT. The simulated irradiations were performed with primary 1H, 4He, 7Li, 12C and 16O ion beams in the energy range 100-400 MeV/u which were directly impinging on the phantoms, i.e. approximating scanned beams, and with a simplified beamline for 12C irradiation. The evaluated absorbed doses to the out-of-field organs were in the range 10-6 to 10-1 mGy per target Gy and with standard deviations 0.5-20%. While the contribution to the organ absorbed doses from secondary neutrons dominated in the ion beams of low atomic number Z, the produced charged fragments and their subsequent charged secondaries of higher generations became increasingly important for the secondary dose delivery as Z of the primary ions increased. As compared to the simulated scanned 12C ion beam, the implementation of a simplified beamline for prostate irradiation with 12C ions resulted in an increase of 2-50 times in the organ absorbed doses depending on the distance from the target volume. Comparison of secondary organ absorbed doses delivered by 1H and 12C beams showed smaller differences when the RBE for local tumor control of the ions was considered and normalization to the RBE-weighted dose to the target was performed.

  20. Absorbed dose response of Al2O3 dosimeter irradiated by 60Co γ spectrum source capture and collimators

    Objective: To investigated the absorbed dose response of Al2O3 dosimeter in water phantom irradiated by 60Co γ spectrum source. Methods: The EGSnrc simulation program code DOSRZnrc was used to calculate the absorbed dose of the Al2O3 dosimeter and that of the equivalent volume of water in the corresponding position, as well as the absorbed dose conversion factor, irradiated by 60Co photon beams in a water phantom. Simulations were done for a cylindrical geometry dosimeter (diameter 0.4 cm and height 0.1 cm) and the dosimeter was placed at the centre of the water phantom at different depths. Results: The average absorbed dose conversion factor is 1.143±0.006 and changes little with the depth of the dosimeter in the water phantom, and the deviation is less than 1.0%. Conclusion: The absorbed dose response of Al2O3 dosimeter irradiated by 60Co γ spectrum source is steady and is independent on the depth of the dosimeter in water phantom in this research. (authors)

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

    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.

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

    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

  3. The proliferative response of mouse intestinal crypts during fractionated irradiation of carbon beams

    Clonogenic assay of jejunal crypt during carbon beam and X-ray irradiations was performed. Fractionation with top-up dose assay revealed carbon beam irradiations caused more damage than X-ray did. To clarify this problem is urgent. (author)

  4. Internal friction of cold worked and irradiated copper

    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

  5. Optical properties of ion irradiated and annealed InGaAs/GaAs quantum wells and semiconductor saturable absorber mirrors

    Optical properties of Ni+ irradiated and thermally annealed InGaAs/GaAs multiple quantum wells and semiconductor saturable absorber mirrors (SESAMs) have been studied using photoluminescence (PL) and non-linear reflectivity measurements. Rapid decrease of PL intensity and lifetime with increasing irradiation dose was accompanied by undesirable degradation of the non-linear optical properties of SESAMs. However, some of the irradiation-created defects could be removed and the non-linear optical properties improved by rapid thermal annealing. The combination of ion irradiation and annealing provided a selective method for controlling the absorption recovery time of SESAMs while preserving the non-linear properties. Irradiation with 1012 cm-2 of 6 MeV Ni+ ions and 1 s annealing at 400 deg. C led to an absorption recovery time of ∼1 ps while the modulation depth, the non-saturable losses and the saturation fluence were all close to their as-grown values

  6. Response Funtions for Computing Absorbed Dose to Skeletal Tissues from Photon Irradiation

    Eckerman, Keith F [ORNL; Bolch, W E [University of Florida, Gainesville; Zankl, M [Institute of Radiation Protection, GSF-National Reserach Center for Environ; Petoussi-Henss, N [Institute of Radiation Protection, GSF-National Reserach Center for Environ

    2007-01-01

    The calculation of absorbed dose in skeletal tissues at radiogenic risk has been a difficult problem because the relevant structures cannot be represented in conventional geometric terms nor can they be visualised in the tomographic image data used to define the computational models of the human body. The active marrow, the tissue of concern in leukaemia induction, is present within the spongiosa regions of trabecular bone, whereas the osteoprogenitor cells at risk for bone cancer induction are considered to be within the soft tissues adjacent to the mineral surfaces. The International Commission on Radiological Protection (ICRP) recommends averaging the absorbed energy over the active marrow within the spongiosa and over the soft tissues within 10 mm of the mineral surface for leukaemia and bone cancer induction, respectively. In its forthcoming recommendation, it is expected that the latter guidance will be changed to include soft tissues within 50 mm of the mineral surfaces. To address the computational problems, the skeleton of the proposed ICRP reference computational phantom has been subdivided to identify those voxels associated with cortical shell, spongiosa and the medullary cavity of the long bones. It is further proposed that the Monte Carlo calculations with these phantoms compute the energy deposition in the skeletal target tissues as the product of the particle fluence in the skeletal subdivisions and applicable fluence-to-dose response functions. This paper outlines the development of such response functions for photons.

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

    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

  8. Proliferation of human melanoma cells after single and fractionated exposure to hyperthermia and irradiation

    The growth, DNA synthesis, distribution of cells in the cell cycle, labeling index, and the formation of micronuclei were measured in a human melanoma cell line after single and fractionated treatment with hyperthermia (three times for 1 hr at 42 degrees C) and X-irradiation (4.0 gray three times) or a combination of both treatments. After fractionation with heat or irradiation alone, the cells showed a greater capacity for recovery than after fractionation with the combined modality. The DNA synthesis returned to the control values after each fraction at later periods. Concomitant with these observations was a decrease of labeled or unlabeled S-phase cells. The effect was more pronounced after the combined fractionation. Hypoploid cells as potentially dead cells were observed after each treatment, but hyperploid cells were observed only after the combined fractionation. According to the cell loss and occurrence of hypoploid cells, micronuclei increased except after heat alone

  9. Fraction of energy absorbed from β-emitting particles in the rat lung

    Forty-four male Fischer-344 rats were exposed, nose only, to a relatively insoluble aerosol of 144Ce-labeled fused aluminosilicate particles. Fractional β energy absorption was measured 7 to 9 days after exposure for 28 rats (ages 12 to 25 weeks and body weights of 183 to 337 g); lung burdens were 13 to 82 nCi. An additional group of 16 rats was exposed when 12 weeks old and maintained for 6 months prior to analysis; body weights and lung burdens 6 months after exposure ranged from 276 to 368 g and 16 to 46 nCi, respectively. Lungs were carefully removed, inflated, and frozen by immersion in liquid nitrogen. The energy spectrum from each lung was measured in a 4π β spectrometer, keeping the lung frozen throughout this procedure. Over the range of lung sizes in this study (0.88 to 1.66 g) the mean fractional energy absorption and standard deviation were 0.23 +- 0.078, respectively. Results agreed well with theory, indicating that calculated values for fractional energy absorption in the lung can be used for a range of lung sizes and β energies. Calculated values for fractional energy absorption as a function of β energy are included for several lung sizes between 0.5 and 10 g

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

    Rahman Ziaur

    2013-01-01

    Full Text Available 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 decreasing trend with an increase in radiation energy. Compared with NIST XCOM and ICRU data, the Geant4-based simulated values of the absorbed fraction remain within a 4.2% and 1.6% deviation, respectively. For electrons and g-photons, the relative difference between the Geant4-based comprehensive model predictions and those of Stabin and Konijnenberg's re-evaluation remains within a 6.8% and 7.4% range, respectively. Ellipsoidal and cylindrical models show 4.9% and 10.1% higher respective values of absorbed dose fractions relative to the spherical model. Target volume dependence of the absorbed fraction values has been found to follow a logical behavior for electrons and Belehradek's equation for g-photons. Gamma-ray absorbed fraction values have been found to be sensitive to the material composition of targets, especially at low energies, while for elections, they remain insensitive to them.

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

    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

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

    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.

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

    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.

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

    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

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

    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.

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

    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.)

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

    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.

  18. Quantitative changes of metabolic and bioenergetic parameters in experimental tumors during fractionated irradiation

    Purpose: Previous studies with rat rhabdomyosarcomas indicate that during fractionated irradiation profound alterations of the tumor microvasculature and the oxygenation status occur when the total dose exceeds 45 Gy. At this dose a destruction which included all structures of the vessels and a significant worsening in tumor oxygenation were found. The aim of the present study was to analyze whether these effects of fractionated irradiation on the microvasculature and on tumor oxygenation also induce changes in the bioenergetic and metabolic status in the tumors during radiation treatment. Methods and Materials: R1H rhabdomyosarcomas of the rat implanted into the flank were irradiated with 60Co-γ-rays using 5 fractions of 3 Gy per week over 5 weeks. During this irradiation schedule, tumors were investigated each week for the microregional distributions of glucose, lactate, and ATP concentrations. For this, tumors were rapidly excised, shock-frozen and quantitative bioluminescence measurements were performed on tumor tissue sections. Results: ATP concentrations remained unchanged during fractionated irradiation up to a total dose of 45 Gy. Above this dose, a significant decrease in ATP levels was observed. Lactate concentrations changed only slightly during irradiation whereas glucose levels increased continuously over the whole irradiation period. Conclusions: During fractionated irradiation of R1H tumors with a total dose of 75 Gy, the bioenergetic and metabolic status of the tumors changed considerably. This became most obvious once a dose of 45 Gy had been achieved. The severe energy depletion and worsening of tumor oxygenation might be the result of destruction of tumor blood vessels as has been described previously in the same tumor model. The modification of the tumor micromilieu appears to be an important parameter in the responsiveness of tumor cells to radiation and for local tumor control

  19. Clinical and immunologic effects of fractionated total lymphoid irradiation in refractory rheumatoid arthritis

    Ten patients with refractory rheumatoid arthritis were given 3000 rad of fractionated total lymphoid irradiation in an uncontrolled therapeutic trial. Total lymphoid irradiation was associated with objective evidence of considerable clinical improvement in eight patients and with reduced blood lymphocyte counts in all 10. On completion of irradiation, there was an abrogation of lymphocyte reactivity in vitro in the patients with clinical responses, but abnormal antibody activities characteristic of rheumatoid arthritis and normal components of humoral immunity were not suppressed. Partial recrudescence of arthritis occurred shortly after a year after the completion of irradiation and was paralleled by a restitution of lymphocyte concentrations and responsiveness to mitogens to levels similar to those observed before irradiation. These data provide further evidence of T-cell involvement in the pathogenesis of rheumatoid arthritis and demonstrate that total lymphoid irradiation can induce temporary relief, but they do not ascertain whether the natural history of this disease was altered

  20. Dietary enhancement of intestinal radioresistance during fractionated irradiation

    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

  1. Enhancement of plant growth activity of irradiated chitosan by molecular weight fractionation

    The chitosan products irradiated at 25-200 kGy in 10% solution showed a positive effect on the growth of barley, while the unirradiated chitosan inhibited the growth of this plant. The 100 kGy irradiated chitosan product with average molecular weight (Mw) approx. 16 kDa was found as optimal to plant growth activity. Separation of the degraded samples was performed using ultrafiltration membranes and was found that the fraction F2 with Mw in range of 1 - 3 kDa not only showed a remarkable effect on the growth of barley and soybean, but also significantly increased the activity of phytoalexin enzymes, namely phenylalanine ammonia lyase (87%) and chitinase (186%). This fraction also increased 15.8% seed yield of soybean after three month cultivation. The results suggested that the irradiated chitosan fraction F2 with Mw in range of 1 - 3 kDa was a trigger for plant growth activity. (author)

  2. Histopathological changes in the irradiated normal organs of guinea pigs with conventional fractionation and hyperfractionation

    Guinea pigs were divided into groups according to four irradiation schedules : 2 Gy/3 Gy x 1/day, five fractions/week, total 80 Gy/81 Gy (A/C group) and 1.0 Gy/1.5 Gy x 2/day, ten fractions/week, total 80 Gy/81 Gy (B/D group). The A group and the C group pathologically caused severe damage in the kidney six and three months after irradiation, respectively. In the B group pathological analysis suggested that only slight-to-moderate changes were occurred in the Bowman's capsule. The D group caused slight damage in the kidney six months after irradiation. Hyperfractionation (B/D group) used in this protocol can clearly reduce radiation damage in the kidney of guinea pigs as compared with conventional fractionation (A/C group). (author)

  3. The clinical research on fractionated irradiation treatment with X knife in patients of PD

    Objective: To explore X knife treatment methods and to seek a new effective way for PD therapy. Methods: Sixteen patients of PD were treated by performing VIM with 2 times of X knife fractionated irradiation (interval, 24 h) to a total dose of 140 Gy, and 8 patients of PD were treated by performing VIM with 3 times of X knife fractionated irradiation (interval, 24 h) to a total of dose of 165 Gy. Results: During 3-24 months follow-up after X knife treatment, tremor was stopped in 19 patients and was relived significantly in 5 patients. Rigidity and bradykinesia of PD were relieved slightly. No complications were observed. Conclusion: To perform VIM with X knife fractionated irradiation can be safely and effectively used to treat PD. The tremor of PD can be relieved slightly

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

    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.

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

    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

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

    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.

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

    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.

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

    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)

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

    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

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

    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.

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

    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.

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

    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.

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

    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...

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

    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.

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

    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.

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

    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.)

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

    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...

  18. Effects of single dose and fractionated irradiation on brain aggregation culture

    Foetal mouse brain cells were grown in vitro. One Gy of X-irradiation was given as a single dose on culture day 2 (corresponding to embryonic day 17 in vivo) or in daily fractions (4 x 0.25 Gy), starting on day 2 in culture. The growth (size) and biochemical differentiation of the aggregates were studied up to day 40 in culture. Aggregates given a single dose (1 Gy) were smaller with lower protein and DNA amount than controls up to day 30-40 in culture. When the dose was fractionated, a partial recovery occurred by day 20, and values returned to control levels by day 30-40. The specific activity of acetylcholine-esterase (AChE) was significantly higher after 10 to 20 days, in the irradiated (1 Gy) aggregates. In fractionated irradiated aggregates, only the specific activity of AChE was increased. This effect was only evident after 10 days in culture. Single irradiation induced, after 10 days in culture, an increase of nerve growth factor (NGF), however after 30 days the NGF amount decreased below control level. A single dose of irradiation produced more permanent changes in the amounts of DNA and protein and in the size and neurochemical activities of cells. (author)

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

    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.

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

    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.

  1. Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma

    Purpose: The rate of hearing loss in a population before and after irradiation was investigated to determine the effect of irradiation on hearing impairment. Methods and materials: In 72 patients with vestibular schwannoma who received fractionated stereotactic irradiation from 1992 to 1999, 21 had had their hearing levels examined 3 months or more before the treatment. The mean time between the initial examination and treatment was 18.6 months (range: 3-89 months), and the mean time between treatment and the last follow-up was 24.2 months (12-69 months). Thirty-six to 50 Gy in 20-25 fractions over 5 to 6 weeks was given using an X-ray beam from a linear accelerator. Pure tone average (PTA) was measured using the mean hearing level at five frequencies, and the annual rate of hearing loss was defined as [(hearing loss in PTA(dB))/(follow-up period (months)x12)]. Results: The actual cumulative curve of decrease in tumor size of 2 mm or more was 38.3% at 2 years and 80.0% at 3 years. The mean of hearing loss in PTA was 11.6±10.3 dB (-1 to 35 dB) from the initial examination to the start of irradiation and 11.9±14.4 dB (-14 to 37 dB) from the start of irradiation to the last follow-up. The mean annual rates of hearing loss before irradiation and in the 1st, 2nd, 3rd and 4th years after irradiation were, respectively, 18.6, 11.2, 6.2, 5.1, and 5.0 dB/year. The annual rates of hearing loss in the 2nd year (P=0.025) and 3rd year (P=0.018) were significantly slower than the rate before irradiation. Conclusions: The mean annual rate of hearing loss was higher before irradiation than after irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, fractionated stereotactic irradiation was suggested to be effective to lower the rate of hearing loss

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

    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.

  3. Effects of keratinocyte growth factor (palifermin) administration protocols on oral mucositis (mouse) induced by fractionated irradiation

    Background and purpose: Aim of this study was to assess the impact of the administration protocol of palifermin on amelioration of oral mucositis after fractionated irradiation. Materials and methods: Mouse tongue ulceration was analysed as the clinically relevant endpoint. Daily fractionated irradiation (5x3 Gy/week, days 0 to +4, +7 to +11, with a weekend gap on days +5 and +6) was followed by graded test doses on day +14, i.e. after a second weekend gap. Palifermin (5 mg/kg) was injected subcutaneously. In the first series of experiments, the effect of three daily injections (days -3, -2 and -1) was compared with a single administration either on day -2 or -1; all animals received a further injection on day +4. In the second series, a single or three injections were given in the weekend gap between fractionated irradiation (days +5 to +6), with an additional administration on day +11. In a final protocol, single weekly injections of palifermin were given either on days -3, +4 and +11, days +4, +11 and +18, or on days -3, +4, +11 and +18. Results: The ED50 (dose after which ulcer induction is expected in 50% of the mice) to single dose irradiation was 11.5±0.7 Gy. The ED50 for test irradiation after 10x3 Gy was 5.7±1.6 Gy. Palifermin administration before the start of fractionated irradiation and on day +4 increased the ED50 to 10-12 Gy, administration over the first weekend and on day +11 to 11-15 Gy. Administration over three consecutive weekends, starting on day -3 or day +4, increased the ED50 to 13.0±0.1 and 14.9±0.3 Gy. Single weekly KGF administrations over four weekends, including the weekend prior to and after completion of radiotherapy, showed no further increase in ED50. Conclusions: A single palifermin injection during the weekend gap before or during fractionated irradiation is as effective as three applications. Onset of the palifermin treatment during the first weekend gap between fractionated irradiation is more effective than during the

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

    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)

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

    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 ...

  6. Influence of post-harvest irradiation time and absorbed dose to potatoes and onions

    Post harvest losses of potatoes and onions were mainly due to sprouting and rotting. Irradiation dose of 50 Gy for onions and of 100 Gy for potatoes applied within the dormancy period effectively inhibited sprouting. In Vietnam conditions the optimal irradiation time after harvest is 3 - 6 weeks for potatoes, within 4 weeks for onions. Irradiated potatoes and onions stored under ambient conditions tend to be more spoiled in comparison with unirradiated ones.Irradiation caused a slight decrease of vitamin C content and an increase of reduced sugars and total sugars for potatoes and onions stored under room temperature. There are no changes in main nutritional properties of irradiated onions, no after-cooking discoloration in irradiated potatoes. (author). 8 refs, 4 tabs, 9 figs

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

    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...

  8. Optical properties of ion irradiated and annealed InGaAs/GaAs quantum wells and semiconductor saturable absorber mirrors

    Hakkarainen, T [Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere (Finland); Pavelescu, E-M [Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere (Finland); Arstila, K [Accelerator Laboratory, University of Helsinki, PO Box 43, FI-00014, Helsinki (Finland); Dhaka, V D S [Institute of Materials Chemistry, Tampere University of Technology, PO Box 541, FI-33101, Tampere (Finland); Hakulinen, T [Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere (Finland); Herda, R [Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere (Finland); Konttinen, J [Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere (Finland); Tkachenko, N [Institute of Materials Chemistry, Tampere University of Technology, PO Box 541, FI-33101, Tampere (Finland); Lemmetyinen, H [Institute of Materials Chemistry, Tampere University of Technology, PO Box 541, FI-33101, Tampere (Finland); Keinonen, J [Accelerator Laboratory, University of Helsinki, PO Box 43, FI-00014, Helsinki (Finland); Pessa, M [Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere (Finland)

    2005-04-07

    Optical properties of Ni{sup +} irradiated and thermally annealed InGaAs/GaAs multiple quantum wells and semiconductor saturable absorber mirrors (SESAMs) have been studied using photoluminescence (PL) and non-linear reflectivity measurements. Rapid decrease of PL intensity and lifetime with increasing irradiation dose was accompanied by undesirable degradation of the non-linear optical properties of SESAMs. However, some of the irradiation-created defects could be removed and the non-linear optical properties improved by rapid thermal annealing. The combination of ion irradiation and annealing provided a selective method for controlling the absorption recovery time of SESAMs while preserving the non-linear properties. Irradiation with 10{sup 12} cm{sup -2} of 6 MeV Ni{sup +} ions and 1 s annealing at 400 deg. C led to an absorption recovery time of {approx}1 ps while the modulation depth, the non-saturable losses and the saturation fluence were all close to their as-grown values.

