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Sample records for 60co gamma-ray irradiation

  1. Qualities of Patin Fishball Irradiated by Gamma Rays (60Co)

    An experiment on patin fishball quality using gamma irradiation (60Co) has been conducted. Samples were irradiated at 0, 1, 3 and 5 kGy and stored in refrigerator at temperature 10 oC for sixty days. Samples were analysed every fifteen days, except content of fat and protein that analysed only at the beginning and the end of storage. The purpose of this experiment is to know the quality changes of patin fishball irradiated during storage, by measuring of chemical (content of fat, protein, water, TVB value, pH value) and microbiology (TPC aerobic and anaerobic bacteria) changes. The results showed that irradiation did not affect macro nutrient contents (content of fat, protein and water) of patin fishball during storage but irradiation can affect TVB and pH values. Irradiation at 1 kGy can reduce one logarithmic cycle of total aerobic and anaerobic bacteria. The storage life of irradiated patin fishball treated at 1, 3 and 5 kGy could be extended up to 15, 30 and 60 days, respectively. Control samples the storage life could be extended less than 15 days. (author)

  2. Biochemical and pharmacological characterization of irradiated crotamine by gamma rays of 60Co

    The serum production in Brazil, the only effective treatment in cases of snakebites, uses horses that although large size, have reduced l lifespan compared with horses not immunized. Ionizing radiation has been shown as an excellent tool in reducing the toxicity of venoms and toxins isolated, and promote the achievement of better immunogens for serum production, and contributing to the welfare of serum-producing animals. It is known, however, that the effects of ionizing radiation on protein are characterized by various chemical modifications, such as fragmentation, cross-linking due to aggregation and oxidation products generated by water radiolysis. However, the action of gamma radiation on toxins is not yet fully understood structurally and pharmacologically, a fact that prevents the application of this methodology in the serum production process. So we proposed in this paper the characterization of crotamine, an important protein from the venom of Crotalus durissus terrificus species, irradiated with 60Co gamma rays. After isolating the toxin by chromatographic techniques and testing to prove the obtaining of pure crotamine, it was irradiated with gamma rays and subjected to structural analysis, Fluorescence and Circular Dichroism. Using high hydrostatic pressure tests were also conducted in order to verify that the conformational changes caused by radiation suffer modifications under high pressures. From the pharmacological point of view, muscle contraction tests were conducted with the objective of limiting the action of crotamine in smooth muscle as well as the change in the action of toxin caused structural changes to the front. Analysis of Circular Dichroism and Fluorescence showed changes in structural conformation of crotamine when subjected to gamma radiation and that such changes possibly occurring in the secondary and tertiary structure of the protein. The observed in pharmacological tests showed that the irradiated crotamine was less effective in

  3. A study on the irradiation effect of 60Co gamma ray on dental polymethylmethacrylate bonded parts

    In this paper we describe an experimental study on the irradiation effect of 60Co gamma ray on dental polymethylmethacrylate (P.M.M.A.) welding part, hot and cold polymerizing adhesion part. It was found that from the result of tension test, no remarkable change of mechanical property is found with any of the bonded parts by the irradiation dose up to 107 r., and no deterioration by irradiation is observed. And then, according to the results of bending test, it is found that, although the three different bonded parts have different features, the strength of the welded part and of the part adhered by hot polymerizing adhesive becomes lower by irradiation, and bending strength of the three parts converges on 6 kg/mm2 after irradiation within a range of 106 - 107 r.. Joint efficiency (= bonded part strength/base material strength) of 65 - 75% in tension and 50 - 62% in bending can be adopted. Fracture of the base material and of the Welded part are similar, and prove high bonding strength. (author)

  4. Study of irradiated bothropstoxin-1 with {sup 60}Co gamma rays: immune system behavior

    Caproni, P.; Baptista, J.A.; Almeida, T.L. de; Nascimento, N. [Nuclear and Energy Research Institute (IPEN/CNEN-SP), SP (Brazil). Biotechnology Center; Passos, L.A.C. [State University of Campinas (UNICAMP), SP (Brazil). Lab. of Genetics and Embryo Cryopreservation

    2009-07-01

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modified antigens with lower toxicity and preserved or improved immunogenicity can be very useful. Ionizing radiation has already been proven to be a powerful tool to attenuate snake venom toxicity without affecting, and even increasing, their immunogenic properties. However, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were analyzed by SDS-PAGE. Isogenic mice were immunized with either the native or the irradiated toxin. The circulating antibodies were isotyped and titrated by ELISA. According to our data, irradiation promoted structural modifications in the toxin characterized by higher molecular weight forms of proteins (aggregates and oligomers). The results also indicated that irradiated toxins were immunogenic and antibodies elicited by them were able to recognize the native toxin in ELISA. These findings suggest that irradiation of toxic proteins can promote significant modifications in their structures; however they still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that irradiated proteins induce higher titers of IgG2a and IgG2b, suggesting that Th1 cells are predominantly involved in the immune response. (author)

  5. Perna perna (LINNAEUS, 1758) mussels irradiated by {sup 60}CO gamma rays cytotoxicity evaluation

    Martini, Gisela A.; Pusceddu, Fabio H.; Rogero, Sizue O.; Rogero, Jose Roberto, E-mail: gisela.martini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to {sup 60}Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  6. Perna perna (LINNAEUS, 1758) mussels irradiated by 60CO gamma rays cytotoxicity evaluation

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to 60Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  7. Evaluation of myotoxic activity of Bothropstoxin-1 irradiated with 60Co gamma rays

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules and has been proven to be a powerful tool to attenuate snake venoms toxicity without affecting their immunogenic properties. Snake venoms and their isolated toxins showed structural modifications after gamma radiation process, in aqueous solution, mainly by water radiolysis sub products. Free radical scavengers, such as NaNO3 and t-butanol, present selective effects on specific radical from water radiolysis. The NaNO3 has affinity by aqueous electron, while the t-butanol has affinity by hydroxyl radical. At the present work, we have investigated the myotoxic activity of Bothropstoxin-1 (BTHX-1), a K49 phospholipase, present in Bothrops jararacussu crude venom, before and after irradiation process, with or without scavenger substances presence. BTHX-1 was irradiated with 2 kGy of 60Co gamma rays, in aqueous solution and in the presence of oxygen. BALB/c mice were inoculated with either native or irradiated toxin, with or without scavenger substances. After 3 hours, blood samples were collected and the myotoxic activity was evaluated by LDH (lactate dehydrogenase) release. The muscular tissue damage was directly related to the LDH amounts released. Irradiated Bothropstoxin-1, with or without NaNO3 substance, caused less damage than their native counterpart. But irradiated toxin, in the presence of t-butanol, was so myotoxic as the native BTHX-1. These results indicate that irradiation of toxic proteins can promote significant modifications on their structures, but still retaining many of the original biological properties of their native counterparts. Additionally, some scavengers substances can change these gamma radiation effects. (author)

  8. Dominant lethal mutation induced by continuous irradiation of 60Co gamma rays in mice

    Female and male mice were exposed to 60Co gamma rays for 10 days, the accumulative doses were 0.396-2.024 and 0.462-2.552 Gy respectively. The number of dominant lethal mutations was calculated as follows: PRE = CL - (ED + LD + VIA). The results showed that Preimplantation Loss (PRE) ranged from 1.222 to 3.714 for female mice and 0.0345 to 2.2308 for male mice. In both cases a linear dose-effect relationship was observed. The PRE of oocytes is 1.66 times higher than that of spermatids

  9. Study on influences of rabbit thyroids irradiated by 60Co-gamma ray

    Effects of radiotherapy on the thyroid gland were evaluated with rabbits. gamma ray of 3.000R was irradiated locally. Thyroid hormone T4 and T3 were assayed by RIA method, blood flow was estimated by sup(99m)Tc-MAA uptake, and histopathological changes were also studied. T4 and T3 markedly decreased one day after irradiation, and a decrease of T4 was greater than that of T3. T4 and T3 continued to decrease until 3 days after irradiation, then, began to increase slowly, 7 days after irradiation, and almost returned to the initial level 14 days after irradiation. T4 kept the level thereafter with little changes, but T3 tended to decrease. sup(99m)Tc uptake decreased sharply one day after irradiation and continued to decrease gradually. It began to increase slowly 28 days after and almost returned to about 2/3 the initial level 56 days after irradiation. Histopathological study revealed no remarkable changes except degeneration and proliferation of follicular epithelium 14 days after irradiation. Changes in T4 and T3 due to decreased thyroid function after irradiation was comparatively parallel to histopathological changes. However, changes in blood flow and those in T4 and T3 were parallel with each other only at the time immediately after irradiation and at the end of the follow-up. This tendency was marked in T4. (Ueda, J.)

  10. Irradiation effect on enzymatic activity of papain with {sup 60}Co-{gamma} rays

    Furuta, Masakazu; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio [Osaka Prefecture Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology

    1998-12-31

    An investigation was made on the durability of enzyme activity against {sup 60}Co-{gamma} irradiation at a dose up to 55 kGy/h using dry powder and aqueous solution of papain preparations on the market. Hybrid materials including bioactive molecules combined with biocompatible synthetic polymers are expected to have biocompatible properties and also biomimetic functions as a component of artificial organs for human body. The activity of papain in an aqueous solution was rapidly decreased at the early stage of irradiation through oxidation of SH group at its active site with active oxygen produced by the irradiation and then, partially recovered since SH group was reproduced in an anoxic state after O{sub 2} consumption in the solution irradiated at a high dose. A usual radiation method for sterilization was found applicable to decontamination of dry and frozen preparations of papain. When suitable conditions for radiation were chosen and N{sub 2} gas was purged to suppress the formation of free radicals, it was possible to keep the enzyme activity at more than 50% of the initial activity after radiation at 30 kGy. (M.N.)

  11. Effect of 60Co gamma-ray irradiation on dilute aqueous solutions of surfactants

    Present work deals with the effects of gamma irradiation from 60Co γ-ray source upon aqueous solutions of three kinds of surfactants. When dilute aqueous solutions of sodium dodecyl sulfate (SDS, anionic), cethyl trimethyl ammonium chloride (CTAC, cationic), and polyoxyethylene lauryl ether (POE, non-ionic) were irradiated with γ-rays at a room temperature, the residual concentration, products, surface tension, and forming power were examined by colorimetric method, IR spectrophotometric method, gaschromatography, Ross-Miles method, and Traube's stalagmometer etc. These surfactants were decomposed by the irradiation and thus the surface tension increased and the forming power, on the contrary, decreased with dose. Radiation chemical yields (G-value) of the degradation were about 1 for the solutions of SDS and CTAC, and about 0.3 for the POE solution. From the experimental results, it was found that following chemical reactions seem to occur followed by the radiolysis of water: a) bond cleavage of ester for SDS, of CN for CTAC, and of oxyethylene for POE, b) hydrogen abstraction from the surfactants, c) production of CO bond in the presence of dissolved oxygen. (auth.)

  12. Chemical changes in the chloroform-paraffin system irradiated by 60Co gamma-rays, 1

    It has been reported that the chloroform-paraffin-dye system have excellent sensitivity for radiation as a solid chemical dosimeter or a phantom. However, the chemical changes in the irradiated system are not examined in detail. In the present study, the effect of paraffin on changes in the above system of a liquid state irradiated by 60Co γ-rays was examined by using various normal paraffin, and the other variable factors on the changes were done. When the chloroform solution and the solution containing 25 per cent of paraffin by volume with 5.0 x 15-5 mol/liter of Methyl Yellow as a dye were irradiated by 2000 R, G values for the formation of hydrogen chloride in the both solutions were 8.4 and 10.8, respectively, and were little affected by the kind of those, from C6 (hexane) to C36 (hexatria-contane). These results suggest that chlorine radical formed by radiolysis of chloroform may react with hydrogen atom from paraffin, thereby increasing the amount of hydrogen chloride. Presence of oxygen increased G value of the chloroform solution from 7.6 to 8.4, but did little that of the solution containing paraffin. (author)

  13. Biochemical and pharmacological characterization of irradiated crotamine by gamma rays of {sup 60}Co; Caracterizacao bioquimica e farmacologica da crotamina irradiada por raios gama de {sup 60}Co

    Oliveira, Karina Corleto

    2014-07-01

    The serum production in Brazil, the only effective treatment in cases of snakebites, uses horses that although large size, have reduced l lifespan compared with horses not immunized. Ionizing radiation has been shown as an excellent tool in reducing the toxicity of venoms and toxins isolated, and promote the achievement of better immunogens for serum production, and contributing to the welfare of serum-producing animals. It is known, however, that the effects of ionizing radiation on protein are characterized by various chemical modifications, such as fragmentation, cross-linking due to aggregation and oxidation products generated by water radiolysis. However, the action of gamma radiation on toxins is not yet fully understood structurally and pharmacologically, a fact that prevents the application of this methodology in the serum production process. So we proposed in this paper the characterization of crotamine, an important protein from the venom of Crotalus durissus terrificus species, irradiated with {sup 60}Co gamma rays. After isolating the toxin by chromatographic techniques and testing to prove the obtaining of pure crotamine, it was irradiated with gamma rays and subjected to structural analysis, Fluorescence and Circular Dichroism. Using high hydrostatic pressure tests were also conducted in order to verify that the conformational changes caused by radiation suffer modifications under high pressures. From the pharmacological point of view, muscle contraction tests were conducted with the objective of limiting the action of crotamine in smooth muscle as well as the change in the action of toxin caused structural changes to the front. Analysis of Circular Dichroism and Fluorescence showed changes in structural conformation of crotamine when subjected to gamma radiation and that such changes possibly occurring in the secondary and tertiary structure of the protein. The observed in pharmacological tests showed that the irradiated crotamine was less effective

  14. Effects of 2.0 Gy of 60Co gamma rays irradiation on rat embryos

    Pregnant rats of Donryu strain were exposed to a whole-body 60Co γ ray irradiation of a single dose of 2.0 Gy (Dose rate: 0.5 Gy/min) on day 7, 8, 9, 10 or 11 of gestation (sperm day = day 0). The rats were sacrificed on day 18 and the offspring were examined for external and visceral malformations. Malformed embryos occurred between days 7 and 11 with the highest incidence occurring on day 9. Dose with 2.0 Gy increased the rate of resorption or death (52.1 %), in the survivors, caused congenital malformation in a majority of embryos (86.5 %) on day 8 of gestation. There is an increase in malformation (93.3 %) and growth retardation, but no increase in mortality (42.9 %) on day 9 of gestation. Relatively few anomalies resulted from irradiation on day 7 of gestation. The peak day for cardiovascular anomalies occurred on day 9 (88.3 % of all survival embryos) with high levels also occurring on day 8 (86.5 %). Cardiovascular anomalies consisted of VSD, hypoplasia of the pulmonary trunk, coarctation of the aorta, double aortic arch, right aortic arch, riding aorta, complete transposition of the aorta, persistent atrioventricular canal, vascular ring, aberrant right subclavian artery and others. Similar anomalies, but at a lower incidence, were produced by 60Co γ ray at dose levels of 2.0 Gy on day 10 or 11 of gestation. Cases of cleft lip and cleft palate or facial cleft were observed seventeen fetuses on day 9 of gestation (31 %). Exencephaly occurred in nine embryos treated on day 9 (16.1 %) and in one embryos treated on day 10. Tail defects appeared with treatment on day 9 with the latter predominating on day 11. The present study show that maximum resorption (52.1 %) was seen with treatment on day 8 whereas the highest rate of malformation (93.3 %) was observed with treatment on day 9. (J.P.N.)

  15. Characteristic evaluation of papain irradiated with {sup 60}Co {gamma}-rays for the purpose of sterilization

    Furuta, Masakazu; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio [Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology

    1998-09-01

    To establish irradiation sterilization method for hybrid biomedical materials containing bioactive molecules together with artificial polymers, we employed dry powder and aqueous solution of papain as a model and examined radiation tolerance with {sup 60}Co {gamma}-rays. The dry powder and frozen aqueous solution showed significant resistance after 30-kGy irradiation, indicating that commercial irradiation sterilization method for disposable medical supplies was applicable. Unfrozen aqueous solutions (10mg/ml), in contrast, showed significant drop of enzymatic activity within the early period of irradiation (ca. 0.5kGy) but 40% of the activity was recovered at ca. 3-kGy before total inactivation at 15kGy. Taking various conditions including dose rate, concentration of enzyme, oxygen and nitrogen bubbling into irradiation inactivation experiments, we demonstrated that inactivation of papain could be controlled under anoxic condition, such as nitrogen bubbling, increasing sample volume at high dose rates and high concentration of enzyme where dissolved oxygen was consumed rapidly. It is suggested that radiation inactivation of papain in the aqueous solution was occurred through reversible oxidation of the sulfhydryl group at the active site by free radicals derived from radiolysis of water and dissolved oxygen. (author)

  16. Structure alteration and immunological properties of {sup 60}Co gamma rays irradiated bothropstoxin-I

    Baptista, Janaina A.; Yonamine, Camila Myiagui; Caproni, Priscila; Casare, Murilo; Spencer, Patrick Jack; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: janabap@gmail.com; Andrade Junior, Heitor Franco de; Vieira, Daniel Perez; Galisteo Junior, Andres Jimenez [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Instituto de Medicina Tropical de Sao Paulo, SP (Brazil). Lab. de Protozoologia

    2007-07-01

    About 20000 ophidic accidents are registered every year in Brazil. Serum therapy with equine antisera is the only efficient treatment. The venoms employed for immunization are fairly toxic and some venoms present low immunogenicity. Thus, the obtention of modified antigens with lower toxicity and preserved or improved immunogenicity would be useful. These toxins, when submitted to gamma radiation, in aqueous solution, present structural modifications. This occurs due to reactions with the radiolysis products of water. Some scavenger substances, such as NaNO{sub 3} and t-butanol, remove selectively the water radiolysis products. Ionizing radiation has proven to be a powerful tool to attenuate snake venoms toxicity without affecting and even increasing their immunogenic properties. However, the immune mechanisms involved in recognition, processing and presentation of irradiated antigens are yet unclear. In the present work, we investigated the immunological behavior of bothropstoxin-I (Bthx-1), before and after irradiation, in the presence of selective scavengers. Isogenic mice were immunized with either the native or the irradiated toxin, either with or without scavengers. After three immunizations, serum samples were collected and the antibody titers and isotypes were determined by Enzyme Linked Immuno Sorbent Assay. The antigenic characterization of native and irradiated bothropstoxin-I was performed by Western blot. The detection of expression of murine cytokines (IFN-{gamma} and IL-10) was analyzed by RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction). According to our data, irradiation process has promoted structural modifications in the toxin, characterized by higher molecular weight forms of the protein (aggregates and oligomers). Our data also indicate that irradiated toxins, alone or in the presence of NaNO{sub 3}, an aqueous electron scavenger, were immunogenic and the antibodies elicited by them were able to recognize the native toxin. On the other

  17. Effect of the irradiation on Salmonella enteretidis var. typhimurium with gamma rays from 60Co

    The use of ionizinf radiation to the destruction of microrganisms responsible for food deterioration, and productive of feeding toxinfections constitute their usefulness for actually peaceful goals of nuclear energy. The feeding toxinfections are, among us, produced in their most part by Salmonella enteritidis var. typhimurim. One hundred nineteen samples of milk containing about 150.000 bacteria per ml, by means doses ranging from 100 to 1.100 gy, two samples of surviving bacteria were again irradiated by doses up to 2.5000 Gy. The bacteria not previously irradiated were throughly killed by means of doses of 1.100 Gy. Salmonella enteritidis var. typhimurium was inactivated by means of 1.200 and 1.900 Gy doses. It was concluded that 60-Cobalt gamma radiation minimal lethal dose to Salmonella enteritidis var. typhimurium is 1.200 Gy; the re-irradiation to the survivors prompts the forthcoming of more resistant germs. (author)

  18. Comparison of base substitutions in response to nitrogen ion implantation and 60Co-gamma ray irradiation in Escherichia coli

    Xie Chuan-Xiao

    2004-01-01

    Full Text Available To identify the specificity of base substitutions, a novel experimental system was established based on rifampicin-resistant (Rif r mutant screening and sequencing of the defined region of the rpoB gene in E. coli. We focused on comparing mutational spectra of base substitutions induced by either low energy nitrogen ion beam implantation or 60Co-gamma rays. The most significant difference in the frequency of specific kinds of mutations induced by low energy nitrogen ion beam was that CG ®TA transitions were significantly increased from 32 to 46, AT ®TA transversions were doubled from 7 to 15 in 50 mutants, respectively. The preferential base substitutions induced by nitrogen ion beam implantation were CG ®TA transitions, AT ®GC transitions, AT ®TA transversions, which account for 92.13% (82/89 of the total. The mutations induced by 60Co-gamma rays were preferentially GC ®AT and AT ®GC transitions, which totaled 84.31% (43/51.

  19. Study of the ionization of alkane-electron scavenger reactant mixtures irradiated by 60Co gamma rays

    This study deals with ionization of alkane-electron scavenger reactant mixtures, irradiated by 60Co γ-rays. It is shown that the extrapolated free-ion yields (extrapolated yield method) decrease with the reactant concentration. On the basis of ONSAGER model and theoretical treatment of MOZUMDER, the cross sections of epithermal electron attachment in hexane, cyclohexane, 2,2-dimethylbutane, cyclopentane, 2,2,4-trimethylpentane for CCl4, C7F14, C6H5Br, C6H5Cl, C6F14, (C6H5)2 are determined. A comparison between gas-phase and liquid-phase cross sections is established

  20. Electrical characteristics of 60Co gamma-ray irradiated pentacene-based organic thin film field effect transistors

    Preliminary studies of the 60Co γ-ray radiation effects on pentacene-based organic thin film transistors (OTFTs) with two kinds of gate insulators have been carried out. Negative threshold voltage shifts of OTFTs with a SiO2 gate insulator are consistent with positive charge trapping, and a rebound effect is observed. Threshold voltage of OTFTs with a polyimide gate insulator continuously decreased with increasing the total dose. When the total dose reached 1200 Gy (Si), the carrier mobility of OTFTs with the SiO2 gate insulator decreased by nearly 80%, while the carrier mobility of OTFTs with the polyimide gate insulator decreased by almost 40%. (author)

  1. Cloning and molecular analysis of GA2ox1 gene mutation generated by gamma-ray 60Co irradiation in mutagenized Tamxoan - TDB06 rice cultivar

    In the present study, we have used various rice cultivars such as Nipponbare, Tamxoan Hai Hau and mutagenized TDB06 which was obtained from Tamxoan Hai Hau calli irradiated by gamma-ray 60Co with the aim of cloning, sequencing and investigating the molecular mutants of GA2ox1 gene which regulates the height of rice cultivars. Interestingly, we have found that the nucleotide sequence of GA2ox1 gene of mutagenized TDB06 is slightly changed compare to that of original Tamxoan Hai Hau and Nipponbare. The GA2ox1 gene sequence differences of mutagenized TDB06 compared to Tamxoan Hai Hau and Nipponbare are 9 and 2 nucleotides, respectively. We have also shown that the amino acid sequence of GA2ox1 protein is also different among various cultivars in which amino acids corresponding to positions 137 (Alanine), 167 (Threonine), 222 (Valine), 227 (Histidin) of mutagenized TDB06 were replaced with other amino acids Valine, Alanine, Arginine and Lysin, respectively. Nucleotide sequences of GA2ox1 gene isolated from mutagenized TDB06 and Tamxoan Hai Hau cultivars have been registered in Genbank/NCBI with accession numbers EF164903 and EF164904. Based on these initial results, we continuously isolate genes related to dwarf character, construct vectors and do transformation. This strategy can significantly contribute to improve efficiency of rice breeding in Vietnam. (author)

  2. Thermoluminescence characteristics of Nd-doped SiO2 optical fibers irradiated with the 60Co gamma rays

    Thermoluminescence (TL) properties (radiation sensitivity, dose response, signal fading) of Nd-doped SiO2 optical fibers irradiated with 1.25 MeV photons to 1–50 Gy were studied. The peak of the glow curve is around 190 °C regardless of the dose. The dose response is linear up to 50 Gy. The radiation sensitivity is 219 nC mg−1 Gy−1. The fiber can be a potential candidate for photon radiotherapy dosimetry due to its high radiation sensitivity, linear dose response in a wide range, slow fading, and high spatial resolution due to the small size of the fiber. - Highlights: • First study of Nd+3 doped optical fibers irradiated by 1250 keV gamma radiation. • Linear response of optical fiber doped with neodymium. • The peak intensity of TL response for 60 Gy is twice that of the 30 Gy. • A potential candidate for photon radiotherapy dosimetry

  3. Chemical changes in the chloroform-paraffin-dye system irradiated with 60Co gamma-rays, 2

    Studies have been carried out on the amount of hydrogen chloride formed by the radiolysis of chloroform in a solid paraffin-chloroform-Methyl Yellow system, and the color changes from yellow to red and absorption energy observed. The amount of hydrogen chloride formed and the intensity of the red color were determined with a pH meter, a spectrophotometer, and a color/ color-difference meter. It was found that the color-difference meter had the most excellent spectral response and sensitivity for measurement of the irradiated sample, and that the color-difference, ΔE, obtained by reflectometry increased proportionally with the increase in the radiation dose throughout a region of 100 -- 5000 R. When a solid sample composed of 1.0 kg paraffin (m.p. 62 -- 640C), 0.74 kg chloroform and 3.4 x 10-3 mol Methyl Yellow was subjected to 1000 R irradiation at 200C, 2.5 x 1014 molecules of hydrogen chloride were formed in 1.0 g of the solid sample with the absorption energy of 5.9 x 1016 eV, 3.2 x 1016 eV of which contributed to chloroform as the absorption energy. (author)

  4. Responses of commercial broiler chicks to 60Co gamma-rays

    A total of 360 chicks of Nichols line at one-day old were used in this study. Within each sex, the chicks were divided into three exposure treatments (non-irradiated, 400 rads and 800 rads). The source of irradiation was 60Co gamma-rays. The results can be summarized as follows: Of the 360 chicks used in this study, only 10 chicks died during the experimental period. Radiation induced a reduction in body weight in both sexes during the growth period. Gamma-rays reduce the feed intake in both sexes. Moreover, the feed conversion ratio for the irradiated chicks was higher than that the non-irradiated birds. While red blood cells and hemoglobin content were higher in the irradiated chicks, white blood cells count and especially lymphocytes did not affect by 60Co gamma-rays. Gamma-rays had no effect on carcass, bone, meat and giblets as fractions of body weight in both sexes. Moreover, meat water content decreased and meat fat content increased in irradiated chicks. The total length and the total weight of the GI tract decreased due to 60Co gamma-rays. The response of the different regions of the GI tract to this rays is different. Moreover, the effect of this radiation on the GI tract is dependent upon the body weight irrespective of the sex. (orig./MG)

  5. Effect of Irradiation of 60CO Gamma Rays on Growth of Garlic (Allium Sativum L) Plants Cv. Lumbu Hijau at Low Land Area

    Garlic originally come from the sub tropical area. In Indonesia, garlic is grown generally in high land area with an altitude between 1000 - 1600 m above sea level. Therefore, the area for growing and producing garlic is limited. Besides, genetic variation of garlic is very narrow since garlic belongs to vegetatively propagated crops. An effort for increasing genetic variation of garlic was done by exposing garlic cloves to gamma rays in order to obtain garlic mutant lines adapted to low land area. Garlic cloves were exposed to different doses of gamma rays 0 (untreated) 2, 4, 6, 8 and 10 Gy at the Centre for Research and Development of Isotope and Radiation Technology. Each dose consisted of 150 garlic cloves. Untreated and irradiated garlic cloves were grown at Bandar Buat Experimental Station (50 m above sea level), Padang, West Sumatera. The experiment was arranged in a randomized block design with three replication. The parameter observed were percentage of grown plants and survival harvested plants, plant height, leaf number, chlorophyll content, number of stomata, plant age, number of cloves per bulbs, fresh, dry weight and diameter of bulbs. The result indicated that the dose of gamma rays 6 Gy is an advantage dose for obtaining well adapted garlic mutant lines in the low land area. (author)

  6. Different gamma ray (60 Co) dose effects on Sorghum genotype germination

    In agriculture, applying irradiation is a very valuable way of obtaining vegetable products for human and animal consumption. Cobalt-60, one of the main sources of gamma-rays, is considered an important tool in plant breeding programs, which have the objective of promoting genetic variability of cultivars with resistance to adverse environments. In this research, the effects of different 60Co doses on germination vigor and seed germination velocity of forage sorghum genotypes were evaluated. The study was carried out at the IPA (Empresa Pernambucana de Pesquisa Agropecuaria) in Recife, Pernambuco, Brazil. The work was installed in germination boxes, following laboratory recommendations. Thus, a experiment involving three sorghum genotypes (IPA 467-4-2, IPA 02-03-01, and Sudan 4202), five 60Co doses (Zero, 150, 300, 350, and 400 Gy), was set up. The sees were irradiated before the beginning of the experiment being exposed to gamma rays from a 60Co-source (cobalt irradiator) at DEN (Nuclear Engineering Department) of the UFPE (Pernambuco Federal University), Brazil. The work also had the objective of evaluating the sorghum genotypes x 60Co dose interaction. The main results obtained showed that the sorghum genotype IPA 02-03-01 presented the greatest values of germination and vigor percentages, and seed germination velocity, when compared to the others evaluated, on 350 and 400 Gy of 60Co doses. (author)

  7. Dosimetric response of united, commercially available CTA foils for 60Co gamma rays

    The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for 60Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for 60Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life. (author)

  8. Treatment of peach seeds with 60Co gamma-rays

    Peach seeds have been treated with gamma-rays during their stratification in February, March and early April to determine the optimal and lethal doses of irradiation. The latter took place at an intensity ranging between 1386 to 1750 r/min in doses of 4, 8, 12, 16, 20 and 24 kR. Untreated seeds have been used for control. The lethal dose (LD100) in irradiation stratified seeds in February and March prove to be about 16 kR. A dose between 4 to 8 kR is found most favourable for irradiation of stratified peach seeds. With raising the doses of irradiation the number of obtained plants declines. The mean height of plants also declines in the initial growth period. Some morphological changes such as shortened internodes, modified leaf shape and size, chlorophyll insufficiency and stopping of growth appear in some plants developing from irradiated seeds. (author)

  9. Activity evaluation from different native or irradiated with 60 Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK2 mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of 60Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  10. Disturbed tooth formation by 60Co-gamma-ray radiation

    The molar of guinea pigs was irradiated with 60Co-#betta# ray for daily observations of the manifestation of disturbed tooth formation by microradiography and the time registration by tetracycline-labelling. Irradiation first injured young blast cells of the dentin in the growth phase, dental pulp cells, and cells of the enamel. The portion composed of injured cells formed a depressed ''constriction'' from the dental pulp side toward the border between the enamel and dentin. The cells of the enamel injured by irradiation in the growth phase later formed a very thin irregular stroma. In contrast, cells in the differentiation or subsequent phase at the time of irradiation and cells probably having started to grow after irradiation proceeded with formation of a normal stroma and calcification. No uniform relation was obtained between the histological staining of the organic stroma of normal or abnormal dentin and calcification. Labelling with tetracycline revealed that the irradiation conditions in the present study provoked hardly any changes in the speed of tooth eruption. (Chiba, N.)

