WorldWideScience

Sample records for irradiation dose level

  1. Studies on chronic effects of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, Y.S.; Yun, M.S.

    1980-01-01

    This experiment is being carried out to elucidate the chronic effects of Co 60 (γ-ray) - low doses irradiation on JCR mice at 3rd week, 6th week, and 5th month after their birth. Experimental mice at 3rd week of age have been irradiated with Co 60 - 60mR weekly, Co 60 - 500mR weekly and Co 60 - 61R biweekly at the dose rate of 60mR per second for 23 weeks until now. Co 60 - 61R irradiated mice were subdivided into Co 60 - alone group and Co 60 combined with red ginseng extracts group. In their survivor's rate and their body weight etc., no significant differences between control groups and test groups in these experimental mice. Experimented mice at 6 weeks and 5 months of age are also being irradiated with Co 60 in the same doses as the above for 14 weeks and 8 weeks until present. In these experimental groups, there are also no significant differences between control groups and experimental groups in their survivor's rate and their body weight

  2. Alternatives to dose, quality factor and dose equivalent for low level irradiation

    International Nuclear Information System (INIS)

    Sondhaus, C.A.; Bond, V.P.; Feinendegen, L.E.

    1988-01-01

    Randomly occurring energy deposition events produced by low levels of ionizing radiation interacting with tissue deliver variable amounts of energy to the sensitive target volumes within a small fraction of the cell population. A model is described in which an experimentally derived function relating event size to cell response probability operates mathematically on the microdosimetric event size distribution characterizing a given irradiation and thus determines the total fractional number of responding cells; this fraction measures the effectiveness of the given radiation. Normalizing to equal numbers of events produced by different radiations and applying this cell response or hit size effectiveness function (HSEF) should define radiation quality, or relative effectiveness, on a more nearly absolute basis than do the absorbed dose and dose evaluation, which are confounded when applied to low level irradiations. Examples using both calculation and experimental data are presented. 15 refs., 18 figs

  3. Effects of irradiation source and dose level on quality characteristics of processed meat products

    Science.gov (United States)

    Ham, Youn-Kyung; Kim, Hyun-Wook; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Choi, Yun-Sang; Song, Beom-Seok; Park, Jong-Heum; Kim, Cheon-Jei

    2017-01-01

    The effect of irradiation source (gamma-ray, electron-beam, and X-ray) and dose levels on the physicochemical, organoleptic and microbial properties of cooked beef patties and pork sausages was studied, during 10 days of storage at 30±1 °C. The processed meat products were irradiated at 0, 2.5, 5, 7.5, and 10 kGy by three different irradiation sources. The pH of cooked beef patties and pork sausages was unaffected by irradiation sources or their doses. The redness of beef patties linearly decreased with increasing dose level (Pchanges in overall acceptability were observed for pork sausages regardless of irradiation source (P>0.05), while gamma-ray irradiated beef patties showed significantly decreased overall acceptability in a dose-dependent manner (Poxidation of samples was accelerated by irradiation depending on irradiation sources and dose levels during storage at 30 °C. E-beam reduced total aerobic bacteria of beef patties more effectively, while gamma-ray considerably decreased microbes in pork sausages as irradiation dose increased. The results of this study indicate that quality attributes of meat products, in particular color, lipid oxidation, and microbial properties are significantly influenced by the irradiation sources.

  4. Studies on the chronic effect of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, E.S.; Chung, I.Y.; Yun, M.S.; Chae, H.S.; Lee, J.Y.

    1982-01-01

    This experiment was carried out to evaluate the chronic hazard of Co-60 low dose radiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages such as below were exposed to 60m rads/week, 500m rads/week and 60 rads/biweek whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period, from 1st week to 3rd week, from 3rd week to 52nd week, from 6th week to 52nd week, and from 22nd week to 52nd week after the birth. All experimental mice were autopsied immediately after being sacrificed at 52nd week. All major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

  5. Pre-1989 epidemiological surveys of low-level dose pre-conception irradiation

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1990-01-01

    Information from 59 pre-1989 epidemiological surveys concerning pre-conception irradiation at doses less than 0.1 Gy has been collated to determine whether any consistent patterns of health effects emerge. The surveys are considered in three groups: childhood malignancies, Down's syndrome and indicators of reproductive damage. Although a pattern is observed for Down's syndrome, no reliable associations are apparent for childhood malignancies (where all surveys pre-date the Gardner survey at Sellafield) or indications of reproductive damage. The twelve surveys of Down's syndrome in relation to maternal pre-conception irradiation received for medical reasons show a pattern consistent with a doubling dose of about 20 mGy. This doubling dose value is, however, not based on individual measurements of ovarian dose and is inconsistent with results from high-level dose surveys. There is no association between paternal irradiation and Down's syndrome. (author)

  6. The Contribution of Tissue Level Organization to Genomic Stability Following Low Dose/Low Dose Rate Gamma and Proton Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Cheryl G. Burrell, Ph.D.

    2012-05-14

    The formation of functional tissue units is necessary in maintaining homeostasis within living systems, with individual cells contributing to these functional units through their three-dimensional organization with integrin and adhesion proteins to form a complex extra-cellular matrix (ECM). This is of particular importance in those tissues susceptible to radiation-induced tumor formation, such as epithelial glands. The assembly of epithelial cells of the thyroid is critical to their normal receipt of, and response to, incoming signals. Traditional tissue culture and live animals present significant challenges to radiation exposure and continuous sampling, however, the production of bioreactor-engineered tissues aims to bridge this gap by improve capabilities in continuous sampling from the same functional tissue, thereby increasing the ability to extrapolate changes induced by radiation to animals and humans in vivo. Our study proposes that the level of tissue organization will affect the induction and persistence of low dose radiation-induced genomic instability. Rat thyroid cells, grown in vitro as 3D tissue analogs in bioreactors and as 2D flask grown cultures were exposed to acute low dose (1, 5, 10 and 200 cGy) gamma rays. To assess immediate (6 hours) and delayed (up to 30 days) responses post-irradiation, various biological endpoints were studied including cytogenetic analyses, apoptosis analysis and cell viability/cytotoxicity analyses. Data assessing caspase 3/7 activity levels show that, this activity varies with time post radiation and that, overall, 3D cultures display more genomic instability (as shown by the lower levels of apoptosis over time) when compared to the 2D cultures. Variation in cell viability levels were only observed at the intermediate and late time points post radiation. Extensive analysis of chromosomal aberrations will give further insight on the whether the level of tissue organization influences genomic instability patterns after

  7. Crystal growth in EPDM by chemi-crystallisation as a function of the neutron irradiation dose and flux level

    International Nuclear Information System (INIS)

    Lambri, O.A.; Salvatierra, L.M.; Sanchez, F.A.; Matteo, C.L.; Sorichetti, P.A.; Celauro, C.A.

    2005-01-01

    Neutron irradiation at room temperature were performed on EPDM (ethylene-propylene-diene monomer) in two different nuclear reactors at different fluxes. The effect of the irradiation on the chain arrangement in the polymer, as a function of the dose is discussed. Different crystal concentrations and crystal shapes, developed by chemi-crystallisation, are obtained depending on the neutron dose. In addition the radiation damage degree in the polymer depends both on the dose and the flux level. Dynamical mechanical analysis, swelling studies, X-ray diffraction, differential thermal analysis and infrared studies were employed as experimental techniques

  8. Irradiation dose of cosmonauts

    International Nuclear Information System (INIS)

    Makra, Zs.

    1978-01-01

    The results obtained by determining the irradiation dose during the spaceflights of Apollo as well as the Sojouz-3 and Sojouz-9 spacecrafts have been compared in the form of tables. In case of Apollo astronauts the irradiation dose was determined by two methods and its sources were also pointed out, in tables. During Sojouz spacetravels the cosmonauts were exposed to a negligible dose. In spite of this fact the radiation danger is considerable. The small irradiation doses noticed so far are due to the fact that during the spaceflights there was no big proturberance. However, during the future long-range spacetravels a better radiation shielding than the one used up to now will be necessary. (P.J.)

  9. Biogenic amines in brain areas of rats and response to varying dose levels of whole body gamma irradiation

    International Nuclear Information System (INIS)

    Abdelhamid, F.M.; Elmossalamy, N.; Othman, S.A.; Roushdy, H.M.; Abdelraheem, K.

    1994-01-01

    The levels of norepinephrine (NE), dopamine (DA), 5-hydroxy-tryptamine (5-HT) and 5-hydroxy-indole acetic acid (5-HIAA) were examined in the brain areas:cortex,: cerebellum, striatum and pons in rats exposed to whole body gamma-irradiation at the dose levels 6.5 and 10 Gy. The data obtained indicated that: 6.5 Gy induced in all brain areas, a slight increase in 5-HT concomitant with significant decrease in NE, DA levels, besides a significant increase in 5-HTAA in cerebellum and pons. After the dose 10 Gy the maximum excitation of 5-HT level was in striatum whereas declines in NE, DA were recorded in all brain areas. 5-HIAA displayed significant increase in cerebellum and pons and maximum decline in the cortex. 4 tab

  10. Dose Distribution of Gamma Irradiators

    International Nuclear Information System (INIS)

    Park, Seung Woo; Shin, Sang Hun; Son, Ki Hong; Lee, Chang Yeol; Kim, Kum Bae; Jung, Hai Jo; Ji, Young Hoon

    2010-01-01

    Gamma irradiator using Cs-137 have been widely utilized to the irradiation of cell, blood, and animal, and the dose measurement and education. The Gamma cell 3000 Elan (Nordion International, Kanata, Ontario, Canada) irradiator was installed in 2003 with Cs-137 and dose rate of 3.2 Gy/min. And the BioBeam 8000 (Gamma-Service Medical GmbH, Leipzig, Germany) irradiator was installed in 2008 with Cs-137 and dose rate of 3.5 Gy/min. Our purpose was to evaluate the practical dosimetric problems associated with inhomogeneous dose distribution within the irradiated volume in open air state using glass dosimeter and Gafchromic EBT film dosimeter for routine Gamma irradiator dosimetry applications at the KIRAMS and the measurements were compared with each other. In addition, an user guideline for useful utilization of the device based on practical dosimetry will be prepared. The measurement results of uniformity of delivered dose within the device showed variation more than 14% between middle point and the lowest position at central axis. Therefore, to maintain dose variation within 10%, the criteria of useful dose distribution, for research radiation effects, the irradiated specimen located at central axis of the container should be placed within 30 mm from top and bottom surface, respectively. In addition, for measurements using the film, the variations of dose distribution were more then 50% for the case of less than 10 second irradiation, mostly within 20% for the case of more than 20 second irradiation, respectively. Therefore, the irradiation experiments using the BioBeam 8000 irradiator are recommended to be used for specimen required at least more than 20 second irradiation time.

  11. The influence of low dose irradiation on intracellular pH level, synthesizing activity and ATP level in cultured chinese fibroblasts

    International Nuclear Information System (INIS)

    Parkhomenko, I.M.; Perishvili, G.V.; Turovetskij, V.B.; Kudryashov, Yu.B.; Rubin, A.B.; Brovko, L.Yu.

    1993-01-01

    X-irradiation of Chinese fibroblasts with doses of 0.05-0.15 Gy was shown to cause intracellular pH (pH i ) changes: its diminishing during the first 40-60 min by 0.16-0.18 pH units, then the return to the control level 120 min after irradiation and, finally, the increase by 0.18-0.20 pH units. Simultaneously, the synthesizing activity of the cells changed in the same way. The ATP level changed in the opposite way: increased when pH fell and decreased when pH grew. It was shown that pH i changes were connected with the changes in Na + /H + -exchange system, and they seemed to be primary in the chain of the alterations observed

  12. Effect of gamma irradiation treatment at phytosanitary dose levels on the quality of ‘Lane Late’ navel oranges

    Science.gov (United States)

    The objectives of this study were to determine the dose tolerance of ‘Lane Late’ navel oranges (Citrus sinensis L. Osbeck) to irradiation for phytosanitary purposes, identify the sensory attributes that may be affected by the treatment, and determine which changes, if any, influence consumer liking....

  13. Low dose irradiation facilitates hepatocellular carcinoma genesis involving HULC.

    Science.gov (United States)

    Li, Yuan; Ge, Chang; Feng, Guoxing; Xiao, Huiwen; Dong, Jiali; Zhu, Changchun; Jiang, Mian; Cui, Ming; Fan, Saijun

    2018-03-24

    Irradiation exposure positive correlates with tumor formation, such as breast cancer and lung cancer. However, whether low dose irradiation induces hepatocarcinogenesis and the underlying mechanism remain poorly defined. In the present study, we reported that low dose irradiation facilitated the proliferation of hepatocyte through up-regulating HULC in vitro and in vivo. Low dose irradiation exposure elevated HULC expression level in hepatocyte. Deletion of heightened HULC erased the cells growth accelerated following low dose irradiation exposure. CDKN1, the neighbor gene of HULC, was down-regulated by overexpression of HULC following low dose irradiation exposure via complementary base pairing, resulting in promoting cell cycle process. Thus, our findings provide new insights into the mechanism of low dose irradiation-induced hepatocarcinogenesis through HULC/CDKN1 signaling, and shed light on the potential risk of low dose irradiation for the development of hepatocellular carcinoma in pre-clinical settings. © 2018 Wiley Periodicals, Inc.

  14. Dose mapping role in gamma irradiation industry

    International Nuclear Information System (INIS)

    Noriah Mod Ali; John Konsoh Sangau; Mazni Abd Latif

    2002-01-01

    In this studies, the role of dosimetry activity in gamma irradiator was discussed. Dose distribution in the irradiator, which is a main needs in irradiator or chamber commissioning. This distribution data were used to confirm the dosimetry parameters i.e. exposure time, maximum and minimum dose map/points, and dose distribution - in which were used as guidelines for optimum product irradiation. (Author)

  15. Changing of expression level of fas-antigen (CD95), cytokines synthesis and production after irradiation in low doses

    International Nuclear Information System (INIS)

    Kalinina, N.M.; Solntceva, O.S.; Bytchkova, N.V.; Nikiforov, A.M.

    1997-01-01

    It is known that bone marrow progenitor (CD34+), tymocytes and peripheral blood lymphocytes (PBL) are most radiosensitive than other cell types. Even low doses of radiation induce apoptosis. The investigators suggest that it is possible relationship between synthesis and production of cytokines and apoptotic process. With the purpose to determine correlation between expression of Fas-antigen and synthesis of cytokines after low doses irradiation the experiments by irradiation PBL of healthy persons in vitro were held. Cells were X-irradiated by 12,5, 25 and 50 cGy. In consequence of the experiments increasing of Fas-antigen was revealed. This increasing correlated with changing in synthesis and production of cytokines. Also the Chernobyl's accident liquidators (CAL) were investigated. After comparison data in the group CAL (I) with data in the control group (II) increasing of Fas-antigen expression was revealed. Also in I group was discovered increasing of the cell number sinthesied interleukine-4 (IL-4) and interleukine-6 (IL-6). Interleukine-lβ (IL-1 β) producing pell were decreased. These changes have been correlated with degree of immunodeficiency at CAL. These data allow to consider the apoptosis as cell mechanism included in pathogenesis of diseases, which can be showed later long time after irradiation. (author)

  16. Evaluation of the effect of radiation levels and dose rates in irradiation of murine fibroblasts used as a feeder layer in the culture of human keratinocytes

    International Nuclear Information System (INIS)

    Yoshito, Daniele; Almeida, Tiago L.; Santin, Stefany Plumeri; Somessari, Elizabeth S.R.; Silveira, Carlos G. da; Mathor, Monica B.; Altran, Silvana C.; Isaac, Cesar

    2009-01-01

    In 1975, Rheinwald and Green published an effective methodology for obtaining and cultivating human keratinocytes. This methodology consisted of seeding keratinocytes onto a feeder layer composed of lineage 3T3 murine fibroblasts, the proliferation rate of which is then controlled through the action of ionizing radiation. The presence of the feeder layer encourages the development of keratinocyte colonies and their propagation in similar cultures, becoming possible several clinical applications as skin substitutes or wound dressings in situations such as post burn extensive skin loss and other skin disorders. However, good development of these keratinocytes depends on a high quality feeder layer among other factors. In the present work, we evaluated the relationship between radiation levels and dose rates applied to fibroblasts used in construction of feeder layers and the radiation effect on keratinocytes colonies forming efficiency. Results indicate 3T3 lineage murine fibroblasts irradiated with doses varying between 60 and 100 Gy can be used as a feeder layer immediately after irradiation or storage of the irradiated cells in suspension at 4 g C for 24 hours with similar results. The exception is when the irradiation dose rate is 2.75 Gyh -1 ; in this case, results suggested that the fibroblasts should be used immediately after irradiation. (author)

  17. Early changes in GABA and dlutamine levels and aminotransferase activity in rat brain after total-body γ-irradiation with absolutely lethal doses

    International Nuclear Information System (INIS)

    Rozanov, V.A.; Karpovich, G.A.

    1985-01-01

    The contents of gaama-aminobutyric acid (GABA) and glutamate (GL) as well as GABA-aspartate- and alanine aminotransferase activities were measured in rat cerebellum, cerebral cortex and truncus cerebri 1, 3, 6, 24 and 48 hr following total-body γ-irradiation ( 60 Co) with a dose of 30 Gy. All the indices under study changed in a similar way in the cortex and truncus cerebri while in the cerebellum, GABA level increased and GABA-α-ketoglutarate aminotransfearse activity decreased 60 min after irradiation. The levels of GABA and GL in the cortex and truncus cerebri decreased immediately and increased 24 hr after irradiation. Activity of aminotransferases changed in a phase manner: changes in aspartate- and alanine aminotransferase activity were more pronounced than those of GABA-α-ketoglutarate aminotransferase activity and correlated with the glutamate level changes

  18. Level of coenzyme A and the activity of certain dehydrogenases under chronic low dose X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Cherkasova, L A; Novik, V A; Tsychun, G F [AN Belorusskoj SSR, Minsk. Inst. Fiziologii

    1975-01-01

    A study was made of the effect of long-term x ray irradiation (cumulative dose 50 R) on: the content of co-enzyme A (KoA) in the brain and liver, the activity of a number of oxydizing reducing enzymes in the brain mitochondria and heart muscle, and the blood glucocorticoid content. It was established that the metabolism of brain and liver KoA is quite stable, the enzymes of the brain tricarbonic acids and pyruvate-dehydrogenase cycle are labile.

  19. Effect of dose rate on residual γ-H2AX levels and frequency of micronuclei in X-irradiated mouse lymphocytes.

    Science.gov (United States)

    Turner, H C; Shuryak, I; Taveras, M; Bertucci, A; Perrier, J R; Chen, C; Elliston, C D; Johnson, G W; Smilenov, L B; Amundson, S A; Brenner, D J

    2015-03-01

    The biological risks associated with low-dose-rate (LDR) radiation exposures are not yet well defined. To assess the risk related to DNA damage, we compared the yields of two established biodosimetry end points, γ-H2AX and micronuclei (MNi), in peripheral mouse blood lymphocytes after prolonged in vivo exposure to LDR X rays (0.31 cGy/min) vs. acute high-dose-rate (HDR) exposure (1.03 Gy/min). C57BL/6 mice were total-body irradiated with 320 kVP X rays with doses of 0, 1.1, 2.2 and 4.45 Gy. Residual levels of total γ-H2AX fluorescence in lymphocytes isolated 24 h after the start of irradiation were assessed using indirect immunofluorescence methods. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used to determine apoptotic cell frequency in lymphocytes sampled at 24 h. Curve fitting analysis suggested that the dose response for γ-H2AX yields after acute exposures could be described by a linear dependence. In contrast, a linear-quadratic dose-response shape was more appropriate for LDR exposure (perhaps reflecting differences in repair time after different LDR doses). Dose-rate sparing effects (P effect across the dose range 24 h or 7 days post exposure. In conclusion, the γ-H2AX biomarker showed higher sensitivity to measure dose-rate effects after low-dose LDR X rays compared to MNi formation; however, confounding factors such as variable repair times post exposure, increased cell killing and cell cycle block likely contributed to the yields of MNi with accumulating doses of ionizing radiation.

  20. Low dose irradiation and biological defense mechanisms

    International Nuclear Information System (INIS)

    Sugahara, Tsutomu; Sagan, L.A.; Aoyama, Takashi

    1992-01-01

    It has been generally accepted in the context of radiation protection that ionizing radiation has some adverse effect even at low doses. However, epidemiological studies of human populations cannot definitively show its existence or absence. Furthermore, recent studies of populations living in areas of different background radiation levels reported some decrease in adverse health effects at high background levels. Genetic studies of atomic bomb survivors failed to produce statistically significant findings on the mutagenic effects of ionizing radiation. A British study however, suggests that a father's exposure to low dose radiation on the job may increase his children's risk of leukemia. On the other hand, many experimental studies have raised the possibility that low doses of ionizing radiation may not be harmful or may even produce stimulating or adaptive responses. The term 'hormesis' has come to be used to describe these phenomena produced by low doses of ionizing radiation when they were beneficial for the organisms studied. At the end of the International Conference on Low Dose Irradiation one conclusion appeared to be justified: radiation produces an adaptive response, though it is not universally detected yet. The conference failed to obtain any consensus on risk assessment at low doses, but raised many problems to be dealt with by future studies. The editors therefore believe that the Proceedings will be useful for all scientists and people concerned with radiation protection and the biological effects of low-dose irradiation

  1. Daily low-dose/continuous capecitabine combined with neo-adjuvant irradiation reduces VEGF and PDGF-BB levels in rectal carcinoma patients

    International Nuclear Information System (INIS)

    Loven, David; B e'Ery, Einat; Yerushalmi, Rinat; Koren, Claude; Sulkes, Aaron; Fenig, Eyal; Lavi, Idit; Shaked, Yuval

    2008-01-01

    Metronomic low-dose chemotherapy regimen was found to have an antiangiogenic effect in tumors. However, its effect on levels of circulating pro-angiogenic and anti-angiogenic factors is not fully explored. Materials and methods. The levels of both VEGF and PDGF-BB were measured in three time points, in the serum of 32 rectal carcinoma patients receiving daily reduced-dose/continuous capecitabine in combination with preoperative pelvic irradiation. Results. We found a significant decrease in VEGF and PDGF-BB serum levels during the combination treatment (p<0.0001), followed by an increase in the successive rest-period (p<0.0001). In addition, substantial changes in platelets counts were observed during treatment in correlation with the changes of VEGF and PDGF-BB serum levels. Discussion. These results suggest that combined chemo-irradiation affect levels of pro-angiogenic factors during treatment, and may reflect an anti-angiogenic window induced during this treatment. The potential implications of this inducible phenomenon, including a possible clinical benefit from the administration of long lasting metronomic chemotherapy immediately following combined chemo-irradiation, would warrant further investigation

  2. Dose distribution of non-coplanar irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Toshiharu; Wada, Yoichi; Takenaka, Eiichi

    1987-02-01

    Non-coplanar irradiations were applied to the treatment of brain tumor. The dose distribution around the target area due to non-coplanar irradiation was half less than the dose when coplanar irradiation used. Integral volume dose due to this irradiation was not always less than that due to conventional opposing or rotational irradiation. This irradiation has the better application to the following;as a boost therapy, glioblastoma multiforme;as a radical therapy, recurrent brain tumor, well differentiated brain tumor such as craniopharyngioma, hypophyseal tumor etc and AV-malformation.

  3. Modifying effect of low dose irradiation

    International Nuclear Information System (INIS)

    Kalendo, G.S.

    1989-01-01

    It is shown that irradiation of Hela cells with stimulating doses of 0,1 Gy changes the cells' response to the subsequent radiation effect of greater value: instead of DNA synthesis inhibition stimulation takes place. Modifying effect of preliminary irradiation with 0,1 Gy manifests it self only in case if there is a certain time interval not less than 3 minutes and not more than 10 minutes (3-5 minutes is optimal interval). Data on modifying effect with 0,1 Gy at subcellular and cellular-population levels are presented. 21 refs.; 6 figs

  4. Insignificant levels of dose

    International Nuclear Information System (INIS)

    Webb, G.A.M.; McLean, A.S.

    1977-01-01

    The procedures recommended by the International Commission on Radiological Protection (ICRP) for making decisions concerning controllable sources of radiation exposure of the public include 'justification' and 'optimisation'. The tool recommended by the ICRP for reaching these decisions is collective dose or dose commitment supplemented by consideration of doses to individuals. In both these considerations the practical problem arises of whether very small doses to large numbers of people should contribute to the final decision-making process. It may be that at levels of dose which are small increments on natural background, the relationship between dose and effect is linear even though the slope may be close to zero. If so, collective dose is a meaningful concept and the calculation of total detriment for the purpose of justification could legitimately include all doses. In the calculation of collective doses for the purpose of optimisation, which involves decisions on how much money or resource should be allocated to dose reduction, it is necessary to appraise radiation detriment realistically. At low levels of dose to the individual such as those small by comparison with variations in natural background within the UK, the risk to the individual is such that his well-being will not be significantly changed by the presence or absence of the radiation dose. These small doses, which are well below the point at which an individual attaches significance, should not carry a societal significance. Societal acceptance of risk is analysed with a view to assessing a level of possible risk, and hence dose, below which resources should not in general be diverted to secure further reduction. A formulation for collective dose commitment is proposed incorporating a cut-off to exclude insignificant doses. The implications of this formulation in practical situations are discussed

  5. Effects of sub-lethal dose of gamma-irradiation on levels of acid phosphatase in cerebellum of pigeons

    International Nuclear Information System (INIS)

    Shah, V.C.; Gadhia, P.K.

    1980-01-01

    The changes in the activities of acid phosphatase in the sham-irradiated and γ-irradiated cerebellum of pigeons have been studied both biochemically as well as histochemically after 400 rads. The specific activity of acid phosphatase decreased significantly after 48h and 72h of irradiation. The histochemical observations following total body irradiation confirmed the results obtained by quantitative biochemical studies. (author)

  6. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. Vol. A: pre-conception irradiation effects. Vol. E (DRAFT A): group collation tables

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1988-01-01

    In this report, the health effects of low-level doses of radiation are considered by reference to published epidemiological surveys. The work was carried out with three objectives in mind: 1. to provide a comprehensive and critical review of the subject; 2. to seek consistent indications of particular health effects by collating results and comparing with those from surveys at moderate-level doses; 3. to provide an authoritative view on the epidemiology of low-level radiation-induced health effects. Vol E (DRAFT A) is appended and contains group collation tables. Epidemiological surveys can be conveniently divided into four classes (A, B, C, D) according to the phase of life when irradiation occurs or the effect is diagnosed. The first of the classes (A) is addressed here; this class is concerned with possible effects arising from radiation received by a parent before conception. Possible effects of preconception irradiation were identified under four broad groupings. These are Down's syndrome, ''Indicators of Reproductive Damage'' (mainly Primary Sterility, Congenital Abnormalities, Sex Ratio, Fetal Mortality, Infant Mortality), Childhood Malignancies, and Chromosomal Changes in Abortuses. Information about each survey, and comparisons with results from moderate-level dose surveys, are contained in synopses that are set out in the Appendix.

  7. Low dose irradiation reduces cancer mortality rates

    International Nuclear Information System (INIS)

    Luckey, T.D.

    2000-01-01

    Low doses of ionizing radiation stimulate development, growth, memory, sensual acuity, fecundity, and immunity (Luckey, T.D., ''Radiation Hormesis'', CRC Press, 1991). Increased immune competence reduces cancer mortality rates and provides increased average lifespan in animals. Decreased cancer mortality rates in atom bomb victims who received low dose irradiation makes it desirable to examine populations exposed to low dose irradiation. Studies with over 300,000 workers and 7 million person-years provide a valid comparison of radiation exposed and control unclear workers (Luckey, T.D., Nurture with Ionizing Radiation, Nutrition and Cancer, 34:1-11, 1999). Careful selection of controls eliminated any ''healthy worker effect''. The person-year corrected average indicated the cancer mortality rate of exposed workers was only 51% that of control workers. Lung cancer mortality rates showed a highly significant negative correlation with radon concentrations in 272,000 U.S. homes (Cohen, B.L., Health Physics 68:157-174, 1995). In contrast, radon concentrations showed no effect on lung cancer rates in miners from different countries (Lubin, J.H. Am. J. Epidemiology 140:323-332, 1994). This provides evidence that excessive lung cancer in miners is caused by particulates (the major factor) or toxic gases. The relative risk for cancer mortality was 3.7% in 10,000 Taiwanese exposed to low level of radiation from 60 Co in their steel supported homes (Luan, Y.C. et al., Am. Nuclear Soc. Trans. Boston, 1999). This remarkable finding needs further study. A major mechanism for reduced cancer mortality rates is increased immune competence; this includes both cell and humoral components. Low dose irradiation increases circulating lymphocytes. Macrophage and ''natural killer'' cells can destroy altered (cancer) cells before the mass becomes too large. Low dose irradiation also kills suppressor T-cells; this allows helper T-cells to activate killer cells and antibody producing cells

  8. High-dose irradiation of food

    International Nuclear Information System (INIS)

    Diehl, J.F.

    1999-01-01

    Studies performed on behalf of the International Project on Food Irradiation in the period from 1971 until 1980 resulted in the concluding statement that ''.the irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard; hence, toxicological testing of foods so treated is no longer required.'' Since then, licenses for food irradiation have been restricted to this maximum dose in any country applying this technology. Further testing programmes have been carried out investigating the wholesomeness or hazards of high-dose irradiation, but there has been little demand so far by the food industry for licensing of high-dose irradiation, as there is only a small range of products whose irradiation at higher doses offers advantages for given, intended use. These include eg. spices, dried herbs, meat products in flexible pouch packagings for astronauts, or patients with immune deficiencies. (orig./CB) [de

  9. Dose rate effect in food irradiation

    International Nuclear Information System (INIS)

    Singh, H.

    1991-08-01

    It has been suggested that the minor losses of nutrients associated with radiation processing may be further reduced by irradiating foods at the high dose rates generally associated with electron beams from accelerators, rather than at the low dose rates typical of gamma irradiation (e.g. 60 Co). This review briefly examines available comparative data on gamma and electron irradiation of foods to evaluate these suggestions. (137 refs., 27 tabs., 11 figs.)

  10. Dose distributions in electron irradiated plastic tubing

    International Nuclear Information System (INIS)

    Miller, A.; Pederson, W.B.

    1981-01-01

    Plastic tubes have been crosslinked by irradiation at a 10 MeV linear electron accelerator and at a 400 keV DC electron accelerator at different irradiation geometries. The diameter of the different tubes was 20, 33 and 110 millimeters. Dose distributions have been measured with thin radiochromic dye films, indicating that in all cases irradiation from two sides is a necessary and sufficient condition for obtaining a satisfactory dose distribution. (author)

  11. Protein aggregation in aqueous casein solution. Effect of irradiation, dose level, concentration, storage and additives (carbohydrate and lipid)

    Energy Technology Data Exchange (ETDEWEB)

    Yousri, R M

    1980-06-01

    From the vast amount of research efforts dealing with various aspects of radiation effects on foods and food components, it is apparent up to now that much remains to be studied in depth, much may have to be added or corrected about radiation-induced physico-chemical changes in foods. A great many reactions that take place when foodstuffs are subjected to ionizing radiation are still not fully understood. The better understanding of some of the radiation-induced changes in pure proteins as such or in mixture with other food constituents could yield much data which could be meaningfully extrapolated to intact foods and consequently could help to improve the assessment of the wholesomeness of irradiated foods. It was the purpose of our investigations to elucidate some of the changes in the chemical structure of a pure protein (casein), irradiated as such or with added carbohydrate and/or lipid. The effect of subsequent storage of the irradiated solutions has been also examined. The formation of protein aggregates was studied by gel filtration technique. The application of thin-layer gel filtration, its speed and adaptability to very small samples facilitated the measurements of the extent of aggregation which occurred in protein molecules after irradiation.

  12. Dose uniformity estimations in the blood irradiator

    International Nuclear Information System (INIS)

    George, J.R.

    2002-01-01

    Use of irradiated blood in transfusions is recognized as the most effective way of preventing Graft Versus Host Disease (GVHD). This paper shows the study carried out in the dose rate variation for various source arrangements for optimising the source-sample chamber geometry, during the development of the Blood Irradiator, Bl-2000

  13. Stimulation of seeds by low dose irradiation

    International Nuclear Information System (INIS)

    Lawson, Helen

    1976-05-01

    The first section of the bibliography lists materials on the stimulation of seeds by low dose irradiation, with particular reference to stimulation of germination and yield. The second section contains a small number of selected references on seed irradiation facilities. (author)

  14. Dose mapping in category I irradiators

    International Nuclear Information System (INIS)

    Mondal, Sandip; Shinde, S.H.; Mhatre, S.G.V.

    2012-01-01

    Category I irradiators such as Gamma Chambers and Blood Irradiators are compact self shielded, dry source storage gamma irradiators offering irradiation volume of few hundred cubic centimeters. In the present work, dose distribution profiles along the central vertical plane of the irradiation volume of Gamma Chamber 900 and Blood Irradiator 2000 were measured using Fricke, FBX, and alanine dosimeters. Measured dose distribution profiles in Gamma Chamber 900 differed from the typical generic dose distribution pattern whereas that in Blood Irradiator 2000 was in agreement with the typical pattern. All reagents used were of analytical reagent grade and were used without further purification. Preparation and dose estimations of Fricke and FBX were carried out as recommended. Alanine pellets were directly placed in precleaned polystyrene container having dimensions 6.5 mm o.d., 32 mm height and 3 mm wall thickness. For these dosimeters, dose measurements were made using e-scan Bruker BioSpin alanine dedicated ESR spectrometer. Specially designed perspex jigs were used during irradiation in Gamma Chamber 900 and Blood Irradiator 2000. These jigs provided the reproducible geometry during irradiation, Absorbance measurements were made using a spectrophotometer calibrated as per the recommended procedure. In Gamma Chamber 900, there is a dose distribution variation of about 34% from top to the center, 18% from center to the bottom, and 15% from center to the periphery. Such a dose distribution profile is largely deviating from the typical profile wherein 15% variation is observed from center to the periphery on all sides. Further investigation showed that there was a nonalignment in the source and sample chamber. However, in Blood Irradiator 2000, there is a dose distribution variation of about 20% from top to the center, 15% from center to the bottom, and 12% from center to the periphery. This pattern is very much similar to the typical profile. Hence it is recommended

  15. Intracranial meningiomas after high-dose irradiation

    International Nuclear Information System (INIS)

    Soffer, D.; Gomori, J.M.; Siegal, T.; Shalit, M.N.

    1989-01-01

    Three patients who presented with intracranial meningiomas 12, 15, and 20 years, respectively, after therapeutic high-dose irradiation of a primary brain tumor are described. Analysis of these cases and similar documented cases suggests that meningiomas after high-dose irradiation constitute a recognizable entity. Patients with such tumors received radiation therapy at a young age (mean age, 9.4 years). After a latent period of 2 to 47 years (mean, 19.8 years) they developed meningiomas at the site of irradiation, at a much younger age than patients with ''spontaneous'' meningiomas. Similar to the situation with meningiomas after low-dose irradiation, a relatively high proportion of meningiomas induced by high-dose irradiation tend to be malignant and biologically aggressive. A very young age at the time of irradiation seems to predispose to the induction of malignant meningiomas, rather than benign tumors. These unusual features provide indirect evidence that high-dose radiation may play a role in the pathogenesis of meningiomas.41 references

  16. Adaptive response after low level irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pelevina, I I; Afanasjev, G G; JaGotlib, V; Tereschenko, D G; Tronov, V A; Serebrjany, A M [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Chemical Physics

    1996-02-01

    The experiments conducted on cultured HeLa (tissue culture) cells revealed that there is a limit of dose above which adaptive response was not observed and a limit of dose below which this response was not induced. The exposure of cells in the territories with elevated radiation background leads to genome instability which results in enhanced radiosensitivity. Investigations on the blood lymphocytes of people living in contaminated regions revealed that adaptive response was more significant in children whereas in adults there was slight increase. Acute irradiation serves as a tool revealing the changes that took place in DNA during chronic low level irradiations after Chernobyl disaster. (author).

  17. Immune reactivity after high-dose irradiation

    International Nuclear Information System (INIS)

    Gassmann, W.; Wottge, H.U.; von Kolzynski, M.; Mueller-Ruchholtz, W.

    1986-01-01

    Immune reactivity after total-body irradiation was investigated in rats using skin graft rejection as the indicator system. After sublethal irradiation with 10.5 Gy (approximately 50% lethality/6 weeks) the rejection of major histocompatibility complex allogeneic skin grafts was delayed significantly compared with nonirradiated control animals (28 versus 6.5 days). In contrast, skin grafts were rejected after 7.5 days in sublethally irradiated animals and 7 days in lethally irradiated animals if additional skin donor type alloantigens--namely, irradiated bone marrow cells--were given i.v. either simultaneously or with a delay of not more than 24 hr after the above conditioning regimen. These reactions were alloantigen-specific. They were observed in six different strain combinations with varying donors and recipients. Starting on day 2 after irradiation, i.v. injection of bone marrow gradually lost its effectivity and skin grafts were no longer rejected with uniform rapidity; skin donor marrow given on days 4 or 8 did not accelerate skin graft rejection at all. These data show that for approximately 1-2 days after high-dose total-body irradiation rats are still capable of starting a vigorous immune reaction against i.v.-injected alloantigens. The phenomenon of impaired rejection of skin grafted immediately after high-dose irradiation appears to result from the poor accessibility of skin graft alloantigens during the early postirradiation phase when vascularization of the grafted skin is insufficient

  18. Panoramic irradiator dose mapping with pin photodiodes

    International Nuclear Information System (INIS)

    Ferreira, Danilo Cardenuto; Napolitano, Celia Marina; Bueno, Carmen Cecilia

    2011-01-01

    In this work we study the possibility of using commercial silicon PIN photodiodes (Siemens, SFH 00206) for dose mapping in the Panoramic Irradiator facility at IPEN-CNEN/SP. The chosen photodiode, that is encased in 1.2 mm thickness polymer layer, displays promising dosimetric characteristics such as small size (sensitive area of 7.00 mm 2 ), high sensitivity and low dark current (≅ 300 pA, at 0 V) together with low-cost and wide availability. The Panoramic facility is an irradiator Type II with absorbed dose certificated by International Dose Assurance Service (IDAS) offered by the International Agency Energy Atomic (IAEA). The charge registered by the diode as a function of the absorbed dose was in excellent agreement with that one calibrated by IDAS. Besides this, the easy handling and fast response of the SFH00206 diode compared to Fricke chemical dosimeters encouraged us to perform dose mapping around the source. (author)

  19. X-raying with low dose irradiation

    International Nuclear Information System (INIS)

    Malevich, E.E.; Kisel, E.M.; Shpita, I.D.; Lazovsky, A.S.

    2001-01-01

    with higher frequency of a pulsation the share of unproductive radiation is higher. At x-raying controlled by the grid pulses are generated by the x-ray tube with the grid control. The grid, located between the cathode and the anode, passes the electron cloud without the expenses of time for dispersal and attenuation. It gives sharply outlined, rectangular x-ray pulses with homogeneous quality of radiation. Function GC F -x-raying controlled by the grid - enables to receive precisely outlined contours of moving objects: a heart, a gullet, - and also to carry out examination of the children without information loss during simultaneous dose decrease. Besides the image remains precise even during the movement of the electron-optical converter. Owing to radiation parameters adjustment during the examination the effect of the lighted image is eliminated. X-raying devices Easy Diagnose and Diagnose-76 'Philips' are equipped with the system of digital x-ray image processing besides they are completed with the x-ray tube with Grid Controlled Fluoroscopy that allows to carry out pulse x-raying with number of pulses 2, 3, 6 and 12 per a second. So, with 12 pulses per second the irradiation dose in comparison with continuous radiation decreases on 40%. The examinations of a chest, gullet, stomach and thick gut were carried out at the frequency of 12 and 6 pulses per second. In the hospital of the Ministry of Internal Affairs where device Easy Diagnose is established, at examinations of a gastro enteric path (stomach x-raying, irrigoscopy) usually pulse x-raying is used with frequency 12 pulses per second. It allows significantly reduce the beam load on a patient. The calculation of beam loads on a patient was carried out on the basis of exposition dose level at the beam input in the body of a patient (entrance dose). The way is applied for especially exact calculations, as definitions of effective doses on separate organs and all body are difficult. The irradiation dose is in

  20. Biological changes in experimental animals after irradiation with sublethal doses

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dae Seong; Park, Yong Dae; Jin, Chang Hyun; Byun, Myung Woo; Jeong, Il Yun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2008-05-15

    The objective of the present study was to investigate general clinical aspects such as weekly body weight and blood changes, and weekly food intake in gamma-irradiated C57BL/6j male mice fed AIN-76A purified rodent diet for 14 weeks. The mice were whole-body irradiated with 0, 2, 4 and 6 Gy of gamma-rays (Gammacell 40 Exactor, {sup 137}Cs, MDS Nordion) at a dose rate of 1.8 {sub c}Gy per second. The mean body weight change of 6 Gy-irradiated mice significantly decreased when compared to that of the non-irradiated control mice. Moreover, high dose of radiation resulted in decreased levels of AST, ALT, but in increased levels of total cholersterol, triglyceride, HDL-C in mice.

  1. low dose irradiation growth in zirconium

    International Nuclear Information System (INIS)

    Fortis, A.M.

    1987-01-01

    Low dose neutron irradiation growth in textured and recrystallized zirconium, is studied, at the Candu Reactors Calandria temperature (340 K) and at 77 K. It was necessary to design and build 1: A facility to irradiate at high temperatures, which was installed in the Argentine Atomic Energy Commission's RA1 Reactor; 2: Devices to carry out thermal recoveries, and 3: Devices for 'in situ' measurements of dimensional changes. The first growth kinetics curves were obtained at 365 K and at 77 K in a cryostat under neutron fluxes of similar spectra. Irradiation growth experiments were made in zirconium doped with fissionable material (0,1 at % 235 U). In this way an equivalent dose two orders of magnitude greater than the reactor's fast neutrons dose was obtained, significantly reducing the irradiation time. The specimens used were bimetallic couples, thus obtaining a great accuracy in the measurements. The results allow to determine that the dislocation loops are the main cause of irradiation growth in recrystallized zirconium. Furthermore, it is shown the importance of 'in situ' measurements as a way to avoid the effect that temperature changes have in the final growth measurement; since they can modify the residual stresses and the overconcentrations of defects. (M.E.L.) [es

  2. The irradiation tolerance dose of the proximal vagina

    International Nuclear Information System (INIS)

    Au, Samuel P.; Grigsby, Perry W.

    2003-01-01

    Purpose: The purpose of this investigation was to determine the irradiation tolerance level and complication rates of the proximal vagina to combined external irradiation and low dose rate (LDR) brachytherapy. Also, the mucosal tolerance for fractionated high dose rate (HDR) brachytherapy is further projected based on the biological equivalent dose (BED) of LDR for an acceptable complication rate. Materials and methods: Two hundred seventy-four patients with stages I-IV cervical carcinoma treated with irradiation therapy alone from 1987 to 1997 were retrospectively reviewed for radiation-associated late sequelae of the proximal vagina. All patients received LDR brachytherapy and 95% also received external pelvic irradiation. Follow-up ranged from 15 to 126 months (median, 43 months). The proximal vagina mucosa dose from a single ovoid (single source) or from both ovoids plus the tandem (all sources), together with the external irradiation dose, were used to derive the probability of a complication using the maximum likelihood logistic regression technique. The BED based on the linear-quadratic model was used to compute the corresponding tolerance levels for LDR or HDR brachytherapy. Results: Grades 1 and 2 complications occurred in 10.6% of patients and Grade 3 complications occurred in 3.6%. There were no Grade 4 complications. Complications occurred from 3 to 71 months (median, 7 months) after completion of irradiation, with over 60% occurring in the first year. By logistic regression analysis, both the mucosal dose from a single ovoid or that from all sources, combined with the external irradiation dose, demonstrate a statistically significant fit to the dose response complication curves (both with P=0.016). The single source dose was highly correlated with the all source dose with a cross-correlation coefficient 0.93. The all source dose was approximately 1.4 times the single source dose. Over the LDR brachytherapy dose rate range, the complication rate was

  3. Alteration of cellular and subcellular electrophysiological parameters in mammalian cells by high- and low-LET irradiation at low dose-levels. Part of a coordinated programme on cell membrane probes as biological indicators in radiation accidents

    International Nuclear Information System (INIS)

    Pohl-Rueling, J.

    1980-12-01

    The transmembrane resting potential (MRP) was chosen as a highly sensitive indicator for cellular reactions. The MRP was studied for its suitability as biological indicator of the level of accidental radiation exposure. The development of methodology and installation of a low-cost test chamber, and dose-response studies of MRP-changes of human cells after irradiation with low- and high-LET radiation were considered. Cultured human embryonic lung fibroblasts and human lung biopsy samples were used, with a Co-60 source for low-LET irradiation at dose rates of 2 rad and 20 rad/min, respectively. For high-LET irradiation an Am-241 source was used. The onset of radiation induced effects on cell membranes was prompt but of short duration. In general, full recovery followed within hours of irradiation, at least under the particular experimental conditions. MRP changes in irradiated cells proved a highly sensitive parameter for assessing radiation effects on cell membranes. It appears premature to draw conclusions on the suitability of the method as a biological indicator of radiation damage from accidental exposure, in view of the short duration and prompt reversibility of the effects, and an incomplete understanding of the radiation-induced reactions involved at different LET's and at different doses and dose-rates

  4. Guidance levels, achievable doses and expectation levels

    International Nuclear Information System (INIS)

    Li, Lianbo; Meng, Bing

    2002-01-01

    The National Radiological Protection Board (NRPB), the International Atomic Energy Agency (IAEA) and the Commission of the European Communities (CEC) published their guidance levels and reference doses for typical X-ray examination and nuclear medicine in their documents in 1993, 1994 and 1996 respectively. From then on, the concept of guidance levels or reference doses have been applied to different examinations in the field of radiology and proved to be effective for reduction of patient doses. But the guidance levels or reference doses are likely to have some shortcomings and can do little to make further reduction of patient dose in the radiology departments where patient dose are already below them. For this reason, the National Radiological Protection Board (NRPB) proposed a concept named achievable doses which are based on the mean dose observed for a selected sample of radiology departments. This paper will review and discuss the concept of guidance levels and achievable doses, and propose a new concept referred to as Expectation Levels that will encourage the radiology departments where patient dose are already below the guidance levels to keep patient dose as low as reasonably achievable. Some examples of the expectation levels based on the data published by a few countries are also illustrated in this paper

  5. Identification of irradiated foods prospects for post-irradiation estimate of irradiation dose in irradiated dry egg products

    International Nuclear Information System (INIS)

    Katusin-Raxem, B.; Mihaljievic, B.; Razem, D.

    2002-01-01

    Radiation-induced chemical changes in foods are generally very small at the usual processing doses. Some exception is radiation degradation of lipids, which are the components most susceptible to oxidation. A possible use of lipid hydroperoxides (LOOH) as indicators of irradiation is described for whole egg and egg yolk powders. A sensitive and reproducible spectrophotometric method for LOOH measurement based on feric thiocyanate, as modified in our laboratory, was applied. This method enabled the determination of LOOH, including oleic acid hydroperoxides, which is usually not possible with some other frequently used methods. The lowest limit of 0.05 mmol LOOH/kg lipid could be measured. The measurements were performed in various batches of whole egg and egg yolk powders by the same producer, as well as in samples supplied by various producers. Baseline level in unirradiated egg powder 0.110 ± 0.067 mmol LOOH /kgL was established. The formation of LOOH with dose, as well as the influence of age, irradiation conditions, storage time and storage conditions on LOOH were investigated. The irradiation of whole egg and egg yolk powders in the presence of air revealed an initially slow increase of LOOH, caused by an inherent antioxidative capacity, followed by a fast linear increase after the inhibition dose (D o ). In all investigated samples D o of 2 kGy was determined. Hydroperoxides produced in irradiated materials decay with time. In whole egg and egg yolk powders, after an initially fast decay, the level of LOOH continued to decrease by the first-order decay. Nevertheless, after a six months storage it was still possible to unambiguously identify samples which had been irradiated with 2 kGy in the presence of air. Reirradiation of these samples revealed a significant reduction of D o to 1 kGy. In samples irradiated with 4 kGy and kept under the same conditions, the shortening of D o to 0.5 kGy was determined by reirradiation. This offers a possibility for the

  6. Absorbed dose to mice in prolonged irradiation by low-dose rate ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shiragai, Akihiro [National Inst. of Radiological Sciences, Chiba (Japan); Saitou, Mikio; Kudo, Iwao [and others

    2000-07-01

    In this paper, the dose absorbed by mice was evaluated as a preliminary study of the late effects of prolonged continuous irradiation of mice with low-dose rate ionizing radiation. Eight-week-old male and female SPF C3H/HeN mice in three irradiation rooms were exposed to irradiation at 8000, 400, and 20 mGy, respectively, using a {sup 137}Cs {gamma}-source. Nine racks were arranged in a circle approximately 2.5 m from the source in each room, and 10 cages were arranged on the 4 shelves of each rack. Dose distributions, such as in air at the source level, in the three rooms were estimated by using ionization chambers, and the absorbed dose distributions in the room and relative dose distributions in the cages in relation to the distance of the cage center were examined. The mean abdomen doses of the mice measured by TLD were compared with the absorbed doses in the cages. The absorbed dose distributions showed not only inverse-inverse-square-law behavior with distance from the source, but geometric symmetry in every room. The inherent scattering and absorption in each room are responsible for such behavior and asymmetry. Comparison of relative dose distributions revealed cage positions that are not suitable for experiments with high precision doses, but all positions can be used for prolonged continuous irradiation experiments if the position of the cages is rotated regularly. The mean abdomen doses of the mice were similar in each cage. The mean abdomen doses of the mice and the absorbed doses in a cage were almost the same in all cages. Except for errors concerning the positions of the racks and cages, the uncertainties in the exposure doses were estimated to be about {+-}12% for 8000 mGy group, 17% for 400 mGy group, and 35% for 20 mGy group. (K.H.)

  7. The irradiation effects and processing dose for pet foods decontamination

    International Nuclear Information System (INIS)

    Zhu Jiating; Feng Min; Liu Chunquan; Zhao Yongfu; Jin Yudong; Ji Ping; Ha Yiming; Gao Meixu; Li Shurong; Wang Feng; Zhou Hongjie

    2009-01-01

    The applied dose range of irradiation processing of 4 kinds of pet foods had been studied. More than 92% microorganisms was inactive at the irradiation dose of 4 kGy, while more than 99% was inactive at 6 kGy. The microorganism load of irradiated pet food by 8 kGy met the requirement of national standards. The 10 kGy irradiation could sterilize the treated pet food. Salmonella had not been checked in irradiated or unirradiated samples. When irradiation dose ranged 4-10 kGy, there was no significant difference on contents of moisture, fat, protein, coarse fiber, carbohydrates, minerals (not including Calcium) or amino acids between irradiated and un-irradiated pet food. There was also no significant change on sensory quality of irradiated samples within this dose range. It is concluded that the recommended irradiation processing dose range for pet foods is 4-10 kGy. (authors)

  8. Establishing the irradiation dose for paper decontamination

    International Nuclear Information System (INIS)

    Moise, Ioan Valentin; Virgolici, Marian; Negut, Constantin Daniel; Manea, Mihaela; Alexandru, Mioara; Trandafir, Laura; Zorila, Florina Lucica; Talasman, Catalina Mihaela; Manea, Daniela; Nisipeanu, Steluta; Haiducu, Maria; Balan, Zamfir

    2012-01-01

    Museums, libraries and archives are preserving documents that are slowly degrading due to the inherent ageing of the cellulose substrate or to the technological errors of the past (acid paper, iron gall ink). Beside this, large quantities of paper are rapidly damaged by biological attacks following natural disasters and improper storage conditions. The treatment of paper documents with ionizing radiation can be used for mass decontamination of cultural heritage items but conservators and restaurators are still reserved because of the radiation induced degradation. We conducted a study for establishing the dose needed for the effective treatment of paper documents, taking into account the biological burden and the irradiation effects on paper structure. We used physical testing specific to paper industry and less destructive analytical methods (thermal analysis). Our results show that an effective treatment can be performed with doses lower than 10 kGy. Old paper appears to be less affected by gamma radiation than recent paper but the sampling is highly affected by the non-uniform degree of the initial degradation status. The extent of testing for degradation and the magnitude of acceptable degradation should take into account the biological threat and the expected life time of the paper documents. - RESEARCH HIGHLIGHTS: ► For doses <15 kGy, the measurement uncertainty of mechanical properties is higher than the radiation induced degradation. ► The statistics of measuring induced degradation may be improved by testing both mechanical properties and thermal decomposition of paper. ►Because of the large variability of paper samples, testing to only one irradiation dose has no or reduced relevance. ►It was choused for the irradiation of paper items from archives and collections a dose range of 5–7 kGy.

  9. Irradiation doses on thyroid gland during the postoperative irradiation for breast cancer.

    Science.gov (United States)

    Akın, Mustafa; Ergen, Arzu; Unal, Aysegul; Bese, Nuran

    2014-01-01

    Thyroid gland is one of the radiosensitive endocrine organs in the body. It has been shown that direct irradiation of thyroid with total doses of 26 to 30 Gy can lead to functional abnormalities. In this study, irradiation doses on thyroid gland of the patients who received postoperative chest-wall/breast and regional nodal irradiation were assessed. Retrospective analyses of treatment plans from 122 breast cancer patients who were treated with 3D conformal radiotherapy (3D CRT) planning was performed. All patients received irradiation to supraclavicular/level III lymph nodes in addition to chest-wall/breast. A total dose of 46 Gy was delivered in 25 days to supraclavicular/level III lymph node region while a total dose of 50 Gy was delivered to whole breast/chest-wall. Thyroid gland was contoured on 2-5 mm thickness of computed tomography scans. Absolute thyroid volume, mean thyroid doses were calculated. The mean thyroid volume of all patients was 16.7 cc (min: 1.9 cc, max: 41.6 cc). The mean irradiation dose on was 22.5 Gy (0.32 Gy-46.5 Gy). The level of dose was higher than 26 Gy in 44% of the patients. In majority of the node-positive breast cancer patients treated with 3D CRT, the thyroid gland was exposed to considerable doses. On the other hand, for 44% of the patients are at risk for developing thyroid function abnormalities which should be considered during the routine follow-up.

  10. Electron beam irradiation facility for low to high dose irradiation applications

    International Nuclear Information System (INIS)

    Petwal, V.C.; Wanmode, Yashwant; Verma, Vijay Pal; Bhisikar, Abhay; Dwivedi, Jishnu; Shrivastava, P.; Gupta, P.D.

    2013-01-01

    Electron beam based irradiation facilities are becoming more and more popular over the conventional irradiator facilities due to many inherent advantages such as tunability of beam energy, availability of radiation both in electron mode and X-ray mode, wide range of the dose rate, control of radiation from a ON-OFF switch and other safety related merits. A prototype experimental facility based on electron accelerator has been set-up at RRCAT to meet the low-dose, medium dose and high-dose requirements for radiation processing of food, agricultural and medical products. The facility can be operated in the energy range from 7-10 MeV at variable power level from 0.05-3 kW to meet the dose rate requirement of 100 Gy to kGy. The facility is also equipped with a Bremsstrahlung converter optimized for X-ray irradiation at 7.5 MV. Availability of dose delivery in wide range with precision control and measurement has made the facility an excellent tool for researchers interested in electron/X-ray beam irradiation. A precision dosimetry lab based on alanine EPR and radiochromic film dosimetry system have been established to characterize the radiation field and precise dose measurements. Electron beam scattering technique has been developed to achieve low dose requirement for EB irradiation of various seeds such as groundnut, wheat, soybeans, moong beans, black gram etc. for mutation related studies. This paper describes various features of the facility together with the dosimetric measurements carried out for qualification of the facility and recent irradiation experiments carried out using this facility. (author)

  11. Dose determination in irradiated chicken meat by ESR method

    International Nuclear Information System (INIS)

    Polat, M.

    1996-01-01

    In this work, the properties of the radicals produced in chicken bones have been investigated by ESR technique to determine the amount of dose applied to the chicken meats during the food irradiation. For this goal, the drumsticks from 6-8 weeks old chickens purchased from a local market were irradiated at dose levels of 0; 2; 4; 6; 8 and 10 kGy. Then, the ESR spectra of the powder samples prepared from the bones of the drumsticks have been investigated. Unirradiated chicken bones have been observed to show a weak ESR signal of single line character. CO-2 ionic radicals of axial symmetry with g=1.9973 and g=2.0025 were observed to be produced in irradiated samples which would give rise to a three peaks ESR spectrum. In addition, the signal intensities of the samples were found to depend linearly on the irradiation dose in the dose range of 0-10 kGy. The powder samples prepared from chicken leg bones cleaned from their meats and marrow and irradiated at dose levels of 1, 2, 3, 4, 5, 6, B, 10, 12,14, 16, 1B, 20 and 22 kGy were used to get the dose-response curve. It was found that this curve has biphasic character and that the dose yield was higher in the 12-1B kGy dose range and a decrease appears in this curve over 18 kGy. The radical produced in the bones were found to be the same whether the irradiation was performed after stripping the meat and removing the marrow from the bone or before the stripping. The ESR spectra of both irradiated and non irradiated samples were investigated in the temperature range of 100 K-450 K and changes in the ESR spectra of CO-2 radical have been studied. For non irradiated samples (controls). the signal intensities were found to decrease when the temperature was increased. The same investigation has been carried out for irradiated samples and it was concluded that the signal intensities relative to the peaks of the radical spectrum increase in the temperature range of 100 K-330 K, then they decrease over 330 K. The change in the

  12. Comparison of responses of thermoluminescent dosemeters irradiated by soft x-rays at very low and very high dose rate levels

    International Nuclear Information System (INIS)

    Pietrikova-Farnikova, M.; Krasa, J.; Juha, L.

    1994-01-01

    Recent great progress in construction and application of bright sources of soft X-rays gave a strong impetus for the development of methods of their dosimetric diagnostics. The soft X-ray sources are primarily represented by synchrotron radiation sources and by sources based on laser-produced plasma, including X-ray lasers. Their characteristics spread over a very wide region of photon energies, peak and average powers and densities. From our preliminary experiments it follows that thermoluminescent dosemeters can serve as a suitable tool for the determination of these characteristics. Problem lies in the fact that routine use of the thermoluminescent dosemeters for the dosimetry of soft X-rays requires their spectral calibration, which can be carried out with low peak power sources (synchrotron radiation and radionuclide sources). On the contrary, many important sources, especially these based on laser-produced plasmas, exhibit a very high peak power, i.e. dosemeters are irradiated at extremely high dose rate. In comparative experiments carried out with laser-produced plasmas and radionuclides using TLD 200 (CaF 2 :Dy) and GR 200A (LiF:Mg,Cu,P) it was satisfactorily proven that total thermoluminescent signals are independent of the dose rate. Dependence of glow curve shapes on the dose, dose rate and photon energy were equally determined

  13. Identification and dose evaluation of irradiated beef containing bones

    International Nuclear Information System (INIS)

    Mangiacotti, M.; Alberti, A.; Fuochi, P.G.; Chiesa, L.M.

    2011-01-01

    Complete text of publication follows. Food irradiation is a well-established technique to extend the food shelf life and to reduce the food-related health hazards caused by pathogenic micro-organisms. At present, radiation treatment is permitted for various categories of food and food ingredients in many countries. At the European level, irradiation of food is regulated by the European Directives 1999/2/EC and 1999/3/EC. Community legislation states that any food or food ingredients, authorised in the European Union, must be labelled with the word 'irradiated' and that every year each Member State has to carry out checks at the product marketing stage to enforce correct labelling. The present work aimed at identifying irradiated beef meat by using a reliable and sensitive detection of DNA comets as screening biological method and performing an Electron Spin Resonance (ESR) spectrometry as confirmatory qualitative standard. The influence of storage conditions and time after irradiation on DNA degradation was also investigated. Furthermore the application of ESR technique as a quantitative method was successfully applied to beef bones, using the approach of calibration curve. Results, although the limited statistics, proved for reliability of the dose reconstruction method and blind tests were carried out resulting in very satisfactory difference between actual treatment dose and reconstructed dose.

  14. Studies of the changes in the level of the serum complement in guinea pigs and golden hamsters irradiated with various doses of gamma rays

    International Nuclear Information System (INIS)

    Shirova, L.D.; Najdenski, Kh.M.; Velyanov, D.K.