  9. Changes in the fraction of total hypoxia and hypoxia subtypes in human squamous cell carcinomas upon fractionated irradiation: Evaluation using pattern recognition in microcirculatory supply units

    Background and purpose: Evaluate changes in total hypoxia and hypoxia subtypes in vital tumor tissue of human head and neck squamous cell carcinomas (hHNSCC) upon fractionated irradiation. Materials and methods: Xenograft tumors were generated from 5 hHNSCC cell lines (UT-SCC-15, FaDu, SAS, UT-SCC-5 and UT-SCC-14). Hypoxia subtypes were quantified in cryosections based on (immuno-)fluorescent marker distribution patterns of Hoechst 33342 (perfusion), pimonidazole (hypoxia) and CD31 (endothelium) in microcirculatory supply units (MCSUs). Tumors were irradiated with 5 or 10 fractions of 2 Gy, 5×/week. Results: Upon irradiation with 10 fractions, the overall fraction of hypoxic MCSUs decreased in UT-SCC-15, FaDu and SAS, remained the same in UT-SCC-5 and increased in UT-SCC-14. Decreases were observed in the proportion of chronically hypoxic MCSUs in UT-SCC-15, in the fraction of acutely hypoxic MCSUs in UT-SCC-15 and SAS, and in the percentage of hypoxemically hypoxic MCSUs in SAS tumors. After irradiation with 5 fractions, there were no significant changes in hypoxia subtypes. Changes in the overall fraction of hypoxic MCSUs were comparable to corresponding alterations in the proportions of acutely hypoxic MCSUs. There was no correlation between radiation resistance (TCD50) and any of the investigated hypoxic fractions upon fractionated irradiation. Conclusions: This study shows that there are large alterations in the fractions of hypoxia subtypes upon irradiation that can differ from changes in the overall fraction of hypoxic MCSUs.

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

    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. International co-operation in the field of food irradiation

    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.)

  12. Evaluation of onion root tip cell surviving fraction by measuring growing speed irradiated by accelerated heavy ions

    Average growth of germinating onion seed roots irradiated with accelerated heavy ions decreased with increase of absorbed dose, and the ratio to the non-irradiated seeds approached asymptotically to about 40% with increasing of the dose and almost converged at 10 Gy. The converged ratio was about 20% for green sorgo seeds and about 80% for alphalfa seeds. Irradiation of the heavy ions and γ-ray larger than 2 Gy delayed appearance of micronuclei in the onion root tip cells. The delay increased with the increase of linear energy transfer (LET) and absorbed dose. (author)

  13. Combined treatment of the immunoconjugate bivatuzumab mertansine and fractionated irradiation improves local tumour control in vivo

    Background and purpose: To test whether BIWI 1 (bivatuzumab mertansine), an immunoconjugate of the humanized anti-CD44v6 monoclonal antibody BIWA 4 and the maytansinoid DM1, given simultaneously to fractionated irradiation improves local tumour control in vivo compared with irradiation alone. Material and methods: For growth delay, FaDu tumours were treated with 5 intravenous injections (daily) of phosphate buffered saline (PBS, control), BIWA 4 (monoclonal antibody against CD44v6) or BIWI 1 (bivatuzumab mertansine) at two different dose levels (50 μg/kg DM1 and 100 μg/kg DM1). For local tumour control, FaDu tumours received fractionated irradiation (5f/5d) with simultaneous PBS, BIWA 4 or BIWI 1 (two dose levels). Results: BIWI 1 significantly improved local tumour control after irradiation with 5 fractions already in the lower concentration. The dose modifying factor of 1.9 is substantial compared to the majority of other modifiers of radiation response. Conclusion: Because of the magnitude of the curative effect, this approach is highly promising and should be further evaluated using similar combinations with improved tumour-specificity.

  14. Fractionated homogenous total-body irradiation prior to bone marrow transplantation

    At the University of Kiel, myeloid and acute lymphatic leukemia is treated since 1983 by total-body irradiation applied prior to bone marrow transplantation. Dose deviations in the midplane caused by the irregular surface and tissue inhomogeneities of the patient are reduced down to +- 3.5% compared to the central ray, with the help of CT-based individual compensators. This method prevents above all an excessive dose to the lungs. The radiobiologic advantages of fractionated irradiation have been employed for all patients treated hitherto (n = 9). At present, a total body dose of 12 Gy in six fractions is applied within three days. There were no undesired acute radiogenic reactions except a mild acute mucositis found in all patients. Chronic side effects, especially in the lungs, were not demonstrated, too. However, the average follow-up time of 149 days has been rather short. One patient died from relapse of leukemia after a total dose of 10 Gy, another patient died because the transplanted bone marrow was rejected, and a third died from catheter sepsis. Six out of nine patients are in complete remission with a maximum index of Karnofsky. The limited experiences gained hitherto show that the homogeneous accelerated-fractionated total-body irradiation offers essential advantages compared to non-compensated single dose irradiation with respect to the prevention of undesired radiogenic effects in sound tissues and that its therapeutic efficacy is at least the same. (orig.)

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

    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

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

    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.)

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

    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

  18. Audiological assessment before and after fractionated stereotactic irradiation for vestibular schwannoma

    Purpose: To find the audiological outcome after LINAC-based fractionated stereotactic irradiation (STI). Materials and methods: Twenty-four patients with vestibular schwannoma treated by fractionated STI between 1991 and 1997 had measurable hearing before STI and were followed audiologically for more than 6 months. The pure tone average (PTA) was measured by averaging the air-conduction threshold for five main frequencies (250-4000 Hz) before and periodically after STI in the 24 patients. Several possible prognostic factors for hearing preservation (defined as a PTA change at the last follow-up of less than 10 dB) were investigated. The median follow-up time was 22 months, ranging from 5 to 69 months. The irradiation schedule was 36 Gy in 20 fractions in 5 weeks to 44 Gy in 22 fractions in 6 weeks followed by 4 Gy/1 fraction boost. Results: The pure tone average before STI was distributed from 7 to 73 dB. Fifty percent of patients showed a change in PTA of less than 10 dB, 79.2% of patients showed a change in PTA of less than 20 dB and 20.8% of patients showed a change in PTA of more than 21 dB at the last follow-up. Only one patient (4%) became deaf. Cases with a sudden loss of hearing were more likely to experience hearing preservation than those with gradual loss of hearing (P<0.05). The mean age was younger in patients whose hearing was preserved (P<0.05). Poor pretreatment PTA appeared to linearly correspond to the changes in PTA (regression coefficient 0.78). The size of the tumor was not related to the change in PTA. No relationship was observed between the maximum or peripheral dose and the PTA change. The real benefit of stereotactic boost after small-field fractionated irradiation was not certain. Conclusion: Fractionated STI produced a hearing preservation rate compatible with meticulously collimated multi-spots single fraction irradiation. Further follow-up is required to confirm the long-term benefits of fractionation. (Copyright (c) 1998 Elsevier

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

    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)

  20. measurement of absorbed dose in mix-dp phantom irradiated by x and gamma rays

    It has been done of x-rays dan gamma rays absorbed dose measurement of mix-dp phantom of 70 kVp.90kvp and 110 kvp x rays kxo-12 medical exposure and cobalt-60 gamma (50 ci) by UD-170A BeO-TLD. Ionization chamber 12 cc NIRS-R2 as reference dosemeter, which was calibrated on primer dosemeter. In X-rays energy used, it was done of absorbed dose measurement on Mix-Dp phantom surface and depth (d= 10cm) beam field area 10 x 10 cm, focus distance (FSD), s=80 cm dose measurement of 90 kvp X-rays on Mix-Dp phantom surface, depth and scattering (d=15 cm) beam field area 12 x 12 cm, focus distance (FSD),s=79 cm and measurement of absorbed dose Co-60 gamma: 5 R, 10R, 20 R, 30R, 40R and 50R by dose rate 0.434 R/min. It was shown that in clinical, effective energy range of X-rays relative lower than dose range Co-60 gamma. BeO-TLD characteristic on energy dependence is low based on TI sensitivity ± 1.3 for energy below 100 keV. Relation between absorbed dose and TL response to 90 kVp X-rays shown that rperm=0.990, r ber=0.995 and r sact=0.962. In measurement of Co-60 gamma absorbed dose by BeO-TLD shown TI sensitivity decrease ± 0.900. The result still needed corrections to achieve optimum measurement of absorbed dose X-rays and gamma by UD-170A BeO-TLD, which were performed optimum fading time and anealling temperature

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

    Lee, Eun-Jung; Kim, Jun Won; Yoo, Hyun; Kwak, Woori; Choi, Won Hoon; Cho, Seoae; Choi, Yu Jeong; Lee, Yoon-Jin; Cho, Jaeho

    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(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. PMID:26047701

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

    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

  3. Model of the absorbed dose on a small sphere into a gamma irradiation field

    Several models of the absorbed dose calculated as the energy deposited by the secondary electrons on a small volume sphere are presented. The calculations use the Compton scattering of a uniform photon beam in water, the photon attenuation and the electron stopping power are included. The sphere total absorbed dose is due to the stopping of the electrons generated in three regions: into the sphere volume, ahead and behind the sphere volume. Calculations are performed for spheres of different radius and placed at various depth of the vacuum - water interface. (author)

  4. Effects of fractionated irradiation on the cytoskeleton and basal lamina in parotid glands. An immunohistochemical study

    Cytoskeletal, cytocontractile and basement membrane proteins were studied using the immunofluorescence technique in the parotid gland in female rats after half-side fractionated megavoltage irradiation. The non-irradiated parallel-handled parotid glands served as controls. The qualitative expression of cytoskeletal proteins remained unchanged 10 days following irradiation compared to controls, i.e. cytokeratin was observed but not vimentin, desmin or GFAP (glial fibrillary acidic proteins). Six months after irradiation the cytokeratin expression adjacent to duct lumina was clearly stronger. Actin staining was more pronounced in the periphery of the acini. Ten days after irradiation no alterations of the basal lamina proteins, laminin and fibronectin, were detected. Six months post-irradiation laminin deposits were detected in areas where the entire acini had degenerated and had been replaced by fibrosis. An increased expression of fibronectin was also observed in the stroma at that time, reflecting an increased fibrosis. In areas where the acini remained, laminin immunofluorescence was mainly found in basal laminae of normal thickness, but the mean diameter of the acini seemed to have increased. This indicates a regeneration of acini and a restructuring of the basal lamina of the parenchyma. (orig.)

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

    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

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

    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

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

    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.)

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

    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

  9. Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses

    Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered. (author). 18 refs.; 7 figs.; 1 tab

  10. 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

    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.

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

    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.

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

    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 BOD5, COD and color were in the range 9%-33%, 14%-38% and 43%-78% respectively

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

    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

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

    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.

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

    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

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

    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

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

    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-cm2 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-33 is

  18. Single fraction prophylactic cranial irradiation for small cell carcinoma of the lung

    The effectiveness of a single 8-Gy fraction prophylactic cranial irradiation regime was assessed in 106 patients with small-cell carcinoma of the lung. All patients had limited stage disease and received combination chemotherapy consisting of either cisplatin or carboplatin with ifosfamide, etoposide, and vincristine (VICE). Cranial irradiation was administered 48 h after the first cycle of chemotherapy and was well tolerated. Actual 2-year survival was 35% and cranial relapse occurred in 22% of those patients who achieved complete remission. This compares favourably with a cranial relapse rate of 45% incomplete remitters previously reported with the same chemotherapy regime after a minimum follow-up of 2 years where PCI was not used. Formal psychometric testing was performed retrospectively on a series of 25 long-term survivors of whom 14 were taken from this reported series. Whilst 75% of patients were impaired on at least one test with 68% performing badly in the most complex task, this was not associated with clinically detectable neurological damage and the patients did not complain of memory or concentration difficulties. In conclusion, single fraction PCI, when used with platinum based combination chemotherapy, appears to be equally effective but may be less neurotoxic than the more standard fractionated regimes

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

    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)

  20. Amelioration of acute oral mucositis by Keratinocyte growth factor: fractionated irradiation

    Purpose: The aim of the present study was to quantify the protective efficacy of recombinant human keratinocyte growth factor (rHuKGF) in oral mucosa. Methods and Materials: Mouse tongue mucosal ulceration was analyzed as the clinically relevant end point. Fractionated irradiation of the snout with 5 daily fractions of 3 Gy was followed by graded test doses, given to a test area of the lower tongue, on Day 7. rHuKGF was injected s.c. in daily doses of 5 mg/kg before radiotherapy, during radiotherapy, over the weekend break, or a combination. Moreover, single rHuKGF injections (5 or 15 mg/kg) were given on Day -1 or on Day 4. Results: In a single-dose control experiment, the ED50, i.e., the dose after which ulcer induction is expected in 50% of the mice, was 10.9 ± 0.7 Gy. Fractionated irradiation without keratinocyte growth factor rendered an ED50 for test irradiation of 5.6 ± 3.7 Gy. Keratinocyte growth factor increased the ED50 values to 7.8 ± 3.3 Gy (Days -3 to -1, p=0.01), 8.3 ± 1.6 Gy (Days -4 to -2, p=0.0008), 10.5 ± 1.4 Gy (Days 0 to +2, p=0.0002), 11.0 ± 0.5 Gy (Days 0 to +4, p=0.002), 10.6 ± 1.4 Gy (Days +4 to +6, p=0.0021), 10 ± 0.07 (Days -3 to +1, p=0.0001) or 11.0 ± 0.02 (Days +4 to +8, p=0.0001). This is equivalent to compensation of approximately 1.5 fractions of 3 Gy when rHuKGF is given before radiotherapy and 3-4 fractions in all other protocols by rHuKGF treatment. Single rHuKGF injections were similarly (5 mg/kg) or more (15 mg/kg) effective. Conclusions: In conclusion, these results indicate a marked increase in oral mucosal radiation tolerance by rHuKGF, which is most pronounced if the growth factor is applied during fractionated radiotherapy. The effect seems to be based on complex mechanisms, predominantly changes in both epithelial proliferation and differentiation processes

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

    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.

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

    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

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

    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

  4. Effect of single and fractionated x-irradiation on maze learning ability of mice

    Fifty-six-day-old male ddk mice at the starting of the investigation were used as subjects through the experiment for 64 weeks. After 15 days' preliminary training, and 16 times of weekly trial training using complete maze, 15 mice received a single 224 rads of x-rays (S group), another 15 mice received two 112 rads spaced two weeks apart (F group) and another 15 mice were sham-irradiated (Control group). Then those mice were tested on the multiple T-maze with nine-choice points and change of performance was observed in terms of errorchoices by giving one test trial a week. We introduced the concept of ''confusional trials'' as an index for surmising to what extent mice failed to exhibit good maze learning habits. In the results, the F group showed significantly worse performance than the two other groups at early stages, opposite to it the S group exhibited the same, but at late stages after irradiation. The worse performance of F group should be considered to be due to the psychological after-effect to fractionated irradiation and that for S group could be assumed to be due to the acceleration of aging by the irradiation. (auth.)

  5. 77 FR 50113 - ASTM International-Food and Drug Administration Workshop on Absorbable Medical Devices: Lessons...

    2012-08-20

    ... Absorbable Medical Devices: Lessons Learned From Correlations of Bench Testing and Clinical Performance... Bench Testing and Clinical Performance.'' FDA is co-sponsoring the workshop together with ASTM... establishing correlations between in vitro and in vivo degradation of absorbable implant devices, and...

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

    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)

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

    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.)

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

    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

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

    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.

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

    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)

  11. Recovery and cycle progression in multicell spheroids after fractionated γ-irradiation and combined hyperthermic treatment

    Spheroids of V79 cells were subjected to fractionated irradiation with two doses of γ-radiation. In addition, a two hours hyperthermic treatment at 420C immediately following the first dose was applied. Cycling and resting cells of this in-vitro tumour model were then assayed for survival as function of the fractionation interval. In parallel, changes in cycle progression between the doses were measured by means of cytofluorometry. As main proliferative effects induced by this combined radiation and heat treatment transient S-phase blocking of cycling and recruitment of resting cells were observed. The split-dose survival curve displayed considerable synergistic action of heat and radiation and a six hours delay of Elkind-recoverey in both cycling and resting cells. (orig.)

  12. Cytogenetic studies on recipients of allogeneic bone marrow transplants after fractionated total body irradiation

    Cytogenetic findings from the bone marrow (BM) and the peripheral blood (PB) of nine consecutive patients after allogeneic bone marrow transplantation (BMT) for acute or chronic myelogenous leukaemia are reported. After a conditioning regimen consisting of cyclophosphamide and fractionated total body irradiation (TBI) given in five or six fractions of 2 Gy, persistence of host cells was detected in four out of seven cases with permanent engraftment. While one of these patients relapsed 4 months after host cells had been found in BM and PB, the other patients stayed relapse-free 124, 257 and 347 d after grafting. Before transplantation, the leukaemic cells in all three cases carried unique cytogenetic abnormalities giving the opportunity to distinguish the leukaemic population from chromosomally non-aberrant cells thought to represent residual normal host cells. As the persisting host cells after BMT lacked any cytogenetic abnormalities, it is suggested that they were members of residual normal clones not involved in the leukaemic process. (author)

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

    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

  14. Cataracts after total body irradiation and marrow transplantation: a sparing effect of dose fractionation

    Two hundred seventy-seven patients, who have been followed for 1 to 12 years after marrow transplantation, have been examined for cataract development. In preparation for transplantation, 96 patients with aplastic anemia were conditioned with chemotherapy only, while 181 patients (two with aplastic anemia and 179 with a hematologic malignancy) were conditioned with a regimen of total body irradiation (TBI) and chemotherapy. TBI was delivered from two opposing 60Co sources at an exposure rate of 4 to 8 cGy/min, either as a single dose of 10 Gy (105 patients) or in fractions (76 patients). To date, 86 patients have developed cataracts. Kaplan-Meier product limit estimates of the incidence of cataracts for patients given chemotherapy only and no TBI, single-dose TBI, and fractionated TBI are 19, 80, 18%, respectively. On the basis of proportional hazards regression analyses, patients given single-dose TBI had a relative risk of developing cataracts that was 4.7-fold higher than in patients given fractionated TBI or chemotherapy only, suggesting a significant sparing effect with use of TBI dose fractionation

  15. Study by internal friction of curing low temperature irradiation defects in graphite

    Micromechanical properties and anelastic effects of neutrons irradiated graphites at 300 and 770K are investigated by internal friction analysis and elasticity modulus variations. Defects created by irradiation are studied and evolution versus dose and annealing is followed

  16. EPR evaluation of absorbed doses in γ-irradiated animal bone tissues

    By the ESR method accumulation of CO2- radicals in γ-irradiated bone tissues of swine, chicken, cattle, navaga and other small fish of the cod family, hen's eggs shell was studied to reveal the fact of radiation exposure and to evaluate exposure dose received during radiation treatment of food stuffs. It is shown that in the range of doses 0-10 kGy dependence of the radicals concentration on dose is of linear character, while coefficient of the radicals radiation-chemical yield variation for diverse biological types of bone tissue does not exceed 30 %. Potentiality of using the method of additive doses for the ESR dosimetry of radiation-treated beef was considered. It is shown that the linear model used in the additive doses method provides overrated results compared to the exponential model

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

    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

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

    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

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

    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)

  20. Sexual dimorphism of newborn mouse epithalamus after fractionated X-irradiation at late stage of organogenesis

    Fractionated X-irradiation with 3 x 0.95-1.35 Gy on gestational days 11-13 in the mouse results in two discrete, clearly distinguishable forms of an epithalamic malformation observable on gestational day 18. Type A is characterized by a rhombic shape of the dorsal diencephalic sulcus which first narrows at the occipital edge. The type B lesion is characterized by a rather narrow epithalamus with a sandglass-shaped dorsal diencephalic sulcus. With the exception of the group with the lowest radiation dose (3 x 0.95 Gy) the type B lesion predominates. Type B lesions occur in female fetuses at a higher frequency than in males. This is again most marked in the 3 x 1.05 Gy dosage group where the type B lesion occurs five times more frequently in females than in males. This sexual dimorphism in the reaction pattern of the epithalamus after X-irradiation in utero can best be explained by postulating a causal link with the forebrain lesions which were recently shown to exhibit similar sexual dimorphism. We therefore postulate a retrograde transsynaptic degeneration of the thalamo-cortical fibres that develop pre-term, which is significantly expressed only after a low X-irradiation dose, but is partly abolished in the higher dosage groups. (orig./MG)

  1. Computer simulation of fractionated radiotherapy: Further results and their relevance to percutaneous irradiation and brachytherapy

    Basing on previous papers, the present communication considers the simulation of the radiotherapeutic treatments of glioblastoma multiforme, rectum adenocarcinoma, and gynaecological tumors of cervix uteri (squamous and adenocarcinoma) in spheroid culture. Starting with a single tumor cell in a nutrient medium and after the corresponding growth of the tumor spheroids, varying irradiation schemes are applied to the carcinoma and are compared with regard to tumor kill effectivity using the LQ-model. The two first-mentioned carcinoma are exposed to the dose fractionation schemes standard-, super-, hyperfractionation, and weekly high single dose. The result is that hyperfractionation (3x1.5 Gy/day) and weekly high single dose (1x6 Gy/week) yield the most effective tumor cell kill. The weekly high single dose may be realized by some different irradiation techniques, e.g. stereotactic irradiation or interstitial high dose rate brachytherapy. The treatment of the cervix uteri tumors is performed by a combined therapy form (high dose rate brachytherapy and percutaneous irradition). A comparing simulation of two typical regimens yield a nearly equivalent tumor kill effectivity. By the integration of in vitro tumor growth and clinical treatment schemes in a computer model, the possibility is made available to test the effectivity of variable regimens with the help of computer experiments. (orig.)

