WorldWideScience

Sample records for 60co gamma 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. 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)

  3. 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)

  4. 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)

  5. 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

  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. 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)

  8. 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

  9. 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)

  10. 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)

  11. 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

  12. 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.)

  13. 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.

  14. 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)

  15. 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.)

  16. 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

  17. 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

  18. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with 60Co gamma radiation

    Graphical abstract: -- Highlights: •Analyzing the impact of 60Co gamma radiation (low doses) in M. rosenbergii. •LD50 identified in 30 Gy; Irradiated exhibits morphological changes than control. •Significantly decreased HSI and histological changes in irradiated groups. •Aberration severities increased as increased of dose level. •Biomonitoring tool in determining low dose radiation pollution in aquatic ecosystem. -- Abstract: This study was framed to investigate the 60Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD50 value of 60Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of the organs it is felt could

  19. Grafting of synthetic polyelectrolyte onto polymer surfaces--comparison of glow discharge and 60Co-gamma-irradiation method

    Water soluble polyelectrolyte synthesized from natural rubber contains sulfamate and carboxylate groups similar to that of heparin. It is observed that synthetic heparinoid polyelectrolyte is capable of inhibiting blood coagulation. In the present study, we attempted to graft the same onto polystyrene and polymethylmethacrylate surfaces using glow discharge technique and 60Co-gamma-irradiation method, and the surfaces were compared with respect to water contact angle and platelet adhesion parameters. Heparinized surfaces are also evaluated for relative comparison

  20. 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

  1. 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)

  2. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with {sup 60}Co gamma radiation

    Stalin, A.; Broos, K.V. [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Sadiq Bukhari, A., E-mail: abjmc@yahoo.in [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Syed Mohamed, H.E. [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Singhal, R.K. [Analytical Spectroscopy Section, Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 4000085 (India); Venu-Babu, P. [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Center, Trombay, Mumbai 4000085 (India)

    2013-11-15

    Graphical abstract: -- Highlights: •Analyzing the impact of {sup 60}Co gamma radiation (low doses) in M. rosenbergii. •LD{sub 50} identified in 30 Gy; Irradiated exhibits morphological changes than control. •Significantly decreased HSI and histological changes in irradiated groups. •Aberration severities increased as increased of dose level. •Biomonitoring tool in determining low dose radiation pollution in aquatic ecosystem. -- Abstract: This study was framed to investigate the {sup 60}Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD{sub 50} value of {sup 60}Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of

  3. 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.)

  4. Cutaneous mitochondrial protection by topical treatment of herbal antioxodiants following 60 Co-gamma irradiation

    To find out the effective dose of herbal antioxidants to elevate the cutaneous lipid peroxidation (LP) at optimal level, gamma irradiation of cutaneous microsomal fraction was performed at different doses and 200 Gy was chosen. The present findings indicate that the failure of succinate in suppression of mitochondrial LP of irradiated rats might be due to diminishing of mitochondrial antioxidants which had been reduced by free radicals (generated by irradiation), since succinate suppressed mitochondrial LKP in antioxidant-treated rats. From these points of view, topical application of either curcumin or ellagic acid could be beneficial in prevention of radiation skin cancer

  5. 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.)

  6. 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

  7. 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)

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

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

  9. 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)

  10. Infection of tissue-culture cells with 60Co gamma-irradiated malaria sporozoites

    Plasmodium berghei sporozoites, attenuated by radiation from a 60Co source (8 or 15 krads) retain the ability to enter WI38 human embryonic lung cells in vitro. During the first 24 hours of incubation, the sporozoites appear to undergo normal development into exoerythrocytic trophozoites. Further development appears abnormal, although the trophozoites persist in culture cells for at least 48 hours. Parasite reactivities to fluorescent-labelled, sporozoite-specific antisera are normal up to 48 hours in culture. These observations suggest that sporozoites used in vaccine preparations may enter host cells and transform into exoerythrocytic trophozoites in vivo, but that maturation of the exoerythrocytic stage may be incomplete. (author)

  11. A comparison of 95 MeV oxygen ions and 60Co gamma irradiation effect on nonlinear optical L-alanine cadmium chloride single crystals

    Single crystal of nonlinear optical (NLO) material L-alanine cadmium chloride (LACC) was grown by slow evaporation method at room temperature. The grown crystals were irradiated with 95 MeV oxygen ions and 60Co gamma radiation at doses of 1 Mrad and 6 Mrad. The structural, chemical, dielectric properties, AC and DC conductivity, refractive index of the crystals were studied before and after irradiation. There is a slight change in the lattice parameters due to compressive strain field generated in the irradiated crystals. The observed increase in dielectric constant was found to be more for 60Co gamma irradiated crystals than 95 MeV oxygen ion irradiated crystal. A considerable change in the values of refractive indices was observed for both gamma and ion irradiated crystals. The AC and DC conductivity was found to increase after irradiation. (author)

  12. 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)

  13. Effect of 60Co gamma irradiation on metal--ceramic systems

    The following systems were studied: silver supported catalysts, silver powders, sandwich type samples (Ag/Ca(OH)2/Ag), calcium hydroxide, calcium carbonate, and a silver galvanic cell. The following experimental methods were used: ethylene oxidation experimental set-up, ESCA and AES, experimental set-up to study gas products from radiation decomposition, x-ray diffraction method, SEM, BET surface measurements, and measurements of current in a silver galvanic cell. It is suggested that observed Co-60 gamma ray effects on metal ceramic systems are electrochemical in nature and can be explained by radiation chemistry. A review of literature dealing with Co-60 gamma rays and solids is presented

  14. Calibration of radioprotection instruments and calibrated irradiation: characterization of gamma beam of 137Cs and 60Co

    Radioprotection Laboratory belongs to Dosimetry Reference Regional Centre of Atomic Energy National Commission, C.A.E. This laboratory offers the service of calibrations for radioprotection instruments as Geiger Muller detector, ionisation chamber, probe, proportional counters, electronic personal dosimeters and others used in nuclear medicine, radiotherapy centres, nuclear power plants, industry and in other applications of ionising radiation. Also it offers the service of calibrated irradiations. A gamma Irradiator and a Stabilipam 300 X-ray are the equipment of the Radioprotection Laboratory used for calibrations. Hopewell Designs Irradiator was installed to improve the quality of services in 2005. The irradiator has a 137Cs source of 10 Curies and a 60Co source of 1 Curie, approximately. Theoretical and experimental studies were done to analyse symmetry, flatness, penumbra and secondary radiation of photon beams. For symmetry, flatness and penumbra X-OMAT-V films and thermoluminescent dosimeters (TLDs) were used. Films were placed to 0.7 and 1 meter from collimator exit receiving 10, 40, 80, 100 and 120mGy. TLDs were placed to 1 and 1.80 meters from collimator on a surface higher than 137Cs beam cross section. Also studies were done to a distance of 1m and 1.80 from exit collimator using LiF powder in capsules. Irradiations were done without attenuators and with a collimator aperture of 8 C degrees. Results were compared to those obtained with Monte Carlo simulation (MCNP5c code). For secondary radiation calculation three methods were employed: Shadow-shield, Multiple distance and Monte Carlo simulation. Finally, from theoretical and experimental studies could conclude that the secondary radiation resulted to be lower than 3.5%, total radiation, symmetry and flatness were higher than 90% and penumbra was lower than 13 mm. Those results agree to recommendations ISO 4037 Standard. (author)

  15. Some Results Of Gamma-60Co Irradiation Application To Breed New Soybean Varieties At Institute Of Agricultural Genetics, 2001 - 2007

    To overcome the disadvantage characters and continue create new genetical materials in new Soybean variety selection to get high yield, resistance to with disadvantage conditions, good quality. The Institute of Agricultural Genetics successfully combinated the good particularities of mutant varieties DT84/DT83 and received DT2001 variety, and from mutant DT90/DT84 received new variety DT96. These varieties quite resists with rare good drought-tolerant, high yield from 2000 to 3500 kg/ha, appropriate with all of 3 crops: spring, summer and winter and have wide adaptation. DT96, DT2001 varieties were adopted by MARD Scientific Council as New National Varieties. cooperated with Dalat Institute of Nuclear research treated the Gamma - 60Co Irradiation on Soybean and Vegetable Soybean. Irradiated dry seed of 3 varieties DT96, DT2001, DT158 with dose levels of 150, 200, 250 Gy in order to shorten the rise time and strengthen the drought resistance. At M3 generation had selected 3 lines D.96/26, D.01/58, D.58/08, D.58/224, which have rise time from 3 to 5 day shorter and yield higher than control (D.96/150, D.01/245). Irradiated the 2 vegetable Soybean DT02 (to ameliorate its thick shell, improve sweetness and resist with collapse) and DT06 (to ameliorate its heat resistance) with dose levels of 100, 140, 180, 220 Gy were received the generations and now continue being researching the M3 generation in 2007 summer crop. (author)

  16. Numerical simulation of 60Co-gamma irradiation effects on electrical characteristics of n-type FZ silicon X-ray detectors

    Vigneshwara Raja, P.; Rao, C. V. S.; Narasimha Murty, N. V. L.

    2016-07-01

    This paper describes the gamma irradiation effects on the electrical characteristics of n-type float zone (FZ) silicon detectors by incorporating a 4-level 60Co-gamma radiation damage model in the commercial device simulator for plasma X-ray tomography diagnostics. In the simulations, a segmented n-type silicon detector (i.e. p+-n-n+ structure) is considered with varying substrate resistivity (ρ = 5.4, 2.5, and 0.3 kΩ cm). The simulation results have been validated with the reported experimental measurements carried out on similar device structures. The 60Co-gamma irradiation induced changes in the electrical characteristics of the detectors are analyzed up to the dose of 3500 Mrad. The possible gamma induced degradation in the X-ray response of the detectors is investigated from the changes in the effective doping concentration and the leakage current of the detectors. The survival of the gamma irradiated detectors is predicted from the simulation studies. The comparison between the 60Co-gamma and 14.1 MeV neutron irradiation effects (typical fusion environments) on silicon detectors is attempted.

  17. 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

  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. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of {sup 60}Co; Estudo bioquimico e farmacologico das crotaminas nativa e irradiada com radiacao gama de {sup 60}Co

    Mitake, Malvina Boni

    2000-07-01

    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 {sup 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 {sup 60} Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD{sub 50} and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of {sup 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 10{sup 6} cpm/mouse) of {sup 125} I native crotamine or with 0.4 mL (1.3 x 10{sup 6} cpm/mouse) of {sup 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

  20. Cytotoxicity evaluation of Diethyltoluamide (DEET) in Perna perna (Linnaeus, 1758) mussels non-irradiated and irradiated with 60Co gamma radiation

    Recent studies have identified the presence of several emerging pollutants in aquatic environments. The occurrence in different environmental matrices has been continuously reported, highlighting the need for toxicity studies. The DEET (N,N-diethyl-meta-toluamide) is the active ingredient used in most insect repellents, and is present in many commercially available formulations. Apart from chemical pollutants, aquatic organisms are subject to exposure of ionizing radiation from natural sources or in the vicinity of nuclear power plants. The present study evaluated the toxicity of DEET in organisms irradiated and non-irradiated with 60Co gamma radiation, and the effects that radiation causes in lysosomes of hemocytes of Perna perna mussel. For this purpose, assays were performed to identify the acute toxicity of DEET concentration and the dose of gamma radiation able to cause mortality. Subsequently, cytotoxicity assays were carried out to assess the stability of the lysosomal membrane in organisms exposed to ionizing radiation and DEET. According to the results obtained in acute toxicity tests, the concentration of DEET that causes mortality of 50% exposed organisms (LC50) is 114,27 mg L-1, and the radiation dose that causes mortality (LD50) is 1068 Gy. In the cytotoxicity assays, the concentration of the non-observed effect (NOEC) for irradiated and non-irradiated organisms 0.0001 mg L-1 and observed effect concentration (LOEC) at concentrations above this. The IC25 (72h) for non-irradiated organisms was 0.0003 mg L-1 and IC50 (72h) was 0.0008 mg L-1 for irradiated and non-irradiated organisms. Despite of the concentrations of effect found in this study were higher than in the environment, both measurements are in the same order of magnitude and should be also take into account the possible synergistic effects of DEET with other contaminants in the aquatic environment. (author)

  1. 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

  2. Toxoplasma gondii gamma irradiation using Co-60; Irradiacao do Toxoplasma gondii com gama do {sup 60} Co

    Serra-Freire, Nicolau Maues [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Parasitologia Animal; Maliska, Carmelindo [Hospital Central do Exercito, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Norberg, Antonio Neres [Instituto de Biologia do Exercito (IBEx), Rio de Janeiro, RJ (Brazil)

    1996-07-01

    The use of nuclear power through radiation for the destruction of microorganisms which cause food deterioration, infections and toxicosis, is specifically for peaceful purposes. Toxoplasma gondii is a protozoa responsible for illnesses in humans and animals. One of the most common ways of transmission is through raw or poorly cooked meat. There is little information on the resistance of T. gondii to radiation. The objective of this research is to determine the Minimum Lethal Dose (MLD) of gamma radiation for those microorganisms. Suspensions of T. gondii containing approximately one million taquizoites/ml were irradiated with doses between up 0,01 up to 0,15 kGy (Kilogray) and inoculated to mice. The surviving T. gondii were re-irradiated with 0,01 up to 0,16 kGy. The irradiated protozoa were totally destroyed with a 0,15 kGy dose (MLD). Taquizoites issued from live protozoa of 0,14 kGy also were completely destroyed with dose of 0,15 kGy. No increase in resistance was observed regarding the non irradiated protozoa. (author)

  3. 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)

  4. 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)

  5. {sup 60}Co gamma-irradiation effects on electrical properties of a rectifying diode based on a novel macrocyclic Zn octaamide complex

    Ocak, Y.S. [Department of Science, Faculty of Education, University of Dicle, Diyarbakir (Turkey); Kilicoglu, T., E-mail: kilicoglutahsin@gmail.co [Department of Physics, Faculty of Art and Science, University of Batman, Batman (Turkey); Department of Physics, Faculty of Art and Science, University of Dicle, Diyarbakir (Turkey); Topal, G. [Department of Chemistry, Faculty of Education, University of Dicle, Diyarbakir (Turkey); Baskan, M.H. [Department of Physics, Faculty of Education, University of Dicle, Diyarbakir (Turkey)

    2010-01-01

    C{sub 36}H{sub 28}N{sub 12}O{sub 8}ZnCl{sub 2}.9/2H{sub 2}O, Zn-octaamide (ZnOA) macrocyclic compound was synthesized to be used in the fabrication of electronic and photoelectronic devices. The structure of new compound was identified by using {sup 1}H NMR, {sup 13}C NMR, IR, UV-vis and LC-MS spectroscopic methods. The Sn/ZnOA/n-Si/Au structure was engineered by forming a thin macrocyclic organic compound layer on n-Si inorganic substrate and then by evaporating Sn metal on the organic layer. It was seen that the device had a good rectifying behaviour and showed Schottky diode properties. The diode was irradiated under {sup 60}Co gamma-source at room temperature. Characteristic parameters of the diode were determined from its current-voltage (I-V) and capacitance voltage (C-V) measurements before and after irradiation. It was observed that gamma-irradiation had clear effects on I-V and C-V properties. Also, it was seen that the barrier height, the ideality factor and the series resistance values decreased after the applied radiation, while the saturation current value increased.

  6. Seabuckthorn leaf extract (SBL-1) counters radiation damage by regulating time kinetics of apoptosis in jejunal crypts in total body 60Co-gamma-irradiated mice

    The radioprotective properties of plant Hippophae rhamnoides L. (common name Seabuckthorn, family Eleagnaceae) were reported and treatment with SBL-1 (herbal preparation from Seabuckthorn leaves), before whole body exposure to 60Co-gamma-rays (10 Gy), rendered >90% survivors in mice population, while 100% mortality was observed in non-SBL-1 treated, 60Co-gamma-irradiated (10 Gy) controls. Purpose of this study was to investigate the early as well as late modifying effects of SBL-1 on radiation induced apoptosis in jejunal crypts and m-RNA levels and protein levels of Bcl2 and Bax. A 30 day study was performed with 8-9 weeks old inbred male Swiss albino Strain 'A mice. Histology study was performed with jejunum to record the time dependent changes in the number of apoptotic cells in Crypts of Lieberkuhn; quantitative reverse polymerase chain reaction was performed to record the time kinetic of changes in m-RNA levels of BcI-2 and Bax genes. The changes in BcI-2 and Bax proteins were also recorded by western blotting. One time administration of SBL-1, prior to lethal whole body irradiation (10 Gy), significantly (p< 0.05) countered the radiation induced increases in cryptal apoptotic cells, Bax levels, and decrease in BcI-2 in a time dependent manner from 24 h till day 30. This study demonstrated that one of the underlying mechanisms of SBL-1 for countering radiation induced GI syndrome was by altering the time kinetics of apoptosis in cryptal cells; besides reducing the early damage. (author)

  7. 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)

  8. 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)

  9. The effect of 60Co gamma radiation on human serum gamma-globulin

    The effect of 60Co gamma radiation on human serum gamma-globulin was studied in vitro experiments. Solutions of 0.5 percent gamma-globulin were exposed to 0.2, 0.5, 1.0 and 1.9 Mrad doses 60Co gamma irradiation. Experiments showed that electrophoretic mobility of serum gamma-globulin decreased after gamma irradiation. No significant change in gamma-globulin UV absorption spectrum was observed at 0.2, 0.5, 1.0 and 1.9 Mrad doses. Gamma-globulin becomes progressively less soluble in water as the radiation doses is increased. Radiation induced transformation into insoluble gamma-globulin agregates and scission products. (author)

  10. 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)

  11. Effects of gamma irradiation of the 60 Co on antimicrobial action of plant extracts of bark and leaves of Schinus terebinthifolius Raddi

    This study aimed to evaluate the potential for antimicrobial activity in vitro of extracts of bark and leaves of S. terebinthifolius treated with 60Co gamma radiation. 5,0 doses were used; 7.5 and 10 kGy, being held non-irradiated controls. To determine the antimicrobial activity was applied to the disc diffusion technique to evaluate the diameter of the inhibition zones against Gram-positive bacteria, gram-negative bacteria, alcohol-acid-resistant and yeast. Antimicrobial activity was considered significant for halos ≥ 15 mm. The results indicate an intensification of antimicrobial action of bark extracts, the 5.0 kGy, against S. aureus. Was held the micro dilution in broth to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of peels extracts, compared to eight clinical isolates of S. aureus. The MBC values showed that ionizing radiation did not produce the increased of anti bacteriostatic action of S. terebinthifolius, but the results indicated that S. terebinthifolius bark extracts can be used as an antimicrobial agent and ionizing radiation as an important alternative in this conservation feature

  12. 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)

  13. 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)

  14. Effect of 60 Co gamma radiation on crystalline proteins

    In order to study the effects of 60 Co gamma radiation on crystalline proteins an in vitro system was set up. For that, aqueous solutions from bovine crystalline were used irradiated with 0, 5.000, 10.000, 15.000, 20.000 and 25.000 Gy. The treatment led to protein alterations determined by different methods. By turbidimetry the formation of aggregates that increased with the radiation dose was revealed. The same observation was done from viscosity data and from the UV spectrum of the samples. From amino acid analysis and fluorimetry determinations, tryptophan appeared as the most sensitive amino acid. An increase in the free-S H-groups was also observed. After the standardization of the method, the radio modifier capability of glutathione, amino ethyl thiourea, mercapto ethyl alanine and dimethyl sulfoxide was tested. The results showed that in the presence of those substances the radiation effect was diminished. (author)

  15. 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)

  16. Thermal stability of formulations of PVC irradiated with {gamma} of {sup 60}; Estabilidad termica de formulaciones de PVC irradiadas con {gamma} de {sup 60} Co

    Martinez P, M.E.; Carrasco A, H. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: memp@nuclear.inin.mx; Castaneda F, A.; Benavides C, R.; Garcia R, S.P. [CIQA, 25100 Saltillo, Coahuila (Mexico)

    2004-07-01

    The industry of cables and wires frequently use cable isolations with base of formulations of PVC, in those that stabilizer has usually been used with the help of heavy metals, as the lead, which is toxic. To solve the problem, from the 2002 one has come studying in combined form in the National Institute of Nuclear Research ININ and the Center of Investigation in Applied Chemistry CIQA, the modifications induced by the radiation in formulations with the help of vinyl poly chloride PVC. In these formulations, prepared with cross linking agent, plastifying industrial grade, stuff and non toxic stabilizers of calcium estearate and zinc industrial grade, it is sought to replace the stabilizer of Pb. For this were irradiated it test tubes of PVC with gamma radiation of cobalt 60 to three different dose in atmospheres of air and argon. Later it was determined their thermal stability at different times of heating and it was measured the Young modulus by means of thermo mechanical analysis. Those results obtained together with other techniques of characterization suggest that the irradiated proposed formulation can substitute the one stabilized with lead. (Author)

  17. Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818) DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818)

    Elaine Barros da Costa CARVALHO; Melo, Ana Maria Mendonça de Albuquerque; Mauricy Alves da MOTTA

    1999-01-01

    The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony...

  18. 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)

  19. Cytotoxicity evaluation of Diethyltoluamide (DEET) in Perna perna (Linnaeus, 1758) mussels non-irradiated and irradiated with {sup 60}Co gamma radiation; Avaliacao da citotoxicidade do dietiltoluamida (DEET) em mexilhoes Perna perna (Linnaeus, 1758) irradiados e nao irradiados com radiacao gama de {sup 60}Co

    Martini, Gisela de Assis

    2013-07-01

    Recent studies have identified the presence of several emerging pollutants in aquatic environments. The occurrence in different environmental matrices has been continuously reported, highlighting the need for toxicity studies. The DEET (N,N-diethyl-meta-toluamide) is the active ingredient used in most insect repellents, and is present in many commercially available formulations. Apart from chemical pollutants, aquatic organisms are subject to exposure of ionizing radiation from natural sources or in the vicinity of nuclear power plants. The present study evaluated the toxicity of DEET in organisms irradiated and non-irradiated with {sup 60}Co gamma radiation, and the effects that radiation causes in lysosomes of hemocytes of Perna perna mussel. For this purpose, assays were performed to identify the acute toxicity of DEET concentration and the dose of gamma radiation able to cause mortality. Subsequently, cytotoxicity assays were carried out to assess the stability of the lysosomal membrane in organisms exposed to ionizing radiation and DEET. According to the results obtained in acute toxicity tests, the concentration of DEET that causes mortality of 50% exposed organisms (LC50) is 114,27 mg L{sup -1}, and the radiation dose that causes mortality (LD50) is 1068 Gy. In the cytotoxicity assays, the concentration of the non-observed effect (NOEC) for irradiated and non-irradiated organisms 0.0001 mg L-1 and observed effect concentration (LOEC) at concentrations above this. The IC25 (72h) for non-irradiated organisms was 0.0003 mg L-1 and IC50 (72h) was 0.0008 mg L{sup -1} for irradiated and non-irradiated organisms. Despite of the concentrations of effect found in this study were higher than in the environment, both measurements are in the same order of magnitude and should be also take into account the possible synergistic effects of DEET with other contaminants in the aquatic environment. (author)

  20. Study of {sup 60}Co as gamma source in backscatter gamma densitometers

    Gholipour Peyvandi, R.; Taheri, A.; Rahmanzadeh Tootkaleh, S.; Askari Lehdarboni, M. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Islami Rad, S.Z. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Univ. of Qom (Iran, Islamic Republic of). Dept. of Physic

    2015-07-15

    In this work the performance of backscatter gamma densitometer is studied using {sup 60}Co as gamma source. The ability of the densitometer to determine the liquid's interfaces in multi-phase flows was assessed. The aim mainly was to investigate the possibility of using {sup 60}Co in this system. Furthermore, a comparison between {sup 60}Co and was done. The obtained results indicate that {sup 60}Co can be advantageous in this regard.

  1. Study of 60Co as gamma source in backscatter gamma densitometers

    In this work the performance of backscatter gamma densitometer is studied using 60Co as gamma source. The ability of the densitometer to determine the liquid's interfaces in multi-phase flows was assessed. The aim mainly was to investigate the possibility of using 60Co in this system. Furthermore, a comparison between 60Co and was done. The obtained results indicate that 60Co can be advantageous in this regard.

  2. Effect of dose-rate of gamma irradiation (60Co) on the anti nutritional compounds phytic acid and antitrypsin on soybean (glycine max L.)

    An investigation on the effect of gamma irradiation at different dose-rate on the anti-nutritional compounds (phytic acid and antitrypsin) and the color of soybean has been conducted. The purpose of the study was to analyze the influence of the dose-rate on the rate of change of anti-nutritional compounds and color. Samples were irradiated with dose-rates of 1.30; 3.17; 5.71 and 8.82 kGy/hour with irradiation time varied from 0.5 to 55 hours. Phytic acid content and antitrypsin activity, as well as their L α b color values were analyzed. Results showed that a simple first order kinetics model can be used to describe changes in the concentration of the anti-nutritional compounds and color soybeans during the radiation processing. Data indicate that irradiation process at higher dose-rate (shorter time) is more effective in destroying anti-nutritional compounds as compared to that of irradiation process at lower dose-rate (longer time). Furthermore, irradiation process at higher dose-rate (shorter time) also have less detrimental effect on color of the soybean and the resulted soybean flour as compared to that of irradiation process at lower dose-rate (longer time). These findings suggest that irradiation process at a same dose may potentially be optimized by selecting the most appropriate combination of dose-rate and time of irradiation. (author)

  3. 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)

  4. 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).

  5. 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)

  6. 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.

  7. Study of the effect of gamma irradiation (60 Co) on the quality of sugar cane spirit and on the cask of maturation

    The ageing or maturing process of drink improves the sensorial characteristics of the product making it a qualified drink with higher economical value. The traditional maturing method of drinks involves their interaction with wood and irradiation can accelerate this ageing process. Sugar cane spirit and oak barrels with a 20 L capacity were treated using gamma irradiation (150 Gy). Physical-chemical and chromatographic analyses were constantly performed for 390 days during the drink ageing period. The sugar cane spirit and barrel irradiation did not change most volatile components of the same type coefficient such as volatile acidity, esters, superior alcohols and furfural throughout the 390 days. There is evidence, however, that some component parameters like aldehydes, tannin, color and copper concentration are in some way influenced resulting in partial acceleration of the ageing or maturing process. At the end of the ageing period, a sensorial analysis was made using 30 non-trained people who tasted the drink. The ageing process acceleration was confirmed by the sensorial evaluation, where the irradiated sugar cane spirit and/or barrel had higher approval regarding all parameters analyzed (scent, flavor and appearance). (author)

  8. Study of the effect of gamma irradiation (60CO) on the quality of sugar cane spirit and on the cask of maturation

    The ageing or maturing process of drink improves the sensorial characteristics of the product making it a qualified drink with higher economical value. The traditional maturing method of drinks involves their interaction with wood and irradiation can accelerate this ageing process. Sugar cane spirit and oak barrels with a 20 L capacity were treated using gamma irradiation (150 Gy). Physical-chemical and chromatographic analyses were constantly performed for 390 days during the drink ageing period. The sugar cane spirit and barrel irradiation did not change most volatile components of the same type coefficient such as volatile acidity, esters, superior alcohols and furfural throughout the 390 days. There is evidence, however, that some component parameters like aldehydes, tannin, color and copper concentration are in some way influenced resulting in partial acceleration of the ageing or maturing process. At the end of the ageing period, a sensorial analysis was made using 30 non-trained people who tasted the drink. The ageing process acceleration was confirmed by the sensorial evaluation, where the irradiated sugar cane spirit and/or barrel had higher approval regarding all parameters analyzed (scent, flavor and appearance)

  9. 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)

  10. Effects of 60Co gamma irradiation on Eimeria falciformis (Eimer 1870) Schneider 1875, a protozoan parasite of the mouse, Mus musculus L

    Oocysts of an E. falciformis strain first isolated in Wuppertal, Germany were exposed to cobalt-60 gamma radiation under different conditions of oocyst age and development. In order to construct survival curves for oocysts irradiated in the unsporulated state, normalized percent sporulation was plotted as a function of radiation dose. Oocysts irradiated in the sporulated state never caused infection after receiving doses of 50 krads or more. Rarely, oocysts which had received 40 krads produced infection and completed their life cycle in susceptible hosts, but usually the doses beyond which infection did not occur ranged from 30 to 35 krads. Immunity was shown best by hosts which had received unirradiated oocysts in vaccinations prior to challenge. When irradiated sporulated oocysts were used in attempts to immunize susceptible hosts against coccidiosis, the most positive results were obtained from oocysts which had been exposed to 20 krads. Animals receiving vaccinations of oocysts exposed to 20 krads always survived the minimal infections caused by vaccination and also exhibited good immunity to challenge

  11. 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)

  12. 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)

  13. 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.)

  14. 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)

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. Effects of gamma irradiation of the {sup 60} Co on antimicrobial action of plant extracts of bark and leaves of Schinus terebinthifolius Raddi; Efeitos da radiacao gama do {sup 60} Co sobre a acao antimicrobiana de extratos vegetais de cascas e folhas de Schinus terebinthifolius Raddi

    Silva, Edvane Borges da; Santos, Gustavo Henrique Farias dos; Amaral, Ademir de Jesus [Universidade Federal da Pernambuco (GERAR/DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia; Lima, Jeniffer Maiza de Souza [Universidade Federal da Pernambuco (CAV/UFPE), Vitoria de Santo Antao, PE (Brazil); Xisto, Kesia; Araujo, Rosilma de Oliveira [Universidade Federal da Pernambuco (DA/UFPE), Recife, PE (Brazil). Dept. de Antibioticos

    2014-07-01

    This study aimed to evaluate the potential for antimicrobial activity in vitro of extracts of bark and leaves of S. terebinthifolius treated with {sup 60}Co gamma radiation. 5,0 doses were used; 7.5 and 10 kGy, being held non-irradiated controls. To determine the antimicrobial activity was applied to the disc diffusion technique to evaluate the diameter of the inhibition zones against Gram-positive bacteria, gram-negative bacteria, alcohol-acid-resistant and yeast. Antimicrobial activity was considered significant for halos ≥ 15 mm. The results indicate an intensification of antimicrobial action of bark extracts, the 5.0 kGy, against S. aureus. Was held the micro dilution in broth to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of peels extracts, compared to eight clinical isolates of S. aureus. The MBC values showed that ionizing radiation did not produce the increased of anti bacteriostatic action of S. terebinthifolius, but the results indicated that S. terebinthifolius bark extracts can be used as an antimicrobial agent and ionizing radiation as an important alternative in this conservation feature.

  20. 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)

  1. Gamma 60 Co D L 50/30 of Biomphalaria glabrata (Say, 1818)

    The variation of resistance to 60 Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60 Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL50/30=218.2 Gy) was found greater than in cross-fecundation forms. These data point to allow radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon. (author)

  2. Gamma {sup 60} Co D L {sub 50/30} of Biomphalaria glabrata (Say, 1818)

    Carvalho, Elaine Barros da Costa; Melo, Ana Maria Mendonca de Albuquerque; Motta, Mauricy Alves da [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    1999-12-01

    The variation of resistance to {sup 60} Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell {sup 60} Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL{sub 50/30}=218.2 Gy) was found greater than in cross-fecundation forms. These data point to allow radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon. (author)

  3. Preparation of low molecular weight chitosan by a combination of chemical treatment and 60Co gamma radiation

    A low molecular weight chitosan finds potential applications in agriculture, medicine, personal health care, cosmetics etc. Chitosan undergoes depolymerization when exposed to ionizing radiation, therefore 60 Co gamma rays or electron beam irradiation appears to be the most promising way to prepare a low molecular weight chitosan

  4. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained. (authors)

  5. 60Co gamma radiation effect on AlGaN/AlN/GaN HEMT devices

    WANG Yan-Ping; LUO Yin-Hong; WANG Wei; ZHANG Ke-Ying; GUO Hong-Xia; GUO Xiao-Qiang; WANG Yuan-Ming

    2013-01-01

    The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established.The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically,and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out.The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated,and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained.

  6. 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)

  7. 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)

  8. Determination of the sterilizing gamma radiation dose of 60Co to ACANTHOSCELIDES OBTECTUS imagos (col. bruchidae)

    This paper relates the results of experiments dealing with irradiation of adults of Acanthoscelides obtectus (Say, 1831). The insects were irradiated with doses of 0 (control), 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 20 krad gamma radiation of a 60Co source. After irradiation, the adults were kept for observation on beans (Phaseolus vulgaris) var. Jalo, in a controlled environmen t chamber at 30 +- 10C and 70 +- 5% relative humidity. Continuous weighing at weekly intervals was done 22 times, showing, by weight loss in percent, that the sterilizing dose for adults was 10,65 krad. It could also be observed that losses of less than 0,5% occured at 9 krad. For a possible employment on commercial scale, the ideal radiation dose for bean desinfestation would be 10 krad, after which no weight loss occurrence. (Author)

  9. 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)

  10. 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)

  11. 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)

  12. 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)

  13. 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)

  14. Study of the effect of gamma irradiation ({sup 60} Co) on the quality of sugar cane spirit and on the cask of maturation; Estudo do efeito da irradiacao gamma ({sup 60} Co) na qualidade da cachaca e no tonel de envelhecimento

    Miranda, Mariana Branco de; Horii, Jorge; Alcarde, Andre Ricardo [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept.de Agroindustria, Alimentos e Nutricao]. E-mails: jhorii@esalq.usp.br; aralcard@esalq.usp.br

    2006-10-15

    The ageing or maturing process of drink improves the sensorial characteristics of the product making it a qualified drink with higher economical value. The traditional maturing method of drinks involves their interaction with wood and irradiation can accelerate this ageing process. Sugar cane spirit and oak barrels with a 20 L capacity were treated using gamma irradiation (150 Gy). Physical-chemical and chromatographic analyses were constantly performed for 390 days during the drink ageing period. The sugar cane spirit and barrel irradiation did not change most volatile components of the same type coefficient such as volatile acidity, esters, superior alcohols and furfural throughout the 390 days. There is evidence, however, that some component parameters like aldehydes, tannin, color and copper concentration are in some way influenced resulting in partial acceleration of the ageing or maturing process. At the end of the ageing period, a sensorial analysis was made using 30 non-trained people who tasted the drink. The ageing process acceleration was confirmed by the sensorial evaluation, where the irradiated sugar cane spirit and/or barrel had higher approval regarding all parameters analyzed (scent, flavor and appearance). (author)

  15. 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

  16. 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

  17. Evaluation of fruit productivity and quality in Hass avocado submitted to 60Co gamma radiation

    Evaluation of productivity, postharvest behavior and fruit quality was performed on four years Hass avocado trees irradiated with 60 Co gamma rays in doses of 5, 10, 15, 20 and 25 Gy, established in the ''La Labor'' Experimental Center of the Centro de Investigaciones Cientificas y Tecnologias del Aguacate en el Estado de Mexico (CICTAMEX) at Temascaltepec Mexico. Productivity had a significant increase in the dose of 15 Gy being the average number of fruits nearly 400 % more than the control at fruit setting, being such difference reduced at fruit harvesting to 300 %. In regard to postharvest performance, the respiration index (mg CO2/kg/hr) did not show significant differences among treatments. Also others variables such as physiological weight losses, texture, maturity pattern, and sensorial tests (color, flavor, aroma, texture) were not different in regard to the control. This mean that radiation has altered productivity but not the quality and postharvest behavior of fruits. (Author)

  18. Effect of 60 Co gamma radiation on Biomphalaria Glabrata (Mollusca, Gastropoda) embryos: mortality, malformation and hatching

    A study was carried out on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10, 15, 20 and 25 Gy of 60 Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality, malformation and hatching were the parameters used to evaluate the damage induced by ionizing radiation. Estimated L D50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). Susceptibility to malformation induction was higher in the blastula, gastrula and young trochophore stages. Several types of morphogenetic malformations were observed, such as head malformations, exogastrulas, shell malformations, and embryos with everted stomodeum, with nonspecific malformations being the most frequent. The types of malformation induced by radiation probably are not radiation-specific and do not depend on the dose applied. The dose of 15 Gy was sufficient to greatly reduce the number of hatching snails regardless of the embryonic stage irradiated. We conclude that the effect of 60 Co gamma radiation on B. glabrata embryos presented a specific pattern. (author)

  19. 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)

  20. Some gamma radiation (60Co) effects on Chrysomya megacephala (Fabricius, 1794) (Diptira-Calliphoridae)

    The effect of different gama radiation (60Co) doses on Chrysomya megcephala (Fabricius) have been studied under laboratory conditions, in the Entomology Section of Centro de Energia Nuclear na Agricultura (CENA-USP), Piracicaba, SP, Brasil. The insects were collected close to sucking animals brooding areas, identified and reared on artificial diet, being kept in a temperature (26 +- 20C) and humidity (66 +- 9%) controlled room, with 12L:12D photopheriod. A Gammabeam type 650 Cobalt-60 gamma irradiation source was used, with 28, 196x1010 Bq activity at the beginning of the experiment. The pupae were submitted to increasing gamma radiation doses. To determine lethal doses, treatments were carried out at four different ages and to determine the sterilizing doses two-three day pupae were used. It was noted pupae radiosensitivity decreased with age, LD50 varying from 14 - 513 Gy. The sterilizing dose for males was 40 Gy and for females 30 Gy. During the individuals life cycle, it was noted that there was a decrease in life expectancy (exo) of adults when the gamma radiation dose was increased. Treated males were more sensitive than females (Crossed with ''normals''), there occurring a marked reduction in the number of eggs and their viability when the used gamma radiation dose was increased. (author)

  1. 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)

  2. Treatment of pituitaary dependent cushing's syndrome with closed stereotactic radiosurgery by means of 60Co gamma radiation

    Four patients with pituitary dependent Cushing's syndrome treated with external irradiation to the pituitary using 60Co gamma irradiation given with a stereotactic technique. The size of the sella turcica was normal or slightly enlarged in all patients. The doses given varied between 7000 and 10000 rad, and the observation time ranged between 14 and 20 months. Three of the patients showed complete clinical remission and one marked improvement. One patient developed ACTH insufficiency, while none developed insufficient secretion of other pituitary hormones. No complications of the irradiation were observed. (author)

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. Estudo do efeito da irradiação gamma (60CO na qualidade da cachaça e no tonel de envelhecimento Study of the effect of gamma irradiation (60co on the quality of sugar cane spirit and on the cask of maturation

    Mariana Branco de Miranda

    2006-12-01

    Full Text Available O processo de envelhecimento ou maturação das bebidas proporciona uma melhora nas características sensoriais da cachaça, tornando-a de qualidade superior e de maior valor econômico. O método tradicional de maturação de bebidas é sua interação com madeiras, sendo que a irradiação pode acelerar este processo de envelhecimento. A cachaça e os tonéis de carvalho de 20 L de capacidade foram submetidos à irradiação gama (150 Gy. Análises físico-químicas e cromatográficas foram realizadas periodicamente ao longo de 390 dias do período de envelhecimento da bebida. A irradiação da cachaça e do tonel não alterou a maioria dos componentes voláteis do coeficiente de congêneres como acidez volátil, ésteres, álcoois superiores e furfural durante os 390 dias. Há evidências, entretanto, de que os parâmetros de alguns componentes como aldeídos, taninos, cor e teor de cobre são de alguma forma influenciados, resultando em aceleração parcial do processo de maturação ou envelhecimento. Ao final do período de envelhecimento, foi feita uma análise sensorial com 30 provadores não treinados. A aceleração do processo de envelhecimento foi confirmada pela avaliação sensorial, e a cachaça e/ou tonel irradiados receberam maior indicação de aprovação em todos os parâmetros analisados (aroma, sabor e aparência.The ageing or maturing process of drink improves the sensorial characteristics of the product making it a qualified drink with higher economical value. The traditional maturing method of drinks involves their interaction with wood and irradiation can accelerate this ageing process. Sugar cane spirit and oak barrels with a 20 L capacity were treated using gamma irradiation (150 Gy. Physical-chemical and chromatographic analyses were constantly performed for 390 days during the drink ageing period. The sugar cane spirit and barrel irradiation did not change most volatile components of the same type coefficient such

  8. 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)

  9. 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)

  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

  11. Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818 DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818

    Elaine Barros da Costa CARVALHO

    1999-11-01

    Full Text Available The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL50/30 = 218.2 Gy was found greater than in cross-fecundation forms. These data point to a low radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon.A variação da resistência entre indivíduos em autofecundação e fecundação cruzada de Biomphalaria glabrata foram estudadas. Uma população de 480 moluscos foi observada durante 29 dias, distribuída em 8 grupos de caramujos isolados e 8 grupos em colônias após a exposição (30 caramujos por grupo-dose a doses crescentes de radiação gama. Foram usadas doses de 10, 20, 40, 60, 80, 160, 320 e 640 Gy de um irradiador Gamma-Cell 60Co. Dois grupos não irradiados - isolado e colônia - foram separados como controle e após a irradiação todos os caramujos voltaram para aquários onde viviam antes. A sobrevida foi estimada pela contagem diária dos animais vivos em cada grupo-dose, a partir do dia da irradiação. O resultado mostrou maior sobrevivência nos grupos isolados (DL50/30 = 218.2 Gy que nos grupos

  12. 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

  13. 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)

  14. 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

  15. Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with 60Co

    The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 μm by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with 60Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

  16. Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with {sup 60}Co; Deteccion y termoluminiscencia del cilantro (Coriandrum sativum L.) irradiado con {sup 60}Co

    Ruiz G, B. [Departamento de Agricultura y Ganaderia, Universidad de Sonora, 083190 Hermosillo, Sonora (Mexico); Cruz Z, E. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, UNAM, A. P. 70-543, 04510 Mexico D. F. (Mexico); Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, A. P. 5-088, 083190 Hermosillo, Sonora (Mexico)

    2009-10-15

    The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 {mu}m by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with {sup 60}Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

  17. 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.