  11. Protective and/or recovering effects of various kinds of chemicals and drugs to the hemopoietic injuries caused by the irradiation of /sup 60/Co. gamma. -rays in the mice

    Kagimoto, Akio

    1987-01-01

    We have injected eleven kinds of chemical substances and drugs intraperitoneally in the male ddN mice, and studied the relative protective and/or recovering effects of them to the hemopoietic injuries caused by the whole body irradiation of 600R of /sup 60/Co ..gamma..-rays. Good radioprotective activity on bone marrow cells in the irradiated mice was found, when we administered AET (S, 2-aminoethylisothiuronium Br. HBr) before irradiation, 5-HTP (5-hydroxytryptophane) in low dosage before irradiation, Glutathione before irradiation, or Serotonin (5-HT; 5-hydroxytryptamine) in high dosage before irradiation. Good radioprotective or recovering activity was observed on the weight of the spleen, by Serotonin in high and low dosage before irradiation, or DBCC (5,6-dimethyl benzimidazolyl cobamide coenzyme; Vitamin B/sub 12/) after irradiation. Positive responses of reticulocytes, erythrocytes, hemoglobin, and hematocrit were obtained in the irradiated mice, when we administered Serotonin in high dosage before irradiation, MET (S-Methyl-l-cysteine sulfoxide) before irradiation, a cocktail of Periactin (Cyproheptadine hydrochloride) and Serotonin before irradiation, MET before and after irradiation or Nucleo (a mixture of products made by degrading yeast-RNA) after irradiation respectively. A good response in leukocyte count was observed when Serotonin in high dosage before irradiation was administered, and in granulocyte count by Serotonin in high dosage before or 5-HTP in low dosage before irradiation. Lymphocyte count was protected or recovered by Serotonin in high dosage before or Nucleo after irradiation. Thrombocyte count was protected by Serotonin in high and low dosage before, Glutathione before, or AET before irradiation.(author).

  12. The radiation effect of 60Co gamma rays on polycarbonate detector

    The irradiation of polymeric materials with ionizing radiation (gamma rays, X rays, accelerated electrons, ion beams) leads to the formation of very reactive intermediates products (excited states, ions and free radicals), which result in rearrangements and/or formation of new bonds. The effects of these reactions are formation of oxidized products, grafts, scission of main chain (degradation) or cross-linking. Often the two processes (degradation - cross- linking) occur simultaneously, and the outcome of the process is determined by a competition between the reactions. Polycarbonate detectors are used as a particle track detector for neutrons and alpha particles detection. This work aims to study the ionizing radiation dose response of polycarbonate samples using spectrophotometric technique. A commercially available polycarbonate was analysed and its dosimetric characteristics were studied: radiation-induced absorption spectra, ambient light, temperature and humidity influence, pre- and post-irradiation stability, reproducibility and dose range useful response. Samples of polycarbonate (3 x 1 cm2) were irradiated with 60Co gamma radiation in free air at electronic equilibrium with absorbed doses between 1 and 95 kGy. When exposed to gamma radiation the polycarbonate detectors undergoes changes in their optical response, the colour variation is used for determining the absorbed dose. A Shimadzu UV- 2101PC spectrophotometer was used for scanning the absorption spectra and measuring the optical density of film detectors irradiated with different radiation doses. Polycarbonate film detector are easy to prepare and to analyse, of good optical quality, inexpensive and of small size. The dosimetric accuracy can be affect by environmental conditions so, the detectors must be stored in appropriate conditions. The reproducibility of the detectors response can be improved by careful monitoring of optical densities before irradiation. The dose response curve presents linear

  13. The radiation effect of 60Co gamma rays on polycarbonate detector

    The irradiation of polymeric materials with ionizing radiation (gamma rays, X rays, accelerated electrons, ion beams) leads to the formation of very reactive intermediates products (excited states, ions and free radicals), which result in rearrangements and/or formation of new bonds. The effects of these reactions are formation of oxidized products, grafts, scission of main chain (degradation) or cross-linking. Often the two processes (degradation - cross- linking) occur simultaneously, and the outcome of the process is determined by a competition between the reactions. Polycarbonate detectors are used as a particle track detector for neutrons and alpha particles detection. This work aims to study the ionizing radiation dose response of polycarbonate samples using spectrophotometric technique. A commercially available polycarbonate was analysed and its dosimetric characteristics were studied: radiation-induced absorption spectra, ambient light, temperature and humidity influence, pre- and post-irradiation stability, reproducibility and dose range useful response. Samples of polycarbonate (3 x 1 cm2) were irradiated with 60Co gamma radiation in free air at electronic equilibrium with absorbed doses between 1 and 95 kGy. When exposed to gamma radiation the polycarbonate detectors undergoes changes in their optical response, the colour variation is used for determining the absorbed dose. A Shimadzu UV-2101PC spectrophotometer was used for scanning the absorption spectra and measuring the optical density of film detectors irradiated with different radiation doses. Polycarbonate film detector are easy to prepare and to analyse, of good optical quality, inexpensive and of small size. The dosimetric accuracy can be affect by environmental conditions so, the detectors must be stored in appropriate conditions. The reproducibility of the detectors response can be improved by careful monitoring of optical densities before irradiation. The dose response curve presents linear

  14. Changes in membrane receptors of B and T human lymphocytes exposed to 60Co gamma rays

    The present report describes the effect of 50 to 2500 rad of 60Co gamma rays on the membrane receptors of B and T lymphocytes. Surface membrane immunoglobulins and Fc receptors were used as markers for B cells, while the formation of rosettes with sheep red blood cells was used as a marker for T cells. The effect of radiation is expressed as the percentage of viable cells that bear membrane receptors. The radiation effects were studied after 2, 24, 36 hr of culture. For B lymphocytes no reduction in SmIg and Fc receptors was seen 2 hr after radiation, whereas a dose-related reduction was observed after 24 and 36 hr. A dose-related inhibition of the ''capping'' of SmIg was observed. For T lymphocytes a reduction of E rosette formation was seen starting 2 hr after irradiation. Electron microscopy of separated B and T cells showed a higher sensitivity of T cells as well as a different structural arrangement of the chromatin as a consequence of radiation damage. These data suggest differentiated behavior of B and T lymphocyte membrane receptors after exposure to radiation

  15. Multistep process of neoplastic transformation of normal human fibroblasts by 60Co gamma rays and Harvey sarcoma viruses

    Namba, M.; Nishitani, K.; Fukushima, F.; Kimoto, T.; Nose, K.

    1986-03-15

    As reported previously (Namba et al., 1985), normal human fibroblasts were transformed by 60Co gamma-ray irradiation into immortal cells with abnormal karyotypes. These transformed cells (KMST-6), however, showed a low cloning efficiency in soft agar and no transplantability. However, upon treatment with Harvey murine sarcoma virus (Ha-MSV), the cells acquired elevated clonability in soft agar and transplantability in nude mice. Ha-MSV alone, however, did not convert normal human fibroblasts into either immortal or tumorigenic cells. The Ha-MSV-transformed KMST-6 cells showed an enhanced expression of the ras oncogene, but normal and 60Co gamma-ray-transformed cells did not. Our current data suggest that gamma rays worked against normal human cells as an initiator, giving rise to chromosome aberrations and immortality, and that Ha-MSV, probably through its ras oncogene, played a role in the progression of the malignant cell population to a more malignant one showing enhanced colony formation in soft agar and tumorigenicity in nude mice.

  16. INCASoy-36: soybean variety obtained in Cuba after the induction of mutations with 60Co gamma rays

    INCASoy-36 variety was obtained after irradiating seeds from INCASoy-15 at doses of 240 Gy 60Co gamma rays. This variety is adapted to summer and winter seedings; however, it can also be used in spring. Besides, its yields can reach up to 3,5-4,0 t.ha-1 grains in summer and spring seedings. It is tolerant to the main pests and diseases; it is especially resistant to Meloidogyne incognita attacks. During the adverse spring season, seeds have been damage tolerant. It can assure high productions with low inputs; therefore, it is feasible to Cuban agriculture. (Author)

  17. Characterization and performance study of high-dose 60Co gamma-ray calibration laboratory for radiation processing

    The 60Co gamma-ray irradiation facility for high absorbed dose calibration at radiation processing dose level was originally designed and constructed in JAERI. Uncertainty in absorbed dose given at JAERI was estimated by reviewing its characteristics and dosimetry performance. Dosimeter calibration equipment consists of the two plaque 60Co gamma-ray radiation sources giving different dose rate range of 5-200 Gy/h and 400 Gy/h-20 kGy/h, a dosimeter holder stage with high-reproducible positioning, a parallel-plate ionization chamber for accurate measurement of exposure-rates, and an auxiliary temperature/humidity-controlled irradiation vessel for dosimeter calibration under specific irradiation condition. The characteristics of the irradiation field and dosimetry performance are sufficient to give a known dose to working dosimeters to be calibrated for absorbed doses in the range of 0.5 Gy to 160 kGy within a reasonable operation time, 8 h, with an uncertainty of ±2.2% at a 95% confidence level. Calibration of dosimeters giving known doses by transfer dosimetry employing alanine dosimeters calibrated at JAERI is also achievable with an uncertainty of ±3.4% at a 95% confidence level. (author)

  18. Analysis of 60Co gamma-ray transport through air by discrete-ordinates transport codes

    An assessment of the calculational accuracy of the discrete-ordinates codes, PALLAS-2DCY and DOT-III, has been performed for gamma-ray transport through air from a 60Co point isotropic source. The first collision source technique was used in the calculations. The results were compared with the measured exposure dose rates near the ground surface. Also, the ratio of the dose rates by gamma rays incident on and reflected from the ground was compared between the calculations. In addition, the calculated angular fluxes were examined. It is shown that the use of a truncated Legendre polynomial expansion implemented on DOT-III is not sufficient for calculations of gamma-ray scattering in air, while the direct application of the Klein-Nishina formula on PALLAS-2DCY is adequate to the calculatons. Both two-dimensional tranport codes, however, are useful for calculating the gamma-ray transport through air with a practical accuracy. PALLAS-2DCY requires one-fifth the central processor unit time as DOT-III

  19. Investigations on Pasteurization of Cold Marinades by 60Co Gamma Rays

    Marinated herring fillets are a fish product matured under the action of acetic acid and salt and marketed in a spiced brine containing about 3% salt and acetic acid (pH 4). Since the usual addition of the preservative hexamethylene-tetramine has been restricted to a limited period of time by the new German food law, investigations were made on pasteurization by means of ionizing rays, as a new method of preservation without the addition of other preservatives. Decay of this food product was caused by heterofermentative lactic-acid bacteria, which decarboxy- lated the amino acids set free from the protein; the decay was a result of carbon dioxide bombardment. The marinades were packed into flat tins holding about 125 g, and exposed to 60Co gamma rays from an under-water source, while being cooled. The shelf life of the tinned marinades was extended by the irradiation. The period up to bombardment at 15°C was three times as long as usual in cases of irradiation with 155 krad. The critical number of 1 million germs per ml at 15°C was also reached after a period three times as long as usual upon irradiation with 160 krad. The LD99 of three isolated strains of lactic-acid bacteria irradiated in a salt-peptone solution was 113, 165 and 144 krad, respectively. Since at 15°C the growth of the germs is retarded, while at 20°C it is practically unrestrained, the period of durability at a storage temperature of 18°C could only be doubled by irradiation with 280 krad. The organoleptic tests were based on preference analyses by means of the nine-step Hedonic scale, and on difference tests (triangle test) and were performed by a paneli At 70 kràd the taste is still acceptable at 140 krad there is a distinct taste of rays and at 280 krad the taste is disagreeable. A distinct improvement in taste is achieved by irradiation at low temperatures (-30°C) and by the addition of ascorbic acid, sorbitol and spices. The experiments are being continued. (author)

  20. Inactivation of citrus tristeza virus by gamma ray irradiation

    The total exposure of gamma ray and the intensity of gamma ray per hour for the inactivation of citrus tristeza virus (CTV) and also the effect on citrus tissues are described. The budwoods of Morita navel orange infected with a severe seedling-yellow strain of CTV were irradiated with gamma ray from a 60Co source for 20 -- 52 hours. The buds or small tissue pieces of the irradiated budwoods were subsequently grafted onto Mexcan lime. CTV was easily inactivated by the irradiation from 10 to 18 kR for from 20 to 52 hours. The higher the total exposure, the higher the rate of inactivation. The CTV in the budwoods was almost inactivated after the irradiation with 20 kR. When the total exposure to gamma ray on budwoods was the same, CTV was more efficiently inactivated by the irradiation for long period with low intensity of gamma ray per hour than that for short period with high intensity per hour. Gamma ray irradiation was effective to eliminate CTV from citrus tissues. (Mori, K.)

  1. Determination of late-time Gamma-Ray (60Co) sensitivity of single diffusion Lot 2N2222A transistors.

    DePriest, Kendall Russell; Kajder, Karen C.; Peters, Curtis D. (American Staff Augmentation Providers, LLC, Albuquerque, NM)

    2008-08-01

    Sandia National Laboratories (SNL) has embarked on a program to develop a methodology to use damage relations techniques (alternative experimental facilities, modeling, and simulation) to understand the time-dependent effects in transistors (and integrated circuits) caused by neutron irradiations in the Sandia Pulse Reactor-III (SPR-III) facility. The development of these damage equivalence techniques is necessary since SPR-III was shutdown in late 2006. As part of this effort, the late time {gamma}-ray sensitivity of a single diffusion lot of 2N2222A transistors has been characterized using one of the {sup 60}Co irradiation cells at the SNL Gamma Irradiation Facility (GIF). This report summarizes the results of the experiments performed at the GIF.

  2. Study on the viability of peach and apple pollen treated with gamma rays 60Co

    Pollen from Marygold peach and from Golden Delicious apple varieties was treated with gamma-rays at rates of 0.5, 1.5, 10.0, 50.0, 100, 200, 300, 400 and 500 kR, the irradiation intensity being 1350 r/min. Results point to a different influence of gamma-rays irradiation on the pollen germination. Apple pollen proved more radiosensitive. Least dose of o.5 kR exerted a stimulative effect in the pollen germination. As the irradiation dose rcse, the germination percentage declined. Doses of over 400 kR destroyed completely pollen viability in both fruit species. A linear semi-logarithmical dependence was ascertained between the irradiation rate and pollen germination. 5 and 10 kR proved most suitable for the purposes of the experimental mutagenesis at peach and apple pollen irradiation. (author)

  3. Radiation quality of tritium: A comparison with 60Co gamma rays

    In a previous study, microdosimetric simulations were performed for tritium uniformly distributed in a medium, and for tritium bound to biologically critical sites of dimensions from 10 nm to 2 μm. Results of local energy density, i.e. energy deposition in microscopic regions, are different for these two cases. Based on the spatial distribution of energy deposition, dose mean lineal energies are calculated for tritium in the forms of tritiated water (HTO) and organically bound tritium (OBT). The dose mean lineal energies of OBT are about a factor of 1.7 higher than those of HTO in a wide range of target dimensions of biological interest. The results are consistent with radiobiological findings that OBT is about twice as effective as HTO. In this study, the same calculations were performed for 60Co gamma rays in a wide range of target dimensions of biological interest (10 nm to 2 μm). Compared with 60Co gamma rays, the estimated relative biological effectiveness could vary from 1.3 to 3.5 for HTO, and 2.3 to 5.6 for OBT. The results are consistent with radiobiological findings for various biological endpoints in different biological systems that OBT is about twice as effective as HTO. (authors)

  4. Microstructural study of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x}/Ag samples irradiated with {sup 60}Co {gamma} rays at high doses

    Rangel, R. [Programa de Postgrado en Fisica de Materiales, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Apartado Postal 2681, CP 22800, Ensenada, BC (Mexico); Galvan, D.H. [CECIMAC-UNAM, Apartado Postal 2681, CP 22800, Ensenada, BC (Mexico); Adem, E. [Instituto de Fisica-UNAM, Apartado Postal 20-364, CP 01000, Mexico DF (Mexico); Bartolo-Perez, P. [CINVESTAV-IPN Unidad Merida, Departamento de Fisica Aplicada, Merida, Yucatan (Mexico); Maple, M.B. [Physics Department and Institute for Pure and Applied Physical Sciences, La Jolla, CA (United States)

    1998-06-01

    We have investigated the damage induced by irradiation in Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x} silver added samples. The samples were prepared with 0 and 6.5 wt% of silver and irradiated by high-energy {gamma} irradiation (50-150 Mrad). The roles of silver and dosage irradiation are discussed in terms of their effects on microstructure, crystallinity, critical temperature (T{sub c}) and zero-resistance temperature (T{sub 0}). After irradiation, T{sub c} decreased while the room-temperature electrical resistance increased by a factor of 8 for some of the samples. The difference in T{sub 0} between irradiated and non-irradiated YBCO samples was of the order of 10 K. We have found that the difference is bigger for silver-added samples. We have also observed several changes in diffraction patterns of YBCO and YBCO-silver samples. SEM images, EDS and XPS analysis showed that silver resided inside the grains as single atoms and as metallic clusters. The relative concentrations of the elements in samples were quantified by Auger electron spectroscopy. The values showed a gradual increase for radiation doses ranging between 0 and 100 Mrad. For doses up to 100 Mrad, J{sub c} decreased because of the weak-link breakage induced by high doses of {gamma} rays. (author)

  5. Influence of gamma ray irradiation on metakaolin based sodium geopolymer

    Effects of gamma irradiation on metakaolin based Na-geopolymer have been investigated by external irradiation. The experiments were carried out in a gamma irradiator with 60Co sources up to 1000 kGy. Various Na-geopolymer with three H2O/Na2O ratios have been studied in terms of hydrogen radiolytic yield. The results show that hydrogen production increases linearly with water content. Gamma irradiation effects on Na-geopolymer microstructure have been investigated with porosity measurements and X-ray pair distribution function analysis. A change of pore size distribution and a structural relaxation have been found after gamma ray irradiation

  6. Effect of ethanolic extract of propolis on cell viability of chinese hamster ovary cells (CHO-K1) irradiated with 60CO gamma-rays using differential staining technique

    The objective of present study was to assess the effect of Brazilian propolis (AF-08) on CHO-K1 cells irradiated with 60Co, through the differential staining technique, using acridine orange and ethidium bromide. The cells were pre-incubated with different concentrations of propolis (50, 100 and 200 μg/mL) for 24h and irradiated with 5 Gy, analyzed at 24 and 48h after exposure. This technique is based on the cell capacity to incorporate fluorescent DNA dyes, where the viable (green), apoptotic (orange/yellow) and necrotic (red) cells can be identified through fluorescence microscopy. Digital high-resolution images were acquired from at least 5 visualization fields, and cells were analyzed using ImageJ and Flowing software. This approach permitted to analyze a large number of cells/sample with the time reduction, much easier and faster, proportioning more statistical power of the technique. The treatment with propolis only was not cytotoxic at 24 and 48h, except for the higher concentration of 200 μg/mL associated or not with radiation, increasing apoptotic and mainly necrotic cells (p<0.001). The data showed a promising use of propolis as well as technique used, pointing out that 200 μg/mL of propolis was cytotoxic, but at lower one (50 μg/mL) presented a radioprotective effect in irradiated CHO-K1 cells. (author)

  7. Effect of ethanolic extract of propolis on cell viability of chinese hamster ovary cells (CHO-K1) irradiated with {sup 60}CO gamma-rays using differential staining technique

    Castro, Marcos P.M. de; Castro, Renato F. de; Okazaki, Kayo; Vieira, Daniel P., E-mail: dpvieira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of present study was to assess the effect of Brazilian propolis (AF-08) on CHO-K1 cells irradiated with {sup 60}Co, through the differential staining technique, using acridine orange and ethidium bromide. The cells were pre-incubated with different concentrations of propolis (50, 100 and 200 μg/mL) for 24h and irradiated with 5 Gy, analyzed at 24 and 48h after exposure. This technique is based on the cell capacity to incorporate fluorescent DNA dyes, where the viable (green), apoptotic (orange/yellow) and necrotic (red) cells can be identified through fluorescence microscopy. Digital high-resolution images were acquired from at least 5 visualization fields, and cells were analyzed using ImageJ and Flowing software. This approach permitted to analyze a large number of cells/sample with the time reduction, much easier and faster, proportioning more statistical power of the technique. The treatment with propolis only was not cytotoxic at 24 and 48h, except for the higher concentration of 200 μg/mL associated or not with radiation, increasing apoptotic and mainly necrotic cells (p<0.001). The data showed a promising use of propolis as well as technique used, pointing out that 200 μg/mL of propolis was cytotoxic, but at lower one (50 μg/mL) presented a radioprotective effect in irradiated CHO-K1 cells. (author)

  8. Molecular analysis of 60Co gamma-ray-induced mutation at HPRT locus in human promyelocyte leukemia cells

    Objective: To explore the spectra and mechanism of human HPRT gene mutation induced by 60Co γ-rays and its relation with anti-tumor effect of radiation. Methods: Single cell clone culturing, two-way screening count, multiplex PCR amplification and electrophoresis technique were used. Results: (1) When doses were increasing, cell plating efficiency reduced and mutation frequency increased. (2) The most frequent spontaneous mutations were point mutation (92.3%) and gamma-ray-induced mutation, including mainly partial deletion and point mutation (61.7% and 38.3%, respectively). (3) There were deletion mutations in all 9 exons of HPRT gene and the most of gamma-ray-induced mutations were chain deletion with multiplex exons (97.9%). Conclusion: The spectra of spontaneous and gamma-ray-induced mutants were different. The bigger changes in genetic structure are related to the antitumor mechanism of radiation

  9. Activity evaluation from different native or irradiated with {sup 60} Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis; Avaliacao da atividade de diferentes venenos de serpentes, nativos ou irradiados, com radiacao gama de {sup 60} Co, quanto ao poder inibitorio do crescimento de Leishmania (Leishmania) amazonensis

    Lourenco, Cecilia de Oliveira

    2000-07-01

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK{sub 2} mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of {sup 60}Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  10. Thermoluminescence of Simulated Interstellar Matter after Gamma-ray Irradiation

    Koike, K; Koike, C; Okada, M; Chihara, H

    2002-01-01

    Interstellar matter is known to be strongly irradiated by radiation and several types of cosmic ray particles. Simulated interstellar matter, such as forsterite $\\rm Mg_{2}SiO_{4}$, enstatite $\\rm MgSiO_{3}$ and magnesite $\\rm MgCO_{3}$ has been irradiated with the $\\rm ^{60}Co$ gamma-rays in liquid nitrogen, and also irradiated with fast neutrons at 10 K and 70 K by making use of the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL. Maximum fast neutron dose is $10^{17}n_f{\\rm /cm^{2}}$). After irradiation, samples are stored in liquid nitrogen for several months to allow the decay of induced radioactivity. We measured the luminescence spectra of the gamma ray irradiated samples during warming to 370K using a spectrophotometer. For the forsterite and magnesite, the spectra exhibit a rather intense peak at about 645 -- 655 nm and 660 nm respectively, whereas luminescence scarcely appeared in olivine sample. The spectra of forsterite is very similar to the ERE of the Red Rectangle.

  11. Development of irradiator {sup 60}Co sources

    Mosca, Rodrigo C.; Moura, Eduardo S.; Zeituni, Carlos A.; Mathor, Monica B., E-mail: rcmosca@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    According to a recent report by the International Agency for Research on Cancer (IARC) / WHO (2008-2010), the global impact of cancer more than doubled in 30 years. In this report, it was estimated that occurred about 12 million new cancer cases and 7 million deaths. In Brazil in 2010, with estimates for the year 2011, point to the occurrence of 489,270 new cases of cancer. Among the possibilities for cancer treatment, radiotherapy is one of the most important therapeutic and resources used to combat it. However, inherent complications of treatment can occur such as tiredness, loss of appetite, radiodermatitis and in more extreme cases late radionecrosis. In order to reproduce a point of radionecrosis in the vicinity of radiodermatitis to mimic these effects in animals, producing a model for assessment of tissue repair, we propose the setting up of an irradiator source of collimated {sup 60}Co. The development of was based on 11 sources of {sup 60}Co with 1 mm thickness that were inserted by inference in stainless steel 'gate-source' screw (patent pending) and later adjusted in a cross-shaped arrangement reinforced so that the beam radiation is directed to a target point, saving for other regions around this target point. The main use of this irradiator with sources of {sup 60}Co is just one cause radionecrosis point (target point) of approximately 5 mm{sup 2} with a surrounding and adjacent area of radiodermatitis around about 8 to 10 mm{sup 2} in laboratory animals for subsequent coating with epidermal-dermal matrix populated by a cell culture of human fibroblasts, keratinocytes and mesenchymal stem cells. With that said, its use will be valuable for evaluation of curative treatments against the bone and radionecrosis or palliative treatment rather than as it is currently assumed. (author)

  12. Development of irradiator 60Co sources

    According to a recent report by the International Agency for Research on Cancer (IARC) / WHO (2008-2010), the global impact of cancer more than doubled in 30 years. In this report, it was estimated that occurred about 12 million new cancer cases and 7 million deaths. In Brazil in 2010, with estimates for the year 2011, point to the occurrence of 489,270 new cases of cancer. Among the possibilities for cancer treatment, radiotherapy is one of the most important therapeutic and resources used to combat it. However, inherent complications of treatment can occur such as tiredness, loss of appetite, radiodermatitis and in more extreme cases late radionecrosis. In order to reproduce a point of radionecrosis in the vicinity of radiodermatitis to mimic these effects in animals, producing a model for assessment of tissue repair, we propose the setting up of an irradiator source of collimated 60Co. The development of was based on 11 sources of 60Co with 1 mm thickness that were inserted by inference in stainless steel 'gate-source' screw (patent pending) and later adjusted in a cross-shaped arrangement reinforced so that the beam radiation is directed to a target point, saving for other regions around this target point. The main use of this irradiator with sources of 60Co is just one cause radionecrosis point (target point) of approximately 5 mm2 with a surrounding and adjacent area of radiodermatitis around about 8 to 10 mm2 in laboratory animals for subsequent coating with epidermal-dermal matrix populated by a cell culture of human fibroblasts, keratinocytes and mesenchymal stem cells. With that said, its use will be valuable for evaluation of curative treatments against the bone and radionecrosis or palliative treatment rather than as it is currently assumed. (author)

  13. Effects of seed treatment with 60Co gamma rays and micronutrients on germination and growth of corn seedlings

    Gamma irradiation and soaking in solutions of some micronutrient elements, as presowing treatments of corn seeds, towards improving the germination of seeds, and increasing the growth of seedlings were investigated. The seeds were exposed to 12 irradiation doses of gamma rays ranging from 250-8000R. It was found that stimulatory effects on the germination percentage and capacity of seeds as well as the height and the dry weight of seedlings were exerted only by the low irradiation doses from 500-1000 R. Soaking cornseeds, before sowing, in any of the 4 concentrations ranging from 250-1000 ppm of molybdenum, manganese and zinc indicated that molybdenum treatment increased plant height the dry weight of seedlings; 500 ppm molybdenum gave the best effect. Irradiation of 500 ppm molybdenum soaked seeds with low doses of gamma rays stimulated the germination process and early growth of seedlings, with the 500 R dose being most effective. (author)

  14. A commercial gamma-ray irradiation plant in Japan

    In 1973, a commercial gamma-ray irradiation plant was constructed in Takasaki, about 100 km north of Tokyo. The plant has been used for both production of irradiated commercial products and irradiation services. The irradiation services are being made available for sterilization of both medical appliances such as disposable medical syringes, catheters, surgical sutures, and sterilization of feed stuffs for animals. Treatment of plastic materials and colouring of both crystals and glass wares are also undertaken. This facility can accommodate 600 kCi of 60Co and has a monthly treating capacity of 12,000 packages ( a standard carton of 340 mm x 400 mm x 500 mm) at an irradiation dose of 1 Mrad/hr. A receiving port for packages is on the second floor and the outlet of the irradiated packages on the first floor, with three lines of connecting loop conveyors between them, and the irradiation compartment in the center section. The space arrangement of the facility is well designed and gravity can be utilized for the transportation of the packages. Polymer impregnated coral is put on the market for ornamental building material on an order contract basis. (author)

  15. Gamma-ray spectroscopy on irradiated fuel rods

    The recording of gamma-ray spectra along an irradiated fuel rod allows the fission products to be qualitatively and quantitatively examined. Among all nondestructive examinations performed on irradiated fuel rods by gamma-ray spectroscopy, the most comprehensive one is the average burnup measurement, which is quantitative. Moreover, burnup measurements by means of gamma-ray spectroscopy are less time-consuming and waste-generating than burnup measurements by radiochemical, destructive methods. This work presents the theoretical foundations and experimental techniques necessary to measure, using nondestructive gamma-ray spectroscopy, the average burnup of irradiated fuel rods in a laboratory equipped with hot cells. (author)

  16. An investigation on the radiation sensitivity of DNA conformations to 60Co gamma rays by using Geant4 toolkit

    To investigate the impact of conformational properties of genetic material of living cells on radiation-induced DNA damage, single strand breaks (SSB), double strand breaks (DSB) and some microdosimetric quantities of A, B and Z-DNA conformations caused by 60Co gamma rays, have been calculated. Based on a previous B-DNA geometrical model, models of A and Z forms have been developed. Simple 34 base pairs segments of each model repeated in high number and secondary electron spectrum of 60Co gamma rays have been simulated in a volume of a typical animal cell nucleus. All simulations in this study have been performed by using the Geant4 (GEometry ANd Tracking 4)-DNA extension of the Geant4 toolkit. The results showed that, B-DNA has the lowest yield of simple strand breaks with 2.23 × 10−10 Gy−1 Da−1 and 1.0 × 10−11 Gy−1 Da−1 for the SSB and DSB damage yield, respectively. The A-DNA has the highest SSB yield with 3.59 × 10−10 Gy−1 Da−1 and the Z-DNA has the highest DSB yields with 1.8 × 10−11 Gy−1 Da−1. It has been concluded that there is a direct correlation between the hit probability, mean specific imparted energy and SSB yield in each model of DNA. Moreover, there is a direct correlation between the DSB yield and both the mean lineal energy and topological characteristics of each model

  17. An investigation on the radiation sensitivity of DNA conformations to {sup 60}Co gamma rays by using Geant4 toolkit

    Semsarha, F. [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Goliaei, B., E-mail: goliaei@ibb.ut.ac.ir [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Raisali, G.; Khalafi, H. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Mirzakhanian, L. [Medical Physics Unit, McGill University, 1650 Cedar Avenue, Montreal, Quebec (Canada)

    2014-03-15

    To investigate the impact of conformational properties of genetic material of living cells on radiation-induced DNA damage, single strand breaks (SSB), double strand breaks (DSB) and some microdosimetric quantities of A, B and Z-DNA conformations caused by {sup 60}Co gamma rays, have been calculated. Based on a previous B-DNA geometrical model, models of A and Z forms have been developed. Simple 34 base pairs segments of each model repeated in high number and secondary electron spectrum of {sup 60}Co gamma rays have been simulated in a volume of a typical animal cell nucleus. All simulations in this study have been performed by using the Geant4 (GEometry ANd Tracking 4)-DNA extension of the Geant4 toolkit. The results showed that, B-DNA has the lowest yield of simple strand breaks with 2.23 × 10{sup −10} Gy{sup −1} Da{sup −1} and 1.0 × 10{sup −11} Gy{sup −1} Da{sup −1} for the SSB and DSB damage yield, respectively. The A-DNA has the highest SSB yield with 3.59 × 10{sup −10} Gy{sup −1} Da{sup −1} and the Z-DNA has the highest DSB yields with 1.8 × 10{sup −11} Gy{sup −1} Da{sup −1}. It has been concluded that there is a direct correlation between the hit probability, mean specific imparted energy and SSB yield in each model of DNA. Moreover, there is a direct correlation between the DSB yield and both the mean lineal energy and topological characteristics of each model.