    1988-01-01

    The serum complement was obtained from whole-body gamma irradiated guinea pigs (0.5 Gy and 2 Gy; 92.5 rad/min) and golden hamsters (0.5 Gy and 6 Gy; 92.5 rad/min). The levels of the serum complement were determined on days 1, 3, 7, 15 and 30 after treatment. A close correlation between the titre levels and radiosensitivity of the species was observed. A statistically significant decrease in the complement titre at the initial intervals after irradiation with sublethal gamma radiation (single or fractionated) was recorded only in guinea pigs - the host with high radiosensitivity. At the same conditions the radioresistant golden hamsters showed higher complement titre with statistical significance only during the first interval of investigation. In the remaining intervals of the study the values obtained did not differ from those of the controls

  15. The application of high dose food irradiation

    International Nuclear Information System (INIS)

    Bruyn, I. De

    1997-01-01

    During the 1950's to end 1970's the United States Army developed the basic methodology to produce shelf stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive 'dried cooked' taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 25 to 45 kGy (depending on the product) at a temperature of between -20 and -40 Centigrade to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions. The product can be guaranteed for more than two years as long as the integrity of the packaging is maintained. (Author)

  16. The application of high dose food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bruyn, I. De [Atomic Energy Corporation of South Africa LTD, Building 2000, P.O. Box 582, Pretoria 0001, (South Africa)

    1997-12-31

    During the 1950`s to end 1970`s the United States Army developed the basic methodology to produce shelf stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive `dried cooked` taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 25 to 45 kGy (depending on the product) at a temperature of between -20 and -40 Centigrade to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions. The product can be guaranteed for more than two years as long as the integrity of the packaging is maintained. (Author)

  17. The researches on the effects of low doses irradiation

    International Nuclear Information System (INIS)

    2009-02-01

    All research conducted as part of 'Risc-Rad' and those conducted by actors in international programs on low doses allow progress in understanding mechanisms of carcinogenesis associated with irradiation. The data do not question the use in radiation protection, risk estimation models based on a linear increase of the risk with the dose of radiation. Nevertheless, they show that the nature of biological responses induced by low doses of radiation has differences with the responses induced by high doses of radiation. They also show the diversity of effects/dose relationships as the mechanism observed and the importance of genetic predisposition in the individual sensitivity to low doses of radiation. It is therefore essential to continue to bring new data to better understand the complex biological effects and their impact on the establishment of radiation protection standards. In addition, the results have often been at the cellular level. The diversity of responses induced by radiations is also a function of cell types observed, the aging of cells and tissue organization. It is essential to strengthen researches at the tissue and body level, involving in vitro and in vivo approaches while testing the hypothesis in epidemiology with a global approach to systems biology. Over the past four years, the collaboration between partners of 'Risc-Rad' using experimental biology approaches and those using mathematical modeling techniques aimed at developing a new model describing the carcinogenesis induced by low radiation doses. On an other hand, The High level expert group on European low dose risk research (H.L.E.G.) develop programmes in the area of low dose irradiation (Germany, Finland, France, Italy and United Kingdom). It proposed a structure of trans national government called M.E.L.O.D.I. ( multidisciplinary european low dose initiative). Its objective is to structure and integrate European research by gathering around a common programme of multidisciplinary

  18. Dose Calculation Evolution for Internal Organ Irradiation in Humans

    International Nuclear Information System (INIS)

    Jimenez V, Reina A.

    2007-01-01

    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

  19. Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

    International Nuclear Information System (INIS)

    Turesson, I.

    1990-01-01

    The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

  20. Ameliorative effects of low dose/low dose-rate irradiation on reactive oxygen species-related diseases model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu

    2008-01-01

    Living organisms have developed complex biological system which protects themselves against environmental radiation, and irradiation with proper dose, dose-rate and irradiation time can stimulate their biological responses against oxidative stress evoked by the irradiation. Because reactive oxygen species are involved in various human diseases, non-toxic low dose/low dose-rate radiation can be utilized for the amelioration of such diseases. In this study, we used mouse experimental models for fatty liver, nephritis, diabetes, and ageing to elucidate the ameliorative effect of low dose/low dose-rate radiation in relation to endogenous antioxidant activity. Single irradiation at 0.5 Gy ameliorates carbon tetrachloride-induced fatty liver. The irradiation increases hepatic anti-oxidative system involving glutathione and glutathione peroxidase, suggesting that endogenous radical scavenger is essential for the ameliorative effect of low dose radiation on carbon tetrachloride-induced fatty liver. Single irradiation at 0.5 Gy ameliorates ferric nitrilotriacetate-induced nephritis. The irradiation increases catalase and decreases superoxide dismutase in kidney. The result suggests that low dose radiation reduced generation of hydroxide radical generation by reducing cellular hydroperoxide level. Single irradiation at 0.5 Gy at 12 week of age ameliorates incidence of type I diabetes in non-obese diabetic (NOD) mice through the suppression of inflammatory activity of splenocytes, and resultant apoptosis of β-cells in pancreas. The irradiation activities of superoxide dismutase and catalase, which coordinately diminish intracellular reactive oxygen species. Continuous irradiation at 0.70 mGy/hr from 10 week of age elongates life span, and suppresses alopecia in type II diabetesmice. The irradiation improved glucose clearance without affecting insulin-resistance, and increased pancreatic catalase activity. The results suggest that continuous low dose-rate irradiation protect

  1. Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

    Science.gov (United States)

    Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

    2017-02-01

    This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

  2. Dose rate distribution for products irradiated in a semi-industrial irradiation plant. 1st stage

    International Nuclear Information System (INIS)

    Mangussi, J.

    2005-01-01

    The model of the bulk product absorbed dose rate distribution in a semi industrial irradiation plant is presented. In this plant the products are subject to a dynamic irradiation process: single-plaque, single-direction, four-passes. The additional two passes, also one on each side of the plaque, serve to minimize the lateral dose variation as well as the depth-dose non-uniformity. The first stage of this model takes only into account the direct absorbed dose rate; the model outputs are the depth-dose distribution and the lateral-dose distribution. The calculated absorbed dose in the bulk product and its uniformity-ratio after the dynamic irradiation process for different products is compared. The model results are in good agreement with the experimental measurements in a bulk of irradiated product; and the air absorbed dose rate in the irradiation chamber behind the product subject to the dynamic irradiation process. (author) [es

  3. Paint compositions for indicating irradiation dose

    International Nuclear Information System (INIS)

    Maruyama, T.; Murata, K.

    1975-01-01

    Paint compositions for indicating irradiation dose are prepared from chlorine-combined polyester, 5 to 30 percent by weight of a reductive discoloring substance or a mixture of said substances, and/or 0.005 to 2.0 percent by weight of a reducing dyestuff or a mixture of said dyestuffs, in which said chlorine-combined polyester is obtained by a chlorinated dibasic acid or its anhydride as an acid component or a part of an acid component selected from a group consisting of 3-chlorophthalic acid, 4-chlorophthalic acid, dichlorinated phthalic acid, tetrachlorophthalic acid, 1,4,5,6,7,7-hexachlorobicyclo-(2,2,1)-5-heptene-2,3-dicarboxylic acid, 4-chloro-4-cyclohexene-1,2-dicarboxylic acid and the anhydrides corresponding to said acids. (auth)

  4. Epidemiological survey of the effects of low level radiation dose: a comparative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1993-10-01

    This volume presents the collations tables of a six volume comparative epidemiological survey of the effects of low level radiation dose. Data are collated for the effects observed in the following irradiated groups:- Preconception irradiation, intra-uterine irradiation, childhood irradiation, adult irradiation. (UK).

  5. Inactive Doses and Protein Concentration of Gamma Irradiated Yersinia Enterocolitica

    International Nuclear Information System (INIS)

    Irawan Sugoro; Sandra Hermanto

    2009-01-01

    Yersinia enterocolitica is one of bacteria which cause coliform mastitis in dairy cows. The bacteria could be inactivated by gamma irradiation as inactivated vaccine candidate. The experiment has been conducted to determine the inactive doses and the protein concentration of Yersinia enterocolitica Y3 which has been irradiated by gamma rays. The cells cultures were irradiated by gamma rays with doses of 0, 100, 200, 400, 600, 800, 1.000 and 1.500 Gy (doses rate was 1089,59 Gy/hours). The inactive dose was determined by the drop test method and the protein concentration of cells were determined by Lowry method. The results showed that the inactive doses occurred on 800 – 1500 Gy. The different irradiation doses of cell cultures showed the effect of gamma irradiation on the protein concentration that was random and has a significant effect on the protein concentration. (author)

  6. Problems following hippocampal irradiation in interventional radiologists - doses and potential effect:a Monte Carlo simulation

    International Nuclear Information System (INIS)

    Cumak, V.; Morgun, A.; Bakhanova, O.; Loganovs'kij, K.; Loganovs'ka, T.; Marazziti, D.

    2015-01-01

    This study aimed at investigating radiation exposure of hippocampus in interventional medical professionals irradiated in the operating room, and to compare doses in the hippocampus with the effective dose (protection quantity), as well as with the doses measured by individual dosimeter, in order to estimate probability of reaching levels of radiation induced cognitive and other neuropsychiatric alterations during their working career, through a Monte Carlo simulation. The results showed that cranial irradiation was very heterogeneous and depended on the projection: doses of left and right hippocampi may be different up to a factor of 2.5; under certain conditions, the dose of the left hippocampus may be twice the effective dose, estimated by conventional double dosimetry algorithm. The professional span doses of the irradiated hippocampus may overcome the threshold able to provoke possible cognitive and emotional-behavioral impairment. Therefore, in-depth studies of the effects of brain irradiation in occupationally exposed interventional medical personnel appear urgently needed and crucial

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

    International Nuclear Information System (INIS)

    Basfar, A.A.; Abdel Rehim, F.

    1997-01-01

    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

  8. Dose-response of photographic emulsions under gamma irradiation

    International Nuclear Information System (INIS)

    Tran Dai Nghiep; Do Thi Nguyet Minh; Le Van Vinh

    2003-01-01

    Photographic emulsion is irradiated under gamma rays irradiation of 137 Cs in the IAEA/WHO secondary standard dosimetry laboratory. Dose-response of the film is established. The sensitivity of the film is determined. The dose-rate effect is studied. (author)

  9. Seed irradiation with continuously increasing doses of thermal neutrons

    International Nuclear Information System (INIS)

    Uhlik, J.; Pfeifer, M.; Pittermann, P.

    1977-01-01

    In the 'Raman' pea cv. the biological activity of thermal neutrons was investigated after irradiation of a 780 mm column of seeds for 3000 and 4167 seconds with a flux of 5.607 x 10 9 n.cm -2 per second. For different fractions of the seed column the average density of the neutron flux was calculated. It was proved that for the described method of seed irradiation it was sufficient to determine only the dose approaching the lethal dose. If a sufficiently high column of seeds is used part of the column of seeds will be irradiated with the optimum range of doses. The advantages of the suggested method of irradiation are not only smaller time and technological requirements resulting from the need for the determination of only the critical lethal dose of radiation by means of inhibition tests performed with seedlings, but also a simpler irradiation procedure. The suggested method of irradiation is at least nine times cheaper. (author)

  10. Relaxation behavior and dose dependence of radiation induced radicals in irradiated mango

    International Nuclear Information System (INIS)

    Kameya, Hiromi; Kakita, Daisuke; Kaimori, Yoshihiko; Ukai, Mitsuko; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Shimoyama, Yuhei

    2010-01-01

    Mangoes are imported to Japan after treated with hot water. Recently, irradiated mangoes imported to U. S. are widely used. This paper reports on the ESR method for analyzing the radiation induced radicals of irradiated mangoes. Upon the γ ray irradiation, a strong single peak in the flesh and skin of mangoes was observed at g=2.004. This singlet peak may be attributed to organic free radicals. The ESR spectra of the flesh and skin of mangoes showed the radiation induced radicals due to cellulose by irradiation over 12 kGy. The relaxation times (T 1 and T 2 ) of the singlet signal were calculated. T 2 showed dose response according to increasing the irradiation dose levels, while T 1 was almost constant. The value of (T 1 T 2 ) 1/2 showed the dependence of irradiation dose level. (author)

  11. Swelling of spinel after low-dose neutron irradiation

    International Nuclear Information System (INIS)

    Coghlan, W.A.; Clinard, F.W. Jr.; Itoh, N.; Greenwood, L.R.

    1986-01-01

    Swelling was determined in samples of single-crystal MgAl 2 O 4 spinel, irradiated to doses as high as 8 x 10 22 n/m 2 (E > 0.1 MeV) at approx. =50 0 C in the Omega West Reactor. Swelling effectively saturated at approx. =2 x 10 22 n/m 2 which corresponds to a damage level of only approx. =2 x 10 -3 dpa. In addition subsequent measurements after irradiation have revealed that the samples continued swelling for several weeks. These results imply that irradiation defects begin to interact by recombination and aggregation at low damage levels in this material at 50 0 C and perhaps continue to cluster at room temperature after irradiation. Rate equations have been employed to determine defect concentrations at saturation. Results to date show that the observed swelling is consistent with the number of surviving defects if swelling per Frenkel defect pair is taken to be one atomic volume

  12. Assessment of population external irradiation doses with consideration of Rospotrebnadzor bodies equipment for monitoring of photon radiation dose

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2016-01-01

    Full Text Available This paper provides review of equipment and methodology for measurement of photon radiation dose; analysis of possible reasons for considerable deviation between the Russian Federation population annual effective external irradiation doses and the relevant average global value. Data on Rospotrebnadzor bodies dosimetry equipment used for measurement of gamma radiation dose are collected and systematized. Over 60 kinds of dosimeters are used for monitoring of population external irradiation doses. Most of dosimeters used in the country have gas-discharge detectors (Geiger-Mueller counters, minor biochemical annunciators, etc. which have higher total values of own background level and of space radiation response than the modern dosimeters with scintillation detectors. This feature of dosimeters is apparently one of most plausible reasons of a bit overstating assessment of population external irradiation doses. The options for specification of population external irradiation doses assessment are: correction of gamma radiation dose measurement results with consideration of dosimeters own background level and space radiation response, introduction of more up-to-date dosimeters with scintillation detectors, etc. The most promising direction of research in verification of population external irradiation doses assessment is account of dosimetry equipment.

  13. Radiation doses inside industrial irradiation installation with linear electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Alexandre R., E-mail: alexandre.lima@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Pelegrineli, Samuel Q.; Alo, Gabriel F., E-mail: samuelfisica@yahoo.com.br, E-mail: gabriel.alo@aceletron.com.br [Aceletron Irradiacao Industrial, Aceletrica Comercio e Representacoes Ltda, Rio de Janeiro, RJ (Brazil); Silva, Francisco C.A. Da, E-mail: dasilva@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

  14. Radiation doses inside industrial irradiation installation with linear electron accelerator

    International Nuclear Information System (INIS)

    Lima, Alexandre R.; Pelegrineli, Samuel Q.; Alo, Gabriel F.; Silva, Francisco C.A. Da

    2015-01-01

    Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

  15. Dose verification by OSLDs in the irradiation of cell cultures

    International Nuclear Information System (INIS)

    Meca C, E. A.; Bourel, V.; Notcovich, C.; Duran, H.

    2015-10-01

    The determination of value of irradiation dose presents difficulties when targets are irradiated located in regions where electronic equilibrium of charged particle is not reached, as in the case of irradiation -in vitro- of cell lines monolayer-cultured, in culture dishes or flasks covered with culture medium. The present study aimed to implement a methodology for dose verification in irradiation of cells in culture media by optically stimulated luminescence dosimetry (OSLD). For the determination of the absorbed dose in terms of cell proliferation OSL dosimeters of aluminum oxide doped with carbon (Al 2 O 3 :C) were used, which were calibrated to the irradiation conditions of culture medium and at doses that ranged from 0.1 to 15 Gy obtained with a linear accelerator of 6 MV photons. Intercomparison measurements were performed with an ionization chamber of 6 cm 3 . Different geometries were evaluated by varying the thicknesses of solid water, air and cell culture medium. The results showed deviations below 2.2% when compared with the obtained doses of OSLDs and planning system used. Also deviations were observed below 3.4% by eccentric points of the irradiation plane, finding homogeneous dose distribution. Uncertainty in the readings was less than 2%. The proposed methodology contributes a contribution in the dose verification in this type of irradiations, eliminating from the calculation uncertainties, potential errors in settling irradiation or possible equipment failure with which is radiating. It also provides certainty about the survival curves to be plotted with the experimental data. (Author)

  16. High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Wirth, Brian; Motta, Athur; Morgan, Dane; Kaoumi, Djamel; Hosemann, Peter; Odette, Robert

    2018-04-30

    Project Objective: The objective of this proposal is to demonstrate the capability to predict the evolution of microstructure and properties of structural materials in-reactor and at high doses, using ion irradiation as a surrogate for reactor irradiations. “Properties” includes both physical properties (irradiated microstructure) and the mechanical properties of the material. Demonstration of the capability to predict properties has two components. One is ion irradiation of a set of alloys to yield an irradiated microstructure and corresponding mechanical behavior that are substantially the same as results from neutron exposure in the appropriate reactor environment. Second is the capability to predict the irradiated microstructure and corresponding mechanical behavior on the basis of improved models, validated against both ion and reactor irradiations and verified against ion irradiations. Taken together, achievement of these objectives will yield an enhanced capability for simulating the behavior of materials in reactor irradiations

  17. Peripheral blood corticotropin-releasing factor, adrenocorticotropic hormone and cytokine (Interleukin Beta, Interleukin 6, tumor necrosis factor alpha) levels after high- and low-dose total-body irradiation in humans

    International Nuclear Information System (INIS)

    Girinsky, T.A.; Pallardy, M.; Comoy, E.; Benassi, T.; Roger, R.; Ganem, G.; Socie, G.; Cossett, J.M.; Magdelenat, H.

    1994-01-01

    Total-body irradiation (TBI) induces an increase in levels of granulocytes and cortisol in blood. To explore the underlying mechanisms, we studied 26 patients who had TBI prior to bone marrow transplantation. Our findings suggest that only a high dose of TBI (10 Gy) was capable of activating the hypothalamopituitary area since corticotropin-releasing factor and blood adrenocorticotropic hormone levels increased at the end of the TBI. There was a concomitant increase in the levels of interleukin 6 and tumor necrosis factor in blood, suggesting that these cytokines might activate the hypothalamo-pituitary adrenal axis. Interleukin 1 was not detected. Since vascular injury is a common after radiation treatment, it is possible that interleukin 6 was secreted by endothelial cells. The exact mechanisms of the production of cyctokines induced by ionizing radiation remain to be determined. 25 refs., 1 fig

  18. Volume dose of organs at risk in the irradiated volume

    International Nuclear Information System (INIS)

    Hishikawa, Yoshio; Tanaka, Shinichi; Miura, Takashi

    1984-01-01

    Absorbed dose of organs at risk in the 50% irradiated volume needs to be carefully monitored because there is high risk of radiation injury. This paper reports on the histogram of threedimensional volume dose of organs at risk, which is obtained by computer calculation of CT scans. In order to obtain this histogram, CT is first performed in the irradiation field. The dose in each pixel is then examined by the computer as to each slice. After the pixels of all slices in the organ at risk of the irradiated field are classified according to the doses, the number of pixels in the same dose class is counted. The result is expressed in a histogram. The histogram can show the differences of influence to organs at risk given by various radiation treatment techniques. Total volume dose of organs at risk after radiotherapy can also be obtained by integration of each dose of different treatment techniques. (author)

  19. Effects of low-dose rate irradiation on two types of type II diabetes model mice

    International Nuclear Information System (INIS)

    Nomura, Takaji; Sakai, Kazuo

    2004-01-01

    The effects of low-dose rate gamma-irradiation were investigated in two mouse strains - C57BL/KsJ-db/db (db mouse) and AKITA (AKITA mouse)-for type II diabetes mellitus. Both strains develop the developed type II diabetes by about 8 weeks of age due to dysfunction of the insulin/insulin receptor. The db Mouse' shows obese and exhibits hyperinsulinism, and the onset of Type II diabetes like resembles that for Westerners. On the other hand, the AKITA mouse has exhibits disordered insulin secretion, and the diabetes such as resembles that of Asians. Ten-week old female mice, in groups of 8 or 12, were irradiated at 0.65 mGy/hr in the low-dose rate irradiation facility in the Low Dose Radiation Research Center. The level of urine glucose was measured with test slips. The urine glucose levels of all of the mice were highly elevated the beginning of the irradiation. In the irradiated group of db mice, three mice showed decrease in glucose level compare to the level of non-irradiated diabetes mice after 35, 52 or 80 weeks of irradiation. All had maintained a normal level thereafter. No such improvement in diabetes was ever observed in the 12 mice of in the non-irradiated control group. The AKITA mice, however, did not decrease the glucose level regardless of the irradiation. Both the db mice and AKITA mice had their lives prolonged their life by the irradiation. The survival rate of db mice at the age of 90 weeks was 75% in the irradiated group, but 50% in the non-irradiated group. The average life span was 104 weeks in the irradiated group and 87 weeks in the control group. Furthermore, a marked difference was furthermore observed in the appearance of the coat hair, skin, and tail; appearances were well preserved in the irradiated group. The average life span in the irradiated AKITA mice was also longer than that for the non-irradiated mice, 51 weeks and 41 weeks in the irradiated and non-irradiated group respectively. These results suggest that the low-dose irradiation

  20. Studies of deep levels in He+-irradiated silicon

    International Nuclear Information System (INIS)

    Schmidt, D.C.; Barbot, J.F.; Blanchard, C.

    1997-01-01

    Deep levels created in n-epitaxial silicon by alpha particle irradiation in the dose range from 10 9 to 10 13 particles/cm 2 have been investigated by the deep level transient spectroscopy technique and capacitance-voltage profiling. Under low fluence irradiation at least four main electron traps have been observed. With further increase in irradiation fluence, two new levels located at E c -0.56 eV and E c -0.64 eV appear on the high-temperature side of the DLTS signal. The slope change observed in the amplitude variations of the singly negative charge state of the divacancy versus the dose takes place when these two new levels appear. This suggests that both are multivacancy-related defects. After annealing at 350 C for 15 min, all electron traps have disappeared. Moreover, no shallow levels are created during the annealing. (orig.)

  1. Dose requirements for microbial decontamination of botanical materials by irradiation

    International Nuclear Information System (INIS)

    Razem, D.; Katusin-Razem, Branka

    2002-01-01

    Microbial contamination levels and corresponding resistivities to irradiation (expressed as dose required for the first 90% reduction, D first 9 0% r ed ) were analyzed in a number of various botanical materials. The following generalizations could be made: total aerobic plate count is the most informative measure of contamination; the probability of contamination depends on available surface of the material and processing history: flowers and leaves usually contain more contamination than fruits and seeds, while crude herbs contain more than extracts; liquid extracts are more contaminated than dry ones. At the same time, resistivity to irradiation increases approximately in the reverse order of contamination level on going from flowers and leaves, to fruits and seeds, to liquid and dry extracts. The two quantities, probability of contamination and D first 9 0% r ed being inversely related, the treatment dose needed to reduce initial contamination to tolerable level amounts to between 4 and 30 kGy under a typical scenario, and between 8 and 40 kGy under the worst-case scenario for the whole range of raw materials and botanical products

  2. Integral dose and evaluation of irradiated tissue volume

    International Nuclear Information System (INIS)

    Sivachenko, T.P.; Kalina, V.K.; Belous, A.K.; Gaevskij, V.I.

    1984-01-01

    Two parameters having potentialities of radiotherapy planning improvement are under consideration. One of these two parameters in an integral dose. An efficiency of application of special tables for integral dose estimation is noted. These tables were developed by the Kiev Physician Improvement Institute and the Cybernetics Institute of the Ukrainian SSR Academy of Science. The meaning of the term of ''irradiated tissue volume'' is specified, and the method of calculation of the irradiated tissue effective mass is considered. It is possible to evaluate with higher accuracy tolerance doses taking into account the irradiated mass

  3. A study on mice exposure dose for low-dose gamma-irradiation using glass dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sung Jin; Kim, Hyo Jin; Kim, Hyun; Jeong, Dong Hyeok; Son, Tae Gen; Kim, Jung Ki; Yang, Kwang Mo; Kang, Yeong Rok [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, Sang Hee [Dept. of Biomedical Engineering, Inje University, Gimhae (Korea, Republic of)

    2015-12-15

    The low dose radiation is done for a long period, thus researchers have to know the exact dose distribution for the irradiated mouse. This research has been conducted in order to find out methods in transmitting an exact dose to mouse in a mouse irradiation experiment carried out using {sup 137}C{sub s} irradiation equipment installed in the DIRAMS (Dongnam Institution of Radiological and Medical Sciences) research center. We developed a single mouse housing cage and shelf with adjustable geometric factors such as distance and angle from collimator. The measurement of irradiated dose showed a maximal 42% difference of absorbed dose from the desired dose in the conventional irradiation system, whereas only 6% difference of the absorbed dose was measured in the self-developed mouse apartment system. In addition, multi mice housing showed much difference of the absorbed dose in between head and body, compared to single mouse housing in the conventional irradiation system. This research may allow further research about biological effect assessment for the low dose irradiation using the self-developed mouse apartment to provide more exact doses which it tries to transmit, and to have more reliability for the biological analysis results.

  4. Hormonal levels after ovarian X-irradiation of ewes

    International Nuclear Information System (INIS)

    Driancourt, M.A.; Blanc, M.R.; Mariana, J.C.

    1983-01-01

    The effects of X-irradiation on ovulation rate, cyclicity and progesterone and FSH levels in Ile-de-France ewes (4 control and 16 irradiated) after they were treated during the breeding season were reported. The doses used (800 and 2400 R) destroyed 50% of all size classes of the follicular population. Ovulation occurred in 87% of the treated ewes (ovulation rate = 1) when they were irradiated 24 h after luteolysis; 78% of the corpora lutea resulting from these ovulations were normal as to length and progesterone production. FSH in treated ewes started to increase 20 h after treatment and remained higher than in the controls until ovulation time. Later, while these levels were similar between groups on the day of ovulation, high ovulatory levels persisted in irradiated ewes. In the next cycles, the length of the follicular phases, ovulation rate and progesterone and FSH levels were similar between groups

  5. Post-irradiation stability of polyvinyl chloride at sterilizing doses

    International Nuclear Information System (INIS)

    Naimian, F.; Katbab, A.A.; Nazokdast, H.

    1994-01-01

    Post-irradiation stability of plasticized PVC irradiated by 60 Co gamma ray at sterilizing doses has been studied. Effects of irradiation upon chemical structure, mechanical properties and rheological behaviour of samples contained different amounts of Di(2-ethylhexyl)phthalate as plasticizer have been investigated. Formation of conjugated double bonds, carbonyl and hydroxyl groups have been followed by UV and FTIR spectrometers up to 6 months after irradiation. FTIR spectra of irradiated samples showed no significant changes in carbonyl and hydroxyl groups even 6 months after irradiation. However, changes in UV-visible spectra was observed for the irradiated samples up to 6 months post-irradiation. This has been attributed to the formation of polyenes which leads to the discoloration of this polymer. Despite a certain degree of discoloration, it appears that the mechanical properties of PVC are not affected by irradiation at sterilizing doses. No change in the melt viscosity of the irradiated PVC samples with post-irradiation was observed, which is inconsistent with the IR results. (author)

  6. High doses dosimetry in irradiation process in Argentine

    International Nuclear Information System (INIS)

    Dorda de Cancio, E.M.

    1997-01-01

    These report describes the lung dose dosimetry procedures of the Semi-Industrial Irradiation Plant in Ezeisa Atomic (500,00 Ci of Co 60) and Industrial Picorrad Plant (400,00 Ci of Co 60) using the nitrate dosimeter

  7. Irradiation preservation study on Beijing roast duck by low dose

    Energy Technology Data Exchange (ETDEWEB)

    Weiguo, Wang; Yongbao, Gu; Fengmei, Li [Beijing Normal Univ., BJ (China). Inst. of Low Energy Nuclear Physics; and others

    1989-02-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as {gamma}-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome.

  8. Irradiation preservation study on Beijing roast duck by low dose

    International Nuclear Information System (INIS)

    Wang Weiguo; Gu Yongbao; Li Fengmei

    1989-01-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as γ-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome

  9. Dose controlled low energy electron irradiator for biomolecular films.

    Science.gov (United States)

    Kumar, S V K; Tare, Satej T; Upalekar, Yogesh V; Tsering, Thupten

    2016-03-01

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at -20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  10. Dose controlled low energy electron irradiator for biomolecular films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. V. K., E-mail: svkk@tifr.res.in; Tare, Satej T.; Upalekar, Yogesh V.; Tsering, Thupten [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India)

    2016-03-15

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at −20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  11. Dose and dose rate effects on coherent-to-incoherent transition of precipitates upon irradiation

    Institute of Scientific and Technical Information of China (English)

    LI Zhengchao

    2006-01-01

    A typical precipitation hardened alloy, Cu-Co dilute alloy was selected to study the precipitation behavior and irradiation effect on precipitates. It is found that the principal effect of ion irradiation on the coherent precipitates is loss of coherency, and TEM cross-section observations show that the fraction of the incoherent precipitates is dependent on dose but not on dose rate during heavy ion irradiation.

  12. Effects of low-level chronic irradiation on aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Etoh, H. (National Inst. of Radiological Sciences, Chiba (Japan))

    1980-10-01

    Effects of continual irradiation for a long term on fishes and aquatic invertebrates were outlined. Effects of low-level chronic irradiation on aquatic organisms were less than acute effects induced when the same dose was irradiated once. The radiosensitivity of the genital organ to continual irradiation was high. There was a difference in radiosensitivity of the genital organ between female and male, and the degree of the difference varied according to kinds of animals. In an experiment on continual irradiation of adult killifishes, ova recovered from radiation damage, but spermatozoa did not recover. Incubation rates of eggs obtained from aquatic organisms which lived in water where radioactive sewage flowed into decreased significantly, and the frequency of reverse position of salivary gland chromosomes which were peculiar to exposed organisms increased in larvae of Chironomus tentans.

  13. Pre-irradiation at a low dose-rate blunted p53 response

    International Nuclear Information System (INIS)

    Takahashi, A.; Ohnishi, K.; Asakawa, I.; Tamamoto, T.; Yasumoto, J.; Yuki, K.; Ohnishi, T.; Tachibana, A.

    2003-01-01

    Full text: We have studied whether the p53-centered signal transduction pathway induced by acute radiation is interfered with chronic pre-irradiation at a low dose-rate in human cultured cells and whole body of mice. In squamous cell carcinoma cells, we found that a challenge irradiation with X-ray immediately after chronic irradiation resulted in lower levels of p53 than those observed after the challenge irradiation alone. In addition, the induction of p53-centered apoptosis and the accumulation of its related proteins after the challenge irradiation were strongly correlated with the above-mentioned phenomena. In mouse spleen, the induction of apoptosis and the accumulation of p53 and Bax were observed dose-dependently at 12 h after a challenge irradiation. In contrast, we found significant suppression of them induced by challenge irradiation at a high dose-rate when mice were pre-irradiated with chronic irradiation at a low dose-rate. These findings suggest that chronic pre-irradiation suppressed the p53 function through radiation-induced p53-dependent signal transduction processes. There are numerous papers about p53 functions in apoptosis, radiosensitivity, genomic instability and cancer incidence in cultured cells or animals. According to our data and other findings, since p53 can prevent carcinogenesis, pre-irradiation at a low dose-rate might enhance the predisposition to cancer. Therefore, it is possible that different maximal permissible dose equivalents for the public populations are appropriate. Furthermore, concerning health of human beings, studies of the adaptive responses to radiation are quite important, because the radiation response strongly depends on experience of prior exposure to radiation

  14. Dose Distribution of Rectum and Bladder in Intracavitary Irradiation

    International Nuclear Information System (INIS)

    Chu, S. S.; Oh, W. Y.; Suh, C. O.; Kim, G. E.

    1984-01-01

    The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiogram and medical records of 206 patients, who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analyzed. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral cervix to the central axis of ovoid were measured for low dose rate irradiation system and high dose rate remote control after loading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as 4-7cm width and high dose rate system showed as 5-6cm. 2. In Horizontal angulation of tandem to body axis, the low dose rate system revealed mid position 64.6%, left deviation 19.2% and right deviation 16.2%. 3. In longitudinal angulation of tandem to body axis, the mid position was 11.8% and anterior angulation 88.2% in low dose rate system but in high dose rate system, anterior angulation was 98.5%. 4. Down ward displacement of ovoid below external os was only 3% in low dose rate system and 66.6% in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses and TDF were 80, 70 Gy and 131, 123 including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 98, 47 Gy and 230, 73 in high dose rate system but in low dose rate system 125, 52 Gy and 262, 75 respectively. 8. Doses

  15. Quality of fresh-cut Iceberg lettuce and spinach irradiated at doses up to 4 kGy

    International Nuclear Information System (INIS)

    Fan Xuetong; Guan Wenqiang; Sokorai, Kimberly J.B.

    2012-01-01

    Fresh-cut Iceberg lettuce packaged in modified atmosphere packages and spinach in perforated film bags were irradiated with gamma rays at doses of 0, 1, 2, 3, and 4 kGy. After irradiation, the samples were stored for 14 days at 4 °C. O 2 levels in the packages of fresh-cut Iceberg lettuce decreased and CO 2 levels increased with increasing radiation dose, suggesting that irradiation increased respiration rates of lettuce. Tissue browning of irradiated cut lettuce was less severe than that of non-irradiated, probably due to the lower O 2 levels in the packages. However, samples irradiated at 3 and 4 kGy had lower maximum force and more severe sogginess than the non-irradiated control. In addition, ascorbic acid content of irradiated lettuce was 22–40% lower than the non-irradiated samples after 14 days of storage. The visual appearance of spinach was not affected by irradiation even at a dose of 4 kGy. Consumer acceptance suggested that more people would dislike and would not buy spinach that was treated at 3 and 4 kGy as compared to the non-irradiated sample. Overall, irradiation at doses of 1 and 2 kGy may be employed to enhance microbial safety of fresh-cut Iceberg lettuce and spinach while maintaining quality. - Highlights: ▶ Headspace composition in the modified atmosphere packages of cut lettuce was affected by irradiation. ▶ Fresh-cut lettuce in adapted atmosphere could tolerate 1 or 2 kGy rays without quality deterioration in look and texture. ▶ Lettuce irradiated at doses higher than 2 kGy developed sogginess. ▶ Irradiated spinach maintained a good appearance at doses of 3 and 4 kGy. ▶ Higher doses (3 and 4 kGy) of radiation decreased consumers' likingness and purchase intent of irradiated spinach.

  16. Dose measurement method suitable for management of food irradiation

    International Nuclear Information System (INIS)

    Tanaka, Ryuichi

    1990-01-01

    The report describes major features of dose measurement performed for the management of food irradiation processes, and dose measuring methods suitable for this purpose, and outlines some activities for establishing international standards for dose measurement. Traceability studies made recently are also reviewed. Compared with the sterilization of medical materials, food irradiation is different in some major points from a viewpoint of dose measurement: foods can undergo significant changes in bulk density, depending on its properties, during irradiation, and the variation in the uniformity of bulk density can be large within an irradiation unit and among different units. An accurate dosimeter and well-established traceability are essential for food irradiation control, and basically a dosimeter should be high in reproducibility and stable in dose response, and should be easy to readjust for eliminating systematic errors. A new type of dosimeter was developed recently, in which ESR is used to measure the free radicals generated by radiations in crystals of alanine, an amino acid. Standardization of large dose measurement procedures has been carried out by committee E10 set up under ASTM. (N.K.)

  17. Evaluation of absorbed doses during irradiation of patients

    International Nuclear Information System (INIS)

    Denisenko, O.N.; Kozlov, V.A.

    1981-01-01

    Provided is an analysis of a general scheme for the method of control over the dose field realization in the patient's body using direct dose measurements in patients. On the basis of data from literature presented are error limits in the stages of preradiation preparation and irradiation of patients, and in the stage of dose measurement for different irradiation techniques and radiation types. The authors also provide scientific data of their own. It has been concluded that the main emphasis should be placed on the improvement of topometry facilities, field calculation, patients posture and visual control methods of the radiation beam position [ru

  18. Dose mapping of the multi-purpose gamma irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Cabalfin, E G; Lanuza, L G; Villamater, D T [Irradiation Services, Nuclear Services and Training Division, Philippine Nuclear Research Institute, Quezon City (Philippines)

    1989-12-01

    In radiation processing, reliable dosimetry constitutes a very important part of process control and quality assurance. Radiation dosimetry is the only acceptable method to guarantee that the irradiated product has undergone the correct radiation treatment. In preparation therefore, for the routine operation of the newly installed multi-purpose gamma irradiation facility at the Philippine Nuclear Research Institute (PNRI), dose mapping distribution studies were undertaken. Results of dose distribution in air as well as in dummy product are presented. The effects of product bulk density, product geometry and product to source distance on minimum absorbed dose and uniformity ratio have been determined. (Author).

  19. Dose mapping of the multi-purpose gamma irradiation facility

    International Nuclear Information System (INIS)

    Cabalfin, E.G.; Lanuza, L.G.; Villamater, D.T.

    1989-01-01

    In radiation processing, reliable dosimetry constitutes a very important part of process control and quality assurance. Radiation dosimetry is the only acceptable method to guarantee that the irradiated product has undergone the correct radiation treatment. In preparation therefore, for the routine operation of the newly installed multi-purpose gamma irradiation facility at the Philippine Nuclear Research Institute (PNRI), dose mapping distribution studies were undertaken. Results of dose distribution in air as well as in dummy product are presented. The effects of product bulk density, product geometry and product to source distance on minimum absorbed dose and uniformity ratio have been determined. (Author)

  20. Accelerated Irradiations for High Dose Microstructures in Fast Reactor Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zhijie [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-03-31

    The objective of this project is to determine the extent to which high dose rate, self-ion irradiation can be used as an accelerated irradiation tool to understand microstructure evolution at high doses and temperatures relevant to advanced fast reactors. We will accomplish the goal by evaluating phase stability and swelling of F-M alloys relevant to SFR systems at very high dose by combining experiment and modeling in an effort to obtain a quantitative description of the processes at high and low damage rates.

  1. The dose effect of irradiated rice pollen on double fertilization

    International Nuclear Information System (INIS)

    Wang Houcong; Chen Zhengming; Chen Ruming; Qiu Simi; Yang Juemin; Yang Huijie

    1995-01-01

    The mature panicles of rice were treated with 60 Co γ-rays in the range of 0∼0.372 kGy. The male sterile line used as the female plants were fertilized with γ-irradiated pollen manually. The dose effect of the irradiated pollen on double fertilization was investigated. It was found that double fertilization of the irradiated pollen was suppressed to different degrees as compared with the control. The effect was noticeable as that the fusion time of the male nucleolus with the female one was delayed with the increasing of γ-radiation dose. The delayed time was less than 13 hours when the dose was below 0.186 kGy and it was more than 15 hours when the dose was above 0.279 kGy. Furthermore, several types of deformed embryonic cells and endosperm nuclei were observed

  2. Effects of low dose rate irradiation on induction of myeloid leukemia in mice

    International Nuclear Information System (INIS)

    Furuse, Takeshi

    1999-01-01

    We investigated the induction of myeloid leukemia and other kinds of neoplasias in C3H male mice irradiated at several dose rate levels. We compared the incidence of neoplasias among these groups, obtained dose and dose rate effectiveness factors (DDREF) for myeloid leukemia. C3H/He male mice were exposed to whole body gamma-ray irradiation at 8 weeks of age. All mice were maintained for their entire life span and teh pathologically examined after their death. Radiation at a high dose-rate of 882 mGy/min (group H), a medium dose-rate of 95.6 mGy/min (group M), and low dose-rates of 0.298 mGy/min (group L-A), 0.067 mGy/min (group L-B) or 0.016 mGy/min (group L-C) were delivered from 137 Cs sources. The mice in group L were irradiated continuously for 22 hours daily up to total doses of 1, 2, 3, 4, 10 Gy over a period of 3 days to 200 days. As for the induction of neoplasias, myeloid leukemia developed significantly more frequently in irradiated groups than in unirradiated groups. The time distribution of mice dying from myeloid leukemia did not show a difference between groups H and L. The incidence of myeloid leukemia showed a greater increase in the high dose-rate groups than in the low and medium dose-rate groups in the dose range over 2 Gy, it also showed significant increases in the groups irradiated with 1 Gy of various dose rate, but the difference between these groups was not clear. These dose effect curves had their highest values on each curve at about 3 Gy. We obtained DDREF values of 2-3 by linear fittings for their dose response curves of dose ranges in which leukemia incidences were increasing. (author)

  3. Threshold irradiation dose for amorphization of silicon carbide

    International Nuclear Information System (INIS)

    Snead, L.L.; Zinkle, S.J.

    1997-01-01

    The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be ∼0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si + at 1 x 10 -3 dpa/s and with fission neutrons irradiated at 1 x 10 -6 dpa/s irradiated to 15 dpa in the temperature range of ∼340±10K

  4. Threshold irradiation dose for amorphization of silicon carbide

    International Nuclear Information System (INIS)

    Snead, L.L.; Zinkle, S.J.

    1997-01-01

    The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface of strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be ∼0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10 -3 dpa/s and with fission neutrons irradiated at 1 x 10 -6 dpa/s irradiated to 15 dpa in the temperature range of ∼340 ± 10K

  5. Adaptation dynamics of laboratory populations of Drosophila Melanogaster to low dose chronic ionizing irradiation

    International Nuclear Information System (INIS)

    Zajnullin, V.G.; Yushkova, E.A.

    2008-01-01

    In genetically non-uniform populations D. melanogaster in conditions of a chronic irradiation in a doze 10-11 about sGy/generation dynamics parameters of populations was investigated. It is established, that number of individuals in irradiated populations is lower, than in control. It is revealed, that viability of populations undergone to a chronic irradiation depends on their genotype. The gradual increase in fruitfulness, viability of individuals and decrease in a level of lethal mutations in a number of generations after of an irradiation in low doses is caused by adaptable opportunities of populations. (authors)

  6. Dose Profiles in ECAL Crystals for Various Irradiation Conditions

    CERN Document Server

    Huhtinen, Mika

    1998-01-01

    Simulated dose profiles in various irradiation and beam test conditions are compared to the expected dose profiles in the ECAL crystals at LHC. Simple front or side irradiations with photons give too steep or too flat dose profiles, respectively. Thus, if dose maxima are fitted to agree, front irradiation underestimate the average dose whereas side irradiations tend to overestimate. Different profiles are difficult to compare reliably, but it seems likely that in both cases the discrepancy is about a factor of 2-3 but in different directions. For most purposes this is likely to be good enough, but should be taken into account in the interpretation of the test results. It is shown that using a customized lead mask between the source and the crystal can significantly improve the agreement between 60 Co side irradiations and the LHC predictions. A 400 MeV/c pion beam incident on a crystal matrix can also reproduce rather well the profiles expected in the barrel ECAL.

  7. Effects on the glucose metabolism in type II diabetes model mice treated with dose-rates irradiation

    International Nuclear Information System (INIS)

    Nomura, Takaharu; Sakai, Kazuo

    2004-01-01

    The effects of low-dose rate gamma-irradiation on the type II diabetes mellitus were investigated in C57BL/KsJ-ab/db (db mouse). This mouse develops the type II diabetes within 8 weeks of the birth due to a dysfunction of the insulin receptors. As a result the db mouse shows obese and exhibits hyperinsulinism. Ten-week old female mice (12 mice in each group) were irradiated with gamma-rays at 0.35 mGy/hr, 0.65 mGy/hr or 1.2 mGy/hr in the low-dose rate irradiation facility in the Low Dose Radiation Research Center. The level of plasma glucose and insulin was measured. After 2 weeks irradiation, the glucose level slightly increased, however the difference between the irradiated mice and non-irradiated groups was not significant. The plasma insulin concentration decreased in the non-irradiated group to half of the initial level. In the irradiated group, it also decreased but in the group of 0.65 mGy/hr and 0.35 mGy/hr, it was significantly differed from that in the non-irradiated group. In the glucose tolerance test, plasma glucose level increased shortly after 0.1 mg/head glucose injection by mouth and reached to a peak at 90-120 min after the injection. The glucose level of the non-irradiated mice was slightly higher than that of irradiated mice. The plasma insulin level of non-irradiated group was enhanced after the injection and maintained the level during the test. However the levels of irradiated mice were decreased at 30-60 min after the injection. Both the level of non-irradiated an irradiated was almost same but the non-irradiated one was a little high. In all of mice, the plasma insulin level was highly elevated right after the 0.05 units/head insulin injection by i.p. and the levels were also gradually decreased. The level of the non-irradiated group was slowly decreased and was higher than the irradiated mice. The plasma glucose levels of all mice did not change after the test; however, the levels of irradiated mice were slightly lower than that of non-irradiated

  8. Serum protein concentration in low-dose total body irradiation of normal and malnourished rats

    International Nuclear Information System (INIS)

    Viana, W.C.M.; Lambertz, D.; Borges, E.S.; Neto, A.M.O.; Lambertz, K.M.F.T.; Amaral, A.

    2016-01-01

    Among the radiotherapeutics' modalities, total body irradiation (TBI) is used as treatment for certain hematological, oncological and immunological diseases. The aim of this study was to evaluate the long-term effects of low-dose TBI on plasma concentration of total protein and albumin using prematurely and undernourished rats as animal model. For this, four groups with 9 animals each were formed: Normal nourished (N); Malnourished (M); Irradiated Normal nourished (IN); Irradiated Malnourished (IM). At the age of 28 days, rats of the IN and IM groups underwent total body gamma irradiation with a source of cobalt-60. Total protein and Albumin in the blood serum was quantified by colorimetry. This research indicates that procedures involving low-dose total body irradiation in children have repercussions in the reduction in body-mass as well as in the plasma levels of total protein and albumin. Our findings reinforce the periodic monitoring of total serum protein and albumin levels as an important tool in long-term follow-up of pediatric patients in treatments associated to total body irradiation. - Highlights: • Low-dose total body irradiation (TBI) in children have repercussions in their body-mass. • Long-term total protein and albumin levels are affected by TBI. • The monitoring of total protein and albumin levels are useful in the follow-up of TBI pediatric patients.

  9. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. V. E

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1990-01-01

    These tables present data on the effects of low-level radiation dose for the following effects:- pre-conception irradiation and Down's Syndrome, pre-conception irradiation and reproductive damage, surveys of effect in relation to the source of radiation, distribution by maternal preconception exposure of the 7 most common major congenital abnormalities in the Japanese, pre-conception irradiation and childhood malignancies, parental gonadal dose at Hiroshima and Nagasaki in relation to leukemia, sex chromosome aneuploids in children of A-bomb survivors, untoward pregnancy outcomes by parental gonad dose, pre-conception irradiation and chromosomal abnormalities, and intra-uterine irradiation and intelligence. (author).

  10. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. V. E

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1990-01-01

    These tables present data on the effects of low-level radiation dose for the following effects:- pre-conception irradiation and Down's Syndrome, pre-conception irradiation and reproductive damage, surveys of effect in relation to the source of radiation, distribution by maternal preconception exposure of the 7 most common major congenital abnormalities in the Japanese, pre-conception irradiation and childhood malignancies, parental gonadal dose at Hiroshima and Nagasaki in relation to leukemia, sex chromosome aneuploids in children of A-bomb survivors, untoward pregnancy outcomes by parental gonad dose, pre-conception irradiation and chromosomal abnormalities, and intra-uterine irradiation and intelligence. (author)

  11. Age-dependent conversion coefficients for organ doses and effective doses for external neutron irradiation

    International Nuclear Information System (INIS)

    Nishizaki, Chihiro; Endo, Akira; Takahashi, Fumiaki

    2006-06-01

    To utilize dose assessment of the public for external neutron irradiation, conversion coefficients of absorbed doses of organs and effective doses were calculated using the numerical simulation technique for six different ages (adult, 15, 10, 5 and 1 years and newborn), which represent the member of the public. Calculations were performed using six age-specific anthropomorphic phantoms and a Monte Carlo radiation transport code for two irradiation geometries, anterior-posterior and rotational geometries, for 20 incident energies from thermal to 20 MeV. Effective doses defined by the 1990 Recommendation of ICRP were calculated from the absorbed doses in 21 organs. The calculated results were tabulated in the form of absorbed doses and effective doses per unit neutron fluence. The calculated conversion coefficients are used for dose assessment of the public around nuclear facilities and accelerator facilities. (author)

  12. Calcium carbonate as a possible dosimeter for high irradiation doses

    International Nuclear Information System (INIS)

    Negron M, A.; Ramos B, S.; Camargo R, C.; Uribe, R. M.; Gomez V, V.; Kobayashi, K.

    2014-08-01

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  13. Calcium carbonate as a possible dosimeter for high irradiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Ramos B, S.; Camargo R, C. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M. [Kent State University, College of Technology, Kent OH (United States); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Kobayashi, K., E-mail: negron@nucleares.unam.mx [Yokohama National University (Japan)

    2014-08-15

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  14. The development of radiocaries after high-dose irradiation

    International Nuclear Information System (INIS)

    Willich, N.; Gundacker, K.; Rohloff, R.

    1988-01-01

    39 patients, who were irradiated with doses of 50 to 70 Gy for ENT-tumors over a period of 3.5 months to three years prior to the examination, showed a rapidly progressing caries of the teeth inside the target volume. The teeth outside the target volume developed a caries of less extent. Radiation induced xerostomia, effects of the irradiation of the soft tissues, nutrition habits and hygienics are discussed as causes for the damage of the teeth. (orig.) [de

  15. Analysis of the radiolytic products on high-dose irradiated food and packing materials

    International Nuclear Information System (INIS)

    Kim, Kyong Su; Shim, Sung Lye; Chung, In Sun

    2010-04-01

    The aims of this study were to prepare the government approval for the extension of food irradiation item to food or its products, to promote the industrial application of radiation technology, and to apply basic data in policy for introduction of irradiation. The change of hydrocarbons by irradiation was evaluated for the detection of irradiated meat. The results showed that hydrocarbons were detected in all of irradiated samples, but these hydrocarbons were not detected in non-irradiated samples. There were no difference between vacuum and N 2 - packaging. According to fatty acid compounds and degradation pathway of beef and pork, it could be deliberated that a great amount of produced hydrocarbons such as 8-heptadenene and 1,7-hexadecadien were able to be used as identification factor of irradiated meat. Effects of γ-irradiation on the volatile organic compounds in agricultural products were determined by analyzing changes of volatile composition. The composition of volatile organic compounds were little changed, but few specific compounds induced by γ-irradiation were identified. The variations of concentration in irradiated samples identified in this study could be due to the radiation sensitivity of compounds with the dose used. Effects of γ-irradiation on the volatile compounds in packaging materials were determined by analyzing changes of volatile composition. In polyethylene and polypropylene, 1,3-DBB was identified only in irradiated samples. Levels of 1,3-DBB increased with increasing irradiation doses. These results suggest may be useful in evaluation of γ-irradiation effects on food packaging materials

  16. Analysis of the radiolytic products on high-dose irradiated food and packing materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyong Su; Shim, Sung Lye; Chung, In Sun [Chosun University, Gwangju (Korea, Republic of)

    2010-04-15

    The aims of this study were to prepare the government approval for the extension of food irradiation item to food or its products, to promote the industrial application of radiation technology, and to apply basic data in policy for introduction of irradiation. The change of hydrocarbons by irradiation was evaluated for the detection of irradiated meat. The results showed that hydrocarbons were detected in all of irradiated samples, but these hydrocarbons were not detected in non-irradiated samples. There were no difference between vacuum and N{sub 2}- packaging. According to fatty acid compounds and degradation pathway of beef and pork, it could be deliberated that a great amount of produced hydrocarbons such as 8-heptadenene and 1,7-hexadecadien were able to be used as identification factor of irradiated meat. Effects of {gamma}-irradiation on the volatile organic compounds in agricultural products were determined by analyzing changes of volatile composition. The composition of volatile organic compounds were little changed, but few specific compounds induced by {gamma}-irradiation were identified. The variations of concentration in irradiated samples identified in this study could be due to the radiation sensitivity of compounds with the dose used. Effects of {gamma}-irradiation on the volatile compounds in packaging materials were determined by analyzing changes of volatile composition. In polyethylene and polypropylene, 1,3-DBB was identified only in irradiated samples. Levels of 1,3-DBB increased with increasing irradiation doses. These results suggest may be useful in evaluation of {gamma}-irradiation effects on food packaging materials

  17. Dose rate modelled for the outdoors of a gamma irradiation

    International Nuclear Information System (INIS)

    Mangussi, J

    2012-01-01

    A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach's the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation as far as 200 m is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on graphics (author)

  18. Effect of radiation doses rate on SOS response induction in irradiated Escherichia coli Cells

    International Nuclear Information System (INIS)

    Cuetara Lugo, Elizabeth B.; Fuentes Lorenzo, Jorge L.; Almeida Varela, Eliseo; Prieto Miranda, Enrique F.; Sanchez Lamar, Angel; Llagostera Casal, Montserrat

    2005-01-01

    The present work is aimed to study the effect of radiation dose rate on the induction of SOS response in Escherichia coli cells. We measured the induction of sul A reporter gene in PQ-37 (SOS Chromotest) cells. Lead devises were built with different diameter and these were used for diminishing the dose rate of PX- -30M irradiator. Our results show that radiation doses rate significantly modifies the induction of SOS response. Induction factor increases proportionally to doses rate in Escherichia coli cells defective to nucleotide excision repair (uvrA), but not in wild type cells. We conclude that the dose rate affects the level of induction of SOS response

  19. Effects of single doses of X-rays on renal function in the pig after the irradiation of both kidneys

    International Nuclear Information System (INIS)

    Robbins, M.E.C.; Hopewell, J.W.

    1988-01-01

    Irradiation of a single kidney in the pig with relatively low doses of X-rays, in the order of 8 Gy, produces a pronounced reduction in both glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). This apparent high radiosensitivity may be due, in part, to the compensatory hypertrophy displayed by the contralateral unirradiated kidney. This could suppress any potential for recovery by the irradiated kidney. To test this hypothesis, both kidneys of 14-week-old Large White pigs were sequentially irradiated with single doses of 250 kV X-rays, in the range 8.8 to 12.6 Gy. Two weeks after irradiation, GFR and ERPF increased markedly in all irradiated kidneys; levels then declined in a dose-dependent manner. Following a dose of 8.8 Gy renal haemodynamics returned to control values within 4 weeks of irradiation. After higher doses, GFR and ERPF decreased markedly and remained below control values up to 24 weeks after irradiation. At all doses the mean functional status of irradiated kidneys in animals in which both kidneys were irradiated was significantly greater than that previously observed in the irradiated kidney of pigs in which only one kidney was irradiated. The findings support the above hypothesis, and indicate that individual kidneys in the same animal may differ in their response to a similar nephrotoxic insult. 35 refs.; 6 figs.; 2 tabs

  20. Parametric relationships for gamma dose and irradiation homogeneity in a sewage sludge irradiator

    International Nuclear Information System (INIS)

    Krishnamurthy, K.

    1986-01-01

    A study on the inter-relationships between factors governing γ dose and irradiation homogeneity in a sewage sludge irradiator is presented here. The analysis involves a 60 Co irradiator of cylindrical irradiation geometry with batchwise operation for hygienisation of liquid sludge. The influence of the parameters such as the source-target geometry, strength of 60 Co sources in the irradiator, hygienisation dose and rheological and hydraulic characteristics of sewage sludge on the selection of the three critical factors viz. the pumping rate (P) required to maintain turbulent flow regime in the irradiation zone; the mininum re-circulation time (Tsub(m)) essential to achieve a certain degree of homogeneity of dose absorption in the fluid; and the irradiation time (Tsub(i)) required to impart the necessary dose for the desired hygienisation effect in the sludge has been discussed in detail and inter-relationships among these three factors have been worked out. The applicability of the relationships to a typical operating plant has also been elucidated. (author)

  1. Estimation of dose in irradiated chicken bone by ESR method

    International Nuclear Information System (INIS)

    Tanabe, Hiroko; Hougetu, Daisuke

    1998-01-01

    The author studied the conditions needed to routinely estimate the radiation dose in chicken bone by repeated re-irradiation and measuring ESR signals. Chicken meat containing bone was γ-irradiated at doses of up to 3kGy, accepted as the commercially used dose. The results show that points in sample preparation and ESR measurement are as follows: Both ends of bone are cut off and central part of compact bone is used for experiment. To obtain accurate ESR spectrum, marrow should be scraped out completely. Sample bone fragments of 1-2mm particle size and ca.100mg are recommended to obtain stable and maximum signal. In practice, by re-irradiating up to 5kGy and extrapolating data of the signal intensity to zero using linear regression analysis, radiation dose is estimated. For example, in one experiment, estimated doses of chicken bones initially irradiated at 3.0kGy, 1.0kGy, 0.50kGy and 0.25kGy were 3.4kGy, 1.3kGy, 0.81kGy and 0.57kGy. (author)

  2. Estimate of absorbed dose received by individuals irradiated with neutrons

    International Nuclear Information System (INIS)

    Fonseca, E.S. da; Mauricio, C.L.P.

    1995-01-01

    An innovating methodology is proposed to estimate the absorbed dose received by individuals irradiated with neutrons in an accident, even in the case that the victim is not using any kind of neutron dosemeter. The method combines direct measurements of 24 Na and 32 P activated in the human body. The calculation method was developed using data taken from previously published papers and experimental measurements. Other irradiations results in different neutron spectra prove the validity of the methodology here proposed. Using a whole body counter to measure 24 Na activity, it is possible to evaluate neutron absorbed doses in the order of 140 μGy of very soft (thermal) spectra. For fast neutron fields, the lower limit for neutron dose detection increases, but the present method continues to be very useful in accidents, with higher neutron doses. (author). 5 refs., 1 fig., 4 tabs

  3. Effects of low priming dose irradiation on cell cycle arrest of HepG2 cells caused by high dose irradiation

    International Nuclear Information System (INIS)

    Xia Jingguang; Jin Xiaodong; Chinese Academy of Sciences, Beijing; Li Wenjian; Wang Jufang; Guo Chuanling; Gao Qingxiang

    2005-01-01

    Human hepatoma cells hepG2 were irradiated twice by 60 Co γ-rays with a priming dose of 5 cGy and a higher dose of 3 Gy performed 4h or 8h after the low dose irradiation. Effects of the priming dose irradiation on cell cycle arrest caused by high dose were examined with flow cytometry. Cells in G 2 /M phase accumulated temporarily after the 5 cGy irradiation, and proliferation of tumor cells was promoted significantly by the low dose irradiation. After the 3 Gy irradiation, G 2 phase arrest occurred, and S phase delayed temporally. In comparison with 3 kGy irradiation only, the priming dose delivered 4h prior to the high dose irradiation facilitated accumulation of hepG2 cells in G 2 /M phase, whereas the priming dose delivered 8h prior to the high dose irradiation helped the cells to overcome G 2 arrest. It was concluded that effects of the priming dose treatment on cell cycle arrest caused by high dose irradiation were dependent on time interval between the two irradiations. (authors)

  4. Colon mucosal cells after high-dose fractional irradiation

    International Nuclear Information System (INIS)

    Zorc-Pleskovic, R.; Vraspir-Porenta, O.; Petrovic, D.; Zorc, M.; Pleskovic, L.

    2000-01-01

    The aim of this study was to investigate histological and stereological changes in cryptal enterocytes, mucosal lymphocytes and mast cells 10 days after irradiation. For experimental model, 24 Beagle dogs 1-2 years old were used. Twelve dogs were irradiated 20 days with 32 Gy over the whole pelvis and tail. Another 12 dogs represented a control group. For the detection of apoptosis, the TUNEL technique was used. Histological and stereological analyses were performed using a Wild sampling microscope M 1000. In the irradiated group, volume density (P < 0.01), numerical density (P < 0.05) and average volume of lymphocytes (P < 0.001) were significantly lower than in the nonirradiated group. Numerical areal density of mast cells in the irradiated group was also significantly lower (P < 0.05). Volume density (P < 0.001) and average volume of mast cells (P < 0.001) were significantly higher in the irradiated group. The results of our experiments show that irradiation causes injury and loss of lymphocytes and mast cells in the colon mucosa. Apoptosis was detected in enterocytes and lymphocytes in the irradiated group and in nonirradiated group in equal numbers (2.5 ± 0.3 vs. 2.3 ± 0.3; ns.), suggesting that 10 days after high-dose irradiation, the cell loss is not due to apoptosis. (author)

  5. Reparative processes in spleen of rats irradiated with higher daily dose rates of continuous irradiation

    International Nuclear Information System (INIS)

    Mackova, N.; Praslicka, M.; Misurova, E.