  18. Gamma irradiation devices

    The main parameters and the preparation procedures of the gamma radiation sources frequently applied for irradiation purposes are discussed. In addition to 60Co and 137Cs sources also the nuclear power plants offer further opportunities: spent fuel elements and products of certain (n,γ) reactions can serve as irradiation sources. Laboratory scale equipments, pilot plant facilities for batch or continuous operation, continuous industrial irradiators and special multipurpose, mobile and panorama type facilities are reviewed including those in Canada, USA, India, the Soviet Union, Hungary, UK, Japan and Australia. For irradiator design the source geometry dependence of the spatial distribution of dose rates can be calculated. (V.N.)

  19. 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

  20. 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)

  1. 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

  2. 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)

  3. 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)

  4. Cataract production in mice by fractionated doses of 12C particles or 60Co gamma radiation

    The objective of our study was to evaluate the sparing effects of long-term dose fractionation with high LET 12C ions and 60Co gamma radiation. Because cataract examinations could be performed nondestructively, mice dedicated to studies of life shortening and carcinogenic response to photons and heavy charged particles were available for study. The project's staffing was such that slit-lamp biomicroscopic examinations could be performed only on CB6F1 male mice that received single or fractionated doses of 225 MeV/amu 12C ions and animals that received a single or fractionated dose of 60Co gamma radiation of 4.17 Gy. A total of 24 fractionated doses were administered weekly. Using a semiquantitative scoring system, the severity of cataract response was evaluated at three sample times following the single dose or first fractionated dose

  5. 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.)

  6. 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)

  7. Viabilidade e micoflora de sementes de amendoim irradiadas com cobalto (60Co Viability and mycoflora of irradiated seeds of peanut with cobalt (60Co

    Niédja M. C. Alves

    2011-03-01

    Full Text Available Estudou-se o efeito de diferentes doses da irradiação gama na germinação e percentagem de infecção fúngica em sementes de amendoim cultivar BR1. Inicialmente, as sementes foram avaliadas quanto à micoflora, utilizando-se o método de papel de filtro umedecido, a germinação em substrato de papel germitest e determinação do teor de umidade em estufa, a 105 ± 2 ºC. Posteriormente, as sementes foram submetidas à irradiação com uma fonte de 60Co, tipo gammacell, onde se estudou o efeito de 8 doses de irradiação na micoflora e germinação das sementes acondicionadas em embalagem de PET e polietileno trançado durante 60 dias de armazenamento, sem controle de temperatura e umidade relativa do ar. Os fatores estudados (doses em kGy, embalagens e tempo de armazenamento foram analisados em um delineamento inteiramente casualizado, dispostos em fatorial. Com base nos resultados, observou-se que a irradiação gama afetou negativamente a germinação das sementes de amendoim e que doses acima de 3,0 kGy comprometem a germinação das sementes. A radiação a partir da dose 1,5 kGy eliminou os fungos Aspergillus niger e, Penicillium a partir da dose de 2,5 kGy.The effect of different doses of the gamma irradiation was studied on germination and percentage of fungal infection in peanut seeds cultivar BR1. Initially the seeds were evaluated for the mycoflora using the method of humidified filter paper, the germination in paper substratum germitest and determination of the moisture content in oven at 105 ± 2 ºC. Later on the seeds were submitted to irradiation with a source of 60Co, type gammacell, where the effect was studied of 8 doses of irradiation in the mycoflora and germination of the seeds conditioned in PET packing and polyethylene tressed during 60 days of storage, without control of temperature and relative humidity of the air. The studied factors (doses in kGy, packing and time of storage were analyzed in a completely

  8. 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.

  9. 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

  10. Aspects of the immune response against proteic antigens submitted to the effects of 60Co gamma radiation

    Considering the effects of gamma radiation on proteins and the capacity of the immune system to recognize modified macromolecules, we decided to evaluate some immunological aspects of B10.PL mice exposed to native or irradiated ovalbumin and bothrops toxin-1 (BthTx-1). In order to evaluate possible structural modifications of the molecules after being irradiated (60Co gamma rays), bothrops toxin-1 was analysed by electrophoresis, while ovalbumin was submitted to analytical size exclusion chromatography. The toxin was also analysed by ESI-mass spectrometry. Our results indicate that radiation promoted modifications on both the molecules. Aiming to compare the toxicity of the native and irradiated forms of the toxin, an in vitro cytotoxicity assay, using CHO cells, was performed. According to our results, the modified toxin was 5 folds less toxic than its native counterpart. Sera of animals immunized with the native and irradiated proteins were analyzed in order to evaluate levels of IgG, as well as to quantify specific isotopes. While the native proteins induced a predominant Th2 response, the irradiated molecules apparently promoted a switch towards a Th1 pattern. We also performed a cell proliferation assay with splenocytes from mice immunized with either the native or the irradiated proteins, cultured in the presence of the antigens. Our results indicate that both the forms of the proteins induced a similar proliferative response. These data indicate a potential use of detoxified proteins as antigens for immunization. (author)

  11. Effect of gamma radiation of 60Co in the variability of chinese bean [Vigna unguiculata (l.) Walpers] en R4M4

    Selection of plants of Chinese bean coming from seed irradiated with gammas of 60Co in the generation R4M4 (fourth recurrent irradiation, fourth segregate generation) were carried out, taking as selection approaches the plant architecture, the numbers of sheaths for plant, sheath longitude, position of the sheaths, grain size and resistance to plagues and illnesses. 17 lines were selected for grain and 3 lines with fodder characteristics of black grain color were also obtained. (Author)

  12. Radiolysis of D(+)-carnitine by /sup 60/Co-. gamma. -radiation and formation of L(+)-. beta. -methylcholine

    Loester, Heinz; Strack, Erich; Seim, Hermann

    1986-06-01

    The radiolysis of D(+)-carnitine by /sup 60/Co-..gamma..-radiation was examined to obtain optically active ..beta..-methylcholine. It was found that the radiolysis leads to a number of trimethylammonium bases but to no other betaines. (+)-..beta..-Methylcholine and acetonyltrimethylammonium could be identified by means of common analytical methods. The amounts of methylamines formed by irradiation were very small. Racemization of the D(+)-carnitine did not occur during irradiation, L(-)-carnitine was not found when an enzymatical determination method was used. The fact that (+)-..beta..-methylcholine was formed from D(+)-carnitine is pharmacologically important, because acetyl-L(+)-..beta..-methylcholine has a strong interaction with muscarinic receptors.

  13. A new parallel-plate graphite ionization chamber as a 60Co gamma radiation reference instrument

    The calibration procedure in radiotherapy treatments is very important and a sensitive task due to the high doses delivered to the patients. Generally, the air-kerma cavity standards for 60Co gamma rays are graphite cavity ionization chambers. In this work a new parallel-plate graphite ionization chamber was studied to analyze its potential use as a reference instrument. In order to evaluate its performance in 60Co beams, it was submitted to several characterization tests. Moreover, Monte Carlo simulations were undertaken using the EGSnrc code to study the influence of the chamber components on its response. The results obtained showed that this new ionization chamber presented a satisfactory performance in all evaluated tests. - Highlights: ► A new ionization chamber was characterized as a reference dosimeter for 60Co beams. ► The EGSnrc code was used to determine the influence of the chamber components. ► The characterization test results were within the recommended limits. ► The results showed that this dosimeter may be used as a reference dosimeter

  14. 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)

  15. 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

  16. 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

  17. 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)

  18. 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)

  19. 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)

  20. 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)

  1. 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)

  2. 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)

  3. Dominant lethal effect of gamma radiation of 60Co in Biomphalaria glabrata (SAY, 1818)

    Germ cell mutations are used in ecotoxicological studies as biomarkers of population effects and indicators of ecological changes. Biomphalaria glabrata, a freshwater mollusk, is a good experimental model for biomonitoring studies due to its biological characteristics and the ecological importance of this invertebrate group. The dominant lethal test was established in B. glabrata for the detection of germ cell mutations. Results with chemical mutagens showed that this system is efficient, specific and sensitive in the evaluation of germ cell mutations induced by reference mutagens. In this work, the dominant lethal effects of gamma radiation of 60Co were studied. A preliminary experiment was done to establish the dose range and to estimate the chronology of spermatogenesis in B. glabrata. This estimate is possible because of the uniformity in response to ionizing radiation between germ cells at homologous stages of spermatogenesis in widely different species. In general, pre-meiotic germ cells are less sensitive to the induction of lethal dominant mutations than post-meiotic cells. This effect can be attributed to: young gametogenic cells - mitotically active - have greater repair ability from sub-lethal DNA damage and there is a selective elimination of the damaged cells. In our system: induction of lethal dominant mutations causes an increase in the frequency of malformations and, cytotoxic effect is displayed as a reduction in the crossing rates. Total duration of spermatogenesis was estimated in approximately 36 days, with the following distribution of stages: 1 to 13 days - spermatogonia, 14 to 20 days - spermatocytes, 21 to 36 days - spermatids and spermatozoa. Based on this chronology, irradiated wild-type snails with 2,5; 10 and 20Gy and crossed with non-irradiated albino snails after 7, 17, 23, 30 and 36 days. The frequencies of malformations in the heterozygous wild-type offspring of the nonirradiated albino snails were used as indicator of germ cell

  4. 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

  5. Use of {sup 60}Co gamma radiation in increased levels of total polyphenol extracts of bark of Schinus terebinthifolius Raddi

    Santos, Gustavo H.F.; Silva, Edvane B.; Silva, Hianna A.M.F.; Amorin, Elba L.C.; Peixoto, Tadeu J.S.; Yara, Ricardo; Lima, Claudia S.A., E-mail: santosghf@hotmail.com, E-mail: edvborges@yahoo.com, E-mail: amdemelo@hotmail.com, E-mail: claudia.salima@gmail.com, E-mail: ricardo.yara@gmail.com, E-mail: tadeu1903@yahoo.com.br, E-mail: elba@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2013-07-01

    Schinus terebinthifolius Raddi (Anacardiaceae) is well known as sources of phenolic compounds. Known as mastic pepper, red pepper tree is a plant native to midsize coast of Brazil. Some of its structures have proven antibacterial, anti-inflammatory, antifungal and healing. The aim of this study was to evaluate the difference in the phenol contents of crude extracts that were measured after irradiating the barks of S. terebinthifolius using gamma radiation from {sup 60}Co. The crude extract were divided into a control group and eight experimental groups, which were separated based on the doses of gamma radiation to which they were exposed: 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 20.0 and 50.0 kGy (Assays were performed in triplicate). The results allow observe that gamma radiation promoted in extracts of bark of S. terebinthifolius, many percents increase (p> 0.05) of total polyphenol content between 2.5 kGy (41.93%) and 50.0 kGy (44.52%) compared to 0 kGy (30.07%), with the same gradual to 10.0 kGy, and reaching peak maximum at 10.0 kGy (68.44%). However, the study puts the process of gamma radiation from {sup 60}Co as an alternative significant increase in the percentage of some natural substances of plant material, and subsequently contribute to the augmentation of various therapeutic applications to which they are assigned. (author)

  6. Use of 60Co gamma radiation in increased levels of total polyphenol extracts of bark of Schinus terebinthifolius Raddi

    Schinus terebinthifolius Raddi (Anacardiaceae) is well known as sources of phenolic compounds. Known as mastic pepper, red pepper tree is a plant native to midsize coast of Brazil. Some of its structures have proven antibacterial, anti-inflammatory, antifungal and healing. The aim of this study was to evaluate the difference in the phenol contents of crude extracts that were measured after irradiating the barks of S. terebinthifolius using gamma radiation from 60Co. The crude extract were divided into a control group and eight experimental groups, which were separated based on the doses of gamma radiation to which they were exposed: 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 20.0 and 50.0 kGy (Assays were performed in triplicate). The results allow observe that gamma radiation promoted in extracts of bark of S. terebinthifolius, many percents increase (p> 0.05) of total polyphenol content between 2.5 kGy (41.93%) and 50.0 kGy (44.52%) compared to 0 kGy (30.07%), with the same gradual to 10.0 kGy, and reaching peak maximum at 10.0 kGy (68.44%). However, the study puts the process of gamma radiation from 60Co as an alternative significant increase in the percentage of some natural substances of plant material, and subsequently contribute to the augmentation of various therapeutic applications to which they are assigned. (author)

  7. 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)

  8. 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

  9. Radiation-induced micronucleus formation in mice bone marrow after exposure to different doses of 60Co gamma radiation

    The frequency of micronuclei formation in the polychromatic erythrocytes and normochromatic erythrocytes was studied at 12 and 24th post-irradiation in mice bone marrow whole-body exposed to 0, 0.5, 1.0, 2.0, 3.0 and 4.0 Gy of 60Co gamma radiation. It was observed that the frequency of MPCE (micronucleated polychromatic erythrocytes) and MNCE (micronucleated normochromatic erythrocytes) increased with increase in exposure dose in both intervals studied. The data analyzed using the linear quadratic (Y+C+αD+βD2) equation. It was found that the data for MPCE and MNCE fitted best for linear quadratic model. (The PCE/NCE ratio declined with increase in exposure dose in both intervals and this decline was dose related. (author). 28 refs., 1 tab

  10. Tl response of KMgF3 :Lu+PTFE depending on the dose of gamma radiation of 60Co

    Due to the great interest in Tl dosimetry for measuring the levels of radiation doses, as environmental as in the different medical radiation applications in different laboratories of the World it is continued in the searching of new Tl materials with optimum dosimetric characteristics and low cost. In this work the obtained results when irradiating Tl dosemeters of KMgF3 :Lu + PTFE with gamma radiation of 60 Co are presented. Such results showed that this material presents linearity of response depending on the dose between 0.016 to 100 Gy. Although it is continued with the characterization tests it is able to say that this Tl new material can be used for dosimetric aims. (Author)

  11. 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.

  12. 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

  13. 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

  14. 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)

  15. 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

  16. 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)

  17. 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.

  18. 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...

  19. 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

  20. 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

  1. Study of gamma radiation from 60Co effects on Apis mellifera venom: biochemical, pharmacological and immunological aspects

    Africanized honeybees are very common insects in Brazil and frequently cause accidents followed by important immunological reactions and even deaths. Their venoms are composed of a complex mixture of substances of general biological actions. Ionizing radiation is able to modify molecular structures affecting the biological properties of proteins. It decreases toxic and enzymatic activities and so, it appears promising as a venom detoxification tool. The main objective of this work was to study the effects of gamma radiation on bee venom, regarding biochemical, pharmacological and immunological aspects. Africanized Apis mellifera whole venom (2 mg/ml) in 0.15 M NaCl solution was irradiated with 2 kGy in a 60Co source. Native and irradiated bee venoms were submitted to high performance size exclusion chromatography (Tosohaas G2000SW column), high performance reversed phase chromatography in a C-18 column under water/acetonitrile gradient, SDS-PAGE. For both venoms studies have been carried out in UV absorption spectrum, protein concentration, hemolytic activity, and PLA2 activity analysis, lethality assay (LD50). Biodistribution studies was carried out after labelling native and irradiated bee venom with 99mTc. The results showed that gamma radiation did not change the protein concentration nor its immunogenicity, although it could be observed that irradiated bee venom UV spectrum and SDS-PAGE profile presented differences when compared to native bee venom. This suggests that some structural alterations in bee venom components could have occurred after irradiation. HPLC-RP profiles showed that gamma radiation could have caused conformational changes, such as unfolding of molecule chains, changing their hydrophobic groups exposuring. The hemolytic and the PLA2 activities of irradiated bee venom were smaller than the native ones. The gamma radiation diminished the toxicity of bee venom, but did not abolish its bioactivity, like hemolysis. Biodistribution studies showed

  2. Aspects of the immune response against proteic antigens submitted to the effects of {sup 60}Co gamma radiation; Aspectos da resposta imune frente a antigenos proteicos irradiados com {sup 60}Co

    Alves, Janaina Baptista. E-mail: janabap@gmail.com

    2004-07-01

    Considering the effects of gamma radiation on proteins and the capacity of the immune system to recognize modified macromolecules, we decided to evaluate some immunological aspects of B10.PL mice exposed to native or irradiated ovalbumin and bothrops toxin-1 (BthTx-1). In order to evaluate possible structural modifications of the molecules after being irradiated ({sup 60}Co gamma rays), bothrops toxin-1 was analysed by electrophoresis, while ovalbumin was submitted to analytical size exclusion chromatography. The toxin was also analysed by ESI-mass spectrometry. Our results indicate that radiation promoted modifications on both the molecules. Aiming to compare the toxicity of the native and irradiated forms of the toxin, an in vitro cytotoxicity assay, using CHO cells, was performed. According to our results, the modified toxin was 5 folds less toxic than its native counterpart. Sera of animals immunized with the native and irradiated proteins were analyzed in order to evaluate levels of IgG, as well as to quantify specific isotopes. While the native proteins induced a predominant Th2 response, the irradiated molecules apparently promoted a switch towards a Th1 pattern. We also performed a cell proliferation assay with splenocytes from mice immunized with either the native or the irradiated proteins, cultured in the presence of the antigens. Our results indicate that both the forms of the proteins induced a similar proliferative response. These data indicate a potential use of detoxified proteins as antigens for immunization. (author)

  3. 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

  4. 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.

  5. Effect of gamma radiation of {sup 60}Co in the variability of chinese bean [Vigna unguiculata (l.) Walpers] en R{sub 4}M{sub 4}; Efecto de la radiacion gamma de {sup 60}Co en la variabilidad de frijol chino [Vigna unguiculata (l.) Walpers] en R{sub 4}M{sub 4}

    Salmeron E, J.; Bueno J, J.E.; Valencia E, F. [CSAEGro, Iguala, Guerrero, Tel and Fax 01 733 (33) 24328 (Mexico); Cervantes S, T. [IREGEP (Mexico); Cruz T, E. De la [ININ, Departamento de Biologia, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: csaegro@prodigy.net.mx

    2007-07-01

    Selection of plants of Chinese bean coming from seed irradiated with gammas of {sup 60}Co in the generation R{sub 4}M{sub 4} (fourth recurrent irradiation, fourth segregate generation) were carried out, taking as selection approaches the plant architecture, the numbers of sheaths for plant, sheath longitude, position of the sheaths, grain size and resistance to plagues and illnesses. 17 lines were selected for grain and 3 lines with fodder characteristics of black grain color were also obtained. (Author)

  6. 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)

  7. 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)

  8. 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.

  9. 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)

  10. 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)

  11. 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)

  12. Gamma radiation effects of {sup 60} Co on Bombyx mori (Lep., Bombycidae) modifying the silk fiber production; Influencia da radiacao gama ({sup 60} Co) na producao de fios de seda em Bombyx mori(Lep.,Bombycidae)

    Carneiro Junior, Francisco [Universidade Metodista de Piracicaba (UNIMEP), SP (Brazil); Bendassolli, Jose A. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1997-12-01

    The present work aimed to verify the biological effects of the application of different doses of gamma radiation during the fifth instar of the silkworm catepillar. Sevently eight silkworm caterpillars (Bombyx mori) were irradiated with {gamma}{sup 60} Co radiation at the initial period of the fifth instar. The caterpillars were divided and classified in six batches of thirteen individuals each. Treatments 1 through 5 received 20, 40, 60, 80 and 100 Gy, respectively, and the control, also consisted of thirteen caterpillars, was not irradiated. The results showed a general increase in the silk fiber content in the irradiated batches compared to the control. The weight of the silk cocoons was higher with increasing doses of irradiation, from 20 to 80 Gy, respectively, followed by a decrease in weight in the treatment irradiated with 100 Gy. the results obtained in this experiment enable the conclusion that the radiation applied to the caterpillars significantly influenced the production of silk fiber in this species. (author). 4 refs., 2 figs., 3 tabs.

  13. 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)

  14. 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%

  15. 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)

  16. 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.)

  17. 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

  18. Evaluation of gamma-sterilization (60Co) by RT-PCR by DHFR expression detection

    The improvement of techniques to detect pathogen agents in blood had reduced significantly the contamination mechanisms by hemocomponents in blood transfusion procedures. Ionizing radiation is a method that has presented several applications on medicine and in currently days has been showing special attention on blood banks which has been applied to avoid TA-GVHD development. DHFR is an enzyme constitutive in Plasmodium protozoa and has an important role in folate metabolism on these parasites. Detecting the expression of RNAm coder for this enzyme is possible to evaluate the viability of this parasite in blood samples. Plasmodium chabaudi AJ is a parasite that induces lethal malaria in rodents similar to human malaria In this work, the objective was to detect the presence of plasmodium protozoa in irradiated blood samples, infected experimentally, through the application of a RT-PCR using primers for the coder sequence of DHFR's mRNA. We studied doses of ionizing radiation between 0 and 75 Gy. The irradiation procedures were accomplished in Center of Radiation Technology of IPEN-CNEN in a 60Co panoramic source. Our results had demonstrated that RT-PCR is a sensible method to evaluate the viability of plasmodium in blood samples because the technique could detect low parasite burden in all tested samples. (author)

  19. Evaluation of gamma-sterilization ({sup 60}Co) by RT-PCR by DHFR expression detection

    Converso, Ana Paula G.; Andrade Junior, Heitor F. de [Instituto de Medicina Tropical de Sao Paulo, Sao Paulo, SP (Brazil)]. E-mail: anapaulagconverso@gmail.com; hfandrad@usp.br; Vieira, Daniel P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Instituto de Medicina Tropical de Sao Paulo, Sao Paulo, SP (Brazil); E-mail: dperezv@usp.br

    2007-07-01

    The improvement of techniques to detect pathogen agents in blood had reduced significantly the contamination mechanisms by hemocomponents in blood transfusion procedures. Ionizing radiation is a method that has presented several applications on medicine and in currently days has been showing special attention on blood banks which has been applied to avoid TA-GVHD development. DHFR is an enzyme constitutive in Plasmodium protozoa and has an important role in folate metabolism on these parasites. Detecting the expression of RNAm coder for this enzyme is possible to evaluate the viability of this parasite in blood samples. Plasmodium chabaudi AJ is a parasite that induces lethal malaria in rodents similar to human malaria In this work, the objective was to detect the presence of plasmodium protozoa in irradiated blood samples, infected experimentally, through the application of a RT-PCR using primers for the coder sequence of DHFR's mRNA. We studied doses of ionizing radiation between 0 and 75 Gy. The irradiation procedures were accomplished in Center of Radiation Technology of IPEN-CNEN in a {sup 60}Co panoramic source. Our results had demonstrated that RT-PCR is a sensible method to evaluate the viability of plasmodium in blood samples because the technique could detect low parasite burden in all tested samples. (author)

  20. 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.)

  1. /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.

  2. 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)

  3. Effects of 60Coirradiation sterilization and influence on the quality of paprika powder

    The pollution of paprika powder was investigated and effects of gamma irradiation on the sterilization and quality were studied. The results showed that paprika powder was seriously polluted and gamma irradiation reduced significantly the total population of mesophilic bacteria, coliforms, lactobacillus, micrococcus, mould and spore. The mortality rate could reach 82%-94% at 2.62 kGy. There was no significant different between three kinds of packaging. The D10 va1ue of coliforms was 2.05-3.21 kGy, which were sensitive to irradiation and were the indicating bacteria of radiation dose setting. The lightness and yellowness of paprika powder decrease at high does, but total color difference and ASTA value had no significant difference, and the same to pungency by Scoville Test. So irradiation sterilization was perfect way to improve the quality paprika powder. (authors)

  4. Determination of the mean energy necessary for the production of an ion pair in air by 60Co gamma radiation

    On the basis of an ionometric and a calorimetric method for determining the absorbed dose in graphite the following values of the mean energy for ion pair production by 60Co gamma radiation has been obtained in dry air: (33.87 +- 0.34) J/C. The errors of the method are discussed. The result is compared with recently published values. (author)

  5. Characterization of 60Co and 137Cs beams from irradiator Shepherd 81 - 14D of LNMRI/IRD in radiation protection

    The objective of this work is the characterization of 60Co beams and the 137Cs irradiator Shepherd 81-14D acquired by the National Metrology Laboratory of Ionising Radiation of the Institute of Radiation Protection and Dosimetry (LNMRI /IRD), for use in calibration of measuring instruments of gamma radiation in air kerma and ambient dose equivalent, irradiation of films and TLD's. Field homogeneity measurements were carried out, calculated input and output time of the source and commissioning of sources. (author)

  6. Influence of rhTPO on hematopoiesis in mice irradiated with 60Co γ-ray

    Objective: Thrombopoietin, a major physiological regulator of megakaryocytopoiesis, has potent effects on megakaryocytopoiesis. With a view to finding a new therapeutic modality for bone marrow injury-induced thrombocytopenia, the authors studied the biological activity of rhTPO in vivo. Methods: The authors recombined hTPO by means of RT-PCR and eukaryotic expression. The rhPTO was administered to 5.0 Gy 60Co γ-ray irradiated male mice, once per day for 20 consecutive days. Peripheral blood counts were monitored and bone marrow was assayed for clonogenic activity. Results: Circulating platelet counts and CFU-MK of the rhTPO-treated mice increased significantly in contrast with the control group. Conclusion: These results show that rhTPO can restore platelets and CFU-MK of irradiated mice in vivo. Clearly, the growing understanding of the biology of TPO will lead to important new in-sights into megakaryocytopoiesis and to improvement in clinical treatment of bone marrow failure

  7. Effects of 60Co gamma radiation on defense function of human polymorphonuclear leukocytes

    The effects of radiation on defense function of polymorphonuclear leukocytes (PMN) were studied following irradiation with 60Co γ radiation (30 - 3,000 rad) using PMN separated from the peripheral blood of healthy volunteers. The migration distances for all three measures of chemotaxis to fMet-Leu-Phe (10-8 M), chemokinesis induced by fMet-Leu-Phe, and random migration tended to decrease with increasing dose, showing 0.0054 μm/rad (p -5 M) in conjunction with cytochalasin B (CB, 5 μg/ml) there was a significant dose trend, showing the dose effects of decreasing 0.0022 % release/rad for BGL and 0.0030 % release/rad for LYZ with increasing dose. In superoxide anion (O2-) production, a slight and marginally significant linear dose trend was found. These results suggest that the defense function of PMN is not so resistant to radiation as predicted from the fact that PMN in the peripheral blood are differentiated and mature. It is thought that radiation inflicts substantially harmful effects on the defense function of peripheral PMN. (author)

  8. Evaluation of fruit productivity and quality in Hass avocado submitted to {sup 60}Co gamma radiation; Evaluacion de productividad y calidad de fruta en aguacate Hass sometido a radiacion gamma de {sup 60}Co

    Cruz T, E. De la; Ibanez P, J.; Mijares O, P.; Garcia A, J.M. [Instituto nacional de Investigaciones Nucleares, Departamento de Biologia, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    Evaluation of productivity, postharvest behavior and fruit quality was performed on four years Hass avocado trees irradiated with {sup 60} Co gamma rays in doses of 5, 10, 15, 20 and 25 Gy, established in the ''La Labor'' Experimental Center of the Centro de Investigaciones Cientificas y Tecnologias del Aguacate en el Estado de Mexico (CICTAMEX) at Temascaltepec Mexico. Productivity had a significant increase in the dose of 15 Gy being the average number of fruits nearly 400 % more than the control at fruit setting, being such difference reduced at fruit harvesting to 300 %. In regard to postharvest performance, the respiration index (mg CO{sub 2}/kg/hr) did not show significant differences among treatments. Also others variables such as physiological weight losses, texture, maturity pattern, and sensorial tests (color, flavor, aroma, texture) were not different in regard to the control. This mean that radiation has altered productivity but not the quality and postharvest behavior of fruits. (Author)

  9. Flux and energy deposition distribution studies inside the irradiation room of the portuguese 60Co irradiation facility

    Full text: In December 2003 the irradiator of the Portuguese 60Co irradiation facility, UTR, was replenished. Eighteen new sources were loaded and the older ones (156) were rearranged. The result was an irradiator with about 10.2 P Bq of total activity. The active area of the irradiator has also increased. Now it uses twenty five of the thirty tubes of the source rack, nine more than in the previous geometry. This facility was designed mainly for sterilisation of medical devices. However it is also used for the irradiation of other products such as cork stoppers, plastics and a limited number of food and feed. The purpose of this work is to perform dosimetric studies inside the irradiation room of a 60Co irradiation facility, particularly, the flux and energy deposition distributions. The MCNPX code was used for the simulation of the facility. The track average mesh tally capabilities of MCNPX were used to plot the photon flux and energy deposition distributions. This tool provides a fast way for flux and energy deposition mapping. The absorbed dose distribution near the walls of the irradiation room was also calculated. Instead of using meshtallys as before, the average absorbed dose inside boxes lined with the walls was determined and afterwards a plot of its distribution was made. The absorbed dose rates obtained ranged from 5 to 500 Gy.h-1 depending on material being irradiated in process and the location on the wall. These positions can be useful for fixed irradiation purposes. Both dosimetric studies were done considering two different materials being irradiated in the process: cork stoppers and water, materials with quite different densities (0.102 and 1 g.cm-3, respectively). These studies showed some important characteristics of the radiation fields inside the irradiation room, namely its spatial heterogeneity. Tunnelling and shadow effects were enhanced when the product boxes increases its density. Besides a deeper dosimetric understanding of the

  10. Effects of 60Co gamma radiations on the conduction properties of frog sciatic nerve

    The effect of Co60 gamma radiations on the amplitude, detection period and duration of the action potential of sciatic nerves of Rana tigrina frogs have been studied. Dose levels of upto 120 kR were employed. Irradiation of the nerves with dose levels upto 30 kR does not seem to affect the action of potential profiles. The amplitude falls rapidly thereafter, registering less than 5% of the original value after irradiation by a dose of 120 kR. Qualitatively similar behaviour is seen in the case of detection period and duration of action potential. These results are examined in the light of data already collected through experiments on the effect of Co60 gamma rays on the enzyme acetyl-cholinesterase (AchE). (author)

  11. Evaluation by EPR of potential antioxidant components of {sup 60}Co-irradiated varieties of soybean; Avaliacao por RPE de componentes com potencial antioxidante de variedades de soja irradiadas com {sup 60}CO

    Oliveira, Marcos Ronaldo Ramos de

    2009-07-01

    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 {sup 60}Co 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)

  12. The effect of 60Co γ-ray irradiation on the growth and regeneration of Cymbidium sinense rhizome

    The effect of 60Co γ-ray irradiation on growth of Cymbidium sinense rhizome and shoot regeneration were studied. The results showed that irradiation with low dose (2, 5 and 8 Gy) promoted the growth of Cymbidium sinense rhizome, while high dose (≥ 10 Gy) inhibited the growth. Shoot differentiation of rhizome was not affected by irradiation of low dose. Biochemical analyses indicated that the soluble protein content of rhizome irradiated with low dose was higher than that of CK, irradiated with 2 and 5 Gy seemed to reduce the activity of peroxidase, while irradiated with 8 Gy increased the activity of peroxidase

  13. Effects on agronomic traits of M1 by pollen of upland cotton irradiated by 60Co-γ ray

    [Objective] The aim was to provide reference for research on radiation and breeding of cotton pollen through irradiating common ripe pollen grain of upland cotton by 60Co-? Ray of varied doses. [Method] Ripe pollen grains of upland cotton were irradiated by 60Co-γ Ray with doses of 5, 10, 15, and 20 Gy, respectively, to learn radiation effect and select appropriate dose. [Result] Most properties of M1 obviously showed variation when dose was over 10 Gy; vitality, growth, and fertility were greatly inhibited when dose was 15 Gy which was almost semi-lethal concentration, and variation species were richest at the same time, which provided materials for practical breeding. [Conclusion] 60Co-γ Ray of 15 Gy was more suitable for inducing research for ripe pollen grains of upland cotton

  14. Use of 60 Co gamma radiation to expend the shell life of packaged sliced loaves

    The evaluation of conservation of sliced loaves (bread cut into slices). baked by five bakeries of Piracicaba, after gamma irradiation and maintained into polyethylene begs of low density, of 47,5 and 85 μm of thicknesses is shown. The sliced loaves were put into the bags and thermo-sealed by hand, like they were handled by the bakers. After this, they were irradiated with doses of 0.0: 2.0; 4.0; 6.0; 8.0 and 10.0 kGy of gamma radiation in a irradiation chamber of Cobalt-60 at a dose rate of 2,68 kGy per hour, at the room temperature (280 C). After irradiation the samples were maintained under at the room temperature (26 - 340 C), and humidity, as similar as possible to the conditions of the markets, bakeries and shops they were sold. The samples were evaluated every days and if any of them presented sign of contamination. It was threw away because it was inappropriate for human consumption. (author)

  15. Study of gamma radiation from {sup 60}Co effects on Apis mellifera venom: biochemical, pharmacological and immunological aspects; Estudo dos efeitos da radiacao gama de {sup 60}Co na peconha de Apis mellifera: aspectos bioquimicos, farmacologicos e imunologicos

    Costa, Helena

    2001-07-01

    Africanized honeybees are very common insects in Brazil and frequently cause accidents followed by important immunological reactions and even deaths. Their venoms are composed of a complex mixture of substances of general biological actions. Ionizing radiation is able to modify molecular structures affecting the biological properties of proteins. It decreases toxic and enzymatic activities and so, it appears promising as a venom detoxification tool. The main objective of this work was to study the effects of gamma radiation on bee venom, regarding biochemical, pharmacological and immunological aspects. Africanized Apis mellifera whole venom (2 mg/ml) in 0.15 M NaCl solution was irradiated with 2 kGy in a {sup 60}Co source. Native and irradiated bee venoms were submitted to high performance size exclusion chromatography (Tosohaas G2000SW column), high performance reversed phase chromatography in a C-18 column under water/acetonitrile gradient, SDS-PAGE. For both venoms studies have been carried out in UV absorption spectrum, protein concentration, hemolytic activity, and PLA{sub 2} activity analysis, lethality assay (LD{sub 50}). Biodistribution studies was carried out after labelling native and irradiated bee venom with {sup 99m}Tc. The results showed that gamma radiation did not change the protein concentration nor its immunogenicity, although it could be observed that irradiated bee venom UV spectrum and SDS-PAGE profile presented differences when compared to native bee venom. This suggests that some structural alterations in bee venom components could have occurred after irradiation. HPLC-RP profiles showed that gamma radiation could have caused conformational changes, such as unfolding of molecule chains, changing their hydrophobic groups exposuring. The hemolytic and the PLA{sub 2} activities of irradiated bee venom were smaller than the native ones. The gamma radiation diminished the toxicity of bee venom, but did not abolish its bioactivity, like hemolysis

  16. Mutant strain screening by 60Co γ-rays irradiation and its cellulase enzyme produce condition

    A mutant strain A50 with high cellulase activity was induced and isolated by using 60Co γ-rays irradiation from the initial Penicillium decumbens A10. The optimum fermentation conditions of A50 were investigated through orthogonal designing experiment, the major carbon resource 5%, the ratio between wheat bran and corn straw 1:1, the concentration of glucose as supplemental carbon 0.1%, the concentration of (NH4)2HPO4 as supplemental nitrogen resource 0.2%, the initial pH of liquid medium 5.0, the inoculated amount for fermentation 10% and the concentration of Tween-80 0.1%, 30 ml initial media filled in the 300 ml flask with culture condition of 32 degree C and 200 r/min. Under the optimum conditions mentioned above, the highest activities of cellulase and filter paper enzyme were 27.28 and 1.98IU/ml at 60 h fermentation, respectively, which was 33.2% and 45.59% higher than those of the initial strain. (authors)

  17. 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

  18. Underwater versus dry irradiation with {sup 60}Co, a qualitative analysis

    Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

    2007-07-01

    The development of gemstone gamma irradiation devices showed that underwater irradiation leads to better results than the irradiation in dry condition. Many reasons may be shown for that behavior. This work intends to analyze qualitatively two of these reasons. The medium discontinuity between the irradiation source, gemstone, and the air inside the irradiation devices, which is minimized in underwater irradiation, is one of them. The other analyzed hypothesis is the differences between the interactions of source's direct radiation and those from the scattered radiation. The numerical study of these hypothesis, as long as some irradiation tests may be presented in future works. The main conclusion of this work is that the absorbed dose may have different behavior view if the depending on the kind and energy level of the absorbed dose. For example, it is not used to consider what portion of the dose is due to source's direct hit, what part is from ejected electrons with high or low energy and how much high, medium and low energy electro-magnetic quanta hit a portion of mass when determining its radiation dose. To know the total absorbed dose is usually, but not always, enough to explain a material response to radiation. (author)

  19. Efficacy of a 60Co irradiated vaccine for experimentally infected calves with dictyocaulus viviparus

    Dictyocaulus viviparus larvae in non-infected stage (L.1) were cultured in vitro to their infective stage (L.3) and were irradiated with 40 Krad from 60Co and used as a vaccine. The oral experimental vaccine dose was 1000 L.3/animal. Three groups were formed with 8 calves in each one: group No. 1 and group No. 2 were vaccinated at 10 weeks of age. Four weeks later group No. 1 was infected with non-irradiated 60 L.3/Kg. of animal weight 'challenge dose'. After four weeks of post-vaccination group No. 2 was revaccinated and 4 weeks later it was infected with the 'challenge dose' as the previous group. Eight calves constituted group No. 3, four in each group; they were infected with only the challenge dose respectively. Information data on respiratory and cardiac frequency, temperature, weight, and L.1 count/g. of feces were obtained from each animal three times a week. After five weeks of post-challenge all animals were slaughtered to observe anatomopathologic lessions in the heart and lungs; the number of adult Dictyocaulus viviparus present in the respiratory tract were search 't'. Student test was used for the statistical analysis. The weight increment difference between animals of group No. 1 related control group was 7Kg.; and 11.25 Kg/animal in group No. 2 respectively. The percentage of protection confered by the vaccine to the subjects in group No. 1 relative to the respectivecontrol group, was 83.2; that for the group No. 2 was 88.5 per cent. Post-morten examination revealed severe anatomopathologic lessions in the control groups; only few lessions were observed in group No. 1 and practically none in group No. 2

  20. (60)Coirradiation affects the enzymatic antioxidant system of the citrus red mite Panonychus citri (Acari: Tetranychidae).

    Zhang, Ke; Li, Zhibin; Zhu, Shaowen; Weng, Qunfang

    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), peroxidase (POD), phenoloxidase (PO) and acetylocholinesterase (AchE) were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Coirradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri. PMID:24853454

  1. 60CoIrradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae

    Ke Zhang

    2014-05-01

    Full Text Available 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, peroxidase (POD, phenoloxidase (PO and acetylocholinesterase (AchE were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Coirradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.

  2. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with {sup 60}Co; Analise da frequencia de alteracoes cromossomicas instaveis em linfocitos humanos irradiados com {sup 60}Co

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F., E-mail: july_cgm@hotmail.com, E-mail: mendes_sb@hotmail.com [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: santos_neide@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2013-07-01

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a {sup 60}Co source at two different doses. Samples were obtained from a healthy donor and exposed to {sup 60}Co 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.