  2. Combined effect of carcinogenic n-nitrosodimethylamine precursors and fractioned γ-irradiation on tumor development in rats

    The influence of combined action of N-nitrosodimethylamine (NDMA) and fractioned γ-irradiation on tumor development in rats was investigated. Both the tumor frequency and tumor plurality coefficient have been studied for two types of treatment: precursors of NDMA (amidopyrine and/or sodium nitrite (SN)) alone and the combination 'precursors plus radiation'. Tumor frequency decreased by about 11% after combination of γ-irradiation and precursors in comparison with precursors alone. Nevertheless, treatment with SN and γ-irradiation did not change tumor frequency in comparison with SN alone. Irradiation of rats treated with precursors led to an increased tumor plurality coefficient

  3. Fractional absorption of active absorbable algal calcium (AAACa) and calcium carbonate measured by a dual stable-isotope method

    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 ...

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

    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

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

    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

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

    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

  7. Fractionated total lymphoid irradiation as preparative immunosuppression in high risk renal transplantation: clinical and immunological studies

    Twenty-two patients at high risk to reject renal allografts have been treated with fractionated total lymphoid irradiation (FTLI) prior to transplantation of primary (2), secondary (16) or teritary (4) renal allografts. All patients undergoing retransplantation had rapidly rejected previous grafts. At 24 months following transplantation, 72% of grafts were functioning in the TLI group compared with a 38% graft function in an historical control group of recipients receiving secondary or tertiary grafts and treated with conventional immunosuppression. Important variables in determining success of transplantation following fractionated TLI include the dose of TLI, the interval from radiation to transplantation, and maintenance, post-transplant immunosuppressive therapy. Optimal results were achieved with 2500 rads delivered in 100 rad fractions followed by transplantation within two weeks, and a tapering prednisone schedule and maintenance azathioprine post-transplantation. Seventeen patients had significant complications of the radiation treatment and there was one death, prior to transplantation, associated with pneumonitis. In vitro assessment of immune function demonstrated marked peripheral T cell depletion and loss of in vitro responsiveness to mitogen and allogeneic stimulation following FTLI. The administration of donor bone marrow at the time of transplantation did not produce chimerism. The results suggest that when properly utilized FTLI can produce effective adjunctive immunosuppression for clinical transplantation

  8. Fractionated total lymphoid irradiation as preparative immunosuppression in high risk renal transplantation

    Najarian, J.S.; Ferguson, R.M.; Sutherland, D.E.; Slavin, S.; Kim, T.; Kersey, J.; Simmons, R.L.

    1982-10-01

    Twenty-two patients at high risk to reject renal allografts have been treated with fractionated total lymphoid irradiation (FTLI) prior to transplantation of primary (2), secondary (16) or tertiary (4) renal allografts. All patients undergoing retransplantation had rapidly rejected previous grafts. At 24 months following transplantation, 72% of grafts were functioning in the TLI group compared with a 38% graft function in an historical control group of recipients receiving secondary or tertiary grafts and treated with conventional immunosuppression. Important variables in determining success of transplantation following fractionated TLI include the dose of TLI, the interval from radiation to transplantation, and maintenance post-transplant immunosuppressive therapy. Optimal results were achieved with 2500 rads delivered in 100 rad fractions followed by transplantation within two weeks, and a tapering prednisone schedule and maintenance azathioprine post-transplantation. Seventeen patients had significant complications of the radiation treatment and there was one death, prior to transplantation, associated with pneumonitis. In vitro assessment of immune function demonstrated marked peripheral T cell depletion and loss of in vitro responsiveness to mitogen and allogeneic stimulation following FTLI. The administration of donor bone marrow at the time of transplantation did not produce chimerism. The results suggest that when properly utilized FTLI can produce effective adjunctive immunosuppression for clinical transplantation.

  9. Fractionated total lymphoid irradiation as preparative immunosuppression in high risk renal transplantation: clinical and immunological studies

    Najarian, J.S.; Ferguson, R.M.; Sutherland, D.E.; Slavin, S.; Kim, T.; Kersey, J.; Simmons, R.S.

    1982-10-01

    Twenty-two patients at high risk to reject renal allografts have been treated with fractionated total lymphoid irradiation (FTLI) prior to transplantation of primary (2), secondary (16) or teritary (4) renal allografts. All patients undergoing retransplantation had rapidly rejected previous grafts. At 24 months following transplantation, 72% of grafts were functioning in the TLI group compared with a 38% graft function in an historical control group of recipients receiving secondary or tertiary grafts and treated with conventional immunosuppression. Important variables in determining success of transplantation following fractionated TLI include the dose of TLI, the interval from radiation to transplantation, and maintenance, post-transplant immunosuppressive therapy. Optimal results were achieved with 2500 rads delivered in 100 rad fractions followed by transplantation within two weeks, and a tapering prednisone schedule and maintenance azathioprine post-transplantation. Seventeen patients had significant complications of the radiation treatment and there was one death, prior to transplantation, associated with pneumonitis. In vitro assessment of immune function demonstrated marked peripheral T cell depletion and loss of in vitro responsiveness to mitogen and allogeneic stimulation following FTLI. The administration of donor bone marrow at the time of transplantation did not produce chimerism. The results suggest that when properly utilized FTLI can produce effective adjunctive immunosuppression for clinical transplantation.

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

    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)

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

    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).

  12. Development of standardized methods to verify absorbed dose of irradiated fresh and dried fruits, tree nuts in trade

    Investigations were carried out on standardization of desired process control parameters such as dose distribution in trade containers, container standardization and development of 'label' dosimeters. A prototype 'label' dose indicators Sterins for threshold doses of 125 Gy and 300 Gy was studied. Dose distribution was studied using fresh fruits and tree nuts in trade and standardized containers with varying product densities. The distribution of absorbed doses was measured by Fricke, Gammachrome YR, clear Polymethylmethacrylate (PMMA), EthanolChlorobenzene (ECB) and Sterin 300. These values are given as Dmax/Dmin ratios in relation to product bulk densities. It was observed that bulk densities varied greatly among different products depending on the types of fruits, containers and pattern of loading which also affected dose distribution. Dmax/Dmin obtained by proper dose mapping could be kept low by arranging proper irradiation conditions which ensured uniform dose distribution. Prototype 'label' dose indicators like Sterins and clear PMMA were used for dose mapping along with the standard primary and secondary dosimeters. Sterins and clear PMMA were also studied for their dosimetric properties, particularly for use in label dosimetry. Sterins 125 and 300 evaluated visually showed their integrity at their threshold doses. The word NOT on Sterin 125 eclipsed after 115 Gy and on Sterin 300 after 270 Gy dose. Clear PMMA samples of 410 mm thickness irradiated at 200-1000 Gy showed linear response and had postirradiation stability for over a month storage at normal temperatures (21-35 deg. C) and humidities. These could be investigated further for developing as 'label' dosimeters in insect control quarantine treatment. Other low dose indicators studied such as coloured perspex, dye solutions were not found useful at quarantine dose levels. Further investigations are required for developing a 'label' dosimeter for commercial use. (author)

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

    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

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

    · 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. Morphological changes in the rat liver following lethal and fractionated telecobalt irradiation studied by transmission and scanning electron microscopy

    Fully grown male albino rats were treated with a single abdominal telecobalt irradiation of 2.000 r or with fractionated irradiation of the right side of the epigastrium with 15 x 500 r. A few days after, the animals were perfusion fixated. One day after irradiation with 2.000 r, the epithelial cells exhibit only slight changes. Three days after the treatment, the glycogen content of the cells is increased. The damage pattern of the endothelial cells of the sinus wall is particularly interesting. After fractionated irradiation of the liver with a total of 7.500 r, a different pattern is found which is similar to the pattern provoked by other noxae. After 120 days, group necroses can be found. (MG)

  16. Diversification of existing reference phantoms in nuclear medicine: Calculation of specific absorbed fractions for 21 mathematical phantoms and validation through dose estimates resulting from the administration of (18)F-FDG.

    Blaickner, Matthias; Kindl, Peter

    2008-12-01

    Current dose assessment in nuclear medicine patient studies relies on published S-values, which are, in turn, based on calculated specific absorbed fractions (SAFs) available for a limited number of anthro-pomorphic computational phantoms. In order to take the individual physiognomy of patients more into account, this study aimed to broaden the supply of phantoms and their respective SAFs. An ensemble of 21 mathematical phantoms was submitted to the Monte Carlo Code MCNP4c2 for the purpose of calculation of SAFs for annihilation radiation. These values were incorporated into an internal dose assessment following the Medical Internal Radiation Dose (MIRD) schema and relying on published biokinetic data for intravenous administration of (18)F-FDG. The results were compared with data from the ICRP, MIRD reports and concurrent calculations with OLINDA/EXM. A very good agreement with sources relying on the SAFs of Cristy and Eckerman (i.e., the ICRP and OLINDA/EXM) was observed, with the absorbed dose in lung being the only exception. In the case of dose to red marrow, the King Spiers factors were omitted in the three-factor approximation, which led to a precise accordance with the Cristy/Eckerman values. Summarizing, one can say that the coincidence with published data justifies the method chosen and demonstrates successfully the expansion of available reference phantoms for dose assessment in nuclear medicine. PMID:19111050

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

    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.

  18. Analyse of the international recommendations on the calculation of absorbed dose in the biota

    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

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

    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.

  20. 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

    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.

  1. Dose Calculation Evolution for Internal Organ Irradiation in Humans

    Jimenez V., Reina A.

    2007-10-01

    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.

  2. Dose Calculation Evolution for Internal Organ Irradiation in Humans

    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. Histologic effect of fractionated doses of selectively applied /sup 60/Co irradiation to the teeth of albino rats

    Sweeney, W.T.; Elzay, R.P.; Levitt, S.H.

    1977-01-01

    This study compares the effects of fractionated 2400, 4800 and 7200 rad doses of Co-60 irradiation on the formed and developing teeth of the rats. The 7200 rad dosage was found to cause damage to both odontoblasts and ameloblasts of developing incisors but to spare previously formed molars.

  4. Histologic effect of fractionated doses of selectively applied 60Co irradiation to the teeth of albino rats

    This study compares the effects of fractionated 2400, 4800 and 7200 rad doses of Co-60 irradiation on the formed and developing teeth of the rats. The 7200 rad dosage was found to cause damage to both odontoblasts and ameloblasts of developing incisors but to spare previously formed molars

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

    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

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

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

    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.

  8. Absorbed dose at subcellular level by Monte Carlo simulation for a 99mTc-peptide with nuclear internalization

    The utility of radiolabeled peptides for the early and specific diagnosis of cancer is being investigated around the world. Recent investigations have demonstrated the specificity of 99mTc-bombesin conjugates to target breast and prostate cancer cells. The novel idea of adding the Tat (49-57) peptide to the radiopharmaceutical in order to penetrate the cell nucleus is a new proposal for therapy at cellular level. 99mTc radionuclide produces Auger energy of 0.9 keV/decay and internal conversion electron energy of 15.4 keV/decay, which represent 11.4% of the total 99mTc energy released per decay. It is expected that the dose delivered at specific microscopic levels in cancer cells induce a therapeutic effect. The aim of this research was to assess in vitro internalization kinetics in breast and prostate cancer cells of 99mTc-Tat(49-57)-bombesin and to evaluate the radiation absorbed dose at subcellular level simulating the electron transport. The pen main program from the 2006 version of the Penelope code was used to simulate and calculate the absorbed dose by Auger and internal conversion electron contribution in the membrane, cytoplasm and nucleus of Pc-3 prostate cancer and MCF7 and MDA human breast cancer cell lines. Nuclear data were obtained from the 2002 BNM-LNHB 99mTc decay scheme. The spatial distribution of the absorbed doses to the membrane, cytoplasm and nucleus were calculated using a geometric model built from real images of cancer cells. The elemental cell composition was taken from the literature. The biokinetic data were obtained evaluating total disintegrations in each subcellular compartment by integration of the time-activity curves acquired from experimental data. Results showed that 61, 63 and 46% of total disintegrations per cell-bound 99mTc-Tat-Bn activity unit occurred in the nucleus of Pc-3, MCF7 and MDA-MB231 respectively. 99mTc--Tat-Bn absorbed doses were 1.78, 5.76 and 2.59 Gy/Bq in the nucleus of Pc-3, MCF7 and MDA-MB231 correspondingly

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

    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)

  10. Enzyme-activity mutations detected in mice after paternal fractionated irradiation

    (101/E1 X C3H/E1)F1-hybrid male mice were exposed in a 24-h fractionation interval to either 3.0 + 3.0-Gy or 5.1 + 5.1-Gy X-irradiation, and mated to untreated Test-stock females. The offspring were examined for mutations at 7 recessive specific loci and for activity alterations of erythrocyte enzymes controlled presumably by 12 loci. No enzyme-activity mutant was found in 3610 F1-offspring of the control group. In the experimental groups, no mutant was detected in 533 (3.0 + 3.0 Gy) and 173 (5.1 + 5.1 Gy) offspring from postspermatogonial germ cells treated. After treatment of spermatogonia, 1 mutant in 3388 F1-offspring of the 3.0 + 3.0-Gy group, and 5 mutants in 3187 F1 offspring of the 5.1 + 5.1-Gy group were found. The mutants were all genetically confirmed. The frequency (expressed as mutants/locus/gamete) of enzyme-activity mutations is 2 (5.1 + 5.1-Gy group) to 10 (3.0 + 3.0-Gy group) times lower than the frequency of recessive specific-locus mutations. (Auth.)

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

    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)

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

    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

  13. Marrow transplantation for leukemia following fractionated total body irradiation. A comparative trial of methotrexate and cyclosporine

    Fifty-six patients, 30-47 yr of age, with leukemia in relapse received allogeneic marrow transplants from HLA-identical siblings. All patients were treated with cyclophosphamide (120 mg/kg) and 7 daily fractions of 2.25 Gy of total body irradiation (TBI) for seven consecutive days. Nine patients (16%) are currently alive, free of disease, 324-845 days from transplantation. Actuarial relapse and survival rates at 2 yr were 56% and 9.5% respectively. These data were not remarkably different from those in previous studies using 10 Gy of TBI administered as a single dose. Thirty patients were randomized to receive methotrexate (MTX) and 26 to receive cyclosporine (CSP) as postgrafting prophylaxis for acute graft-versus-host disease (GVHD). Probability of developing significant acute GVHD by day 100 post-transplant was 71% for patients in the MTX group and 45% for patients in the CSP group (p<0.05). Probability of relapse was 37% for patients in the MTX group and 70% for patients in the CSP group (p<0.05). Transplant-related deaths were more frequent in the MTX group and leukemic deaths more frequent in the CSP group although this may have been related to an uneven distribution of high-risk patients. Long term disease-free survival was comparable. (author)

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

    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

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

    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

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

    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.

  17. The influence of fractionated thymocytes of intact and irradiated mice on restoration of CFUs content in bone marrow after sublethal irradiation

    In studying the influence of thymocytes fractionated by their size in the ficoll density gradient on the CFUs content of the irradiated mouse bone marrow, two subpolations of T-cells were isolated; the administration of the first thymocyte subpopulation decreased the CFUs content during the postirradiation recovery period while thymocytes of the second subpopulation increased the content of CFUs in the bone marrow. When thymocytes of mice exposed to low-level radiation were separated a considerable stimulatory effect was produced by certain tthymus cell fractions on the number of CFUs in the bone marrow of exposed recipients; no inhibitory effect was registered

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

    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...... albedo plus the weighted distance between the underlying vegetation canopy albedo and the albedo over deep snow. The LAI/FAPAR and surface albedo values estimated using this framework were compared with MODIS collection 5 eight-day 1-km LAI/FAPAR products (MOD15A2) and 500-m surface albedo product (MCD43......-surface parameter profiles from MODIS time-series reflectance data even if some of the reflectance data are contaminated by residual cloud or are missing and that the retrieved LAI, FAPAR, and surface albedo values are physically consistent. The root mean square errors of the retrieved LAI, FAPAR, and surface...

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

    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.)

  20. The effect of the number of fractions of cranial irradiation on growth in children with acute lymphoblastic leukaemia

    Growth was documented over a period of 7 years in all long-term survivors treated for acute lymphoblastic leukaemia (ALL) with the DAL-70- and BFM-70-protocol. Normal growth was documented in patients of the DAL-70-protocol during and after therapy. In contrast, in children treated with the BFM-70-protocol the mean height standard deviation score (SDS) decreased significantly from 1.21 SDS prior to therapy to 0.80 SDS at the end of therapy and remained unchanged thereafter. Prophylatic cranial irradiation was given in total doses of 15 to 30 Gy. Ten children of the DAL-70- and 20 children of the BFM-70-protocol received 24 Gy of cranial irradiation. No significant change in height-SDS was observed in any patients of the DAL-70- and in 8 patients of the BFM-70-group, who received 24 Gy of cranial irradiation on 16-26 fractions. Adult height in 7 girls and 6 boys was normal and 3.15 cm and 5.06 cm above target height. In the remaining 12 patients of the BFM-70-protocol the total dose of 24 Gy of cranial irradiation was applied in 11-14 fractions. Their height-SDS had fallen significantly from 1.24 SDS before to 0.66 SDS at the end of therapy. Adult height in 4 girls and 6 boys was also normal, but the height increase was comparatively smaller, -2.20 cm below target height in the girls and 1.91 cm above in the boys. We conclude, that the loss of height-SDS in patients with ALL receiving 24 Gy of cranial irradiation is most probably due to the number of fractions of irradiation and not to the total radiation dose or the type of chemotherapy

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

    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)

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

    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.)

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

    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 mm3), 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.)

  4. Response of the immune system of monkeys to single and fractionated low-level gamma-irradiation

    A study was made of total and local imminity of two groups of Papio hamadryads subjected to single and ten-fold external gamma-irradiation at a cumulative dose of 5 cGy. It has been shown that with equal dosages changes in the relative and absolute number of lymphocytes in the peripheral blood, the number of circulating T-cells and their functional activity are more pronounced in animals subjected to fractionated irradiation. Both groups exhibited similar disturbances in the functional activity of antibody-dependent kilers and in local immunity of stomatopharynx

  5. 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

    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.

  6. Evaluation of onion root tip cell surviving fraction by measuring growing speed irradiated by accelerated heavy ions

    Irradiation of accelerated heavy ions to germinated onion seeds reduced the root growth. The extent of the root shortening increased with the increase of the absorbed dose and with the increase of linear energy transfer (LET). The growing curve looks like converging to a limited curve with increase of the dose and the growing did not stop even at highest dose of 100 Gy. Germinated seeds of green sorgo and alphalfa were investigated for comparison and they showed different dose responses from onion. Growth of green sorgo germs almost stopped at high doses. Growth of alphalfa germs was unaffected by radiations. (author)

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

    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 ...

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

    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.

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

    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)

  10. Experiences of an international trade action with irradiated onions between GDR and Hungary

    Extensive work has been carried out in the field of food irradiation in the GDR and Hungary in recent years. The irradiation of onions for sprout inhibition has reached a commercial stage in the GDR of more than 5,000 tons in 1986. The export of onions is the first example of international trade in irradiated food between socialist countries. Experiences of this trade is presented in the paper. Results of quality control of the bulbs (losses in weight an quality) after an intermediate storage period are discussed. Hungarian consumer reactions to irradiated onions is also evaluated. (author)

  11. Expression of P-glycoprotein and multidrug resistance associated protein in Ehrlich ascites tumor cells after fractionated irradiation

    Nielsen, D; Maare, C; Eriksen, J;

    2001-01-01

    ATPase activity was neither stimulated by vinblastine nor VER. CONCLUSION: Irradiation induced a multidrug-resistant phenotype in sensitive tumor cells. This phenotype was characterized by increased expression of Mrp1 mRNA, Mrp1, and PGP but decreased expression of mdr1a + b mRNA. The influence of......PURPOSE: To characterize irradiated murine tumor cells with respect to drug resistance, drug kinetics, and ATPase activity, and to evaluate the possible role of P-glycoprotein (PGP) and murine multidrug resistance associated protein (Mrp1) in the drug-resistant phenotype of these cells. METHODS AND...... MATERIALS: Sensitive Ehrlich ascites tumor cells (EHR2) were in vitro exposed to fractionated irradiation (60 Gy). Western blot analysis was performed for determination of PGP and Mrp1, reverse transcriptase-polymerase chain reaction (RT-PCR) for determination of mdr1a + b mRNA, and semiquantitative RT...

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

    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)

  13. 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)

    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.

  14. Internal irradiation of the carcinoma of the prostate

    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.)

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

    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.)

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

    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.)