  18. Gamma ray irradiation for sludge solubilization and biological nitrogen removal

    This study was conducted to investigate the effects of gamma ray irradiation on the solubilization of waste sewage sludge. The recovery of an organic carbon source from sewage sludge by gamma ray irradiation was also studied. The gamma ray irradiation showed effective sludge solubilization efficiencies. Both soluble chemical oxygen demand (SCOD) and biochemical oxygen demand (BOD5) increased by gamma ray irradiation. The feasibility of the solubilized sludge carbon source for a biological nitrogen removal was also investigated. A modified continuous bioreactor (MLE process) for a denitrification was operated for 20 days by using synthetic wastewater. It can be concluded that the gamma ray irradiation was useful for the solubilization of sludge and the recovery of carbon source from the waste sewage sludge for biological nitrogen removal. - Research highlights: → This study was conducted to investigate the effects of gamma ray irradiation on the solubilization of waste sewagesludge. → The recovery of an organic carbon source from sewage sludge by gamma ray irradiation was also studied. → It can be concluded that the gamma ray irradiation was useful for the solubilization of sludge and the recovery of carbon source from the waste sewage sludge for biological nitrogen removal.

  19. Gamma-ray Irradiation Induces Useful Morphological Variation in Bermudagrass

    Songul SEVER MUTLU

    2015-12-01

    Full Text Available Bermudagrass, Cynodon dactylon (L. Pers. is a widely used warm-season turfgrass species in warmer regions of the world. Gamma (ɣ irradiation has been used to generate useful variations in turfgrass breeding for various morphological traits. The objective of the present study was to measure and determine variations in morphology and turfgrass characteristics of a native drought resistant bermudagrass germplasm irradiated with 70, 90 or 110 Gy using a 60Co source. The stolons containing a single node were irradiated and immediately planted for regeneration in a greenhouse at the Akdeniz University, Antalya, Turkey. Selected mutants regenerated from the irradiated stolons were clonally propagated and transplanted into plastic pots for further observations of turfgrass characteristics.  Survival rates of stolons exposed to 70, 90 and 110 Gy were 76%, 43% and 17% respectively, 6 weeks after treatment. Dosages of 85 and 57 Gy were determined as LD50 and LD20 for the cuttings, respectively. The linear reduction of survival rate with increasing gamma-rays was highly correlated (r2=0.99. A total of four mutant lines (0.3 % of the irradiated plants showed a distinct dwarfed growth habit. Three of these lines were originated from 70 Gy and one from 110 Gy. These mutant lines exhibited more dwarf growth habit, higher shoot density, finer leaf texture than parental genotype. Mutant lines developed in this study can be used for the development of improved bermudagrass cultivars for landscaping and sports turf.

  20. Displacement correction factor versus effective point of measurement in depth dose curve measurements at 60Co gamma rays

    The discrepancies in data sets of values of the Displacement Factor pd recommended by different codes of practices for calibration purpose still demand further investigation to clarify this point. In this paper, we propose an experimental method to determine the displacement factor for cylindrical ionization chambers (thimble chambers) in photon beams. Measurements of pd for several depths were performed for 60Co gamma rays. From these results we calculated the shift of the effective point of measurement (z-zeff) for different depths. The results obtained in this work shown: (a) there is no significant change in pd from 2 cm to 17 cm of depth in water; (b) the value of pd for a ion-chamber Farmer type (inner radius r = 3.15 cm) is pd 0.988; (c) the shift of the effective point of measurement has a smooth variation with depth; (d) the value of (z-zeff) at the recommended calibration depth for 60Co beams (5 cm) is 0.6r (with r: inner radius of the chamber). The result (b) confirms the value of pd suggested by the SEFM and NACP protocols and differs with that of the AAPM. The value obtained for (z - zeff) (d) is very closed to that recommended by the IAEA TRS-277. Finally, the results (a) and (c) suggest that it should be preferable to use the displacement factor instead of effective point of measurement to perform measurements of depth dose curves, since the use of zeff should take into account its dependence on depth. (author). 7 refs, 4 figs

  1. Effect of gamma ray irradiation on sodium borate single crystals

    Kalidasan, M.; Asokan, K.; Baskar, K.; Dhanasekaran, R.

    2015-12-01

    In this work, the effects of 5 kGy, 10 kGy and 20 kGy doses of gamma ray irradiation on sodium borate, Na2[B4O5(OH)4]·(H2O)8 single crystals have been studied. Initially these crystals were grown by solution growth technique and identified as monoclinic using X-ray diffraction analysis. X-ray rocking curves confirm the formation of crystalline defects due to gamma rays in sodium borate single crystals. The electron paramagnetic resonance spectra have been recorded to identify the radicals created due to gamma ray irradiation in sodium borate single crystals. The thermoluminescence glow curves due to the defects created by gamma rays in this crystal have been observed and their kinetic parameters were calculated using Chen's peak shape method. The optical absorption increases and photoluminescence spectral intensity decreases for 5 kGy and 20 kGy doses gamma ray irradiated crystals compared to pristine and 10 kGy dose irradiated one. The effect of various doses of gamma rays on vibrational modes of the sodium borate single crystals was studied using FT-Raman and ATR-FTIR spectral analysis. The dielectric permittivity, conductance and dielectric loss versus frequency graphs of these crystals have been analyzed to know the effect of gamma ray irradiation on these parameters.

  2. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages

    The purpose was to investigate the uptake and endocytosis of 2000 Gy 60Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy 60 Co γ-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays (60 Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  3. Effect of gamma-ray and electron irradiation on the response of solid-state track detectors

    Specimens of muscovite mica were first exposed to fission fragments and then to various gamma-ray fields from a 60Co source ranging from 1.9 x 103 to 1.6 x 104 Mrad dose. The results show that the average etched width of fission-fragment tracks decreases with increasing gamma-ray dose. Shallow pits were observed in etched specimens when the gamma-ray dose exceeded 5 x 103 Mrad. Numerous shallow etch pits caused by the gamma-ray irradiation interfered with the observation of fission tracks in the specimens. No shallow etch pits were observed in the specimen annealed for 100 min at 6000C before the gamma-ray irradiation. Pre-annealing extends the ''safety limits'' of gamma background below which muscovite mica can be used to observe fission tracks without any gamma-ray interference. Gamma-ray and electron irradiation caused significant increase of the resistance to thermal decomposition of muscovite mica. The resistance increased markedly in the dose range from 5 x 103 to 8 x 103 Mrad. These phenomena suggest the use of mica to assess radiation doses of gamma rays and electrons up to several thousand megarads. (author)

  4. Pagure 60Co panoramic irradiation facility

    After a description of the various parts of 'PAGURE', a 10 KCi panoramic irradiation facility, and of the operations data, a critic scrutiny is given. From the experience of five years operations, working of the facility can be thought of very satisfying. From the point of view of standardization of irradiation facilities, PAGURE can be taken, in its range, as a standard design. (authors)

  5. Sensitivity of P-Channel MOSFET to X- and Gamma-Ray Irradiation

    Milić Pejović

    2013-01-01

    Full Text Available Investigation of Al-gate p-channel MOSFETs sensitivity following irradiation using 200 and 280 kV X-ray beams as well as gamma-ray irradiation of 60Co in the dose range from 1 to 5 Gy was performed in this paper. The response followed on the basis of threshold voltage shift and was studied as a function of absorbed dose. It was shown that the most significant change in threshold voltage was in the case of MOSFET irradiation in X-ray fields of 200 kV and when the gate voltage was +5 V. For practical applications in dosimetry, the sensitivity of the investigated MOSFETs was also satisfactory for X-ray tube voltage of 280 kV and for gamma rays. Possible processes in gate oxide caused by radiation and its impact on the response of MOSFETs were also analyzed in this paper.

  6. Gamma-ray irradiation tests of High-Tc SQUID

    Gamma-ray irradiation tests of High-Tc SQUIDs were carried out to examine their workability in nuclear reactor environments. The SQUIDs were made of a HoBa2Cu3O7-x superconductive thin film on SrTiO3 substrates. Some were encapsulated in separate cases of glass-fiber-rein-forced epoxy resin. Gamma-ray irradiation was performed with a Co-60 gamma-ray source. Irradiation dose rates were (8.1 to 12.2) x 103 Gy/h (i.e., (1.0 to 1.5) x 106 R/h), and the maximum absorption dose was about 10.4 MGy. During and after irradiation, noises of SQUIDs were measured with a power spectrum analyzer. Changes in modulation voltage were also investigated. No gamma-ray induced noise was observed during irradiation. The noise level and modulation voltage did not change until a total irradiation dose of about 3 MGy, and after that it decreased slightly. We concluded that the tested high-Tc SQUIDs are very resistant to gamma-ray irradiation, and thus the application of high-Tc SQUIDs in inspection of reactor components seems promising. (author)

  7. Decontamination of fermented chicken feet by 60Co irradiation

    Fermented chicken feet was treated by 60Co irradiation, and the aerobic plate count, enumeration of coliforms, pathogens and TBARS value were measured during storage. The results showed that, aerobic plate count of all irradiated samples was lower than control, and enumeration of coliforms, and pathogens of Staphylococcus aureus, Shigella, Salmonella were not detected. TBARS value of all treatments was stable during 60 d storage. It could be concluded that 60Co irradiation of chicken feet was an effective method to prolong its shelf life. (authors)

  8. Gamma-ray irradiation tests of CMOS sensors used in imaging techniques

    Cappello Salvatore G.

    2014-01-01

    Full Text Available Technologically-enhanced electronic image sensors are used in various fields as diagnostic techniques in medicine or space applications. In the latter case the devices can be exposed to intense radiation fluxes over time which may impair the functioning of the same equipment. In this paper we report the results of gamma-ray irradiation tests on CMOS image sensors simulating the space radiation over a long time period. Gamma-ray irradiation tests were carried out by means of IGS-3 gamma irradiation facility of Palermo University, based on 60Co sources with different activities. To reduce the dose rate and realize a narrow gamma-ray beam, a lead-collimation system was purposely built. It permits to have dose rate values less than 10 mGy/s and to irradiate CMOS Image Sensors during operation. The total ionizing dose to CMOS image sensors was monitored in-situ, during irradiation, up to 1000 Gy and images were acquired every 25 Gy. At the end of the tests, the sensors continued to operate despite a background noise and some pixels were completely saturated. These effects, however, involve isolated pixels and therefore, should not affect the image quality.

  9. Thermal decomposition of ammonium perchlorate during gamma-ray irradiation

    To assess radiation damage effects in propellants, pyrotechnics, and similar materials, thermal decomposition measurements were made on ammonium perchlorate powders and crystals during gamma-ray irradiation. Gas evolution studies were made on single crystals and powders of ammonium perchlorate, both at room temperature and at 2270C. The results are discussed. (U.S.)

  10. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with 60Co gamma rays, in Leishmania spp

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 μg/ml (EC50), L.(V.) panamensis (0.78 |μg/ml) and L.(L.) chagasi (0.63 (μg/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC50 of 11|μg/ml. Irradiation of LAO with 60Co gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC50 of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  11. (60)Co in cast steel matrix: A European interlaboratory comparison for the characterisation of new activity standards for calibration of gamma-ray spectrometers in metallurgy.

    Tzika, Faidra; Burda, Oleksiy; Hult, Mikael; Arnold, Dirk; Marroyo, Belén Caro; Dryák, Pavel; Fazio, Aldo; Ferreux, Laurent; García-Toraño, Eduardo; Javornik, Andrej; Klemola, Seppo; Luca, Aurelian; Moser, Hannah; Nečemer, Marijan; Peyrés, Virginia; Reis, Mario; Silva, Lidia; Šolc, Jaroslav; Svec, Anton; Tyminski, Zbigniew; Vodenik, Branko; Wätjen, Uwe

    2016-08-01

    Two series of activity standards of (60)Co in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of (60)Co in the cast steel standards were (1.077±0.019) Bqg(-1) on 1 January 2013 12h00 UT and (1.483±0.022) Bqg(-1) on 1 June 2013 12h00 UT, respectively. PMID:27236833

  12. Radiolytic degradation scheme for 60Co-irradiated corticosteroids

    Kane, M.P.; Tsuji, K.

    1983-01-01

    The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain on the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.

  13. Calculation of direct effects of 60Co gamma rays on the different DNA structural levels: A simulation study using the Geant4-DNA toolkit

    In this study, simple single strand breaks (SSB) and double strand breaks (DSB) due to direct effects of the secondary electron spectrum of 60Co gamma rays on different organizational levels of a volume model of the B-DNA conformation have been calculated using the Geant4-DNA toolkit. Result of this study for the direct DSB yield shows a good agreement with other theoretical and experimental results obtained by both photons and their secondary electrons; however, in the case of SSB a noticeable difference can be observed. Moreover, regarding the almost constant yields of the direct strand breaks in the different structural levels of the DNA, calculated in this work, and compared with some theoretical studies, it can be deduced that the direct strand breaks yields depend mainly on the primary double helix structure of the DNA and the higher-order structures cannot have a noticeable effect on the direct DNA damage inductions by 60Co gamma rays. In contrast, a direct dependency between the direct SSB and DSB yields and the volume of the DNA structure has been found. Also, a further study on the histone proteins showed that they can play an important role in the trapping of low energy electrons without any significant effect on the direct DNA strand breaks inductions, at least in the range of energies used in the current study

  14. Humoral immune response against native or 60Co irradiated venom and mucus from stingray Paratrygon aiereba

    Poisonings and traumas caused by poisonous freshwater fish such as rays are considered a major public health problem and draw attention because of accidents involving these animals cause serious local symptoms and are disabling, keeping the victim away from work. The therapy of these cases is based only on the symptoms of patients, which implies in its low efficiency, causing suffering for the victims. This study aims to evaluate and compare the humoral immune response in animals inoculated with native or 60Co irradiated Paratrygon aiereba venom and mucus. Ionizing radiation has proven to be an excellent tool to decrease the toxicity of venoms and isolated toxins. The mucus and venom samples of P. aiereba were irradiated using gamma rays from a 60Co source. Animals models were immunized with the native or irradiated mucus or venom. The assays were conducted to assess the production of antibodies by the immunized animals using enzyme immunoassay and western blotting. Preliminary results show the production of antibodies by the immunized animals. The resulting sera were also checked for antigenic cross- reactivity between venom and mucus, demonstrating the potential of mucus as an antigen for serum production for the specific treatment for accidents by stingrays. However, it is essential to carry out further tests in order to verify the neutralization of the toxin by antibodies formed by animals. (author)

  15. Planning a 60Co Irradiation Facility for Fruit Preservation

    A conceptual design for a conveyor system is proposed for use in fruit irradiation. The seasonal nature of the fruit harvest requires that the 60Co source inventory should be sufficient to meet the demand at peak season, but this would be excessive at the beginning and towards the end of the harvest. Because of the short crop period the possibility of other irradiation services should be exploited to ensure full utilization of the facility. For successful extension of fruit shelf-life rigid practices in pre-irradiation treatment are essential and careful packaging is indispensable to the operation of the irradiator. Based on the time required for construction and equipment supply, a period of 18 months should be assumed for completion of the project. (author)

  16. Planning a 60Co irradiation facility for fruit preservation

    A conceptual design for a conveyor system is proposed for use in fruit irradiation. The seasonal nature of the fruit harvest requires that the 60Co source inventory should be sufficient to meet the demand at peak season, but this would be excessive at the beginning and towards the end of the harvest. Because of the short crop period the possibility of other irradiation services should be exploited to ensure full utilization of the facility. For successful extension of fruit shelf-life rigid practices in pre-irradiation treatment are essential and careful packaging is indispensable to the operation of the irradiator. Based on the time required for construction and equipment supply, a period of 18 months should be assumed for completion of the project. (author)

  17. Degradation of dibutyl phthalate in water by the aid of metals under {gamma}-ray irradiation

    Yoshida, Tomoko; Tanabe, Tetsuo [Nagoya Univ., Center for Integrated Research in Science and Engineering, Nagoya, Aichi (Japan); Miyashita, Yoshinori; Yoshida, Hisao; Hattori, Tadashi [Nagoya Univ., Department of Applied Chemistry, Nagoya, Aichi (Japan)

    2001-09-01

    The degradation of dibutyl phthalate (DBP), one of endocrine disrupters, by {gamma}-ray irradiation was enhanced by the effective energy conversion of {gamma}-ray through the interaction with some kind of metal materials. (author)

  18. Apoptosis and necrosis in testes irradiated with gamma rays

    The present study focused on sub-microscopical investigation of apoptotic and necrotic cells in the testes of dogs subjected to single local irradiation with gamma rays at three different doses, 1.5 Gy, 3 Gy and 4 Gy, on days 1, 15, 30, 45, 120 and 150 after irradiation. On day 1 after irradiation, no necrotic cells were observed in the testicular tissue. The first cells in which apoptosis was observed on days 15 and 30 after irradiation with the lower dose were spermatogonia, spermatocytes and round spermatids. These cells showed morphological changes typical of apoptosis. Their depletion was observed on day 45 after irradiation and they were found in the lumen of seminiferous tubuli. Some dead cells were eliminated from seminiferous tubuli by phagocytosis by means of Sertoli cells. After irradiation with higher doses of gamma rays some cells of seminiferous epithelium showed morphological signs of apoptosis while other manifested necrosis. Sertoli cells and Leydig cells were considerably resistant to radiation. However, after irradiation with the highest dose of 4 Gy sporadic cells showed signs of apoptosis. On day 120 after irradiation the testes contained no necrotic cells and by day 150 spermiogenesis was recovered. (authors)

  19. Expression of FHIT in AHH-1 cells irradiated by 60Co γ-ray and bystander effect cells

    Objective: To investigate the expression of FHIT gene in the 60Co gamma-ray irradiated human lymphocytoblast (AHH-1) cell and the bystander effect cell, and to explore the function of FHIT gene in the bystander effect of ionizing radiation. Method: Preparation of bystander effect cell model: after inadiated with different dose of 60Co gamma-ray (0, 2, 5 Gy), the directly irradiated AHH-1 cells were collected immediately by centrifugation and co-cultivated with non-irradiated cells in Transwell, forming the bystander effect group P1. In addition, some culture media supematant of directly irradiated cells were transferred to the non- irradiated cells culture medium, forming the group P2. Then cells were collected at 0, 6, 12, and 24 h after irradiation and the total RNA and protein were extracted. RT-PCR and Western blot were performed to determine the FHIT mRNA and protein level, respectively. Flow cytometry assay and cell counting were conducted to detect the alteration of cell cycle and cell proliferation, respectively at 0, 24 h after irradiation. Results: The mRNA level of FHIT gene among control cells, directly irradiated cells and bystander cells showed no obvious difference, while the FHIT protein level of the directly irradiated cells and bystander cells was significantly down-regulated compared with the control cells (F=102.45, P2 phase arrest and obviously inhibited the proliferation ability. Conclusions: 2 and 5 Gy of 60Co γ-ray irradiated AHH-1 cells can result in down regulation of the FHIT protein expression, which suggests that FHIT gene is involved in the process of bystander effect induced by irradiation. (authors)

  20. Effects of gamma Rays Irradiation on resistance of Pseudomonas aeruginosa in various condition

    The investigation of gamma tays 60Co irradiation effect on resistance of bacteri P.aeruginosa has been done.The objective of the research was to know the D10 value of bacteria P.aeruginosa. By using of distilled water,talc and peanut powder as carrier in dry,wet,O2 and N2 condition the bacteria of P.aeruginosa were irradiated on gamma rays of 60Co with dose of O to 2.5 kGy,and with dose rate of 5 and 10 kGy/h.After irradiation the bacteria of P. aeruginosa were cultured in media of the Tryptone Soya Agar and incubatedat temperature of 32±2oC for 3 days. The survival colonies were calculated,and the data were used to make the curve and to determine the D10 value. The results of the experiments showed that D10 value of irradiated bacteria of P.aeruginosain the disitilled water,talc and peanut powder as carrier were not high significant.Nevertheless the D10 value of the irradiated at dose rate 10kGy/h show more higher tendency than at dose rate 5kGy/h. The D10 value of irradiated bacteria in the N2 condition was higher,if compared with in the O2 condition

  1. Seed germination of peanuts irradiated with cobalt (60CO)

    This work was realized to evaluate the effect of gamma irradiation (60Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  2. In service identification of the heterogeneous zone in petrochemical pipeline by using sealed gamma-ray source (60Co, 137Cs)

    In-service diagnoses of pipeline facilities are important for a systematic maintenance of them. Field applications by using sealed gamma-ray sources (60Co, 137Cs) were performed of identify the heterogeneous zone in the pipelines of a distillation tower and a flare stack respectively, From the results, the heterogeneous zones in the pipelines were successfully identified. In the case of the pipeline connected to the distillation tower, a vapor pocket was detected in the fluid under hydrodynamic conditions, which could explain the reason for a decrease of the flow rate. In another case, an area with some amount of catalyst deposits was found at the bottom of the gas pipeline which was connected to the flare stack. And these findings provided important information for the process operators. Diagnosis technique by using gamma radiation sources has been proven to be an effective and reliable method for providing information on a media distribution in a facility.

  3. Induction with 60Co gamma rays of modification variability and mutation of China aster (Callistephus chinensis Nees

    A. Wosińska

    2013-12-01

    Full Text Available The effect of radiation on variability was investigated in plants of five varieties of China aster, grown from seeds pretreated with various doses of gamma rays (generation M1 and in the progeny of these plants (generation M2. Both in generation M1 and in M2 the frequency of occurrence of radiation induced changes varied. In the M1 generation, beside teratological changes found most frequently in early periods, the observed variability concerned mostly leaves, their colour and size and the form of the lingual flowers. Plants with a different colour of flowers or a different habit were only sporadic. The changes induced by radiation were more frequently observed in the M2 generation than in the M1 They involved the following characters: height and habit of plants, colour of shoots, leaves and flowers, the forms of lingual marginal flowers, the time of flowering and the perfume. Most frequently changes were observed in several characters. When the shoots and leaves colour showed changes of anthocyanin type, the colour of the flowers was usually also modified. Most changed plants were noted after a dose of 9 kR in the M1 generation, and after 6-9 kR in the M2 generation. These doses were described in generation M1 at the stage of flowering in most of the tested varieties as LD50.

  4. Effects of flavonoids of Astragali Complanali against damage induced by 60Co γ-ray irradiation

    Objective: To study on the radioprotective effect of flavonoids of Astragali Complanali on γ-ray induced injury. Methods: Female mice were fed with FAC at different doses for 17 days, positive control were administered with Leucogen Tablets, irradiation and negative control were administered with distilled water only, then all mice except the negative control group were exposed to 6 Gy 60Co γ-ray for whole-body-irradiation at the 7th day, observe the protective effect of FAC against damage of irradiation and its effects on antioxidant system and immune function. Results: The 21-day survival rate of FAC-protected mice were higher than that in the control group, blood cell counts of FAC-protected mice were higher than those in the control group such as WBC, RBC, PLT, HGB and LY counts; superoxide dismutase and lymphocyte proliferation index of FAC-protected mice were much higher than those in the control group and malondiadehyde counts lower. Conclusion: These results suggest that FAC can alleviate irradiation damage induced by gamma-ray, might be associated with ameliorating antioxidant level and immune function. (authors)

  5. Biochemical and immunological alterations of 60 Co irradiated Bothrops jararacussu venom

    Proteins irradiation leads to structural alterations resulting in activity and function loss. This process has been useful to detoxify animal venoms and toxins, resulting in low toxicity products which increased immunogenicity. The Bothrops jararacussu venom behaves as a weak immunogen and its lethal activity in not neutralized by either autologous, heterologous or bothropic polyvalent antisera. This venom is markedly myotoxic and and the commercial bothropic antiserum does not neutralize this activity, because of this low immunogenicity of the myotoxins. This present work was done in order to evaluate the possibility of irradiating Bothrops jararacussu, intending to increase the immunogenicity of the myotoxic components, leading to productions of myotoxins neutralizing antibodies. Bothrops jararacussu venom samples were irradiated with 500, 1000 and 2000 Gy of 60 Co gamma rays. A 2.3 folds decrease of toxicity was observed for the 1000 Gy irradiated samples while the 2000 Gy irradiated sample was at least 3.7 folds attenuated. On the other hand, the 500 Gy did not promote any detoxification. Electrophoresis and HPLC data indicate that the irradiation lead to the formation of high molecular weight products (aggregates). The proteolytic and phospholipasic activities decreased in a dose dependent manner, the phospholipases being more resistant than the proteases. Both the animals (rabbit) immunized with either native or 2000 Gy irradiated venom produced native venom binding antibodies, a slightly higher titer being obtained in the serum of the rabbit immunized with the irradiated samples. Western blot data indicate that the anti-irradiated venom Ig Gs recognised a greater amount of either autologous or heterologous venom bands, both sera behaving as genus specific. The anti-native serum did not neutralize the myotoxic activity of native venom, while the anti-irradiated one was able to neutralize this activity. (author)

  6. Synergistic effects of neutron and gamma ray irradiation of a commercial CHMOS microcontroller

    This paper presents the experimental results of a combined irradiation environment of neutron and gamma rays on 80C196KC20, which is a 16-bit high performance member of the MCS96 microcontroller family. The electrical and functional tests were made in three irradiation environments: neutron, gamma rays, combined irradiation of neutron and gamma rays. The experimental results show that the neutron irradiation can affect the total ionizing dose behaviour. Compared with the single radiation environment, the microcontroller exhibits considerably more severe degradation in neutron and gamma ray synergistic irradiation. This phenomenon may cause a significant hardness assurance problem. (condensed matter: structure, thermal and mechanical properties)

  7. 60Co γ-irradiation induced mutation breeding of ginger

    Sprout rhizome and plumelet rhizome of Laiwu ginger were irradiated by 60Co γ-rays at different doses (20, 25, 30 and 35 Gy), and the variations at the VM1, VM2, and VM3 generations were studied. The results showed that the inhibition effect of irradiation on the VM1 generation was found to be increased as the dose increased, and the sprout rhizome was more sensitive to γ-irradiation than the plumelet rhizome. The LD50 and LD60 dose of plumelet rhizomes were 20 and 25 Gy, respectively, and the optimum irradiation dose was 25Gy. The LD50 and LD60 dose of sprout rhizomes were below 20 Gy. Seven types of mutants were found and selected in VM2 generation. The induced mutation characters were unstable in the VM3 generation. Three mutant lines (GDC2531, PZC3026, ZLX2007) selected from VM3 generation showed high yield, and fresh weight of rhizomes increased 33.5%, 27.5% and 24.9%, respectively compared to control. (authors)

  8. Response of adrenal gland to whole body 60Co irradiation

    Whole body of the adult albino rates was exposed to 60Co radiation in a single dose of 600 R. Following irradiation the adrenal serotonin level was found higher till the end of 8th week except a fall on 14th day, whereas the blood 5HT level remained lower than the normal except a slight rise at the end of 1st week and dropped down at 14 days followed by a further rise. The blood catecholamine level was found increased at the end of 14th day followed by a fall at 4th and 8th weeks, but the levels were moving round the normal value. The histological studies of adrenal gland showed degranulation and hypertrophy of adrenal cortex and medullary cells at various intervals of post-irradiation. On the whole it is observed that maximum changes in the level of biogenic amines take place within 14 days after irradiation, and maximum rate of mortality also coincide with this period. Thus bringing out the fact that adrenal bioamines play an important role in the vital activities of the animals. (author)

  9. 60Co gamma-rays induce predominantly C/G to G/C transversions in double-stranded M13 DNA.

    Hoebee, B.; J. Brouwer; van de Putte, P; Loman, H; Retèl, J

    1988-01-01

    Upon irradiation with gamma rays of an oxygenated aqueous solution of double-stranded M13 DNA, a very specific mutation spectrum was found with respect to both the type and the positions in the DNA sequence. Of the 23 mutations, which were sequenced, 16 represent a C/G to G/C transversion. A C/G to T/A transition was found once and a G/C to T/A transversion twice. The remaining 4 mutations are frameshifts, 2 are identical and formed by the insertion of a G/C basepair; the other 2 mutations ar...