    1975-01-01

    Histological and DNA content values were used in evaluating repair processes in the spleen of rats at various intervals following continuous irradiation with daily doses of 50 R, 100 R, 200 R and 500 R (a total dose of 1000 R), and following a single exposure to 1000 R. Histological changes found immediately after irradiation indicated the induction of significant injuries, this mainly as a result of daily doses of 200 R and 500 R. The complete repair of the DNA content and of a number of erythroid elements and also a 70 to 80% regeneration of the white pulp took place within 25 days. The same period was found to be insufficient for the complete repair of megakaryocytes. No signs of repair were observed in spleen in the histological picture or DNA content after a single irradiation with a dose of 1000 R. (author)

  6. Reparative processes in spleen of rats irradiated with higher daily dose rates of continuous irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Mackova, N; Praslicka, M; Misurova, E [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Prirodovedecka Fakulta

    1975-01-01

    Histological and DNA content values were used in evaluating repair processes in the spleen of rats at various intervals following continuous irradiation with daily doses of 50 R, 100 R, 200 R and 500 R (a total dose of 1000 R), and following a single exposure to 1000 R. Histological changes found immediately after irradiation indicated the induction of significant injuries, this mainly as a result of daily doses of 200 R and 500 R. The complete repair of the DNA content and of a number of erythroid elements and also a 70 to 80% regeneration of the white pulp took place within 25 days. The same period was found to be insufficient for the complete repair of megakaryocytes. No signs of repair were observed in spleen in the histological picture or DNA content after a single irradiation with a dose of 1000 R.

  7. Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

    Science.gov (United States)

    Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

    2001-01-01

    The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p < 0.05). Basal proliferation of leukocytes in the blood and spleen increased significantly with increasing dose (p < 0.05). Significant dose rate effects were observed only in thrombocyte counts. Plasma levels of transforming growth factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

  8. Oxidative stress and low dose irradiation

    International Nuclear Information System (INIS)

    Emerit, I.; Alaoui-Youssefi, A.; Cernjavski, L.

    1997-01-01

    Studies of this working group indicate a shift of the prooxidant - antioxidant balance to the prooxidant side for a large proportion of workers engaged in the clean-up of the Chernobyl Nuclear Power Plant in 1986-87. Similar findings were obtained in children exposed to radiation after the explosion or still living within contaminated regions. Increased superoxide and hydrogen peroxide production by phagocytes were correlated with an increase in lipid peroxiation products and a decrease in the enzymatic and non enzymatic antioxidant defenses of the organism. The calstogenic factor test, which detects the presence of lipid peroxidation products and cytokines due to their chromosome damaging effects, yielded positive results for 41% of 89 workers from Armenia and 52% of 200 workers from St. Petersburg. Clastogenic plasma activity was increased even in those workers, who had received radiation doses between 5 and 10 cGy only. The number of CF-positive workers increased in the subgroups with increasing radiation dose. In children, the data varied according to sites and suggested correlations with the radioactive contamination of the soil. Treatments with antioxidant vitamins, flavonoids and terpenes improved the health status of this high risk population. However, the type of antioxidant, the treatment schedule and the dosage have to be standardized in order to obtain comparable results. (author)

  9. Lipid peroxidation in microsomes of murine bone marrow after low-dose γ-irradiation

    International Nuclear Information System (INIS)

    Schwenke, K.; Coslar, S.; Muehlensiepen, H.; Altman, K.I.; Feinendegen, L.E.

    1994-01-01

    The principal aim of the study was to investigate the effect of low-dose γ-irradiation on lipid peroxidation (LPO) in murine bone marrow. To this end, the degree of LPO in suspensions of microsomes of murine bone marrow cells (BMC) was determined in terms of malondialdehyde (MDA) formation after whole-body or in vitro exposure to various doses of γ-radiation. These effects were compared to some extent with similar effects in liver and spleen preparations. As to the effect of γ-irradiation on LPO in BMC, the response depends on the dose level and on whether whole-body or in vitro exposures are involved. Whole-body irradiation did not result in an increase in LPO in BMC microsomes, even at such high doses as 15 Gy, although hepatic microsomes showed a marked increase. In contrast, in vitro irradiation of BMC microsomes with 0.1, 10 and 50 Gy brought about an increase in LPO. This increase was already significant (P < 0.05) at 0.1 Gy following a post-irradiation incubation and substantial at 50 Gy, even without subsequent incubation. The results show that low doses of γ-irradiation are able to induce an elevation of LPO in murine BMC microsomes, but only after in vitro irradiation. In the case of whole-body irradiation cellular radical scavengers and other metabolic reactions may prevent a measurable increase in LPO. This is partly illustrated by the case of vitamin-E deficiency, where a substantial increase in LPO in BMC microsomes is observed even without γ-irradiation in comparison with euvitaminotic mice because normally occurring radicals are not scavenged sufficiently. (orig.)

  10. The investigation of fetal doses in mantle field irradiation

    International Nuclear Information System (INIS)

    Karacam, S. C; Gueralp, O. S; Oeksuez, D. C; Koca, A.; Cepni, I.; Cepni, K.; Bese, N.

    2009-01-01

    To determine clinically the fetal dose from irradiation of Hodgkin's disease during pregnancy and to quantify the components of fetal dose using phantom measurements. The fetal dose was measured with phantom measurements using thermoluminescent dosemeters (TLDs). Phantom measurements were performed by simulating the treatment conditions on an anthropomorphic phantom. TLDs were placed on the phantom 41, 44, 46.5 and 49.5 cm from the centre of the treatment field. Two TLDs were placed on the surface of the phantom. The estimated total dose to all the TLDs ranged from 8.8 to 13.2 cGy for treatment with 60 Co and from 8.2 to 11.8 cGy for 4 MV photons. It was concluded that the doses in different sections were evaluated to investigate dose changes in different points and depths of fetal tissues in phantom. Precise planning and the use of supplemental fetal shielding may help reduce fetal exposure. (authors)

  11. The effects of chronic low dose irradiation on drosophila melanogaster

    International Nuclear Information System (INIS)

    Zajnullin, V.G.; Moskalev, A.A.; Shaposhnikov, M.V.; Yuraneva, I.N.; Taskaev, A.I.

    2001-01-01

    It was investigated the influence of the chronic gamma-irradiation in the dose rate of 0.17 cGy/h on the rate of genetic variability and on the life-span in the laboratory strains of Drosophila melanogaster with genotypic distinguishes in mobile genetic elements and defects in the DNA repair processes. It is shown that the radiation-induced alteration of the traits under study depends from genotype of investigated strains. In the different strains we have observed an increase as well as a decrease of the mutation rate and life-span. Also it was established that irradiation leads to the frequencies of the GD-sterility and mutability of the snw and h(w+) in the P-M and H-E dysgenic crosses. The obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation. (author)

  12. Genetic effects of low-dose irradiation in Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Zajnulin, V.G.; Shaposhnikov, M.V.; Yuraneva, I.N.

    2000-01-01

    Influence of chronic γ-irradiation at the dose rate of 0.17 cGy/h on the rate of genetic variability in the laboratory strains of Drosophila Melanogaster with genotypic distinguishes by families of mobile genetic elements and of systems of hybrid disgenesis and also violations in reparation processes control mechanisms. It was shown that the rates of induction of recessive lethal mutations depended on genotype of investigated strains. In the different strains an increase as well as a decrease of the mutation rate were observed. Also in was established that irradiation leads to the increase in frequencies of the gonads sterility and mutability of the sn w and h(w + ) in the P-M and H-E dysgenic crosses. Obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation [ru

  13. Genetic efficiency of low-dose chronic irradiation in mammals and fish

    International Nuclear Information System (INIS)

    Goncharova, R.; Ryabokon, N.; Smolich, I.; Slukvin, A.

    2001-01-01

    The problem of biological effects of low-dose chronic irradiation is central radiobiological problem and seems to be very important for human monitoring and risk assessment Since 1986 we are engaged in studying genetic effects of low-dose chronic irradiation in natural populations of small mammals (bank vole - Clethrioiiomys glareolus) inhabiting radiocontaminated monitoring sites, in laboratory hybrid mice CBA*C57BI/6 j exposed to chronic irradiation at radiocontaminated sites, as well as in pond carp (Cyprinus carpio) reared in fish farms in areas contaminated due to the Chernobyl accident. The mean ground depositions in monitoring sites were 8-2330 kBq/m 2 and the mean bottom depositions in ponds were 52-3235 Bq/kg for Cs 137. We used conventional cytogenetics and genetics tests [1-3] and the following approaches in studying on genetic effects of low-dose chronic irradiation: Radiation exposures from external γ- and internal α, β, γ-irradiation from incorporated radionuclides were estimated for each specimen tested. Regression analysis of dose-effect relationships based on comparison of individual genetic end-points with individual absorbed doses was carried out We observed statistically significant changes in the frequencies of genetic end-points, which have been studied in somatic and germ cells, as well as in embryos of irradiated mammals and fish. So, the frequencies of chromosome aberrations in bank vole populations had up to 7-fold increase in comparison with background and pre-accident levels. It is of great importance to emphasize high radio-sensitivity of fertilized eggs (zygotes) and pond carp, embryos produced by chronically irradiated parents. Regression analysis allowed to reveal dependence of the studied parameters' frequencies on radiation exposure namely on the concentrations of basic dose forming radionuclides, absorbed dose rate and whole body absorbed dose. In most cases, dose-effect relationships were better approximated by non

  14. Threshold irradiation dose for amorphization of silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Snead, L.L.; Zinkle, S.J. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface of strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10{sup {minus}3} dpa/s and with fission neutrons irradiated at 1 x 10{sup {minus}6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340 {+-} 10K.

  15. Method for dose calculation in intracavitary irradiation of endometrical carcinoma

    International Nuclear Information System (INIS)

    Zevrieva, I.F.; Ivashchenko, N.T.; Musapirova, N.A.; Fel'dman, S.Z.; Sajbekov, T.S.

    1979-01-01

    A method for dose calculation for the conditions of intracavitary gamma therapy of endometrial carcinoma using spherical and linear 60 Co sources was elaborated. Calculations of dose rates for different amount and orientation of spherical radiation sources and for different planes were made with the aid of BEhSM-4M computer. Dosimet were made with the aid of BEhSM-4M computer. Dosimetric study of dose fields was made using a phantom imitating the real conditions of irradiation. Discrepancies between experimental and calculated values are within the limits of the experiment accuracy

  16. Dose Response of Alanine Detectors Irradiated with Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

    2011-01-01

    Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions......-dose curves deviate from predictions in the peak region, most pronounced at the distal edge of the peak. Conclusions: The used model and its implementation show a good overall agreement for quasi mono energetic measurements. Deviations in depth-dose measurements are mainly attributed to uncertainties...

  17. Two-peaked dose curves for irradiated pollen growth

    International Nuclear Information System (INIS)

    Andrejchenko, S.V.; Grodzinskij, D.M.

    1992-01-01

    The effect of γ-radiation on growth activity of bicellular pollen of hybrid petunia has been investigated. Irradiation of pollen with doses of 5 to 70 Gy increases the pollen tube growth in an artificial culture medium. As the radiation dose increases the germination ability of pollen gradually decreases and the mean pollen tube length shortens, which is accompanied by the suppression of the generative cell division into spermia and inhibition of the unscheduled incorporation of labelled thymidine into DNA. With radiation doses of 1200 to 1700 Gy some pollen tubes grow intensively. It is suggested that the phenomenon observed lays the basis for the gametic transformation

  18. Effects of low dose rate irradiation on life span prolongation of human premature-aging syndrome model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu

    2006-01-01

    We previously showed that Type II diabetes model mice prolonged of their life span by life long low dose rate irradiation. We also found that antioxidant function in variety tissues of some strain of mice were enhancement after low dose/low dose rate irradiation. The prolongation of life span might depend on certain damaged level of reactive oxygen species. We thought the effect of the prolongation was due to the enhancement of the antioxidant activities after irradiation. We investigated whether the enhancement of antioxidant activities after low dose rate irradiation had an effect on life span prolongation. Four-week-old female human premature-aging syndrome model mice, kl/kl (klotho) mice, which the life span of this model mouse is about 65 days, were irradiated with gamma rays at 0.35, 0.70 or 1.2 mGy/hr. The 0.70 mGy/hr-irradiated group remarkably effected on the prolongation of their life span. Some mice of the group were extremely survived for about and more 100 days. Antioxidant activities in the irradiated groups were enhancement by low dose rate irradiation, however the dependence of the dose rates were not clearly difference. These results suggest that the antioxidant activities in this model mouse were enhanced by the low dose rate irradiation, and may make it possible to prolong the life span of this mouse. (author)

  19. SU-E-T-481: In Vivo and Post Mortem Animal Irradiation: Measured Vs. Calculated Doses

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, P [Univ New Mexico Radiology Dept., Albuquerque, NM (United States); Heintz, B [Texas Oncology, PA, Southlake, TX (United States); Sandoval, D [University of New Mexico, Albuquerque, NM (United States); Weber, W; Melo, D; Guilmette, R [Lovelace Respiratory Research Institute, Albuquerque, NM (United States)

    2015-06-15

    Purpose: Computerized radiation therapy treatment planning is performed on almost all patients today. However it is seldom used for laboratory irradiations. The first objective is to assess whether modern radiation therapy treatment planning (RTP) systems accurately predict the subject dose by comparing in vivo and decedent dose measurements to calculated doses. The other objective is determine the importance of using a RTP system for laboratory irradiations. Methods: 5 MOSFET radiation dosimeters were placed enterically in each subject (2 sedated Rhesus Macaques) to measure the absorbed dose at 5 levels (carina, lung, heart, liver and rectum) during whole body irradiation. The subjects were treated with large opposed lateral fields and extended distances to cover the entire subject using a Varian 600C linac. CT simulation was performed ante-mortem (AM) and post-mortem (PM). To compare AM and PM doses, calculation points were placed at the location of each dosimeter in the treatment plan. The measured results were compared to the results using Varian Eclipse and Prowess Panther RTP systems. Results: The Varian and Prowess treatment planning system agreed to within in +1.5% for both subjects. However there were significant differences between the measured and calculated doses. For both animals the calculated central axis dose was higher than prescribed by 3–5%. This was caused in part by inaccurate measurement of animal thickness at the time of irradiation. For one subject the doses ranged from 4% to 7% high and the other subject the doses ranged 7% to 14% high when compared to the RTP doses. Conclusions: Our results suggest that using proper CT RTP system can more accurately deliver the prescribed dose to laboratory subjects. It also shows that there is significant dose variation in such subjects when inhomogeneities are not considered in the planning process.

  20. Melanin is Effective Radioprotector against Chronic Irradiation and Low Radiation Doses

    International Nuclear Information System (INIS)

    Mosse, I.; Plotnikova, S.; Kostrova, L.; Molophei, V.; Dubovic, B.

    2001-01-01

    Full text: Earlier we found pigment melanin ability to reduce significantly genetic consequences of acute irradiation in animals (drosophila, mice) and cultured human cells and to decrease strongly 'genetic load' accumulated in irradiated populations. The influence of melanin isolated from human hair on genetic effects of chronic irradiation in mice has been investigated. Melanin suspension or distilled water were injected every day into stomach of animals during 1-3 Gy g-irradiation with dose rate 0.007Gy/h. Levels of reciprocal translocations in germ cells were analysed cytologically. Melanin influence on genetic effect of chronic irradiation was shown to be even more effective than that of acute one. Radioadaptive response was used in order to study melanin influence on low radiation dose effect. We have demonstrated adaptive response in mice germ cells and bone marrow cells frequency of chromosomal aberrations in these cells after 0.2+1.5 Gy was about half as much as 1.7 Gy effect. Melanin injection 2 hours before the conditioning dose of 0.2 Gy resulted in the same mutation level as before 1.7 Gy adaptive response was not found. If melanin was applied between the first and second doses, both adaptive reaction and protection led to 4-fold decrease in aberration level. Thus melanin is able to remove completely low radiation dose effect. Complete toxicological tests have been conducted. The pigment melanin is not toxic and does not possess a mutagenic, teratogenic or carcinogenic activity. Melanin could be used in medicine for people protection against genetic consequences of long-term irradiation at low doses. (author)

  1. Analytical dose modeling for preclinical proton irradiation of millimetric targets.

    Science.gov (United States)

    Vanstalle, Marie; Constanzo, Julie; Karakaya, Yusuf; Finck, Christian; Rousseau, Marc; Brasse, David

    2018-01-01

    Due to the considerable development of proton radiotherapy, several proton platforms have emerged to irradiate small animals in order to study the biological effectiveness of proton radiation. A dedicated analytical treatment planning tool was developed in this study to accurately calculate the delivered dose given the specific constraints imposed by the small dimensions of the irradiated areas. The treatment planning system (TPS) developed in this study is based on an analytical formulation of the Bragg peak and uses experimental range values of protons. The method was validated after comparison with experimental data from the literature and then compared to Monte Carlo simulations conducted using Geant4. Three examples of treatment planning, performed with phantoms made of water targets and bone-slab insert, were generated with the analytical formulation and Geant4. Each treatment planning was evaluated using dose-volume histograms and gamma index maps. We demonstrate the value of the analytical function for mouse irradiation, which requires a targeting accuracy of 0.1 mm. Using the appropriate database, the analytical modeling limits the errors caused by misestimating the stopping power. For example, 99% of a 1-mm tumor irradiated with a 24-MeV beam receives the prescribed dose. The analytical dose deviations from the prescribed dose remain within the dose tolerances stated by report 62 of the International Commission on Radiation Units and Measurements for all tested configurations. In addition, the gamma index maps show that the highly constrained targeting accuracy of 0.1 mm for mouse irradiation leads to a significant disagreement between Geant4 and the reference. This simulated treatment planning is nevertheless compatible with a targeting accuracy exceeding 0.2 mm, corresponding to rat and rabbit irradiations. Good dose accuracy for millimetric tumors is achieved with the analytical calculation used in this work. These volume sizes are typical in mouse

  2. Pre-irradiation at a low dose-rate blunted p53 response

    International Nuclear Information System (INIS)

    Takahashi, Akihisa

    2002-01-01

    We investigated whether chronic irradiation at a low dose-rate interferes with the p53-centered signal transduction pathyway induced by radiation in human cultured cells and C57BL/6N mice. In in vitro experiments, we found that a challenge with X-ray irradiation immediately after chronic irradiation resulted in lower levels of p53 than those observed after the challenge alone in glioblastoma cells (A-172). In addition, the levels of p53-centered apoptosis and its related proteins after the challenge were strongly correlated with the above-mentioned phenomena in squamous cell carcinoma cells (SAS/neo). In in vivo experiments, the accumulation of p53 and Bax, and the induction of apoptosis were observed dose-dependently in mouse spleen at 12 h after a challenge with X-rays (3.0 Gy). However, we found significant suppression of p53 and Bax accumulation and the induction of apoptosis 12 h after challenge irradiation at 3.0 Gy with a high doses-rate following chronic pre-irradiation (1.5 Gy, 0.001 Gy/min). These findings suggest that chronic pre-irradiation suppressed the p53 function through radiation-induced signaling and/or p53 stability. (author)

  3. Orientation of streptococcus agalactiae irradiation dose for subclinical mastitis vaccine in dairy cows

    International Nuclear Information System (INIS)

    Tuasikal, B.J.; Estuningsih, S.; Pasaribu, F.H.; Wibawan, I.W.T.

    2012-01-01

    An experiment to determine the effect of gamma-ray irradiation in debilitating Streptococcus agalactiae as a cause of subclinical mastitis (inflammation of the udder) in cows has been conducted. S. agalactiae bacteria was isolated from subclinical mastitis found in dairy cows in the field was then observed for its cell growth. The bacteria which have reached mid-log phase of growth, were divided into 5 treatment groups, of which each was irradiated at dose level of 0; 25; 50; 75; and 100Gy. Irradiated bacteria subsequently were grown on Brain Heart Infusion agar (BHI), and each of its colonies was counted for LD50 determination. The obtained curves from irradiated treatment bacterial shown viability percentage by the linier equation of Y = 95.414 e -0,0371X ; R 2 = 0.9979, while Y = % viability and X = dose of irradiation. The calculation done in this experiment shows that irradiation dose of 17.4 Gy weaken the bacteria pathogenicity of S. agalactiae to the level of LD 50 . (author)

  4. Reduction in flatulence factors in mung beans (Vigna radiata) using low-dose gamma-irradiation

    International Nuclear Information System (INIS)

    Machaiah, J.P.; Pednekar, M.D.; Thomas, P.

    1999-01-01

    Mungbeans (Vigna radiata), control and gamma-irradiated at insect disinfestation dose levels (0.25 and 0.75 kGy) were germinated (0-6 Bays) and the qualitative and quantitative changes in soluble carbohydrates were studied in detail. The key flatulence-producing raffinose family oligosaccharides inmungbeans were degraded in the irradiated samples at the onset of the germination (0-2 days) compared to the control where it occurred much later (>4days). However, the reducing sugars, mainly glucose, fructose and galactose, which are metabolised easily, were enhanced in the irradiated samples. At low dose (0.25 kGy), irradiation had no effect on germination and sprout length, indicating that irradiated beans are suitable for use as sprouted beans. These observations clearly indicate that gamma-irradiation at insect disinfestation dose levels improved the digestibility and nutritional quality of mung beans by reducing the content of oligosaccharides responsible for intestinal gas production. (C) 1999 Society of Chemical Industry

  5. Specification of absorbed dose for reporting a therapeutic irradiation

    International Nuclear Information System (INIS)

    Wambersie, A.; Chassagne, D.

    1981-01-01

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

  6. Genetic effects of low-level irradiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    1980-01-01

    Recent estimates of the genetic effects of radiation by two widely recognized committees (BEIR III and UNSCEAR 1977) are based to a large extent on data collected in mice using either the specific-locus method or the approach of empirically determining the nature and extent of radiation-induced genetic damage to the skeleton. Both committees made use of doubling-dose and direct methods of estimating genetic hazard. Their estimates can be applied to assessments of risk resulting from medical irradiation in terms both of risk to the population at large and to the individual

  7. Dose determination of 600 MeV proton irradiated specimens

    International Nuclear Information System (INIS)

    Gavillet, D.

    1991-01-01

    The calculation method for the experimental determination of the atomic production cross section from the γ activity measurements are presented. This method is used for the determination of some isotope production cross sections for 600 MeV proton irradition in MANET steel, copper, tungsten, gold and titanium. The results are compared with some calculation. These values are used to determine the dose of specimens irradiated in the PIREX II facility. The results are discussed in terms of the irradiation parameters. A guide for the use of the production cross section determined in the dosimetry experiment are given. (author) tabs., refs

  8. Uterine malignant degeneration after low-dose endometrial irradiation

    International Nuclear Information System (INIS)

    Nikkanen, V.; Salmi, T.; Groenroos, M.

    1980-01-01

    The effectiveness of low-dose intrauterine irradiation for benign diseases and its possible carcinogenic effect on the uterus was studied in 190 patients who were treated during the years 1952-1974. The indications for irradiation were premenopausal functional bleeding, leukemia, hemophilia, fibroids, endometriosis or other benign reason. Radiation was also performed on patients with severe neurologic diseases that contraindicated surgery and on some mentally retarded patients whose restlessness and epileptic seizures were aggravated premenstrually and during menstruation. The mean follow-up period was 15 years. Uterine bleeding recurred in 21 percent of the patients. No cases of uterine malignant degeneration were found. (author)

  9. High-dose irradiated food: Current progress, applications, and prospects

    Science.gov (United States)

    Feliciano, Chitho P.

    2018-03-01

    Food irradiation as an established and mature technology has gained more attention in the food industry for ensuring food safety and quality. Primarily used for phytosanitary applications, its use has been expanded for developing various food products for varied purposes (e.g. ready-to-eat & ready-to-cook foods, hospital diets, etc.). This paper summarized and analyzed the recent progress and application of high-dose irradiation and discussed its prospects in the field of food product development, its safety and quality.

  10. Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

    Science.gov (United States)

    Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

    2011-01-01

    Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

  11. Effect of low doses gamma irradiation of cotton seeds

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Khalifa, Kh.

    1996-01-01

    Field experiments and then large scale application of irradiated cotton seeds (C.V. Aleppo-40) were carried out during three seasons (1986, 1987 and 1988) for field experiment at ACSAD Station in Dier-Ezzor and 1988, 1989 and 1990 for large scale application at Euphrate's Basin, Al-Ghab and Salamia, farmers farms. The above areas were selected as they represent major cotton production areas in Syria. The aims of the experiments were to study the effect of low doses of gamma irradiation 0, 5, 10, 20, 30, 40 and 50 Gy on cotton yield and to look for the optimum dose of gamma irradiation to obtain best results. The results show that, there were positive effect (P<0.95) for doses 5-30 Gy in increasing cotton yield. The highest increase was at dose of 10 Gy. which as 19.5% higher than control. For the large scale application using 10 Gy the increase in cotton yield varied from 10-39% compared to control. (author). 11 refs., 6 figs

  12. Effect of large dose gamma-ray irradiation on polyimide

    International Nuclear Information System (INIS)

    Morita, Yohsuke; Watanabe, Kiyoshi; Yagyu, Hideki.

    1988-01-01

    In the radiation environment of atomic energy, space and so on, with the heightening of the performance of equipment, the organic materials having the radiation resistance up to several hundreds MGy have been demanded. Polyimide is one of a small number of the polymers which are considered to be applicable to such environment. However, actually the characteristics as the insulator for such large dose radiation environment have not been sufficiently verified. In this study, the gamma-ray of as large dose as 100 MGy was irradiated on the polyimides having different chemical structure in the air and in nitrogen, and the change of their mechanical and electrical characteristics was elucidated, at the same time, the structural change was examined. The four kinds of polyimides used for the experiment were three kinds of thermosetting type and thermoplastic polyether imide. Co-60 gamma-ray was irradiated at the dose rate of 17 kGy/h at room temperature. The tensile properties, volume resistivity, dielectric tangent, gel fraction, glass transition temperature and IR spectra were examined. In the air, the characteristics lowered by large dose irradiation due to the severance of main chains. In nitrogen, the deterioration was extremely slight, and cross-linking occurred. (K.I.)

  13. Prediction of midline dose from entrance ad exit dose using OSLD measurements for total irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chang Heon; Park, Jong Min; Park, So Yeon; Chun, Min Soo; Han, Ji Hye; Cho, Jin Dong; Kim, Jung In [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-06-15

    This study aims to predict the midline dose based on the entrance and exit doses from optically stimulated luminescence detector (OSLD) measurements for total body irradiation (TBI). For TBI treatment, beam data sets were measured for 6 MV and 15 MV beams. To evaluate the tissue lateral effect of various thicknesses, the midline dose and peak dose were measured using a solid water phantom (SWP) and ion chamber. The entrance and exit doses were measured using OSLDs. OSLDs were attached onto the central beam axis at the entrance and exit surfaces of the phantom. The predicted midline dose was evaluated as the sum of the entrance and exit doses by OSLD measurement. The ratio of the entrance dose to the exit dose was evaluated at various thicknesses. The ratio of the peak dose to the midline dose was 1.12 for a 30 cm thick SWP at both energies. When the patient thickness is greater than 30 cm, the 15 MV should be used to ensure dose homogeneity. The ratio of the entrance dose to the exit dose was less than 1.0 for thicknesses of less than 30 cm and 40 cm at 6 MV and 15 MV, respectively. Therefore, the predicted midline dose can be underestimated for thinner body. At 15 MV, the ratios were approximately 1.06 for a thickness of 50 cm. In cases where adult patients are treated with the 15 MV photon beam, it is possible for the predicted midline dose to be overestimated for parts of the body with a thickness of 50 cm or greater. The predicted midline dose and OSLD-measured midline dose depend on the phantom thickness. For in-vivo dosimetry of TBI, the measurement dose should be corrected in order to accurately predict the midline dose.

  14. High dose rate (HDR) and low dose rate (LDR) interstitial irradiation (IRT) of the rat spinal cord

    International Nuclear Information System (INIS)

    Pop, Lucas A.M.; Plas, Mirjam van der; Skwarchuk, Mark W.; Hanssen, Alex E.J.; Kogel, Albert J. van der

    1997-01-01

    Purpose: To describe a newly developed technique to study radiation tolerance of rat spinal cord to continuous interstitial irradiation (IRT) at different dose rates. Material and methods: Two parallel catheters are inserted just laterally on each side of the vertebral bodies from the level of Th 10 to L 4 . These catheters are afterloaded with two 192 Ir wires of 4 cm length each (activity 1-2.3 mCi/cm) for the low dose rate (LDR) IRT or connected to the HDR micro-Selectron for the high dose rate (HDR) IRT. Spinal cord target volume is located at the level of Th 12 -L 2 . Due to the rapid dose fall-off around the implanted sources, a dose inhomogeneity across the spinal cord thickness is obtained in the dorso-ventral direction. Using the 100% reference dose (rate) at the ventral side of the spinal cord to prescribe the dose, experiments have been carried out to obtain complete dose response curves at average dose rates of 0.49, 0.96 and 120 Gy/h. Paralysis of the hind-legs after 5-6 months and histopathological examination of the spinal cord of each irradiated rat are used as experimental endpoints. Results: The histopathological damage seen after irradiation is clearly reflected the inhomogeneous dose distribution around the implanted catheters, with the damage predominantly located in the dorsal tract of the cord or dorsal roots. With each reduction in average dose rate, spinal cord radiation tolerance is significantly increased. When the dose is prescribed at the 100% reference dose rate, the ED 50 (induction of paresis in 50% of the animals) for the HDR-IRT is 17.3 Gy. If the average dose rate is reduced from 120 Gy/h to 0.96 or 0.49 Gy/h, a 2.9- or 4.7-fold increase in the ED 50 values to 50.3 Gy and 80.9 Gy is observed; for the dose prescribed at the 150% reference dose rate (dorsal side of cord) ED 50 values are 26.0, 75.5 and 121.4 Gy, respectively. Using different types of analysis and in dependence of the dose prescription and reference dose rate, the

  15. Calculation of dose conversion factors for doses in the fingernails to organ doses at external gamma irradiation in air

    International Nuclear Information System (INIS)

    Khailov, A.M.; Ivannikov, A.I.; Skvortsov, V.G.; Stepanenko, V.F.; Orlenko, S.P.; Flood, A.B.; Williams, B.B.; Swartz, H.M.

    2015-01-01

    Absorbed doses to fingernails and organs were calculated for a set of homogenous external gamma-ray irradiation geometries in air. The doses were obtained by stochastic modeling of the ionizing particle transport (Monte Carlo method) for a mathematical human phantom with arms and hands placed loosely along the sides of the body. The resulting dose conversion factors for absorbed doses in fingernails can be used to assess the dose distribution and magnitude in practical dose reconstruction problems. For purposes of estimating dose in a large population exposed to radiation in order to triage people for treatment of acute radiation syndrome, the calculated data for a range of energies having a width of from 0.05 to 3.5 MeV were used to convert absorbed doses in fingernails to corresponding doses in organs and the whole body as well as the effective dose. Doses were assessed based on assumed rates of radioactive fallout at different time periods following a nuclear explosion. - Highlights: • Elemental composition and density of nails were determined. • MIRD-type mathematical human phantom with arms and hands was created. • Organ doses and doses to nails were calculated for external photon exposure in air. • Effective dose and nail doses values are close for rotational and soil surface exposures.

  16. Uniform dose compensation using field within a field technique in T-shaped irradiation for esophageal cancer

    International Nuclear Information System (INIS)

    Murakami, Ryuji; Sugahara, Takeshi; Baba, Yuji; Yamashita, Yasuyuki

    2003-01-01

    We devised a uniform compensation method to improve dose distribution using the field within a field technique in T-shaped irradiation for esophageal cancer. Isodose curves and dose volume histograms (DVH) of the esophagus in the treatment volume were examined in ten patients treated for esophageal cancers. For the DVH analysis, the prescription dose was 40 Gy to the center of the treatment volume, and the volume ratio of the esophagus receiving within ±5% of the prescription dose (38-42 Gy) was regarded as an index of dose homogeneity (V±5%). The peak dose in the conventional antero-posterior opposed fields irradiation existed at the clavicular level, and the 90% isodose curve crossing the esophagus almost corresponded to the top level of the aortic arch. When 40 Gy is irradiated, the maximum dose of the esophagus and V±5% were 45.55±0.55 Gy and 59.7±13.2% respectively. The dose distribution of the esophagus became relatively homogeneous when a 10% dose was added using the field within a field technique to the area under the bottom level of the aortic arch, and the maximum dose and V±5% were 42.53±0.94 Gy and 91.7±7.1% respectively. A 10% and more overdose area existed at the clavicular level in the conventional antero-posterior opposed fields irradiation. A relatively homogeneous dose distribution could be obtained using the field within a field technique. (author)

  17. Transcriptome profiling of mice testes following low dose irradiation

    DEFF Research Database (Denmark)

    Belling, Kirstine C.; Tanaka, Masami; Dalgaard, Marlene Danner

    2013-01-01

    ABSTRACT: BACKGROUND: Radiotherapy is used routinely to treat testicular cancer. Testicular cells vary in radio-sensitivity and the aim of this study was to investigate cellular and molecular changes caused by low dose irradiation of mice testis and to identify transcripts from different cell types...... in the adult testis. METHODS: Transcriptome profiling was performed on total RNA from testes sampled at various time points (n = 17) after 1 Gy of irradiation. Transcripts displaying large overall expression changes during the time series, but small expression changes between neighbouring time points were...... selected for further analysis. These transcripts were separated into clusters and their cellular origin was determined. Immunohistochemistry and in silico quantification was further used to study cellular changes post-irradiation (pi). RESULTS: We identified a subset of transcripts (n = 988) where changes...

  18. Hematological changes after single large dose half-body irradiation

    International Nuclear Information System (INIS)

    Herrmann, T.; Friedrich, S.; Jochem, I.; Eberhardt, H.J.; Koch, R.; Knorr, A.

    1981-01-01

    The determination of different peripheral blood parameters aimed at the study of side effects on the hematological cellular system following a 5 - 8 Gy single large dose half-body irradiation in 20 patients. Compared to the initial values the leukocytes between the 6. and 14., the thrombocytes between the 14. and 21. postirradiation day as well as the lymphocytes between 3 hours and 4 weeks postirradiation were significantly decreased without exhibiting complications such as hemorrhages or infections. The hemoglobin, hematocrit and reticulocyte values revealed but a slight decrease normalized within a 28 days postirradiation period. Transfusions were necessary when a tumor-caused anemia was present prior to irradiation. Changes in serum activity of aminotransferases and lactate dehydrogenase occured during the first hours after irradiation and were due to enzyme release from destroyed tumor cells

  19. Calculation of midplane dose for total body irradiation from entrance and exit dose MOSFET measurements.

    Science.gov (United States)

    Satory, P R

    2012-03-01

    This work is the development of a MOSFET based surface in vivo dosimetry system for total body irradiation patients treated with bilateral extended SSD beams using PMMA missing tissue compensators adjacent to the patient. An empirical formula to calculate midplane dose from MOSFET measured entrance and exit doses has been derived. The dependency of surface dose on the air-gap between the spoiler and the surface was investigated by suspending a spoiler above a water phantom, and taking percentage depth dose measurements (PDD). Exit and entrances doses were measured with MOSFETs in conjunction with midplane doses measured with an ion chamber. The entrance and exit doses were combined using an exponential attenuation formula to give an estimate of midplane dose and were compared to the midplane ion chamber measurement for a range of phantom thicknesses. Having a maximum PDD at the surface simplifies the prediction of midplane dose, which is achieved by ensuring that the air gap between the compensator and the surface is less than 10 cm. The comparison of estimated midplane dose and measured midplane dose showed no dependence on phantom thickness and an average correction factor of 0.88 was found. If the missing tissue compensators are kept within 10 cm of the patient then MOSFET measurements of entrance and exit dose can predict the midplane dose for the patient.

  20. Response of human fibroblasts to low dose rate gamma irradiation

    International Nuclear Information System (INIS)

    Dritschilo, A.; Brennan, T.; Weichselbaum, R.R.; Mossman, K.L.

    1984-01-01

    Cells from 11 human strains, including fibroblasts from patients with the genetic diseases of ataxia telangiectasia (AT), xeroderma pigmentosum (XP), and Fanconi's anemia (FA), were exposed to γ radiation at high (1.6-2.2 Gy/min) and at low (0.03-0.07 Gy/min) dose rates. Survival curves reveal an increase inthe terminal slope (D 0 ) when cells are irradiated at low dose rates compared to high dose rates. This was true for all cell lines tested, although the AT, FA, and XP cells are reported or postulated to have radiation repair deficiencies. From the response of these cells, it is apparent that radiation sensitivities differ; however, at low dose rate, all tested human cells are able to repair injury

  1. Pathological consequences of chronic low daily dose gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Seed, T.M.; Miller, A.C.; Ramakrishnan, N. [Armed Forces Radiobiology Research Inst., Bethesda, MD (United States); Fritz, T.E.

    2000-07-01

    The quantitative relationships between the chronic radiation exposure parameters of dose-rate and total dose in relation to associated health risks was examined in dogs. At a dose-rate of 75, 128, and 263 mGy/d the incidence of acute lymphohematopoietic suppression (aplastic anemia) and associated septic complications was 73%, 87%, and 100%, respectively, and it increased in dose-dependent manner. By contrast, at dose-rates below 75 mGy/d, late cancers contributed significantly to the death of relatively long-lived animals, whose mean survival time was 1800 days. Myeloproliferative disease (MPD), mainly myeloid leukemia, was the dominant pathology seen at the higher daily dose-rates (18.8-75 mGy/d). When daily exposure was carried out continuously, the incidence of MPD was quite high. It should be noted that the induction radiation-induced MPD in this study was highly significant, because spontaneous MPD is exceedingly rare in the dog. However, when the daily dose-rate was reduced further or exposure was discontinued, the incidence of MPD declined significantly. At these lower dose-rates, solid tumors contributed heavily to the life-shortening effects of chronic irradiation. The induction and progression of these survival-compromising, late forms of pathology appeared to be driven by the degree of hematopoietic suppression that occurred early during the exposure phase, and in turn by the capacity of hematopoietic system to repair itself, recover, and to accommodate under chronic radiation stress. (K.H.)

  2. Avoidance behaviour and anxiety in rats irradiated with a sublethal dose of gamma-rays.

    Science.gov (United States)

    Tomášová, Lenka; Smajda, B; Bona, M

    2011-12-01

    The aim of this study was to assess, whether a sublethal dose of gamma-rays will influence the avoidance behaviour and anxiety in rats and whether the response to radiation depends on time of day of its application. Adult male Wistar rats were tested in elevated plus-maze, in hot plate test and in the light/dark box in 4 regular intervals during a day. After two weeks the animals were irradiated with a whole-body dose 6 Gy of gamma-rays. One day after irradiation the animals were repeatedly tested in the same way, as before irradiation. In the plus-maze test an increased level of anxiety was established. The irradiation significantly decreased the locomotor activity of rats, but the extent of exploratory and comfortable behaviour were not altered. After irradiation, an elevated aversion to the thermal stimulus was observed in the hot plate test. The effects of radiation were more pronounced in the light period of the day, than in the dark one. No significant differences in aversion to light were detected after irradiation. The obtained results indicate, that sublethal doses of ionizing radiation can markedly influence the reactivity of animals to adverse stimuli, their motoric activity and emotional status, as well.

  3. Use of high irradiation doses for preservation of canned beef

    International Nuclear Information System (INIS)

    Hammad, A.A.I; Salem, F.A.; El-Sahy, K.M.; Rady, A.; Badr, H.H.

    1997-01-01

    The effect of high irradiation doses (11.25,22.5 and 45 KGy) on the bacteriology, organoleptic quality and shelf - life extension of beef meat that are hermetically sealed in metal cans was investigated in comparison with commercial heat sterilization. The unirradiated cans of pre cooked (enzyme inactivated) unirradiated beef were swollen after only one month of storage at ambient temperature (20-30 degree). Application of 11.25 and 22.5 kGy to vacuum packed and enzyme inactivated beef was not enough for sterilization and only delayed swelling of beef cans. Application of 45 KGy irradiation dose prevented swelling of beef vans up to 12 months at ambient temperature and provided meat product, similar to the commercial heat sterilized one, organoleptically acceptable and microbiologically safe. Running title: Radiation sterilization of meat

  4. Evaluation of dose to cardiac structures during breast irradiation

    DEFF Research Database (Denmark)

    Aznar, M C; Korreman, S-S; Pedersen, A N

    2011-01-01

    delivered to the heart and the LAD in respiration-adapted radiotherapy of patients with left-sided breast cancer. METHODS: 24 patients referred for adjuvant radiotherapy after breast-conserving surgery for left-sided lymph node positive breast cancer were evaluated. The whole heart, the arch of the LAD...... and the whole LAD were contoured. The radiation doses to all three cardiac structures were evaluated. RESULTS: For 13 patients, the plans were acceptable based on the criteria set for all 3 contours. For seven patients, the volume of heart irradiated was well below the set clinical threshold whereas a high dose...

  5. Irradiation in helical scanner: doses estimation, parameters choice

    International Nuclear Information System (INIS)

    Cordoliani, Y.S.; Boyer, B.; Jouan, E.; Beauvais, H.

    2001-01-01

    The new generation of helical scanners improves the diagnosis abilities and the service done to the patients. The rational use allows to give the patients a ratio benefit/risk far better than the almost medical examinations. It is particularly true for over sixty years old aged people, that have a null genetic risk and a practically null carcinogen risk; However, for young adults and children, it is necessary to banish any useless irradiation and limit exposure to the strict necessary for the diagnosis. It is necessary to develop a radiation protection culture, possible by the radiation doses index display and doses benchmarks knowledge. (N.C.)

  6. Irradiation of meningioma: a prototype circumscribed tumor for planning high-dose irradiation of the brain

    International Nuclear Information System (INIS)

    Friedman, M.

    1977-01-01

    The purpose of this report is to provide specific data concerning the radiation dose required to destroy meningioma, and to demonstrate that radiation doses much greater than the alleged tolerance dose, can be administered to the brain in some patients. Most meninglomas are not responsive to irradiation, but, some surgically incurable lesions benefit from irradiation with radically high doses to small volumes of tissue. The arrest of 7 of 12 consecutive meningiomas in adults for periods of 2 to 17 years following maximum tumor doses up to 8800 R in 40 days is reported in this paper. All patients, when irradiated, had active tumor in the form of inoperable primary tumor, recurrence, or known postoperative residual tumor. Three of the successful results were achieved with orthovoltage radiation. The incidence of brain damage may be acceptable to the patient when it is related to arrest of tumor growth but he must be forewarned of possible brain damage. The factors influencing the radioresponsiveness of meningioma are: the required tumor lethal dose, histology and vascularity of the tumor, anatomical site in the brain, treatment technique for each tumor site, small size of the treated volume, growth rate of the tumor, displacement of normal brain tissue by tumor, inherent individual variations of tumor and normal tissues, quality of the radiation, and tolerance of normal brain tissues. The role of these factors is discussed in the light of modern radiobiological concepts

  7. The effect of low-dose neutron irradiation on extracellular matrix

    International Nuclear Information System (INIS)

    Chen Tiehe; Lu Yongjie; Chai Mingsheng; Peng Wulin; Yang Yifang; Pan Yan; Chen Jinguo

    2003-01-01

    Projective: To study the effect of neutron irradiation on extracellular matrix. Methods: 120 male wistar rats were divided into four groups at random, and then exposed to neutron of 252 Cf-source at the doses of 0, 0.29, 0.62 and 1.20 Gy, respectively. After the exposure of 3 days, 1 month and 2 months, the rats were sacrificed and lung tissue specimens stored at -30 degree C. Hyaluronan, laminin, type III procollagen and type IV collagen in the lung tissue were detected by the method of radioimmunoassay. Results: The differences of the levels of hyaluronan in lung tissue among the groups were unsignificant. The levels of laminin in 0.29, 0.62 and 1.20 Gy groups after the 3-day exposure were remarkably different to those of the control group, and unable to recover completely even 2 months after the exposure. The levels of type IV collagen in higher three irradiated groups were all higher, but not significantly. The levels of type III procollagen in the early stage after exposure were higher, and later they lowered. Conclusion: The levels of some components of extracellular matrix in the lung tissue of rat can be changed by low-dose of neutron irradiation, but their variational modes and degrees depend on the dose of neutron irradiation and the length of period after exposure

  8. Thermal stability of low dose Ga+ ion irradiated spin valves

    International Nuclear Information System (INIS)

    Qi Xianjin; Wang Yingang; Zhou Guanghong; Li Ziquan

    2009-01-01

    The thermal stability of low dose Ga + ion irradiated spin valves has been investigated and compared with that of the as-prepared ones. The dependences of exchange field, measured using vibrating sample magnetometer at room temperature, on magnetic field sweep rate and time spent at negative saturation of the pinned ferromagnetic layer, and training effect were explored. The training effect is observed on both the irradiated spin valves and the as-prepared ones. The magnetic field sweep rate dependence of the exchange bias field of the irradiated spin valves is nearly the same as that of the as-prepared ones. For the as-prepared structure thermal activation has been observed, which showed that holding the irradiated structure at negative saturation of the pinned ferromagnetic layer for up to 28 hours results in no change in the exchange field. The results indicate that the thermal stability of the ion irradiated spin valves is the same as or even better than the as-prepared ones.

  9. Effect of single-dose low-level helium-neon laser irradiation on orthodontic pain: a split-mouth single-blind placebo-controlled randomized clinical trial.

    Science.gov (United States)

    Sobouti, Farhad; Khatami, Maziar; Chiniforush, Nasim; Rakhshan, Vahid; Shariati, Mahsa

    2015-01-01

    Pain is the most common complication of orthodontic treatment. Low-level laser therapy (LLLT) has been suggested as a new analgesic treatment free of the adverse effects of analgesic medications. However, it is not studied thoroughly, and the available studies are quite controversial. Moreover, helium neon (He-Ne) laser has not been assessed before. This split-mouth placebo-controlled randomized clinical trial was performed on 16 male and 14 female orthodontic patients requiring bilateral upper canine retraction. The study was performed at a private clinic in Sari, Iran, in 2014. It was single blind: patients, orthodontist, and personnel were blinded of the allocations, but the laser operator (periodontist) was not blinded. Once canine retractor was activated, a randomly selected maxillary quarter received a single dose of He-Ne laser irradiation (632.8 nm, 10 mw, 6 j/cm(2) density). The other quarter served as the placebo side, treated by the same device but powered off. In the first, second, fourth, and seventh days, blinded patients rated their pain sensed on each side at home using visual analog scale (VAS) questionnaires. There was no harm identified during or after the study. Pain changes were analyzed using two- and one-way repeated-measures ANOVA, Bonferroni, and t-test (α = 0.01, β > 0.99). This trial was not registered. It was self-funded by the authors. Sixteen males and 11 females remained in the study (aged 12-21). Average pain scores sensed in all 4 intervals on control and laser sides were 4.06 ± 2.85 and 2.35 ± 1.77, respectively (t-test P < 0.0001). One-way ANOVA showed significant pain declines over time, in each group (P < 0.0001). Two-way ANOVA showed significant effects for LLLT (P < 0.0001) and time (P = <0.0001). Single-dose He-Ne laser therapy might reduce orthodontic pain caused by retracting maxillary canines.

  10. Dose compensation of the total body irradiation therapy

    International Nuclear Information System (INIS)

    Lin, J.-P.; Chu, T.-C.; Liu, M.-T.

    2001-01-01

    The aim of the study is to improve dose uniformity in the body by the compensator-rice and to decrease the dose to the lung by the partial lung block. Rando phantom supine was set up to treat bilateral fields with a 15 MV linear accelerator at 415 cm treatment distance. The experimental procedure included three parts. The first part was the bilateral irradiation without rice compensator, and the second part was with rice compensator. In the third part, rice compensator and partial lung block were both used. The results of thermoluminescent dosimeters measurements indicated that without rice compensator the dose was non-uniform. Contrarily, the average dose homogeneity with rice compensator was measured within ±5%, except for the thorax region. Partial lung block can reduce the dose which the lung received. This is a simple method to improve the dose homogeneity and to reduce the lung dose received. The compensator-rice is cheap, and acrylic boxes are easy to obtain. Therefore, this technique is suitable for more studies

  11. Effects of irradiation at different dose rates on the onset of type I diabetes in model mice

    International Nuclear Information System (INIS)

    Nomura, Takashi; Sakai, Kazuo

    2003-01-01

    We previously demonstrated that low-dose irradiation (0.5 Gy) increased the level of antioxidants and decreased the level of lipid peroxide in normal mice. We also found that 0.5 Gy-irradiation of NOD mice suppressed the onset of type I diabetes. These results were obtained by the irradiation at high dose rate. The aim of the present study is to examine the effects at the low dose rate. The mice were acutely irradiated with 0.5 Gy of X-rays (300 kVp) at 94.2 Gy/hr at 10, 11, 12, 13 or 14 weeks of age, or chronically irradiated with 0.5 Gy of 137 Cs γ-rays at 0.95 mGy/hr starting at 10,11,12,13 or 14 weeks of age. When irradiated at 12th week with the high dose rate X-rays, the onset of diabetes suppressed, and the increase in the specific activity of superoxide dismutase (SOD) in pancreas was observed. On the other hand, the low dose rate γ-rays delivered from 12th week of age to 14th was less effective in the suppression of the incidence of diabetes than the high dose rate X-rays at the 12-14 weeks of age. Furthermore, the significant increase in pancreatic SOD activity was not observed after the low dose irradiation. Splenic macrophage activities of superoxide generation were not affected by the high dose rate irradiation nor the low dose rate irradiation. (author)

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

    International Nuclear Information System (INIS)

    Doerr, W.; Kummermehr, J.

    1990-01-01

    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

  13. Anomalous dose rate effects in gamma irradiated SiGe heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Banerjee, G.; Niu, G.; Cressler, J.D.; Clark, S.D.; Palmer, M.J.; Ahlgren, D.C.

    1999-01-01

    Low dose rate (LDR) cobalt-60 (0.1 rad(Si)/s) gamma irradiated Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) were studied. Comparisons were made with devices irradiated with 300 rad(Si)/s gamma radiation to verify if LDR radiation is a serious radiation hardness assurance (RHA) issue. Almost no LDR degradation was observed in this technology up to 50 krad(Si). The assumption of the presence of two competing mechanisms is justified by experimental results. At low total dose (le20 krad), an anomalous base current decrease was observed which is attributed to self-annealing of deep-level traps to shallower levels. An increase in base current at larger total doses is attributed to radiation induced generation-recombination (G/R) center generation. Experiments on gate-assisted lateral PNP transistors and 2D numerical simulations using MEDICI were used to confirm these assertions

  14. Changes in Serum Zinc, Copper and Ceruloplasmin Levels of Whole Body Gamma Irradiated Rats

    International Nuclear Information System (INIS)

    Abdou, M.I.; Shaban, H.A.; El Gohary, M.I.

    2011-01-01

    Rats are whole body irradiated with different Gamma radiation doses. Zinc and Copper, two important trace elements in the biological processes and Ceruloplasmin, a protein which carries more than 95% of serum Cu and has important roles in many vital processes are followed up in the irradiated rat sera. This work aimed to determine the changes in the serum levels of the three parameters (Zinc, Copper and Ceruloplasmin) through eight weeks follow up period (1st, 2nd, 3rd, 4th, 6th, and 8th week) post whole body gamma irradiation with three sub-lethal doses (2, 3.5 and 5 Gy) of rats. All the experimental animals did not receive any medical treatment. Zinc and Copper were measured using discrete nebulization flame atomic absorption spectrometry. Ceruloplasmin was measured using a colorimetric method. The statistical analyses of the results show that the Zinc levels of the irradiated groups decreased significantly post irradiation and then were recovered at the 6th week post irradiation. The Copper levels of the irradiated groups increased significantly and then were recovered at 6th week post irradiation. The levels of Ceruloplasmin in the same groups increased significantly throughout the whole follow up period. The conclusion is that, Zinc, Copper and Ceruloplasmin levels changed significantly in the irradiated groups compared to the control group with a maximum effect noted in the groups irradiated with the higher doses and that the lower dose irradiated groups recover earlier than the higher ones. Also the correlation between Copper and Zinc is reversible at different doses and that between Copper and Ceruloplasmin is direct

  15. Estimation of effective dose equivalente from external irradiations

    International Nuclear Information System (INIS)

    Wakabayashi, T.

    1985-07-01

    A methodology for computing effective dose equivalent, derived from the computer code ALGAM: Monte Carlo Estimation of Internal Dose from Gamma-ray Sources in a Phantom Man, developed at Oak Ridge National Laboratory, is presented. The modified code was run for 12 different photon energy levels, from 0,010 Mev to 4.0 Mev, which provides computing the absorved dose, for these energy levels, in each one of the 97 organs of the original code. The code also was run for the principal energy levels used in the calibration of the dosimetric films. The results of the absorved doses per photon obtained for these levels of energy have been transformed in effective dose equivalents. (M.A.C.) [pt

  16. Inverse dose-rate-effects on the expressions of extra-cellular matrix-related genes in low-dose-rate γ-ray irradiated murine cells

    International Nuclear Information System (INIS)

    Sugihara, Takashi; Tanaka, Kimio; Oghiso, Yoichi; Murano, Hayato

    2008-01-01

    Based on the results of previous microarray analyses of murine NIH3T3/PG13Luc cells irradiated with continuous low-dose-rate (LDR) γ-ray or end-high-dose-rate-irradiations (end-HDR) at the end of the LDR-irradiation period, the inverse dose-rate-effects on gene expression levels were observed. To compare differences of the effects between LDR-irradiation and HDR-irradiation, HDR-irradiations at 2 different times, one (ini-HDR) at the same time at the start of LDR-irradiation and the other (end-HDR), were performed. The up-regulated genes were classified into two types, in which one was up-regulated in LDR-, ini-HDR-, and end-HDR irradiation such as Cdkn1a and Ccng1, which were reported as p53-dependent genes, and the other was up-regulated in LDR- and ini-HDR irradiations such as pro-collagen TypeIa2/Colla2, TenascinC/Tnc, and Fibulin5/Fbln5, which were reported as extra-cellular matrix-related (ECM) genes. The time dependent gene expression patterns in LDR-irradiation were also classified into two types, in which one was an early response such as in Cdkn1a and Ccng1 and the other was a delayed response such as the ECM genes which have no linearity to total dose. The protein expression pattern of Cdkn1a increased dose dependently in LDR- and end-HDR-irradiations, but those of p53Ser15/18 and MDM2 in LDR-irradiations were different from end-HDR-irradiations. Furthermore, the gene expression levels of the ECM genes in embryonic fibroblasts from p53-deficient mice were not increased by LDR- and end-HDR-irradiation, so the delayed expressions of the ECM genes seem to be regulated by p53. Consequently, the inverse dose-rate-effects on the expression levels of the ECM genes in LDR- and end-HDR-irradiations may be explained from different time responses by p53 status. (author)

  17. Combined low- and high-dose irradiation and its interpretation from the point of view of radiation protection

    International Nuclear Information System (INIS)

    Beno, M.

    1996-01-01

    During the last decade some 'stimulating' or 'hormetic' effects have been ascribed to low-levels of radiation. The adaptive response was a phenomenon recently used as an argument among others advertising such hormetic effects of low dose irradiation. Human peripheral blood lymphocytes may show a decrease of chromosomal aberrations (CA) after high doses of ionizing radiation if they have been previously irradiated by small doses of internally deposited tritium from labelled thymidine, or by small doses of X-rays. This response looks as if some adaptation would take place to the low-dose irradiation and was called 'adaptive response' (AR). It was attributed to repair mechanisms elicited by damaging the lymphocyte DNA by small doses of radiation so that after the high dose, delivered at times when higher levels of repair proteins and other molecules are still present in cells, a lower damaging effect may be expressed. Our work was aimed at gaining information about the frequency distribution of the responses to a combination of low-dose irradiation with tritium and high-dose irradiation with gamma rays and at comparing two endpoints: counts of CA with counts of micronuclei (M) in lymphocytes from the same donors in a human population sample

  18. Enhanced aflatoxin production by aspergillus parasiticus and aspergillus flavus after low dose gamma irradiation

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1992-01-01

    Spores of Aspergillus parasiticus IFO 30179 and A. flavus var. columnaris S46 were irradiated at 0.05, 0.2 and 0.4 kGy in the synthetic low salts (SL) broth, and the effect on aflatoxin production was examined after 10 days incubation at 30 or 25degC. In these two strains, irradiation of spores at 0.05 kGy resulted in higher B1 or G1 production than the non-irradiated controles. However, spores of the both strains irradiated at 0.2 or 0.4 kGy produced less aflatoxins than non-irradiated controles. In the SL broth, apparent stimulation by low dose irradiation was slight, and these enhanced effects were not observed after reinfection to fresh SL broth. In the case of food samples, the levels of aflatoxin B 1 and G 1 with A. parasiticus were increased from 15 to 90% by incubation of irradiated spores at 1 kGy in autoclaved polished rice, black pepper, white pepper and red pepper. These enhancement would be induced by change of composition in each substrates. Mutations of fungi induced by irradiation is not effective for enhancement of aflatoxin production. (author)

  19. Minimizing and measuring lens dose when giving cranial irradiation

    International Nuclear Information System (INIS)

    Woo, S.Y.; Donaldson, S.S.; Heck, R.J.; Nielson, K.L.; Shostak, C.

    1989-01-01

    Three different techniques of administering cranial irradiation were used to determine the dose to the lens as measured in the Rando phantom. The techniques employed were as follows: (1) the central axis of the radiation beam was placed at the thickest portion of the cranium; (2) the central axis of the radiation beam was placed at the lateral orbital rim (bon canthus); (3) the central axis of the radiation beam was placed at the thickest portion of the cranium but with the beam angled 5deg posteriorly away from the eye. Thermal luminescent dosimeters (TLD) were placed in a phantom, at a point determined from a life-sized anatomical section of the plane through the midsection of the eye, to be at the location of the posterior capsule of the lens. In addition, TLDs were placed on the outer surface of the phantom head, directly lateral to the location determined to be where the lens would lie. With equally weighted lateral opposed beams, delivering a midplane dose of 200cGy, the TLDs at the point of the lens measured 21, 9.9 and 10.6% of the midplane doses from the three techniques respectively. TLDs placed directly lateral to the lens on the surface of the phantom head gave an approximation of the lens dose, particularly when techniques 2 and 3 were used. Isodose curve generated by a General Electric treatment planning computer gave lens doses similar to those of the phantom data for each of the three different radiotherapy techniques. Cranial irradiation should be carried out by either technique 2 or technique 3 to minimize radiation dose to the lens. (author). 11 refs.; 2 figs.; 3 tabs

  20. Effect of ultra-low dose whole-body-irradiation on severe patients with myasthenia gravis

    International Nuclear Information System (INIS)

    Arimori, Shigeru; Koriyama, Kenji

    1982-01-01

    An ultra-low dose whole body irradiation therapy was given to 5 patients with intractable bulbar syndrome, in a dose of 10 rad/fraction, 2 times a week for 5 weeks, with a total of 100 rad; and effects of this therapy on their clinical symptoms and immunological ability were discussed. In 3 of them, bulbar syndrome was improved, and the other one, the first irradiation was effective. The peripheral leukocyte count and lymphocyte count became lowest immediately after completion of the irradiation, and returned to the normal level within 1 to 2 months. The function of T-cells, especially suppressive T-cells, was recovered; and decrease in B-cells, resulted in a decrease in the AChR antibody titer. (Ueda, J.)

  1. Effect of ultra-low dose whole-body-irradiation on patients with severe myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Arimori, Shigeru; Koriyama, Kenji (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

    1982-12-01

    An ultra-low dose whole body irradiation therapy was given to 5 patients with intractable bulbar syndrome, in a dose of 10 rad/fraction, 2 times a week for 5 weeks, with a total of 100 rad; and effects of this therapy on their clinical symptoms and immunological ability were discussed. In 3 of them, bulbar syndrome was improved, and the other one, the first irradiation was effective. The peripheral leukocyte count and lymphocyte count became lowest immediately after completion of the irradiation, and returned to the normal level within 1 to 2 months. The function of T-cells, especially suppressive T-cells, was recovered; and decrease in B-cells, resulted in a decrease in the AChR antibody titer.