  3. Response of avocado genotypes to improvement through {sup 60}Co gamma radiation; Respuesta de diversos genotipos de aguacate al mejoramiento por radiacion gamma de {sup 60}Co

    Cruz, E. De la; Rubi A, M.; Garcia A, J.M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Ten avocado genotypes were subjected to gamma radiation from 0 to 45 Gy in 1993. Vegetative and reproductive data were analysed in a factorial design. Genotypes differed significative on height and fruit number. Radiation affected significative fruit number but not tree height. ''Hass'' showed strongest interaction between genotype and doses, for fruit number. (Author)

  4. Gamma irradiators: developments in India

    A comprehensive programme for the production of 60Co sources and their applications was initiated at the Bhabha Atomic Research Centre in 1970. Initially a series of research irradiators called Gamma Chambers and Panoramic Batch Irradiators (PANBITs) was fabricated for R and D and pilot scale studies. In 1974 the first commercial scale, gamma sterilization plant ISOMED was commissioned with UNDP assistance. Subsequently two more plants were designed and built indigenously, one at Bangalore and the other at Delhi. A radiation plant for sludge hygienisation was built at Baroda and commissioned in 1992. The current interest in radiation vulcanization of natural rubber latex (NRL) prompted the development and commissioning of a pilot scale NRL, irradiator at Kottayam, Kerala in 1992. A multipurpose irradiator is built recently at Jodhpur, as an upgraded version of the vintage PANBIT. Salient feature of these plants are presented . (author). 6 figs

  5. Effect of gamma radiation (60Co) on the growth of Aspergillus ochraceus coffee (Coffea arabica L.)

    Coffee is a major product on the world market. Its acceptance depends strongly on the sensory characteristics of the beverage, that is its aroma and flavor. One of the most important aspects of coffee culture today is the cup quality as such all segments of coffee production network are concentrating efforts to improve this trait. Foods that have been contaminated with fungi may contain may produce many mycotoxins including ochratoxim A (OTA). To prevent OTA in foodstuffs, it is necessary detect the producing fungi early. Ionizing radiation is a safe, environmentally clean, energy efficient process that can be used to increase the quality and reducing the microbiological contamination of the coffee. The aim of the present study was to evaluate the effects of different gamma radiation doses (0.0, 6.0, 12.0 and 18.0 kGy) on the growth of Aspergillus ochraceus in coffee (Coffee arabica L.). The analysis were performed to determine the fungi contamination the results were expressed as the viable counts per gram of sample (CFU/g) coffee samples irradiated and unirradiated. The results shows that microbiological contamination of coffee disagrees when increase doses of irradiation. The radiation doses 6.0, 12.0 and 18.0 kGy used resulted in a elimination of the number of Aspergillus ochraceus CFU/g when compared to the nonirradiated control group. Under the present conditions, gamma radiation was found to be an alternative for the control of Aspergillus ochraceus. (author)

  6. Influence of 60Co γ irradiation on fertility of Japanese pine sawyer beetle Monochamus alternatus hope (Coleoptera: Cerambycidae)

    The fertility of the Japanese pine sawyer beetle Monochamus alternatus (Coleoptera: Cerambycidae) irradiated with 60Co γ-rays was remarkable reduced at the doses of 30Gy, 35Gy and 40Gy, especially at 40Gy. When the non-irradiated females were coupled with the irradiated males first, and then coupled with non-irradiated males, the hatchability and the fertility had little higher but lower than the control. It explained that radiation has certain influence to the female gonad. It also has difference between the hatching rate and the amount of eggs in different match. (authors)

  7. Radiosensibilidad de semillas de soya a los rayos gamma 60Co

    C. de la Fé

    2000-01-01

    Full Text Available El presente estudio se desarrolló en las instalaciones del Instituto Nacional de Ciencias Agrícolas, con el objetivo de evaluar la radiosensibilidad de semillas de soya a los rayos gamma 60Co. Para su ejecución, se seleccionaron e irradiaron muestras de 50 semillas de la variedad Cubasoy-23, las que fueron sembradas en condiciones semicontroladas (macetas en la campaña de primavera, 1997. Las dosis de radiación fueron desde los 50 hasta los 480 Gy, con incrementos de 50 Gy entre las dosis de 50 y 200 Gy e incrementos de 40 Gy entre esta última y la dosis de 480 Gy. Las evaluaciones realizadas consistieron en porcentaje de semillas germinadas a los tres, seis y nueve días de la siembra, altura de las plantas a los 10, 20 y 50 días y número de pares de hojas emitidas a los 10 y 20 días de la siembra. El estudio realizado evidenció la ocurrencia de un efecto fuerte de las dosis aplicadas en el porcentaje de semillas germinadas, resultando las dosis próximas a los 280 Gy las de mayor efecto radioestimulador de la germinación. Desde el punto de vista de la altura de las plantas, el efecto de las dosis aplicadas se correspondió con el descrito para otros materiales biológicos irradiados, caracterizándose este por un aumento a dosis bajas seguido por una reducción cada vez mayor a medida que las dosis aplicadas se incrementaron. Por su parte, la emisión de hojas por las plantas mantuvo un comportamiento en correspondencia con la altura de las plantas. Los resultados del estudio permiten sugerir la aplicación de dosis próximas a los 360 Gy en los trabajos dirigidos a la creación de variabilidad genética en programas de mejora por inducción de mutaciones

  8. Strand breaks and lethal damage in plasmid DNA subjected to 60CO-γirradiation

    Experiments with calf thymus DNA subjected to extracellular irradiation yield information on the role of direct and indirect effects in single-strand breakage, if this is evaluated with reference to the scavenger activity in respect of OH radicals. The role of the two processes in the occurrence of double-stand breaks and further damage leading to cell decay has so far remained largely obscure. It was the aim of the study described here to contribute to research in this field by performing in vitro experiments on biologically active DNA. For this purpose, DNA from pBR322 plasmids was irradiated in the presence of OH-radical scavengers. The number of single-strand and double-strand breaks was determined on the basis of the system's ability to eliminate OH radicals. In order to asses the influence of irradiation processes on the biological activity of DNA, investigations were carried out in E. coli for transformations caused by irradiated plasmid DNA. The results were interpreted in the light of theories about inhomogenous reaction kinetics put forward by Mark et al. (1989). It was finally discussed, which of the gamma-irradiation injuries occurring in DNA was to be held responsible for the inactivation of plasmid DNA and which enzymatic processes were additionally at work here. (orig./MG)

  9. 60Co irradiation effect on color in minimally processed cauliflower (Brassica spp)

    Irradiation is a well-established process with clearly documented safety and efficacy. Consumers require a quality product that is convenient and has fresh-like characteristics and take product appearance, like color, into consideration as a primary criterion; it is considered a key role in food choice, food preference and acceptability. The objective of the present work was to investigate color degradation of cauliflower treated with gamma radiation during 14 days. Cauliflower irradiated samples with 0 and 1.5 kGy showed significant differences for value 'L' on the 10th and 14th day, respectively for value 'b' only the 0 kGy sample showed significant difference on day 10 of storage. On day 10 of shelf-life the irradiated cauliflower with doses of 1 and 1.5 kGy became more yellow compared to the control. The authors concluded that the treatment with low gamma radiation doses keeps the quality of fresh-cut vegetables. (author)

  10. {sup 60}Co irradiation effect on color in minimally processed cauliflower (Brassica spp)

    Nunes, Thaise C.F.; Rogovschi, Vladimir D.; Santillo, Amanda G.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: thaisecfnunes@hotmail.com; Michels, Robert [Hydrofarm Comercio e Representacao de Produtos Agricolas Ltda., Sao Roque, SP (Brazil); Pitombo, Ronaldo N.M. [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental

    2009-07-01

    Irradiation is a well-established process with clearly documented safety and efficacy. Consumers require a quality product that is convenient and has fresh-like characteristics and take product appearance, like color, into consideration as a primary criterion; it is considered a key role in food choice, food preference and acceptability. The objective of the present work was to investigate color degradation of cauliflower treated with gamma radiation during 14 days. Cauliflower irradiated samples with 0 and 1.5 kGy showed significant differences for value 'L' on the 10th and 14th day, respectively for value 'b' only the 0 kGy sample showed significant difference on day 10 of storage. On day 10 of shelf-life the irradiated cauliflower with doses of 1 and 1.5 kGy became more yellow compared to the control. The authors concluded that the treatment with low gamma radiation doses keeps the quality of fresh-cut vegetables. (author)

  11. The influence of whole body 60Co-irradiation on distribution of 67Ga in tumor-bearing mice

    Since the initial findings that 67Ga has a preferential affinity for soft tissue tumors, in humans numerous suggestions have been advanced for the basic mechanism involved. The effects produced by whole-body X-irradiation on the excretion and tissue distribution of 67Ga have been reported by Swartzendruber and others. Bradley and coworkers have shown that these irradiation effects were associated with an increase in serum iron. The present investigation was undertaken in order to study the relationships between the change in the serum iron concentration and 67Ga accumulation in the tumor and soft tissues in mice bearing Ehrlich's ascites tumor. The following results were obtained. (1) The serum iron concentration was significantly decreased between 3 and 6 hours after 10 Gy (1,000 rad) dose of whole-body 60Co-irradiation. Subsequently, the serum iron levels were slowly elevated. (2) The uptake of 67Ga in the tumor and soft tissues was increased if the serum iron concentration was decreased by whole-body 60Co-irradiation during the early phase. On the contrary, if the serum iron concentration was high, the uptake of 67Ga in the tumor was decreased. (3) The excretion of 67Ga from the body was delayed if the serum iron concentration was decreased by whole-body 60Co-irradiation. However, if the serum iron concentration was high, the excretion of 67Ga from the body significantly increased. (author)

  12. Effect of 60Co gamma radiation on insects infesting rice during storage. Part III. Oryzaephylus surinamensis L., Cryptolestes pusillus S. and Cryptolestes ferrugineus S. (Cucujidae; Coleoptera)

    Losses in rice grain in quantity and quality during storage are caused by insects infestations. In this paper the effect of 60Co gamma radiation on the mortality of Oryzaephilus surinamensis L., Cryptolestes pusillus S. and Cryptolestes ferrugineus S. adults was study. Insects were irradiated with doses from 0,20 to 1,00 kGy at dose rates from 0,97 to 0,94 kGy.h-1. After the treatment, the radiation damages were evaluated taking in consideration the sterility and mortality produced in the irradiated populations. According to the experimental results it was confirmed that irradiation doses from 0,40 to 0,60 kGy were effective to control the insects pests of stored rice in Cuba

  13. 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

  14. Effect of irradiation using 60Co on Trichinella spiralis larvae and on the eggs and protoscolices of Echinococcus granulosus

    The effect of irradiation using 60Co on Trichinella spiralis larvae and on the eggs and protoscolices of Echinococcus granulosus was studied. A dose of 30 Gy had no effect on T. spiralis larvae and on the eggs and protoscolices of E. granulosus. Irradiation of free T. spiralis larvae from muscle in normal saline exposed to 90 Gy and higher doses produced loss of infection in mice. There was reduction in the infectivity of eggs and protoscolices of E. granulosus by irradiation at a dose of 120 Gy, while there was complete loss of activity at a dose of 500 Gy. (author). 5 refs, 2 figs

  15. PENELOPE-2008 Monte Carlo simulation of gamma exposure induced by 60Co and NORM-radionuclides in closed geometries

    We present Monte Carlo simulations of the gamma exposure in closed rooms made of steel or concrete and contaminated by 60Co or NORM radionuclides. The computer code PENELOPE-2008 (Salvat et al., 2009) was used. Our simulations for 60Co suggest considering detailed Monte Carlo simulations in future recommendations on clearance and exemption of materials with low radioactivity. For NORM nuclides our calculations suggest that Monte Carlo simulations are a possible alternative in case a material fails the dose rate criteria by using the RP 112 screening method. - Highlights: • PENELOPE-2008 was used for Monte Carlo simulations of gamma exposure in closed rooms made of steel or concrete. • Findings support introducing IAEA SR 44 activity concentration value of 0.1 Bq/g as exemption value for 60Co. • PENELOPE-2008 calculations show good agreement with a density corrected Berger model for dose rate calculations concerning NORM building materials. • Monte Carlo calculations or a density corrected Berger model could be used to modify the model suggested in RP 112

  16. Study on the energy dependence of gamma radiation detectors for {sup 137}Cs and {sup 60}Co; Estudo da dependencia energetica de detectores de radiacao gama para {sup 137}Cs e {sup 60}Co

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: rediniz@ipen.b, E-mail: vcsouza@ipen.b, E-mail: vivolo@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    38 Geiger-Mueller radiation detectors and 9 ionization chambers were calibrated, viewing to study the energy dependence of the monitor response for gamma radiation fields ({sup 137}Cs and {sup 60}Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  17. Differential gene expression in human fibroblasts after alpha-particle emitter (211)At compared with (60)Co irradiation

    Danielsson, Anna; Claesson, Kristina; Parris, Toshima Z; Helou, Khalil; Nemes, Szilárd; Elmroth, Kecke; Elgqvist, Jörgen; Jensen, Holger; Hultborn, Ragnar

    2013-01-01

    Purpose: The aim of this study was to identify gene expression profiles distinguishing alpha-particle (211)At and (60)Co irradiation. Materials and methods: Gene expression microarray profiling was performed using total RNA from confluent human fibroblasts 5 hours after exposure to (211)At labeled...... trastuzumab monoclonal antibody (0.25, 0.5, and 1 Gy) and (60)Co (1, 2, and 3 Gy). Results: We report gene expression profiles that distinguish the effect different radiation qualities and absorbed doses have on cellular functions in human fibroblasts. In addition, we identified commonly expressed transcripts...... transcription, cell cycle regulation, and cell cycle arrest, whereas mitosis, spindle assembly checkpoint, and apoptotic chromosome condensation were uniquely enriched for alpha particle irradiation. Conclusions: LET-dependent transcriptional modulations were observed in human fibroblasts 5 hours after...

  18. Study on irradiation-induced-degradation of five fishery drugs in aqueous solution by 60Co γ-rays

    The degradation of five kinds of fishery drugs in aqueous solution irradiated by 60Co γ-rays at the absorbed dose of 0-10 kGy was investigated. The effects of acid/base, degassing and temperature on the degradation of fishery drugs were studied. The results show that fishery drugs can be degraded significantly with 60Co γ-rays irradiation,and the higher absorbed dose the higher degradation efficiency. The degradation percentage increases with the decrement of initial concentration of fishery drugs. More than 90% degradation of five fishery drugs has been achieved at absorbed dose of 8 kGy. The effects of acid/base and degassing environments on the degradation of fishery drugs are different. The lower temperature can inhibit remarkably the degradation of fishery drugs in aqueous solution. (authors)

  19. Regulation of Guzhen Fang on neuroendocrine and immune systems of rats irradiated with 60Co γ-rays

    Rats were singly irradiated with 6.8 Gy 60Co γ-rays. The changes of monoamine neurotransmitters in hypothalamus, luteinizing hormone (LH), estradiol (E2), testosterone (Ts) in serum, β-endorphin (β-EP) in plasma and the immunologic function of lymphocytes in spleen of rats were observed. The effects of Guzhen Fang (a traditional Chinese Medical prescription) composed of polygoni multiflori, cistanche salsa etc, were studied. The results were as follows: 1. After the rats were irradiated with 60Co γ-rays, the contents of monoamine neurotransmitters in hypothalamus decreased, β-EP in plasma increased, and the hyperfunction of hypothalamus-hypophysis-gonadal (HHG) axis and the hypofunction of lymphocytes appeared. The Guzhen Fang, however, could improve the above changes obviously. 2. Si Junzi Tang (also a traditional Chinese medical prescription) could also increase the immunologic function as Guzhen Fang did, but its effect on neuroendocrine system is not significant

  20. Effect of 60Co γ-rays irradiation pretreatment on callus inductivity and differentiation of strawberry anther

    Strawberry buds, in which a majority of pollen had single nuclear keeping to the side, were pretreated by 60Co γ-rays irradiation at different doses. The irradiation effect on the callus inductivity and plant differentiation rate of strawberry anther were studied. The results indicated that the pretreatment by 60Co γ-rays could increase the anther callus inductivity and plant differentiation rate significantly, and 20 Gy was the best dose. The callus inductivity of Akihime and Toyonoka increased by 39.09% and 35.68%, respectively, compared with the no-pretreatment materials. On the same media, the plant differentiation rate of Akihime and Toyonoka were also increased by 6.67%-6.72% and 4.73%-6.45%, respectively, compared with the two varieties of no-pretreatment. (authors)

  1. Prevention and control of pneumonia induced by 60Co γ irradiation of thorax in rats of selenium-enriched Spirulina

    From the indicators including body weight, wet lung weight, percentage of T lymphocytes in peripheral blood, the cell count of broncho-alveolar lavage fluid and its chemoluminescence, contents of hydroxyproline and collagen mRNA synthesis in lung, and pathological changes in pulmonary tissue, the preventive and curative effects of selenium-enriched Spirulina on the pneumonia induced by 60Co γ irradiation of thorax in rats were demonstrated during 90 days of observation

  2. Resposta de sementes de amendoim a diferentes doses de radiação gama (60Co Response of peanut seeds to different levels of gamma radiation (60Co

    Tatiana da S. Santos

    2010-10-01

    Full Text Available A radiação gama, proveniente da fonte de 60Co, é bastante utilizada para esterilização, visando a prevenção da decomposição e a toxidez de origem microbiana em diversos produtos. O grau de radiossensibilidade de um embrião vegetal depende da espécie, do estágio de seu desenvolvimento durante a radiação, da dose empregada e do critério usado para medir o efeito biológico, sendo comumente utilizado o teste de germinação. Objetivou-se, com este trabalho, estudar a sensibilidade do amendoim a radiação gama e seus efeitos na germinação, no vigor e na micoflora das sementes da cultivar BRS Havana, irradiadas com uma fonte de 60Co, tipo gammacell, com taxa de dosagem de 12,5 kGy h-1. As doses testadas em kGy foram as seguintes: 0; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 6,0; 9,0; 12,0; 15,0; 18,0; 21,0 e 24,0. Com os resultados obtidos, concluiu-se que as doses acima de 3,0 kGy prejudicaram a viabilidade das sementes e as doses acima de 12 kGy comprometeram totalmente o vigor e a germinação das sementes de amendoim. A radiação a partir da dose 2,0 kGy eliminou os fungos Aspergillus flavus e Aspergillus niger e, a partir da dose 3,0 kGy, eliminou o Aspergillus glaucus. O Penicilium spp. permaneceu em mais de 30% das sementes em todos os tratamentos com radiação, não sendo eliminado até a dose de 24 kGy.The gamma radiation from 60Co source is widely used for sterilization aiming at preventing decomposition and toxicity from microbes in several products. The degree of radiosensitvity of a plant embryo depends on the species, the development stage during radiation, doses used and the criteria used to measure the biological effect, the germination test, being commonly used.This work aimed to study the peanut sensitivity to gamma radiation and its effects in the germination, in the vigour and seeds microflora of cultivar BRS Havana, irradiated with 60Co source, type gammacell with rate of dosage of 12.5 kGy h-1. The tested doses were the

  3. Studies on the function of pokeweed mitogen inducing lymphocytes and 60Co γ-ray irradiation effects

    T and B lymphocytes in human periphery blood were seperated by rosette procedure. After lymphocytes were labelled with T4+ McAB, T4+ and non-T4+ lymphocytes were isolated by cell affinity chromatography method. When parts of T, B, T4+ and non-T4+ cells were exposed to 10 Gy 60Co γ-rays, the function of poke weed mitogen (PWM) and 60Co-rays irradiation effect on lymphocytes were investigated by technique of 3H-TdR incorporation. The results showed that PWM can induce both T and B lymphocytes but B lymphocytes were more sensitive to PWM. The response of B lymphocytes to PWM was the same as that of non-T4+ cells, the response of T4+ cells to PWM was the lowest. DNA synthesis of both T and T4+ lymphocytes were synergistic to B lymphocytes. The synergistic effect in T and B lymphocytes were irradiated by 10 Gy 60Co γ-rays, the synergistic effect disappeared. Neither synergistic nor suppressive effect was found between non-T4+ and B lymphocytes. When T4+, B and non-T4+ lymphocytes had been exposed to 10 Gy irradiation, the percentage suppression of 3H-TdR incorporation between B and non-T4+ lymphocytes had no significant difference but was higher than that in T4+ lymphocytes

  4. Study on the down-regulation of PKCα by tamoxifen combined with 60Co γ-irradiation in glioma cells

    The mechanism of radio-sensitizing effect of tamoxifen on the influence of PKCα expression has been explored by tamoxifen combined with 60Co γ-irradiation in human glioma cells. The protein expression of PKCα and CyclinD1 were detected by using Western-Blot. The level of DNA strand breaks was detected by the alkaline single-cell gel electrophoresis assay. The results demonstrated that the combination of tamoxifen and 60Co γ-irradiation could reduce expression of PKCα and CyclinD1. And it also enhanced the radiation-induced DNA damage and attenuated the repair of damaged DNA. The above results reveal that the combination of tamoxifen and 60Co γ-irradiation can enhance the downregulation of the expression of PKCα and the induction in the low expression of CyclinD1 as well at the delay of DNA repair. All these may be related to the impairment of the radioresistance of SHG-44 cells by tamoxifen. (authors)

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

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

  6. Effect of 60Co-irradiation on the development and immunogenicity of Plasmodium berghei sporozoites in Anopheles stephensi mosquitoes

    Smrkovski, L.L.; McConnell, E.; Tubergen, T.A.

    1983-10-01

    Protection conferred to mice by Plasmodium berghei sporozoites increased significantly when the time interval between 60Co-irradiation of the infected mosquitoes and harvest of sporozoites increased. One thousand sporozoites conferred no protection against challenge if harvested on the day of irradiation, but protected 60% of recipient mice when harvested 28 days postirradiation. When the time between feeding of mosquitoes and irradiation was varied, sporozoites from mosquitoes irradiated 3 days after feeding were infective for mice. Sporozoites from mosquitoes irradiated on day 10 postfeeding were not infective, but were immunogenic. In all experiments a decline occurred in the number of recoverable sporozoites over a 28-day period postirradiation to less than 10% of the yield on the day of irradiation.

  7. 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

  8. Effects of accumulated 60Co γ-ray irradiation on the small molecular metabolites in rats urine

    Objective: To explore the effects of accumulated 60Co γ-ray irradiation on small molecular metabolites in rats urine. Methods: Ten healthy male SD rats were irradiated by 60Co γ-rays in 5 days and the accumulated doses were 0, 0.2, 0.4, 0.6, 0.8, 1.0 Gy, respectively. The metabolites in urine of different groups were measured with 1H-NMR combined with principal components analysis (PCA) and partial least square discriminate analysis (PLS-DA). Results: The metabolites in rat urine were obviously changed after irradiation. Compared with control group, the amount of acetoacetate decreased after irradiation (t=29.7-30.7, P<0.05), but its relative level was stable when the dose increased (P>0.05). Meanwhile,the relative level of hippuric acid increased (t=4.4-21.6, P<0.05) especially when the accumulated dose was higher than 1 Gy (t=21.6, P<0.05). The relative level of proline, taurine and trimethylamine-N-oxide increased after irradiation with the same trend(t=3.5-13.4, 4.7-11.5, 2.9-12.7, P<0.05). Conclusions: The acetoacetate, hippuric acid, proline, taurine, and trimethylamine-N-oxide may be applicable for biomarkers of accumulative irradiation on rat. (authors)

  9. Effects of 60Co gamma radiation on Biomphalaria glabrata (Say, 1818) Embryo, I. Mortality

    A study was conducted on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10,15,20 and 25 Gy of 60Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality was the parameter used to evaluated the damage induced by ionizing radiation. Susceptibility decreased with increasing embryo age and with decreased radiation dose. Estimated LD50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). The survival curves obtained for each embryo stage are discussed on the basis of the multitarget theory. (author)

  10. The protector role of Mn2+ in Saccharomyces cerevisiae exposed to 60Co gamma radiation

    The radiation is present on all over the world and can be classified, according to the effect that produces on matter, as non-ionizing and ionizing. The ionizing radiations transfer a sufficient amount of energy to the molecule and charged atoms called ions can be formatted. The biological organisms have approximately 70% of water and when submit to the incident radiation occur the radiolysis of water. Water radiolysis produces highly reactive oxygen species (ROS) known as free radicals. The ROS can interact with all important biomolecules like lipid, protein and DNA. This interaction can cause the loss of functions of theses molecules and thus lead to cell death. The manganese is a heavy metal that at low concentrations is essential for the biological system, since it is cofactor for action of several enzymes. At high concentrations the manganese is toxic to the organisms. Recently was observed that manganese can have a protector role against oxidative stress. In this work, it was studied the anti-oxidant role of manganese in cells submitted to gamma irradiation. It was performed the determination of two oxidative stress indicators: lipid peroxidation and determination of thiol group, the results presented suggest that the manganese had protective role against lipid damage and in this way, has an antioxidant role. (author)

  11. Effects of 60Co γ-ray irradiation on expression of surface antigens in endothelial cells of human umbilical veins

    Culture of endothelial cells of human umbilical veins and avidin-biotin peroxidase complex (ABC) immunochemical technique were used in the experiment to detect the surface antigens in endothelial cells. Endothelial cells separated from five umbilical cords in original culture were divided into two groups, irradiated and non-irradiated. The cells were irradiated with 15 Gy of 60Co γ-rays at dose rates of 21.78 cGy/min. Then antigens RBC A, HLA-ABC, HLA-DR, CD4 and CD8 were assayed for both groups by the method of ABC. The results showed that the values of integrated optical density (IOD) for the surface antigens in the irradiated cells were lower than those in the non-irradiated cells with the difference in antigen expression in endothelial cells being significant (P<0.05) between the two groups

  12. A prototype of an ionization chamber for gamma radiation beams of 60Co: Experimental and Monte Carlo preliminary results

    Ionization chambers are the most widely used instruments for dosimetry in radiotherapy. With the aim to test new configurations and materials using low-cost and easily-available components, verify the possibility of its application in the gamma radiation field of 60Co and fulfill the need of a chamber for scientific metrological purposes, in this paper the prototype of a plane-parallel ionization chamber has been designed and built, and its performance has been studied at the SSDL of KARAJ. The front wall and back wall of the chamber were made of graphite and Plexiglas respectively, as opposed to the one type of material in commercially available chambers. The collecting electrode has a diameter of 20 mm. The sensitive volume is 0.63 cm3. It was found that the Leakage current, the short-term stability and the polarity effect were within the international recommendations. The results were compared with those of a reference cylindrical chamber. The maximum difference observed in this comparison was 1.1%. The relative uncertainty was below 0.2%. Moreover, Monte Carlo simulation was undertaken using MCNP4C code and the relative difference of 1.9% was observed compared to the experiment. As a result the chamber presented a satisfactory performance in all evaluated tests in Gamma radiation field of 60Co. -- Highlights: • The prototype of a plane-parallel Ionization Chamber was designed. • Its performance was studied in Gamma radiation field of 60Co. • The response of the chamber was measured and compared with that of the cylindrical ionization chamber. • The chamber was simulated using the MCNP4C Monte Carlo code. • The Leakage current, the short-term stability and the polarity effect were within the international recommendations

  13. 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

  14. Comparison of the standards of absorbed dose to water of the METAS and the BIPM for 60Co gamma radiation

    A comparison of the standards of absorbed dose to water of the Swiss Federal Office of Metrology and Accreditation (METAS), Switzerland and of the Bureau International des Poids et Mesures (BIPM) has been made in 60Co gamma radiation. The results show that the METAS and the BIPM standards for absorbed dose to water are in agreement, yielding a comparison result of 1.0001 for the mean ratio of the calibration coefficients for the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0054). (authors)

  15. 60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

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

    1983-01-01

    The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found.

  16. 60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

    The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found

  17. 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)

  18. Suppression by ellagic acid of 60Co-irradiation-induced lipid peroxidation in placenta and fetus of rats

    The effect of ellagic acid, a component of Eucalyptus maculata, on lipid peroxidation was examined in placenta and fetus of pregnant rats irradiated with 60Co. The increase in lipid peroxide levels by the irradiation of the placenta and fetus brain as well as those of the serum and organs of mother was suppressed by treatment of the mother rats with ellagic acid. This suppressing effect found in placenta and fetus was significantly correlated with that found in mother rats. Moreover, ellagic acid suppressed the morphological changes such as degeneration in the endothelial cells of placenta and liver cells of fetus caused by the irradiation and improved the survival rate after the irradiation. These suppressing effects of ellagic acid were approximately the same as those of α-tocopherol. (author)

  19. A general review on the effects of 60Co γ-rays irradiation on vitamin C in fruits and vegetables

    Vitamin C is a nutrient component in fruits and vegetables, it's also an important bioactive substance in human body, and there are also many factors that affect the contents of vitamin C in fruits and vegetables. There papers reported that 60Co γ-rays irradiation has effects on vitamin C in fruits and vegetables, but the effect degree has some differences. Some reports says the contents of vitamin C in fruits and vegetables could be significantly reduced by irradiation, while some literatures reported that irradiation at low doses had no significant effect. The content of vitamin C in fruits and vegetables could be influenced by various factors, such as ascorbic oxidative enzyme, chemical composition, irradiation dose, irradiation environment, physiological metabolism of fruits and vegetables, etc. Irradiation treatment is an important preservation technique of fruits and vegetables. Though there were some effects of irradiation on vitamin C of fruits and vegetables, it would not influence the applications of irradiation technology in the fruit and vegetable storage, because the effects of irradiation on vitamin C could be avoided or minimized through appropriate technical treatment. This paper tries systematically analyses and summarizes the results of related investigation and provides a helpful reference in scientific applications of irradiation technology on fruits and vegetables preservation. (authors)

  20. Storage pool water condition of multipurpose compact 60Co irradiator of IPEN-CNEN/SP

    A new type compact gamma irradiator was developed and installed at IPEN-CNEN/SP, it is classified as category IV irradiator according to International Atomic Energy Agency-IAEA. The originality of its design remains on the rotating concrete door, which integrates the shielding system with the product handling system, permitting the input and output of the products in a continuous way, without the necessity to lower the sources and open the irradiator chamber to change the batch. The licensed capacity of this irradiator is 37 P Bq (1 MCi) and the water pool liner, manufactured in stainless steel, has 7.0 m deep and 2.7 m diameter. A sealed radiation source may be defined as a quantity of radioactive material sealed within non-radioactive material, which the confining barrier is intended to prevent leakage or escape of the radioactive material under normal handling conditions and also under foreseeable mishaps. The use of cobalt-60 radiation sources in a wet storage environment requires care in the control of that environment to avoid the potential for deterioration of the stainless steel. In the literature, the tests performed demonstrated that stainless steel had excellent performance under controlled environment conditions. The inspection includes assessing the condition of storage pool water and measuring the pool water conductivity. The demineralized water normally used in storage pools is usually an effective and secure medium in which to store stainless steel. However, there are certain constituents and contaminants in the water which can affect this behaviour. For instance, the pH has a small but definite effect on the tendency for pitting corrosion. Nevertheless, there is also evidence that both strongly alkaline and strongly acid environments can encourage pitting corrosion. In general, an around neutral pH is recommended. The conductivity is used as a measure of the extent to which ionic species are present in the pool water. International recommendations

  1. Effect of combination of STAT3 RNAi and 60Co γ-irradiation on U251 cell proliferation

    Objective: To construct signal transduction and activators of transcription 3 (STAT3) small interference RNA (siRNA) expression vector and to study its effect on STAT3 expression and U251 cell line proliferation. Methods: STAT3 specific 19 bp oligonucleotides were designed and synthesized. These oligonucleotides were annealed to form the double strand DNA fragments and these fragments were cloned into Psilence2.1-U6-H1 vector. The recombinant of STAT3-siRNA expressing construction was confirmed by Hind III and BamH I double digestion and sequencing. The STAT3-siRNA was transfected into U251 cell. The inhibitory effect of STAT3-siRNA construction was tested by Western blot. Cellular proliferation activities were measured by tetrazolium bromide (MTT) colorimetry. Cloning efficiency and MTF were used to confirm the radiation dose. Results: STAT3-siRNA expression vector was successfully constructed, and it could effectively down-regulate the protein levels of STAT3 in transfected U251 cell line; and the radiation dose was confirmed to 2 Gy. U251 cells transfected with STAT3-siRNA expression vector showed lower cellular proliferation compared with non-transfected U251 cells (P60Co γ-irradiation showed lower cellular proliferation compared with non-irradiated U251 cells (P60Co γ irradiation can enhance the inhibitory efficiency. (authors)

  2. Regulation of photosynthetic performance and antioxidant capacity by 60Co γ-irradiation in Zizania latifolia plants

    The aim of the present work was to investigate the photosynthetic performance and antioxidant enzyme activities in response to γ-irradiation of an aquatic plant Zizania latifolia. The Z. latifolia seedlings at 6-leaf stage were exposed to 25, 50 and 100 Gy of γ rays from a 60Co source. The growth parameters, chlorophyll contents, photosynthetic gas exchange, chlorophyll fluorescence, malondialdehyde (MDA) content, antioxidant enzyme activities and antioxidant contents were examined at 1–5 weeks post-irradiation (WPI). The results showed that plant height, leaf number and tiller (branch close to ground) number were significantly suppressed by 50 and 100 Gy irradiation at 5, 3–5 and 4–5 WPI, respectively, but they were not significantly different from control by 25 Gy irradiation. Chlorophyll a, chlorophyll b, and total chlorophyll contents were also found to be significantly decreased by irradiation. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) generally declined in a dose-dependent manner. As for the chlorophyll fluorescence parameters, maximum quantum efficiency of PSII photochemistry (Fv/Fm), actual photochemical efficiency of PSII (ΦPSII) and photochemical quenching (qP) were observed to be significantly decreased compared to the control at 3 WPI, while non-photochemical quenching (NPQ) significantly increased by 100 Gy. γ-irradiation induced substantial increase in MDA content, ascorbate peroxidase (APX) activity, reduced ascorbate (AsA) content and reduced glutathione (GSH) content, suggesting a protective mechanism of Z. latifolia plant against oxidative stress when exposed to γ-irradiation. - Highlights: • The responses of Zizania latifolia plants to 60Co γ-irradiation were examined. • Plant growth was suppressed by high doses of irradiation but slightly affected by low doses. • γ-irradiation reduced PSII activity and chlorophyll content. • γ-irradiation

  3. Effects of total base of sophora alopecuroides on lipid peroxidation of 60Co γ-rays irradiated mice

    Objective: To study the effects of total base of Sophora alopecuroides on lipid peroxidation of irradiated mice. Methods: The mice were treated orally with different doses of total base of Sophora alopecuroides, after exposed to whole-body 60Co γ-rays at a dose of 5.0 Gy. The content of MDA in the liver and activities of Se-GSH-PX, SOD, GPT, GOT were measured. Results: After irradiation, the general status of the mice were changed such as hair deprivation, body weight reduction, blood spots appeared on the tail. Activities of Se-GSH-PX, SOD decreased remarkably, whereas those of GPT and GOT increased. MDA contents increased obviously. Oral administration of total base of Sophora alopecuroides could accelerate restoration of these indexes. Conclusion: Total base of Sophora alopecuroides has certain protective effects on irradiated mice, the mechanism of which may be related with antioxidation

  4. The sensitivity of the most common microorganisms of pig liquid manure to the effect of 60Co irradiation

    In model experiments the most common representatives of pathogens and facultative pathogens of pig liquid manure contaminating bacterial flora were examined for their sensitivity to different doses of 60Co, using liquid medium supplemented with 1% glucose, as well as Korthof-medium and different kinds of selective media. Erysipelothrix rhusiopathiea, Brucella suis, Mycoplasma hyorhinis and Pasteurella haemolytica proved to be the most senstive ones to irradiation, as they did not survive 100 krad dose. The highest resistances were observed in the cases of the following microorganisms: the spore containing Bacillus anthracis, killed by 700 krad irradiation dose, the saprophytic and pathogenic Mycobacteria and the spore containing Clostridium perfringens, killed by 1000-1500 krad irradiation. (author)

  5. A case of AML with preceding hypoplastic stage after oophoro-hysterectomy and 60Co-irradiation

    A case of AML (preceded by a hypoplastic stage) which developed after oophoro-hysterectomy and 60Co-irradiation is presented, and related literature concerning irradiation-induced leukemia and the early diagnosis of leukemia and/or preleukemia are discussed. The patient, a 47 year old female had had surgery and irradiation with a subsequent normachromic anemia necessitating transfusions 11 years prior to her presenting herself at our hospital because of anemia. Her pancytopenic peripheral blood picture combined with a relatively hypererythroid marron led to a diagnosis of atypical hypoplastic anemia. Two years after this she suddenly developed a high fever, general fatigue and a severe anemia. Hematological studies revealed acute myeloblastic leukemia. A combination therapy consisting of DM, 6MP, prednisolon and blood transfusions was given with no effect and 3 months after the onset, the patient died of asphyxia resulting from gross hemoptysis. Autopsy revealed pulmonary hemorrhage secondary to the leukemia. (J. Evans)

  6. Biological changes in Musca domestica L., 1758 (Diptera:Muscidae), induced by gamma radiation (60 Co)

    This work was carried out in the Entomology Section of the Centre of Nuclear Energy in Agriculture (CENA), University of Sao Paulo, Piracicaba, Sao Paulo, Brazil. The objective of the present research work was to investigate some effects of gamma radiation on the various stages of M. domestica life cycle. (author)

  7. Response of avocado genotypes to improvement through 60Co gamma radiation

    Ten avocado genotypes were subjected to gamma radiation from 0 to 45 Gy in 1993. Vegetative and reproductive data were analysed in a factorial design. Genotypes differed significative on height and fruit number. Radiation affected significative fruit number but not tree height. ''Hass'' showed strongest interaction between genotype and doses, for fruit number. (Author)

  8. The variation of short-branch type pear induced by 60Co γ-ray irradiation

    The variation of short-branch type Apple pear and Korean pear(Pyrus communis) induced by γ-ray irradiation was discussed. The results obtained are as follows: In comparing with Apple pear, Korean pear appeared more susceptible to γ-ray treatment; γ-ray irradiation increased the frequency of the short-branch variation; The character of short-branch induced by γ-ray irradiation could be directly introduced to the V(vegetative) generation

  9. Influence of 60Co-γ ray and electron beam irradiation on physicochemical characteristic of pork

    The effects of γ ray and electron-beam irradiation on the physicochemical characteristic of chilled pork were investigated to determine the appropriate irradiation mode. Pork was soaked in antioxidant solution (1 g/L), packaged in vacuum, irradiated at 3 kGy, and refrigerated storage for 30 d. Total bacterial counts, peroxide values, thiobarbituric acid reactive substances, volatiles and off-odor of irradiated pork were analyzed. Total bacterial counts of irradiated pork reduced and were <10 cfu/g at 30 d. Peroxide values, thiobarbituric acid reactive substances and volatiles contents of pork irradiated by y ray were higher than pork irradiated by electron-beam Pork irradiated by γ ray combined with antioxidant was most close to nonirradiated pork in odor, and similarity was 89.68%. Results showed that electron-beam irradiation reduced lipid oxidation and volatiles contents, and γ ray helped to reduce off-odor, furthermore, addition of antioxidant could effectively reduce lipid oxidation and off-odor. (authors)

  10. 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

  11. 60Co γ-irradiation mutation induction for screening of avilamycin strains with high productivity and its culture medium optimization

    60Co γ-irradiation was used for mutation treatment to screen high avilamycin production strains. Irradiation at 350 Gy gave a positive mutation ratio at 26.5%. The derived mutant H-15 strain of Streptomyces viridoehrongenes showed high avilamycin productivity at 68.5mg/L. Then effects of different carbon and nitrogen sources on the producing strain H-15 were investigated by one factor test and optimized with Response Surface Methodology. The results indicated that the optimum carbon and nitrogen source were soluble starch 20.12g/L, ribose 7.81 g/L, soy powder 25.23 g/L and soy peptone 5.06 g/L. Under those conditions, the predicted consistent value of avilamycins yield was 101.48 mg/L, which was in consistent with the measured value. (authors)

  12. 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)

  13. COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for {sup 60}Co {gamma} radiation

    Buermann, L. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Oborin, A.V. [D I Mendeleyev Institute for Metrology (VNIIM), St Petersburg (Russian Federation); Dobrovosky, J. [3 Slovensky Metrologicky Ustav (SMU), Bratislava (Slovakia); Milevsky, V.S. [Belarussian State Institute for Metrology (BelGIM), Minsk (Belarus); Walwyn Salas, G. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Habana (Cuba); Lapenas, A. [Radiation Metrology and Testing Centre of the Latvian National Metrology Centre Ltd (RMTC), Salaspils (Latvia)

    2009-12-15

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for {sup 60}Co {gamma} radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. (authors)

  14. 60Co irradiation effects on cooked rice texture and amylopectin structure

    The effect of γ irradiation on the cooked rice texture and amylopectin structure is studied with three varieties (Zhefu 504, Zhefu 802 and Zaogeng T2) subjected to 4 kGy, 8 kGy and 12 kGy irradiation. The results indicate that irradiation has significant effect on the texture of the cooked rice; the hardness, cohesiveness, gumminess and chewiness reduce significantly with the increase of the irradiation dose. Irradiation also affects the chain length distribution of the amylopectin, the side-chains of amylopectin of Zhefu 504 with the 12 ≥ DP, Zhefu 802 with 24 ≥ DP ≥ 13 and Zaogeng T2 with 24 ≥ DP ≥13 and 36 ≥ DP ≥ 25 are broken

  15. Influence of 60Co γ irradiation pre-treatment on characteristics of hot air drying sweet potato slices

    The influences of irradiation, hot air temperature and thicknesses of the slices on the characters of dehydration and surface temperature of 60Co γ-rays irradiated sweet potato were investigated. Meanwhile, microscopic observation and determination of water activity of irradiated sweet potato were conducted. The results show that the drying rate and the surface temperature rose with the increasing of irradiation dose. When the dry basis moisture content was 150%, the drying rate of the samples were 1.92, 1.97, 2.05, 2.28, 3.12% /min while the irradiation dose were 0, 2, 5, 8, 10 kGy, and the surface temperature were 48.5 ℃, 46.3℃, 44.5 ℃, 42.2 ℃, 41.5 ℃, respectively. With higher air temperature and thinner of the sweet potato slices, the dehydration of the irradiated sweet potato slices were faster. The drying speed of sweet potato slices at 85 ℃ was 170 min faster than that of 65 ℃. The drying speed of 7 mm sweet potato slices was 228 min faster than that of 3 mm sample. The cell wall and the vacuole of the sweet potato slices were broken after irradiation, and its water activity increased with the increase is radiation dose. The water activity of the irradiated samples were 0.92, 0.945, 0.958, 0.969, 0.979 with the irradiation doses of 0, 2, 5, 8, 10 kGy, respectively. The hot air drying rate, surface temperature and water activity of sweet potato are significantly impacted by irradiation. The conclusion provides a theoretical foundation for further processing technology of combined radiation and hot air drying sweet potato. (authors)

  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. 60Co-γ-irradiation of dried DNA and isolated cell nuclei of chicken erythrocytes