  10. Gamma Rays Irradiation Effects on Polysulfones at Elevated Temperature

    Polysulfone has excellent mechanical and thermal properties. Its application covers a wide rage such as nuclear facilities and space environment. The radiation chemical scheme on polysulfone is not well established as it undergoes both scission and cross-linking. In this study, the temperature dependence of the irradiation effect on polysulfone was studied by measuring glass transition temperature, gel fraction, molecular weight and gas evolution. Polysulfone film of 50 micrometer thickness was irradiated with gamma rays at dose rate of 5-7 kGy/h to absorbed dose of 0.1-4 MGy under vacuum in glass ampoules at room temperature, 100, 150, 180, 210 degree. Glass transition temperature (Tg) measured with differential scanning calorimeter lowered with dose upon irradiation at room temperature and 100 centigrade, though Tg rose upon irradiation above 180 centigrade, respectively. Gel fraction in chloroform at room temperature was measured. Pristine polysulfone is soluble to chloroform but after irradiation it formed gel. The decrease of gel dose, and the increase of gel fraction were observed with elevation of irradiation temperature. The number average molecular weight measured with gel permeation chromatography decreased with dose at irradiation temperatures except for 210 degree, where slight increase was observed. On the other hand, weight average molecular weight increased at all temperatures. The molecular weight distribution changed towards lower direction and became broad at all cases examined. These results indicate that the predominant scheme is scission but simultaneous cross-linking occurs, especially at elevated temperature. The probability of the cross-linking was increased by irradiation at elevated temperature above 180 degree, though the probability of main chain scission was not changed very much. The yield of evolution of total gas, CO, CO2 and SO2 gases increased at elevated temperature, while yield of evolved H2 was independent of irradiation

  11. Comparative nephrotoxicity of native or Co-60 gamma rays irradiated crotoxin in mice

    Snake venoms are complex mixtures of proteins and peptides with a wide spectrum of physiological targets such as the blood coagulation and cardiovascular systems and the motor end plate among others. Acute renal failure is a common complication in accidents with the South American rattlesnake. The toxin involved in this pathology is the crotoxin, a major component of the venom in terms of concentration and toxicity. Snake venoms, when irradiated with 60Co gamma rays present a significant decrease in toxicity while the immunogenic properties of its components are preserved. The use of irradiated venom is an attractive alternative for antisera production since it might reduce the appearance of renal lesions improving the welfare and lifespan of those animals employed on antivenom production. At the present work, we have compared the effects of native and irradiated crotoxin on the mice renal function. Tubular lesions were observed in all the samples from the animal group injected with native crotoxin. Animals injected with the irradiated toxin presented alteration only after 30 minutes and 1 hour after injection. These data suggest that the onset of the renal lesions is delayed and that the severity of the lesions might be lower when using irradiated crotoxin. (author)

  12. Comparative nephrotoxicity of native or Co-60 gamma rays irradiated crotoxin in mice

    Rocha, Andre Moreira; Alves, Glaucie J.; Aires, Raquel da Silva; Turibio, Thompson O.; Thomazi, Gabriela O. Coelho; Spencer, Patrick J.; Nascimento, Nanci do, E-mail: andrerocha@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Nascimento-Rocha, Josefa M.; Magalhaes Filho, Asterio Souza, E-mail: 0304@prof.itpacporto.com.br [Instituto Tocantinense Presidente Antonio Carlos Porto (ITPAC), Porto Nacional, TO (Brazil)

    2015-07-01

    Snake venoms are complex mixtures of proteins and peptides with a wide spectrum of physiological targets such as the blood coagulation and cardiovascular systems and the motor end plate among others. Acute renal failure is a common complication in accidents with the South American rattlesnake. The toxin involved in this pathology is the crotoxin, a major component of the venom in terms of concentration and toxicity. Snake venoms, when irradiated with {sup 60}Co gamma rays present a significant decrease in toxicity while the immunogenic properties of its components are preserved. The use of irradiated venom is an attractive alternative for antisera production since it might reduce the appearance of renal lesions improving the welfare and lifespan of those animals employed on antivenom production. At the present work, we have compared the effects of native and irradiated crotoxin on the mice renal function. Tubular lesions were observed in all the samples from the animal group injected with native crotoxin. Animals injected with the irradiated toxin presented alteration only after 30 minutes and 1 hour after injection. These data suggest that the onset of the renal lesions is delayed and that the severity of the lesions might be lower when using irradiated crotoxin. (author)

  13. Selective expression of mutated p53 in human cells immortalized with either 4-nitroquinoline 1-oxide or 60Co gamma rays

    Many studies on in vitro transformation of human cells indicate that the cells must be immortalized before they can be neoplastically transformed, indicating that immortalization is a critical step in multistep neoplastic transformation of human cells. We immortalized three human cell lines by repeated treatment with either 60Co gamma rays or a chemical carcinogen, 4-nitroquinoline 1-oxide, and found that all three immortalized cell lines have mutations in the tumor suppressor gene, p53. Direct sequencing of the reverse-transcribed mRNA and immunoprecipitation of p53 protein revealed that mutant p53 is selectively expressed in all the immortalized cell lines, whereas the genomic fragments of the immortalized cells contain wild-type and mutated p53 alleles. Although the mutated p53 is selectively expressed in the immortalized cells, expression of the wild-type p53 was induced by treatment of the cells with a hypomethylating reagent, 5-azacytidine, indicating that the wild-type p53 allele might be inactivated by hypermethylation of DNA. Actually, the entire genomic locus including the promoter region of p53 is hypermethylated in all the immortalized cell lines. Expression and phosphorylation of Rb was normal in these three cell lines. Thus, inactivation of both wild type p53 alleles and selective expression of mutated p53 seem to be key factors in the immortalization of human fibroblasts. (author)

  14. Measurements of the optical density and the thermoluminescent response of LiF:Mg,Ti exposed to high doses of 60Co gamma rays

    The absorption spectra and glow curves of LiF:Mg,Ti exposed to high doses of 60Co gamma rays as well as the optical density curves and thermoluminescent (TL) response as a function of dose were measured. Absorption peaks around 442 nm (2.8 eV), 307 nm (4.0 eV) and 248 nm (5.0 eV) were observed. The optical density is a linear function of dose up to 2500 Gy and then sub-linear for the 5.0 eV band, and for the 4.0 eV band it is sub-linear with a filling constant of 2.1 x 10-4 and 6.2 x 10-4 Gy-1. The dose response of the 2.8 eV band is linear from 2500 Gy to 10 kGy with a slope of 1.0 x 10-5 Gy-1. Once the absorption spectra were obtained, the glow curves and the TL response were obtained. In the dose range, 290-10,000 Gy, the TL response of peaks 5 and 7 was supra-linear-sub-linear. (authors)

  15. Water radiolysis in a crack tip under gamma ray irradiation

    Under a non-irradiation condition, oxidant, e.g., O2 and H2O2, in a crack tip is supplied from the bulk water. But under irradiation conditions, even if the diffusion of radiolytic species is not sufficient, direct radiolysis in the crack tip causes high concentrations of radiolytic species. As a result of measurements and Monte Carlo calculation of gamma ray energy deposition, it has been confirmed that the energy deposition rate in the gap water is larger than that in the bulk water. The energy absorption rate increases as the gap width decreases and reaches 1.3 times that in the bulk water. In order to evaluate crack propagation rate for irradiation assisted stress corrosion cracking (IASCC) of stainless steel, a water radiolysis model in a crevice is proposed. A larger energy deposition rate in the crevice water produces many more radiolytic species, which causes high oxidant concentrations in spite of enhanced recombination of the species at the crevice inner surface. So, for IASCC evaluation, crevice water chemistry plays an important role to determine the crack propagation rate under irradiation. (authors)

  16. Physico-chemical characterization of gamma rays irradiated crotamine

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. It has been employed to attenuate animal toxins. Crotamine, a toxin from Crotalus durissus terrificus (Cdt), is a highly basic polypeptide (pI - 10.3), with myotoxic activity and molecular weight of 4882 Da. It is composed of 42 amino acids residues and reticulated by three disulfide bonds. This study aimed the characterization of irradiated crotamine using Circular Dichroism (CD), Fluorescence Spectroscopy and Differential Scanning Calorimetry (DSC) techniques. We used size exclusion and ion-exchange chromatography to purify it from Cdt crude venom. The pure crotamine was irradiated with 2.0 kGy from a 60Co source. Native and irradiated crotamine were analyzed in a fluorescence spectrophotometer (Hitachi F-4500), under excitation wavelength at 275 nm and the emission was scanned from 300 to 500 nm. The analysis of fluorescence quenching showed that the irradiated form displayed a lower quantum yield when compared to the native form. CD spectra, obtained from a Jasco, J-180 spectropolarimeter, of native and irradiated crotamine solutions, showed a discrete change between the samples, from apparently ordered conformation to a random coil. Finally, the thermodynamics analysis, realized in a calorimeter METTLER TOLEDO, DSC 822e, showed that irradiation promoted changes in the calorimetric profile. Our results indicate that irradiation leads to progressive changes in the structure of the toxin, which could explain the decrease in myotoxic activity. (author)

  17. Pagure {sup 60}Co panoramic irradiation facility; Pagure irradiateur panoramique au {sup 60}Co

    Puig, J.R.; Laizier, J.; Lorin, M.; Laroche, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    After a description of the various parts of 'PAGURE', a 10 KCi panoramic irradiation facility, and of the operations data, a critic scrutiny is given. From the experience of five years operations, working of the facility can be thought of very satisfying. From the point of view of standardization of irradiation facilities, PAGURE can be taken, in its range, as a standard design. (authors) [French] Apres avoir decrit les differents elements constitutifs de 1'irradiateur panoramique de 10 KCi 'PAGURE' et precise les donnees d'exploitation, on en fait l'examen critique. A la lumiere de cinq annees d'utilisation, le fonctionnement de 1'irradiateur apparait extremement satisfaisant. Dans une perspective de standardisation des appareils, on peut, dans sa gamme, le considerer comme une realisation type. (auteurs)

  18. Meiotic chromosome behaviours in M1 generation of bread wheat irradiated by gamma-rays

    Growing plants of bread wheat (Triticum aestivum L. 2 n=6x=42, AABBDD) were subjected to acute or chronic irradiation by gamma-rays from 60Co and meiotic chromosome behaviours of PMCS in M1 generation were cytologically compared. Both acute and chronic irradiations produced different types of chromosomal aberrations at the meiotic stages. Among them, translocation type was the most frequent, followed by univalent type. A mixed type, i. e. translocation accompanying one or more univalents was often detected. Even normal type which lacked translocation and univalent included laggards and briclges without exception. Other meiotic abnormalities such as deletion, iso-chromosome and micronuclei were observed frequently in both treatments. Dose dependency of translocation frequency was not recognized in this experiment. In chronic irradiation, different chromosome numbers and meiotic behaviours were found not only among florets of a spike but also among anthers of a floret. A number of plants with aneuploid-like grass types occurred at a high frequency in M1, especially with low exposure

  19. Investigation of effects of gamma ray irradiation on pyrolysis properties of glove-box panel materials

    The glove box (GB) is a device with some plastic components and is used for the containment of radioactive materials. In a MOX fuel fabrication facility, MOX is also handled in the GB. Since the plastic panel, which has the largest area in the GB, is used over a long period, it is exposed to a high dose of MOX continuously. In this study, to confirm whether the containment capability of GB can be maintained even under external thermal stress, the effects of gamma ray irradiation with 60Co on the pyrolysis properties of the common panel materials were investigated by TG-DTA. As a result, polymethylmethacrylate showed a large peak of the mass loss rate at about 260 degrees under the nonirradiation and air condition, but it separated into lower and higher temperature sides above 25 kGy. This effect was not observed up to 10 kGy for polymethylmethacrylate and up to 880 kGy for polycarbonate. By comparison with the estimated total dose of the GB panel irradiated in the operation period, it was found that the irradiation from MOX does not significantly affect the pyrolysis properties of the GB panel in the actual facility. (author)

  20. Inverse dose-rate effect for the induction of 6-thioguanine-resistant mutants in Chinese hamster V79-S cells by 60Co gamma rays

    Chinese hamster V79-S cells capable of growing in suspension culture were exposed to 60Co gamma rays at a high dose rate (84 Gy/h), low dose rates (200, 50, and 39 mGy/h), and a spectrum of very low dose rates (between 29 and 4.5 mGy/h). Following time for appropriate expression the cultures were assayed for the induction of 6-thioguanine-resistant mutants. For a given dose, a decrease in mutation induction occurred as the dose rate was reduced from high dose rates to low dose rates. However, further reduction in dose rate resulted in a reverse dose-rate effect, and an increase in the frequency of mutants was observed. The contribution of background mutation frequency to this reverse dose-rate effect was studied, both by examining fluctuations of mutation frequency in nonirradiated culture and by its impact upon the dose-rate-independent nature of the reversed effect, and it was found to be negligible. The physiological state of the suspension culture under periods of protracted exposure to very low dose rates was also investigated. The effect of doubling time, plating efficiency, cell cycle distribution, and sensitivity on survival and mutation were examined. In no case was a change apparent during the very low-dose-rate exposures. The results are discussed in terms of the possible expression of cryptic radiation damage after prolonged culture times and/or the involvement of an error-free repair system which requires a certain amount of radiation damage to become active

  1. Preliminary research on death pattern in PC12 cell after high-dose of gamma-ray irradiation

    Objective: To investigate the death pattern of pheochromocyoma cell line (PC12 cell) irradiated with ionizing radiation and to search for a model of radiation-induced neuron injury in vitro. Methods: PC12 cell was irradiated with different doses of 60Co γ-rays. The effect of radiation on cell cycle, development, differentiation and death rate were detected by flow cytometry, light microscope, and transmission electron microscope (TEM). Results: Irradiated PC12 cell showed cell cycle retardation and differentiation, but some cells died due to swelling. Apoptosis was observed in few cells. TEM examination indicated that mitochondrion and endoplasmic reticulum were dilated markedly, chromatin was concentrated and scattered near karyotheca or around the nucleolus, which characterized oncosis. Conclusions: PC12 cell died through oncosis after gamma-ray irradiation of high-dose, and can be used as a radiation-induced neuron injury model. (authors)

  2. Effect of gamma-ray irradiation on starch in sweet popato roots

    Starch contents, as well as the size and molecular weight, in sweet potato roots decreased during steerage at 30 degrees C after gamma-ray irradiation, accompanying the increase of sucrose content. No change in the starch and sucrose contents was observed in unirradiated specimens. By microscopy damaged starch granules were observed only in gamma-ray irradiated root. The results suggested that starch was converted into sucrose unirradiated sweet potato roots by the enzymes responsible for starch-sugar interconversion of which the activities were enhanced by gamma-ray irradiation

  3. Chromatographic study of gamma-ray irradiated degradation of chlorinated hydrocarbon in water

    Degradation of chlorinated hydrocarbon in gamma ray irradiation was examined in order to get information on treatment of groundwater. Water chloroform was sealed into a vial irradiated with gamma ray. Both gas chromatography and ion chromatography were applied for determination of degradation products. Carbon dioxide, carbon monoxide, methane, ethane and chloride ion were detected in the irradiated system. Effect of radiation dose on the gamma ray induced chloroform degradation was investigated. The elimination of chloride ion and the degradation of chloroform were promoted by gamma irradiation in a dose-dependent manner. The G(CHCl3), which was defined as the number of degraded chloroform molecules when absorbed 100eV, was inferred to be 3.1. The degradation mechanism of chloroform irradiated with gamma ray seemed to involve that chloroform reacted with electron from radiolysis of water and the elimination of chloride ion occurred. (author)

  4. Induction by gamma irradiation (60Co), characterization and utilization of mutants for economic traits in Isabgol (Plantago ovata Forsk.)

    Plantago ovata (Isabgol) is an annual herb which attains a height of 30-40 cm. The stem is wholly underground and covered with fine hairs. It is important for its seeds and husk which have been used as laxative for centuries all over the world. Induced mutation breeding was initiated for augmenting the spectrum of variability as also to select a genotype adaptable to north Indian conditions. Dry seeds of P. ovata (three generations selfed) were irradiated with gamma rays (60Co, 10-100 kR) at the interval of 10 kR and treated with the chemical mutagen, ethidium bromide (EB-0.2%). Mutagenesis resulted in useful qualitative and quantitative variations and changed the mean values for different agronomical traits in both positive and negative directions. A wide range of viable morphological mutants was isolated and the spectrum of viable mutations was wider. Pollen fertility declined in various directions with increased doses of gamma rays as compared to control. Irradiation at more than 50 kR doses reduced seed germination. LD50 was found to be between 40-50 kR doses. Earlier a promising mutant was released as a variety Niharika and now another mutant FEA-5 is in pipeline for release for commercial cultivation in North Indian plains. (author)

  5. Humoral immune response against native or {sup 60}Co irradiated venom and mucus from stingray Paratrygon aiereba

    Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Aires, Raquel da Silva; Turibio, Thompson de Oliveira; Rocha, Andre Moreira; Spencer, Patrick Jack; Nascimento, Nanci do, E-mail: 0916@prof.itpacporto.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Seibert, Carla Simone, E-mail: carlaseibert@yahoo.com [Universidade Federal do Tocantins (UFT), Porto Nacional, TO (Brazil)

    2015-07-01

    Poisonings and traumas caused by poisonous freshwater fish such as rays are considered a major public health problem and draw attention because of accidents involving these animals cause serious local symptoms and are disabling, keeping the victim away from work. The therapy of these cases is based only on the symptoms of patients, which implies in its low efficiency, causing suffering for the victims. This study aims to evaluate and compare the humoral immune response in animals inoculated with native or {sup 60}Co irradiated Paratrygon aiereba venom and mucus. Ionizing radiation has proven to be an excellent tool to decrease the toxicity of venoms and isolated toxins. The mucus and venom samples of P. aiereba were irradiated using gamma rays from a {sup 60}Co source. Animals models were immunized with the native or irradiated mucus or venom. The assays were conducted to assess the production of antibodies by the immunized animals using enzyme immunoassay and western blotting. Preliminary results show the production of antibodies by the immunized animals. The resulting sera were also checked for antigenic cross- reactivity between venom and mucus, demonstrating the potential of mucus as an antigen for serum production for the specific treatment for accidents by stingrays. However, it is essential to carry out further tests in order to verify the neutralization of the toxin by antibodies formed by animals. (author)

  6. Assays of residual antibiotics after treatment of {gamma}-ray and UV irradiation

    Shin, Ji Hye; Nam, Ji Hyun; Lee, Dong Hun [Chungbuk National University, Cheongju (Korea, Republic of); Yu, Seung Ho; Lee, Myun Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-03-15

    The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and {gamma}-ray irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after {gamma}-ray and UV irradiation. Most samples were degraded by {gamma}-ray irradiation (1 {approx} 2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with {gamma}-ray and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of {gamma}-ray irradiated cephradine measured by AMS test were 2 times higher than of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that {gamma}-ray irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation.

  7. Wavelet analysis of scintillation discharge current on DC tracking resistance of gamma-ray irradiated polyethylene and polycarbonate

    The use of organic insulating materials in environments such as space and nuclear power stations is spreading rapidly. There is increasing concern about the reliability of electrical insulation in these environments due to radiation effects on the surface characteristics of polymeric materials. Irradiation effects on tracking resistance should be investigated due to the increasing usage of organic materials in radiation-prone environments. This paper presents a study on the DC tracking resistance of gamma-ray irradiated polyethylene and polycarbonate materials by use of the International Electrotechnical Commission (IEC) Publication (Publ.) 112 method. Polyethylene and polycarbonate materials as the test samples were irradiated in air up to 1 x 105 Gy and 1 x 106 Gy with dosage rates of 104 Gy/h using a 60Co gamma source. The total radiation effects on erosion depth, weight loss, contact angle and scintillation discharge energy levels were studied. A gaussian wavelet analysis was applied to show these scintillation discharge energy levels. (author)

  8. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    Ferreto, H. F. R., E-mail: hferreto@ipen.br, E-mail: ana-feitoza@yahoo.com.br; Oliveira, A. C. F., E-mail: hferreto@ipen.br, E-mail: ana-feitoza@yahoo.com.br; Parra, D. F., E-mail: dfparra@ipen.br, E-mail: ablugao@ipen.br; Lugão, A. B., E-mail: dfparra@ipen.br, E-mail: ablugao@ipen.br [Center of Chemistry and Environment, Institute of Energy and Nuclear Research - IPEN (Brazil); Gaia, R., E-mail: renan-gaia7@hotmail.com [Faculdades Oswaldo Cruz (Brazil)

    2014-05-15

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  9. Dose Distribution Calculation Using MCNPX Code in the Gamma-ray Irradiation Cell

    60Co-gamma irradiators have long been used for foods sterilization, plant mutation and development of radio-protective agents, radio-sensitizers and other purposes. The Applied Radiological Science Research Institute of Cheju National University has a multipurpose gamma irradiation facility loaded with a MDS Nordin standard 60Co source (C188), of which the initial activity was 400 TBq (10,800 Ci) on February 19, 2004. This panoramic gamma irradiator is designed to irradiate in all directions various samples such as plants, cultured cells and mice to administer given radiation doses. In order to give accurate doses to irradiation samples, appropriate methods of evaluating, both by calculation and measurement, the radiation doses delivered to the samples should be set up. Computational models have been developed to evaluate the radiation dose distributions inside the irradiation chamber and the radiation doses delivered to typical biolological samples which are frequently irradiated in the facility. The computational models are based on using the MCNPX code. The horizontal and vertical dose distributions has been calculated inside the irradiation chamber and compared the calculated results with measured data obtained with radiation dosimeters to verify the computational models. The radiation dosimeters employed are a Famer's type ion chamber and MOSFET dosimeters. Radiation doses were calculated by computational models, which were delivered to cultured cell samples contained in test tubes and to a mouse fixed in a irradiation cage, and compared the calculated results with the measured data. The computation models are also tested to see if they can accurately simulate the case where a thick lead shield is placed between the source and detector. Three tally options of the MCNPX code, F4, F5 and F6, are alternately used to see which option produces optimum results. The computation models are also used to calculate gamma ray energy spectra of a BGO scintillator at

  10. Gamma-ray irradiation tests of CMOS sensors used in imaging techniques

    Cappello Salvatore G.; Pace Calogero; Parlato Aldo; Rizzo Salvatore; Tomarchio Elio

    2014-01-01

    Technologically-enhanced electronic image sensors are used in various fields as diagnostic techniques in medicine or space applications. In the latter case the devices can be exposed to intense radiation fluxes over time which may impair the functioning of the same equipment. In this paper we report the results of gamma-ray irradiation tests on CMOS image sensors simulating the space radiation over a long time period. Gamma-ray irradiation tests were carrie...

  11. Application of nondestructive gamma-ray and neutron techniques for the safeguarding of irradiated fuel materials

    Nondestructive gamma-ray and neutron techniques were used to characterize the irradiation exposures of irradiated fuel assemblies. Techniques for the rapid measurement of the axial-activity profiles of fuel assemblies have been developed using ion chambers and Be(γ,n) detectors. Detailed measurements using high-resolution gamma-ray spectrometry and passive neutron techniques were correlated with operator-declared values of cooling times and burnup

  12. Manufacture of 60Co source irradiation facility and measurement of radiation filed

    60Co source radiation facility is an important equipment to produce reference radiation filed, according to national standard, the scattered dose rate must be less than 5% of the total dose rate in the reference radiation filed. Scattered radiation contribution and uniformity of reference radiation field are important parameters to describe the radiation performance of 60CO source irradiation device, Monte Carlo method was used to study the scattered radiation and uniformity of the reference radiation filed to provide theoretical basis for the design of 60CO source irradiating device in order to avoid economic losses caused by design mistakes. When 60CO source irradiating device was manufactured, PTW ionization chamber was used to measure the irradiation field. The results showed that the scattered radiation and uniformity of the radiation filed were in good agreement with the simulation results. The radiation performance met the design requirements. (authors)

  13. Effect of 60Co-gamma whole-body irradiation on serum amylase level

    Changes of serum amylase activity in rats, after several doses of acut 60Co-gamma irradiation as a function of time were investigated. These changes proved to be of no diagnostic value in early radiation damage. (author)

  14. Obtainment of a drug delivery system from PVAL irradiated by gamma rays

    The poly(vinyl alcohol) (PVAL) is a polymer used as biomaterial. In this work the PVAL was irradiated by gamma rays from 60Co source with doses up to 200 kGy. The PVAL was used to prepare hydrogels that may be used as a drug delivery system in ocular implant, for pair PVAL/dihidroxypropoximethyl guanine, where the last one is used for treatment of people with retinite caused by cytomegalovirus. The dose effect was studied on various properties of PVAL: the molecular weight by viscosity, the crosslink degree (Gcross-link= 8,5) calculated from gel dose (Dg = 7,8 kGy), the average molecular weight between crosslinks, crosslinking density, tensile strength at break and the degree of crystallinity by differential scanning calorimetry. Formation and thermal decay radical were studied by electronic paramagnetic resonance. It was used the technique of superposition and subtraction of spectra obtained at various temperatures (77 K, 125 K, 170 K, 230 K and 280 K). The radicals formed were identified on irradiated PVAL on vacuum and air at 77K with 20 kGy. The thermal decay showed that air caused polymer oxidation, even after end the irradiation, because the ·OH, RO· and ROO · radicals were formed. The dose effect on molecular structure of PVAL was studied by transmission spectroscopy on infrared region and nuclear magnetic resonance of proton. The PVAL structural alteration was not observed up to 200kGy, although crosslink occurred on PVAL. The PVAL hydrogel formation occurred at doses upper 70 kGy and drug controlled released occurred with zero order kinetic on PVAL hydrogel irradiated with 80 kGy. (author)

  15. Detection of Argentine onions treated with 60 Co irradiation

    Brazil has been the most important MERCOSUL's purchaser of fresh onions from Argentina. The increased claim for this fresh product has forced a consensus between the members nations, as regards to phytosanitary restrictions. The radio inhibition is described on National Food Codes in Brazil and Argentina. Methods of food irradiation detection must be performed, since they increase the consumer confidence. Quick and simple screening tests indicate whether a food product has been irradiated or not. This present study verified the DNA fragments of argentine fresh onions, produced during radiation process and 6 months of storage period. The DNA fragments are analyzed for detection of irradiated foods. The irradiated onions presented extensive DNA migrations, as comets, when submitted to agarose gel electrophoresis. They also showed more shelf life compared to the unirradiated onions. The unirradiated samples exhibited only limited DNA migration. This initial screen method showed to be effective for detection of irradiated onions. (author)

  16. Electrical conduction and photoresponses of gamma-ray-irradiated single-stranded DNA/single-walled carbon nanotube composite systems

    Hong, W.; Lee, E.M.; Kim, D.W.; Lee, Cheol Eui, E-mail: rscel@korea.ac.kr

    2015-04-15

    Highlights: •Effects of gamma-ray irradiation on single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. •Barrier for thermally activated conduction in the composite systems modified by the gamma-ray irradiation. •Photoresponses reveal photoexcitation and oxygen photodesorption modified by gamma-ray irradiation. -- Abstract: Effects of gamma-ray irradiation on the electrical conductivity and photoresponse have been studied for single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. The temperature-dependent electrical conductivity of the ssDNA/SWNT composite films, well described by a fluctuation-induced tunneling model, indicated modification of the barrier for thermally activated conduction by the gamma-ray irradiation. Besides, the photoresponse measurements indicated modified photoexcited charge carrier generation and oxygen photodesorption in the composite systems due to the gamma-ray irradiation.

  17. Dose-dependent and gender-related radiation-induced transcription alterations of Gadd45a and Ier5 in human lymphocytes exposed to gamma ray emitted by 60Co

    Growth arrest DNA damage-inducible 45a gene (Gadd45a) and immediate early response gene 5 (Ier5) have been emphasised as ideal radiation bio-markers in several reports. However, some aspects of radiation-induced transcriptional alterations of these genes are unknown. In this study, gender-dependency and dose-dependency as two factors that may affect radiation induced transcription of Gadd45a and Ier5 genes were investigated. Human lymphocyte cells from six healthy voluntary blood donors (three women and three men) were irradiated in vitro with doses of 0.5-4.0 Gy from a 60Co source and RNA isolated 4 h later using the High Pure RNA Isolation Kit. Dose and gender dependency of radiation-induced transcriptional alterations of Gadd45a and Ier5 genes were studied by quantitative real-time polymerase chain reaction. The results showed that as a whole, Gadd45a and Ier5 gave responses to gamma rays, while the responses were independent of radiation doses. Therefore, regardless of radiation dose, Gadd45a and Ier5 can be considered potential radiation bio-markers. Besides, although radiation-induced transcriptional alterations of Gadd45a in female and male lymphocyte samples were insignificant at 0.5 Gy, at other doses, their quantities in female samples were at a significantly higher level than in male samples. Radiation induced transcription of Ier5 of females samples had a reduction in comparison with male samples at 1 and 2 Gy, but at doses of 0.5 and 4 Gy, females were significantly more susceptible to radiation-induced transcriptional alteration of Ier5. (authors)

  18. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose

  19. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    Li, Bin [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Feng, Yi, E-mail: fyhfut@163.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Gang; Zhang, Jingcheng [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zhuang, Zhong; Wang, Xianping [Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2013-11-15

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose.

  20. Histological variations in liver of freshwater fish Oreochromis mossambicus exposed to 60Co gamma irradiation

    The irradiation effect of 60Co at the three dose level of 3 mGy, 30 mGy and 300 mGy on the histology of liver of the freshwater fish Oreochromis mossambicus was investigated. The liver of O. mossambicus was dissected out and processed for light microscopy studies. 60Co exposed O. mossambicus were found to result in several alterations in the histoarchitecture of liver. The alterations included mild congestion of blood vessels, structural alteration, cellular swelling, vacuolation and necrotic liver cells, indicating a definite response to 60Co irradiation. The results suggest that the liver of O. mossambicus exposed to 60Co were structurally altered with increasing dose levels. It is to record that alteration in the liver does not affect the physiology, behaviour or lethality of the individuals. Self regulating mechanisms would have influenced the liver to remain sustained. To confirm the same further studies in the direction by increasing dose level is required. - Highlights: ► Fish Oreochromis mossambicus irradiated to the dose of 3 mGy, 30 mGy and 300 mGy. ► Histoarchitecture of liver altered with increasing dose levels of 60Co. ► Alteration in the liver does not affect the physiology, behaviour or lethality. ► Self regulating mechanisms might have prevented from Lethality. ► HSI index value for exposed group reported (60Co.