  2. Patient absorbed radiation doses estimation related to irradiation anatomy

    International Nuclear Information System (INIS)

    Soares, Flavio Augusto Penna; Soares, Amanda Anastacio; Kahl, Gabrielly Gomes

    2014-01-01

    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

  3. Shelf-stable food through high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Placek, V. E-mail: pla@ujv.cz; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M

    2004-10-01

    Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO{sub x}-containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested.

  4. Shelf-stable food through high dose irradiation

    International Nuclear Information System (INIS)

    Placek, V.; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M.

    2004-01-01

    Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO x -containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested

  5. Development of a dose simulation software for gamma irradiation systems

    International Nuclear Information System (INIS)

    Omi, Nelson Minoru

    2000-01-01

    The use of high temperature, thermal and chemical treatment are among the used sterilization process of food and many products. The ionizing radiation came as another option, it has being used for many purposes and it became available due to the technological development in the second half of the 20 th century. Together with sterilization, many uses of the ionizing radiation were developed, such as applications on health, industrial products and waste recycling, food irradiation, vulcanizing, polymerization and gems color enhancing. The 60 Co gamma stands out among the used radiation sources on commercial facilities. lt is used to optimize this process with many dose mapping tests. The objective of this work is to develop a software to simulate the doses in 60 Co gamma irradiation systems. lt can be used to optimize a process on the project stage of a facility and to make viability studies for new applications in installations already set up. The validation of this software was done comparing the simulation results with the dosimetry data of an operating irradiation plant. The flexibility of the software was verified with extra dosimetry tests performed in another sterilization facility. (author)

  6. The application of high dose food irradiation in South Africa

    Science.gov (United States)

    de Bruyn, Ingrid Nine

    2000-03-01

    During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive "dried cooked" taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between -20 and -40°C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa.

  7. The application of high dose food irradiation in South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Bruyn, Ingrid Nine de E-mail: debruyni@mweb.co.za

    2000-03-01

    During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive 'dried cooked' taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between -20 and -40 deg. C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa. (author)

  8. The application of high dose food irradiation in South Africa

    International Nuclear Information System (INIS)

    Bruyn, Ingrid Nine de

    2000-01-01

    During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive 'dried cooked' taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between -20 and -40 deg. C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa. (author)

  9. High dose neutron irradiation damage in beryllium as blanket material

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V.P. E-mail: fae@niiar.ru; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B. E-mail: vniinm.400@g23.relkom.ru

    2001-11-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10{sup 22} and 8.0x10{sup 22} cm{sup -2} (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10{sup 22} cm{sup -2} (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10{sup 22} cm{sup -2} (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket.

  10. High dose neutron irradiation damage in beryllium as blanket material

    International Nuclear Information System (INIS)

    Chakin, V.P.; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B.

    2001-01-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10 22 and 8.0x10 22 cm -2 (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10 22 cm -2 (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10 22 cm -2 (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket

  11. Conditioned instrumental behaviour in the rat: Effects of prenatal irradiation with various low dose-rate doses

    International Nuclear Information System (INIS)

    Klug, H.

    1986-01-01

    4 groups of rats of the Wistar-strain were subjected to γ-irradiation on the 16th day of gestation. 5 rats received 0,6 Gy low dose rate irradiation, 5 animals received 0,9 Gy low dose and 6 high dose irradiation, 3 females were shamirradiated. The male offspring of these 3 irradiation groups and 1 control group were tested for locomotor coordination on parallel bars and in a water maze. The female offspring were used in an operant conditioning test. The locomotor test showed slight impairment of locomotor coordination in those animals irradiated with 0,9 Gy high dose rate. Swimming ability was significantly impaired by irradiation with 0,9 Gy high dose rate. Performance in the operant conditioning task was improved by irradiation with 0,9 Gy both low and high dose rate. The 0,9 Gy high dose rate group learned faster than all the other groups. For the dose of 0,9 Gy a significant dose rate effect could be observed. For the dose of 0,6 Gy a similar tendency was observed, differences between 0,6 Gy high and low dose rate and controls not being significant. (orig./MG) [de

  12. Hematopoietic tissue repair under chronic low daily dose irradiation

    International Nuclear Information System (INIS)

    Seed, T.M.

    1994-01-01

    The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). We have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3-26.3 cGy d -1 ). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup (1), the failure to augment basic m-pair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments particularly marked within erythroid compartments. that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccomodated and either prone- or not prone to ML, subgroup 2 ampersand 3 appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high- tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity

  13. Dose-time relationships for post-irradiation cutaneous telangiectasia

    International Nuclear Information System (INIS)

    Cohen, L.; Ubaldi, S.E.

    1977-01-01

    Seventy-five patients who had received electron beam radiation a year or more previously were studied. The irradiated skin portals were photographed and late reactions graded in terms of the number and severity of telangiectatic lesions observed. The skin dose, number of fractions, overall treatment time and irradiated volume were recorded in each case. A Strandqvist-type iso-effect line was derived for this response. A multi-probit search program also was used to derive best-fitting cell population kinetic parameters for the same data. From these parameters a comprehensive iso-effect table could be computed for a wide range of treatment schedules including daily treatment as well as fractionation at shorter and longer intervals; this provided a useful set of normal tissue tolerance limits for late effects

  14. Dose-response studies of depletion and repopulation of rat intestinal mucosal mast cells after irradiation

    International Nuclear Information System (INIS)

    Sedgwick, D.M.; Ferguson, A.

    1994-01-01

    The effects of radiation on gut mucosal mast cells (MMC) and tissue eosinophils were examined. Groups of rats were given single doses of whole-body irradiation from 0.5 to 5 Gy. Serum rat mast cell protease II (RMCPII) concentration showed a significant dose-dependent fall after 1 Gy on day 3 and 1.5 Gy on day 7. MMC counts and tissue RMCPII values on day 7 decreased significantly by 70% after 1 Gy and were undetectable with larger doses. Rats with normal and expanded MMC populations were irradiated or given anaphylaxis. Serum RMCPII concentrations did not change after irradiation, but there was a 10-fold increase in RMCPII after anaphylaxis. Tissue eosinophils in jejunum were 50% of control at 7 days after 2 Gy, and this effect was progressively more marked with higher doses. Similar effects on MMC and eosinophils were demonstrated in ileum, ascending colon and rectum. After 4.5 Gy, repopulation of the gut with MMC did not occur until week 3-4 postirradiation and MMC counts were still 50% below those of controls at 5 weeks postirradiation. Counts of tisse eosinophils 5 weeks after 4.5 Gy irradiation had returned to control levels in jejunum but were still significantly depleted in colon. (Author)

  15. Study on cellular survival adaptive response induced by low dose irradiation of 153Sm

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Xiao Dong

    1999-01-01

    The present study engages in determining whether low dose irradiation of 153 Sm could cut down the responsiveness of cellular survival to subsequent high dose exposure of 153 Sm so as to make an inquiry into approach the protective action of adaptive response by second irradiation of 153 Sm. Experimental results indicate that for inductive low dose of radionuclide 153 Sm 3.7 kBq/ml irradiated beforehand to cells has obvious resistant effect in succession after high dose irradiation of 153 Sm 3.7 x 10 2 kBq/ml was observed. Cells exposed to low dose irradiation of 153 Sm become adapted and therefore the subsequent cellular survival rate induced by high dose of 153 Sm is sufficiently higher than high dose of 153 Sm merely. It is evident that cellular survival adaptive response could be induced by pure low dose irradiation of 153 Sm only

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

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

    International Nuclear Information System (INIS)

    Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade

    2009-01-01

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

  18. Development of computerized dose planning system and applicator for high dose rate remote afterloading irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. J. [Keimyung Univ., Taegu (Korea); Kim, S. W. [Fatima Hospital, Taegu (Korea); Kim, O. B.; Lee, H. J.; Won, C. H. [Keimyung Univ., Taegu (Korea); Yoon, S. M. [Dong-a Univ., Pusan (Korea)

    2000-04-01

    To design and fabricate of the high dose rate source and applicators which are tandem, ovoids and colpostat for OB/Gyn brachytherapy includes the computerized dose planning system. Designed the high dose rate Ir-192 source with nuclide atomic power irradiation and investigated the dose characteristics of fabricated brachysource. We performed the effect of self-absorption and determining the gamma constant and output factor and determined the apparent activity of designed source. he automated computer planning system provided the 2D distribution and 3D includes analysis programs. Created the high dose rate source Ir-192, 10 Ci(370GBq). The effective attenuation factor from the self-absorption and source wall was examined to 0.55 of the activity of bare source and this factor is useful for determination of the apparent activity and gamma constant 4.69 Rcm{sup 2}/mCi-hr. Fabricated the colpostat was investigated the dose distributions of frontal, axial and sagittal plane in intra-cavitary radiation therapy for cervical cancer. The reduce dose at bladder and rectum area was found about 20 % of original dose. The computerized brachytherapy planning system provides the 2-dimensional isodose and 3-D include the dose-volume histogram(DVH) with graphic-user-interface mode. emoted afterloading device was built for experiment of created Ir-192 source with film dosimetry within {+-}1 mm discrepancy. 34 refs., 25 figs., 11 tabs. (Author)

  19. Characterizing low dose and dose rate effects in rodent and human neural stem cells exposed to proton and gamma irradiation

    Directory of Open Access Journals (Sweden)

    Bertrand P. Tseng

    2013-01-01

    Full Text Available Past work has shown that exposure to gamma rays and protons elicit a persistent oxidative stress in rodent and human neural stem cells (hNSCs. We have now adapted these studies to more realistic exposure scenarios in space, using lower doses and dose rates of these radiation modalities, to further elucidate the role of radiation-induced oxidative stress in these cells. Rodent neural stem and precursor cells grown as neurospheres and human neural stem cells grown as monolayers were subjected to acute and multi-dosing paradigms at differing dose rates and analyzed for changes in reactive oxygen species (ROS, reactive nitrogen species (RNS, nitric oxide and superoxide for 2 days after irradiation. While acute exposures led to significant changes in both cell types, hNSCs in particular, exhibited marked and significant elevations in radiation-induced oxidative stress. Elevated oxidative stress was more significant in hNSCs as opposed to their rodent counterparts, and hNSCs were significantly more sensitive to low dose exposures in terms of survival. Combinations of protons and γ-rays delivered as lower priming or higher challenge doses elicited radioadaptive changes that were associated with improved survival, but in general, only under conditions where the levels of reactive species were suppressed compared to cells irradiated acutely. Protective radioadaptive effects on survival were eliminated in the presence of the antioxidant N-acetylcysteine, suggesting further that radiation-induced oxidative stress could activate pro-survival signaling pathways that were sensitive to redox state. Data corroborates much of our past work and shows that low dose and dose rate exposures elicit significant changes in oxidative stress that have functional consequences on survival.

  20. Impacts of low dose rate irradiation on the fertility, fecundity and hatchling survival of Japanese rice fish (medaka, Oryzias latipes)

    International Nuclear Information System (INIS)

    Hinton, T.G.; Coughlin, D.P.; Marsh, L.C.; Yi, Yi; Winn, R.

    2004-01-01

    A renewed international interest in the effects on biota from low dose rate irradiation has recently occurred. Much of that interest is centered on the relevance of previously accepted dose rate guidelines (e.g. 10 mGy d -1 for aquatic biota) suggested by the ICRP and IAEA. All parties concerned seem to agree that additional data are needed on population level impacts from chronic low-level exposures to radionuclides. Using a Low Dose Rate Irradiation Facility (LoDIF), we conducted an experiment on the fecundity, fertility and hatchling survival of Japanese Rice Fish (medaka, Oryzias latipes). Fish were exposed externally to 137 Cs from juvenile through adulthood at mean dose rates of 3.5, 35 and 350 mGy d -1 . Fish were bred at maturity and the following endpoints were examined: 1) the number of eggs produced; 2) the percent of eggs that hatched; and 3) the survival of hatchlings 20-days post hatch. The influence of gender was examined by breeding irradiated males with control females; control males with irradiated females; irradiated males with irradiated females; and control males with control females. The data contribute to our understanding the impacts of low dose rate irradiation. (author)

  1. The disturbances of lipid metabolism regulation after the prenatal low-level irradiation

    International Nuclear Information System (INIS)

    Rogov, Yu.I.; Danil'chik, V.S.; Spivak, L.V.; Rubchenya, I.N.

    2000-01-01

    The objective of this study was to assess the influence of low-level irradiation on lipid metabolism in rats after prenatal exposure. Pregnant rats were irradiated during the period of gestation with the whole final dose 0,5 Gy/rat. The blood lipid fractions were investigated in newborn rats and in 6-month age rats. In irradiated offspring the lipo synthesis processes exceeded lipolysis in comparison with that of the control. The negative consequences of embryo low-level irradiation in the lipid metabolism regulation are discussed in this report. (authors)

  2. Introduction of guidance dose levels inpaediatrics CT

    International Nuclear Information System (INIS)

    Verdun, F.R.; Valley, J.F.; Bernasconi, M.; Schnyder, P.; Gudinchet, F.

    2001-01-01

    The purpose of this work is to present a methodology in order to define reference levels for chest or abdominal CT examinations performed on children. For children aged from 0 to 6 the CTDI w measured in the head test object (i.e. diameter 16 cm) should be used as a dose indicator. For children older than 12 years old the CTDI w measured in the body test object (i.e. 32 cm) should be used as a dose indicator. For children aged between 6 to 12 we propose to use an intermediate CTDI w in order to avoid an over or underestimation of the dose delivered in the slices. Finally a set of dose length products (DLP) measured in our centre for standard abdominal acquisitions will be given. (author)

  3. Shelf Life of Tilapia Fillets Treated with low dose Gamma Irradiation

    International Nuclear Information System (INIS)

    Mohamed, W.S.; El-Mossalami, I.I.

    2009-01-01

    The bacterial load (total bacterial count), Psychrophilic count, chemical and sensory examinations in Tilapia fish fillets were determined to evaluate its sanitary status and to increase its storage period during storage at -18 degree C for one year. The experiment was carried out at the time of receiving the samples and after gamma radiation treatment with dose levels of 1, 2 and 3 kGy. The initial total bacterial count was 5.4x10 0 cfu/gm and the psychrophilic count was 4x10 5 cfu/gm; it was slightly increased during freezing storage. The chemical parameters were more indicative in evaluating the shelf life of frozen fish; as they exceeded the permissible limits, so that the frozen non-irradiated samples were rejected after 6 months. The exposure to gamma irradiation at a dose of 1 kGy extended the storage time of the samples to 9 months while irradiation with 3 kGy extended the storage time of the samples to 12 months without changing its quality attributes. The quality during storage at -18 degree C of non irradiated and irradiated fish fillets was investigated every 3 months for one year by measuring the bacterial counts, chemical parameters and sensorial evaluation of the samples to study the effect of irradiation on increasing the storage time of fish fillets. So, it is recommended that fish fillets should be properly cleaned, packaged and exposed to gamma irradiation at a dose of 3 kGy to extend its freezing storage period

  4. Constant-dose microwave irradiation of insect pupae

    Science.gov (United States)

    Olsen, Richard G.

    Pupae of the yellow mealworm Tenebrio molitor L. were subjected to microwave irradiation for 1.5-24 hours at power density levels adjusted to produce a total dosage of approximately 1123 J/g in each insect for every experiment. Insects without visible blemishes were exposed in a standing wave irradiation system such that half of them were exposed in the plane of maximum electric field (E field) and the other half were exposed in the plane of maximum magnetic field (H field). Both E field and H field insects exhibited nearly the same specific absorption rate (SAR) for pupal orientation parallel to the magnetic field vector at 5.95 GHz. Irradiations were conducted both with and without the use of a ventilating fan to control the temperature rise in the irradiation chamber. Abnormal development as a result of the microwave exposure was seen only in the high-power, short-duration experiment without chamber ventilation. This result suggests a thermal interaction mechanism for explanation of observed microwave-induced abnormalities. A study of the time course of the average temperature rise in the irradiated insects indicates that teratological effects for this configuration have a temperature threshold of approximately 40°C.

  5. Recovery Effect and Life Prolong Effect of Long Term Low-Dose Rate Irradiation on Type II Diabetes Model Mice

    International Nuclear Information System (INIS)

    Nomura, T.; Makino, N.; Oda, T.; Suzuki, I.; Sakai, K

    2004-01-01

    The effects of low-dose rate gamma-irradiation were investigated on model mice for type II diabetes mellitus, C57BL/KsJ-db/db. The mice develop the type II diabetes by 10 weeks of age due to obesity and are characterized by hyperinsulinemia. Female 10-week old mice, a group of 12 mice, were irradiated at 0.65 mGy/hr from 137-Cs (370 GBq). The urine glucose levels of all of the mice were strongly positive at the beginning of the irradiation. In the irradiated group, the decrease in the glucose level was observed in 3 mice. Such recovery from the diabetes was never observed in 12 mice of non-irradiated control group. There is no systematic difference in the change of body weight, food assumption, and amount of drinking water, between the irradiated group and the non-irradiated group or between the recovered mice and the non-recovered mice. The survival was better in the irradiated group: the surviving fraction at the age of 90 weeks was 75% in the irradiated group, while 40% in the non-irradiated. Marked difference was also observed in the appearance of the coat hair, skin, and tail; better condition was kept in the irradiated group. In the irradiated mice mortality was delayed and the healthy appearance was prolonged in the irradiated mice by about 20 ? 30 weeks compared with the non-irradiated mice. These results suggest that the low-dose irradiation modified the condition of the diabetic mice, which lead not only to the recovery of the diabetes, but also to the suppression of the aging process. (Author)

  6. Optical fiber sensor for low dose gamma irradiation monitoring

    Science.gov (United States)

    de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

    2016-05-01

    An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

  7. Effect of gamma irradiation at doses of 5-15 kGy on the quality properties of durum wheat semolina

    International Nuclear Information System (INIS)

    Taha, S.A.

    1990-01-01

    Semolina purified from four durum wheat varieties were gamma-irradiated with doses of 0, 5, 10 and 15 kGy, i.e., dose levels expected to improve the colour of pasta products, suitable for reduction of microbial contamination, and high doses required for insect disinfestation. The irradiation resulted in significant losses in carotenoid content and oxidative enzyme activities. Gamma irradiation slightly affected the mixing properties, greatly reduced the gluten strength and adversely affected firmness of cooked pasta. Consequently, preservative gamma irradiation of durum wheat semolina should be limited to a maximum dose of 5 kGy. (author) 39 refs.; 3 tabs

  8. Dose volume relationships for intraoperatively irradiated saphenous nerve

    International Nuclear Information System (INIS)

    Gillette, E.L.; Powers, B.E.; Gillette, S.M.; Thames, H.D.; Childs, G.; Vujaskovic, Z.; LaRue, S.M.

    1995-01-01

    Purpose/Objective: Intraoperative radiation therapy (IORT) is used to deliver high single doses of radiation to the tumor bed following surgical removal of various abdominal malignancies. The advantage of IORT is the ability to remove sensitive normal tissues from the treatment field and to limit the volume of normal tissue irradiated. The purpose of this study was to determine dose-volume relationships for retroperitoneal tissues. Materials and methods: 134 adult beagle dogs were irradiated to the surgically exposed paraaortic area. Normal tissues included in the treatment field were aorta, peripheral nerve, ureter, bone and muscle. Groups of 4 - 8 dogs were irradiated to doses ranging from 18 - 54 Gy for a 2x5 cm field, from 12 - 46 Gy for a 4x5 cm field, and 12 - 42 Gy to an 8x5 cm field. The radiations were done using 6 MeV electrons from a linear accelerator. Dogs were observed for three years after radiation. Electrophysiologic procedures were done prior to irradiation and annually following irradiation. The procedures included electromyography of the pelvic limb and paralumbar muscles supplied by the L1 to S1 spinal nerves to determine presence and degree of motor unit disease. Motor nerve conduction velocities of the proximal and distal sciatic nerves were determined. Sensory nerve conduction velocities of the saphenous nerve were also determined. Evoked lumbosacral and thoraco-lumbar spinal cord potentials were evaluated following stimulation of the left sciatic nerve. In addition to electrophysiologic studies, neurologic examinations were done prior to treatment and at six month intervals for the three year observation period. At the three year time period, dogs were euthanatized, sections of peripheral nerve taken, routinely processed, stained with Masson's trichrome and evaluated histomorphometrically using point count techniques. Results: Twenty-two dogs were euthanatized prior to the three year observation period due to peripheral nerve damage

  9. Dose rate and dose fractionation studies in total body irradiation of dogs

    International Nuclear Information System (INIS)

    Kolb, H.J.; Netzel, B.; Schaffer, E.; Kolb, H.

    1979-01-01

    Total body irradiation (TBI) with 800-900 rads and allogeneic bone marrow transplantation according to the regimen designated by the Seattle group has induced remissions in patients with otherwise refractory acute leukemias. Relapse of leukemia after bone marrow transplantation remains the major problem, when the Seattle set up of two opposing 60 Co-sources and a low dose rate is used in TBI. Studies in dogs with TBI at various dose rates confirmed observations in mice that gastrointestinal toxicity is unlike toxicity against hemopoietic stem cells and possibly also leukemic stem cells depending on the dose rate. However, following very high single doses (2400 R) and marrow infusion acute gastrointestinal toxicity was not prevented by the lowest dose rate studied (0.5 R/min). Fractionated TBI with fractions of 600 R in addition to 1200 R (1000 rads) permitted the application of total doses up to 300 R followed by marrow infusion without irreversible toxicity. 26 dogs given 2400-3000 R have been observed for presently up to 2 years with regard to delayed radiation toxicity. This toxicity was mild in dogs given single doses at a low dose rate or fractionated TBI. Fractionated TBI is presently evaluated with allogeneic transplants in the dog before being applied to leukemic patients

  10. Quality characteristics of mechanically deboned chicken meat irradiated with different dose rates

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Poliana de Paula; Roque, Claudio Vitor; Fukuma, Henrique Takuji; Gomes, Heliana de Azevedo [Brazilian Nuclear Energy Commission (CNEN-MG), Pocos de Caldas, MG (Brazil)]. E-mails: polibrito@yahoo.com.br; cvroque@cnen.gov.br; htfukuma@cnen.gov.br; hgomes@cnen.gov.br; Cipolli, Katia Maria Vieira Avelar Bittencourt [Sao Paulo Agribusiness Technology Agency (APTA), Monte Alegre do Sul, SP (Brazil). Polo Regional do Leste Paulista]. E-mail: katiacipolli@aptaregional.sp.gov.br; Pereira, Jose Luiz [Campinas State University UNICAMP, Campinas, SP (Brazil). Dept. of Food Sciences]. E-mail: pereira@fea.unicamp.br

    2007-07-01

    Mechanically Deboned Chicken Meat (MDCM) is a low cost raw material used in the production of emulsified prepared food, but presents a favorable medium for development of microorganisms. Several studies were carried out with irradiation of edible goods in order to establish a dose that would be capable of decreasing levels of microorganisms without altering the sensorial and nutritional characteristics of the food. Frozen samples of MDCM with skin were irradiated with doses of 0.0 kGy, 3.0 kGy-4.04 kGy.h{sup -1}, and 3.0- 0.32 kGy.h{sup -1}. Individual lots of irradiated and control samples were evaluated during the 11 day refrigeration period for the following parameters: total count of psychotropic bacteria, substances reactive to Thiobarbituric Acid, sensorial evaluation (irradiated odor, oxidized odor, pink and brown colors). The average values in this period were 4.28 log (CFU.g{sup -1}), 2.32 log (CFU.g{sup -1}), and 1.68 log (CFU.g{sup -1}) for control samples, low and high dose rate, respectively. TBARS average values for control samples, low and high dose rate were 0.38 mg.Mal.kg{sup -1}, 2.89 mg.Mal.kg{sup -1}, and 3.64 mg.Mal.kg{sup -}'1, respectively. A difference between irradiated samples and the control sample was observed. The 3.0 kGy-4.04 kGy.h{sup -1} dose rate was verified as the best condition for MDCM processing through the evaluation of all the variables in the conditions of the present study. (author)

  11. Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

    International Nuclear Information System (INIS)

    Mansonr, S.Z.

    2009-01-01

    Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

  12. Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

    International Nuclear Information System (INIS)

    Mansonr, S.Z.

    2008-01-01

    Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

  13. Identification of irradiated meat using electron spin resonance (ESR) spectroscopy and estimation of applied dose using re-irradiation

    International Nuclear Information System (INIS)

    Chawla, S.P.; Thomas, Paul; Bongirwar, D.R.

    2001-01-01

    An in-house blind trail on bone-in meat chunks was carried out in which 35 coded samples were correctly identified. The samples were either left unirradiated or had been irradiated to dose of 1, 2.5 or 4 kGy. Using re-irradiation, the dose received by the samples were determined with either linear, quadratic or exponential equation. The quadratic or exponential equation gave more successful estimates of irradiation dose whereas linear fit equations tend to over estimate the dose. (author)

  14. Effects of low-dose fractionated external irradiation on metabolic and structural characteristics of rat thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Nadolnik, L.; Niatsetskaya, Z. [Institute of Biochemistry, National Academy of Sciences of Belarus, Grodno (Belarus)

    2006-07-01

    Full text of publication follows: The problem of thyroid radiosensitivity to the effect of low dose external ionizing irradiation presently seems to be the least studied, and the experimental findings - the most contradictory. The aim of the work was to study the effects of long-term low-dose fractionated irradiation on the iodide metabolism and structure of the thyroid. Female Wistar rats weighing 140-160 g were irradiated 20 times (5 times a week, for 4 weeks) using a 60 Co installation. The single absorbed doses were 0.1, 0.25 and 0.5 Gy and the total ones - 2.0, 5.0 and 10.0 Gy, respectively. The animals were decapitated after 1 day, 4 and 24 weeks following the last irradiation. The thyroid tissue was used to assay for thyro-peroxidase (T.P.O.) activity as well as total, protein -bound and free iodide concentrations. Microscopic and morphometric examination of histologic thyroid preparations was carried out. Blood was assayed for thyroxin (T4) and triiodothyronine (T3) concentrations. After a day following the irradiation, the thyroid showed a pronounced increase in the concentration of total iodide (30.0-54.4%) as well in that of free (32.1-60.8%) and protein-bound ones (24.4-37.4%). The most pronounced iodide concentration elevation was noted in the 0.1 -Gy animals, with thyroid T.P.O. activity being raised by 48.0%. Only the 0.5 Gy-group had 1.4-1.5-fold reduced thyroid hormone levels. Four weeks after the irradiation, studied parameters of irradiated rats were brought back to the control values, except for the 0.5 Gy-group. However, after 24-weeks, the 0.5-and 0.25- irradiated rats experienced a 12-20% thyroid weight elevation in comparison with the control. The thyroid of these animals demonstrated reduced contents of total and free iodide as well as T.P.O. activity by 24.5 and 34.8%. The 0.1 Gy-group had a 1.7-fold increased T.P.O. activity. The concentration of the thyroid hormones was maintained diminished only in the 0.5 Gy -irradiated group. However

  15. Equivalent uniform dose concept evaluated by theoretical dose volume histograms for thoracic irradiation.

    Science.gov (United States)

    Dumas, J L; Lorchel, F; Perrot, Y; Aletti, P; Noel, A; Wolf, D; Courvoisier, P; Bosset, J F

    2007-03-01

    The goal of our study was to quantify the limits of the EUD models for use in score functions in inverse planning software, and for clinical application. We focused on oesophagus cancer irradiation. Our evaluation was based on theoretical dose volume histograms (DVH), and we analyzed them using volumetric and linear quadratic EUD models, average and maximum dose concepts, the linear quadratic model and the differential area between each DVH. We evaluated our models using theoretical and more complex DVHs for the above regions of interest. We studied three types of DVH for the target volume: the first followed the ICRU dose homogeneity recommendations; the second was built out of the first requirements and the same average dose was built in for all cases; the third was truncated by a small dose hole. We also built theoretical DVHs for the organs at risk, in order to evaluate the limits of, and the ways to use both EUD(1) and EUD/LQ models, comparing them to the traditional ways of scoring a treatment plan. For each volume of interest we built theoretical treatment plans with differences in the fractionation. We concluded that both volumetric and linear quadratic EUDs should be used. Volumetric EUD(1) takes into account neither hot-cold spot compensation nor the differences in fractionation, but it is more sensitive to the increase of the irradiated volume. With linear quadratic EUD/LQ, a volumetric analysis of fractionation variation effort can be performed.

  16. Cation disorder in high-dose, neutron-irradiated spinel

    International Nuclear Information System (INIS)

    Sickafus, K.E.; Larson, A.C.; Yu, N.; Nastasi, M.; Hollenberg, G.W.; Garner, F.A.; Bradt, R.C.

    1994-08-01

    The objective of this effort is to determine whether MgAl 2 O 4 spinel is a suitable ceramic for fusion applications. Here, the crystal structures of MgAl 2 O 4 spinel single crystals irradiated to high neutron fluences [>5·10 26 n/m 2 (E n > 0.1 MeV)] were examined by neutron diffraction. Crystal structure refinement of the highest dose sample indicated that the average scattering strength of the tetrahedral crystal sites decreased by ∼ 20% while increasing by ∼ 8% on octahedral sites. Since the neutron scattering length for Mg is considerably larger than for Al, this results is consistent with site exchange between Mg 2+ ions on tetrahedral sites and Al 3+ ions on octahedral sites. Least-squares refinements also indicated that, in all irradiated samples, at least 35% of Mg 2+ and Al 3+ ions in the crystal experienced disordering replacements. This retained dpa on the cation sublattices is the largest retained damage ever measured in an irradiated spinel material

  17. Absorbed dose distribution analyses in irradiation with adjacent fields

    International Nuclear Information System (INIS)

    Cudalbu, C.; Onuc, C.; Andrada, S.

    2002-01-01

    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

  18. Biophysical Monitoring and dose response characteristics of irradiated hemoglobin

    International Nuclear Information System (INIS)

    Elshemey, W.M; Selim, N.S.; Desouky, O.

    2003-01-01

    The present work aims to move a step forward towards a deeper understanding of the scattering of x-ray, from lyophilized biological samples. Comparative study has been performed using LAXS and UV-visible spectrophotometry for monitoring the dose response characteristics of the hemoglobin molecule of irradiated blood. Blood samples were irradiated at doses ranging from 5 up to 100 Gy. Diluted hemoglobin solution was scanned in the UV- visible range (200-700 nm), and lyophilized hemoglobin was prepared for LAXS measurement. The radiation-induced changes in the hemoglobin structure have been evaluated. The LAXS profile of hemoglobin molecule is characterized by the presence of two peaks in the forward direction of scattering. These peaks were found to be sensitive to the variations in the molecular structure of a given sample. The obtained results suggest that the 1 s t peak, recorded at 4.65 o , is sensitive to the tertiary and quaternary structure of the globin part, while the major peak, recorded at 10.5 o , appeared to be related to its primary and secondary structure

  19. Stock selection of high-dose-irradiation-resistant materials for filter press under high-dose irradiation operation

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro; Minami, Mamoru; Hara, Kouji; Yamashita, Manabu

    2015-01-01

    In a volume reduction process for the decontamination of contained soil, the performance degradation of a filter press is expected owing to material deterioration under high-dose irradiation. Eleven-stock selection of candidate materials including polymers, fibers and rubbers for the filter press was conducted to achieve a high performance of volume reduction of contaminated soil and the following results were derived. Crude rubber and nylon were selected as prime candidates for packing, diaphragm and filter plate materials. Polyethylene was also selected as a prime candidate for the filter cloth material. (author)

  20. Stimulation effects of low dose-rate irradiation on pancreatic antioxidant activity in type II diabetes model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu; Sakai, Kazuo

    2005-01-01

    The effects of low dose-rate gamma irradiation on the type II diabetes mellitus were investigated in BKS.Cg-+Lepr db /+Lepr db /Jcl (DB mice). Ten-week-old female DB mice (5 mice in each group) were irradiated with gamma ray at 0.35, 0.70, or 1.2 mGy/hr. During the course of the 12 weeks the glucose level slightly increased with little difference between the irradiated and the non-irradiated groups. The plasma insulin concentration decreased within the first 4 weeks in all groups. The level was kept low in the non-irradiated mice; while the insulin level in the irradiated groups showed a tendency to increase. In the 0.70 mGy/hr group the increase was statistically significant after 12 weeks of irradiation. Total activity of SOD, one of antioxidative enzymes, decreased both in non-irradiated and irradiated groups; however the decrease was less in the irradiated groups, especially 0.70 mGy/hr group. In the 0.70 mGy/hr group Mn-SOD activity, one of the components of total SOD activity, increased after 12-week irradiation. A pathological examination of the pancreas revealed that damage to β cells responsible for the secretion of insulin was much less in the 0.70 mGy/hr group compared to that in the non-irradiated group. These results indicated that the low dose-rate irradiation increase the antioxidative capacity in the pancreas to protect β cells from oxidative damage, and the to increase the insulin level. This mechanism would lead the mice to the recovery from the disease and the prolongation of the life span as is demonstrated in our previous report. (author)

  1. Marrow toxicity of fractionated vs. single dose total body irradiation is identical in a canine model

    International Nuclear Information System (INIS)

    Storb, R.; Raff, R.F.; Graham, T.; Appelbaum, F.R.; Deeg, H.J.; Schuening, F.G.; Shulman, H.; Pepe, M.

    1993-01-01

    The authors explored in dogs the marrow toxicity of single dose total body irradiation delivered from two opposing 60 Co sources at a rate of 10 cGy/min and compared results to those seen with total body irradiation administered in 100 cGy fractions with minimum interfraction intervals of 6 hr. Dogs were not given marrow transplants. They found that 200 cGy single dose total body irradiation was sublethal, with 12 of 13 dogs showing hematopoietic recovery and survival. Seven of 21 dogs given 300 cGy single dose total body irradiation survived compared to 6 of 10 dogs given 300 cGy fractionated total body irradiation. One of 28 dogs given 400 cGy single dose total body irradiation survived compared to none of six given fractionated radiation. With granulocyte colony stimulating factor (GCSF) administered from day 0-21 after 400 cGy total body irradiation, most dogs survived with hematological recovery. Because of the almost uniform success with GCSF after 400 cGy single dose total body irradiation, a study of GCSF after 400 cGy fractionated total body irradiation was deemed not to be informative and, thus, not carried out. Additional comparisons between single dose and fractionated total body irradiation were carried out with GCSF administered after 500 and 600 cGy of total body irradiation. As with lower doses of total body irradiation, no significant survival differences were seen between the two modes of total body irradiation, and only 3 of 26 dogs studied survived with complete hematological recovery. Overall, therefore, survival among dogs given single dose total body irradiation was not different from that of dogs given fractionated total body irradiation (p = .67). Similarly, the slopes of the postirradiation declines of granulocyte and platelet counts and the rates of their recovery in surviving dogs given equal total doses of single versus fractionated total body irradiation were indistinguishable. 24 refs., 3 figs., 2 tabs

  2. Nicotinamide adenosine dinucleotide level in dimethylsulfate-treated or UV-irradiated mouse epidermis

    International Nuclear Information System (INIS)

    Balard, B.; Giacomoni, P.U.

    1989-01-01

    The level of nicotinamide (NAD) has been determined in the epidermis of 30 mice. Its value is 0.63+-0.15 μg/mg protein. Upon treatment with dimethylsulfate (DMS), the level of NAD drops in a dosedependent fashion. This diminution is reversible when low doses of DMS are used. Upon irradiation with ultraviolet light, the level of NAD drops in the irradiated epidermis, the treshold of saturation being below 1200 J/m 2 . There is also a drop in the level of NAD in the epidermis protected against irradiation with a black rubber sheet. (author). 17 refs.; 6 figs.; 1 tab

  3. Gamma knife radiosurgery for ten or more brain metastases. Analysis of the whole brain irradiation doses

    International Nuclear Information System (INIS)

    Nakaya, Kotaro; Hori, Tomokatsu; Izawa, Masahiro; Yamamoto, Masaaki

    2002-01-01

    Gamma knife (GK) radiosurgery has recently been recognized as the most powerful treatment modality in managing patients with brain metastasis, be they radioresistant or not, solitary or multiple. Very recently, this treatment has been employed in patients with numerous brain metastases, even those with 10 or more lesions. However, cumulative irradiation doses to the whole brain, with such treatment, remain unknown. Since the Gamma Plan ver. 5.10 (ver. 5.30 is presently available, Leksell Gamma Plan) became available in November, 1998, 105 GK procedures have been performed at our two facilities, Tokyo Women's Medical University and Katsuta Hospital Mito Gamma House. The median lesion number was 17, ranging 10-43, and the median cumulative volume of all tumors was 8.72 cm 3 , ranging 0.41-81.41 cm 3 . The selected doses at the lesion periphery ranged 12-25 Gy, the median being 20 Gy. Based on these treatment protocols, the cumulative irradiation dose was computed. The median cumulative irradiation dose to the whole brain was 4.83, ranging 2.16-8.51 Gy: the median integrated dose to the whole brain was 6.2 J, ranging 2.16-11.9 J. The median brain volumes receiving ≥2, ≥5, ≥10, ≥15 and ≥20 Gy were 1105 (range: 410-1501), 309 (46-1247), 64 (13-282), 24 (2-77), and 8 (0-40) cm 3 , respectively. The cumulative whole brain irradiation doses for patients with numerous radiosurgical targets were considered not to exceed the threshold level of normal brain necrosis. (author)

  4. 1H MRS can detect dose dependent effects in irradiated tumor cells and spheroids

    International Nuclear Information System (INIS)

    Grande, S.; Viti, V.; Guidoni, L.; Luciani, A.M.

    2003-01-01

    Full text: 1 H MR spectra of tumour cells are often characterised by the presence of intense signals from the methylene fatty acid chains of mobile lipids (ML), mostly triglycerides (TG). In previous work (Magnetic Resonance in Medicine ,1999, 42:248-257), we showed that the intensity of these signals is modulated by cell proliferation. Polyunsaturation levels of the fatty acid chains were also found higher when mobile lipid signals were intense, in agreement with independent findings by other authors (Nat. Med . 1999, 5:1323-1327). Cells from breast carcinoma (MCF 7) were irradiated at increasing doses (5 - 40 Gy) to detect spectral differences in irradiated cells and to relate them to the metabolic breakdown accompanying cell death. Early and late, metabolism mediated , effects were observed. The main effect observed shortly after treatment was a decrease in ML peak intensity, probably from the oxidative damage to the involved lipid structures. On the other hand, when cells were observed after 24, 48 and 72 hours, irradiated cells displayed more intense ML peaks, with a maximum effect after 48 hours, irrespective of the initial intensity of ML signals. The effect was found dose dependent. Also peaks from lipid polyunsaturation were found higher in irradiated samples. Moreover, also phosphorylcholine and glutathione signals were affected by irradiation. Similar effects were found in multicellular spheroids from the same cell strain. Association of the observed changes with apoptotic death is currently under consideration

  5. Wholesomeness of food irradiated with doses above 10 kGy

    Energy Technology Data Exchange (ETDEWEB)

    Kaferstein, F [Director, Programme of Food Safety and Food Aid, WHO, CH-1211, Geneva 27, (Switzerland)

    1998-12-31

    Strictly from the scientific point of view, no ceiling should be set for food irradiated with doses greater than the currently recommended upper level of 10 kGy by the Codex Alimentarius Commission. The food irradiation technology itself is safe to such a degree that as long as sensory qualities of food are retained and harmful microorganisms are destroyed, the actual amount of ionizing radiation applied is of secondary consideration. That was the main conclusion of a week-long meeting on high dose irradiation organized jointly by the World Health Organization (WHO), the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA). The knowledge of what can and does occur chemically in high dose irradiated foods which derives from over 50 years of research tells us that one can go as high as 75 kGy, as has already been done in some countries, and the result is the same food is safe and wholesome and nutritionally adequate. (Author)

  6. Wholesomeness of food irradiated with doses above 10 kGy

    International Nuclear Information System (INIS)

    Kaferstein, F.

    1997-01-01

    Strictly from the scientific point of view, no ceiling should be set for food irradiated with doses greater than the currently recommended upper level of 10 kGy by the Codex Alimentarius Commission. The food irradiation technology itself is safe to such a degree that as long as sensory qualities of food are retained and harmful microorganisms are destroyed, the actual amount of ionizing radiation applied is of secondary consideration. That was the main conclusion of a week-long meeting on high dose irradiation organized jointly by the World Health Organization (WHO), the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA). The knowledge of what can and does occur chemically in high dose irradiated foods which derives from over 50 years of research tells us that one can go as high as 75 kGy, as has already been done in some countries, and the result is the same food is safe and wholesome and nutritionally adequate. (Author)

  7. Wholesomeness of food irradiated with doses above 10 kGy

    Energy Technology Data Exchange (ETDEWEB)

    Kaferstein, F. [Director, Programme of Food Safety and Food Aid, WHO, CH-1211, Geneva 27, (Switzerland)

    1997-12-31

    Strictly from the scientific point of view, no ceiling should be set for food irradiated with doses greater than the currently recommended upper level of 10 kGy by the Codex Alimentarius Commission. The food irradiation technology itself is safe to such a degree that as long as sensory qualities of food are retained and harmful microorganisms are destroyed, the actual amount of ionizing radiation applied is of secondary consideration. That was the main conclusion of a week-long meeting on high dose irradiation organized jointly by the World Health Organization (WHO), the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA). The knowledge of what can and does occur chemically in high dose irradiated foods which derives from over 50 years of research tells us that one can go as high as 75 kGy, as has already been done in some countries, and the result is the same food is safe and wholesome and nutritionally adequate. (Author)

  8. Diagnostic radiography dose and guidance levels

    International Nuclear Information System (INIS)

    Cuadros, M.; Augusto, A.

    2001-01-01

    This work shows a study done on conventional radiodiagnostic equipment. The evaluation was implemented throughout different areas of Bolivia, covering not only single equipment radiographs used in the cities, but also the ones used in rural areas. There have been more than 90 equipment pieces evaluated of which the dose received by a patient for a given exam has been considered an essential element. For this purpose two types of examinations have been selected, these being considered the more frequent. Not only the dose aspect was taken into consideration but the technique used as well. These elements that support very important information have been related to orientative levels. (author)

  9. Pretreatment with low-dose gamma irradiation enhances tolerance to the stress of cadmium and lead in Arabidopsis thaliana seedlings.

    Science.gov (United States)

    Qi, Wencai; Zhang, Liang; Wang, Lin; Xu, Hangbo; Jin, Qingsheng; Jiao, Zhen

    2015-05-01

    Heavy metals are important environmental pollutants with negative impact on plant growth and development. To investigate the physiological and molecular mechanisms of heavy metal stress mitigated by low-dose gamma irradiation, the dry seeds of Arabidopsis thaliana were exposed to a Cobalt-60 gamma source at doses ranging from 25 to 150Gy before being subjected to 75µM CdCl2 or 500µM Pb(NO3)2. Then, the growth parameters, and physiological and molecular changes were determined in response to gamma irradiation. Our results showed that 50-Gy gamma irradiation gave maximal beneficial effects on the germination index and root length in response to cadmium/lead stress in Arabidopsis seedlings. The hydrogen peroxide and malondialdehyde contents in seedlings irradiated with 50-Gy gamma rays under stress were significantly lower than those of controls. The antioxidant enzyme activities and proline levels in the irradiated seedlings were significantly increased compared with the controls. Furthermore, a transcriptional expression analysis of selected genes revealed that some components of heavy metal detoxification were stimulated by low-dose gamma irradiation under cadmium/lead stress. Our results suggest that low-dose gamma irradiation alleviates heavy metal stress, probably by modulating the physiological responses and gene expression levels related to heavy metal resistance in Arabidopsis seedlings. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Dose rate and total dose dependence of the 1/f noise performance of a GaAs operational amplifier during irradiation

    International Nuclear Information System (INIS)

    Hiemstra, D.M.

    1995-01-01

    A pictorial of a sectioned view of the torus of the International Thermonuclear Experimental Reactor (ITER) is shown. Maintenance and inspection of the reactor are required to be performed remotely. This is due to the high gamma radiation environment in vessel during inspection and maintenance activities. The custom GaAs operational amplifier is to be used to readout sensors on the in-vessel manipulator and inspection equipment. The gamma dose rate during maintenance and inspection is anticipated to be 3 Mrad(GaAs)/hour. Here, dose rate and total dose dependence of the 1/f noise performance of a custom GaAs MESFET operational amplifier during irradiation are presented. Dose rate dependent 1/f noise degradation during irradiation is believed to be due to electron trapping in deep levels, enhanced by backgating and shallow traps excited during irradiation. The reduction of this affect with accumulated total dose is believed to be due a reduction of deep level site concentration associated with substitutional oxygen. Post irradiation 1/f noise degradation is also presented.The generation-recombination noise observed post irradiation can be attributed to the production of shallow traps due to ionizing radiation

  11. Relationship of dose rate and total dose to responses of continuously irradiated beagles

    International Nuclear Information System (INIS)

    Fritz, T.E.; Norris, W.P.; Tolle, D.V.; Seed, T.M.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.

    1978-01-01

    Young-adult beagles were exposed continuously (22 hours/day) to 60 Co gamma rays in a specially constructed facility. The exposure rates were 5, 19, 17 or 35 R/day, and the exposures were terminated at 600, 1400, 2000 or 4000 R. A total of 354 dogs were irradiated; 221 are still alive as long-term survivors, some after more than 2000 days. The data on survival of these dogs, coupled with data from similar preliminary experiments, allow an estimate of the LD 50 for gamma-ray exposures given at a number of exposure rates. They also allow comparison of the relativeimportance of dose rate and total dose, and the interaction of these two variables, in the early and late effects after protracted irradiation. The LD 50 for the beagle increases from 344 R (258 rads) delivered at 15 R/minute to approximately 4000 R (approximately 3000 rads) at 10 R/day. Over this entire range, the LD 50 is dependent upon haematopoietic damage. At 5 R/day and less, no definitive LD 50 can be determined; there is nearly normal continued haematopoietic function, survival is prolonged, and the dogs manifest varied individual responses in the organ systems. Although the experiment is not complete, interim data allow serveral important conclusions. Terminated exposures, while not as effective as irradiation continued until death, can produce myelogenous leukaemia at the same exposure rate, 10 R/day. More importantly, at the same total accumulated dose, lower exposure rates appear more damaging than higher rates on the basis of the rate and degree of haematological recovery that occurs after termination of irradiation. Thus, the rate of haematologic depression, the nadir of the depression and the rate of recovery are dependent upon exposure rate; the latter is inversely related and the first two are directly related to exposure rate. ( author)

  12. Effect of high dose irradiation on the red cell span in rabbits

    International Nuclear Information System (INIS)

    Kang, T.W.; Koh, J.W.; Woo, K.S.; Lee, O.H.; Youn, C.S.

    1982-01-01

    As a part of studies on acute effects of high dose irradiation in vivo, the present report was carried out to evaluate the changes of the red cell life span in the white rabbits by a single whole body exposure to gamma rays from 60 Co teletherapy unit. The exposure was done in dose levels of 100, 600 and 900 rads to each experimental group of 10 rabbits. The life span apparent half survival time of red cells, and that the red cell volume in the circulting blood were measured by ICSH Reference method using 51 Cr. (Author)

  13. Quantitative analysis of biological responses to low dose-rate γ-radiation, including dose, irradiation time, and dose-rate

    International Nuclear Information System (INIS)

    Magae, J.; Furukawa, C.; Kawakami, Y.; Hoshi, Y.; Ogata, H.

    2003-01-01

    Full text: Because biological responses to radiation are complex processes dependent on irradiation time as well as total dose, it is necessary to include dose, dose-rate and irradiation time simultaneously to predict the risk of low dose-rate irradiation. In this study, we analyzed quantitative relationship among dose, irradiation time and dose-rate, using chromosomal breakage and proliferation inhibition of human cells. For evaluation of chromosome breakage we assessed micronuclei induced by radiation. U2OS cells, a human osteosarcoma cell line, were exposed to gamma-ray in irradiation room bearing 50,000 Ci 60 Co. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, cytoplasm and nucleus were stained with DAPI and propidium iodide, and the number of binuclear cells bearing micronuclei was determined by fluorescent microscopy. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [3H] thymidine was pulsed for 4 h before harvesting. Dose-rate in the irradiation room was measured with photoluminescence dosimeter. While irradiation time less than 24 h did not affect dose-response curves for both biological responses, they were remarkably attenuated as exposure time increased to more than 7 days. These biological responses were dependent on dose-rate rather than dose when cells were irradiated for 30 days. Moreover, percentage of micronucleus-forming cells cultured continuously for more than 60 days at the constant dose-rate, was gradually decreased in spite of the total dose accumulation. These results suggest that biological responses at low dose-rate, are remarkably affected by exposure time, that they are dependent on dose-rate rather than total dose in the case of long-term irradiation, and that cells are getting resistant to radiation after the continuous irradiation for 2 months. It is necessary to include effect of irradiation time and dose-rate sufficiently to evaluate risk

  14. Investigation of cortisole levels at exposure to small doses of ionizing radiation at working out and identification of mathematical model

    International Nuclear Information System (INIS)

    Yishkhanova, M.A.; Anyipko, O.B.; Myitryajeva, N.A.; Gubs'kij, V.Yi.

    1993-01-01

    The authors report primary data to create the model of animals irradiation in the doses of 0.13 - 1.15 Gy during 0.5 - 42 days. Dependence of blood cortisole level on the dose of irradiation (0.13 - 1.15 Gy) during 0.5 - 1.5 days was determined. The dependence of cortisole level on the doses and the length of the period after the irradiation was found to be a complicated function. Within the dose range of 0.13 - 1.15 Gy during 0.5 -1.5 days cortisole level does not depend on the dose value. The study of influence of the terms duration on cortisole level has showed that within 0.5 - 1.5 days it increases irrespective of the dose of irradiation, and within 4 - 42 days it decreases

  15. Radiation effect and response of DNA synthesis in lymphocytes induced by low dose irradiation

    International Nuclear Information System (INIS)

    Zhao Yujie; Su Liaoyuan; Zou Huawei; Kong Xiangrong

    1999-01-01

    The ability of DNA synthesis in lymphocytes were measured by using 3 H-TdR incorporation method. This method was used to observe the damage of lymphocytes irradiated by several challenge doses (0.5-0.8 Gy) and adaptive response induced by previous low dose irradiation. The results show that DNA synthesis was inhibited by challenge dose of radiation and was adapted by previous 0.048 Gy irradiation

  16. Cytogenetic investigations of persons exposed to professional chronic low-dose irradiation

    International Nuclear Information System (INIS)

    Rangelov, V.; Mitev, L.; Petrunov, P.; Vesselinova, L.

    2005-01-01

    The problem of long term influence of low-doses occupational irradiation is connected with the real assessment of their consequences. The current cytogenetic investigations were done on persons working under occupational chronic external partial irradiation. Accumulated doses of external irradiation are surveyed. Data give ground for suggestion about the relationship between accumulated dose and chromosomal aberrations. The additional damage factors (diagnostic investigations, chemical substances, tobacco addict) have done the more significant influence upon aberrations appearance increasing

  17. Dose dependence of the microstructural evolution in neutron-irradiated austenitic stainless steel

    International Nuclear Information System (INIS)

    Zinkle, S.J.; Maziasz, P.J.; Stoller, R.E.

    1993-01-01

    Microstructural data on the evolution of the dislocation loop, cavity, and precipitate populations in neutron-irradiated austenitic stainless steels are reviewed in order to estimate the displacement damage levels needed to achieve the 'steady state' condition. The microstructural data can be conveniently divided into two temperature regimes. In the low temperature regime (below about 200 degrees C) the microstructure of austenitic stainless steel is dominated by 'black spot' defect clusters and faulted interstitial dislocation loops. The dose needed to approach saturation of the loop and defect cluster densities is generally on the order of 1 displacement per atom (dpa) in this regime. In the high temperature regime (∼300 to 700 degrees C), cavities, precipitates, loops and network dislocations are all produced during irradiation; doses in excess of 10 dpa are generally required to approach a 'steady state' microstructural condition. Due to complex interactions between the various microstructural components that form during irradiation, a secondary transient regime is typically observed in commercial stainless steels during irradiation at elevated temperatures. This slowly evolving secondary transient may extend to damage levels in excess of 50 dpa in typical 300-series stainless steels, and to >100 dpa in radiation-resistant developmental steels. The detailed evolution of any given microstructural component in the high-temperature regime is sensitive to slight variations in numerous experimental variables, including heat-to-heat composition changes and neutron spectrum

  18. Effect of low dose x irradiation on the succinate dehydrogenase activity of guinea pig, rat and mouse tissues

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V C; Bhatavdekar, J M; Aravinda Babu, K [Gujarat Univ., Ahmedabad (India). Dept. of Zoology

    1976-07-01

    The histochemical changes in succinate dehydrogenase (SDH) were investigated in pectoralis major muscle of guinea pig, rat and mouse after level X-irradiation (72 R and 240 R) and compared with control animals. Biochemical studies were carried out on liver, kidney, muscle (pectoralis major), adrenal and spleen of these animals after low dose local X-irradiation and compared with control animals. Changes in SDH activity were studied up to 72-h post-irradiation, which shows that low dose local X-irradiation leads to increased enzymic activity. The increase in enzymic activity was remarkable in mouse tissues as compared with guinea pig and rat. Adrenals of all the three animals showed significant activation after all the doses of radiation studied. The significance of these results, with special reference to oxidative metabolism, has been discussed.

  19. Differential response of two cell lines sequentially irradiated with low X-ray doses.

    Science.gov (United States)

    Güerci, A M; Dulout, F N; Grillo, C A; Seoane, A I

    2005-05-01

    An experiment was designed to compare the effect of repeated low doses of X-rays in two different cell lines: one transformed, epithelial like and aneuploid Chinese hamster ovary K-1 (CHO-K1); the other originated from a human primary culture, fibroblast, diploid and non-transformed, MRC-5. CHO and MRC-5 cells were cultured for 14 or eight passages, respectively. Irradiation was performed once per passage when cells were in the quiescent state (90 - 95% in G1/G0). Cells were exposed to 10.0 mSv X-ray doses. Ionizing radiation did not induce apoptosis or necrosis in the exposed CHO cell population. Significant increases of low-level damaged cells (degrees 1 and 2) were found for the 14 cycles of radiation when compared with controls, except for the first irradiation cycle. No significant increases in the frequency of cells with severe damage were observed. The frequency of MRC-5 cells with low-level damage increased significantly when compared with controls for radiation cycles seven and eight. Significant increases of apoptosis, necrosis and severe damage were found only for the highest dose. Transformed and non-transformed cell types responded differently to direct and indirect damage using low-dose repeat exposures to ionizing radiation. Though more investigation is needed to understand the mechanisms of radiation effects in chronic low-dose-exposed cell populations, cellular type should be taken into account in the design of in vitro experiments for understanding low-dose-irradiation effects.

  20. Determination of ionizing irradiation summary dose for animals of West Kazakstan

    International Nuclear Information System (INIS)

    Gal'tsev, V.E.; Nasirov, R.N.; Gal'tseva, E.V.; Lebedev, Ya.S.; Bubnov, N.N.

    1996-01-01

    By mean of tooth enamel EPR dosimetry the accumulated radiation doses received animals near Azgyr and Tajsojgan nuclear test sites (West Kazakstan) were determined . In the work camel's two teeth (Tajsojgan) and cow's two teeth (from Azgyr and Tajsojgan test sites - accordingly) were used. Registration of EPR spectrum has been carried out on production-type EPR-spectrometer ESR-300 of Bruker firm under temperature 77 K. SHF power level is 5 MW. Constant magnetic field's modulation frequency was equal to 100 k Hz and modulation amplitude was equal to 3,2 Gs. Received data allow to make conclusion that all tested animals have got summary dose exceeded significantly a natural background radiation dose (1-1,5 μGy/y. Comparison of irradiation dose accumulated in both the front and back tooth walls testifies about predominance of hard γ-rays in the spectrum. 4 refs., 2 figs

  1. Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Manuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-08-01

    The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential

  2. OMI/Aura Surface UVB Irradiance and Erythemal Dose Daily L2 Global 0.25 deg Lat/Lon Grid V003

    Data.gov (United States)

    National Aeronautics and Space Administration — The Version 003 of Aura-OMI Spectral Surface UVB Irradiance and Erythemal Dose Level-2G data product (Daily level-2 data binned into global 0.25 deg Lat/Lon grids)...

  3. Preservation of Minced Meats by Using Medium and High-doses Irradiation

    International Nuclear Information System (INIS)

    Hammad, A.A.I.; Swailam, H.M.H.; Taha, S.M.A.

    2003-01-01

    The effect of medium (2.5-10 kGy) dose irradiation and high(20-70 kGy) dose irradiation on the microbiological, chemical and organoleptic properties of minced meat samples was studied. It was found that irradiation dose of only 5 kGy greatly reduced all microbial counts and completely eliminated all non-spore forming pathogenic bacteria contaminated minced meat samples. Consequently this irradiation dose extended the refrigerated (3 degree ±1) storage life of these products for more than 8 weeks. This irradiation dose almost did not affect the chemical composition, particularly the main amino acids and main fatty acids of minced meat samples. Panelists could not differentiate between irradiated minced meat samples at this dose and unirradiated samples. High doses irradiation, i.e.40 and 70 kGy were sufficient and efficient in sterilization of minced meat samples and in obtaining long-stable minced meat products (Two years) at ambient temperature. These irradiation doses slightly reduced (not more than 7%) aspartic acid, glutamic acid, methionine and lysine of minced meat. It also decreased the relative percentage of total unsaturated fatty acids by not more than 17 % . These high irradiation doses caused loss of C 18:3 and C 20:1

  4. Secondary radiation dose during high-energy total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Janiszewska, M.; Raczkowski, M. [Lower Silesian Oncology Center, Medical Physics Department, Wroclaw (Poland); Polaczek-Grelik, K. [University of Silesia, Medical Physics Department, Katowice (Poland); Szafron, B.; Konefal, A.; Zipper, W. [University of Silesia, Department of Nuclear Physics and Its Applications, Katowice (Poland)

    2014-05-15

    The goal of this work was to assess the additional dose from secondary neutrons and γ-rays generated during total body irradiation (TBI) using a medical linac X-ray beam. Nuclear reactions that occur in the accelerator construction during emission of high-energy beams in teleradiotherapy are the source of secondary radiation. Induced activity is dependent on the half-lives of the generated radionuclides, whereas neutron flux accompanies the treatment process only. The TBI procedure using a 18 MV beam (Clinac 2100) was considered. Lateral and anterior-posterior/posterior-anterior fractions were investigated during delivery of 2 Gy of therapeutic dose. Neutron and photon flux densities were measured using neutron activation analysis (NAA) and semiconductor spectrometry. The secondary dose was estimated applying the fluence-to-dose conversion coefficients. The main contribution to the secondary dose is associated with fast neutrons. The main sources of γ-radiation are the following: {sup 56}Mn in the stainless steel and {sup 187}W of the collimation system as well as positron emitters, activated via (n,γ) and (γ,n) processes, respectively. In addition to 12 Gy of therapeutic dose, the patient could receive 57.43 mSv in the studied conditions, including 4.63 μSv from activated radionuclides. Neutron dose is mainly influenced by the time of beam emission. However, it is moderated by long source-surface distances (SSD) and application of plexiglass plates covering the patient body during treatment. Secondary radiation gives the whole body a dose, which should be taken into consideration especially when one fraction of irradiation does not cover the whole body at once. (orig.) [German] Die zusaetzliche Dosis durch sekundaere Neutronen- und γ-Strahlung waehrend der Ganzkoerperbestrahlung mit Roentgenstrahlung aus medizinischen Linearbeschleunigern wurde abgeschaetzt. Bei der Emission hochenergetischer Strahlen zur Teletherapie finden hauptsaechlich im Beschleuniger

  5. Low-dose irradiation for controlling prostate cancer

    International Nuclear Information System (INIS)

    Cuttler, J.M.

    2003-01-01

    Prostate cancer is the second most commonly diagnosed cancer among North American men and the second leading cause of death in those aged 65 and over. The American Cancer Society recommends testing those over age 50 who are expected to live at least 10 years, even though the ability of early detection to decrease prostate cancer mortality has not been demonstrated. So controversy exists about the appropriateness of screening because of the considerable economic and social burden of diagnosing and treating prostate cancer, coupled with the projected large increase in the number of new cases as the population ages. This very important public health issue could be addressed at low cost by total-body low-dose irradiation therapy to stimulate the patient's own defences to prevent and control most cancers, including prostate cancer, with no symptomatic side effects. (author)

  6. Comparative influence of dose rate and radiation nature, on lethality after big mammals irradiation

    International Nuclear Information System (INIS)

    Destombe, C.; Le Fleche, Ph.; Grasseau, A.; Reynal, A.