  17. Effect of gamma irradiation on ethylene-octene copolymers

    Two ethylene-octene copolymers (POE) were irradiated with 60Co gamma radiation and influence of irradiation atmosphere, absorbed dose and heat treatment of samples on the crosslinking were studied. Thermal properties and crystalline morphology of non-irradiated and irradiated POE were determined by using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXS), respectively. The Charlesby-Pinner equation was used to describe the relationship between absorbed dose and sol fraction. The gel fraction of irradiated POE was lower and decreased with the increase of octene content when irradiated in oxygen, compared to irradiation in nitrogen atmosphere. The gel fraction increased significantly with the increasing of absorbed dose for the two copolymers. Heat treatment of samples prohibited the crosslinking of irradiated POE. The DSC results indicated that a subtle change of thermal properties of POE was observed before and after gamma irradiation at low dose. No change was found from the WAXS spectra of non-irradiated and irradiated POE. For heat-treating samples, the Charlesby-Pinner equation can not fit perfectly with the relationship between the sol fraction and absorbed dose, but it fits well with the crosslinking reaction of POE pellets

  18. Pre-treatment number of clonogenic cells and their radiosensitivity are major determinants of local tumour control after fractionated irradiation

    Objective: The response of tumours to fractionated radiotherapy is determined by many factors including repopulation, reoxygenation, the number of clonogenic cells, and their intrinsic radiosensitivity. However, after single radiation doses given under conditions of clamp hypoxia, the dose to control a tumour locally is dependent only on the number of clonogenic cells and their cellular radiosensitivity. Therefore, these parameters were investigated using local control after single doses given under hypoxia, to predict the outcome of fractionated irradiation. Materials and methods: Ten hSCC cell lines (FaDu, UT-SCC-15, UT-SCC-14, XF354, UT-SCC-5, UT-SCC-45, SAS, CAL-33, UT-SCC-8, and HSC-4) were transplanted subcutaneously into the right hind-leg of NMRI nude mice. At 7 mm in diameter, tumours were irradiated either with graded single doses under clamp blood flow conditions (n = 873) or with 30 graded fractions within 6 weeks (n = 905) under ambient conditions. Local tumour control was determined 120 days after irradiation. Radiation response was quantified in terms of TCD50, i.e. the dose required to control 50% of tumours locally. Results: Ten tumour lines investigated showed a pronounced heterogeneity in both TCD50(30fx/6w) after fractionated irradiation and TCD50(SDclamp) after single dose irradiation. TCD50(30fx/6w) varied between 45 Gy for UT-SCC-45 and 127 Gy for SAS; TCD50(SDclamp) varied between 42 Gy for UT-SCC-14 and 66 Gy for CAL-33. Two tumours were excluded from further analysis due to immunogenicity or non-defined TCD50. Linear regression analysis revealed a significant positive correlation between TCD50(SDclamp) and TCD50(30fx/6w) (R 2 = 0.82, p = 0.002). Conclusions: Significant association between TCD50(SDclamp) and TCD50(30fx/6w) suggests that the pre-treatment number of clonogenic tumour cells and their cellular radiosensitivity have a major impact on local control after fractionated radiotherapy

  19. Hourly distributions of the diffuse fraction of global solar irradiation in Cordoba (Spain)

    Posadillo, R.; Lopez Luque, R. [Grupo de Investigacion de Fisica para las Energias y Recursos Renovables, Dpto. de Fisica Aplicada/UCO, Edificio C2 Campus de Rabanales, 14071 Cordoba (Spain)

    2009-02-15

    Hourly global irradiations on tilted planes are required for dimensioning PV systems. However, for most sites, only global irradiations on a horizontal plane are available, and, given that to calculate the global irradiation on inclined planes the first step is to determine the diffuse component and this is not collected, we have studied the behaviour of the diffuse component on an hourly basis. Most parametrization models for the derivation of hourly diffuse irradiance from hourly global irradiance involve the clearness index, a parameter that implicitly includes solar altitude. The present paper has focused on the possibility of also including ''mean solar altitude anti {alpha}'' explicitly as a parameter in addition to the clearness index. Several analytical models are proposed, validated and compared here, using solar data collected on our station located in Cordoba (Spain). (author)

  20. Hourly distributions of the diffuse fraction of global solar irradiation in Cordoba (Spain)

    Hourly global irradiations on tilted planes are required for dimensioning PV systems. However, for most sites, only global irradiations on a horizontal plane are available, and, given that to calculate the global irradiation on inclined planes the first step is to determine the diffuse component and this is not collected, we have studied the behaviour of the diffuse component on an hourly basis. Most parametrization models for the derivation of hourly diffuse irradiance from hourly global irradiance involve the clearness index, a parameter that implicitly includes solar altitude. The present paper has focused on the possibility of also including 'mean solar altitude α-bar' explicitly as a parameter in addition to the clearness index. Several analytical models are proposed, validated and compared here, using solar data collected on our station located in Cordoba (Spain)

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

    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

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

    Edmondson, Elijah F., E-mail: elijah.edmondson@colostate.edu [Environmental and Radiological Health Sciences Department, Colorado State University, Fort Collins, Colorado (United States); Hunter, Nancy R. [Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Weil, Michael M. [Environmental and Radiological Health Sciences Department, Colorado State University, Fort Collins, Colorado (United States); Mason, Kathryn A. [Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States)

    2015-07-15

    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

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

    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)

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

    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...

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

    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)

  6. Turbulent effects of strong irradiance fluctuations on the orbital angular momentum mode of fractional Bessel Gauss beams.

    Gao, Jie; Zhang, Yixin; Dan, Weiyi; Hu, Zhengda

    2015-06-29

    The turbulent effects of strong irradiance fluctuations on the probability densities and the normalized powers of the orbital angular momentum (OAM) modes are modeled for fractional Bessel Gauss beams in paraxial turbulence channel. We find that the probability density of signal OAM modes is a function of position deviation from the beam center, and the farther away from the beam center the detection position is, the smaller the probability density is. For fractional OAM quantum numbers, the average probability densities of signal/crosstalk modes oscillate along the beam radius except the half-integer. When the beam waist of source decreases or the irradiance fluctuation increases, the average probability density of the signal OAM mode drops. The peak of the average probability density of crosstalk modes shifts to outward of the beam center as beam waist gets larger. In the nearby region of beam center, the larger the quantum number deviation of OAM, the smaller the beam waist and the turbulence fluctuations are, the lower average probability densities of crosstalk OAM modes are. Especially, the increase of turbulence fluctuations can make the crosstalk stronger and more concentrated. Lower irradiance fluctuation can give rise to higher the normalized powers of the signal OAM modes, which is opposite to the crosstalk normalized powers. PMID:26191711

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

    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.

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

    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

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

    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

  10. The relationship of irradiation creep, the local stress state and void swelling in PWR austenitic internals

    'Full text:' Swelling-induced distortion of PWR austenitic internals has been raised as a potential issue for plant life extension. Although void swelling generates volumetric strains, it is irradiation creep that responds to the local stress state to distribute the linear strains. The situation is complicated in that swelling gradients or constraints against swelling generate stresses that drive irradiation creep which attempts to lower the stresses, but swelling rates are accelerated by the stress. Finally, the creep rate accelerates in proportion to the swelling rate, leading to a complex relationship between irradiation creep, swelling, swelling gradients arising from gradients in temperature and dpa rate, and the distribution of internal stresses. An analysis of swelling and creep data for annealed 304 and cold-worked 316 is presented to show that irradiation creep is accelerated by swelling, and that swelling is accelerated by stress. The relationship between swelling and creep is independent of the steel identity and thermo-mechanical condition. (author)

  11. International symposium on developmental disturbances after prenatal irradiation

    This book contains abstracts of 31 papers from the 'International symposium on developmental disturbances after prenatal radiation' exposure. Most of the papers deal with the effects of externally applied, prenatal radiation exposure in mice, rats, and humans, in the latter radiation exposure was mostly due to X-ray examinations during pregnancy. The effects of prenatal exposure to internal radionuclides, expecially tritium, are discussed in some of the papers, as well as enhanced radiation effects due to the action of radiosensitizers. (MG)

  12. Investigation of high flux test module for the international fusion materials irradiation facilities (IFMIF)

    This report describes investigation on structure of a high neutron flux test module (HFTM) for the International Fusion Materials Irradiation Facilities (IFMIF). The HFTM is aimed for neutron irradiation of a specimen in a high neutron flux domain of the test cell for irradiation ground of IFMIF. We investigated the overall structure of the HFTM that was able to include specimens in a rig and thermocouple arrangement, an interface of control signal and support structure. Moreover, pressure and the amount of the bend in the module vessel (a rectangular section pressure vessel) were calculated. The module vessel did a rectangular section from limitation of a high neutron flux domain. Also, we investigated damage of thermocouples under neutron irradiation, which was a temperature sensor of irradiation materials temperature control demanded high precision. Based on these results, drawings on the HTFM structure. (author)

  13. 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

    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)

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

    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)

  15. 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

    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

  16. 15 years of existence of the International Consultative Group on Food Irradiation (ICGFI)

    The ICGFI essentially contributed to international dissemination of unbiased information about the advantages and risks of food irradiation. The body has issued ICGFI publications containing codes of good practice for a variety of purposes, as eg. for operation of irradiation facilities for the treatment of food (GIP), or guidelines for due handling of irradiated food (GMP). Training courses have been offered to scientists, especially from developing countries, as well as for inspectors of national supervisory authorities. The activities of the advisory group as well as the conditions governing future activities are discussed. (orig./CB)

  17. Effects of fractionated abdominal irradiation on small intestinal motility. Studies in a novel in vitro animal model

    Disordered small intestinal motility occurs frequently during acute radiation enteritis. However, the characteristics and time course of the motor dysfunction are poorly defined. These parameters were assessed in a novel animal model of radiation enteritis. Ileal pressures were recorded in vitro with perfused microanometric catheter using an arterially perfused ileal loop in 22 ferrets following fractionated abdominal irradiation (9 doses 2.50 Gz thrice weekly for 3 weeks). Tissue damage was graded histologically. Studies were performed 3 to 29 days after irradiation. Tissue from 7 control animals was also studied. All treated animals developed diarrhoea. Histology showed changes consistent with mild to moderate radiation enteritis. Following irradiation, there was an initial increase in frequency followed by a non-significant reduction in the frequency, but not the amplitude of ileal pressure waves. The frequency of pressure waves showed an inverse relationship with time after radiation (r=-0.634, p<0.002). There was no relationship between motility and histology. We conclude that abdominal irradiation is associated with a time-dependent reduction in ileal motility which does not correlate with light microscopic changes. (orig.)

  18. Effects of fractionated abdominal irradiation on small intestinal motility. Studies in a novel in vitro animal model

    Fraser, R.; Frisby, C.; Horowitz, M. [Royal Adelaide Hospital (Australia). Dept. of Medicine; Schirmer, M.; Yeoh, E. [Royal Adelaide Hospital (Australia). Dept. of Radiation Oncology; Blackshaw, A. [Royal Adelaide Hospital (Australia). Dept. of Gastrointestinal Medicine; Langman, J.; Rowland, R. [Division of Tissue Pathology, Inst. of Medical and Veterinary Science, Adelaide (Australia)

    1997-12-31

    Disordered small intestinal motility occurs frequently during acute radiation enteritis. However, the characteristics and time course of the motor dysfunction are poorly defined. These parameters were assessed in a novel animal model of radiation enteritis. Ileal pressures were recorded in vitro with perfused microanometric catheter using an arterially perfused ileal loop in 22 ferrets following fractionated abdominal irradiation (9 doses 2.50 Gz thrice weekly for 3 weeks). Tissue damage was graded histologically. Studies were performed 3 to 29 days after irradiation. Tissue from 7 control animals was also studied. All treated animals developed diarrhoea. Histology showed changes consistent with mild to moderate radiation enteritis. Following irradiation, there was an initial increase in frequency followed by a non-significant reduction in the frequency, but not the amplitude of ileal pressure waves. The frequency of pressure waves showed an inverse relationship with time after radiation (r=-0.634, p<0.002). There was no relationship between motility and histology. We conclude that abdominal irradiation is associated with a time-dependent reduction in ileal motility which does not correlate with light microscopic changes. (orig.).

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

    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

  20. Comparison of acute adverse effect between hypofractionated and conventionally fractionated whole-breast irradiation in early breast cancer patients

    We have conducted a clinical trial to evaluate whether the hypofractionated whole-breast irradiation (HF-WBI) is equally effective and safe with conventional fractionated whole-breast irradiation (CF-WBI) The HF-WBI consisted of 43.2 Gy/16 f to the whole breast with additional tumor bed boost of 8.1 Gy/3 f for positive or less than 5 mm surgical margins. From 1 of April 2006 to 31 of December 2009, 831 cases were registered and 848 breasts were treated. Grade 2 acute skin reactions were observed in 21 cases (4%) in HF-WBI and 40 cases (13%) in CF-WBI (p<0.001). In short-term results, we might conclude that HF-WBI has almost the same effectiveness and safety as CF-WBI. (author)

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

    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.)

  2. Accelerated partial breast irradiation: Bi-fractionated 40 Gy in one week. A French pilot phase II study

    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 MammositeR (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 cm3 (range: 5.2-28.7 cm3) and 117 cm3 (range: 52-185 cm3). 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)

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

    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. Relationship of time--dose fractionation factors to complications in the treatment of pituitary tumors by irradiation

    The records of the Radiotherapy Division of the Radiology Department of Vanderbilt University Hospital were reviewed for the years 1952 to 1971. During that period of time, 122 patients with diagnosis of pituitary adenomas were treated by external irradiation. A variety of techniques (2 or 3 stationary fields, 1800 rotational fields), equipment (60Co, 6 MeV Linac) and fractionation schedules (treating 4, 5 or 6 days per week, doses ranging between 150 and 280 rad per fraction), were used. Five patients developed severe complications: 1 with brain necrosis and 4 with blindness related radiation damage to optic pathways. From analysis of time--dose factors (TDF), it is evident that the risk of complications increases from 0% to 25% as the dose exceeds a TDF of 80. Although a significant increase in success rate has resulted from doses in excess of 3500 rad, there is little support for believing that doses in excess of 5000 rad (TDF 80) achieve improved results

  5. Stimulation of antibody formation through polypeptide thymic fraction (TP) in irradiated animals. [X radiation, rabbits

    Milcu, S.M.; Potop, I.; Boeru, V.; Olinici, N.

    1975-02-28

    Total sublethal irradiation with x-rays of the rabbits immunized with the Salmonella TH 901 antigen induces a decrease in the serum antibody level as compared with nonirradiated controls. Administration of the polypeptide thymic (TP) extract to rabbits immunized with antigen and x-rayed in similar conditions produces a stimulation of antibody formation in these animals as compared to the nontreated controls. The level of antibodies is altered in the animals irradiated, and treatment with the TP extract shows that it has a protective effect on the organism.

  6. Stimulation of antibody formation through polypeptide thymic fraction (TP) in irradiated animals

    Total sublethal irradiation with x-rays of the rabbits immunized with the Salmonella TH 901 antigen induces a decrease in the serum antibody level as compared with nonirradiated controls. Administration of the polypeptide thymic (TP) extract to rabbits immunized with antigen and x-rayed in similar conditions produces a stimulation of antibody formation in these animals as compared to the nontreated controls. The level of antibodies is altered in the animals irradiated, and treatment with the TP extract shows that it has a protective effect on the organism

  7. On the definition of absorbed dose

    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

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

    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

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

    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

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

    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.

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

    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.

  12. The combined effect of vitamin C and single or fractionated gamma irradiation on serum contents of proteins and urea in albino rats

    Whole body gamma irradiation of rats at 7.5 Gy (single dose), caused a significant decrease in the content of serum proteins accompanied by a significant increase of urea level as recorded on 7.10, and days after irradiation. Exposure at 7.5 Gy in 3 successive doses, 2.5 Gy each, delivered at an interval of 72 hours; decreased the levels of serum proteins and urea at all the experimental time periods. Treatment of rats with vitamin C for one time (10 mg/100 g body weight) 15 minutes; pre-irradiation at 7.5 Gy (single dose), improved the changes induced in serum proteins and urea. Treatment of rats with vitamin C for three times; each at 15 minutes pre-irradiation at each fraction (7.5 Gy fractionated in 2.5 Gy fractions) improved the changes induced in serum urea

  13. IAEA international database on irradiated nuclear graphite properties

    This report describes an IAEA database containing data on the properties of irradiated nuclear graphites. Development and implementation of the graphite database followed initial discussions at an IAEA Specialists' Meeting held in September 1995. The design of the database is based upon developments at the University of Bath (United Kingdom), work which the UK Health and Safety Executive initially supported. The database content and data management policies were determined during two IAEA Consultants' Meetings of nuclear reactor graphite specialists held in 1998 and 1999. The graphite data are relevant to the construction and safety case developments required for new and existing HTR nuclear power plants, and to the development of safety cases for continued operation of existing plants. The database design provides a flexible structure for data archiving and retrieval and employs Microsoft Access 97. An instruction manual is provided within this document for new users, including installation instructions for the database on personal computers running Windows 95/NT 4.0 or higher versions. The data management policies and associated responsibilities are contained in the database Working Arrangement which is included as an Appendix to this report. (author)

  14. Irradiation-Induced Degradation Effects on Baffle-Former-Barrel Assembly of Reactor Vessel Internal

    Components of RVI are consisted of austenitic stainless steel materials which are known to have good strength, ductility, toughness and corrosion resistance. However, when placed in a PWR environment, these properties undergo changes due to long-term exposure to neutron irradiation, high temperature, reactor water, and loading. Especially irradiation aging in the reactor vessel internal components is characterized by a decrease in ductility and fracture toughness, increase in yield and ultimate tensile strength, and potential volume changes due to void formation. It is very important to determine when and where irradiation susceptibility may occur for the continued operation. This paper introduces the aging management strategy for the pressurized water reactor internal and investigates the effects of the irradiation-induced degradation of the baffle-former-barrel (BFB) assembly of the pressurized water reactor operating in Korea. This paper provides the methodologies and results for the functionality analysis on the baffle-former-barrel assembly. The highest temperatures are yielded from EOC of high leakage loading. The most highly irradiated areas are also closed to the core such as internal corners of the baffle plates. Coincidentally, the largest distortion occurs between these baffle plates. The distortion is carried by the bolts holding these plates. Characteristic to void swelling is the exponential growth with time. Void swelling predictions are therefore highly sensitive to the assumed fuel cycle management

  15. Scanning electron microscopy and recording of the physiological activity of tracheal ciliated cells treated by fractionated irradiation

    The ciliated epithelium of the rabbit's trachea was irradiated with daily fractions of 2 Gy to an accumulated dose of 20 Gy. The beat frequency of the cilia was recorded and specimens were taken for SEM-, TEM- and LM-investigations. Examination was made 1-10 days after each fractionation schedule. An increased ciliary beat frequency was recorded at 2 Gy and 4 Gy. With increasing dose, there was an inverted relationship to the frequency. Light-microscopy showed edema and an increased amount of goblet cells in relation to the increasing dose. With SEM an increased number of ciliary blebs could be seen. These could be classified according to size and number, and showed a positive correlation to the dose. TEM-investigations showed signs of increased intracellular activity at higher doses in the form of multilobulated nuclei and an increasing number of nuclear pores. At lower doses, an increased amount of mitochondria appeared in the apical part of the cell. It is at present difficult to evaluate any correlation between the physiological activity and the morphology. More biological data are needed to explain the early irradiation effects

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

    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.)

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

    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).

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

    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

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

    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

  20. Alterations in growth phenotype and radiosensitivity after fractionated irradiation of breast carcinoma cells from a single patient

    The purpose was to investigate growth regulation and radiosensitivity in surviving clonogens after fractionated irradiation. Four breast carcinoma cell lines isolated from the primary tumor (21NT, 21PT) and metastases (21MT-1, 21MT-2) of a single patient were exposed to cumulative radiation doses of 30 Gy yielding cell lines designated -IR with respect to their parent. The irradiated lines were then compared to their parent for serum- and growth factor-requirements under defined media conditions, ability to proliferate in soft agar, concentration of TGF-alpha in conditioned medium, and radiosensitivity. The irradiated lines showed no change in proliferative doubling times under serum- and growth factor-supplemented media conditions. A single line, 21MT-1-IR, acquired a limited ability to proliferate in serum- and growth factor-deplete medium with a day 2-4 doubling time of 44.5 hr. Three lines, 21MT-1-IR, 21MT-2-IR, and 21NT-IR, formed colonies in soft agar in contrast to none of the unirradiated parent lines. There were significant 6-8 fold increases in conditioned media TGF-alpha concentrations for 21MT-2-IR and 21NT-IR cells. The 21MT-1-IR and 21NT-IR cells were significantly less radiosensitive than their respective parent lines. This decrease in radiosensitivity appeared to be at least partially mediated by a released factor as the radiosensitivity of 21MT-1 cells was significantly decreased by pre-incubation with conditioned medium from 21MT-1-IR cells. Radiation-induced changes in growth phenotype vary with respect to clonal origin of the cell line and may influence the radiosensitivity of surviving clonogens after fractionated treatment. 18 refs., 4 figs., 3 tabs

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

    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...

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

    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

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

    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...

  4. Destruction and Dechlorination of Aroclor1254 in Real Waste Transformer Oil Using Microwave Irradiation, Microwave Absorbent and Reactive Materials

    Bahram Kamarehie; Hassan Asilian Mahabadi; Ahmad Joneidi Jafari

    2014-01-01

    Background: In this research, the decomposition of Aroclor 1254, including 20 kinds of poly chlorinated biphenyls (PCBs), in real waste transformer oil in the presence of PEG1000, NaOH, zero valent iron and H2O by microwave (MW) irradiation was studied. Methods: Central composites design (CCD) method was carried out for experimental design. The effects of microwave power levels (200- 1000 W), reaction time (30-600 s), polyethylene glycol (PEG) (1.5-7.5 g), zero valent iron powder (0.3-1.5 ...

  5. Development of label dosimeters and analytical methods to verify absorbed dose in irradiated dried fruits/tree nuts

    Density measurements of fresh/dried fruits and tree nuts varied depending upon the package size, type and the nature of the sample. For the development of label dosimeters, the samples of clear PMMA in the thickness range of 410 mm gave a linear response in relation to the irradiation doses (0.125-1.0 kGy) and the optical response was stable almost for 6 months at ambient storage (20-35 deg. C; R.H 40-80%). Flexible polymers (polyethylene and PVC) materials were not found suitable in the dose range of 0.1-3.0 kGy. Subjective evaluation of Sterin indicator, an ISP product from USA, revealed that this new material is generally reliable, however, they were also affected by the doses lower than their threshold values (125 and 300 Gy) as well as exposure to light during storage. The yellow PMMA dosimeter (YLPMMA) developed by China was useful in the range of 125-1000 Gy of gamma radiation. Dose distribution studies of research irradiator at NIFA and a commercial gamma source (PARAS) at Lahore, indicated almost a good dose uniformity in the product containers in each case. Among the analytical methods (thermoluminescence and gas chromatography) the thermoluminescence measurements exhibited clearly reproducible and dose dependent differences between treated (0.5-1.5 kGy) and untreated samples of dried fruits/nuts. (author)

  6. Elective Lymph Node Irradiation With Intensity-Modulated Radiotherapy: Is Conventional Dose Fractionation Necessary?

    Purpose: Intensity-modulated radiation therapy (IMRT) is the standard of care for head-and-neck cancer (HNC). We treated patients with HNC by delivering either a moderate hypofractionation (MHF) schedule (66 Gy at 2.2 Gy per fraction to the gross tumor [primary and nodal]) with standard dose fractionation (54–60 Gy at 1.8–2.0 Gy per fraction) to the elective neck lymphatics or a conventional dose and fractionation (CDF) schedule (70 Gy at 2.0 Gy per fraction) to the gross tumor (primary and nodal) with reduced dose to the elective neck lymphatics. We analyzed these two cohorts for treatment outcomes. Methods and Materials: Between November 2001 and February 2009, 89 patients with primary carcinomas of the oral cavity, larynx, oropharynx, hypopharynx, and nasopharynx received definitive IMRT with or without concurrent chemotherapy. Twenty patients were treated using the MHF schedule, while 69 patients were treated with the CDF schedule. Patient characteristics and dosimetry plans were reviewed. Patterns of failure including local recurrence (LR), regional recurrence (RR), distant metastasis (DM), disease-free survival (DFS), overall survival (OS), and toxicities, including rate of feeding tube placement and percentage of weight loss, were reviewed and analyzed. Results: Median follow-up was 31.2 months. Thirty-five percent of patients in the MHF cohort and 77% of patients in the CDF cohort received chemotherapy. No RR was observed in either cohort. OS, DFS, LR, and DM rates for the entire group at 2 years were 89.3%, 81.4%, 7.1%, and 9.4%, respectively. Subgroup analysis showed no significant differences in OS (p = 0.595), DFS (p = 0.863), LR (p = 0.833), or DM (p = 0.917) between these two cohorts. Similarly, no significant differences were observed in rates of feeding tube placement and percentages of weight loss. Conclusions: Similar treatment outcomes were observed for MHF and CDF cohorts. A dose of 50 Gy at 1.43 Gy per fraction may be sufficient to

  7. Derivation and application of equations describing the effects of fractionated protracted irradiation, based on multiple and incomplete repair processes. Pt. 1

    A general model is developed where the induction and interaction rates of sublethal radiation damage with subsequent irradiation are represented as polynomial functions of the dose-rate. The effect of incomplete multiple repair processes is also included. Equations are evaluated for fractionated protracted irradiation where the dose-rate is constant during each fraction. However, both the dose-rate and the fractional dose are permitted to change from fraction to fraction. The resultant equations show that the apparent α/β ratio derived from the analysis of equivalent protocols may be protocol dependent. Also, the α/β ratio calculated from experimental data, assuming a single repair half-life, will appear to be protocol dependent if in reality more than one repair process is involved in the repair of sublethal damage. (author)

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

    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.)

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

    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

  10. The 3D plant canopy radiative transfer analysis in an Alaskan black spruce forest: the characteristics of fraction of absorbed photosynthetically active radiation in the heterogeneous landscape

    Kobayashi, H.; Suzuki, R.; Nagai, S.; Nakai, T.; Kim, Y.

    2012-12-01

    Over the last couple of decades, the three dimensional plant canopy radiative transfer models have been developed, improved and used for the retrievals of biophysical variables of vegetative surface. Fraction of absorbed photosynthetically active radiation (FAPAR) by plant canopy, a similar variable to heating rate in the atmosphere, is one of the important biophysical variables to infer the terrestrial plant canopy photosynthesis. FAPAR can be estimated by the radiative transfer model inversion or the empirical relationships between FAPAR and vegetation indices such as normalized difference vegetation index (NDVI). To date, some global FAPAR products are publicly available. These products are estimated from the moderate resolution satellites such as MODIS and SPOT-VEGETATION. One may apply the similar FAPAR algorithms to higher spatial resolution satellites if the ecosystem structures are horizontally homogeneous, which means that the adjacent satellite pixels have a similar spectral properties. If the vegetation surface is highly heterogeneous, "domain average FAPAR", which assumes no net horizontal radiation fluxes, can be unrealistically high (more than 1). In this presentation, we analyzed the characteristics of FAPAR in a heterogeneous landscape. As a case study, we selected our study site in a sparse black spruce forest in Alaska. We conducted the field campaigns to measure forest structural and optical properties that are used in the radiative transfer simulation. We used a 3D radiative transfer, FLiES (Kobayashi, H. and H. Iwabuchi (2008), A coupled 1-D atmosphere and 3-D canopy radiative transfer model for canopy reflectance, light environment, and photosynthesis simulation in a heterogeneous landscape, Remote Sensing of Environment, 112, 173-185) to create a high resolution simulated spectral reflectance and FAPAR images over the course of the growing season. From the analysis, we show (1) FAPAR with no net horizontal fluxes assumption can be higher than

  11. In vitro assessment of the immunosuppressive effect of fractionated total lymphoid irradiation in renal allotransplantation

    Ferguson, R.M.; Sutherland, D.E.R.; Kim, T.; Simmons, R.L.; Najarian, J.S.

    1981-09-01

    Ten uremic patients at high risk for rejection (nine patients with previous rapid rejection of a first transplant and one recipient of a two-haplotype mismatch primary graft) were treated with total lymphoid irradiation (TLI) prior to transplantation. TLI was delivered to mantle and inverted-Y fields simultaneously. Patients received either 125 or 100 rads daily for no more than 5 doses per week. Total dose ranged from 1800 to 3200 rads given over 29-67 days prior to transplantation. All patients received maintenance azathioprine and prednisone after the transplantation, but antilymphocyte globulin was not given.

  12. In vitro assessment of the immunosuppressive effect of fractionated total lymphoid irradiation in renal allotransplantation

    Ten uremic patients at high risk for rejection (nine patients with previous rapid rejection of a first transplant and one recipient of a two-haplotype mismatch primary graft) were treated with total lymphoid irradiation (TLI) prior to transplantation. TLI was delivered to mantle and inverted-Y fields simultaneously. Patients received either 125 or 100 rads daily for no more than 5 doses per week. Total dose ranged from 1800 to 3200 rads given over 29-67 days prior to transplantation. All patients received maintenance azathioprine and prednisone after the transplantation, but antilymphocyte globulin was not given

  13. Evaluation of the efficacy of palliative irradiation with high fractionated doses and planned intervals of patients with advanced cancer of the oral cavity and pharynx

    200 patients, previously not treated, with advanced highly differentiated cancer of the oral cavity and pharynx have been palliatively irradiated in the Oncology Center in Cracow in the years 1976-1985. Megavoltage irradiation with fractionated doses 4-5 Gy up to the dose of 20 Gy to the tumor with 4-5 fractions during 4-7 days has been applied. 64 patients received 20 Gy as simple dose, in 65 cases such dose has been repeated after month. 71 patients have been irradiated for the third time with similar dose after another 1 month interval. Partial regression of 25-50% of the tumor volume has been obtained after the first series of irradiation in 19% of patients and more than 50% in 28% of patients, complete regression in 4% of patients. 15,5% of the total number of patients survived 1 year since the initiation of the irradiation, 5% without symptoms of the neoplasm. Worse prognosis is connected with major advancement of the tumor (T4, N2), poor general condition, cachexia and alcohol addition. Absence of improvement after the first series of irradiations indicates the non-effectiveness of the treatment. Palliative treatment by irradiation with high fractionated doses and planned interval is a safe and efficacious method. 1 fig., 6 tabs., 14 refs. (author)

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

    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)

  15. Effect of respiratory motion on internal radiation dosimetry

    Xie, Tianwu [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Geneva Neuroscience Center, Geneva University, Geneva CH-1205 (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB (Netherlands)

    2014-11-01

    Purpose: Estimation of the radiation dose to internal organs is essential for the assessment of radiation risks and benefits to patients undergoing diagnostic and therapeutic nuclear medicine procedures including PET. Respiratory motion induces notable internal organ displacement, which influences the absorbed dose for external exposure to radiation. However, to their knowledge, the effect of respiratory motion on internal radiation dosimetry has never been reported before. Methods: Thirteen computational models representing the adult male at different respiratory phases corresponding to the normal respiratory cycle were generated from the 4D dynamic XCAT phantom. Monte Carlo calculations were performed using the MCNP transport code to estimate the specific absorbed fractions (SAFs) of monoenergetic photons/electrons, the S-values of common positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82, Y-86, and I-124), and the absorbed dose of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) in 28 target regions for both the static (average of dynamic frames) and dynamic phantoms. Results: The self-absorbed dose for most organs/tissues is only slightly influenced by respiratory motion. However, for the lung, the self-absorbed SAF is about 11.5% higher at the peak exhale phase than the peak inhale phase for photon energies above 50 keV. The cross-absorbed dose is obviously affected by respiratory motion for many combinations of source-target pairs. The cross-absorbed S-values for the heart contents irradiating the lung are about 7.5% higher in the peak exhale phase than the peak inhale phase for different positron-emitting radionuclides. For {sup 18}F-FDG, organ absorbed doses are less influenced by respiratory motion. Conclusions: Respiration-induced volume variations of the lungs and the repositioning of internal organs affect the self-absorbed dose of the lungs and cross-absorbed dose between organs in internal radiation dosimetry. The dynamic

  16. Effect of respiratory motion on internal radiation dosimetry

    Purpose: Estimation of the radiation dose to internal organs is essential for the assessment of radiation risks and benefits to patients undergoing diagnostic and therapeutic nuclear medicine procedures including PET. Respiratory motion induces notable internal organ displacement, which influences the absorbed dose for external exposure to radiation. However, to their knowledge, the effect of respiratory motion on internal radiation dosimetry has never been reported before. Methods: Thirteen computational models representing the adult male at different respiratory phases corresponding to the normal respiratory cycle were generated from the 4D dynamic XCAT phantom. Monte Carlo calculations were performed using the MCNP transport code to estimate the specific absorbed fractions (SAFs) of monoenergetic photons/electrons, the S-values of common positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82, Y-86, and I-124), and the absorbed dose of 18F-fluorodeoxyglucose (18F-FDG) in 28 target regions for both the static (average of dynamic frames) and dynamic phantoms. Results: The self-absorbed dose for most organs/tissues is only slightly influenced by respiratory motion. However, for the lung, the self-absorbed SAF is about 11.5% higher at the peak exhale phase than the peak inhale phase for photon energies above 50 keV. The cross-absorbed dose is obviously affected by respiratory motion for many combinations of source-target pairs. The cross-absorbed S-values for the heart contents irradiating the lung are about 7.5% higher in the peak exhale phase than the peak inhale phase for different positron-emitting radionuclides. For 18F-FDG, organ absorbed doses are less influenced by respiratory motion. Conclusions: Respiration-induced volume variations of the lungs and the repositioning of internal organs affect the self-absorbed dose of the lungs and cross-absorbed dose between organs in internal radiation dosimetry. The dynamic anatomical model provides

  17. Measuring temperatures on absorbers irradiated in a solar furnace by flash assisted multi-wavelength pyrometry (FAMP)

    Tschudi, H.R.; Schubnell, M.; Muller, Chr. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-03-01

    In a solar furnace, the sample is heated by concentrated solar radiation of which a certain fraction will be reflected. If the thermal (Planckian) emission of the sample shall be used to measure its surface temperature one has to either separate the thermally emitted from the reflected radiation or to make sure that the reflected solar radiation is negligible compared to the emitted thermal radiation. Furthermore, the accuracy of radiation thermometry significantly relies on an accurate knowledge of the sample emittance which generally depends on wavelength as well as on temperature. In this paper, we propose a multiwavelength analysis for the separation of emitted and reflected radiation and the use of an additional flash to probe the spectral emittance. We first outline the basic ideas and discuss their limitations. We then show experimental and numerical results and add some comments addressing the possibility of avoiding the need for a flash. (authors)

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

    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

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

    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. 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). 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. 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 differentiate a subset of patients with a higher rate of IBF

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

    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

  1. Expression of P-glycoprotein and multidrug resistance associated protein in Ehrlich ascites tumor cells after fractionated irradiation

    Purpose: To characterize irradiated murine tumor cells with respect to drug resistance, drug kinetics, and ATPase activity, and to evaluate the possible role of P-glycoprotein (PGP) and murine multidrug resistance associated protein (Mrp1) in the drug-resistant phenotype of these cells. Methods and Materials: Sensitive Ehrlich ascites tumor cells (EHR2) were in vitro exposed to fractionated irradiation (60 Gy). Western blot analysis was performed for determination of PGP and Mrp1, reverse transcriptase-polymerase chain reaction (RT-PCR) for determination of mdr1a + b mRNA, and semiquantitative RT-PCR for Mrp1 mRNA. The clonogenic assay was applied to investigate sensitivity, whereas the steady-state drug accumulation of daunorubicin (DNR), 3H-vincristine (VCR), and 3H-etoposide (VP16) was measured by spectrofluorometry and scintillation counting, respectively. For determining of ATPase activity, the release of inorganic phosphate from ATP was quantified using a colorimetric method. Results: Compared with EHR2, the irradiated cell line EHR2/irr showed increased expression of PGP (threefold), Mrp1 (eightfold), and Mrp1 mRNA (sixfold), and a slight reduction of mdr1b mRNA, whereas mdr1a was present in EHR2 but could not be detected in EHR2/irr. EHR2/irr developed sixfold resistance to VP16, twofold resistance to vincristine, but remained sensitive to DNR. Addition of the PGP inhibitor, verapamil (VER) or depletion of glutathione by buthionine sulfoximine (BSO) partly reversed the resistance in EHR2/irr. In EHR2/irr, the steady-state accumulation of 3H-VCR and 3H-VP16 was significantly decreased as compared with EHR2, whereas the accumulation of DNR was unchanged. The ATPase activity of plasma membrane vesicles prepared from EHR2/irr cells was similar to that of wild-type EHR2 cells. The ATPase activity was neither stimulated by vinblastine nor VER. Conclusion: Irradiation induced a multidrug-resistant phenotype in sensitive tumor cells. This phenotype was

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

    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. Estimation of specific absorbed fractions for selected organs due to photons emitted by activity deposited in the human respiratory tract using ICRP/ICRU male voxel phantom in FLUKA

    The ICRP/ICRU adult male reference voxel phantom incorporated in Monte Carlo code FLUKA is used for estimating specific absorbed fractions (SAFs) for photons due to the presence of internal radioactive contamination in the human respiratory tract (RT). The compartments of the RT, i.e. extra-thoracic (ET1 and ET2) and thoracic (bronchi, bronchioles, alveolar interstitial) regions, lymph nodes of both regions and lungs are considered as the source organs. The nine organs having high tissue weighting factors such as colon, lungs, stomach wall, breast, testis, urinary bladder, oesophagus, liver and thyroid and the compartments of the RT are considered as target organs. Eleven photon energies in the range of 15 keV to 4 MeV are considered for each source organ and the computed SAF values are presented in the form of tables. For the target organs in the proximity of the source organ including the source organ itself, the SAF values are relatively higher and decrease with increase in energy. As the distance between source and target organ increases, SAF values increase with energy and reach maxima depending on the position of the target organ with respect to the source organ. The SAF values are relatively higher for the target organs with smaller masses. Large deviations are seen in computed SAF values from the existing MIRD phantom data for most of the organs. These estimated SAF values play an important role in the estimation of equivalent dose to various target organs of a worker due to intake by inhalation pathway. (authors)

  4. Absorbed radiation dose in plants of natural complexes in Belarus over the past 10 years following the Chernobyl accident

    An absorbed radiation dose in plant of the natural complexes in Belarus for 10 years following the Chernobyl accident was calculated. The data on dynamics of the exposure dose rate in the area for 10 years were used for calculating the absorbed dose due to external irradiation and the data on the specific activity of the plants due to incorporation of cesium 137 and strontium 90 were taken into consideration when calculating the absorbed dose due to internal irradiation. Maximal absorbed doses in plants (to 40 Gy) were fixed in the zone with the high density of contamination. It resulted in visible somatic damages of separated plant organs. The highest contribution to formation of absorbed doses of ionizing radiation in plants in the contaminated zones belongs to internal irradiation of plant organisms due to incorporated radionuclides, in particular cesium 137

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

    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

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

    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.)

  7. Destruction and Dechlorination of Aroclor1254 in Real Waste Transformer Oil Using Microwave Irradiation, Microwave Absorbent and Reactive Materials

    Bahram Kamarehie

    2014-09-01

    Full Text Available Background: In this research, the decomposition of Aroclor 1254, including 20 kinds of poly chlorinated biphenyls (PCBs, in real waste transformer oil in the presence of PEG1000, NaOH, zero valent iron and H2O by microwave (MW irradiation was studied. Methods: Central composites design (CCD method was carried out for experimental design. The effects of microwave power levels (200- 1000 W, reaction time (30-600 s, polyethylene glycol (PEG (1.5-7.5 g, zero valent iron powder (0.3-1.5 g, NaOH (0.3-1.5 g and H2O (0.4-2 ml were surveyed on the decomposition efficiency of PCBs. Results: The results specified that polyethylene glycol and NaOH, as reactants, greatly influenced the decomposition of PCBs. Nevertheless, zero valent iron had no effect, and H2O decreased the decomposition efficiency of PCBs. Furthermore, experimental results showed that at the optimum amounts of variables (PEG = 5.34g, NaOH= 1.17g, Fe= 0.6g, H2O= 0.8 ml, microwave power 800 w, 93% of PCBs were decomposed over the reaction duration of 6 min. Therefore, PCBs degradation efficiency without water rose up to 99.99% under the MW at 6 min. Conclusion: The results indicated that MW, PEG and NaOH were important variables on PCBs degradation from real waste transformer oil. It is therefore suggested that microwave radiation with the assistance of PEG and alkali can be introduced as a potential technology for PCBs removal from real waste PCB-contaminated oil.

  8. Long-term renal toxicity in children following fractionated total-body irradiation (TBI) before allogeneic stem cell transplantation (SCT)

    Gerstein, Johanna; Meyer, Andreas; Fruehauf, Joerg; Karstens, Johann H.; Bremer, Michael [Dept. of Radiation Oncology, Medical School Hannover (Germany); Sykora, Karl-Walter [Dept. of Pediatric Hematology and Oncology, Medical School Hannover (Germany)

    2009-11-15

    Purpose: to retrospectively assess the incidence and time course of renal dysfunction in children ({<=} 16 years) following total-body irradiation (TBI) before allogeneic stem cell transplantation (SCT). Patients and methods: between 1986 and 2003, 92 children (median age, 11 years; range, 3-16 years) underwent TBI before allogeneic SCT. 43 of them had a minimum follow-up of 12 months (median, 51 months; range, 12-186 months) and were included into this analysis. Conditioning regimen included chemotherapy and fractionated TBI with 12 Gy (n = 26) or 11.1 Gy (n = 17). In one patient, renal dose was limited to 10 Gy by customized renal shielding due to known nephropathy prior to SCt. Renal dysfunction was defined as an increase of serum creatinine > 1.25 times the upper limit of age-dependent normal. Results: twelve children (28%) experienced an episode of renal dysfunction after a median of 2 months (range, 1-10 months) following SCT. In all but one patient renal dysfunction was transient and resolved after a median of 8 months (range, 3-16 months). One single patient developed persistent renal dysfunction with onset at 10 months after SCT. None of these patients required dialysis. The actuarial 3-year freedom from persistent renal toxicity for children surviving > 12 months after SCt was 97.3%. Conclusion: the incidence of persistent renal dysfunction after fractionated TBI with total doses {<=} 12 Gy was very low in this analysis. (orig.)

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

    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

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

    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)

  11. Determination of absorbed dose in a patient irradiated by beams of X or gamma rays in radiotherapy procedures. ICRU report 24

    ICRU Report 10d, Clinical Dosimetry, was published in 1963. It covered the steps pertaining to dosimetry in the radiotherapy clinic, from the determination of the output of the therapy machine to the assessment of the tumor dose in the patient. The present report is the second of three reports which are collectively to be regarded as the successor to Report 10d. The first of the three, Report 23, published in 1973, was concerned with those procedures which enable the absorbed dose to be determined at any point in a cuboid water phantom. The present report is concerned essentially with the transition from a water phantom to a human patient. A certain degree of overlap with Report 23 has been inevitable and even desirable and may be summarized as follows: (i) the water phantom is replaced by a patient; and (ii) the experimental technique is replaced by a clinical irradiation procedure. These changes lead to a number of complications which will be discussed in detail: (a) The shape, size and composition of the patient do not correspond to that of the phantom. In particular, the human body has a curved and irregular surface and is heterogeneous in composition. (b) The radiation beam may enter the body obliquely. (c) The position of any given point in the body, relative to the surface and deep anatomy of the patient and to the radiation beam, may not be determinable with the same accuracy as the position of a point in a phantom; furthermore, the position may vary from one irradiation to the next. (d) Achieving a particular pattern of absorbed dose distribution within the body may necessitate the use of more than one radiation beam, or movement of the beam(s); also, the beam(s) may need to be modified in order to take account of surface obliquity and/or body heterogeneity. (e) The practical setting up of the radiation beams with respect to the patient is likely to introduce errors over and above those incurred at the water phantom stage. 193 refs., 25 figs., 12 tabs

  12. Retroductal Submandibular Gland Instillation and Localized Fractionated Irradiation in a Rat Model of Salivary Hypofunction.

    Nair, Renjith Parameswaran; Zheng, Changyu; Sunavala-Dossabhoy, Gulshan

    2016-01-01

    Normal tissues that lie within the portals of radiation are inadvertently damaged. Salivary glands are often injured during head and neck radiotherapy. Irreparable cell damage results in a chronic loss of salivary function that impairs basic oral activities, and increases the risk of oral infections and dental caries. Salivary hypofunction and its complications gravely impact a patient's comfort. Current symptomatic management of the condition is ineffective, and newer therapies to assuage the condition are needed. Salivary glands are exocrine glands, which expel their secretions into the mouth via excretory ducts. Cannulation of these ducts provides direct access to the glands. Retroductal delivery of a contrast agent to major salivary glands is a routine out-patient procedure for diagnostic imaging. Using a similar procedure, localized treatment of the glands is feasible. However, performing this technique in preclinical studies with small animals poses unique challenges. In this study we describe the technique of retroductal administration in rat submandibular glands, a procedure that was refined in Dr. Bruce Baum's laboratory (NIH)(1), and lay out a procedure for local gland irradiation. PMID:27168158

  13. Evaluation of the potential carcinogenic action of radiocalcium internal irradiation in Swiss albino mice

    The carcinogenic action of 45Ca on inducing hepatocelluar carcinoma (HCC) in Swiss albino mice has been statistically evaluated. HCC proved to be radiation-induced and not due to spontaneous origin. Also, the higher incidence of male hepatocarcinogenesis due to internal irradiation has been found to be significant. The precise possible mechanism regarding the higher male susceptibility to liver cancer has been discussed in the light of available literature. (author)

  14. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Executive summary

    This report is a summary of 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

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

    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.

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

    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

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

    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.

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

    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

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

    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.

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

    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

  1. NFκB signaling related molecular alterations in human neuroblastoma cells after fractionated irradiation

    Radiotherapy has been used as an adjunctive local-control modality for high-risk neuroblastoma. However, relapse due to radioresistance affects the success of radiotherapy. Ascertaining the fractionated radiation (FIR) modulated molecular targets is imperative in targeted molecular therapy. Accordingly, we investigated the expression of genes representing six functional pathways; NFκB DNA-binding activity and expression of radioresponsive molecules after single dose (10 Gy) radiation (SDR) and FIR (2 Gy x 5) in human neuroblastoma cells. Alterations in gene expression were analyzed using QPCR-profiling, NFκB activity using electrophoretic mobility shift assay (EMSA) and pIκBα using immunoblotting. Modulations in TNFα, IL-1α, pAKT, IAP1, IAP2, XIAP, survivin, MnSOD, BID, Bak, MyD88 and Vegfc were determined using quantitative real-time PCR (Q-PCR) and immunoblotting. Compared to SDR, FIR significantly induced the expression of 25 genes and completely suppressed another 30 genes. Furthermore, FIR induced NFκB-DNA-binding activity and IκBα phosphorylation. Similarly, we observed an induced expression of IAP1, IAP2, XIAP, survivin, IL-1α, MnSOD, Bid, Bak, MyD88, TNFα and pAKT in cells exposed to FIR. The results of the study clearly show distinct differences in the molecular response of cells between SDR and FIR. We identified several potential targets confining to NFκB signaling cascade that may affect radio-resistance after FIR. (author)

  2. Calculation of pressure rise in electrical installations due to internal arcs considering SF{sub 6}-air mixtures and arc energy absorbers

    Anantavanich, Kittipong

    2010-07-01

    Internal arcs cause sudden temperature and thus pressure increase in electrical installations, which may endanger personnel, installation rooms or buildings as well as the security of power supply. Overpressure can be controlled by e.g. relief openings. The proof of internal arc withstand is usually performed by tests in high power laboratories or by pressure calculations especially in cases, where tests are impractical. Nowadays, there exist reliable pressure calculation methods, which are able to determine pressure rise due to internal arcing. For practical applications, two methods are of importance, the CFD calculation method, which provides spatially resolved results, and the standard calculation method providing spatially averaged results. However, the application range of these methods is limited. This is especially true if SF{sub 6}-air mixtures have to be considered (SF{sub 6}-insulated switchgear) or if arc energy absorbers are installed. In this thesis, both effects, which are important for pressure rise in the case of internal arcing, are treated. The key point of modelling SF{sub 6}-air mixture flows of changing composition is the generation and treatment of reliable gas data. A further main focus is the modelling of arc energy absorbers. For this purpose, heat absorption and flow resistance are considered first of all separately. In order to describe both effects simultaneously, existing and improved model approaches are evaluated and appropriate model combinations are proposed. SF{sub 6}-air mixtures and the effect of arc absorbers are implemented in both calculation methods for the first time with reliable gas data. Special care is taken on data handling and modification of the equation systems. The inclusion of the effect of absorbers is achieved by considering heat sinks and friction forces. Based on the standard calculation method, a versatile improved software tool (Improved Standard Calculation Method) for the determination of pressure

  3. Clinical evaluation of the hypoxic cytotoxin tirapazamine (SR-4233): phase I experience with repeated dose administration during fractionated irradiation

    Purpose: Regions of chronic or transient hypoxia are common in many human tumors and are thought to limit tumor cell killing and tumor control with conventional irradiation and some chemotherapeutic agents. Tirapazamine (3-amino-1,2,4-benzotriazine-1,4-di-N-oxide) forms a cytotoxic free radical during reductive metabolism in regions of hypoxia. In well oxygenated regions, the tirapazamine radical reacts with molecular oxygen to form the inactive parent drug. This results in markedly greater toxicity for hypoxic cells than for the well oxygenated cells that comprise most normal tissues. Tirapazamine increased the anti-tumor effects of single dose or fractionated irradiation or cis-platin chemotherapy in murine tumors,in vivo . This study evaluated the ability to repeat the administration of Tirapazamine during courses of fractionated irradiation in humans after an earlier phase I trial established a maximum tolerated dose of 390 mg per square meter of body surface area (mg/m2) when given as a single dose with radiotherapy. Materials and Methods: Between December 1993 and August 1995 22 patients with locally advanced or metastatic tumors of varying histology, normal renal, hepatic, and hematologic functions, and Karnofsky performance status ≥ 60 received repeated doses of Tirapazamine during a planned, 6 weeks course of standardly fractionated radiotherapy. After anti-emetic treatment with ondansetron (32 mg) and dexamethasone (16 mg), Tirapazamine was administered during a 2 hour intravenous infusion that ended from 30 to 90 minutes before a radiation treatment. Patients were monitored for acute toxicity during the course of treatment and for a minimum of one month after radiotherapy. Results: The study was initiated with three, biweekly doses of Tirapazamine at 330 mg/m2. Four of 7 patients who initiated treatment at this dose refused the second (1 patient) or third dose of Tirapazamine (3 patients). Two of the three patients who received three doses developed

  4. 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

    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

  5. Radiation-induced transformation of SV40-immortalized human thyroid epithelial cells by single and fractionated exposure to γ-irradiation in vitro

    Radiation-induced transformation of a human thyroid epithelial cell line (HTori-3) has been investigated following exposure to single and fractionated doses of γ-irradiation. The human epithelial cells were irradiated in vitro and following passaging, transplanted to the athymic nude mouse. Following a single exposure to γ-irradiation in the range 0.5-4Gy, 22 tumours were observed in 45 recipients and following three equal fractions in the range 0.5-4Gy per fraction, 18 tumours were observed in 31 recipients. Tumours were undifferentiated carcinomas and were observed from 7 to 20 weeks after transplantation. They occurred after similar radiation doses to those received by the children in the Belarus region of Ukraine, who developed thyroid tumours. The number of tumours observed, in each group receiving cells irradiated with a single dose of γ-irradiation in the range 0.5-4 Gy, was similar. Cell lines were established from some tumours and the tumorigenicity confirmed by retransplantation. These tumour cell lines were more radiosensitive than the human thyroid epithelial cell line they were derived from. This indicates that transformed cells were not being selected from a subpopulation within the parent cell line but that radiation-induced transformants were being induced de novo. The human origin of the tumours was established by karyotyping, immunocytochemical demonstration of human epithelial cytokeratins and p53 analysis. DNA fingerprinting confirmed that the tumours were derived from the original cell line. (author)

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

    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)

  7. 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

    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

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

    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

  9. Irradiation for international trade in agricultural products: The case of citrus fruit

    The paper analyses the influence of irradiation techniques on the Uruguayan market and their repercussions on international trade, with emphasis on the important and steadily growing citrus sector. This growth of citrus cultivation in Uruguay has been based on increasing international trade, and therefore producers and exporters have shown particular interest in the plant protection requirements which the European Economic Community (EEC) may adopt to govern the import of citrus fruit into its area. Over the past few years, the sector has become a net exporter, increasing its turnover from one harvest to the next. However, it is currently facing problems caused by the citrus plant disease known as canker, which is caused by a bacterium (Xanthomonas campestris, pv citri). The EEC is considering plant protection measures which could close its market to Uruguayan citrus fruit. Likewise, the North American market does not accept fruit from regions affected by canker. It is intended to treat fruit ready for export (wax-treated and packed) by irradiation at 0.7 kGy, combined with heat treatment for 5 min at 50 deg. C at the first rinsing stage during packing. Citrus fruit irradiation thus appears as an alternative treatment which would solve the problem by allowing a quality product to be offered on the foreign market, thereby improving commercial prospects as well as avoiding non-tariff barriers. (author). 9 refs, 1 tab

  10. The peculiarities of the changes in medullar hematopoetic system of animals exposed to internal irradiation with 90Sr

    The changes in medullar hemopoietic system of rats of Vistar line under the internal irradiation with 90Sr have been investigated. It has been determined that internal irradiation of animals with osteotropic radionuclides caused dishemopoiesis in early terms. The disturbances in ratio of the number of myelocytes and erythrocytes, proliferative activity, pathological vitosis appearance and high level of the cells with micronuclei. In addition, the hyperproliferative reaction has been observed that indicate the unfordable state and can be used for forecast hematopoetic diseases

  11. Internal sources dosimetry

    The absorbed dose, need of estimation in risk evaluation in the application of radiopharmaceuticals in Nuclear Medicine practice,internal dosimetry,internal and external sources. Calculation methodology,Marinelli model,MIRD system for absorbed dose calculation based on biological parameters of radiopharmaceutical in human body or individual,energy of emitted radiations by administered radionuclide, fraction of emitted energy that is absorbed by target body.Limitation of the MIRD calculation model. A explanation of Marinelli method of dosimetry calculation,β dosimetry. Y dosimetry, effective dose, calculation in organs and tissues, examples. Bibliography .

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

    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)

  13. Internal friction study of dislocation dynamics in neutron irradiated iron, and iron-copper alloys

    Konstantinovic, M.J., E-mail: mkonstan@sckcen.b [Studiecentrum voor Kernenergie/Centre d' Etude de l' Energie Nucleaire (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium)

    2009-12-15

    The temperature dependent internal friction spectra of cold-worked and neutron irradiated iron and iron-copper binary alloys are investigated. By increasing dose, both gamma- and Snoek-Koester-relaxation peaks exhibit strong shift towards low temperatures, as a consequence of the reduction of double kink activation energy. This shift is found to be the largest in alloys with the highest copper content. Besides, new modes appear in the spectra at energies of about 410 and 540 K. The 410 K peak intensity increases at the expense of Snoek-Koester peak intensity, indicating that redistribution of carbon takes place under irradiation, most probably as a result of grain boundary segregation. The presence of copper impedes the carbon redistribution by influencing the formation of carbon-vacancy complexes, which causes the grain boundary segregation, and activation of the 410 K relaxation process at larger neutron fluence in comparison with pure iron.

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

    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

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

    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

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

    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.

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

    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)

  18. Effect of black pepper (piper nigrum) on body weight and some serum lipid fractions in whole body gamma irradiated albino rats

    Two experiments were conducted to determine effect of sublethal body gamma irradiation (6.0 Gy as a single dose) on body weight and some serum lipid fractions in female and male rats. The beneficial efficacy of intragastric administration of black pepper (in two doses of 160 and 320 mg/kg bw) was also investigated. The results obtained revealed that the sublethal irradiated rats showed a drastic loss in body weight reached 39.5% less than the normal males and significant alterations in serum triglycerides, cholesterol, high density lipoprotein (HDL-cholesterol) and low density lipoprotein (LDL-cholesterol) levels, 5 weeks post exposure to gamma irradiation in female and male rats. Black pepper showed a beneficial effect on these significant changes in lipid fractions in irradiated female and male rats. Treatment with the two doses of black pepper up to 14 weeks, 5 days/week, showed a slight effect on body gain and fluctuations in the lipid fractions at 5.10 and 14 weeks for both sexes

  19. IAEA International Database on Irradiated Nuclear Graphite Properties. 7th meeting of the Technical Steering Committee

    This report summarizes the Consultant Meeting '7th Meeting of the Technical Steering Committee for the International Database on Irradiated Nuclear Graphite Properties' held on 16-17 March 2005 at the IAEA Headquarters, Vienna, Austria. The purposes of the meeting were to review the matters and actions identified in the previous meeting, undertake a review of the current status of the database and to make recommendations for actions for the next year. The purposes of the meeting were fully met. This report contains the current status of the identified actions as well as a summary of the recommendations on enhancements to the database. (author)

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

    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.

  1. IAEA International Database on Irradiated Nuclear Graphite Properties. 6th meeting of the Technical Steering Committee

    This report summarizes the Consultant Meeting 6th Meeting of the Technical Steering Committee for the International Database on Irradiated Nuclear Graphite Properties' held on 16-17 September 2004 at Plas Tan-Y-Bwlch, Maentwrog, Gwynedd, UK. The purposes of the meeting were to review the matters and actions identified in the previous meeting, undertake a review of the current status of the database and to make recommendations for actions for the next year. The purposes of the meeting were fully met. This report contains the current status of the identified actions as well as a summary of the recommendations on enhancements to the database. (author)

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

    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)

  3. Summary report of consultants' meeting on IAEA international database on irradiated nuclear graphite properties

    The '9th Meeting of the Technical Steering Committee for the International Database on Irradiated Nuclear Graphite Properties' was held on 26-27 March 2007 at the IAEA Headquarters, Vienna, Austria. All discussions, recommendations and actions of this Consultants' Meeting are recorded in this report. The purposes of the meeting were to review the matters and actions identified in the previous meeting, undertake a review of the current status of the database and make recommendations for actions for the next year. This report contains the current status of the identified actions as well as a summary of the recommendations on enhancements to the database. (author)

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

    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)

  5. 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)

    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.

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

    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

  7. Calculation of pressure rise in electrical installations due to internal arcs considering SF 6-air mixtures and arc energy absorbers

    Anantavanich, Kittipong

    2010-01-01

    Internal arcs cause sudden temperature and thus pressure increase in electrical installations, which may endanger personnel, installation rooms or buildings as well as the security of power supply. Overpressure can be controlled by e.g. relief openings. The proof of internal arc withstand is usually performed by tests in high power laboratories or by pressure calculations especially in cases, where tests are impractical. Nowadays, there exist reliable pressure calculation methods, which are a...

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

    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)

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

    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

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

    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.

  11. On the definition of absorbed dose

    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.

  12. In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

    To assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir. Fifty patients with 76 malignant liver tumors treated by computed tomography (CT)-guided high-dose-rate brachytherapy (HDR-BT) were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI) datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas) by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients. Positioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p < 0.001, respectively), as were the shifts between 6 and 12 weeks examinations (p = 0.001 and p = 0.004, respectively). There was a significant shift of the irradiation effect towards the catheter entry site compared with the

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

    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

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

    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. Relationship between total iso-effect dose and number of fractions for the treatment of uterine cervical carcinoma by high dose-rate intracavitary irradiation. Chapter 18

    Results are compared in Japan for patients with cervical carcinoma treated by either 1) manual afterloading with low intensity 60Co or 137Cs or 2) remote afterloading with high intensity 60Co sources (Ralstron). No significant difference between them was found for the 5-year survival rates. The relationship between the total tumour dose at point A and the results of high and low dose-rate intracavitary treatment of the patients classified by the number of fractions was also investigated. From this, the optimal dose ranges for each of the fractionation schemes of both high and low dose-rate intracavitary irradiation were determined. (U.K.)

  16. The formation of trinitite-like surrogate nuclear explosion debris (SNED) and extreme thermal fractionation of SRM-612 glass induced by high power CW CO2 laser irradiation

    We describe a new approach to the bench top production of surrogate nuclear explosion debris by employing high power continuous wave CO2 laser irradiation. High surface temperatures >2,500 K can be rapidly attained, allowing virtually any combination of materials to be fused into a glassy matrix that can display high levels of elemental fractionation. Examples of the laser fused glasses will be presented and compared to trinitite nuclear explosion glass along with the elemental fractionation effects that were induced in the NIST glass standard SRM-612 by this method. (author)

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

    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

  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

    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. Irradiation of dehydrated vegetables

    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

  20. Analysis of cell-survival fractions for heavy-ion irradiations based on microdosimetric kinetic model implemented in the particle and heavy ion transport code system

    It is considered that the linear energy transfer (LET) may not be the ideal index for expressing the relative biological effectiveness (RBE) of cell killing for heavy-ion irradiation, as the ion-species dependencies have clearly been observed in the relation between LET and RBE derived from cell-survival fraction data. The previously measured survival fractions of four cell lines irradiated by various ion species, employing the saturation-corrected dose-mean lineal energy, γ*, instead of LET as the index of the RBE were therefore re-analysed. In the analysis, the initial slopes of the survival fractions, the so-called α-parameter in the linear-quadratic model, were plotted as a function of γ*, which was calculated by the microdosimetric kinetic (MK) model implemented in the Particle and Heavy Ion Transport code System. It was found from the analysis that the ion-species dependencies observed in the relations between α and LET disappeared from those between α and γ*, and their relations can be well reproduced by a simple equation derived from the MK model. These results clearly indicate the suitability of γ* to be used in the estimation of the RBE of cell killing for heavy-ion irradiations, which is of great importance in the treatment planning of charged-particle therapy. (authors)

  1. Microstructural characterization and model of hardening for the irradiated austenitic stainless steels of the internals of pressurized water reactors

    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)

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

    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.

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

    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

  4. 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

    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.

  5. 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

    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

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

    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)

  7. A case report of image-based dosimetry of bone metastases with Alpharadin ((223)Ra-dichloride) therapy: inter-fraction variability of absorbed dose and follow-up.

    Pacilio, Massimiliano; Ventroni, Guido; Cassano, Bartolomeo; Ialongo, Pasquale; Lorenzon, Leda; Di Castro, Elisabetta; Recine, Federica; Sternberg, Cora N; Mango, Lucio

    2016-02-01

    A 70-year-old man affected by bone metastases from castration resistant prostate cancer underwent Alpharadin ((223)Ra-dichloride) therapy (6 administrations of 50 kBq per kg i.v., once every 4 weeks). The inter-fraction variability of the absorbed dose to lesions was evaluated for four injections. Dosimetric assessments were performed following the MIRD approach and a recently published methodology. The mean absorbed dose and standard deviation for 4 lesions [mean (σ %)] were: 434 mGy (15 %) and 516 mGy (21 %) for the right and left humeral head, 1205 mGy (14 %) and 781 mGy (8 %) for the right and left glenoid. The estimated total absorbed dose after the whole treatment, considering also the relative-biological effectiveness of alpha particles (RBE = 5), yielded a D RBE range of 13-36 Gy. A good correlation between (99m)Tc and (223)Ra uptake was obtained (R (2) = 0.7613). The tumour-non-tumour (TNT) ratio of 8 lesions (those above, plus 4 additional), monitored by six (99m)Tc-MDP bone scans over a period of about 10 months, evidenced a TNT reduction in two lesions (-42 and -48 %), but in most lesions the TNT remained fairly constant, evidencing that (223)Ra-dichloride therapy tends to prevent further progression of osseous disease, leading to chronicity of the metastatic status. PMID:26613714

  8. Thermal-hydraulic analysis of the International Fusion Materials Irradiation Facility

    Since 1994 the International Fusion Materials Irradiation Facility is under development. Up till now only design activities have been performed aimed at providing a reference design, evaluating remaining design uncertainty, reducing the costs and the key technology risk factors to reach the specified requirements with sufficient availability and reliability. From the beginning ENEA is engaged in the design of all the systems. In particular for the Lithium Target System, its activities are mainly focused on risk analysis, transient analysis, thermal-hydraulics and stability of lithium jet. This paper deals with the analysis of the behaviour of the Lithium Target System under normal and incident conditions, performed with a version of the RELAP5/Mod3.2 code modified to allow for specific features of the system itself (Lithium and organic oil as cooling fluids).(author)

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

    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.

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

    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

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

    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)

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

    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)

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

    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.

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

    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.

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

    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.

  16. 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?

    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.

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

    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

  18. No effect of the hemoglobin solution HBOC-201 on the response of the rat R1H tumor to fractionated irradiation

    Background and Purpose: Tumor hypoxia is regarded as one important underlying feature of radioresistance. The authors report on an experimental approach to improve tumor response to radiation by combining fractionated irradiation with HBOC-201, an ultrapurified polymerized hemoglobin solution, which is currently used in clinical phase II/III trials as alternative oxygen carrier and proved to be highly effective in tissue oxygenation (tpO2). Material and Methods: Subcutaneously growing rhabdomyosarcoma R1H tumors of the rat were treated with either 40 Gy (2 Gy/fraction, 20 fractions in 2 weeks, ambient) followed by grade top-up doses (clamped) alone, or in combination with HBOC-201, or with HBOC-201 plus carbogen (95% O2+5% CO2). Local tumor control (TCD50%) and growth delay were used as endpoints. In addition, the effect of HBOC-201 alone or in combination with carbogen on the tpO2 of tumor and muscle was determined using a flexible stationary probe (Licox, GMS). Results: TCD50% values of 119 Gy (95% confidence interval 103; 135), 111 Gy (84; 138), and 102 Gy (83; 120) were determined for tumors irradiated alone, in combination with HBOC-201, and with HBOC-201 plus carbogen, respectively. Although the dose-response curves showed a slight shift to lower doses when HBOC-201 or HBOC-201 plus carbogen was added, the differences in TCD50% were not statistically significant. No effect was seen on the growth delay of recurrent tumors. HBOC-201 alone did not effect tumor or muscle tpO2. In combination with carbogen the mean tpO2 muscle raised from 23.9 mmHg to 59.3 mmHg (p2 by carbogen alone. Conclusion: Low-dose application of HBOC-201 does not improve the response of the rhabdomyosarcoma R1H of the rat to fractionated irradiation. (orig.)

  19. 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

    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

  20. 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

    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.

  1. 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

    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.)

  2. Absorber pin development in Europe

    The neutron absorbing material chosen for the absorber elements of the European fast reactor (EFR) is boron carbide. Various pin designs are studied in Europe: (1) vented helium-bonded pins chosen for prototype fast reactor (PFR) control rods, (2) vented sodium-bonded pins chosen for the Phenix and Superphenix control rods, (3) vented shrouded sodium-bonded pins chosen for future loads of Superphenix control ros. There are three aspects to the research and development program to evaluate absorber pin performance: (1) experimental irradiation program dealing with basic studies and validation design experiments, (2) modeling of B4C physical properties, descriptive laws, and code development, (3) design optimization and innovative studies (various B4C enrichments and pellet densities, new absorber materials). The irradiation program is being performed in Phenix and PFR using either control rods or static rigs

  3. 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

    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)

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

    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

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

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

    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...

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

    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)

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

    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.)

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

    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

  10. Cytosteatonecrosis after breast accelerated conformational partial irradiation at 40 Gy in 10 fractions a week: multicentre prospective study; Cytosteatonecrose apres irradiation partielle acceleree conformationnelle du sein a 40 Gy en 10 fractions par semaine: etude prospective multicentrique

    Levy, A.; Bourgier, C. [Institut Gustave-Roussy, Villejuif (France); Taghian, A.; Ancukiewicz, M.; MacDonald, S.; Smith, B. [Massachusetts General Hospital, Boston MA (United States); Hirsch, A.; Kachnic, L. [Boston Medical Center, Boston MA (United States); Recht, A. [Beth Israel Deaconess Medical Center, Boston MA (United States)

    2011-10-15

    Conformational accelerated partial irradiation is always more often used but the optimal dose is not yet known. Therefore, the authors report an assessment of the cytosteatonecrosis rate within a multicentre prospective study which delivered 40 Gy over 5 days. They analyse and comment the results obtained on a range of more than 150 women treated for breast cancer. Results are discussed in terms of age, tumour size. The method resulted in an acceptable cytosteatonecrosis rate in comparison with other accelerated partial irradiation. But a more precise assessment of the toxicity rate requires further investigations. Short communication

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

    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

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

    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.

  13. Liquid metal reactor absorber technology

    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

  14. Liquid metal reactor absorber technology

    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. 3 refs., 3 figs

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

    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

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

    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

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

    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

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

    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

  19. Fractionated stereotactic irradiation by Cyberknife of choroid melanomas: repositioning validation, closed eyelids; Irradiation stereotaxique fractionnee par Cyberknife des melanomes choroidiens: validation du repositionnement, paupieres fermees

    Horn, S.; Rezvoy, N.; Lacornerie, T.; Mirabel, X.; Labalette, P.; Lartigau, E. [Centre Oscar-Lambret, Service de Radiotherapie, 59 - Lille (France)

    2009-10-15

    The fractionated stereotactic radiotherapy by Cyberknife is an option in the treatment of eyes tumors. The advantages of the Cyberknife in the choroid melanomas are in its infra-millimetric precision, to the automated repositioning on the skull bones and to the conformity brought by the stereotaxy. The objective of this study was to validate the quality of repositioning and the immobility of the eyes with closed eyelids. Conclusion: the reproducibility of the eye positioning with closed eyelids seems enough to consider the conservative treatment of choroid melanomas by fractionated stereotactic radiotherapy by Cyberknife without implementation of fiducials nor retrobulbar anaesthesia. (N.C.)

  20. Pre-therapeutic radiobiological experiments performed at Cyclone with d(50)-Be neutrons. Comparison of RBE/absorbed dose relationships obtained for several biological criteria

    The RBE/absorbed dose relationships for d(50)-Be neutrons were determined for several biological criteria. Irradiations were performed with the isochronous cyclotron Cyclone at Louvain-la-Neuve. Neutrons are produced by bombarding a thick beryllium target with 50MeV deuterons. This energy is to be used for the clinical applications. As first biological criterion, early intestinal tolerance was assessed in BALB/c mice from LD50 determination. Abdomen only was irradiated in order to avoid interference from the bone marrow syndrome. For single fraction irradiation, an RBE value of 1.8+-0.2 was observed (LD50 neutron absorbed dose: 525 rad). Fractionated irradiation had to be used to study smaller doses per fraction. The RBE increases progressively with decreasing dose and reaches 2.8 for a neutron absorbed dose of 80 rad (i.e. for a gamma absorbed dose of about 225 rad). A further RBE increase is unlikely since, for smaller absorbed doses, the survival curve for gamma rays nearly coincides with its initial tangent. The RBE/absorbed dose relationships observed for several mammalian cell lines in vitro, although they have a rather similar shape, show significant differences. For a neutron absorbed dose of 100 rad, the RBE is about 3 for EMT6 mouse cancer cells and 2 for HF19 human fibroblasts. For chromosome aberrations in Allium cepa onion roots, observed RBE values are much higher than for mammalian cell lethality. The RBE increases regularly from 7 to 12 with decreasing neutron dose from 40 to 10 rad. Two criteria were selected: (i) the mean number of aberrations (mainly breaks) per cell in anaphase and telophase, and (ii) the fraction of cells in anaphase and telophase having at least one aberration. For growth delay in Vicia faba, the RBE increases from 2.8 to 4.4 when the neutron absorbed dose decreases from 90 to 20 rad. (author)

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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 engineering practice

  7. Gamma-irradiation of liposomes composed of saturated phospholipids: effect of bilayer composition, size, concentration and absorbed dose on chemical degradation and physical destabilization of liposomes.

    Zuidam, N J; Versluis, C; Vernooy, E A; Crommelin, D J

    1996-04-01

    Liposomes composed of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG), or mixtures of these two phospholipids were exposed to gamma-irradiation in an air environment. Disappearance of the mother compounds was monitored by HPLC analysis. Plotting of the logarithmic values of residual DPPC or DPPG concentration versus irradiation dose resulted in straight lines. The slopes of these lines (overall degradation constants) depended on the type of phospholipids, concentration of the liposomes and the size of the liposomes. Under the chosen conditions, addition of DPPG in DPPC-liposomes did not affect the degradation rate constant of DPPC and vice versa. The presence of phosphate buffer (pH 7.4), pH or presence of sodium chloride did not affect the irradiation damage either. Minor changes were found upon analysis of total fatty acids by GLC and upon measurement of water soluble phosphate compounds. These changes were less pronounced than the changes monitored by HPLC of phospholipids, because the HPLC analysis monitored the overall degradation of the liposomal phospholipids. Thin-layer chromatography/fast atom bombardment mass spectrometry (TLC/FAB-MS) analysis of irradiated and non-irradiated DPPC or DPPG provided information on the structure of several degradation products. Degradation routes which include these degradation products are proposed. Gamma-irradiation neither affected the size of the liposomes nor the bilayer rigidity as determined by dynamic light scattering and fluorescence anisotropy of the probe 1,6-diphenyl-1,3,5-hexatriene (DPH), respectively. However, upon gamma-irradiation, changes in the melting characteristics of the liposomes were found by differential scanning calorimetry (DSC) measurements. The pre-transition melting enthalpy of the liposomal bilayer decreased or disappeared and the main-transition broadened. The changes found in DSC scans correlated qualitatively well with the changes recorded after HPLC analysis

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

    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).

  9. Models for pulmonary lethality and morbidity after irradiation from internal and external sources

    This report provides a hazard-function model for estimating the risk of death from radiation pneumonitis and/or pulmonary fibrosis following a light-water nuclear power accident. A similar model is also provided for estimating the prevalence of respiratory functional morbidity among those that survive death from acute effects. Hazard-function models for lethality and for morbidity were constructed using the cumulative hazard estimator H, which is related to the risk estimator R through the equation R = 1-exp(-H). The estimator H can be calculated using information provided in the report. The method of calculation depends on the exposure scenario. In general, the total normalized dose X for lethality or for morbidity is calculated. For lethality, X = 1 corresponds to a median lethal dose (LD50); for morbidity, X = 1 corresponds to a median effective dose (ED50). H is related to X by the equation H = 1n(2)X/sup V/, where V depends on the type of radiation (or radiations) involved. Contributions to X can arise from each of two main modes of exposure: (1) brief exposure of the lung, at a relatively high dose rate, to mainly external gammas, followed by (2) chronic internal alpha, and/or beta, and/or gamma irradiation of the lung. Equations are provided for calculating the contributions to X from both modes of exposure. 73 refs., 16 figs., 2 tabs

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

    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

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

    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.

  12. IFMIF (International Fusion Materials Irradiation Facility) key element technology phase task description

    In 2000, a 3 year Key Element technology Phase (KEP) of the International Fusion Materials Irradiation Facility (IFMIF) has been initiated to reduce the key technology risk factors needed to achieve continuous wave (CW) beam with the desired current and energy and to reach the corresponding power handling capabilities in the liquid lithium target system. In the KEP, the IFMIF team (EU, Japan, Russian Federation, US) will perform required tasks. The contents of the tasks are described in the task description sheet. As the KEP tasks, the IFMIF team have proposed 27 tasks for Test Facilities, 12 tasks for Target, 26 tasks for Accelerator and 18 tasks for Design Integration. The task description by RF is not yet available. The task items and task descriptions may be added or revised with the progress of KEP activities. These task description sheets have been compiled in this report. After 3 years KEP, the results of the KEP tasks will be reviewed. Following the KEP, 3 years Engineering Validation Phase (EVP) will continue for IFMIF construction. (author)

  13. Maintenance method for irradiation assisted stress corrosion cracking of PWR core internals

    Irradiation-assisted stress corrosion cracking of IASCC is a well-known result of age-related degradation of baffle former bolts which are an integral component of PWR core internals. However, methods for analyzing the causes and assessing IASCC have yet to be established and are being studied. The baffle former bolts are components of the baffle structure and in order to maintain the integrity of the baffle structure, an effective approach for maintaining the bolts must be provided. This paper proposes an effective method of maintaining the functions of the baffle structure by improving the configuration and/or material of baffle former bolts. A relaxed configuration of the bolt neck reduces the stress and can approximately halve the damage caused by IASCC. An improvement in the threshold value of materials vulnerability to IASCC would not only extend the service life of all bolts but could also substantially retard IASCC of the bolts installed at upper and lower ends where flux is low. If the threshold fluence to IASCC could be made higher than approximately 5x1025 n/m2 (E>0.1 MeV, 340degC), the bolts installed at lower and upper ends, which are conventionally replaced 30 years after plant start-up, would remain intact for 60 years after start-up. Hence, this approach is a very effective maintenance measure. (author)

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

    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.

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

    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.

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

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

    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

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

    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

  19. Mutant frequencies in lacZ transgenic mice following the internal irradiation from 89Sr or the external γ-ray irradiation

    Mutagenesis assays using transgenic mice have been recently developed and applied to the studies on the mutagenesis. The present study was undertaken to clarify whether the mutagenesis assay with transgenic mice could detect the mutations induced by the internal β-ray irradiation from 89Sr or the external γ-ray irradiation. The transgenic mice used were MutaTM mouse strain, which carries 80 copies of the bacterial lacZ gene per cell as a target of mutagenesis. Female animals were given intraperitoneal injections of ethylnitrosourea (50 mg/kg per day) for five days, a single intravenous injection of 89Sr (7.4 and 74 MBq/kg), or daily irradiation with 1.5 Gy γ-rays for five days. The liver, spleen, and bone marrow were collected 15 days after the treatment with each agent. After the genomic DNA was extracted from each tissue, mutation analysis at lacZ locus was carried out. The spontaneous lacZ mutant frequencies were 2-4 x 10-5. The frequencies of mutants induced by ethylnitrosourea in the liver, spleen and bone marrow were 68, 55, and 11 x 10-5, respectively. In contrast, the mutant frequencies detected after the treatment with γ-rays were not so high in all three tissues as those treated with ethylnitrosourea. The injection of 89Sr at a dose of 74 MBq/kg induced mutation at significantly higher frequencies in the bone marrow, but not in the liver and spleen. The results clearly showed that the mutation assay system used here could detect mutagenic effects of the local irradiation from 89Sr, but was relatively insensitive to the β- and γ-ray irradiation compared with the chemical mutagens such as ethylnitrosourea. (author)

  20. The estimations of some morphofunctional changes in organs of reproductive system and liver of male rats after fractional irradiation at 1,0 Gy dose at the stage of early ontogenesis and in theirs progeny

    Relative organ weight of reproductive system and liver, the number of spermatozoa from epididymis, RNA, DNA and protein content in testes and liver tissue of rats fractionally irradiated at 1,0 Gy dose in early ontogenetic stage and in their first progeny from irradiated females (male rats in 2 and 6 month age) were analyzed. Essential changes of the studied parameters of rats reproductive system since 1 and 6 months after irradiation and moderate deviations of relative organ weight of reproductive system and biochemical indices in testes tissue of first progeny from irradiated parents were revealed. The morphofunctional indices of rat reproductive system can be used as markers of ionizing radiation action

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

    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.

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

    Gobin, R; Bogard, D; Cara, P; Chauvin, N; Chel, S; Delferrière, O; Harrault, F; Mattei, P; Mosnier, A; Senée, F; Shidara, H; Okumura, Y

    2014-02-01

    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. PMID:24593497

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

    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

  4. Dosimetry of total body irradiation

    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

  5. Estimation of doses of an internal irradiation of a Scots pine (Pinus silvestris) at flooding and full territory flooding

    The value of equivalent dose found in the aboveground phytomass elements of Pinus silvestris L. is formed due to the internal b-radiation emitted by incorporated radionuclides, and depends on the level of ground waters. The highest Cs (3-ir-radiation dose are observed on a study site with the level of ground waters of 40-60 cm, while the minimum values are found on waterless areas - 245 cm. The opposite effect is observed in respect of Sr 90 and a daughter product Y 90. The large internal irradiation doses of the pine bark is determined by its significant Sr 90 uptake (up to 140 x 10-3 m2/kg). (authors)

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

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

    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...... insulation thicknesses between 0.4 and 0.8 mm. The plastic dosimeter simulating polyethylene insulations was a thin radiochromic polyvinyl butyral film wrapped several times around the copper wire, such that when unwrapped and analyzed optically on a scanning microspectrophotometer, high-resolution radial...

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

    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,

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

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

    2013-01-01

    Aims: Hypofractionation of postoperative radiotherapy for breast cancer has been evaluated in a number of large randomised clinical trials, but concerns remain over the late cardiac toxicity. In this study, we examined the predictions of the linear quadratic model on the estimated fraction size-c...... quadratic model, will generally be lower after hypofractionated compared with normofractionated schedules, even for very low values of alpha/beta. (C) 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved....

  9. Induction of premature senescence by single and fractionated irradiation in human cancer cell line and xenografted mice model

    Radiation therapy (RT) is one of the best therapeutic strategies for cancer treatment. The cellular responses to ionizing radiation (IR) are varied ranging from cellular senescence to apoptotic cell death. To increase the efficacy of IR treatment is a major issue of radiation biology. From the point of view, the induction of premature senescence using the therapeutic dose of IR could be a promising treatment for tumors. The aim of this study is whether the premature senescence could contribute to cancer treatment by irradiation

  10. Influence of L-dopa and of thymus fraction on the survival rate of whole-body irradiated mice

    Busse, E.; Helmholz, M. (Humboldt-Universitaet, Berlin (German Democratic Republic). Bereich Medizin (Charite))

    1982-06-01

    The survival rate of mice with exposure of the whole body (7 Gy) was hardly changed by one dose as well as several doses of the phosphodiesterase inhibitor amantadine and the interferon inductor measles vaccine. However, the survival rates were increased by one administration of L-dopa or by the long-term therapy using L-dopa at 7 and 9 Gy, resp. The survival rates were also increased at 7 and 9 Gy, resp. if the thymus factor was three times applied to the animals after irradiation. The increased survival rates gained by using L-dopa and thymus factor are correlated with the leukocyte values determined.

  11. The influence of L-dopa and of thymus fraction on the survival rate of whole-body irradiated mice

    The survival rate of mice with exposure of the whole body (7 Gy) was hardly changed by one dose as well as several doses of the phosphodiesterase inhibitor amantadine and the interferon inductor measles vaccine. However, the survival rates were increased by one administration of L-dopa or by the long-term therapy using L-dopa at 7 and 9 Gy, resp. The survival rates were also increased at 7 and 9 Gy, resp. if the thymus factor was three times applied to the animals after irradiation. The increased survival rates gained by using L-dopa and thymus factor are correlated with the leukocyte values determined. (author)

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

    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

  13. 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

    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)

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

    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. PMID:26609927

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

    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.

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

    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.

  17. 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

    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. (paper)

  18. Role of internal stresses in the transient of irradiation growth of zircaloy-2

    A 'self-consistent' polycrystalline model is used to simulate irradiation growth of Zircaloy-2 samples irradiated at about 330 K. The predictions of the model are compared with experimental measurements obtained from specimens irradiated in the Advanced Test Reactor (ATR) at Idaho Falls. Three types of material are studied here: annealed, cold worked in tension and cold worked by rolling. In general, the growth rate attains a steady-state value after it goes through a transient that depends on the initial state of the material. The transient growth behaviour is explained in terms of the evolution of intergranular residual stresses that are present in the sample, and in terms of the dislocation structure. From this study, information regarding irradiation creep and growth mechanisms occurring at the single crystal level is obtained. (author). 28 refs., 1 tab., 4 figs

  19. 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

    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

  20. 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

    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.

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

    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

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

    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.

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

    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...

  4. Elective lymph node irradiation late course accelerated hyper-fractionated radiotherapy plus concurrent cisplatin-based chemotherapy for esophageal squamous cell carcinoma: a phase II study

    In this phase II study, we evaluated the efficacy, toxicity, and patterns of failure of elective lymph node irradiation (ENI) late course accelerated hyper-fractionated radiotherapy (LCAHRT) concurrently with cisplatin-based chemotherapy (CHT) for esophageal squamous cell carcinoma (ESCC). Patients with clinical stage II-IVa (T1-4N0-1M0 or M1a) ESCC were enrolled between 2004 and 2011. Radiation therapy (RT) comprised two courses: The first course of radiation covered the primary and metastatic regional tumors and high risk lymph nodal regions, given at 2 Gy per fraction for a dose of 40 Gy. In the second course, LCAHRT was delivered to the boost volume twice a day for an additional 19.6 Gy in 7 treatment days, using 1.4 Gy per fraction. Two cycles of CHT were given at the beginning of RT. The median age and Karnofsky performance status were 63 years and 80, respectively. The American Joint Committee on Cancer stage was II in 14 (20.6%) patients, III in 32 (47.1%), and IVa in 22 (32.3%). With a median follow-up of 18.5 months, the overall survival at 1-, 3-, 5-year were 75.5%, 46.5%, 22.7% for whole group patients, versus 78.6%, 49.4%, 39.9% for patients with stage II–III. The patterns of first failure from local recurrence, regional failure, and distant metastasis were seen in 20.6%, 17.6%, and 19.1%, respectively. The most frequent acute high-grade (≥ 3) toxicities were esophagitis and leucopenia, occurred in 26.4% and 32.4%. ENI LCAHRT concurrently with CHT was appeared to be an effective regimen for ESCC patient with a favorable and tolerated profile. Further observation with longer time and randomized phase III trial is currently underway.