  1. Molecular exclusion chromatographic analysis on 60Co irradiated rattlesnake

    Ionizing radiations are sufficiently energetic to be able of breaking chemical bonds and as result of that molecules of substances present in the irradiated will be chemically changed and their biological properties affected also. In this paper the effects of gamma radiation of Co-60 on the rattlesnake venom were studied. A pool of positive crotamina Crotalus durissus terrificus venom was dissolved in 0,15 M NaCl and irradiated with Co-60. Doses of 100, 250, 500, 750, 1500 and 2000 Gy were applied at the dose rate of 1190 Gy/h. With doses over 500 Gy the solutions became turbid, suggesting the presence of aggregates and structural changes of the proteins. The concentration of proteins from the filtered solution was measured by the Lowry method. One ml samples were measured at 230 nm. The partition coefficients and the areas of the three main fraction obtained were calculated. (author)

  2. Effect of 60Co γ-ray irradiation on salmonella in high immunity egg yolk

    Salmonella were inoculated into the yolk and irradiated with different dose of 60Co γ-ray. The results show that 3 kGy irradiation dose can kill all Salmonella in the yolk and D10 value of Salmonella in the yolk is 0.36-0.46 kGy

  3. Suppressing effect of low-dose gamma-ray irradiation on collagen-induced arthritis

    We previously reported attenuation of autoimmune disease by low-dose gamma-ray irradiation in MRL-lpr/lpr mice. Here, we studied the effect of low-dose gamma-ray irradiation on collagen-induced arthritis (CIA) in DBA/1J mice. Mice were immunized with type II collagen, and exposed to low-dose gamma-rays (0.5 Gy per week for 5 weeks). Paw swelling, redness, and bone degradation were suppressed by irradiation, which also delayed the onset of pathological change and reduced the severity of the arthritis. Production of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6, which play important roles in the onset of CIA, was suppressed by the irradiation. The level of anti-type II collagen antibody, which is essential for the onset of CIA, was also lower in irradiated CIA mice. The population of plasma cells was increased in CIA mice, but irradiation blocked this increase. Since regulatory T cells are known to be involved in suppression of autoimmune disease, the population of CD4+CD25+Foxp3+ regulatory T cells was measured. Intriguingly, a significant increase of these regulatory T cells was found in irradiated CIA mice. Overall, our data suggest that low-dose gamma-ray irradiation could attenuate CIA through suppression of pro-inflammatory cytokines and autoantibody production, and induction of regulatory T cells. (author)

  4. Obtained and evaluation of antisera raised against irradiated crotalic whole venom or crotoxin in 60 Co source

    Snake bite is a great Public Health problem in our country. The accidents with snakes from Crotalus genus are the most severe. About 1% of the victims die without seratherapy. The antivenons are obtained from hyper immune horse plasma. During the production these animals present signs of envenoming that result in a decrease of organic resistance besides the horses maintenance is very expensive and the producers are fewer, so the sera production is restrict. Many techniques which could reduce the venoms toxicity and increase the sera production using chemical and physical agents have been studied. The gamma rays are excellent tool to detoxify venoms and toxins. It is able to modify protein structures that decrease lethally, toxic and enzymatic activities without modifying the immunogenicity. So, it is important evaluate the sera production in rabbits using gamma rays detoxified venom and crotoxin as immunogen and their power as reagents in immuno assays. In order to obtain the antisera, Crotalus durissus terrificus whole venom or isolated crotoxin was irradiated with 2.000 Gy in 60 Co source, in a 150 mM NaCl solution, and inoculated in rabbits. The sera production were screened by immunoprecipitation, immuno enzymatic (ELISA) and immunoradiometric (IRMA) assays. The specificity was studied by immuno-electrophoresis, ELISA and western blot techniques. The neutralizing power was evaluated by neutralization of phospholipase A2 activity of toxin in vitro. The antisera were used as reagents in antigen capture assays ELISA and IRMA immuno assays to detect circulant antigens in sera of mice experimentally inoculated with crotalic venom or crotoxin. The results showed that both detoxified venom or crotoxin were good immunogens, and they were able to induce antibodies that could recognize non-irradiated venom or isolated crotoxin. The data suggest that those antibodies present more specificity and higher in vitro neutralizing power, when compared with commercial

  5. Effect of gamma ray irradiation on seed germination of Ardisia crenata

    The seeds of Ardisia crenata were used as experimental material and treated with gamma ray under the irradiative doses ranging from 50∼500 Gy. The results showed that the seed germination rates were not affected under the irradiative dose of 150 Gy and below. The germination potentiality turned to reduce while the irradiative dose was higher than 250 Gy. And in the range of 300∼500 Gy the germination rates were decreased with the increase of the irradiative dose. (authors)

  6. Effect of 60Co γ irradiation and GA3 treatment on mutation of Carica papaya L

    The seeds of Carica papaya L. were irradiated by 60Co γ-rays of 10-40 Gy and treated by GA3 of 10-50 mg/L after irradiation. The results showed that small nuclear cell percentage, chromosome variation percentage and leaf variability of papaya seedling increased with increase of irradiation dose, the pollen fertility and fruit quality decreased. GA3 of 10-50 mg/L treatment after irradiation could alleviate the irradiation harm, and the effect of lower concentration of GA3 was better than higher concentration with lower dose irradiation, however, the effect of higher concentration of GA3 was better with higher dose irradiation

  7. The Cellular Differences between Acute and Chronic Neutron and Gamma-Ray Irradiation in Mice

    Data on the shortening of the life span in mice by radiation show that an acute dose of gamma-rays may be as much as four times as effective as an equal dose of the same radiation administered chronically. However, for neutrons, chronic and acute administrations are equally effective. An analysis of these effects shows that for gamma-rays a certain fraction of the radiation injury is reparable, and that the value of this fraction depends on the dose and the dose rate. With neutrons, none of the damage appears reparable. For acute irradiation, the RBE is about 2 for shortening of the life span, but for chronic, may be as high as 8. Chromosome aberrations have been scored in liver cells of mice when treated with both chronic and acute doses of both gamma-rays and thermal neutrons. In all cases the percentage of aberrent cells is proportional to the shortening of the life span produced by the treatment. Further, with neutrons, acute and chronic irradiation is equally effective in producing chromosome abberations. For gamma-rays, acute irradiation may produce as much as four times the chromosomal damage as does chronic irradiation. This shows that some chromosomes can heal themselves following small doses of gamma-rays, but there is no chromosome healing following any dose of neutrons. The RBE using chromosome aberrations as a criterion is the same as for life shortening. These results give a firm cellular basis for the known biological differences between gamma rays and neutrons, and in addition give strong support to the concept that natural and radiation-induced aging are caused by spontaneous and radiation-induced mutations, respectively, in the somatic cells of animals. (author)

  8. Changes of collagen metabolism induced by 60Co γ-ray external irradiation

    Objective: To study the changes and molecular mechanism of collagen metabolism induced by 60Co γ-ray external irradiation of local tissues. Methods: After the hip skin of rabbits was irradiated with 60Co γ-rays, the changes of collagen metabolism and collagen contents of the rabbits' skin of different sex groups were determined. Results: The γ-rays decreased the soluble collagen contents (especially type III) and increased the activity of MMPs in local tissues. Although the radiation affected the contents of serum SOD, 5-HT, and LPO, its influence on the contents in local tissues was not remarkable. There were changes of collagen metabolism in local tissues after radiation injury, but no differences were found in SOD, 5-HT, LPO, and glucosamine of tissues. Conclusion: The main mechanism of skin burn induced by 60Co γ-rays may be that the changes of collagen metabolism bring about the pathological effect

  9. Mutation induction in Philippine bananas c.v. 'Lakatan' thru gamma ray irradiation

    Banana is the most important crop grown in the Philippines. Among the cultivars grown, 'Lakatan' is the most popular and commands a higher price in the local market. Despite high production, losses due to over ripening, bruising and short shelf life is one of the major constraints in a successful banana industry. The use of chemicals for delayed ripening however, remains an issue of concern due to economic and organic products advocacy. Thus, development and generation of new improved 'Lakatan' cultivar through gamma ray irradiation was carried out. Mutation was induced in 'Lakatan', a popular Philippine cultivar using gamma ray irradiation. Radio sensitivity was established at 50Gy. Morphological, cytological and molecular analysis done showed significant variations between the irradiated samples and the non-irradiated plants. In terms of morphological parameters, gamma ray irradiation affected leaf traits resulting to increased leaf width, leaf length, and number of leaves. Stem girth on the other hand was significantly reduced. Cytological observations showed that gamma irradiation increased the epidermal width, leaf thickness and size of stomates but reduced the number of stomates. For post harvest attributes, gamma irradiation prolonged the shelf life of banana fruits from 11 days to 14 days. Molecular analysis showed that some markers (RAPD and AFLP) were able to detect unique bands in samples irradiated with 50Gy while the SSR markers did not detect any band difference between the irradiated samples and the control. (author)

  10. A description of 60Co gamma irradiation facilities in the Radiation Biology and Health Physics branch

    The Radiation Biology and Health Physics Branch manages three 60Co irradiation facilities, to (Gammabeam 150C, Gammacell 200 and Gammacell 220) provide a range of dose rates suitable for variety of applications. This report describes the physical characteristics of the facilities, a description of the dosimetry and operating procedures. (author). 6 refs., tabs., figs

  11. Performance analysis of gamma-ray-irradiated color complementary metal oxide semiconductor digital image sensors

    The performance parameters of dark output images captured from color complementary metal oxide semiconductor (CMOS) digital image sensors before and after gamma-ray irradiation were studied. The changes of red, green and blue color parameters of dark output images with different gamma-ray doses and exposure times were analyzed with our computer software. The effect of irradiation on the response of blue color was significantly affected at a lower dose. The dark current density of the sensors increases by three orders at > 60 krad compared to that of unirradiated sensors. The maximum and minimum analog output voltages all increase with irradiation doses, and are almost the same at > 120 krad. The signal to noise ratio is 48 dB before irradiation and 35 dB after irradiation of 180 krad. The antiradiation threshold for these sensors is about 100 krad. The primary explanation for the changes and the degradation of device performance parameters is presented. (author)

  12. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min-1 (120 gal min-1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater

  13. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    Kurucz, Charles N.; Waite, Thomas D.; Otaño, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-11-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater.

  14. Influence of irradiation of gamma-ray on the pulping and paper making, (2)

    In kraft pulping and neutral sulphite pulping of gamma-ray irradiated chips, the influence of irradiation on the defiberability of the yielded pulps were investigated. The results were summerized as follows: 1) In kraft pulping, the defiberability becomes inferior by the irradiation of 5 x 105R. 2) In neutral sulphite pulping, the defiberability seems to become somewhat better by the irradiation of 106R. And kapper number does not change within the area of the high pulp yield but it becomes smaller according to the decrease of the total pulping yield by the irradiation of 106R, in comparison with the case of no-irradiation. (author)

  15. Analysis of the microbial growth in {sup 60}Co {gamma}-irradiated foods by calorimetry

    Furuta, Masakazu; Hayashi, Toshio [Osaka Pref. Univ., Research Institute for Advanced Science Technology, Sakai, Osaka (Japan); Hamasaki, Koji; Wirkner, Sandra; Constantinoiu, Elena; Takahashi, Katsutada [Osaka Pref. Univ., College of Agriculture, Sakai, Osaka (Japan)

    2002-09-01

    Using a heat conduction calorimeter equipped with 24 sample units the heat evolutions from growing {sup 60}Co {gamma}-irradiated bioburden of black pepper seeds and frozen beef were detected in the form of growth thermograms. {sup 60}Co {gamma}-irradiation affected the growth pattern in which a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. We successfully determined the minimal inactivation doses for the two food samples using the relationship between the irradiation dose and the retardation in growth t{sub {alpha}}, or the growth rate constant {mu} obtained from the growth thermograms. These results strongly suggested the possibility of calorimetry as measure of predictive microbiology in food irradiation. (author)

  16. Assessment of differences between X and gamma rays in order to validate a new generation of irradiators for insect sterilization

    Mastrangelo, Thiago; Walder, Julio M.M., E-mail: piaui@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Parker, Andrew G.; Jessup, Andrew; Orozco-Davila, Dina; Islam, Amirul; Dammalage, Thilakasiri, E-mail: A.Jessup@iaea.or [Joint FAO/IAEA-UN A-2444, Seibersdorf (Austria). Insect Pest Control Subprogramme; Pereira, Rui, E-mail: R.Cardoso-Pereira@iaea.or [Joint FAO/IAEA-UN, Vienna (Austria). Insect Pest Control Subprogramme

    2009-07-01

    Recent fears of terrorism provoked an increase in delays and denials of transboundary shipments of radioisotopes. This represents a serious constraint to sterile insect technique (SIT) programs around the world as they rely on the use of ionizing energy from radioisotopes for insect sterilization. In order to validate a novel Xray irradiator, a series of studies on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) were carried out, comparing the relative biological effectiveness (RBE) between X-rays and traditional gamma radiation from {sup 60}Co. Male C. capitata pupae and pupae of both sexes of A. fraterculus, both 24 to 48 h before adult emergence, were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Estimated mean doses of 91.2 Gy of X and 124.9 Gy of gamma radiation induced 99% sterility in C. capitata males. Irradiated A. fraterculus were 99% sterile at about 40-60 Gy for both radiation treatments. Standard quality control parameters were not significantly affected by the two types of radiation. There were no significant differences between X and gamma radiation regarding mating indices. The RBE did not differ significantly between the tested X and gamma radiation, and X-rays are as biologically effective for SIT purposes as gamma rays are. This work confirms the suitability of this new generation of X-ray irradiators for pest control programs in UN Member States. (author)

  17. Effect of gamma-ray irradiation on cord blood lymphocyte proliferation and NK cell activity

    Objective: To investigate the effects of gamma-ray irradiation on cord blood lymphocyte proliferation and NK cell activity. Methods: Freshly isolated mononuclear cells from human cord blood were irradiated with different doses (0.248-15.872 Gy) of gamma-rays. The lymphocyte proliferation and NK cell activity were measured using 3H-TdR incorporation assay and 3H-TdR release assay, respectively. Results: In dose range of 0.248-15.872 Gy, lymphocyte proliferation was inhibited and the inhibition rate was positively correlated with the irradiation dose(r=0.839, P<0.05). Lymphocyte proliferation was not found in dose range of 3.968-15.872 Gy. Irradiation doses from 0.248 to 1.984 Gy could enhance NK cell activity. The activity of NK cells was reserved after irradiated with 3.968 Gy. Within the dose range of 5.952-15.872 Gy, NK cell activity was significantly inhibited. Conclusion: Lymphocyte proliferation is inhibited and the activity of NK cell is reserved when irradiated with the dose of 3.968 Gy gamma-rays. So if the lymphocytes are irradiated with such a dose before donor lymphocytes infusion or mix-cord blood transplantation, the effect of graft versus host disease (GVHD) could be decreased whereas the effect of graft versus leukemia (GVL) reaction could be reserved simultaneously during adoptive cellular immunotherapy. (authors)

  18. Effects of gamma-ray irradiation on leaching of simulated 133Cs+ radionuclides from geopolymer wasteforms

    Highlights: • γ-ray irradiation caused more Cs+ leaching out from geopolymer wasteform. • Pore structure change induced by irradiation caused the increase of leachability. • Fly-ash-based geopolymer is a potential material for radionuclide immobilization. - Abstract: Leaching of simulated 133Cs+ radionuclides from geopolymer wasteforms was examined with regard to effects from gamma-ray irradiation. Specifically, the compressive strengths, microstructures, pore structures, and leaching resistance of geopolymer wasteforms before and after irradiation were characterized. The leaching experiments were performed by immersion of wasteforms in deionized water, ground water, and seawater. It was found that gamma rays did not produce significant morphological changes, except for changes in the pore size distribution. The cumulative leaching fraction of all the leachants from the irradiated samples increased relative to the non-radiated samples, particularly during long leaching periods (11–42 days). These results, and those from a mercury intrusion porosimeter analysis, can be attributed to irradiation-induced changes in pore structure. All the leaching indexes were greater than the minimum acceptable value of 6.0 set by the American Nuclear Society Standards committee, which indicated that the fly-ash geopolymers are suitable for radionuclide immobilization. However, the effects of gamma-ray irradiation on the immobilization of radionuclides cannot be ignored

  19. Studies of Gamma-Ray-Irradiated Human Immunoglobulin G

    Freeze-dried IgG with incomplete anti-Rh0(D) activity retained its reactivity after irradiation with a dose of 1.5 - 2.5 Mrad γ-rays. A portion of the irradiated protein was insoluble. Gel-filtration on Sephadex G-200 indicated the presence of aggregated IgG in addition to the non-aggregated form. Proteolytic experiments revealed an altered digestibility of the protein with papain after irradiation. (author)

  20. Germination Viability of Maize M1 Seeds (Zea mays L.) after Gamma Ray Irradiation

    Rafiuddin; Dahlan, Dahliana; Musa, Yunus; Rasyid, Burhanuddin; BDR, Muh. Farid

    2013-01-01

    A series of researches was carried out to obtain mutant of maize induced by gamma rays irradiation. This initial report was from a study confirming the best dosage of irradiation at 50% lethal dosage (LD50) conducted at the Laboratory of Seed Science and Technology, Faculty of Agriculture, Hasanuddin University, Makassar from March to June 2012. The research was set up using split plot design of the Randomized Complete Block design. Data were analyzed using analysis of variance...

  1. Effects of gamma-ray irradiation on cellulase secretion of Trichoderma reesei

    Trichoderma reesei was irradiated with gamma rays to investigate the effects of different dosages on cellulase production. Doses above 0.7 kGy induced cell lysis. Cell growth began to be obstructed at 2.0 kGy. As a result, the cells irradiated at 2.0 kGy secreted 1.8 times as much cellulase as the untreated cells

  2. Effect of 60Co-γ ray irradiation on green coffee beans, 1

    Green coffee beans were irradiated with 60Co-γ rays at doses of 0, 0.05, 0.5, 5.0 and 10.0 Mrad and the changes of general components in green and roast coffee beans were investigated together with those of the organoleptic properties of roast beans during storage according to the cup testing. In case of Brazil santos beans, irradiation of some 0.05 Mrad 60Co-γ ray gave rather favourable mild flavour and no harmful influence on the quality of coffee, and moreover, would tend to extend the shelf life of roast beans. But influence of irradiation on the quality of coffee differed somewhat between two cultivars, Brazil santos and Colombia. (auth.)

  3. SV40 DNA amplification and reintegration in surviving hamster cells after 60Co γ-irradiation

    SV40-transformed Chinese hamster embryo cells were exposed to 60Co γ-irradiation and the fate of the integrated SV40 sequences was pursued over a period of 20 days following radiation exposure. As shown by colony hybridization, integrated SV40 sequences were amplified in surviving and non-surviving cells. At later times, however, clonal sublines of surviving cells grown for 20-30 cell generations after irradiation had lost most of their amplified SV40 copies but showed altered restriction fragment patterns indicating reintegration of SV40 sequences at new sites of the hamster genome. This suggest that 60Co γ-irradiation can generate mutations by inducing over-replication of chromosome segments that are then substrates of enzymatic rearrangements. (author)

  4. Gamma ray irradiated silicon nanowires: An effective model to investigate defects at the interface of Si/SiOx

    The effect of gamma ray irradiation on silicon nanowires was investigated. Here, an additional defect emerged in the gamma-ray-irradiated silicon nanowires and was confirmed with electron spin resonance spectra. 29Si nuclear magnetic resonance spectroscopy showed that irradiation doses had influence on the Q4 unit structure. This phenomenon indicated that the unique core/shell structure of silicon nanowires might contribute to induce metastable defects under gamma ray irradiation, which served as a satisfactory model to investigate defects at the interface of Si/SiOx

  5. Gamma ray irradiated silicon nanowires: An effective model to investigate defects at the interface of Si/SiOx

    Yin, Kui; Zhao, Yi; Liu, Liangbin; Lee, Shuit-Tong; Shao, Mingwang, E-mail: wxlthefirst@gmail.com, E-mail: xuegi@nju.edu.cn, E-mail: mwshao@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices and Collaborative Innovation, Center of Suzhou Nano Science and Technology, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123 (China); Wang, Xiaoliang, E-mail: wxlthefirst@gmail.com, E-mail: xuegi@nju.edu.cn, E-mail: mwshao@suda.edu.cn; Xue, Gi, E-mail: wxlthefirst@gmail.com, E-mail: xuegi@nju.edu.cn, E-mail: mwshao@suda.edu.cn [State Key Laboratory of Co-ordination Chemistry, Department of Polymer Science and Engineering, Nanjing University, No. 20, Hankou Road, Nanjing 210093 (China)

    2014-01-20

    The effect of gamma ray irradiation on silicon nanowires was investigated. Here, an additional defect emerged in the gamma-ray-irradiated silicon nanowires and was confirmed with electron spin resonance spectra. {sup 29}Si nuclear magnetic resonance spectroscopy showed that irradiation doses had influence on the Q{sup 4} unit structure. This phenomenon indicated that the unique core/shell structure of silicon nanowires might contribute to induce metastable defects under gamma ray irradiation, which served as a satisfactory model to investigate defects at the interface of Si/SiOx.

  6. Modified the optical and electrical properties of CR-39 by gamma ray irradiation

    A.M. Abdul-Kader

    2014-07-01

    Full Text Available The radiation technique is a useful technology technique to induce suitable modifications of the polymeric materials. In the present work, poly allyl diglycol carbonate (CR-39 solid state nuclear track detector samples were irradiated using different doses (150–950 kGy of gamma ray irradiations. The effect of gamma ray irradiations on the optical and electrical, properties of CR-39 was investigated. The obtained results showed a decrease in the optical energy gap with increasing the gamma dose. Increase in the numbers of carbon atoms (N in a formed cluster with increasing the irradiation dose was observed. Meanwhile, an increase in the Ac conductivity was obtained with increasing the gamma dose. Also, the variation in the dielectric constant and loss with irradiation dose was studied at the room temperature. The results indicate that the gamma ray irradiations in the dose range 150–950 kGy enhance the optical and electrical properties of the CR-39 polymer samples.

  7. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages; Avaliacao do mecanismo de captacao e endocitose de crotoxina submetida a acao da radiacao, por macrofagos peritoneais de camundongos

    Cardi, Bruno Andrade

    1999-07-01

    The purpose was to investigate the uptake and endocytosis of 2000 Gy {sup 60}Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy {sup 60} Co {gamma}-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays ({sup 60} Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  8. Selection of variants with high levels of biotin from cultured green Lavandula vera cells irradiated with gamma rays

    Cultured green Lavandula vera cells were irradiated with various dosages of gamma rays which increased the variation in the amount of free biotin produced by the cell clones. Variant sublines containing much more free biotin than the original line were obtained by repeated selection. The effectiveness of gamma rays for the induction of the variant sublines is described

  9. Low temperature gamma-ray irradiation effects on polymer materials

    The gamma radiation induced degradation of glass fiber reinforced plastic (GFRP) and polymethylmethacrylate (PMMA) at 77K was examined by flexural test and gas analysis after irradiation and compared by the irradiation at room temperature. The decrease in flexural strength at break was much less at 77K than at RT. The evolution of CH4, CO and CO2 was also depressed at 77K. The temperature dependence of the degradation closely relates to the local molecular motion of matrix resin during irradiation. Polytetrafluoroethylene (PTFE) was also studied by irradiation at RT, 77K and 4K in terms of tensile elongation and molecular weight. The degradation was much less at 77K and 4K than at RT, and the same between 77K and 4K. (author)

  10. Gamma-ray irradiation induced bulk photochromism in WO3-P2O5 glass

    Shen, Wei; Baccaro, Stefania; Cemmi, Alessia; Xu, Xiaoqing; Chen, Guorong

    2015-11-01

    In the present work, photochromism of WO3-P2O5 glass under gamma-ray irradiation was reported. As-prepared glass samples with different WO3 content are all optically transparent in the visible wavelength range thanks to the addition of a small amount of oxidizing couple Sb2O3-NaNO3. The photochromic properties are identified by transmission spectra of the glasses before and after irradiation. The results show that the irradiation induced darkening results from the reduction of W6+ to W5+ or W4+. The existence of WO6 clusters in glasses of high WO3 content is proved by XPS, which is the main reason for the obvious photochromic effects. The WO3-P2O5 glass is a promising candidate in gamma-ray sensitive detector.

  11. Electrochemical and corrosion behavior of passive film on stainless steels after gamma-ray irradiation

    The nature and structure of passive film on AISI 304L and AISI 446 stainless steels, after bare metal anodic oxidation and after the subsequent galvanostatic reduction or gamma-ray irradiation of the oxide film formed, were investigated by XPS and Electrochemical Impedance Spectroscopy (EIS). Atomic Absorption Spectroscopic (AAS) analysis of irradiated solution was also undertaken. Results obtained from XPS measurement indicated that gamma-ray irradiation can have significant effects on the stability of passive film due to the release of iron and corresponding enrichment in chromium oxides. The EIS technique was used to elucidate the physical structure of passive film after irradiation and galvanostatic reduction. The passive film formed on AISI 304L and AISI 446 stainless steels have a compact structure. The galvanostatic treatment leads to a film composed of two layers, the external one showing a spongy-like structure, while the gamma-ray irradiation treatment leads to a thinner compact film exhibiting higher capacitive behavior compared to that of unirradiated samples

  12. The studies on apple preservation by 60Coirradiation

    Studies on 60Coirradiation of Golden Delicious apple have been carried out. The results showed that the optimum irradiation dosage for stored apple was ranged from 0.3-0.5 kGy. With this dosage, the contents of vitamin C and titratable acidity in these apples had no significant change compared with unirradiated apples. The respiratory rate and the amount of ethylene release were decreased after irradiation. The mortality of the verticillate pathogenic fungi was 97% at the dose of 0.5 kGy

  13. Effect of Low Dose gamma-ray Irradiation on the Germination and Growth in Red Pepper (Capcicum annuum L.)

    This study was conducted to determine the effect of low dose gamma-ray irradiation in red pepper. The germination percentage, plant, the number of flower, chlorophyll contents, leaf length and width were observed from plants grown with red pepper seeds irradiated with various low dose of gamma-ray. The germination percentage of irradiation group treatmented gamma-ray was much higher than that of the control. Specially the germination percentage after sowing red pepper seeds on paper towel was higher than 1,000 and 2,000 rad irradiation group. The height of plants grown with red pepper seeds irradiated with gamma-ray was increased in 100, 200 and 400 rad irradiation group compared to that of the control. The height of plant from 2,400 rad irradiation group, however, was shorter than that of the control. Nutrient contents of leaves of plants grown with red pepper seeds irradiated with various dose of gamma-ray were significantly increased in 800 and 1,200 rad irradiation group. Electric conductivity (EC) of the water used for seed germination was lower irradiation group than control group. Therefore, there was the possibility to increase the germination and plant growth with gamma-ray of adequate low dose

  14. Gamma-ray irradiation of a boreal forest ecosystem

    A long-term radiation ecology research project called Field Irradiator - Gamma (FIG) began at the Whiteshell Nuclear Research Establishment in 1968. The experimental area is in southeastern Manitoba and is located on the western edge of the Precambrian shield. The project studies the ecological effects continuous exposure to a gradient of gamma radiation has on a mixed boreal forest ecosystem. The gradient ranges from 1 to 460,000 times the natural background radiation level. This paper describes the forest, the gamma irradiator and its radiation field, and the research program

  15. Experiments for inactivation of mycoplasms and bacteria in calf sera, using 60Co irradiation

    The use of 60Co gamma radiation to inactivate mycoplasms in calf serum, newborn calf serum, and fetal calf serum is reported. A dose of 3 kGy, independent of dose rate, was found to be sufficient for inactivation in the above sera of several mycoplasms, including Acholeplasma laidlawii, Mycoplasma orale, M. arginini, M. hyorhinis, and M. bovis. The critical dose proved to be at 2 kGy. No difference was found to exist between the above species in susceptibility to irradiation in diluted sera (50% and 10% in Eagle MEM). Sensibility of wild mycoplasm strains was found to be identical with that of laboratory strains. Hence, 60Co gamma irradiation of sera appears to be a safe method by which to make sera free of mycoplasms. Bacillus subtilis in calf serum was inactivated by doses above 18 kGy, with the critical dose being 15 kGy. (author)

  16. Effect of cobalt 60 gamma-ray irradiation on the hatching process of chicken eggs

    An experiment on fertilized chicken eggs was carried out to determine the effects of 60Co irradiation on the embryos, their fatality, and growth impairment or deformity, in particular. The experimental groups, consisting of 10 eggs each, recieved a 60Co irradiation of 50 to 2,000 rads on any one day between day 0 and day 20 of incubation. The larger the irradiation dose, the greater was the number of dead embryos. The fatality was higher in the groups receiving irradiation in the earlier stage (1st week). The resultant death was a chronic one. The irradiation also caused body weight decrease and growth impairment. A decrease in the brain and liver weights was noted, suggesting insufficiency in these organs. Deformity occurred in 4%, most of which involved impairments of skeletal growth, of the bones of the extremities and the bill, in particular. Administration of the SH amino acid, cysteine tended to alleviate the adverse effects of the 60Co irradiation. These results for fertilized chicken eggs suggest the possibility of abortion and the occurrence of deformities in human fetuses if they should be subjected to 60Co irradiation. (author)

  17. Glasses, Coatings, Glues and Gamma-ray Irradiation

    Barcala, J.M.; Fernandez, M. G.; Ferrando, A.; Fuentes, J.; Josa, M. I.; Molinero, A.; Oller, J. C. [Ciemat. Madrid (Spain); Arce, P.; Calvo, E.; Figueroa, C. F.; Rodrigo, T.; Vila, I.; Virto, A. L. [Universidad de Cantabria. Santander (Spain); Beigveder, J. M.; Genova, I.; Perez, G.; Ruiz, J. A. [CIDA. Madrid (Spain)

    2001-07-01

    Most of the alignment systems for LHC experiments use optomechanical elements confirming a network of points that are monitored by laser beams. LHC experiments, working at the expected nominal luminosity, will induce an extremely high irradiation. basic components such as glasses, coatings and glues may change and their performance may degrade significantly. We have tested various components and identified some of them that can stand 10 years of LHC operation. (Author) 11 refs.

  18. High energy irradiations simulating cosmic-ray-induced planetary gamma ray production. I - Fe target

    Metzger, A. E.; Parker, R. H.; Yellin, J.

    1986-01-01

    Two thick Fe targets were bombarded by a series of 6 GeV proton irradiations for the purpose of simulating the cosmic ray bombardment of planetary objects in space. Gamma ray energy spectra were obtained with a germanium solid state detector during the bombardment, and 46 of the gamma ray lines were ascribed to the Fe targets. A comparison between observed and predicted values showed good agreement for Fe lines from neutron inelastic scattering and spallation reactions, and less satisfactory agreement for neutron capture reactions, the latter attributed to the difference in composition between the Fe target and the mean lunar abundance used in the modeling. Through an analysis of the irradiation results together with continuum data obtained in lunar orbit, it was found that 100 hours of measurement with a current instrument should generate a spectrum containing approximately 20 lines due to Fe alone, with a 2-sigma sensitivity for detection of about 0.2 percent.

  19. One-step synthesis of graphene-Pt nanocomposites by gamma-ray irradiation

    Tokai, Akihiro; Okitsu, Kenji; Hori, Fuminobu; Mizukoshi, Yoshiteru; Iwase, Akihiro

    2016-06-01

    We developed a one-step gamma-ray irradiation method to synthesize nanocomposites composed of graphene and Pt nanoparticles from aqueous solution containing graphene and Pt(IV) complex ions in the presence of 2-propanol (IPA) or sodium dodecyl sulfate (SDS). It was confirmed that gamma-ray irradiation provided carbonyl groups on graphene and Pt nanoparticles formed from the radiolytic reduction of Pt(IV) complex ions were deposited onto the carbonyl modified graphene. In the presence of IPA, small Pt nanoparticles were deposited on graphene, but large Pt nanoparticles were deposited in the presence of SDS: the size of Pt nanoparticles formed was larger in the presence of SDS than IPA. Based on the results, formation and deposition mechanisms of Pt nanoparticles were proposed.