    1997-01-01

    For the same dose and the 30 days lethality as biological criterion, the dose rate influence is more important than the radiation nature on the results of an big mammals total body irradiation. (authors)

  7. Dose dependence of true stress parameters in irradiated bcc, fcc, and hcp metals

    Science.gov (United States)

    Byun, T. S.

    2007-04-01

    The dose dependence of true stress parameters has been investigated for nuclear structural materials: A533B pressure vessel steels, modified 9Cr-1Mo and 9Cr-2WVTa ferritic martensitic steels, 316 and 316LN stainless steels, and Zircaloy-4. After irradiation to significant doses, these alloys show radiation-induced strengthening and often experience prompt necking at yield followed by large necking deformation. In the present work, the critical true stresses for deformation and fracture events, such as yield stress (YS), plastic instability stress (PIS), and true fracture stress (FS), were obtained from uniaxial tensile tests or calculated using a linear strain-hardening model for necking deformation. At low dose levels where no significant embrittlement was detected, the true fracture stress was nearly independent of dose. The plastic instability stress was also independent of dose before the critical dose-to-prompt-necking at yield was reached. A few bcc alloys such as ferritic martensitic steels experienced significant embrittlement at doses above ∼1 dpa; and the true fracture stress decreased with dose. The materials fractured before yield at or above 10 dpa.

  8. Relationship of dose rate and total dose to responses of continuously irradiated beagles

    International Nuclear Information System (INIS)

    Fritz, T.E.; Norris, W.P.; Tolle, D.V.; Seed, T.M.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.

    1978-01-01

    Young-adult beagles were exposed continuously (22 hours/day) to 60 Co γ rays in a specially constructed facility. The exposure rates were either 5, 10, 17, or 35 R/day, and the exposures were terminated at either 600, 1400, 2000, or 4000 R. A total of 354 dogs were irradiated; 221 are still alive as long-term survivors, some after more than 2000 days. The data on survival of these dogs, coupled with data from similar preliminary experiments, allow an estimate of the LD 50 for γ-ray exposures given at a number of exposure rates. They also allow comparison of the relative importance of dose rate and total dose, and the interaction of these two variables, in the early and late effects after protracted irradiation. The LD 50 for the beagle increases from 258 rad delivered at 15 R/minute to approximately 3000 rad at 10 R/day. Over this entire range, the LD 50 is dependent upon hematopoietic damage. At 5 R/day and less, no meaningful LD 50 can be determined; there is nearly normal continued hematopoietic function, survival is prolonged, and the dogs manifest varied individual responses in other organ systems. Although the experiment is not complete, interim data allow several important conclusions. Terminated exposures, while not as effective as radiation continued until death, can produce myelogenous leukemia at the same exposure rate, 10 R/day. More importantly, at the same total accumulated dose, lower exposure rates are more damaging than higher rates on the basis of the rate and degree of hematological recovery that occurs after termination of irradiation. Thus, the rate of hematologic depression, the nadir of the depression, and the rate of recovery are dependent upon exposure rate; the latter is inversely related and the former two are directly related to exposure rate

  9. Effect of continuous low-dose γ-irradiation on rat Sertoli cell function

    International Nuclear Information System (INIS)

    Kamtchouing, P.; Papadopoulos, V.; Drosdowsky, M.A.; Carreau, S.; Pinon-Lataillade, G.; Maas, J.; Guillaumin, J.M.; Bardos, P.; Perreau, C.; Hochereau de Reviers, M.T.

    1988-01-01

    Continuous low-dose γ-irradiation of mature rats induced a progressive degeneration of the germ cells. Blood FSH increased by 127, 176 and 214%, respectively, after 55, 70 and 85 days of treatment when compared to FSH levels in control rats (8.50 ± 0.60 ng/ml); conversely, serum LH and testosterone levels were unchanged. The Sertoli cell function was affected by the treatment from 70 days on, as attested by androgen binding protein (ABP) and transferrin secretions which diminished 35-40%. Serum ABP levels were not altered, whatever the duration of irradiation, even though epididymal ABP contents (as well as concentrations) diminished 34-60% when compared to those of the controls. Moreover, in purified Leydig cells, LH-stimulated intracellular cAMP levels, which were decreased by seminiferous tubule medium (STM) from control rats, were enhanced in presence of STM from treated animals. Testosterone output was stimulated 9-fold in presence of oLH and further increased (46-76%) from stages XIV-V by STM prepared from control and irradiated rats, respectively. After 85 days the STM effects on both cAMP and testosterone syntheses were zero. These results demonstrate a probable alteration of Sertoli cell function after irradiation, but also a role of the germ cells in the regulation of the synthesis of ABP, transferrin and Sertoli cell paracrine factors

  10. Recovery of the proliferative and functional integrity of mouse bone marrow in long-term cultures established after whole-body irradiation at different doses and dose rates

    International Nuclear Information System (INIS)

    Bierkens, J.G.; Hendry, J.H.; Testa, N.G.

    1991-01-01

    Injury inflicted upon the bone marrow stroma following whole-body irradiation and its repair over a 1-year period has been assessed in murine long-term bone marrow cultures established at increasing time intervals after irradiation. Different doses at different dose rates (10 Gy at 0.05 cGy/min, 4.5 Gy and 10 Gy at 1.6 cGy/min, and 4 x 4.5 Gy [3 weeks between doses] at 60 cGy/min) were chosen so as to maximize differences in effect in the stroma. The cellularity of the adherent layer in long-term cultures established 1 month after irradiation was reduced by 40%-90% depending on the dose and dose rate. Simultaneous with the poor ability of the marrow to form adherent layers, the cumulative spleen colony-forming unit (CFU-S) and granulocyte-macrophage colony-forming cell (GM-CFC) production over a 7-week period was reduced to 0% and 30% of control cultures, respectively. The slow recovery of the adherent layer was paralleled by an increase in the numbers of CFU-S and GM-CFC in the supernatant. Cultures established from repeatedly irradiated mice performed poorly over the entire 1-year period. Whereas the regeneration of the stroma was near complete 1 year after irradiation, the CFU-S and GM-CFC levels reached only between 50% and 80% of control cultures, respectively. Also, the concentration of CFU-S and GM-CFC in the supernatant remained persistently lower in cultures established from irradiated mice as compared to control cultures. The levels of sulfated glycosaminoglycans, which have been implicated in the establishment of the functional integrity of the microenvironment, were not reduced in the adherent layers at any time after irradiation. These results indicate that the regeneration of the stroma is accompanied by an incomplete recovery of active hemopoiesis in vitro

  11. Effects of two different high doses of irradiation on antioxidant system in the liver of guinea pigs.

    Science.gov (United States)

    Guney, Yildiz; Bukan, Neslihan; Dizman, Aysen; Hicsonmez, Ayse; Bilgihan, Ayse

    2004-03-01

    To examine the state of the oxidant-antioxidant system in the liver of guinea pig caused by high doses of ionizing radiation in the early period. The research was carried out on guinea pigs irradiated with the doses of 8 Gy (group 2) or 15 Gy (group 3) (single dose/whole body) in comparison with control group (group 1). The levels of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH), the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the levels of selenium in the liver were measured. TBARS levels in the irradiated animals were markedly higher than those in controls. In group 3, GSH levels and GSH-Px activity were significantly increased while activity of SOD and CAT were significantly decreased compared to groups 1 and 2. Liver selenium levels were not influenced by irradiation. The data have shown that gamma-irradiation at the doses of 8 Gy or 15 Gy results in significant increase in free radical formation while antioxidant enzymes were affected only at a dose of 15 Gy.

  12. Absorbed dose modeled for a liquid circulating around a Co-60 irradiator

    International Nuclear Information System (INIS)

    Mangussi, J.

    2013-01-01

    A model for the distribution of the absorbed dose in a volume of liquid circulating into an active tank containing a Co-60 irradiator is presented. The absorbed dose, the stir process and the liquid recirculation into the active tank are modeled. The absorbed dose for different fractions of the volume is calculated. The necessary irradiation times for the achievement of the required absorbed dose are evaluated. (author)

  13. Comparison of radiosensitization by 41 deg. C hyperthermia during low dose rate irradiation and during pulsed simulated low dose rate irradiation in human glioma cells

    International Nuclear Information System (INIS)

    Raaphorst, G. Peter; Ng, Cheng E.; Shahine, Bilal

    1999-01-01

    Purpose: Long duration mild hyperthermia has been shown to be an effective radiosensitizer when given concurrently with low dose rate irradiation. Pulsed simulated low dose rate (PSLDR) is now being used clinically, and we have set out to determine whether concurrent mild hyperthermia can be an effective radiosensitizer for the PSLDR protocol. Materials and Methods: Human glioma cells (U-87MG) were grown to plateau phase and treated in plateau phase in order to minimize cell cycle redistribution during protracted treatments. Low dose rate (LDR) irradiation and 41 deg. C hyperthermia were delivered by having a radium irradiator inside a temperature-controlled incubator. PSLDR was given using a 150 kVp X-ray unit and maintaining the cells at 41 deg. C between irradiations. The duration of irradiation and concurrent heating depended on total dose and extended up to 48 h. Results: When 41 deg. C hyperthermia was given currently with LDR or PSLDR, the thermal enhancement ratios (TER) were about the same if the average dose rate for PSLDR was the same as for LDR. At higher average dose rates for PSLDR the TERs became less. Conclusions: Our data show that concurrent mild hyperthermia can be an effective sensitizer for PSLDR. This sensitization can be as effective as for LDR if the same average dose rate is used and the TER increases with decreasing dose rate. Thus mild hyperthermia combined with PSLDR may be an effective clinical protocol

  14. Interface effects on dose distributions in irradiated media

    International Nuclear Information System (INIS)

    Wright, H.A.; Hamm, R.N.; Turner, J.E.

    1980-01-01

    It has long been recognized that nonuniformities in dose distributions may occur in the immediate vicinity of a boundary between two different media. Considerable work has been done to determine interface effects in media irradiated by photons or in media containing β- or α-particle emitters. More recently interface effects have become of interest in additional problems, including pion radiotherapy and radiation effects in electronic microcircuits in space vehicles. These problems arise when pion capture stars or proton-nucleus interactions produce a spectrum of charged nuclear fragments near an interface. The purpose of this paper is to examine interface effects in detail as to their specific origin. We have made Monte Carlo calculations of dose distributions near an interface in a systematic way for a number of idealized cases in order to indicate the separate influences of several factors including different stopping powers of the two media, nonconstancy (e.g., Bragg peak) in the energy loss curve for the particles, different particle spectra in the two media, and curvature of the boundary between the two media

  15. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

    International Nuclear Information System (INIS)

    Belley, Matthew D.; Wang, Chu; Nguyen, Giao; Gunasingha, Rathnayaka; Chao, Nelson J.; Chen, Benny J.; Dewhirst, Mark W.; Yoshizumi, Terry T.

    2014-01-01

    Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs

  16. Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

    International Nuclear Information System (INIS)

    Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

    2014-01-01

    With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

  17. Effect of low-dose irradiation on pregnant mouse haemopoiesis

    International Nuclear Information System (INIS)

    Weinberg, S.R.; McCarthy, E.G.; MacVittie, T.J.; Baum, S.J.

    1981-01-01

    The effects of low-dose gamma radiation to haemopoietic progenitor cell compartments of the marrow and spleen of virgin female mice and pregnant mice were studied. Microplasma clot cultures were used to assess burst-forming uniterythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) activity, and double-layer agar cultures were established to evaluate granulocyte-macrophage colony-forming cell (GM-CFC) and macrophage colony-forming cell (M-CFC). The apparent shift in maternal erythropoiesis from the bone marrow to the enlarged spleen was reflected by an increase in CFU-E and BFU-E per spleen and a concomitant decrease in CFU-E and BFU-E per femur. Whereas maternal GM-CFC values per femur increased 36%, maternal GM-CFC per spleen increased by 172% compared to virgin values. Total-body irradiation to the day-10.5 pregnant mouse caused a further suppression of day-14.5 medullary erythropoiesis (i.e. decreased CFU-E values) compared to the virgin female mouse. An ability of the maternal spleen to support further compensatory erythropoiesis following increasing doses of radiation was demonstrated. Four days after 1.0 Gy exposure, maternal values for GM-CFC per femur or spleen decreased to nonirradiated virgin mice values. M-CFC per maternal femur decreased to nonirradiated virgin mice values. M-CFC per maternal femur decreased following 1.5 Gy, but M-CFC per spleen appeared to be unaffected with doses from 0.5 to 2.0 Gy. (author)

  18. New method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. Clinical and hormonal studies

    Energy Technology Data Exchange (ETDEWEB)

    Gronroos, M.; Turunen, T.; Raekallio, J.; Ruotsalinen, P.; Salmi, T. (Turku Univ. (Finland). Dept. of Obstetrics and Gynecology)

    1982-08-01

    The authors present a new method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. The problem with this method has been how to inactivate the endometrium while maintaining the physiological function of the ovaries. In 5/29 young patients regular or irregular bleedings occurred after an endometrial dose of 11+-1 Gy. These subjects were given a repeat low dose intrauterine irradiation. Thereafter no bleedings were found in four out of five patients. Two to 9 years after the repeat irradiation the plasma levels of E/sub 1/, E/sub 2/, FSH and LH corresponded closely to those of healthy women in reproductive age in three out of five patients; some high plasma P levels indicated ovulation. In two patients the E/sub 1/, E/sub 2/, and P values were more likely postmenopausal but, on the other hand, FSH and LH values reproductive ones. 19 refs.

  19. A new method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. Clinical and hormonal studies

    International Nuclear Information System (INIS)

    Gronroos, M.; Turunen, T.; Raekallio, J.; Ruotsalinen, P.; Salmi, T.

    1982-01-01

    The authors present a new method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. The problem with this method has been how to inactivate the endometrium while maintaining the physiological function of the ovaries. In 5/29 young patients regular or irregular bleedings occurred after an endometrial dose of 11+-1 Gy. These subjects were given a repeat low dose intrauterine irradiation. Thereafter no bleedings were found in four out of five patients. Two to 9 years after the repeat irradiation the plasma levels of E 1 , E 2 , FSH and LH corresponded closely to those of healthy women in reproductive age in three out of five patients; some high plasma P levels indicated ovulation. In two patients the E 1 , E 2 , and P values were more likely postmenopausal but, on the other hand, FSH and LH values reproductive ones. (author)

  20. Decreasing Irradiated Rat Lung Volume Changes Dose-Limiting Toxicity From Early to Late Effects

    Energy Technology Data Exchange (ETDEWEB)

    Veen, Sonja J. van der; Faber, Hette; Ghobadi, Ghazaleh [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Brandenburg, Sytze [KVI Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

    2016-01-01

    Purpose: Technological developments in radiation therapy result in smaller irradiated volumes of normal tissue. Because the risk of radiation therapy-induced toxicity generally depends on irradiated volume, changing volume could change the dose-limiting toxicity of a treatment. Recently, in our rat model, we found that early radiation-induced lung dysfunction (RILD) was closely related to irradiated volume dependent vascular remodeling besides inflammation. The exact relationship between early and late RILD is still unknown. Therefore, in this preclinical study we investigated the dose-volume relationship of late RILD, assessed its dependence on early and late pathologies and studied if decreasing irradiated volume changed the dose-limiting toxicity. Methods and Materials: A volume of 25%, 32%, 50%, 63%, 88%, or 100% of the rat lung was irradiated using protons. Until 26 weeks after irradiation, respiratory rates were measured. Macrovascular remodeling, pulmonary inflammation, and fibrosis were assessed at 26 weeks after irradiation. For all endpoints dose-volume response curves were made. These results were compared to our previously published early lung effects. Results: Early vascular remodeling and inflammation correlated significantly with early RILD. Late RILD correlated with inflammation and fibrosis, but not with vascular remodeling. In contrast to the early effects, late vascular remodeling, inflammation and fibrosis showed a primarily dose but not volume dependence. Comparison of respiratory rate increases early and late after irradiation for the different dose-distributions indicated that with decreasing irradiated volumes, the dose-limiting toxicity changed from early to late RILD. Conclusions: In our rat model, different pathologies underlie early and late RILD with different dose-volume dependencies. Consequently, the dose-limiting toxicity changed from early to late dysfunction when the irradiated volume was reduced. In patients, early and late

  1. Tensile stress corrosion cracking of type 304 stainless steel irradiated to very high dose

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. M.; Ruther, W. E.; Strain, R. V.; Shack, W. J.

    2001-09-01

    Certain safety-related core internal structural components of light water reactors, usually fabricated from Type 304 or 316 austenitic stainless steels (SSs), accumulate very high levels of irradiation damage (20--100 displacement per atom or dpa) by the end of life. The data bases and mechanistic understanding of, the degradation of such highly irradiated components, however, are not well established. A key question is the nature of irradiation-assisted intergranular cracking at very high dose, i.e., is it purely mechanical failure or is it stress-commotion cracking? In this work, hot-cell tests and microstructural characterization were performed on Type 304 SS from the hexagonal fuel can of the decommissioned EBR-11 reactor after irradiation to {approximately}50 dpa at {approximately}370 C. Slow-strain-rate tensile tests were conducted at 289 C in air and in water at several levels of electrochemical potential (ECP), and microstructural characteristics were analyzed by scanning and transmission electron microcopies. The material deformed significantly by twinning and exhibited surprisingly high ductility in air, but was susceptible to severe intergranular stress corrosion cracking (IGSCC) at high ECP. Low levels of dissolved O and ECP were effective in suppressing the susceptibility of the heavily irradiated material to IGSCC, indicating that the stress corrosion process associated with irradiation-induced grain-boundary Cr depletion, rather than purely mechanical separation of grain boundaries, plays the dominant role. However, although IGSCC was suppressed, the material was susceptible to dislocation channeling at low ECP, and this susceptibility led to poor work-hardening capability and low ductility.

  2. Analysis of volatile organic compounds and sensory characteristics of pork loin samples irradiated to high doses

    International Nuclear Information System (INIS)

    Hou Zhengchi; Sun Dakuan; Qin Zongying; Jin Jiang; Zhu Liandi; Yao Side; Sheng Kanglong

    2005-01-01

    Fresh pork loin samples, protein enzyme inactivated at (72 ± 3) degree C and vacuum packaged, were irradiated to up to 45 kGy at -20 degree C by 60 Co γ-rays. The irradiated samples were examined by various kinds of method to study high dose irradiation effects of sensory changes (meat color and off-odor), transverse shearing strength, weight loss in steam cooking, volatile organic compounds, and lipid oxidation. The results showed that the high dose irradiation produced no serious effects to the pork loin samples, and volunteer responses showed fine acceptability to the irradiated meat. (authors)

  3. Retention of radiolytic CO gas in irradiated pepper grains and irradiation detection of spices and dry grains with the level of stocked CO gas

    International Nuclear Information System (INIS)

    Furuta, M.; Dohmaru, T.; Katayama, T.; Toratani, H.; Takeda, A.

    1995-01-01

    The release of radiolytic CO gas from 60Co gamma-irradiated pepper seeds was unexpectedly slower than that of radiolytic H2 gas during a storage period after irradiation. These gases were retained in the grains and could be recovered by pulverization under gaslight condition. Using this procedure, 10-kGy-irradiated pepper grains could be distinguished from nonirradiated samples for more than 2 months by the level of CO and H2 gases. The patterns of CO change at 10, 20, and 30 kGy were similar, and the CO amounts were proportional to irradiation doses at any point of the storage period after irradiation. 60Co gamma-irradiated grains of allspice, cinnamon, cumin, polished rice, and wheat could be distinguished from nonirradiated ones by the level of retained CO gas even after 2 months of storage at room temperature. Thus, radiolytic CO gas could be an effective probe for rapid screening of irradiated pepper and dry grains

  4. Dose distribution, using homogeneous material before the reload of the JS-6500 irradiator

    International Nuclear Information System (INIS)

    Carrasco A, H.

    1991-10-01

    The objective of this report is to determine the dose distribution inside the aluminum containers used for the industrial irradiation, as well as to locate the positions of maximum and minimum doses, before the reloading of the JS-6500 Irradiator. (Author)

  5. Dose level of occupational exposure in China

    International Nuclear Information System (INIS)

    Tian, Y.; Zhang, L.; Ju, Y.

    2008-01-01

    This paper discusses the dose level of Chinese occupational exposures during 1986-2000. Data on occupational exposures from the main categories in nuclear fuel cycle (uranium enrichment and conversion, fuel fabrication, reactor operation, waste management and research activity, except for uranium mining and milling because of the lack of data), medical uses of radiation (diagnostic radiation, nuclear medicine and radiotherapy) and industrial uses of radiation (industrial radiography and radioisotope production) are presented and summarised in detail. These are the main components of occupational exposures in China. In general, the average annual effective doses show a steady decreasing trend over periods: from 2.16 to 1.16 mSv in medical uses of radiation during 1990-2000; from 1.92 to 1.18 mSv in industrial radiography during 1990-2000; from 8.79 to 2.05 mSv in radioisotope production during the period 1980-2000. Almost all the average annual effective doses in discussed occupations were lower than 5 mSv in recent years (except for well-logging: 6.86 mSv in 1999) and no monitored workers were found to have received the occupational exposure exceeding 50 mSv in a single year or 100 mSv in a five-year period. So the Chinese protection status of occupation exposure has been improved in recent years. However, the average annual effective doses in some occupations, such as diagnostic radiology and coal mining, were still much higher than that of the whole world. There are still needs for further improvement and careful monitoring of occupational exposure to protect every worker from excessive occupational exposure, especially for the workers who were neglected before. (authors)

  6. Inhibition of alloxan diabetes by low dose {gamma}-irradiation before alloxan administration

    Energy Technology Data Exchange (ETDEWEB)

    Yamaoka, Kiyonori [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.; Takehara, Yoshiki; Yoshioka, Tamotsu; Utsumi, Kozo

    1994-10-01

    We evaluated the inhibitory effects of whole body {sup 60}Co-{gamma} irradiation at a single low dose on alloxan-induced hyperglycemia in rats. (1) In rats that received alloxan, SOD activity in pancreas significantly decreased, but the decrease was inhibited by irradiation at a dose of 0.5 Gy. (2) Similarly, plasma peroxide, pancreatic peroxide, and blood glucose increased. However, the increase in pancreatic peroxide was inhibited by irradiation at a dose of 0.5 or 1.0 Gy and the increase in blood glucose by irradiation at 0.5 Gy. (3) After alloxan administration, degranulation was observed in cells, but this was inhibited by irradiation at 0.5 Gy. These results suggest that alloxan diabetes was inhibited by the increase of SOD activity in pancreas after low dose irradiation at 0.5 Gy. (author).

  7. Inhibition of alloxan diabetes by low dose γ-irradiation before alloxan administration

    International Nuclear Information System (INIS)

    Yamaoka, Kiyonori; Takehara, Yoshiki; Yoshioka, Tamotsu; Utsumi, Kozo.

    1994-01-01

    We evaluated the inhibitory effects of whole body 60 Co-γ irradiation at a single low dose on alloxan-induced hyperglycemia in rats. (1) In rats that received alloxan, SOD activity in pancreas significantly decreased, but the decrease was inhibited by irradiation at a dose of 0.5 Gy. (2) Similarly, plasma peroxide, pancreatic peroxide, and blood glucose increased. However, the increase in pancreatic peroxide was inhibited by irradiation at a dose of 0.5 or 1.0 Gy and the increase in blood glucose by irradiation at 0.5 Gy. (3) After alloxan administration, degranulation was observed in cells, but this was inhibited by irradiation at 0.5 Gy. These results suggest that alloxan diabetes was inhibited by the increase of SOD activity in pancreas after low dose irradiation at 0.5 Gy. (author)

  8. Low-dose-rate total lymphoid irradiation: a new method of rapid immunosuppression

    International Nuclear Information System (INIS)

    Blum, J.E.; de Silva, S.M.; Rachman, D.B.; Order, S.E.

    1988-01-01

    Total Lymphoid Irradiation (TLI) has been successful in inducing immunosuppression in experimental and clinical applications. However, both the experimental and clinical utility of TLI are hampered by the prolonged treatment courses required (23 days in rats and 30-60 days in humans). Low-dose-rate TLI has the potential of reducing overall treatment time while achieving comparable immunosuppression. This study examines the immunosuppressive activity and treatment toxicity of conventional-dose-rate (23 days) vs low-dose-rate (2-7 days) TLI. Seven groups of Lewis rats were given TLI with 60Co. One group was treated at conventional-dose-rates (80-110 cGy/min) and received 3400 cGy in 17 fractions over 23 days. Six groups were treated at low-dose-rate (7 cGy/min) and received total doses of 800, 1200, 1800, 2400, 3000, and 3400 cGy over 2-7 days. Rats treated at conventional-dose-rates over 23 days and at low-dose-rate over 2-7 days tolerated radiation with minimal toxicity. The level of immunosuppression was tested using allogeneic (Brown-Norway) skin graft survival. Control animals retained allogeneic skin grafts for a mean of 14 days (range 8-21 days). Conventional-dose-rate treated animals (3400 cGy in 23 days) kept their grafts 60 days (range 50-66 days) (p less than .001). Low-dose-rate treated rats (800 to 3400 cGy total dose over 2-7 days) also had prolongation of allogeneic graft survival times following TLI with a dose-response curve established. The graft survival time for the 3400 cGy low-dose-rate group (66 days, range 52-78 days) was not significantly different from the 3400 cGy conventional-dose-rate group (p less than 0.10). When the total dose given was equivalent, low-dose-rate TLI demonstrated an advantage of reduced overall treatment time compared to conventional-dose-rate TLI (7 days vs. 23 days) with no increase in toxicity

  9. Evaluation of absorbed dose-distribution in the X-ray or gamma-irradiator for blood products

    International Nuclear Information System (INIS)

    Moriyama, Satoshi; Kurihara, Katsuhiko; Yokokawa, Nobuhiko; Satake, Masahiro; Juji, Takeo

    2001-01-01

    Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be recognized that the delivered dose in the instrument canister might differ from the actual dose absorbed by the blood bag. This study have evaluated the actual dose distribution under practical conditions where a container was loaded with blood products or water bags, or filled with distilled water. This approach provides data that the maximum attenuation occurred when the container was completely filled with a blood-compatible material. Thus, an error of approximately 20 percent should be considered in the dose measured in the in-air condition. A dose calibration in an in-air condition may lead to substantial underexposure of the blood products. A dose distribution study using adequately prearranged exposure period verified that the absorbed dose of 15 Gy was attained at any point in the container for both linear accelerator and gamma-irradiator. The maximal difference in the absorbed dose between measured points was 1.5- and 1.6-fold for linear accelerator and gamma-irradiator, respectively. In conclusion, using blood-compatible materials, a careful dose calibration study should be employed in which the absorbed dose of 15 Gy is obtained at the point where the lowest dose could be expected. (author)

  10. Low Dose Gamma Irradiation Does Not Affect the Quality or Total Ascorbic Acid Concentration of "Sweetheart" Passionfruit (Passiflora edulis).

    Science.gov (United States)

    Golding, John B; Blades, Barbara L; Satyan, Shashirekha; Spohr, Lorraine J; Harris, Anne; Jessup, Andrew J; Archer, John R; Davies, Justin B; Banos, Connie

    2015-08-26

    Passionfruit ( Passiflora edulis , Sims, cultivar "Sweetheart") were subject to gamma irradiation at levels suitable for phytosanitary purposes (0, 150, 400 and 1000 Gy) then stored at 8 °C and assessed for fruit quality and total ascorbic acid concentration after one and fourteen days. Irradiation at any dose (≤1000 Gy) did not affect passionfruit quality (overall fruit quality, colour, firmness, fruit shrivel, stem condition, weight loss, total soluble solids level (TSS), titratable acidity (TA) level, TSS/TA ratio, juice pH and rot development), nor the total ascorbic acid concentration. The length of time in storage affected some fruit quality parameters and total ascorbic acid concentration, with longer storage periods resulting in lower quality fruit and lower total ascorbic acid concentration, irrespective of irradiation. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not influence the effect of storage on passionfruit quality. The results showed that the application of 150, 400 and 1000 Gy gamma irradiation to "Sweetheart" purple passionfruit did not produce any deleterious effects on fruit quality or total ascorbic acid concentration during cold storage, thus supporting the use of low dose irradiation as a phytosanitary treatment against quarantine pests in purple passionfruit.

  11. Biosynthesis of phenolic compounds and water soluble vitamins in culantro (Eryngium foetidum L. plantlets as affected by low doses of gamma irradiation

    Directory of Open Access Journals (Sweden)

    Amina Abd El-Hamid ALY

    2010-11-01

    Full Text Available Explants obtained from in-vitro propagated plantlets of Culantro (Eryngium foetidum L. were exposed to four dose levels of γ-irradiation (0.0, 10.0, 20.0 and 40.0 Gy to investigate the biosynthesis of phenolic compounds and water soluble vitamins in Culantro fresh plantlets. Among six identified phenolic compounds, the content of p-cumaric acid was the highest in the extracts, followed by caffeic acid, coumarin, benzoic acid, salicylic acid and apigenin. Significant increases were observed at dose 40.0 Gy (61.66 mg/g d.w. for flavonoids, 18.02 mg/g d.w, for flavonone and 5.06 mg/g d.w for anthocyanin compared to control. On the other hand, the flavonols were decreased by increasing the irradiation dose. Vitamin C was increased in irradiated samples and this increase was in correlation with irradiation dose level. Thiamin, riboflavin and nicotinic acid were enhanced by the applied dose level 10 Gy. In addition, folic acid was enhanced by the dose levels 20 and 40 Gy and not detected for the control and 10 Gy treatments. Meanwhile, pyridoxine was decreased by increasing the irradiation dose level. The results obtained suggested that both low doses of γ-irradiation and tissue culture technique could be used to produce plantlets with high amount of phenolic compounds and water soluble vitamins.

  12. Low dose irradiation of 'Rainer' sweet cherries as a quarantine treatment

    International Nuclear Information System (INIS)

    Drake, S.R.; Moffitt, H.R.; Eakin, D.E.

    1994-01-01

    'Rainier' cherries, with and without gibberellic acid treatment were subjected to radiation at dose levels of 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, and 1.0 KGy and held for 14 and 21 days at 1C before removal from storage and quality determined. No variation in fruit or stem color, soluble solids, titratable acidity or sensory difference was noted at any of the radiation dose levels. There was 13% loss in-firmness due to radiatlon treatment between 0.4 and 1.0 KGy. Cherries that were treated with gibberellic acid were superior canidates for radiation treatment. 'Rainier' cherries can be irradiated as soon as quality parameters have reached acceptable levels for commercial harvest

  13. Effect of repeated small-dose γ-ray irradiation on atopic dermatitis in NC/Nga mice

    International Nuclear Information System (INIS)

    Fang, Su-Ping; Muto, Yasuko; Tago, Fumitoshi; Simura, Noriko; Kojima, Shuji

    2006-01-01

    We previously showed that several small-dose 0.5 Gy whole-body γ-ray irradiation inhibits tumor growth in mice via elevation of the interferon (IFN)-γ/interleukin 4 (IL-4) ratio concomitantly with a decrease in the percentage of B cells. Here, we examined whether repeated small-dose (0.5 Gy, 10 times) γ-ray irradiation influences atopic dermatitis in an NC/Nga mouse model. It was found that repeated γ-ray irradiation increased total IgE in comparison with the disease-control group. Levels of IL-4 and IL-5 were increased versus the disease-control group, while IFN-γ was slightly decreased, resulting in a further decrease of the IFN-γ/IL-4 ratio compared with the disease-control group. These results indicate that repeated small-dose γ-ray irradiation may exacerbate atopic dermatitis. This may be because the irradiation induces not helper T lymphocyte 1 (Th1), but Th2 polarization in this atopic mouse model, i.e., the effects of small-dose irradiation may be different in conditions involving immune hypersensitivity and impaired immunity. (author)

  14. Accelerated hyperfractionated hepatic irradiation in the management of patients with liver metastases: Results of the RTOG dose escalating protocol

    International Nuclear Information System (INIS)

    Russell, A.H.; Clyde, C.; Wasserman, T.H.; Turner, S.S.; Rotman, M.

    1993-01-01

    This study was prepared to address two objectives: (a) to determine whether progressively higher total doses of hepatic irradiation can prolong survival in a selected population of patients with liver metastases and (b) to refine existing concepts of liver tolerance for fractionated external radiation. One hundred seventy-three analyzable patients with computed tomography measurable liver metastases from primary cancers of the gastrointestinal tract were entered on a dose escalating protocol of twice daily hepatic irradiation employing fractions of 1.5 Gy separated by 4 hr or longer. Sequential groups of patients received 27 Gy, 30 Gy, and 33 Gy to the entire liver and were monitored for acute and late toxicities, survival, and cause of death. Dose escalation was implemented following survival of 10 patients at each dose level for a period of 6 months or longer without clinical or biochemical evidence of radiation hepatitis. The use of progressively larger total doses of radiation did not prolong median survival or decrease the frequency with which liver metastases were the cause of death. None of 122 patients entered at the 27 Gy and 30 Gy dose levels revealed clinical or biochemical evidence of radiation induced liver injury. Five of 51 patients entered at the 33 Gy level revealed clinical or biochemical evidence of late liver injury with an actuarial risk of severe (Grade 3) radiation hepatitis of 10.0% at 6 months, resulting in closure of the study to patient entry. The study design could not credibly establish a safe dose for hepatic irradiation, however, it did succeed in determining that 33 Gy in fractions of 1.5 Gy is unsafe, carrying a substantial risk of delayed radiation injury. The absence of apparent late liver injury at the 27 Gy and 30 Gy dose levels suggests that a prior clinical trial of adjuvant hepatic irradiation in patients with resected colon cancer may have employed an insufficient radiation dose (21 Gy) to fully test the question

  15. High-dose irradiation: Wholesomeness of food irradiated with doses above 10 kGy. Report of a joint FAO/IAEA/WHO study group

    International Nuclear Information System (INIS)

    1999-01-01

    This report presents the recommendations of an international group of experts convened by the World Health Organization, in association with the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency, to consider the implications of food irradiated to doses higher than those recommended in 1980 by the Joint Expert Committee on the Wholesomeness of Irradiated Food. Irradiation ensures the hygienic quality of food and extends shelf-life. The public perception of the safety of food irradiation has generally precluded its widespread use. However, current applications of food irradiation to doses over 10 kGy have been in the development of high-quality shelf-stable convenience foods for specific target groups such as immunosuppressed individuals and those under medical care, astronauts and outdoor enthusiasts. The Study Group reviewed data relating to the toxicological, nutritional, radiation chemical and physical aspects of food irradiated to doses above 10kGy from a wide range and number of studies carried out over the last forty years. This report presents a comprehensive summary, along with references, of the effectiveness and safety of the irradiation process. It concludes that foods treated with doses greater than 10kGy can be considered safe and nutritionally adequate when produced under established Good Manufacturing Practice

  16. Absence of single critical dose for the amorphization of quartz under ion irradiation

    Science.gov (United States)

    Zhang, S.; Pakarinen, O. H.; Backholm, M.; Djurabekova, F.; Nordlund, K.; Keinonen, J.; Wang, T. S.

    2018-01-01

    In this work, we first simulated the amorphization of crystalline quartz under 50 keV 23 Na ion irradiation with classical molecular dynamics (MD). We then used binary collision approximation algorithms to simulate the Rutherford backscattering spectrometry in channeling conditions (RBS-C) from these irradiated MD cells, and compared the RBS-C spectra with experiments. The simulated RBS-C results show an agreement with experiments in the evolution of amorphization as a function of dose, showing what appears to be (by this measure) full amorphization at about 2.2 eVṡatom-1 . We also applied other analysis methods, such as angular structure factor, Wigner-Seitz, coordination analysis and topological analysis, to analyze the structural evolution of the irradiated MD cells. The results show that the atomic-level structure of the sample keeps evolving after the RBS signal has saturated, until the dose of about 5 eVṡatom-1 . The continued evolution of the SiO2 structure makes the definition of what is, on the atomic level, an amorphized quartz ambiguous.

  17. Quantitative detection of absorbed dose of irradiated dried fruit by ESR spectroscopy method

    International Nuclear Information System (INIS)

    Li Weiming; Ha Yiming; Zhao Yongfu; Zhang Yanli

    2011-01-01

    Sunflower seeds, walnuts, pistachios, and hazelnuts were used as experimental materials which were irradiated at 1.0, 3.0, 5.0 and 10.0 kGy, respectively. The relationships and correlations between ESR signal intensity and irradiation dosages were studied. The results showed that ESR spectra of irradiated samples were obviously different from that of CK, and the ESR signal intensity was positively related with the irradiation dose. After irradiation, the ESR intensity and spectrum shapes all changed and all four samples were clearly identified irradiated or unirradiated. The appearances of the two weak satellite lines which situated left and right to the intense singlet line in walnuts and pistachios proved the existence of cellulose radical. The detection dose limit of irradiated walnut was 1 kGy, and the detection limits of the other three samples were lower than 1 kGy. In conclusion, the ESR method could be used to irradiated. (authors)

  18. Effect of low-dose gamma irradiation on storage properties in light salted Pseudosciaena crocea

    International Nuclear Information System (INIS)

    Zhang Xiaoyan; Yang Xianshi; Li Xueying; Guo Quanyou

    2012-01-01

    To explore the preservation effect of γ irradiation on light salted Pseudosciaena crocea, the influence of 1 kGy low-dose γ irradiation on sensory quality, microbiological and chemical quality including TVC, TVB-N and TBARS contents of light salted P. crocea stored at 25 ℃ was discussed. The results showed that the number of total viable counts significantly decreased after irradiation, during the whole storage, the bacteria numbers of light salted P. crocea treated with irradiation were still less than the control. The concentrations of TVB-N was significantly reduced after irradiation, whereas lipid oxidation was less accelerated. The shelf life could be remarkably prolonged after low-dose γ irradiation. While the shelf life of control group were 9 and 11 days, the shelf life of irradiated light salted P. crocea were extended to 16 and 20 days, respectively. The results can provide technical references for commercial application of seafood irradiation. (authors)

  19. Effects of split-dose irradiation of the rabbit's eye - a histopathological study

    International Nuclear Information System (INIS)

    Grabenbauer, G.G.

    1987-01-01

    Thirty-six rabbits were included in a study investigating into the effects of split-dose 300 KV X-irradiation on the cornea, ciliary body, nictitating membrane and lacrimal gland. In each animal, soly the right the eye was irradiated using total doses of 21 Gy, 30 Gy, 36 Gy and 45 Gy that were administered according to a fixed schedule in fractions of 3 Gy five times per week. After latency periods of six weeks, three months and six months the animals receiving 21 Gy, 30 Gy and 36 Gy showed no changes of the bulbi, eye lids and lacrimal glands that could be ascertained by histopathological evaluation. In the animals exposed to the 45 Gy dose, changes of the cornea and conjunctiva caused by radiation injuries to the lacrimal glands and conjunctival goblet cells started to appear after a minimum period of 3 months. This dose level was also the threshold for the occurrence of corneal damage or even ulceration as a result of secondary reduction or qualitative change of lacrimal secretions. (ECB) [de

  20. Use of computer code for dose distribution studies in A 60CO industrial irradiator

    Science.gov (United States)

    Piña-Villalpando, G.; Sloan, D. P.

    1995-09-01

    This paper presents a benchmark comparison between calculated and experimental absorbed dose values tor a typical product, in a 60Co industrial irradiator, located at ININ, México. The irradiator is a two levels, two layers system with overlapping product configuration with activity around 300kCi. Experimental values were obtanied from routine dosimetry, using red acrylic pellets. Typical product was Petri dishes packages, apparent density 0.13 g/cm3; that product was chosen because uniform size, large quantity and low density. Minimum dose was fixed in 15 kGy. Calculated values were obtained from QAD-CGGP code. This code uses a point kernel technique, build-up factors fitting was done by geometrical progression and combinatorial geometry is used for system description. Main modifications for the code were related with source sumilation, using punctual sources instead of pencils and an energy and anisotropic emission spectrums were included. Results were, for maximum dose, calculated value (18.2 kGy) was 8% higher than experimental average value (16.8 kGy); for minimum dose, calculated value (13.8 kGy) was 3% higher than experimental average value (14.3 kGy).

  1. Studies on adaptive response of lymphocyte transformation induced by low-dose irradiation

    International Nuclear Information System (INIS)

    Du Zeji; Su Liaoyuan; Tian Hailin; Zou Huawei

    1995-10-01

    Human peripheral blood lymphocytes stimulated by mitogen in vitro for 24 h were exposed to low-dose γ-ray irradiation (0.5∼4.0 cGy, adaptive dose). They showed an adaptive response to the inhibition of 3 H-TdR incorporation by subsequent higher acute doses of γ-ray (challenge dose). At the interval of 24 h between adaptive dose and challenge dose, the strongest adaptive response induced by low-dose irradiation was found. It is also found that the response induced by 1.0 cGy of adaptive dose was more obvious than that by other doses and that 3.0 Gy of challenge dose produced the strongest adaptive response. As the challenge doses increased, the adaptive response reduced. (2 figs., 2 tabs.)

  2. Effects of low-dose irradiation of X-rays on IUdR incorporation into mouse tissues

    International Nuclear Information System (INIS)

    Misonoh, J.; Ishii, K.; Yoshida, M.; Okumura, Y.; Kodama, S.

    1992-01-01

    It is well known that biological responses get smaller when a radiation dose gets lower, and it makes it difficult to detect them with significant differences from background levels. Therefore we know little about biological effects arisen from very low-dose radiation in mammals and mammalian cells. Feinendegen et al. detected a significant reduction of 125 I-UdR uptake in bone marrow cells at doses below 0.01 Gy. Using this extremely sensitive biological response, they also indicated that cells of mice irradiated twice with an interval of 4 hours did not show any reaction after the second irradiation. This meant that cells became radio-resistant after whole-body irradiation with low-doses. This phenomenon, an acquired radio-resistance after low-dose irradiation, is explained as an adaptive response to radiation , which is recently well documented in cytogenic studies. In order to confirm that whether it is common in the cell renewal systems, IUdR incorporation into mouse spleen and the other tissues were studied after whole-body irradiation. (author). 7 refs., 1 fig., 2 tabs

  3. Boron neutron capture irradiation of the rat spinal cord: effects of variable doses of borocaptate sodium

    International Nuclear Information System (INIS)

    Morris, Gerard M.; Coderre, Jeffrey A.; Hopewell, John W.; Micca, Peggy L.; Fisher, Craig

    1996-01-01

    The Fischer 344 rat spinal cord model has been used to evaluate the response of the central nervous system to boron neutron capture irradiation with variable doses of the neutron capture agent, borocaptate sodium (BSH). Three doses of BSH, 190, 140 and 80 mg/kg body weight, administered by i.p. injection, were used to establish the time course of 10 B accumulation in and removal from the blood. After administration of the two lower doses of BSH, blood 10 B levels peaked at 0.5 h after injection, with no significant (P > 0.1) change at 1 h after injection. Beyond this time point, levels of 10 B in the blood began to decrease after a dose of 80 mg/kg BSH, but remained constant until 3 h after administration after the two higher doses of BSH. Myelopathy developed after latent intervals of 20.4 ± 0.1, 20.8 ± 1.4, 15.0 ± 0.8, 15.4 ± 0.4 and 15.6 ± 0.4 weeks, following irradiation with thermal neutrons in combination with BSH at doses of 20, 40, 80, 140 and 190 mg/kg body weight, respectively. The radiation-induced lesion in the spinal cord was white matter necrosis. ED 50 values for myelopathy were calculated from probit-fitted dose-effect curves. Expressed as total physical absorbed doses, these values were 20.7 ± 1.9, 24.9 ± 1.2, 27.2 ± 0.9, 28.4 ± 0.6 and 32.4 ± 1.9 Gy after irradiation with thermal neutrons in the presence of 20, 40, 80, 140 and 190 mg/kg body weight of BSH, respectively. The compound biological effectiveness (CBE) factor values, estimated from this data, were in the range 0.49-0.55. There was no significant (P >0.1) variation in the CBE factor for BSH as a function of increasing 10 B concentration in the blood. It was concluded that there was no significant synergistic interaction between the low and high linear energy transfer (LET) components of the boron neutron capture (BNC) radiation field

  4. Effect of low dose irradiation of pork loins on the microflora, sensory characteristics and fat stability

    International Nuclear Information System (INIS)

    Mattison, M.L.; Kraft, A.A.; Olson, D.G.; Walker, H.W.; Rust, R.E.; James, D.B.

    1986-01-01

    The effects of low dose (100 krad) irradiation on microflora, sensory characteristics, and development of oxidative rancidity of vacuum packaged pork loins was investigated after irradiation and during low temperature (4 0 C) storage up to 21 days. Irradiation reduced numbers of mesophiles, psychrotrophs, anaerobic bacteria (P<0.01), and staphylococci (P<0.05), with the effect on mesophiles and psychrotrophic spoilage organisms the greatest. Effect of irradiation on sensory characteristics of pork loin was minimal with no detectable differences between irradiated and nonirradiated pork after 14 days of storage. Irradiation of pork did not affect cooking loss or thiobarbituric acid values

  5. Changes of some serum proteins in rats continuously irradiated with daily dose rate of 0. 0258 C/kg

    Energy Technology Data Exchange (ETDEWEB)

    Chlebovska, K; Chlebovsky, O; Praslicka, M [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

    1976-01-01

    Changes of serum albumin, haptoglobin, hemopexin and IgG in rats during chronic /sup 60/Co gamma irradiation with a daily dose rate of 0.0258 C/kg within 44 days were investigated by the method of two-dimensional quantitative immunoelectrophoresis. In comparison with normal levels, the values of albumin and IgG in rats during irradiation decreased until the death of animals to 50%, the values of haptoglobin increased till the 39th day of irradiation to 250% and hemopexin values increased to 150%.

  6. Sexual Competitiveness, Field Survival, and Dispersal of Anastrepha obliqua (Diptera: Tephritidae) Fruit Flies Irradiated at Different Doses.

    Science.gov (United States)

    Gallardo-Ortiz, Uriel; Pérez-Staples, Diana; Liedo, Pablo; Toledo, Jorge

    2018-04-02

    The sterile insect technique (SIT) is used in area-wide pest management programs for establishing low pest prevalence and/or areas free of fruit flies (Diptera: Tephritidae). The aim of this technique is to induce high levels of sterility in the wild population, for this the released insects must have a high sexual competitiveness and field dispersal. However, radiation decreases these biological attributes that do not allow it to compete successfully with wild insects. In this study the sexual competitiveness, field survival and dispersal of Anastrepha obliqua (Macquart; Diptera: Tephritidae) irradiated at 0, 40, 50, 60, 70, and 80 Gy were evaluated in laboratory. A dose of 60 Gy produced 98% sterility, whereas doses of 70 and 80 Gy produced 99% sterility. Sexual competitiveness was assessed in field cages, comparing males irradiated at 0, 50, 60, 70, and 80 Gy against wild males for mating with wild fertile females. Males irradiated at 50 and 60 Gy achieved more matings than those irradiated at 70 and 80 Gy. Wild males were more competitive than mass-reared males, even when these were not irradiated (0 Gy). There was no effect of irradiation on mating latency, yet wild males showed significantly shorter mating latency than mass-reared males. Female remating did not differ among those that mated with wild males and those that mated with males irradiated with different doses. The relative sterility index (RSI) increased from 0.25 at 80 Gy to 0.37 at 60 Gy. The Fried competitiveness index was 0.69 for males irradiated at 70 Gy and 0.57 for those irradiated at 80 Gy, which indicates that a 10 Gy reduction in the irradiation dose produces greater induction of sterility in the wild population. There were no significant differences in field survival and dispersal between flies irradiated at 70 or 80 Gy. Reducing the irradiation dose to 60 or 70 Gy could improve the performance of sterile males and the effectiveness of the SIT. Our results also distinguish between the

  7. Polyelectrolytes processing at pilot scale level by electron beam irradiation

    International Nuclear Information System (INIS)

    Martin, D.; Cirstea, E.; Craciun, G.; Ighigeanu, D.; Marin, Gheorghe G.

    2002-01-01

    Three years of research, combined with engineering activities, have culminated in the development of a new method of electron beam processing applicable up to the pilot scale level, namely, the polyelectrolytes (acrylamide - acrylic acid copolymers) electron beam processing. This new radiation processing method has been achieved by bilateral co-operation between the National Institute for Laser, Plasma and Radiation Physics (NILPRP) and the Electrical Design and Research Institute, EDRI - Bucharest. The polyelectrolytes electron beam (EB) processing was put in operation at EDRI, where, recently, an industrial electron accelerator of 2 MeV and 20 kW, manufactured by Institute of Nuclear Physics, Novosibirsk, Russia was installed in a specially designed irradiation facility. Automatic start-up via computer control makes it compatible with industrial processing. According to the first conclusions, which resulted from our experimental research with regard to acrylamide - acrylic acid copolymers production by EB irradiation, the proper physical and chemical characteristics can be well controlled by chemical composition to be treated and by suitable adjustment of absorbed dose and absorbed dose rate. So, it was possible to obtain a very large area of characteristics and therefore a large area of applications. The conversion coefficient is very high (> 98%) and concentration of the residual monomer is under 0.05%. The tests applied to some wastewaters from the vegetable oil plants demonstrated that the fatty substances, matters in suspension, chemical oxygen demand and biological oxygen demand over 5 days were much reduced, in comparison with classical treatment. Also, sedimentation time was around four times smaller and sediment volume was 60% smaller than the values obtained in case of classical treatment. The necessary EB absorbed dose for the acrylamide - acrylic acid aqueous solution polymerization, established by optimization of chemical composition and irradiation

  8. SU-F-T-113: Inherent Functional Dependence of Spinal Cord Doses of Variable Irradiated Volumes in Spine SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L; Braunstein, S; Chiu, J [University of California San Francisco, San Francisco, CA (United States); Sahgal, A [Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario (Canada)

    2016-06-15

    Purpose: Spinal cord tolerance for SBRT has been recommended for the maximum point dose level or at irradiated volumes such as 0.35 mL or 10% of contoured volumes. In this study, we investigated an inherent functional relationship that associates these dose surrogates for irradiated spinal cord volumes of up to 3.0 mL. Methods: A hidden variable termed as Effective Dose Radius (EDR) was formulated based on a dose fall-off model to correlate dose at irradiated spinal cord volumes ranging from 0 mL (point maximum) to 3.0 mL. A cohort of 15 spine SBRT cases was randomly selected to derive an EDR-parameterized formula. The mean prescription dose for the studied cases was 21.0±8.0 Gy (range, 10–40Gy) delivered in 3±1 fractions with target volumes of 39.1 ± 70.6 mL. Linear regression and variance analysis were performed for the fitting parameters of variable EDR values. Results: No direct correlation was found between the dose at maximum point and doses at variable spinal cord volumes. For example, Pearson R{sup 2} = 0.643 and R{sup 2}= 0.491 were obtained when correlating the point maximum dose with the spinal cord dose at 1 mL and 3 mL, respectively. However, near perfect correlation (R{sup 2} ≥0.99) was obtained when corresponding parameterized EDRs. Specifically, Pearson R{sup 2}= 0.996 and R{sup 2} = 0.990 were obtained when correlating EDR (maximum point dose) with EDR (dose at 1 mL) and EDR(dose at 3 mL), respectively. As a result, high confidence level look-up tables were established to correlate spinal cord doses at the maximum point to any finite irradiated volumes. Conclusion: An inherent functional relationship was demonstrated for spine SBRT. Such a relationship unifies dose surrogates at variable cord volumes and proves that a single dose surrogate (e.g. point maximum dose) is mathematically sufficient in constraining the overall spinal cord dose tolerance for SBRT.

  9. Estimation of the fetal dose by dose measurement during an irradiation of a parotid tumor; Estimation de la dose foetale par mesure de dose lors d'une irradiation d'une tumeur de la parotide

    Energy Technology Data Exchange (ETDEWEB)

    Marchesi, V.; Graff-Cailleaud, P.; Peiffert, D. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France); Noel, A. [Institut National Polytechnique de Lorraine, CRAN CNRS UMR-7039, 54 - Vandoeuvre-les-Nancy (France)

    2006-11-15

    The irradiation of a five months pregnant patient has been made for a right parotid attack. In conformation with the legislative texts relative to radiation protection ( publication 84 of the ICRP) an estimation of the dose received for the fetus has been led by dose measurement on phantom. With the dose limit ( 100 mGy) recommended in the publication 84 of the ICRP neither modification of the treatment nor abortion was necessary. (N.C.)

  10. Low- and high-dose laser irradiation effects on cell migration and destruction

    Science.gov (United States)

    Layton, Elivia; Gallagher, Kyra A.; Zukerman, Sara; Stevens, Brianna; Zhou, Feifan; Liu, Hong; Chen, Wei R.

    2018-02-01

    Metastases are the cause of more than 90 percent of cancer-related deaths. Current treatment methods, including chemotherapy, radiation, and surgery, fail to target the metastases effectively. One potential treatment for metastatic cancer is laser immunotherapy (LIT). LIT combines the use of a photothermal laser with an immunoadjuvant, Glycated Chitosan (GC). GC combined with single-walled carbon nanotubes (SWNTs) has proven to be a viable alternative to traditional cancer treatment methods, when under irradiation of laser with appropriate wavelength. In this study, the effects of low dose and high dose laser irradiation on metastatic pancreatic cancer cell migration were observed. It was found that low dose irradiation increased the migration rate, but the high dose irradiation significantly decreased the migration rate of the cancer cells. When using LIT, the goal is to kill tumor cells and to prompt the correct immune response. If the tumor were irradiated with a low dose, it would promote metastasis. If the dose of irradiation were too high, it would destroy the entire tumor and the immune response would not recognize the tumor. Therefore, the laser dose plays an important role in LIT, particularly when using SWNT as light absorbing agent. Our results from this study will delineate the optimal laser irradiation dose for destroying tumor cells and at the same time preserve and release tumor antigens as a precursor of antitumor immune response.

  11. Individual and collective doses associated with the transport of irradiated magnox fuel within the UK

    International Nuclear Information System (INIS)

    Macdonald, H.F.; Mairs, J.H.

    1978-12-01

    A method is described of evaluating the individual and collective doses arising during the transport of irradiated fuel from a system of nuclear power stations to a central reprocessing plant. The doses associated with irradiated Magnox fuel movements in the UK are estimated and compared with those resulting from other phases of the nuclear fuel cycle. In addition, the individual and collective doses implied by the accidental activity release limits contained within the 1973 IAEA Tranport Regulations are discussed. (author)

  12. CONTRASTING DOSE-RATE EFFECTS OF GAMMA-IRRADIATION ON RAT SALIVARY-GLAND FUNCTION

    NARCIS (Netherlands)

    VISSINK, A; DOWN, JD; KONINGS, AWT

    The aim of this study was to investigate the effects of Co-60 irradiation delivered at high (HDR) and low (LDR) dose-rates on rat salivary gland function. Total-body irradiation (TBI; total doses 7.5, 10 and 12.5 Gy) was applied from a Co-60 source at dose-rates of 1 cGy/min (LDR) and 40 cGy/min

  13. Effect of low-dose gamma irradiation on enterotoxin-positive strains of Clostridium perfringens Type A

    International Nuclear Information System (INIS)

    Barnhart, H.M. Jr.

    1976-01-01

    The effect of low-dose gamma irradiation on selected enterotoxin producing strains of Clostridium perfringens Type A was studied. The radioresistance of three strains NCTC-8239, NCTC-10239 and NCTC-8798 in 0.1 percent peptone water, beef gravy and ground beef was determined for both vegetative cells and spores. D 10 values were approximately 30 Krad in 0.1 percent peptone water and 175 Krad in beef menstruums. D 10 values for spores were approximately 250 Krad in 0.1 percent peptone water and 335 Krad in beef. Low-level irradiation induced a 2 hr lag for cell recovery at 37 0 C following irradiation though this was strain dependent. Heat resistance of vegetative cells decreased following irradiation, although one strain was stimulated in growth response and unaltered in its heat resistance. Spore activation and germination were not affected by low-level irradiation. Spores were not significantly inactivated at this level. Irradiation had no effect on subsequent survival of vegetative cells stored at cold temperatures. Enterotoxin production by irradiated cultures was not affected by the irradiation treatment. A method for quantitating C. perfringens enterotoxin using crossed-immunoelectrophoresis was developed. It was found that this technique could detect at least .05 g of enterotoxin, could utilize crude enterotoxin preparations and was more sensitive than other methods based on biological activity

  14. Elevation of blood levels of zinc protoporphyrin in mice following whole-body irradiation

    International Nuclear Information System (INIS)

    Walden, T.L. Jr.

    1983-01-01

    Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. The author has discovered that sublethal doses of whole body irradiation with X-rays also elevates ZPP two- to three-fold over normal levels. The ZPP level does not begin to increase until days 12 to 14 post-irradiation and peaks between days 18 to 20 before returning to normal levels between days 28 to 35. Increasing the radiation dose delays the onset of the rise in ZPP but does not affect the magnitude of the elevation. At lethal doses, ZPP elevation is not observed. Neither of the two previously described mechanisms which cause elevations of ZPP, namely iron deficiency and inhibition of ferrochelatase, are responsible for the radiation induced elevation of ZPP. The elevation of ZPP appears to be correlated with the recovery of the hematopoietic system from radiation injury

  15. Dose rate determinations in the Portuguese Gamma Irradiation Facility: Monte Carlo simulations and measurements

    International Nuclear Information System (INIS)

    Oliveira, C.; Salgado, J.; Ferro de Carvalho, A.

    2000-01-01

    A simulation study of the Portuguese Gamma Irradiation Facility, UTR, has been carried out using the MCNP code. The work focused on the optimisation of the dose distribution inside the irradiation cell, dose calculations inside irradiated samples and dose calculations in critical points for protection purposes. Calculations were carried out at points inside and outside the irradiation cell, where different behaviour was expected (distance from the source, radiation absorption and scattering in irradiator structure and walls). The contributions from source, irradiator structure, sample material, carriers, walls, ceiling and floor to the photon spectra and air kerma at those points are reported and discussed. Air kerma measurements were also carried out using an ionisation chamber. Good agreement was found between experimental and calculated air kermas. (author)

  16. Dose rate distribution of the GammaBeam: 127 irradiator using MCNPX code

    International Nuclear Information System (INIS)

    Gual, Maritza Rodriguez; Batista, Adriana de Souza Medeiros; Pereira, Claubia; Faria, Luiz O. de; Grossi, Pablo Andrade

    2013-01-01

    The GammaBeam - 127 Irradiator is widely used for biological, chemical and medical applications of the gamma irradiation technology using Cobalt 60 radioactive at the Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil. The source has maximum activity of 60.000Ci, which is composed by 16 double encapsulated radioactive pencils placed in a rack. The facility is classified by the IAEA as Category II (dry storage facility). The aim of this work is to present a modelling developed to evaluate the dose rates at the irradiation room and the dose distribution at the irradiated products. In addition, the simulations could be used as a predictive tool of dose evaluation in the irradiation facility helping benchmark experiments in new similar facilities. The MCNPX simulated results were compared and validated with radiometric measurements using Fricke and TLDs dosimeters along several positions inside the irradiation room. (author)

  17. ATM phosphorylation in HepG2 cells following continuous low dose-rate irradiation

    International Nuclear Information System (INIS)

    Mei Quelin; Du Duanming; Chen Zaizhong; Liu Pengcheng; Yang Jianyong; Li Yanhao

    2008-01-01

    Objective: To investigate the change of ATM phosphorylation in HepG2 cells following a continuous low dose-rate irradiation. Methods: Cells were persistently exposed to low dose-rate (8.28 cGy/h) irradiation. Indirect immunofluorescence and Western blot were used to detect the expression of ATM phosphorylated proteins. Colony forming assay was used to observe the effect of a low dose-rate irradiation on HepG2 cell survival. Results: After 30 min of low dose-rate irradiation, the phosphorylation of ATM occurred. After 6 h persistent irradiation, the expression of ATM phosphorylated protein reached the peak value, then gradually decreased. After ATM phosphorylation was inhibited with Wortmannin, the surviving fraction of HepG2 cells was lower than that of the irradiation alone group at each time point (P<0.05). Conclusions: Continuous low dose-rate irradiation attenuated ATM phosphorylation, suggesting that continuous low dose-rate irradiation has a potential effect for increasing the radiosensitivity of HepG2 cells. (authors)

  18. Contribution to the understanding of zirconium alloy deformation under irradiation at high doses

    International Nuclear Information System (INIS)

    Gharbi, Nesrine

    2015-01-01

    The growth of zirconium alloy tubes of PWR fuel assemblies is the result of two phenomena: axial irradiation creep and stress 'free' growth which is correlated to the formation of c-loops at high irradiation doses. This PhD work aims at investigating the coupling between these two phenomena through a fine Transmission Electron Microscopy analysis of the effect of a macroscopic applied stress on the c-loop microstructure. 600 keV Zr + ion irradiations were performed at 300 C on two recrystallized zirconium alloys: Zircaloy-4 and M5. Thanks to a device specifically designed, different tensile or compressive stress levels were applied under ion irradiation. The microstructural observations have shown that the c-loop density reduces in grains oriented with the c-axis close to the direction of the applied tensile stress or far from the direction of the applied compressive stress, which is in good agreement with the SIPA mechanism. Nevertheless, the examination of a large number of grains has revealed dispersion from grain to grain. This dispersion, which could be explained by the intergranular heterogeneities, reduces the magnitude of the stress effect on c-loop microstructure. In parallel to this experimental study, a cluster dynamics model has been able to describe the evolution under irradiation of zirconium and Zircaloy-4 microstructure and to assess the effect of stress on c-loop microstructure. On the macroscopic scale, a physical model was also developed to predict the irradiation growth and creep behaviour of zirconium alloy tubes. (author) [fr

  19. Analysis of Low Dose Irradiation Damages in Structural Ferritic/Martensitic Steels by Proton Irradiation and Nanoindentation

    International Nuclear Information System (INIS)

    Waseem, Owais A.; Ryu, Ho Jin; Park, Byong Guk; Jeong, Jong Ryul; Maeng, Cheol Soo; Lee, Myoung Goo

    2016-01-01

    As a result, ferritic-martensitic steels find applications in the in-core and out-of-core components which include ducts, piping, pressure vessel and cladding, etc. Due to ferromagnetism of F/M steel, it has been successfully employed in solenoid type fuel injector. Although the irradiation induced degradation in ferritic martensitic steels is lower as compare to (i) reduced activation steels, (ii) austenitic steels and (iii) martensitic steels, F/M steels are still prone to irradiation induced hardening and void swelling. The irradiation behavior may become more sophisticated due to transmutation and production of helium and hydrogen. The ductile to brittle transition temperature of F/M steels is also expected to increase due to irradiation. These irradiation induced degradations may deteriorate the integrity of F/M components. As a result of these investigations, it has found that the F/M steels experience no irradiation hardening above 400 .deg. C, but below this temperature, up to 350 .deg. C, weak hardening is observed. The irradiation hardening becomes more pronounced below 300 .deg. C. Moreover, the irradiation hardening has also found dependent upon radiation damage. The hardening was found increasing with increasing dose. Due to pronounced irradiation hardening below 300 .deg. C and increasing radiation damage with increasing dose (even at low dpa), it is required to investigate the post irradiation mechanical properties of F/M steel, in order to confirm its usefulness in structural and magnetic components which experience lifetime doses as low as 1x10"-"5 dpa.