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

    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

  6. Paired organs--Should they be treated jointly or separately in internal dosimetry?

    Parach, Ali-Asghar; Rajabi, Hossein; Askari, Mohammad-Ali [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran-Iran (Iran, Islamic Republic of)

    2011-10-15

    Purpose: Size, shape, and the position of paired organs are different in abdomen. However, the counterpart organs are conventionally treated jointly together in internal dosimetry. This study was performed to quantify the difference of specific absorbed fraction of organs in considering paired organs jointly like single organs or as two separate organs. Methods: Zubal phantom and GATE Monte Carlo package were used to calculate the SAF for the self-absorption and cross-irradiation of the lungs, kidneys, adrenal glands (paired organs), liver, spleen, stomach, and pancreas (single organs). The activity was assumed uniformly distributed in the organs, and simulation was performed for monoenergetic photons of 10, 50, 100, 500, 1000 keV and mono-energetic electrons of 350, 500, 690, 935, 1200 keV. Results: The results demonstrated that self-absorption of left and right counterpart organs may be different depending upon the differences in their masses. The cross-irradiations between left-to-right and right-to-left counterpart organs are always equal irrespective of difference in their masses. Cross-irradiation from the left and right counterpart organs to other organs are different (4-24 times in Zubal phantom) depending on the photon energy and organs. The irradiation from a single source organ to the left and right counterpart paired organs is always different irrespective of activity concentration. Conclusions: Left and right counterpart organs always receive different absorbed doses from target organs and deliver different absorbed doses to target organs. Therefore, in application of radiopharmaceuticals in which the dose to the organs plays a role, counterpart organs should be treated separately as two separate organs.

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

    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)

  8. Heterogeneous neutron absorbers development

    The use of solid burnable absorber materials in power light water reactors has increased in the last years, specially due to improvements attained in costs of generated electricity. The present work summarizes the basic studies made on an alumina-gadolinia system, where alumina is the inert matrix and gadolinia acts as burnable poison, and describes the fabrication method of pellets with that material. High density compacts were obtained in the range of concentrations used by cold pressing and sintering at 1600 deg C in inert (Ar) atmosphere. Finally, the results of the irradiation experiences made at RA-6 reactor, located at the Bariloche Atomic Center, are given where variations on negative reactivity caused by introduction of burnable poison rods were measured. The results obtained from these experiences are in good agreement with those coming from calculation codes. (Author)

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

    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.

  10. Comparison of the immunosuppressive effect of fractionated total lymphoid irradiation (TLI) vs conventional immunosuppression (CI) in renal cadaveric allotransplantation

    Waer, M.; Vanrenterghem, Y.; Ang, K.K.; van der Schueren, E.; Michielsen, P.; Vandeputte, M.

    1984-02-01

    Beginning in November 1981, eight patients with end stage diabetic nephropathy underwent renal cadaveric transplantation after TLI. Transplantation was done between 2 to 11 days after the end of a fractionated TLI to a total dose of 20 to 30 Gy. During the same observation period, 60 nondiabetic patients with end stage renal disease of different origin also received a cadaveric kidney graft, with a conventional regimen of immunosuppression that consists of anti-lymphocyte-globulin, tapering high doses of prednisone, and azathioprine. Phytohemagglutinin (PHA)-, concanavalin A (con A)-, and pokeweed mitogen (PWM)-induced blastogenesis, as well as the mixed lymphocyte reaction (MLR) and the cell-mediated lympholysis (CML) decreased progressively during the first months after conventional immunosuppression to 50% of the pretransplantation level, and remained there for the first year after transplantation. These tests were much more impaired after TLI and again no recovery occurred during the first year. In the clinic, the more profound immunosuppression in TLI patients was more frequently associated with viral infections (cytomegalovirus and herpes zoster). The incidence of rejections, however, was somewhat less frequent in the TLI-treated group and occurred significantly later. After TLI, the mean cumulative dose of steroids needed for kidney transplantation during the first year after transplantation could be substantially reduced.

  11. Comparison of the immunosuppressive effect of fractionated total lymphoid irradiation (TLI) vs conventional immunosuppression (CI) in renal cadaveric allotransplantation

    Beginning in November 1981, eight patients with end stage diabetic nephropathy underwent renal cadaveric transplantation after TLI. Transplantation was done between 2 to 11 days after the end of a fractionated TLI to a total dose of 20 to 30 Gy. During the same observation period, 60 nondiabetic patients with end stage renal disease of different origin also received a cadaveric kidney graft, with a conventional regimen of immunosuppression that consists of anti-lymphocyte-globulin, tapering high doses of prednisone, and azathioprine. Phytohemagglutinin (PHA)-, concanavalin A (con A)-, and pokeweed mitogen (PWM)-induced blastogenesis, as well as the mixed lymphocyte reaction (MLR) and the cell-mediated lympholysis (CML) decreased progressively during the first months after conventional immunosuppression to 50% of the pretransplantation level, and remained there for the first year after transplantation. These tests were much more impaired after TLI and again no recovery occurred during the first year. In the clinic, the more profound immunosuppression in TLI patients was more frequently associated with viral infections (cytomegalovirus and herpes zoster). The incidence of rejections, however, was somewhat less frequent in the TLI-treated group and occurred significantly later. After TLI, the mean cumulative dose of steroids needed for kidney transplantation during the first year after transplantation could be substantially reduced

  12. 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

    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)

  13. IAEA International Database on Irradiated Nuclear Graphite Properties. Summary report of consultants' meeting. 12. meeting of the Technical Steering Committee

    The 12th Meeting of the Technical Steering Committee for the International Database on Irradiated Nuclear Graphite Properties was held on 12-13 November 2009 at the IAEA Headquarters, Vienna, Austria. All discussions, recommendations and actions of this Consultants' Meeting are recorded in this report. The purposes of the meeting were to review the matters and actions identified in the previous meeting, undertake a review of the current status of the database, and make recommendations for action over the next year. This report contains the status of the identified actions as well as a summary of the recommendations on enhancements to the database. (author)

  14. Anomalous Diffusion with Absorbing Boundary

    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...

  15. Measurement of absorbed doses in a homogeneous β rays fields with an extrapolation chamber

    The main characteristics of a variable cavity ionization chamber are described. Using the ionization current of the detector irradiated in homogeneous β rays fields, the tissue absorbed dose is determined. The corrective factors required to compute this quantity are analysed. Finally, international recommandations (ISO standards) relating to β rays reference fields are given, with the characteristics of β sources required for the energy response study of radiation protection instruments

  16. A study by internal friction of defects produced in iron and nickel irradiated at very low temperatures; Etude au moyen du frottement interne des defauts crees par irradiation a tres basse temperature dans le fer et le nickel

    Keating-Hart, G. de [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    This work represents a contribution to the study of point defects in metals. After a brief review of the theory of internal friction we will discuss some technical innovations aimed at increasing the flexibility of the apparatus at our disposal. These innovations have allowed us to extend our range of measurements down to 20 deg. K. We will then discuss our experimental results. Firstly, we describe preliminary experiments on electron irradiated iron and the evidence for a laminar structure. Secondly, we present and account of the first measurements on nickel after neutron irradiation at 27 deg. K. We will compare the results with those obtained by other methods in this laboratory. Essentially we have observed transitory peaks at low temperature due to close Frenkel pairs and we have noticed the absence of a peak which would correspond to the magnetic after effect band of stage I{sub E}. An attempt is made to explain the disappearance of the observed peaks upon the application of an internal saturating magnetic field. (author) [French] Ce memoire constitue une contribution a l'etude des defauts ponctuels dans les metaux. Apres un bref apercu theorique sur le frottement interne, nous presenterons quelques realisations techniques destinees a accroitre les possibilites des instruments qui nous ont ete confies. Ces dernieres nous ont permis d'etendre la gamme des mesures jusqu'a 20 deg. K. Nous parlerons ensuite de nos resultats experimentaux. En premier lieu, ceux obtenus au cours de premieres experiences, sur le fer irradie aux electrons mettent en evidence des structures de laminage. En second lieu, nous exposerons les premieres mesures realisees sur du nickel irradie aux neutrons; nous comparerons ces resultats avec ceux obtenus par d'autres moyens experimentaux dans le laboratoire. Nous avons observe essentiellement des pics fugitifs a basse temperature dus aux paires proches de Frenckel et nous avons constate l'absence d'un pic

  17. Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

    Kovalchuk, O.; Kovalchuk, I.; Hohn, B. [Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel (Switzerland); Arkhipov, A. [Chernobyl Scientific and Technical Center of International Research, Shkolnaya Str. 6, 255620 Chernobyl (Ukraine); Barylyak, I.; Karachov, I. [Ukrainian Scientific Genetics Center, Popudrenko Str. 50, 253660 Kiev (Ukraine); Titov, V. [Ivano-Frankivsk State Medical Academy, Galitska Str.2, 284000 Ivano-Frankivsk (Ukraine)

    2000-04-03

    different chemical composition, but equal radioactivity, exhibited different levels of HR, dependent upon the absorbed dose of radiation. Remarkably, we observed a much higher frequency of HR in plants exposed to chronic irradiation when compared to acutely irradiated plants. Although acute application of 0.1-0.5 Gy did not lead to an increase of frequency of HR, the chronic exposure of the plants to several orders of magnitude lower dose of 200 {mu}Gy led to a 5-6-fold induction of the frequency of HR as compared to the control.

  18. Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

    chemical composition, but equal radioactivity, exhibited different levels of HR, dependent upon the absorbed dose of radiation. Remarkably, we observed a much higher frequency of HR in plants exposed to chronic irradiation when compared to acutely irradiated plants. Although acute application of 0.1-0.5 Gy did not lead to an increase of frequency of HR, the chronic exposure of the plants to several orders of magnitude lower dose of 200 μGy led to a 5-6-fold induction of the frequency of HR as compared to the control

  19. Synthesis and characterization of super absorbent poly (acrylamide-co-potassium acrylate) hydrogels by radiation technique

    A series of super absorbent hydrogels were prepared from acrylamide (AAm) and potassium acrylate (KA) by gamma irradiation technique at room temperature. The solution containing potassium acrylate 15% and different concentrations of AAm (10-16%) were irradiated by gamma rays (20-40 kGy). The hydrogels produced by irradiation were characterized by fourier transform infra red spectroscopy (FT-IR). The gel fraction, kinetics of swelling and the equilibrium degree of swelling (EDS) were studied. Under irradiation dose of 20 kGy and concentration of AAM 10 %), poly(AAm-co-KA) hydrogel with high gel fraction (99.08%) and very high EDS (420 g/g) were obtained. The capacity of hydrogel to adsorb metal ion Cu2+and Fe3+were investigated. It is shown than 10 minutes the hydrogel could adsorb Cu2+ ion up to 95 %, and Fe3+ ion up to 55 % in 80 minutes. This hydrogel has a potential to be used for soil conditioning and ion metal absorbent. (author)

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

    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)

  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

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

    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. 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. 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 < 0.05), and to the number of interventions. In addition, we observed a significant inverse correlation (p = 0.037) between D90 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. 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

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

    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.

  4. A study by internal friction of defects produced in iron and nickel irradiated at very low temperatures

    This work represents a contribution to the study of point defects in metals. After a brief review of the theory of internal friction we will discuss some technical innovations aimed at increasing the flexibility of the apparatus at our disposal. These innovations have allowed us to extend our range of measurements down to 20 deg. K. We will then discuss our experimental results. Firstly, we describe preliminary experiments on electron irradiated iron and the evidence for a laminar structure. Secondly, we present and account of the first measurements on nickel after neutron irradiation at 27 deg. K. We will compare the results with those obtained by other methods in this laboratory. Essentially we have observed transitory peaks at low temperature due to close Frenkel pairs and we have noticed the absence of a peak which would correspond to the magnetic after effect band of stage IE. An attempt is made to explain the disappearance of the observed peaks upon the application of an internal saturating magnetic field. (author)

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

    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. Hypothalamus-hypophysical system of the rat females under conditions of the prolonged internal irradiation

    Arcuate and suprachiasmatic hypothalamus nuclei, median eminence and adenohypothysis in female rats under prolonged inner irradiation conditions were studied by the electron-microscopic method. Changes in secretory neurocytes accumulation of secretory granules and neural terminals of median eminence, intensive formation of thyrotropin and prolactin secretion with productive hypothysis cells have been discovered. Develapment mechanisms of remote sequences of the ionizing radiation effect on the genital system of female rats are discussed

  7. 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

    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

  8. Absorber materials in CANDU PHWRs

    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

  9. [Long-term results and cause of failure analysis in larynx cancer patients irradiated conventionally and with accelerated fractionation schedules in 1995-1998].

    Szutkowski, Zbigniew; Kawecki, Andrzej; Jarząbski, Andrzej

    2014-01-01

    The clinical material consists of 217 patients with squamous cell carcinoma in supraglottic and glottic larynx in clinical stage T1-3N0M0 irradiated radically in Warsaw Oncology Centre in 1995-1998. All patients were treated with Co-60, according to two schedules of fractionation, with maintenance of the consistent therapeutic protocol. The same team of doctors worked on the treatment of patients and on the follow-up as well. The clinical material is a part of a three-phased clinical trial KBN 0295. In the course of observation, the progression of cancer was not observed in 157 patients, among whom, 66% were treated conventionally and 79% with accelerated fractionation method. 60 cases of loco-regional recurrences were noted, among which 55 were regional. The majority of failure cases was observed until the 30(th) of the month after the radiotherapy ended. In conventional fractionation treatment, recurrences in T1 were 8/31 (26%), in T2 22/59 (37%) and in T3 8/20 (40%). In patients treated with AF, recurrences were T1 5/39 (13%), T2 15/55 (27%) and T3 2/13 (15%) respectively. The percentage of primary site tumour recurrences for each localization and kind of treatment was analysed. In CF 28/78 (37%) of glottic tumour recurrences and 10/34 (29%) of supraglottic tumour, recurrences were observed. In AF, 12/71 (17%) and 10/36 (28%) were observed respectively. In 48 cases salvage surgery was used, and 12 patients were not qualified because of tumour massive progression or because they refused to have a surgery. Among 34 cases (16%) of the second primary tumour or distant methastases, 25 were observed with glottic cancer, among which 23 were observed in early stages, and 9 cases with supraglottic cancer, among which, 6 showed early stage of tumour. In only 3 cases out of all the patients, distant methastases were confirmed in histopatology examination. The main cause of failure in larynx cancer patients in stage T1 is that 3N0M0 are local recurrences. Second primary or

  10. Derivation and application of equations describing the effects of fractionated protracted irradiation, based on multiple and incomplete repair processes. Pt. 2

    General equations for fractionated protracted irradiation have been applied to the analysis of mouse lung data derived from isoeffect protocols. The data were accrued from different radiation qualities, interfraction times and dose-rates. This analysis, based upon two component repair rate processes, suggests two repair-rate processes are involved in the repair of sublethal lung damage. The two repair half-lives were 0.32 and 1.92 with a low dose-rate partitioning of 1:0.38 between the amount of lethal damage resulting from rapid and slow sublethal damage repair processes at low dose-rates. The analysis also indicates a possible dose-rate amplification of the amount of resultant lethal damage, deriving from sublethal damage, associated with the longer repair process. It is also shown that the α/β ratio is probably independent of radiation quality and that the ratios of multiple to single event damage for 240kVp X-rays and 60Co are almost identical. (author)

  11. Influence of continuous low-dose irradiation of male sex cells in postmeiotic phase of gametogenesis on spermatogenesis in their offspring

    Chronic combined (internal and external) low doses irradiation (absorbed dose 0.15-1.4 cGy) does not influence spermatologic parameters in Wistar male rats and does not have genotoxic action. The offsprings, received from them, have the features of disturbance of gamete morphogenesis (teratospermia) and increased sensitivity to weak irradiation (with development of olygozoospermia)

  12. Understanding Trends Associated with Clouds in Irradiated Exoplanets

    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...

  13. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates

    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.

  14. FFTF absorber-pin performance verification test

    The FFTF (Fast Flux Test Facility) Absorber Pin Performance Verification Test - (HA006) is an irradiation test of neutron absorber pins with integral temperature and pressure monitoring instrumentation. The pins, containing boron carbide, are representative of the FFTF Row 3 Safety, Row 5 Control and Row 7 Fixed Shim Absorber Assemblies. In the 300 full power days (FPD) this test will reside in its 2610 Position in the reactor, it will generate test data that will be used to infer the effects of irradiation on the absorber assemblies it simulates. Design and fabrication of the test vehicle began in 1976 and the forty-foot test assembly was loaded in the FFTF on February 10, 1981. The test provided data in March 1981 during a series of natural circulation tests, and again in November 1981 during the eight-day full power run establishing base-line data

  15. 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

    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。

  16. Production and in vivo imaging of (203)Pb as a surrogate isotope for in vivo (212)Pb internal absorbed dose studies.

    Máthé, Domokos; Szigeti, Krisztián; Hegedűs, Nikolett; Horváth, Ildikó; Veres, Dániel S; Kovács, Béla; Szűcs, Zoltán

    2016-08-01

    (212)Pb is a clinically relevant therapeutic alpha emitter isotope. A surrogate, (203)Pb, if prepared with sufficiently high specific activity could be used to estimate (212)Pb in vivo absorbed doses. An improved production procedure of (203)Pb with a simple, new separation method and high specific radioactivity for imaging is reported. We determined the in-vivo biodistribution of (203)Pb in mice by SPECT/CT. This highlights application possibilities of (203)Pb for further in vivo and clinical uses (radiolabeled (212)Pb-peptide co-injection, dosimetry calculation). PMID:27156049

  17. Analysis of internal crack propagation in silicon due to permeable pulse laser irradiation: study on processing mechanism of stealth dicing

    Ohmura, Etsuji; Kawahito, Yuta; Fukumitsu, Kenshi; Okuma, Junji; Morita, Hideki

    2011-02-01

    Stealth dicing (SD) is an innovative dicing method developed by Hamamatsu Photonics K.K. In the SD method, a permeable nanosecond laser is focused inside a silicon wafer and scanned horizontally. A thermal shock wave propagates every pulse toward the side to which the laser is irradiated, then a high dislocation density layer is formed inside the wafer after the thermal shock wave propagation. In our previous study, it was concluded that an internal crack whose initiation is a dislocation is propagated when the thermal shock wave by the next pulse overlaps with this layer partially. In the experimental result, the trace that a crack is progressed gradually step by step was observed. In this study, the possibility of internal crack propagation by laser pulses was investigated. A two-dimensional thermal stress analysis based on the linear fracture mechanics was conducted using the stress distribution obtained by the axisymmetric thermal stress analysis. As a result, the validity of the hypothesis based on a heat transfer analysis result previously presented was supported. Also it was concluded that the internal crack is propagated by at least two pulses.

  18. Objectives and Activities of the International Facility for Food Irradiation Technology

    The general scope of this project is to conduct research and development, including pilot-scale studies in the field of food irradiation, aiming to achieve the commercialization of selected food items of interest to the region. The RPFI is one of the projects under the Regional Co-operative Agreement for Research Development and Training related to Nuclear Science and Technology (RCA). The Project Agreement of the RPFI already entered into force on 28 August 1980. At present (January 1981), the following Governments have already notified the Agency of their acceptance of, and have become parties to the Project Agreement as Participating Members: Bangladesh, Indonesia, Republic of Korea, Malaysia, Pakistan, Philippines, Sri Lanka, and Thailand. The Government of Japan has agreed to be a party to the RPFI as a Donor Government and to sponsor the Project for three years at a total cost of US $236 000, starting from the fiscal year 1980.

  19. Acoustic coherent perfect absorbers

    In this paper, we explore the possibility of achieving acoustic coherent perfect absorbers. Through numerical simulations in two dimensions, we demonstrate that the energy of coherent acoustic waves can be totally absorbed by a fluid absorber with specific complex mass density or bulk modulus. The robustness of such absorbing systems is investigated under small perturbations of the absorber parameters. We find that when the resonance order is the lowest and the size of the absorber is comparable to the wavelength in the background, the phenomenon of perfect absorption is most stable. When the wavelength inside both the background and the absorber is much larger than the size of the absorber, perfect absorption is possible when the mass density of the absorber approaches the negative value of the background mass density. Finally, we show that by using suitable dispersive acoustic metamaterials, broadband acoustic perfect absorption may be achieved. (papers)

  20. Measurement of ion species in high current ECR H+/D+ ion source for IFMIF (International Fusion Materials Irradiation Facility)

    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+) 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+) ratio reached 75% at the deuterium ion beam extraction of 100 keV/113 mA. It is found that the H+ 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+/D+ ratio estimated by the emittance monitor was more than 90% at those extraction currents