  20. Post irradiation changes of haematological parameters in mammals blood after high dose gamma rays

    In our experiment we monitored post irradiation changes of haematological parameters in rats after single total - body dose of gamma rays 15 Gy. Significant decrease was in the erythrocyte count at 6th day (P th day (P th day. In the white blood picture in all experimental groups was leukopenia (P < 0.001), which was characterized by neutrophilia (P < 0.001) and lymphopenia (P < 0.001). (authors)

  1. Modification of morphological traits of common beans through gamma-ray irradiation: analysis of three consecutive generations

    The objective of this investigation were to study the effects of different levels of gamma-rays on some morphological characteristics of a nearly-white seed coat color bean (Phaseolus vulgaris L.) cultivar, and to determine the radiation level which would generate the greatest genetic variability. Breeder seeds of EMGOPA 201 - Ouro cv, a beige seed coat color cultivar, were submitted to gamma-ray irradiation (60 Co). Treatments consisted of eight levels of radiation: 0,10, 15, 20, 25, 30, 35 and 40 Krad. The experimental design was a randomized complete block with four replications. In the field, plots consisted of 100 seeds. The following data were collected: percent germination, plant height, final stand, plant yield and yield components, number of chlorotic and albino mutants, leaf mutants, growth habit alterations, earliness, seed coat brightness, halo color, seed size and format. Among traits greatest variations were observed seed morphology. Seed coat color varied from completely white to a dark-brownish color. Halo color was also modified from yellow (normal) to pink. Brightness of seeds varied from opaque to bright. Seed varied from squared to rounded, and from very small to large. treatments with 20 and 25 Krad generated the greatest variability for several morphological traits from the M1 to M3 generations, a dosage equivalent to the LD50 observed in the M1 generation. Traits such as percent germination, plant height and some yield components were highly and negatively affected by increasing levels of radiation. Modification of yield components as well as many unusual characteristics with late onset were observed in advanced generations, suggesting that late selection would also be useful. (author)

  2. The influence of 60Co gamma rays to cell reproduction (An experiment using low dose levels on vero and primary monkey kidney cells)

    Vero and primary monkey kidney cells in culture were gamma irradiated with doses of 0, 0.4 and 0.8 Gy at a dose-rate of 1.30-1.45x103Gy/hour. At harvest time 3 days post irradiation, 0.4 Gy proved to be able to lower the number of vero cells in such a degree that it became significantly different from the control, whereas 0.8 Gy could not suppress the number of primary cells to a level that differed significantly from its control. At harvest time of 7 days post irradiation, 0.4 Gy was found effective in lowering both vero and primary cells so that the number of the harvested cells were significantly different from the controls. At harvest time of 3 days post irradiation, 0.8 Gy caused both cell types reached levels that were not significantly different from 0.4 Gy, but at 7 days post irradiation the number of vero cells was very significantly different from that of 0.4 Gy, while the number of primary cells remained equal to that of 0.4 Gy. This phenomenon showed that irradiation could cause greater injurious effect at more advanced post irradiation times, while the more proliferative vero cells proved to be more susceptible to irradiation than primary cells, but at the same time more potential in performing repair. (author)

  3. Inactivation effect of 60Co gamma ray on cysticerci of Taenia solium in pork%60Coγ射线对猪肉中囊尾蚴的辐照杀灭效应

    钟凯; 高翔; 计融

    2011-01-01

    Objective revealing the relationship between irradiation dose and inactivation ratio for eysticerei of Taenia solium in pork, determining the minimal dose for totally killing cysticerci and providing scientific evidence for setting up relevant hygienic standards of radiation. Methods After Taenia solium infected pork being treated with different irradiation doses; cysticerci were separated and incubated in fresh swine bile. The adjusted inactivation ratio was calculated according to the survival rate. Results There was a linear correlation between irradiation dose and adjusted inactivation ratio, the D10 value was about 3.8 kGy, and a totally killing could be achieved by 4.5 kGy irradiation. Conclusion Irradiation at a dose of 4.5 kGy could be applied as the maximum dose to inactivate cysticerci of Taenia solium in pork processing.%目的 揭示猪肉中囊尾蚴灭活率与辐照剂量的相关关系及最小杀灭剂量,为制定相应辐照卫生规范提供科学依据.方法 以不同剂量Co γ射线处理感染囊尾蚴的猪肉,并用新鲜猪胆汁孵化剥离出的囊尾蚴,根据成活率计算校正灭活率.结果 辐照剂量与校正灭活率具有线性相关,D值约为3.8 kGy,4.5 kGy可完全杀灭囊尾蚴.结论 4.5 kGy γ射线对猪肉中囊尾蚴有很好的杀灭效果.

  4. Effect of 60Co-irradiation on penicillin G procaine in veterinary mastitis products

    The effect of 60Co-irradation on penicillin G procaine in a peanut oil-based veterinary mastitis product was examined by reversed-phase high-performance liquid chromatography (HPLC). The HPLC method is capable of separating and quantifiying procaine, penicillin G, and various degradation compounds. Values obtained by the HPLC method on the product irradiated and stored at various temperatures correlated well with those of the microbiological assay. No significant decrease in the procaine was detected even after 4.0-Mrad irradiation. The HPLC method is applicable for analysis of other beta-lactam antibiotics

  5. Effects of 60Co-γ ray irradiation on antioxidant enzyme activities in tobacco

    Effects of 300Gy 60Co-γ ray irradiation on the activities of 3 antioxidant enzymes in tobacco were studied in this paper. The results showed that the activities of superoxide dismutase (SOD), peroxidas (POD) and catalse (CAT) in tobacco were gradually increased. All the activities of SOD POD and CAT reached the maximums at 12 h and then gradually decreased. Similar results were also observed in the expression of sod, pod and cat genes. These results indicated that the activities of antioxidant enzymes could play an important role in tobacco tolerance against irradiation

  6. Economic effectiveness of irradiation with gamma rays on maize grains

    Gamma irradiation of maize grains before sowing increses the yield and improves the quality of agricultural produce. The positive results consist in the net income from silage maize from 45 to 85 per ha and from the grain maize from 85 to 109,9 per ha; the level of raw protein from the silage maize with 11,30% and from the grain maize with 6 to 12%; the level of feed units from the silage maize with 5 to 13% and from grain maize with 6 to 12%. Such direct effect in the same time is a stimulating one and raises the effectiveness of the animal production due to the better feeding of animals

  7. Effect of dosage on property and structure of gelatin irradiated by 60Co γ-ray

    The gelatin was irradiated for 0-60 kGy dosages by 60Co γ-ray. The relationship of dosage and properties including viscosity, gel strength, mechanical property, molecular weight and protein component was discussed. The results show that there is a negative correlation between the dosage and intrinsic viscosity, relative viscosity, gel strength and molecular weight. With the increase of irradiation dosage, the γ, β, α chain content of gelatin decreases but the small molecules content increases, and relative molecular weight distribution changes wider. The elongation decreases but tensile strength of gelatin film increases. Compared with no irradiation one, the irradiation gelatin has more compact and smooth surface texture. It is assumed that when the limited water and oxygen exist during the irradiation process, cross-linking and degradation of gelatin molecular produce simultaneously and the main reaction is cross-linking. The reaction degree increases with the dosage. (authors)

  8. Biological effects of 60Co γ-irradiation on Laiwu ginger VM1 growth

    Rhizome of Laiwu ginger were treated with γ-irradiation at the doses of 0, 20, 40 and 60 Gy. The results showed that 60Co γ-irradiation inhibited the rhizome burgeoning, and decreased the survival rate of the seedlings, rate of leaf- expansion and the growth of plants (VM1). The inhibition effects became stronger with the increase of the irradiation dose. Different bands were found through the analysis of POD, EST isozymes and RAPD of VM1 plants, which showed that variation on molecular level occurred in VM1 plants. LD30-40 was appropriate for the irradiation of rhizomes of Laiwu ginger and the optimal irradiation dose was about 20- 30 Gy. (authors)

  9. Decontamination of salmonella from the coastal fish meals by 60Co γ ray irradiation

    The decontamination fo salmonellae from fish meal samples by irradiation which 60Co γ ray was examined. Sixteen strains of Salmonella were used. A composite fish meal sample was prepared by mixing with different coastal meals, and after radiation sterilization at a dose of 20 kGy 60Co γ ray, which was employed as the salmonella-free meal sample. D10 values of test strains determined in buffered saline were found to range from 0.08 to 0.36 kGy, and inactivation factors at a dose of 1 kGy ranged from 102.8 to 1013. D10 values of test strains determined in the salmonella-free meal sample ranged from 0.59 to 1.64 kGy, and the inactivation factors at a dose of 10 kGy were found to range from 106.1 to 1017. Interestingly the D10 values of salmonellae determined in fish meal samples were 10 times as much compared with those determined in buffered saline. From the commercial aspects of coastal fish meal production, destruction of salmonellae in fish meals by 60Co γ ray irradiation was found to be much more practical than other methods such as dry heating and ethylene oxide fumigation. (author)

  10. Effects of testicular irradiation with 60Co in guinea pigs CAVIA PORCELLUS

    Improvements were made in restaint systems and in the technique of electroejaculation in guinea pigs, emphasizing safety, effectiveness and repetition. Arrangements for simultaneous testicular irradiation with 60Co in 5 animals and a phantom to test dose levels in the target region and scattering were also made. Effects of single and fractionated exposures on sperm were studied. A collimated point-shaped 60Co-machine calibrated to 7 R/min was used as radiation source. Groups of five 12 month aged male guinea pigs were exposed to either single testicular irradiation of 50, 100, 200 and 400 R or fractionated weekly testicular irradiation of 2, 5, 10 and 20 R, during 10 weeks. A last group was exposed to 4 fractionated testicular irradiations of 20 R at time intervals of 21 days and a group of 8 animals was used as control. Semen samples evaluations were made during 5 weeks before irradiation and in the subsequent 11 weeks. Abnormalities in sperm morphology were studied by William's method and phase contrast microscopy. Mean percentages of semen normal espermatzoons and spermatic abnormalities are shown in figures and photomicrographs. Marked differences on concentration, sperm motility and sperm abnormalities were found, but not on volume, in favour of 100 and 200 R single doses levels, as compared to fractionated 10 and 20 R. (Author)

  11. Effects of 60Co γ-rays irradiation on seed growth of ground-cover chrysanthemum

    The seeds of ground-cover chrysanthemum were used to study the effects of different doses of 60Co γ-rays irradiation(10-50 Gy) on seed germination and physiological characteristics. The results showed that the rate of seed germination and seedling survival decreased significantly with the irradiation doses. With the increase of irradiation dose to above 20 Gy, the content of malondialdehyde (MDA) and activity of peroxidase (POD) in seedlings significantly increased. The similar trends were found in the activities of superoxide dismutase (SOD) and glutathione reductase (GR). Catalase (CAT) activity increased at doses lower than 20 Gy, and then decreased at the higher doses, whereas ascorbate peroxidase (APX) activity did not alter except for 40 Gy. It is concluded that the suitable irradiation dose of mutation breeding is 20 Gy for the seeds of ground-cover chrysanthemum. Although 60Co γ-rays irradiation resulted in damage of membrane lipid peroxidation in the survival seedlings, the increased activity of CAT and POD could protect them against the damage. (authors)

  12. Protective effect of gingerol on leucocyte and bone marrow DNA of 60Co γ-rays irradiated mice

    In this article, the effect of gingerol on peripheral leucocyte and bone marrow DNA of 60Co γ-rays irradiated mice was developed., Twenty-four healthy healthy female Kunming mice were randomly divided into 4 groups: control, gingerol, irradiation and gingerol + irradiation group. Gingerol group and gingerol + irradiation group were given gingerol intragastrically once a day for five days. Irradiation group and gingerol + irradiation group were suffered from 5 Gy 60Co γ-rays irradiation at the rate of 1.2 Gy/min on the 6th day. Blood samples, spleens, livers and thigh bones were collected to be measured after 48 h. The results showed that, compared with irradiation group, gingerol + irradiation group had significantly higher spleen index (p60Co γ-rays irradiated mice. (authors)

  13. Allogenic bone rods with freeze drying and gamma rays irradiation for treatment of fracture

    Opened reduction and internal fixation are the usual treatment of fracture, but both methods need a second operation for removal implants. The benefits of the bone rods are that they can avoid the removement of internal fixation and will be absorbed spontaneously. The bone rods are made of allogeneic compact bones with freeze-drying and gamma rays irradiation supplied by Shanxi Provincial Tissue Bank. The purpose of this study is to evaluate allograft reaction, the stability of the internal fixation, osteoinduction in the treatment of fracture using allogeneic bone rods with freeze drying and gamma rays irradiation. From May 1997 to May 1998, fourteen cases (male 12, female 2) of treatment were reviewed. The mean age was 37.3 (21-5 1). There were 3 medial malleolus fractures, 7 tibia and fibula fractures, 1 ulna and radius fracture, 1 lateral condyle of humerus fracture. The clinical results were satisfactory. Because the strength of the bone rods are weaker than that of screws, the bone rods are only indicated in the fixation of cancellous bones fracture and unloaded bone fracture. It can be used as a supplementary fixation of loaded bone. It is not indicated for fixation of comminuted fracture. More than two bone rods may be used in the fixation of fracture in order to get stability of the fracture and decrease stress between rods which will prevent the break of the bone rods. Allogeneic bone rods with freeze-drying and gamma rays irradiation can be used as implants of non-immunogenicity. There are no allograft reactions in all cases (including fever, leukocytosis, exudation or swelling in the wound). Although plenty of experimental studies have showed that freeze drying with gamma rays irradiation (below 50 KGy) would not destroy BMP of bone allograft, but there is no osteoinduction in our cases. The healing of a fracture and bridging external callus are similar as other operations. This new technique may have the following advantages compare with the screws: 1

  14. Removal of endocrine disruptors PAEs in drinking water by gamma-ray irradiation

    Phthalic acid esters (PAEs) belong to environmental endocrine disruptor. The dimethyl phthalate (DMP), diethyl phthalate (DEP) and di-n-butyl phthalate (DBP) were selected for the radiation study. The removal efficiencies of DMP, DEP and DBP in drinking water by gamma-ray irradiation are discussed. The results show that these PAEs could be efficiently removed by gamma-ray irradiation. The removal efficiencies of DMP, DEP and DBP (12 mg/L) in aqueous solutions by 0.8 kGy gamma-ray treatment were 96.6%, 94.5% and 86.2%. The absorbed dose needed for the removal of total carbon in aqueous solutions was much larger than the doses for PAEs degradation. When 2 kGy was selected, the removal efficiencies of TC for DMP, DEP and DBP were only 23.6%, 14.3% and 12.9%. The study results also show that the radiation degradation reaction of PAEs should be divided into two stages: low dose addition reaction and high dose ring-opening reaction. This study is of significance in the disposal of micro-polluted drinking water. (authors)

  15. Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation.

    Polf, J C; Peterson, S; McCleskey, M; Roeder, B T; Spiridon, A; Beddar, S; Trache, L

    2009-11-21

    In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. PMID:19864704

  16. The study of mildew proof effect of 60Co γ irradiation on leather shoes

    Leather products occupy an important place in the national economy. In order to prevent from mildewing of leather products in storage, transportation and sale, the packed shoes were irradiated with 60Co γ ray. Test materials are cattle, sheep and pig leather shoes. The results shows that: 1. There are 11 types of molds which make leather shoes mildewed: Oospora sp, Rhizopus oryzae Went and Grrelings, Aspergillus flavus Link, Aspergillus terreus thom, Monilia sp, Botrytis sp, Aspergillus niger V. Tiegh, Penicillum Lividum Westling, Penicillum Corylophilum Dieckx, Penicillum Cyaneum (B. and S.) Biourge and Penicillum Verrulosum Peeyrone. 2. The three types of shoes packed with polyethylene film can be prevented from mildewing after irradiation at level of 12 kGy. 3. The irradiation at 30 kGy does not change the physical properties of the shoes. 4. The irradiated shoes packed with polyethylene film can prevent mildewing, but unpacked ones would be mildewed again

  17. Possibilities for creating high protein bean forms by irradiation with cesium 137 gamma-rays

    Six Columbia lines bean plants suitable for direct combine-harvesting are used to induced mutation variations. The seeds are irradiated presowing with gamma-rays (Cs-137) in two ways - only once with 120 Gy and six times 4 hours daily with 20 Gy. The applied irradiation resulted into increase variability in protein content of the seeds of M2 plants. Variations of diverse character are established, depending on the genotype varieties. Mutant forms of more than 29% protein content which are of interest to the plant breeding, are obtained. 12 refs., 3 tabs. (author)

  18. Distribution of 60Co and 54Mn in graphite material of irradiated HTGR fuel assemblies

    Distribution of 60Co and 54Mn was measured in the graphite sleeves and blocks of the third and fourth HTGR fuel assemblies irradiated in the Oarai Gas Loop-1 (OGL-1), which is a high temperature inpile gas loop installed in the Japan Materials Testing Reactor (JMTR) of Japan Atomic Energy Research Institute (JAERI). Axial and circumferential profiles were obtained by gamma spectrometry, and radial profiles by lathe sectioning with gamma spectrometry. Distribution of 60Co is in good agreement with that of thermal neutron flux, and the Co content in the graphite is estimated to be -- 1 x 10-9 in weight fraction. Concentration of 54Mn decreases toward the axial center in its axial profile, and radially is almost uniform inside and appreciably higher at free surfaces. An estimated Fe content of --10-8 in wight fraction is smaller by two orders of magnitude than that from chemical analysis. Higher concentraion of 60Co and 54Mn at the free surfaces suggests the importance of transportation process of these nuclides in the coolant loop. (author)

  19. Phenotype and molecular analysis of M1 generation of stylosanthes irradiated by 60Co

    The seeds of Stylosanthes guianensis SW. ‘Reyan No.13’ were irradiated by 60Co at 0, 325, 487 and 974 Gy. Phenotype and molecular variations of Stylosanthes M1 generations were studied. Germination percentage, plant height, leaf length and stem diameter of M1 seedlings were determined using SRAP-PCR. Results showed that biological character indices of treatments were significantly lower than that of control (CK). Irradiation inhibited plant growth. Growth indices of 974 Gy treatment, except leaf length, were significantly lower than CK and other two treatments. Eight effective primers selected from 24 primers combination were used for SRAP-PCR. SRAP analysis revealed that the 57 of 88 DNA fragments were amplified showing polymorphisms. The average percentage of polymorphic bands was 64.77%. The effects of 60Coγ irradiation on DNA variation of seedlings were varied from different treatments. Numbers of polymorphic bands changed after irradiation. Coefficient of variation was in direct proportion to irradiation doses. Variation rates of 325 Gy, 487 Gy and 974 Gy treatments were 22.0%, 38.1% and 41.5%, respectively. The Nei’s genetic similarity coefficient of all treatments was ranged from 0.585 to 0.780 by software NTSYSpc 2.1 based on SRAP results and the average Nei's coefficient was 0.678. The Nei’s genetic similarity coefficient of 974 Gy treatment was 0.585 and variation degree was highest among all treatments, 487 Gy treatment was second and 325 Gy treatment was the lowest one. Based on present bands, four irradiated treatments were classified into two major groups by UPGMA cluster analysis. Group 1 included CK, 325 Gy and 487 Gy treatment and group 2 included 974 Gy. SRAP analysis determined variation of Stylosanthes after irradiation and the results of SRAP analysis were consistent with their biological indexes in some extent

  20. An aberration in gamma-ray enhanced reactivation of irradiated adenovirus in ataxia telangiectasia fibroblasts

    Ataxia telangiectasia (AT) is a rare human genetic disorder which includes a predisposition to lymphoreticular cancers and a hypersensitivity to conventional radiotherapy. Furthermore, AT cells in vitro exhibit a hypersensitivity to ionising radiation that appears to be correlated with an increased frequency of chromosomal aberrations, a resistance of de novo DNA synthesis to inhibition by radiation-induced DNA damage, a reduced mitotic delay and possible defects in DNA repair. A sensitive viral assay has been used to investigate the capacity of gamma-irradiated AT cells to support the replication of undamaged virus, as well as the extent to which the survival of radiation-damaged virus was affected by gamma-irradiation of these host cells prior to infection. The expression of such enhanced reactivation (ER) of both u.v.-irradiated and gamma-irradiated adenovirus type 2 (Ad2) was examined in a variety of normal and AT human fibroblast strains. For immediate infection of normal human fibroblasts, both a decrease in unirradiated virus expression and an increase in ER were observed with increasing gamma-ray dose to the cells. In contrast, AT fibroblasts were found to be deficient in gamma-ray ER of irradiated Ad2, and this defect appeared to be related to a marked relative radioresistance of unirradiated virus expression in AT compared to normal cells. (author)

  1. Genetic variation of natural orchid phalaenopsis amabilis (L.) blume produce gamma ray irradiation

    New cultivars of Phalaenopsis amabilis (L.) Blume were obtained through gamma-rays Co-60 irradiation. The result showed phenotypic variation which justifies a molecular biology observation to investigate whether the variation was caused by the change on cultivar’s genotypic traits. A study to describe the genetic variability among individuals of the irradiated cultivars was then conducted using RAPD Technique. The materials used were cultivars obtained by 0, 15, 20, 25, 20+20 and 40 Gray irradiations. DNA genome of each plant was isolated and was amplified with 22 primers randomly. The PCR analysis was done with 1.5 % agarose. The DNA analysis used 8 selected primers out of 22. Polymorphism and molecular diversity were analyzed with Nei’s gene diversity method through GenAlex 6.1 program. The study showed that genetic diversity might be detected at the early growth stage of the gamma ray Co-60 irradiated cultivars using RAPD, and irradiation dose of 15 and 40 Gray gave high genetic diversity compared to control. (author)

  2. Study on Several Characteristics of Agaricus blazei Murril Strain J3 Irradiated by 60Co

    WENG Bo-qi; JIANG Zhi-he; HUANG Ting-jun; CHEN Jian; ZHENG Wei-wen

    2003-01-01

    A new mutant strain J3 from Agaricus blazei Murril was obtained by 60Co irradiation. The yields of successive generations were increased more than 70% to compare with their original strain. The component analysis on amino acids and fatty acid illuminated that the nutrient value of strain J3 fruiting body was better than the original strain. The apparent nodule structure was found in the hyphea of J3 strain through the observation by scanning electron microscope. RAPD analysis showed the great difference of PCR fingerprints between J3 and its original strain. It is a promising mutant strain for further commercial development in the future.

  3. The influence of 60Co gamma irradiation for downy mildew infection on corn

    Corn seeds of Genjah kertas variety were irradiated with 60Co gamma in the range of 0 rad - 40.000 rads, at interval of 2000 rads, as preliminary investigation to obtain possibilities of corn mutation. Several agronomical effects of radiation on the seedling-plant such as seed germination, height of the seedling, ages of flowering, ages of harvesting, length and circle of the cob, 100U dry seeds weight, number and diameter of stomata, and percentage of downy mildew infection have been observed. The exact conclusion can be obtained only after testing the results of M2 and M3. (author)

  4. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Lucas de Oliveira, P.C.; Madruga, R.A.; Barbosa, N.P.U. [Uberaba School of Veterinary Medicine (UNIUBE), MG (Brazil)]. E-mail: pedrolucaso@uol.com.br; Sakate, M. [UNESP, Botucatu, SP (Brazil). School of Veterinary Medicine and Animal Husbandry

    2007-07-01

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from {sup 60}Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a {sup 60}Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  5. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from 60Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a 60Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  6. Grafting of HEMA onto dopamine coated stainless steel by 60Coirradiation method

    A novel method for grafting of 2-hydroxyethyl methacrylate (HEMA) onto the surface of stainless steel (SS) was explored by using 60Coirradiation. The surface of SS was modified by coating of dopamine before radiation grafting. The grafting reaction was performed in a simultaneous irradiation condition. The chemical structures change of the surface before and after grafting was demonstrated by Fourier transform infrared (FTIR) spectrometer. The hydrophilicity of the samples was determined by water contact angle measurement in the comparison of the stainless steel in the conditions of pristine, dopamine coated and HEMA grafted. Surface morphology of the samples was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The corrosion resistance properties of the samples were evaluated by Tafel polarization curve. The hemocompatibility of the samples were tested by platelet adhesion assay. - Highlights: • Poly-HEMA was grafted onto the surface of SS by 60Co-γ-ray irradiation. • Pristine SS was coated by dopamine to form a dense poly-dopamine film before radiation grafting. • The biocompatibility and hydrophility of SS were improved after the grafting of HEMA

  7. Effect of 60Co γ-irradiation on the infectivity of toxoplasma gondii bradyzoites

    Homogenates of mouse brains harboring toxoplasma NT strain cysts were irradiated at various doses of 60Co γ ray and digested with 0.4% trypsin buffer to release bradyzoites from cysts. The suspensions containing various number bradyzoites were obtained through a serial 10-fold dilution in saline solution and inoculated intraperitoneally into mice separately. Infectivity of toxoplasma bradyzoites was determined by bioassay of mice. A group of mice inoculated with non-irradiated bradyzoites was used as control. Results showed that the minimal effective dose of γ rays controlling infectivity of toxoplasma NT strain bradyzoites was 0.55 kGy. Effect of 0.1 kGy γ rays on infectivity of toxoplasma bradyzoites was not significant. Infectivity of bradyzoites irradiated at 0.45 kGy had 104 fold reduction in comparison with that of 0.1 kGy

  8. Effects of 60Co irradiation on virulent Toxoplasma gondii and its use in experimental immunization

    The effects of 60Co irradiation on the virulence and immunogenicity of the RG strain of Toxoplasma gondii was studied by infecting batches of mice with graded inocula of tachyzoites that had been exposed to radiation doses ranging from 0 to 20 000 rad. While doses of 15 000 and 20 000 rads appeared to be effective, and 10 000 rad nearly effective in annulling the virulence, irradiation at 5000 rad was only partially effective in rendering the organisms avirulent and could achieve only a prolongation of survival time of the inoculated mice. The survivors of higher irradiation inocula showed no evidence of the development of the parasite in them, but could resist a limited virulent challenge. The use of a booster inoculation improved both the quality and the duration of protective effect. (author)

  9. Cell survival of human tumor cells compared with normal fibroblasts following 60Co gamma irradiation

    Three tumor cell lines, two of which were shown to be HeLa cells, were irradiated with 60Co gamma irradiation, together with two cell cultures of normal human diploid fibroblasts. Cell survival was studied in three different experiments over a dose range of 2 to 14 gray. All the tumor cell lines showed a very wide shoulder in the dose response curves in contrast to the extremely narrow shoulder of the normal fibroblasts. In addition, the D/sub o/ values for the tumor cell lines were somewhat greater. These two characteristics of the dose response curves resulted in up to 2 orders of magnitude less sensitivity for cell inactivation of HeLa cells when compared with normal cells at high doses (10 gray). Because of these large differences, the extrapolation of results from the irradiation of HeLa cells concerning the mechanisms of normal cell killing should be interpreted with great caution

  10. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    The effects of neutrons and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 1013 n/cm 2 and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are given in this paper. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed

  11. Effects of 60Co irradiation on the genetics of indian meal moth

    4 ∼ 5 days old male pupae of Indian meal moth, Plodia interpunctella Hubner were irradiated with 1, 3, 5, 7 and 10 krad of 60Co γ-ray. The male moths developed from treated pupae and their F1 generation were put together with normal female moths for copulation separately. The genetic effects of irradiation was studied and the results showed that the effects of irradiation were significant, which related to the irradiation dosage, on both parental and filial generations. Only 40% of the pupae was emerged, when they were irradiated at 10 krad. The effects on deformation rates, survival rates, copulation abilities, fecundities, hatching rates and genetic sterilities varied with different irradiation dosage treatment. With consideration of the total irradiation effect, the dosage lower than 5 krad is desirable for inducing the sterility of adults and sex chain recessive lethal gene. With 1, 5 and 7 krad of irradiation, a mutant of P. interpunctella with transparent wings was induced, which provides a marking feature in control of Indian meal moth by sex chain recessive lethal gene

  12. Seed germination of peanuts irradiated with cobalt ({sup 60}CO); Germinacao de sementes de amendoim irradiadas com cobalto ({sup 60}Co)

    Alves, Niedja Marrize C.; Almeida, Francisco de Assis C.; Gomes, Josivanda P.; Pessoa, Elvira B., E-mail: niedjamarizze@yahoo.com.b, E-mail: josivanda@deag.ufcg.edu.b, E-mail: elvirabe@gmail.co [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia Agricola; Leal, Artur S. Cavalcanti, E-mail: arturcleal@yahoo.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    This work was realized to evaluate the effect of gamma irradiation ({sup 60}Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  13. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

  14. Study for optimization of a 60 Co industrial irradiator of 250 k Ci

    This work presents results of a benchmark between calculated and experimental absorbed dose values for a typical product, in a 60 Co industrial irradiator, located at ININ, Mexico. The goal of this work is to reach a ± 10 % approximation between both values. ININ 60 Co industrial irradiator is a two level, two layer system with overlapping product configuration, 56 irradiation positions with an activity of around 250 k Ci. Calculated values were obtained by QAD-CGGP code. This code uses a point kernel technique, build-up factors fitting was done by geometrical progression and combinatorial geometry was used for 3 D system description. Main code modifications were related with source simulation by punctual sources and energy spectrum (16 energy groups) and anisotropic emission were also considered. Experimental data were obtained from routine dosimetry which was done with red acrylic pellets; they were irradiated together the product in predetermined positions, for 36 maximum and minimum absorbed dose values. Typical product was polypropylene Petri dish packages, apparent density 0.13 g/cm3. It was chosen because regular geometry (2 packages per full irradiator container) and enough amount for considering homogeneous loading inside irradiation chamber. Required minimum dose was 15 kGy. Results showed a 8% variation between calculated and experimental values for maximum absorbed dose (18.2 kGy vs 16.8 kGy) and 3 % variation for minimum absorbed dose (13.8 kGy vs 14.3 kGy); these results fixed with the original proposal. (Author)

  15. Effect of slow irradiation of gamma rays on growth, yield and quality of Coleus forskohlii briq

    Terminal cuttings of coleus cv Garmai is slowly irradiated by using lead filter in the gamma chamber. It has been observed that LD50 of gamma rays was observed at 40Gy dose. Similarly the LD50 for EMS was 1.00 %. Based on this data treatments were formulated in Randomized Block Design and the terminal cuttings were planted in the main field for observation. The results of the study V1M1 indicated that the combined effect of mutagens at higher dosage shows reduced growth characters than the untreated control. The treatment with 50Gy gamma rays + 0.5% EMS exhibited maximum number of tubers (25.50) and maximum length of tubers (17.60 cm) than all other treatments. Maximum fresh and dry weight of tubers (580.50 and 71.20 g) was noticed by the untreated control. The maximum forskolin content (0.66 %) was exerted by the treatment 20Gy gamma rays + 0.5% EMS. However, most of other treatments exhibited same forskolin content (0.42%). The secondary shoots were considered as the second vegetative generation. Secondary shoots were obtained by cutting back the primary shoot and planted for the study of V2M1 generation. The data on plant height expressed at higher side than that earlier generation. The quality parameters like essential oil (0.09%) and total alkaloids (1.05%) was greater at very high doses of mutagen. However, the occurrence of forskolin mutant was stabilized over the generations in 20Gy gamma rays + 1.00% EMS treatment. From the study it was inferred that sudden exposure of materials causes more lethality with poor field establishment and the chance of occurrence of mutants were comparatively lesser. (author)

  16. 60CoIrradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae)

    Ke Zhang; Zhibin Li; Shaowen Zhu; Qunfang Weng

    2014-01-01

    Radio-(60Co), which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Coirradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Coirradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD), catalase (CAT), p...