  20. Analysis of Low Dose Irradiation Damages in Structural Ferritic/Martensitic Steels by Proton Irradiation and Nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Waseem, Owais A.; Ryu, Ho Jin; Park, Byong Guk [KAIST, Daejeon (Korea, Republic of); Jeong, Jong Ryul [Chungnam University, Daejeon (Korea, Republic of); Maeng, Cheol Soo; Lee, Myoung Goo [KEPCO, Daejeon (Korea, Republic of)

    2016-05-15

    As a result, ferritic-martensitic steels find applications in the in-core and out-of-core components which include ducts, piping, pressure vessel and cladding, etc. Due to ferromagnetism of F/M steel, it has been successfully employed in solenoid type fuel injector. Although the irradiation induced degradation in ferritic martensitic steels is lower as compare to (i) reduced activation steels, (ii) austenitic steels and (iii) martensitic steels, F/M steels are still prone to irradiation induced hardening and void swelling. The irradiation behavior may become more sophisticated due to transmutation and production of helium and hydrogen. The ductile to brittle transition temperature of F/M steels is also expected to increase due to irradiation. These irradiation induced degradations may deteriorate the integrity of F/M components. As a result of these investigations, it has found that the F/M steels experience no irradiation hardening above 400 .deg. C, but below this temperature, up to 350 .deg. C, weak hardening is observed. The irradiation hardening becomes more pronounced below 300 .deg. C. Moreover, the irradiation hardening has also found dependent upon radiation damage. The hardening was found increasing with increasing dose. Due to pronounced irradiation hardening below 300 .deg. C and increasing radiation damage with increasing dose (even at low dpa), it is required to investigate the post irradiation mechanical properties of F/M steel, in order to confirm its usefulness in structural and magnetic components which experience lifetime doses as low as 1x10{sup -5} dpa.

  1. Changes in plasma (hydrocortisone) levels after whole-body irradiation with ultraviolet rays of defined wavelengths

    International Nuclear Information System (INIS)

    Bartelt, R.N.

    1983-01-01

    One hour after whole-body irradiation with a radiation source having its maximum of emission in the UVB range, at a radiation dose of 0.44 J/cm 2 , a significant fall in the mean values of the blood plasma hydrocortisone level (p [de

  2. ANALYSIS OF DATA ON DOSES OF EXTERNAL TERRIGENOUS IRRADIATION OF THE RUSSIAN FEDERATION POPULATION IN MUNICIPAL CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2015-01-01

    Full Text Available By this time in the Russian Federation there is collected a huge file of data describing the influence of all natural sources of ionizing radiation on population in municipal conditions. These data are collected and generalized in radiation hygiene passports of the Russian Federation for the last 16 years and in the reporting forms of federal statistical supervision No 4-DOZ “Data on doses of population irradiation due to the natural and manchanged radiation background” for a period of 14 years. These data are received by direct measurements of gamma radiation dose rate in the premises and in the open air on the territory of settlements. Measurements were made with the most different dosimeters; their technical and metrological parameters differ considerably. In this regard of certain interest is evaluation of this data reliability degree; that will help to find out the reasons of higher levels of the Russian Federation population external irradiation in comparison with average global dose values.In this article an attempt was made to evaluate reliability degree of data on the population external irradiation doses using the radiation hygiene passports of territories and reporting forms No 4-DOZ for the whole period of supervision. For this there was used the known dependence between the gamma radiation dose rate and natural radionuclides effective specific activity (AEFF in inhabitancy objects. For this purpose there were used the data on average AEFF values of building raw materials and of local manufacture materials, which are presented in radiation hygiene passports of territories. Definition of design value of gamma radiation dose rate in the buildings and in the open air according to AEFF measurement data in building raw materials and in local manufacture materials actually enables to get an independent evaluation of the population external irradiation doses. Comparison of two evaluations of the population external irradiation levels

  3. Gamma irradiator dose mapping simulation using the MCNP code and benchmarking with dosimetry

    International Nuclear Information System (INIS)

    Sohrabpour, M.; Hassanzadeh, M.; Shahriari, M.; Sharifzadeh, M.

    2002-01-01

    The Monte Carlo transport code, MCNP, has been applied in simulating dose rate distribution in the IR-136 gamma irradiator system. Isodose curves, cumulative dose values, and system design data such as throughputs, over-dose-ratios, and efficiencies have been simulated as functions of product density. Simulated isodose curves, and cumulative dose values were compared with dosimetry values obtained using polymethyle-methacrylate, Fricke, ethanol-chlorobenzene, and potassium dichromate dosimeters. The produced system design data were also found to agree quite favorably with those of the system manufacturer's data. MCNP has thus been found to be an effective transport code for handling of various dose mapping excercises for gamma irradiators

  4. Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

    Science.gov (United States)

    Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

    2001-01-01

    The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

  5. Establishment and validation of a method for multi-dose irradiation of cells in 96-well microplates

    International Nuclear Information System (INIS)

    Abatzoglou, Ioannis; Zois, Christos E.; Pouliliou, Stamatia; Koukourakis, Michael I.

    2013-01-01

    Highlights: ► We established a method for multi-dose irradiation of cell cultures within a 96-well plate. ► Equations to adjust to preferable dose levels are produced and provided. ► Up to eight different dose levels can be tested in one microplate. ► This method results in fast and reliable estimation of radiation dose–response curves. -- Abstract: Microplates are useful tools in chemistry, biotechnology and molecular biology. In radiobiology research, these can be also applied to assess the effect of a certain radiation dose delivered to the whole microplate, to test radio-sensitivity, radio-sensitization or radio-protection. Whether different radiation doses can be accurately applied to a single 96-well plate to further facilitate and accelerated research by one hand and spare funds on the other, is a question dealt in the current paper. Following repeated ion-chamber, TLD and radiotherapy planning dosimetry we established a method for multi-dose irradiation of cell cultures within a 96-well plate, which allows an accurate delivery of desired doses in sequential columns of the microplate. Up to eight different dose levels can be tested in one microplate. This method results in fast and reliable estimation of radiation dose–response curves

  6. High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

    Science.gov (United States)

    Kaschieva, S.; Angelov, Ch; Dmitriev, S. N.

    2018-03-01

    The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.

  7. The radiosensitizing effect of doranidazole on human colorectal cancer cells exposed to high doses of irradiation

    International Nuclear Information System (INIS)

    Zhang, Li; Gong, Aimin; Ji, Jun; Wu, Yuanyuan; Zhu, Xiaoyu; Lv, Suqing; Lv, Hongzhu; Sun, Xizhuo

    2007-01-01

    This paper investigates the effects of a new radiosensitizer, doranidazole, and enhancing irradiation on colorectal cancer cells. The radiosensitizing effect of doranidazole was determined using colony formation and propidium iodide (PI) assays to measure cell growth inhibition and the cell killing effect of human colorectal cancer cell lines exposed to high doses of γ-ray irradiation under hypoxic conditions in vitro. Fluorescence staining and cell migration assays were also used to assess the radiosensitizing effect. Cell proliferation evaluated by clonogenic survival curves was significantly inhibited by 5 mmol/L doranidazole, particularly at doses ranging from 10 to 30 Gy of irradiation. The radiosensitizing effect of doranidazole on colorectal cancer cells occurs in a time- and dose-dependent manner. Doranidazole also inhibited the mobility of cell invasion and migration. Doranidazole can enhance the killing effect and the cell growth inhibition of colorectal cancer after high-dose irradiation in a time and dose-dependent manner

  8. [Induction of glutathione and activation of immune functions by low-dose, whole-body irradiation with gamma-rays].

    Science.gov (United States)

    Kojima, Shuji

    2006-10-01

    We first examined the relation between the induction of glutathione and immune functions in mice after low-dose gamma-ray irradiation. Thereafter, inhibition of tumor growth by radiation was confirmed in Ehrlich solid tumor (EST)-bearing mice. The total glutathione level of the splenocytes transiently increased soon after irradiation and reached a maximum at around 4 h postirradiation. Thereafter, the level reverted to the 0 h value by 24 h postirradiation. A significantly high splenocyte proliferative response was also recognized 4 h postirradiation. Natural killer (NK) activity was also increased significantly in a similar manner. The time at which the response reached the maximum coincided well with that of maximum total glutathione levels of the splenocytes in the gamma-ray-irradiated mice. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced the proliferative response and NK activity in a dose-dependent manner. The inhibitory effects of radiation on tumor growth was then examined in EST-bearing mice. Repeated low-dose irradiation (0.5 Gy, four times, before and within an early time after inoculation) significantly delayed the tumor growth. Finally, the effect of single low-dose (0.5 Gy), whole-body gamma-ray irradiation on immune balance was examined to elucidate the mechanism underlying the antitumor immunity. The percentage of B cells in blood lymphocytes was selectively decreased after radiation, concomitant with an increase in that of the helper T cell population. The IFN-gamma level in splenocyte culture prepared from EST-bearing mice was significantly increased 48 h after radiation, although the level of IL-4 was unchanged. IL-12 secretion from macrophages was also enhanced by radiation. These results suggest that low-dose gamma-rays induce Th1 polarization and enhance the activities of tumoricidal effector cells, leading to an inhibition of tumor growth.

  9. The effect of irradiation dose and age of bird on the ESR signal in irradiated chicken drumsticks

    International Nuclear Information System (INIS)

    Gray, R.; Stevenson, M.H.; Kilpatrick, D.J.

    1990-01-01

    Groups of 20 broiler chickens of the same genetic strain and reared under identical conditions were slaughtered at either 4, 5, 6, 7 or 8 weeks of age. Pairs of drumsticks were removed from each bird and groups were either not irradiated or irradiated at 2.5, 5.0, 7.5 or 10.0 kGy using a cobalt 60 source. Bone samples were excised, fragmented, freeze dried and ground prior to the determination of free radical concentration using electron spin resonance (ESR) spectroscopy. Increasing irradiation dose gave a highly significant increase in free radical concentration whilst for each irradiation dose, bones from younger birds gave significantly lower concentrations compared to those for older birds. Crystallinity coefficient increased linearly with age of bird and this may account in part for the increased signal observed as the birds aged. (author)

  10. Plasma TGF beta level in rats after hemithoracic irradiation

    NARCIS (Netherlands)

    Vujaskovic, Z; Down, JD; vanWaarde, MAWH; vanAssen, AJ; Szabo, BG; Konings, AWT

    Changes in TGF-beta plasma levels were observed 18 weeks after hemithoracic irradiation in rats. This coincides with an increase in the breathing frequency, being most pronounced between 22 and 28 weeks after irradiation. The correlation suggests a potential role of the circulating TGF-beta in the

  11. Dose mapping using MCNP code and experiment for SVST-Co-60/B irradiator in Vietnam.

    Science.gov (United States)

    Tran, Van Hung; Tran, Khac An

    2010-06-01

    By using MCNP code and ethanol-chlorobenzene (ECB) dosimeters the simulations and measurements of absorbed dose distribution in a tote-box of the Cobalt-60 irradiator, SVST-Co60/B at VINAGAMMA have been done. Based on the results Dose Uniformity Ratios (DUR), positions and values of minimum and maximum dose extremes in a tote-box, and efficiency of the irradiator for the different dummy densities have been gained. There is a good agreement between simulation and experimental results in comparison and they have valuable meanings for operation of the irradiator. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. Response of irradiated cotton seeds to different levels of phosphorus fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Janat, M; Khalifa, K [Atomic Energy Commission, P.O.Box 6091, Damasucs, (Syrian Arab Republic)

    1995-10-01

    A two years field experiment 1990, 1991 was conducted over two different locations in order to evaluate the response of cotton seeds exposed to various doses of gamma radiation 0,5, 10 and 20 Gy, to different levels of phosphorous fertilizer, 0,60, 100, 140 and kg P{sub 2} O{sub 5}/ha. Irradiation doses and P. Fertilizer levels arranged in split plot design, where irradiation doses made up the main plots and the P-levels the subplots. Representative soil samples were collected and analyzed before planting. Soil test for P revealed that enough P was available in the top soil. With a few exceptions, results showed no positive response of cotton crop to P-fertilizer and gamma rays stimulation. 8 tabs.

  13. Response of irradiated cotton seeds to different levels of phosphorus fertilizer

    International Nuclear Information System (INIS)

    Janat, M.; Khalifa, K.

    1995-07-01

    A two year field experiments 1990, 1991 was conducted over two different locations in order to evaluate the response of cotton seeds exposed to various doses of gamma radiation 0, 5, 10 and 20 Gy, to different levels of phosphorous fertilizer, 0, 60, 100, 140 and 180 Kg P sub 2 O sub 5 ha- sub 1. Irradiation doses and P-Fertilizer levels were arranged in split plot design, where irradiation doses made up the main plots and the P-levels the sub-plots. Representative soil samples were collected and analyzed before planting and after harvesting. Soil test for P revealed enough P was available in the top soil. With a few exceptions, results showed no positive response of cotton crop to P-fertilizer and gamma rays stimulation. (author). 26 refs., 49 tabs

  14. Effects of prolonged irradiation by low dose-rate ionizing radiation on the gene expression of hemopoietic factors of mice

    Energy Technology Data Exchange (ETDEWEB)

    Shirata, Katsutoshi; Saitou, Mikio; Yanai, Takanori; Sato, Fumiaki [Institute for Environmental Science, Rokkasho, Aomori (Japan)

    2000-07-01

    To evaluate the effect of prolonged low-dose irradiation on the gene expression of hemopoietic factors in tissues, gene expression was analyzed in the spleen as a hemopoietic tissue that is well known to be one of the most sensitive tissues to irradiation. SPF C3H/HeN female mice (Clea Japan Inc.) were irradiated under SPF conditions with {sup 137}Cs {gamma}-rays at doses of 2, 4, 6, and 8 Gy and a dose rate of 20 mGy/day. Non-irradiated mice of the same age were maintained as controls. At the end of the period of irradiation, both groups of mice were sacrificed and dissected to extract total RNA from their tissues. Reverse transcriptase-polymerase chain reaction (RT-PCR) and the Northern hybridization were employed to detect gene expression. RT-PCT showed no marked changes in the gene expression of GM-CSF. IL-6 gene expression was shown to tend to be enhanced by prolonged low-dose irradiation. The results of Northern hybridization showed that IL-6 mRNA was expressed slightly in both groups, and it was too weak to compare the difference in mRNA expression level between the irradiated group and the controls. No mRNA expression of GM-CSF was detected by Northern hybridization. Based on these results, it was concluded that the gene expression levels of IL-6 and GM-CSF were inadequate to detect the chemiluminescence signals without amplification. It was therefore concluded that improvement of detection sensitivity and larger RNA samples would be necessary for further analysis of the gene expression of hemopoietic factors. (K.H.)

  15. Cell kinetic changes in the follicular epithelium of pig skin after irradiation with single and fractionated doses of X rays

    International Nuclear Information System (INIS)

    Morris, G.M.; Hopewell, J.W.

    1989-01-01

    Changes in cell kinetics of the follicular epithelium of the pig were studied after x-irradiation with single and fractionated doses (30 fractions/39 days) and compared with previous epidermal data. In the follicular epithelium there was an initial degenerative phase, when the rate of cell depletion was independent of radiation dose and mode of administration. Repopulation was seen between the 14th and 18th days after single doses (15 or 20 Gy) and by the 28th day after the start of irradiation with fractionated doses (52.3-80.0 Gy). The degree of cell depletion and subsequent rate of repopulation were independent of dose. The regenerative phase was characterized by an increased cell proliferation. Islands of cells with appearance similar to cells in the normal follicular epithelium, were seen 18 days after a single dose of 20 Gy and 42 days after the start of fractionated irradiation. Compared with the epidermis, the follicular epithelium exhibited considerably less evidence of damage after both single and fractionated doses. There was a lower incidence of degenerate cells and reduced levels of cell depletion in the follicular epithelium. (author)

  16. Effects of high dose gamma irradiation on ITO thin film properties

    Energy Technology Data Exchange (ETDEWEB)

    Alyamani, A. [National Nanotechnology Center, King Abdul-Aziz City for Science and Technology (KACST), Riyadh (Saudi Arabia); Mustapha, N., E-mail: nazirmustapha@hotmail.com [Dept. of Physics, College of Sciences, Al Imam Mohammad Ibn Saud Islamic University, P.O. Box 90950, Riyadh 11623 (Saudi Arabia)

    2016-07-29

    Transparent thin-film Indium Tin Oxides (ITO) were prepared on 0.7 mm thick glass substrates using a pulsed laser deposition (PLD) process with average thickness of 150 nm. The samples were then exposed to high gamma γ radiation doses by {sup 60}Co radioisotope. The films have been irradiated by performing exposure cycles up to 250 kGy total doses at room temperature. The surface structures before and after irradiation were analysed by x-ray diffraction. Atomic Force Microscopy (AFM) was performed on all samples before and after irradiation to investigate any change in the grain sizes, and also in the roughness of the ITO surface. We investigated the influence of γ irradiation on the spectra of transmittance T, in the ultraviolet-visible-near infrared spectrum using spectrophotometer measurements. Energy band gap E{sub g} was then calculated from the optical spectra for all ITO films. It was found that the optical band gap values decreased as the radiation dose was increased. To compare the effect of the irradiation on refractive index n and extinction coefficient k properties, additional measurements were done on the ITO samples before and after gamma irradiation using an ellipsometer. The optical constants n and k increased by increasing the irradiation doses. Electrical properties such as resistivity and sheet resistance were measured using the four-point probe method. The good optical, electrical and morphological properties maintained by the ITO films even after being exposed to high gamma irradiation doses, made them very favourable to be used as anodes for solar cells and as protective coatings in space windows. - Highlights: • Indium Tin Oxide (ITO) thin films were deposited by pulsed laser deposition. • Effects of Gamma irradiation were investigated. • Changes of optical transmission and electrical properties of ITO films were studied. • Intensity of the diffraction peaks and the film's structure changed with increasing irradiation doses.

  17. Radiation doses to normal tissues during craniospinal irradiation ...

    African Journals Online (AJOL)

    Mohamed Farouk Mostafa

    2011-10-15

    Oct 15, 2011 ... not in the center of the brain as this shows lower doses to eyes and lenses. ª 2011 Alexandria .... dose plan function was used to check the dose coverage of the .... maximum dose received by the right and left lens were listed.

  18. Alterations in water and electrolyte absorption in the rat colon following neutron irradiation: influence of neutron component and irradiation dose.

    Science.gov (United States)

    Dublineau, I; Ksas, B; Joubert, C; Aigueperse, J; Gourmelon, P; Griffiths, N M

    2002-12-01

    To study the absorptive function of rat colon following whole-body exposure to neutron irradiation, either to the same total dose with varying proportion of neutrons or to the same neutron proportion with an increasing irradiation dose. Different proportions of neutron irradiation were produced from the reactor SILENE using a fissile solution of uranium nitrate (8, 47 and 87% neutron). Water and electrolyte fluxes were measured in the rat in vivo under anaesthesia by insertion into the descending colon of an agarose gel cylinder simulating the faeces. Functional studies were completed by histological analyses. In the first set of experiments, rats received 3.8 Gy with various neutron percentages and were studied from 1 to 14 days after exposure. In the second set of experiments, rats were exposed to increasing doses of irradiation (1-4Gy) with a high neutron percentage (87%n) and were studied at 4 days after exposure. The absorptive capacity of rat colon was diminished by irradiation at 3-5 days, with a nadir at 4 days. The results demonstrate that an increase in the neutron proportion is associated with an amplification of the effects. Furthermore, a delay in the re-establishment of normal absorption was observed with the high neutron proportion (87%n). A dose-dependent reduction of water absorption by rat colon was also observed following neutron irradiation (87%n), with a 50% reduction at 3 Gy. Comparison of this dose-effect curve with the curve obtained following gamma (60)Co-irradiation indicates an RBE of 2.2 for absorptive colonic function in rat calculated at 4 days after exposure.

  19. Low-level laser irradiation induces in vitro proliferation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Barboza, Carlos Augusto Galvão; Ginani, Fernanda; Soares, Diego Moura; Henriques, Águida Cristina Gomes; Freitas, Roseana de Almeida

    2014-01-01

    To evaluate the effect of low-level laser irradiation on the proliferation and possible nuclear morphological changes of mouse mesenchymal stem cells. Mesenchymal stem cells derived from bone marrow and adipose tissue were submitted to two applications (T0 and T48 hours) of low-level laser irradiation (660nm; doses of 0.5 and 1.0J/cm"2). The trypan blue assay was used to evaluate cell viability, and growth curves were used to analyze proliferation at zero, 24, 48, and 72 hours. Nuclear alterations were evaluated by staining with DAPI (4'-6-diamidino-2-phenylindole) at 72 hours. Bone marrow-derived mesenchymal stem cells responded to laser therapy in a dose-dependent manner. Higher cell growth was observed when the cells were irradiated with a dose of 1.0J/cm"2, especially after 24 hours (p<0.01). Adipose-derived mesenchymal stem cells responded better to a dose of 1.0J/cm"2, but higher cell proliferation was observed after 48 hours (p<0.05) and 72 hours (p<0.01). Neither nuclear alterations nor a significant change in cell viability was detected in the studied groups. Low-level laser irradiation stimulated the proliferation of mouse mesenchymal stem cells without causing nuclear alterations. The biostimulation of mesenchymal stem cells using laser therapy might be an important tool for regenerative therapy and tissue engineering

  20. Low-level laser irradiation induces in vitro proliferation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Carlos Augusto Galvão; Ginani, Fernanda [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Soares, Diego Moura [Universidade Federal de Pernambuco, Recife, PE (Brazil); Henriques, Águida Cristina Gomes; Freitas, Roseana de Almeida [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)

    2014-07-01

    To evaluate the effect of low-level laser irradiation on the proliferation and possible nuclear morphological changes of mouse mesenchymal stem cells. Mesenchymal stem cells derived from bone marrow and adipose tissue were submitted to two applications (T0 and T48 hours) of low-level laser irradiation (660nm; doses of 0.5 and 1.0J/cm{sup 2}). The trypan blue assay was used to evaluate cell viability, and growth curves were used to analyze proliferation at zero, 24, 48, and 72 hours. Nuclear alterations were evaluated by staining with DAPI (4'-6-diamidino-2-phenylindole) at 72 hours. Bone marrow-derived mesenchymal stem cells responded to laser therapy in a dose-dependent manner. Higher cell growth was observed when the cells were irradiated with a dose of 1.0J/cm{sup 2}, especially after 24 hours (p<0.01). Adipose-derived mesenchymal stem cells responded better to a dose of 1.0J/cm{sup 2}, but higher cell proliferation was observed after 48 hours (p<0.05) and 72 hours (p<0.01). Neither nuclear alterations nor a significant change in cell viability was detected in the studied groups. Low-level laser irradiation stimulated the proliferation of mouse mesenchymal stem cells without causing nuclear alterations. The biostimulation of mesenchymal stem cells using laser therapy might be an important tool for regenerative therapy and tissue engineering.

  1. Effect of low dose x-irradiation on alloantigen sensitized and unsensitized lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Dohi, Kiyohiko; Yahata, Hiroshi; Fukuda, Yasuhiko; Asahara, Toshimasa; Ono, Eiji; Ezaki, Haruo

    1984-12-01

    The effect of local graft irradiation on immune response in allograft in which acute rejection occurs was studied using an in vitro model. Unidirectional mixed lymphocyte culture (MLC) was used as the in vitro model of acute rejection. 150 and 300 rad x-irradiation suppressed mixed lymphocyte reaction (MLR) but did not cell-mediated-lympholysis (CML) of unsensitized lymphocytes. X-irradiated alloantigen sensitized cells (ASC) generated in 6-day MLC suppressed MLR and CML of unsensitized lymphocytes. Suppressive effects of x-irradiated ASC were of the same degree by x-irradiation doses of 150-500 rad. Suppressive effect of x-irradiation was maintained for only a short period after x-irradiation. Potential function of suppressor precursor cells among unsensitized lymphocytes was abolished by x-irradiation of 300 rad. (author).

  2. Development of radiation fusion technology with food technology by the application of high dose irradiation

    International Nuclear Information System (INIS)

    Lee, Juwoon; Kim, Jaehun; Choi, Jongil

    2012-04-01

    This study was performed to achieve stable food supply and food safety with radiation fusion technology as a preparation for food weaponization. Results at current stage are following: First, for the development of radiation and food engineering fusion technology using high dose irradiation, the effects of high dose irradiation on food components were evaluated. The combination treatment of irradiation with food engineering was developed. Irradiation condition to destroy radiation resistant foodborne bacteria were determined. Second, for the development of E-beam irradiation technology, the effects of radiation sources on food compounds, processing conditions, and food quality of final products were compared. Food processing conditions for agricultural/aquatic products with different radiation sources was developed and the domination of E-beam irradiation foods were determined. The physical marker for E-beam irradiated foods or not was developed. Third, for the fundamental researches to develop purposed foods to extreme environmental, ready-to-eat foods were developed using high dose irradiation. Food processing for export strategy foods such as process ginseng were developed. Food processing with irradiation to destroy mycotoxin and to inhibit production of mycotoxin was developed. Mathematical models to predict necessary irradiation doses and radiation sources were developed and validated. Through the fundamental researches, the legislation for irradiation approval on meat products, sea foods and dried sea foods, and use of E-beam was introduced. Results from this research project, the followings are expected. Improvement of customer acceptance and activation of irradiation technology by the use of various irradiation rays. Increase of indirect food productivity, and decrease of SOC and improvement of public health by prevention of foodborne outbreaks. Build of SPS/TBT system against imported products and acceleration of domestic product export. Systemized

  3. Development of Radiation Fusion Technology with Food Technology by the Application of High Dose Irradiation

    International Nuclear Information System (INIS)

    Kim, Ju Won; Kim, Jae Hun; Choi, Jong Il

    2010-04-01

    This study was studied to achieve stable food supply and food safety with radiation fusion technology as a preparation for food weaponization. Results at current stage are following: First, for the development of radiation and food engineering fusion technology using high dose irradiation, the effects of high dose irradiation on food components were evaluated. The combination treatment of irradiation with food engineering were developed. Irradiation condition to destroy radiation resistant food borne bacteria were determined. Second, for the development of E-beam irradiation technology, the effects of radiation sources on food compounds, processing conditions, and food quality of final products were compared. Food processing conditions for agricultural/aquatic products with different radiation sources were developed and the domination of E-beam irradiation foods were determined. The physical marker for E-beam irradiated foods or not were developed. Third, for the fundamental researches to develop purposed foods to extreme environmental, ready-to-eat foods were developed using high dose irradiation. Food processing for export strategy foods such as process ginseng were developed. Food processing with irradiation to destroy mycotoxin and to inhibit production of mycotoxin were developed. Mathematical models to predict necessary irradiation doses and radiation sources were developed and validated. Through the fundamental researches, the legislation for irradiation approval on meat products, sea foods and dried sea foods, and use of E-beam were introduced. Results from this research project, the followings are expected. (1) Improvement of customer acceptance and activation of irradiation technology by the use of various irradiation rays. (2) Increase of indirect food productivity, and decrease of SOC and improvement of public health by prevention of food borne outbreaks. (3) Build of SPS/TBT system against imported products and acceleration of domestic product export

  4. Development of Radiation Fusion Technology with Food Technology by the Application of High Dose Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Won; Kim, Jae Hun; Choi, Jong Il

    2010-04-15

    This study was studied to achieve stable food supply and food safety with radiation fusion technology as a preparation for food weaponization. Results at current stage are following: First, for the development of radiation and food engineering fusion technology using high dose irradiation, the effects of high dose irradiation on food components were evaluated. The combination treatment of irradiation with food engineering were developed. Irradiation condition to destroy radiation resistant food borne bacteria were determined. Second, for the development of E-beam irradiation technology, the effects of radiation sources on food compounds, processing conditions, and food quality of final products were compared. Food processing conditions for agricultural/aquatic products with different radiation sources were developed and the domination of E-beam irradiation foods were determined. The physical marker for E-beam irradiated foods or not were developed. Third, for the fundamental researches to develop purposed foods to extreme environmental, ready-to-eat foods were developed using high dose irradiation. Food processing for export strategy foods such as process ginseng were developed. Food processing with irradiation to destroy mycotoxin and to inhibit production of mycotoxin were developed. Mathematical models to predict necessary irradiation doses and radiation sources were developed and validated. Through the fundamental researches, the legislation for irradiation approval on meat products, sea foods and dried sea foods, and use of E-beam were introduced. Results from this research project, the followings are expected. (1) Improvement of customer acceptance and activation of irradiation technology by the use of various irradiation rays. (2) Increase of indirect food productivity, and decrease of SOC and improvement of public health by prevention of food borne outbreaks. (3) Build of SPS/TBT system against imported products and acceleration of domestic product export

  5. Development of radiation fusion technology with food technology by the application of high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Juwoon; Kim, Jaehun; Choi, Jongil; and others

    2012-04-15

    This study was performed to achieve stable food supply and food safety with radiation fusion technology as a preparation for food weaponization. Results at current stage are following: First, for the development of radiation and food engineering fusion technology using high dose irradiation, the effects of high dose irradiation on food components were evaluated. The combination treatment of irradiation with food engineering was developed. Irradiation condition to destroy radiation resistant foodborne bacteria were determined. Second, for the development of E-beam irradiation technology, the effects of radiation sources on food compounds, processing conditions, and food quality of final products were compared. Food processing conditions for agricultural/aquatic products with different radiation sources was developed and the domination of E-beam irradiation foods were determined. The physical marker for E-beam irradiated foods or not was developed. Third, for the fundamental researches to develop purposed foods to extreme environmental, ready-to-eat foods were developed using high dose irradiation. Food processing for export strategy foods such as process ginseng were developed. Food processing with irradiation to destroy mycotoxin and to inhibit production of mycotoxin was developed. Mathematical models to predict necessary irradiation doses and radiation sources were developed and validated. Through the fundamental researches, the legislation for irradiation approval on meat products, sea foods and dried sea foods, and use of E-beam was introduced. Results from this research project, the followings are expected. Improvement of customer acceptance and activation of irradiation technology by the use of various irradiation rays. Increase of indirect food productivity, and decrease of SOC and improvement of public health by prevention of foodborne outbreaks. Build of SPS/TBT system against imported products and acceleration of domestic product export. Systemized

  6. Radiation dose in critical organs due to non-coplanar irradiation of the pituitary gland

    International Nuclear Information System (INIS)

    Schulte, R.W.M.; Rittmann, K.L.; Meinass, H.J.; Rennicke, P.

    1996-01-01

    In order to estimate the somatic and genetic risk associated with a non-coplanar linac-based radiation technique of the pituitary gland, systematic secondary-dose measurements in a phantom and sample measurements of the dose near critical organs of patients were performed. For measurements of the dose outside the primary radiation field an acrylic-PVC phantom was used which was irradiated with a single field (4x4 cm 2 ). Eight patients with pituitary tumors were treated isocentrically with a combination of sagittal and transverse rotational arcs. To measure the dose in critical organs, LiF thermoluminescence dosimeters (TLD) in chip form were placed onto 1 eyelid, the skin over the thyroid, and the patient's clothes covering the region of breasts and ovaries of female patients and the testicles of male patients. Measurements were performed for all patients during 1 sagittal irradiation and for the majority of patients during 1 transverse irradiation. The phantom measurements demonstrated that the secondary dose measured on the patients surface can be considered as a good approximation for the dose in adjacent organs. The median dose in critical organs for sagittal irradiation was in the range of 25.8 mGy (eyes) to 1.9 mGy (testicles), and for transverse irradiation in the range of 23.3 mGy (eyes) to 1.3 mGy (testicles). The ratio of median organ doses for sagittal and transverse irradiation was 2.1 for the thyroid gland, 1.1 for the eyes, and 1.5 for the other organs. The dose in critical organs due to non-coplanar irradiation of the pituitary gland is only a small fraction of the dose delivered to the reference point of the planning target volume. The risk of a radiation-induced tumor and a genetic consequence associated with these small doses is generally less than 1% and 0.1%, respectively. (orig./MG) [de

  7. Long term low dose rate irradiation causes recovery from type II diabetes and suppression of aging in type II diabetes-prone mice

    International Nuclear Information System (INIS)

    Namura, T.; Oda, T.

    2003-01-01

    The effects of low dose rate gamma irradiation on model C57BL/KsJ-db/db mice with Type II diabetes mellitus was investigated. These mice develop Type II diabetes by 10 weeks of age, due to obesity, and are characterized by hyperinsulinemia. A group of 12 female 10-week old mice were irradiated at 0.65 mGy/hr in the low dose rate irradiation facility in the Low Dose Radiation Research Center. The urine glucose levels of all of the mice were strongly positive at the beginning of the irradiation. In the irradiated group, a decrease in the glucose level was observed in three mice, one in the 35th week, another in the 52nd week and the third in the 80th week. No recovery from the diabetes was observed in the 12 mice of non-irradiated control group. There was no systematic change of body weight or consumption of food and drinking water between the irradiated group and the non-irradiated group or between the recovered mice and the non-recovered mice. Survival was better in the irradiated group. The surviving fraction at the age of 90 weeks was 75 % in the irradiated group but only 40 % in the non-irradiated. A marked difference was also observed in the appearance of the coat hair, skin and tail. The irradiated group was in much better condition. Mortality was delayed and the healthy appearance was prolonged in the irradiated mice by about 20-30 weeks compared with the control mice. These results suggest that the low dose irradiation modified the condition of the diabetic mice, leading not only to recovery from diabetes, but also to suppression of the aging process

  8. Regularity of wound healing in rats irradiated locally with different doses of soft X-rays

    International Nuclear Information System (INIS)

    Liu Jianzhong; Zhou Yuanguo; Cheng Tianmin; Zhou Ping; Liu Xia; Li Ping

    2002-01-01

    Objective: To study the regular patter of wound healing in rats irradiated locally with different doses of soft X-rays. Methods: Rats were locally irradiated, and wounded immediately thereafter. Gross observation, histopathology and immunohistochemistry examinations, and image analysis were used to study the wound healing process. Results: The authors found that the delayed time of wound healing induced by soft X-ray irradiation of 0.50, 1.01, 1.96, 3,26, 4.00, 5.21 Gy was 1.6, 4.2, 5.4, 6.6, 8.2 and 9.4 days, respectively. Irradiation with 7.0 and 10.0 Gy caused failure of wound healing (up to 40 days). Compared to the non-irradiated wounds, the healing rates of irradiation-impaired wounds were lower during the whole healing process. From day 3 to day 9 after irradiation, the healing rates decreased along with increasing of the radiation dose, indicating the key phase of wound healing was delayed. After irradiation, the collagen synthesis was decreased, its arrangement was disordered, and the structure of granulation tissue was irregular. Conclusion: Soft X-rays irradiation may cause a delay of wound healing in a dose-dependent manner, and irradiation with 7.0 and 10.0 Gy cause failure of wound healing

  9. An algorithm to evaluate solar irradiance and effective dose rates using spectral UV irradiance at four selected wavelengths

    International Nuclear Information System (INIS)

    Anav, A.; Rafanelli, C.; Di Menno, I.; Di Menno, M.

    2004-01-01

    The paper shows a semi-analytical method for environmental and dosimetric applications to evaluate, in clear sky conditions, the solar irradiance and the effective dose rates for some action spectra using only four spectral irradiance values at selected wavelengths in the UV-B and UV-A regions (305, 320, 340 and 380 nm). The method, named WL4UV, is based on the reconstruction of an approximated spectral irradiance that can be integrated, to obtain the solar irradiance, or convoluted with an action spectrum to obtain an effective dose rate. The parameters required in the algorithm are deduced from archived solar spectral irradiance data. This database contains measurements carried out by some Brewer spectrophotometers located in various geographical positions, at similar altitudes, with very different environmental characteristics: Rome (Italy), Ny Aalesund (Svalbard Islands (Norway)) and Ushuaia (Tierra del Fuego (Argentina)). To evaluate the precision of the method, a double test was performed with data not used in developing the model. Archived Brewer measurement data, in clear sky conditions, from Rome and from the National Science Foundation UV data set in San Diego (CA, USA) and Ushuaia, where SUV 100 spectro-radiometers operate, were drawn randomly. The comparison of measured and computed irradiance has a relative deviation of about ±2%. The effective dose rates for action spectra of Erythema, DNA and non-Melanoma skin cancer have a relative deviation of less than ∼20% for solar zenith angles <50 deg.. (authors)

  10. Evaluation of low-dose irradiation on microbiological quality of white carrots and string beans

    International Nuclear Information System (INIS)

    Koike, Amanda C.R.; Santillo, Amanda G.; Rodrigues, Flávio T.; Duarte, Renato C.; Villavicencio, Anna Lucia C.H.

    2012-01-01

    The minimally processed food provided the consumer with a product quality, safety and practicality. However, minimal processing of food does not reduce pathogenic population of microorganisms to safe levels. Ionizing radiation used in low doses is effective to maintain the quality of food, reducing the microbiological load but rather compromising the nutritional values and sensory property. The association of minimal processing with irradiation could improve the quality and safety of product. The purpose of this study was to evaluate the effectiveness of low-doses of ionizing radiation on the reduction of microorganisms in minimally processed foods. The results show that the ionizing radiation of minimally processed vegetables could decontaminate them without several changes in its properties.

  11. Evaluation of low-dose irradiation on microbiological quality of white carrots and string beans

    Science.gov (United States)

    Koike, Amanda C. R.; Santillo, Amanda G.; Rodrigues, Flávio T.; Duarte, Renato C.; Villavicencio, Anna Lucia C. H.

    2012-08-01

    The minimally processed food provided the consumer with a product quality, safety and practicality. However, minimal processing of food does not reduce pathogenic population of microorganisms to safe levels. Ionizing radiation used in low doses is effective to maintain the quality of food, reducing the microbiological load but rather compromising the nutritional values and sensory property. The association of minimal processing with irradiation could improve the quality and safety of product. The purpose of this study was to evaluate the effectiveness of low-doses of ionizing radiation on the reduction of microorganisms in minimally processed foods. The results show that the ionizing radiation of minimally processed vegetables could decontaminate them without several changes in its properties.

  12. Effects of in vivo irradiation on plasma levels of carotenoids and vitamin A

    International Nuclear Information System (INIS)

    White, W.S.; Roe, D.A.

    1986-01-01

    The aims of this investigation were to determine whether ultraviolet irradiation induces alterations in plasma carotenoid and vitamin A levels in human subjects. Twelve Caucasian women participated in an 8-week crossover trial. UV exposures were given to the anterior and posterior sides of the body on 11 days of a 2-week period. Mean cumulative UVA (320-400 nm) doses of 17.9 +/- 2.6 J/cm 2 and 24.1 +/- 1.5 J/cm 2 were delivered to the anterior and posterior sides, respectively. UVB (280-320 nm) doses were equivalent to 10% of the UVA doses given. Intake of carotenoids and preformed vitamin A was held constant. Plasma samples were collected weekly for spectrophotometric analysis of total carotenoids and vitamin A. A significant reduction (p < 0.003) in plasma carotenoid levels was observed following repeated irradiation. Although a significant treatment response could not be demonstrated for plasma vitamin A (p=0.11), a significant test for carryover (p < 0.02) suggested a delayed or continuing increase in plasma levels following irradiation. It is concluded that UV irradiation can reduce plasma carotenoid levels in vivo and may also affect plasma vitamin A levels in an adaptive response

  13. Clinical application of a OneDose(TM) MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast

    International Nuclear Information System (INIS)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-01-01

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose(TM) in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs. (note)

  14. Clinical application of a OneDose MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast.

    Science.gov (United States)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-07-21

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs.

  15. A track length estimator method for dose calculations in low-energy X-ray irradiations. Implementation, properties and performance

    Energy Technology Data Exchange (ETDEWEB)

    Baldacci, F.; Delaire, F.; Letang, J.M.; Sarrut, D.; Smekens, F.; Freud, N. [Lyon-1 Univ. - CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Centre Leon Berard (France); Mittone, A.; Coan, P. [LMU Munich (Germany). Dept. of Physics; LMU Munich (Germany). Faculty of Medicine; Bravin, A.; Ferrero, C. [European Synchrotron Radiation Facility, Grenoble (France); Gasilov, S. [LMU Munich (Germany). Dept. of Physics

    2015-05-01

    The track length estimator (TLE) method, an 'on-the-fly' fluence tally in Monte Carlo (MC) simulations, recently implemented in GATE 6.2, is known as a powerful tool to accelerate dose calculations in the domain of low-energy X-ray irradiations using the kerma approximation. Overall efficiency gains of the TLE with respect to analogous MC were reported in the literature for regions of interest in various applications (photon beam radiation therapy, X-ray imaging). The behaviour of the TLE method in terms of statistical properties, dose deposition patterns, and computational efficiency compared to analogous MC simulations was investigated. The statistical properties of the dose deposition were first assessed. Derivations of the variance reduction factor of TLE versus analogous MC were carried out, starting from the expression of the dose estimate variance in the TLE and analogous MC schemes. Two test cases were chosen to benchmark the TLE performance in comparison with analogous MC: (i) a small animal irradiation under stereotactic synchrotron radiation therapy conditions and (ii) the irradiation of a human pelvis during a cone beam computed tomography acquisition. Dose distribution patterns and efficiency gain maps were analysed. The efficiency gain exhibits strong variations within a given irradiation case, depending on the geometrical (voxel size, ballistics) and physical (material and beam properties) parameters on the voxel scale. Typical values lie between 10 and 103, with lower levels in dense regions (bone) outside the irradiated channels (scattered dose only), and higher levels in soft tissues directly exposed to the beams.

  16. Pathomorphology of spleen lymphocyte apoptosis in large dose 60Co γ-irradiated mice

    International Nuclear Information System (INIS)

    Gao Linlu; Cui Yufang; Yang Hong; Xia Guowei; Peng Ruiyun; Gao Yabing; Wang Dewen

    2000-01-01

    Objective: The aim of the authors was to investigate the pathomorphology changes of spleen lymphocyte apoptosis after 60 Co γ-irradiation. Methods: The mice were irradiated with 6, 9, 12, 15 and 20 Gy of 60 Co γ-rays. At different times after irradiation, the mice were sacrificed and the pathological changes of spleen lymphocyte were observed by light and transmission electron microscopies. Results: Spleen lymphocyte decreased evidently and the peak of apoptosis in spleen lymphocyte was dependent on radiation dose and the time after irradiation. Conclusion: After γ-irradiation with large doses, pathological changes of spleen lymphocyte apoptosis in mice can be divided into obviously different stages. The main causes of death of spleen lymphocytes are different in different dose groups

  17. Inhibitory effects of prior low-dose X-ray irradiation on carbon tetrachloride-induced hepatopathy in acatalasemic mice

    International Nuclear Information System (INIS)

    Yamaoka, Kiyonori; Kataoka, Takahiro; Taguchi, Takehito; Wang, Da-Hong; Mori, Shuji; Hanamoto, Katsumi; Kira, Shohei; Nomura, Takaharu

    2004-01-01

    The catalase activities in blood and organs of the acatalasemic (C3H/AnLCs b Cs b ) mouse of C3H strain are lower than those of the normal (C3H/AnLCs a Cs a ) mouse. We examined the effects of prior low-dose (0.5 Gy) X-ray irradiation, which reduced the oxidative damage under carbon tetrachloride-induced hepatopathy in the acatalasemic or normal mice. The acatalasemic mice showed a significantly lower catalase activity and a significantly higher glutathione peroxidase activity compared with those in the normal mice. Moreover, low-dose irradiation increased the catalase activity in the acatalasemic mouse liver to a level similar to that of the normal mouse liver. Pathological examinations and analyses of blood glutamic oxaloacetic and glutamic pyruvic transaminase activity and lipid peroxide levels showed that carbon tetrachloride induced hepatopathy was inhibited by low-dose irradiation. These findings may indicate that the free radical reaction induced by the lack of catalase and the administration of carbon tetrachloride is more properly neutralized by high glutathione peroxidase activity and low-dose irradiation in the acatalasemic mouse liver. (author)

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

    International Nuclear Information System (INIS)

    Siddiqui, A.K.; Amin, M.R.; Chowdhury, N.A.; Begum, F.; Mollah, A.S.; Mollah, R.A.; Chowdhury, A.H.

    2001-01-01

    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)

  19. Recent results on the linearity of the dose-response relationship for radiation-induced mutations in human cells by low dose levels

    International Nuclear Information System (INIS)

    Traut, H.

    1987-01-01

    Five studies made by various authors in the last years are discussed, which are significant in that the response of human cells to low-dose irradiation is determined directly and not by extrapolation, and which also provide information on the mutagenic effects of low radiation doses. The results of these studies do not indicate any other than a linear response for induction of mutations by low-dose irradiation, nor are there any reasons observable for assuming the existence of a threshold dose. It is very likely therefore that cancer initiation at the low dose level also is characterized by a linear relationship. Although threshold dose levels cannot generally be excluded, and maybe are only too low to be detected by experiment, there is no plausible biophysical argument for assuming the existence of such microdose threshold. (orig./MG) [de

  20. In vitro analysis of low-level laser irradiation on human osteoblast-like cells proliferation

    Science.gov (United States)

    Bloise, Nora; Saino, Enrica; Bragheri, Francesca; Minzioni, Paolo; Cristiani, Ilaria; Imbriani, Marcello; Visai, Livia

    2011-07-01

    The objective of this study was to examine the in vitro effect of a single or a multiple doses of low-level laser irradiation (LLLI) on proliferation of the human osteosarcoma cell line, SAOS-2. SAOS-2 cells were divided in five groups and exposed to LLLI (659 nm diode laser; 11 mW power output): group I as a control (dark), group II exposed to a single laser dose of 1 J/cm2, group III irradiated with a single dose of 3 J/cm2, and group IV and V exposed for three consecutive days to 1 or 3 J/cm², respectively. Cellular proliferation was assessed daily up to 7 days of culturing. The obtained results showed an increase in proliferative capacity of SAOS-2 cells during the first 96 h of culturing time in once-irradiated cells, as compared to control cells. Furthermore, a significantly higher proliferation in the group IV and V was detected if compared to a single dose or to control group after 96 h and 7 days. In conclusion, the effect of the single dose on cell proliferation was transitory and repeated irradiations were necessary to observe a strong enhancement of SAOS-2 growth. As a future perspective, we would like to determine the potential of LLLI as a new approach for promoting bone regeneration onto biomaterials.

  1. High dose rate intracavitary afterloading irradiation in malignant inoperable obturation of bile ducts

    Energy Technology Data Exchange (ETDEWEB)

    Itami, J.; Saegusa, K.; Mamiya, T.; Miyoshi, T.; Arimizu, N.; Tsuchiya, Y.; Ohto, M.

    1986-02-01

    After decompression of the bile duct with PTCD, seven patients with carcinomas of the bile ducts were submitted to an intracavitary Ir-afterloading irradiation performed according to the high-dose-rate method with a Buchler device. Most of the patients were irradiated with 30 Gy in two fractions. Five patients were also exposed to percutaneous radiation with 40 to 50 Gy. Local control was achieved in six patients. One patient developed a locoregional recurrence which was possibly due to a so-called 'geographic miss'. In one patient a benign fibrotic stenosis of the bile duct was found at the site of most intensive irradiation. Intracavitary irradiation is very important in the treatment of malignant of bile ducts. However, there is an urgent need of research with regard to the combined method with percutaneous irradiation and to the optimum fractionation of intracavitary high dose rate irradiation.

  2. Measurements of integrated components' parameters versus irradiation doses gamma radiation (60Co) dosimetry-methodology-tests

    International Nuclear Information System (INIS)

    Fuan, J.

    1991-01-01

    This paper describes the methodology used for the irradiation of the integrated components and the measurements of their parameters, using Quality Insurance of dosimetry: - Measurement of the integrated dose using the competences of the Laboratoire Central des Industries Electriques (LCIE): - Measurement of irradiation dose versus source/component distance, using a calibrated equipment. - Use of ALANINE dosimeters, placed on the support of the irradiated components. - Assembly and polarization of components during the irradiations. Selection of the irradiator. - Measurement of the irradiated components's parameters, using the competences of the societies: - GenRad: GR130 tests equipement placed in the DEIN/SIR-CEN SACLAY. - Laboratoire Central des Industries Electriques (LCIE): GR125 tests equipment and this associated programmes test [fr

  3. Effect of low doses of gamma irradiation and N-fertilizer on N-sources in chickpea, using 15N

    International Nuclear Information System (INIS)

    Kurd Ali, F.; Al-Shamma, M.; Al-Ayyobi, Z.

    1998-07-01

    A pot experiment was conducted to study the effect of low doses of gamma irradiation on the performance of winter chickpea in the presence of different levels of ammonium sulfate. The results showed an apparent effect of radiation and N-fertilizer on nodulation and N sub 2 -fixation. High levels of N-NH sup + sup 4 decreased N sub 2 - fixation but not nodule formation. However, the Presowing irradiation of chickpea with 10 Gy reduced the negative effect on N - fertilizer on N sub 2 - fixation (Author)

  4. Measurement of radiation dose to the eye-lens with bilateral whole brain irradiation

    International Nuclear Information System (INIS)

    Kim, Ki Hwan; Park, Charn Il; Kang, Wee Saing; Choo, Dong Woon

    1985-01-01

    In 40 patients with metastatic brain tumor and acute lymphoblastic leukemia received whole brain irradiation, the dose delivered to the eye lens was measured using T.L.D. chips applied on the eyes as usual shield. The dose to the eye lens was expressed the relative dose to the mid brain dose. Radiotherapy was administrated using Co-60 teletherapy with bilateral whole brain irradiation. The results are as follows: 1. The dose to the right eye from its incipient field is 16.6% of tumor dose while the dose to the same eye from the opposite field is 41.2%. On left eye, 19.2% from incipient field while 39.2% from the opposite field. 2. Total received dose to right and left eyes is 28.9%, 29.8% of tumor dose respectively. 3. Comparing lens shield group with orbit shield group dose is 22.5%, 15.8% of tumor dose, respectively. 4. The dose delivered to the eye lens in ipsilateral side depends upon internal scattering, location of lead shield and penetrating dose of lead in itself. The dose in contralateral side depends upon divergency of radiation beam and patient's malposition. 5. The dose to the eye lens should be less than 10% of tumor dose with adequate shield, also not missing the chance of leptomeningeal recurrence because of overshielding.

  5. Dose calculation at distance of irradiation beams: case of women treated for the Hodgkin disease

    International Nuclear Information System (INIS)

    Poupon, E.; Alziar, I.; Vathaire, F. de; Diallo, I.; Bridier, A.; Bonniaud, G.; Lefkopoulos, D.; Ruaud, J.B.; Rousseau, V.; Kafrouni, H.

    2007-01-01

    The interest of precise calculation of radiation doses distributions remote areas of irradiation is to open new prospects in the knowledge of the contribution of radiotherapy in the occurrence of iatrogenic early and delayed effects. (N.C.)

  6. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    CERN Document Server

    Shamma, M A; Sharabi, N

    2002-01-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays.

  7. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    International Nuclear Information System (INIS)

    Shamma, M.; Al-Adawi, M.; Sharabi, N.

    2002-11-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays. (author)

  8. Model of the dose rate for a semi industrial irradiation plant. Pt. 2

    International Nuclear Information System (INIS)

    Mangusi, Josefina

    2004-01-01

    The second stage of the model for the absorbed dose rate in air for the enclosure of a half-industrialist irradiation plant operating with cobalt-60 sources holden in plan geometry is presented. The sensibility of the model with the treatment of the support structure of the irradiator is analyzed and verified with experimental measurements with good accord. The model of the absorbed dose rate in air in the case of an interposed material between the radioactive sources and the point of interest includes in its calculation a set of secondary radioactive sources created by the Compton scattering of the primary radiation. The accord of the calculated absorbed dose rate and the experimental measured ones is good. The transit dose due to the irradiator moving until its dwell position is also modeled. The isodose curves for a set of irradiator parallel planes are also generated. (author) [es

  9. Outcomes of high-dose unilateral kidney irradiation in patients with gastric lymphoma

    International Nuclear Information System (INIS)

    Maor, Moshe H.; North, Luceil B.; Cabanillas, Fernando F.; Ames, Angie L.; Hess, Mark A.; Cox, James D.

    1998-01-01

    Purpose: To review the long-term clinical effects of unilateral kidney irradiation on overall renal function and blood pressure in patients with gastric lymphoma. Methods and Materials: In the study were 27 patients with Stage I or II gastric lymphoma who had undergone irradiation of at least 24 Gy to ≥1/3 of the left kidney. They include 16 women and 11 men, aged 31 to 77, with a mean age of 57.6 years (median 56). Fifteen patients had Stage I and 12 had Stage II disease. In 13 patients the whole kidney had been irradiated, and 14 had had partial kidney irradiation, at doses ranging between 24 and 40.5 Gy. All patients received combined chemotherapy with various drugs: all patients received corticosteroids, and five received cis-platinum. Their follow-up ranged between 0.7 and 7.8 years (mean 3.4 years). Data on possible effects of the treatment on blood pressure, renal function as assessed by blood urea and creatinine, and kidney shrinkage as seen by serial computed tomography scanning were collected on all patients. Results: Three patients had persistent, mild elevations of urea and creatinine levels, which did not require special treatment. All three also received cis-platinum. Ipsilateral kidney shrinkage was evident in most patients. In 19 patients the craniocaudal measurement of the kidney shrank by ≥1.6 cm. Shrinkage in other dimensions was also evident. The degree of atrophy was related to the volume of kidney irradiated. Only two patients developed hypertension, both at a low level of 150/90; one patient had had 40 Gy to the whole kidney, the other 40 Gy to half the kidney. Neither patient had elevated urea or creatinine. Conclusions: Notwithstanding the shrinkage to the irradiated part of the kidney, the treatment did not lead to clinically significant hypertension or renal dysfunction. The administration of cis-platinum to patients with gastric lymphoma that requires kidney irradiation should be further evaluated

  10. Comparison of the kidney dose between supine and prone position for pelvic and periaortic irradiation

    International Nuclear Information System (INIS)

    Mison, Chun; Haejin, Kang; Juree, Kim; Heesuk, Ryu; Hyunsoo, Shin

    1996-01-01

    We compared the doses received by the kidney in supine and prone positions for pelvic and periaortic irradiation. Kidney locations were verified by CT images taken with patients in the same position as during the treatment. Due to the shift of the kidney anteriorly during prone position, treatment in supine position delivered a much lower dose to most of the kidney than treatment in the prone position. Therefore, for periaortic irradiation treatment, the supine position should be considered to minimize the dose to the kidneys, even though the prone position with a belly board can reduce the dose to the small bowel

  11. High total dose proton irradiation effects on silicon NPN rf power transistors

    International Nuclear Information System (INIS)

    Bharathi, M. N.; Praveen, K. C.; Prakash, A. P. Gnana; Pushpa, N.

    2014-01-01

    The effects of 3 MeV proton irradiation on the I-V characteristics of NPN rf power transistors were studied in the dose range of 100 Krad to 100 Mrad. The different electrical characteristics like Gummel, current gain and output characteristics were systematically studied before and after irradiation. The recovery in the I-V characteristics of irradiated NPN BJTs were studied by isochronal and isothermal annealing methods

  12. High total dose proton irradiation effects on silicon NPN rf power transistors

    Energy Technology Data Exchange (ETDEWEB)

    Bharathi, M. N.; Praveen, K. C.; Prakash, A. P. Gnana, E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore-570006, Karnataka (India); Pushpa, N. [Department of PG Studies in Physics, JSS College, Ooty Road, Mysore-570025, Karnataka (India)

    2014-04-24

    The effects of 3 MeV proton irradiation on the I-V characteristics of NPN rf power transistors were studied in the dose range of 100 Krad to 100 Mrad. The different electrical characteristics like Gummel, current gain and output characteristics were systematically studied before and after irradiation. The recovery in the I-V characteristics of irradiated NPN BJTs were studied by isochronal and isothermal annealing methods.

  13. The biological effect of 125I seed continuous low dose rate irradiation in CL187 cells

    Directory of Open Access Journals (Sweden)

    Zhuang Hong-Qing

    2009-01-01

    Full Text Available Abstract Background To investigate the effectiveness and mechanism of 125I seed continuous low-dose-rate irradiation on colonic cell line CL187 in vitro. Methods The CL187 cell line was exposed to radiation of 60Coγ ray at high dose rate of 2 Gy/min and 125I seed at low dose rate of 2.77 cGy/h. Radiation responses to different doses and dose rates were evaluated by colony-forming assay. Under 125I seed low dose rate irradiation, a total of 12 culture dishes were randomly divided into 4 groups: Control group, and 2, 5, and 10 Gy irradiation groups. At 48 h after irradiation, apoptosis was detected by Annexin and Propidium iodide (PI staining. Cell cycle arrests were detected by PI staining. In order to investigate the influence of low dose rate irradiation on the MAPK signal transduction, the expression changes of epidermal growth factor receptor (EGFR and Raf under continuous low dose rate irradiation (CLDR and/or EGFR monoclonal antibodies were determined by indirect immunofluorescence. Results The relative biological effect (RBE for 125I seeds compared with 60Co γ ray was 1.41. Apoptosis rates of CL187 cancer cells were 13.74% ± 1.63%, 32.58% ± 3.61%, and 46.27% ± 3.82% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 1.67% ± 0.19%. G2/M cell cycle arrests of CL187 cancer cells were 42.59% ± 3.21%, 59.84% ± 4.96%, and 34.61% ± 2.79% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 26.44% ± 2.53%. P 2/M cell cycle arrest. After low dose rate irradiation, EGFR and Raf expression increased, but when EGFR was blocked by a monoclonal antibody, EGFR and Raf expression did not change. Conclusion 125I seeds resulted in more effective inhibition than 60Co γ ray high dose rate irradiation in CL187 cells. Apoptosis following G2/M cell cycle arrest was the main mechanism of cell-killing effects under low dose rate irradiation. CLDR could

  14. Sterility and Sexual Competitiveness of Tapachula-7 Anastrepha ludens Males Irradiated at Different Doses.

    Science.gov (United States)

    Orozco-Dávila, Dina; Adriano-Anaya, Maria de Lourdes; Quintero-Fong, Luis; Salvador-Figueroa, Miguel

    2015-01-01

    A genetic sexing strain of Anastrepha ludens (Loew), Tapachula-7, was developed by the Mexican Program Against Fruit Flies to produce and release only males in programs where the sterile insect technique (SIT) is applied. Currently, breeding are found at a massive scale, and it is necessary to determine the optimum irradiation dose that releases sterile males with minimum damage to their sexual competitiveness. Under laboratory and field conditions, we evaluated the effects of gamma irradiation at doses of 0, 20, 40, 60 and 80 Gy on the sexual competitiveness of males, the induction of sterility in wild females and offspring survivorship. The results of the study indicate that irradiation doses have a significant effect on the sexual behavior of males. A reduction of mating capacity was inversely proportional to the irradiation dose of males. It is estimated that a dose of 60 Gy can induce more than 99% sterility in wild females. In all treatments, the degree of offspring fertility was correlated with the irradiation dose of the parents. In conclusion, the results of the study indicate that a dose of 60 Gy can be applied in sterile insect technique release programs. The application of this dose in the new genetic sexing strain of A. ludens is discussed.

  15. Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    D' Oca, Maria Cristina, E-mail: mcristina.doca@unipa.it [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Bartolotta, Antonio [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy)

    2011-09-15

    The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

  16. Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

    International Nuclear Information System (INIS)

    D'Oca, Maria Cristina; Bartolotta, Antonio

    2011-01-01

    The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

  17. The genetic effects induced by an irradiation in low doses at Drosophila melanogaster

    International Nuclear Information System (INIS)

    Zajnullin, V.G.; Taskaev, A.I.; Moskalev, A.A.; Shaposhnikov, M.V.

    2006-01-01

    The review generalizes the results obtained in researches of genetic radiation effects for Drosophila melanogaster from contamination regions near the Chernobylsk NPP. The results of laboratory investigations of low dose irradiation effects on genotype variability and lifetime of Drosophila are presented too. It supposed that the main effect of low dose irradiation is caused by the induced genetic instability against the background of which the realization of different-directed radiobiological reactions is possible [ru

  18. Epithelial regeneration of transposed intestine after high doses of X irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Both, N.J. de; Vermey, M [Erasmus Universiteit, Rotterdam (Netherlands)

    1976-01-01

    The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of x irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation.

  19. Dose dependent oxidation kinetics of lipids in fish during irradiation processing

    International Nuclear Information System (INIS)

    Tukenmez, I.; Ersen, M.S.; Bakioglu, A.T.; Bicer, A.; Pamuk, V.

    1997-01-01

    Kinetic aspects of the development of lipid oxidation in complex foods as fish in the course of irradiation were analyzed with respect to the associated formation of malonaldehyde (MA) through the reactions modified so as to be consistent with those in complex foods as fish. Air-packed anchovy (Engraulis encrasicholus) samples in polyethylene pouches were irradiated at the doses of 1, 2, 5, 10, 15,20 and 25 kGy at 20 o C in a Cs-137 gamma irradiator of 1.806 kGy/h dose rate. Immediately after each irradiation, MA contents of irradiated and unirradiated samples were determined by thiobarbituric acid test. Based on the MA formation, a kinetic model to simulate the apparent oxidation of lipid in fish as a function of irradiation dose was derived from the rate equations consistent with modified reactions. Kinetic parameters and simulation were related to conditions of lipid oxidation, and associated rancidity state of fish with respect to the doses applied in different irradiation-preservation processes. Numerical values of kinetic parameters based on the MA formation were found as a threshold dose of 0.375 kGy, an apparent yield of 1.871 μmol/kg kGy, and a maximum attainable concentration of 15.853 μmol/kg which may be used for process control and dosimetry. (author)

  20. Nanoindentation and in situ microcompression in different dose regimes of proton beam irradiated 304 SS

    Energy Technology Data Exchange (ETDEWEB)

    Reichardt, A. [Department of Nuclear Engineering, University of California, Berkeley, CA (United States); Lupinacci, A. [National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Frazer, D.; Bailey, N.; Vo, H.; Howard, C. [Department of Nuclear Engineering, University of California, Berkeley, CA (United States); Jiao, Z. [Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI (United States); Minor, A.M. [National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Chou, P. [Electric Power Research Institute, Palo Alto, CA (United States); Hosemann, P., E-mail: peterh@berkeley.edu [Department of Nuclear Engineering, University of California, Berkeley, CA (United States)

    2017-04-01

    Recent developments in micromechanical testing have allowed for the efficient evaluation of radiation effects in micron-scale volumes of ion-irradiated materials. In this study, both nanoindentation and in situ SEM microcompression testing are carried out on 10 dpa proton beam irradiated 304 stainless steel to assess radiation hardening and radiation-induced deformation mechanisms in the material. Using a focused ion beam (FIB), arrays of 2 μm × 2 μm cross-section microcompression pillars are fabricated in multiple dose regimes within the same grain, providing dose-dependent behavior in a single crystal orientation. Analysis of the microcompression load-displacement data and real-time SEM imaging during testing indicates significant hardening, as well as increased localization of deformation in the irradiated material. Although nanoindentation results suggest that irradiation hardening saturates at low doses, microcompression results indicate that the pillar yield stress continues to rise with dose above 10 dpa in the tested orientation. - Highlights: •Mechanical properties are probed in small volumes of proton irradiated 304SS. •Nanoindentation indicates saturation of irradiation hardening at doses of 5–10 dpa. •Microcompression of irradiated specimens suggest localized deformation.

  1. The statistics of dose/cure relationships for irradiated tumours

    International Nuclear Information System (INIS)

    Porter, E.H.

    1980-01-01

    Consideration is given to the theoretical effects of different factors on the form of dose/cure relationships. Single-clonogen recurrences, dominant anoxic fractions, asymptotically straight survival curves, variable tumour sizes and variable radiation doses are all discussed. Statistical methods are then reviewed, and the conclusions are summarized in the form of advice to experimenters who are studying dose/cure relationships. (UK)

  2. The Optimum Irradiation Dose in Preservation of Mahkota Dewa (Phaleria macrocarpa (Scheff) Boerl.) As Anticancer Agent

    International Nuclear Information System (INIS)

    Hendig Winarno; Ermin Katrin W; Wisnurahadi; Swasono R Tamat

    2010-01-01

    The purpose of this experiment was to obtain the optimum irradiation dose, in order to preserve and protect the damage of anticancer compounds in mahkota dewa bark. The specimens of mahkota dewa bark were irradiated using 60 Co at the variation doses of 0; 5; 7,5 ; 10; 15; and 20 kGy, respectively at the dose rate of 10 kGy/h. The irradiated and control samples were macerated in n-hexane and ethyl acetate, respectively, then the ethyl acetate extract was then fractionated using chromatography column to obtain 8 fractions. The examination of irradiated and control samples of mahkota dewa bark against microbe contaminants showed that irradiation at doses ≥5 kGy could inhibit the growth of bacteria, mold and yeast and destroyed them. The cytotoxicity test of irradiated ethyl acetate extract of mahkota dewa bark against leukemia L1210 cell showed that irradiation at the dose up to 20 kGy can decreased cytotoxic activities performance, however these IC 50 values lower than 50 μg/ml, which is the cytotoxic activity threshold for extract. The cytotoxic activity test of fraction 6, the most active fraction in mahkota dewa bark, showed that irradiation at the dose up to 20 kGy can also decreased the cytotoxic activities performance, however these IC 50 values was lower than 20 μg/ml, which is the cytotoxic activity threshold for fraction. Analysis of 2,4’-dihydroxy-4 methoxy benzophenone-2-O-β-D-glucopyranoside by high performance liquid chromatography (HPLC) in fraction 6 of irradiated samples showed that the concentration of this compound in irradiated samples significantly decreased, compared to the control sample. Decreasing the concentration of 2,4’-dihydroxy-4 methoxy benzophenone-2-O-β-D-glucopyranoside was not comparable to the cytotoxic activity of ethyl acetate extract or fraction 6, therefore this compound can not be used as marker of irradiation effect on decreasing the cytotoxic activity of the mahkota dewa bark. Irradiation at doses of 5 up to 20 k

  3. Quality changes of the Mediterranean horse mackerel (Trachurus mediterraneus) during chilled storage: The effect of low-dose gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Mbarki, Raouf [Institut National des Sciences et Technologies de la Mer, La Goulette 2060 (Tunisia); Sadok, Saloua [Institut National des Sciences et Technologies de la Mer, La Goulette 2060 (Tunisia)], E-mail: salwa.sadok@instm.rnrt.tn; Barkallah, Insaf [Centre National des Sciences et Technologies Nucleaires, Sidi-Thabet 2020 (Tunisia)

    2009-04-15

    Pelagic fishes represent the main Mediterranean fisheries in terms of quantity. However, waste and spoilage of pelagic fish are substantial for a variety of reasons, such as their high perishability and the lack or inadequate supply of ice and freezing facilities. In this work, fresh Mediterranean horse mackerel (Trachurus mediterraneus) were irradiated at 1 and 2 kGy and stored in ice for 18 days. Quality changes during storage were followed by the determination of microbial counts, trimethylamine (TMA) and volatile basic nitrogen contents. Similarly, lipid composition and sensory analysis were carried out. Irradiation treatment was effective in reducing total bacterial counts throughout storage. Total basic volatile nitrogen content (TVB-N) and TMA levels increased in all lots with storage time, their concentrations being significantly reduced by irradiation, even when the lower level (1 kGy) was used. According to the quality index method, the control lot had a sensory shelf-life of 4 days, whereas those of the irradiated lots were extended by 5 days. Also, low-dose irradiation had no adverse effect on the nutritionally important polyunsaturated fatty acids (PUFA) of Mediterranean horse mackerel. In the same way, thiobarbituric acid-reactive substances values increased with irradiation during the first day, but these values were lower at the end of storage, compared to the control. Results confirm the practical advantages of using {gamma} irradiation as an additional process to chilled storage to enhance the microbiological quality and to extend the shelf-life of small pelagic species.

  4. Quality changes of the Mediterranean horse mackerel (Trachurus mediterraneus) during chilled storage: The effect of low-dose gamma irradiation

    International Nuclear Information System (INIS)

    Mbarki, Raouf; Sadok, Saloua; Barkallah, Insaf

    2009-01-01

    Pelagic fishes represent the main Mediterranean fisheries in terms of quantity. However, waste and spoilage of pelagic fish are substantial for a variety of reasons, such as their high perishability and the lack or inadequate supply of ice and freezing facilities. In this work, fresh Mediterranean horse mackerel (Trachurus mediterraneus) were irradiated at 1 and 2 kGy and stored in ice for 18 days. Quality changes during storage were followed by the determination of microbial counts, trimethylamine (TMA) and volatile basic nitrogen contents. Similarly, lipid composition and sensory analysis were carried out. Irradiation treatment was effective in reducing total bacterial counts throughout storage. Total basic volatile nitrogen content (TVB-N) and TMA levels increased in all lots with storage time, their concentrations being significantly reduced by irradiation, even when the lower level (1 kGy) was used. According to the quality index method, the control lot had a sensory shelf-life of 4 days, whereas those of the irradiated lots were extended by 5 days. Also, low-dose irradiation had no adverse effect on the nutritionally important polyunsaturated fatty acids (PUFA) of Mediterranean horse mackerel. In the same way, thiobarbituric acid-reactive substances values increased with irradiation during the first day, but these values were lower at the end of storage, compared to the control. Results confirm the practical advantages of using γ irradiation as an additional process to chilled storage to enhance the microbiological quality and to extend the shelf-life of small pelagic species

  5. Gamma irradiator dose mapping: a Monte Carlo simulation and experimental measurements

    International Nuclear Information System (INIS)

    Rodrigues, Rogerio R.; Ribeiro, Mariana A.; Grynberg, Suely E.; Ferreira, Andrea V.; Meira-Belo, Luiz Claudio; Sousa, Romulo V.; Sebastiao, Rita de C.O.

    2009-01-01

    Gamma irradiator facilities can be used in a wide range of applications such as biological and chemical researches, food treatment and sterilization of medical devices and products. Dose mapping must be performed in these equipment in order to establish plant operational parameters, as dose uniformity, source utilization efficiency and maximum and minimum dose positions. The isodoses curves are generally measured using dosimeters distributed throughout the device, and this procedure often consume a large amount of dosimeters, irradiation time and manpower. However, a detailed curve doses identification of the irradiation facility can be performed using Monte Carlo simulation, which reduces significantly the monitoring with dosimeters. The present work evaluates the absorbed dose in the CDTN/CNEN Gammacell Irradiation Facility, using the Monte Carlo N-particles (MCNP) code. The Gammacell 220, serial number 39, was produced by Atomic Energy of Canada Limited and was loaded with sources of 60 Co. Dose measurements using TLD and Fricke dosimeters were also performed to validate the calculations. The good agreement of the results shows that Monte Carlo simulations can be used as a predictive tool of irradiation planning for the CDTN/CNEN Gamma Cell Irradiator. (author)

  6. Irradiation Creep of Ferritic-Martensitic Steels EP-450, EP-823 and EI-852 Irradiated in the BN-350 Reactor over Wide Ranges of Irradiation Temperature and Dose

    International Nuclear Information System (INIS)

    Porollo, S.I.; Konobeev, Y.V.; Ivanov, A.A.; Shulepin, S.V.; Garner, F.

    2007-01-01

    Full text of publication follows: Ferritic/martensitic (F/M) steels appear to be the most promising materials for advanced nuclear systems, especially for fusion reactors. Their main advantages are higher resistance to swelling and lower irradiation creep rate as has been repeatedly demonstrated in examinations of these materials after irradiation. Nevertheless, available experimental data on irradiation resistance of F/M steels are insufficient, with the greatest deficiency of data for high doses and for both low and high irradiation temperatures. From the very beginning of operation the BN-350 fast reactor has been used for irradiation of specimens of structural materials, including F/M steels. The most unique feature of BN-350 was its low inlet sodium temperature, allowing irradiation at temperatures over a very wide range of temperatures compared with the range in other fast reactors. In this paper data are presented on swelling and irradiation creep of three Russian F/M steels EP-450, EP-823 and EI-852, irradiated in experimental assemblies of the BN-350 reactor at temperatures in the range of 305-700 deg. C to doses ranging from 20 to 89 dpa. The investigation was performed using gas-pressurized creep tubes with hoop stresses in the range of 0 - 294 MPa. (authors)

  7. Dose-escalated total body irradiation and autologous stem cell transplantation for refractory hematologic malignancy

    International Nuclear Information System (INIS)

    McAfee, Steven L.; Powell, Simon N.; Colby, Christine; Spitzer, Thomas R.

    2002-01-01

    Purpose: To evaluate the feasibility of dose escalation of total body irradiation (TBI) above the previously reported maximally tolerated dose, we have undertaken a Phase I-II trial of dose-escalated TBI with autologous peripheral blood stem cell transplantation (PBSCT) for chemotherapy-refractory lymphoma. Methods and Materials: Nine lymphoma patients with primary refractory disease (PRD) or in resistant relapse (RR) received dose-escalated TBI and PBSCT. The three dose levels of fractionated TBI (200 cGy twice daily) were 1,600 cGy, 1,800 cGy, and 2,000 cGy. Lung blocks were used to reduce the TBI transmission dose by 50%, and the chest wall dose was supplemented to the prescribed dose using electrons. Shielding of the kidneys was performed to keep the maximal renal dose at 1,600 cGy. Three patients, two with non-Hodgkin's lymphoma (NHL) in RR and one with PRD Hodgkin's disease, received 1,600 cGy + PBSCT, three patients (two NHL in RR, one PRD) received 1,800 cGy + PBSCT, and three patients with NHL (two in RR, one PRD) received 2,000 cGy + PBSCT. Results: Toxicities associated with this high-dose TBI regimen included reversible hepatic veno-occlusive disease in 1 patient, Grade 2 mucositis requiring narcotic analgesics in 8 patients, and neurologic toxicities consisting of a symmetrical sensory neuropathy (n=4) and Lhermitte's syndrome (n=1). Interstitial pneumonitis developed in 1 patient who received 1,800 cGy after receiving recombinant α-interferon (with exacerbation after rechallenge with interferon). Six (66%) patients achieved a response. Four (44%) patients achieved complete responses, three of which were of a duration greater than 1 year, and 2 (22%) patients achieved a partial response. One patient remains disease-free more than 5 years posttransplant. Corticosteroid-induced gastritis and postoperative infection resulted in the death of 1 patient in complete response, 429 days posttransplant. Conclusion: TBI in a dose range 1,600-2,000 cGy as

  8. Effect of low level doses of fast neutrons on the activity of the snake venom

    International Nuclear Information System (INIS)

    Hanafy, Magda S.; Amin, Aida M.

    1998-01-01

    In this work, the effect of low level doses of fast neutrons from 252 Cf on snake venom (Cerastes cerastes) was studied through measurements of biophysical and haematological changes. The absorption spectrum (200-700 nm) of haemoglobin (Hb) collected from the blood of rats after 3 and 24 hours post injection with irradiated and non-irradiated snake venom with neutron fluences of 3x10 6 , 2.8x10 7 and 3X10 8 n/cm 2 was measured. The results indicated that injection of animals with either non- irradiated or irradiated venom ( with different neutron fluences) resulted into the decrease of the absorption band intensities of Hb. These changes in the properties of the characteristic band showed to be a marker for irradiated venom and is dose dependent. It was concluded that neutron irradiation of the venom leads to the decrease of its toxicity and, consequently, to the increase of the chance of repair mechanism in livings. Obvious changes of most haematological erythrocytic values of Hb, packed cell volume (PCV), red blood counts (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCHb) and mean corpuscular haemoglobin concentration (MCHC) were observed in the blood of the rats injected with non-irradiated venom (as a first group) and those injected with the irradiated venom (as a second group). The microcytic haemolytic anemia was more acute in the first group than in the second one which showed lesser extent. It is concluded from this study that low level doses of fast neutrons could postpone and lower acute haematological action induced by the venom. (authors)

  9. Histochemical changes of capillaries in rat brain cortex after irradiation with supralethal doses of gamma radiation

    International Nuclear Information System (INIS)

    Kamarad, V.; Dosoudilova, M.

    1987-01-01

    Changes were studied in the activities of alkaline phosphatase, ATP-splitting enzyme, thiaminepyrophosphatase, acetylcholinesterase, and of butyrylcholinesterase in the capillary sheet of the rat brain cortex of the laterobasal section of a parietal lobe following irradiation with 150 and 300 Gy. The animals were exposed to local irradiation of the head with gamma radiation using 60 Co at a dose rate of 6.9 Gy per min. The material was removed at the intervals of 30 and 60 mins after irradiation. All the studied enzymes, except the ATP-splitting enzyme, showed identical reaction to irradiation. At both intervals, the reaction after irradiation with 300 Gy was lower when compared to that after irradiation with 150 Gy. 30 mins after irradiation with 150 Gy an increased enzyme activity was shown followed by a marked decrease in the activity 60 mins after irradiation, compared with findings obtained from control animals. No similar time dependence was observed after irradiation with 300 Gy. The ATP-splitting enzyme showed a significant decrease in the activity 30 mins after irradiation with 150 Gy. On the other hand, 60 mins after irradiation with 150 Gy and at both time intervals after irradiation with 300 Gy, the activity was higher than that in control animals. (author). 6 figs., 14 refs

  10. High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

    International Nuclear Information System (INIS)

    Zheng Yongnan; Xu Yongjun; Yuan Daqing

    2014-01-01

    Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

  11. Non-linear failure analysis of HCPB blanket for DEMO taking into account high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Aktaa, J., E-mail: jarir.aktaa@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Kecskés, S.; Pereslavtsev, P.; Fischer, U.; Boccaccini, L.V. [Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-10-15

    Highlights: • First non-linear structural analysis for the European Helium Cooled Pebble Bed Blanket Module taking into account high dose irradiation. • Most critical areas were identified and analyzed with regard to the effect of irradiation on predicted damage at these areas. • Despite the extensive computing time 100 cycles were simulated by using the sub-modelling technique investigating damage at most critical area. • The results show a positive effect of irradiation on calculated damage which is mainly attributed to the irradiation induced hardening. - Abstract: For the European helium cooled pebble bed (HCPB) blanket of DEMO the reduced activation ferritic martensitic steel EUROFER has been selected as structural material. During operation the HCPB blanket will be subjected to complex thermo-mechanical loadings and high irradiation doses. Taking into account the material and structural behaviour under these conditions is a precondition for a reliable blanket design. For considering high dose irradiation in structural analysis of the DEMO blanket, the coupled deformation damage model, extended recently taking into account the influence of high dose irradiation on the material behaviour of EUROFER and implemented in the finite element code ABAQUS, has been used. Non-linear finite element (FE) simulations of the DEMO HCPB blanket have been performed considering the design of the HCPB Test Blanket Module (TBM) as reference and the thermal and mechanical boundary conditions of previous analyses. The irradiation dose rate required at each position in the structure as an additional loading parameter is estimated by extrapolating the results available for the TBM in ITER scaling the value calculated in neutronics and activation analysis for ITER boundary conditions to the DEMO boundary conditions. The results of the FE simulations are evaluated considering damage at most critical highly loaded areas of the structure and discussed with regard to the impact of

  12. Non-linear failure analysis of HCPB blanket for DEMO taking into account high dose irradiation

    International Nuclear Information System (INIS)

    Aktaa, J.; Kecskés, S.; Pereslavtsev, P.; Fischer, U.; Boccaccini, L.V.

    2014-01-01

    Highlights: • First non-linear structural analysis for the European Helium Cooled Pebble Bed Blanket Module taking into account high dose irradiation. • Most critical areas were identified and analyzed with regard to the effect of irradiation on predicted damage at these areas. • Despite the extensive computing time 100 cycles were simulated by using the sub-modelling technique investigating damage at most critical area. • The results show a positive effect of irradiation on calculated damage which is mainly attributed to the irradiation induced hardening. - Abstract: For the European helium cooled pebble bed (HCPB) blanket of DEMO the reduced activation ferritic martensitic steel EUROFER has been selected as structural material. During operation the HCPB blanket will be subjected to complex thermo-mechanical loadings and high irradiation doses. Taking into account the material and structural behaviour under these conditions is a precondition for a reliable blanket design. For considering high dose irradiation in structural analysis of the DEMO blanket, the coupled deformation damage model, extended recently taking into account the influence of high dose irradiation on the material behaviour of EUROFER and implemented in the finite element code ABAQUS, has been used. Non-linear finite element (FE) simulations of the DEMO HCPB blanket have been performed considering the design of the HCPB Test Blanket Module (TBM) as reference and the thermal and mechanical boundary conditions of previous analyses. The irradiation dose rate required at each position in the structure as an additional loading parameter is estimated by extrapolating the results available for the TBM in ITER scaling the value calculated in neutronics and activation analysis for ITER boundary conditions to the DEMO boundary conditions. The results of the FE simulations are evaluated considering damage at most critical highly loaded areas of the structure and discussed with regard to the impact of

  13. Improvement of dose distribution of esophageal irradiation using the field-within-a-field technique

    International Nuclear Information System (INIS)

    Iwai, Tsugunori; Okabe, Keigo; Yamato, Hidetada; Murakami, Jyunji; Nakazawa, Yasuo; Kato, Mitsuyoshi

    2002-01-01

    The wide radiation field for mediastinal dose distribution should be inhomogeneous with the usual simple opposed beam irradiation. The purpose of this study was to improve the dose distribution of the mediastinum using a conventional planning system with a dose-volume histogram (DVH) and the field-in-field technique. Three-dimensional (3D) dose distribution is obtained in bilateral opposed-field irradiation. An overdose area obtained from the 3D dose distribution is defined and reprojected into the irradiation field. A new reduced field is created by removing the reprojected overdose area. A 3D dose distribution is again obtained and compared with the results from first one. Procedures were repeated until each of the target volumes was within ±5% of the prescribed dose and the irradiation volume within 107% or less of the prescribed dose. From the DVH analysis, our field-within-a-field technique resulted in a more uniform dose distribution within the conventional planning. The field-within-a-field technique involves many parameters, and an inverse planning algorithm is suitable for computation. However, with our method, the forward planning system is adequate for planning, at least in a relatively straightforward planning system such as bilateral opposed fields therapy. (author)

  14. Dose response of artificial irradiation of fluvial sediment sample for ESR dating

    International Nuclear Information System (INIS)

    Liu Chunru; Yin Gongming; Gao Lu; Li Jianping; Han Fei; Lin Min

    2011-01-01

    ESR dating samples need be irradiated to obtain dose response curve and the equivalent dose. The artificial dose rate is about 1 x 10 -1 -1 x 10 2 Gy/min, whereas the natural dose rate is about 3 Gy/ka. Therefore, one must be sure whether the much higher artificial dose rate is suitable for the ESR dating study. In this paper, we use different artificial dose rate to irradiate the same fluvial sample and measure the quartz Al centre ESR signal under the same conditions. The dose response curves are compared, in an attempt to gain a preliminary knowledge on that problem and build a good foundation for our ESR dating studies on fluvial samples. (authors)

  15. Medical irradiation and the use of the ''effective dose equivalent'' concept

    International Nuclear Information System (INIS)

    Persson, B.R.R.

    1980-01-01

    The aim of this paper is to demonstrate the use of the effective dose for all kinds of medical irradiation. In order to estimate the 'somatic effective dose' the weighting factors recommended by ICRP 26 have been separated into those for somatic effects and for genetic effects. Calculation of the effective dose in diagnostic radiology procedures must consider the various technical parameters which determine the absorbed dose in the various organs, i.e. beam quality, typical entrance dose and the number of films of each view. Knowledge about these parameters is not always well established and therefore the effective dose estimates are very uncertain. The average dose absorbed by various organs in the case of administration of radionuclides to the body depends to a much higher degree on biological parameters than in the case of external irradiation. In contrast to the variability and lack of reliability of biological data, the physical methods for internal dose calculation are quite elaborate. However, these methods have to be extended to involve the target dose from the radioactivity distributed within the remaining parts of the body. An attempt was made to estimate the somatic effective dose for the most common diagnostic X-ray and nuclear medicine procedures. This would make it possible to compare the risk of X-ray and nuclear medicine techniques on a more equitable basis. The collective effective dose from medical irradiation is estimated for various countries on the basis of reported statistical data. (H.K.)

  16. Experimental research on fresh mussel meat irradiated by high-dose electron beam

    International Nuclear Information System (INIS)

    Xiao Lin; Lu Ruifeng; Hu Huachao; Wang Chaoqi; Liu Yanna

    2011-01-01

    The sterilization storage of fresh mussel irradiated high-dose electron beam was studied. From the subjective assessment by the weighted average of the test and other determined parameters, it can be concluded that the flavor of fresh mussel meat sealed canned food irradiated by high-dose electron beam has not been significant affected, and various micro-organisms can be killed effectively, which means that the irradiated fresh mussel meat can be preserved for long-term at room temperature. Therefore the method might resolve the problems induced by traditional frozen preservation methods. (authors)

  17. Active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue

    International Nuclear Information System (INIS)

    Ogawa, Y.; Imanaka, K.; Ashida, C.; Takashima, H.; Imajo, Y.; Kimura, S.

    1983-01-01

    Active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was studied on the transplanted MM46 tumor of female C3H/He mice after radiotherapy. MM46 tumor cells were inoculated into the right hind paws of mice. On the 5th day, irradiation with the dose irradiated tumor tissue (2000 rad on the fifth day), were injected into the left hind paws of the tumor-bearing mice. Effectiveness of this active specific immunotherapy against tumor was evaluated by the regression of tumor and survival rate of mice. Tumor was markedly regressed and survival rate was significantly increased by the active specific immunitherapy

  18. Dose and dose rate effects of whole-body gamma-irradiation: I. Lymphocytes and lymphoid organs

    Science.gov (United States)

    Pecaut, M. J.; Nelson, G. A.; Gridley, D. S.

    2001-01-01

    The major goal of part I of this study was to compare varying doses and dose rates of whole-body gamma-radiation on lymphoid cells and organs. C57BL/6 mice (n = 75) were exposed to 0, 0.5, 1.5, and 3.0 Gy gamma-rays (60Co) at 1 cGy/min (low-dose rate, LDR) and 80 cGy/min (high-dose rate, HDR) and euthanized 4 days later. A significant dose-dependent loss of spleen mass was observed with both LDR and HDR irradiation; for the thymus this was true only with HDR. Decreasing leukocyte and lymphocyte numbers occurred with increasing dose in blood and spleen at both dose rates. The numbers (not percentages) of CD3+ T lymphocytes decreased in the blood in a dose-dependent manner at both HDR and LDR. Splenic T cell counts decreased with dose only in HDR groups; percentages increased with dose at both dose rates. Dose-dependent decreases occurred in CD4+ T helper and CD8+ T cytotoxic cell counts at HDR and LDR. In the blood the percentages of CD4+ cells increased with increasing dose at both dose rates, whereas in the spleen the counts decreased only in the HDR groups. The percentages of the CD8+ population remained stable in both blood and spleen. CD19+ B cell counts and percentages in both compartments declined markedly with increasing HDR and LDR radiation. NK1.1+ natural killer cell numbers and proportions remained relatively stable. Overall, these data indicate that the observed changes were highly dependent on the dose, but not dose rate, and that cells in the spleen are more affected by dose rate than those in blood. The results also suggest that the response of lymphocytes in different body compartments may be variable.

  19. Protection of lethally irradiated mice with allogeneic fetal liver cells: influence of irradiation dose on immunologic reconstitution

    International Nuclear Information System (INIS)

    Tulunay, O.; Good, R.A.; Yunis, E.J.

    1975-01-01

    After lethal irradiation long-lived, immunologically vigorous C3Hf mice were produced by treatment with syngeneic fetal liver cells or syngeneic newborn or adult spleen cells. Treatment of lethally irradiated mice with syngeneic or allogeneic newborn thymus cells or allogeneic newborn or adult spleen cells regularly led to fatal secondary disease or graft-versus-host reactions. Treatment of the lethally irradiated mice with fetal liver cells regularly yielded long-lived, immunologically vigorous chimeras. The introduction of the fetal liver cells into the irradiated mice appeared to be followed by development of immunological tolerance of the donor cells. The findings suggest that T-cells at an early stage of differentiation are more susceptible to tolerance induction than are T-lymphocytes at later stages of differentiation. These investigations turned up a perplexing paradox which suggests that high doses of irradiation may injure the thymic stroma, rendering it less capable of supporting certain T-cell populations in the peripheral lymphoid tissue. Alternatively, the higher and not the lower dose of irradiation may have eliminated a host cell not readily derived from fetal liver precursors which represents an important helper cell in certain cell-mediated immune functions, e.g., graft-versus-host reactions, but which is not important in others, e.g., allograft rejections. The higher dose of lethal irradiation did not permit development or maintenance of a population of spleen cells that could initiate graft-versus-host reactions but did permit the development of a population of donor cells capable of achieving vigorous allograft rejection

  20. Low-Dose Aspirin Treatment Alleviates Gamma Irradiation Impaired Fertility in Female Albino Rats

    International Nuclear Information System (INIS)

    Ibrahim, M.F.

    2013-01-01

    Recent experimental evidence suggests that Aspirin (acetylsalicylic acid), the extensively prescribed analgesic, can improve female fertility by suppressing the prostaglandin (PG) biosynthesis and modulating the uterine circulation. Aspirin has also been found to exhibit a protective ability on the radiation induced oxidative stress. Thus the present work aims to investigate the effect of oral low-dose Aspirin treatment on the radiation induced female reproductive disturbance. Adult female rats were used in the current experiment. All rat group treatments started at the onset of the proestrus phase and terminated at the diestrus encompassing 2 complete estrus cycles. Subsequently, the rats were divided into 4 equal groups: Group 1-Control: female rats receiving distilled water via an oral gavage; Group 2- Irradiation: female rats subjected to 6 Gy gamma rays at the proestrus cycle and receiving distilled water; Group 3-Aspirin: rats orally administered a daily dose of 7mg/kg body weight aspirin dissolved in distilled water via an oral gavage and Group 4- Irradiation + Aspirin: female rats irradiated as group 2 and receiving aspirin treatment. A number of rats from each experimental group were allowed to mate following every treatment to serve as Control mated (Subgroup 1), Irradiated mated (Subgroup 2), Aspirin administered mated (Subgroup 3) and Irradiated + Aspirin treated mated (Subgroup 4). At the assigned day of the second estrus cycle completion, blood was collected from Groups 1-4 for subsequent hormonal assay, lipid peroxides and glutathione (GSH) estimation whereas Subgroups 1-4 were carefully monitored for reproduction and infertility rates. Results have shown that the 6 Gy γ- irradiation of the rats at the proestrus cycle (Group 2) caused a decrease in follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and estradiol (E2) levels associated with a drastic increase in the progesterone levels in addition to the significant

  1. Caries experience among adults exposed to low to moderate doses of ionizing irradiation in childhood - the Tinea Capitis Cohort

    Directory of Open Access Journals (Sweden)

    Yuval eVered

    2016-02-01

    Full Text Available While the impact of therapeutic levels of ionizing radiation during childhood on dental defects has been documented, the possible effect of low doses on dental health is unknown. The study aims were to assess the association between childhood exposure to low-moderate doses of therapeutic radiation and caries experience among a cohort of adults 50 years following the exposure.The analysis was based on a sample of 253 irradiated (in the treatment of Tinea Capitis and 162 non-irradiated subjects. The DMFT (Decayed, Missing, and Filled Teeth index was assessed during a clinical dental examination and questions regarding dental care services utilization, oral hygiene behavior, current self-perceived mouth dryness, socio-demographic parameters and health behavior variables were obtained through a face to face interview.An ordered multivariate logistic regression model was used to assess the association of the main independent variable (irradiation status and other relevant independent variables on the increase in DMFT.Mean caries experience levels (DMFT were 18.6+7.5 for irradiated subjects compared to 16.4+7.2 for the non-irradiated (p=0.002. Controlling for gender, age, education, income, smoking, dental visit in the last year and brushing teeth behavior, irradiation was associated with a 72% increased risk for higher DMFT level (95% CI 1.19-2.50. A quantification of the risk by dose absorbed in the salivary gland and in the thyroid gland showed adjusted ORs of 2.21 per 1Gy (95% CI 1.40-3.50 and 1.05 per 1cGy (95% CI 1.01-1.09, respectively.Childhood exposure to ionizing radiation (0.2-0.4Gy might be associated with late outcomes of dental health. In line with the guidelines of the American Dental Association, these results call for caution when using dental radiographs.

  2. The application dose of irradiation for decontamination of dried marine fish

    International Nuclear Information System (INIS)

    Feng Min; Ji Ping; Li Lili; Zhu Jiating; Yang Ping; Lin Jiabing; Tang Yuxin; Wang Dening; Liu Chunquan

    2009-01-01

    The effects of irradiation decontamination on golden stripe fish, needle fish and blue whiting fish were studied based on analysis the contents of protein, fat, trace elements, heavy metals etc. before and after irradiation. The irradiation dose of 2.55 ∼ 13.65kGy was applied. The results show that 3kGy is enough to drop the number of total bacteria to less than 10 4 cfu/g; meanwhile, 5kGy is enough to drop the number of coliform bacteria to less than 30MPN/100g, which could meet the requirement of national hygiene standard of marine products of animal origin. Compared with the contents of protein, fat, trace elements, heavy metals, moisture and ash in control, all the contents of these indexes in irradiated samples are not changed significantly, though the content of protein is increased with irradiation dose and the content of moisture is decreased a little, while some trace elements contents are increased if irradiation dose is more than 10.4kGy. It is concluded that, the appropriate irradiation dose range for decontamination application of dried marine fishes is 5 ∼ 10kGy. (authors)

  3. Analysis of gamma irradiator dose rate using spent fuel elements with parallel configuration

    International Nuclear Information System (INIS)

    Setiyanto; Pudjijanto MS; Ardani

    2006-01-01

    To enhance the utilization of the RSG-GAS reactor spent fuel, the gamma irradiator using spent fuel elements as a gamma source is a suitable choice. This irradiator can be used for food sterilization and preservation. The first step before realization, it is necessary to determine the gamma dose rate theoretically. The assessment was realized for parallel configuration fuel elements with the irradiation space can be placed between fuel element series. This analysis of parallel model was choice to compare with the circle model and as long as possible to get more space for irradiation and to do manipulation of irradiation target. Dose rate calculation were done with MCNP, while the estimation of gamma activities of fuel element was realized by OREGEN code with 1 year of average delay time. The calculation result show that the gamma dose rate of parallel model decreased up to 50% relatively compared with the circle model, but the value still enough for sterilization and preservation. Especially for food preservation, this parallel model give more flexible, while the gamma dose rate can be adjusted to the irradiation needed. The conclusion of this assessment showed that the utilization of reactor spent fuels for gamma irradiator with parallel model give more advantage the circle model. (author)

  4. Dose levels in conventional X-rays

    International Nuclear Information System (INIS)

    Guerra M, J. A.; Gonzalez G, J. A.; Pinedo S, A.; Salas L, M. A.; Vega C, H. R.; Rivera M, T.; Azorin N, J.

    2009-10-01

    There were a series of measures in the General Hospital of Fresnillo in the X-ray Department in the areas of X-1 and X-2-ray rooms and in the neonatal intensive care unit 2, was determined the dose surface entry in eyes, thyroid and gonads for patients undergoing to X-ray study of chest Tele by thermoluminescent dosimetry. Five dosemeters were used in each one of the scans; so find the following dose ranges 20 + - 23 mGy to 350 + - 41 mGy. With the results obtained we can conclude that the procedures used and the equipment calibration is adequate. (Author)

  5. On possible risks of low-dose irradiation

    International Nuclear Information System (INIS)

    Hug, O.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Neuherberg/Muenchen

    1974-01-01

    The survey on more recent experimental and epidemiological data and newer concepts for a realistic estimation of the radiation risk leads to the conclusion that for radiation late damages and possibly also for genetic damages with a chronical radiation exposure in the order of magnitude of the natural radiation exposure and probably also in the order of magnitude of the maximum permissible radiation dose, the risk is very probably lower than is to be expected based on the findings after relatively high doses and dose rates. A few less direct comparative studies have detected a time factor of 3 to 5. Considering the analysis of the RBW demely ionizing radiation which at high doses is not greater than 3, increases with decreasing dose and according to biophysical considerations, can possibly reach a value of 30, an effectiveness reduced by a factor of 10 of small doses and dose rates of loosely ionizing radiation would be even to be expected. All radiobiological knowledge on the effect of ionizing radiation allows one to expect that even smallest radiation doses can cause cellular damages due to the linear irreversable components of the radiation effect and probably that these damages can even be the starting point of a malignant tumour. Regarding this cancer-initiating effect however, the effectiveness of loosely ionizing radiation per rad in the region of natural radiation exposure lie considerably below that existing at high doses and dose rates. Whether however this initial carcinogenic effect of very small doses is at all noticeable during the average life duration in an increase of the spontaneous age-specific tumour rate is questionable if the assumption is confirmed that with decreasing dose, the time manifestation of the radiation induced tumours is delayed. (orig./LH) [de

  6. Hesperidin and low dose gamma irradiation alleviate rosiglitazone -induced cardiotoxicity in type 2 diabetic rats

    International Nuclear Information System (INIS)

    Morcos, N.Y.; Abdel-Ghaffar, A.B.; Osman, S.A.; Mohamed, M.Kh.; Arbid, M.S.; El-Eraky, W.I.

    2012-01-01

    Aim: The present study was designed to investigate the cardio protective effect of hesperidin and low dose γ- irradiation (LDR) against rosiglitazone cardiotoxicity. Experiment: Type 2 diabetes mellitus (T2DM) was induced in rats by single intraperitoneal injection of streptozotocin (STZ) followed by nicotinamide (NIC) (65 and 110 mg/kg b.wt, respectively). The diabetic rats were divided into 5 groups: untreated, LDR, LDR+ rosiglitazone, LDR + Hesperidin, LDR+ rosiglitazone + Hesperidin for one month, and blood and tissue samples were collected. Results: The diabetic rats showed elevated serum creatine kinase (CK-MB), lactate dehydrogenase (LDH), C-reactive protein (CRP), hyaluronidase activity, and reduced serum nitric oxide (NO) level, hematocrit % as well as final body weight, and pathological alterations in myocardial tissue. Treatment with LDR + rosiglitazone + Hesperidin ameliorated all these abnormalities approaching control levels. Conclusion: Results indicate the possible cardio protective role of hesperidin and LDR against rosiglitazone cardiotoxicity.

  7. Can prenatal low-dose irradiation affect behavior of adult rats?

    International Nuclear Information System (INIS)

    Smajda, B.; Tomasova, L.; Kokocova, N.

    2011-01-01

    The aim of our study was to determine whether exposure of very low dose gamma-rays during the critical phase of brain development affects some selected behavioral parameters in adult rats. Pregnant female Wistar rats were irradiated with 1 Gy gamma-rays from a cobalt source at 17 th day of pregnancy. The progeniture of irradiated as well as non-irradiated females have undergone behavioral tests at the age of 3 months. Irradiated animals exhibited lower locomotor and exploratory activity in the open field test. (authors)

  8. The clinic and pathologic picture in the lethal dose irradiated ewes

    International Nuclear Information System (INIS)

    Halagan, J.; Stanikova, A.; Maracek, I.

    2004-01-01

    The history of clinical symptoms as well as pathologic histological and morphological changes after long/lasting gamma irradiation were estimated in seven clinical healthy ewes. The animals were irradiated continually seven days with totally 6.7 Gy per ewe. Clinically recognizable symptoms of the radiation sickness were observed commencing the 4 th after last dose of irradiation. Sharp increase of the body temperature, heart and respiratory frequency rate as well as apathy, anorexia, arrhythmia, dyspnoe, diarrhea, dehydration, polyuria were prevalent in clinical founding . All of the animals were death in course of seven days after last irradiated dose. The gastrointestinal radiation syndrome was typical evidence of gastrointestinal tract and the general hemorrhagic enhancing of the gamma irradiation damage effects was confirmed. (authors)

  9. Prediction of response to continuous irradiation at low dose rate for repeated administrations in radiotherapy with beta emitters

    International Nuclear Information System (INIS)

    Calderon, Carlos; Gonzalez, Joaquin; Quesada, Waldo

    2009-01-01

    The absorbed dose to tumors after systemic administration of radiopharmaceuticals is not sufficient to achieve acceptable levels of probability of tumor control without compromising on critical tissue toxicity (kidney and / or bone marrow (BM)). There are reports of trials with multiple administrations, about tolerance level inter-administration intervals to allow recovery of the BM, with good results. The biokinetic behavior of some radiopharmaceuticals known makes possible the application of several administrations with short intervals of time.It is the present work combines two kinetic models of tumor growth and cell kinetics in the BM for predicting the response to continuous irradiation at low dose rate. The estimation of the effects of irradiation on tumor and kidneys was done using a formulation of the linear-quadratic model functions suitable for dose rate and multi-exponential repair. The estimation of the response in WB performed using a compartmental model previously reported. The absorbed dose to organs were calculated using the MIRD formulation taking into account the effect of irradiation cross. Biokinetic data were used for therapeutic radiopharmaceuticals 90Y, 131I and 177Lu, as well as radiobiological parameters reported for experimental animals. The effect on the response by the variation of inter-administration interval in slow-growing tumors and fast, so as the radiosensitive and radioresistant tumors. You can set conditions irradiation to an acceptable level of thrombocytopenia (onset and duration of the minimum in the curve) and renal irradiation below the limit of tolerance. It is possible to design experiments evaluation of therapeutic radiopharmaceuticals with a greater degree of refinement. (author)

  10. Effects of low doses gamma irradiation on yield and nitrogen utilization in potato

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Sharanik, A.

    1997-12-01

    Twelve field experiments were conducted in two seasons (1992 and 1993) in three regions of Syria (Damascus, Al-Salamia and Al-Ghab). Tubers of potato (Solanum tuberosum L. var Diamont) were irradiated with gamma-radiation from a 60 Co source, using doses of 0,1,2,3,5 and 10 Gy, at dose rate of 0.15 Gy/min. The irradiated tubers were sown 5-6 days after irradiation, in a randomized complete block design with four replicates and two rates of nitrogen fertilizer (0 and 120 Kg/N/ha). Irradiation and N application significantly increased dry matter production by 24% (for optimal dose) and 38% respectively. The tuber yields were increased by 28.7% for N application and between 13.6 and 19.7 for optimal dose, as a mean for all experiments and regions. Presowing tubers irradiation with 3 Gy. dose also Increased N uptake at harvest by 21.6, 16.6 and 18% for Damascus, Al-Salamia and Al-Ghab respectively. irradiation had negligible effects on N concentration and both Scratch and Vitamin C contents in tubers. (author)

  11. Effect of low doses gamma-irradiation on yield and nitrogen utilization in potato

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Sharanek, A.

    1998-01-01

    Twelve field experiments were conducted in two seasons (1992 and 1993) in three regions of Syria (Damascus, Al-Salamia and Al-Ghab). Tubers of potato (Solanum tuberosum L. var Diamont) were irradiation with gamma-radiation from a 60 Co source, using doses of 0,1,2,3,5 and 10 Gy, at dose rate of 0.15 Gy/min. The irradiated tubers were sown 5-6 days after irradiation, in a randomized complete block design with four replicates and two rates of nitrogen fertilizer (0 and 120 Kg/N/ha). Irradiation and N application significantly increased dry matter production by 24% (for optimal dose) and 38% respectively. The tuber yields were increased by 28.7% for N application and between 13.6 and 19.7 for optimal dose, as a mean for all experiments and regions. Presowing tubers irradiation with 3 Gy. dose also Increased N uptake at harvest by 21.6, 16.6 and 18% for Damascus, Al-Salamia and Al-Ghab respectively. irradiation had negligible effects on N concentration and both Scratch and Vitamin C contents in tubers. (author)

  12. Cytogenetic characterization of low-dose hyper-radiosensitivity in Cobalt-60 irradiated human lymphoblastoid cells

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Gnanada S. [Department of Biological Sciences, Wayne State University, Detroit, MI 48202 (United States); Joiner, Michael C. [Department of Radiation Oncology, Wayne State University, Detroit, MI 48201 (United States); Tucker, James D., E-mail: jtucker@biology.biosci.wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, MI 48202 (United States)

    2014-12-15

    Highlights: • Human cells were irradiated in G1 or G2 and evaluated for micronuclei and bridges. • Cells irradiated in G2 but not in G1 exhibit low dose hyper-radiosensitivity. • Response curves of cells irradiated in G2 do not fit a linear-no-threshold model. • Response curves of cells irradiated in G1 fit a linear-no-threshold model. - Abstract: The dose-effect relationships of cells exposed to ionizing radiation are frequently described by linear quadratic (LQ) models over an extended dose range. However, many mammalian cell lines, when acutely irradiated in G2 at doses ≤0.3 Gy, show hyper-radiosensitivity (HRS) as measured by reduced clonogenic cell survival, thereby indicating greater cell lethality than is predicted by extrapolation from high-dose responses. We therefore hypothesized that the cytogenetic response in G2 cells to low doses would also be steeper than predicted by LQ extrapolation from high doses. We tested our hypothesis by exposing four normal human lymphoblastoid cell lines to 0–400 cGy of Cobalt-60 gamma radiation. The cytokinesis block micronucleus assay was used to determine the frequencies of micronuclei and nucleoplasmic bridges. To characterize the dependence of the cytogenetic damage on dose, univariate and multivariate regression analyses were used to compare the responses in the low- (HRS) and high-dose response regions. Our data indicate that the slope of the response for all four cell lines at ≤20 cGy during G2 is greater than predicted by an LQ extrapolation from the high-dose responses for both micronuclei and bridges. These results suggest that the biological consequences of low-dose exposures could be underestimated and may not provide accurate risk assessments following such exposures.

  13. Low level dose induced chromosome aberrations in human blood lymphocytes

    International Nuclear Information System (INIS)

    Pohl-Rueling, J.

    1992-01-01

    Unstable structural aberrations in chromosomes of human blood lymphocytes cannot be used as biological dosemeters in the low dose range, when extrapolating from high doses using a linear dose response, as required by the original formula of the dual radiation action theory. A survey is given of experimental dose-response curves of chromosome aberrations, obtained in investigations not only by this institute, in cooperation with many other laboratories, but also by various authors in different areas of the world. The results are not compatible with the predicted linear dose relationships at in vivo dose ranges up to 30 mGy.y -1 . The aberration frequencies rise sharply with dose within the normal environmental exposure up to about twice that level. At higher doses, aberration frequencies increase less rapidly and reach a plateau. Some in vitro experiments of various authors with higher doses of low LET radiations, up to about 400 mGy have found dose responses with steps. (author)

  14. A practical and transferable methodology for dose estimation in irradiated spices based on thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    D'Oca, M.C.; Bartolotta, A.; Cammilleri, C.; Giuffrida, S.; Parlato, A.; Di Stefano, V.

    2008-01-01

    Full text: Among the industrial applications of ionizing radiation, the treatment of food for preservation purposes is a worldwide recognized tool, provided that proper and validated identification methods are available and used. The thermoluminescence (TL) dosimetry is the physical method validated by the European Committee for Standardization for food from which silicate minerals can be isolated, such as spices and aromatic herbs. The aim of this work was to set up a reasonably simple procedure, alternative to the recommended one, for the identification of irradiated spices and to estimate at the same time the original dose in the irradiated product, using TL and the additive dose method, even after months storage. We have already shown that the additive dose method can be applied with TL dosimetry, if the TL response of the silicate specimen after extraction is always added to the response after each irradiation; the applied added doses were higher than 1 kGy, that can however give saturation problems. The new proposed methodology makes use of added doses lower than 600 Gy; the entire process can be completed within few hours and a linear fit can be utilized. The method was applied to the silicates extracted from oregano samples soon after the radiation treatment (original dose: 2 - 3 - 5 kGy), and after one year storage at room conditions in the dark (original dose: 1-2 kGy). The procedure allows the identification of irradiated samples, without any false positive, together with an estimation of the dose range

  15. Prooxidate - antioxidate homeostasis in guinea pigs after fractional low-dose irradiation

    International Nuclear Information System (INIS)

    Baraboj, V.A.; Olyijnik, S.A.; Khmelevs'kij, Yi.V.

    1993-01-01

    We studied the influence of fractional total irradiation in the total dose of 1 Gy on the amount of lipids peroxide oxidation (LPO) products and ascorbic acid in the spleen, intestine and brain of guinea-pigs. The obtained date suggest that it is advisable to use ascorbic acid to correct postirradiation changes in the organism exposed to small doses of ionizing radiation

  16. An exponential model equation for thiamin loss in irradiated ground pork as a function of dose and temperature of irradiation

    Science.gov (United States)

    Fox, J. B.; Thayer, D. W.; Phillips, J. G.

    The effect of low dose γ-irradiation on the thiamin content of ground pork was studied in the range of 0-14 kGy at 2°C and at radiation doses from 0.5 to 7 kGy at temperatures -20, 10, 0, 10 and 20°C. The detailed study at 2°C showed that loss of thiamin was exponential down to 0kGy. An exponential expression was derived for the effect of radiation dose and temperature of irradiation on thiamin loss, and compared with a previously derived general linear expression. Both models were accurate depictions of the data, but the exponential expression showed a significant decrease in the rate of loss between 0 and -10°C. This is the range over which water in meat freezes, the decrease being due to the immobolization of reactive radiolytic products of water in ice crystals.

  17. Lethal doses of ionizing radiation versus endogenous level of superoxide dismutase

    Energy Technology Data Exchange (ETDEWEB)

    Lipecka, K; Domanski, T; Dniaszewska, K; Grabowska, B; Pietrowicz, D; Lindner, P; Cisowska, B; Gorski, H [Military Medical Academy, Lodz (Poland). Inst. of Occupational Medicine

    1982-06-22

    The stability of superoxide dismutase (SOD) as well as its activity distribution in a human population were investigated. The SOD activity level of the erythrocytes proved to be an index for the endogenous SOD activity in the whole body. In a rat population, having similar SOD frequency distribution as a human population, the mortality due to acute irradiation depended on the SOD level; after a single acute dose approximating the lethal dose (LD/sub 50/30/) the survival depended distinctly on the endogenous SOD activity level.

  18. Pituitary-ovarian hormones after low-dose endometrial afterloading irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Groenroos, M.; Kauppila, O.; Pulkkinen, M.; Turunen, S.; Salmi, T.; Raekallio, J. (Turku Univ. (Finland). Dept. of Obstetrics and Gynecology)

    1983-10-01

    Low-dose endometrial after loading irradiation was used in 19 mentally retarded women for the induction of therapeutic amenorrhea. They were divided into two groups on the basis of age: 13 young patients (mean age 17 years, range 13-26 years) and six patients of middle age (mean age 42 years, range 34-44 years). In the young patients, during the 10 month follow-up period, the plasma E/sub 2/ levels did not decrease. However, the FSH concentration increased. Later on, 2-9 years after treatment, the E/sub 2/ levels were significantly higher than those of healthy postmenopausal women and did not differ from the values of healthy women in the six to seven days of the menstrual cycle. At that time the FSH and LH levels were similar to reference values in reproductive age. The E/sub 2//E/sub 1/ ratio was significantly higher than that of healthy women in the six to seven days of the cycle and that of postmenopausal women. Most of the menstrual cycles were anovulatory but some ovulatory also occurred. The testosterone concentrations did not differ from reference values. The ovaries of the middle age patients were more sensitive to irradiation than those of the younger patients. 7 refs.

  19. Pituitary-ovarian hormones after low-dose endometrial afterloading irradiation

    International Nuclear Information System (INIS)

    Groenroos, M.; Kauppila, O.; Pulkkinen, M.; Turunen, S.; Salmi, T.; Raekallio, J.

    1983-01-01

    Low-dose endometrial after loading irradiation was used in 19 mentally retarded women for the induction of therapeutic amenorrhea. They were divided into two groups on the basis of age: 13 young patients (mean age 17 years, range 13-26 years) and six patients of middle age (mean age 42 years, range 34-44 years). In the young patients, during the 10 month follow-up period, the plasma E 2 levels did not decrease. However, the FSH concentration increased. Later on, 2-9 years after treatment, the E 2 levels were significantly higher than those of healthy postmenopausal women and did not differ from the values of healthy women in the six to seven days of the menstrual cycle. At that time the FSH and LH levels were similar to reference values in reproductive age. The E 2 /E 1 ratio was significantly higher than that of healthy women in the six to seven days of the cycle and that of postmenopausal women. Most of the menstrual cycles were anovulatory but some ovulatory also occurred. The testosterone concentrations did not differ from reference values. The ovaries of the middle age patients were more sensitive to irradiation than those of the younger patients. (author)

  20. Suppression of carcinogenesis in mice by adaptive responses to low dose rate irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Kazuo; Iwasaki, Toshiyasu; Hoshi, Yuko; Nomura, Takaharu; Ina, Yasuhiro; Tanooka, Hiroshi [Central Research Institute of Electric Power Industry, Low Dose Radiation Research Center, Komae, Tokyo (Japan)

    2003-07-01

    Effects of prolonged low-dose-rate irradiation on the process of carcinogenesis were examined in mice treated with chemical carcinogen or irradiated with high doses of X-rays. Female ICR mice, 5 week-old, 35 in each group, were exposed to gamma-rays from a {sup 137}Cs source in the long-term low dose rate irradiation facility at CRIEPI. The dose rate was 2.6 mGy/hr (A), 0.96 mGy/hr (B), or 0.30 mGy/hr (C). Thirty-five days later, the mice were injected into the groin with 0.5 mg of methylcholanthrene (MC) dissolved in olive oil and irradiation was continued. Cumulative tumor incidences after 216 days following MC injection were 89% in group A, 76% in group B, and 94% in group C. That in non-irradiated control group was 94%. The difference in the tumor incidence between the control and position B was statistically significant, indicating the suppressive effect of the low dose rate irradiation on the process of MC-induced carcinogenesis with an optimum dose rate around 1 mGy/hr. In B6C3F1 mice, although the suppression of tumor incidence was not observed, there was a significant delay in tumor appearance in the irradiated mice between 100-150 days after MC injection. A group of 20 female C57BL/6N mice, 5 weeks old, were exposed to gamma-rays at 0.95 mGy/hr for 5 weeks. Then, they were exposed weekly to 1.8 Gy whole body X-irradiation (300 kVp) for consecutive 4 weeks to induce thymic lymphoma. Another group received only the fractionated irradiation. The first mouse died from thymic lymphoma appeared 89 days after the last irradiation in the group received only the fractionated irradiation, while 110 days in the group combined with the low dose rate irradiation. (author)

  1. Self-ion emulation of high dose neutron irradiated microstructure in stainless steels

    Science.gov (United States)

    Jiao, Z.; Michalicka, J.; Was, G. S.

    2018-04-01

    Solution-annealed 304L stainless steel (SS) was irradiated to 130 dpa at 380 °C, and to 15 dpa at 500 °C and 600 °C, and cold-worked 316 SS (CW 316 SS) was irradiated to 130 dpa at 380 °C using 5 MeV Fe++/Ni++ to produce microstructures and radiation-induced segregation (RIS) for comparison with that from neutron irradiation at 320 °C to 46 dpa in the BOR60 reactor. For the 304L SS alloy, self-ion irradiation at 380 °C produced a dislocation loop microstructure that was comparable to that by neutron irradiation. No voids were observed in either the 380 °C self-ion irradiation or the neutron irradiation conditions. Irradiation at 600 °C produced the best match to radiation-induced segregation of Cr and Ni with the neutron irradiation, consistent with the prediction of a large temperature shift by Mansur's invariant relations for RIS. For the CW 316 SS alloy irradiated to 130 dpa at 380 °C, both the irradiated microstructure (dislocation loops, precipitates and voids) and RIS reasonably matched the neutron-irradiated sample. The smaller temperature shift for RIS in CW 316 SS was likely due to the high sink (dislocation) density induced by the cold work. A single self-ion irradiation condition at a dose rate ∼1000× that in reactor does not match both dislocation loops and RIS in solution-annealed 304L SS. However, a single irradiation temperature produced a reasonable match with both the dislocation/precipitate microstructure and RIS in CW 316 SS, indicating that sink density is a critical factor in determining the temperature shift for self-ion irradiations.

  2. The hazards of low dose irradiation - science or science fiction

    International Nuclear Information System (INIS)

    Danster, Kh.

    1987-01-01

    The data on the dependence of radiobiological effect on radiation dose, in particular, leuhemia and pulmonary cancer in people are given in the lecture of Director of National Office of Radiation Safety of Great Britain. The thresholdless linear hypothesis is analyzed as well as objections to it. The conclusion is made that low radiation doses can not bring about disastrous effects

  3. Radiation doses to normal tissues during craniospinal irradiation ...

    African Journals Online (AJOL)

    Objective: This dosimetric study is aiming to report the results of the analysis of doses received by target volumes and organs outside the target volumes during the treatment of medulloblastoma patients. And also by comparing the doses reaching the eyes and the lens with the use of different shielding methods.

  4. Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry

    International Nuclear Information System (INIS)

    Beshir, W.B.

    2014-01-01

    The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cardamom and cloves and assesses the absorbed dose to radiation processed cardamom and cloves are examined. The results were successful for identifying both irradiated and unirradiated cardamom and cloves. Additive reirradiation of cardamom and cloves produces reproducible dose–response functions, which can be used to assess the initial dose by back-extrapolation. Third degree polynomial function was used to fit the EPR signal/dose curves. It was found that this 3rd degree polynomial function provides satisfactory results without correction of decay for free radicals. The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over a storage period of almost 8 months. The calculated G-value (The number of radicals per 100 eV of absorbed energy) for cardamom and cloves was found 0.07±0.01 and 0.055±0.01, respectively. - Highlights: • The EPR analysis of cardamom and cloves prove the sample has been irradiated or not. • Dose additive can be used for evaluation of the absorbed dose in cardamom and cloves. • The 3rd polynomial function can be used to fit the data and the estimated dose. • The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over 2 months

  5. Effect of quality control implementation on image quality of radiographic films and irradiation doses to patients

    International Nuclear Information System (INIS)

    Cheng Yuxi; Zhou Qipu; Ge Lijuan; Hou Changsong; Qi Xuesong; Yue Baorong; Wang Zuoling; Wei Kedao

    1999-01-01

    Objective: To study the changes in the image quality of radiographic films and the irradiation doses to patients after quality control (QC) implementation. Methods: The entrance surface doses (ESD) to patients measured with TLD and the image quality of radiographic films were evaluated on the basis of CEC image quality criteria. Results: The ESD to patients were significantly reduced after QC implementation (P 0.05), but the post-QC image quality was significantly improved in chest PA, lumbar spine AP and pelvis AP(P0.01 or P<0.05). Conclusion: Significantly reduced irradiation dose with improved image quality can be obtained by QC implementation

  6. Simulation of the field dose of the irradiator PX γ 30 using MCNP

    International Nuclear Information System (INIS)

    Torres, N.; Prieto, E. F.; Chavez, A.; Rosales, J.