    In this work low molecular products, which resulted from γ-irradiation of dried DNA, were isolated and quantitatively determined. Unchanged nucleic bases were released. The irradiation was successful in a vacuum as well as in oxygen. In the case of the drily irradiated DNA, the base release made up 30% of the total strand breaks. The release of DNA bases was also first studied in cell nuclei of eucaryotic cells, the erythrocyte nuclei of chicken blood. The second part of this work dealt with the isolation and identification of radiation induced changes in the 2-dioxyribose unit of DNA. In the third part it was investigated, whether as a result of γ-irradiation of DNA malonic dialdehyde was formed. It could be shown that neither malonic aldehyde nor basic propenal were formed, but instead products, which were still bound to the DNA and formed a chromophore with 2-thio barbituric acid. In this work the direct irradiation effect was investigated in DNA systems as well as in erythrocyte nuclei. By the isolation of low molecular irradiation products this work offers a contribution to the understanding of the irradiation chemistry in an eucaryotic cell, in which the direct effect on the DNA and the resulting radiation damage were given a deciding role for genetic information. (orig./MG)

  19. Effect of gamma radiation (60Co) on the organoleptic and nutritive properties of common beans (Phaseolus vulgaris L., cv. mulatinho)

    The study of the influence of gamma radiation on the organoleptic and nutritive properties of kidney beans is presented. Samples of this vegetable were irradiated with 15 krad and stored for five months. Immediately after irradiation and monthly, sensory evaluations and chemical analysis of the vitamins thiamin (B1) and riboflavin (B2) were accomplished in the samples. The results showed an evident influence of radiation during its application since the higher losses occurred immediately after this treatment, mainly in riboflavin, which from the total losses observed, 47,9% occurred during irradiation. The riboflavin is much more sensitive to gamma radiation and in terms of organoleptic properties it was observed the development of an undesirable flavor and a hardening of the texture in the irradiated samples. However, at the end of the experiment no difference was found between control and irradiated samples

  20. Effect of 60Coirradiation on mating ability of males of Helicoverpa armigera

    The effects of γ-rays irradiation on the mating ability and flight capability of male cotton bollworm Helicoverpa armigera were studied in laboratory and field cages. The results showed that when the irradiation dose increased from 0Gy to 400Gy, the flight capability decreased: flight distance decreased from 69.65km to 38.30km; average flight distance decreased from 44.19km to 13.55km. The longevity of the irradiated males was significantly shorter than that of the wilds but there was no significant difference according to different doses. Egg hatchability was affected significantly by irradiation but there was no significant difference in eggs laid per female, fecundation eggs as increasing treated doses. When the ratio of sterilized males (treated dose 200 Gy) to fertile males was as 5:1 in field cages, the F1 hatchability was significantly decreased and the purpose of controlling cotton bollworm population could be effectively achieved. (authors)

  1. Comparison of the generation of interface states in MOS structures due to 60Co and VUV irradiation accompanied with photo-injection of electrons

    The buildup of interface states in MOS structures with differently annealed oxides is studied under vacuum ultraviolet (VUV) and 60Co irradiation. A larger creation of interface states is observed if photoinjection of electrons is applied simultaneously with the VUV irradiation. The presence of electrons at the Si/SiO2 interface favors the generation and explains the larger amount of interface states after 60Co irradiation. After VUV irradiation the interface state density increases in n-samples to a specific saturation value which is reached earlier if gate voltage is made more positive or samples are exposed to photoinjection. This is due to the increase of the radiation peak which is located in the upper half of the silicon gap. The impact of post oxidation annealing on the interface state generation is investigated due to VUV and 60Co irradiation. (author). 26 refs., 9 figs., 1 tab

  2. Studies on acute toxicity and mutagenicity of 60Co irradiated pollens

    The acute toxicity test showed that the oral LD50 values were >21500 mg/kg for male and female mice, indicating that irradiated pollens belong to low toxicity grade or practically non-toxic. Mutagenicity were studied in three short-term tests. Ames test showed that irradiated pollens did not induce mutation towards strains TA99, TA97, TA100 and TA102. Micronucleus test in the bone marrow cells indicated that the percentage of polychromatic erythrocytes with micronuclei in exposed groups had no significant difference in comparison with the controlled ones. Chromosomal test for reproduction cells showed that the increase of chromosomal aberration rate was not observed. All the above results suggest that irradiated pollens are safe for human consumption

  3. Induction of mutation in Jujube (Zizyphus jujuba Mill) using tissue culture combined with 60Coγ-ray irradiation

    In vivo and in vitro mutagenesis techniques were assayed to explore effects of irradiation in jujube (Ziziphus jujuba Mill) improvement. 60Co γ-ray irradiated seeds and shoot tips of a land race of jujube originating in Shangdong province of China were micropropagated up to M1V4 generation on MS basal medium containing 2 mg/L BA and 0.4 mg/L IBA. The rooting MS medium contained 1 mg/L BA and 0.6 mg/L IAA, ZEA 1 mg/L, 2, 4-D 0.5 mg/L, and NAA 0.5 mg/L in different combinations. Adventitious buds were also produced from irradiated calli derived from leaf and hypocotyl fragments and the elongated adventitious buds rooted in vitro prior to green house transfer. Different doses (20 to 900Gy) were tested for in vitro explants as well as the jujube kernels irradiation. Six types of leaf shape and seven types of fruit shape mutations were observed and different ripening characters and growth habits were recorded in the orchard on putatively mutated mature trees. Even though there is a need for confirmation and molecular characterization, these mutations may be considered as a new and powerful way for jujube improvement in order to develop genotypes with promising value added traits. (author)

  4. 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

  5. Fire Events Effect on Concrete Shielding of 60Co Industrial Irradiation Facilities

    Concrete is the most important structural which is used in radiation shielding for owing to its low price and good shielding performance. In concrete structures, of industrial irradiation facilities cracks occur due to thermal stress, hydration he at, weather, dry storage radiation of sources and fire events nuclear reaction. Shielding performance is effected according to the crack size geometry (width, depth and bending). However, there are no design criteria providing the allowable crack size limits for concrete shielding. Three different methods are applied in this work wbere the measuring instrument for qualifying the effect of cracks on shielding performance in concrete mass. The correlation between crack size and concrete shielding performance is deduced. The surface dose rate increased logarithmically according to the increase in crack width. The results are compared by the effects of fire events inside industrial irradiation facilities cold sterilization which led to change the effected mechanical parts and electrical components. Radiation concrete shielding is repaired. Radiation standard measurements outside irradiation concrete facility recorded normal radiation values. Radiation safety is maintained

  6. Double strand breaks in DNA in vivo and in vitro after 60Co-γ-irradiation

    The questions of what the correlation is between double strand breaks in DNA in the cell and lethal radiation damage and by means of which possible mechanisms DNA double strand breaks could occur were studied. E. coli served as test system. In addition to this the molecular weight of the DNA from irradiated E. coli as a function of the radiation dose under various conditions was measured. This data was compared on the one hand to the survival of the cell and on the other hand to the formation of DNA double strand breaks in an aqueous buffer system, which in its ionic characteristics was similar to cell fluids. (orig./MG)

  7. The use of 60Co-γ-irradiation for the production of vaccines

    The polymerization conditions for the incorporation of virus antigens into poly(methyl methacrylate) particles were investigated. The dose and the dose rate appeared to be the relevant factors for optimizing the polymerization conditions. It was concluded that a dose of 500 krads at a dose rate of 2.2 krads min-1 leads to a satisfactory product. With these irradiation conditions the antibody inducing properties of fluid influenza and polio vaccines were not affected. Influenza virions incorporated into poly(methyl methacrylate) particles exhibited strong adjuvant properties during revaccination. (author)

  8. 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

  9. High dose rate 60Co remote afterloading irradiation in cancer of the cervix in Haiti, 1977-1984

    From 1977 through 1984, 293 previously untreated patients with biopsy proven carcinoma of the uterine cervix were treated by whole pelvis irradiation and high intensity 60Co remote afterloading (RAL) intrauterine tandem techniques in Haiti. The treatment results were analyzed retrospectively to evaluate the therapeutic results and prognostic factors of a strict protocol involving 40 Gy to the whole pelvis (2 Gy/day, 5 days/week). In addition, on the 5th day of the 3rd week, the first outpatient 60Co remote afterloading intracavitary insertion, delivering 7.5 Gy to point A with each insertion, repeated 3 times by a week separation for a total of 4 times. The total TDF for external beam plus RAL was 158 and 175 for early and late effects respectively. One hundred-four patients were evaluable after 1 year or more follow-up, with a median of 26.5 months. No evidence of disease (NED) by Stage at 1 year was: Stage I of 100% (3/3), Stage II of 82% (9/11), Stage III of 80% (47/59), and Stage IV of 58% (18/31). The post-therapeutic complication rate was 7.7%, with no fistulas or requirement of surgical intervention. Those with documented follow-up of at least 2 years (74 patients) had comparable survival to other high dose rate and low dose rate studies. This study shows that outpatient brachytherapy can be carried out without sophisticated and expensive equipment with minimal staff trained in radiation therapy. A detailed description of this outpatient RAL technique and results are described so that this method can be adapted to other developing and industrialized nations where cost containment is becoming a key issue

  10. Effect of 60Co-gamma radiation on the random walk error of interferometric fiber optic gyroscopes

    2010-01-01

    Two 60Co-gamma radiation experiments were launched to explore the radiation effect on optical components and interferometric fiber optic gyroscope (IFOG). In optical components radiation experiment, the result showed that polarization-maintaining (PM) fiber coil loss was the most affected parameter in all the RWC (random walk coefficient) related parameters, compared with the weak sensitivity of other components parameters. In the IFOG radiation experiment, the RWC performance degradation was found to be almost due to an increase of the PM fiber attenuation. Based on the experiment result, a RWC prediction model in radiation, which is obtained by embedding PM fiber loss expression into the RWC model, was built following a power law of dose and dose rate. An IFOG RWC in space radiation environment was predicted from radiation dose and dose rate by the RWC prediction model. This RWC value calculated from test data is fully accorded to the RWC value predicted from radiation dose.

  11. Influence of natural antioxidants on lipid composition of beef burgers submitted to irradiation in 60 Co source and electron beams

    Radiation processing has been employed in some countries as a mean of treatment to assure microbiological safety of meat and meat products, avoiding the occurrence of food-borne disease. The ionizing radiation may cause some undesirable changes on chemistry composition of food and the lipid oxidation is one of the main reactions. In meat products processing industry, the lipid composition is directly related to nutritional and sensory quality of the product. For preventing oxidation, use of antioxidants which can be synthetic or natural, has been practically applied in some products. Currently, most attention has been given to natural antioxidants from herbs and spices like rosemary and oregano. The aim this study was to assess the antioxidant effects of either rosemary and oregano extract in beef burgers submitted to irradiation in 60Co source with dose 6, 7 e 8 kGy, electron beams with dose 3,5 e 7 kGy and storage under freeze along 0, 45 e 90 days. The results showed that rosemary extract has the major antioxidant effects when it is used on heterogeneous food matrix like beef burger, but oregano extract was better efficient to delay lipid oxidation along storage time when it is used in synergism with rosemary and/or BHT/BHA. Although to have occurred changes in the fatty acids composition it was not possible to demonstrate a straight dependence of irradiation dose and/or storage time. Sensory analysis showed that between the samples prepared with natural antioxidants, the beef burger prepared with oregano has received better scores by panelists. Irradiated beef burger prepared with rosemary has received better scores when compared to non-irradiated one. The use of spices with antioxidant activity to avoid the oxidative damage in foods that contain fats in their formulation is thought to be promising to application in food facilities. (author)

  12. Day-and-night rhythm change in the contents of 5-hydroxytryptamine (5-HT) of brains and livers of mice irradiated by 5Gy 60Co γ rays

    The day-and-night rhythm changes in the contents of 5-HT of the brains and livers of mice treated by whole-body irradiation with 5 Gy 60Co γ rays were investigated by means of fluorescent spectrophotometry. The results showed that compared with control, the 5-HT contents in both tissues, generally speaking, were increased significantly after diurnal irradiation, but decreased insignificantly after night irradiation

  13. Modifications of Viscoelastic Properties of Polysaccharides by Gamma Irradiation

    The aim of this work was to establish the effect of gamma irradiation on the viscoelastic properties of the sodium alginate. Aqueous suspensions of sodium alginate at different concentrations (0.25 - 4%) were irradiated using a 60Co gamma-ray source (10, 25 and 50 kGy). The monitored rheological parameters showed the non-Newtonian behavior of the samples is kept by gamma irradiation. The decrease tendency of the apparent viscosity by irradiation samples and with decrease of the concentration as well has been noticed

  14. Study of the action of 60Co gamma radiation on Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris in mango pulp

    The application of non-thermal treatments has proven effective in inhibiting bacteria such as Salmonella and Escherichia coli. Mango is a fruit of national consumption with a great exportation potential. Meanwhile, outbreaks of food borne disease related to mango consumption caused mistrust on the degree of food security offered by the product. The objective of this work was to establish the radioresistance of bacteria Escherichia coli, Salmonella Poona and Alicyclobacillus acidoterrestris on the mango pulp by the calculation of the D10 values and to know the radiation effect on the sensory characteristics of the fruit pulp. The microbiological profile of frozen mango pulp available at the local market was also established using conventional methods of plating and Most Probable Number (MPN). The pulps experimentally inoculated with the bacteria listed above were irradiated with doses of 0, 1, 2, 3, 4 and 5kGy in a 60Co source. The sensory analysis was performed using a dose of 5 kGy, using the triangular test and the test of acceptance with hedonic scale. The results of this study show that the quality of mango pulp sell in the local market is not satisfactory in accordance with the standards established by the Brazilian law and the literature, showing the need of using other tools to achieve acceptable levels of quality. The D10 values obtained are in the range of 1.01 and 1.09kGy for E. coli ATCC 8739, 0.60 and 0.98kGy for S. poona and 0.72 e 0.88kGy for A. acidoterrestris respectively. The triangular test showed that a 5kGy radiation dose changed the sensory characteristics of mango pulp. Nevertheless, sensory analysis of a food product prepared with the irradiated pulp obtained good acceptance in the attributes of global appearance, flavor and aroma. (author)

  15. Study of the action of 60Co gamma radiation on Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris in mango pulp

    The application of non-thermal treatments has proven effective in inhibiting bacteria such as Salmonella and Escherichia coli. Mango is a fruit of national consumption with a great exportation potential. Meanwhile, outbreaks of foodborne disease related to mango consumption caused mistrust on the degree of food security offered by the product. The objective of this work was to establish the radioresistance of bacteria Escherichia coli, Salmonella Poona and Alicyclobacillus acidoterrestris on the mango pulp by the calculation of the D10 values and to know the radiation effect on the sensory characteristics of the fruit pulp. The microbiological profile of frozen mango pulp available at the local market was also established using conventional methods of plating and Most Probable Number (MPN). The pulps experimentally inoculated with the bacteria listed above were irradiated with doses of 0, 1, 2, 3, 4 and 5 kGy in a 60Co source. The sensory analysis was performed using a dose of 5 kGy, using the triangular test and the test of acceptance with hedonic scale. The results of this study show that the quality of mango pulp sell in the local market is not satisfactory in accordance with the standards established by the Brazilian law and the literature, showing the need of using other tools to achieve acceptable levels of quality. The D10 values obtained are in the range of 1.01 and 1.09 kGy for E. coli ATCC 8739, 0.60 and 0.98 kGy for S. poona and 0.72 and 0.88 kGy for A. acidoterrestris respectively. The triangular test showed that a 5 kGy radiation dose changed the sensory characteristics of mango pulp. Nevertheless, sensory analysis of a food product prepared with the irradiated pulp obtained good acceptance in the attributes of global appearance, flavor and aroma. (author)

  16. Effect of low dose irradiation of 60Co γ-rays on seed germination, seedling growth and enzymes activity of Lactuca sativa

    The seeds of Lactuca sativa were irradiated by different doses (10, 20, 30, 40, 50 Gy) of 60Co γ-rays. The effects of low dose irradiation on seed germination, seedling growth and enzymes activity were investigated. The results indicated that low dose irradiation could promote germination rate, germinating viability, germination rate in the field, root length and height of seedling. The suitable dosage for low dose irradiation for Lactuca sativa was 30 Gy. POD activity after irradiation treatment in the range of 10 to 50 Gy and CAT activity after irradiation treatment in the range of 20 Gy to 40 Gy was lower than that of control. (authors)

  17. Effects of 60Co gamma radiation on toxicity and hemorrhagic, myonecrotic, and edema-forming activities of Cerastes cerastes venom

    Antisera are used as effective antidotes against the local effects of snake bites. To improve antisera production and extend the life of surrogates used to produce antibodies, the chronic effects of venom toxicity must be reduced. The present study evaluated the effectiveness of gamma irradiation to reduce the local effects associated with viperid snake bites by evaluating in NMRI mice the toxicity and edematic, hemorrhagic, and myonecrotic activities of native and irradiated Cerastes cerastes venoms. These results indicated that the toxicity of irradiated venoms (1 and 2 kGy) decreased as compared with that of native venom. The edematic and hemorrhagic activities were also reduced in the detoxified samples, particularly with the 2-kGy radiation dose. Furthermore, the creatine phosphokinase (CPK) activity was significantly increased in the serum and decreased in the myocardium after envenomation with native venom, but no significant enzymatic changes were observed in mice envenomated with irradiated venom. Histopathologic evaluation showed that native venom caused severe degenerative changes in the myocardium. In the case of 2-kGy-irradiated venom, no tissue alterations were observed. These results indicate that irradiation of venom with a 2-kGy dose may offer an effective method for reducing the chronic toxic effects of venom in immunized animals. (author)

  18. Comparative studies on chromosome aberrations in rhesus monkeys induced by 60Co γ ray irradiation under different irradiation conditions

    Rhesus monkeys were irradiated by 60Cr γ ray exposure under different conditions, and comparative studies on their chromosome aberrations have been made. The dose rate of single acute irradiation was 223 mGy/min, the dose rate of fractionated curmulative irradiation was 223 mGy/min, and the dose of 0.25 Gy was delivered once a week, the dose rate of chronic continuous irradiation was 0.26 mGy/min for 190 min, 5 days per week. The total coumulative dose for each group was 2.0 Gy. It was found that the types of chromosome aberrations were mainly dicentric aberrations and acentric fragments in single acute irradiation, and acentric fragments in both fractionated coumulative and chronic continuous irradiation groups. The frequencies of chromosome aberrations in these groups increase linearly with increasing dose. The degree of chromosome damage in single acute irradiation group was much greater than those in the other groups, but degree and characteristics of chromosome damage between fractionated cumulative and chronic continuous irradiation groups was not significantly different. Acentric fragments in lymphocyte chromosomes ceased to increase when the cumulated dose in fractionated cumulative or chronic continuous irradiation reached to more than 1.0 Gy. The frequencies of chromosome aberrations basically decreased to control level within a year following the termination of irradiation

  19. Differential expression profiles of microRNAs in liver of 60Co γ-ray irradiated mice

    Objective: To investigate the differential expression profiles of microRNAs in the liver of 60Co γ-ray irradiated mice using microRNA microarray and to explore their main functions by bioinformatic analysis. Methods: After SPF C57BL/6J mice expose to 4 Gy-single whole body radiation,total number of peripheral WBC and the fMNPCE were measured at 3 d.The differentially expressed miRNAs in mouse liver were detected with miRNA microarray, miRNA-124 and miR-34a were confirmed by real time RT-PCR assay. Bioinformatic analysis was applied to explore target genes and the main functions of the differential expressed miRNAs. Results: Compared with control group, the total number of peripheral WBC decreased (t=2.87, P<0.05), while the fMNPCE in bone marrow increased (t=-2.91, P<0.05) after 4 Gy γ-ray irradiation.miRNA microarray revealed that 17 miRNAs were differentially expressed, in which 9 up-regulated, 8 down-regulated. The expression levels of miR-124 and miR-34a were coincident with the result of real time RT-PCR. GO analysis showed that some pathways including adherens junction and cell cycle were suppressed, while some immune-related pathways were activated. Conclusions: miR-34a and miR-194 were involved in the regulation of acute radiation damage, some other miRNAs including miR-124, miR-382 and miR-92a* also played important roles in radiation process. (authors)

  20. The effects of low-dose 60Co-γ rays irradiation on some enzyme activities and isoenzyme zymogram in pak-choi seedlings

    The changes in activities of ascorbate oxidase, polyphenol oxidase, catalase and zymogram of peroxidase isoenzyme, esterase isoenzyme in pak-choi seedlings induced by low-dose 60Co-γ rays irradiation were studied. The results indicated that the activities of ascorbate oxidase and polyphenol oxidase were enhanced. Zymogram of peroxidase isoenzyme and esterase isoenzyme also changed. And the effect of 6'0Co-γ ray on catalase was different. All these changes indicated the possibility of enhancing plant resistance, promoting growth and raising the yield of pak-choi

  1. Soil compaction and gamma radiation (60Co) in the development of the cowpea beans (Vigna unguiculata, (L) Walp

    The objective is to investigate the effect of compaction and increased doses of gamma radiation on the development of cowpea [Vigna unguiculata, (L) Walp] var. IPA-206 cultivated in a Neossolo fluvic soil, artificially compacted. Significant differences were observed in plant height, with the increase doses in soil density (1.30 Mg.m-3 - compacted soil and 1.70 Mg.m-3 - non-compacted soil), and in response to increased doses of irradiation (y-rays) [ [0, 100, 200 and 300 Gy). The diameter of the stem was significantly reduced in response to the increase in soil density, however the same did not occur in relation to the doses of irradiation (y-rays) holding capacity of the soil was reduced in response to the increase in soil density. (author)

  2. 60Co-γ辐射对菊苣种子发芽及幼苗生理的影响%Effects of 60Co-γ-rays Irradiation on Chicory Seed Germination and Seedling Physiology

    张玉; 白史且; 李达旭; 王曾珍

    2013-01-01

    Chicory seeds were irradiated with 60Co-γ-rays at 100, 150, 200 and 300 Gy to determine germination rate and physiological characteristics from mutagenic effects of irradiation doses. Results showed that seed germination rate decreased as the irradiation dosage increased. There was significant difference between 200 Gy irradiation dosage and control(P<0. 05). Superoxide dismutase (SOD) activities, peroxi-dase (POD) activities, soluble protein and soluble sugar contents first increased then declined with a gradual irradiation increase, and differed significantly between control and 150 Gy, 100 Gy, 150 Gy, 150 Gy treatments (P<0. 05), respectively. MDA content increased with increased irradiation dosage, and there was significant difference between control and the treatments above 150 Gy dose (P<0. 05). The protein content first increased then declined, and differed significantly between control and treatments (P<0. 05). It was concluded that the mutagenic effect of chicory irradiated by low dosage (below 150 Gy) was not obvious. However, physiological and biochemical characteristics of chicory irradiated above 200 Gy were significantly altered. The study provides a theoretical basis for chicory radiation mutation breeding.%为明确60 Co-γ射线对菊苣(Cichorium intybus L.)辐照诱变效果,采用不同剂量60Co-γ射线(100 Gy,150 Gy,200 Gy和300 Gy)辐照处理菊苣种子,测定其发芽率和相关生理指标.结果表明:随着辐照剂量的增加,菊苣发芽率降低,200 Gy以上辐照处理发芽率与对照差异显著(P<0.05);超氧化物歧化酶(SOD)、过氧化物酶(POD)活性、可溶性蛋白和可溶性糖含量随着辐照剂量增加均表现为先升后降的趋势,分别在辐射剂量为150 Gy,100 Gy,150Gy,150 Gy及以上时与对照差异显著(P<0.05);丙二醛(MDA)含量随着辐照剂量增加而逐渐升高,150 Gy以上辐照处理与对照差异显著(P<0.05);蛋白含量呈现先增后减的趋

  3. Effect of gamma radiation of 60Co in the conservation of seeds and on the productivity of bean plant (Phaseolus vulgaris L.)

    Seeds of the field bean variety 'Goiano Precoce' (Phaseolus vulgaris L.) subjected to various radiation doses (60Co) ( Co) were used in a series of experiments with the objective of studying the different aspects of seed behavior thus treated. The radiation doses, comprising six treatments, varied from 0,0 to 6,4 krad of gamma radiation. Effect on seed germination and seedling dry weight was studied by means of a factorial experiment conducted under laboratory controlled conditions. The factors used were the radiation doses and nine increasing lengths of time from date of seed irradiation. Seed vigor was determined by the rate of seedling emergence when planted in small field plots. A factorial design was used. The variables were the radiation dosages and six lengths of time elapsed since date of seed irradiation. The effect of seed irradiation on yield was evaluated by means of two randomized block design field experiments. After the seed vigor experiment was conducted infestation by the bean weevil, Acanthoscelidcs obtectus Say , was observed in irradiated seeds stored under normal conditions, indicating a relationship between radiation dosage and insect damage. An analysis was made of this effect at fourteen increasing time intervals. The analysis was made according to a factorial scheme considering as factors radiation dosage and time interval. The following conclusions could be drawn from the analysis and discussion of the results obtained: a) Seed germination was adversely affected by all radiation doses in relation to the check treatment. This effect however decreased significantly with storing time. b) Seed vigor was higher for those treated with 0,4 , 0,8 and 1,6 krad when compared with those that were not irradiated. c) Pod and seed weight were lowered by the 1,6 and 6,4 krad radiation doses in relation to the check treatment. d) Infestation by the bean weevil was significantly checked by all radiation treatments in relation to the check treatment. e) The

  4. The effects of seeds irradiation with 60Co γ-ray on seed germination and shoot growth of Brassica campetris L. ssp. Chinensis var. utilis

    Seeds of Brassica campetris L. ssp. Chinensis var. utilis pre-soaked with water for 1h were irradiated with 60Co γ-ray. Irradiation delayed the germination of seeds but did not affect the germination rate. The height, root length, fresh weight and survival rate of seedlings decreased with the increasing of irradiation dose. There were significant negative correlation between death rate and the height, root length and fresh weight. The dose of 200 - 300 Gy were recommended as suitable irradiation doses for pre-soaked seeds

  5. Immune response against the irradiated Bothropstoxin-1 with {sup 60}Co: identification of main cytokines involved and the participation of scavengers substances; Resposta imune frente a Bothropstoxina-1 irradiada com {sup 60}Co: identificacao das principais citocinas envolvidas e a participacao de substancias scavengers

    Alves, Janaina Baptista

    2009-07-01

    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- IFN{gamma} 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 ({sup 60}Co 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-{gamma}, 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-{gamma} and IL-2 (Th1 response) than the control sample. The cells of Knockout-IFN{gamma} 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)

  6. Brain anomalies induced by gamma irradiation in prenatal period

    Gamma irradiation has been utilized in order to produce cortical and callosal abnormalities. We have also checked for the presence of the aberrant longitudinal bundle in the brains of mice born acallosal due to prenatal irradiation is also checked. Pregnant mice were exposed to gamma irradiation from a 60 Co source at 16, 17 and 19 days of gestational age (E 16, E 17 and E 19) with total doses of 2 Gy and 3 Gy. At 60 days postnatal the offspring of irradiated animals were intra cardiac perfused, the brains were removed from the cranio and cut into coronal or para sagittal sections. (author)

  7. The effects of 60Co γ-ray irradiation on the DC characteristics of enhancement-mode AlGaN/GaN high-electron-mobility transistors

    Chen Chao; Tian Ben-Lang; Liu Xing-Zhao; Dai Li-Ping; Deng Xin-Wu; Chen Yuan-Fu

    2012-01-01

    The effects of 60Co y-ray irradiation on the DC characteristics of AlGaN/GaN enhancement-mode high-electronmobility transistors (E-mode HEMTs) are investigated.The results show that having been irradiated by 60Coγ-rays at a dose of 3 Mrad (Si),the E-mode HEMT reduces its saturation drain current and maximal transconductance by 6% and 5%,respectively,and significantly increases both forward and reverse gate currents,while its threshold voltage is affected only slightly.The obvious performance degradation of E-mode AlGaN/GaN HEMTs is consistent with the creation of electronegative surface state charges in the source-gate spacer and gate-drain spacer after being irradiated.

  8. Microbial determination of Cumin by gamma irradiation

    Cumin is one of the valuable export items of Iran, and like most of the agricultural products it is contaminated by microorganisms. Due to importance of this product, the gamma irradiation method, which has applications in microbial decontamination, has been used for the improving its quality and increasing the shelf life-time. For this purpose pak ages of 10 gr of cumin were irradiated by 2,4,6 and 8 KGy from 60Co source. With each dose, four samples were irradiated and results were compared with controlled not irradiated samples. According to the standard limitation of bacteria and molds the total optimum doses are 7.5 and 5 KGy respectively

  9. The effect of combination of ErbB2 RNAi and 60Co γ-irradiation on U251 cell apoptosis

    To construct erythroblastic leukemia viral oncogene homolog 2 (ErbB2) small interference RNA (siRNA) expression vector and to study its effect on U251 cell line proliferation and apoptosis combining with 60Co γ-irradiation. ErbB2 specific 19bp oligonucleotides were designed and synthesized. These oligonucleotides were annealed to form the double strand DNA fragments, which was cloned into pSilence2.1-U6-H1 vector. The recombinant pSilence2.1-ErbB2 expression construct was confirmed by Hind III and BamH I double digestion and sequencing. The pSilence 2.1-ErbB2 was transfected into U251 cell. Cellular proliferation activities were assayed by tetrazolium bromide (MTT) colorimetry. The apoptosis of transfected U251 cell was examined with Hoechst 33258 staining and Annexin-V kit. Psilence 2.1-ErbB2 expression vector was successfully constructed and it can effectively inhibit pro- liferation(p60Co γ-irradiation, the effect of inhibiting proliferation was more significant compared with non-irradiated U251 cells(p60Co γ-irradiation can enhance the inhibitory efficiency in U251 cell line. (authors)

  10. Enhancing the lipid content of the diatom Nitzschia sp. by 60Coirradiation mutation and high-salinity domestication

    To improve the lipid accumulation of diatom cells, Nitzschia sp. was mutated by 60Co-γ-ray irradiation and cultivated with high salinity. The biomass and lipid yields of Nitzschia sp. mutated by 60Co-γ-ray irradiation at 900 Gy were increased by 53.8% and 28.1%, respectively. The lipid content of Nitzschia sp. mutant cells cultivated with gradually increased salinity of up to 30‰ was increased from 11.9% to 27.2%. This was because that the increased demand for nitrogen to keep cells healthy growth under high salinity conditions resulted in lipid accumulation, which was beneficial to prevent cell membranes from being destroyed by changing osmotic pressure. When the Nitzschia-ZJU1 strain obtained from Nitzschia sp. by irradiation mutation and salinity domestication was cultured in the growth media with no nitrogen and no silicon, the lipid content of cells was dramatically increased to 51.2%. - Highlights: • Nitzschia species were mutated by 60Coirradiation for high lipid production. • Mutants were domesticated with high salinity to increase lipid content in cells. • Lipid content of domesticated mutants was 1.3 times higher than original strain. • Lipid content reached 51.2% under 30‰ salinity, nitrogen and silicon deprivation

  11. 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)

  12. The response to climate factors for the different specificity in M2 physiology of 60Co γ-ray irradiated flowers

    Physiology and climate factor of different M2 flower (Begonia tuberhybrida Voss and Dahlia pinnata Cav root) after 60Co γ-ray irradiated were determined. The result showed that transpiration rate, stoma conductance, intercellular CO2 concentration of M2 of Dahlia pinnata Cav are affected obviously with climate factors, however, effect on the photosynthetic speed was not found, and M2 of Begonia tuberhybrida Voss was not significant for physiology to climate

  13. (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

  14. The effects of chloramphenicol and 60Co irradiation on the experimental mycosis in mice inoculated intragastrically with two kinds of pathogenic yeast-like fungi

    Two kinds of pathogenic yeast, Cryptococcus neoformans and Candida albicans were inoculated into the stomachs of mice. The effects of intragastric administration of chloramphenicol (CM) and systemic irradiation with 60Co on the acceralation of infection were studied in intragastrically inoculated mice. When Cryptococcus neoformans were simply inoculated, it was difficult for them to reside in the alimentary canal to cause infection. In case of candida albicans inoculated simply, they were also unable to induce infection though they remained in the alimentary canal for a long time. In the experiment combining intragastric administration of the fungi and CM some mice contracted the disease and died. The effect of CM in causing infection was not proved. In the experiments combining 60Co irradiation and intragastric administration of CM and fungi, a high incidence of fungus infection was noted with both Cryptococcus neoformans and Candida albicans. Fungus lesions were observed in many organs, and in all of the mice which died systemic fungus lesions were noted. It was shown that systemic irradiation with 60Co had a specific effect on facilitating the infection. In these studies no difference was observed in the incidence of the fungus disease in respect of the origin of the causative fungi. (J.P.N.)

  15. Luminescence characteristics of C5+ ions and 60Co irradiated Li2BaP2O7:Dy3+ phosphor

    Wani, J. A.; Dhoble, N. S.; Lochab, S. P.; Dhoble, S. J.

    2015-04-01

    In this work a study on some thermoluminescence characteristics of Li2BaP2O7:Dy phosphor is presented. The phosphor was synthesized by solid state diffusion method and characterized for its phase purity by X-ray diffraction (XRD). FT-IR spectrum was also carried out to confirm the presence of phosphate family and vibrations corresponding to P-O-P group. Spectroscopic investigation was approached through photoluminescence (PL) and thermoluminescence (TL). PL emission spectrum of Dy3+ ions corresponding to 4F9/2 → 6H13/2 (483 nm) and 4F9/2 → 6H15/2 (574 nm) transitions is revealed under 351 nm excitation wavelength. This characteristic emission confirms the presence of Dy3+ ions in the Li2BaP2O7 host matrix. To induce TL properties in Li2BaP2O7:Dy phosphor was irradiated with C5+ ion beams and gamma rays (60Co). A nearly simple glow curve was observed for Li2BaP2O7:Dy under two different excitation sources. TL response is almost linear over a wide range. Average absorbed dose (D bar) and mean linear energy transfer (LET ‾) of C5+ ion beams in Li2BaP2O7:Dy have also been calculated. Values of parameters like E and S known as trap depth and frequency factor respectively were obtained by using TLanal computer program. Also SRIM based calculations were performed to study the effect of C5+ ion beams on the samples of Li2BaP2O7:Dy. SRIM calculations show that Ba2+ vacancies are highest in number. Till date no such luminescence information on Li2BaP2O7:Dy phosphor is available.

  16. Description of morphologic characters in avocado trees (Persea americana. Mill) var. Hass, submitted to gamma radiation of 60 Co

    It was carried out the characterization of 77 trees of avocado ''Hass'' subjected to gamma radiation of Co60, in doses of 0, 5, 10,15, 20 and 25 Gy based on previous studies of radiosensitivity with ends of improvement located in the experimental center ''La Labor'' belonging to the foundation Salvador Sanchez Colin. CICTAMEX. S C. in Temascaltepec, Mexico. It was carried out the morphological characterization of this variety according to the nomenclature settled down by the International Office of Genetic Resources (IBPGRI), registering 27 variables for the description of the tree, 33 for description of the fruit and 14 for the characterization of the seed. Regarding the architectural characterization 10 variables were evaluated. Using gamma radiation of Co60 in the doses of 15 and 20 Gy it was detected a reduction of 22% in the portage of the tree, likewise had reduction the diameter of the trunk and of the foliage. It was found that the reduction in the behavior of the tree induces to a bigger variation of the form of the same one, in the distribution of the branches in the form of the fruit and in the form of the seed you Also detects a remarkable increment in the productivity of some hoist irradiated regarding the architecture of the tree one observes that the angle of inclination of the branches increase when being increased the radiation dose and that the longitude of the annual section of growth decreased significantly in the doses of 20 and 25 Gy. One observes a significant Increment in the I number of buds prolepticos in those hoist irradiated in the I finish mbdulo of rhythmic growth. Io that indicates a change substantial in the I inhabit of growth With the purpose of determining if the changes in morphology and architecture of the tree corresponded with the modification at level meristematico, they were carried out observations to the court microscope of having knitted apical vegetative meristematico in samples of you hoist of all the treatments

  17. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of 60 Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

  18. Effect of 60Co γ irradiation with seed and shoot-tip of Brassica campestris L. var on its culture in vitro

    The survival rate in vitro of shoot-tips of Brassica campestris L. var from seeds irradiated by 60Co γ-rays decreased with the increase of dose. Irradiation inhibited proliferation of shoot-tip, induction of callus from cotyledons and differentiation of the callus. The age of explant contributed to the effect of irradiation in the culture. Irradiation stimulated the proliferation of shoot-tip with dose less than 50 Gy. Based on the effect of irradiation in the tissue culture, the effective dose recommended was about 200 Gy for seeds, 50-100 Gy for pre-soaked germinating seeds and 40-70 Gy for shoot-tips in vitro, respectively

  19. A primary study on mutation induction of in-vitro cultured garlic shoots by 60Co γ-ray irradiation

    In vitro cultured shoots of four garlic cultivars were used to estimate radio-sensitivities and mutation rate by 60Co γ-ray. LD50 of the tested materials was around 7∼9 Gy with a mutation rate of 5%. Two mutants, Tai-R1 and Cang R2 were proved to be genetical variants by the investigation on agronomic characters and the analysis of peroxidase isozyme

  20. Comparisons of the standards for air kerma of the PTB and the BIPM for {sup 60}Co and {sup 137}Cs gamma radiation

    Allisy-Roberts, P.J.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Buermann, L.; Kramer, H.M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2005-11-15

    Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the {sup 60}Co and {sup 137} Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in {sup 60}Co of 9.9 x 10{sup -3} with a combined standard uncertainty of 1.8 x 10{sup -3}, and in {sup 137}Cs of 6.4 x 10{sup -3} with a combined standard uncertainty of 2.8 x 10{sup -3}. The earlier comparisons in {sup 60}Co {gamma} rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10{sup -3}. The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, k{sub wall} and k{sub pn}, for the PTB standards, which were calculated using Monte Carlo methods. (authors)

  1. Sterilization by gamma irradiation

    Since 1980 the National Institute of Nuclear Research counts with an Industrial Gamma Irradiator, for the sterilization of raw materials and finished products. Through several means has been promoted the use of this technology as alternative to conventional methods of sterilization as well as steam treatment and ethylene oxide. As a result of the made promotion this irradiator has come to its saturation limit being the sterilization irradiation one of the main services that National Institute of Nuclear Research offers to producer enterprises of disposable materials of medical use also of raw materials for the elaboration of cosmetic products and pharmaceuticals as well as dehydrated foods. It is presented the trend to the sterilization service by irradiation showed by the compilation data in a survey made by potential customers. (Author)

  2. INCASOY-35: PRIMERA VARIEDAD DE SOYA OBTENIDA EN CUBA A PARTIR DEL EMPLEO DE TÉCNICAS DE IRRADIACIÓN DE RAYOS GAMMA DE 60Co

    Ortiz, R.; C. de la Fé; M. Ponce

    2005-01-01

    La variedad INCASoy-35 fue obtenida a partir de la irradiación de semillas de la variedad INCASoy-15 con dosis de 240 Gy de rayos gamma 60Co; esta variedad se adapta a siembras de primavera, verano e invierno y puede alcanzar rendimientos de 3 t.ha-1 de granos. Tolera las principales plagas y enfermedades y, en especial, resiste el ataque de nemátodos Meloidogyne incognita. En la época adversa de primavera, las semillas han mostrado tolerancia al deterioro. Tiene capacidad de garantizar altas...

  3. Effect of hydrogen on change carrier dissipation in 60Co irradiated by γ-quanta and non-alloyed n-type GaAs

    The pretreatment in hydrogen plasma (the hydrogenation) influences on the charge carrier dissipation processes in the non-alloyed gallium arsenide of n-type with no = (5...7) centre dot 1015 cm-3 and μo = (5...6) centre dot 10 13 cm2 / (V centre dot c) irradiated by γ-quantum 60Co was studied. The comparison of experimental dependence μ (T) with the designed one in the temperature range 77...291 K for non-hydrogenized and hydrogenized non irradiated and γ-quantum irradiated crystals was carried out. It is shown that the main dissipative mechanism that determine the charged carrier mobility in the non hydrogenized material is the dissipation on the charged centers - the radiation defects in the γ-quantum irradiated GaAs; the presence of double ionized defects is possible

  4. Effect of 60Co γ-rays irradiation on growth and anti-oxidant enzyme activities of rhizomes in cymbidium goeringii

    The rhizomes of Cymbidium goeringii were cut into tip, middle and basal segments with a length of about 1 cm, and the segments were irradiated with 60Co γ-rays at doses of 0, 5, 10, 20, 30 and 50 Gy, respectively. The growth characters, the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (G-POD), and peroxidase isozyme of the were measured. The results showed that the segments irradiated at the dose of 30 and 50 Gy could survive, but couldn't form new rhizomes and the growth was almost stagnated. With the increase of the doses, the SOD and CAT activities of the rhizome were increased first, then significantly decreased, but the reverse effect was observed in G-POD activities, which was decreased first, then increased. Combining both the effect resuhson the growth characters, on activity changes of peroxidase isozyme and the changes of the anti-oxidant enzymes after irradiation, it was concluded that the appropriate doses of 60Co γ-rays irradiation for mutation breeding of Cymbidium goeringii should be in the rage of 20 to 30 Gy, and the optimal part of the rhizome seems to be the tip segment. (authors)

  5. Comparison of the standards of air kerma of the OMH and the BIPM for 60Co gamma radiation

    A direct comparison between the standards for air kerma of the Orszagos Meresugyi Hivatal (OMH) and of the Bureau International des Poids et Mesures (BIPM) has been carried out in the 60Co radiation beams of the BIPM. The result, expressed as a ratio of the OMH and the BIPM standards for air kerma, indicates a relative difference of 10.9 x 10-3 with a combined standard uncertainty of 2.2 x 10-3. This new result agrees at the level of 0.4 x 10-3 with the earlier direct comparisons performed in 1986 and 1994, as modified in 2001 by the application of wall and axial non-uniformity correction factors, calculated for the OMH standards using the Monte Carlo method. (authors)

  6. Decontamination of spices by gamma irradiation

    Decontamination of spices (onion powder, cardamom, red pepper powder, etc.) used for special types of Bulgarian sausages was investigated. Gamma irradiation (60Co) at doses of 4, 6, 8 and 10 kGy was applied. It was found that the total count of microorganisms in spices was between 1.85.105 and 3.8.107. The largest was the amount of the coliforms and the staphylococci in the onion powder. The cardamom and onion powder were free of coliforms with dose of 4 kGy. The staphylococci were eliminated with doses of 6 kGy. The number of proteolytic microorganisms was decreased but they were isolated from spices irradiated even with 10 kGy. (author)

  7. Evaluation of immunity and protection induced in experimental models by soluble extract of Toxoplasma gondii tachyzoites irradiated by 60Co

    Toxoplasmosis affects 1/3 of the human population and only a vaccine for veterinary use. Gamma radiation alters the proteins making them more immunogenic by oxidation and better antigen presentation in the absence of adjuvants. Radiate soluble extract of RH strain tachyzoites of T. gondii (AgTg), and evaluate its use as a vaccine in BALB/c. Doses below 500Gy not affected and destroyed 2000Gy doses above extract, whereas animals immunized with irradiated extract at 1000, 1500 and 2000Gy had more of specific IgG avidity , compared to native AgTg (p<0,05) . AgTg 1500GY the immunized animals had increased proliferation of splenocytes, phenotyped as CD3+CD4+, CD3+CD8+ and B-lymphocytes immunized animals compared to the native AgTg . Animals immunized by AgTg 1500GY after challenge with strain ME- 49 cystogenic showed lower number of brain cysts and greater survival after challenge with virulent RH. Ionizing radiation in extracts of T. gondii increases the immune response and immune memory in the absence of adjuvants. (author)

  8. Soil compaction and gamma radiation ({sup 60}Co) in the development of the cowpea beans [Vigna unguiculata, (L) Walp]; Compactacao do solo e radiacao gama ({sup 60}Co) no desenvolvimento do feijao caupi [Vigna unguiculata, (L) Walp

    Viana, Eliane Ferreira; Colaco, Waldeciro [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Radioagronomia]. E-mails: aroucha@ufpe.br; wcolaco@ufpe.br

    2005-08-15

    The objective is to investigate the effect of compaction and increased doses of gamma radiation on the development of cowpea [Vigna unguiculata, (L) Walp] var. IPA-206 cultivated in a Neossolo fluvic soil, artificially compacted. Significant differences were observed in plant height, with the increase doses in soil density (1.30 Mg.m{sup -3} - compacted soil and 1.70 Mg.m{sup -3} - non-compacted soil), and in response to increased doses of irradiation (y-rays) [ [0, 100, 200 and 300 Gy). The diameter of the stem was significantly reduced in response to the increase in soil density, however the same did not occur in relation to the doses of irradiation (y-rays) holding capacity of the soil was reduced in response to the increase in soil density. (author)

  9. 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

  10. 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.

  11. Physiological characteristics of cucumber seed production plants by presowing laser and gamma irradiation

    Seeds from G-3 maternal line of hybrid cucumber cultivar Pobeda F1 were treated with helium-neon 632.8 nm laser-exit power 20 mW and gamma-rays (60Co) in a field experiment under conditions suitable for hybrid seed production. The irradiation was carried out a week before sowing and the following variants were investigated: 1. sevenfold laser irradiation; 2. 10 Gy gamma irradiation; 3. combined laser + gamma rays irradiation. Seeds from the parent line were not irradiated. A positive effect of irradiation on the photosynthetic intensity, content of plastid pigments in leaves and activity of catalase and peroxidase has been observed. (author)

  12. Effect of 60Co γ ray irradiation on electrical parameters of MOVPE grown GaAs epilayer and p-i-n detectors

    60Co γ ray irradiation on GaAs epilayer and p-i-n detectors structures was carried out to determine the radiation hardness of the devices. The carrier density and mobility decreases with increasing radiation doses due to the creation of Ga vacancies. The generation recombination centers increases with increasing radiation doses that leads to five fold increase in the dark current of the p-i-n device at 50 KGy. The radiation hardness value obtained was 4.7x10-19 A/cm. (author)

  13. Gamma ({sup 60}CO) radiation effects on arcelin protein and evaluation of bean lineages against Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boh.) (Col.: Bruchidae);Efeito da radiacao gama ({sup 60}CO) sobre a proteina arcelina e avaliacao de linhagens de feijoeiro a Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boh.) (Col.: Bruchidae)

    Botelho, Ana Claudia Girardo

    2006-07-01

    The resistance of arcelin carrying seeds of bean lineages (Phaseolus vulgaris L.) against the bean weevils Acanthoscelides obtectus (Say, 1831) and Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Bruchidae), and the influence of gamma radiation ({sup 60}CO) on the manifestation of arcelin resistance to Z. subfasciatus were verified. Laboratorial tests, in choice and non-choice tests, with wild specimens carrying Arc-1, Arc-2, Arc-3, Arc-4, Raz-56 and Raz-59 (with Arc-5 alleles) and commercial lineages as control IAC - Carioca and IAC - Arua were conducted. Statistical design was completely randomized, with five repetitions, with 10 g of grains from each lineage samples by portion. Attractiveness, oviposition, emergence, mortality, adults' weigh and longevity, developing period, sexual rate, seeds' weigh loss, infestation and fecundity (Z. subfasciatus) were observed. Gamma radiation doses irradiations, in general, haven't affected the resistance manifestation of lineages carrying arcelin protein variants against the Z. subfasciatus bean weevil, thus, joint application use of both control methods can be recommended. Raz-56 lineage showed high resistance of the antibiosis types and non-preference for oviposition and feeding to Z. subfasciatus, while Raz-59 showed antibiosis and non-preference for feeding, and both (Raz-56 and Raz-59) showed intermediate resistance to A. obtectus, against which lineage Arc-2 was the most harmful to its development, expressing non-preference to feeding and/or antibiosis. (author)

  14. Economics of gamma irradiation processing

    The gamma-ray irradiation business started at the Takasaki Laboratory of Japan Atomic Energy Research Institute. The irradiation facilities were constructed thereafter at various sites. The facilities must accept various types of irradiation, and must be constructed as multi-purpose facilities. The cost of irradiation consists of the cost of gamma sources, construction expense, personnel expense, management expense, and bank interest. Most of the expenses are considered to be fixed expense, and the amount of irradiation treatment decides the original costs of work. The relation between the irradiation dose and the construction expense shows the larger facility is more economical. The increase of amount of treatment reduces the original cost. The utilization efficiency becomes important when the amount of treatment and the source intensity exceed some values. The principal subjects of gamma-ray irradiation business are the sterilization of medical tools and foods for aseptic animals, the improvement of quality of plastic goods, and the irradiation of foods. Among them, the most important subject is the sterilization of medical tools. The cost of gamma irradiation per m3 in still more expensive than that by ethylene oxide gas sterilization. However, the demand of gamma-ray irradiation is increasing. For the improvement of quality of plastic goods, electron irradiation is more favourable than the gamma irradiation. In near future, the economical balance of gamma irradiation can be achieved. (Kato, T.)

  15. Effect of fractionated 60Co γ-ray irradiation on 8-epi-prostaglandin F2α in plasma and RBC membrane of dogs

    Objective: By observing the alteration of 8-epi-prostaglandin F2α(8-epi-PGF2α) in plasma and RBC membrane of dogs during and after γ irradiation, and comparing it with malondialdehyde (MDA), the authors aimed to assess the value of measuring its concentrations in realizing the irradiation-induced lipid peroxidative reaction, and to detect the effect of superoxide dismutase (SOD) on this procedure. Methods: 18 adult out bred dogs (6 dogs each were randomly assigned to low-dose SOD treatment group, high-dose SOD treatment group and control group) were irradiated with 60Co γ-rays at a dose of 0.6 Gy per day for 5 days, and the concentrations of 8-epi-PGF2α and MDA in plasma and RBC membrane were assayed before, during, and after the irradiation. Results: The mean plasma 8-epi-PGF2α level in dogs was significantly increased during the γ-irradiation, and gradually decreased after the irradiation was ended, while the enhanced 8-epi-PGF2α concentration in RBC membrane was higher than that in plasma, and it reached the peak level at the 2nd day after the irradiation was ended and then started to decrease; SOD could markedly inhibit its increase. The levels of MDA in plasma and RBC membrane were not significantly changed. Conclusion: 8-epi-PGF2α can serve as a new and more sensitive index for reflecting the irradiation-induced lipid peroxidative reaction

  16. Destruction of Radiation-Resistant Micro-Organisms on Surgical Sutures by 60Co-Irradiation Under Manufacturing Conditions

    Any process adopted for producing sterile medical products must be demonstrated to produce sterility under reproducible manufacturing conditions. In addition, a margin of safety is required to guard against non-sterility due to undetected departures from standard operating practices. This study reports the results of exposure to 60Co γ-rays of surgical sutures intentionally contaminated with known radiation-resistant organisms, including St. faecalis, M. radiodurans and B. pumilus, under normal manufacturing conditions. Additionally, the results of over 20 000 sterility tests under prolonged incubation are reported to indicate that routine sterility testing of radiation-sterilized sutures is adequate to detect radiation survivors. The nature and level of the natural contaminants of surgical sutures before sterilization is tabulated and discussed from the standpoint of the safety factor inherent in the process. (author)

  17. Differential expression profile in the progeny of normal human liver cells irradiated by 60Co γ-rays

    Objective: To investigate the differential expression profile in the progeny of human liver cells surviving from ionizing radiation. Methods: Complemental DNA gene chip was used to measure the transcriptional profile in progeny of HL-7702 cells exposed to 0, 2, 4, and 6 Gy of 60Co γ-rays, and the differentially expressed genes HAVCR2 and RAN were further identified by real-time PCR. Results: The transcription level of 262 genes, 2746 genes and 3406 genes changed in the progeny of survival cells at 2, 4 and 6 Gy, respectively. A total of 71 common differentially expressed genes were screened, most of which were associated with transduction, cell cycle regulation, cellular immunity, cytoskeleton and movement, cell replication and repair mechanism. Conclusions: Ionizing radiation could induce the expression changes of many genes, which might reveal the molecular mechanisms of gene expression in radiation induced genomic instability. (authors)

  18. Dose-rate effect on chromosomal aberrations induced by 60Co γ-rays irradiation in human peripheral blood lymphocyte

    To estimate exactly the biological dose of persons exposed to different dose rate, human peripheral blood was exposed to 60Co γ-rays in vitro at low, middle and high dose rates respectively and chromosome samples were prepared, then dose-response curves were established according to the dicentrics and ring frequencies. The result showed that the aberration frequency at same dose level increased with dose rate and there was an obvious dose-rate effect. Absorbed dose estimated with low dose-rate dose-response curve was higher markedly than that with high dose-rate dose-response curve. So, considering the effect of dose-rate, approximate dose-rate dose-response curve should be chosen when absorbed dose estimation and the result will be credible. (authors)

  19. Simulation smuggling study for shielded sources of 235U, 238U, 232Th, 137Cs and 60Co by using gamma detection

    In the present time, smuggling and illicit trafficking of nuclear and radioactive materials are targeted by international groups and networks. Hundreds of smuggled nuclear and radioactive materials have been seized and currently recorded in the Illicit Trafficking Database (ITDB) of the International Atomic Energy Agency (IAEA). As a matter of fact, these materials can be used for manufacturing of dirty or Radiological Dispersal Device (RDD) or for sabotage and malicious purposes. This work deals with gamma detection of shielded sources containing natural 235U , 238U , standard 232Th and mixed 137Cs and 60Co sources by using HpGe and NaI detectors. The detection was carried out through the main characteristic γ- energies ; 185.7 KeV for 235U ,(63.3 ,1001 KeV) for 238U , (583 and 911.2 KeV) for 232Th, 661.6 KeV for 137Cs and (1173.2 and 1332.5 keV) for 60Co. The radioactive sources used are 30nCi of 232Th , 1.99 μCi of mixed 137Cs and 60Co source and uranyl nitrate crystals. These radioactive sources were separately hid (placed) in containers of different materials; aluminum (Al) , cupper (Cu) and iron (Fe) of different wall thickness; 3, 6, 9, 12, 15, 18 mm. The sources were also measured together by NaI and HpGe detector. Overlapping of different gamma transitions leads to some difficulties to identify and discriminate between the investigated γ-energies particularly with using the low resolution NaI detector. The attenuation factors (I/Io), ratio of radiation intensity with and without shield (containers), were calculated for all the investigated energies. The relationship between the attenuation factor of γ-energies and the studied thickness was depicted and discussed. It was observed, as expected, that the studied gamma transitions were attenuated by the used different thickness of Fe, Cu and Al and hardly detected especially for low energy and at 18mm thickness. Generally, it can concluded that radioactive materials of small activity can easily be smuggled

  20. Differential Expression of Retrotransposon WIS 2-1A Response to Vacuum, Low-Energy N+ Implantation and 60Coγ-ray Irradiation in Wheat

    Zhao, Huiru; Gu, Yunhong; Ya, Huiyuan; Jiao, Zhen; Qin, Guangyong

    2009-02-01

    Mutagenesis and retrotransposons have a close relationship, but little attention has been paid yet to the activity of retrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat (Triticum aestivum L.) embryos at three different growth times (30 h, 45 h and 60 h) was investigated after they had been treated with N+ implantation in a vacuum of 5 × 10-2 Pa and irradiation by 60Coγ-ray respectively. For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation, upregulation, then downregulation, and upregulation again with the increase in dose of N+ implantation, but the expression appeared irregular with the increase in irradiation of 60Coγ-ray. In conclusion, the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N+ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.

  1. Differential Expression of Retrotransposon WIS 2-1A Response to Vacuum,Low-Energy N+ Implantation and 60Coγ-ray Irradiation in Wheat

    ZHAO Huiru; GU Yunhong; YA Huiyuan; JIAO Zhen; QIN Guangyong

    2009-01-01

    Mutagenesis and retrotransposons have a close relationship,but little attention has been paid yet to the activity of rtrotransposons produced by physical mutagens. The variation of retrotransposon WIS 2-1A activity in wheat(Triticum aestivum L.)embryos at three different growth times(30 h,45 h and 60 h)was investigated after they had been treated with N+ implantation in a vacuum of 5x10-2 Pa and irradiation by 60Coγ-ray respectively.For each of the three growth times the expression of WIS 2-1A showed almost entirely a same trend of downregulation,upregulation,then downregulation,and upregulation again with the increase in dose of N+ implantation,but the expression appeared irregular with the increase in irradiation of 60Coγ-ray.In conclusion,the acutely activating effect of WIS 2-1A stimulated by vacuum and high dose N+ implantation within a shorter incubation time may provide a convenient tool to advance the research on mutagenic breeding and function genes.

  2. Breeding of Xinchun No.30 with early maturity, good quality and high yield by hybridization and 60Co γ-rays irradiation

    F1 hybrid seeds of Xinchun 9/xinchun 6 were treated by 80 Gy 60Co γ-rays irradiation,after many generations' selection on single spike in progenies, Xinchun No.30 with early maturity, good quality and high yield was bred. Xinchun No.30 was officially registered by Xinjiang Crops Variety Examination and Approval Committee in March 2009. It was characterized by high and stable yield(5250-900 kg/hm2), wide adaptation area,good resistance to rust and powdery mildew, lodging resistance and medium to strong gluten quality. The results showed that hybridization combined with irradiation is a useful breeding approach to develop new varieties with drought resistance, good quality and high yield potential. (authors)

  3. Rapid rejoining of DNA strand breaks in resting human lymphocytes after irradiation by low doses of 60Co γ rays or 14.6-MeV neutrons

    The production and repair of DNA strand breaks was studied in human lymphocytes by means of a sensitive fluorometric technique. Lymphocytes were isolated by conventional methods and air-equilibrated suspensions were irradiated by low doses (less than or equal to 2 Gy) of either 60Co γ rays or 14.6-MeV neutrons at 00C. The apparent yield of initial strand breaks induced by neutrons was only 36% of that induced by γ rays, in agreement with the observations of other workers. Resting lymphocytes were found to be proficient in their ability to rejoin γ-induced strand breaks at 370C; rejoining followed biphasic kinetics, with 70% of the breaks disappearing with a half-life of about 3 min. Although the initial number of breaks induced by neutron irradiation was low, after 20 min of incubation the residual number of breaks was very similar for the two forms of radiation

  4. A study on the irradiation effect of 60Co-γ ray for dental P.M.M.A. bonded parts

    In this paper we describe an experimental study on the irradiation effect of 60Co-γ ray for dental P.M.M.A. welding parts, hot polymerizing adhesion parts and cold polymerizing adhesion parts. As a result of this series of test and experiments, it was found that from the result of tension test, no remarkable change is found with any of the bonded materials 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 materials have different features, high strength of the welded material and of the material adhered by hot polymerizing adhesive becomes lower by irradiation, and strength of the three materials converges after irradiation within the range of 106-107 r. Joint efficiency of 65-75% in tension and 50-62% in bending can be adopted. With regard to fracture, blocks of each specimen are finely divided and show tendency of becoming brittle by irradiation. Fracture of the base material and of the bonded materials are similar and prove bonding of high strength. (author)

  5. Effects of prenatal 60Co irradiation on postnatal neural, learning, and hormonal development of the squirrel monkey

    The goals of this study were to examine the effects of 0, 50, and 100 rad of 60Co administered prenatally on postnatal development of neuromuscular coordination, visual discrimination learning, spontaneous light-dark stabilimeter activity, plasma cortisol, and somatometric growth rates of diurnal squirrel monkeys from birth to 90 days. In terms of accuracy, completeness, and time required for performance of reflexes and neuromuscular coordination, the performance of 50- and 100-rad offspring was less accurate and poorly coordinated and required more time for completion to that of controls. In visual orientation, discrimination, and reversal learning, the percentage correct responses of the 50- and 100-rad offspring were significantly lower than those of controls. Spontaneous light-dark stabilimeter activity of 50- and 100-rad offspring was significantly higher in the dark session than that of controls. Plasma cortisol was significantly higher in 100-rad infants than in controls. Comparisons of somatometric growth rates indicated that postnatal head circumference, crown-rump length, and to a lesser extent body weight increased at significantly slower rates in 50- and 100-rad offspring. These findings should provide essential information for formulating and carrying out multivariate behavioral, biochemical, and morphometric assessments of low-dose effects on the brain of primate offspring within demonstrable dose-response curves

  6. Effect of 60Co γ-irradiation on postharvest quality of pleurotus nebrodensis stored at 4 degree C

    The effect of γ-rays irradiation on the fresh-keeping of Pleurotus nebrodensis fruit bodies was reported in this paper. Fresh harvested fruit bodies of Pleurotus nebrodensis were irradiate at different doses levels (0.8-2.0 kGy) and stored for 22 days at 4 degree C. The fruit bodies treated with 1.2 kGy irradiation retained the highest soluble protein contents, and exhibited less postharvest softening throughout the storage period. Regression analysis plots of fruit body hardness versus soluble protein content were linear (t>0.05). Increases in mushroom cell permeability observed throughout the storage period were directly related to irradiation dose. Too higher dose(≥2.0 kGy) of irradiation will accelerate the nutrition degradation and rotting of the fruit bodies. (authors)

  7. Change of microflora of two starch samples by gamma irradiation

    Starch is the basic component of a larger number of manufactured foods. The disinfection of such a powder by 60Co is studied here. Gamma irradiation of two starch samples with different degrees of contamination allows the assumption that, in most cases, good radio-pasteurization can be achieved with 300 krad. The radio-pasteurization doses (varying from 300 to 600 krad) are a function of the initial contamination. Irradiation effects are spectacular with moulds. Activation of spores of some Clostridium species leads us to recommend an irradiation level higher than 200 krad. The most resistant organisms to gamma irradiation are the aerobic and anaerobic sporulated bacteria. The thermophilic forms are the most important. Spores of Bacillus, chiefly Bacillus licheniformis and Bacillus brevis, are the most frequent bacteria. Storage of irradiated starch at room temperature has little effect upon the number of revivable survivors. (orig.)

  8. Experimental infection with Klebsiella pneumoniae and its gentamicin therapy in guinea pigs 60Co irradiated with 4 Gy

    Sublethal irradiation was used to suppress the immunity response of the organism. Following the development of infection with Klebsiella pneumoniae the therapeutical effect was compared of intramuscular administration and of inhalation of gentamicin. Intramuscular administration was statistically significant for reducing the mortality of infected guinea pigs as against non-treated animals at days 7 to 10 after irradiation. Administration by inhalation had the same effect between days 12 and 25 after irradiation. The weight and blood counts of the animals were observed during the experiment. (M.D.)

  9. The effects of 60Coirradiation on the cell proliferation kinetics of DMBA-induced tongue carcinoma in hamster

    In the occation of the radiation therapy, it is very important to analize the cell kinetics of the normal and tumor tissues, and the radiation effects. Thus, this study analizes the effects of 60Coirradiation to DMBA-induced hamster tongue carcinoma (hereafter ''the Tumor'') and normal tongue epithelium (hereafter ''the Normal'') by using 3H-TdR puls labeling technics and percentage labeled mitoses (PLM) method. Result : 1) Cell cycle time (Tc) of the Normal was 42.0 hours, and that of the Tumor was 18.1 hours. After irradiation, Tc of the Tumor was prolonged, but that of the Normal was shortened by about 11 hours. 2) Initial labeling index (L.I.) of the Tumor was decreased immidiately after irradiation, but on 7 and 10 days L.I. gained back to the pre-irradiation rate. 3) Tumor doubling time (Td) was 6.4 ± 1.6 days, and potential doubling time (Tp) was 18.9 hours. 4) Time of pre-DNA synthetic stage (Tg1) of the Normal was 31.0 hours and that of the Tumor was 8.7 hours. After irradiation, Tg1 of the Normal was shortened by about 10 hours and that of the Tumor was prolonged. 5) After irradiation, Time of synthetic stage (Ts) of both the Normal and the Tumor was slightly prolonged. 6) After irradiation, Mitotic stage (Tm) of both the Normal and the Tumor was not changed. 7) Growth fraction (GF) of the Normal was 64.5 %, and that of the Tumor was 79.8 %. After irradiation, it was decreased, while it of the Tumor was increased temporarily after irradiation. 8) The rate of cell loss facter of the tumor was 0.88. (author)

  10. Measurement of 60CO gamma radiation induced attenuation in multimode step-index POF at 530 nm

    Kovačević Milan S.

    2013-01-01

    Full Text Available As optical fibres are used ever more extensively in space applications, nuclear industry, medicine and high-energy physics experiments, it has become essential to investigate the influence of ionizing radiation on their characteristics. In this work, the radiation-induced attenuation at 530 nm is investigated experimentally in step-index multimode polymethyl-methacrylate plastic optical fibres exposed to low dose-rate gamma radiation. Cumulative doses ranged from 50 Gy to 500 Gy. The radiation induced attenuation has been empirically found to obey the power law RIA= aDb, where D is the total radiation dose and a and b are the constants determined by fitting.

  11. Effects of {gamma} ({sup 60}Co) and {beta} ({sup 90}Sr) radiations in Chinese hamster ovarian cells (CHO-K1): induction of micronuclei and cell death; Efeitos das radiacoes {gamma} ({sup 60}Co) e {beta} ({sup 90}Sr) em celulas de ovario de hamster chines (CHO-K1): inducao de micronucleos e morte celular

    Murakami, Daniella

    2003-07-01

    Among various types of ionising radiation, the beta emitter radionuclides are involved in many sectors of human activity, such as nuclear medicine, nuclear industries and biomedicine, with a consequent increased risk of accidental, occupational or therapeutic exposure. Despite their recognized importance, there is little information about the effect of beta particles at the cellular level when compared to other types of ionizing radiation. Thus, the objective of the present study was to evaluate the genotoxic and cytotoxic effects of {sup 90}Sr, a pure, highly energetic beta source, on CHO-K1 cells and to compare them with data obtained with {sup 60}Co. CHO-K1 cells irradiated with different doses (1.0, 2.5, 5.0, 7.5 Gy) of {sup 60}Co (0.34 Gy.min{sup -1}) and {sup 90}Sr (0.23 Gy.min{sup -1}) were processed for analysis of clonogenic death, induction of micronuclei (MN) and necrotic and apoptotic death. The survival curves obtained for both types of radiation were better fitted by the linear-quadratic model and were similar. However, the cytogenetic results showed that both the proportion of micronucleated cells and the magnitude of radioinduced lesions demonstrated by the analysis of MN distribution were significantly higher in cells irradiated with {sup 60}Co than in cells irradiated with {sup 90}Sr, whereas {sup 90}Sr was more damaging than {sup 60}Co in terms of cell death induction. Necrosis was the major type of death observed in CHO-K1 cells. The data obtained suggest that the low incidence of micronucleated cells after exposure to {sup 90}Sr may be a consequence of selective elimination of severely damaged cells from the population by the necrotic process at a higher rate than observed with {sup 60}Co exposure. The data obtained also demonstrated the need to use several parameters for a better estimate of cellular sensitivity to the action of genotoxic agents, which would be important in terms of radiobiology, oncology and therapeutics. (author)

  12. The effects of 60Co γ-ray irradiation on the cytoskeleton of mouse peritoneal macrophages and human peripheral blood monocytes in vitro

    The whole mount cell electron microscopy in combination with selective extraction method for preparing cytoskeletal framework was applied. Cy toskeleton prepared by Triton X-100 treatment of mouse peritoneal macrophages and human peripheral blood monocytes appeared in electron microscopy as a highly organized and interconnected three-dimensional matrix of different fibrous elements. Since such cytoskeletons are open membrane-free system, individual fibrous organizations can be identified by specific antibodies. An indirect immunogold procedure using monoclonal anti-tubulin or anti-actin antibodies was applied to visualize tubulin-or actin-containing structures. The three-dimensional visualization of Triton X-100 resistant cytoskeletons had been used to demonstrate that different doses of 60Co γ-ray caused a distinctive and reproducible alterations of the cytoskeletons of intact mouse peritoneal macrophages and human peripheral blood monocytes in vitro. The results showed that there were some similar alterations with those caused by cytochalasin B and by colchicine. From these observations and other workers' studies, it's likely that 60Co γ-ray irradiation may inhibit cytoplasmic microtubule and microfilament assembling

  13. Performance of p-bulk microstrip sensors under 60Co γ irradiation at rates expected at the HL-LHC

    Takahashi, Y.; Hara, K.; Kim, S.; Ikegami, Y.; Takubo, Y.; Terada, S.; Unno, Y.; Mitsui, S.; Kamada, S.; Yamamura, K.

    2013-01-01

    We are developing p-bulk microstrip sensors for the high luminosity upgrade of the LHC accelerator, HL-LHC. The stability of FZ (float zone) wafers available to Hamamatsu Photonics was examined by irradiating them at rates expected at the HL-LHC. They show degradation in the operational voltage at low dose but recover after the dose is accumulated. The instability is dependent on the bias voltage and dose rate, and also on the irradiation history. We have characterized the instability and attributed the cause to the charge concentration at the electrode edge. The strip isolation, which is degraded while in irradiation, is shown not to induce any practical problem for the operation.

  14. Preparation and Characterization of Fe3O4 Magnetic Nano-particles by 60Co γ-ray Irradiation

    Mingcheng YANG; Hongyan SONG; Chengshen ZHU; Suqin HE; Ya GAO

    2007-01-01

    By using a new method, 60C0 γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM), respectively. The radiation formation mechanism was also discussed. The results show that the absorbed dose can greatly influence the structure, morphology and magnetic properties of the products. XRD and TEM studies show that the product prepared by γ-ray irradiation (10 kGy) is pure FesO4 phase and the mean diameter of these nano-particles is about 21 nm. The Fe3O4 nano-particles synthesized by γ-ray irradiation (10 kGy) are mainly in small cubic shape and the size uniformity of these particles is good.

  15. Preliminary study on effects of 60Co γ-irradiation on video quality and the image de-noising methods

    There will be variable noises appear on images in video once the play device irradiated by γ-rays, so as to affect the image clarity. In order to eliminate the image noising, the affection mechanism of γ-irradiation on video-play device was studied in this paper and the methods to improve the image quality with both hardware and software were proposed by use of protection program and de-noising algorithm. The experimental results show that the scheme of video de-noising based on hardware and software can improve effectively the PSNR by 87.5 dB. (authors)

  16. Studies on progenitor cell compartments of 60Co irradiated and normal fetuses at 55 days of gestation

    Studies were performed on canine fetal tissues obtained from animals exposed to in vivo chronic irradiation and unexposed controls. CFU-GM, CFU-F and CFU-L assays were done using placental conditioned medium (PCM) or Concanavalin-A (Con-A) as the colony stimulating factor. Preliminary work using medium conditioned with canine spleen cells (SCM) was also begun which indicated that this colony stimulating factor greatly increases the number of colonies observed in both the CFU-GM and CFU-L assays. Chronic irradiation may adversely affect PCM responsive CFU-GM and CFU-F but not Con-A-reactive CFU-L

  17. The use of ionising radiation from 60CO gamma source in controlling mouldiness in dried cocoa beans

    Mouldiness in stored cocoa beans in Ghana and the production of aflatoxin have been studied. Based on actual weight of discarded beans, mouldy beans have been estimated to constitute 0.13 % and 0.00002 % of marketable beans at the farmers' level and the buying agents' depots respectively in the Tafo District. This is contrasted with an estimated value of 0.16 % obtained in a questionnaire type study involving farmers. Estimated mouldy beans at the Tema port was 0.69 % per year (based on the cut test) representing a financial loss of $1,688,637.19 per year at $989/T should the mouldy beans be discarded. Fifty-eight (58) internally- and externally- borne fungal species were isolated from dried cocoa beans. Of these, forty-eight (48) were internally- borne and ten (10) were superficial. Twenty-nine (29) of the internally occurring fungi have been recorded for the first time on cocoa beans in Ghana. Twenty-six (26) of the fungi isolated belong to Aspergillus group. They included A. parasiticus and A. flavus, which can produce aflatoxins. Five (5) belong to Penicillium, eight (8) to Fusarium and nineteen (19) to other species. Ionising radiation effectively controlled fungi associated with mouldiness in cocoa beans in a dose - dependent manner. A radiation dose of 6 kGy completely inactivated the moulds. A. flavus and A. tamarii were the most radiation - resistant moulds encountered. The moisture content of the beans before, during and after irradiation influenced the effect of radiation. The relative humidity during storage and the type of packaging also influenced the radiation effect. Conidia of A. flavus subjected to moist heat at temperatures 20 0C to 60 0C for 2.5, 5 and 10 min respectively were not significantly affected by heating up to 50 0C. Heating an aqueous conidial suspension at 60 0C for at least 2.5 min reduced the number of fungal colonies by at least 5 log cycles when the suspension was assayed on agar plate media. Heating at 59 0C for 10 min

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

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

    1977-01-01

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

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

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

  20. 60Co-gamma radiolysis of the trisoxalato cobalt(III) ions in deoxygenated neutral aqueous solution

    Radiolysis of the trisoxalato cobalt(III) ions in deoxygenated neutral aqueous medium have been undertaken at low and high doses. At low doses, the rate of radiolysis is independent of the concentration of the complex ion in the range 3.24 x 10-3 to 10-2 mol dm-3 and is enhanced by the addition of free oxalate ions. On prolonged irradiation, the rate of degradation gradually increases. Initially H and e-sub(aq) reduces the complex ion, but at later stages, oxalate ion radical C2O4sup(.1-), produced by the interaction of OH radicals with the generated C2O42- ions during the radiolysis, also reduce the [Co(C2O4)3]3- ions. (author)

  1. Comparison of the protective resistance induced by 60Co-irradiated cercariae and schistosomula of the WFFS and NMRI strains of Schistosoma mansoni

    Mice, CBA/HT6T6 and C57BL/10, were vaccinated with 1 x 350 or 1 x 500 Schistosoma mansoni cercariae or schistosomula attenuated with 20 or 56 krad 60Co irradiation and challenged with 200 cercariae. Protective resistance against homologous strain challenge was compared using the Winches Farm Field Station (WFFS) and Naval Medical Research Institute (NMRI) strains of S. mansoni. Maximal resistance to challenge was obtained in both strains of mice with cercariae or schistosomula of either WFFS or NMRI strain attenuated with 20 krad. Protection using organisms attenuated with 56 krad was significantly lower. Since previous studies with the two parasite strains have shown that the biological effects of irradiation are similar, the difference in the immunogenicity of the 56 krad-irradiated NMRI strain in this study from earlier studies must be due either to different local conditions for irradiation or to adaptation of the NMRI strain to a new laboratory environment. This finding may have important implications for vaccination studies and investigations of the mechanisms of immunity where radiation-attenuated parasites are used. (author)

  2. X-ray versus gamma irradiation effects on polymers

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to 60Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties

  3. X-ray versus gamma irradiation effects on polymers

    Croonenborghs, B. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium); Smith, M.A. [Sterigenics International, 10811 Withers Cove Park Drive, Charlotte, NC 28278 (United States); Strain, P. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium)], E-mail: pstrain@eu.sterigenics.com

    2007-11-15

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to {sup 60}Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties.

  4. X-ray versus gamma irradiation effects on polymers

    Croonenborghs, B.; Smith, M. A.; Strain, P.

    2007-11-01

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to 60Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties.

  5. Licensing of a Type B(U) package design for the transport of industrial 60Co sealed sources and the use as irradiator facility in Argentina

    This paper points out the relevant regulatory issues related to the licensing process of a Type B(U) package design, EMI-9 model, approved for the transport and the use as irradiator facility. The radioactive contents is 60Co sealed sources of up to 2,96 PBq, as a special form radioactive material for industrial use. The correspondent Approval Certificate was issued by the Nuclear Regulatory Authority of Argentina in accordance with the Regulatory Standard AR 10.16.1 that is coincident with the 1985 Edition (As Amended 1990) of the IAEA Regulations. It is described the most significant activities performed during the licensing process as well as brief comments are made on the experience gained from previous Type B(U) package design developments. (author)

  6. 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.

  7. 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.)

  8. Influence of rhTPO/GM-CSF fusion protein on hemopoiesis in mice irradiated with 60Co γ-rays

    Objective: To find a new biological therapy for secondary hematopoietic failure including anemia, infection and hemorrhage after administration of chemotherapeutic drugs etc. Methods: hGM-CSF gene was ligated with hTPO gene isolated from human fetal liver mRNA and a new fusion protein rh TPO/GM-CSF obtained. Results: The new fusion protein could promote recovery of peripheral WBC and PLT of 5.0 Gy irradiated mice. BFU-E, CFU-Meg and CFU-GM in bone marrow of mice after irradiation recovered significantly by treatment with rhTPO/GM-CSF fusion protein for 10 days. Conclusion: These results suggest that the new fusion protein has the biological activity of both hTPO and hGM-CSF simultaneously and can stimulate the proliferation of megakaryocytes and granulocyte progenitors

  9. Effects of 60CoIrradiation Intensity on Watermelon Seed Germination and Seedling Growth%60Co-γ辐射对西瓜种子萌发和幼苗生长的效应

    李玉明; 杨世梅; 纪海波; 方春媛; 潘从祥; 陈年来

    2013-01-01

    In order to investigate the effects of different doses of 60Co-γ radiation on watermelon seed germination and seedling growth, watermelon seeds with different qualities of 12 varieties were used as the test materials to investigate the effects of six different doses of radiation on emergence rate, surviving rate, emergence time, cotyledon area, plant height and stem diameter. The results showed that medium size seeds of watermelon demonstrated a promoting effect on seedling growth under the dose of 200 Gy and 400 Gy. When the radiation dose exceed 600 Gy, all watermelon seeds showed the extremely significant level (P small seed > medium seeds.%为了探讨60Co-γ辐射剂量对不同质量西瓜种子萌发和幼苗生长的影响,以不同质量的12个西瓜品种干种子为材料,通过6个剂量的辐射处理,研究辐射剂量对西瓜干种子出苗率、存活率、出苗时间、子叶面积、株高及茎粗等的影响.结果表明,200和400 Gy辐射对中等种子出苗有促进作用,超过600 Gy都具有显著(P<0.05)抑制作用;随着辐射剂量的增加,植株出苗时间延长,幼苗生长缓慢;根据半致死剂量确定西瓜种子适宜辐射剂量为600~800 Gy.不同大小西瓜种子对60Co-γ辐射的敏感性表现为大种子>小种子>中等种子.

  10. 60Co γ-ray irradiation effect on germination and seedling growth of dry Buchloe dactyloides seeds

    The dry seeds of Buchloe dactyloides were irradiated by γ-ray at dose of 25-300 Gy. Seed germination and seedling characters were surveyed in laboratory and field. The results indicated that radiation could promote seed germination, and the optimum dose was 100 Gy. The dose of 150 Gy was the up limit to germination rate, root length and seedling height in field. When the radiation dose was bellow 100 Gy, the fresh weight of stems, leaves and roots of seedlings were increased. From this study, the recommended radiation does for Buchloe dactyloides dry seeds treatment was between 100-150 Gy for the purpose of promoting germination. (authors)

  11. Effect of physical exercise on the state of the heart and central hemodynamics in dogs exposed to external (60Co) and internal (239PuO2) irradiation

    Experiments were conducted on mongrel dogs aged 2 to 4 with the body mass of 15.1 ± 0.9 kg. The animals were exposed to combined and isolated γ-irradiation at a dose of 51.6 mC/kg and submicron 239PuO2 in the amount not less than 7 kBq/kg. Single circular irradiation was provided from 60Co γ-sources at a dose rate of 1.03-1.3 mA/kg. 239PuO2 was inhaled 6 days after irradiation. 20 min. running on a tredbahn with the speed of 4.7 km/h served as a physical exercise model. The dogs were examined 0.5, 1, 1.5 and 4 yrs. after the initiation of the experiment at rest and within 1 h after physical exercise. Methods of tetrapolar chest rheography and electrocardiography were employed. It was shown that in the combined effect of two radiation factors the rates of increase in the cardiac index were inhibited at the expense of physical exercise influence as compared to those in the isolated radionuclide effect and resulted from less ''economical'' heart action

  12. DOMI: mutant of tomato of double purpose obtained by means of the induction of mutations with rays gamma of 60Co

    DOMI is a tomato mutant obtained at the National Institute of Agricultural Sciences (INCA) after irradiating seeds from Amalia variety with 500 Gy gamma rays. This variety has a high productive potential and an appropriate quality for fresh consumption and industrial purposes

  13. A comparison of the 60Co gamma radiation hardness, breakdown characteristics and the effect of SiN x capping on InAlN and AlGaN HEMTs for space applications

    Smith, M. D.; O'Mahony, D.; Vitobello, F.; Muschitiello, M.; Costantino, A.; Barnes, A. R.; Parbrook, P. J.

    2016-02-01

    Electrical performance and stability of InAlN and AlGaN high electron mobility transistors (HEMTs) subjected 9.1 mrad of 60Co gamma radiation and off-state voltage step-stressing until breakdown are reported. Comparison with commercially available production-level AlGaN HEMT devices, which showed negligible drift in DC performance throughout all experiments, suggests degradation mechanisms must be managed and suppressed through development of advanced epitaxial and surface passivation techniques in order to fully exploit the robustness of the III-nitride material system. Of the research level devices without dielectric layer surface capping, InAlN HEMTs exhibited the greater stability compared with AlGaN under off-state bias stressing and gamma irradiation in terms of their DC characteristics, although AlGaN HEMTs had significantly higher breakdown voltages. The effect of plasma-enhanced chemical vapour deposition SiN x surface capping is explored, highlighting the sensitivity of InAlN HEMT performance to surface passivation techniques. InAlN-SiN x HEMTs suffered more from trap related degradation than AlGaN-SiN x devices in terms of radiation hardness and step-stress characteristics, attributed to an increased capturing of carriers in traps at the InAlN/SiN x interface.

  14. The effect of vitamin A on CD4+ and CD8+ cells irradiated by 60Co γ-ray

    The monocyte-depleted peripheral blood mononuclear cells were separated into CD4+ and CD8+ subpopulations by panning technique with McAb CD4 and CD8. The purity of CD4+ and CD8+ cells was 89.2% and 85.8% respectively, which was estimated by an indirect immunofluorescence technique. The radiosensitivities of CD4+ and CD8+ cells and the effect of DNA synthesis in both cells' subpopulations influenced by Vit A were assessed by 3H-TdR incorporation. The experimental result showed that after γ-radiation in different doses on CD4+ and CD8+ cells, the 3H-TdR incorporation was significantly decreased. The 3H-TdR incorporation rate in CD8+ cells irradiated with addition of 5 μg/ml Vit A increased significantly (p<0.05)

  15. Utilization of an elite rice germplasm-Yangdao 6 with high combining ability created by 60Co γ-irradiation

    Yangdao 6, a new rice variety bred by irradiation induced mutation, is an elite Indica germplasm with a higher general combining ability (GCA) and specific combining ability (SCA) compared with other restorer lines in yield composing traits, including total grains per panicle, filling grains per panicle, seed setting, 1000-grain weight, grain plumpness, yield per plant, etc. Used as a parent with high yield, good quality and multi-resistance, it has a good probability for breeding super-high-yield hybrid combinations both for the 'two-line' and Honglian-type CMS lines. And as a restorer line, it accelerates both the breeding of hybrid combinations and routine cultivars with a mode of 'boat goes up as river rises'. (authors)

  16. Seeds of Camargue rice (Oryza Sativa L. Var Cigalon) and their responses to exposure to 60-Co gamma radiations. Study of the natural phenomenon of radiation protection

    Within the frame of a project aiming at improving a technique of experimental mutagenesis (seed processing by cobalt-60 gamma rays), this research thesis reports the radiobiological characterization of Cigalon rice seeds, the adjustment of techniques of radiation protection, and the definition of processing and irradiation conditions which could reduce the undesirable physiological effects of cobalt-60 gamma radiation on rice seeds. The author reports the study of variations of physiological radio-sensitivity. Damages are assessed by comparing the growth of irradiated seeds with that of non-irradiated seeds. The mechanism of radiation natural protection is studied by comparing an inhibition in distilled water at two temperatures (5 and 24 C) with that obtained with cysteamine (an efficient radiation protection compound)

  17. Effects of Pre-exposure Mouse Pituitary with Low-dose 60Co γ-ray on Growth Hormone (GH) and Body Mass Induced by Subsequent High-dose Irradiation

    ZhangHong; LiWenjian; JingXiaodong; LiuBing; MinFengling; ZhouQingming; XieYi

    2003-01-01

    The pituitary of the B6C3F1 hybrid strain mice were irradiated with 0.05 Gy of 60Co γ-ray as the pre-exposure dose (D1), and were then irradiated with 2 Gy of 60Co γ-ray as challenging irradiation dose (D2) at 4h after per-exposure. Body weight and serum growth hormone (GH) were measured at 35th day after irradiation. The results showed that irradiation of mouse testes with 2 Gy of 60Co γ-ray significantly diminished mousebody weight and level of serum GH (Table). Pre-exposure with a low-dose (0.05 Gy) of 60Co γ-ray significantly alleviated reductions of mouse body weight and level of serum GH induced by subsequent a high-dose (2 Gy) irradiation (Table). The data suggested that low-dose ionizing irradiation can induce adaptive responses to the harmful effects of pituitary by subsequent high-dose exposure.

  18. The influence of α-amylase supplementation, γ-irradiation (60Co) as well as long time of storage of wheat grain on flour technological properties

    The varieties of winter wheat, Aria and Beta, were studied. The Aria variety was stored for the period of four years. The part of wheat grain from Beta variety was irradiated with γ rays (60Co). In extracts from wheat kernels and flour protein content, total α- and β-amylolytic activity as well as α-amylolytic activity were determined, α-amylases of native and fungal origin were added to the flour obtained from samples of stored wheat kernels (Aria), irradiated and non-irradiated (Beta). Consequently native α-amylase activity of flour increased by 25% and 50%, respectively. Extensive technological estimation of grain and flour with amylase supplements was carried out. The study included: sedimentation analysis, falling number test, milling experiment, farinogram and extensogram analyses, measurement of the degree of damaged starch and flour colour, as well as baking experiment. The obtained experimental loaves of bread were tested for their ability to remain fresh. It was found out that the stored grain flour was characterized by the highest α-amylolytic activity and the lowest falling number value, whereas the irradiated grain flour showed the highest degree of starch damage and water absorption. When α-amylase supplementation to doughs was not accompanied by either irradiation or storage of grain, it definitely changed their physical properties for the worse. The negative influence of native α-amylases appeared to be less significant than that of fungal α-amylases. The positive influence of α-amylase supplementations, especially of those increasing by 25% the native α-amylolytic activity of flour on volume, and freshness of loaves of bread was observed. (author)

  19. Change in the amino acid composition of calf skin collagen after. gamma. -irradiation in aqueous solution

    Duzhenkova, N.A.; Savich, A.V. (Institut Biofiziki, Moscow (USSR))

    A study was made of the amino acid composition of calf skin collagen after ..gamma..-irradiation (/sup 60/Co) of 2.5x10/sup -6/ M aerated aqueous protein solution within the dose range from 30 to 2000 Gy. The radiosensitivity of amino acid residues was compared.

  20. Effect of gamma irradiation on ethylene-octene copolymers

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

  1. 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)

  2. Carcinogenic effect of in utero 252Cf and 60Co irradiation in C57BL/6N x C3H/He F1 (B6C3F1) mice

    C57BL/6N x C3H/He F1 mice were exposed in utero to 0, 1.0 and 2.7 Gy of 252Cf or 60Co at day 16.5th of gestation. Mice of both sexes were observed for 2 years. The females in the irradiated groups showed increases in the incidences of pituitary, mammary gland, liver and lung tumors. 252Cf was more effective in inducing tumors than was 60Co. Interestingly, the incidence of hematopoietic tumors decreased by irradiations with 252Cf but not with 60Co. The incidences of liver tumors in males increased by 252Cf-irradiation, whereas, the incidences of skin and soft tissue tumors increased by 60Co-irradiation. These results indicate that irradiation in utero during the late embryonic stage can induce tumors postnatally after a long latency. Moreover, females irradiated in utero had disfunction of the ovaries, evidence of impairment of the female's specific hormonal environment. This may be the cause of the low incidence of ovarian tumors and the high incidences of liver, lung and pituitary tumors in these female mice. Females with pituitary tumors had a high serum prolactin, which might be responsible for the concurrence of mammary gland tumors. These results indicate the importance of host factors in the development of radiation-induced tumors. (author)

  3. 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)

  4. 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)

  5. Damage to plasmid DNA produced by 60Co-gamma radiation and subsequent repair processes in E. coli with and without SOS induction

    This study was carried out to provide information on the question as to whether radiation-induced separation of double-stranded DNA in E. coli is followed by repair processes leading to the formation of replicable material. For the detection of those double-strand breaks, E. coli was first transformed using enzymatically linearised dBR 322-DNA. This served as a reference standard to compare the transformations using radiated DNA. DNA was either exposed to increasing doses of 60Co-gamma radiation or separated into one oc-fraction and one lin-fraction following exposure to 30 Gy. The DNA samples thus obtained were then used to transform three different strains of E. coli (wild strain, SFX, SFXrecA-). In order to improve the repair yield, the cells were additionally SOS-induced using ultraviolet radiation. The mutation rates were a measure of the number of errors occurring during the various repair processes. Restriction analysis was carried out to characterise the resulting mutants in greater detail. (orig./MG)

  6. Effect of dose fractionation of 60Co gamma radiation on longevity and reproduction of Sitophilus granarius (L., 1785) (Col., Curculionidae) in wheat

    The effects of fractionated doses of gamma radiation in different interval of time on longevity and reproductivity of Sitophilus granarius (L., 1785) are studied. Gamma radiation was provided at dose rate of 1.56 kGy/hour by a Cobalt 60 source (Gammabeam-650). The insects were divided in two sets: one was irradiated at acute doses and the other in fractionated doses, with interval of 48 hours. Both sets received doses of 0,40, 50, 60, 70, 80, 90 and 100Gy. Mortality and and emergency were determined weekly. (M.A.C.)

  7. Irradiation dose and effect on germination and growth of desert shrub Nitraria tangutorum Bobr. with two gamma irradiation modes

    The seeds of Nitraria tangutorum were exposed to different doses of gamma radiation from 60Co gamma rays based on the two irradiation modes of without dose rate and with dose rate of 25Gy/hr. The effects of different irradiation modes and irradiation dose on the seed germination rate, emerged seedling rate and phenotypic characters of seedling have been studied. The semi-lethal dose and critical dose were determined for different irradiation mode. It has been found that there were the differences of irradiation effects between the two irradiation modes. Promotion effect on the seed germination rate, emerged seedling rate, seedling height and ground diameter in lower dose treatment were observed, while inhibition in higher dose. As compared to control, the irradiation effects on the seed germination rate and seedling height and ground diameter present the very remarkable differences at above 15000y dose without dose rate mode, while above 2400Gy with dose rate mode. The negative relativity exists between the relative emerged seedling rate and irradiation dose, the emerged seedling rate decreased with increasing dose. The semi-lethal dose based on the emerged seedling rate was 985Gy and 1363Gy for the irradiation without dose rate and with 25Gy/hr dose rate, respectively. The Appropriate 60Co gamma irradiation dose for the Nitraria tangutorum seeds was ranging from 950Gy to 1500Gy without dose rate irradiation mode, while 1300Gy to 2400Gy with 25Gy/hr dose rate mode

  8. DOSKMF2 - a contribution to the computer-aided evaluation of radiation fields in gamma irradiation plants

    The performance of the computer programs DOSKMF2 and ISORADL written for the computation of radiation fields in 60Co-gamma irradiation plants has been assessed. The programs are applicable to irradiation plants in operation and for computer-aided design of parts of those plants

  9. Gamma irradiators for radiation processing

    Radiation technology is one of the most important fields which the IAEA supports and promotes, and has several programmes that facilitate its use in the developing Member States. In view of this mandate, this Booklet on 'Gamma Irradiators for Radiation Processing' is prepared which describes variety of gamma irradiators that can be used for radiation processing applications. It is intended to present description of general principles of design and operation of the gamma irradiators available currently for industrial use. It aims at providing information to industrial end users to familiarise them with the technology, with the hope that the information contained here would assist them in selecting the most optimum irradiator for their needs. Correct selection affects not only the ease of operation but also yields higher efficiency, and thus improved economy. The Booklet is also intended for promoting radiation processing in general to governments and general public

  10. Quality comparison between gamma-irradiated and E-beam irradiated pork patties

    This study compared the effects of gamma and electron beam (e-beam) irradiation on the quality of pork patties. Pork patties (diameter: 100 mm, thickness: 10 mm) were vacuum-packaged and irradiated by gamma ray (60Co with a 490 kCi source) and e-beam (2.5 MeV) at five, ten, 15, and 20 kGy at room temperature. During accelerated storage at 30 deg C for 10 d, determination of total bacterial populations, hardness, and sensory evaluation was conducted at appropriate sampling intervals. The results of total bacterial populations showed that the gamma-irradiated (GR) samples had lower (P < 0.05) total bacterial counts than e-beam-irradiated (EB) samples during storage at 30 deg C for 10 d, regardless of irradiation dose. The hardness and sensory properties such as colour, chewiness, taste, and overall acceptability of pork patties were decreased depending upon irradiation dose. GR samples had lower hardness and sensory scores than those of EB samples. In conclusion, gamma irradiation on pork patties should be useful in decreasing bacterial populations when compared with e-beam irradiation. However, further studies should be conducted to reduce the quality deterioration of GR pork patties. (author)

  11. Gemstone dedicated gamma irradiation development

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  12. Gemstone dedicated gamma irradiation development

    Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

    2007-07-01

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  13. Influence of 60Co γ-ray irradiation and applied bias voltages on dielectric properties of Al/SiO2/p-Si (MIS) structures

    The MIS structures were exposed to 60Co γ-ray source at 5 kGy and radiation effect on dielectric properties has been investigated using admittance method (C-V and G/ω-V) by applying a small ac signal of 40 mV amplitude at 1 MHz and room temperature. The voltage dependent dielectric constant (ε'), dielectric loss (ε''), loss tangent (tanδ), electric modulus(M*) and ac electrical conductivity (σac) profiles show an intersection behavior about 1.6 V. The ε', ε'', tanδ and σac values decrease with increasing dose before intersection point after than they become increase. Such behavior can be explained on the basis of Maxwell-Wagner interfacial polarization and restructuring and reordering of interface states charges due to the effect of γ-ray irradiation. Also, the imaginer part of M* exhibits a peak. It is concluded that all these parameters of MIS structure are strongly dependent on the radiation dose and applied bias voltage especially in depletion region.

  14. 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.

  15. 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

  16. Differential radio-sensitivities of human chromosomes 1 and 2 in one donor in interphase- and metaphase-spreads after 60Co γ-irradiation

    Radiation-induced chromosome aberrations lead to a plethora of detrimental effects at cellular level. Chromosome aberrations provide broad spectrum of information ranging from probability of malignant transformation to assessment of absorbed dose. Studies mapping differences in radiation sensitivities between human chromosomes are seldom undertaken. Consequently, health risk assessment based on radio-sensitivities of individual chromosomes may be erroneous. Our efforts in this article, attempt to demonstrate differences in radio-sensitivities of human chromosome-1 and/or -2, both in interphase and metaphase spreads. Upon blood collection, dosimetry and irradiation were performed. Lymphocytes were isolated after whole-blood irradiation with 60Co γ-rays in the dose range of 0–5 Gy for both interphase, and metaphase aberration studies. Induction of premature chromosome condensation in interphase cells was accomplished using a phosphatase inhibitor, calyculin-A. Metaphase spreads were harvested from short-term peripheral blood lymphocyte cultures following colcemid arrest and using an automated metaphase harvester and spreader. Aberration analysis in both interphase and metaphase spreads were done using FISH. In interphase, aberrant cell and aberration frequency involving chromosome 1 and/or 2 increased linearly with radiation dose. In metaphase, aberrations increased in a linear-quadratic manner with dose. Our studies ascertain that chromosome-2 is more radio-sensitive than chromosome-1 in both interphase and metaphase stages, albeit the DNA content of chromosome-2 is lesser than chromosome-1 by almost 10 million base pairs. Differences in radio-sensitivities of chromosomes have implications in genetic damage, chromosome organization, and chromosome function. Designing research experiments based on our vital findings may bring benefit to radiation-induced risk assessment, therapeutics and development of chromosome specific biomarkers

  17. Low dose gamma irradiation has no effect on the functionality of fish proteins

    Indian mackerel in ice was gamma irradiated to 1.5 and 3.0 kGy using 60Co source. Washed meat from the treated fish was homogenised in cold water and the viscosity and solubility characteristics of the homogenates were measured with respect to protein concentration, pH and temperature. Irradiation did not cause significant alterations in viscosity and solubility characteristics of the proteins. (author)

  18. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60Co γ radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 μg/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400μ/ml) in PC3 cells irradiated with 5 Gγ. The survival curves obtained were adequately fitted by a linear-quadratic model, where the α coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 μg/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data obtained in vitro showed a

  19. Effect of 60Co γ-ray Irradiation on Growth Characteristics of Chamaecrista%60Co-γ射线辐照处理对决明若干生长特性的影响

    翁伯琦; 徐国忠; 郑向丽; 应朝阳; 黄毅斌

    2005-01-01

    利用60℃o-γ射线(辐照剂量为300 Gy,剂量率为4.687 5 Gy/min)辐照豆科决明属5个牧草品种的种子,通过盆栽收集各个品种的M1代种子,然后进行M2代试验与观察.结果表明,辐照后5个决明M2代的种子出苗率、植株的茎长、叶宽均无显著差异;34721号决明植株冠高有显著增长、2219号决明茎径有显著增长、86134号决明分枝数有极显著增长,92985号决明分枝数则有显著降低、86134号决明叶数和地上部植株干重有显著增长、2219号决明叶长增长显著,其余参试品种则无显著差异.植株的营养成分测定表明:仅2219号决明K含量呈显著下降、其他品种的N,P,K含量则无显著差异;2219不仅氨基酸总量呈显著下降、而且17种氨基酸都表现为不同程度的下降,86134氨基酸总量有显著增长、同时17种氨基酸都表现为不同程度的增长,而其余3个参试品种都无显著差异.经60Co-γ射线辐照处理后的34721,86134,92985的酯酶同工酶谱与相应的对照有明显差别.生长观察结果表明,参试的5个决明品种M2代植株生长的现蕾期、初花期、盛花期、初荚期、盛荚期、成熟期表现为双向性,既有提早,也有推迟.

  20. Gamma irradiation service in Mexico

    In 1980 it was installed in Mexico, on the National Institute of Nuclear Research, an irradiator model J S-6500 of a canadian manufacture. Actually, this is the greatest plant in the Mexican Republic that offers a gamma irradiation process at commercial level to diverse industries. However, seeing that the demand for sterilize those products were not so much as the irradiation capacity it was opted by the incursion in other types of products. During 17 years had been irradiated a great variety of products grouped of the following form: dehydrated foods, disposable products for medical use, cosmetics, medicaments, various. Nowadays the capacity of the irradiator is saturated virtue of it is operated the 24 hours during the 365 days of the year and only its operation is suspended by the preventive and corrective maintenance. However, the fresh food market does not be attended since this irradiator was designed for doses greater than 10 kGy (1.0 Mrad)

  1. 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...

  2. Properties of Pulsed Photostimulated Luminescence and Thermoluminescence for Detection of Gamma-Irradiated Teas during Storage

    Green, black and oolong teas were irradiated by @@€@@60Co-gamma rays (0~10 kGy) and were investigated for detection of irradiation treatment using pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL) during storage. Teas irradiated at 2.5 kGy or more showed a photon count of greater than 5000 counts/60 sec while the non-irradiated yielded only 650~1000 count/60 sec. Correlation coefficients between irradiation dose and photon counts/60 sec were 0.8951, 0.7934 and 0.9007 for green, black and oolong teas, respectively

  3. Effect of 60Co radiation on peritoneal cells

    This work deals with the effect of 60Co gamma irradiation on the levels and quality of peritoneal cells of albino mice. The cells were obtained from peritoneal exudate, fixed and stained in 30% glacial acetic acid containing 0,5% cristal violet. Os exudates from irradiated and control animals the qualitative analysis and the counting of different cell populations were performed one hour, three days and six days after irradiation with 9 Gy. All the cell populations from the peritoneal exudate shown a decrease 3 days after the irradiation with 9.0. Gy but the different cellular populations dimished in unlike proportions. The data reaffirm the discrepance in radiosensivity of the diverse peritoneal cell populations. (author)

  4. Gamma irradiation treatment of cereal grains for chick diets

    Wheat (W), triticale (T), hulled barley (HB), hull-less barley (HLB), hulled oats (HO), and hull-less oats (HLO) were gamma irradiated (60Co) at 0, 3, 6 and 9 Mrad to study the effect of irradiation on the nutritional value of cereal grains for chicks. A significant curvilinear relationship between radiation dose and 3-wk body weight of chicks fed irradiated cereals was noted for T, HB, HLB, HO and HLO. Chicks fed W or T showed no effect or lower body weight, respectively, while body weights of chicks fed barley or oat samples were higher with irradiation. The improvement tended to be maximal at the 6 Mrad level. Irradiation significantly improved the gain-to-feed ratio for chicks fed either HO or HLO. Apparent fat retention and tibia ash were higher in chicks fed irradiated HLO than in those fed untreated HLO. In a second experiment chick body weight, apparent amino acid and fat retention, tibia ash, and gain-to-feed ratios were lower in chicks fed autoclaved (121 degrees C for 20 min) barley than in those fed untreated barley. Irradiation (6 Mrad) subsequent to autoclaving barley samples eliminated these effects. Irradiation appears to benefit cereals containing soluble or mucilagenous fiber types as typified by beta-glucan of barley and oats. These fibers appear prone to irradiation-induced depolymerization, as suggested by increased beta-glucan solubility and reduced extract viscosity for irradiated barley and oat samples

  5. Gamma Irradiation of Polyesters Film

    Experimental investigations on the effects of gamma irradiation in air of aromatic polyesters are carried out, in order to evaluate the influence of aromatic density and the role of oxygen on the radiation resistance. The thermoplastic polyesters PolyEthyleneTerephthalate (PET), PolyButylene Terephthalate (PBT), PolyEthyleneNaphthalate (PEN), Poly1,4-cyclohexanedimethylen terephthalate-co-ethyleneterephthalate (PCT-co-ET) are moulded in thin films of 50 micron and irradiated at different absorbed doses, ranging from 0 to 1000 kGy, using a Co-60 gamma source. The structural changes in the polymers are studied by means of several physical-chemical and nuclear techniques. Electron Paramagnetic Resonance analyses are carried out to detect the radicals induced by irradiation and to follow their decay by oxygen permeation. Viscometric measurements show a similar trend for the different irradiated polyesters: in particular, chain scission induced by irradiation depends on the aromatic density contained in the polymer and shows a saturation effect at the highest doses. Positron Annihilation Lifetime Spectroscopy points out a decrease of the ortho-positronium signal caused by the production of oxidized species inhibiting the positronium formation. Finally, the experimental results obtained on the irradiated films are compared with previous studies carried out on the same polyesters moulded in sheets of 1-2 mm of thickness and γ-irradiated at the same adsorbed doses

  6. Gamma-irradiation of tomatoes

    The influence of gamma-ray on tomatoes picked in a pink-red ripening stage, good for consumption, is studied. For that purpose tomatoes of ''Pioneer 2'' variety packed in perforated 500 g plastic bags were irradiated on a gamma device (Cobalt-60) at a dose power of 1900 rad/min with doses 200 or 300 krad. Samples were stored after irradiation at room temperature (20 - 22sup(o)C). Microbiological studies demonstrated that 44 resp. 99.96 per cent of the initial number of microorganisms was destroyed after irradiation with 200 resp. 300 krad. The time required for the number of microorganisms to be restored was accordingly increased. Irradiation delayed tomato ripening by 4 to 6 days, demonstrable by the reduced content of the basic staining substances - carotene and licopine. Immediately after irradiation the ascorbic acid content was reduced by an average of 13 per cent. After 18 days the amount of ascorbic acid in irradiated tomatoes was increased to a higher than the starting level, this is attributed to reductone formation during irradiation. The elevated total sugar content shown to be invert sugar was due to further tomato ripening. (Ch.K.)

  7. Effect of gamma radiation from {sup 60}C in conservation and quality of pepper fresh and pulp; Efeito da radiacao gama do {sup 60}Co na conservacao e qualidade de pimenta in natura e em polpa

    Milagres, Regina Celia Rodrigues de Miranda

    2014-07-01

    Capsicum peppers are among the most used and most valued seasoning spices in the world. They are highly susceptible to post harvest decay, therefore the use of irradiation may contribute to conservation of this fruit which has significant nutritional, economic and social value. Were evaluated the effects of gamma radiation of {sup 60}Co in increasing the shelf-life and preservation of quality of pepper 'Dedo-de-moca' (Capsicum baccatum var. Pendulum) fresh and pulp associated or not with another conservation methods. Gamma radiation doses were investigated of 0,25; 0,50; 0,75; 1,00; 1,25; 1,50; 2,00 e 3,00 kGy in fresh fruit and 1,50; 2,00; 3,00; 4,50 e 6,00 kGy in pepper pulp. The use of laboratory pasteurization (85°C/3min), the addition of citric acid (5%) and 5% NaCl were also investigated in the pepper pulp. The samples were stored at 5 °C and or 25 °C. Were performed analysis: visual (disease incidence, turgidity and color); bioactive compounds (carotenoids, capsaicinoids, antioxidant capacity and phenolic compounds); physicochemical (Weight loss, firmness, soluble solids (SS), pH, titratable acidity (TA), ratio, color and moisture); respiratory rate and ethylene production; proximate composition (moisture, soluble and insoluble fiber, ash, protein, ether extract, total and available carbohydrate); microbiological contamination (mesophilic aerobic microorganisms, coliforms at 45 °C, Salmonella spp. and yeasts and molds) and sensory (acceptance test, difference test and paired preference). Radiation doses between 0.25 and 3.00 kGy were not effective to increase shelf-life and maintain fresh pepper quality during storage. There was increased intensity of red color, of incidence of disease, decreased turgidity and changes in physical, chemical and nutritional parameters. In pulp, the doses of gamma radiation of 4.50 and 6.00 kGy and the addition of 5% NaCl no changing sensory attributes, physical-chemical and bioactive compounds. Only the

  8. 6Co γ射线诱发小鼠DNA甲基化改变%DNA methylation changes induced by 60 Co γ-ray irradiation

    黄铖铖; 孙秀锦; 胡明江; 程跃进; 古桂雄; 崔凤梅

    2011-01-01

    Objective To study the change and significance of DNA methylation pattern and DNA methyltransferase (DNMT1) protein in 60Co γ-ray irradiated mice tissues. Methods Twelve SPF C57BL/6J mice were randomly divided in-tocontrol group and radiation group. The radiation group were exposed to 4Gy-single whole body radiation. All mice were sacrificed 3 days after the radiation. The total number of peripheral white blood cells and the frequencies of micronucleated polychromatic erythocytes(fMNPCE) were measured. Methylated DNA immunoprecipitation-chip(MeDIP-chip) was adopted to investigate the differentially expressed CpG islands methylation profiles in mouse liver genome promoter. The immunohisto-chemical(SP method) and western blot method were used to check the expression of DNMT1 protein in tissues. Results Compared with the control group,the promoter methylation profiles of irradiated mice changed obviously, with 1300 genes methylated and 660 genes demethylated. With the improvement of the screening criteria,the obviously methylated genes were Trim71,Sema3f, Pcdh8,Sox4,1110034A24Rik, Limkl, Nefl, and Xprl and the demethylated genes were Sfrsl8,Drl, Ankrd42,Nael ,Sfil ,Accnl ,Srd5al ,Nsun2,Eifla,and Dusp5. Except in the lung,the expression of DNMT1 protein in liver, kidney, testicle, and brain tissues were all increased (P < 0.05). Conclusion There are methylation changes of gene promoter in ionizing radiation injury and the increased expression of DNMT1 may be the reason of gene promoter methylation.%目的 探讨基因组启动子甲基化谱及DNA甲基化酶1(DNMT1)表达量在60Co-γ射线照射小鼠各组织的变化及其意义.方法SPF级C57BL/6J雄性小鼠12只随机分为对照组和照射组,照射组小鼠接受4Gy60 Co-y射线单次全身照射后,均眼球摘除取血后处死,收集各脏器组织,进行外周血白细胞计数和骨髓嗜多染红细胞微核计数,应用甲基化DNA免疫沉淀-芯片(MeDIP-chip)杂交技术对y射线

  9. Gamma irradiation of fruits

    At a Joint FAO/IAEA/WHO Expert Committee on Food Irradiation (JECFI) meeting held in 1976, recommendations were made to rationalize the unnecessarily elaborate wholesomeness evaluation procedures for irradiated foodstuffs. Irradiation at the commercially recommended doses did not adversely affect the constituents of mangoes, papayas, litchis and strawberries at the edible-ripe stage. These favourable radiation-chemical results justified the development of a theoretical model mango which could be used for extrapolation of wholesomeness data from an individual fruit species to all others within the same diet class. Several mathematical models of varying orders of sophistication were evolved. In all of them, it was assumed that the radiant energy entering the system reacted solely with water. The extent of the reaction of the other components of the model fruit with the primary water radicals was then determined. No matter which mathematical treatment was employed, it was concluded that the only components which would undergo significant modification would be the sugars. In order to extrapolate these data from the mango to other fruits, mathematical models of three fruits containing less sugar than the mango, viz. the strawberry, tomato and lemon, were compiled. With these models, the conclusion was reached that the theoretical degradation spectra of these fruits were qualitatively similar to the degradation pattern of the model mango. Theory was again substantiated by the practical demonstration of the protective effect of the sugars in the tomato and lemon. The decrease in radiation damage was enhanced by the mutual protection of the components of the whole synthetic fruits with ultimate protection being afforded by the biological systems of the real fruits

  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. On enzyme kinetic parameters modification of gamma irradiation

    To elucidate the molecular mechanisms of gamma-ray action on biomolecules there were investigated the modifications in activity and other kinetic parameters for some enzymes irradiated in pure dry state at relative high doses. There were considered bacterial and fungal α-amylases, glucoamylase and Mucor sp. protease irradiated by a 60 Co gamma-ray source in the dose range 1.0-30.0 kGy, at different dose-rates between 0.5-2.0 kGy/h, at room temperature. Considering the enzyme inactivation in this dose range, the dose-effect relationships have an expected form and depend on the irradiation conditions but not significantly on the dose rate. The catalytic properties of enzymes were modified by irradiation. By usual methods it is evidenced a direct correlation between the enzymatic activities, Michaelis-Menten constant, Km, reaction velocities, v, and the irradiation dose. These experimental findings can support a self-consistent theoretical approach on biophysical radiation action on biological active molecules like enzymes. At the same time, some enzyme behaviour to irradiation could be considered like a good biological indicator of radiation response. (Author) 4 Figs., 19 Refs

  12. Food irradiation: Gamma processing facilities

    Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

    1997-12-31

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  13. Food irradiation: Gamma processing facilities

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  14. The influence of {sup 60}Co gamma radiation on the action of phenolic compounds Anadenanthera colubrina (Vell.) Brenan in the microbiological control of crude extracts

    Santos, Gustavo Henrique F. dos; Silva, Edvane B. da, E-mail: santosghf@hotmail.co [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR); Sena, Kesia Xisto da Fonseca R. de; Silva, Bruna L., E-mail: kxfrs@bol.com.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Antibioticos; Lima, Claudia S. de A., E-mail: claudia.salima@gmail.co [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    2009-07-01

    Anadenanthera colubrina (Vell.) Brenan, known popularly as angico is a tree founded in northeastern of Brazil, and has great economic and ecological interest. These trees are characterized by high levels of tannins. To evaluate the influence of gamma radiation in plant extracts of barks and leaves of angico, we got extracts of barks and leaves in 70% ethanol, which was filtered and evaporated until dryness. It were classified in four groups (non-irradiated, 5; 7.5 and 10 kGy). The total phenols were quantified by Folin-Ciocalteau method, and the tannins, using the precipitation of casein. The antimicrobial activity of extracts was observed using the paper disk diffusion methods against Gram-positive, Gram-negative, acid-alcohol-resistant bacteria: and yeasts. The halos greater than 10 mm were considered actives. It was also performed the Minimal Inhibitory Concentration (MIC) using Gram positive and alcohol-acid resistant bacteria. The results showed that tannins of A. colubrina, were 52 to 57% of total phenols, and leaves, 58 to 60%. The percentage of total phenols and tannins in the barks and leaves of A. colubrina have not statistically significant change when compared with the irradiated control. These results suggest that A. colubrina has antimicrobial activity against the Gram-positive and alcohol-acid -resistant bacteria, confirmed by MIC. The extracts of leaves it was additionally actives against the Gram-negative and against the yeast C. albicans. These results show that the gamma radiation has not influence about the antimicrobial activity of crude extracts of barks and leaves of A. colubrina. (author)

  15. The influence of 60Co gamma radiation on the action of phenolic compounds Anadenanthera colubrina (Vell.) Brenan in the microbiological control of crude extracts

    Anadenanthera colubrina (Vell.) Brenan, known popularly as angico is a tree founded in northeastern of Brazil, and has great economic and ecological interest. These trees are characterized by high levels of tannins. To evaluate the influence of gamma radiation in plant extracts of barks and leaves of angico, we got extracts of barks and leaves in 70% ethanol, which was filtered and evaporated until dryness. It were classified in four groups (non-irradiated, 5; 7.5 and 10 kGy). The total phenols were quantified by Folin-Ciocalteau method, and the tannins, using the precipitation of casein. The antimicrobial activity of extracts was observed using the paper disk diffusion methods against Gram-positive, Gram-negative, acid-alcohol-resistant bacteria: and yeasts. The halos greater than 10 mm were considered actives. It was also performed the Minimal Inhibitory Concentration (MIC) using Gram positive and alcohol-acid resistant bacteria. The results showed that tannins of A. colubrina, were 52 to 57% of total phenols, and leaves, 58 to 60%. The percentage of total phenols and tannins in the barks and leaves of A. colubrina have not statistically significant change when compared with the irradiated control. These results suggest that A. colubrina has antimicrobial activity against the Gram-positive and alcohol-acid -resistant bacteria, confirmed by MIC. The extracts of leaves it was additionally actives against the Gram-negative and against the yeast C. albicans. These results show that the gamma radiation has not influence about the antimicrobial activity of crude extracts of barks and leaves of A. colubrina. (author)

  16. Variation in electrical properties of gamma irradiated cadmium selenate nanowires

    Chauhan, R. P.; Rana, Pallavi; Narula, Chetna; Panchal, Suresh; Choudhary, Ritika

    2016-07-01

    Preparation of low-dimensional materials attracts more and more interest in the last few years, mainly due to the wide field of potential commercial applications ranging from life sciences, medicine and biotechnology to communication and electronics. One-dimensional systems are the smallest dimension structures that can be used for efficient transport of electrons and thus expected to be critical to the function and integration of nanoscale devices. Nanowires with well controlled morphology and extremely high aspect ratio can be obtained by replicating a nanoporous polymer ion-track membrane with cylindrical pores of controlled dimensions. With this technique, materials can be deposited within the pores of the membrane by electrochemical reduction of the desired ion. In the present study, cadmium selenate nanowires were synthesized potentiostatically via template method. These synthesized nanowires were then exposed to gamma rays by using a 60Co source at the Inter University Accelerator Centre, New Delhi, India. Structural, morphological, electrical and elemental characterizations were made in order to analyze the effect of gamma irradiation on the synthesized nanowires. I-V measurements of cadmium selenate nanowires, before and after irradiation were made with the help of Keithley 2400 source meter and Ecopia probe station. A significant change in the electrical conductivity of cadmium selenate nanowires was found after gamma irradiation. The crystallography of the synthesized nanowires was also studied using a Rigaku X-ray diffractrometer equipped with Cu-Kα radiation. XRD patterns of irradiated samples showed no variation in the peak positions or phase change.

  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. Effect of gamma irradiation on nutrient digestibility in SPF mini-pig

    This study was carried out to evaluate the effect of gamma irradiation on nutrient digestibility of either soy-based or milk-based diet for specific pathogen-free (SPF) mini-pigs. Gamma irradiation of the diets was done at dosage of 10 kGy with 60Co whereas autoclaving was executed at 121 oC for 20 min. Apparent crude protein digestibilities of gamma irradiated diets were higher (p<0.05) than those of autoclaved diets regardless of diet type. Digestibilities of dry matter, gross energy and total carbohydrate in the irradiated diet were higher than those of the autoclaved diet. From the results of nutrient digestibility of mini-pig diets in this study, 10 kGy gamma radiation was suggested as a convenient diet radicidation method that can minimize the decrease in nutrient digestibility on feeding to SPF mini-pigs.

  19. Effect of gamma irradiation on nutrient digestibility in SPF mini-pig

    Lee, Jun-Yeob; Cho, Sung-Back; Kim, Yoo-Yong; Ohh, Sang-Jip

    2011-01-01

    This study was carried out to evaluate the effect of gamma irradiation on nutrient digestibility of either soy-based or milk-based diet for specific pathogen-free (SPF) mini-pigs. Gamma irradiation of the diets was done at dosage of 10 kGy with 60Co whereas autoclaving was executed at 121 °C for 20 min. Apparent crude protein digestibilities of gamma irradiated diets were higher ( pdiets regardless of diet type. Digestibilities of dry matter, gross energy and total carbohydrate in the irradiated diet were higher than those of the autoclaved diet. From the results of nutrient digestibility of mini-pig diets in this study, 10 kGy gamma radiation was suggested as a convenient diet radicidation method that can minimize the decrease in nutrient digestibility on feeding to SPF mini-pigs.

  20. Gamma irradiation of starch samples contaminated with anaerobic germs

    Starch samples were mixed with spores of Clostridium botulinum and Clostridium perfringens and irradiated with 60Co γ-rays of different intensities. The radiosensitivity and the survival rates of the spores were determined. Of the starch samples examined only a small part contained spores of mesophilic Clostridia. None of the samples showed signs of presence of rigidly thermophilic varieties and of Clostridium botulinum or Clostridium perfringens. 14 groups of germs were isolated from the dry products of starch industry. At least one germ group showed an activation phenomenon and a probable survival rate of 300% at 75 krad. This is true for the germ group which appears most frequently with starch and can be identified as Clostridium sporogenes. Gamma irradiation does not neutralize lysozyme dependence of the Clostridium perfringens germ which has this property. With a few reservations the standards for germ content which have been set for Bacillus spores can be also used for Clostridium spores. (orig./AJ)

  1. Gamma irradiation of unsaturated hydrocarbons in presence of hydrogen

    Only small increases in yield (G values) of saturated products are observed in the irradiation with 60Co gamma radiation, of ethylene and 1-butene. The values obtained are: G(C2H6)=0,3-0,4 (for ethylene/H2) and G(n-C4H10)=2,1 (for 1-butene/H2), with total dose of 8 to 9.1019 eV. In a similar irradiation of acetylene in presence of hydrogen, ethylene was obtained with relatively high G-values: G=5,4 for a dose of 2.1018 eV G=17,5 for 2,5x1019 eV and G=8,4 for 2,3.1020 eV. Benzene yield shows some increases (G=6,6-9,1) in relation to values in absence of hydrogen. (author)

  2. Chemical constituents of Panax ginseng exposed to. gamma. irradiation

    Kwon, Joongho; Belanger, J.M.R.; Sigouin, M.; Lanthier, J.; Willemot, C.; Pare, J.R.J. (Agriculture Canada, Saint-Hyacinthe, Quebec (Canada))

    1990-03-01

    Chemical constituents were monitored to assess the biochemical and nutritional safety of Panax ginseng powders that were irradiated at doses of 1-10 kGy. Quantitative analysis has shown that the main effective components - saponins - are not altered by {sup 60}Co {gamma} irradiation. Ginsenoside-Rg{sub 1} was not affected by the treatment. Negligible changes were observed in the free carbohydrate contents. Doses of more than 5 kGy caused significant decreases in sulfur-containing amino acids and in tyrosine. At doses of 10 kGy, free amino acids, such as proline and lysine, showed an appreciable increase. The composition in minerals was not altered irrespective of the applied doses.

  3. Gamma-irradiated cationic starches: Paper surface-sizing agents

    Cationic starches, precisely depolymerized by gamma-irradiation (60Co), were dispersed in mild alkali and evaluated as surface sizes for bond paper on a pilot paper machine. The irradiated products had excellent dispersion properties, were well retained on fibers when sized wastepaper (broke) was repulped and had an ability to enhance paper properties that was comparable to that of starch-based materials used commercially. A yellow corn flour, cationized by an essentially dry reaction process recently developed at this Center, was also radiolyzed and evaluated as a size. This latter product was unique in that all drying steps were eliminated in the preparation of a cationic ceral product of reduced viscosity. (orig.)

  4. Dose-dependence of the chromosome aberration yield in a human lymphocyte culture after. gamma. -irradiation with high doses

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

    A study was made of the yield of chromosome aberrations in a human lymphocyte culture at the G/sub 0/ stage after /sup 60/Co-..gamma..-irradiation with doses of 5-12 Gy. It was shown that a linear-quadratic dependence of the aberration frequency observed with median doses became purely linear at high doses.

  5. [Changes in the collagen amino acid composition of calf skin after gamma-irradiation in an aqueous solution].

    Duzhenkova, N A; Savich, A V

    1983-01-01

    A study was made of the amino acid composition of calf skin collagen after gamma-irradiation (60Co) of 2.5 X 10(-6) M aerated aqueous protein solution within the dose range from 30 to 2000 Gy. The radiosensitivity of amino acid residues was compared. PMID:6657935

  6. Determination of the correction factor for attenuation, dispersion and production of electrons (Kwall) in the wall of graphite of a ionization chamber Pattern National Type CC01 in fields of gamma radiation of 60Co

    It was determined the Kwall correction factor for the wall of graphite of the chamber of the pattern national type CC01 series 133 for a radiation field Gamma of 60Co. With this end to measured the currents of ionization l(x) as function of the thickness of the wall of the chamber: X=4,8,12,16 and 20 mm.The mensurations for each thickness consisting of three groups, of sizes n = 30 or 60 data for each group; obtaining 8 complete groups of mensurations independent in eight different dates.The determinate the factor carried out using three regression models: lineal, logarithmic and quadratic, models that were tried to validate with the tests of : i) Shapiro-Wilk and χ2 for the normality of the entrance data ii) Tests of Bartlett for variances homogeneity among groups for each thickness iii) The tests of Duncan for the stockings among groups of each thickness, and iv) The tests of adjustment lack (LOF) for the models used. Nevertheless, alone the models of the group of corresponding mensurations at 01-03-2000 17-08-2001 they can be validated by LOF, but not for tests of normality and homogeneity of variances. Among other assignable causes of variation we have: i) The values captured by the system of mensuration of the variables of it influences: pressure, temperature and relative humidity dont belong together with the existent ones to the moment to capture the l(x). ii) The mensuration room presents flows of air, for what was suited o diminish their volume and to eliminate the flows of air. iii) A protocol settled down of taking of measures that it consisted in: - Pre-irradiation 5 minutes the chamber after the change of polarity and hood change, with a period of stabilization of 5 minutes after the pre-irradiation. - Pre-irradiation for 5 minutes before the taking of the readings, with the object of eliminating variation sources assigned to currents of escapes or due variations to transitory. iv) To realize corrections for relative humidity of agreement with the

  7. Experimental calibration and determination of the relative response for Lif: Mg, Ti(TLD-100) dosemeters at 60Co gamma and 60 kVp X-ray energies

    The thermoluminescence efficiency of LiF: Mg, Ti (TLD-100) dosemeters has been determined for photon beams from 60Co gamma rays and 60 kVp X-rays. It has been proven that light yield varies as a function of the photon energy. An experiment was performed using an X-ray beam whose spectrum has been determined by an X-ray fluorescence method. This enabled a direct calculation of the absorbed doses in the T1 material for the different operation conditions. These values and the experimental ones from measuring T1 intensities have been used to obtain the efficiency for energy X-ray spectrum. From the above values, the dosemeter T1 response, relative to 60Co, has been evaluated. (author)

  8. Comparisons of the standards for air kerma of the PTB and the BIPM for 60Co and 137Cs gamma radiation

    Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the 60Co and 137 Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in 60Co of 9.9 x 10-3 with a combined standard uncertainty of 1.8 x 10-3, and in 137Cs of 6.4 x 10-3 with a combined standard uncertainty of 2.8 x 10-3. The earlier comparisons in 60Co γ rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10-3. The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, kwall and kpn, for the PTB standards, which were calculated using Monte Carlo methods. (authors)

  9. 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. Gammairradiation 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.

  10. 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)

  11. The resistance of salmonella typhirium on gamma irradiation

    This research intended to investigate the registance of S. typhimurium on the gamma irradiation, temperature and pH in the cell suspension of 10 exp. 8 and homogenants sludge medium. The resistance of bacteria S. typhimurium in cells suspension of 10 exp. 8 was irradiated with gamma ray (60-Co) at the doses of 0; 0.15; 0.30; and 0.45 kGy. The dose rate was 1.00 kGy/h, in the gamma cell 220 irradiator and then the suspension was plated on the media, which have pH from 6, 7, and 8. Then incubated at temperature of 30, 37 and 42 Celcius centigrade for 2 x 24 hours. The resistance of bacteria S. typhimorium in 10% sludge homogenate in TGY broth was iradiated with gamma ray at doses of 0; 0.5; 1.0; 1.5; 2.0; and 2.5 kGy with dose rate of 0.95 kGy/h. After irradiation the bacteria was incubated for 24 hours at room temperature (28 +/- 2) Celcius centigrade then innoculate on SS, Mac Conkey, and XLD media. After 2 x 24 hours grows on petri dishes, the growth of colonies were observed and total bacterial counts per ml was calculated. The results showed irradiation and pH media gave significant decrease in the total bacterial count. Irradiation doses of 0.45 kGy reduced the total number of bacterial counts by 5 log cycles with the pH variation from 6 - 8 while the results in the sludge homogenete showed that the media give no significant effect on the ground capabilities of S. typhimorium. (author). 7 refs, 4 figs, 4 tabs

  12. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice root product

    Licorice root products were irradiated at doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on product, chemical changes and sensory properties of produced solution of licorice root products were evaluated after 0 and 12 months of storage. The results indicated that gamma irradiation reduced the counts of microorganisms on licorice root products. D10 of total count and klebsiella spp. were about 1.4 and 0.7 kGy, respectively. The mineral ions (Na, Ca and K) concentration in solution produced from irradiated products were lower than non-irradiated ones. Glycyrrhezinic acid and maltose concentration in solution produced from irradiated products were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences (P<0.05) were found between solution produced from irradiated and unirradiated products in color, flavor, texture, or taste

  13. Determination of the correction factor for attenuation, dispersion and production of electrons (K{sub wall}) in the wall of graphite of a ionization chamber Pattern National Type CC01 in fields of gamma radiation of {sup 60}Co; Determinacion del factor de correccion por atenuacion, dispersion y produccion de electrones (K{sub wall}) en la pared de grafito de una Camara de Ionizacion Patron Nacional Tipo CC01 en campos de radiacion gamma de {sup 60} Co

    Alvarez R, J.T.; Morales P, J.; Cruz E, P. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-12-15

    It was determined the Kwall correction factor for the wall of graphite of the chamber of the pattern national type CC01 series 133 for a radiation field Gamma of {sup 60}Co. With this end to measured the currents of ionization l(x) as function of the thickness of the wall of the chamber: X=4,8,12,16 and 20 mm.The mensurations for each thickness consisting of three groups, of sizes n = 30 or 60 data for each group; obtaining 8 complete groups of mensurations independent in eight different dates.The determinate the factor carried out using three regression models: lineal, logarithmic and quadratic, models that were tried to validate with the tests of : i) Shapiro-Wilk and {chi}{sup 2} for the normality of the entrance data ii) Tests of Bartlett for variances homogeneity among groups for each thickness iii) The tests of Duncan for the stockings among groups of each thickness, and iv) The tests of adjustment lack (LOF) for the models used. Nevertheless, alone the models of the group of corresponding mensurations at 01-03-2000 17-08-2001 they can be validated by LOF, but not for tests of normality and homogeneity of variances. Among other assignable causes of variation we have: i) The values captured by the system of mensuration of the variables of it influences: pressure, temperature and relative humidity don{sup t} belong together with the existent ones to the moment to capture the l(x). ii) The mensuration room presents flows of air, for what was suited o diminish their volume and to eliminate the flows of air. iii) A protocol settled down of taking of measures that it consisted in: - Pre-irradiation 5 minutes the chamber after the change of polarity and hood change, with a period of stabilization of 5 minutes after the pre-irradiation. - Pre-irradiation for 5 minutes before the taking of the readings, with the object of eliminating variation sources assigned to currents of escapes or due variations to transitory. iv) To realize corrections for relative humidity of

  14. Gamma Irradiation does not Cause Carcinogenesis of Irradiated Herbs

    Full text: Microbial contamination of medicinal herbs can be effectively reduced by gamma irradiation. Since irradiation may cause carcinogenicity of the irradiated herbs, the objective of this research is to study the effect of gamma irradiation (10 and 25 kGy) from cobalt-60 on carcinogenicity. The herbs studied were Pueraria candollei Grah., Curcuma longa Linn. Zingiber montanum, Senna alexandrina P. Miller, Eurycoma Longifolia Jack, Gymnostema pentaphylum Makino, Ginkgo biloba, Houttuynia cordata T., Andrographis paniculata, Thunbergia laurifolia L., Garcinia atroviridis G., and Cinnamomum verum J.S.Presl. The results showed that gamma irradiation at the dose of 10 and 25 kGy did not cause carcinogenicity of the irradiated herbs

  15. Effect of 60Co gamma radiation on the levels of phenolic compounds from crude extracts of bark of Spondias luta L

    Spondias luta L. (Anacardiaceae), popularly known as cajazeira, is a plant widespread in several regions of Brazil, famous for containing phenolic compounds, which are responsible for your characteristic astringent. Ionizing radiations have the ability to cross the material, ionizing atoms and molecules, causing changes in atoms and molecules important. It is known ionizing radiation promotes quantitative and qualitative changes in plant materials, increasing, decreasing or inactivating secondary substances. The objective of this work was to evaluate the effect of gamma radiation as a modifier of the activity of the phenolic compounds of the bark extract of S. luta L. Methods: For the dosage of phenol extracts (control, irradiated with 5 kGy, 10 kGy, 15 kGy and 20 kGy) were diluted in methanol to a final concentration of 200 mg / L. In test tubes were added 50 μL of extract plus 1 ml of distilled water and 500 μl of Folin (diluted 1:10). After 10 minutes in a dark chamber was added 2.5 ml of calcium carbonate to 20% and the content of the tube was homogenized. After 20 minutes was performed with a spectrophotometer at 735 nm. The assay was performed in triplicate and calculated from a standard curve solution of gallic acid and expressed in μEAG (GAE/mg extract). Results: The control extracts, irradiated to 5 kGy, 10 kGy, 15 kGy and 20 kGy, had, respectively, 6.25, 6.70, 6.25, 6.85, 6.45 μEAG/mg of extract. Conclusion: The results showed no significant change in the amount of phenolic compounds, showing that these compounds are radioresistant extract these doses. (author)

  16. Effect of {sup 60}Co gamma radiation on the levels of phenolic compounds from crude extracts of bark of Spondias luta L

    Santos, Gustavo H.F.; Silva, Hianna A.M.F.; Melo, Mychely S., E-mail: santosghf@hotmail.com, E-mail: hiannaamfs@gmail.com, E-mail: mychely.melo@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Silva, Edvane B., E-mail: edvborges@yahoo.com [Universidade Federal de Pernambuco (UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academinco de Vitoria

    2013-07-01

    Spondias luta L. (Anacardiaceae), popularly known as cajazeira, is a plant widespread in several regions of Brazil, famous for containing phenolic compounds, which are responsible for your characteristic astringent. Ionizing radiations have the ability to cross the material, ionizing atoms and molecules, causing changes in atoms and molecules important. It is known ionizing radiation promotes quantitative and qualitative changes in plant materials, increasing, decreasing or inactivating secondary substances. The objective of this work was to evaluate the effect of gamma radiation as a modifier of the activity of the phenolic compounds of the bark extract of S. luta L. Methods: For the dosage of phenol extracts (control, irradiated with 5 kGy, 10 kGy, 15 kGy and 20 kGy) were diluted in methanol to a final concentration of 200 mg / L. In test tubes were added 50 μL of extract plus 1 ml of distilled water and 500 μl of Folin (diluted 1:10). After 10 minutes in a dark chamber was added 2.5 ml of calcium carbonate to 20% and the content of the tube was homogenized. After 20 minutes was performed with a spectrophotometer at 735 nm. The assay was performed in triplicate and calculated from a standard curve solution of gallic acid and expressed in μEAG (GAE/mg extract). Results: The control extracts, irradiated to 5 kGy, 10 kGy, 15 kGy and 20 kGy, had, respectively, 6.25, 6.70, 6.25, 6.85, 6.45 μEAG/mg of extract. Conclusion: The results showed no significant change in the amount of phenolic compounds, showing that these compounds are radioresistant extract these doses. (author)

  17. Improved performance of Tectona grandis seeds with gamma irradiation

    Tectona grandis Linn., commonly known as 'Teak' is grown in gardens and parks for the leaf shape and size. However, the major problem in cultivation of this plant is poor seed germination. Therefore, investigations on the effect of gamma irradiation in the seeds of Teak were undertaken. Genetically pure seeds were treated with 10, 20, 30, 40 and 50 kR in a 60Co-Gamma Cell administered at 1.2 kR/min. Irradiation with lower doses improved seed germination. Similarly, 20 and 30 kR influenced the seedling growth to a significant extent and different degrees of stimulation was observed in almost all the treated plant population. As a result of better seed establishment, the number of leaves and branches were considerably higher. Girth of the stem at different levels of growth varied, maximum being in 10 kR plants. In these treatments, a plant type was obtained which had altered leaf shape and prolonged leaf bearing phase. The photosynthetic area in this plant was significantly more than control and had its reflection on growth. The data obtained indicate considerable improvement in the overall performance of seeds irradiated with gamma rays. (author)

  18. Effect of gamma irradiation on storability and chemical properties of different depth samples of luncheon

    To investigate the effect of gamma irradiation on shelf-life of luncheon, meat packs were exposed to doses of 0, 1, 2 and 3 kGy in a 60Co package irradiator, and the irradiated and unirradiated samples were stored at refrigeration temperature (1-3 centigrade). Microbial population and chemical changes were evaluated through storage periods (2, 4, 6 weeks) on the surface and depth in the of meat packs. The results indicated that gamma irradiation reduced the counts of microorganisms inside the samples more than the surfaces. Also the shelf-life of luncheon meat increased from two weeks for the control to 5 weeks for irradiated samples (2 and 3 kGy). Total acidity, lipid oxidation and the volatile basic nitrogen (VBN) increased during the first stage of storage up to 2 weeks of irradiation, furthermore these values were significantly higher (P> 0.05) on the surface than inside the meat packs. (author)

  19. Evaluating the effect of gamma radiation (60Co) on protein arcelin and its influence in the resistance of Zabrotes subfasciatus (Boh., 1833) (Coleoptera: Bruchidae)

    The objective of this research was to evaluate the effects of different gamma doses of Cobalt-60 on arcelin protein in the manifestation of resistance to Zabrotes subfasciatus (Boh., 1833). Seeds of four lines of Phaseolus vulgaris carriers of arcelin protein (Arcelin-1, Arcelin-2, Arcelin-3 and Arcelin-4) and a cultivar without this protein were used as control (IAC-Carioca Akyta) obtained from the Instituto Agronomico do Estado de Sao Paulo - Nucleo Experimental de Campinas (IAC), were irradiated in a source of Cobalt-60, of the panoramic type, from the Instituto de Pesquisas Energeticas e Nucleares/CNEN/SP. The activity was approximately 2218.79 Ci, and the dose rate 0.678 kGy/h. The doses used were 0; 0.25; 0.5; 1.0 and 2.0 kGy. The results showed that the radiation doses did not influence the parameters evaluated in the resistance because a high degree of antibiose in the Arcelin-1 and Arcelin-2 lines was maintained. The Arcelin-3 and Arcelin-4 lines also maintained their behavior less expressive of resistance by antibiose only prolonging the period from egg to adult. The electrophoretic analysis of the lines and cultivar were not changed in relation to the radiation doses. But there was a decrease in relation to the intensity of color of the bands (absorbance) with the increase of the doses. (author)

  20. Lipoperoxides, alpha-tocopherol and ceruloplasmin in gamma-irradiated blood plasma

    Ceruloplasmin, alpha-tocopherol and lipid peroxide concentrations are evaluated in blood plasma for transfusion following exposure to irradiation with 60Co gamma rays at doses 23, 50, 100 and 200 Gy. In plasma exposed to irradiation an increase in lipid peroxides and decrease in alpha-tocopherol and ceruloplasmin are observed. The addition of 2.3 U/ml ceruloplasmin to plasma prior to irradiation reduces the quantity of lipid peroxides and protects alpha-tocopherol. The possible explanation is that the metal helates prevent the formation of free hydroxyl radicals and thus inhibit the oxidation of lipid membranes. 15 refs., 1 tab. (author)

  1. Crosslinking of metallocenic α-olefin propylene copolymers by vacuum gamma irradiation

    Satti, A. J.; Andreucetti, N. A.; Quijada, R.; Vallés, E. M.

    2012-12-01

    Metallocenic polypropylene and copolymers with 3.7, and 9.2 mol% of hexene and 3.0 mol% of octadecene comonomer content were synthesized without the presence of additives and irradiated with 60Co gamma radiation under vacuum at room temperature. Size Exclusion Cromatography and gel extraction data showed that scission reactions predominate over crosslinking in the homopolymer and that there is a dose from where crosslinking started to increase considerably, in the irradiated copolymers. Rheology also showed evidence of chain-enlargements on the copolymers by means of an increase in the viscoelastic properties of the irradiated material.

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

    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 60Co γ-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 B12) 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)

  3. Comunicación corta. RADIOESTIMULACIÓN DE LA GERMINACIÓN EN Stevia rebaudiana CULTIVAR KH-IAN VC-142 (EIRETÉ, MEDIANTE EL EMPLEO DE RAYOS GAMMA 60CO

    María C. González

    2015-01-01

    Full Text Available El presente trabajo tuvo como objetivo evaluar el efecto de bajas dosis de rayos gamma 60 Co en la germinación de las semillas de Stevia rebaudiana . Para ello se irradiaron semillas del cultivar KH-IAN VC-142 (Eireté, con dosis de 10 a 90 Gray (Gy. Se determinó que todas las dosis empleadas incrementaron el número de semillas germinadas pero la dosis de 10 Gy fue la que provocó la mayor estimulación en la germinación de las semillas.

  4. Comunicación corta. RADIOESTIMULACIÓN DE LA GERMINACIÓN EN Stevia rebaudiana CULTIVAR KH-IAN VC-142 (EIRETÉ), MEDIANTE EL EMPLEO DE RAYOS GAMMA 60CO

    María C. González; Héctor D. Nakayama

    2015-01-01

    El presente trabajo tuvo como objetivo evaluar el efecto de bajas dosis de rayos gamma 60 Co en la germinación de las semillas de Stevia rebaudiana . Para ello se irradiaron semillas del cultivar KH-IAN VC-142 (Eireté), con dosis de 10 a 90 Gray (Gy). Se determinó que todas las dosis empleadas incrementaron el número de semillas germinadas pero la dosis de 10 Gy fue la que provocó la mayor estimulación en la germinación de las semillas.

  5. Study of recombination processes for 'electron-hole' pairs in germanium irradiated by γ rays from 60Co using the photovoltaic effect in P-N junctions

    Using the photo-voltaic effect in p-n junctions, we have studied, during bombardment, the mechanism of the recombination of 'electron-hole' pairs in the presence of structure defects produced in germanium of the N and P types by γ rays from a Co60 source. At 310 K the level of the recombination centres is situated 0.25 eV above the conduction band and the capture cross-sections of the holes and of the electrons have the respective values of: σp = 4 X 10-15 cm2 and σn = 3 X 10-15 cm2. The value of σn appears to be under-estimated because the number of defects in P-type samples appears to be lower than that in N-type samples. These results lead to the conclusion that the interstitials are responsible for the recombination. At 80 K it has been found that in N-type samples, a shallow level exists at O.05 eV below the conduction band with a capture cross-section for the holes of σp ≥ 10-14 cm2. We believe that in this case the recombination of charge carriers is controlled by the neighbouring 'defect-interstitial' pairs. In P-type samples at low temperature, the life-time is practically constant during irradiation. This fact is attributed to a spontaneous annealing of defects ol purely electrical origin. In the last part of the work the study of the photo-voltaic effect applied to the problem of gamma radiation dosimetry is considered. It is shown that such dosimeters, based on this principle, make it possible to measure the intensity of gamma rays over a very wide range. (author)

  6. The effect of gamma irradiation on insect pest of rice in storage

    This study was conducted to determine the effect of gamma irradiation on insect pest of rice, stored for a period of 24 months, and packed in four different packaging materials. They were then exposed to gamma radiation using Gamma Cell 220, in a 60Co source. Samples were randomly sampled at the initial storage period and there after at 3 months interval. At each sampling time the grain weight loss and insect count, both dead and alive, were determined. The increasing dosages of irradiation did not show any consistent effect on the insect population in all the four packaging materials which indicated that the rice was already infested even before it was irradiated. The range of percentage weight loss for all the dosages of irradiation in all of the four packaging materials is 0.99 to 2.02. (A.J.)

  7. Effect of gamma-irradiation on the survival of Listeria monocytogenes and allergenicity of cherry tomatoes

    The presence of Listeria monocytogenes in fresh produce is a growing concern because of the possibility of food-borne illness. Ionizing radiation is an effective non-thermal means of eliminating pathogenic bacteria in fresh produce; however, the effect of ionizing irradiation on the allergenic properties of the host commodities remains unknown. This study aimed (i) to determine the effective dose of gamma-irradiation in eliminating L. monocytogenes on whole cherry tomatoes and (ii) to evaluate the effect of gamma-irradiation on the allergenic properties of tomato proteins. Cherry tomatoes that were inoculated with a mixture of five L. monocytogenes strains were treated with gamma-rays from a 60Co source. A 1.25 kGy dose of gamma-irradiation was found to be sufficient to eliminate L. monocytogenes on whole cherry tomatoes. The immunoblot profile of serum samples obtained from two patients with tomato allergy revealed that gamma-irradiation did not affect the allergenicity of tomato proteins for up to 7 days after irradiation when the tomatoes were stored at 20 deg. C. Additionally, the m-RNA levels of β-fructofuranosidase, polygalacturonase, pectin esterase, and superoxide dismutase, the main allergenic proteins in tomato, were not affected by the applied irradiation dose. Thus, this study demonstrated that a 1.25 kGy dose of gamma-irradiation effectively eliminates L. monocytogenes on cherry tomatoes without affecting the expression of allergenic proteins in the fruits.

  8. Effect of gamma-irradiation on the survival of Listeria monocytogenes and allergenicity of cherry tomatoes

    Todoriki, Setsuko; Bari, Latiful; Kitta, Kazumi; Ohba, Mika; Ito, Yasuhiro; Tsujimoto, Yuka; Kanamori, Norihito; Yano, Erika; Moriyama, Tatsuya; Kawamura, Yukio; Kawamoto, Shinichi

    2009-07-01

    The presence of Listeria monocytogenes in fresh produce is a growing concern because of the possibility of food-borne illness. Ionizing radiation is an effective non-thermal means of eliminating pathogenic bacteria in fresh produce; however, the effect of ionizing irradiation on the allergenic properties of the host commodities remains unknown. This study aimed (i) to determine the effective dose of gamma-irradiation in eliminating L. monocytogenes on whole cherry tomatoes and (ii) to evaluate the effect of gamma-irradiation on the allergenic properties of tomato proteins. Cherry tomatoes that were inoculated with a mixture of five L. monocytogenes strains were treated with gamma-rays from a 60Co source. A 1.25 kGy dose of gamma-irradiation was found to be sufficient to eliminate L. monocytogenes on whole cherry tomatoes. The immunoblot profile of serum samples obtained from two patients with tomato allergy revealed that gamma-irradiation did not affect the allergenicity of tomato proteins for up to 7 days after irradiation when the tomatoes were stored at 20 °C. Additionally, the m-RNA levels of β-fructofuranosidase, polygalacturonase, pectin esterase, and superoxide dismutase, the main allergenic proteins in tomato, were not affected by the applied irradiation dose. Thus, this study demonstrated that a 1.25 kGy dose of gamma-irradiation effectively eliminates L. monocytogenes on cherry tomatoes without affecting the expression of allergenic proteins in the fruits.

  9. Effect of gamma-irradiation on the survival of Listeria monocytogenes and allergenicity of cherry tomatoes

    Todoriki, Setsuko [National Food Research Institute, Tsukuba, Ibaraki 305-8642 (Japan)], E-mail: setsuko@affrc.go.jp; Bari, Latiful; Kitta, Kazumi; Ohba, Mika; Ito, Yasuhiro; Tsujimoto, Yuka [National Food Research Institute, Tsukuba, Ibaraki 305-8642 (Japan); Kanamori, Norihito [Japan International Research Center for Agricultural Science, Tsukuba, Ibaraki 305-8686 (Japan); Yano, Erika; Moriyama, Tatsuya; Kawamura, Yukio [School of Agriculture, Kinki University, Nara-city, Nara 631-8505 (Japan); Kawamoto, Shinichi [National Food Research Institute, Tsukuba, Ibaraki 305-8642 (Japan)

    2009-07-15

    The presence of Listeria monocytogenes in fresh produce is a growing concern because of the possibility of food-borne illness. Ionizing radiation is an effective non-thermal means of eliminating pathogenic bacteria in fresh produce; however, the effect of ionizing irradiation on the allergenic properties of the host commodities remains unknown. This study aimed (i) to determine the effective dose of gamma-irradiation in eliminating L. monocytogenes on whole cherry tomatoes and (ii) to evaluate the effect of gamma-irradiation on the allergenic properties of tomato proteins. Cherry tomatoes that were inoculated with a mixture of five L. monocytogenes strains were treated with gamma-rays from a {sup 60}Co source. A 1.25 kGy dose of gamma-irradiation was found to be sufficient to eliminate L. monocytogenes on whole cherry tomatoes. The immunoblot profile of serum samples obtained from two patients with tomato allergy revealed that gamma-irradiation did not affect the allergenicity of tomato proteins for up to 7 days after irradiation when the tomatoes were stored at 20 deg. C. Additionally, the m-RNA levels of {beta}-fructofuranosidase, polygalacturonase, pectin esterase, and superoxide dismutase, the main allergenic proteins in tomato, were not affected by the applied irradiation dose. Thus, this study demonstrated that a 1.25 kGy dose of gamma-irradiation effectively eliminates L. monocytogenes on cherry tomatoes without affecting the expression of allergenic proteins in the fruits.

  10. Effects of gamma irradiation on long-storage seeds of Oryza sativa (cv. 2233) and their surface infecting fungal diversity

    We have reported an effective 60Co gamma irradiation method for the removal and long-time prevention of contaminating fungi of Oryza sativa cv-2233, without the losses of seed viabilities. The fungal growth and their population on gamma treated seeds was found to decrease significantly (p50%) at 2 kGy, whereas total inhibition was noticed at 3 kGy after 1.5 month.

  11. Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NIM, China and the BIPM in 60Co gamma radiation

    Kessler, C.; Burns, D.; Wang, K.; Fan, Y.; Jin, S.; Yang, X.

    2016-01-01

    An indirect comparison of the standards for air kerma of the National Institute of Metrology (NIM), China and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in November 2015. The comparison result, evaluated as a ratio of the NIM and the BIPM standards for air kerma, is 0.9997 with a combined standard uncertainty of 2.7 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  12. Gamma irradiations of the seeds and pollen grains of oil palm (Elaeis guineensis Jacq.)

    The pollen grains and seeds of oil palm (Elaeis guineensis Jacq.) were irradiated with up to 1400 Gy of gamma rays from a 60Co source. Pollen viability tests and subsequent development of embryos from the irradiated seeds showed that a dosage of up to 50 Gy could be tolerated by both the pollen grains and the seeds. Higher doses caused a drastic drop in the germination of seeds, thus reducing the potential size of any population for further studies. Plants of high bunch production were identified in both irradiated and non-irradiated materials. The potential use of gamma irradiation to induce useful mutation in the characters contributing to yield in the oil palm is discussed. (author). 2 refs, 3 figs, 1 tab

  13. Influence of gamma irradiation on conductivity of YBa2Cu3O7

    Manjunatha, H. C.

    2015-08-01

    We report a study on influence of gamma irradiation on conductivity of YBa2Cu3O7. We have measured the mass attenuation coefficient, effective atomic number, electron density and electrical conductivity for various gamma sources of energy ranging from 0.084 MeV to 1.330 MeV (170Tm, 57Co, 141Ce, 203Hg, 51Cr, 113Sn, 22Na, 137Cs, 60Co, 22Na and 60Co). The measured values agree with the theoretical values. The values of these parameters have been found to change with energy and interaction of gamma. We find evidence for a variation of the electrical conductivity of YBa2Cu3O7 with the irradiated photon energy and this variation is shown in figures up to 105 MeV. The variations of effective atomic number and electron density with energy are shown graphically for all photon interactions. Conductivity found to vary with the energy of the irradiated gamma radiation and interaction process of gamma. This kind of studies is important in the field of superconductivity.

  14. A comparison of the biological effects of 125I seeds continuous low-dose-rate radiation and 60Co high-dose-rate gamma radiation on non-small cell lung cancer cells.

    Zhongmin Wang

    Full Text Available To compare the biological effects of 125I seeds continuous low-dose-rate (CLDR radiation and 60Co γ-ray high-dose-rate (HDR radiation on non-small cell lung cancer (NSCLC cells.A549, H1299 and BEAS-2B cells were exposed to 125I seeds CLDR radiation or 60Co γ-ray HDR radiation. The survival fraction was determined using a colony-forming assay. The cell cycle progression and apoptosis were detected by flow cytometry (FCM. The expression of the apoptosis-related proteins caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, BAX and Bcl-2 were detected by western blot assay.After irradiation with 125I seeds CLDR radiation, there was a lower survival fraction, more pronounced cell cycle arrest (G1 arrest and G2/M arrest in A549 and H1299 cells, respectively and a higher apoptotic ratio for A549 and H1299 cells than after 60Co γ-ray HDR radiation. Moreover, western blot assays revealed that 125I seeds CLDR radiation remarkably up-regulated the expression of Bax, cleaved-caspase-3 and cleaved-PARP proteins and down-regulated the expression of Bcl-2 proteins in A549 and H1299 cells compared with 60Co γ-ray HDR radiation. However, there was little change in the apoptotic ratio and expression of apoptosis-related proteins in normal BEAS-2B cells receiving the same treatment.125I seeds CLDR radiation led to remarkable growth inhibition of A549 and H1299 cells compared with 60Co HDR γ-ray radiation; A549 cells were the most sensitive to radiation, followed by H1299 cells. In contrast, normal BEAS-2B cells were relatively radio-resistant. The imbalance of the Bcl-2/Bax ratio and the activation of caspase-3 and PARP proteins might play a key role in the anti-proliferative effects induced by 125I seeds CLDR radiation, although other possibilities have not been excluded and will be investigated in future studies.

  15. Production of modified starches by gamma irradiation

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch

  16. Study on the dosimetric characteristics of indigenously developed computer-controlled multisource gamma irradiation system

    A computer-controlled multisource gamma (60Co, 137Co, and 241Am) irradiation system has been developed indigenously for the purpose of strengthening the quality assurance program of individual monitoring service in India. The system can be used for the irradiation of personnel dosimeters both in panoramic and collimated modes in a well-reproduced geometry. Measurements of output (air-kerma rate) of the sources in both collimated and panoramic modes and transit dose were carried out. The study also includes radiation protection survey of the installation. Depending upon the distance from the source, the Monte Carlo-calculated air-kerma rates of the 60Co and 137Cs sources compare within 5-10% against measurements. In the collimated mode, the calculated beam uniformity is within 3% in the area of 20 cm x 20 cm centered on the collimator axis. (author)

  17. Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the PTB, Germany and the BIPM in 60Co gamma radiation

    Kessler, C.; Burns, D. T.; Kapsch, R.-P.; Krauss, A.

    2016-01-01

    An indirect comparison has been made of the standards for absorbed dose to water in 60Co radiation of the Physikalisch-Technische Bundesanstalt, (PTB), Germany and of the Bureau International des Poids et Mesures (BIPM). The measurements at the BIPM were carried out in October 2015. The comparison result, based on the calibration coefficients for two transfer standards and evaluated as a ratio of the PTB and the BIPM standards for absorbed dose to water, is 0.9977 with a combined standard uncertainty of 3.8 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  18. Thermoluminescence in gamma irradiated iPP-VGVGCNF

    Nanocomposites have been obtained by dispersing various amounts of vapor grown carbon nanofibers within isotactic polypropylene via melt mixing. The as obtained nanocomposites were gamma irradiated at various integral doses by using a 60Co source. The irradiation was performed in air, at room temperature, and at a dose rate of about 1 kGy/h up to an integral dose of 28 kGy. Thermoluminescence investigations revealed the role of carbon nanotubes in the radiation-induced modification of polymer-based nanocomposites. Almost all samples (pristine polymer and polymer-based nanocomposites irradiated and not irradiated) showed two overlapping thermoluminescence signals. It is concluded that the dispersion of carbon nanotubes decreases the amount of trapped electrons improving eventually the radiation stability of the polymeric matrix. The low temperature thermoluminescence peak was tentatively associated to melting phenomena. The origin of the high temperature thermoluminescence peak is more complex. Nevertheless, the experimental data suggests that this peak is sensitive to the polymer-filler interface.

  19. Thermoluminescence in gamma irradiated iPP-VGVGCNF

    Cherestes, Margareta [S. C. Dozimed SRL, Bucharest (Romania); Constantinescu, Livia Maria [University of Bucharest, Faculty of Physics, Magurele, Bucharest (Romania); Chipara, Dorina Magdalena, E-mail: dchipara@utpa.edu [The University of Texas Pan-American, Department of Physics and Geology, Edinburg, TX 78539 (United States); Cherestes, Codrut [S. C. Dozimed SRL, Bucharest (Romania); Chipara, Mircea [The University of Texas Pan-American, Department of Physics and Geology, Edinburg, TX 78539 (United States)

    2013-06-15

    Nanocomposites have been obtained by dispersing various amounts of vapor grown carbon nanofibers within isotactic polypropylene via melt mixing. The as obtained nanocomposites were gamma irradiated at various integral doses by using a {sup 60}Co source. The irradiation was performed in air, at room temperature, and at a dose rate of about 1 kGy/h up to an integral dose of 28 kGy. Thermoluminescence investigations revealed the role of carbon nanotubes in the radiation-induced modification of polymer-based nanocomposites. Almost all samples (pristine polymer and polymer-based nanocomposites irradiated and not irradiated) showed two overlapping thermoluminescence signals. It is concluded that the dispersion of carbon nanotubes decreases the amount of trapped electrons improving eventually the radiation stability of the polymeric matrix. The low temperature thermoluminescence peak was tentatively associated to melting phenomena. The origin of the high temperature thermoluminescence peak is more complex. Nevertheless, the experimental data suggests that this peak is sensitive to the polymer-filler interface.

  20. Dose measurements at the Philippine multipurpose gamma irradiation facility

    The Philippine Nuclear Research Institute has recently set up a pilot scale multipurpose gamma irradiation facility. In January 1989, the irradiator was initially loaded with 1 PBq 60Co. Dosimetry measurements made during the commissioning and routine operation of the facility are described. Different dosimeter systems such as ethanol monochlorobenzene, red 4034 Perspex, potassium dichromate, GAMMACHROME YR and FWT-60 radiochromic film were used. The dosimeters were calibrated against a Fricke dosimeter. To determine the dose distribution in air, dosimeters were placed on polystyrene sheets, which were positioned at different distances from the source. The dose distribution and dose uniformity ratio in dummy products of different bulk densities, irradiated at different distances from the source, were determined. Two types of cardboard boxes, one for mangoes and the other for medical products, were utilized. Newspaper was used as dummy product to fill the boxes. The effect of vertical turning on dose uniformity ratio was also investigated. The dose distribution and uniformity ratio were also determined during the routine irradiation of onions and mangoes. (author). 7 refs, 4 figs, 6 tabs

  1. Radiation safety and accident experience at gamma irradiation plants

    Gamma irradiation plants for the sterilization of medical products, preservation of food grains and for various other applications employ multikilocurie 60Co sealed sources inside shielded irradiation cells. A number of interlocks are provided between the cell entry door and the source raise mechanisms, in order to prevent the entry of any person to the cell when the source is in the exposed condition. The present paper gives the general safety features and the interlocks employed in these plants along with the safety features of irradiation plants at BARC, namely 106 Ci Isomed plant for the sterilization of medical products, 105 Ci FIPLY plant for research in food preservation and 105 Ci PANBIT plant for industrial research. Over the last two decades five cases of accidental exposure have been reported in literature in which the operator gained entry to the irradiation cell when the source was in the exposed condition. Two of these cases resulted in fatalities while the remaining three cases resulted in hospitalization of the exposed individuals for six to seven weeks. A brief outline of these accidental exposure cases and the causes of the accidents are discussed in this paper. (author). 19 refs

  2. Influence of natural antioxidants on lipid composition of beef burgers submitted to irradiation in {sup 60} Co source and electron beams; Influencia de antioxidantes naturais sobre o perfil lipidico de hamburgueres bovinos submetidos a irradiacao por {sup 60}Co e aceleradores de eletrons

    Trindade, Reginaldo Almeida da

    2007-07-01

    Radiation processing has been employed in some countries as a mean of treatment to assure microbiological safety of meat and meat products, avoiding the occurrence of food-borne disease. The ionizing radiation may cause some undesirable changes on chemistry composition of food and the lipid oxidation is one of the main reactions. In meat products processing industry, the lipid composition is directly related to nutritional and sensory quality of the product. For preventing oxidation, use of antioxidants which can be synthetic or natural, has been practically applied in some products. Currently, most attention has been given to natural antioxidants from herbs and spices like rosemary and oregano. The aim this study was to assess the antioxidant effects of either rosemary and oregano extract in beef burgers submitted to irradiation in {sup 60}Co source with dose 6, 7 e 8 kGy, electron beams with dose 3,5 e 7 kGy and storage under freeze along 0, 45 e 90 days. The results showed that rosemary extract has the major antioxidant effects when it is used on heterogeneous food matrix like beef burger, but oregano extract was better efficient to delay lipid oxidation along storage time when it is used in synergism with rosemary and/or BHT/BHA. Although to have occurred changes in the fatty acids composition it was not possible to demonstrate a straight dependence of irradiation dose and/or storage time. Sensory analysis showed that between the samples prepared with natural antioxidants, the beef burger prepared with oregano has received better scores by panelists. Irradiated beef burger prepared with rosemary has received better scores when compared to non-irradiated one. The use of spices with antioxidant activity to avoid the oxidative damage in foods that contain fats in their formulation is thought to be promising to application in food facilities. (author)

  3. Thermal analysis of polypropylene modified by gamma irradiation composites under outdoor conditions

    Komatsu, Luiz G.H.; Oliani, Washington L.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: dfparra@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This work reports the influence of the clay in the degradation process of the HMSPP.The polypropylene (PP) was irradiated under acetylene atmosphere in gamma irradiation source ({sup 60}Co) to obtain the HMSPP (high melt strength polypropylene). Composites of HMSPP were processed in twin-screw extruder with clay Cloisite 20A and Maleic Anhydride (PP-g-MA) as coupling agent. The obtained composites were exposed under outdoor conditions for 6 months. The ageing effects were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetry Analysis (TGA). Chemical oxidation was evaluated by Carbonyl Index (IC) through infrared Spectroscopy (FT-IR). The results showed correlation between carbonyl index and ageing time. (author)

  4. Influence of gamma irradiation on conductivity of YBa2Cu3O7

    We report a study on influence of gamma irradiation on conductivity of YBa2Cu3O7. We have measured the mass attenuation coefficient, effective atomic number, electron density and electrical conductivity for various gamma sources of energy ranging from 0.084 MeV to 1.330 MeV (170Tm, 57Co, 141Ce, 203Hg, 51Cr, 113Sn, 22Na, 137Cs, 60Co, 22Na and 60Co). The measured values agree with the theoretical values. The values of these parameters have been found to change with energy and interaction of gamma. We find evidence for a variation of the electrical conductivity of YBa2Cu3O7 with the irradiated photon energy and this variation is shown in figures up to 105 MeV. The variations of effective atomic number and electron density with energy are shown graphically for all photon interactions. Conductivity found to vary with the energy of the irradiated gamma radiation and interaction process of gamma. This kind of studies is important in the field of superconductivity. - Highlights: • We have studied the influence of gamma irradiation on conductivity of YBa2Cu3O7. • We find evidence for a variation of the electrical conductivity of YBa2Cu3O7 with the irradiated photon energy. • The conductivity of YBa2Cu3O7 found to vary with the interaction process of gamma. • This kind of studies is important in the field of superconductivity

  5. 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

  6. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of aniseed (anisum vulgare)

    Seeds of ansium were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator, Irradiated and unirradiated samples were stored at room temperature. Microbial population on seeds, dissolved organic and inorganic solids in extract and sensory properties of extract were evaluated after 0, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the aerobic plate counts. Immediately after irradiation, the dissolved organic solids in extract of irradiated seeds were higher than those of non-irradiated ones. The dissolved organic matter in extract of irradiated and un-irradiated ansium seeds increased. After 6 and 12 months of storage. There were no significant differences in dissolved solids between the extract of irradiated and non-irradiated ansium seeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of ansium seed extract tested immediately after irradiation; however, after 12 months of storage, no significant differences (P>0.05) were found in color, taste or odor between extract of irradiated and unirradiated ansium seeds. (author)

  7. Crosslinking of metallocenic α-olefin propylene copolymers by vacuum gamma irradiation

    Metallocenic polypropylene and copolymers with 3.7, and 9.2 mol% of hexene and 3.0 mol% of octadecene comonomer content were synthesized without the presence of additives and irradiated with 60Co gamma radiation under vacuum at room temperature. Size Exclusion Cromatography and gel extraction data showed that scission reactions predominate over crosslinking in the homopolymer and that there is a dose from where crosslinking started to increase considerably, in the irradiated copolymers. Rheology also showed evidence of chain-enlargements on the copolymers by means of an increase in the viscoelastic properties of the irradiated material. - Highlight: ► Vacuum gamma irradiation of metallocenic isotactic propylene copolymers. ► We examine the radioinduced changes in rheological properties and molecular weights. ► Radioinduced crosslinking in the copolymers, without the presence of additives. ► Dependence of crosslinking with copolymer′s length and amount of short branches.

  8. 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)

  9. Response of reptilian live to external gamma irradiation

    Adult healthy specimens of Uromastix hardwickii were exposed to three doses (i.e. 2.25, 4.50 and 9.00 Gy) of gamma radiation from a 60Co source (experimental group). Five animals were sacrificed at each post-irradiation intervals of 1, 2, 3, 7 and 14 days. The liver was fixed in Bouin's fluid and after processing in a routine way, it was examined histologically. Five sham-irradiated animals (control group) were also sacrificed to compare the results. Low dose (i.e. 2.25 Gy) did not produce any apparent radiolesions in the liver. Changes in the form of cytoplasmic degranulation, swollen hepatocytes, pycnosis, increases in bile pigmentation were noticed after 4.50 and 9.00 Gy gamma ray exposure. Hyperaemia, widening of sinusoids and cytoplasmic vacuolation were also noticed in 9.00 Gy group. The liver exhibited normal picture on day 14 after exposure to both the doses. The radiolesions were found dose dependent. (author)

  10. Effect of gamma irradiation on the behavioral properties of crotoxin

    E.G. Moreira

    1997-02-01

    Full Text Available Crotoxin has been detoxified with gamma radiation in order to improve crotalic antiserum production. Nevertheless, present knowledge of the biological characteristics of irradiated crotoxin is insufficient to propose it as an immunizing agent. Crotoxin is known to increase the emotional state of rats and to decrease their exploratory behavior (Moreira EG, Nascimento N, Rosa GJM, Rogero JR and Vassilieff VS (1996 Brazilian Journal of Medical and Biological Research, 29: 629-632. Therefore, we decided 1 to evaluate the effects of crotoxin in the social interaction test, which has been widely used for the evaluation of anxiogenic drugs, and 2 to determine if irradiated crotoxin induces behavioral alterations similar to those of crotoxin in the social interaction, open-field and hole-board tests. Male Wistar rats (180-220 g were used. Crotoxin (100, 250, and 500 µg/kg was injected intraperitoneally 2 h before the social interaction test. Similarly, irradiated crotoxin (2000 Gy gamma radiation from a 60Co source was administered at the doses of 100, 250, and 500 µg/kg for the hole-board test, and at the doses of 1000 and 2500 µg/kg for the open-field and social interaction tests. ANOVA complemented with the Dunnett test was used for statistical analysis (P<0.05. Crotoxin decreased the social interaction time (s at the doses of 100, 250 and 500 µg/kg (means ± SEM from 51.6 ± 4.4 to 32.6 ± 3.7, 28.0 ± 3.6 and 31.6 ± 4.4, respectively. Irradiated crotoxin did not induce behavioral alterations. These results indicate that 1 crotoxin may be an anxiogenic compound, and 2 in contrast to crotoxin, irradiated crotoxin was unable to induce behavioral alterations, which makes it a promising compound for the production of crotalic antiserum

  11. Free radicals in pyrimidines: ESR of. gamma. -irradiated 5-cyclohexenyl-1,5-dimethyl barbituric acid. [/sup 60/Co

    Benson, B. (Lehigh Univ., Bethlehem, PA); Erich, L.

    1981-06-01

    ESR studies have determined that ionizing radiation damage of hexobarbital (5-cyclohexenyl-1,5-dimethylbarbituric acid) causes the formation of a free radical (A) by hydrogen abstraction from the cyclohexenyl group. Hyperfine coupling tensors were determined for coupling of the unpaired electron to four protons. Visible light of wavelengths near 450 nm reversibly converts this radical to a second free radical (B) which also has the unpaired electron localized in the cyclohexenyl group. The activation energy for a thermally induced reverse conversion (B ..-->.. A) was determined to be 1.4 eV.

  12. Comparison of results of the manual and automated scoring of micronucleus frequencies in 60Co-irradiated peripheral blood lymphocytes for triage dosimetry

    Scoring micronuclei in the peripheral blood lymphocytes of individuals exposed to ionizing radiation is a rapid biodosimetry assay. Peripheral blood lymphocytes from five individuals were exposed in vitro to 0–5 Gy of 60Co γ-radiation at a dose rate of 0.76 Gy/min. The blood cultures were initiated with RPMI-1640 (80%) supplemented with FBS (20%), stimulated with mitogen and incubated at 37 °C for 44 h. At the 44th hour, cytochalasin-B (6 µg/mL) was added, and the cultures were incubated for 28 h more. The cells were harvested with a pre-chilled hypotonic solution (0.075 M) and fixed with a Carnoy's solution (methanol/acetic acid 5:1). Giemsa- and propidium-iodide-stained cells affixed to slides for microscopy were scored manually and automatically with the micronucleus scoring software from MetaSystems. The micronucleus frequencies determined in the Giemsa-stained cells by manual and automated scoring were 23.6% different (P<0.0001) with an efficiency of 24.9%. Slides stained with propidium iodide are a better choice for automated scoring than Giemsa-stained ones. - Highlights: • Stains (Giemsa and PI) used did not influence the MN dose response. • No significant variation in the MN yield at lower doses between scoring methods. • Automated scoring of MN in PI stained cells would be the choice for triage

  13. Study on the grafting of N-vinypyrrolidone onto xanthan gum by 60Co γ-irradiation and properties of the grafted copolymer

    Simultaneous radiation grafting method (60Co γ-rays as the radiation source) was used to prepare xanthan gum-graft-N-vinypyrrolidone (XG-g-NVP), and the influence factors of the grafting degree was preliminarily studied. The structure of the grafted copolymer was characterized by the Fourier-transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA), and the solution viscosity properties of the grafted copolymer in low grafting rate were studied by rheometer. The results show that the grafting rate increases with absorbed dose and gradually achieve to the balance. The grafting rate reaches maximum when the xanthan gum concentration is 10 g/L or the mass ratio is 10:1 meanwhile the other two factors are in a certain experimental value range. FT-IR figure shows that the grafting reaction occurs in NVP vinyl part and lactam structure is retained. Thermo-gravimetric analysis shows that XG-g-NVP enhanced thermal stability of xanthan gum. The properties of XG-g-NVP solution show that grafting to enhance the performance of resisting high temperature and shear strength. (authors)

  14. Microstructural study of Y1Ba2Cu3O7-x/Ag samples irradiated with 60Co γ rays at high doses

    We have investigated the damage induced by irradiation in Y1Ba2Cu3O7-x silver added samples. The samples were prepared with 0 and 6.5 wt% of silver and irradiated by high-energy γ irradiation (50-150 Mrad). The roles of silver and dosage irradiation are discussed in terms of their effects on microstructure, crystallinity, critical temperature (Tc) and zero-resistance temperature (T0). After irradiation, Tc decreased while the room-temperature electrical resistance increased by a factor of 8 for some of the samples. The difference in T0 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, Jc decreased because of the weak-link breakage induced by high doses of γ rays. (author)

  15. Study of the action of {sup 60}Co gamma radiation on Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris in mango pulp; Estudo da acao da radiacao gama de {sup 60}Co sobre Salmonella poona, Escherichia coli e Alicyclobacillus acidoterrestris em polpa de manga congelada

    Pereira, Marco Antonio dos Santos

    2009-07-01

    The application of non-thermal treatments has proven effective in inhibiting bacteria such as Salmonella and Escherichia coli. Mango is a fruit of national consumption with a great exportation potential. Meanwhile, outbreaks of food borne disease related to mango consumption caused mistrust on the degree of food security offered by the product. The objective of this work was to establish the radioresistance of bacteria Escherichia coli, Salmonella Poona and Alicyclobacillus acidoterrestris on the mango pulp by the calculation of the D10 values and to know the radiation effect on the sensory characteristics of the fruit pulp. The microbiological profile of frozen mango pulp available at the local market was also established using conventional methods of plating and Most Probable Number (MPN). The pulps experimentally inoculated with the bacteria listed above were irradiated with doses of 0, 1, 2, 3, 4 and 5kGy in a {sup 60}Co source. The sensory analysis was performed using a dose of 5 kGy, using the triangular test and the test of acceptance with hedonic scale. The results of this study show that the quality of mango pulp sell in the local market is not satisfactory in accordance with the standards established by the Brazilian law and the literature, showing the need of using other tools to achieve acceptable levels of quality. The D10 values obtained are in the range of 1.01 and 1.09kGy for E. coli ATCC 8739, 0.60 and 0.98kGy for S. poona and 0.72 e 0.88kGy for A. acidoterrestris respectively. The triangular test showed that a 5kGy radiation dose changed the sensory characteristics of mango pulp. Nevertheless, sensory analysis of a food product prepared with the irradiated pulp obtained good acceptance in the attributes of global appearance, flavor and aroma. (author)

  16. Study of the action of {sup 60}Co gamma radiation on Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris in mango pulp;Estudo da acao da radiacao gama de {sup 60}Co sobre Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris em polpa de manga congelada

    Pereira, Marco Antonio dos Santos

    2009-07-01

    The application of non-thermal treatments has proven effective in inhibiting bacteria such as Salmonella and Escherichia coli. Mango is a fruit of national consumption with a great exportation potential. Meanwhile, outbreaks of foodborne disease related to mango consumption caused mistrust on the degree of food security offered by the product. The objective of this work was to establish the radioresistance of bacteria Escherichia coli, Salmonella Poona and Alicyclobacillus acidoterrestris on the mango pulp by the calculation of the D10 values and to know the radiation effect on the sensory characteristics of the fruit pulp. The microbiological profile of frozen mango pulp available at the local market was also established using conventional methods of plating and Most Probable Number (MPN). The pulps experimentally inoculated with the bacteria listed above were irradiated with doses of 0, 1, 2, 3, 4 and 5 kGy in a {sup 60}Co source. The sensory analysis was performed using a dose of 5 kGy, using the triangular test and the test of acceptance with hedonic scale. The results of this study show that the quality of mango pulp sell in the local market is not satisfactory in accordance with the standards established by the Brazilian law and the literature, showing the need of using other tools to achieve acceptable levels of quality. The D10 values obtained are in the range of 1.01 and 1.09 kGy for E. coli ATCC 8739, 0.60 and 0.98 kGy for S. poona and 0.72 and 0.88 kGy for A. acidoterrestris respectively. The triangular test showed that a 5 kGy radiation dose changed the sensory characteristics of mango pulp. Nevertheless, sensory analysis of a food product prepared with the irradiated pulp obtained good acceptance in the attributes of global appearance, flavor and aroma. (author)

  17. Tolerance of edible flowers to gamma irradiation

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  18. Tolerance of edible flowers to gamma irradiation

    Koike, Amanda C.R.; Araujo, Michel M.; Costa, Helbert S.F.; Almeida, Mariana C.; Villavicencio, Anna Lucia C.H., E-mail: ackoike@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

    2011-07-01

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  19. The combined effect of the gamma radiations of 60 Co and different chemicals on the cells of the radicular vegetative tip of Allium sativum L

    The gamma ionizing radiations used alone in the treatment of Allium Sativum L. affected differently the cells belonging to the two zones of the root causing modifications of the cellular parameters which have been previously estimated. Data in the literature established that the damage of the interphasic nucleus of the cells determines the obstruction of the DNA synthesis and the delay of the cell mitosis. Sparrow, A. H., Miller, M. W. and Al-Rubeai confirmed the existence of a relationship between the nuclear volumes and the radiosensitivity of the different types of cells. The aim of this experiment was to counteract the harmful effect of gamma radiations at cellular level with the help of combined treatments, namely, the gamma radiations associated with different chemicals having radioprotective effects. The biological significance of the obtained values was established by statistical calculations with the help of the Student (t) test. The values of the estimated cellular parameters, NV, ICV, CV, NCR showed that, although there were certain fluctuations, their values were not always significant. (author)

  20. Analysis of the chromosome damage and repair kinetics in CHL cells after 6'0Co γ-irradiation by PCC technique

    The kinetics of chromosome damage and repair was determined by PCC. Chromosome damage repair was not detectable until 30 min after irradiation and nearly half of chromosome damage was repaired by 6 h. In contrast, significant DNA repair occurred at 5 min after γ-irradiation measured by FADU technique. These results suggest that the early repairing DNA SSBs are not important in the formation of chromosome aberration, the different repair kinetics between DNA and chromosome damages might reflect their different repair mechanism

  1. Use of Gamma Irradiation for Prolonging Shelf Life of Garden Pea (Pisum sativum L.)

    Garden pea pods of variety 'Arkel' were irradiated with 5 doses of 60Co gamma rays ranging from 0.5-3.0 kGy and stored at ambient temperature up to 9 days along with control to study the effect of radiation in prolonging shelf life of pea pods and stabilizing its market demand. Physiological weight loss (%) decreased as the doses of gamma radiation increased. Minimum weight loss was noted in pods irradiated with 3.0 kGy gamma rays compared to control. Decay loss % showed an inverse relationship with dose of gamma radiation. Minimum decay loss was recorded with 3.0 kGy gamma ray dose. Pea pods irradiated with 1.0 kGy gamma rays recorded maximum sugar content. Pods irradiated with 0.5 kGy and 1.0 kGy gamma rays retained their green colour for a longer period. Based on a 9 point hedonic scale the highest acceptability for appearance, taste and texture was observed in pods treated with the 1.0 kGy dose. (author)

  2. Alterations in monoamine oxidase activity of the mouse brain and liver after mixed neutron-gamma irradiation

    The activity of monoamine oxidase (MAO) was determined in mouse brain and liver after exposure to different kinds of ionizing radiation and after pretreatment with a radioprotective agent. After a lethal dose of mixed neutron-gamma irradiation the MAO activity decreased in the brain and increased in the liver. In contrast, after a lethal dose of 60Co-gamma irradiation enzyme activity was considerably increased in the brain while in the liver it increased like after mixed neutron-gamma irradiation. AET (S2-aminoethyl-isothiuronium-Br x HBr), when administered in a radioprotective dose, inhibited MAO activity in the brain, while it increased in the liver. Even more marked changes of enzyme activity were observed in both brain and liver after AET pretreatment and mixed neutron-gamma irradiation. The possible role of lipid peroxidation in alteration of MAO activity is discussed. (author)

  3. Changes of gene expression of platelet-derived growth factor-β and transforming growth factor-β1 mRNA in wound tissues after 60Co γ-irradiation and role of phenytoin sodium

    Objective: To study the changes of gene expression of growth factors in wound tissues after 60Co γ-irradiation and the role of phenytoin sodium. Methods: Wound tissues were collected from dorsum incision in rats, in which polyvinyl alcohol sponges had been implanted. The expressions of platelet-derived growth factor-B (PDGF-B) mRNA and transforming growth factor-β1 (TGF-β1) mRNA in wound tissues were determined by in situ bybridization. Results: It was found that the expressions of PDGF-B mRNA and TGF-β1 mRNA were decreased after 6 Gy whole-body irradiation, and phenytoin sodium significantly increased the expressions of PDGF-B mRNA and TGF-β1 mRNA in both irradiated and non-irradiated wounds. Conclusion: It is suggested that the decrease of expressions of growth factors in wound tissues plays an important role in the impairment of wound healing by systemic irradiation. Phenytoin sodium enhances the expression of growth factors in wound and helps improve wound healing

  4. 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.

  5. Influence of hormonal anabolic agents on hematopoietic system of gamma-irradiated laying hens

    Thirty laying hens were randomly divided into 3 groups (control), thiourea and estradiol benzoate) of 10 hens each, to find out the hematological response to ionizing radiation and hormonal treatments. Five hens from each group were exposed to 600 r whole body 60Co-gamma rays. Hematological parameters and plasma proteins were measured after 4 weeks post-irradiation gamma-irradiation significantly decreased WBCs, Hb, plasma total proteins and albumin. Estradiol benzoate injection significantly increased RBCs, Hb, plasma total proteins and albumin indicating that estradiol benzoate could minimize the reducing effect of gamma-rays. Thiourea administration depressed all of the studied hematological parameters and significantly increased plasma total proteins and significantly increased plasma total proteins and globulin. It can be concluded that ionizing radiation decreased the production and increased the destruction of Hb, RBCs, WBCs and plasma proteins. 4 tab

  6. Performance of p-bulk microstrip sensors under {sup 60}Co γ irradiation at rates expected at the HL-LHC

    Takahashi, Y. [IPAS, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Hara, K., E-mail: hara@hep.px.tsukuba.ac.jp [IPAS, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Kim, S. [IPAS, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Ikegami, Y.; Takubo, Y.; Terada, S.; Unno, Y. [INPS, High Energy Accelerator Research Org. (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Mitsui, S. [Sokendai, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Kamada, S.; Yamamura, K. [Hamamatsu Photonics Co. Ltd., Ichino, Hamamatsu Shizuoka 435-0051 (Japan)

    2013-01-21

    We are developing p-bulk microstrip sensors for the high luminosity upgrade of the LHC accelerator, HL-LHC. The stability of FZ (float zone) wafers available to Hamamatsu Photonics was examined by irradiating them at rates expected at the HL-LHC. They show degradation in the operational voltage at low dose but recover after the dose is accumulated. The instability is dependent on the bias voltage and dose rate, and also on the irradiation history. We have characterized the instability and attributed the cause to the charge concentration at the electrode edge. The strip isolation, which is degraded while in irradiation, is shown not to induce any practical problem for the operation.

  7. 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.

  8. The effect of gamma irradiation on the microbial load, mineral concentration and sensory characteristics of licorice (Glycyrrhiza glabra L.)

    Ground licorice roots were exposed to 0, 5, 10, 15 and 20 kGy of gamma radiation in a 60Co source. Irradiated and non-irradiated samples were stored at room temperature. Microbial population, viscosity, concentration of some minerals and sensory properties of the extract were evaluated after 0 and 12 months of storage. The results indicated that, immediately after irradiation, used doses reduced the microbial count and D10 was at about 2 kGy. No effect was observed in total dissolved solids in the extract of licorice roots. Glycyrrhizinic acid concentration in extract and viscosity of suspension produced from irradiated roots were lower than in non-irradiated ones. Sensory evaluation indicated that no significant differences (P+, Ca++ and K+) concentration in extract produced from irradiated roots were lower than in non-irradiated ones, and no significant differences (P< 0.05) were found in viscosity between suspension of irradiated and non-irradiated roots. (author)

  9. Effect of 60CO radiation processing in mate (Ilex paraguariensis)

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 3, 5, 7 and 10kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative and

  10. Effect of 60Co radiation processing in mate (Ilex paraguariensis)

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 3, 5, 7 and 10 kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10 kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10 kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative and

  11. Resistance of acrylic vessel to gamma irradiation

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the 222Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  12. Resistance of acrylic vessel to gamma irradiation

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  13. The influence of gamma irradiation in poultry

    The effect of a single whole - body gamma - irradiation of broiler chickens with a dose of 15.0 Gy on the activities of alaninaminotransferase (ALT) and aspartataminotransferase (AST) in the serum was investigated 1, 3, 5 and 7 days post irradiation. The numbers of erythrocytes and leucocytes and concentrations of haemoglobin in peripheral blood was investigated 1, 2, 4, 7, 9 and 14 days post irradiation. (authors)

  14. Preservation of potatoes by gamma irradiation

    In Algeria, potatoes are a major food item in nutrition habits. Because of lack of cold storage facilities, losses can reach up to 40% of the total output of summer harvest. This paper describes the first experiments on the application of gamma irradiation for the preservation of local varieties of potatoes. Losses are strongly reduced by inhibition sprouting effect of irradiation and reduction of sugars content has no significant influence on the acceptability of irradiated potatoes

  15. Effects of gamma irradiation and moisture absorption on mechanical properties of PA6/PTFE blends

    罗文波; 肖华明; 谭江华; 吴国忠; 林明丽

    2008-01-01

    PA6/PTFE blends with varying polytetrafluoroethylene content from 3% to 15%(mass fraction) were irradiated by 60Co gamma-ray with various doses(20,50 and 100 kGy) under ambient conditions.Moisture absorption test,U-notched Charpy impact test and quasi-static tension and bending were conducted to investigate the effect of irradiation on moisture absorption and mechanical properties of the blends.It is shown that the exposure of the blend to 60Co irradiation improves the tensile modulus,tensile strength and flexural modulus due to irradiation induced cross-linking in PA6 phase.However,the Charpy impact strength of the blends is much lower than that of the original PA6 and it decreases slightly with the increase of irradiation dose.Moreover,the flexural modulus increases to a maximum value and then decreases with further increasing the PTFE content,and the moisture absorption decreases with the increase of the PTFE content and irradiation dose.

  16. Severe acute radiation syndrome. Treatment of a lethally 60Co-source irradiated accident victim in China with HLA-mismatched peripheral blood stem cell transplantation and mesenchymal stem cells

    This is a case report of a 32-year-old man exposed to a total body dose of 14.5 Gy γ-radiation in a lethal 60Co-source irradiation accident in 2008 in China. Frequent nausea, vomiting and marked neutropenia and lymphopenia were observed from 30 min to 45 h after exposure. HLA-mismatched peripheral blood stem cell transplantation combined with infusion of mesenchymal stem cells was used at Day 7. Rapid hematopoietic recovery, stable donor engraftment and healing of radioactive skin ulceration were achieved during Days 18-36. The patient finally developed intestinal obstruction and died of multi-organ failure on Day 62, although intestinal obstruction was successfully released by emergency bowel resection. (author)

  17. Gamma radiation sensitivity in tomato tree and response of plants proceeding from salinity irradiated seeds

    Preliminary experiments were conducted to evaluate the radiosensitivity of tomato {Lycopersicon esculentum L. cultivars IPA-6, IPA-8, and Lycopersicum hirsutum glabratum - } to gamma rays from a 60Co source, considering future induced mutation studies aiming at the improvement of plant salinity tolerance. Sets of dry seeds were exposed to gamma radiation doses (300 - 600 Gy and 100-400 Gy) and compared to a control without irradiation (0 Gy) under greenhouse conditions. The radiosensitivity was initially evaluated through germination of irradiated dry seeds determined at 13 and 30 days after irradiation and also through seedling survival. Seed germination was delayed by gamma irradiation and especially reduced at higher doses (300- 600 Gy). Survival of tomato plants was decreased with increased dose of radiation and was reduced by < 16% at the 300-600 Gy doses. Growth of plants was enhanced at low doses of gamma rays; higher doses reduced plant size. Gamma irradiation had significant effects on tomato plants generated from dry seed and submitted to different levels of salinity. It is recommended a dose range of 100-200 Gy for mutation breeding purpose using the varieties tested. (author)

  18. Research of Effect of 60Co γ-ray Irradiation on Cell Cycle of SMMC, 7721 Tumor Cell with Flow Cytometery

    DangBingrong; MaQiufeng; GaoQingxiang; LiWenjian; HaoJifang; XieYi; GuoChuanling

    2003-01-01

    The resultsMost researchof cell cycle play an important role in resear, ching tumor occurrence, development and treatment. results show that malignant grade and pharmic sensitivity of tumor are relative to cell cycle. The sensitivity of medications is different to different phases of cell cycle of tumor. In general, the cell of M are more sensitivity. On the side, different medications have different action in different cell cycle. The irradiation can change cell cycle proccss and can induce the pattern of changes in cell cycle. For cxamplc, G1 arrest, G2 arrest and S arrest. So, thc research rcsults of tumor cell cycle in different irradiation have not only biological means but also realistic means for selecting chemical therapy medication after radiotherapy.

  19. Stability of vitamin E content of {gamma}-irradiated biscuits

    Taipina, Magda S.; Mastro, Nelida L. del [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@ipen.br; magtaipina@ig.com.br; Lamardo, Leda C.A. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Quimica Biologica]. E-mail: llamardo@ial.sp.gov.br

    2007-07-01

    The technology of food irradiation is seen by the industry as a means of ensuring food safety, since it exposes foods to ionizing radiation that kills insects, moulds and bacteria. The need to eliminate bacterial pathogens from read-to-eat food products must always be balanced with the maintenance of product quality. In addition to determining the effective ionizing radiation doses required for pathogen elimination the effects of irradiation on product chemistry, nutritional value and quality must also been determined. Vitamin E ({alpha}-tocopherol) is one of the most potent natural lipophilic antioxidants commonly present in the human diet. As it is considered a free radical scavenger there is a growing concern that irradiation might reduce the vitamin E content of food products prepared with ingredients rich in any of the dietary source of the vitamin. This work describes the effects of ionizing radiation on the vitamin E content of some biscuits commercially found in the market. Three lots of biscuits were used. Irradiation was performed in a {sup 60}Co Gammacell 220 source, dose rate of about 3.5 kGy/h at doses of 1 kGy and 3 kGy. For vitamin E determination samples were saponified with ethanolic potassium hydroxide in the presence of pyrogallol, and the tocopherols were extracted with petroleum ether. The absorbance was measured at 520 nm. From the obtained results it is possible to conclude that there was a notorious stability of the vitamin content of the biscuits submitted to gamma-irradiation at the assayed doses. (author)

  20. Effects of restrain and regulation on production of β-adrenergic receptors in lung of Sprague-Dawley rats by 60Co γ-ray irradiation

    Objective: To study the restrain and regulation on production of β-adrenergic receptors in Sprague-Dawley rat lung by 20 Gy γ-ray irradiation. Methods: To determine production of β-adrenergic receptors (Bmax) after irradiation and BAAM irreversible blockade by radioligand binding assay of receptors. Results: β-adrenergic receptors were sensitive to γ-rays, and the sensitivity level declined to the lowest on day 20 after radiation, then the receptors were recovered gradually. But the receptor production rate (Pr) was slower, i. e., Pr was (0.36±0.03) x 109 sites/mg protein/h [control groups, (8.20 ± 1.47) x 109]. The half-time of update (T1/2 ) was put off for 10.9 days as compared to BAAM group. Conclusion: Production of receptors can be restrained by 20 Gy γ-ray irradiation, resulting in lower receptor production rate, and longer half-time of update (T1/2 ). (authors)

  1. The effect of gamma irradiation on the germination and growth of certain Nigerian agricultural crops

    Mokobia, C E; Anomohanran, O [Department of Physics, Delta State University, Abraka, Delta State (Nigeria)

    2005-06-01

    Gamma irradiation has been found to be very useful both for sterilisation in medicine and the preservation of food and cereals in nutrition and agriculture. This investigation was carried out to determine the effect of gamma irradiation on the subsequent germination and growth of irradiated seeds. Thirty seeds each of maize, okra and groundnut were irradiated to varying doses of 150, 300, 500, 700, 900, 1000 Gy using the {sup 60}Co gamma cell irradiator facility at the Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife. These, as well as the controls (unirradiated seeds), were planted on the same day in an already prepared area of farmland during the rainy season to ensure a constant moisture flow. The times of germination and subsequent growth were monitored. Results show that maize, okra and groundnut seeds needed for planting can be safely stored using gamma irradiation. However, the study reveals that the number of germinated seeds and the growth rate for the crops decrease with increase in the radiation dose the seeds were exposed to. Third-degree polynomial equations were derived which describe the percentage germination of the crops at various levels of exposure. A chart of percentage germination of seeds versus exposure dose is also presented as a quick guide to farmers, policy makers and agricultural institutions. (note)

  2. The effect of gamma irradiation on the germination and growth of certain Nigerian agricultural crops

    Gamma irradiation has been found to be very useful both for sterilisation in medicine and the preservation of food and cereals in nutrition and agriculture. This investigation was carried out to determine the effect of gamma irradiation on the subsequent germination and growth of irradiated seeds. Thirty seeds each of maize, okra and groundnut were irradiated to varying doses of 150, 300, 500, 700, 900, 1000 Gy using the 60Co gamma cell irradiator facility at the Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife. These, as well as the controls (unirradiated seeds), were planted on the same day in an already prepared area of farmland during the rainy season to ensure a constant moisture flow. The times of germination and subsequent growth were monitored. Results show that maize, okra and groundnut seeds needed for planting can be safely stored using gamma irradiation. However, the study reveals that the number of germinated seeds and the growth rate for the crops decrease with increase in the radiation dose the seeds were exposed to. Third-degree polynomial equations were derived which describe the percentage germination of the crops at various levels of exposure. A chart of percentage germination of seeds versus exposure dose is also presented as a quick guide to farmers, policy makers and agricultural institutions. (note)

  3. Decoloration Kinetics of Waste Cooking Oil by 60Co γ-ray/H2O2

    Xiang, Yulin; Xiang, Yuxiu; Wang, Lipeng

    2016-03-01

    In order to decolorize, waste cooking oil, a dark red close to black solution from homes and restaurants, was subjected to 60Co γ-ray/H2O2 treatment. By virtue of UV/Vis spectrophotometric method, the influence of Gamma irradiation to decoloration kinetics and rate constants of the waste cooking oil in the presence of H2O2 was researched. In addition, the influence of different factors such as H2O2 concentration and irradiation dose on the decoloration rate of waste cooking oil was investigated. Results indicated that the decoloration kinetics of waste cooking oil conformed to the first-order reaction. The decoloration rate increased with the increase of irradiation dose and H2O2 concentration. Saponification analysis and sensory evaluation showed that the sample by 60Co γ-ray/H2O2 treatment presented better saponification performance and sensory score. Furthermore, according to cost estimate, the cost of the 60Co γ-ray/H2O2 was lower and more feasible than the H2O2 alone for decoloration of waste cooking oil.

  4. Investigation of Thermoluminescence Properties of Gamma- Irradiated Synthetic TL -Compound

    Calcium sulphate doped by dysprosium (CaSO4:Dy) has been locally prepared under laboratory controlled condition. Two standard techniques were used during the course of this work to achieve the optimum concentration of the activator (Dy). The obtained samples were thermally treated to improve its sensitivity as well as its stability. The glow curves of the prepared CaSO4:Dy have been taken after gamma irradiation and show three glow peaks at about 140, 225 and 350 degree C. The main dosimetric glow peak is located at 225 degree C. . It is observed also that the dosimetry peak is shifted to lower direction by increasing the dopant concentration from 0.5% up to 3% by about 15 degree C. The experimental results show that the optimum concentration of Dy in CaSO4 could be achieved when 2% by Wt. of the dopant is added to the host lattice. Also maximum sensitization is obtained when the samples are thermally annealed at 600 degree C for 100 minutes. The prepared samples are also sensitized by high dose ?-irradiation (7 kGy) from 60Co source. The rate of fading of these TL detectors is 11% after storage for three months in ambient temperature. These results have been discussed in greater details

  5. Toxoplasma gondii vs ionizing radiation: cell and humoral immunity in spleen and gut of isogenic mice immunized with 60Co irradiated tachyzoites

    We are developing a vaccine for toxoplasmosis, using ionizing radiation as a tool. Here we analyzed the production of systemic and intestinal immunity, with protection studies, in several strains of inbred mice, by oral or parenteral route, using 255 Gy irradiated tachyzoites of T. gondii RH strain, with challenge with cysts of ME- 49 strain. C57Bl/6j, BALB/c and C57Bl/6j IFN-γ-/- mice were immunized with 107 irradiated tachyzoites, be parenteral or oral route. Those preparations, both by parenteral or oral routes, induced the production of specific IgG, mainly of the lgG2b subclass, and IgA immunoglobulins in serum, , as determined by ELISA. IgM production was negligible. Parenteral immunized mice showed higher IgG avidity maturation, as compared to oral immunized mice. Fecal excretion of IgG, IgA and IgM was detected in stools of immunized animals, more intense in oral immunized mice. In cellular immunity studies, induced by antigen, with detection of cytokine production by quantitative real-time PCR, there are a great production of IFN-y by spleen cells, with lower levels in Peyer patches cells, where there are a greater IL-2 production. Challenge studies in immunized mice demonstrated protection to infection in all used schedules, greater in BALB/c mice. C57Bl/6j IFN-γ -/- mice, when immunized, showed no signs of disease and produced similar or greater levels of antibodies than wild type mice. They also excreted S-lgA and S-IgM in stools, but with low numbers of brain cysts in parenteral immunized mice, despite similar mortality. Our data points to a fair possibility of use of those irradiated parasites as an oral vaccine, devised to use for veterinary or wild felines vaccination, reducing the production of oocysts by those hosts and interrupting the chain transmission of human toxoplasmosis. (author)

  6. The use of gamma irradiation for improving microbiological qualities of spices

    The ability of gamma irradiation in reducing microbial contamination was investigated in turmeric, black pepper and chilli. The initial total plate count varied from 104-106, coliform count from 102-105, spores from 1 2-105 and yeast and moulds from 102-103 per gram of the sample. Treatment with γ-rays (60Co) at dose levels of 1-10 kGy were studied. From the data, it was concluded that dose levels of 4-5 kGy were sufficient to reduce the bioburden to acceptable levels. (author). 3 figs., 19 refs

  7. Inactivation of mildew in rough rice and wheat by gamma irradiation

    Rough rice and wheat were irradiated by gamma ray (60Co) with different doses and the mildew inactivation efficacy was investigated after 0, 6 and 12 month storage. Five genera of mildew in rough rice and wheat were detected, including Alternaria, Fusarium, Aspergillus, Penicillium and Rhizopus. For Aspergillus, four genera of mold were detected, including Aspergillus Kawachii, Aspergillus glaucus, Aspergillus niger, Aspergillus flavus. Detection rates of the five genera of mildew and four genera of Aspergillus were all reduced with increasing dose after 0, 6 and 12 months storage. The detection rates of the other four genera of mildew had no significant change during storage.

  8. Inactivation of mildew in rough rice and wheat by gamma irradiation

    Wang Jun, E-mail: jwang@zju.edu.c [Department of Biosystems Engineering, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029 (China); Yu Yong [Department of Biosystems Engineering, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029 (China)

    2010-06-15

    Rough rice and wheat were irradiated by gamma ray ({sup 60}Co) with different doses and the mildew inactivation efficacy was investigated after 0, 6 and 12 month storage. Five genera of mildew in rough rice and wheat were detected, including Alternaria, Fusarium, Aspergillus, Penicillium and Rhizopus. For Aspergillus, four genera of mold were detected, including Aspergillus Kawachii, Aspergillus glaucus, Aspergillus niger, Aspergillus flavus. Detection rates of the five genera of mildew and four genera of Aspergillus were all reduced with increasing dose after 0, 6 and 12 months storage. The detection rates of the other four genera of mildew had no significant change during storage.

  9. Five detector set-up for positron 1D-ACAR study of 60Co containing materials

    Design of the five detector set-up, for 1-Dimensional Angular Correlation of Annihilation Radiation (1-ACAR) study of 60Co-containing materials as well as test measurements are described. The equipment is based on simultaneous registration of a starting positron (by detection of gamma-photon with energy 1274 keV) and its annihilation with an electron in the studied material (by detection of two annihilation gamma photons with the energy 511 keV emitted mainly at the 180o-angle). Through this triple coincidence the distributing 60Co-contribution (gamma-photons with energy of 1.17 and 1.33 MeV) can be effectively separated from the annihilation spectra of irradiated reactor pressure vessel steel specimens. (author). 8 refs, 2 figs

  10. Quality of gamma irradiated California Valencia oranges

    The effects of gamma irradiation at 0.30-1.0 kGy (30-100 krad) on sensory qualities, certain biochemical components, and short-term storage life of Valencia oranges were examined. Irradiation at 0.75 kGy maintained food quality during 7°C storage for 7 weeks, while 0.50 kGy irradiation retained food quality at 21 °C. Irradiation at 0.26-0.30 kGy accomplished fruit fly disinfection while preserving market qualities of the oranges

  11. Simulation of gamma irradiation system for a ballast water treatment

    Invasion by different kinds of ballast the water microorganisms is one of the most important marine environment problems around the world therefore preventing the invasion of these unwanted and harmful stowaways is one of the main strategies of responsible agencies. Some of these methods such as ocean exchange, heating, filtration, hydro cyclones, UV irradiation and chemical treatment, have various problems such as technical deficiency, high costs, lack of safety and environmental side effects. Materials and Methods: A novel system of treatment by Gamma irradiation is designed to irradiate the blast water uniformly and effectively. To determine the dose distribution as a function of distance from the irradiation source, the MCNP code was used. The systems used for source implant in this simulation were Paterson-Parker, Paris and Network systems. In each system, Sivert-integral and inverse square law were used in MATLAB program to determine the dose distribution. Results: Results of initial laboratory tests on offshore water samples of Siri Island indicated that the appropriate dose for deactivation of organisms of water samples is approximately one kGy. It has been demonstrated that the dose can be provided by twenty five 100,000 Ci line sources of '60Co in a triangle implant arranged in a 1*1*1 m3 cubic shape water pipe. In order to increase efficiency and radiation safety, water passed from two other coaxial and bigger cubes, after passing from the first cube. A one meter thick wall of concrete around the cubes was adequate to shield the system completely. Conclusion: The main advantages of this system such as high efficiency, safety, reliability, minimum environmental adverse effects, proves that this novel method not only can be used for ballast water treatment, but is also effective for drinking water purification

  12. Application of gamma irradiation technique for the preservation of propolis

    Irradiation has been recognized as an efficient method for the reduction of deteriorating and pathogenic microorganisms in foods. Propolis is a resinous product made by bees from material processed by the bee's own metabolism and resins from plants. The aim of this work was the application of gamma irradiation technique for the preservation of propolis, because of its efficiency in the reduction of the microbial load. The changes on the total flavonoids content, phenolic compounds and other characteristics required for the qualification and characterization of Brazilian propolis were also analysed. Propolis samples from Juiz de Fora region, Minas Gerais, were irradiated in a 60Co source, with doses from 0 to 10kGy for the microbiological analyses and 5.0, 7.0 and 10.0kGy for the physico-chemical analyses. The physico-chemical that have been made were: determination of total flavonoids content, semi-quantitative determination of phenolic compounds (artepelin-C, kempferol, chrysin, galangin and quercetin), dry matter analysis, humidity, ash content, mechanical mass and waxes. The ionizing radiation has shown to be efficient in the reduction of the microbial load. Total coliforms determination showed a great reduction with the dose of 3kGy and concerning mesophile aerobic bacteria a systematic reduction was observed, achieving values <10 UFC/g for the dose of 10kGy; similar results was obtained for molds and yeasts. Salmonella assays were negative for all samples. There was no significant alteration on total flavonoids contents nor on the composition of phenolic compounds as a consequence of radiation application at the assayed conditions. The complementary analyses of dry matter and humidity contents, ashes, mechanical mass and waxes did not shown changes after irradiation even with the maximum dose of 10kGy, remaining the results within the standards required by the Brazilian legislation. (author)

  13. Protective effect of poly ({alpha}-L-glutamate) against UV and {gamma}-irradiation

    Furuta, Masakazu E-mail: mfuruta@riast.osakafu-u.ac.jp; Huy, Nguyen Quang; Tsuchiya, Akihito; Nakatsuka, Hiroshige; Hayashi, Toshio

    2004-10-01

    We occasionally found that poly ({alpha}-L-glutamate) showed a superior protective effect on enzymes against UV and {sup 60}Co-{gamma} irradiation. We selected papain and {alpha}-amylase as a model enzyme and irradiated the aqueous solution (10 mg/ml) of each enzyme with UV and {sup 60}Co-{gamma} rays in the presence of poly ({alpha}-L-glutamate) ({alpha}-PGA), poly (glucosyl oxyethyl methacrylate (GEMA)), and glucose (1.25% w/v each). The mixture of the three compounds has a significant protective effect on the activity of papain solution showing 40% of remaining activity twice as much as the control containing no additive at the dose of 15 kGy. Among them, {alpha}-PGA showed the highest protecting effect on the both papain and {alpha}-amylase even after 10-kGy irradiation at which 50% of the activity was retained. {alpha}-PGA also showed significant protective activity on {alpha}-amylase against UV both in solution and under dried state.

  14. Gemstone enhancing dedicated gamma irradiator development

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to it's poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator raised in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations were performed. With the definitive irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. (author)

  15. Development of modified starch by gamma irradiation

    The purpose of this study was to develop the production technology of modified starch. Corn starches were gamma irradiated at 0-110 kGy and the effect of irradiation dose levels on the physicochemical properties of corn starches were investigated. Blue value linearly decreased, while alkali number and solubility markedly increased as irradiation dose levels were increased. The optical transmittance increased as applied irradiation dose levels were increased in the temperature range of 65-95 deg. C. Water binding capacity and swelling power showed maximum value at 30 and 10 kGy, respectively and they tended to decrease thereafter. Gelatinization viscosity of the gamma irradiated starch considerably decreased as compared to that of the non-irradiated starch. Irradiation at 110kGy resulted in a marked reduction of peak viscosity and cooling viscosity at 30 deg. C by 100 and 300 times, respectively. The physicochemical properties of corn starch irradiated at 30 kGy were similar to those of commercial acid-modified starch, while those of corn starch irradiated at 100 kGy were similar to those if oxidized starch

  16. Analysis of gamma irradiated pepper constituents, 5

    Gamma irradiated peppers (10 krad, 100 krad, 1 Mrad) were analyzed by HPLC. The extraction method and HPLC conditions were same as the first report, that is, the extraction from pepper was performed by Automatic Air Hammer and the extracted samples were separated on a reversed phase C8 column with a concave gradient from 0.1% trifluoro aceticacid (TFA) in water to 75% acetonitrile-0.1% TFA in water for 60 minutes and detected at 210 nm, 280 nm. It is difficult to compare with irradiated and unirradiated pepper constituents by their peak height or area. And the method of multi variant statistically analysis was introduced. The 'peak n area/peak n + 1 area' ratio was calculated by computer. Each peak area was accounted by integrator. The value of these ratio were called 'parameter'. Each chromatogram has 741 parameters calculated with 39 chromatographic peaks. And these parameters were abopted to the multi variant statiscally analysis. Comparison of constituents between irradiated pepper and unirradiated pepper was done by 741 parameters. The correlation of parameters between irradiated and unirradiated was investigated by use of computer. Some parameters of irradiated case were selected as which had no correlation with unirradiated case. That is to say these parameters were thought to be changed with gamma spectrum irradiation. By this method, Coumarin was identified as a changed component with gamma irradiation. (author)

  17. 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.

  18. Use of gamma irradiation for prolonging shelf life of Garden pea (Pisum sativum L.)

    Garden pea pods of variety Arkel were irradiated with 5 doses of 60Co gamma rays ranging from 0.5-3 kGy and stored at ambient temperature up to 9 days along with control to study the effect of radiation in prolonging shelf life of pea pods and stabilizing its market demand. Physiological weight loss percentage decrease as the doses of gamma radiation increased. Minimum weight loss was noted in pods treated with 3 kGy gamma radiation as compared to control. Decay loss percent showed inverse relation with dose of gamma radiation. The minimum decay loss was recorded in 3 kGy and the organisms identified for decay loss were Alternaria and Cladosporium species of fungi. With regard to sugar content, pea pods irradiated with 1 kGy gamma rays recorded maximum sugar content. Pods irradiated with 0.5 kGy and 1 kGy gamma rays retained their green colour for a long period (up to 9th day of storage). Based on 9 point's hedonic scale the overall acceptability for appearance, taste and texture was observed in 1 kGy treatment. (author)

  19. Evaluation of gamma irradiation impact on antibacterial activity, chemical and physical characteristics of the sodium cifteraxon compound

    To investigate the effect of gamma irradiation on the solid state of ceftriaxon sodium salt (C18H16N8Na2O7S3) as a member of the third generation of cephalosporins. Solid Ceftriaxon as a pharmaceutical dosage was exposed to doses of 0, 5, 10, 15, 20, 25, and 50 kGy in 60Co package irradiator. Physical and chemical characteristics of ceftriaxon have been investigated by using UV (Ultra Violet) and IR (Infra Red) spectroscopic, pH, solubility and DSC (Differential Scanning Calorimetric) methods. Antibacterial activity of ceftriaxon was investigated using Escherichia coli ATCC 25922 as a strain of bacteria. The obtained results indicated that gamma irradiation have no effect on physical and chemical characteristics of ceftriaxon, No significant differences were found between irradiated and non-irradiated samples in the Antibacterial activity of ceftriaxon on E. Coli.(author)

  20. Sewage Water Treatment by Gamma Irradiation

    This study indicates that Gamma irradiation could be the solution for raising the standards of disinfection in waste water of Damascus city up to the international standards, when samples of the inlet of the planet was irradiated with Gamma radiation at dose rate of 3.4 KGy./hr The radiation sensitivity of total micro-organisms, fungi, and pathogenic bacteria was 0.316, 0.318 , 0.306 KGy respectively Also the results showed the absence of Ascaris Lumbricoides ova which permit reusing the recycled waste water in irrigation safely. (authors)