  17. Studies on mutagenic activity of 60Co γ-ray irradiated rape pollen

    In the present study on disinfection, the rape pollen was irradiated with 2.5 kGy 60Co γ-ray. Micronuclei, sister chromatid exchanges (SCE) of bone marrow cells and chromosomal aberrations of meiotic cells in mice were used as an indicater of chromosomal damage to study the mutagenicity of irradiated rape pollen. The results are as follows: (1) The frequency of micronuclei in polychromatic erythrocytes is 2.00 per mille; nucleated cells is 0.8 per mille in control group. In the numbers of polychromatic erythrocytes and nucleated cells with micronuclei, there is no obviously difference in irradiated and unirradiated groups. (2) SCE incidence of control group is 2.01 ± 0.12/cell. No significant difference in the frequency of SCE exists between non-irradiated rape pollen and the control groups. But the frequency of SCE in irradiated rape pollen group (3000 mg/kg/day x 7) is 2.36 ± 0.12/cell; high dose group (6000 mg/kg/day x 7) is 2.96 ± 0.14/cell. In comparison with control group, there is a significant difference. (3) The chromatid breaks, fragments, and univalents in primary spermatocytes have been obseved. The frequencies of chromosomal aberration showed no obviously difference among irradiated and non-irradiated rape pollen groups

  18. A comparative study on experimental and theoretical ESR spectra of lactic acid polymers irradiated by gamma rays

    Homo polymers of L-Lactic acid (LLA) and D,L-Lactic acid (DLLA), being biocompatible and absorbable in body iluids have recently found wide applications in the preparation of surgical sutures, controlled drug delivery systems, burn wound coverings etc. For sometime these polymers have also been prepared in the form of plates and screws for mandibular fracture fixation, tissue implants. Their chemical sensitivities against relatively high temperatures and hydrolysis with water make them unsuitable for conventional sterilization techniques like hot water vapor and ethylene oxide. Sterilization of the devices made of these polymers is therefore possible by gamma ray irradiation. This has initiated a number of research works in order to better understand the effects of ionizing radiation on this polymer. The aim of this study is to determine the possible radical types, their location on macromolecular structure and the reasons for peak shifts in the experimental and theoretical ESR spectra. Polymer samples were irradiated in air and in vacuum (10□□ torr) to 25 kGy sterilization dose at the dose rate 0.59 kGy/h and at room temperature by 60Co γ-irradiator. Despite being chemically the same radical type, some differences were observed in the splitting of peaks of PLLA and PDLLA samples. These differences were determined and compared by means of fitting studies. Firstly, PLLA was characterized and its g and hyperfine splitting values were found as 2.0032±0.0002 and 20.37±0.2. In the characterization study of PDLLA, it was found that one of the nearest two radicals was on the upper and the other one was on the lower plane of PDLLA chain. (author)

  19. Human fibroblasts (KMST-6/RAS line) transformed with 60Co gamma-rays and c-Ha-ras oncogene constitutively produce a large amount of human granulocyte-colony stimulating factor (G-CSF)

    Human fibroblasts (KMST-6/RAS) transformed with 60Co gamma-rays and the Ha-ras oncogene formed tumors in nude mice. These mice showed splenomegaly and an increase in granulocytes in the peripheral blood. There was a direct correlation between tumor size and spleen size. Histologically, prominent proliferation of granulocytes was observed in the enlarged spleen. These findings indicated that KMST-6/RAS cells might have been producing granulocyte colony-stimulating factor (G-CSF) in the nude mice. In fact, in vitro studies demonstrated that the cells produced G-CSF in the culture medium and that production of G-CSF was greater during the logarithmic growth than during the stationary phase. Nearly equal amounts of G-CSF were produced by cells grown in serum-free or 10% serum-supplemented medium. Neither expression of the ras oncogene nor the tumorigenicity of cells correlated with the production of G-CSF. G-CSF production in KMST-6/RAS cells was significantly stimulated by butyrate, but not by dexamethasone or 5-azacytidine. (author)

  20. Chemical and physical changes of packaging materials for food by gamma-ray irradiation

    Kawamura, Yoko; Yamada, Takashi [National Inst. of Health Sciences, Tokyo (Japan)

    2000-02-01

    Film and sheet of polyethylene and polystyrene added with BHT, Irganox 1076, Irgafos 168 and Irganox 1010 as antioxidant were treated by gamma-ray irradiation. The change of additive residues, monomer and decomposition products of additives, the tensile strength and change of tone and odor were studied. Polystyrene was the most stable for irradiation. Polypropylene products and large amount of decomposition products indicated very decrease of tensile strength. Polyethylene was more stable than polypropylene, but yellowing was very large. Acetic acid, propion acid, 2-butanone and 2, 4-penyanedione in the decomposition products were controlled by adding antioxidants. Their irradiated decompositions, DTBBQ and 2, 4-DP, were observed. Decreasing of the tensile strength of polypropylene was improved by addition of Irganox 1010 and Irgafos 168. The antioxidants were decreased by irradiation, especially BHC and Irgafos 168. (S.Y.)

  1. Chemical and physical changes of packaging materials for food by gamma-ray irradiation

    Film and sheet of polyethylene and polystyrene added with BHT, Irganox 1076, Irgafos 168 and Irganox 1010 as antioxidant were treated by gamma-ray irradiation. The change of additive residues, monomer and decomposition products of additives, the tensile strength and change of tone and odor were studied. Polystyrene was the most stable for irradiation. Polypropylene products and large amount of decomposition products indicated very decrease of tensile strength. Polyethylene was more stable than polypropylene, but yellowing was very large. Acetic acid, propion acid, 2-butanone and 2, 4-penyanedione in the decomposition products were controlled by adding antioxidants. Their irradiated decompositions, DTBBQ and 2, 4-DP, were observed. Decreasing of the tensile strength of polypropylene was improved by addition of Irganox 1010 and Irgafos 168. The antioxidants were decreased by irradiation, especially BHC and Irgafos 168. (S.Y.)

  2. Gamma-ray irradiation on polystyrene in the presence of crosslinking agents

    The radiation induced crosslinking of polystyrene is difficult because of its aromatic units, and the polymer degrades when irradiated in air. Therefore, the authors studied the effects of gamma-ray irradiation on polystyrene in the presence of polyfunctional monomers such as trimethyl propanetrimethacrylate (TMPTM), dimethyleneglycol bisallycarbonate (DEGBAC), etc. These monomers readily polymerize by irradiation with small dose. When polystyrene was mixed with 20% by weight of TMPTM, the toluene insoluble polymer obtained after the irradiation with a dose of 10 Mrad had a polystyrene TMPTM ratio of 1 and with a dose of 20 Mrad, the radio became 6. Since TMPTM alone polymerizes with a dose much smaller than these doses, it is likely that the chain breaking and recombination between polystyrene and poly TMPTM takes place. In the case of DEGBAC, the dose required for crosslinking of polystyrene was higher than that with TMPTM. The relationships between doses and radiochemical yields for gelation and degradation for various polyfunctional monomers are presented

  3. Influence of gamma-ray irradiation on Faraday effect of Cu-doped germano-silicate optical fiber

    Influence of gamma-ray irradiation on the Faraday effect of the Cu-doped germano-silicate optical fiber was investigated. The Verdet constant of the gamma-ray irradiated optical fiber at 660 nm was measured to be 3.07 rad T−1 m−1, 1.46 times larger than that of before the irradiation at total dose of 1200 Gy. Cu-related radiation-induced defect centers and Cu metal particles which were reduced from Cu2+ ions by the irradiation are thought to be responsible for the increase in the Verdet constant of the optical fiber

  4. DNA double-strand break and apoptosis induction in human lymphocytes in different cycle cell phases by 60Co gamma rays and Bragg peak protons of a medical beam

    A comparative analysis is made of the regularities in the formation of DNA double-strand break and apoptosis induction in peripheral human blood lymphocytes in different cell cycle phases after 60Co gamma and extended Bragg peak proton irradiation. It is shown that the formation of apoptotic cells in a lymphocyte population increases linearly in all the cell cycle stages after proton irradiation. The maximal DNA double-strand break and apoptosis yield in lymphocytes is observed in the S phase of the cell cycle

  5. Safeguards on the depleted uranium used in gamma ray irradiator as shield material

    Depleted uranium used in gamma ray irradiator as the shielding material was not completely investigated and properly reported by the Atomic Energy Act until now, The IAEA required to report the status of the companies using small amount of uranium and information for 42 NDT companies was declared in 1999. And IAEA inspector visited some company to confirm their declarations. The Additional protocol proposed as the strengthened safeguards system by the IAEA, which was ratified through the national assembly on February 9, 2004, and was entered into force on February 19, 2004. The government is investigating the amount, purpose and location of depleted uranium in the area of non-nuclear use.

  6. Borohydride-reducible components in soluble collagen irradiated with gamma rays in solution

    Irradiation with 100 krad of gamma rays of neutral-soluble rat skin collagen decreased the content of aldol cross-links by a factor of three, whereas it did not affect the content of allysine. On reduction with tritiated sodium borohydride, five new components were detected showing different stability towards acid and alkali. (author) tetracycline. The results of kinetic and autoradiographic studies and microscopical analysis of bone preparations suggest that stable strontium inhibits the mineralization of newly formed bone tissue without affecting the physicochemical processes related to ion exchange. (author)

  7. A case of radiation gastroduodenitis caused by 60Co-irradiation therapy for hepatoma

    A 56-year-old man with hepatoma, who had been treated with total 3,960 rad of 60Co-irradiation 2 months previously, was readmitted to the hospital because of fever and anemia. Following admission, he passed tarry stools every day. Barium meal examination revealed esophageal varices and erosive gastritis of the antrum. At endoscopy, many hemorrhagic erosions were found in the gastric antrum and the first part of duodenum, which were located in the irradiation area. Since repeated blood transfusion failed to improve anemia, a complete fasting with intravenous hyperalimentation and antacid therapy were started. Two months later, feeding was started and thereafter continued without any appreciable GI bleeding or worsening of anemia. Endoscopic examination at this time revealed only a few erosions scattered over the edematous antral mucosa as well as the proximal duodenum. IVH, antacids and abstinence from food seem to be an effective measure in the treatment of radiation injury of the gut. (author)

  8. The degradation of p-chloronitrobenzene in aqueous solution by 60Coirradiation

    The degradation of p-Chloronitrobenzene (p-CNB) in aqueous solution was investigated by 60Coirradiation. The concentrations of p-CNB and inorganic ions generated during the irradiation process were measured by HPLC and Ion Chromatography technology. And also, the factors affecting degradation degree, such as absorbed dose, radiation aura, were studied in detail. It was found that the degradation degree of p-CNB and the concentrations of ions increased with absorbed dose. The presence of O2 was more favorable to the degradation of p-CNB. Furthermore, the experimental results showed that both hydrated electron and hydroxyl radical generated from water radiolysis could degrade p- CNB effectively and produce Cl-, NO3-, NH4- in the solutions. (authors)

  9. Primary Observations on the Influence of 60Co Local Irradiation on Free Skin Flaps

    杨建荣; 张园

    2002-01-01

    Objective To study the effect of postoperative radiation on free skin flaps.Methods Twenty-nine patients with free skin flaps applied to the plerosis of the postoperative defectwere followed up. Twenty-eight out of 29 patients received forearm free flaps while 1 had anterolater-al femoris skin flaps in a size ranging from 14 cm× 6 cm to 8 cm× 4 cm. These flaps were exposedto 60Co radiation ranging 40-69 Gy. Results Observation during irradiation: no visible changes ofskin flaps and oral mucous membrane were detected when irradiation dose was within 40 Gy; somechanges may be detected over 40 Gy. Observation 1 - 4 months after irradiation: pigmentations werefound in areas of erosion epidermis; skin flaps got dark but without evidence of necrosis. Observation2 years after irradiation: no necrosis happened in 29 skin flaps. Hairs were found on 15 of 29flaps. Sensation occurred within the margin of 1 cm. Conclusion Free skin flap can endure irradi-ation at the dose of 60 Gy.

  10. Behavior of Random Hole Optical Fibers under Gamma Ray Irradiation and Its Potential Use in Radiation Sensing Applications

    Anbo Wang

    2007-05-01

    Full Text Available Effects of radiation on sensing and data transmission components are of greatinterest in many applications including homeland security, nuclear power generation, andmilitary. A new type of microstructured optical fiber (MOF called the random hole opticalfiber (RHOF has been recently developed. The RHOFs can be made in many differentforms by varying the core size and the size and extent of porosity in the cladding region.The fibers used in this study possessed an outer diameter of 110 μm and a core ofapproximately 20 μm. The fiber structure contains thousands of air holes surrounding thecore with sizes ranging from less than 100 nm to a few μm. We present the first study ofthe behavior of RHOF under gamma irradiation. We also propose, for the first time to ourknowledge, an ionizing radiation sensor system based on scintillation light from ascintillator phosphor embedded within a holey optical fiber structure. The RHOF radiationresponse was compared to normal single mode and multimode commercial fibers(germanium doped core, pure silica cladding and to those of radiation resistant fibers (puresilica core with fluorine doped cladding fibers. The comparison was done by measuringradiation-induced absorption (RIA in all fiber samples at the 1550 nm wavelength window(1545 ± 25 nm. The study was carried out under a high-intensity gamma ray field from a 60Co source (with an exposure rate of 4x104 rad/hr at an Oak Ridge National Laboratory gamma ray irradiation facility. Linear behavior, at dose values less than 106 rad, was observed in all fiber samples except in the pure silica core fluorine doped cladding fiber which showed RIA saturation at 0.01 dB. RHOF samples demonstrated low RIA (0.02 and 0.005 dB compared to standard germanium doped core pure silica cladding (SMF and MMF fibers. Results also showed the possibility of post-fabrication treatment to improve the radiation resistance of the RHOF fibers.

  11. Dose Response and Optical Properties of Dyed Poly Vinyl Alcohol-Trichloroacetic Acid Polymeric Blends Irradiated with Gamma-Rays

    Susilawati

    2009-01-01

    Full Text Available Problem statement: The effects of gamma irradiation on optical properties of cresol-red dyed Poly Vinyl Alcohol (PVA blended with Trichloroacetic Acid (TCA for possible use in dosimetry and measurement of radiation dose in gamma rays have been studied using both Raman spectroscopy and UV-Visible spectrophotometer method. Approach: The dosimeters are composed of Poly Vinyl Alcohol (PVA, Trichloroacetic Acid (TCA at various concentrations are 20, 25, 30 and 35%, and acid-base indicator cresol-red dyed. Results: The dosimeters were irradiated to doses up 12 kGy using 60Co gamma ray source at a constant dose rate. The polymeric films undergo color change from purple to yellow due to radiation-induced acid formation. The molecular vibrational spectra were measured using Raman spectroscopy, resulting in a decrease of the Raman intensity inelastic scattering of C-Cl molecular stretching from TCA with increasing dose. The absorption spectra were measured using UV-visible spectrophotometer in the wavelength range 350-700 nm, resulting in a decrease of the absorbance at 575 nm band peak with increasing dose. The dose sensitivity D0 increases with increasing TCA concentration for both scattering and absorption methods. The optical absorption studies show that the direct and indirect optical energy band gaps and optical activation energies are dependent on dose and TCA concentration. Conclusion: The shift in the optical band gap Eg values towards lower energy with radiation dose leads to a shift of the optical activation energy DeltaE value towards the lower energy region with increasing dose. The optical band gap (Eg and the absorption edge decrease with increasing dose attributed to the structural disorder of polymer blends due to dehydrochlorination of trichloroacetic acid with increasing dose. The energy width of the tail of localized state in the forbidden band gap was evaluated using the Urbach-edges method. It was found that the activation energy

  12. Synergism of. gamma. -ray irradiation and temperature on the deterioration of flame-retardant cables

    Okamoto, Shinichi (Radiation Center of Osaka Prefecture, Sakai (Japan)); Katayama, Shiro; Takeya, Chikashi; Hayakawa, Tsutomu; Iwata, Seiji

    1981-03-01

    Characteristic changes of frame-retardant cables, C*V and P*N having excellent resistance to heating and ..gamma..-ray irradiation for nuclear power generating stations, were studied under combined environments of ..gamma..-ray irradiation (2 x 10 sup(g) r and less) and elevated temperature (150/sup 0/C and 170/sup 0/C). They included the changes in appearance, elongation, insulation resistance, AC breakdown voltage, and power factor. The synergistic effects were observed in them. That is, the synergism of PVC (V) and Neoprene rubber (N) appeared after irradiation with 2.5 x 10/sup 7/ r at 150/sup 0/C, while that of XLPE (C*) and EPR (P*) appeared under conditions of heavier exposure doses at higher temperature. These test conditions were more severe than normal service condition in the plant which was assumed as 40 years at 70/sup 0/C and total dosage of 70 mega-rads. The mechanism of deterioration in characteristics of the cables in this test may be different from that of aging in the plant.

  13. BROCCOLI Spears Yield Affected By GAMMA Rays Irradiated Seeds And Foliar Application Of Some Growth Regulators

    Two field experiments were carried out during 2004/2005 and 2005/2006 winter growing seasons at the experimental farm of Nuclear Research Centre, Atomic Energy Authority, Inshas, Egypt.The experiments were conducted to study the effect of pre-sowing broccoli seeds (cv. F1 175) irradiated with different doses of gamma rays (2, 3 and 4 Gy). The plants were sprayed with GA3 at rate of 50 ml/liter/fed and 20 ml/liter/fed for NAA. Main spear fresh and dry weight per plant, total spears fresh and dry weight per plant, total spears yield, ascorbic acid, TSS, carbohydrates, total chlorophyll, NPK and total protein content of spears were evaluated. The results showed that broccoli seeds irradiated with gamma rays up to 4 Gy pre-sowing increased the abovementioned parameters with different magnitudes comparing with the non-irradiated control plants except spears N, P and protein contents showed decrease in their values comparing with un-treated plants.It could be concluded that the foliar application of GA3 and NAA on broccoli spears increased all the abovementioned parameters, except spears N, P and protein contents showed decrease in their values.

  14. Influence of gamma rays irradiation to chlorphyriphos insecticides residues in grapes (vitis vinifera L.)

    Simulation methods to determination of chlorphyriphos insecticides residue in grapes cause effect gamma rays, was done. Fruits of grapes soaked with chlorpyriphos insecticide solution high level concentrated (100 ppm; 200 ppm; and 300 ppm) for 3 (three minutes). The treatment of the sample was direct of extraction after soaks; extract after storage for one week after soak, and extract after soak after storage for one week after irradiation at 0.5 kGy; 1.0 kGy; and 1.5 kGy dose. Extraction methods using ethyl acetate solvent, and using sodium sulphate as to dryed water level in grapes, and then extractan was injected to chromatography gas use electron capture detector. The result indicated that occur of descent of chlorpyrifos residues from eachs soaked consequence at storage for one week was amount 7,55; 8,42; and 18,88% respectively, while of consequence irradiation of gamma ray at 0,5 kGy doses, will be descent of chlorpyrifos residues in amount 13,90; 19,16; and 52,79% respectively, and at 1,0 kGy doses irradiation will be descent in amount 34,45; 36,15 and 49,79%, respectively. (author)

  15. Evaluation of the effect of gamma-ray irradiation on starch by near-infrared spectroscopy

    In order to evaluate the effect of gamma-ray irradiation on starch, near-infrared absorption spectra of four groups of starch samples, control, 10, 20 and 30 kGy irradiated, were measured. By the preliminary analysis, it was revealed that 1 702 and 2 100 nm were effective in predicting the irradiation dose on starch. On the other hand, samples were divided into calibration and validation set. The multi-regression analysis of the calibration set was carried out with adopting 1702 or 2100nm as the first wavelength, and the resulting calibration curves were named calibration A and B. Using these calibration curves, the irradiation dose of the validation set was predicted. Although the accuracy of the prediction was poor, it seemed that the non-irradiated and the irradiated samples could be discriminated by an appropriate borderline. Therefore, a new irradiation index was defined as non-irradiated = 0 and irradiated = 1. In the same way as the case of four groups, calibration C and D, in addition, calibration E, which using 1702 nm only, were developed and the irradiation index of the validation set was predicted. Although there were a few samples that could not be accurately predicted with calibration C and D, there was only one wrong discrimination with calibration E and its prediction accuracy was 96.2%

  16. Electron beam and gamma ray irradiated polymer electrolyte films: Dielectric properties

    S. Raghu

    2016-04-01

    Full Text Available In this study, polymer electrolyte films were irradiated with electron beam (EB and Gamma ray (GR at 50 and 150 kGy. The induced chemical changes in films due to irradiations have been confirmed from the Fourier Transform Infra red (FT-IR spectra. The X-ray Diffractometry (XRD results show that crystallinity decreases by ∼20% in EB and ∼10% in GR irradiated films respectively compared to non-irradiated film. The micro structural arrangement was investigated by Scanning Electronic Microscopy (SEM and the images reveal that there is a substantial improvement in the surface morphology in irradiated films. The real (ε′ and imaginary (ε″ dielectric constant and AC conductivity are found to increase with increase in irradiation dose. Improved dielectric properties and conductivity (1.74 x 10−4 & 1.15 x 10−4 S/cm, respectively, for EB and GR irradiated films at room temperature after irradiation and it confirm that EB and GR irradiation can be simple and effective route to obtaining highly conductive polymer electrolytes. From this study it is confirm that EB is more effectiveness than GR irradiation.

  17. Characteristic evaluation of papain irradiated with 60Co γ-rays for the purpose of sterilization

    To establish irradiation sterilization method for hybrid biomedical materials containing bioactive molecules together with artificial polymers, we employed dry powder and aqueous solution of papain as a model and examined radiation tolerance with 60Co γ-rays. The dry powder and frozen aqueous solution showed significant resistance after 30-kGy irradiation, indicating that commercial irradiation sterilization method for disposable medical supplies was applicable. Unfrozen aqueous solutions (10mg/ml), in contrast, showed significant drop of enzymatic activity within the early period of irradiation (ca. 0.5kGy) but 40% of the activity was recovered at ca. 3-kGy before total inactivation at 15kGy. Taking various conditions including dose rate, concentration of enzyme, oxygen and nitrogen bubbling into irradiation inactivation experiments, we demonstrated that inactivation of papain could be controlled under anoxic condition, such as nitrogen bubbling, increasing sample volume at high dose rates and high concentration of enzyme where dissolved oxygen was consumed rapidly. It is suggested that radiation inactivation of papain in the aqueous solution was occurred through reversible oxidation of the sulfhydryl group at the active site by free radicals derived from radiolysis of water and dissolved oxygen. (author)

  18. Evaluation by EPR of potential antioxidant components of 60Co-irradiated varieties of soybean

    Brazil is today the second main producer of soybean in the world with a planted ground of about 21 million hectares and an annual production of 60 million tons in 2008, being slight more than a fourth of the annual production. The presence of flavonoids, particularly isoflavones in soybean products has been related as important for human health. It has been suggested that flavonoids play a role in the protection of plants by screening vital cellular components from damaging UV radiation. Electron paramagnetic resonance (EPR) spectroscopy can measure free radicals produced by dissociation molecules resulting from irradiation. It has been successfully employed for the detection of some irradiated food products. Twenty one Brazilian soybean cultivars from two crops were gamma-irradiated with a 60Co source and evaluated by EPR. Correlation coefficients were made among the central EPR signal (g = 2.0039) and the total and partial isoflavones contents. There was no correlation with total contents, though glicitein and acetyl-daidzin showed a negative correlation. Even 7 months after irradiation the intensity of central EPR signal were high enough to distinguish the irradiated samples. EPR measurements of separated parts of the grain were more efficient for that purpose, particularly from hilum and coat. The radiation did not change substantially the total isoflavone contents, although there were some evidences suggesting some conversion of glycosides to aglycones. (author)

  19. Effect of 60Co γ-rays irradiation on antioxidant enzymes activities in transgenic and non-transgenic tobacco seedlings

    Changes of activities of antioxidant enzymes in pprI-transgenic tobacco seedlings and non-transgenic tobacco seedlings after different doses 60Co γ-rays irradiation were studied. The results showed that the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in pprI-transgenic tobacco seedlings and non-transgenic tobacco seedlings were gradually increased after different doses 60Co γ-rays irradiation. The activity of SOD was to the maximum at 100 Gy treatment, but the activity of POD and CAT at 300 Gy treatment, and then these three antioxidant enzymes gradually decreased with the increase of irradiation dose. Quantitative real-time PCR analysis also revealed that the over-express of these antioxidant enzymes were induced after different doses 60Co γ-rays irradiation and were consistent with the variance of their enzymic activities, which enhanced the tolerance of tobacco against irradiation. (authors)

  20. The influence of irradiation of gamma-rays on the pulping and paper making, (4)

    The influence of gamma-irradiation on the beating properties of unbleached kraft pulps was studied, and the changes of the mechanical and chemical properties of the sheet made from those pulps were also investigated. The results obtained were as follows: (1) When the unbeaten pulp was treated with gamma-ray, the degree of polymerization of cellulose was decreased rapidly and the formation of aldehyde and carboxyl groups in pulp was observed in addition to that the beating time of irradiated pulps was reduced comparing with non-irradiated pulp. These effects increased roughly in proportion to the radiation dose. (2) Gamma-irradiation was more effective in wet state (moisture content = 70 - 80%) than air dry state. This may be due to the degradation products of water by gamma-irradiation. (3) The mechanical properties (breaking length, tear and burst factors) of the sheets made from irradiated pulps were considerably deteriorated at 107R, but there was a slight deterioration up to 106R. (4) Comparing the result of the mechanical properties, the strengths of the various sheets were shown in the following order: the sheet irradiated after paper making gt the sheet irradiated before beating (air dry state) gt the sheet irradiated before beating (wet state). (author)

  1. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of 60Co

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from the South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of this thesis was carry out biochemical and pharmacological studies of native and irradiated crotamine with 60 Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast Performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 M Na Cl with 2.0 kGy gamma radiation emitted by a 60 Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD50 and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of 125 I using chloramine T method, and separated in a Sephadex G-50 column. Male Swiss mice (35± 5 g), were injected i.p. with o.1 mL (2.4 x 106 cpm/mouse) of 125 I native crotamine or with 0.4 mL (1.3 x 106 cpm/mouse) of 125 I irradiated crotamine. At 0.08; 0.25; 0.5; 1; 2; 4; 8; 12 and 24 hours the animal were killed by ether inhalation. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change the protein concentration, the electroforetic profile or the primary structure of the protein, although differences were shown by spectroscopic techniques. The gamma radiation diminished the toxicity of crotamine, but it did not abolish bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. The native and irradiated crotamine have affinity by skeletal muscle and they did not pass the blood - brain

  2. Study on 99Mo production by solution irradiation method (2). Characterization of aqueous molybdate solutions under gamma-ray irradiation

    The solution irradiation method is proposed as a new production technique for 99Mo, which is the parent nuclide of 99mTc used as a radiopharmaceutical. In this new method, an aqueous molybdenum solution is irradiated with neutrons in a nuclear reactor, and more efficient and lower-cost 99Mo production than conventional 99Mo production can be realized by using the 98Mo (n,γ) 99Mo reaction and the molybdenum adsorbent of PZC. Aiming at the practical application of this method, unirradiation tests, gamma-ray irradiation tests, and neutron irradiation tests should be needed in order to characterize the aqueous molybdenum solution as the irradiation target. In the present study, using two kinds of aqueous molybdate solutions (an aqueous ammonium molybdate solution and an aqueous potassium molybdate solution) selected as candidates for the irradiation target of the new method, the compatibility between the solutions and structural materials, the chemical stability, the circulation characteristics, the radiolysis, and the gamma heating of the solutions were investigated under gamma-ray irradiation. In addition, the integrity of PZC was investigated under gamma-ray irradiation. As a result, the following were found: 1) the compatibility between the solutions and stainless steel is very well, 2) the solutions are chemically stable and have a smooth circulation, 3) the ratios of hydrogen in the gases generated by the radiolysis of the solutions are higher than that of pure water, 4) the effect of gamma heating on the solutions is the same level as that on pure water, and 5) the integrity of PZC is maintained. (author)

  3. Effects of gamma ray irradiation on the struvite crystallization of livestock wastewater

    Yoo, Byeong Hak; Jo, Seong Hui; Lee, Myun Joo; Kim, Tak Hyun [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-12-15

    The struvite crystallization was applied to remove NH{sub 4}{sup +} in livestock wastewater. The ammonium ions can be very toxic to the aquatic creatures. In this experiments, the livestock wastewater from Gongju livestock wastewater treatment plant was used. The behaviors of various parameters such as pH, mole ratio of Mg{sup 2+} : NH{sub 4}{sup +}: PO{sub 4}{sup 3-} and reaction temperature for struvite crystallization of livestock wastewater and the effect of gamma ray irradiation were evaluated. As results, for the pH variation, the NH{sub 4}{sup +} removal efficiency showed the highest, 88%, at pH 9 {approx} 9.25. The removal efficiency of NH{sub 4}{sup +}, Mg{sup 2+} and PO{sub 4}{sup 3-} was showed highest when same molar ratio of Mg{sup 2+} and PO{sub 4}{sup 3-} were applied. The NH{sub 4}{sup +} removal efficiency showed 82% at 7 .deg. C, and 90% at 30 .deg. C, with temperature. When the wastewater was irradiated with 20 kGy of gamma ray, NH{sub 4}{sup +} was removed as much as 83%.