    2011-01-01

    Given the acceptance and actual application of radiation technology for research purposes, industrial and trade is increasing, and that safety and quality of the product being treated by radiation technology is a function of absorbed dose, it becomes necessary to have a good characterization of the radiation field at processing volume, avoiding in this way that the product receives a different dose that affects its properties, or failure to reach the desired effect, which in many cases would be embarrassing. The simulation using the MCNP program, which uses probabilistic Monte Carlo code, can correctly characterize the dose field in the irradiation chamber of research irradiator PX γ 30 used in the CEADEN. (Author)

  7. The biochemical changes of bone collagen after high-dose irradiation

    International Nuclear Information System (INIS)

    Tajiri, Ken

    1980-01-01

    In our clinic, patients with malignant bone tumors have been treated by high-dose irradiation therapy, 10,000-20,000 rads, for primary lesions. In order to study the biochemical changes of normal bone around tumor tissue, especially bone collagen, after high-dose irradiation, the author performed the following experiments. The right knee joint of rabbits was irradiated with either 6,000, 10,000, or 15,000 rads by 60 Co-γ ray. The cortical bone of the right tibial metaphysis was used for analyses and compared with the left tibia of the same rabbit. These studies were followed for one year after the final irradiation. The calcium, phosphorous and collagen contents of irradiated bone were remarkably changed. These data indicate that collagen biosynthesis of irradiated bone was decreased and the calcification was disturbed. An increase in the amount of total soluble collagen and a decrease in the amount of hydroxylysine bound sugar were observed. The ratio of β to α chains of the collagen molecule was also changed by the irradiation. The amount of reducible cross-links per hydroxyproline residue was strikingly increased three months after the final irradiation. These changes were remarkable especially in the 10,000 and 15,000 rads irradiated group and found to be recovered approximately six months to one year after the final irradiation. These findings indicate that high-dose irradiation reduces the stability of bone collagen both with the destruction of sugar bonds of hydroxylysine residues and the replacement of matured collagen matrix to immatured one which contain mostly labile reducible cross-links. (author)

  8. Levels of 2-dodecylcyclobutanone in ground beef patties irradiated by low-energy X-ray and gamma rays.

    Science.gov (United States)

    Hijaz, Faraj M; Smith, J Scott

    2010-01-01

    Food irradiation improves food safety and maintains food quality by controlling microorganisms and extending shelf life. However, acceptance and commercial adoption of food irradiation is still low. Consumer groups such as Public Citizen and the Food and Water Watch have opposed irradiation because of the formation of 2-alkylcyclobutanones (2-ACBs) in irradiated, lipid-containing foods. The objectives of this study were to measure and to compare the level of 2-dodecylcyclobutanone (2-DCB) in ground beef irradiated by low-energy X-rays and gamma rays. Beef patties were irradiated by low-energy X-rays and gamma rays (Cs-137) at 3 targeted absorbed doses of 1.5, 3.0, and 5.0 kGy. The samples were extracted with n-hexane using a Soxhlet apparatus, and the 2-DCB concentration was determined with gas chromatography-mass spectrometry. The 2-DCB concentration increased linearly (P irradiation dose for gamma-ray and low-energy X-ray irradiated patties. There was no significant difference in 2-DCB concentration between gamma-ray and low-energy X-ray irradiated patties (P > 0.05) at all targeted doses. © 2010 Institute of Food Technologists®

  9. Effects of Gamma Irradiation and Dose Accumulation on the Histology of Spodoptera littoralis (Boisd.) Male Testes

    International Nuclear Information System (INIS)

    Sallam, H.A.; El-Naggar, S.E.M.; Shibel, M.M.; El-Dossouki, S.A.

    2000-01-01

    Full-grown male pupae of the cotton leaf worm Spodoptera littoralis (Boisd.) were gamma irradiated with low doses of 25, 50, 75 or 100 Gy. The effects of accumulating doses applied to these pupae through three consequent filial generations and the retarded influence on their F 1 , F 2 and F 3 generations progeny were examined. The histological observations showed that the damage in the testes was correlated with increasing the dose applied to the male parents and was the highest among the adults of F 1 . Also, the damage at any acute dose was less than the damage occurred in the same accumulated dose. The deteriorations on the testes were more evident in case of F 1 males resulting from parental males irradiated through two or three successive generations or three accumulated doses of 25 or 50 Gy

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

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1979-01-01

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

  11. The Effect of A Single Sub-Lethal Dose of Whole Body Irradiation on the Small Intestine of Rats

    International Nuclear Information System (INIS)

    Al-Ramli, M. A.; Kubba, M. A.; Al-Bassam, L. S.; Belhaj, K.; Al-shawish, N. M.

    2007-01-01

    The effect of whole body radiation with a single sub-lethal dose at 4 Gy on rat small intestine was studied histologically and quantitatively. Irradiated animals were euthanized at 24 hours, 3, 7, 14, 21 and 28 days post- irradiation. Crypts of Leiberkuhn and peyer's patches were especially targeted by irradiation. The crypts showed severe cellular fragmentation in the germinal cellular compartments twenty Four hours after irradiation resulting in partial denudation of villi especially at their Tips. At three days, these cells resumed their proliferative activity with the appearance of unusually large numbers of mitotic figures. Cellular regeneration in the crypts and on the villous surface showed improvement with advancing time till day 28 when the villi had complete epithelial covering and the proliferative activity of the germinal cryptic cells returned to normal. The quantitative study included the measurement of about fifty villi at each time after irradiation. A significant decrease in villous length was noticed at twenty four hours post-irradiation compared to the control values. The length of villi plateaued at about this level till day twenty one when it slightly increased to reach a sub normal mean length on day 28. We concluded that whole body irradiation with a single dose at 4 Gy was enough to induce cryptic cellular necrosis with sloughing of epithelial villous columnar covering. This cellular damage was, however, sub- total since quick regenerative cellular activity was noticed three days post-irradiation. The decrease in the villous length paralleled the cryptic cellular damage whereas full recovery was not achieved despite obvious cellular regeneration.

  12. Statistical evaluation of the dose-distribution charts of the National Computerized Irradiation Planning Network

    International Nuclear Information System (INIS)

    Varjas, Geza; Jozsef, Gabor; Gyenes, Gyoergy; Petranyi, Julia; Bozoky, Laszlo; Pataki, Gezane

    1985-01-01

    The establishment of the National Computerized Irradiation Planning Network allowed to perform the statistical evaluation presented in this report. During the first 5 years 13389 dose-distribution charts were calculated for the treatment of 5320 patients, i.e. in average, 2,5 dose-distribution chart-variants per patient. This number practically did not change in the last 4 years. The irradiation plan of certain tumour localizations was performed on the basis of the calculation of, in average, 1.6-3.0 dose-distribution charts. Recently, radiation procedures assuring optimal dose-distribution, such as the use of moving fields, and two- or three-irradiation fields, are gaining grounds. (author)

  13. Distinguishing of artificial irradiation by α dose: a method of discriminating imitations of ancient pottery

    International Nuclear Information System (INIS)

    Wang Weida; Xia Junding; Zhou Zhixin; Leung, P.L.

    2003-01-01

    If a modern pottery is artificially irradiated by γ-rays of 60 Co source, the modern will become ancient when the pottery is dated by the thermoluminescence technique. For distinguishing artificial irradiation a study was made. Meanwhile the 'fine-grain' and 'pre-dose' techniques were used respectively for measurement of the paleodose in a fine-grain sample from the same pottery. If the paleodose measured by the fine-grain technique is greater than that by the pre-dose techniques, we can affirm that the difference between two paleodoses is due to α dose and this paleodose containing α component results from natural radiation, the pottery therefore is ancient. If two paleodoses are equal approximately, i.e. α dose is not included in the paleodose, the paleodose comes from artificial γ irradiation and the pottery is an imitation

  14. Effect of prolonged irradiation by low dose-rate ionizing radiation on the hemopoiesis of mice

    Energy Technology Data Exchange (ETDEWEB)

    Yanai, Takanori; Shirata, Katsutoshi; Saitou, Mikio; Tanaka, Satoshi; Onodera, Junichi; Otsu, Hiroshi; Sato, Fumiaki [Institute for Environmental Sciences, Department of Radiobiology, Rokkasho, Aomori (Japan)

    1999-07-01

    To evaluate effects of prolonged irradiation by low dose-rate ionizing radiation on the hemopoiesis of mice, SPF C3H/HeN female mice were irradiated by {sup 137}Cs {gamma}-rays with doses of 1-8 Gy at the dose rate of 20 mGy (22 h-day){sup -1}. After irradiation, the number of hemopoietic cells contained in bone marrow was determined by the methods of CFU-S and CFU-GM assay, and the number of peripheral blood cells was counted. It was shown that the day 12-CFU-S, which is in the earlier stage of differentiation, decreased as the dose increased. Decreases of the numbers of day 7-CFU-S and CFU-GM were also observed. However, there were no remarkable changes in the number of peripheral blood cells. (author)

  15. Effect of prolonged irradiation by low dose-rate ionizing radiation on the hemopoiesis of mice

    Energy Technology Data Exchange (ETDEWEB)

    Yanai, Takanori; Shirata, Katsutoshi; Yamada, Yutaka; Saitou, Mikio; Izumi, Jun; Tanaka, Satoshi; Otsu, Hiroshi; Sato, Fumiaki [Institute for Environmental Sciences, Rokkasho, Aomori (Japan)

    2000-07-01

    For evaluation of effects of prolonged irradiation by low dose-rate ionizing radiation on the hemopoiesis of mice, SPF C3H/HeN female mice were irradiated with {sup 137}Cs {gamma}-rays with doses of 1-4 Gy at the dose rate of 20 mGy/22h-day. After irradiation, the number of hemopoietic cells contained in spleen was determined by the methods of CFU-S and CFU-GM assay, and the number of peripheral blood cells was counted. It was shown that the number of CFU-S colonies on day 12, which is in the earlier stage of differentiation, decreased as dose increased. No remarkable changes in the number of peripheral blood cells, however, were observed. (author)

  16. Undetectable inhibin B serum levels in men after testicular irradiation

    DEFF Research Database (Denmark)

    Petersen, P M; Andersson, A M; Rørth, M

    1999-01-01

    A group of men treated with testicular irradiation for carcinoma in situ in the remaining testis after orchidectomy for unilateral testicular germ cell cancer was used as a model to study of the effect of selective eradication of germ cells on the levels of serum inhibin B in the human male....... Thirteen men with verified spermatogenesis and detectable preirradiation levels of serum inhibin B (median, 55; range, 23-193 pg/mL) were investigated before and after testicular irradiation (14-20 Gy). All patients had undetectable levels of inhibin B 2-12 months (median, 5 months) after radiotherapy (...

  17. Retinopathy after low dose irradiation for an intracranial tumor of the frontal lobe

    International Nuclear Information System (INIS)

    Elsaas, T.; Thorud, E.; Jetne, V.; Conradi, I.S.

    1988-01-01

    A 32-year-old man underwent an operation for an oligodendroglioma of the left frontal lobe. Postoperatively he was irradiated to a target dose of 54 Gy. One year later hedeveloped bilateral retinopathy quite similar to diabetic retinopathy. There were no clinical or biochemical signs of diabetes or hematological disease. The calcultated maximum dose to the retina was 11 Gy. This is to our knowledge the lowest retinal dose of ionizing radiation reported to produce retinopathy. (author)

  18. Repair of sublethal damage in mammalian cells irradiated at ultrahigh dose rates

    International Nuclear Information System (INIS)

    Gerweck, L.E.; Epp, E.R.; Michaels, H.B.; Ling, C.C.; Peterson, E.C.

    1979-01-01

    The lethal response of asynchronous Chinese hamster ovary (CHO) cells exposed to single and split doses of radiation at conventional or ultrahigh dose rates has been examined to determine whether repair of sublethal damage occurs in cells irradiated at ultrahigh dose rates. The high-intensity irradiations were performed with electrons delivered in single 3-nsec pulses from a 600-kV field emission source under medium-removed, thin-layer conditions. Conventional dose-rate experiments were done under identical thin-layer conditions with 50-kVp x rays, or under full-medium conditions with 280-kVp x rays. Oxygenated cells were irradiated and maintained at 22 to 24 0 C between exposures. Survival did not increase as the time between two doses of pulsed electrons increased from 0 to 4 min, indicating no evidence of fast repair. However, increased survival was observed when 30 to 90 min was allowed to elapse between the split doses. The half-time for maximum repair was approx. = 30 min irrespective of the exposure conditions and radiation modality used. Observed repair ratios increased from approx. = 2 to 4 as the single-dose surviving fraction decreased from 10 -2 to 5 x 10 -4 . Over this survival range the repair ratios, measured at the same value of surviving fraction, were independent of dose rate. The observed repair ratios imply that the shoulder regions of the nonfractionated x-ray and pulsed-electron survival curves were not completely restored between the split doses. However, the fraction of the shoulder restored between split doses of radiation was dose-rate-independent. It is concluded that sublethal damage can be repaired in oxygenated CHO cells irradiated at dose rates of the order of 10 11 rad/sec

  19. Electroencephalogram in relation to brain glycogen level in irradiated rats treated with vitamin E as a radioprotective compound

    International Nuclear Information System (INIS)

    Mahdy, A.M.

    1992-01-01

    Whole body gamma irradiation of untreated rats at the dose of 7 Gy induced severe abnormalities in the brain electrical activity, electroencephalogram (EEG), patterns of both frontal and occipital cortical areas. The visual analysis of the frontal EEG records showed a significant shift of frequencies towards faster and higher voltage activity along the experiment period (first , third, seventh and tenth days post irradiation). However, an opposite picture was prominent on the occipital EEG records after irradiation. On the other hand,the level of brain glycogen, which is considered as an important energy source for brain functions, significantly increased at all intervals of post irradiation. The treatment of rats with intraperitoneal injection of vitamin E pre-irradiation succeeded in diminishing the deleterious abnormalities in the EEG records in both frontal and occipital areas as well as the changes induced in the level of brain glycogen after whole body gamma irradiation.4 fig

  20. Dose-volume analysis of hypothyroidism in patients irradiated to the neck

    International Nuclear Information System (INIS)

    Te, Vuong; Liu, Mitchell C.C.; Parker, William; Curtin-Savard, Arthur J.; Clark, Brenda

    1997-01-01

    Purpose: To determine if the incidence of hypothyroidism in patients who have received radiation therapy to the neck region has any relationship with the total dose to the thyroid and volume of thyroid irradiation. Methods and Materials: From 1988 to 1996, TSH levels were measured at regular intervals of every 3 to 6 months in 528 patients with head and neck cancers or lymphomas (Hodgkin and non-Hodgkin) who had received radiation therapy to the neck region. Hypothyroidism was defined by TSH of ≥ 5 (normal range: 0.5 - 4mU/L). Medical charts, radiotherapy charts, treatment planning films, dosimetry and CT scans/MRI were reviewed. Thyroid volume was determined utilizing treatment planning films and CT scans/MRI. Four hundred and six patients had normal TSH prior to radiation and sufficient information to be eligible for analysis. There were 264 (65%) male and 142 (35%) female, median age was 59 yr (range: 12 - 85). Median follow-up was 39.5 months (range: 1 - 289 months). Results: Out of the 406 eligible patients, 152 (37%) had developed hypothyroidism. The actuarial incidence of hypothyroidism at 1 yr, 3 yr and 5 yr are 9.1%, 29% and 38.5%, respectively. Analysis of volume effect and dose effect are as follows: When the radiation dose to the thyroid and the volume of thyroid irradiated are analyzed together, the group of patients who received ≥ 60Gy to half of thyroid or received ≥ 30Gy to the whole thyroid has increased risk of developing hypothyroidism as compared to those receiving <60Gy to half the thyroid or <30Gy to the whole thyroid (p=.0001). Conclusions: The actuarial incidence of hypothyroidism at 5 year in patients who had received radiation to the neck is 38.5%. Patients who received ≥ 60Gy to half the thyroid or received ≥ 30Gy to the whole thyroid are at higher risk of developing hyperthyroidism

  1. Increase of onion yield through low dose of gamma irradiation of its seeds

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Wiendl, F.W.; Wiendl, J.A.; Vedovatto, A.; Arthur, V.

    1995-01-01

    The increase of onions' yield could be achieved by the common farmer through the use of nuclear techniques. This report describes the results obtained with the irradiation of onion seeds, with low doses of gamma radiations (Cobalt-60), at doses of 0 (control), 150, 400 and 700 Gy. Beyond the proper onion's variety als use of low dose rates of 13.1, 39.2 and 52.3 Gy per hour were of the great importance during irradiation. The results showed to be promising both in laboratory studies and in the field, resulting in an increase of onions production: A greater number of seedlings, bulbs and a higher yield in weight per hectar were planted. In the field the most promising dose and dose rate to the variety ''Super-X'' were respectively 150 Gy and 13.1 Gy per hour, yielding an 24.9 percent heavier weight of onions than the control. The other tested variety was ''Granex-33'', which did not respond so favorable to irradiation. However, also with this variety we harvested a 2.1 percent heavier weight than its control, if the onion seeds were irradiated with the dose of 700 Gy at a dose rate of 13.1 Gy per hour. (Author)

  2. Low level chronic irradiation of salmon. Annual progress report

    International Nuclear Information System (INIS)

    Hershberger, W.K.; Donaldson, L.R.; Bonham, K.; Brannon, E.L.

    1975-01-01

    A question of primary importance in the use of nuclear energy is what effect the effluent from a reactor will have on the aquatic life in the water used for cooling. Of particular concern in the Pacific Northwest are the effects of chronic irradiation on salmon that use the rivers for spawning and nursery area. The present program was designed in the early days of the atomic era to address this concern, and to provide some insight into the long-term consequences of exposure of fish to chronic, low levels of irradiation. The experimental techniques are described and data are summarized on irradiation effects on the entire life cycle of the chinook salmon. Also, long-term effects transmitted to future generations were assessed in F 1 offspring of irradiated parents

  3. Effect of Gamma Irradiation Doses on Some Chemical Characteristics of Cotton Seed Oil

    International Nuclear Information System (INIS)

    Saleh, O.I.

    2011-01-01

    Cotton Seeds c.v. Giza 85 (Gossypium hirsutum L.) were exposed to gamma irradiation doses of 0.5, 1.0 and 1.5 kGy to improve some chemical characteristics of cotton seed oil i.e. saturated and unsaturated fatty acids, gossypol and βsitosterol that were bound oil. The presented study showed that, the saturated fatty acids; lauric, palmitic and stearic increased when the cotton seeds were exposed to gamma irradiation doses of 0.5 up to 1.5 kGy, On the other hand, arachidic acid content decreased in all the irradiated treatments compared with untreated cotton seed. The unsaturated fatty acid oleic was increased in irradiated cotton seed samples compared with untreated one, while linoleic, the major unsaturated fatty acid decreased in irradiated cotton seed oil than untreated seeds. Gossypol and βsitosterol, bound oil, in irradiated cotton seeds increased gradually with gamma irradiated doses compared with untreated control samples

  4. Radioprotective effect of RSP-CM on mice irradiated with different doses

    International Nuclear Information System (INIS)

    Zhang Xia; Yang Rujun; Zhang Xin; Yang Yunfang; Jin Zhijun; Xiang Yingsong

    2000-01-01

    Objective: To investigate the radioprotective effects of cytokines on hematopoietic impairment of irradiated mice. Methods: Using RSP-CM and LP3-CM respectively originated GM-CSF and G-CSF to treat ICR mice irradiated with different doses of 60 Co γ-rays. The 30-day survival rate of mice, the mean survival days of dead mice were determined and the numbers of peripheral white blood cells and BMC of part of the mice were counted. At the same time, GM clonogenic activity of BM was assayed. Results:RSP-CM could effectively raise 30-day survival rate of mice irradiated with 7.5 Gy. However, LP3-CM had no obvious effect. Judging from the comparative survival ratio, only the RSP-CM treated group showed protective effect on the 8.0 Gy -irradiated mice. The 8.5 Gy-irradiated mice all died within 30 days, indicating that GM-CSF had weak effect on higher dose-irradiated mice. Conclusion: GM-CSF can stimulate the hematopoietic system of irradiated mice, and has dose-effect and time-effect relations. M-CSF used singly has no obvious effect

  5. Effects of gamma irradiation dose rate on microbiological and physical quality of mushrooms (Agaricus bisporus)

    International Nuclear Information System (INIS)

    Beaulieu, M.; Lacroix, M.; Charbonneau, R.; Laberge, I.; Gagnon, M.

    1992-01-01

    The effects of gamma irradiation (2 kGy) and dose rate of irradiation (4.5 and 32.0 kGy/h) on increasing the shelf-life and some quality properties of the mushrooms (Agaricus bisporus) were investigated during storage at 15 deg C and 90% R.H. The retardation of mushroom growth and ageing by reduction of gamma irradiation dose rate (4.5 kGy) was observed by measurements of the cap opening, the stipe increase, the cap diameter, the weight loss and the color of the caps. The color was measured in order to evaluate the lightness with the L value measurement and the color changes were measured in terms of lightness, hue and chroma. The control of fungal and bacterial diseases were also evaluated. The irradiation of mushrooms at both dose rates of irradiation was found to be effective in lowering microorganism counts initially and throughout storage and increased the shelf-life by four days. This study also showed that mushrooms exposed to a lower dose rate (4.5 kGy/h) of irradiation preserve the whiteness and reduce the stripe increase of mushrooms during storage

  6. Effects of low dose irradiation on NK activity of normal individuals and patients with cancer

    International Nuclear Information System (INIS)

    Tian Hailin; Su Liaoyuan

    1994-10-01

    Effects of low dose irradiation on NK activity of lymphocytes and on K 562 cells were studied. The NK activity was determined by means of 3 H-TdR release assay. While 3 H-TdR incorporation was used to reflect functional changes of K 562 cells after low dose irradiation. 21 patients with cancer and 10 normal individuals were detected. The results indicated that the NK activity of lymphocytes in normal individuals increased significantly after 10 and 50 cGy γ-ray irradiation, while in patients with cancer the NK activity of lymphocytes increased only at the dose of 50 cGy irradiation. The increase of NK activity in normal individuals was higher than that in patients with cancer after same doses of irradiation. When K 562 cells were irradiated by 10 cGy γ-rays, the 3 H-TdR incorporation value increased. After exposed to over 50 cGy the stimulating effect disappeared

  7. Search for the lowest irradiation dose from literatures on radiation-induced breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

    1975-12-01

    A survey of past case reports concerning radiation-induced breast cancer was carried out in order to find the lowest irradiation dose. The search of literature published since 1951 revealed 10 cases of radiation-induced breast cancer. Only 5 cases had precise descriptions of the irradiation dose. The lowest irradiation dose was estimated at 1470 rads in the case of external X-ray irradiation for tuberous angioma. All of cases of radiation-induced breast cancer had received radiation for the treatment of nonmalignant tumors, such as pulmonary tuberculosis, mastitis, and tuberous angioma. There also were three statistical studies. The first concerned atomic bomb survivors, the second, pulmoanry tuberculous patients subjected to frequent fluoroscopies, and the third, patients of acute post partum mastitis. These statistical studies had revealed a significant increase in the incidence of breast cancer in the irradiated group, but there was little information about the lowest irradiation dose. It was noticed that radiation-induced breast cancer was more numerous in the upper inner quadrant of the breast. Most histopathological findings of radiation-induced breast cancer involved duct cell carcinoma. The latent period was about 15 years.

  8. [Doses to organs at risk in conformational radiotherapy and stereotaxic irradiation: The heart].

    Science.gov (United States)

    Vandendorpe, B; Servagi Vernat, S; Ramiandrisoa, F; Bazire, L; Kirova, Y M

    2017-10-01

    Radiation therapy of breast cancer, Hodgkin lymphoma, lung cancer and others thoracic irradiations induce an ionizing radiation dose to the heart. Irradiation of the heart, associated with patient cardiovascular risk and cancer treatment-induced cardiotoxicity, increase cardiovascular mortality. The long survival after breast or Hodgkin lymphoma irradiation requires watching carefully late treatment toxicity. The over-risk of cardiac events is related to the dose received by the heart and the irradiated cardiac volume. The limitation of cardiac irradiation should be a priority in the planning of thoracic irradiations. Practices have to be modified, using modern techniques to approach of the primary objective of radiotherapy which is to optimize the dose to the target volume, sparing healthy tissues, in this case the heart. We have reviewed the literature on cardiac toxicity induced by conformational tridimensional radiation therapy, intensity-modulated radiation therapy or stereotactic body radiation therapy, in order to evaluate the possibilities to limit cardiotoxicity. Finally, we summarise the recommendations on dose constraints to the heart and coronary arteries. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  9. Time-dose relationship of erythema in high energy photon irradiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hidetoshi (Gifu Prefectural Tajimi Hospital (Japan)); Sakuma, Sadayuki

    1992-01-01

    Skin doses of 100 patients who were treated with high energy ionizing irradiation during conventional irradiation therapy were measured by thermoluminescence dosimeter (TLD). In 87 of the 100 patients, acute hyperemic change of the skin (erythema) of the irradiated region was observed. In the other 13 patients, alopetia of the scalp was observed. The following conclusions were reached. The time-dose relationship was linear when erythema tolerance was used as an index, but not when alopecia was used. The tolerance dose for erythema was lower than previously reported. The slope of the isoeffect curve on the log-log plot of total absorbed skin dose against total number of days after the first irradiation was 0.68 when erythema was used as an index. This number is larger than previously reported results. We considered that erythema is significantly influenced by fraction size and that hyperfractionation is a promising method of irradiation, especially in Japan. Combined use of chemotherapeutic agents, such as 5-FU, accelerated erythema. The slope of combined treatment was 0.86. Observing acute hyperemic change of skin is considered to be a useful method of investigating the combined effects of chemotherapeutic agents on irradiation. (author).

  10. Effect Of Irradiation Temperature and Dose On Mechanical Properties And Fracture Characteristics Of Cu//SS Joints For ITER

    International Nuclear Information System (INIS)

    Fabritsiev, S.A.; Pokrovsky, A.S.; Peacock, A.; Roedig, M.; Linke, J.; Gervash, A.; Barabash, V.

    2007-01-01

    Full text of publication follows: By now, a number of technologies have been proposed for the production of Cu//SS joints for ITER, such as brazing, friction welding, HIP and cast-copper-to-steel (CC). The two last-mentioned technologies ensure sufficiently high mechanical properties and a high joint quality, when unirradiated. The data, however, on mechanical characteristics of irradiated of Cu//SS HIP joints are limited. In this paper, the authors present the results of investigations into the mechanical characteristics after irradiation of GlidCopAl25/316L(N) and Cu-Cr-Zr/316L(N)-type joints produced by the HIP and CC technologies. Specimens of the joints were irradiated in the RBT-6 reactor in the dose range of 10 -3 - 10 -1 dpa at T irr = 200 deg. C and 300 deg. C. The tensile stress-strain curves for irradiated and unirradiated joint specimens show deformation processes occurring in both the Cu and SS parts of the specimens. Irradiation at T irr = 200 deg. C causes strengthening of the joints specimens (by about 100 MPa at the maximum dose). The uniform elongation drops from 8% in the initial state to 2-3 %. But the total elongation remains at a relatively high level of ∼ 7%. Irradiation at T irr = 300 deg. C causes a slight strengthening of the joints specimens (∼30 MPa). The uniform elongation remains unchanged at ∼ 7%. The total elongation also maintains a relatively high level of ∼9-13%. SEM investigations revealed that fracture occurs only in the copper part of the irradiated specimens, and ductile trans-crystalline fracture predominates in the joints. 3D finite element analysis of the tensile test indicates that the concentration of stresses and deformations in the copper layer adjacent to the joint line is responsible for this typical failure of the irradiated joints specimens. Comparison of the behavior of the joints irradiated at T irr = 200 deg. C and 300 deg. C indicate an increased embrittlement at lower irradiation temperatures. At a

  11. Prostaglandin levels and lysosomal enzyme activities in irradiated rats

    International Nuclear Information System (INIS)

    Trocha, P.J.; Catravas, G.N.

    1980-01-01

    Whole-body irradiation of rats results in the release of hydrolases from lysosomes, an increase in lysosomal enzyme activities, and changes in the prostaglandin levels in spleen and liver tissues. A transient increase in the concentration of prostaglandins E and F and leakage of lysosomal hydrolases occurred in both spleen and liver tissues 3-6 hours after the animals were irradiated. Maximal values for hydrolase activities, prostaglandin E and F content, and release of lysosomal enzymes were found 4 days postirradiation in rat spleens whereas in the liver only slight increases were observed at this time period for prostaglandin F levels. On day 7 there was a final rise in the spleen's prostaglandin E and F concentrations and leakage of hydrolases from the lysosomes before returning to near normal values on day 11. The prostaglandin F concentration in liver was also slightly elevated on the 7th day after irradiation and then decreased to control levels. (author)

  12. Nucleic acids levels in X-irradiated 5th instar nymphs of Dysdercus koenigii F

    International Nuclear Information System (INIS)

    Harwalkar, M.R.; Ramakrishnan, V.

    1993-01-01

    Irradiation of early 5th instar nymphs of Dysdercus koenigii F. with X-ray doses ranging from 10 to 70 Gy affected their metamorphosis in a dose dependent manner. At 70 Gy dose, metamorphosis of nymphs was completely inhibited although these nymphs survived for more than 10 days. In unirradiated 5th instar nymphs, DNA content doubled between 2nd and 3rd day and it remained at this level till these nymphs completed metamorphosis. However, DNA content of nymphs exposed to metamorphosis inhibition dose of 70 Gy X-rays showed only slight increase from 4th day and its profile remained at lower level throughout 5th instar nymphal period. Though the increase in RNA content in both the groups was found to be gradual upto 3rd day, the increase was more pronounced in case of unexposed insects. (author). 9 refs., 2 tabs

  13. Time and dose dependent expression in the proteome of human peripheral blood mononuclear cells with γ-irradiation

    International Nuclear Information System (INIS)

    Nishad, S.; Ghosh, Anu

    2014-01-01

    The aim of present study is to investigate time and dose dependent differential protein expression pattern of human peripheral blood mononuclear cells (PBMCs) after acute gamma irradiation. For this purpose, PBMCs extracted from eight healthy individuals were irradiated using 60 Co gamma rays (0.3 Gy and 1 Gy) and compared with sham irradiated controls. Total proteins were extracted 1 and 4 hour post irradiation and analyzed using 2-D gel electrophoresis. A fold change of 1.5 in spot intensity was considered as 'biological significant'. Protein identification was performed by MALDI-TOF mass spectrometry. The MS/MS spectra were interrogated using Mascot 2.1 for searching against SWISS-PROT database. One-hour post irradiation, 18 proteins showed a significant difference between the sham (0 Gy) and 0.3 Gy irradiated group (6 proteins up-regulated and 12 proteins down-regulated) and 17 proteins between the sham (0 Gy) and 1 Gy irradiated group (9 proteins up-regulated and 8 down-regulated). Four hours after irradiation, 16 proteins were differentially expressed between the sham irradiated and 0.3 Gy treated group (5 proteins up-regulated and 11 proteins downregulated). Relatively high dose of 1 Gy showed modulation of 13 proteins (5 proteins upregulated and 8 proteins down regulated) after 4 hours. There were 15 proteins that were observed both at the early time point of 1-hour and the late time point of 4-hour. Important among these were, proteins involved in cytoskeletal organization like Actin, Plastin-2, Vinculin, PDZ and LIM domain protein, WD repeat containing protein and the chaperone proteins like HSP 90-alpha and Protein disulfide-isomerase A3. Proteins like thiol specific antioxidant peroxiredoxin-6 (indicating increased levels of ROS and oxidative stress) showed dose specific expression while proteins like Ras-related Rap-1b-like protein (involved in cell survival) were observed with both 0.3 Gy and 1 Gy. During the study, human peripheral blood

  14. Dose and time relationships in the endocrine response of the irradiated adult rat testis

    International Nuclear Information System (INIS)

    Delic, J.I.; Hendry, J.H.; Morris, I.D.; Shalet, S.M.

    1986-01-01

    The dose- and time-dependent responses for the interstitial and tubular compartments in irradiated adult rat testes are described. Leydig cell dysfunction, as indicated by increased serum LH (to a maximum of 385% of control after 5 Gy) and decreased serum T (to a minimum of 30% of control after 10 Gy), was observed at 8 weeks postirradiation. Subsequent recovery of Leydig cell function was then observed, so that after 9 months serum T was normal but LH was still marginally elevated. The dysfunction, with a threshold of about 4 to 5 Gy, was associated with a loss of Leydig cells from the testis. Spermatogenic damage was observed; after doses of 3 Gy and above a marked dose-response was recorded as assessed by counts of tubule cross sections exhibiting spermatogenesis. Reduced serum levels of androgen binding protein indicated Sertoli cell dysfunction at 8 weeks after 3 Gy and above, with values of less than one half of those seen in the controls. Serum FSH also was elevated to between 150% and 200% of control, and after 9 months closely reflected androgen binding protein changes. Unlike the Leydig cell, no recovery with time was observed for this aspect of Sertoli cell function

  15. The elevation of blood levels of zinc protoporphyrin in mice following whole body irradiation

    International Nuclear Information System (INIS)

    Walden, T.L.; Draganac, P.S.; Farkas, W.R.

    1984-01-01

    Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. We have discovered that sublethal doses of whole body irradiation with x-rays also elevates ZPP 2-3-fold over normal levels. The ZPP level does not begin to increase until days 12-14 postirradiation and peaks between days 18 and 20 before returning to normal levels between days 28 and 35. Increasing the radiation dose delays the onset of the rise in ZPP, but does not affect the magnitude of the elevation. At lethal doses, ZPP elevation is not observed. Neither of the two previously described mechanisms that cause elevations of ZPP, namely iron deficiency and inhibition of ferrochelatase, are responsible for the radiation-induced elevation of ZPP. The elevation of ZPP appears to be correlated with the recovery of the hematopoietic system from radiation injury

  16. Degradation and annealing studies on gamma rays irradiated COTS PPD CISs at different dose rates

    International Nuclear Information System (INIS)

    Wang, Zujun; Ma, Yingwu; Liu, Jing; Xue, Yuan; He, Baoping; Yao, Zhibin; Huang, Shaoyan; Liu, Minbo; Sheng, Jiangkun

    2016-01-01

    The degradation and annealing studies on Colbalt-60 gamma-rays irradiated commercial-off-the-shelf (COTS) pinned photodiode (PPD) CMOS image sensors (CISs) at the various dose rates are presented. The irradiation experiments of COTS PPD CISs are carried out at 0.3, 3.0 and 30.0 rad(Si)/s. The COTS PPD CISs are manufactured using a standard 0.18-μm CMOS technology with four-transistor pixel PPD architecture. The behavior of the tested CISs shows a remarkable degradation after irradiation and differs in the dose rates. The dark current, dark signal non-uniformity (DSNU), random noise, saturation output, signal to noise ratio (SNR), and dynamic range (DR) versus the total ionizing dose (TID) at the various dose rates are investigated. The tendency of dark current, DSNU, and random noise increase and saturation output, SNR, and DR to decrease at 3.0 rad(Si)/s are far greater than those at 0.3 and 30.0 rad(Si)/s. The damage mechanisms caused by TID irradiation at the various dose rates are also analyzed. The annealing tests are carried out at room temperature with unbiased conditions after irradiation.

  17. Degradation and annealing studies on gamma rays irradiated COTS PPD CISs at different dose rates

    Science.gov (United States)

    Wang, Zujun; Ma, Yingwu; Liu, Jing; Xue, Yuan; He, Baoping; Yao, Zhibin; Huang, Shaoyan; Liu, Minbo; Sheng, Jiangkun

    2016-06-01

    The degradation and annealing studies on Colbalt-60 gamma-rays irradiated commercial-off-the-shelf (COTS) pinned photodiode (PPD) CMOS image sensors (CISs) at the various dose rates are presented. The irradiation experiments of COTS PPD CISs are carried out at 0.3, 3.0 and 30.0 rad(Si)/s. The COTS PPD CISs are manufactured using a standard 0.18-μm CMOS technology with four-transistor pixel PPD architecture. The behavior of the tested CISs shows a remarkable degradation after irradiation and differs in the dose rates. The dark current, dark signal non-uniformity (DSNU), random noise, saturation output, signal to noise ratio (SNR), and dynamic range (DR) versus the total ionizing dose (TID) at the various dose rates are investigated. The tendency of dark current, DSNU, and random noise increase and saturation output, SNR, and DR to decrease at 3.0 rad(Si)/s are far greater than those at 0.3 and 30.0 rad(Si)/s. The damage mechanisms caused by TID irradiation at the various dose rates are also analyzed. The annealing tests are carried out at room temperature with unbiased conditions after irradiation.

  18. Late effects of chronic low dose-rate γ-rays irradiation on mice

    International Nuclear Information System (INIS)

    Tanaka, Satoshi; Sasagawa, Sumiko; Ichinohe, Kazuaki; Matsumoto, Tsuneya; Otsu, Hiroshi; Sato, Fumiaki

    2002-01-01

    To evaluate late biological effects of chronic low dose-rate radiation, we are conducting two experiments. Experiment 1 - Late effects of chronic low dose-rate g-rays irradiation on SPF mice, using life-span and pathological changes as parameters. Continuous irradiation with g-rays for 400 days was performed using 137 Cs γ-rays at dose-rates of 20 mGy/day, 1 mGy/day and 0.05 mGy/day with accumulated doses equivalent to 8,000 mGy, 400 mGy and 20 mGy, respectively. All mice were kept until they died a natural death. As of 2002 March 31, 3,999 of the total 4,000 mice have died. Preliminary analyses of data show that 20 mGy/day suggested a shortened life span in both sexes. Partial results show that the most common lethal neoplasms in the pooled data of non-irradiated control and irradiated male mice, in order of frequency, were neoplasms of the lymphohematopoietic system, liver, and lung. In female mice, neoplasms of the lymphohematopoietic system, soft tissue, and endocrine system were common. Experiment 2 - Effects on the progeny of chronic low dose-rate g-ray irradiated SPF mice: pilot study, was started in 1999 and is currently in progress. (author)

  19. ESR spectroscopy for detecting gamma-irradiated dried vegetables and estimating absorbed doses

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joong-Ho; Chung, Hyung-Wook; Byun, Myung-Woo

    2000-03-01

    In view of an increasing demand for food irradiation technology, the development of a reliable means of detection for the control of irradiated foods has become necessary. Various vegetable food materials (dried cabbage, carrot, chunggyungchae, garlic, onion, and green onion), which can be legally irradiated in Korea, were subjected to a detection study using ESR spectroscopy. Correlation coefficients (R{sup 2}) between absorbed doses (2.5-15 kGy) and their corresponding ESR signals were identified from ESR signals. Pre-established threshold values were successfully applied to the detection of 54 coded unknown samples of dried clean vegetables (chunggyungchae, Brassica camestris var. chinensis), both non-irradiated and irradiated. The ESR signals of irradiated chunggyungchae decreased over a longer storage time, however, even after 6 months of ambient storage, these signals were still distinguishable from those of non-irradiated samples. The most successful estimates of absorbed dose (5 and 8 kGy) were obtained immediately after irradiation using a quadratic fit with average values of 4.85 and 8.65 kGy being calculated. (author)

  20. The high dose and low dose food irradiation programmes in the United States of America

    International Nuclear Information System (INIS)

    Brynjolfsson, A.

    1978-01-01

    Many highly acceptable shelf-stable irradiated food items have been developed in the United States of America. The most extensive wholesomeness studies ever carried out on any food-processing method continue to indicate that irradiated foods are wholesome. (author)

  1. Radiation tolerance of the spinal cord previously-damaged by tumor operation: long term neurological improvement and time-dose-volume relationships after irradiation of intraspinal gliomas

    International Nuclear Information System (INIS)

    Kopelson, G.

    1982-01-01

    Of 26 patients with intramedullary spinal cord gliomas (9 astrocytomas, 5 glioblastomas, 12 ependymomas) seen at the Massachusetts General Hospital from 1962-1980, 24 were irradiated (21 initially and 3 after post-surgical recurrence). Those 19 patients who survived at least 1 year after completion of irradiation were evaluated for post-irradiation neurological changes.No patient developed radiation myelopathy. Return to a permanently and completely normal neurological status occured for 33/51 (65%) of pre-irradiation neurological deficits. The major cause of post-irradiation neurological deterioration was tumor recurrence. Although 18/19 patients had their thoracic or lumbar spinal cords irradiated, each with field sizes greater than 10 cm, spinal cord doses approaching, equalling, or occasionally exceeding various definitions of spinal cord tolerance were tolerated well without evidence of radiation myelopathy. Spinal cords of patients with intramedullary gliomas, often with major neurological deficits prior to irradiation, may be treated safely to doses approaching or equalling spinal cord tolerance levels. These doses are expected to locally control most ependymomas and astrocytomas without an increased radiation myelopathy. Caution should be observed if doses higher than this are contemplated in an attempt to cure glioblastoma, because the 5% tolerance level of the damaged spinal remains to be defined

  2. Clinical effects of chronic low doses irradiation (11 years after Chernobyl accident)

    International Nuclear Information System (INIS)

    Romanenko, A.Y.; Bebeshko, V.G.

    1997-01-01

    Estimation of clinical effects of influence low doses of irradiation as the result of the Chernobyl accident on the human organism is presented in this report. The results of the investigations are concerning to changings in different organs and systems of inhabitants of the contamination territories and among clean-up workers. Increasing of morbidity of digestive and nervous systems is notified. Increase of thyroid cancer, chronic thyroidities and hypothyreouses is resisted in clean-up workers in dynamic observation. Highly morbidity of bronchopulmonal system and blood circulation system is revealed. High level of compensative and adaptive reactions of immune and hemopoietic systems is notified. Excesses of leukemias and lymphomas in inhabitants of the contamination territories is not demonstrated but tendency for increasing quantity cases of oncohematological diseases (leukemias, lymphomas, MDS) among clean-up workers IV-VII 1986 are absent. A dynamic of health state of children injured as a result of Chernobyl accident is characterized with continues negative tendencies. (author)

  3. Effect of high-dose irradiation on quality characteristics of ready-to-eat chicken breast

    International Nuclear Information System (INIS)

    Yun, Hyejeong; Haeng Lee, Kyung; Jung Lee, Hyun; Woon Lee, Ju; Uk Ahn, Dong; Jo, Cheorun

    2012-01-01

    High-dose (higher than 30 kGy) irradiation has been used to sterilize specific-purposed foods for safe and long-term storage. The objective of this study was to investigate the effect of high-dose irradiation on the quality characteristics of ready-to-eat chicken breast in comparison with those of the low-dose irradiation. Ready-to-eat chicken breast was manufactured, vacuum-packaged, and irradiated at 0, 5, and 40 kGy. The populations of total aerobic bacteria were 4.75 and 2.26 Log CFU/g in the samples irradiated at 0 and 5 kGy, respectively. However, no viable cells were detected in the samples irradiated at 40 kGy. On day 10, bacteria were not detected in the samples irradiated at 40 kGy but the number of bacteria in the samples irradiated at 5 kGy was increased. The pH at day 0 was higher in the samples irradiated at 40 kGy than those at 0 and 5 kGy. The 2-thiobarbituric acid reactive substance (TBARS) values of the samples were not significantly different on day 0. However, on day 10, the TBARS value was significantly higher in the samples irradiated at 40 kGy than those at 0 and 5 kGy. There was no difference in the sensory scores of the samples, except for off-flavor, which was stronger in samples irradiated at 5 and 40 kGy than control. However, no difference in off-flavor between the irradiated ones was observed. After 10 days of storage, only the samples irradiated at 40 kGy showed higher off-flavor score. SPME-GC–MS analysis revealed that 5 kGy of irradiation produced 2-methylbutanal and 3-methylbutanal, which were not present in the control, whereas 40 kGy of irradiation produced hexane, heptane, pentanal, dimethly disulfide, heptanal, and nonanal, which were not detected in the control or the samples irradiated at 5 kGy. However, the amount of compounds such as allyl sulfide and diallyl disulfide decreased significantly in the samples irradiated at 5 kGy and 40 kGy. - Highlights: ► Comparison of high (40 kGy) and low-dose irradiation (5 kGy) on

  4. Monitoring PAI-1 and VEGF Levels in 6 Human Squamous Cell Carcinoma Xenografts During Fractionated Irradiation

    International Nuclear Information System (INIS)

    Bayer, Christine; Kielow, Achim; Schilling, Daniela; Maftei, Constantin-Alin; Zips, Daniel; Yaromina, Ala; Baumann, Michael; Molls, Michael; Multhoff, Gabriele

    2012-01-01

    Purpose: Previous studies have shown that the plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are regulated by hypoxia and irradiation and are involved in neoangiogenesis. The aim of this study was to determine in vivo whether changes in PAI-1 and VEGF during fractionated irradiation could predict for radiation resistance. Methods and Materials: Six xenografted tumor lines from human squamous cell carcinomas (HSCC) of the head and neck were irradiated with 0, 3, 5, 10, and 15 daily fractions of 2 Gy. The PAI-1 and VEGF antigen levels in tumor lysates were determined by enzyme-linked immunosorbent assay kits. The amounts of PAI-1 and VEGF were compared with the dose to cure 50% of tumors (TCD 50 ). Colocalization of PAI-1, pimonidazole (hypoxia), CD31 (endothelium), and Hoechst 33342 (perfusion) was examined by immunofluorescence. Results: Human PAI-1 and VEGF (hVEGF) expression levels were induced by fractionated irradiation in UT-SCC-15, UT-SCC-14, and UT-SCC-5 tumors, and mouse VEGF (msVEGF) was induced only in UT-SCC-5 tumors. High hVEGF levels were significantly associated with radiation sensitivity after 5 fractions (P=.021), and high msVEGF levels were significantly associated with radiation resistance after 10 fractions (P=.007). PAI-1 staining was observed in the extracellular matrix, the cytoplasm of fibroblast-like stroma cells, and individual tumor cells at all doses of irradiation. Colocalization studies showed PAI-1 staining close to microvessels. Conclusions: These results indicate that the concentration of tumor-specific and host-specific VEGF during fractionated irradiation could provide considerably divergent information for the outcome of radiation therapy.

  5. Irradiation of the foetus and the child during radiodiagnosis. Low doses

    International Nuclear Information System (INIS)

    Grellet, J.

    1994-01-01

    Controlling irradiation of the conceptus, the child and the adolescent due to radiodiagnosis techniques is of particular importance since these age groups are more sensitive to ionizing irradiation than adults. In addition the conceptus (embryo or foetus) often receives whole-body irradiation. Based on the data in the literature, it can only be demonstrated that, under normal diagnostic conditions, irradiation risks do exist. However, the aim of applying ethical standards based on the ''ALARA'' concept is to reduce the potential irradiation-related risk and to sustain a sufficiently high level of awareness of the potential danger in health careworkers. (author). 15 refs., 1 fig

  6. Relative biological effectiveness of 125I seeds for low-dose-rate irradiation of PANC-1

    International Nuclear Information System (INIS)

    Wang Jidong; Wang Junjie; Zhuang Hongqing; Liao Anyan; Zhao Yong

    2008-01-01

    Objective: To investigate the relative biological effectiveness(RBE) of National Model 6711 125 I seeds and the response patterns of PANC-1 exposed to 125 I seeds irradiation. Methods: PANC-1 cells in exponential growth were irradiated at initial dose rate of 2.59 cGy/h in vitro and exposed to 1, 2, 4, 6, 8 and 10 Gy. Meanwhile, the other part of cells were exposed to the same doses by 60 Co at dose rate of 2.21 Gy/min. After irradiation, the cells were stained by trypan blue to measure the cellular mortality rate and to compare the changes along with plating times of 12, 24, 48 and 72 h after 4 Gy. The colonies were counted to obtain the plating efficiencies by colony-forming assay and the cell surviving faction was calculated to plot cell survival curves, and RBE of 125 I seeds relative to 60 Co was determined. Results: The cell death rate for continuous low- dose-rate (LDR) irradiation by 125 I seeds was greater than 60 Co at the same doses above or equal to 4 Gy. After 4 Gy irradiation, the cellular mortality rates were increased with times. The difference was significant between 125 I seeds and 60 Co. The survival fractions of 125 I were lower than those of 60 Co, and the RBE of 125 I relative to 60 Co was determined to be 1.45. Conclusion: The cell-killing effects for continuous low-dose-rate (LDR) irradiation by 125 I seeds are greater than acute high-dose-rate of 60 Co. (authors)

  7. The effect of low-dose X-irradiation on immune system

    International Nuclear Information System (INIS)

    Ishii, Keiichiro

    1996-01-01

    The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB 4 and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB 4 of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-α production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. (author). 127 refs

  8. The effect of low-dose X-irradiation on immune system

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Keiichiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1996-06-01

    The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB{sub 4} and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB{sub 4} of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-{alpha} production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. 127 refs.

  9. Effect of low doses gamma irradiation on seed, bulblets and bulbs of onion

    International Nuclear Information System (INIS)

    Al-Oudat, Mohammad

    1991-10-01

    Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on onion in Syria. The effect of low doses gamma irradiation on onion seeds, bulblets and bulbs of two local varieties, red and white, was studied during three consecutive seasons (1986 - 1988). Air dried seeds were irradiated by gamma rays from 137 Cs source. Five, 10, 15, 20 and 30 GY, were applied at dose rate of 9.8 Gy/min. The irradiation of onion bulblets and bulbs were carried out with gamma-rays from 60 Co source at a dose rate of 0.5 Gy/min. using 1, 2, 3, 4 and 5 Gy. Within 7 - 10 days after irradiation, both controlled and irradiated seeds, bulblets and bulbs were sown in the field in complete randomized block design with 4 replicates. Irradiation of seeds with doses of 5, 10 and 15 Gy led to highly significant increases in bulblets yield in the three seasons. The increases ranged from 14.5 to 22.1 for red variety and from 16.2 to 22.3 for white variety. The irradiation of bulblets with 1 and 2 Gy increase significantly the yield of bulbs by 21.6 - 26.0% for red variety and 21.6 - 24.4% for white variety. A considerable increase in seed yield was obtained after irradiation of bulbs with 1 and 2 Gy doses. The average increment was about 21.0% for both varieties. Large scale application were performed in 1989 and 1990 using doses of 10 Gy for seeds and 1 Gy for bulblets and bulbs. A considerable increase in the yield was obtained. The average percentage increment was 16.9% and 23.3% for seeds, 18.6 and 20.9% for bulblets, 24.8 and 27.3% for bulbs, for red and white varieties respectively. Therefore, presowing irradiation of seeds, bulblets and bulbs of onion with low doses of gamma-rays (5 - 15 Gy for seeds and 1 - 2 Gy for bulblets and bulbs) can be of practical application resulting in improvement of yield of

  10. Evaluation of skyshine dose due to gamma-rays from a cobalt-60 irradiation facility

    International Nuclear Information System (INIS)

    Kanazawa, Tamotsu; Okamoto, Shinichi; Ohnishi, Tokuhiro; Tsujii, Yukio

    1991-01-01

    We attempted to evaluate skyshine dose due to gamma-rays from a cobalt-60 irradiation facility. As the first step, the results of measurements and calculations were compared of the skyshine dose due to gamma-rays from the cobalt-60 source of 1.45 PBq set in the No.4 irradiation room of our laboratory. Distances of measuring points from the cobalt source were in the range from 17 m to about 100 m in the site of our office. Calculation was carried out with simplified single scattering method. The calculated values of the skyshine dose were higher than the measured values. For more precise evaluation of the skyshine dose, the following factors are to be considered; the dose rate distribution on the roof above the source and the attenuation of gamma-rays by air. (author)

  11. Facility for gamma irradiations of cultured cells at low dose rates: design, physical characteristics and functioning

    International Nuclear Information System (INIS)

    Esposito, Giuseppe; Anello, Pasquale; Pecchia, Ilaria; Tabocchini, Maria Antonella; Campa, Alessandro

    2016-01-01

    We describe a low dose/dose rate gamma irradiation facility (called LIBIS) for in vitro biological systems, for the exposure, inside a CO_2 cell culture incubator, of cells at a dose rate ranging from few μGy/h to some tens of mGy/h. Three different "1"3"7Cs sources are used, depending on the desired dose rate. The sample is irradiated with a gamma ray beam with a dose rate uniformity of at least 92% and a percentage of primary 662 keV photons greater than 80%. LIBIS complies with high safety standards. - Highlights: • A gamma irradiation facility for chronic exposures of cells was set up at the Istituto Superiore di Sanità. • The dose rate uniformity and the percentage of primary 662 keV photons on the sample are greater than 92% and 80%, respectively. • The GEANT4 code was used to design the facility. • Good agreement between simulation and experimental dose rate measurements has been obtained. • The facility will allow to safely investigate different issues about low dose rate effects on cultured cells.

  12. Effects of low-dose continuously fractionated X-ray irradiation on murine peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Xie Yi; Zhang Hong; Dang Bingrong; Hao Jifang; Guo Hongyun; Wang Xiaohu

    2007-01-01

    For estimating biological risks from low doses continual irradiation, we investigated the effects of exposure to continuously fractionated X-rays on murine immune system. The BALB/c mice were irradiated with 0.07Gy at the first day and 0.08 Gy/d in the following 12 days at a dose rate of 0.2 Gy/min. The peripheral blood lymphocyte cycle and death were determined by flow cytometry at the cumulative doses of 0, 0.07, 0.23, 0.39, 0.55, 0.71, 0.87 and 1.03 Gy respectively. The results showed that the cycle of peripheral blood lymphocyte was arrested in G 0 /G 1 at cumulative doses of 0.07, 0.23, 0.71 and 0.87 Gy, and in G 2 /M at cumulative doses of 0.39 and 1.03 Gy; the percentage of death of peripheral blood lymphocyte was ascended with dose increasing, and reached the death peak at cumulative doses of 0.71 Gy. The results suggested that low doses continual X-rays total-body irradiated could result in changes of cellular cycle and death, and some damages to immunocytes, which accorded to linear square model. (authors)

  13. Dose calculation method with 60-cobalt gamma rays in total body irradiation

    International Nuclear Information System (INIS)

    Scaff, Luiz Alberto Malaguti

    2001-01-01

    Physical factors associated to total body irradiation using 60 Co gamma rays beams, were studied in order to develop a calculation method of the dose distribution that could be reproduced in any radiotherapy center with good precision. The method is based on considering total body irradiation as a large and irregular field with heterogeneities. To calculate doses, or doses rates, of each area of interest (head, thorax, thigh, etc.), scattered radiation is determined. It was observed that if dismagnified fields were considered to calculate the scattered radiation, the resulting values could be applied on a projection to the real size to obtain the values for dose rate calculations. In a parallel work it was determined the variation of the dose rate in the air, for the distance of treatment, and for points out of the central axis. This confirm that the use of the inverse square law is not valid. An attenuation curve for a broad beam was also determined in order to allow the use of absorbers. In this work all the adapted formulas for dose rate calculations in several areas of the body are described, as well time/dose templates sheets for total body irradiation. The in vivo dosimetry, proved that either experimental or calculated dose rate values (achieved by the proposed method), did not have significant discrepancies. (author)

  14. Results of film dosemeter control irradiations of German dose measurements services, 1969-1974

    International Nuclear Information System (INIS)

    Gummi, V.; Taubert, R.

    1976-01-01

    The dose measurement services of the FRG have been controlling themselves since 1961 by evaluating film dosimeters irradiated in the PTB under standard conditions. This control method is now embodied in a law by the second decree about the standardization of measuring instruments dt. 6th August 1975. During the time 1969-74 the PTB carried out more than 800 annual control irradiations of film dosimeters. In 30% of the cases the evaluation by the measuring services showed an errory higher than +50%/-30%. The dose measuring services partially diverge considerably concerning the distribution of evaluation errors. Particular difficulties seem to exist in the soft x-ray radiation with effective energies less than 30 keV, in the energy range about 100 keV, and in the evaluation of dosemeter irradiated with two different qualities of radiation (double irradiation). (orig.) [de

  15. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation

    International Nuclear Information System (INIS)

    Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P.

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of γ radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [fr

  16. Dose response of thin-film dosimeters irradiated with 80-120 keV electrons

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; Sharpe, P.

    2005-01-01

    Thin-film dosimeters (Riso B3 and alanine films) were irradiated at 10 MeV and 80-120 keV electron accelerators, and it has been shown that the radiation response of the dosimeter materials (the radiation chemical yields) are constant at these irradiation energies. However, dose gradients within ...... are present within the dosimeter. (C) 2005 Elsevier Ltd. All rights reserved....

  17. Effect of chromic γ-irradiation with small doses on candidiasis development in white rats

    International Nuclear Information System (INIS)

    Berchev, K.; Krushkov, Iv.

    1976-01-01

    Rats continuously exposed to 2 rads/day during eight months (cumulative dose of 400 rads) and nonirradiated rats were infected with a candida cells administered intravenously. All the irradiated animals died ten days after infection while only ten per cent of the control animals died for the same period of time. A morphological study has revealed candidiasis in the irradiated rats; changes, mainly in the kidneys, and formation of candidiasis granulomas have been detected in the control animals

  18. Permanent metabolic stimulation of leaves by low-dose irradiation

    International Nuclear Information System (INIS)

    Barabas, Z.

    1979-01-01

    By X-ray and colchicin treatment male-sterile mutants were produced from the Ra K9 Sorghum species. The characteristics of the mutants are compared with those of the original species. By this means the bisexual plant became unisexual, in later generations even asexual forms of reproduction were observed. This mutation chain is regarded as an artificially induced recapitulation of the natural evolution. Irradiation experiments were carried out in order to obtain wheat types resistant to brownrot, however, no success could be achieved with the present methods. (L.E.)

  19. Irradiation of esophagus carcinoma with small single doses

    International Nuclear Information System (INIS)

    Dalluege, K.H.; Grunau, H.

    1984-01-01

    In a prospective study 30 patients with histologically proved esophagus carcinomas were irradiated after a beginning target dosis of 4.5 Gy with daily 1.8 Gy up to 56.0 Gy, 32.0 Gy of which were applied in a long radiation field. 33% of the patients lived longer than one year. Three patients survived 5 years. Nine of the patients underwent perforation of the esophagus in the tumor area. In 20 autopsies only 3 local tumors were detected. (author)

  20. Overview of Radiosensitivity of Human Tumor Cells to Low-Dose-Rate Irradiation

    International Nuclear Information System (INIS)

    Williams, Jerry R.; Zhang Yonggang; Zhou Haoming; Gridley, Daila S.; Koch, Cameron J.; Slater, James M.; Little, John B.

    2008-01-01

    Purpose: We compared clonogenic survival in 27 human tumor cell lines that vary in genotype after low-dose-rate (LDR) or high-dose rate (HDR) irradiation. We measured susceptibility to LDR-induced redistribution in the cell cycle in eight of these cell lines. Methods and Materials: We measured clonogenic survival after up to 96 hours of LDR (0.25 Gy/h) irradiation. We compared these with clonogenic survival after HDR irradiation (50 Gy/h). Using flow cytometry, we measured LDR-induced redistribution as a function of time during LDR irradiation in eight of these cell lines. Results: Coefficients that describe clonogenic survival after both LDR and HDR irradiation segregate into four radiosensitivity groups that associate with cell genotype: mutant (mut)ATM, wild-type TP53, mutTP53, and an unidentified gene in radioresistant glioma cells. The LDR and HDR radiosensitivity correlates at lower doses (∼2 Gy HDR, ∼6 Gy LDR), but not at higher doses (HDR > 4 Gy; LDR > 6 Gy). The rate of LDR-induced loss of clonogenic survival changes at approximately 24 hours; wild-type TP53 cells become more resistant and mutTP53 cells become more sensitive. Redistribution induced by LDR irradiation also changes at approximately 24 hours. Conclusions: Radiosensitivity of human tumor cells to both LDR and HDR irradiation is genotype dependent. Analysis of coefficients that describe cellular radiosensitivity segregates 27 cell lines into four statistically distinct groups,