  4. Digested livestock wastewater treatment using gamma-ray irradiation and struvite crystallization

    Kim, Tak Hyun; Lee, Sang Ryul; Nam, Youn Ku; Lee, Myun Joo [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2009-06-15

    Livestock wastewater generally contains high strength of organics (COD), ammonia nitrogen (NH{sub 4}{sup +} -N), phosphate phosphorus (PO{sub 4}{sup 3-} -P) and suspended solids. It is very difficult to treat by conventional wastewater treatment techniques. In this study, struvite crystallization was carried out to treat the digested livestock wastewater. 1.0 :1.2 :1.2 was determined as an optimal NH{sub 4}+ :Mg{sup 2+} : PO{sub 4}{sup 3-} mol ratio of struvite crystallization. For the digested livestock wastewater, COD, NH{sub 4}{sup +} -N and PO{sub 4}{sup 3-} -P removal efficiencies by struvite crystallization were 72.4%, 98.9%, and 74.8%, respectively. Gamma-ray irradiation was carried out prior to struvite crystallization of livestock wastewater. The enhancement of struvite crystallization efficiency could be obtained by the pretreatment of gamma-ray irradiation due to the decrease of COD, NH{sub 4}{sup +} -N and PO{sub 4}{sup 3-} -P concentration.

  5. Radiation-induced degradation of cyclohexanebutyric acid in aqueous solutions by gamma ray irradiation

    Jia, Wenbao; He, Yanquan; Ling, Yongsheng; Hei, Daqian; Shan, Qing; Zhang, Yan; Li, Jiatong

    2015-04-01

    The radiation-induced degradation of cyclohexanebutyric acid under gamma ray irradiation was investigated. Degradation experiments were performed with 100 mL sealed Pyrex glass vessels loaded with 80 mL of cyclohexanebutyric acid solutions at various initial concentrations of 10, 20, and 40 mg L-1. The absorbed doses were controlled at 0, 0.65, 1.95, 3.25, 6.5, 9.75, and 13 kGy. The results showed that gamma ray irradiation could effectively degrade cyclohexanebutyric acid in aqueous solutions. The removal rate of cyclohexanebutyric acid increased significantly with the increase of absorbed dose and the decrease of its initial concentration. At the same time, the removal of chemical oxygen demand (COD) was as effective as that of cyclohexanebutyric acid. The kinetic studies showed that the degradation of cyclohexanebutyric acid followed pseudo first-order reaction. Above all, the proposed mechanism obtained when NaNO2, NaNO3 and tert-butanol were added showed that the •OH radical played a major role in the gamma degradation process of cyclohexanebutyric acid, while •H and eaq- played a minor role in the gamma degradation process. The degradation products were identified by Fourier transform infrared spectroscopy (FTIR) and gas chromatography/mass spectrometry (GC/MS) during cyclohexanebutyric acid degradation.

  6. Studies on the use of 60Co irradiation to control infectivity of Toxoplasma gondii

    Toxoplasma gondii cysts in minced pig brain, tongue, liver, heart and muscle were placed into plastic vials. These materials were irradiated at various doses. The irradiated tissue was then treated with artificial digestive juice and the suspension of bradyzoites prepared. The suspension was used to infect mice intraperitoneally and kittens orally. Unirradiated tissue with T. gondii was given to mice and kittens to serve as controls. Determination of infectivity was done on the 50th day after the mice were infected or 3-15 days after the kittens were infected. Loss of infectivity was confirmed according to the following criteria: no cyst in mouse brain impression smears; no oocyst in faeces of kittens; subinoculation in mice and indirect haemagglutination tests were negative, while all bioassay, parasitological examinations and serological tests in the control group were positive. Repeated experiments were done in order to calculate the minimal effective irradiation dose (MED). Activity of radiation source: 37 x 1013 bq; uniform dosage: 12.38 Gy/min. Results showed that (1) the MED of gammar rays to control infectivity of the Chinese NT strain and the US ME-49 and TS-2 strains of T. gondii cysts in pork was approximately 0.6 kGy; and (2) infectivity for mice of NT strain bradyzoites released from cysts irradiated with gamma rays at a dose of 0.45 kGy decreases to 1/10,000. These data could be valuable in practical operations to control T. gondii in pork products. (author). 7 refs, 1 fig., 4 tabs

  7. Immune response against the irradiated Bothropstoxin-1 with 60Co: identification of main cytokines involved and the participation of scavengers substances

    Considering the effects of gamma radiation on proteins and the ability of immune system to recognize modified macromolecules, we have identified the major cytokines involved in immune response of B10.PL, BALB/c and Knockout- IFNγ mice exposed to native or irradiated bothropstoxin-1 (BTHX-1), in the presence and absence of scavengers substances. In order to evaluate possible molecule structural modifications after being irradiated (60Co gamma rays), bothropstoxin-1 was submitted to SDS-PAGE analyses. Our results indicated that irradiation process has promoted modifications in the BTHX-1 molecule, however, in the presence of scavengers and even after irradiation process, the main band of toxin was preserved (14 kDa). Sera of animals immunized with the native or irradiated toxin, in the presence or not of scavengers, were analyzed in order to quantify specific isotopes. While the native BTHX-1 induced a predominant Th2 response, the irradiated toxin apparently promoted a switch towards a Th1 pattern. The toxin, when irradiated in the presence of t-butanol, induced to a lower production of IgG2b (Th1 response) if compared with the irradiated toxin without scavengers. We also performed a Real-time PCR to quantify the expression of cytokines IFN-γ, IL-2, IL-4 and IL-10 in spleen cells from mice. The cells of B10.PL and BALB/c mice immunized with native BTHX-1 and in vitro stimulated with irradiated toxin, showed higher expression of IFN-γ and IL-2 (Th1 response) than the control sample. The cells of Knockout-IFNγ mice immunized with native BTHX-1 showed higher expression of IL-4 (Th2 response). The cells obtained of B10.PL and BALB/c mice immunized with BTHX-1 + t-butanol, showed higher expression of IL-4 and IL-10, respectively. These facts reinforce the involvement of OH in the modulation of immune response against the irradiated toxin. (author)

  8. Dose-response for bone regeneration after single doses of 60Co irradiation

    The Bone Growth Chamber (BGC) methodology was used to establish a dose-response relationship for regeneration of mature bone tissue after irradiation of 5, 8, 11, 15 and 25 Gy single dose 60Co. The BGC, which is a titanium implant, was inserted in the proximal tibial metaphyses, bilaterally, of a rabbit immediately following local irradiation to one tibia. Each animal thus served as its own control. During a healing period of 4 weeks, the two canals penetrating the implant became filled with more or less newly formed bone. At the end of the healing period, the implants were removed and taken apart and the newly formed bone was collected and its volume measured by microradiography and microdensitometry. It was found that in the dose range of 5 to 8 Gy bone regeneration was reduced by about 20% as compared to non-irradiated controls. Between 8 and 11 Gy, there was a critical range in that a small increase in dose resulted in a greatly reduced bone formation. At 11 Gy and above, the depression in bone formation, as compared to non-irradiated controls, was about 65 to 75%

  9. Proteomics study of progeny of normal human liver cells irradiated by 60Co γ-rays

    Objective: To characterize the differential protein expression in the progeny of human liver cells surviving from ionizing radiation by the proteomic analysis. Methods: Two-dimensional electrophoresis gel coupled with mass spectrometry was used to explore the specific protein expression in the progeny of 7702 human liver cells surviving from ionizing radiation. Alterations in expression level of protein spots between the control and the progeny groups were statistically analyzed by ImageMaster 2D Platinum software and mass spectrometry was used to identify the protein spots with significantly altered expression-level. Results: The progeny of irradiated ceils were derived from human liver cell line exposed to 0, 2, 4, 6 Gy of 60Co γ-irradiation. A total of 42 differentially expressed proteins between the control and the progeny of the irradiated cells groups were screened, of which 17 were identified by matrix assistant laser desorption ion-top off light-mass spectrometry (MALDI-TOF MS) analysis, including 4 up-regulated and 13 down-regnlated proteins. Conclusions: The differentially expressed proteins profile could be significantly altered in the progeny of irradiated cells. The proteomics approach has the potential to detect the protein changes relevant to radiatian-induced genomic instability (RIGI). Further study of differentially expressed proteins would likely reveal the molecular mechanisms of gene expression in RIGI. (authors)

  10. Irradiation effect on enzymatic activity of papain with 60Co-γ rays

    An investigation was made on the durability of enzyme activity against 60Coirradiation at a dose up to 55 kGy/h using dry powder and aqueous solution of papain preparations on the market. Hybrid materials including bioactive molecules combined with biocompatible synthetic polymers are expected to have biocompatible properties and also biomimetic functions as a component of artificial organs for human body. The activity of papain in an aqueous solution was rapidly decreased at the early stage of irradiation through oxidation of SH group at its active site with active oxygen produced by the irradiation and then, partially recovered since SH group was reproduced in an anoxic state after O2 consumption in the solution irradiated at a high dose. A usual radiation method for sterilization was found applicable to decontamination of dry and frozen preparations of papain. When suitable conditions for radiation were chosen and N2 gas was purged to suppress the formation of free radicals, it was possible to keep the enzyme activity at more than 50% of the initial activity after radiation at 30 kGy. (M.N.)

  11. Decomposition of ρ-nonylphenols in water by 60Co γ-ray irradiation

    ρ-Nonylphenols (NPs), one of endocrine disrupting chemicals, are used as plastic flexibilizers or nonionic surfactants, and widely released into the water environment. Hydroxyl radicals produced from water molecules by γ-ray irradiation have high oxidation reactivity. Recently, treatments with the hydroxyl radicals have drawn much attention to conserve the water environment. In this study, decompositions of NPs in water were investigated using hydroxyl radicals by 60Co γ-rays irradiation. The concentrations of the NPs at initial concentration from 45 to 1000 nM were decomposed by γ-ray irradiation. Qualitative and quantitative analyses of NPs were carried out by high performance liquid chromatography. The decomposition curves of NPs at each initial concentration were analyzed as single exponential functions. Alkylphenol activity of aqueous NPs solution, which was estimated by enzyme-linked immunosorbent assay, implies the irradiation products have alkylphenol activity. Two products having molecular weight of 236 were investigated by liquid chromatography-mass spectrometry, and were considered to be ρ-nonylcatechol and 1-(ρ-hydroxyphenyl)-1-nonanol on the basis of the oxidation mechanisms of ρ-cresol and 4-ethylphenol. (author)

  12. Effects of 60Co γ-ray irradiation on growth characters of Chamaecrista seeds

    The seeds of 5 Chamaecrista varieties were irradiated by 60Co γ-ray of 300 Gy and the effects on M1 generation were studied. The results showed that the emergence of 5 Chamaecrista varieties decreased in some degree ; the stem-length of variety 34721 was significantly decreased, the stem-diameter of variety 2219 and the leaf-width of variety 2219 were significantly increased. The number of branch, leaf and leaf-length had no significant difference, but there were many black blots in the leaf during early period; the dry-weight of aerial part changed in two directions, either increased (92985) or decreased (34721). The total N of variety 2217 were significantly increased and the total P of variety 92985 were significantly decreased. The squaring stage, initiate flower stage, full bloom stage, pod-bearing stage, peak pod setting stage and maturing stage had changed in two direction, either early, or late

  13. Effect of gamma rays on sex ratio, emergence and lifespan of cucurbits fruit fly dacus ciliatus (low) irradiated as pupae

    The result showed the pupae at the age 1 or 2 days old was very sensitive to all doses of gamma rays, the percentage of adults emerged was zero at the dose of 45 gray and highest and the gigh percentage of adults emergence was recorded when the pupae irradiated at five days ald and the mean percentage of emerged adults was approximated with that of the control group. This study also showed that there was an effect of gamma radiation on the average percentage of deformed at adult stage and it was about 1:1 (male: female). On the other hand, the mean lifespan of females and mice s adult were decreased as the dose of gamma rays increases and the pupae irradiated at youngest ages. The longest life span of females was recorded when the pipa irradiated at five days old with any of the gamma rays dose. (Author)

  14. Formation of fine solid particles from aqueous solutions of sodium chloropalladate by gamma-ray irradiation

    Studies have been carried out on the radiation chemical formation of palladium fine particles in argon saturated aqueous solutions of sodium chloropalladate without organic stabilizer. The solutions were irradiated with gamma-rays from a cobalt gamma-ray source and the irradiated solutions were subjected to the dynamic light scattering analysis for the particle diameter measurements, and to the UV-visible optical absorption spectroscopy for the measurements of turbidity (absorption at 700 nm) and remaining chloropalladate ion concentrations in the solution. In the solution of pH = 1.95 by HCl, the turbidity increased after the irradiation and then decreased with time. The concentration of remaining palladate ion in the solution decreased by the irradiation, but it gradually increased with time after the irradiation. These phenomena were qualitatively explained by the reaction scheme in that a precursor to the solid particles still exists in the solution after the irradiation was terminated, and that intermediates including the precursor reacted with chloride ion to re-form chloropalladate ions. The average diameter of the particles after the irradiation was ca. 20 nm and it increased with time to 40 nm at 2.75 kGy, and to 80 nm at 8.25 kGy absorption of radiation. The solution of pH = 0.65 by HCl was found to give lower yields of particles than those observed for the solution of pH = 1.95, and to give the particles of diameters about 150-200 nm. In the solution containing HClO4 instead of HCl, palladium particles were also formed by the irradiation, whereas no backward reaction after the irradiation was observed due to the low concentration of chloride ion in the solution. The average diameter of the particles after the irradiation was about 300 nm and increased with time after the irradiation to a final values which was found to depend on pH of the solution and dose. (author)

  15. Relationship between free volume and mechanical properties of polyurethane irradiated by gamma rays

    Polyurethane was irradiated at various gamma radiation doses up to 1,000 kGy at room temperature in nitrogen. Positron annihilation lifetime spectroscopy, tensile test and dynamic mechanical analysis were used to find the relationship between free volume and mechanical properties. An increase of the free volume fraction in soft segments (SS) and a decrease of the free volume fraction in hard segments (HS) during gamma radiation was observed and analyzed. The results showed that HS in polyurethane had the excellent resistance to gamma radiation, whereas SS had a tendency to degrade. The reason for the decrease of the strain at break and the ultimate tensile strength was analyzed, which showed the changes in the mechanical properties of polyurethane irradiated by gamma rays were mainly determined by the changes of free volume in SS. If the resistance properties of polyurethanes exposed to radiations need to be improved, SS should be paid more attention to. (author)

  16. Survival of embryo irradiated with gamma rays by embryo culture in Brassica pekinensis Rupr

    The effect of irradiation on the survival rates and embryonic development of Brassica pekinensis RUPR. (Varieties; Kashin, Kohai 65 nichi and kairyochitose) was investigated. The purpose of this study was to seek ways of increasing the survival rates of embryos such as B.oleracea obtained through embryo culture techniques after irradiation doses affecting seed fertility and germination, for the purpose of increasing mutation rates. Embryos at different developmental stages ranging from the globular to the early heart stages were irradiated with 20 KR of gamma rays at the daily rate 0L 20 KR or 10 KR (Fig.1 and Table 1). The embryos were excised from ovules 4 to 10 days after irradiation and cultured on White's medium. The shooting and rooting rates on the 34th day of culture were higher at the dose of 10 KR/day than 20 KR/day and were lower when the materials were irradiated at the young embryonic stage (Table 3). Varietal differences in the shooting and rooting rates were also observed. The irradiated embryos survived mainly in the state of callus. It was concluded that the embryo culture technique was successful when applied to irradiated embryos excised at the young embryonic stage and that the technique affected B.pekinensis less than B.oleracea

  17. Detection of irradiated fresh fruits treated by e-beam or gamma rays

    Marin-Huachaca, Nélida Simona; Lamy-Freund, Maria Tereza; Mancini-Filho, Jorge; Delincée, Henry; Villavicencio, Anna Lúcia C. H.

    2002-03-01

    Since about 1990, the amount of commercially irradiated food products available worldwide has increased. Commercial irradiation of foods has been allowed in Brazil since 1973 and now more than 20 different food products are approved. Among these products are a number of fresh fruits which may be irradiated for insect disinfestation, to delay ripening and to extend shelf-life. Today, there is a growing interest to apply radiation for the treatment of fruits instead of using fumigation or e.g. vapour-heat treatments, and an increased international trade in irradiated fruits is expected. To ensure free consumer choice, methods to identify irradiated foods are highly desirable. In this work, three detection methods for irradiated fruits have been employed: DNA Comet Assay, the half-embryo test and ESR. Both electron-beam (e-beam) and gamma rays were applied in order to compare the response with these two different kinds of radiation. Fresh fruits such as oranges, lemons, apples, watermelons and tomatoes were irradiated with doses in the range 0, 0.50, 0.75, 1.0, 2.0 and 4.0kGy. For analysis, the seeds of the fruits were utilized. Both DNA Comet Assay and the half-embryo test enabled an easy identification of the radiation treatment. However, under our conditions, ESR measurements were not satisfactory.

  18. Detection of irradiated fresh fruits treated by e-beam or gamma rays

    Since about 1990, the amount of commercially irradiated food products available worldwide has increased. Commercial irradiation of foods has been allowed in Brazil since 1973 and now more than 20 different food products are approved. Among these products are a number of fresh fruits which may be irradiated for insect disinfestation, to delay ripening and to extend shelf-life. Today, there is a growing interest to apply radiation for the treatment of fruits instead of using fumigation or e.g. vapour-heat treatments, and an increased international trade in irradiated fruits is expected. To ensure free consumer choice, methods to identify irradiated foods are highly desirable. In this work, three detection methods for irradiated fruits have been employed: DNA Comet Assay, the half-embryo test and ESR. Both electron-beam (e-beam) and gamma rays were applied in order to compare the response with these two different kinds of radiation. Fresh fruits such as oranges, lemons, apples, watermelons and tomatoes were irradiated with doses in the range 0, 0.50, 0.75, 1.0, 2.0 and 4.0 kGy. For analysis, the seeds of the fruits were utilized. Both DNA Comet Assay and the half-embryo test enabled an easy identification of the radiation treatment. However, under our conditions, ESR measurements were not satisfactory

  19. Influence of 60Co irradiation on the mandible of adult rabbit

    This study was performed in order to observe the effect of 60Co γ-ray irradiation (5000, 8000 and 10000R) on rabbits' mandible, for as long as possible, approximately 18 months. Radiographical and histopathological studies were done after irradiation. The upper anterior teeth of all experimental animals showed elongation, lateral flection and diasthema. The lower anterior teeth showed shortening or disappearance of the crowns and resorption of the root apex in all. These teeth were lost eventually. Molar teeth disclosed shortening of crowns and irregular and partial loss on the surface of the dentine. Pulp chambers were extremely narrowed. These changes were most conspicuous in the 10,000R irradiation group. Mandibular fractures occurred in 13 cases, which include 3 cases with 5,000R, 4 cases with 8,000R and 6 cases with 10,000R. The alveolar bones were resorped, and were replaced with mandibular bone trabeculae. Various types of ankylosis of root surface and mandibulars were seen. These changes were more frequently noted in the molar regions that the anterior regions and in the groups with higher doses and longer days after irradiation. Bone trabeculae and cortex of the mandibles were resorped in the 3 irradiation groups in the early stage, but regeneration and thickening of the bones occured later. The usual case was that the anterior bone marrow became more gelatinous and the molar marrow became more fibrous. Hyperemia and abscess formation were recognized in some cases. Although in the molar regions these pathological changes were conspicuous in proportion to the amount of dose, in the anterior regions, the same changes were more conspicuous in the 5,000R irradiation group than in the 8,000R group. (J.P.N.)

  20. Chemical and Biological Studies on Cumin Fruits Irradiated by GAMMA Rays for Conservation

    The aim of this study was to investigate the effect of different doses of gamma irradiation (0, 5, 10 and 15 KGy) and different storage periods (0, 3 and 6 months) in different package materials (cotton or polyethylene bags) on essential oil quality and chemical composition of cumin (Cuminum cyminum) fruits. On the other hand antimicrobial activity of treated cumin fruits essential oil and its extracts at 0, 5000, 10000, 20000 and 40000 ppm were investigated. Results showed that the highest essential oil % was obtained from fruits stored for 3 months in cotton bag without gamma irradiation. Concerning the effect of essential oil as antimicrobial agent, the highest antibacterial activity was obtained by essential oil isolated from irradiated polyethylene packed fruits at 5 KGy then stored for 3 months (Staphylococcus aureus) or irradiated polyethylene packed ones at 15 KGy without storage (Salmonella typhimurium). On the other hand, the highest antifungal activity against Aspergillus niger and Penicillium digitatum was obtained by essential oil isolated from unirradiated packed in polyethylene fruits then stored for 6 months. Non-stored packed in cotton bag fruits irradiated with gamma rays at 10 KGy produced essential oil with highest antiyeastal activity. Cumin fruits extract at 40000 ppm when combined with different treatments presented the highest antimicrobial activity (represents as inhibition zone) against all studied microbes except with P. digitatum. Cumin extract at 40000 ppm when extracted from irradiated packed fruits in polyethylene bags with gamma rays at 5 KGy without storage or with 6 months storage or irradiated at 15 KGy of packed fruits in cotton bag with storage for 3 months presented the highest significant inhibition zones against S. aureus. The same concentration of extracted cumin from uni radiated packed in cotton bag fruits and storage for 6 months presented the highest inhibition zone of S. typhimurium. Also, with the same concentration

  1. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 x 10-15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of several of the antibiotics and steroids were developed. The rates of degradation and radiolytic degradation schemes for the majority of the compounds were elucidated. (author)

  2. /sup 60/Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Tsuji, K.; Kane, M.P.; Rahn, P.D.; Steindler, K.A. (Upjohn Co., Kalamazoo, MI (USA))

    1981-01-01

    Effects of /sup 60/Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 x 10/sup -15/ assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of several of the antibiotics and steroids were developed. The rates of degradation and radiolytic degradation schemes for the majority of the compounds were elucidated.

  3. 60Co γ-irradiation induced polymerization of methyl methacrylate in imidazolium ionic liquids

    Room temperature ionic liquids (RTILs), as a class of novel environmental benign 'green solvents', have been used as reaction media for various polymerizations due to their unique properties of non-volatility, high polarity, ease of recycling and chirality. In radiation polymerization, the energetic photons or electrons result in the formation of solvated electron and radical ions in ionic liquids, which initiate polymerization of monomers without any chemical initiator. In this work, effects of gamma ray irradiation on pure ionic liquid [bmim][PF6] was investigated in detail in a dose range of 5-400 kGy. The ionic liquids were quite stable under low dose irradiations, but underwent notable radiolysis with high doses. With the irradiated [bmim][PF6], the UV-Vis absorbance increased and the fluorescence intensity decreased with increasing doses. Raman spectra proved that gamma radiation induced significant chemical scission of n-butyl group (e.g. C-H and C-C scission), along with damages to the [PF6]- anion. In cooled samples of the irradiated [bmim][PF6] we found two coexist crystal structures, which had suffered a continuous destruction under high dose irradiation. After ensuring stability of the ionic liquids to low dose irradiation, radiation polymerization of methyl methacrylate (MMA) in ionic liquids and IL/organic solutions was performed. By adding the ionic liquids, the monomer conversion and molecular weight (Mw) of the polymer increased significant. Mw of PMMA in neat ionic liquid increased by about 60 times, from 3 x 104 with pure organic solvent to about 2 x 106. Molecular weight of the polymer increased with the IL fraction in the IL/organic solutions, and it was dependent on ionic liquids and solvents used, too. It was also found that the polymer obtained in the existence of IL showed multi-modal broadened molecular weight distribution (MWD). A reasonable explanation is the inhomogeneous nature of the ionic liquid in micron scale and the complicated

  4. Effect of gamma irradiation dose on the fabrication of α-elastin nanoparticles by gamma-ray crosslinking

    Nanoparticles were prepared utilizing the thermosensitive aggregation of α-elastin and gamma-ray crosslinking. We investigated the effect of the α-elastin irradiation doses to verify the yield of crosslinked nanoparticles. Aqueous solution of α-elastin (10 mg/ml) was used for the aggregation on raising temperature above its cloudy point (CP), followed by gamma-ray crosslinking. A slow heating process (1.9 oC/min) effectively led to aggregation of polypeptide and irradiation with more than 15 kGy yielded stable crosslinked nanoparticles with diameters less than ca. 200 nm and a narrow size distribution.

  5. A comparative experiments for tube agglutination test of pullorum antiserum with gamma ray Co60 irradiated salmonella pullorum

    An agglutinability between naturally infected positive chicken serum of pullorum disease and hyperimmunized rabbit antiserum was compared. And the following results were obtained and summarized. On the agglutinability, Salmonella pullorum antigen which irradiated gamma-ray was better than another both formalized and heated antigen. Time of judgemented as positive titer in the tube agglutination test to the naturally infected positive chicken serum was it most suitable for 12 hours at 37°C. Agglutination titer of positive immune chicken serum against gamma-ray irradiate Salmonella pullorum were as 320 approximately 640x. (author).

  6. Reaction of nuclear graphite with oxygen under gamma-ray irradiation

    The reaction of four kinds of nuclear graphites with oxygen under Co-60 gamma-ray irradiation were examined in the gas flow at 1atm, at temperatures 25 - 2040C and gamma dose rates 3.8 - 12.5 x 105R/hr. Air and oxygen diluted with helium were also used as the atmosphere. Radiation induced oxidation rates of the graphites in pure oxygen at dose rate 12.5 x 105R/hr were found to be 6.6 - 7.5 x 108g/g.hr, showing little differences between the graphites. Over all oxidation rate of the graphites increased with temperature, but the radiation induced rate kept constant with temperature. The increase of the over all rate at high temperatures was concluded to be due to the increase in thermally induced oxidation rate. The radiation induced oxidation rate was expressed as R = 8.3 x 10-12(D)sup(0.64), where R is the radiation induced oxidation rate in g/g.hr and D is the dose rate in R/hr. Oxidation rate of the graphite in air was about 40% of that in pure oxygen, and that in the oxygen diluted with helium was constant 15% in 0.2 - 1.0 vol.% oxygen. It was shown that the gamma-rays in a reactor would little influence oxidation of the structural graphite at high temperatures. (author)

  7. EFFECT OF GAMMA RAY IRRADIATION ON INTERLAMINAR SHEAR STRENGTH OF GLASS FIBER REINFORCED PLASTICS AT 77 K

    It is known that an organic material is damaged by gamma ray irradiation, and the strength after irradiation has dependence on the gamma ray dose. These issues are important not only to make global understanding of electric insulating performance of glass fiber reinforced plastics (GFRP) under irradiation condition but also to develop new insulation materials. This paper presents the dependence of fracture mode and interlaminar shear strength (ILSS) on the material and the gamma ray irradiation effect on the fracture mode and the ILSS. 6 mm radius loading nose and supports were used to prompt ILS fracture for a short beam test. A 2.5 mm thick small specimen machined out of a 13 mm thick G-10CR GFRP plate (sliced specimen) showed lower ILSS and translaminar shear (TLS) fracture, although the same size specimen prepared from a 2.5 mm G-10CR GFRP plate (non-sliced specimen) showed ILS fracture and the higher ILSS. Both type of specimens showed the degradation of ILSS after gamma ray irradiation. The fracture mode of the non-sliced specimen changed from ILS to TLS fracture and no bending fracture was observed. The resistance to shear deformation of glass cloth/epoxy laminate structure would be damaged by the irradiation

  8. biotechnological studies on the irradiated potato (solanum tuberosum) with gamma rays

    Bacterial wilt or brown rot disease caused by Ralstonia solanacearum causes extensive annual losses of different crops especially potato crop. It is considered as one of the limiting factors for potato production and exportation in Egypt. Therefore, the main purposes of this study were to investigate the effect of gamma rays on two potato cultivars (Diamant and Spunta). And, to obtain new genotypes of potato resistant to bacterial wilt disease. This study was carried out in the field and Biotechnology laboratory of the Plant Res. Dept., Nuclear Res. Center, Inshas, Egypt and Genetics Dept., Faculty of Agricultural., Cairo Univ., during 2008-2011. In the field experiment, dry tubers of potato cultivars were irradiated by different doses of gamma rays (20, 30 and 40 Gy) to study the effect of gamma rays on the vegetative and yield traits. The results showed that there are no significant differences between cultivars for all studied traits except a number of tubers per plant trait. Also, there are only highly significant and significant differences between treatments for weight of tubers per plant and number of tubers per plant traits, respectively. However, there are only significant differences between the interactions of cultivars and treatments for plant height and weight of tubers per plant traits. Six genotypes were selected from M1V2 generation depending on high yield for RAPD analysis to determine their genetic variability from its parents at molecular level using 11 primers. The results of RAPD analysis showed that 11 primers generated 56 distinct bands of which 31 (55.4%) were considered as polymorphic. The similarity indices of six genotypes of potato and its parents ranged from 70 to 91%. The highest genetic similarity 91% was found between D20 genotype and its parent D0 (Diamant control). On the other hand, the lowest genetic similarity 70% was found between S30, S40 genotypes and its parent S0 (Spunta control). In the artificial infection experiment

  9. Radiation-induced degradation of cyclohexanebutyric acid in aqueous solutions by gamma ray irradiation

    The radiation-induced degradation of cyclohexanebutyric acid under gamma ray irradiation was investigated. Degradation experiments were performed with 100 mL sealed Pyrex glass vessels loaded with 80 mL of cyclohexanebutyric acid solutions at various initial concentrations of 10, 20, and 40 mg L−1. The absorbed doses were controlled at 0, 0.65, 1.95, 3.25, 6.5, 9.75, and 13 kGy. The results showed that gamma ray irradiation could effectively degrade cyclohexanebutyric acid in aqueous solutions. The removal rate of cyclohexanebutyric acid increased significantly with the increase of absorbed dose and the decrease of its initial concentration. At the same time, the removal of chemical oxygen demand (COD) was as effective as that of cyclohexanebutyric acid. The kinetic studies showed that the degradation of cyclohexanebutyric acid followed pseudo first-order reaction. Above all, the proposed mechanism obtained when NaNO2, NaNO3 and tert-butanol were added showed that the ∙OH radical played a major role in the gamma degradation process of cyclohexanebutyric acid, while ∙H and eaq− played a minor role in the gamma degradation process. The degradation products were identified by Fourier transform infrared spectroscopy (FTIR) and gas chromatography/mass spectrometry (GC/MS) during cyclohexanebutyric acid degradation. - Highlights: • Gamma irradiation was efficient for removing cyclohexanebutyric acid from water. • The degradation kinetics of cyclohexanebutyric acid followed pseudo first-order reaction. • OH radical played a major role for oxidative degradation. • Some possible intermediate products were identified

  10. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with 60Co

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a 60Co source at two different doses. Samples were obtained from a healthy donor and exposed to 60Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN