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Sample records for gamma-irradiated tobacco cultured

  1. Study of free radicals in gamma irradiated cellulose of cultural heritage materials using Electron Paramagnetic Resonance

    NASA Astrophysics Data System (ADS)

    Kodama, Yasko; Rodrigues, Orlando, Jr.; Garcia, Rafael Henrique Lazzari; Santos, Paulo de Souza; Vasquez, Pablo A. S.

    2016-07-01

    Main subject of this article was to study room temperature stable radicals in Co-60 gamma irradiated contemporary paper using Electron Paramagnetic Resonance spectrometer (EPR). XRD was used to study the effect of ionizing radiation on the morphology of book paper. SEM images presented regions with cellulose fibers and regions with particles agglomeration on the cellulose fibers. Those agglomerations were rich in calcium, observed by EDS. XRD analysis confirmed presence of calcium carbonate diffraction peaks. The main objective of this study was to propose a method using conventional kinetics chemical reactions for the observed radical formed by ionizing radiation. Therefore, further analyses were made to study the half-life and the kinetics of the free radical created. This method can be suitably applied to study radicals on cultural heritage objects.

  2. Resistance of a cultured fish cell line (CAF-MM1) to. gamma. irradiation

    SciTech Connect

    Mitani, H.; Etoh, H.; Egami, N.

    1982-02-01

    Fish are generally more resistant to whole-body ionizing radiation than mammals. To study the radiosensitivity of fish in vitro, CAF-MM1 cells derived from the fin of the goldfish, Carassius auratus, were used. The survival parameters of CAF-MM1 obtained after ..gamma.. irradiation at 26/sup 0/C were 325 rad for D/sub o/, 975 rad for Dq, and 15 for n. No mammalian cell line with such a low sensitivity in the presence of O/sub 2/ has been reported. It was found that the large initial shoulder of the survival curve was paralleled by substantial repair of sublethal damage as evidenced by split-dose experiments. This low sensitivity to ..gamma.. irradiation did not change upon the administration of caffeine or postirradiation illumination, although these treatments were effective after uv irradiation. The decrease in the mitotic index in CAF-MM1 occurred immediately after irradiation, and it recovered within a very short time. This indicated that the duration of G2 arrest was shorter than that observed in mammalian cells. The data also suggest that the resistance of fish to whole-body irradiation is attributable to resistance at the cellular level.

  3. Effect of gamma irradiation on Korean traditional multicolored paintwork

    NASA Astrophysics Data System (ADS)

    Yoon, Minchul; Kim, Dae-Woon; Choi, Jong-il; Chung, Yong-Jae; Kang, Dai-Ill; Hoon Kim, Gwang; Son, Kwang-Tae; Park, Hae-Jun; Lee, Ju-Woon

    2015-10-01

    Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d'Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.

  4. Evolution of DNA strand-breaks in cultured spermatocytes: the Comet Assay reveals differences in normal and gamma-irradiated germ cells.

    PubMed

    Perrin, J; Lussato, D; De Méo, M; Durand, P; Grillo, J-M; Guichaoua, M-R; Botta, A; Bergé-Lefranc, J-L

    2007-02-01

    In reproductive toxicity assessment, in vitro systems can be used to determine mechanisms of action of toxicants. However, they generally investigate the immediate effects of toxicants, on isolated germ cells or spermatozoa. We report here the usefulness of in vitro cultures of rat spermatocytes and Sertoli cells, in conjunction with the Comet Assay to analyze the evolution of DNA strand-breaks and thus to determine DNA damage in germ cells. We compared cultures of normal and gamma-irradiated germ cells. In non-irradiated spermatocytes, the Comet Assay revealed the presence of DNA strand-breaks, which numbers decreased with the duration of the culture, suggesting the involvement of DNA repair mechanisms related to the meiotic recombination. In irradiated cells, the evolution of DNA strand-breaks was strongly modified. Thus our model is able to detect genotoxic lesions and/or DNA repair impairment in cultured spermatocytes. We propose this model as an in vitro tool for the study of genotoxic injuries on spermatocytes.

  5. Production of modified starches by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kang, Il-Jun; Byun, Myung-Woo; Yook, Hong-Sun; Bae, Chun-Ho; Lee, Hyun-Soo; Kwon, Joong-Ho; Chung, Cha-Kwon

    1999-04-01

    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.

  6. Inactivation of fungal contaminants on Korean traditional cashbox by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Choi, Jong-il; Lim, Sangyong

    2016-01-01

    In this study, gamma irradiation was applied to decontaminate a Korean cultural artifact, a wooden cashbox stored in local museum. Fungi isolated from the wooden cashbox were identified by 18S rDNA sequencing methods. It was observed that the isolated fungi exhibited high similarity to Aspergillus niger, Penicillium verruculosum, and Trichoderma viride. Each strain was tested for sensitivity to gamma irradiation, and was inactivated by the irradiation at a dose of 5 kGy. The wooden cashbox was thus gamma-irradiated at this dose (5 kGy), and consequently decontaminated. Two months after the irradiation, when the wooden cashbox was retested to detect biological contamination, no fungi were found. Therefore, these results suggest that gamma irradiation at a low dose of 5 kGy can be applied for successful decontamination of wooden artifacts.

  7. Hardness Evolution of Gamma-Irradiated Polyoxymethylene

    NASA Astrophysics Data System (ADS)

    Hung, Chuan-Hao; Harmon, Julie P.; Lee, Sanboh

    2016-12-01

    This study focuses on analyzing hardness evolution in gamma-irradiated polyoxymethylene (POM) exposed to elevated temperatures after irradiation. Hardness increases with increasing annealing temperature and time, but decreases with increasing gamma ray dose. Hardness changes are attributed to defects generated in the microstructure and molecular structure. Gamma irradiation causes a decrease in the glass transition temperature, melting point, and extent of crystallinity. The kinetics of defects resulting in hardness changes follow a first-order structure relaxation. The rate constant adheres to an Arrhenius equation, and the corresponding activation energy decreases with increasing dose due to chain scission during gamma irradiation. The structure relaxation of POM has a lower energy barrier in crystalline regions than in amorphous ones. The hardness evolution in POM is an endothermic process due to the semi-crystalline nature of this polymer.

  8. Trafficking in tobacco farm culture: Tobacco companies use of video imagery to undermine health policy

    PubMed Central

    Otañez, Martin G; Glantz, Stanton A

    2009-01-01

    The cigarette companies and their lobbying organization used tobacco industry-produced films and videos about tobacco farming to support their political, public relations, and public policy goals. Critical discourse analysis shows how tobacco companies utilized film and video imagery and narratives of tobacco farmers and tobacco economies for lobbying politicians and influencing consumers, industry-allied groups, and retail shop owners to oppose tobacco control measures and counter publicity on the health hazards, social problems, and environmental effects of tobacco growing. Imagery and narratives of tobacco farmers, tobacco barns, and agricultural landscapes in industry videos constituted a tobacco industry strategy to construct a corporate vision of tobacco farm culture that privileges the economic benefits of tobacco. The positive discursive representations of tobacco farming ignored actual behavior of tobacco companies to promote relationships of dependency and subordination for tobacco farmers and to contribute to tobacco-related poverty, child labor, and deforestation in tobacco growing countries. While showing tobacco farming as a family and a national tradition and a source of jobs, tobacco companies portrayed tobacco as a tradition to be protected instead of an industry to be regulated and denormalized. PMID:20160936

  9. Use of gamma irradiation to prevent aflatoxin B 1 production in smoked dried fish

    NASA Astrophysics Data System (ADS)

    Ogbadu, G. H.

    Smoked dried fish bought from the Nigerian market was inoculated with spores of barAspergillus flavus (U.I. 81) and irradiated with doses of 0.625, 1.25, 2.50 and 5.00 KGy gamma irradiation. The effect of aflatoxin B 1 production on subsequent incubation for 8 days as stationary cultures was measured. The amount of aflatoxin B 1 produced was found to decrease with increased gamma irradiation dose levels. While the non-irradiated control produced significantly (at 1% level) greater amounts of aflatoxin B 1 as compared to the treated cultures.

  10. White spot syndrome virus inactivation study by using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Heidareh, Marzieh; Sedeh, Farahnaz Motamedi; Soltani, Mehdi; Rajabifar, Saeed; Afsharnasab, Mohammad; Dashtiannasab, Aghil

    2014-09-01

    The present study was conducted to investigate the effect of gamma irradiation on white spot syndrome virus (WSSV). White spot syndrome virus is a pathogen of major economic importance in cultured penaeid shrimp industries. White spot disease can cause mortalities reaching 100% within 3-10 days of gross signs appearing. During the period of culture, immunostimulant agents and vaccines may provide potential methods to protect shrimps from opportunistic and pathogenic microrganisms. In this study, firstly, WSSV was isolated from infected shrimp and then multiplied in crayfish. WSSV was purified from the infected crayfish haemolymph by sucrose gradient and confirmed by transmission electron microscopy. In vivo virus titration was performed in shrimp, Penaeus semisulcatus. The LD50 of live virus stock was calculated 10 5.4/mL. Shrimp post-larvae (1-2 g) were treated with gamma-irradiated (different doses) WSSV (100 to 10-4 dilutions) for a period of 10 days. The dose/survival curve for irradiated and un-irradiated WSSV was drawn; the optimum dose range for inactivation of WSSV and unaltered antigenicity was obtained 14-15 kGy. This preliminary information suggests that shrimp appear to benefit from treatment with gammairradiated WSSV especially at 14-15 KGy.

  11. Effects of gamma irradiation on deteriorated paper

    NASA Astrophysics Data System (ADS)

    Bicchieri, Marina; Monti, Michela; Piantanida, Giovanna; Sodo, Armida

    2016-08-01

    Even though gamma radiation application, also at the minimum dosage required for disinfection, causes depolymerization and degradation of the paper substrate, recently published papers seemed, instead, to suggest that γ-rays application could be envisaged in some conditions for Cultural Heritage original documents and books. In some of the published papers, the possible application of γ-rays was evaluated mainly by using mechanical tests that scarcely reflect the chemical modifications induced in the cellulosic support. In the present article the effect of low dosage γ-irradiation on cellulosic substrates was studied and monitored applying different techniques: colorimetry, spectroscopic measurements, carbonyl content and average viscometric degree of polymerization. Two different papers were investigated, a non-sized, non-filled cotton paper, and a commercial permanent paper. To simulate a real deteriorated document, which could need γ-rays irradiation, some samples were submitted to a hydrolysis treatment. We developed a treatment based on the exposition of paper to hydrochloric acid vapors, avoiding any contact of the samples with water. This method induces a degradation similar to that observed on original documents. The samples were then irradiated with 3 kGy γ-rays at a 5258 Gy/h rate. The aforementioned analyses were performed on the samples just irradiated and after artificial ageing. All tests showed negative effects of gamma irradiation on paper. Non-irradiated paper preserves better its appearance and chemical properties both in the short term and after ageing, while the irradiated samples show appreciable color change and higher oxidation extent. Since the Istituto centrale restauro e conservazione patrimonio archivistico e librario is responsible for the choice of all restoration treatments that could be applied on library and archival materials under the protection of the Italian State (http://www.icpal.beniculturali.it/allegati/DM-7

  12. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS

    SciTech Connect

    Clark, E.

    2011-09-22

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Polymeric materials become damaged by exposure over time to ionizing radiation. Despite the limited lifetime, polymers have unique engineering material properties and polymers continue to be used in tritium handling systems. In tritium handling systems, polymers are employed mainly in joining applications such as valve sealing surfaces (eg. Stem tips, valve packing, and O-rings). Because of the continued need to employ polymers in tritium systems, over the past several years, programs at the Savannah River National Laboratory have been studying the effect of tritium on various polymers of interest. In these studies, samples of materials of interest to the SRS Tritium Facilities (ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, Teflon{reg_sign}), Vespel{reg_sign} polyimide, and the elastomer

  13. Activation of tobacco retrotransposons during tissue culture.

    PubMed Central

    Hirochika, H

    1993-01-01

    Sequences of at least three new families of retrotransposons (Tto1-Tto3) were amplified by PCR from cDNA prepared from protoplasts of an established tobacco cell line, based on the fact that certain amino acids are highly conserved in the reverse transcriptases encoded by retrotransposons. Structural analysis indicates that Tto1 is 5.5 kb long and has features typical of retrotransposons. Transcription of Tto1 starting in the long terminal repeat was active only in cultured cells. Protoplast formation enhanced the transcription. The copy number of Tto1 increased 10-fold in established cell lines; it also increased in plants regenerated from tissue cultures and in transgenic plants. These results indicate that Tto1 is activated during tissue culture. This is the first demonstration of activation of a plant retrotransposon by tissue culture. The copy number of Tto2 and a previously isolated transposon, Tnt1, also increased in established cell lines, indicating that these two retrotransposons may also be activated by tissue culture. These three retrotransposons are cryptic in normally propagated plants: no difference in the copy number was observed between individuals of the same cultivars or even between different cultivars. Images PMID:8389699

  14. Degradation of microcystin by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Zhang, J. B.; Zheng, Z.; Yang, G. J.; Zhao, Y. F.

    2007-09-01

    The radiolysis of microcystins by gamma irradiation and effects of additives were studied. The degradation value of microcystin-LR was 98.8% at the dose of 8 kGy, while all microcystin-RR could be removed at 5 kGy. Na 2CO 3 and H 2O 2 as additives could enhance the degradation efficiency of microcystins. Furthermore, the increase of Na 2CO 3 would result in the increase of the degradation efficiencies. However, the addition of Triton X-100, NaNO 3 and NaNO 2 inhibited the degradation value of microcystins. The effects of additives were more obvious when the lower doses were selected.

  15. Amino Acid Transport into Cultured Tobacco Cells

    PubMed Central

    Harrington, H. Michael; Henke, Randolph R.

    1981-01-01

    Lysine transport into suspension-cultured Wisconsin-38 tobacco cells was observed. Uptake was linear (up to 90 minutes) with respect to time and amount of tissue only after 4 to 6 hours preincubation in calcium-containing medium. The observed cellular accumulation of lysine was against a concentration gradient and not due to exchange diffusion. Transport was stimulated by low pH and characterized by a biphasic uptake isotherm with two Km values for lysine. System I (Km ≃ 5 × 10−6 molar; Vmax ≃ 180 nanomoles per gram fresh weight per hour) and system II (Km ≃ 10−4 molar; Vmax ≃ 1900 nanomoles per gram fresh weight per hour) were inhibited by N-ethylmaleimide and a variety of respiratory inhibitors. This inhibition was not due to increased efflux. In antagonism experiments, system I was inhibited most effectively by basic amino acids, followed by the sulfur amino acids. System I was only slightly inhibited by the neutral and aromatic amino acids and was not inhibited by the acidic amino acids aspartic and glutamic acids. Transport by system II was inhibited by all of the tested amino acids (including aspartic and glutamic acids) and analogs; however, this system was not inhibited by d-arginine. Neither system was strongly inhibited by d-lysine or the lysine analog S-2-aminoethyl-l-cysteine. Arginine was shown to be a competitive inhibitor of both systems with values for Ki similar to the respective Km values. These studies suggest the presence of at least two amino acid permeases in W-38 tobacco cells. PMID:16661678

  16. Cysteine Transport into Cultured Tobacco Cells

    PubMed Central

    Harrington, H. Michael; Smith, Ivan K.

    1977-01-01

    Cysteine transport by tobacco cells (Nicotiana tabacum L. var. Xanthi) cultured on liquid B-5 medium was examined. Transport was linear with time or amount of tissue and had a pH optimum of 4.5. Cysteine transport over a wide concentration range was biphasic. The isotherm, for descriptive convenience, was divided into two segments both of which obeyed Michaelis-Menten kinetics. The Km for high affinity transport was in the range 1.7 × 10−5m(±0.17) while the Km for low affinity transport was in the range 3.5 × 10−4m(±0.13). Maximum velocities were 3 to 6 nmoles/g fresh weight/minute and 13 to 16 nmoles/g fresh weight/minute, respectively. Azide and 2,4-dinitrophenol caused more than 90% inhibition of net transport by either system. N,N′-Dicyclohexylcarbodiimide was not inhibitory while the inhibition by carbonylcyanide m-chlorophenylhydrazone was dependent on the cysteine concentration. Only those compounds that were inhibitory to transport caused significant efflux of labeled material from preloaded cells. Tobacco cells that had been preincubated in iodoacetamide or N-ethylmaleimide did not transport cysteine while similar treatments with dithiothreitol were only slightly inhibitory or had no effect on transport. Transport by either system was, to some extent, inhibited by all other tested amino acids and analogs. Alanine, methionine, and S-methyl cysteine were most effective in inhibiting cysteine transport. Both alanine and methionine were competitive inhibitors of cysteine transport by either system with inhibition constants that were similar to the Km for the particular system. PMID:16660190

  17. EPR investigation of some gamma-irradiated excipients

    NASA Astrophysics Data System (ADS)

    Aleksieva, Katerina; Yordanov, Nicola D.

    2012-09-01

    The results of electron paramagnetic resonance (EPR) studies on some excipients: lactose, microcrystalline cellulose (avicel), starch, dioxosilane (aerosil), talc and magnesium stearate before and after gamma-irradiation are reported. Before irradiation, all samples are EPR silent except talc. After gamma-irradiation, they show complex spectra except magnesium stearate, which is EPR silent. Studies show the influence of gamma-irradiation on EPR spectra and stability of gamma-induced radicals. Analysis of the EPR spectrum of gamma-irradiated talc shows that this material is radiation insensitive. Only lactose forms stable-free radicals upon gamma sterilization and can be used for identification of radiation processing for a long time period thereafter.

  18. Effect of gamma irradiation on the structure of fucoidan

    NASA Astrophysics Data System (ADS)

    Choi, Jong-il; Gu Lee, Sung; Jong Han, Se; Cho, Minho; Cheon Lee, Pyung

    2014-07-01

    The change of molecular structure of fucoidan by gamma irradiation was analyzed by spectral and chemical methods. Fucoidan samples with different molecular weights of 85, 30, 15, and 7 kDa were prepared by radiation degradation of 217 kDa fucoidan. In the molecular weight analysis, the polydispersity decreased by gamma radiation because of further degradation of higher weight molecules. Ultraviolet absorption and Fourier-transform infrared spectroscopy analyses were carried out to define the changes of the functional groups in fucoidan by gamma irradiation. Carboxyl groups and carbon double bonds increased by gamma irradiation; however, sulfate content remained unchanged. The granular fissures were observed from scanning electron microscopy in gamma-irradiated fucoidan.

  19. Application of gamma irradiation for inhibition of food allergy

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Lee, Ju-Woon; Yook, Hong-Sun; Jo, Cheorun; Kim, Hee-Yun

    2002-03-01

    This study was carried out to evaluate the application of food irradiation technology as a method for reducing food allergy. Milk β-lactoglobulin, chicken egg albumin, and shrimp tropomyosin were used as model food allergens for experiments on allergenic and molecular properties by gamma irradiation. The amount of intact allergens in an irradiated solution was reduced by gamma irradiation depending upon the dose. These results showed that epitopes on the allergens were structurally altered by radiation treatment and that the irradiation technology can be applied to reduce allergenicity of allergic foods.

  20. Degradation of crosslinked polyethylene in water by gamma-irradiation

    NASA Astrophysics Data System (ADS)

    Matsui, Tatsuro; Takano, Tadao; Takayama, Shigeru; Ito, Masayuki; Narisawa, Ikuo

    2002-02-01

    The degradation of crosslinked polyethylene by gamma-irradiation in water was studied. Change in the physical properties and the growth of carbonyl group after irradiation showed a good correlation. The degradation observed at 80°C is the least, and that at 60°C is the severest. The distribution of the oxidized layer in the sample was measured and was also calculated from the diffusion model using the observed parameters. Comparison of both results suggest that some products caused by gamma-irradiation of water supress the degradation of XLPE at 80°C.

  1. Sterile, injectable cyclodextrin nanoparticles: effects of gamma irradiation and autoclaving.

    PubMed

    Memisoglu-Bilensoy, Erem; Hincal, A Atilla

    2006-03-27

    Sterility is required as stated by compendial requirements and registration authorities worldwide for an injectable drug carrier system. In this study, injectable nanospheres and nanocapsules prepared from amphiphilic beta-cyclodextrin, beta-CDC6, were assessed for their in vitro properties such as particle size distribution, zeta potential, nanoparticle yield (%), drug entrapment efficiency and in vitro drug release profiles. Different sterilization techniques such as gamma irradiation and autoclaving were evaluated for their feasibility regarding the maintenance of the above mentioned nanoparticle properties after sterilization. It was found that amount these techniques, sterilization with gamma irradiation seemed to be the most appropriate technique with no effect on particle size, drug loading and drug release properties. Gamma irradiation causes some chemical changes on beta-CDC6 observed as changes in zeta potential but this does not lead to any significant changes for nanoparticle properties. Autoclaving caused massive aggregation for the nanoparticles followed by precipitation, which led to the conclusion that excessive heat disrupted nanoparticle integrity. Sterile filtration was not feasible since nanoparticle sizes were larger than the filter pore size and the yield after sterilization was very low. Thus, it can be concluded that blank and drug loaded beta-CDC6 nanospheres and nanocapsules are capable of being sterilized by gamma irradiation.

  2. Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hun; Sung, Nak-Yun; Raghavendran, H. Balaji; Yoon, Yohan; Song, Beom-Seok; Choi, Jong-il; Yoo, Young-Choon; Byun, Myung-Woo; Hwang, Young-Jeong; Lee, Ju-Woon

    2009-07-01

    Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-α and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX ( P<0.05). In vivo study on the tumor mass inhibition, gamma-irradiated DOX showed a considerable inhibition of tumor mass and this effect was statistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.

  3. Tobacco use in the Dominican Republic: understanding the culture first

    PubMed Central

    Dozier, A M; Ossip‐Klein, D J; Diaz, S; Chin, N P; Sierra, E; Quiñones, Z; Dye, T D; McIntosh, S; Armstrong, L

    2006-01-01

    Objective To conduct formative research on the landscape of tobacco use to guide survey and subsequent intervention development in the Dominican Republic (DR). Design Rapid Assessment Procedures, systematic qualitative methods (participant‐observations, in‐depth interviewing, focus groups) using bilingual mixed age and gendered teams from the United States and DR. Subjects Over 160 adults (men and women), ages 18 to 90 years, current, former and never smokers, community members and leaders from six underserved, economically disadvantaged DR communities. Main outcome measures Key domains: tobacco use patterns and attitudes; factors affecting smoking initiation, continuation, quitting; perceived risks/benefits/effects of smoking; and awareness/effects of advertising/regulations. Results Perceptions of prevalence varied widely. While “everybody” smokes, smokers or ex‐smokers were sometimes difficult to find. Knowledge of health risks was limited to the newly mandated statement “Fumar es prejudicial para la salud” [Smoking is harmful to your health]. Smokers started due to parents, peers, learned lifestyle, fashion or as something to do. Smoking served as an escape, relaxation or diversion. Quit attempts relied on personal will, primarily for religious or medical reasons. Social smoking (custom or habit) (< 10 cigarettes per day) was viewed as a lifestyle choice rather than a vice or addiction. Out of respect, smokers selected where they smoked and around whom. Health care providers typically were reactive relative to tobacco cessation, focusing on individuals with smoking related conditions. Tobacco advertising was virtually ubiquitous. Anti‐tobacco messages were effectively absent. Cultures of smoking and not smoking coexisted absent a culture of quitting. Conclusions Systematic qualitative methods provided pertinent information about tobacco attitudes and use to guide subsequent project steps. Integrating qualitative then quantitative research can

  4. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)

    SciTech Connect

    Clark, E.

    2013-09-13

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Revision 1 adds a comparison with results of a study of tritium exposed EPDM. The amount of gas produced by the gamma irradiation was found to be equivalent to about 280 days exposure to initially pure tritium gas at one atmosphere. The glass transition temperature of the tritium exposed EPDM rose about 10°C. over 280 days, while no glass transition temperature change was observed for gamma irradiated EPDM. This means that gamma irradiation in deuterium cannot be used as a surrogate for tritium exposure.

  5. The effect of gamma irradiation on injectable human amnion collagen

    SciTech Connect

    Liu, B.C.; Harrell, R.; Davis, R.H.; Dresden, M.H.; Spira, M. )

    1989-08-01

    The effect of gamma irradiation on the physicochemical properties of injectable human amnion collagen was investigated. Pepsin-extracted human amnion collagen was purified, reconstituted, and irradiated with varying doses of gamma irradiation (0.25 Mrads to 2.5 Mrads). Gamma irradiation had a significant impact on the physical characteristics of the collagen. The neutral solubility of collagen in PBS at 45{degrees}C was decreased from 100% for the nonirradiated control sample to 16% for the 2.5 Mrads irradiated sample. SDS polyacrylamide gel electrophoresis also demonstrated the dose-dependent effect of gamma irradiation on collagen cross-links. Electron microscopic observation revealed that even at low irradiation dose (0.25 Mrads), collagen fibril diameter increased. The average diameter was 50 nm for nonirradiated control fibrils, while 4.4% of the irradiated collagen fibrils had a diameter greater than 100 nm. Irradiated collagen showed little evidence of damage. Well-preserved cross-striations were found in collagen fibrils at all doses of irradiation. Native amnion collagen irradiated with gamma rays demonstrated a slight increase in resistance to collagenase degradation compared with nonirradiated native collagen samples. Increased resistance to collagenase did not correlate with increasing irradiation dose. After 30 min of incubation at 37{degrees}C, both irradiated and nonirradiated collagen was completely digested by collagenase. However, gamma-irradiated collagen did become more sensitive to hydrolysis by trypsin. The higher the irradiation doses used, the greater sensitivity to trypsin was observed. At 0.25 Mrads irradiation only a slight increase was found. No marked differences in amino acid composition were noted among the high dose irradiated, low dose irradiated and control amnion collagen.

  6. Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy include senescence, necrosis, and autophagy, but not apoptosis.

    PubMed

    Frame, Fiona M; Savoie, Huguette; Bryden, Francesca; Giuntini, Francesca; Mann, Vincent M; Simms, Matthew S; Boyle, Ross W; Maitland, Norman J

    2016-01-01

    In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer.

  7. The response characteristics of tetrazolium violet solutions to gamma irradiation

    NASA Astrophysics Data System (ADS)

    Emi-Reynolds, G.; Kovács, András; Fletcher, J. J.

    2007-08-01

    The dosimetry characteristics of various solutions of tetrazolium violet, TV, (2,5-diphenyl-3-(1-naphthyl)-2H-tetrazolium chloride) to gamma irradiation are reported. The optical absorption spectra of these solutions show peaks between 400 and 600 nm with a shoulder at around 550 nm. The dose response of the optical absorbance values of aqueous and aqueous-alcoholic solutions containing different concentrations of TV was measured in the 250 Gy up to 75 kGy dose range. The formation of formazan product was observed due to radiolytic reduction in both solutions. Its formation was found more pronounced in N 2-saturated as well as in alkaline solutions. The results indicate that the 1 mM TV solution can be used for food irradiation and medical sterilization dosimetry at gamma irradiation facilities.

  8. Neutron and gamma irradiation effects on power semiconductor switches

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.; Frasca, A. J.

    1990-01-01

    The performance characteristics of high-power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

  9. Elementary radical formation and conversion processes in. gamma. -irradiated polyvinylchloride

    SciTech Connect

    Torikai, A.; Adachi, T.; Fueki, K.

    1981-11-01

    Elementary processes of ..gamma..-irradiated polyvinylchloride (PVC) have been investigated by both electron spin resonance (ESR) and optical absorption measurements. On irradiating PVC film with ..gamma.. rays at -196/sup 0/C, alkyl-type radicals are produced. When the PVC film is warmed to room temperature, the radicals convert to polyenyl type. ..gamma.. irradiation of PVC film containing biphenyl (Ph/sub 2/) or pyrene (Py) at -196/sup 0/C yields the corresponding radical cation. The relative ESR peak heights of the radicals decrease and the G values for the formation of cation radicals increase with increasing additive concentrations. These facts indicate that energy is transferred from the precursor of the radicals to the additive. In the case of PVC film containing Py, the Py cation radical decreases the cyclohexadienyl-type radical from Py is produced by thermal annealing. A possible mechanism for radical formation and conversion is proposed.

  10. Neutron and gamma irradiation effects on power semiconductor switches

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.; Frasca, A. J.

    1990-01-01

    The performance characteristics of high power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

  11. Preparation of pinewood/polymer/composites using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Ajji, Zaki

    2006-09-01

    Wood/polymer composites (WPC) have been prepared from pinewood with different compounds using gamma irradiation: butyl acrylate, butyl methacrylate, styrene, acrylamide, acrylonitrile, and unsaturated polyester styrene resin. The polymer loading was determined with respect to the compound concentration and the irradiation dose. The polymer loading increases generally with increase in the monomer or polymer concentration. Tensile and compression strength have been improved in the four cases, but no improvement was observed using unsaturated polyester styrene resin or acrylamide.

  12. Thermoluminescence and dielectric response of gamma irradiated muscovite mica

    SciTech Connect

    Kaur, Sukhnandan Singh, Surinder Singh, Lakhwant; Lochab, S. P.

    2014-04-24

    The effect of gamma radiation dose on the thermoluminescence (TL) and dielectric properties of muscovite mica was studied. TL glow curves exhibited a single peak around 141 {sup 0}C and its activation energy was estimated to be about 0.89 eV. Different dielectric parameters like dielectric constant, dielectric loss and ac conductivity have been calculated in both pristine and gamma irradiated samples. These dielectric parameters have been studied as a function of irradiation dose.

  13. Effects of combined neutron and gamma irradiation upon silicone foam

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Wang, Pu-Cheng; Ao, Yin-Yong; Zhao, Yan; An, You; Chen, Hong-Bing; Huang, Wei

    2017-04-01

    The total dose effect of combined fast-neutron beam and 60Co γ-ray radiation on silicone foam in air and nitrogen were investigated, respectively. The results show that foam hardening occurs and crystallization of polymer matrix decreases with increasing dose. Gas chromatograph was used to identify the kinetics of volatile products generating, which generally increase with increasing total dose. The study indicates that combined neutron and gamma irradiation would influence silicone foam property obviously during the investigated dose range.

  14. Thermoluminescence and dielectric response of gamma irradiated muscovite mica

    NASA Astrophysics Data System (ADS)

    Kaur, Sukhnandan; Singh, Surinder; Singh, Lakhwant; Lochab, S. P.

    2014-04-01

    The effect of gamma radiation dose on the thermoluminescence (TL) and dielectric properties of muscovite mica was studied. TL glow curves exhibited a single peak around 141 0C and its activation energy was estimated to be about 0.89 eV. Different dielectric parameters like dielectric constant, dielectric loss and ac conductivity have been calculated in both pristine and gamma irradiated samples. These dielectric parameters have been studied as a function of irradiation dose.

  15. Regeneration of sulfamethoxazole-saturated activated carbon using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Chu, Libing; Wang, Jianlong

    2017-01-01

    Activated carbon (AC) has been widely used for reclamation and reuse of the effluent of wastewater treatment plant to further remove the emerging contaminants, such as PPCPs in recent years. How to regenerate the exhausted AC effectively and economically is still a challenge. In the present study, the regeneration of AC exhausted with SMX was performed by gamma irradiation to simultaneously recover the spent AC and degrade the pollutants. The results showed that the adsorption of SMX onto AC can be described by the Langmuir isotherm and the adsorption capacity was about 417 mg/g. SMX can be removed rapidly when exposed to gamma irradiation, with the initial concentration of 100 mg/L, more than 99% of SMX was removed at 5.0 kGy, while an extremely high dose (150 kGy) was needed to reach 80% mineralization ratio. The regeneration efficiency was about 21-30% at 50-200 kGy. The absorbed SMX and the intermediates formed during gamma irradiation were released into aqueous solution from AC and mineralized, leading to the partial regeneration of the adsorption capacity of AC. Further studies are needed to optimize the experimental conditions to increase the regeneration efficiency.

  16. The study of gamma irradiation effects on poly (glycolic acid)

    NASA Astrophysics Data System (ADS)

    Rao Nakka, Rajeswara; Rao Thumu, Venkatappa; Reddy SVS, Ramana; Rao Buddhiraju, Sanjeeva

    2015-05-01

    We have investigated the effects of gamma irradiation on chemical structure, thermal and morphological properties of biodegradable semi-crystalline poly (glycolic acid) (PGA). PGA samples were subjected to irradiation treatment using a 60Co gamma source with a delivered dose of 30, 60 and 90 kGy, respectively. Gamma irradiation induces cleavage of PGA main chains forming ∼OĊH2 and ĊH2COO∼ radicals in both amorphous and crystalline regions. The free radicals formed in the amorphous region abstract atmospheric oxygen and convert them to peroxy radicals. The peroxy radical causes chain scission at the crystal interface through hydrogen abstraction from methylene groups forming the ∼ĊHCOO∼ (I) radical. Consequently, the observed electron spin resonance (ESR) doublet of irradiated PGA is assigned to (I). The disappearance of the ESR signal above 190°C indicates that free radicals are formed in the amorphous region and decay below the melting temperature of PGA. Fourier transform infrared and optical absorption studies confirm that the ? groups are not influenced by gamma irradiation. Differential scanning calorimetry (DSC) studies showed that the melting temperature of PGA decreased from 212°C to 202°C upon irradiation. Degree of crystallinity increased initially and then decreased with an increase in radiation as per DSC and X-ray diffraction studies. Irradiation produced changes in the physical properties of PGA as well as affecting the morphology of the material.

  17. Gamma irradiation of Egyptian Cobra (Naja haje) Venom.

    PubMed

    Shaban, E A; Ahmed, A A; Ayobe, M H

    1996-01-01

    The aim of the present study was to prepare an effective and safe toxoid for the Egyptian Cobra (Naja haje) Venom by gamma irradiation. The effects of gamma irradiation (0.1-10 M rad) on the toxicity, as well as the antigen antibody complex formation reactivity was described. It appears from the results that the lethality of Naja haje venom irradiated in the dry form was not affected up to a dose of 10 M rad (100 KGy). On the other hand, the venom irradiated in the aqueous solution form showed a decrease in its lethality, and this was proportionately related to the dose of irradiation, while the ability of the venom antigens to react with its corresponding antibodies was retained up to irradiation dose of 5 M rad. The results of double immunodiffusion of non irradiated and the different dose levels of gamma irradiated venom (0.1-5 M rad) against a commercial Egyptian polyvalent antivenin, all showed similar patterns, the four visible lines obtained in the immunodiffusion reactions were identical and joined smoothly at the corners, indicating that there was no change in antigenic reactivity with antibodies determinants.

  18. Improvement of saccharification process for bioethanol production from Undaria sp. by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Yoon, Minchul; Choi, Jong-il; Lee, Ju-Woon; Park, Don-Hee

    2012-08-01

    Recently, many research works have reported on improvements to the saccharification process that increase bioethanol production from cellulosic materials. Gamma irradiation has been studied as an effective method for the depolymerization of complex polysaccharides. In this study, the effect of gamma irradiation on saccharification of Undaria biomass for bioethanol production was investigated. The Undaria biomass was irradiated at doses of 0, 10, 50, 100, 200 and 500 kGy and then hydrolyzed using sulfuric acid. The effects of gamma irradiation were measured through microscopic analysis to determine morphological changes and concentration of the reducing sugar of hydrolysates. Microscopic images show that gamma irradiation causes structure breakage of the Undaria cell wall. The concentration of reducing sugar of hydrolysates significantly increased as a result of gamma irradiation, with or without acid hydrolysis. These results indicate that the combined method of gamma irradiation with acid hydrolysis can significantly improve the saccharification process for bioethanol production from marine algae materials.

  19. Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Sung, Nak-Yun; Choi, Jong-il

    2015-06-01

    Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants

  20. Resistance of some common fungi to gamma irradiation.

    PubMed Central

    Saleh, Y G; Mayo, M S; Ahearn, D G

    1988-01-01

    Ten species of fungi representing the genera Alternaria, Aspergillus, Caldosporium, Curvularia, Fusarium, and Penicillium were examined for their relative resistance to gamma irradiation from a 137Cs source. Inactivation doses for dematiaceous fungi in agar medium ranged from 0.6 to greater than 1.7 megarads, whereas those for moniliaceous fungi were less than 0.3 megarad. D10 values (the dose required to reduce the inoculum by 1 log) for Curvularia geniculata (greater than 0.29 megarad) exceeded those for control spores of Bacillus pumilus (0.15 megarad). PMID:3178216

  1. Raman and AFM study of gamma irradiated plastic bottle sheets

    NASA Astrophysics Data System (ADS)

    Ali, Yasir; Kumar, Vijay; Sonkawade, R. G.; Dhaliwal, A. S.

    2013-02-01

    In this investigation, the effects of gamma irradiation on the structural properties of plastic bottle sheet are studied. The Plastic sheets were exposed with 1.25MeV 60Co gamma rays source at various dose levels within the range from 0-670 kGy. The induced modifications were followed by micro-Raman and atomic force microscopy (AFM). The Raman spectrum shows the decrease in Raman intensity and formation of unsaturated bonds with an increase in the gamma dose. AFM image displays rough surface morphology after irradiation. The detailed Raman analysis of plastic bottle sheets is presented here, and the results are correlated with the AFM observations.

  2. Resistance of some common fungi to gamma irradiation

    SciTech Connect

    Saleh, Y.G.; Mayo, M.S.; Ahearn, D.G.

    1988-08-01

    Ten species of fungi representing the genera Alternaria, Aspergillus, Caldosporium, Curvularia, Fusarium, and Penicillium were examined for their relative resistance to gamma irradiation from a /sup 137/Cs source. Inactivation doses for dematiaceous fungi in agar medium ranged from 0.6 to greater than 1.7 megarads, whereas those for moniliaceous fungi were less than 0.3 megarad. D10 values (the dose required to reduce the inoculum by 1 log) for Curvularia geniculata (greater than 0.29 megarad) exceeded those for control spores of Bacillus pumilus (0.15 megarad).

  3. Dosimetry commissioning of the gamma irradiation facility ``ROBO''

    NASA Astrophysics Data System (ADS)

    Kovacs, A.; Moussa, A.; Othman, I.; Alnaal, K.

    1998-06-01

    A product-overlap type gamma irradiation facility with wet storage was put into operation recently in Damascus, Syria and its technical specifications were controlled by dosimetry commissioning experiments and compared to the data specified by the supplier. In the course of this procedure detailed dose mapping using different density products was carried out, and thus the minimum and maximum dose locations within the product boxes were determined. Using these data the plant efficiency and the dose uniformity ratio have been calculated. The dose distribution was also determined vertically along the product carrier. The results were then analyzed with respect to the construction of the facility.

  4. gamma-Irradiation effects on the thermal decomposition behaviour and IR absorption spectra of piperacillin

    NASA Astrophysics Data System (ADS)

    Mahfouz, R. M.; Gaffar, M. A.; Abu El-Fadl, A.; Hamad, Ar. G. K.

    2003-11-01

    The thermal decomposition behaviour of unirradiated and pre-gamma-irradiated piperacillin (pipril) as a semi-synthetic penicillin antibiotic has been studied in the temperature range of (273-1072 K). The decomposition was found to proceed through three major steps both for unirradiated and gamma-irradiated samples. Neither appearance nor disappearance of new bands in the IR spectrum of piperacillin was recorded as a result of gamma-irradiation but only a decrease in the intensity of most bands was observed. A degradation mechanism was suggested to explain the bond rupture and the decrease in the intensities of IR bands of gamma-irradiated piperacillin.

  5. Cultural Perspectives Concerning Adolescent Use of Tobacco and Alcohol in the Appalachian Mountain Region

    ERIC Educational Resources Information Center

    Meyer, Michael G.; Toborg, Mary A.; Denham, Sharon A.; Mande, Mary J.

    2008-01-01

    Context: Appalachia has high rates of tobacco use and related health problems, and despite significant impediments to alcohol use, alcohol abuse is common. Adolescents are exposed to sophisticated tobacco and alcohol advertising. Prevention messages, therefore, should reflect research concerning culturally influenced attitudes toward tobacco and…

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Chemical investigation of gamma-irradiated saffron (Crocus sativus L.).

    PubMed

    Zareena, A V; Variyar, P S; Gholap, A S; Bongirwar, D R

    2001-02-01

    Changes in aroma and coloring properties of saffron (Crocus sativus) after gamma-irradiation at doses of 2.5 and 5 kGy (necessary for microbial decontamination) were investigated. The volatile essential oil constituents responsible for aroma of the spice were isolated by steam distillation and then subsequently analyzed by gas chromatography/mass spectrometry (GC/MS). No significant qualitative changes were observed in these constituents upon irradiation, although a trained sensory panel could detect slight quality deterioration at a dose of 5 kGy. Carotene glucosides that impart color to the spice were isolated by solvent extraction and then subjected to thin-layer chromatography and high-performance liquid chromatography (HPLC). Fractionation of the above pigments into aglycon and glucosides was achieved by using ethyl acetate and n-butanol, respectively. Analysis of these fractions by HPLC revealed a decrease in glucosides and an increase in aglycon content in irradiated samples. The possibility of degradation of pigments during gamma irradiation is discussed.

  8. Albumin grafting on biomaterial surfaces using gamma-irradiation

    SciTech Connect

    Kamath, K.R.

    1993-01-01

    Surface modification has been used extensively in various fields to introduce desirable surface properties without affecting the bulk properties of the material. In the area of biomaterials, the approach of surface modification offers an effective alternative to the synthesis of new biomaterials. The specific objective of this study was to modify different biomaterial surfaces by albumin grafting to improve their blood compatibility. The modified surfaces were characterized for surface-induced platelet activation and thrombus formation. This behavior was correlated with the conditions used for grafting. In particular, albumin was functionalized to introduce pendant double bonds into the molecule. The functionalized albumin was covalently attached to various surfaces, such as dimethyldichlorosilane-coated glass, polypropylene, polycarbonate, poly(vinyl chloride), and polyethylene by gamma-irradiation. Platelet adhesion and activation on these surfaces was examined using video microscopy and scanning electron microscopy. The extent of grafting was found to be dependent on the albumin concentration used for adsorption and the gamma-irradiation time. Release of the grafted albumin during exposure to blood was minimal. The albumin-grafted fibers maintained their thromboresistant properties even after storage at elevated temperatures for prolonged time periods. Finally, the approach was used to graft albumin on the PLEXUS Adult Hollow Fiber Oxygenators (Shiley). The blood compatibility of the grafted oxygenators improved significantly when compared to controls.

  9. Gamma irradiation influence on physical properties of milk proteins

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Salmieri, S.; Lacroix, M.; Tien, C. Le

    2004-09-01

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling.

  10. Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation

    PubMed Central

    Horn, Lydia N.; Ghebrehiwot, Habteab M.; Shimelis, Hussein A.

    2016-01-01

    Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985), Shindimba (IT89KD-245-1), and Bira (IT87D-453-2) were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colors and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants’ lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding. PMID:27148275

  11. Health protection and food preservation by gamma irradiation

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Results of several major studies on food systems for space missions beginning with Apollo 12 through Apollo-Soyuz and investigations of the application of irradiation to food for manned space flight are reported. The study of flight food systems involved the application of radurization (pasteurizing levels) doses of gamma irradiation to flour and bread supplied by Pepperidge Farms in advance of the missions. All flights from Apollo 12 through 17 carried irradiated fresh bread. On Apollo 17, cooperation with Natick Laboratories permitted the introduction of a ham sandwich using irradiated bread and irradiated sterile ham. Investigations centered on irradiated bread were conducted during the course of these missions. Studies were applied to the concept of improving fresh bread from the point of view of mold inhibition. The studies considered how irradiation could best be applied at what levels and on a variety of bread types. Throughout the studies of the application of gamma irradiation the emphasis was placed upon using low levels of irradiation in the pasteurizing or radurizing doses--under a Megarad. The primary goal was to determine if a public health benefit could be demonstrated using radurization along with food preservation and food quality improvements. The public health benefit would be parallel to that of pasteurization of milk as a concept. Publications are included providing the details of these observations, one dealing with the flour characteristics and the other dealing with the influence on fresh bread types. These demonstrate the major findings noted during the period of the studies examining bread.

  12. Effect of gamma irradiation on antinutritional factors in broad bean

    NASA Astrophysics Data System (ADS)

    Al-Kaisey, Mahdi T.; Alwan, Abdul-Kader H.; Mohammad, Manal H.; Saeed, Amjed H.

    2003-06-01

    The effect of gamma irradiation on the level of antinutritional factors (trypsin inhibitor (TI), phytic acid and oligosaccharides) of broad bean was investigated. The seeds were subjected to gamma irradiation at 0, 2.5, 5, 7.5 and 10 kGy, respectively using cobalt-60 gamma radiation with a dose rate 2.37 kGy/h. TI activity was reduced by 4.5%, 6.7%, 8.5% and 9.2% at 2.5, 5, 7.5 and 10 kGy, respectively. Meanwhile, irradiation at 10.2, 12.3, 15.4 and 18.2 kGy reduced the phytic acid content. The flatulence causing oligosaccharides were decreased as the radiation dose increased. The chemical composition (protein, oil, ash and total carbohydrates) of the tested seeds was determined. Gamma radiation seems to be a good procedure to improve the quality of broad bean from the nutritional point of view.

  13. Production of high melt strength polypropylene by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Lugão, A. B.; Artel, B. W. H.; Yoshiga, A.; Lima, L. F. C. P.; Parra, D. F.; Bueno, J. R.; Liberman, S.; Farrah, M.; Terçariol, W. R.; Otaguro, H.

    2007-11-01

    High melt strength polypropylene (HMS-PP) has been recently developed and introduced in the market by the major international producers of polypropylene. Therefore, BRASKEM, the leading Brazilian PP producer, together with EMBRARAD, the leading Brazilian gamma irradiator, and the IPEN (Institute of Nuclear Energy and Research) worked to develop a national technology for the production of HMS-PP. One of the effective approaches to improve melt strength and extensibility is to add chain branches onto polypropylene backbone using gamma radiation. Branching and grafting result from the radical combinations during irradiation process. Crosslinking and main chain scission in the polymer structure are also obtained during this process. In this work, gamma irradiation technique was used to induce chemical changes in commercial polypropylene with two different monomers, Tri-allyl-isocyanurate (TAIC) and Tri-methylolpropane-trimethacrylate (TMPTMA), with concentration ranging from 1.5 to 5.0 mmol/100 g of polypropylene. These samples were irradiated with a 60Co source at dose of 20 kGy. It used two different methods of HMS-PP processing. The crosslinking of modified polymers was studied by measuring gel content melt flow rate and rheological properties like melt strength and drawability. It was observed that the reaction method and the monomer type have influenced the properties. However, the concentration variation of monomer has no effect.

  14. The influence of antiorthostatic unloading and long gamma-irradiation on rat bone marrow (MSCs)

    NASA Astrophysics Data System (ADS)

    Roe, Maria; Bobyleva, Polina; Shtemberg, Andrey; Buravkova, Ludmila

    With the prospect of long interplanetary spaceflight becoming a real possibility there are some important questions that need to be answered regarding the combined effects of microgravity and long gamma-irradiation.The aim of this study was to evaluate the effects of synchronous antiorthostatic unloading and fractional gamma-irradiation on the functional characteristics of rat bone marrow multipotent stromal cells (MSCs).This experiment was carried out following all rules laid out by the Commission on Bioethics at the SSC RF - IBMP RAS. In this experiment the Wistar rats were kept in an unloaded position for a duration of 30 days. They were also subjected to 6 doses of gamma-radiation on the “GOBO-60” with a source of (137) Cs. The dose rate set to 1 meter 50 sGr / H (Total dose of 3 Gr).The study revealed a significant reduction in the number of colonies (CFU-F) in all cultures from the experimental groups when compared to the control groups. The most significant reduction was observed in the group, which had been subject to combined unloading, and radiation. This result was confirmed by examination of cell cultures during 10 days of growth.We found that the CD45 expression was increased in the groups exposed to radiation. At the same time a reduction in the expression of CD90 was observed during combination of radiation and unloading we found.The experimental groups also differed from the control group showing smaller lipid inclusions and decreased expression of alkaline phosphates in the MSCs. This experiment concluded that the bone marrow MSCs after a combination of unloading and multiple radiation sessions, showed a decrease in proliferation and differentiation potential which could reduce the adaption and reparative capacity of the organism.

  15. Effects of gamma irradiation on physicochemical properties of Korean red ginseng powder

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Yook, Hong-Sun; Kwon, Oh-Jin; Kang, Il-Jun

    1997-04-01

    Gamma irradiation was applied to Korean red ginseng powder to improve its quality. Major physicochemical properties (approximate composition, pH, acidity, browning pigment, hydrogen donating activity, fatty acids, minerals and saponin) were not significantly changed by gamma irradiation up to 10 kGy. The TBA value was increased depending on the increment of irradiation dose level. In free amino acids, threonine was increased while, serine and glutamic acid were decreased by gamma irradiation. In total amino acids, total contents were not significantly changed by gamma irradiation though tyrosine was slightly decreased P ⩽ 0.05. In free sugar, glucose, sucrose and maltose were significantly increased by 7.5 and 10 kGy gamma irradiation P ⩽ 0.05

  16. Gamma-Irradiated Sterile Cornea for Use in Corneal Transplants in a Rabbit Model

    PubMed Central

    Yoshida, Junko; Heflin, Thomas; Zambrano, Andrea; Pan, Qing; Meng, Huan; Wang, Jiangxia; Stark, Walter J.; Daoud, Yassine J.

    2015-01-01

    Purpose: Gamma irradiated corneas in which the donor keratocytes and endothelial cells are eliminated are effective as corneal lamellar and glaucoma patch grafts. In addition, gamma irradiation causes collagen cross inking, which stiffens collagen fibrils. This study evaluated gamma irradiated corneas for use in corneal transplantations in a rabbit model comparing graft clarity, corneal neovascularization, and edema. Methods: Penetrating keratoplasty was performed on rabbits using four types of corneal grafts: Fresh cornea with endothelium, gamma irradiated cornea, cryopreserved cornea, and fresh cornea without endothelium. Slit lamp examination was performed at postoperative week (POW) one, two, and four. Corneal clarity, edema, and vascularization were graded. Confocal microscopy and histopathological evaluation were performed. A P < 0.05 was statistically significant. Results: For all postoperative examinations, the corneal clarity and edema were statistically significantly better in eyes that received fresh cornea with endothelium compared to the other three groups (P < 0.05). At POW 1, gamma irradiated cornea scored better than the cryopreserved and fresh cornea without endothelium groups in clarity (0.9 vs. 1.5 and 2.6, respectively), and edema (0.6 vs. 0.8 and 2.0, respectively). The gamma irradiated corneas, cryopreserved corneas and the fresh corneas without endothelium, developed haze and edema after POW 2. Gamma irradiated cornea remained statistically significantly clearer than cryopreserved and fresh cornea without endothelium during the observation period (P < 0.05). Histopathology indicated an absence of keratocytes in gamma irradiated cornea. Conclusion: Gamma irradiated corneas remained clearer and thinner than the cryopreserved cornea and fresh cornea without endothelium. However, this outcome is transient. Gamma irradiated corneas are useful for lamellar and patch grafts, but cannot be used for penetrating keratoplasty. PMID:26180475

  17. TEST RESULTS FROM GAMMA IRRADIATION OF ALUMINUM OXYHYDROXIDES

    SciTech Connect

    Fisher, D.; Westbrook, M.; Sindelar, R.

    2012-02-01

    Hydrated metal oxides or oxyhydroxides boehmite and gibbsite that can form on spent aluminum-clad nuclear fuel assemblies during in-core and post-discharge wet storage were exposed as granular powders to gamma irradiation in a {sup 60}Co irradiator in closed laboratory test vessels with air and with argon as separate cover gases. The results show that boehmite readily evolves hydrogen with exposure up to a dose of 1.8 x 10{sup 8} rad, the maximum tested, in both a full-dried and moist condition of the powder, whereas only a very small measurable quantity of hydrogen was generated from the granular powder of gibbsite. Specific information on the test setup, sample characteristics, sample preparation, irradiation, and gas analysis are described.

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

    SciTech Connect

    Kwon, Joongho; Belanger, J.M.R.; Sigouin, M.; Lanthier, J.; Willemot, C.; Pare, J.R.J. )

    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.

  19. Neutron and gamma irradiation damage to organic materials.

    SciTech Connect

    White, Gregory Von, II; Bernstein, Robert

    2012-04-01

    This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

  20. Cobalt 60 gamma irradiation current status, trends and insights

    NASA Astrophysics Data System (ADS)

    Corley, John T.

    1998-06-01

    This paper discusses the current status, trends and insights into the continued, safe use of cobalt 60 gamma irradiation. Also presented are some of the many initiatives undertaken at MDS Nordion. Topics covered include our investment for the future supply of raw materials and the latest news from source production. Briefly presented are the tasks associated with the safe transport of cobalt 60 around the world. Discussed is cobalt 60 usage at the customer site; more specifically maintaining source integrity, source utilization and irradiator design trends. Highlighted are industry trends for North America, Europe and the rest of the world. Finally presented are the challenges and opportunities for the industry. Stressed in the paper is the need to work together.

  1. Chemometric characterization of gamma irradiated chestnuts from Turkey

    NASA Astrophysics Data System (ADS)

    Barreira, João C. M.; Antonio, Amilcar L.; Günaydi, Tugba; Alkan, Hasan; Bento, Albino; Luisa Botelho, M.; Ferreira, Isabel C. F. R.

    2012-09-01

    Chestnut (Castanea sativa Miller) is a valuable natural resource, with high exportation levels. Due to their water content, chestnuts are susceptible to storage problems like dehydration or development of insects and microorganisms. Irradiation has been revealing interesting features to be considered as an alternative conservation technology, increasing food products shelf-life. Any conservation methodology should have a wide application range. Hence, and after evaluating Portuguese cultivars, the assessment of irradiation effects in foreign cultivars might act as an important indicator of the versatility of this technology. In this work, the effects of gamma irradiation (0.0, 0.5 and 3.0 kGy) on proximate composition, sugars, fatty acids (FA) and tocopherols composition of Turkish chestnuts stored at 4 °C for different periods (0, 15 and 30 days) were evaluated. Regarding proximate composition, the storage time (ST) had higher influence than the irradiation dose (ID), especially on fat, ash, carbohydrates and energetic value. Sucrose exhibited similar behavior in response to the assayed ST and ID. The prevalence of ST influence was also verified for FA, tocopherols and sucrose. Lauric, palmitoleic and linolenic acids were the only FA that underwent some differences with ID. Saturated, monounsaturated and polyunsaturated fatty acids levels were not affected either by storage or irradiation. α-Tocopherol was the only vitamer with significant differences among the assayed ST and ID. Overall, Turkish cultivars showed a compositional profile closely related with Portuguese cultivars, and seemed to confirm that gamma irradiation in the applied doses did not change chestnut chemical and nutritional composition.

  2. Effect of gamma irradiation on commercial eggs experimentally inoculated with Salmonella enteritidis

    NASA Astrophysics Data System (ADS)

    Tellez, I. G.; Trejo, R. M.; Sanchez, R. E.; Ceniceros, R. M.; Luna, Q. P.; Zazua, P.; Hargis, B. M.

    1995-02-01

    Using intact, fresh shell eggs, inoculated with 10 8 colony-forming units (cfu) of S. enteritidis, the effect of three doses of gamma irradiation on bacteriologic population and physical characteristics (Haugh units and yolk color) of the eggs was determinated. Penetration test area was picked at random just off the air cell of each egg. Aluminum cylinders were attached to the egg surface with a rim of molten paraffin, and 10 8S. enteritidis was then applied to inoculate the egg. Eggs were then irradiated within 2 hours using a Cobalt-60 gamma source at either 1, 2, or 3 kGy. A second set of inoculated, non-irradiated was used as controls. Following irradiation, eggs were maintained at 4°C for 42 hours prior culture. Irradiation with 1 kGy resulted in a significant (P < .05), 3.9 log reduction in detectable S. enteritidis in the shell and a higly significant (P < .025) 95% reduction in detectable S. enteritidis in the internal shell membranes. Irradiation of eggs with either 2 or 3 kGy reduced bacterial contamination to non-detectable levels in both the shell and internal membranes. However, irradiation at either 1, 2 or 3 kGy resulted in a significant (P <- .05) decrease (approximately 50%) in Haugh units. Additionally, irradiation of intact shell eggs at 2 or 3 Kgy significantly (P ≤ .05) reduced yolk color regardless of the level of irradiation exposure implemented. This data indicates that gamma irradiation of intact raw eggs is effective in reducing (1 kGy) or eliminating (2 or more kGy) S. enteritidis contamination. However, each of the levels of irradiation used in the present experiments caused marked reduction of selected measures of egg quality.

  3. Gamma irradiation: a method to produce an abiotic control for biological activated carbon.

    PubMed

    Stoquart, C; Vázquez-Rodríguez, G A; Servais, P; Barbeau, B

    2013-01-01

    The aim of this paper was to investigate the feasibility of using gamma irradiation to inhibit the microbial activity of biological powder activated carbon (PAC) without impacting its adsorptive properties. First of all, the range of dose of gamma rays required to produce abiotic PAC was selected on the basis of heterotrophic plate counts (HPC) inactivation and methylene blue (MB) adsorption kinetics. Doses inferior to 10 kGy were not sufficient to inhibit the culture of heterotrophic bacteria. On the other hand, doses superior to 15 kGy were demonstrated to affect the adsorption rate of MB. Consequently, a dose comprised between 10 and 15 kGy was selected for further investigation. In order to validate the adequacy of the range of dose (i.e. 10-15 kGy), adsorption characteristics were tested by monitoring the removal kinetics of refractory dissolved organic carbon (RDOC). No significant differences were observed between irradiated and non-irradiated biological PAC for the adsorption of RDOC. Irradiated, non-irradiated and virgin PAC were also evaluated in terms of abundance of viable (using the LIVE/DEAD BacLight method) bacteria and in terms of heterotrophic biomass activity. The results of the BacLight method demonstrated that attachment of the biofilm on the PAC was not impacted by the irradiation and heterotrophic activity measurements demonstrated that the latter could be radically reduced in the range of dose selected. In conclusion, when using a proper dose, the gamma irradiation of colonized activated carbon drastically reduced the heterotrophic activity on activated carbon without significantly impacting its adsorptive behaviour.

  4. Effect of Gamma Irradiation on Structural and Biological Properties of a PLGA-PEG-Hydroxyapatite Composite

    PubMed Central

    Shahabi, Sima; Najafi, Farhood; Majdabadi, Abbas; Hooshmand, Tabassom; Haghbin Nazarpak, Masoumeh; Karimi, Batool

    2014-01-01

    Gamma irradiation is able to affect various structural and biological properties of biomaterials In this study, a composite of Hap/PLGA-PEG and their ingredients were submitted to gamma irradiation doses of 25 and 50 KGy. Various properties such as molecular weight (GPC), thermal behavior (DSC), wettability (contact angle), cell viability (MTT assay), and alkaline phosphatase activity were studied for the composites and each of their ingredients. The results showed a decrease in molecular weight of copolymer with no change in the glass transition and melting temperatures after gamma irradiation. In general gamma irradiation can increase the activation energy ΔH of the composites and their ingredients. While gamma irradiation had no effect on the wettability of copolymer samples, there was a significant decrease in contact angle of hydroxyapatite and composites with increase in gamma irradiation dose. This study showed an increase in biocompatibility of hydroxyapatite with gamma irradiation with no significant effect on cell viability in copolymer and composite samples. In spite of the fact that no change occurred in alkaline phosphatase activity of composite samples, results indicated a decrease in alkaline phosphatase activity in irradiated hydroxyapatites. These effects on the properties of PLGA-PEG-hydroxyapatite can enhance the composite application as a biomaterial. PMID:25574485

  5. Cytokinin Activation of Thiamine Biosynthesis in Tobacco Callus Cultures

    PubMed Central

    Digby, John; Skoog, Folke

    1966-01-01

    Bioassays of tissue extracts show that high (500-1000 μg/liter) kinetin concentrations which permit growth of tobacco callus cultures on media without added thiamine activate the biosynthesis of this vitamin by the tissues. Although the tissue concentration of thiamine may fall appreciably, it is maintained at a level adequate for survival and slow growth of the cultures, and there is a large net increase in total thiamine content per culture with time. In the second and subsequent passages of tissue on a thiamine free medium, growth is obtained only when high kinetin concentrations are maintained. Effective inhibition of growth by antithiamines suggests that thiamine is utilized by the high-kinetin tissue. In the presence of low (30-100 μg/liter) kinetin concentrations, which would be optimal for growth in the presence of thiamine, growth only occurs early in the first passage of tissue from a medium with the vitamin to one without it. The thiamine concentration in the tissues falls to low levels, and no net biosynthesis is apparent. The tissues turn dark and die after 2 to 3 weeks. In contrast with this, in the absence of both added thiamine and kinetin no appreciable growth occurs, but the tissues keep their normal appearance, retain their thiamine content, and may stay alive for several weeks. PMID:16656301

  6. Effect of gamma irradiation on DC electrical conductivity of ZnO nanoparticles

    SciTech Connect

    Swaroop, K.; Somashekarappa, H. M.; Naveen, C. S.; Jayanna, H. S.

    2015-06-24

    The temperature dependent dc electrical conductivity of gamma irradiated Zinc oxide (ZnO) nanoparticles is presented in this paper. The X-ray diffraction (XRD) pattern shows hexagonal wurtzite structure of ZnO. Fourier Transform Infrared Spectroscopy (FTIR) confirms Zn-O stretching vibrations. UV-Visible spectroscopy studies show that the energy band gap (E{sub g}) of the prepared ZnO nanoparticles increases with respect to gamma irradiation dose, which can be related to room temperature dc electrical conductivity. The result shows significant variation in the high temperature dc electrical conductivity of ZnO nanoparticles due to gamma irradiation.

  7. Study of gamma irradiation effect on commercial TiO2 photocatalyst.

    PubMed

    Bello Lamo, M P; Williams, P; Reece, P; Lumpkin, G R; Sheppard, L R

    2014-07-01

    The aim of this work is to understand the effect of gamma irradiation on commercial TiO2 photocatalyst for water treatment applications. Previous studies concluded that gamma-irradiation is able to modify the electronic properties of TiO2 based photocatalysts and consequently their photocatalytic performance. However, there are some discrepancies in the literature where on one hand a significant enhancement of the material properties is reported and on the other hand only a weak effect is observed. In this study a surface effect on TiO2 is confirmed by using low and medium gamma irradiation doses.

  8. Identification of gamma-irradiated fruit juices by EPR spectroscopy

    NASA Astrophysics Data System (ADS)

    Aleksieva, K. I.; Dimov, K. G.; Yordanov, N. D.

    2014-10-01

    The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to "cellulose-like" EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical "sugar-like" spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation.

  9. Gamma irradiation treatment of cereal grains for chick diets

    SciTech Connect

    Campbell, G.L.; Classen, H.L.; Ballance, G.M.

    1986-04-01

    Wheat (W), triticale (T), hulled barley (HB), hull-less barley (HLB), hulled oats (HO), and hull-less oats (HLO) were gamma irradiated (/sup 60/Co) 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.

  10. Gamma irradiation enhances biological activities of mulberry leaf extract

    NASA Astrophysics Data System (ADS)

    Cho, Byoung-Ok; Che, Denis Nchang; Yin, Hong-Hua; Jang, Seon-Il

    2017-04-01

    The purpose of this study was to investigate the influence of irradiation on the anti-oxidative, anti-inflammatory and whitening effects of mulberry leaf extract. This was done by comparing the phenolic contents; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects; 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical scavenging effects; in vitro tyrosinase inhibitory effects and the production of IL-6, TNF-α, PGE2, and NO in lipopolysaccharide-stimulated RAW264.7 macrophages and the production of IL-6 and TNF-α in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 cells, respectively. The results showed that irradiated mulberry leaf extract possesses more anti-oxidant, anti-inflammatory, and tyrosinase inhibitory activities than their non-irradiated counterpart, probably due to increase in phenolic contents induced by gamma irradiation at dose of 10kGy. This research stresses on the importance of irradiation in functional foods.

  11. Degradation of poly(carbonate urethane) by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Özdemir, T.; Usanmaz, A.

    2007-06-01

    Poly(carbonate urethane) (PCU), is a valuable commercial engineering polymer. In order to understand the possible use of PCU in radioactive waste management as a solidifying agent or as a disposal container, radiation stability of the PCU is studied by Co-60 gamma irradiations at two different dose rates of 1540 and 82.8 Gy/h. The total dose of irradiation was up to 6.24 MGy. Degradation nature was tested by studying the changes in mechanical and thermal properties with rate and total dose of irradiation. Ultimate tensile strength and toughness first increased and then decreased with the irradiation dose. Half value dose (HVD) for elongation was 4010 kGy and for tensile strength 6010 kGy at the dose rate of 1540 Gy/h. The non-irradiated PCU transparent color changed to yellow and then brown with increased irradiation dose. The FTIR spectral analysis showed a random scission of polymer with irradiation. From the experimental observation, it was shown that PCU can be used for embedding radioactive waste for about 300 years.

  12. Modification of LDPE molecular structure by gamma irradiation for bioapplications

    NASA Astrophysics Data System (ADS)

    Ferreira, L. M.; Falcão, A. N.; Gil, M. H.

    2005-07-01

    The surface properties of low-density polyethylene (LDPE) can be modified by the grafting of 2-hydroxyethyl methacrylate (HEMA). This was done aiming at the production of new materials suitable for bioapplications. Samples with different monomer concentrations were prepared from LDPE particles by gamma irradiation, following different irradiation protocols, including irradiation in presence and absence of air. The samples were characterized by thermal analysis techniques (DSC and TGA) and by Fourier transform infrared spectroscopy (FTIR). The results obtained show a decrease in the crystallinity of the supporting matrix for copolymers with high yields of grafting. However, the new materials prepared maintain good structural order resulting from the protective effect of polyHEMA grafted onto LDPE backbone. These effects can improve the diffusion of other species deeper inside the matrix and increase the material hydrophilicity. The studies performed made possible the selection of experimental protocols adequate for the production of new copolymeric materials with high grafting yield. These were used in the production of new LDPE films with enhanced hydrophilic properties.

  13. EPR study on non- and gamma-irradiated herbal pills

    NASA Astrophysics Data System (ADS)

    Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N. D.

    2011-06-01

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show "cellulose-like" EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  14. Increasing genetic variability in black oats using gamma irradiation.

    PubMed

    Silveira, G; Moliterno, E; Ribeiro, G; Costa, P M A; Woyann, L G; Tessmann, E W; Oliveira, A C; Cruz, C D

    2014-12-04

    The black oat (Avena strigosa Schreb) is commonly used for forage, soil cover, and green manure. Despite its importance, little improvement has been made to this species, leading to high levels of genotypic disuniformity within commercial cultivars. The objective of this study was to evaluate the efficiency of different doses of gamma rays [(60)Co] applied to black oat seeds on the increase of genetic variability of agronomic traits. We applied doses of 0, 10, 50, 100, and 200 Gy to the genotype ALPHA 94087 through exposure to [(60)Co]. Two experiments were conducted in the winter of 2008. The first aimed to test forage trait measurements such as plant height, dry matter yield, number of surviving tillers, and seedling stand. The second test assessed seed traits, such as yield and dormancy levels. Gamma irradiation seems not to increase seed yield in black oats, but it was effective in generating variability for the other traits. Tiller number and plant height are important selection traits to increase dry matter yield. Selection in advanced generations of mutant populations can increase the probability of identifying superior genotypes.

  15. DECOMMISSIONING THE BROOKHAVEN NATIONAL LABORATORY BUILDING 830 GAMMA IRRADIATION FACILITY.

    SciTech Connect

    BOWERMAN, B.S.; SULLIVAN, P.T.

    2001-08-13

    The Building 830 Gamma Irradiation Facility (GIF) at Brookhaven National Laboratory (BNL) was decommissioned because its design was not in compliance with current hazardous tank standards and its cobalt-60 sources were approaching the end of their useful life. The facility contained 354 stainless steel encapsulated cobalt-60 sources in a pool, which provided shielding. Total cobalt-60 inventory amounted to 24,000 Curies when the sources were shipped for disposal. The decommissioning project included packaging, transport, and disposal of the sources and dismantling and disposing of all other equipment associated with the facility. Worker exposure was a major concern in planning for the packaging and disposal of the sources. These activities were planned carefully according to ALARA (As Low As Reasonably Achievable) principles. As a result, the actual occupational exposures experienced during the work were within the planned levels. Disposal of the pool water required addressing environmental concerns, since the planned method was to discharge the slightly contaminated water to the BNL sewage treatment plant. After the BNL evaluation procedure for discharge to the sewage treatment plant was revised and reviewed by regulators and BNL's Community Advisory Council, the pool water was discharged to the Building 830 sanitary system. Because the sources were sealed and the pool water contamination levels were low, most of the remaining equipment was not contaminated; therefore disposal was straightforward, as scrap metal and construction debris.

  16. Tissue banking in India: gamma-irradiated allografts.

    PubMed

    Lobo Gajiwala, A

    2003-01-01

    In India, the procurement of tissues for transplantation is governed by the Transplantation of Human Organs Act, 1994. Although this law exists, it is primarily applied to organ transplantation and rules and regulations that are specific to tissue banking which have yet to be developed. The Tata Memorial Hospital (TMH) Tissue Bank was started in 1988 as part of an International Atomic Energy Agency (IAEA) programme to promote the use of ionising radiation for the sterilisation of biological tissues. It represents the Government of India within this project and was the first facility in the country to use radiation for the sterilisation of allografts. It is registered with the Health Services Maharashtra State and provides freeze-dried, gamma irradiated amnion, dura mater, skin and bone. The tissues are obtained either from cadavers or live donors. To date the TMH Tissue Bank has provided 6328 allografts which have found use as biological dressings and in various reconstructive procedures. The TMH Tissue Bank has helped initiate a Tissue Bank at the Defence Laboratory (DL), Jodhpur. At present these are the only two Banks in the country using radiation for the terminal sterilisation of preserved tissues. The availability of safe, clinically useful and cost effective grafts has stimulated innovative approaches to surgery. There is an increased demand for banked tissues and a heightened interest in the development of tissue banks. Inadequate infrastructure for donor referral programmes and the lack of support for tissue transplant co-ordinators however, continue to limit the availability of donor tissue.

  17. A small size continuous run industrial gamma irradiator

    NASA Astrophysics Data System (ADS)

    Calvo, Wilson A. P.; Rela, Paulo R.; Springer, Francisco E.; Costa, Fábio E. da; Omi, Nelson M.; Silva, Leonardo G. A. e.

    2004-09-01

    A new small size gamma irradiator is being set up at Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil, with a revolutionary design. The developed technology for this facility consists of continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m 2 of floor area, the irradiator design is product overlap sources and the maximum capacity of Cobalt-60 wet sources is 37 PBq (1 MCi). The irradiator is being installed in a Governmental Institution and it will be used as a demonstration facility for manufacturers, who need an economic and logistic in-house irradiation system alternative. Also, it will be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers.

  18. Reduction of pathogenic bacteria in organic compost using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Yun, Hye-Jeong; Lim, Sang-Yong; Song, Hyun-Pa; Kim, Byung-Keun; Chung, Byung-Yeoup; Kim, Dong-Ho

    2007-11-01

    Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm products because most of the composts are originated from excremental matters of domestic animals. In this study, the radiation treatment was performed to improve microbiological safety of organic compost and the effectiveness of gamma irradiation for inactivating Salmonella Typhimurium and Escherichia coli was investigated. The total aerobic and coliform bacteria in the 16 commercial composts were ranged from 10 5 to 10 7 CFU/ml and 0 to 10 3 CFU/ml, respectively. All coliform bacteria in the composts were eliminated by irradiation at a dose of 3 kGy, while about 10 2 CFU/ml of the total aerobic bacteria were survived up to 10 kGy. In the artificial inoculation test, the test organisms (inoculated at 10 7 CFU/g) were eliminated by irradiation at 3 kGy. Approximate D10 values of Salmonella Typhimurium and E. coli in the compost were 0.40 and 0.25 kGy, respectively. In the cultivation test, the test organisms of the compost had transfer a lettuce leaves. The growth pattern of lettuce was not different between irradiated and non-irradiated composts.

  19. A Review of Culturally Targeted/Tailored Tobacco Prevention and Cessation Interventions for Minority Adolescents

    PubMed Central

    Singh, Nisha; Krishnan-Sarin, Suchitra

    2012-01-01

    Aim: Emerging racial/ethnic disparities in tobacco use behaviors and resulting long-term health outcomes highlight the importance of developing culturally tailored/targeted tobacco prevention and cessation interventions. This manuscript describes the efficacy and the components of prevention and cessation interventions developed for minority adolescents. Methods: Thirteen studies focused on culturally tailoring and targeting tobacco prevention/cessation interventions were selected and information on intervention design (type, number of sessions), setting (school or community), theoretical constructs, culture-specific components (surface/deep structures), and treatment outcomes were extracted. Results: Of the 13 studies, 5 focused on prevention, 4 on cessation, and 4 combined prevention and cessation, and most of the studies were primarily school-based, while a few used community locations. Although diverse minority groups were targeted, a majority of the studies (n = 6) worked with Hispanic adolescents. The most common theoretical construct examined was the Social Influence Model (n = 5). The overall findings indicated that culturally tailoring cessation interventions did not appear to improve tobacco quit rates among minority adolescents, but culturally tailored prevention interventions appeared to produce lower tobacco initiation rates among minority adolescents than control conditions. Conclusions: The results of review suggest that there is a critical need to develop better interventions to reduce tobacco use among minority adolescents and that developing a better understanding of cultural issues related to both cessation and initiation of tobacco use among minority populations is a key component of this endeavor. PMID:22614548

  20. Effect of gamma irradiation on the conversion of ginsenoside Rb1 to Rg3

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hun; Kwon, Sun-Kyu; Sung, Nak-Yun; Jung, Pil-Mun; Choi, Jong-il; Kim, Jae-Kyung; Sharma, Arun K.; Lee, Ju-Woon

    2012-08-01

    Ginsenosides, the most important secondary metabolites in ginseng, have various biological activities. Many studies have focused on the conversion of one of the major ginsenosides, Rb1, to the more active minor ginsenoside, Rg3. This study was carried out to investigate the effect of gamma irradiation on the conversion of Rb1 to Rg3. Rb1 solutions were gamma-irradiated at doses of 10 and 30 kGy and analyzed by high performance liquid chromatography (HPLC). HPLC chromatograms showed a decreased content of Rb1 with increasing irradiation dose, but the content of Rg3 was increased. The highest content of Rg3 was present in the 30 kGy-irradiated Rb1 sample. The cytotoxic effects tested in cancer cell lines were increased in the gamma-irradiated group. Therefore, these results suggest that gamma irradiation can be an effective method for the conversion of the ginsenoside Rb1 to Rg3.

  1. Comparative Effects of Gamma Irradiation and Ozone Treatment on Hygienic Quality of Korean Red Ginseng Powder

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Yook, Hong-Sun; Kang, Il-Jun; Chung, Cha-Kwon; Kwon, Joong-Ho; Choi, Kang-Ju

    1998-06-01

    For the purpose of improving hygienic quality of Korean red ginseng powder, the comparative effects of gamma irradiation and ozone treatment on the microbial and physicochemical properties were investigated. Gamma irradiation at 7.5 kGy resulted in sterilization of total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the microorganisms of the red ginseng powder. Physicochemical properties including compositions of the red ginseng saponin (ginsenosides) and fatty acids, pH and hydrogen doanting activity were not significantly changed by gamma irradiation, whereas, ozone treatment caused significant changes in fatty acid compositions, TBA value, pH, acidity and hydrogen donating activity. The results from this study led us to conclude that gamma irradiation was more effective than ozone treatment both for the improvement of hygienic quality and for the maintenance of physicochemical quality of red ginseng powder.

  2. [Transformation of free radicals of gamma-irradiated enzymes during long-term storage].

    PubMed

    Ryl'tsev, V V; Virnik, R B; Dovbiĭ, E V; Filatov, V N

    1988-01-01

    The ESR method was used to study free radical processes occurring in gamma-irradiated enzymes upon their long-term storage (up to 4 years) both at room temperature and at 4 degrees C. Simultaneously, studied was the biological activity of gamma-irradiated enzymes subjected to a long-term storage. The immobilization of enzymes on dialdehyde cellulose or polycaproamine was shown to preserve their biological activity during the postirradiation storage.

  3. The gamma irradiation effects on structural and optical properties of silk fibroin/HPMC blend films

    NASA Astrophysics Data System (ADS)

    Shetty, G. Rajesha; Rao, B. Lakshmeesha; Gowda, Mahadeva; Shivananda, C. S.; Asha, S.; Byrappa, K.; Sangappa, Y.

    2016-05-01

    In this paper the structural, chemical and optical properties of gamma irradiated silk fibroin/Hydroxypropyl methyl cellulose (SF-HPMC) blend films were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-visible spectroscopy. The results indicate that the gamma radiation did not affect significantly the primary structure of polypeptide arrangement in the blend films. But the optical properties of the blends changed with gamma irradiation dosage.

  4. Production of Haploid Tobacco Plants Using Anther Culture.

    ERIC Educational Resources Information Center

    Smith, Robert A.; Belzer, Norbert F.

    2002-01-01

    Presents a tobacco haploid experiment in which students learn the cytogenetic technique of metaphase analysis of chromosomes and experience the basic principles of haploidy, diploidy, and polyploidy. (YDS)

  5. Tobacco

    MedlinePlus

    ... from poor households are frequently employed in tobacco farming to provide family income. These children are especially ... 19% of the world's population, meet the best practice for pictorial warnings, which includes the warnings in ...

  6. Improvement of color and physiological properties of tuna-processing by-product by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Choi, Jong-il; Kim, Hyun-Joo; Kim, Jae-Hun; Song, Beom-Seok; Chun, Byeong-Soo; Ahn, Dong-Hyun; Byun, Myung-Woo; Lee, Ju-Woon

    2009-07-01

    Although the by-products from fishery industry had many nutrients, it is being wasted or only used as bacteria media. In this study, the effect of a gamma irradiation on the cooking drips of Thunnus thynnus (CDT) was investigated to examine the possible use of the cooking drips as a functional material for food and cosmetic composition. Total aerobic bacteria, and yeasts/molds from CDT were detected at the level of 2.79 and 2.58 Log CFU/mL, respectively. But, CDT was efficiently sterilized by a gamma irradiation at a low dose of 1 kGy. The Hunter L* value of the gamma-irradiated ethanol extract of CDT was increased, and the a* and b* values were decreased compared to the non-irradiated extract, showing color improvement. Antioxidant activity of the ethanol extract of CDT was increased by a gamma irradiation depending on the irradiation dose. The increased contents of polyphenolic compounds and proteins in CDT extract by gamma irradiation may be the reason of the increased biological activity. These results suggested that the wasted cooking drips can be successfully used as functional components with gamma irradiation treatment.

  7. ESR and TL investigations on gamma irradiated linden (Tilia vulgaris).

    PubMed

    Paksu, Ufuk; Aydaş, Canan; Yüce, Ülkü Rabia; Aydın, Talat; Polat, Mustafa; Engin, Birol

    2013-05-01

    Electron spin resonance (ESR) and thermoluminescence (TL) signals induced by gamma irradiation in linden (Tilia vulgaris) were studied for detection and dosimetric purposes. Before irradiation, linden leaf samples exhibit one singlet ESR signal centred at g = 2.0088. Besides this central signal, in spectra of irradiated linden samples, two weak satellite signals situated about 3 mT left (g = 2.0267) and right (g = 1.9883) were observed. Dose-response curves for the left satellite signal and the central single signal were constructed, and it was found that both of these curves can be described best by the combination of two exponential saturation functions. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in linden leaf samples are very sensitive to temperature. The stabilities of the left satellite (g = 2.0267) and the central single (g = 2.0088) signal at room temperature over a storage period of 126 days turned out to be best described by a sum of two first-order decay functions. The kinetic features of the left satellite signal were studied over the temperature range of 313-373 K. The results indicate that the isothermal decay curves of the left satellite ESR signal also proved to be best fitted by the combination of two first-order decay functions. Fading and annealing studies suggested the existence of two different radiation-induced free radical species. At the same time, Arrhenius plots evidenced two different kinetic regimes with two different activation energies. TL investigation of polyminerals from the linden samples allowed to discriminate clearly between irradiated and unirradiated samples even 75 days after irradiation.

  8. Comparison of kinetic models to describe high pressure and gamma irradiation used to inactivate Vibrio vulnificus and Vibrio parahaemolyticus prepared in buffer solution and in whole oysters.

    PubMed

    Hu, Xiaopei; Mallikarjunan, Parameswarakumar; Koo, Jaheon; Andrews, Linda S; Jahncke, Michael L

    2005-02-01

    Comparisons of different models in inactivation kinetics were conducted on data obtained from high-pressure and gamma-irradiation processing. Vibrio vulnificus (MO-624) and Vibrio parahaemolyticus (O3:K6 TX-2103) suspended in phosphate-buffered saline (pH 7.4, 10(7) CFU/ml) were exposed to pressures from 207 to 379 MPa for 1 to 20 min. Inoculated whole oysters (106 CFU/g) were exposed to pressure from 276 to 379 MPa for 1 to 15 min. Pure cultures and inoculated oysters (10(6) CFU/g) also were irradiated (gamma irradiation) at doses of less than 3 kGy. Four mathematical models, the Bigelow model, Arrhenius equation, Fermi equation, and Weibull frequency distributions, were applied to microbial survival data, and performances of the different kinetic models were compared. Weibull frequency distributions can predict the high-pressure inactivation of Vibrio spp. with more accuracy in both pure cultures and inoculated oyster samples. The Fermi model provided a better description of gamma-irradiation inactivation kinetics compared with the traditional Bigelow model.

  9. Tobacco: Its historical, cultural, oral, and periodontal health association

    PubMed Central

    Mishra, Shanu; Mishra, M. B.

    2013-01-01

    This article provides information on the origin of tobacco and its subsequent spread throughout the world. In the era of the migration of communities, tobacco use gradually gained access and subsequently migrated along with the migrants, establishing in different locations. Probably at that time people were unaware of the health hazards and were using tobacco in treating certain ailments. Much has been known and written about tobacco in the context of oral and general health hazards but little has been explored and is known to many about where from and how this plant, which is now used in various forms, and speading widely. In what form, where, and how it had been served in religious rituals and considered for treatment or remedy of certain ailments in those days could not certainly be known. In the 21st century, people are considering hazardous tobacco as beneficial for their teeth, good for concentration of mind, and something which keeps them engaged. Even many professionals, though knowing the deleterious effects, are still using tobacco and gutkha in one or the other form. This article has been designed to revive the awareness for health hazards of tobacco and similar products. A pilot project questionnaire survey comprising this subject involving the educated mass has already been started and will be produced after analysis of data in part II of this paper. PMID:24478974

  10. Cultural competency and tobacco control training in US medical schools: many but missed opportunities.

    PubMed

    Powers, Catherine A; Zapka, Jane; Biello, Katie B; O'Donnell, Joseph; Prout, Marianne; Geller, Alan

    2010-09-01

    Tobacco-related morbidity and mortality disproportionately burdens America's most vulnerable populations, and many physicians in the USA are untrained in smoking cessation skills with patients of various literacy levels and races and ethnicities. An anonymous survey was administered to 860 second year and 827 fourth year students at 12 medical schools. A faculty representative at each of the schools completed an assessment of the curriculum and rated medical students' knowledge and skills for cultural competency. Report of experience in tobacco counseling for persons of various literacy levels and ethnicities rose from 42% (second year students) to 82% (fourth year students) and 48% (second year students) to 91% (fourth year students), respectively. However, only 37% of second year students and 40% of fourth year students reported that they had ever been taught to employ culturally competent strategies for tobacco cessation. This study found that almost two thirds of students in 12 medical schools reported no exposure to teaching about cultural competency and tobacco cessation, and approximately one third reported no practical experience with tobacco cessation counseling persons of various races and ethnicities. Effective cultural competency training for tobacco control should include teaching the social constructs of race, ethnicity, and socio-cultural concepts within a medical context. Additionally, students should receive supervised clinical opportunities to practice counseling, including opportunities to discuss and reflect on their experiences.

  11. Caffeine enhanced measurement of mutagenesis by low levels of [gamma]-irradiation in human lymphocytes

    SciTech Connect

    Puck, T.P.; Johnson, R.; Waldren, C.A. ); Morse, H. )

    1993-09-01

    The well-known action of caffeine in synergizing mutagenesis (including chromosome aberrations) of agents like ionizing radiation by inhibition of cellular repair processes has been incorporated into a rapid procedure for detection of mutagenicity with high sensitivity. Effects of 5-10 rads of [gamma]-irradiation, which approximate the human lifetime dose accumulation from background radiation, can be detected in a two-day procedure using an immortalized human WBC culture. Chromosomally visible lesions are scored on cells incubated for 2 h after irradiation in the presence and absence of 1.0 mg/ml of caffeine. An eightfold amplification of scorable lesions is achieved over the action of radiation alone. This approach provides a closer approximation to absolute mutagenicity unmitigated by repair processes, which can vary in different situations. It is proposed that mutagenesis testing of this kind, using caffiene or other repair-inhibitory agents, be employed to identify mutagens in their effective concentrations to which human populations may be exposed; to detect agents such as caffeine that may synergize mutagenic actions and pose epidemiologic threats; and to discover effective anti-mutagens. Information derived from the use of such procedures may help prevent cancer and newly acquired genetic disease.

  12. Imaging of gamma-Irradiated Regions of a Crystal

    NASA Technical Reports Server (NTRS)

    Dragoi, Danut; McClure, Steven; Johnston, Allan; Chao, Tien-Hsin

    2004-01-01

    A holographic technique has been devised for generating a visible display of the effect of exposure of a photorefractive crystal to gamma rays. The technique exploits the space charge that results from trapping of electrons in defects induced by gamma rays. The technique involves a three-stage process. In the first stage, one writes a holographic pattern in the crystal by use of the apparatus shown in Figure 1. A laser beam of 532-nm wavelength is collimated and split into signal and reference beams by use of a polarizing beam splitter. On its way to the crystal, the reference beam goes through a two-dimensional optical scanner that contains two pairs of lenses (L1y, L2y and L1x,L2x) and mirrors M1 and M2, which can be rotated by use of micrometer drives to make fine adjustments. The signal beam is sent through a spatial light modulator that imposes the holographic pattern, then through two imaging lenses L(sub img) on its way to the crystal. An aperture is placed at the common focus of lenses Limg to suppress high-order diffraction from the spatial light modulator. The hologram is formed by interference between the signal and reference beams. A camera lens focuses an image of the interior of the crystal onto a charge-coupled device (CCD). If the crystal is illuminated by only the reference beam once the hologram has been formed, then an image of the hologram is formed on the CCD: this phenomenon is exploited to make visible the pattern of gamma irradiation of the crystal, as described next. In the second stage of the process, the crystal is removed from the holographic apparatus and irradiated with rays at a dose of about 100 krad. In the third stage of the process, the crystal is remounted in the holographic apparatus in the same position as in the first stage and illuminated with only the reference beam to obtain the image of the hologram as modified by the effect of the rays. The orientations of M1 and M2 can be adjusted slightly, if necessary, to maximize the

  13. Rat germinal cells require PARP for repair of DNA damage induced by gamma-irradiation and H2O2 treatment.

    PubMed

    Atorino, L; Di Meglio, S; Farina, B; Jones, R; Quesada, P

    2001-03-01

    The ability of rat germinal cells to recover from genotoxic stress has been investigated using isolated populations of primary spermatocytes and round spermatids. Using a comet assay at pH 10.0 to assess single strand breakage (SSB) in DNA, it was found that a high level of damage was induced by 5 Gy gamma-irradiation and acute exposure to 50 microM H2O2. This damage was effectively repaired during a subsequent recovery period of 1-3 hours culture in vitro but repair was significantly delayed in the presence of the poly(ADP-ribose)polymerase (PARP) inhibitor 3-aminobenzamide (3-ABA). Immunofluorescence detection of PARP with specific antibodies localised the protein to discrete foci within the nucleus of both spermatocytes and spermatids. Poly(ADP-ribose) (pADPR) could also be detected in spermatid nuclei following gamma-irradiation or H2O2 treatment. Moreover, PARP activation occurs both in spermatocytes and spermatids left to recover after both genotoxic stresses. The NO donors, 3-morpholino-sydnonimine (SIN-1) and S-nitrosoglutathione (SNOG), caused significant SSBs in both spermatocytes and spermatids. The effects of SIN-1 could be prevented by exogenous catalase (CAT), but not superoxide dismutase (SOD), in the cell suspensions. SNOG-induced SSBs were insensitive to both CAT and SOD. It is concluded that DNA in spermatocytes and spermatids is sensitive to damage by gamma-irradiation and H2O2 and that efficient repair of SSBs requires PARP activity.

  14. Gamma irradiation of Tetrapleura tetraptera fruit as a post-harvest technique and its subsequent effect on some phytochemicals, free scavenging activity and physicochemical properties

    NASA Astrophysics Data System (ADS)

    Darfour, B.; Agbenyegah, S.; Ofosu, D. O.; Okyere, A. A.; Asare, I. K.

    2014-09-01

    Herbs, spices and medicinal plants have been cherished by many ancient cultures for their use in curing common ailments and promoting good health. The dry fruit of Tetrapleura tetraptera has a pleasant aroma and hence used as a spice for seasoning in many parts of Ghana. Contamination of the fruit can occur at any stage during harvesting, drying, processing, transportation and storage. T. tetraptera is prone to microbial contamination and insect infestation resulting in quality deterioration and economic loss. The study aimed at establishing the effect of gamma irradiation as a post-harvest processing technique on T. tetraptera fruit and the subsequent effect of the gamma irradiation on some phytochemicals, free radical scavenging activity and physicochemical properties. The T. tetraptera powder was packed in polythene bags and gamma irradiated with Cobalt 60 source at 5 kGy and 10 kGy at room temperature at a dose rate of 2 kGy/h. The total phenolic content, total flavonoid and DPPH free radical scavenging activity, pH, lactic acid, vitamin C, moisture, carbohydrate, protein and trace element content of the samples were analysed. The antioxidant potential of the T. tetraptera extract was observed to be enhanced in the solvent used for the extraction after the irradiation but not the radiation dose used. Irradiation only had substantial impacts on carbohydrate and protein, Cu, Mg, and Mn. The T. tetraptera studied was safe for human consumption as far as trace metal levels are concerned. This study therefore suggest that gamma irradiation up to 10 kGy could be used as a post-harvest technique in T. tetraptera as a spice or herb.

  15. Efficiency of gamma irradiation to inactivate growth and fumonisin production of Fusarium moniliforme on corn grains.

    PubMed

    Mansur, Ahmad Rois; Yu, Chun-Cheol; Oh, Deog-Hwan

    2014-02-28

    The efficiency of gamma irradiation (0, 1, 5, 10, 15, 20, and 30 kGy) as a sterilization method of corn samples (30 g) artificially contaminated with Fusarium moniliforme stored at normal condition (25ºC with approximate relative humidity (RH) of 55%) and optimal condition (25ºC with a controlled RH of 97%) was studied. The results showed that the fungal growth and the amount of fumonisin were decreased as the dose of gamma irradiation increased. Gamma irradiation at 1-5 kGy treatment significantly inhibited the growth of F. moniliforme by 1-2 log reduction on corn samples (P < 0.05). Sublethal effect of gamma irradiation was observed at 10-20 kGy doses after storage, and a complete inactivation required 30 kGy. Fungal growth and fumonisin production increased with higher humidity and longer storage time in all corn samples. This study also demonstrated that there was no strict correlation between fungal growth and fumonisin production. Storage at normal condition significantly resulted in lower growth and fumonisin production of F. moniliforme as compared with those stored at optimal condition (P < 0.05). Gamma irradiation with the dose of ≥ 5 kGy followed by storage at normal condition successfully prolonged the shelf life of irradiated corns, intended for human and animal consumptions, up to 7 weeks.

  16. Gamma irradiation improves the antioxidant activity of Aloe vera (Aloe barbadensis miller) extracts

    NASA Astrophysics Data System (ADS)

    Mi Lee, Eun; Bai, Hyoung-Woo; Sik Lee, Seung; Hyun Hong, Sung; Cho, Jae-Young; Yeoup Chung, Byung

    2012-08-01

    Aloe has been widely used in food products, pharmaceuticals, and cosmetics because of its aromatic and therapeutic properties. In the present study, the ethanolic extracts of aloe gel were gamma-irradiated from 10 to 100 kGy. After gamma irradiation, the color of the ethanolic extracts of aloe gel changed to red; this color persisted up to 40 kGy but disappeared above 50 kGy. Liquid chromatography/mass spectrometry analysis demonstrated the production of a new, unknown compound (m/z=132) after gamma irradiation of the ethanolic extracts of aloe gel. The amount of this unknown compound increased with increasing irradiation up to 80 kGy, and it was degraded at 100 kGy. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by the 1,1-diphenyl-2-picrylhydrazyl-radical scavenging capacity. The antioxidant activity of aloe extract was dramatically increased from 53.9% in the non-irradiated sample to 92.8% in the sample irradiated at 40 kGy. This strong antioxidant activity was retained even at 100 kGy. These results indicate that gamma irradiation of aloe extract can enhance its antioxidant activity through the formation of a new compound. Based on these results, increased antioxidant activity of aloe extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Reigniting Tobacco Ritual: Waterpipe Tobacco Smoking Establishment Culture in the United States

    PubMed Central

    Carroll, Mary V.; Chang, Judy; Sidani, Jaime E.; Barnett, Tracey E.; Soule, Eric; Balbach, Edith

    2014-01-01

    Introduction: Waterpipe tobacco smoking (WTS) is an increasingly prevalent form of tobacco use in the United States. Its appeal may stem from its social, ritualistic, and aesthetic nature. Our aim in this study was to understand WTS as a social ritual with the goal of informing prevention efforts. Methods: We conducted a covert observational study consisting of 38 observation sessions in 11 WTS establishments in 3 U.S. cities. Data collection was based on an established conceptual framework describing ritualistic elements of tobacco use. Iterative codebook development and qualitative thematic synthesis were used to analyze data. Results: Atmospheres ranged from quiet coffee shop to boisterous bar party environments. While some children and older adults were present, the majority of clientele were young adults. Men and women were evenly represented. However, there were 19 occurrences of a male smoking by himself, but no women smoked alone. The vast majority (94%) of the clientele were actively smoking waterpipes. All 83 observed groups manifested at least 1 of the ritual elements of our conceptual framework, while 41 of the 83 observed groups (49%) demonstrated all 4 ritual elements. Conclusions: Despite its heterogeneity, WTS is often characterized by 1 or more established elements of a tobacco-related social ritual. It may be valuable for clinical and public health interventions to acknowledge and address the ritualistic elements and social function of WTS. PMID:24972889

  19. Autologous Transplantation of Adult Mice Spermatogonial Stem Cells into Gamma Irradiated Testes

    PubMed Central

    Koruji, Morteza; Movahedin, Mansoureh; Mowla, Seyed Javad; Gourabi, Hamid; Pour-Beiranvand, Shahram; Jabbari Arfaee, Ali

    2012-01-01

    Objective: We evaluated structural and functional changes of fresh and frozen-thawed adult mouse spermatogonial stem cells following auto-transplantation into gamma-irradiated testes. Materials and Methods: In this experimental research, the right testes from adult mice (n=25) were collected, then Sertoli and spermatogonial cells were isolated using two-step enzymatic digestion, lectin immobilization and differential plating. Three weeks after cultivation, the Bromodeoxyuridine (BrdU)-labeled spermatogonial cells were transplanted, via rete testis, into the other testis of the same mouse, which had been irradiated with 14Gy. The mice were transplanted with: fresh cells (control 1), fresh cells co-cultured with Sertoli cells (control 2), the frozen-thawed cells (experimental 1) and frozen-thawed cells co-cultured with Sertoli cells (experimental 2). The morphological changes between different transplanted testes groups were compared in 8 weeks after transplantation. The statistical significance between mean values was determined by Kruskal Wallis and one-way analysis of variance in efficiency of transplantation. Results: The statistical analysis revealed significant increases in the mean percentage of testis weight and normal seminiferous tubules following spermatogonial stem cells transplantation in the recipient'fs testes. The normal seminiferous tubules percentage in the co-culture system with fresh cells and frozen-thawed groups were more than those in non-transplanted and fresh cell transplanted groups (p≤0.001). Conclusion: Our results demonstrated that spermatogonial stem cells in the colonies could result sperm production in the recipient’s testes after autologous transplantation. PMID:23507977

  20. Photo-annealing effect of gamma-irradiated erbium-doped fibre by femtosecond pulsed laser

    NASA Astrophysics Data System (ADS)

    Hsiung Chang, Sheng; Liu, Ren-Young; Lin, Chu-En; Chou, Fong-In; Tai, Chao-Yi; Chen, Chii-Chang

    2013-12-01

    In this work, a photo-annealing effect of gamma-irradiated erbium-doped glass fibre is investigated. Two commercial erbium-doped fibres (EDFs) with different doping concentrations were sealed inside a chamber with a cobalt-60 gamma source for 6 h to give an accumulated dose of 3.18 kGy. A tunable femtosecond pulsed laser with a repetition rate of 80 MHz was then used to pump EDF to generate 1550 nm fluorescence and green up-conversion emission, resulting in the annealing effect of the gamma-irradiated EDF. The fluorescence power of gamma-irradiated EDF with a moderate level of doping was almost returned to the initial state by photo-annealing, unlike that of a heavily doped EDF. This finding may facilitate the development of anti-irradiated superfluorescence fibre source for space navigation.

  1. Effect of gamma irradiation on viscosity reduction of cereal porridges for improving energy density

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Woon; Kim, Jae-Hun; Oh, Sang-Hee; Byun, Eui-Hong; Yook, Hong-Sun; Kim, Mee-Ree; Kim, Kwan-Soo; Byun, Myung-Woo

    2008-03-01

    Cereal porridges have low energy and nutrient density because of its viscosity. The objective of the present study was to evaluate the effect of irradiation on the reduction of viscosity and on the increasing solid content of cereal porridge. Four cereals, wheat, rice, maize (the normal starchy type) and waxy rice, were used in this study. The porridge with 3000 cP was individually prepared from cereal flour, gamma-irradiated at 20 kGy and tested. Gamma irradiation of 20 kGy was allowed that the high viscous and rigid cereal porridges turned into semi-liquid consistencies. The solid contents of all porridges could increase by irradiation, compared with non-irradiated ones. No significant differences of starch digestibility were observed in all cereal porridge samples. The results indicated that gamma irradiation might be helpful for improving energy density of cereal porridge with acceptable consistency.

  2. Effect of gamma irradiation on HPMC/ZnO nanocomposite films

    SciTech Connect

    Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shivananda, C. S.; Harish, K. V.; Sangappa; Shetty, G. Rajesha

    2015-06-24

    The present work looks into the structural and mechanical properties modification in ZnO nanoparticle incorporated Hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in gamma chamber at room temperature by use of Cobalt-60 source (Average energy of 1.25MeV) at different doses: 0, 50, 100, 150 and 200 kGy respectively. The changes in structural parameters and mechanical properties in pure and gamma irradiated HPMC/ZnO nanocomposite films have been studied using X-ray scattering (XRD) data and universal testing machine (UTM). It is found that gamma irradiation decreases the structural parameters and improves the mechanical properties of nanocomposite films.

  3. Effect of gamma irradiation on HPMC/ZnO nanocomposite films

    NASA Astrophysics Data System (ADS)

    Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shetty, G. Rajesha; Shivananda, C. S.; Harish, K. V.; Sangappa

    2015-06-01

    The present work looks into the structural and mechanical properties modification in ZnO nanoparticle incorporated Hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in gamma chamber at room temperature by use of Cobalt-60 source (Average energy of 1.25MeV) at different doses: 0, 50, 100, 150 and 200 kGy respectively. The changes in structural parameters and mechanical properties in pure and gamma irradiated HPMC/ZnO nanocomposite films have been studied using X-ray scattering (XRD) data and universal testing machine (UTM). It is found that gamma irradiation decreases the structural parameters and improves the mechanical properties of nanocomposite films.

  4. Effect of gamma irradiation on HPMC/ZnO nanocomposite films

    NASA Astrophysics Data System (ADS)

    Rao, B. L.; Sangappa, Y.

    2015-06-01

    The present work looks into the structural, chemical, mechanical, optical and thermal modification in ZnO nanoparticle incorporated hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in a gamma chamber at room temperature using Cobalt-60 source (average energy of 1.25 MeV) at different doses: 0, 50, 100, 150 and 200 kGy. The modifications in structural, chemical, mechanical, optical and thermal properties, due to gamma irradiation in HPMC/ZnO nanocomposite films, have been studied using wide angle X-ray scattering (XRD), Fourier transform infrared spectroscopy, universal testing machine, ultraviolet-visible spectrophotometry and thermogravimetric analysis. It is found that gamma irradiation improves the mechanical and thermal properties of nanocomposite films.

  5. X-ray absorption studies of gamma irradiated Nd doped phosphate glass

    SciTech Connect

    Rai, V. N.; Rajput, Parasmani; Jha, S. N.; Bhattacharyya, D.

    2015-06-24

    This paper presents the X-ray absorption near edge structure (XANES) studies of Nd doped phosphate glasses before and after gamma irradiation. The intensity and location of L{sub III} edge white line peak of Nd changes depending on its concentration as well as on the ratio of O/Nd in the glass matrix. The decrease in the peak intensity of white line after gamma irradiation indicates towards reduction of Nd{sup 3+} to Nd{sup 2+} in the glass matrix, which increases with an increase in the doses of gamma irradiation. Similarity in the XANES spectra of Nd doped phosphate glasses and Nd{sub 2}O{sub 3} suggests that coordination geometry around Nd{sup 3+} in glass samples may be identical to that of Nd{sub 2}O{sub 3}.

  6. The effects of gamma irradiation on neutron displacement sensitivity of lateral PNP bipolar transistors

    NASA Astrophysics Data System (ADS)

    Wang, Chenhui; Chen, Wei; Liu, Yan; Jin, Xiaoming; Yang, Shanchao; Qi, Chao

    2016-09-01

    The effects of gamma irradiation on neutron displacement sensitivity of four types of lateral PNP bipolar transistors (LPNPs) with different neutral base widths, emitter widths and the doping concentrations of the epitaxial base region are studied. The physical mechanisms of the effects are explored by defect analysis using deep level transient spectroscopy (DLTS) techniques and numerical simulations of recombination process in the base region of the lateral PNP bipolar transistors, and are verified by the experiments on gate-controlled lateral PNP bipolar transistors (GCLPNPs) manufactured in the identical commercial bipolar process with different gate bias voltage. The results indicate that gamma irradiation increases neutron displacement damage sensitivity of lateral PNP bipolar transistors and the mechanism of this phenomenon is that positive charge induced by gamma irradiation enhances the recombination process in the defects induced by neutrons in the base region, leading to larger recombination component of base current and greater gain degradation.

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

    NASA Astrophysics Data System (ADS)

    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 ( 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.

  8. Gamma-irradiation improves the color and antioxidant properties of Chaga mushroom (Inonotus obliquus) extract.

    PubMed

    Kim, Jae-Hun; Sung, Nak-Yun; Kwon, Sun-Kyu; Srinivasan, Periasamy; Song, Beom-Seok; Choi, Jong-Il; Yoon, Yohan; Kim, Jin Kyu; Byun, Myung-Woo; Kim, Mee-Ree; Lee, Ju-Woon

    2009-12-01

    The objective of this study was to evaluate the effect of ionizing radiation on color and antioxidative properties of Chaga mushroom (Inonotus obliquus) extract (CME). CME (10 mg/mL) was gamma-irradiated at 0, 3, 5, 7, and 10 kGy, and color, antioxidant activity, and total phenolic compound levels were then determined. The lightness and yellowness were increased (P < .05), and the redness was decreased (P < .05), as irradiation dose increased. The antioxidant parameters such as the 2-diphenyl-1-picrylhydrazyl, superoxide, and hydroxyl radical scavenging activities, ferric reducing/antioxidant power, and inhibition of lipid peroxidation increased as the irradiation dose increased. Also, the total phenolic compound levels of CME were increased (P < .05) by gamma-irradiation. These results suggest that gamma-irradiation could be considered a means for improving the antioxidant properties and the color of CME.

  9. Recycling of gamma irradiated inner tubes in butyl based rubber compounds

    NASA Astrophysics Data System (ADS)

    Karaağaç, Bağdagül; Şen, Murat; Deniz, Veli; Güven, Olgun

    2007-12-01

    Recycling of gamma irradiated inner tubes made of butyl rubber in butyl based rubber compounds was studied. Gamma irradiated inner tube wastes and commercial butyl rubber crumbs devulcanized by conventional methods were replaced with butyl rubber up to 15 phr in the compound recipe. The rheological and mechanical properties and carbon black dispersion degree for both types of compounds were measured and then compared to those of virgin butyl rubber compound. It is well known that mechanical properties are deteriorated when rubber crumb is added to the virgin compound. The deterioration in the mechanical properties for the compounds prepared by recycling of irradiated inner tubes at 120 kGy is much lower than the compounds prepared by using commercial butyl crumbs. It has been observed that gamma irradiated used inner tubes were compatible with butyl rubber and could be recycled within butyl based rubber compounds.

  10. Preliminary investigations into the bioconversion of gamma irradiated agricultural waste by Pleurotus spp.

    NASA Astrophysics Data System (ADS)

    Gbedemah, C. M.; Obodai, M.; Sawyerr, L. C.

    1998-06-01

    The application of gamma irradiation for pretreatment of lignocellulosic materials for their hydrolysis and to increase their digestibility for rumen animal have been reported in the literature. Gamma irradiation of corn stover in combination with sodium hydroxide for bioconversion of polysaccharide into protein by Pleurotus spp has also been reported. In this study experiments were designed to find out whether gamma radiation could serve both as a decontaminating agent as well as hydrolytic agent of sawdust for the bioconversion of four varieties of Pleurotus spp. Preliminary results indicate that a dose of 20kGy of gamma irradiation increase the yield of Pleurotus eous var ET-8 whilst decreasing the yield of other varieties.

  11. Improvement of shelf stability and processing properties of meat products by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Lee, Ju-Woon; Yook, Hong-Sun; Lee, Kyong-Haeng; Kim, Hee-Yun

    2002-03-01

    To evaluate the effects of gamma irradiation on the processing properties of meat products, emulsion-type sausage, beef patties and pork loin ham were manufactured. Most contaminated bacteria were killed by 3 kGy-irradiation to raw ground beef, and sausage can be manufactured with desirable flavor, a reduction of NaCl and phosphate, and extension of shelf life using gamma irradiation on the raw meat. The beef patties were manufactured with the addition of antioxidants (200 ppm), BHA, ascorbyl palmitate, α-tocopherol, or β-carotene, and gamma-irradiation. Retardation of lipid oxidation appeared at the patties with an antioxidant. A dose of 5 kGy was observed to be as effective as the use of 200 ppm NaNO 2 to provide and maintain the desired color of the product during storage. After curing, irradiation, heating and smoking could extensively prolong the shelf life of the hams.

  12. Effects of gamma irradiation on chemical composition and ruminal protein degradation of canola meal

    NASA Astrophysics Data System (ADS)

    Shawrang, P.; Nikkhah, A.; Zare-Shahneh, A.; Sadeghi, A. A.; Raisali, G.; Moradi-Shahrebabak, M.

    2008-07-01

    Gamma irradiation of canola meal (at doses of 25, 50 and 75 kGy) could alter its ruminal protein degradation characteristics by cross-linking of the polypeptide chains. This processing resulted in decrease (linear effect, P<0.001) of ruminal protein degradation and increase (linear effect, P<0.001) of intestinal protein digestibility. The results showed that gamma irradiation at doses higher than 25 kGy can be used as a cross-linking agent to improve protein properties of supplements in ruminant nutrition.

  13. Effect of gamma irradiation on curcuminoids and volatile oils of fresh turmeric ( Curcuma longa)

    NASA Astrophysics Data System (ADS)

    Dhanya, R.; Mishra, B. B.; Khaleel, K. M.

    2011-11-01

    In our earlier study a radiation dose of 5 kGy was reported to be suitable for microbial decontamination and shelf life extension of fresh turmeric ( Curcuma longa), while maintaining its quality attributes. In continuation of that work, the effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric was studied. Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. Curcuminoid content and volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. The curcuminoid content was slightly increased by gamma irradiation. No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents.

  14. Wastewater treatment using gamma irradiation: Tétouan pilot station, Morocco

    NASA Astrophysics Data System (ADS)

    Tahri, Loubna; Elgarrouj, Driss; Zantar, Said; Mouhib, Mohamed; Azmani, Amina; Sayah, Fouad

    2010-04-01

    The increasing demand on limited water supplies has accelerated the wastewater reuse and reclamation. We investigated gamma irradiation effects on wastewater by measuring differences in the legislated parameters, aiming to reuse the wastewater. Effluents samples were collected at the urban wastewater treatment station of Tetouan and were irradiated at different doses ranging from 0 to 14 kGy using a Co 60 gamma source. The results showed an elimination of bacterial flora, a decrease of biochemical and chemical oxygen demand, and higher conservation of nutritious elements. The results of this study indicated that gamma irradiation might be a good choice for the reuse of wastewater for agricultural activities.

  15. Gamma irradiation of yellow and blue colorants in polystyrene packaging materials

    NASA Astrophysics Data System (ADS)

    Komolprasert, V.; Diel, Todd; Sadler, G.

    2006-01-01

    The effect of 10- and 20-kGy gamma irradiation was studied on chromophtal yellow 2RLTS (Yellow 110-2, 3, 4, 5-tetrachloro-6-cyanobenzoic acid) and Irgalite Blue GBP (copper (II) phthalocyanine blue) colorants, which were added to polystyrene (PS) material used to package food prior to irradiation. Analytical results obtained suggest that irradiation did not generate any new chemicals in the PS polymer containing either yellow or blue colorant at a concentration of up to 1% (w/w). Both yellow and blue colorants are relatively stable to gamma irradiation.

  16. Performance degradation of QAM based inter-satellite optical communication system under gamma irradiation

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Zhao, Shanghong; Gong, Zizheng; Zhao, Jing; Li, Xuan

    2016-01-01

    Main devices in quadrature amplitude modulation (QAM) based inter-satellite optical communication system were irradiated to a total dose of 20 krad with the dose rate of 5 rad/s using a Co60 radiation source. Gamma irradiation impacts on devices were analyzed and on the basis, system performance degradation was simulated. Variety of system BER along with onboard working time for different inter-satellite links was presented. In addition, some adaption methods were proposed to reduce gamma irradiation induced degradation.

  17. Gamma-irradiated carbon nanotube yarn as substrate for high-performance fiber supercapacitors.

    PubMed

    Su, Fenghua; Miao, Menghe; Niu, Haitao; Wei, Zhixiang

    2014-02-26

    As an electrical double layer capacitor, dry-spun carbon nanotube yarn possesses relatively low specific capacitance. This can be significantly increased as a result of the pseudocapacitance of functional groups on the carbon nanotubes developed by oxidation using a gamma irradiation treatment in the presence of air. When coated with high-performance polyaniline nanowires, the gamma-irradiated carbon nanotube yarn acts as a high-strength reinforcement and a high-efficiency current collector in two-ply yarn supercapacitors for transporting charges generated along the long electrodes. The resulting supercapacitors demonstrate excellent electrochemical performance, cycle stability, and resistance to folding-unfolding that are required in wearable electronic textiles.

  18. Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black pepper and red pepper by gamma irradiation.

    PubMed

    Song, Won-Jae; Sung, Hye-Jung; Kim, Sung-Youn; Kim, Kwang-Pyo; Ryu, Sangryeol; Kang, Dong-Hyun

    2014-02-17

    This study evaluated the efficacy of gamma irradiation to inactivate foodborne pathogens in black pepper (Piper nigrum) and red pepper (dried Capsicum annuum). Black pepper and red pepper inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were subjected to gamma irradiation in the range of 0, 1, 2, 3 and 5 kGy, and color change was evaluated after treatment. Pathogen populations decreased with increasing treatment doses. A gamma irradiation dose of 5 kGy decreased E. coli O157:H7 and S. Typhimurium populations >4.4 to >5.2 log CFU/g in black pepper without causing color change. Similarly, 5 kGy of gamma irradiation yielded reduction of 3.8 to >5.2 log CFU/g for E. coli O157:H7 and S. Typhimurium in red pepper. During gamma irradiation treatment, L*, a* and b* values of red pepper were not significantly changed except for 297 μm to 420 μm size red pepper treated with 5 kGy of gamma irradiation. Based on the D-value of pathogens in black pepper and red pepper, S. Typhimurium showed more resistant to gamma irradiation than did E. coli O157:H7. These results show that gamma irradiation has potential as a non-thermal process for inactivating foodborne pathogens in spices with minimal color changes.

  19. Effects of gamma-irradiation and air annealing on Yb-doped Y3Al5O12 single crystal.

    PubMed

    Zeng, Xionghui; Xu, Xiaodong; Wang, Xiaodan; Zhao, Zhiwei; Zhao, Guangjun; Xu, Jun

    2008-03-01

    The effects of gamma-irradiation on the air-annealed 10at.% Yb:Y(3)Al(5)O(12) (YAG) and air annealing on the gamma-irradiated 10at.% Yb:YAG have been studied by the difference absorption spectra before and after treatment. The gamma-irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAG crystal. After air annealing, the gamma-irradiation induced centers were totally removed and the concentration of Fe(3+) and Yb(3+) were lightly increased. For the first time, the gamma-irradiation induced valence changes between Yb(3+) and Yb(2+) ions in Yb:YAG crystals have been observed.

  20. Response of thyroid follicular cells to gamma irradiation compared to proton irradiation: II. The role of connexin 32

    NASA Technical Reports Server (NTRS)

    Green, L. M.; Tran, D. T.; Murray, D. K.; Rightnar, S. S.; Todd, S.; Nelson, G. A.

    2002-01-01

    The objective of this study was to determine whether connexin 32-type gap junctions contribute to the "contact effect" in follicular thyrocytes and whether the response is influenced by radiation quality. Our previous studies demonstrated that early-passage follicular cultures of Fischer rat thyroid cells express functional connexin 32 gap junctions, with later-passage cultures expressing a truncated nonfunctional form of the protein. This model allowed us to assess the role of connexin 32 in radiation responsiveness without relying solely on chemical manipulation of gap junctions. The survival curves generated after gamma irradiation revealed that early-passage follicular cultures had significantly lower values of alpha (0.04 Gy(-1)) than later-passage cultures (0.11 Gy(-1)) (P < 0.0001, n = 12). As an additional way to determine whether connexin 32 was contributing to the difference in survival, cultures were treated with heptanol, resulting in higher alpha values, with early-passage cultures (0.10 Gy(-1)) nearly equivalent to untreated late-passage cultures (0.11 Gy(-1)) (P > 0.1, n = 9). This strongly suggests that the presence of functional connexin 32-type gap junctions was contributing to radiation resistance in gamma-irradiated thyroid follicles. Survival curves from proton-irradiated cultures had alpha values that were not significantly different whether cells expressed functional connexin 32 (0.10 Gy(-1)), did not express connexin 32 (0.09 Gy(-1)), or were down-regulated (early-passage plus heptanol, 0.09 Gy(-1); late-passage plus heptanol, 0.12 Gy(-1)) (P > 0.1, n = 19). Thus, for proton irradiation, the presence of connexin 32-type gap junctional channels did not influence their radiosensitivity. Collectively, the data support the following conclusions. (1) The lower alpha values from the gamma-ray survival curves of the early-passage cultures suggest greater repair efficiency and/or enhanced resistance to radiation-induced damage, coincident with the

  1. Synergistic effect of the combined treatment with gamma irradiation and sodium dichloroisocyanurate to control gray mold (Botrytis cinerea) on paprika

    NASA Astrophysics Data System (ADS)

    Yoon, Minchul; Jung, Koo; Lee, Kwang-Youll; Jeong, Je-Yong; Lee, Ju-Woon; Park, Hae-Jun

    2014-05-01

    Gray mold (Botrytis cinerea) is one of the most major fungal pathogens in paprika. Generally, gamma irradiation over 1 kGy is effective for the control of fungal pathogens; however, a significant change in fruit quality (physical properties) on paprika was shown from gamma irradiation at over 0.6 kGy (p<0.05). Therefore, in this study, the synergistic disinfection effect of the combined treatment with gamma irradiation and sodium dichloroisocyanurate (NaDCC) was investigated to reduce the gamma irradiation dose. In an artificial inoculation experiment of B. cinerea isolated from naturally-infected postharvest paprika, fungal symptoms were observed in the stem and exocarp of paprika after conidial inoculation. From the sensitivity of gamma irradiation and NaDCC, B. cinerea conidia were fully inactivated by 4 kGy of gamma irradiation (D10 value 0.99 kGy), and were fully inactivated by 50 ppm NaDCC treatment. The fungal symptoms were not detected by the dose-dependent gamma irradiation (>4 kGy) and NaDCC (>50 ppm). As a result of the combined treatment of gamma irradiation and NaDCC, the D10 value was significantly reduced by 1.06, 0.88, 0.77, and 0.58 kGy (p<0.05). Moreover, fungal symptoms were more significantly reduced in combined treatment groups (gamma irradiation and NaDCC) than single treatment groups (gamma irradiation or NaDCC). These results suggest that combined treatment with irradiation and NaDCC treatment can be applied to preserve quality of postharvest paprika or other fruits.

  2. Chemical composition and lipoxygenase activity in soybeans (Glycine max L. Merr.) submitted to gamma irradiation

    NASA Astrophysics Data System (ADS)

    Barros, Érica Amanda de; Broetto, Fernando; Bressan, Dayanne F.; Sartori, Maria M. P.; Costa, Vladimir E.

    2014-05-01

    Soybeans are an important food due to their functional and nutritional characteristics. However, consumption by western populations is limited by the astringent taste of soybeans and their derivatives which results from the action of lipoxygenase, an enzyme activated during product processing. The aim of this study was to evaluate the effect of gamma irradiation on the chemical composition and specific activity of lipoxygenase in different soybean cultivars. Soybeans were stored in plastic bags and irradiated with doses of 2.5, 5 and 10 kGy. The chemical composition (moisture, protein, lipids, ashes, crude fiber, and carbohydrates) and lipoxygenase specific activity were determined for each sample. Gamma irradiation induced a small increase of protein and lipid content in some soybean cultivars, which did not exceed the highest content of 5% and 26%, respectively, when compared to control. Lipoxygenase specific activity decreased in the three cultivars with increasing gamma irradiation dose. In conclusion, the gamma irradiation doses used are suitable to inactivate part of lipoxygenase while not causing expressive changes in the chemical composition of the cultivars studied.

  3. Gamma irradiation of Cryptosporidium parvum oocysts affects intracelluar levels of the viral symbiont CPV

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown a dose-dependent effect of gamma irradiation on Cryptosporidium parvum development in neonatal mice and newborn calves. In mice, C. parvum oocysts exposed to 200 Gy showed nearly complete inability to develop as measured by C. parvum-specific quantitative PCR of ileal ti...

  4. Enhanced mass transfer during solid liquid extraction of gamma-irradiated red beetroot

    NASA Astrophysics Data System (ADS)

    Nayak, Chetan A.; Chethana, S.; Rastogi, N. K.; Raghavarao, K. S. M. S.

    2006-01-01

    The exposure to gamma-irradiation pretreatment increases cell wall permeabilization, resulting in loss of turgor pressure, which led to the increase of extractability of betanin from red beetroot. The degree of extraction of betanin was investigated using gamma irradiation as a pretreatment prior to the solid-liquid extraction process and compared with control beetroot samples. The beetroot subjected to different doses of gamma irradiation (2.5, 5.0, 7.5, 10.0 kGy) and control was dipped in an acetic acid medium (1% v/v) to extract the betanin. The diffusion coefficients for betanin as well as ionic component were estimated considering Fickian diffusion. The results indicated an increase in the diffusion coefficient of betanin (0.302×10 -9-0.463×10 -9 m 2/s) and ionic component (0.248×10 -9-0.453×10 -9 m 2/s) as the dose rate increased (from 2.5 to 10.0 kGy). The degradation constant was found to increase (0.050-0.079 min -1) with an increase gamma-irradiation doses (2.5-10.0 kGy), indicating lower stability of the betanin as compared to control sample at 65 °C.

  5. Effect of gamma irradiation on starch viscosity and physicochemical properties of different rice

    NASA Astrophysics Data System (ADS)

    Wu, Dianxing; Shu, Qingyao; Wang, Zhonghua; Xia, Yingwu

    2002-08-01

    Three types of rice cultivars (indica, japonica and hybrid rice) with similar intermediate apparent amylose content (AAC) as well as early indica rice cultivars with different amounts of AAC were selected for studying the effects of gamma irradiation on starch viscosity, physicochemical properties and starch granule structure. Four major parameters of RVA profile, that was determined by a rapid visco analyser (RVA, Model-3D), peak viscosity, hot pasting viscosity, cool pasting viscosity, and setback viscosity, were considerably decreased with increasing dose levels. Gamma irradiation reduced the amylose contents in the cultivars with low AAC, intermediate AAC, and glutinous rice, but had no effects on the high AAC cultivar. No visible changes in gelatinization temperature were detected after irradiation, but the peak time was reduced with the dose levels. Gel consistency was significantly increased in the tested cultivars, especially in the high AAC indica rice. The starch granules were somewhat deformed by gamma irradiation. These results suggested that it is promising to use gamma irradiation to improve rice eating or cooking quality.

  6. ATM is required for rapid degradation of cyclin D1 in response to {gamma}-irradiation

    SciTech Connect

    Choo, Dong Wan; Baek, Hye Jung; Motoyama, Noboru; Cho, Kwan Ho; Kim, Hye Sun; Kim, Sang Soo

    2009-01-23

    The cellular response to DNA damage induced by {gamma}-irradiation activates cell-cycle arrest to permit DNA repair and to prevent replication. Cyclin D1 is the key molecule for transition between the G1 and S phases of the cell-cycle, and amplification or overexpression of cyclin D1 plays pivotal roles in the development of several human cancers. To study the regulation of cyclin D1 in the DNA-damaged condition, we analyzed the proteolytic regulation of cyclin D1 expression upon {gamma}-irradiation. Upon {gamma}-irradiation, a rapid reduction in cyclin D1 levels was observed prior to p53 stabilization, indicating that the stability of cyclin D1 is controlled in a p53-independent manner. Further analysis revealed that irradiation facilitated ubiquitination of cyclin D1 and that a proteasome inhibitor blocked cyclin D1 degradation under the same conditions. Interestingly, after mutation of threonine residue 286 of cyclin D1, which is reported to be the GSK-3{beta} phosphorylation site, the mutant protein showed resistance to irradiation-induced proteolysis although inhibitors of GSK-3{beta} failed to prevent cyclin D1 degradation. Rather, ATM inhibition markedly prevented cyclin D1 degradation induced by {gamma}-irradiation. Our data indicate that communication between ATM and cyclin D1 may be required for maintenance of genomic integrity achieved by rapid arrest of the cell-cycle, and that disruption of this crosstalk may increase susceptibility to cancer.

  7. Labile iron pool and ferritin content in developing rat brain gamma-irradiated in utero.

    PubMed

    Robello, Elizabeth; Galatro, Andrea; Puntarulo, Susana

    2009-05-01

    This study was aimed to assess the content of total Fe, Ferritin (Ft) and labile Fe pool (LIP) in developing rat brain exposed in utero to 1 Gy of gamma-irradiation. A significant increase (2.3-fold) in the total Fe content of the fetal rat brain irradiated in utero was observed from 1 to 4h post-irradiation, as compared to the content in non-irradiated brain. Ft was analyzed by immunoblotting. The Ft protein was composed by 20 kDa subunits. According to the analysis of the band density in the Western blot, the Ft content decreased by 77+/-15% 2h after gamma-irradiation, as compared to the values in non-irradiated samples. The effect of gamma-irradiation on the LIP was studied by both electron paramagnetic resonance (EPR) and by a fluorescence technique employing calcein (CA). A reduction on the LIP was detected at 2h post-irradiation, independently of the methodology employed for the assay. Since NO content increased in the same time frame of LIP decreasing, a protective role for NO is suggested in fetal rat brain exposed to gamma-irradiation. The data presented in this work are the first experimental evidence suggesting that, as part of the network of the cellular response to limit irradiation-dependent injury, a complex interaction between Fe and NO could be triggered.

  8. Degradation of 3-chloro-4-hydroxybenzoic acid in biological treated effluent by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Chu, Libing; Wang, Jianlong

    2016-02-01

    Gamma irradiation-induced degradation of a chlorinated aromatic compound, 3-chloro-4-hydroxybenzoic acid (CHBA) in biological treated effluent was studied and the results were compared with those obtained in deionized water. Gamma irradiation led to a complete decomposition of CHBA and a partial mineralization in the treated effluent. The removal of CHBA followed the pseudo first-order reaction kinetic model and the rate constant in the treated effluent was 1.7-3.5 times lower than that in deionized water. The CHBA degradation rate was higher at acidic condition than at neutral and alkaline conditions. The radiolytic yield, G-value for CHBA degradation was lower in the treated effluent, which decreased with increase in absorbed doses and increased with increase in initial concentrations of CHBA. The degradation mechanism of CHBA using gamma irradiation was proposed through the oxidation by -OH and reduction by eaq- and H- radicals. As exposed to gamma irradiation, dechlorination takes place rapidly and combines with the oxidation and cleavage of the aromatic ring, producing chloride ions, small carboxylic acids, acetaldehyde and other intermediates into the solution.

  9. Effect of gamma irradiation on thermophysical properties of plasticized starch and starch surfactant films

    NASA Astrophysics Data System (ADS)

    Cieśla, Krystyna; Watzeels, Nick; Rahier, Hubert

    2014-06-01

    In this work the influence of gamma irradiation on the thermomechanical properties of the films formed in potato starch-glycerol and potato starch-glycerol-surfactant systems were examined by Dynamic Mechanical Analysis, DMA, and Differential Scanning Calorimetry, DSC, and the results were correlated to the amount of the volatile fraction in the films.

  10. Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation

    SciTech Connect

    Withers, Nathan J.; Sankar, Krishnaprasad; Akins, Brian A.; Memon, Tosifa A.; Gu Tingyi; Gu Jiangjiang; Smolyakov, Gennady A.; Greenberg, Melisa R.; Osinski, Marek; Boyle, Timothy J.

    2008-10-27

    Effects of {sup 137}Cs gamma irradiation on photoluminescent properties of CdSe/ZnS colloidal quantum dots are reported. Optical degradation is evaluated by tracking the dependence of photoluminescence intensity on irradiation dose. CdSe/ZnS quantum dots show poor radiation hardness, and severely degrade after less than 20 kR exposure to 662 keV gamma photons.

  11. The effect of cryogenic freezing and gamma irradiation on the survival of Salmonella on frozen shrimp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unfortunately, contraction of foodborne illness due to consumption of contaminated seafood, including shrimp, is an occasional occurrence. Cryogenic freezing and gamma irradiation are safe and effective technologies that can be used to control and inactivate pathogenic bacteria in foods. In this stu...

  12. Immunization of baboons with Schistosoma mansoni cercariae attenuated by gamma irradiation

    SciTech Connect

    Stek, M. Jr.; Minard, P.; Dean, D.A.; Hall, J.E.

    1981-06-26

    Studies on the efficacy of a vaccine against schistosomiasis in young baboons (Papio anubis) disclosed that immunization with Schistosoma mansoni cercariae attenuated by gamma irradiation induced significant protection against subsequent infection with normal, viable S. mansoni cercariae. Such immunization resulted in reduced worm burdens (70%) and egg excretion rates (82%). These results support immunization as a potential method for schistosomiasis control.

  13. Immunization of Baboons with Schistosoma mansoni Cercariae attenuated by gamma irradiation

    SciTech Connect

    Stek, M.; Minard, P.; Dean, D.A.; Hall, J.E.

    1981-06-01

    Studies on the efficacy of a vaccine against schistosomiasis in young baboons (Papio anubis) disclosed that immunization with Schistosoma mansoni cercariae attenuated by gamma irradiation induced significant protection against subsequent infection with normal, viable S. mansoni cercariae. Such immunization resulted in reduced worm burdens (70 percent) and egg excretion rates (82 percent). These results support immunization as a potential method for schistosomiasis control.

  14. Mechanical properties of acellular mouse lungs after sterilization by gamma irradiation.

    PubMed

    Uriarte, Juan J; Nonaka, Paula N; Campillo, Noelia; Palma, Renata K; Melo, Esther; de Oliveira, Luis V F; Navajas, Daniel; Farré, Ramon

    2014-12-01

    Lung bioengineering using decellularized organ scaffolds is a potential alternative for lung transplantation. Clinical application will require donor scaffold sterilization. As gamma-irradiation is a conventional method for sterilizing tissue preparations for clinical application, the aim of this study was to evaluate the effects of lung scaffold sterilization by gamma irradiation on the mechanical properties of the acellular lung when subjected to the artificial ventilation maneuvers typical within bioreactors. Twenty-six mouse lungs were decellularized by a sodium dodecyl sulfate detergent protocol. Eight lungs were used as controls and 18 of them were submitted to a 31kGy gamma irradiation sterilization process (9 kept frozen in dry ice and 9 at room temperature). Mechanical properties of acellular lungs were measured before and after irradiation. Lung resistance (RL) and elastance (EL) were computed by linear regression fitting of recorded signals during mechanical ventilation (tracheal pressure, flow and volume). Static (Est) and dynamic (Edyn) elastances were obtained by the end-inspiratory occlusion method. After irradiation lungs presented higher values of resistance and elastance than before irradiation: RL increased by 41.1% (room temperature irradiation) and 32.8% (frozen irradiation) and EL increased by 41.8% (room temperature irradiation) and 31.8% (frozen irradiation). Similar increases were induced by irradiation in Est and Edyn. Scanning electron microscopy showed slight structural changes after irradiation, particularly those kept frozen. Sterilization by gamma irradiation at a conventional dose to ensure sterilization modifies acellular lung mechanics, with potential implications for lung bioengineering.

  15. Evaluating the Effects of Gamma-Irradiation for Decontamination of Medicinal Cannabis

    PubMed Central

    Hazekamp, Arno

    2016-01-01

    In several countries with a National medicinal cannabis program, pharmaceutical regulations specify that herbal cannabis products must adhere to strict safety standards regarding microbial contamination. Treatment by gamma irradiation currently seems the only method available to meet these requirements. We evaluated the effects of irradiation treatment of four different cannabis varieties covering different chemical compositions. Samples were compared before and after standard gamma-irradiation treatment by performing quantitative UPLC analysis of major cannabinoids, as well as qualitative GC analysis of full cannabinoid and terpene profiles. In addition, water content and microscopic appearance of the cannabis flowers was evaluated. This study found that treatment did not cause changes in the content of THC and CBD, generally considered as the most important therapeutically active components of medicinal cannabis. Likewise, the water content and the microscopic structure of the dried cannabis flowers were not altered by standard irradiation protocol in the cannabis varieties studied. The effect of gamma-irradiation was limited to a reduction of some terpenes present in the cannabis, but keeping the terpene profile qualitatively the same. Based on the results presented in this report, gamma irradiation of herbal cannabis remains the recommended method of decontamination, at least until other more generally accepted methods have been developed and validated. PMID:27199751

  16. Low doses of gamma-irradiation induce an early bystander effect in zebrafish cells which is sufficient to radioprotect cells.

    PubMed

    Pereira, Sandrine; Malard, Véronique; Ravanat, Jean-Luc; Davin, Anne-Hélène; Armengaud, Jean; Foray, Nicolas; Adam-Guillermin, Christelle

    2014-01-01

    The term "bystander effect" is used to describe an effect in which cells that have not been exposed to radiation are affected by irradiated cells though various intracellular signaling mechanisms. In this study we analyzed the kinetics and mechanisms of bystander effect and radioadaptation in embryonic zebrafish cells (ZF4) exposed to chronic low dose of gamma rays. ZF4 cells were irradiated for 4 hours with total doses of gamma irradiation ranging from 0.01-0.1 Gy. In two experimental conditions, the transfer of irradiated cells or culture medium from irradiated cells results in the occurrence of DNA double strand breaks in non-irradiated cells (assessed by the number of γ-H2AX foci) that are repaired at 24 hours post-irradiation whatever the dose. At low total irradiation doses the bystander effect observed does not affect DNA repair mechanisms in targeted and bystander cells. An increase in global methylation of ZF4 cells was observed in irradiated cells and bystander cells compared to control cells. We observed that pre-irradiated cells which are then irradiated for a second time with the same doses contained significantly less γ-H2AX foci than in 24 h gamma-irradiated control cells. We also showed that bystander cells that have been in contact with the pre-irradiated cells and then irradiated alone present less γ-H2AX foci compared to the control cells. This radioadaptation effect is significantly more pronounced at the highest doses. To determine the factors involved in the early events of the bystander effect, we performed an extensive comparative proteomic study of the ZF4 secretomes upon irradiation. In the experimental conditions assayed here, we showed that the early events of bystander effect are probably not due to the secretion of specific proteins neither the oxidation of these secreted proteins. These results suggest that early bystander effect may be due probably to a combination of multiple factors.

  17. Culture Change From Tobacco Accommodation to Intolerance: Time to Connect the Dots.

    PubMed

    Livingood, William C; Allegrante, John P; Green, Lawrence W

    2016-04-01

    Broad changes in normative health behavior are critical to overcoming many of the contemporary challenges to public health. Reduction in tobacco use during the last third of the 20th century-one of the greatest improvements in public health-illustrates such change. The culture change from accommodation to intolerance of smoking is irrefutable. The role of health communication in predisposing, enabling, and reinforcing the normative social changes that ensued, however, has been less well documented with the linear, cause-and-effect methods of controlled intervention research. We examine the role of mass communication in the cultural transformation that reduced tobacco use, concluding that its influence on reduction in tobacco use follows a pathway as much through secondary transmissions within groups of people as through direct influence on individuals.

  18. A Mitochondria-Targeted Nitroxide/Hemigramicidin S Conjugate Protects Mouse Embryonic Cells Against Gamma Irradiation

    SciTech Connect

    Jiang Jianfei; Belikova, Natalia A.; Hoye, Adam T.; Zhao Qing; Epperly, Michael W.; Greenberger, Joel S.; Wipf, Peter; Kagan, Valerian E.

    2008-03-01

    Purpose: To evaluate the in vitro radioprotective effect of the mitochondria-targeted hemigramicidin S-conjugated 4-amino-2,2,6,6-tetramethyl-piperidine-N-oxyl (hemi-GS-TEMPO) 5-125 in {gamma}-irradiated mouse embryonic cells and adenovirus-12 SV40 hybrid virus transformed human bronchial epithelial cells BEAS-2B and explore the mechanisms involved in its radioprotective effect. Methods and Materials: Cells were incubated with 5-125 before (10 minutes) or after (1 hour) {gamma}-irradiation. Superoxide generation was determined by using dihydroethidium assay, and lipid oxidation was quantitated by using a fluorescence high-performance liquid chromatography-based Amplex Red assay. Apoptosis was characterized by evaluating the accumulation of cytochrome c in the cytosol and externalization of phosphatidylserine on the cell surface. Cell survival was measured by means of a clonogenic assay. Results: Treatment (before and after irradiation) of cells with 5-125 at low concentrations (5, 10, and 20 {mu}M) effectively suppressed {gamma}-irradiation-induced superoxide generation, cardiolipin oxidation, and delayed irradiation-induced apoptosis, evaluated by using cytochrome c release and phosphatidylserine externalization. Importantly, treatment with 5-125 increased the clonogenic survival rate of {gamma}-irradiated cells. In addition, 5-125 enhanced and prolonged {gamma}-irradiation-induced G{sub 2}/M phase arrest. Conclusions: Radioprotection/mitigation by hemi-GS-TEMPO likely is caused by its ability to act as an electron scavenger and prevent superoxide generation, attenuate cardiolipin oxidation in mitochondria, and hence prevent the release of proapoptotic factors from mitochondria. Other mechanisms, including cell-cycle arrest at the G{sub 2}/M phase, may contribute to the protection.

  19. Regulation of gene expression by tobacco product preparations in cultured human dermal fibroblasts

    SciTech Connect

    Malpass, Gloria E.; Arimilli, Subhashini; Prasad, G.L.; Howlett, Allyn C.

    2014-09-01

    Skin fibroblasts comprise the first barrier of defense against wounds, and tobacco products directly contact the oral cavity. Cultured human dermal fibroblasts were exposed to smokeless tobacco extract (STE), total particulate matter (TPM) from tobacco smoke, or nicotine at concentrations comparable to those found in these extracts for 1 h or 5 h. Differences were identified in pathway-specific genes between treatments and vehicle using qRT-PCR. At 1 h, IL1α was suppressed significantly by TPM and less significantly by STE. Neither FOS nor JUN was suppressed at 1 h by tobacco products. IL8, TNFα, VCAM1, and NFκB1 were suppressed after 5 h with STE, whereas only TNFα and NFκB1 were suppressed by TPM. At 1 h with TPM, secreted levels of IL10 and TNFα were increased. Potentially confounding effects of nicotine were exemplified by genes such as ATF3 (5 h), which was increased by nicotine but suppressed by other components of STE. Within 2 h, TPM stimulated nitric oxide production, and both STE and TPM increased reactive oxygen species. The biological significance of these findings and utilization of the gene expression changes reported herein regarding effects of the tobacco product preparations on dermal fibroblasts will require additional research. - Highlights: • Tobacco product preparations (TPPs) alter gene expression in dermal fibroblasts. • Some immediate early genes critical to the inflammatory process are affected. • Different TPPs produce differential responses in certain pro-inflammatory genes.

  20. A blocking ELISA for detection of antibody to a subgroup-reactive epitope of African horsesickness viral protein 7 (VP7) using a novel gamma-irradiated antigen.

    PubMed

    House, J A; Stott, J L; Blanchard, M T; LaRocco, M; Llewellyn, M E

    1996-07-23

    A novel gamma irradiated inactivated cell culture derived African horsesickness viral (AHSV) antigen was used in a blocking ELISA (B-ELISA) for detecting antibody to a subgroup-reactive epitope of AHSV. A monoclonal antibody (MAB), class IgM, against an epitope on African horsesickness (AHS) viral protein 7 (VP7) was developed in BALBc mice and used in the B-ELISA. The MAB, designated F9H, was blocked by 69 serums from equidae with antibody to AHS, but its binding activity was not appreciably affected by 301 serums that did not contain antibodies to AHS virus. An ELISA protocol using a blocking format is described.

  1. Cultural Orientation as a Protective Factor against Tobacco and Marijuana Smoking for African American Young Women

    ERIC Educational Resources Information Center

    Nasim, Aashir; Corona, Rosalie; Belgrave, Faye; Utsey, Shawn O.; Fallah, Niloofar

    2007-01-01

    The present study examined cultural orientation as a protective factor against tobacco and marijuana smoking for African American young women (ages 18 to 25). African American college students (N = 145) from a predominantly White university were administered subscales from the African American Acculturation Scale-Revised (AAAS-R); the shortened…

  2. Stress and Tobacco Use among African-American Adolescents: The Buffering Effect of Cultural Factors

    ERIC Educational Resources Information Center

    Belgrave, Faye Z.; Johnson, Jessica; Nguyen, Anh; Hood, Kristina; Tademy, Raymond; Clark, Trenette; Nasim, Aashir

    2010-01-01

    Tobacco is a leading contributor to morbidity and mortality and a primary reason for health disparities among African Americans. In this study we explore the role of stress in smoking and cultural factors that protect against stress among African-American adolescents. Our sample consisted of 239 youth who were recruited into the study while…

  3. Culture Change from Tobacco Accommodation to Intolerance: Time to Connect the Dots

    ERIC Educational Resources Information Center

    Livingood, William C., Jr.; Allegrante, John P.; Green, Lawrence W.

    2016-01-01

    Broad changes in normative health behavior are critical to overcoming many of the contemporary challenges to public health. Reduction in tobacco use during the last third of the 20th century--one of the greatest improvements in public health--illustrates such change. The culture change from accommodation to intolerance of smoking is irrefutable.…

  4. Effects of Apollo 12 lunar material on lipid levels of tobacco tissue and slash pine cultures

    NASA Technical Reports Server (NTRS)

    Weete, J. D.

    1972-01-01

    Investigations of the lipid components of pine tissues (Pinus elloitii) are discussed, emphasizing fatty acids and steroids. The response by slash pine tissue cultures to growth in contact with Apollo lunar soil, earth basalt, and Iowa soil is studied. Tissue cultures of tobacco grown for 12 weeks in contact with lunar material from Apollo 12 flight contained 21 to 35 percent more total pigment than control tissues. No differences were noted in the fresh or dry weight of the experimental and control samples.

  5. Thirdhand tobacco smoke: procedures to evaluate cytotoxicity in cell cultures.

    PubMed

    Figueiró, Luciana Rizzieri; Dantas, Denise Conceição Mesquita; Linden, Rafael; Ziulkoski, Ana Luiza

    2016-06-01

    The risks associated to tobacco smoking are not ceased with smoke extinction. Many toxic compounds remain in the environment after the cigarette is extinguished and accumulated in the air or on surfaces. However, little is known about the risks of this exposure. The aim of this study was to evaluate procedures to collect thirdhand smoke (THS) and prepare the samples to perform three in vitro toxicity tests. Cellulose papers and cotton wipes were used to impregnate with nicotine solution and smoke cigarette in a chamber or in smoker's home. Samples were immersed in methanol or Dulbecco's modified Eagle's medium (DMEM) to expose Hep-2 cells. MTT, neutral red uptake (NRU) and trypan blue assays were performed. The concentration of nicotine in DMEM extract of THS in paper and cotton was similar to those in methanol extract (p > 0.05). Alterations in the mitochondrial and lysosomal functions were found in both paper and cotton samples; however, the cytotoxic effect was not always observed. There was a decrease of 21-31% in MTT assay and 38-56% in NRU assay (p < 0.003). There was a dose-response relationship between the amount of cigarettes and lysosomal viability; the correlation was higher for cotton samples (r = -0.843, p < 0.001). As a dose-response relationship was found only in NRU assay, this test may be a more suitable choice rather than the MTT assay. Paper and wipe sampling can be reliable markers of tobacco smoke contamination. Moreover, these materials, if properly prepared, can be used as substrate providers to perform cellular assays.

  6. Low Dose Gamma Irradiation Potentiates Secondary Exposure to Gamma Rays or Protons in Thyroid Tissue Analogs

    SciTech Connect

    Green, Lora M

    2006-05-25

    We have utilized our unique bioreactor model to produce three-dimensional thyroid tissue analogs that we believe better represent the effects of radiation in vivo than two-dimensional cultures. Our thyroid model has been characterized at multiple levels, including: cell-cell exchanges (bystander), signal transduction, functional changes and modulation of gene expression. We have significant preliminary data on structural, functional, signal transduction and gene expression responses from acute exposures at high doses (50-1000 rads) of gamma, protons and iron (Green et al., 2001a; 2001b; 2002a; 2002b; 2005). More recently, we used our DOE funding (ending Feb 06) to characterize the pattern of radiation modulated gene expression in rat thyroid tissue analogs using low-dose/low-dose rate radiation, plus/minus acute challenge exposures. Findings from these studies show that the low-dose/low-dose rate “priming” exposures to radiation invoked changes in gene expression profiles that varied with dose and time. The thyrocytes transitioned to a “primed” state, so that when the tissue analogs were challenged with an acute exposure to radiation they had a muted response (or an increased resistance) to cytopathological changes relative to “un-primed” cells. We measured dramatic differences in the primed tissue analogs, showing that our original hypothesis was correct: that low dose gamma irradiation will potentiate the repair/adaptation response to a secondary exposure. Implications from these findings are that risk assessments based on classical in vitro tissue culture assays will overestimate risk, and that low dose rate priming results in a reduced response in gene expression to a secondary challenge exposure, which implies that a priming dose provides enhanced protection to thyroid cells grown as tissue analogs. If we can determine that the effects of radiation on our tissue analogs more closely resemble the effects of radiation in vivo, then we can better

  7. Regulation of gene expression by tobacco product preparations in cultured human dermal fibroblasts.

    PubMed

    Malpass, Gloria E; Arimilli, Subhashini; Prasad, G L; Howlett, Allyn C

    2014-09-01

    Skin fibroblasts comprise the first barrier of defense against wounds, and tobacco products directly contact the oral cavity. Cultured human dermal fibroblasts were exposed to smokeless tobacco extract (STE), total particulate matter (TPM) from tobacco smoke, or nicotine at concentrations comparable to those found in these extracts for 1h or 5h. Differences were identified in pathway-specific genes between treatments and vehicle using qRT-PCR. At 1h, IL1α was suppressed significantly by TPM and less significantly by STE. Neither FOS nor JUN was suppressed at 1h by tobacco products. IL8, TNFα, VCAM1, and NFκB1 were suppressed after 5h with STE, whereas only TNFα and NFκB1 were suppressed by TPM. At 1h with TPM, secreted levels of IL10 and TNFα were increased. Potentially confounding effects of nicotine were exemplified by genes such as ATF3 (5h), which was increased by nicotine but suppressed by other components of STE. Within 2h, TPM stimulated nitric oxide production, and both STE and TPM increased reactive oxygen species. The biological significance of these findings and utilization of the gene expression changes reported herein regarding effects of the tobacco product preparations on dermal fibroblasts will require additional research.

  8. Gamma-irradiated and nonirradiated Eimeria tenella sporozoites exhibit differential uracil uptake and expression of a 7- to 10-kDa metabolic antigen.

    PubMed

    Jenkins, M C; Chute, M B; Danforth, H D; Lillehoj, H S

    1995-06-01

    Eimeria tenella sporozoites were exposed in the oocyst form to either an optimum (15 kRad) or a high (25 kRad) dose of gamma irradiation and used to infect cultured chicken embryo fibroblasts (CEF). The sporozoite-infected CEF monolayer was pulsed at time of infection or 24 hr postinfection with [3H]uracil and harvested 24 hr later to measure sporozoite metabolic activity. Sporozoites exposed to either 0 or 15 kRad gamma irradiation incorporated similar (P > 0.05) amounts of [3H]uracil during the first and second 24-hr periods after infection. However, there was a significant decrease (P < 0.05) in [3H]uracil uptake by 25 kRad-exposed sporozoites compared to nonirradiated and 15 kRad-irradiated sporozoites. Indirect immunofluorescence (IFA) staining of E. tenella sporozoite-infected CEFs using monoclonal antibodies (MAb) specific for somatic or "metabolic" antigens showed that gamma irradiation also affected the release of intracellular metabolites. Regardless of irradiation dose, extracellular sporozoites exhibited similar intensity of immunofluorescence when stained with either somatic antigen- or metabolic antigen-reactive MAb. Also, somatic antigen expression was similar for intracellular parasites irrespective of radiation dose. However, metabolic 7- to 10-kDa antigen expression by 25 kRad-irradiated sporozoites was markedly reduced compared to nonirradiated or 15 kRad-irradiated intracellular sporozoites. These results were corroborated by immunostaining sporozoite/CEF protein-impregnated Immobilon membrane with somatic or metabolic 7- to 10-kDa antigen-reactive MAb. These findings may indicate that the metabolic 7- to 10-kDa antigen is involved in protective immunity elicited by nonirradiated and/or 15 kRad-irradiated E. tenella sporozoites.

  9. Ultrastructure of Campylobacter jejuni in gamma-irradiated mouse jejunum

    SciTech Connect

    Sosula, L.; Nicholls, E.M.; Skeen, M.

    1988-04-01

    This paper describes the ultrastructure of intracellular elongated, transitional and coccoid forms of Campylobacter jejuni, in irradiated mouse jejunum infected both in vitro and in vivo and in cultured human skin fibroblasts. Jejunum of irradiated mouse incubated for 1 hour under conditions favorable to the organisms showed minimal tissue degeneration. The intracellular organisms in this material were free cytoplasmic forms showing inner membrane degeneration, loss of cytoplasmic granules, and absence of flagella. The diameter of the coccoids was up to four times that of the elongated forms, as in plate cultures. Intracellular organisms were not found in challenged unirradiated controls, indicating that irradiation of mouse cells may be required for intracellular infection with human strains of C jejuni. In contrast, challenged human fibroblasts contained typical elongated organisms in cytoplasmic vacuoles. These findings are discussed with reference to Campylobacter strain, host resistance, and natural animal and human Campylobacter infections.

  10. Ultrastructure of Campylobacter jejuni in gamma-irradiated mouse jejunum.

    PubMed Central

    Sosula, L.; Nicholls, E. M.; Skeen, M.

    1988-01-01

    This paper describes the ultrastructure of intracellular elongated, transitional and coccoid forms of Campylobacter jejuni, in irradiated mouse jejunum infected both in vitro and in vivo and in cultured human skin fibroblasts. Jejunum of irradiated mouse incubated for 1 hour under conditions favorable to the organisms showed minimal tissue degeneration. The intracellular organisms in this material were free cytoplasmic forms showing inner membrane degeneration, loss of cytoplasmic granules, and absence of flagella. The diameter of the coccoids was up to four times that of the elongated forms, as in plate cultures. Intracellular organisms were not found in challenged unirradiated controls, indicating that irradiation of mouse cells may be required for intracellular infection with human strains of C jejuni. In contrast, challenged human fibroblasts contained typical elongated organisms in cytoplasmic vacuoles. These findings are discussed with reference to Campylobacter strain, host resistance, and "natural" animal and human Campylobacter infections. Images Figure 1 Figure 2 Figure 3 PMID:3354638

  11. Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation

    SciTech Connect

    Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

    1982-10-01

    Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with /sup 60/CO gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of /sup 60/CO radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. The authors found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents.

  12. Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation

    SciTech Connect

    Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

    1982-10-01

    Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with /sup 60/Co gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of /sup 60/Co radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. We found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents.

  13. Sterilization of ready-to-cook Bibimbap by combined treatment with gamma irradiation for space food

    NASA Astrophysics Data System (ADS)

    Park, Jae-Nam; Song, Beom-Seok; Kim, Jae-Hun; Choi, Jong-il; Sung, Nak-Yun; Han, In-Jun; Lee, Ju-Woon

    2012-08-01

    Bibimbap, Korean traditional cooked rice mixed with various kinds of vegetables, together with mushrooms and a ground meat, and seasoned with red pepper paste, was developed as a ready-to-cook food by combined treatment with irradiation for the use in space. By gamma irradiation of 25 kGy, the total aerobic bacteria of Bibimbap that was initial by 6.3 log CFU/g decreased to below detection limit, but its sensory qualities were drastically decreased. To enhance the sensory quality, the effects of antioxidant in Bibimbap were evaluated. A treatment with 0.1% of vitamin C, vacuum packaging and gamma-irradiated at 25 kGy and -70 °C showed higher sensory scores than only the irradiation process. This result indicates that the radiation technology may be useful to produce a variety of space foods with high quality of taste and flavor, when combined with other methods.

  14. Suitability of gamma irradiation for preserving fresh-cut watercress quality during cold storage.

    PubMed

    Pinela, José; Barreira, João C M; Barros, Lillian; Verde, Sandra Cabo; Antonio, Amilcar L; Carvalho, Ana Maria; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2016-09-01

    The suitability of gamma irradiation (1, 2 and 5kGy) for preserving quality parameters of fresh-cut watercress (Nasturtium officinale R. Br.) during storage at 4±1°C for 7d was investigated. The storage time decreased the protein content and the main carbohydrates, and increased the levels of malic and fumaric acids, sucrose and mono- and polyunsaturated fatty acids (MUFA and PUFA). The different irradiation doses did not caused any significant colour change. In general, the 2kGy dose favoured PUFA and was the most suitable to preserve the overall postharvest quality of fresh-cut watercress during cold storage. In turn, the 5kGy dose better preserved the antioxidant activity and total flavonoids and favoured MUFA, tocopherols and total phenolics, thus originating a final product with enhanced functional properties. Therefore, the suitability of gamma irradiation for preserving fresh-cut watercress quality during cold storage was demonstrated.

  15. Analytical and toxicological studies of decomposition of insecticide parathion after gamma-irradiation and ozonation.

    PubMed

    Bojanowska-Czajka, Anna; Torun, Murat; Kciuk, Gabriel; Wachowicz, Mariusz; Ozbay, Dilek Solpan; Guven, Olgun; Bobrowski, Krzysztof; Trojanowicz, Marek

    2012-01-01

    The decomposition of the widely used organophosphorus pesticide parathion was carried out in aqueous solutions by the use of gamma-irradiation from a 60Co source or ozonation by means of an ozone generator, and by combined processes of ozonation and radiolysis. Factors affecting the parathion decomposition as well formation and decomposition of the main by-products, including irradiation dose, length of ozonation time, and presence of common scavengers, were investigated. The most efficient was found to be the gamma-irradiation process combined with a short ozonation period; about 1 kGy irradiation dose was sufficient to decompose the pesticide in 15 mg/L solutions. Chemical studies of the decomposition of parathion were accompanied by monitoring of toxicity changes of irradiated solutions with the Microtox test.

  16. Role of gamma irradiation on the natural antioxidants in cumin seeds

    NASA Astrophysics Data System (ADS)

    Kim, Jae Hun; Shin, Mee-Hye; Hwang, Young-Jeong; Srinivasan, Periasamy; Kim, Jae Kyung; Park, Hyun Jin; Byun, Myung Woo; Lee, Ju Woon

    2009-02-01

    Antioxidants quench oxidation by transferring hydrogen atoms to free radicals. In the present investigation, the effect of gamma irradiation on the natural antioxidants of irradiated cumin was studied. Cumin samples were purchased from retailers and then irradiated in a cobalt-60 irradiator to 0, 1, 3, 5 and 10 kGy at ambient temperature. The effect of irradiation on the antioxidant properties of the cumin seed were investigated by evaluating the radical-scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, determination of ferric reducing antioxidant power (FRAP), total polyphenol content (TPC) and the antioxidant index by β-carotene/linoleic acid co-oxidation. Electron spin resonance (ESR) was performed to assess ionization of cumin seeds by gamma irradiation. Irradiation was found to nonsignificantly increase and/or maintain all antioxidant parameters, TPC and the ESR signal intensity was found to be increased in cumin seeds.

  17. Gamma-irradiation of malic acid in aqueous solutions. [prebiotic significance

    NASA Technical Reports Server (NTRS)

    Negron-Mendoza, A.; Graff, R. L.; Ponnamperuma, C.

    1980-01-01

    The gamma-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the nonvolatile products. Thin layer chromatography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the gamma-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

  18. The influence of Gamma Irradiation on flavonoïds content during storage of irradiated clementina

    NASA Astrophysics Data System (ADS)

    Oufedjikh, H.; Mahrouz, M.; Lacroix, M.; Amiot, M. J.; Taccini, M.

    1998-06-01

    The influence of Gamma irradiation on content of some important flavonoïds (flavonones glycosides and polymethoxylated flavones) was evaluated during storage of Moroccan clementina treated at a mean dose of 0.3 kGy and stored three months at 3'C. Results shows that at day one, gamma irradiation induced degradation of small quantities of these flavonoïds, however after 14 days of storage, the content of these compounds was significantly higher (p≤0.05) in irradiated samples. Irradiation stimulated biosynthesis of flavonoïds after 14 days of storage. Hesperidin was the major flavanones compounds in clementines. Nobiletin and Heptamethoxyflavone were the major polymethoxylated flavones in clementines. Our study demonstrated that the content of these compounds was significantly higher (p≤0.05) in irradiated samples.

  19. Studies on the physicochemical characteristics of oil extracted from gamma irradiated pistachio (Pistacia vera L.).

    PubMed

    Al-Bachir, Mahfouz

    2015-01-15

    The present study evaluated the quality of pistachio oil, as a function of irradiation, to determine the dose level causing undesirable changes to pistachio oil. Physicochemical fatty acid composition, acidity value, peroxide value, iodine value specification number, thiobarbituric acid (TBA) value and colour of pistachio oil extracted from samples treated with 0, 1, 2 and 3 kGy doses of gamma irradiation were determined. Gamma irradiation caused the alteration of fatty acids of pistachio oil which showed a decrease in oleic acid (C18:1) and an increase in linoleic acid (C18:2). All other fatty acids remained unaffected after irradiation. The higher used doses (2 and 3 kGy) decreased acidity value, peroxide value and iodine value, and increased specification number, with no effect on TBA value. Irradiation had a significant effect on colour values of pistachio oil. Parameters L, a and b increased at doses of 1 and 2 kGy.

  20. Characterization of LWRS Hybrid SiC-CMC-Zircaloy-4 Fuel Cladding after Gamma Irradiation

    SciTech Connect

    Isabella J van Rooyen

    2012-09-01

    The purpose of the gamma irradiation tests conducted at the Idaho National Laboratory (INL) was to obtain a better understanding of chemical interactions and potential changes in microstructural properties of a mock-up hybrid nuclear fuel cladding rodlet design (unfueled) in a simulated PWR water environment under irradiation conditions. The hybrid fuel rodlet design is being investigated under the Light Water Reactor Sustainability (LWRS) program for further development and testing of one of the possible advanced LWR nuclear fuel cladding designs. The gamma irradiation tests were performed in preparation for neutron irradiation tests planned for a silicon carbide (SiC) ceramic matrix composite (CMC) zircaloy-4 (Zr-4) hybrid fuel rodlet that may be tested in the INL Advanced Test Reactor (ATR) if the design is selected for further development and testing

  1. Investigation of the formation of peroxide in. gamma. -irradiated polyethylene by the method of iodometric titration

    SciTech Connect

    Savost'yanov, V.S.; Kritskaya, D.A.; Ponomarev, A.N.

    1986-09-01

    The concentrations of hydroperoxides (HP) and dialkyl peroxides (DAP) in polyethylene (PE) powder, ..gamma.. irradiated in air at 295 K at a dose of 0.22-2.8 J/(kg x sec) up to doses of 16-300 kJ/kg, were determined by various methods of iodometric titration. Under the indicated conditions, the HP concentration reached 0.18 mole/kg, DPA 0.07 mole/kg, G /SUB HP/ was 8.3 1/100 eV; G /SUB GP/ ..integral..I /SUP -0.5/ . On the basis of the total absence of grafting of acrylamide onto ..gamma..-irradiated PE after reduction during titration of HP in it, it was concluded that grafted polymerization is initiated by the radicals of thermal decomposition of HP in PE.

  2. Degradation of trimethoprim by gamma irradiation in the presence of persulfate

    NASA Astrophysics Data System (ADS)

    Zhang, Zhonglei; Yang, Qi; Wang, Jianlong

    2016-10-01

    The degradation and mineralization of trimethoprim (TMP) by gamma irradiation was investigated in the presence of persulfate (PS). The TMP was degraded at initial concentration of 20 mg/L in aqueous solution with addition of 0, 0.5, 1, 1.5, 2 mM persulfate respectively. The effect of pH values (6.5, 7.5 and 8.5) on TMP degradation was also determined. The experimental results showed that the degradation and mineralization of TMP could be significantly enhanced by persulfate at acidic condition (pH=6.5). Several intermediate products generated during gamma irradiation process through hydroxylation, demethylation and cleavage were identified using liquid chromatography with tandem mass spectrometry (HPLC-MS). The degradation pathway of TMP was tentatively proposed based on the identification of intermediate products.

  3. Evaluation of the effects of paederus beetle extract and gamma irradiation on HeLa cells

    PubMed Central

    Samani, Fariba; Monfared, Ali Shabestani; Zabihi, Ebrahim; Khafri, Soraya; Karimi, Maesoumeh; Akhavan Niaki, Haleh

    2014-01-01

    Objective(s): Cervical cancer is a malignancy that is the second most common cause of death from cancer in women throughout the world. Paederus beetle (Paederus fuscipes) extract (PBE), contains bioactive compounds such as pederine which has cytotoxic properties and blocks DNA and protein synthesis at very low concentrations. In this investigation we tried to determine the effects co-treatment with PBE and gamma irradiation on HeLa cells. Materials and Methods: The viability of the cells was measured by two methods: MTT and Colony assay. Results: We found that supplementing gamma irradiation therapy with PBE does not increase cell death and it might even interfere with its cytotoxicty at the concentrations below 0.1 ng/ml and the viability for irradiation vs irradiation + PBE was 37%: 60%. Conclusion: This finding might be due to radioprotective effects of the very low doses of PBE against gamma radiation. PMID:24904724

  4. Variation of deep electron traps created by. gamma. irradiation of GaAs

    SciTech Connect

    Hashizume, T. ); Hasegawa, H. )

    1990-11-01

    The effect of {gamma} irradiation on deep electron states in liquid encapsulated Czochralski (LEC) grown GaAs has been investigated by deep-level transient spectroscopy (DLTS) and photocapacitance measurements. With {gamma} rays of 2{times}10{sup 8} R, EL6 was reduced in concentration by a factor of 3--5, whereas EL3 was increased about one order of magnitude, as compared with those in as-grown material. In addition to {ital E} traps that were previously reported in electron-irradiated material, two new traps were observed near the surface region. From their concentration profiles and annealing behavior, the new traps were most likely created by the interaction of the primary irradiation-induced defects with the grown-in defects. In contrast to these results, neither the DLTS spectrum nor the metastable behavior of EL2 was affected by {gamma} irradiation.

  5. Major alteration of the pathological phenotype in gamma irradiated mdx soleus muscles

    SciTech Connect

    Weller, B.; Karpati, G.; Lehnert, S.; Carpenter, S. )

    1991-07-01

    Two thousand rads of gamma irradiation delivered to the lower legs of ten day old normal and x-chromosome linked muscular dystrophy (mdx) mice caused significant inhibition of tibial bone and soleus muscle fiber growth. In the irradiated mdx solei, there was a major loss of muscle fibers, lack of central nucleation, and some endomysial fibrosis. These features were caused by a failure of regeneration of muscle fibers due to impaired proliferative capacity of satellite cells. Gamma irradiation transforms the late pathological phenotype of mdx muscles, so that in one major aspect (muscle fiber loss) they resemble muscles in Duchenne muscular dystrophy. However, extensive endomysial fibrosis which is another characteristic feature of Duchenne muscular dystrophy did not develop. This experimental model could be useful for the functional investigation of possible beneficial effects of therapeutic interventions in mdx dystrophy.

  6. Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)

    NASA Astrophysics Data System (ADS)

    Rehman, Fazal-ur; Adeel, Shahid; Qaiser, Summia; Ahmad Bhatti, Ijaz; Shahid, Muhammad; Zuber, Mohammad

    2012-11-01

    Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash -SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.

  7. Effect of gamma irradiation on the thermal and rheological properties of grain amaranth starch

    NASA Astrophysics Data System (ADS)

    Kong, Xiangli; Kasapis, Stefan; Bao, Jinsong; Corke, Harold

    2009-11-01

    Physical properties of starch from two cultivars of gamma-irradiated grain amaranth with different amylose content were investigated. Pasting viscosities decreased continuously with the increase in dosages of irradiation. Furthermore, different irradiation dosages resulted in modification of the thermal properties and crystallinity of starch. Dynamic oscillation on shear was also employed, temperature and frequency sweeps showed that changes in storage modulus and loss modulus were significant, with Tibet Yellow producing more elastic gels as compared to Hy030 at different irradiation dosages.

  8. Microbial analysis and survey test of gamma-irradiated freeze-dried fruits for patient's food

    NASA Astrophysics Data System (ADS)

    Park, Jae-Nam; Sung, Nak-Yun; Byun, Eui-Hong; Byun, Eui-Baek; Song, Beom-Seok; Kim, Jae-Hun; Lee, Kyung-A.; Son, Eun-Joo; Lyu, Eun-Soon

    2015-06-01

    This study examined the microbiological and organoleptic qualities of gamma-irradiated freeze-dried apples, pears, strawberries, pineapples, and grapes, and evaluated the organoleptic acceptability of the sterilized freeze-dried fruits for hospitalized patients. The freeze-dried fruits were gamma-irradiated at 0, 1, 2, 3, 4, 5, 10, 12, and 15 kGy, and their quality was evaluated. Microorganisms were not detected in apples after 1 kGy, in strawberries and pears after 4 kGy, in pineapples after 5 kGy, and in grapes after 12 kGy of gamma irradiation. The overall acceptance score, of the irradiated freeze-dried fruits on a 7-point scale at the sterilization doses was 5.5, 4.2, 4.0, 4.1, and 5.1 points for apples, strawberries, pears, pineapples, and grapes, respectively. The sensory survey of the hospitalized cancer patients (N=102) resulted in scores of 3.8, 3.7, 3.9, 3.9, and 3.7 on a 5-point scale for the gamma-irradiated freeze-dried apples, strawberries, pears, pineapples, and grapes, respectively. The results suggest that freeze-dried fruits can be sterilized with a dose of 5 kGy, except for grapes, which require a dose of 12 kGy, and that the organoleptic quality of the fruits is acceptable to immuno-compromised patients. However, to clarify the microbiological quality and safety of freeze-dried fruits should be verified by plating for both aerobic and anaerobic microorganisms.

  9. Radiation effects on rat testes. IX. Studies on oxidative enzymes after partial body gamma irradiation.

    PubMed

    Gupta, G S; Bawa, S R

    1975-08-01

    Oxidative enzymes in the rat testes have been studied after gamma irradiation. The role of these enzymes in relation to spermatogenesis and steroidogenesis after radiation injury to testis has been discussed. Loss of succinic dehydrogenase and sorbitol dehydrogenase reflects the losts of germ cell population. Malic enzyme and malic dehydrogenase seem to the related to the deficiency of steroid hormones, whereas increase in glucose-6-phosphate dehydrogenase and NADP isocitric dehydrogenase is due to secondary stimulation of pituitary.

  10. Synthesis and characterization of azo acrylates grafted onto polyethylene terephthalate by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Bucio, Emilio; Skewes, Phill; Burillo, Guillermina

    2005-07-01

    Polyethylene terephthalate (PET) films were grafted with acryloyl chloride by gamma irradiation, and the grafted films were reacted with Disperse Red 1 or 4-phenylazophenol. The films where characterized by atomic force microscopy, differential scanning calorimetry, FTIR-ATR, light polarized microscopy, elemental analysis and UV spectroscopy. The surface of the films was homogeneous, and the dye underwent trans to cis photoreaction, whereby the red films became colorless by the irradiation of UV light at room temperature.

  11. Gamma irradiation of isolated rat islets pretransplantation produces indefinite allograft survival in cyclosporine-treated recipients

    SciTech Connect

    James, R.F.; Lake, S.P.; Chamberlain, J.; Thirdborough, S.; Bassett, P.D.; Mistry, N.; Bell, P.R.

    1989-06-01

    In this study we have examined the use of low-dose gamma-irradiation for the reduction of islet immunogenicity in the strong allogeneic combination of WAG rat islets transplanted into diabetic AUG recipients. First, we determined that gamma-irradiation reduced immunogenicity in vitro by use of a modified MLR with WAG islets as stimulators and AUG splenocytes as responders. We then determined the maximum dose of gamma-irradiation that could be used (250 rads) before islet function was affected. As 250 rads islet pretreatment alone was ineffective in prolonging allograft survival, we combined the pretreatment with a short course (days 0, 1, 2; 30 mg/kg) of cyclosporine. We found that CsA was only effective in significantly prolonging allograft survival when given subcutaneously in olive oil. The CsA treatment alone gave a significantly prolonged survival time for the islet allografts (median, 37 days vs. 6 days for controls), but when combined with the 250 rads islet pretreatment a synergistic effect was seen with 100% becoming long-term survivors (greater than 100 days). The long-term surviving AUG rats from both the CsA alone group and the CsA plus 250 rads pretreated islets group were challenged with WAG dendritic cells (DC). The islets from the 250 rads pretreated group were subsequently rejected (day 6) while the CsA alone group were not affected. The role of low dose gamma-irradiation when combined with CsA treatment of islet graft recipients in inducing specific unresponsiveness will be discussed.

  12. Developmental toxicity and oxidative stress induced by gamma irradiation in zebrafish embryos.

    PubMed

    Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong

    2016-11-01

    This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1-1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner.

  13. Effect of Low Dose Gamma Irradiation together with Lipid A on Human Leukocytes Activities In Vitro

    NASA Astrophysics Data System (ADS)

    Belyakova, E.; Dubnickova, M.; Boreyko, A.

    2010-01-01

    The influence of gamma irradiation and of Lipid A from Escherichia coli on phagocytosis, lyzosyme and peroxidase activities of human leukocytes, in vitro was investigated. Leukocytes samples were irradiated with 1 and 5 Gy, respectively. The number of irradiated leukocytes was decreased in the irradiated samples. Only samples with additive Lipid A were not damaged by irradiation. The Lipid A had positive influence on biological activities of the irradiated leukocytes.

  14. Electron spin resonance of gamma-irradiated poly/ethylene 2,6-naphthalene dicarboxylate/.

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Pezdirtz, G. F.

    1971-01-01

    The two types of radicals trapped in gamma-irradiated PEN 2,6 are identified by ESR as - O - CH - CH2 - O - (radical I) and a radical located on the naphthalene ring (radical II). The concentrations of the radicals in the gross polyer are 10 to 20% of I and 80 to 90% of II. Similar trapped radicals are established in beta-irradiated PET, a structurally related polymer.

  15. The morphological changes of Ascaris lumbricoides ova in sewage sludge water treated by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Shamma, M.; Al-Adawi, M. A.

    2002-10-01

    Untreated wastewater sampled from Damascus sewage water treatment plant containing nematode Ascaris lumbricoides ova were treated using gamma irradiation (doses between 1.5 and 8 kGy), immediately after irradiation the morphological and developmental status of eggs was examined microscopically. Major morphological changes of the contents of the eggs were detected. These eggs were incubated for 8 weeks, after this period no larvae "inside the eggs" were observed. Thus the morphological changes can be used as a viable parameter.

  16. Defect formation of gamma irradiated MoO3-doped borophosphate glasses

    NASA Astrophysics Data System (ADS)

    Abdelghany, A. M.; Ouis, M. A.; Azooz, M. A.; EllBatal, H. A.

    2013-10-01

    Borophosphate glasses of the basic composition (50P2O5, 30B2O3, 20Na2O mol%) containing different doping molybdenum oxide percents (0.16-0.98) were prepared by melting and annealing method. Infrared and UV-visible absorption spectroscopic measurements before and after gamma irradiation were carried out. The base undoped borophosphate glass reveals strong UV absorption bands but with no visible bands and these UV bands are related to unavoidable trace iron impurities contaminated within the raw materials used for the preparation of this glass. The introduction of MoO3 (in doping ratio) into this glass produces an additional UV band and a broad visible band and their intensities increase with the MoO3 content. These additional bands are related to both Mo6+ and Mo5+ ions. The base undoped borophosphate glass shows retardation effect towards gamma irradiation. Gamma irradiation produces marked changes in the UV-visible spectra of Mosbnd O3-doped glasses. Such changes can be related to the production of induced defects from photochemical reactions and the generation of positive holes. Infrared absorption spectrum of the undoped borophosphate glass reveals complex vibrational bands due to the presence of both phosphate groups beside borate groups with triangular and tetrahedrally coordinated units. The introduction of MoO3 causes some limited variations in the FTIR spectra. Gamma irradiation produces minor changes in the intensities of some IR bands. Such changes are related to the changes in the bond angles and/or bond lengths of few structural groups upon irradiation while the main structural groups remain unchanged in their number and position.

  17. Effect of gamma irradiation on the physiological activity of Korean soybean fermented foods, Chungkookjang and Doenjang

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Son, Jun-Ho; Yook, Hong-Sun; Jo, Cheorun; Kim, Dong-Ho

    2002-06-01

    Effects of gamma irradiation on the physiological activity of Korean soybean fermented foods were investigated. Chungkookjang, the whole cooked soybean product and Doenjang, soybean paste were purchased and irradiated at 5, 10 and 20 kGy of absorbed doses. The physiological activity was evaluated by angiotensin converting enzyme inhibition, xanthine oxidase inhibition, tyrosinase inhibition and radical scavenging ability and results indicated that at 10 kGy or below did not show any significant change on physiological activities by irradiation.

  18. Effects of Gamma Irradiation and Pasteurization on the Nutritive Composition of Commercially Available Animal Diets

    PubMed Central

    Caulfield, Catherine D; Cassidy, Joseph P; Kelly, John P

    2008-01-01

    Gamma radiation is used to sterilize diets for specific pathogen-free (SPF) animals. Because a gamma-irradiated diet was linked to leukoencephalomyelopathy in SPF cats, we investigated the effects of ‘typical’ (28.9–34.3 kGy) and ‘high-end’ (38.4–48.7 kGy) doses of gamma irradiation and of pasteurization (at 107 °C for 15 min) on the amounts of fat; protein; carbohydrate (and taurine in cat diet); vitamins A, E, B1, B2, B6, and B12; and peroxide in commercially available dry cat, dog, and rodent diets. The only treatment-related changes occurred with vitamin A and peroxide. The typical and high-end doses of gamma irradiation reduced the vitamin A level of the cat diet to 42% and 30% of the untreated value, respectively—levels below recommended allowances for growth and reproduction. Only the higher irradiation dose reduced vitamin A in the rodent diet, and neither dose altered the canine diet. Pasteurization reduced the vitamin A content of the cat diet to 50% of its original level, which was within the recommended level for this species. Irradiation increased the peroxide content of all 3 animal diets: by approximately 11-fold with the typical dose and by 14- to 25-fold with the high-end dose. Therefore gamma irradiation can have profound, selective effects on the vitamin A and peroxide contents of dry diets, and caution is advised when feeding such diets long-term and exclusively to SPF animals, particularly cats. Furthermore, pasteurization (with its fewer deleterious effects) may represent an alternative method of decontaminating diets for rodents, dogs, and cats. PMID:19049256

  19. Effects of gamma irradiation as a quarantine treatment on development of codling moth larvae

    SciTech Connect

    Burditt, A.K. Jr.; Moffitt, H.R.; Hungate, F.P.

    1985-03-01

    Codling moth, Cydia pomonella (L.), larvae were exposed to gamma radiation at doses upto 160 Gy. Following irradiation the larvae were permited further development, pupation and adult emergence. The number of adults emerging, mature larvae and pupae present were determined. Data from these studies will be used to predict doses of gamma irradiation required as a quarantine treatment to prevent emergence of codling moth adults from fruit infested by larvae. 5 refs., 1 tab.

  20. Transitions and relaxations in gamma-irradiated polypropylene studied by positron annihilation lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Djourelov, N.; Suzuki, T.; Shantarovich, V. P.; Dobreva, T.; Ito, Y.

    2005-01-01

    The changes in the relaxation and transition temperatures in PP due to gamma irradiation in a vacuum were measured by means of positron annihilation lifetime spectroscopy. It was shown that the gamma and beta relaxation temperatures, as well as the melting point follow the changes in the crystallinity with the irradiation dose. For the glass transition temperatures and premelting point, after irradiation dose of 88 kGy, an inverse of the changes was observed.

  1. Gamma-irradiated bacterial preparation having anti-tumor activity

    SciTech Connect

    Vass, A.A.; Tyndall, R.L.; Terzaghi-Howe, P.

    1999-11-16

    This application describes a bacterial preparation from Pseudomonas species isolated {number{underscore}sign}15 ATCC 55638 that has been exposed to gamma radiation exhibits cytotoxicity that is specific for neoplastic carcinoma cells. A method for obtaining a bacterial preparation having antitumor activity consists of suspending a bacterial isolate in media and exposing the suspension to gamma radiation. A bacterial preparation of an aged culture of an amoeba-associated bacteria exhibits anti-reverse transcriptase activity. A method for obtaining a bacterial preparation having anti-reverse transcriptase activity from an amoeba-associated bacterial isolate grown to stationary phase is disclosed.

  2. Gamma-irradiated bacterial preparation having anti-tumor activity

    DOEpatents

    Vass, Arpad A.; Tyndall, Richard L.; Terzaghi-Howe, Peggy

    1999-01-01

    A bacterial preparation from Pseudomonas species isolated #15 ATCC 55638 that has been exposed to gamma radiation exhibits cytotoxicity that is specific for neoplastic carcinoma cells. A method for obtaining a bacterial preparation having antitumor activity consists of suspending a bacterial isolate in media and exposing the suspension to gamma radiation. A bacterial preparation of an aged culture of an amoeba-associated bacteria exhibits anti-reverse transcriptase activity. A method for obtaining a bacterial preparation having anti-reverse transcriptase activity from an amoeba-associated bacterial isolate grown to stationary phase is disclosed.

  3. EPR investigation of gamma irradiated single crystal guaifenesin: A combined experimental and computational study

    NASA Astrophysics Data System (ADS)

    Tasdemir, Halil Ugur; Sayin, Ulku; Türkkan, Ercan; Ozmen, Ayhan

    2016-04-01

    Gamma irradiated single crystal of Guaifenesin (Glyceryl Guaiacolate), an important expectorant drug, were investigated with Electron Paramagnetic Resonance (EPR) spectroscopy between 123 and 333 K temperature at different orientations in the magnetic field. Considering the chemical structure and the experimental spectra of the gamma irradiated single crystal of guaifenesin sample, we assumed that alkoxy or alkyl-type paramagnetic species may be produced by irradiation. Depending on this assumption, eight possible alkoxy and alkyl-type radicals were modeled and EPR parameters of these modeled radicals were calculated using the B3LYP/6-311++G(d,p)-level of density functional theory (DFT). Theoretically calculated values of alkyl-type modeled radical(R3) are in good agreement with experimentally determined EPR parameters of single crystal. Furthermore, simulation spectra which are obtained by using the theoretical initial values are well matched with the experimental spectra. It was determined that a stable Cα •H2αCβHβCγH2γ (R3) alkyl radical was produced in the host crystal as a result of gamma irradiation.

  4. Free radicals properties of gamma-irradiated penicillin-derived antibiotics: piperacillin, ampicillin, and crystalline penicillin.

    PubMed

    Wilczyński, Sławomir; Pilawa, Barbara; Koprowski, Robert; Wróbel, Zygmunt; Ptaszkiewicz, Marta; Swakoń, Jan; Olko, Paweł

    2014-03-01

    The aim of this work was to determine the concentrations and properties of free radicals in piperacillin, ampicillin, and crystalline penicillin after gamma irradiation. The radicals were studied by electron paramagnetic resonance (EPR) spectroscopy using an X-band spectrometer (9.3 GHz). Gamma irradiation was performed at a dose of 25 kGy. One- and two-exponential functions were fitted to the experimental data, in order to assess the influence of the antibiotics' storage time on the measured EPR lines. After gamma irradiation, complex EPR lines were recorded confirming the presence of a large number of free radicals formed during the irradiation. For all tested antibiotics, concentrations of free radicals and parameters of EPR spectra changed with storage time. The results obtained demonstrate that concentration of free radicals and other spectroscopic parameters can be used to select the optimal parameters of radiation sterilization of β-lactam antibiotics. The most important parameters are the constants τ (τ (1(A),(I)) and τ (2(A),(I))) and K (K (0(A),(I)), K (1(A),(I)), K (2(A),(I))) of the exponential functions that describe free radicals decay during samples storage.

  5. Effect of gamma irradiation on hyperthermal composting microorganisms for feasible application in space

    NASA Astrophysics Data System (ADS)

    Yoon, Minchul; Choi, Jong-il; Yamashita, Masamichi

    2013-05-01

    The composting system is the most efficient method for processing organic waste in space; however, the composting activity of microorganisms can be altered by cosmic rays. In this study, the effect of ionizing irradiation on composting bacteria was investigated. Sequence analyses of amplified 16S rRNA, 18S rRNA, and amoA genes were used to identify hyperthermal composting microorganisms. The viability of microorganisms in compost soil after gamma irradiation was directly determined using LIVE/DEAD BacLight viability kit. The dominant bacterial genera were Weissella cibaria and Leuconostoc sp., and the fungal genera were Metschnikowia bicuspidata and Pichia guilliermondii. Gamma irradiation up to a dose of 10 kGy did not significantly alter the microbial population. Furthermore, amylase and cellulase activities were maintained after high-dose gamma irradiation. Our results show that hyperthermal microorganisms can be used to recycle agricultural and fermented material in space stations and other human-inhabiting facilities on the Moon, Mars, and other planets.

  6. Using gamma irradiation and low temperature on microbial decontamination of red meat in Iran.

    PubMed

    Sedeh, F M; Arbabi, K; Fatolahi, H; Abhari, M

    2007-03-01

    Gamma irradiation can be used as one of the most efficient methods to reduce microorganisms in food. The irradiation of food is used for a number of purposes, including microbiological control, insects control and inhibition of sprouting and delay of senescence of living food. The aim of this study was to study effects of gamma irradiation, refrigeration and frozen storage as the combination process for improvement of red meat shelf-life. The bovine meat samples were treated with 0, 0.5, 1, 2 and 3 kGy of gamma irradiation and kept in refrigerator for 3 weeks and in freezer for 8 months. The control and irradiated samples were stored at 4-7°C and at -18°C for refrigeration and frozen storage, respectively; and microbial and chemical analyze was done at 1 week and 2 months intervals. In this study the optimum dose of gamma radiation in order to decrease the total count of Mesophilic bacteria, Coliforms, Staphylococcus aureus and especially for elimination of Salmonella was obtained at 3 kGy. Microbial analysis indicated that irradiation and storage at low temperature had a significant effect on the reduction of microbial loads. There was no significant difference in chemical characteristics during freezing storage in bovine meat. Also, irradiated meat samples (3 kGy) were stored in 4-7°C for 14 days, compared to 3 days for non irradiated samples.

  7. Gelam honey protects against gamma-irradiation damage to antioxidant enzymes in human diploid fibroblasts.

    PubMed

    Ahmad, Tengku Ahbrizal Farizal Tengku; Jubri, Zakiah; Rajab, Nor Fadilah; Rahim, Khairuddin Abdul; Yusof, Yasmin Anum Mohd; Makpol, Suzana

    2013-02-11

    The present study was designed to determine the radioprotective effects of Malaysian Gelam honey on gene expression and enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) of human diploid fibroblasts (HDFs) subjected to gamma-irradiation. Six groups of HDFs were studied: untreated control, irradiated HDFs, Gelam honey-treated HDFs and HDF treated with Gelam honey pre-, during- and post-irradiation. HDFs were treated with 6 mg/mL of sterilized Gelam honey (w/v) for 24 h and exposed to 1 Gray (Gy) of gamma rays at the dose rate of 0.25 Gy/min. Gamma-irradiation was shown to down-regulate SOD1, SOD2, CAT and GPx1 gene expressions (p < 0.05). Conversely, HDFs treated with Gelam honey alone showed up-regulation of all genes studied. Similarly, SOD, CAT and GPx enzyme activities in HDFs decreased with gamma-irradiation and increased when cells were treated with Gelam honey (p < 0.05). Furthermore, of the three different stages of study treatment, pre-treatment with Gelam honey caused up-regulation of SOD1, SOD2 and CAT genes expression and increased the activity of SOD and CAT. As a conclusion, Gelam honey modulates the expression of antioxidant enzymes at gene and protein levels in irradiated HDFs indicating its potential as a radioprotectant agent.

  8. Effect of gamma irradiation on the properties of plastic bottle sheet

    NASA Astrophysics Data System (ADS)

    Kumar, Vijay; Ali, Yasir; Sonkawade, R. G.; Dhaliwal, A. S.

    2012-09-01

    In this article, the effects of gamma irradiation on the optical and structural properties of plastic bottle sheets have been studied. Bottle sheets were exposed with 1.25 MeV 60Co γ-ray's source at various dose levels within the range from 0 to 670 kGy. The changes so induced were analyzed by using UV-Vis and X-ray diffraction spectroscopy. UV-Vis spectra show the peaks, their shifting and broadening as a result of gamma irradiation. With increasing γ-dose, the values of the direct and indirect band gap are found to be decreased. These results are in good agreement with the corresponding results published previously for polyethylene terephthalate polymer. We also calculated numbers of carbon atoms per conjugation length. The X-ray diffraction spectra exhibited an increase in peak intensity after gamma irradiation. Furthermore, the percentage crystallinity and crystallite size for pristine and irradiated sample have been calculated. It has been found that both crystallinity and crystallite size increase due to irradiation. In addition, interchain distances, micro strain, inter planar distance, dislocation density and distortion parameters were calculated. The analysis revealed there is the significant decrease in micro strain, dislocation density and distortion parameters with an increase of gamma dose, which is in line with the crystallinity calculation. Moreover, Interchain and Interplanar distances were marginally changed. These results demonstrated the applicability of sheets as a cost-effective dosimeter.

  9. The effect of gamma-irradiation on the antibacterial activity of honey.

    PubMed

    Molan, P C; Allen, K L

    1996-11-01

    There is increasing usage of honey as a dressing on infected wounds, burns and ulcers, but there is some concern that there may be a risk of wound botulism from the clostridial spores sometimes found in honey. It is well-established that the antibacterial activity is heat-labile so would be destroyed if honey were sterilized by autoclaving, but the effect of gamma-irradiation on the antibacterial activity of honey is not known. Therefore an investigation was carried out to assess the effect on the antibacterial activity of honey when the honey was subjected to a commercial sterilization procedure using gamma-irradiation (25 kGy). Two honeys with antibacterial activity due to enzymically-generated hydrogen peroxide and three manuka honeys with non-peroxide antibacterial activity were investigated. The honeys were tested against Staphylococcus aureus in an agar well diffusion assay. There was no significant change found in either type of antibacterial activity resulting from this form of sterilization of honey, even when the radiation was doubled (to 50 kGy). Testing of honey seeded with spores of Clostridium perfringens and C. tetani (10000 and 1000 spores g-1 of honey, respectively) showed that 25 kGy of gamma-irradiation was sufficient to achieve sterility.

  10. Some microbial, chemical and sensorial properties of gamma irradiated sesame (Sesamum indicum L.) seeds.

    PubMed

    Al-Bachir, Mahfouz

    2016-04-15

    The effect on microbial, chemical and sensorial properties of sesame seeds was determined after irradiation and storage. The sesame seeds were analyzed before and after irradiation with 3, 6 and 9 kGy of gamma irradiation, and after 6 and 12 months of storage. The results showed that gamma irradiation had no significant (p>0.05) effect on the moisture, ash and fat content on sesame seeds. While, small differences, but sometimes significant (p<0.05), on protein and sugar contents were recorded between irradiated and non-irradiated samples. Total acidity percentage decreased significantly (p<0.05), while total volatile basic nitrogen (TVBN) increased significantly (p<0.05) due to irradiation. During storage, total acidity increased (p<0.05) and TVBN decreased (p<0.05). Gamma irradiation reduced the microorganisms of sesame seeds. Samples treated with 3 kGy or more remained completely free of fungi throughout the storage. While, only the samples treated with 9 kGy remained completely free of bacteria at the end of storage period (after 12 months). The scores for taste, flavor, color and texture of irradiated samples were higher, but not significantly (p>0.05) than those of non-irradiated samples.

  11. Biochemical composition and antioxidant activities of Arthrospira (Spirulina) platensis in response to gamma irradiation.

    PubMed

    Shabana, Effat Fahmy; Gabr, Mahmoud Ali; Moussa, Helal Ragab; El-Shaer, Enas Ali; Ismaiel, Mostafa M S

    2017-01-01

    Arthrospira (Spirulina) platensis is a blue-green alga, rich with bioactive components and nutrients. To evaluate effect of gamma irradiation, A. platensis was exposed to different doses of 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5kGy. The data showed that the phenolic and proline contents significantly increased with the increase of gamma irradiation doses up to 2.0kGy, above which a reduction was observed. The soluble proteins and malondialdehyde (MDA) contents were stimulated by all tested irradiation doses. Furthermore, the vitamins (A, K and B group) and mineral contents (N, P, Na, K, Ca, Mg and Fe) were stimulated by the irradiation doses compared with the control. The activities of some N-assimilating and antioxidant enzymes were significantly increased with the irradiation doses up to 2.0kGy. This study suggests the possible use of gamma irradiation as a stimulatory agent to raise the nutritive value and antioxidant activity of A. platensis.

  12. Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors.

    PubMed

    Hume, Adam J; Ames, Joshua; Rennick, Linda J; Duprex, W Paul; Marzi, Andrea; Tonkiss, John; Mühlberger, Elke

    2016-07-22

    Effective inactivation of biosafety level 4 (BSL-4) pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using "worst-case scenario" procedures to ensure complete sample inactivation.

  13. Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors

    PubMed Central

    Hume, Adam J.; Ames, Joshua; Rennick, Linda J.; Duprex, W. Paul; Marzi, Andrea; Tonkiss, John; Mühlberger, Elke

    2016-01-01

    Effective inactivation of biosafety level 4 (BSL-4) pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using “worst-case scenario” procedures to ensure complete sample inactivation. PMID:27455307

  14. Degradation of sulfamethazine by gamma irradiation in the presence of hydrogen peroxide.

    PubMed

    Liu, Yuankun; Wang, Jianlong

    2013-04-15

    The gamma irradiation-induced degradation of sulfamethazine (SMT) in aqueous solution in the presence of hydrogen peroxide (H2O2) was investigated. The initial SMT concentration was 20mg/L and it was irradiated in the presence of extra H2O2 with initial concentration of 0, 10 and 30 mg/L. The results showed that gamma irradiation was effective for removing SMT in aqueous solution and its degradation conformed to the pseudo first-order kinetics under the applied conditions. When initial H2O2 concentration was in the range of 0-30 mg/L, higher concentration of H2O2 was more effective for the decomposition and mineralization of SMT. However, the removal of total organic carbon (TOC) was not as effective as that of SMT. Total nitrogen (TN) was not removed even at absorbed dose of 5 kGy, which was highest dose applied in this study. Major decomposition products of SMT, including degradation intermediates, organic acids and some inorganic ions were detected by high performance liquid chromatography (HPLC) and ion chromatography (IC). Sulfate (SO4(2-)), formic acid (HCOOH), acetic acid (CH3COOH), 4-aminophenol, 4-nitrophenol were identified in the irradiated solutions. Possible pathways for SMT decomposition by gamma irradiation in aqueous solution were proposed.

  15. Texture, color, lipid oxidation and sensory acceptability of gamma-irradiated marinated anchovy fillets

    NASA Astrophysics Data System (ADS)

    Tomac, Alejandra; Cova, María C.; Narvaiz, Patricia; Yeannes, María I.

    2015-01-01

    The effect of gamma irradiation (0, 2, 3 and 4 kGy) on vacuum-packed marinated anchovy fillets was analyzed for their texture, color, lipid oxidation and sensory acceptability after 10 months under refrigeration. Marinated (3% acetic acid, 10% sodium chloride and 0.2% citric acid) Engraulis anchoita fillets were vacuum-packed and irradiated with a cobalt-60 source at a semi-industrial irradiation facility. The irradiation caused a slight increase in hardness values regardless of the applied dose but maintained a consistent texture over the 10 months, even though the control samples softened, most likely due to degradation. This hardness increase did not affect the textural sensory acceptability. Irradiation did not modify the color but still reduced color changes during storage, benefitting the product's quality. TBARS was increased in every sample throughout storage, but irradiation decreased these values. Sensory acceptability was not affected by gamma irradiation. Therefore, gamma irradiation could be successfully applied to this type of product for the purpose of shelf-life extension.

  16. Effect of gamma irradiation on the hemocyte-mediated immune response of Aedes aegypti against microfilariae

    SciTech Connect

    Christensen, B.M.; Huff, B.M.; Li, J. )

    1990-07-01

    The effect of gamma irradiation on the melanotic encapsulation response of Aedes aegypti black eye Liverpool strain against inoculated Dirofilaria immitis microfilariae (mff) was assessed at 1, 2, 3, and 6 days postinoculation (PI). Mosquitoes received 6000 rad from a 137Cs source (Shepard Mark I irradiator) at 3 days postemergence and were inoculated with 15-20 mff 24 hr later. These mosquitoes were compared to nonirradiated controls that also were inoculated with 15-20 mff at 3 days postemergence. The immune response was significantly reduced in irradiated mosquitoes as compared with controls at all days PI. Although the response was significantly inhibited compared with controls, irradiated mosquitoes were still capable of eliciting a response against 69% of recovered mff at 6 days PI. External gamma irradiation did not significantly affect the proliferation of hemocytes associated with the melanotic encapsulation response of A. aegypti. The number of circulating hemocytes increased in irradiated mosquitoes in response to inoculated mff in a manner similar to nonirradiated, inoculated controls. Hemocyte monophenol oxidase activity, however, was significantly reduced in gamma-irradiated mosquitoes at 12 hr PI as compared with controls. The reduced immunological capacity of irradiated mosquitoes might be related to an interference with gene activity required for the synthesis or activation of enzymes that are directly or indirectly involved in the biochemical processes associated with the production of melanotic substances that sequester mff.

  17. Interaction between the microtubule inhibitor tubulozole and gamma-irradiation in murine tumors in vivo

    SciTech Connect

    Distelmans, W.; Van Ginckel, R.; Vanherck, W.; Willebrords, R.; De Brabander, M.; Wouters, L.; Van den Winkel, P.; De Backer, G.

    1989-01-01

    The combined effect of the microtubule inhibitor tubulozole and gamma-irradiation has been investigated in vivo in subcutaneous MO4 fibrosarcomas and Lewis Lung carcinomas. A marked interactive effect on tumor growth was observed when 160 mg/kg tubulozole was orally administered before the tumors were treated with 10 Gy radiation. Dose dependency and optimal effect were obtained on tumor growth of MO4 tumor bearing animals when the drug treatment was given 6 hr prior to the irradiation. The optimal pretreatment time coincided with the time at which a peak mitotic index in the tumor tissue was observed. An enhancing effect is also noticed at other doses of radiation in MO4 tumors pretreated 6 hr before with 160 mg/kg tubulozole. The interactive effect is maintained in a clinically relevant dose fractionation schedule whereby 8 fractions of 2 Gy each were pretreated 6 hr before with 80 mg/kg tubulozole. Tubulozole-T, the stereo-isomer of tubulozole, neither exhibits any antimicrotubular action nor exerts an antitumoral effect on its own or in combination with gamma-irradiation. The possible mechanisms of interaction between tubulozole and gamma-irradiation in tumor tissue are discussed.

  18. Thermal behavior of gamma-irradiated low-density polyethylene/paraffin wax blend

    NASA Astrophysics Data System (ADS)

    Abdou, Saleh M.; Elnahas, H. H.; El-Zahed, H.; Abdeldaym, A.

    2016-05-01

    The thermal properties of low-density polyethylene (LDPE)/paraffin wax blends were studied using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and melt flow index (MFI). Blends of LDPE/wax in ratios of 100/0, 98/2, 96/4, 94/6, 92/8, 90/10 and 85/15 (w/w) were prepared by melt-mixing at the temperature of 150°C. It was found that increasing the wax content more than 15% leads to phase separation. DSC results showed that for all blends both the melting temperature (Tm) and the melting enthalpy (ΔHm) decrease linearly with an increase in wax content. TGA analysis showed that the thermal stability of all blends decreases linearly with increasing wax content. No clear correlation was observed between the melting point and thermal stability. Horowitz and Metzger method was used to determine the thermal activation energy (Ea). MFI increased exponentially by increasing the wax content. The effect of gamma irradiation on the thermal behavior of the blends was also investigated at different gamma irradiation doses. Significant correlations were found between the thermal parameters (Tm, ΔHm, T5%, Ea and MFI) and the amount of wax content and gamma irradiation.

  19. Hepatoprotective effects of gamma-irradiated caraway essential oils in experimental sepsis.

    PubMed

    Fatemi, F; Allameh, A; Khalafi, H; Ashrafihelan, J

    2010-02-01

    Irradiation is an important method of processing herbal drugs, while our understanding of the effects of gamma-irradiation on pharmacological properties of seed products such as caraway essential oils is however still very limited. In this study, caraway seeds were irradiated at dose levels of 0, 10 and 25kGy. After extracting the essential oils, the effects of fresh and gamma-irradiated caraway oils (100mg/kg b.w) on preventing septic-related oxidative liver injury induced by cecal ligation and puncture (CLP) model were investigated by measuring oxidative stress parameters in the liver. CLP operation caused a marked increase in myeloperoxidase (MPO) activity which was readily reversed in rats treated with fresh and irradiated caraway oils. Likewise, thiobarbituric acid reactive substances (TBARS) level in the liver was compensated in rats treated with the fresh and irradiated caraway oils. Moreover, liver GSH which was initially depleted due to CLP was recovered by essential oil treatments. The protective role of oils was further confirmed by showing that liver function tests (ALT/AST) as well as histopathological changes following CLP operation were recovered in rats treated with oils from either fresh or irradiated caraway seeds. These data may suggest that gamma-irradiation to caraway seeds at 10 and 25kGy has no influence on the antioxidative properties of caraway essential oils.

  20. "Asian yuppies...are always looking for something new and different": creating a tobacco culture among young Asians

    PubMed Central

    Knight, J; Chapman, S

    2004-01-01

    Objective: To identify and analyse the themes employed by the Asian based transnational tobacco companies to construct a tobacco culture among Asian young men and women. Methods: Systematic review of relevant tobacco industry documents made public through the Master Settlement Agreement. Results: The industry utilised six vehicles and themes to construct a tobacco culture in Asia: music, entertainment (including nightclubs, discos, and movies), adventure, sport (including motorsports, soccer, and tennis), glamour (beauty and fashion), and independence. Conclusions: The tobacco industry set about constructing a tobacco culture that sought to make smoking desirable, even normal, for young men and women. Understanding the way industry constructed this culture provides insights into ways that culture might now be challenged. Countering the transnational nature of many activities will require coordinated effort at the international, regional, and national levels. Implementation of the Framework Convention on Tobacco Control (FCTC) will be a powerful tool in this process. All nations throughout Asia are encouraged to support the FCTC and its broad protocols addressing advertising and sponsorship. Measures are also required to disassociate smoking from progress in sex equality. PMID:15564216

  1. Physiological and molecular characterization of the enhanced salt tolerance induced by low-dose gamma irradiation in Arabidopsis seedlings

    SciTech Connect

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

    2014-07-25

    Highlights: • 50-Gy gamma irradiation markedly promotes the seedling growth under salt stress in Arabidopsis. • The contents of H{sub 2}O{sub 2} and MDA are obviously reduced by low-dose gamma irradiation under salt stress. • Low-dose gamma irradiation stimulates the activities of antioxidant enzymes under salt stress. • Proline accumulation is required for the low-gamma-ray-induced salt tolerance. • Low gamma rays differentially regulate the expression of genes related to salt stress. - Abstract: It has been established that gamma rays at low doses stimulate the tolerance to salt stress in plants. However, our knowledge regarding the molecular mechanism underlying the enhanced salt tolerance remains limited. In this study, we found that 50-Gy gamma irradiation presented maximal beneficial effects on germination index and root length in response to salt stress in Arabidopsis seedlings. The contents of H{sub 2}O{sub 2} and MDA in irradiated seedlings under salt stress were significantly lower than those of controls. The activities of antioxidant enzymes and proline levels in the irradiated seedlings were markedly increased compared with the controls. Furthermore, transcriptional expression analysis of selected genes revealed that some components of salt stress signaling pathways were stimulated by low-dose gamma irradiation under salt stress. Our results suggest that gamma irradiation at low doses alleviates the salt stress probably by modulating the physiological responses as well as stimulating the stress signal transduction in Arabidopsis seedlings.

  2. Low-dose gamma irradiation enhances superoxide anion production by nonirradiated cells through TGF-β1-dependent bystander signaling.

    PubMed

    Temme, Jennifer; Bauer, Georg

    2013-04-01

    We show here that low-dose gamma irradiation substantially increase in extracellular superoxide anion production in oncogenically transformed cells and tumor cells but not by nontransformed cells. The transfer of only a few cells from an irradiated culture to nonirradiated control cells was sufficient for the transmission of a signal to induce superoxide anion production in the nonirradiated cells. The number of irradiated cells that was necessary for the successful induction of superoxide anion production in the nonirradiated cells depended on radiation dose. When irradiated cells were allowed to incubate for 1 h before transmission to the nonirradiated cultures, nearly all of the cells from the irradiated cell population were able to communicate the inducing signal to nonirradiated cells. siRNA-dependent knockdown and reconstitution experiments showed that TGF-β1 was sufficient to mediate the bystander effect triggered by low-dose radiation in this experimental system. A kinetic analysis demonstrated that the enhanced superoxide anion production was substantially reduced before the release of the bystander signal by activated TGF-β.

  3. Bioconversion of stilbenes in genetically engineered root and cell cultures of tobacco.

    PubMed

    Hidalgo, Diego; Martínez-Márquez, Ascensión; Moyano, Elisabeth; Bru-Martínez, Roque; Corchete, Purificación; Palazon, Javier

    2017-03-27

    It is currently possible to transfer a biosynthetic pathway from a plant to another organism. This system has been exploited to transfer the metabolic richness of certain plant species to other plants or even to more simple metabolic organisms such as yeast or bacteria for the production of high added value plant compounds. Another application is to bioconvert substrates into scarcer or biologically more interesting compounds, such as piceatannol and pterostilbene. These two resveratrol-derived stilbenes, which have very promising pharmacological activities, are found in plants only in small amounts. By transferring the human cytochrome P450 hydroxylase 1B1 (HsCYP1B1) gene to tobacco hairy roots and cell cultures, we developed a system able to bioconvert exogenous t-resveratrol into piceatannol in quantities near to mg L(-1). Similarly, after heterologous expression of resveratrol O-methyltransferase from Vitis vinifera (VvROMT) in tobacco hairy roots, the exogenous t-resveratrol was bioconverted into pterostilbene. We also observed that both bioconversions can take place in tobacco wild type hairy roots (pRiA4, without any transgene), showing that unspecific tobacco P450 hydroxylases and methyltransferases can perform the bioconversion of t-resveratrol to give the target compounds, albeit at a lower rate than transgenic roots.

  4. Bioconversion of stilbenes in genetically engineered root and cell cultures of tobacco

    PubMed Central

    Hidalgo, Diego; Martínez-Márquez, Ascensión; Moyano, Elisabeth; Bru-Martínez, Roque; Corchete, Purificación; Palazon, Javier

    2017-01-01

    It is currently possible to transfer a biosynthetic pathway from a plant to another organism. This system has been exploited to transfer the metabolic richness of certain plant species to other plants or even to more simple metabolic organisms such as yeast or bacteria for the production of high added value plant compounds. Another application is to bioconvert substrates into scarcer or biologically more interesting compounds, such as piceatannol and pterostilbene. These two resveratrol-derived stilbenes, which have very promising pharmacological activities, are found in plants only in small amounts. By transferring the human cytochrome P450 hydroxylase 1B1 (HsCYP1B1) gene to tobacco hairy roots and cell cultures, we developed a system able to bioconvert exogenous t-resveratrol into piceatannol in quantities near to mg L−1. Similarly, after heterologous expression of resveratrol O-methyltransferase from Vitis vinifera (VvROMT) in tobacco hairy roots, the exogenous t-resveratrol was bioconverted into pterostilbene. We also observed that both bioconversions can take place in tobacco wild type hairy roots (pRiA4, without any transgene), showing that unspecific tobacco P450 hydroxylases and methyltransferases can perform the bioconversion of t-resveratrol to give the target compounds, albeit at a lower rate than transgenic roots. PMID:28345676

  5. Low Doses of Gamma-Irradiation Induce an Early Bystander Effect in Zebrafish Cells Which Is Sufficient to Radioprotect Cells

    PubMed Central

    Pereira, Sandrine; Malard, Véronique; Ravanat, Jean-Luc; Davin, Anne-Hélène; Armengaud, Jean; Foray, Nicolas; Adam-Guillermin, Christelle

    2014-01-01

    The term “bystander effect” is used to describe an effect in which cells that have not been exposed to radiation are affected by irradiated cells though various intracellular signaling mechanisms. In this study we analyzed the kinetics and mechanisms of bystander effect and radioadaptation in embryonic zebrafish cells (ZF4) exposed to chronic low dose of gamma rays. ZF4 cells were irradiated for 4 hours with total doses of gamma irradiation ranging from 0.01–0.1 Gy. In two experimental conditions, the transfer of irradiated cells or culture medium from irradiated cells results in the occurrence of DNA double strand breaks in non-irradiated cells (assessed by the number of γ-H2AX foci) that are repaired at 24 hours post-irradiation whatever the dose. At low total irradiation doses the bystander effect observed does not affect DNA repair mechanisms in targeted and bystander cells. An increase in global methylation of ZF4 cells was observed in irradiated cells and bystander cells compared to control cells. We observed that pre-irradiated cells which are then irradiated for a second time with the same doses contained significantly less γ-H2AX foci than in 24 h gamma-irradiated control cells. We also showed that bystander cells that have been in contact with the pre-irradiated cells and then irradiated alone present less γ-H2AX foci compared to the control cells. This radioadaptation effect is significantly more pronounced at the highest doses. To determine the factors involved in the early events of the bystander effect, we performed an extensive comparative proteomic study of the ZF4 secretomes upon irradiation. In the experimental conditions assayed here, we showed that the early events of bystander effect are probably not due to the secretion of specific proteins neither the oxidation of these secreted proteins. These results suggest that early bystander effect may be due probably to a combination of multiple factors. PMID:24667817

  6. Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

    NASA Astrophysics Data System (ADS)

    Chu, Eun-Hee; Shin, Eun-Jung; Park, Hae-Jun; Jeong, Rae-Dong

    2015-10-01

    Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, 'Shooting Star' and 'Babe'. The irradiating dose required to reduce the population by 90%, D10, was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (p<0.05) in both varieties. Although there is no significant difference in both varieties for fresh weight, in the case of flower rate, 'Babe' shows more sensitivity than 'Shooting Star'. In vivo assays demonstrated that established doses in in vitro, over 4 kGy, could completely inactive fungal pathogens, but such high doses can cause severe flowers damage. Thus, to eliminate negative impact on their quality, gamma irradiation was evaluated at lower doses in combination with an eco-friendly chemical, sodium dichloroisocyanurate (NaDCC) to examine the inhibition of B. cinerea. Intriguingly, only the combined treatment with 0.2 kGy of gamma irradiation and 70 ppm of NaDCC exhibited significant synergistic antifungal activity against blue mold decay in both varieties. Together, these results suggest that a synergistic effect of the combined treatment with gamma irradiation and NaDCC can be efficiently used to control the postharvest diseases in cut rose flowers, and will provide a promising technology for horticulture products for exportation.

  7. Change in colony morphology and kinetics of tylosin production after UV and gamma irradiation mutagenesis of Streptomyces fradiae NRRL-2702.

    PubMed

    Khaliq, Shazia; Akhtar, Kalsoom; Afzal Ghauri, Muhammad; Iqbal, Ruqia; Mukhtar Khalid, Ahmad; Muddassar, Muhammad

    2009-01-01

    Tylosin is a macrolide antibiotic used as veterinary drug and growth promoter. Attempts were made for hyper production of tylosin by a strain of Streptomyces fradiae NRRL-2702 through irradiation mutagenesis. Ultraviolet (UV) irradiation of wild-type strain caused development of six morphologically altered colony types on agar plates. After screening using Bacillus subtilis bioassay only morphological mutants indicated the production of tylosin. An increase of 2.7+/-0.22-fold in tylosin production (1500mg/l) in case of mutant UV-2 in complex medium was achieved as compared to wild-type strain (550mg/l). Gamma irradiation of mutant UV-2 using (60)Co gave one morphologically altered colony type gamma-1, which gave 2500mg/l tylosin yield in complex medium. Chemically defined media promoted tylosin production upto 3800mg/l. Maximum value of q(p) (3.34mg/gh) was observed by mutant gamma-1 as compared to wild strain (0.81mg/gh). Moreover, UV irradiation associated changes were unstable with loss of tylosin activity whereas mutant gamma-1 displayed high stability on subsequent culturing.

  8. Influence of some factors affecting antibacterial activity of PVA/Chitosan based hydrogels synthesized by gamma irradiation.

    PubMed

    Tahtat, Djamel; Mahlous, Mohamed; Benamer, Samah; Nacer Khodja, Assia; Larbi Youcef, Souad; Hadjarab, Nadjet; Mezaache, Wassila

    2011-11-01

    Poly (vinyl alcohol) hydrogels containing different concentrations of chitosan with molecular weight of 471 and 101 kDa were crosslinked by gamma irradiation at a dose of 25 kGy. The swelling behavior, gel content and morphological structure of the blend were investigated. The antibacterial effect, as a function of chitosan content and molecular weight in the hydrogel, was investigated against Escherichia coli and Bacillus subtilis. With increasing chitosan content the equilibrium degree of swelling of the blend increased and the gel fraction decreased. Results of antibacterial activity of chitosan revealed that chitosan was more effective in inhibiting growth of gram positive bacteria than that of gram negative ones. It was observed that, the chitosan content as well as its molecular weight has a direct influence on bacteria growth inhibition. The higher the chitosan content in the blend and the higher its initial molecular weight, the larger was the inhibition zone diameter. The bacteria growth inhibition was attributed to the diffusion of entrapped chitosan from the hydrogel blend to the culture medium.

  9. Gamma irradiation of sun-dried apricots ( Prunus armeniaca L.) for quality maintenance and quarantine purposes

    NASA Astrophysics Data System (ADS)

    Hussain, Peerzada R.; Meena, Raghuveer S.; Dar, Mohd A.; Wani, Ali M.

    2011-07-01

    The study is aimed at the optimization of gamma irradiation treatment of sun-dried apricots for quality maintenance and quarantine purposes. Sun-dried apricots pre-treated with potassium meta-bisulphite (KMS) at 2.5% w/v were procured from progressive apricot grower of district Kargil, Ladakh region of Jammu and Kashmir state. The sun-dried apricots were packed in 250 gauge polyethylene packs and gamma irradiated in the dose range 1.0-3.0 kGy. The gamma irradiated fruit including control was stored under ambient (15±2-25±2 °C, RH 70-80%) conditions and periodically evaluated for physico-chemical, sensory and microbial quality parameters. Radiation treatment at dose levels of 2.5 and 3.0 kGy proved significantly ( p≤0.05) beneficial in retention of higher levels of β-carotene, ascorbic acid, total sugars and color values without impairing the taste as perceived by the sensory panel analysists. The above optimized doses retained the β-carotene content of sun-dried apricots to the extent of 71.2% and 72.6% compared to 63.9% in control samples after 18 months of storage. Irradiation treatment facilitated the release of residual sulfur dioxide in KMS pre-treated sun-dried apricots significantly ( p≤0.05) below the prescribed limit for dried products. During storage, two-fold decrease in sulfur dioxide content was recorded in irradiated samples (3.0 kGy) as compared to 16.9% in control. The above optimized doses besides maintaining the higher overall acceptability of sun-dried apricots resulted in 5 log reductions in microbial load just after irradiation and 1.0 and 1.3 log reductions in yeast and mold and bacterial count after 18 months of ambient storage.

  10. Physicochemical, functional and pasting properties of flour produced from gamma irradiated tiger nut (Cyperus esculentus L.)

    NASA Astrophysics Data System (ADS)

    Ocloo, Fidelis C. K.; Okyere, Abenaa A.; Asare, Isaac K.

    2014-10-01

    Tiger nut (Cyperus esculentus L.) has been recognised as one of the best nutritional crops that can be used to augment the Ghanaian diet. The application of gamma irradiation as means of preserving tiger nut could modify the characteristics of resultant flour. The purpose of this study was to determine the physicochemical, functional and pasting characteristics of flour from gamma irradiated tiger nut. The yellow and black types of tiger nut were sorted, washed and dried in an air-oven at 60 oC for 24 h. The dried tiger nut samples were irradiated at 0.0, 2.5, 5.0 and 10.0 kGy and then flours produced from them. Moisture, ash, pH, titratable acidity, water and oil absorption capacities, swelling power, solubility, bulk density and pasting properties of the flours were determined using appropriate analytical methods. Results showed that irradiation did not significantly (P>0.05) affect the moisture and ash contents of the resultant flours. Gamma irradiation significantly (P≤0.05) increased titratable acidity with concomitant decrease in pH of the flours. No significant differences were observed for water and oil absorption capacities, swelling power as well as bulk density. Solubility significantly (P≤0.05) increased generally with irradiation dose. Peak viscosity, viscosities at 92 °C and 55 °C, breakdown and setback viscosities decreased significantly with irradiation dose. Flour produced from irradiated tiger nut has a potential in complementary food formulations due to its low viscosity and increased solubility values.

  11. Low pressure influence on the electrets stability of gamma irradiated PP and PET films

    NASA Astrophysics Data System (ADS)

    Viraneva, A.; Bodurov, I.; Yovcheva, T.

    2017-01-01

    The influence of low pressure on the surface potential decay of gamma irradiated polymer films of polypropylene (PP) and poly(ethylene terephtalate) (PET) were studied. Polymer film samples were subjected to integral irradiation doses (Ey = 1.25 MeV, 60Co source) of 5 kGy and 25 kGy accumulated in air at a dose rate of 0.26 Mrad/h. After irradiation, the samples were charged in a corona discharge by means of a corona triode system for 1 minute under room conditions. Positive or negative 5 kV voltages were applied to the corona electrode. Four different voltages of the same polarity as that of the corona electrode were applied to the grid. The electret surface potential V0 was measured by the method of the vibrating electrode with compensation. After charging the electrets were placed into a vacuum chamber as the pressure was reduced step by step in the range of 1000 mbar to 0.1 mbar. At each step the samples were stored for 1 minute and the surface potential V was measured again. Then values of the normalized surface potential V/V0 were calculated. Low pressure dependences of the normalized surface potential for positively and negatively charged PP and PET films were presented. It was established that the low pressure led to the surface potential decay of the electrets. The influence of low pressure was analyzed by the equation that describes processes of desorption from the electret surface accompanied with surface diffusion. The experimental results obtained show a significant change in the electret behaviour of the polimer films after gamma irradiation and storage at different low pressure. It was established that the surface potential decay depends on the corona polarity, gamma irradiation and the values of low pressure.

  12. Effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone.

    PubMed

    Cornu, O; Banse, X; Docquier, P L; Luyckx, S; Delloye, C

    2000-05-01

    Freeze-drying and gamma irradiation are commonly used for preservation and sterilization in bone banking. The cumulative effects of preparation and sterilization of cancellous graft material have not been adequately studied, despite the clinical importance of graft material in orthopaedic surgery. Taking benefit from the symmetry of the left and right femoral heads, the influence of lipid extraction followed by freeze-drying of a femoral head and a final 25-kGy gamma irradiation was determined, with the nonirradiated, nonprocessed counterpart as the control. Five hundred and fifty-six compression tests were performed (137 pairs for the first treatment and 141 pairs for the second). Mechanical tests were performed after 30 minutes of rehydration in saline solution. Freeze-dried femoral heads that had undergone lipid extraction experienced reductions of 18.9 and 20.2% in ultimate strength and stiffness, respectively. Unexpectedly, the work to failure did not decrease after this treatment. The addition of gamma irradiation resulted in a mean drop of 42.5% in ultimate strength. Stiffness of the processed bone was not modified by the final irradiation, with an insignificant drop of 24%, whereas work to failure was reduced by a mean of 71.8%. Freeze-dried bone was a bit less strong and stiff than its frozen control. Its work to failure was not reduced, due to more deformation in the nonlinear domain, and it was not brittle after 30 minutes of rehydration. Final irradiation of the freeze-dried bone weakened its mechanical resistance, namely by the loss of its capacity to absorb the energy (in a plastic way) and a subsequent greater brittleness.

  13. The role of gamma irradiation on the extraction of phenolic compounds in onion (Allium cepa L.)

    NASA Astrophysics Data System (ADS)

    Yang, Eun In; Lee, Eun Mi; Kim, Young Soo; Chung, Byung Yeoup

    2012-08-01

    The effect of gamma irradiation on the content of total phenolic compounds, especially quercetin (Q), in onion (Allium cepa L.) skin was investigated. Onion skin extracts contained two predominant flavonoid compounds, Q and quercetin-4'-glucoside (Q4'G). After 10 kGy gamma irradiation, the yield of Q in the extracts increased significantly from 36.8 to 153.9 μg/ml of the extract, and the Q4'G content decreased slightly from 165.0 to 134.1 μg/ml. In addition, the total phenolic compound content also increased after irradiation at 10 kGy, from 228.0 μg/g of fresh weight to 346.6 μg/g; negligible changes (237.1-256.7 μg/g) occurred at doses of up to 5 kGy. As we expected, radical-scavenging activity was enhanced remarkably (by 88.8%) in the 10 kGy irradiated sample. A dose-dependent increase in the peak intensity of the electron paramagnetic resonance (EPR) spectra was observed in all irradiated samples, with a maximum increase at 10 kGy. The intensity relative to that of the control was 0.15, and it increased to 1.10 in 10 kGy irradiated samples. The optimum gamma irradiation dose, which is sufficient to break the chemical or physical bonds and release soluble phenols of low molecular weight in onion skin, is about 10 kGy.

  14. Modification of the genetic effect of gamma irradiation by electric current

    SciTech Connect

    Grigor'eva, N.N.; Shakbazov, V.G.

    1985-09-01

    The authors study the effect of direct current of varying strength and polarity on the genetic damage due to gamma irradiation of Vicia faba seedlings. The modificational effect of direct current observed earlier is confirmed here. The extent and nature of this effect depends on the strength and polarity of the current as well as interval between irradiation and exposure to the electric field. Conditions having no effect on the irradiated seedlings, those protecting the cells from damage and enhancing the irradiation effect, are identified.

  15. The effect of gamma irradiation on the viscosity of two barley cultivars for broiler chicks

    NASA Astrophysics Data System (ADS)

    Al-Kaisey, Mahdi T.; Mohammed, Mahmoud A.; Alwan, Abdul-Kader H.; Mohammed, Manal H.

    2002-03-01

    Seeds of two barley cultivars (Local Black and Shoaa) were gamma irradiated at 0, 10, 50, 100, 150 and 200 kGy doses using Cobalt-60 source to decrease the viscosity. The viscosity was determined in the flour of the seeds using Ostwald U-tube viscometer. The viscosity values were reduced by 25%, 50%, 65%, 72% and 74% in Local Black barley cultivar, while, in Shoaa cultivar the reductions were 15%, 30%, 52%, 69% and 67% at 10, 50, 100, 150 and 200 kGy, respectively. The chemical compositions of the seeds were determined in all treatments.

  16. Determination of dosimetric and kinetic features of gamma irradiated solid calcium ascorbate dihydrate using ESR spectroscopy

    NASA Astrophysics Data System (ADS)

    Tuner, H.

    2013-01-01

    Effects of gamma radiation on solid calcium ascorbate dihydrate were studied using electron spin resonance (ESR) spectroscopy. Irradiated samples were found to present two specific ESR lines with shoulder at low and high magnetic field sides. Structural and kinetic features of the radicalic species responsible for experimental ESR spectrum were explored through the variations of the signal intensities with applied microwave power, variable temperature, high-temperature annealing and room temperature storage time studies. Dosimetric potential of the sample was also determined using spectrum area and measured signal intensity measurements. It was concluded that three radicals with different spectroscopic and kinetic features were produced upon gamma irradiation.

  17. Changes of the immune reactivities of antibodies produced against gamma-irradiated antigen

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Lee, Ju-Woon; Seo, Ji-Hyun; Kim, Jae-Hun; Jo, Cheorun; Kim, Dong-Ho; Chung, Hyung-Wook

    2004-09-01

    To observe the changes of immunogenicity and antigenicity of gamma-irradiated ovalbumin (OVA), an antigen (Ag) solution (2.0 mg/ml) was prepared and irradiated with the absorbed doses of 3 and 10 kGy. Immunoglobulin G (IgG) was produced for each Ag. 0, 3 and 10 kGy-IgG were individually reacted against 3 Ags in an ELISA cross reactivity test. Cross reactivity of each IgG was significantly different for each Ag. Especially the 10 kGy-irradiated OVA lost most antigenicity compared to the 0 kGy-IgG.

  18. The impact of hyper-gravity and gamma-irradiation on physiology of wheat seedlings.

    NASA Astrophysics Data System (ADS)

    Singh, Sandhya; Vidyasagar, Pandit

    2016-07-01

    Exposing plants to altered gravity and gamma radiation can provide us with a fundamental knowledge of plant behavior in such conditions, since the mechanisms involved in response of plants to these stresses is still unclear. The more we understand these mechanisms the more we can apply this information to take the journey of life beyond the boundaries of earth. Hence many experiments were performed on pre-imbibed wheat seeds (Lok-1 variety), wherein they were exposed to hyper-gravity stress (300g-1500g) and gamma-irradiation (Dose 20Gy-100Gy) separately. After exposure these seeds were grown in normal conditions and their growth, fluorescence parameters, and total proline content were observed on the 5th day of their growth. A gradual decline in overall growth and fluorescence parameters, with increase in hyper-gravity stress value (300g-1500g) or gamma-irradiation dose (20Gy-100Gy) was observed. Interestingly in the hyper-gravity studies a consistent increase in the total proline content was observed only till 1200g but the total proline content deteriorated thereafter for higher 'g' values. On the other hand gamma irradiation studies revealed that the total proline content continuously increased with increase in the gamma radiation dose (20Gy-100Gy). Later, pre-imbibed seeds were exposed to both stresses (combined as hyper-gravity (300g-1500g) + gamma-irradiation (40Gy)) and same parameters were studied revealing that there was comparatively greater decline in overall growth and fluorescence parameters of wheat seedlings. Also the total proline content gradually increased ( from 300g+40Gy-900g+40Gy) with 900g+40Gy stress value having highest value of total proline content but the total proline content decreased subsequently for higher stress values (1200g+40Gy, 1500g+40Gy). Results obtained in the current research showed that exposing pre-imbibed wheat seeds to hyper-gravity stress, gamma radiation or both combined together may affect the proline biosynthesis and

  19. Effects of Gamma Irradiation on Optical Properties of Colloidal Nano-crystals

    SciTech Connect

    Withers, Nathan J.; Sankar, Krishnaprasad; Akins, Brian A.; Memon, Tosifa A.; Smolyakov, Gennady A.; Osinski, Marek; Gu, Jiangjiang; Gu, Tingyi; Bowers, Shin T. |; Greenberg, Melisa R. |; Busch, Robert D.

    2008-07-01

    The effects of {sup 137}Cs gamma irradiation on photoluminescence properties, such as spectra, light output, and lifetime, of several types of colloidal nano-crystals have been investigated. Irradiation-induced damage testing was performed on CdSe/ZnS, LaF{sub 3}:Eu, LaF{sub 3}:Ce, ZnO, and PbI{sub 2} nano-crystals synthesized on a Schlenk line using appropriate solvents and precursors. Optical degradation of the nano-crystals was evaluated based on the measured dependence of their photoluminescence intensity on the irradiation dose. Radiation hardness varies significantly between various nano-crystalline material systems. (authors)

  20. The effects of lipid A on gamma-irradiated human peripheral blood lymphocytes in vitro

    NASA Astrophysics Data System (ADS)

    Dubničková, M.; Kuzmina, E. A.; Chausov, V. N.; Ravnachka, I.; Boreyko, A. V.; Krasavin, E. A.

    2016-03-01

    The modulatory effects of lipid A (diphosphoryl lipid A (DLA) and monophosphoryl lipid A (MLA)) on apoptosis induction and DNA structure damage (single and double-strand breaks (SSBs and DSBs, respectively)) in peripheral human blood lymphocytes are studied for 60Co gamma-irradiation. It is shown that in the presence of these agents the amount of apoptotic cells increases compared with the irradiated control samples. The effect is most strongly pronounced for DLA. In its presence, a significant increase is observed in the number of radiation-induced DNA SSBs and DSBs. Possible mechanisms are discussed of the modifying influence of the used agents on radiation-induced cell reactions

  1. Gamma-irradiated onions as a biological indicator of radiation dose.

    PubMed

    Vaijapurkar, S G; Agarwal, D; Chaudhuri, S K; Senwar, K R; Bhatnagar, P K

    2001-10-01

    Post-irradiation identification and dose estimation are required to assess the radiation-induced effects on living things in any nuclear emergency. In this study, radiation-induced morphological/cytological changes i.e., number of root formation and its length, shooting length, reduction in mitotic index, micronuclei formation and chromosomal aberrations in the root tip cells of gamma-irradiated onions at lower doses (50-2000 cGy) are reported. The capabilities of this biological species to store the radiation-induced information are also studied.

  2. Viruslike particles in the tissues of normal and gamma-irradiated Drosophila melanogaster.

    NASA Technical Reports Server (NTRS)

    Miquel, J.; Bensch, K. G.; Philpott, D. E.

    1972-01-01

    A new finding of viruslike particles in the salivary and accessory glands, muscles, and nerves of normal and gamma-irradiated Drosophila melanogaster is discussed. In morphology and size, the particles seemed identical to those described in earlier reports. On the basis of the available results, it cannot be affirmed that these particles infect only dividing cells, since they are found in all the Drosophila tissues so far examined. Their relation to the aging process is felt to be an interesting subject for further study.

  3. Shellfish depuration by gamma irradiation. Progress report No. 1, October 1, 1985-July 25, 1986

    SciTech Connect

    Beghian, L.; Melnick, J.

    1986-07-25

    Objective is to investigate the feasibility of employing food irradiation technology to reduce or eliminate the threat of viral diseases contracted as a result of consumption of raw or inadequately cooked shellfish. Several recently published studies warn of the health risks associated with eating of raw shellfish - particularly American oysters, Crassostrea virginica, and the hardshelled clam, Mercenaria mercenaria. This study addresses the possibility of reducing the incidence of molluscanborne diseases through the application of /sup 60/Co gamma irradiation processing to effect the inactivation of pathogenic viruses in live, raw shwllfish. Dosimetry, D/sub 10/ doses, and organoleptic effects were studied.

  4. State of synapses of the cortex of cerebral hemispheres on gamma-irradiation

    SciTech Connect

    Gaidamakin, N.A.; Ushakov, I.B.

    1989-11-01

    In adult rats with developing neurological disorders we detected destructive changes in most of the synapses of the brain sensorimotor cortex 1.6-4.3 h after a single dose of gamma-irradiation (200 Gy). All functionally important parts on the axonal and dendritic sides of the synapses had undergone changes: mitochondria, synaptic vesicles, pre- and postsynaptic membranes, synaptic complexes, and subsynaptic consolidations, axonal and dendritic plasma, and their inclusions. These changes possibly cause disconnection of the neurons and provide a structural basis for neurological deficiencies following a high substantial ionizing radiation.

  5. Detection of gamma-irradiated peanuts by ESR spectroscopy and GC analysis of hydrocarbons

    NASA Astrophysics Data System (ADS)

    Ming Li, Wei; Li, An; Ming Ha, Yi; Wang, Feng; Li Zhang, Yan

    2011-03-01

    Peanuts were analyzed by electron spin resonance (ESR) spectroscopy and gas chromatography (GC) before and after gamma irradiation. Using European protocols, the validity and effectiveness of these two techniques were compared with regard to sample preparation, sample and solvent consumption and dose-response curves after irradiation. The results showed the possibility of using ESR and GC for distinguishing between irradiated and unirradiated peanuts. A radiation dose of 0.1 kGy could be detected by ESR but not by GC. The results also indicated that GC is an effective method for qualitative analysis of irradiated peanut, while ESR is suitable for the rapid detection of irradiated peanuts.

  6. Effects of gamma irradiation for inactivating Salmonella Typhimurium in peanut butter product during storage.

    PubMed

    Ban, Ga-Hee; Kang, Dong-Hyun

    2014-02-03

    Three types (A, B, and C) of peanut butter product with different water activities (0.18, 0.39, and 0.65 aw) inoculated with a 3-strain mixture of Salmonella Typhimurium were subjected to gamma irradiation (⁶⁰Co) treatment, with doses ranging from 0 to 3 kGy. The inactivation of S. Typhimurium in the 3 types of treated peanut butter product over a 14 day storage period and the influence of storage temperature at 4 (refrigerated) and 25 °C (ambient), and peanut butter product formulation were investigated. Three types of peanut butter product inoculated with S. Typhimurium to a level of ca. 6.6 log CFU/g and subjected to gamma irradiation experienced significant (p<0.05) reductions of 1.3 to 1.9, 2.6 to 2.8, and 3.5 to 4.0 log CFU/g at doses of 1, 2, and 3 kGy, respectively. The time required to reduce S. Typhimurium in peanut butter product to undetectable levels was 14, 5, and 5 days at 25°C after exposure to 3 kGy for products A, B, and C, respectively, and 7 days at 25 °C following exposure to 2 kGy for product C. During storage at 4 and 25 °C, survival of S. Typhimurium was lowest in product C compared to products A and B. Water activity (a(w)) of peanut butter product was likely the most critical factor affecting pathogen survival. When a(w) is reduced, radiolysis of water is reduced, thereby decreasing antimicrobial action. Overall, death was more rapid at 25 °C versus 4 °C for all peanut butter products during 14 day storage. Following gamma irradiation, acid values of peanut butter product were not significantly different from the control, and general observations failed to detect changes in color and aroma, even though lightness observed using a colorimeter was slightly reduced on day 0. The use of gamma irradiation has potential in preventing spoilage of post-packaged food by destroying microorganisms and improving the safety and quality of foods without compromising sensory quality.

  7. Gamma irradiation of municipal sludge for safe disposal and agricultural use.

    PubMed

    Gautam, Satyendra; Shah, Mahesh R; Sabharwal, Sunil; Sharma, Arun

    2005-01-01

    Gamma radiation was found to be an effective tool for hygienization of municipal wastewater sludge. The sludge received from the primary settling tank of a municipal wastewater treatment plant was gamma irradiated using a cobalt-60 source in a sludge hygienization research irradiator. The process parameters were adjusted to effectively eliminate coliform bacteria in the sludge and to prevent their regrowth. Irradiated sludge was found to be free of fecal coliform and could be directly disposed after drying in a landfill or used as manure. It could also be used as a medium for growth of Rhizobium sp for obtaining a bio-fertilizer.

  8. Postharvest Disease Control of Colletotrichum gloeosporioides and Penicillium expansum on Stored Apples by Gamma Irradiation Combined with Fumigation

    PubMed Central

    Cheon, Wonsu; Kim, Young Soo; Balaraju, Kotnala; Kim, Bong-Su; Lee, Byeong-Ho; Jeon, Yongho

    2016-01-01

    To study the control of postharvest decay caused by Colletotrichum gloeosporioides and Penicillium expansum, gamma irradiation alone or in combination with fumigation was evaluated to extend the shelf life of apples in South Korea. An irradiation dose of 2.0 kGy resulted in the maximum inhibition of C. gloeosporioides and P. expansum spore germination. The gamma irradiation dose required to reduce the spore germination by 90% was 0.22 and 0.35 kGy for C. gloeosporioides and P. expansum, respectively. Microscopic observations revealed that when the fungal spores were treated with gamma irradiation (4.0 kGy), conidial germination was stopped completely resulting in no germ tube formation in C. gloeosporioides. Treatment with the eco-friendly fumigant ethanedinitrile had a greater antifungal activity against C. gloeosporioides and P. expansum in comparison with the non-treated control under in vitro conditions. The in vitro antifungal effects of the gamma irradiation and fumigation treatments allowed us to further study the effects of the combined treatments to control postharvest decay on stored apples. Interestingly, when apples were treated with gamma irradiation in combined with fumigation, disease inhibition increased more at lower (< 0.4 kGy) than at higher doses of irradiation, suggesting that combined treatments reduced the necessary irradiation dose in phytosanitary irradiation processing under storage conditions. PMID:27721696

  9. Postharvest Disease Control of Colletotrichum gloeosporioides and Penicillium expansum on Stored Apples by Gamma Irradiation Combined with Fumigation.

    PubMed

    Cheon, Wonsu; Kim, Young Soo; Balaraju, Kotnala; Kim, Bong-Su; Lee, Byeong-Ho; Jeon, Yongho

    2016-10-01

    To study the control of postharvest decay caused by Colletotrichum gloeosporioides and Penicillium expansum, gamma irradiation alone or in combination with fumigation was evaluated to extend the shelf life of apples in South Korea. An irradiation dose of 2.0 kGy resulted in the maximum inhibition of C. gloeosporioides and P. expansum spore germination. The gamma irradiation dose required to reduce the spore germination by 90% was 0.22 and 0.35 kGy for C. gloeosporioides and P. expansum, respectively. Microscopic observations revealed that when the fungal spores were treated with gamma irradiation (4.0 kGy), conidial germination was stopped completely resulting in no germ tube formation in C. gloeosporioides. Treatment with the eco-friendly fumigant ethanedinitrile had a greater antifungal activity against C. gloeosporioides and P. expansum in comparison with the non-treated control under in vitro conditions. The in vitro antifungal effects of the gamma irradiation and fumigation treatments allowed us to further study the effects of the combined treatments to control postharvest decay on stored apples. Interestingly, when apples were treated with gamma irradiation in combined with fumigation, disease inhibition increased more at lower (< 0.4 kGy) than at higher doses of irradiation, suggesting that combined treatments reduced the necessary irradiation dose in phytosanitary irradiation processing under storage conditions.

  10. Apollo 12 lunar material - Effects on lipid levels of tobacco tissue cultures.

    NASA Technical Reports Server (NTRS)

    Weete, J. D.; Walkinshaw, C. H.; Laseter, J. L.

    1972-01-01

    Tobacco tissue cultures grown in contact with lunar material from Apollo 12, for a 12-week period, resulted in fluctuations of both the relative and absolute concentrations of endogenous sterols and fatty acids. The experimental tissues contained higher concentrations of sterols than the controls did. The ratio of campesterol to stigmasterol was greater than 1 in control tissues, but less than 1 in the experimental tissues after 3 weeks. High relative concentrations (17.1 to 22.2 per cent) of an unidentified compound or compounds were found only in control tissues that were 3 to 9 weeks of age.

  11. Apollo 12 lunar material: effects on lipid levels of tobacco tissue cultures.

    PubMed

    Weete, J D; Walkinshaw, C H; Laseter, J L

    1972-02-11

    Tobacco tissue cultures grown in contact with lunar material from Apollo 12, for a 12-week period, resulted in fluctuations of both the relative and absolute concentrations of endogenous sterols and fatty acids. The experimental tissues contained higher concentrations of sterols than the controls did. The ratio of campesterol to stigmasterol was greater than 1 in control tissues, but less than 1 in the experimental tissues after 3 weeks. High relative concentrations (17.1 to 22.2 percent) of an unidentified compound or compounds were found only in control tissues that were 3 to 9 weeks of age.

  12. Effect of gamma irradiation on storability of two cultivars of Syrian grapes ( Vitis vinifera)

    NASA Astrophysics Data System (ADS)

    Al-Bachir, M.

    1999-06-01

    This study was initiated to investigate the effect of gamma irradiation on storability of two local table grape varieties: Baladi and Helwani. The experiments were performed in 1995 and 1996, when both varieties were treated with 0, 0.5, 1.0 and 1.5 kGy in the first year. In the second year two additional doses were used 0.1 and 0.25 kGy for Helwani and 2.0 and 2.5 kGy for Baladi. Irradiated and unirradiated fruits were stored in a refrigerated room (temperature, 1-2°C). Weight loss, spoilage and total loss were evaluated every 2 and 4 weeks of storage for Baladi and Helwani, respectively. The results have shown that gamma irradiation improved the storability of both varieties. In addition, irradiation prevented molding and prolonged the storage time. The optimum doses for improving the storability were 0.5-1.0 kGy for Helwani and 1.5-2.0 kGy for Baladi, and the storage periods can be extended by 50% using these optimal doses for both varieties.

  13. Effect of gamma irradiation on molecular structure and physicochemical properties of corn starch.

    PubMed

    Chung, H-J; Liu, Q

    2009-06-01

    Carboxyl content and amylose leaching of gamma-irradiated corn starch increased and swelling factor decreased with increasing radiation dose. The apparent amylose content decreased gradually from 28.7% for native starch to 20.9% for 50 kGy irradiated starch. The proportion of short amylopectin branch chains (DP 6 to 12) increased, while the proportion of longer branch chains (DP > or = 37) decreased with increasing radiation dose. The relative crystallinity and the degree of granule surface order decreased from 28.5% and 0.631 in native starch to 26.9% and 0.605 in 50 kGy irradiated starch, respectively. Pasting viscosity and gelatinization temperatures decreased with an increase in radiation dose. At a high dose (50 kGy), melting of amylose-lipid complex in DSC thermogram was not observed. The rapidly digestible starch (RDS) content slightly decreased up to 10 kGy but increased at 50 kGy. The resistant starch (RS) content slightly decreased at 2 kGy and then increased up to 50 kGy. The slowly digestible starch (SDS) content showed the opposite trend to RS content. Slower irradiation dose rate reduced carboxyl content, swelling factor, and amylose leaching. The apparent amylose content and amylopectin chain length distribution were not significantly affected by dose rate of gamma irradiation. However, the relative crystallinity and gelatinization enthalpy increased with slower dose rate. Slower dose rate decreased RDS and SDS contents, and increased RS content.

  14. Tumor induction in BALB/c female mice after fission neutron or. gamma. irradiation

    SciTech Connect

    Ullrich, R.L.

    1983-03-01

    This study was designed to examine the dose-response relationships for tumor induction after neutron irradiation in female BALB/c mice, with emphasis on the response in the dose range 0 to 50 rad. Tumors induced after radiation exposure included ovarian tumors, lung adenocarcinomas, and mammary adenocarcinomas. For comparison the dose responses for induction of these tumors after /sup 137/Cs ..gamma.. irradiation were also examined. As previously described for the female RFM mouse, the data for ovarian tumor induction after neutron and ..gamma.. irradiation were consistent with a threshold model. For lung and mammary tumors the dose-response curve after neutron irradiation appeared to ''bend over'' in the dose range 10 to 20 rad. The factors responsible for this bend-over and their relative contributions to the overall form of the dose-response relationship are not presently known. However, these data strongly indicate that extrapolation from data above 50 rad could result in a significant underestimate of risks. Further, it is clear that current models of neutron carcinogenesis are inadequate, since such a bend-over is not predicted at these low dose levels.

  15. Gamma irradiation of pharmaceutical compounds, nitroimidazoles, as a new alternative for water treatment.

    PubMed

    Sánchez-Polo, M; López-Peñalver, J; Prados-Joya, G; Ferro-García, M A; Rivera-Utrilla, J

    2009-09-01

    The main objectives of this study were: (1) to investigate the decomposition and mineralization of nitroimidazoles (Metronidazole [MNZ], Dimetridazole [DMZ], and Tinidazole [TNZ]) in waste and drinking water using gamma irradiation; (2) to study the decomposition kinetics of these nitroimidazoles; and (3) to evaluate the efficacy of nitroimidazole removal using radical promoters and scavengers. The results obtained showed that nitroimidazole concentrations decreased with increasing absorbed dose. No differences in irradiation kinetic constant were detected for any nitroimidazole studied (0.0014-0.0017 Gy(-1)). The decomposition yield was higher under acidic conditions than in neutral and alkaline media. Results obtained showed that, at appropriate concentrations, H(2)O(2) accelerates MNZ degradation by generating additional HO(); however, when the dosage of H(2)O(2) exceeds the optimal concentration, the efficacy of MNZ degradation is reduced. The presence of t-BuOH (HO() radical scavenger) and thiourea (HO(), H() and e(aq)(-) scavenger) reduced the MNZ irradiation rate, indicating that degradation of this pollutant can take place via two pathways: oxidation by HO() radicals and reduction by e(aq)(-) and H(). MNZ removal rate was slightly lower in subterranean and surface waters than in ultrapure water and was markedly lower in wastewater. Regardless of the water chemical composition, MNZ gamma irradiation can achieve i) a decrease in the concentration of dissolved organic carbon, and ii) a reduction in the toxicity of the system with higher gamma absorbed dose.

  16. Induction of L-arabinose isomerase in gamma-irradiated Escherichia coli

    SciTech Connect

    Chatterjee, A.; Bhattacharya, A.K.

    1986-11-01

    Gamma irradiation of Escherichia coli B/r caused a dose-dependent inhibition of the capacity of the cells to synthesize L-arabinose isomerase in response to the inducer. At higher doses (18 krad and above), postirradiation incubation led to further inhibition of the capacity to synthesize L-arabinose isomerase, whereas cells receiving lower doses recovered from the damage to the enzyme synthesizing system following incubation. Cyclic AMP partially reversed the inhibitory effect on L-arabinose isomerase induction produced immediately after irradiation by all gamma-ray doses (up to 30 krad), but the enhanced inhibitory effect caused by induction in cells irradiated at higher doses could not be reversed by the nucleotide. It is suggested that although catabolite repression is partly responsible for causing the inhibition of the enzyme synthesizing capacity of the cells observed immediately after gamma irradiation, the enhanced inhibition caused by incubating cells irradiated at higher doses is not due to interference with the control mechanism regulated by catabolite repression.

  17. Shelf life extension of minimally processed ready-to-cook (RTC) cabbage by gamma irradiation.

    PubMed

    Banerjee, Aparajita; Chatterjee, Suchandra; Variyar, Prasad S; Sharma, Arun

    2016-01-01

    Gamma irradiation (0.5-2.5 kGy) in combination with low temperature (4-15 °C) storage was attempted to increase shelf life of ready-to-cook shredded cabbage wrapped in cling films. A maximum extension in shelf life of 8 days, while retaining the microbial and sensory quality, was obtained with an irradiation dose of 2 kGy and storage at 10 °C. Gamma irradiation also inhibited browning of shredded cabbage at their cut edges resulting in enhanced visual appeal. An increase in total antioxidant activity was observed with respect to DPPH and hydroxyl radical scavenging ability while the nitric oxide radical scavenging activity and ferric reducing property remained unaffected with irradiation. Total phenolic, flavonoid and vitamin C content remained unchanged due to irradiation. No significant migration of additives from cling films into stimulant water was observed up to a radiation dose of 2 kGy thus demonstrating the feasibility of such films for above applications.

  18. Gamma irradiation effect on the chemical composition and the antioxidant activity of Ipomoea batatas L

    SciTech Connect

    Tahir, D. Halide, H. Kurniawan, D.; Wahab, A. W.

    2014-09-25

    The chemical composition and antioxidant activity of Ipomoea batatas L. (sweet potato) were studied by x-ray fluorescence (XRF) spectroscopy, Fourier transform infrared spectroscopy, and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity. The irradiation treatment was performed by using Cs-137 as a gamma sources in experimental equipment. Treatment by irradiation emerges as a possible conservation technique that has been tested successfully in several food products. The amount of chemical composition was changed and resulting new chemical for absorbed dose 40 mSv. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by DPPH radical scavenging capacity. The antioxidant activity of Ipomoea batatas L. extract was dramatically increased in the non-irradiated sample to the sample irradiated at 40 mSv. These results indicate that gamma irradiation of Ipomoea batatas L. extract can enhance its antioxidant activity through the formation of a new chemical compound. Based on these results, increased antioxidant activity of Ipomoea batatas L. extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

  19. Gamma irradiation induced in situ synthesis of lead sulfide nanoparticles in poly(vinyl alcohol) hydrogel

    NASA Astrophysics Data System (ADS)

    Kuljanin-Jakovljević, Jadranka Ž.; Radosavljević, Aleksandra N.; Spasojević, Jelena P.; Carević, Milica V.; Mitrić, Miodrag N.; Kačarević-Popović, Zorica M.

    2017-01-01

    In this study, the nanocomposites based on semiconductor lead sulfide (PbS) nanoparticles and poly(vinyl alcohol) (PVA) were investigated. The gamma irradiation induced in situ incorporation of PbS nanoparticles in crosslinked polymer network i.e. PVA hydrogel was performed. PVA hydrogel was previously obtained also under the influence of gamma irradiation. UV-Vis absorption and X-ray diffraction measurements were employed to investigate optical and structural properties of PbS nanoparticles, respectively, and obtained results indicates the presence of nanoparticles with approximately 6 nm in diameter and face centered cubic rock-salt crystal structure. The porous morphology was confirmed by scanning electron microscopy. Swelling data revealed that investigated hydrogels (PVA and PbS-PVA nanocomposite) shows non-Fickian diffusion, indicating that both diffusion and polymer relaxation processes controlled the fluid transport. The values of diffusion coefficients have an order of magnitude 10-9 cm2/s (typical values for water diffusion in polymers) and the best fit with the experimental results showed the Etters approximation. Comparing the thermal properties of PbS-PVA xerogel nanocomposite with PVA xerogel it was observed that incorporation of PbS nanoparticles in crosslinked PVA matrix just slightly enhanced the thermal stability of nanocomposite.

  20. Study of the effect of gamma irradiation on a commercial polycyclooctene I. Thermal and mechanical properties

    NASA Astrophysics Data System (ADS)

    García-Huete, N.; Laza, J. M.; Cuevas, J. M.; Vilas, J. L.; Bilbao, E.; León, L. M.

    2014-09-01

    A 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 able to induce chain scission or recombination of radicals, which induces annihilation, branching or crosslinking processes. The aim of this work is to research the structural, thermal and mechanical changes induced on a commercial polycyclooctene (PCO) when it is irradiated with a gamma source of 60Co at different doses (25-200 kGy). After gamma irradiation, gel content was determined by Soxhlet extraction in cyclohexane. Furthermore, thermal properties were evaluated before and after Soxhlet extraction by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), as well as mechanical properties were measured by Dynamic Mechanical Thermal Analysis (DMTA). The results showed the variations of the properties depending on the irradiation dose. Finally, a first approach to evaluate qualitatively the shape memory behaviour of all irradiated PCO samples was performed by a visually monitoring shape recovery process.

  1. Atomic hydrogen in. gamma. -irradiated hydroxides of alkaline-earth elements

    SciTech Connect

    Spitsyn, V.I.; Yurik, T.K.; Barsova, L.I.

    1982-04-01

    Atomic hydrogen is an important intermediate product formed in the radiolysis of compounds containing X-H bonds. H atoms have been detected in irradiated matrices of H/sub 2/ and inert gases at 4/sup 0/K, in irradiated ice and frozen solutions of acids in irradiated salts and in other systems. Here results are presented from a study of the ESR spectra of H atoms generated in polycrystalline hydroxides of alkaline-earth elements that have been ..gamma..-irradiated at 77/sup 0/K, after preliminary treatment at various temperatures. For the first time stabilization of atomic hydrogen in ..gamma..-irradiated polycrystalline alkaline-earth element hydroxides has been detected. Depending on the degree of dehydroxylation, several types of hydrogen atoms may be stabilized in the hydroxides, these hydrogen atoms having different radiospectroscopic parameters. In the magnesium-calcium-strontium-barium hydroxide series, a regular decrease has been found in the hfi constants for H atoms with the cations in the immediate surroundings. A direct proportionality has been found between the parameters ..delta..A/A/sub 0/ and the polarizability of the cation.

  2. Synergistic effect of mixed neutron and gamma irradiation in bipolar operational amplifier OP07

    NASA Astrophysics Data System (ADS)

    Yan, Liu; Wei, Chen; Shanchao, Yang; Xiaoming, Jin; Chaohui, He

    2016-09-01

    This paper presents the synergistic effects in bipolar operational amplifier OP07. The radiation effects are studied by neutron beam, gamma ray, and mixed neutron/gamma ray environments. The characterateristics of the synergistic effects are studied through comparison of different experiment results. The results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects in the mixed neutron and gamma irradiation. The bipolar transistor is identified as the most radiation sensitive unit of the operational amplifier. In this paper, a series of simulations are performed on bipolar transistors in different radiation environments. In the theoretical simulation, the geometric model and calculations based on the Medici toolkit are built to study the radiation effects in bipolar components. The effect of mixed neutron and gamma irradiation is simulated based on the understanding of the underlying mechanisms of radiation effects in bipolar transistors. The simulated results agree well with the experimental data. The results of the experiments and simulation indicate that the radiation effects in the bipolar devices subjected to mixed neutron and gamma environments is not a simple combination of total ionizing dose (TID) effects and displacement damage. The data suggests that the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

  3. Identification of estrogenic activity change in sewage, industrial and livestock effluents by gamma-irradiation

    NASA Astrophysics Data System (ADS)

    Ahn, Byeong-Yong; Kang, Sung-Wook; Yoo, Jisu; Kim, Woong-Ki; Bae, Paek-Hyun; Jung, Jinho

    2012-11-01

    In this study, reduction of estrogenic activity in three different types of effluents from sewage, industrial and livestock wastewater treatment plants by gamma-irradiation was investigated using the yeast two-hybrid assay. After gamma-ray treatment at a dose of 10 kGy, estrogenic activities of sewage, industrial and livestock effluents decreased from 4.4 to 3.0, 1.5 to 1.0 and 16 to 9.9 ng-EEQ L-1, respectively. The substantial reduction of estrogenic activity in livestock effluent was attributable to the degradation of 17β-estradiol (E2), estrone (E1) and 17α-ethynylestradiol (EE2). Although bisphenol A (BPA) was found at the highest concentration in all effluents, its contribution to the estrogenic activity was not significant due to its low relative estrogenic potency. Meanwhile, the calculated estrogenic activity based on concentrations of E2, E1, EE2 and BPA in the effluents significantly differed from the measured ones. Overestimation may have resulted by dissolved organic matters in effluents inhibiting the estrogenic activity of E2, E1, EE2 and BPA, whereas underestimation was likely due to estrogenic by-products generated by gamma-irradiation.

  4. Structural characterization of gamma irradiated lithium phosphate glasses containing variable amounts of molybdenum

    NASA Astrophysics Data System (ADS)

    ElBatal, F. H.; Abdelghany, A. M.; Elwan, R. L.

    2011-08-01

    MoO 3-doped lithium phosphate glasses with varying molybdenum contents were prepared and characterized. Combined UV-visible and infrared (FT/IR) spectroscopic studies were measured before and after gamma irradiation. Experimental results indicate that molybdenum ions occupy different local sites including presence of Mo 3+, Mo 4+ and Mo 5+ with different ratio depending on the host lithium phosphate glass composition and concentration of molybdenum ions. Undoped lithium phosphate glass reveal UV absorption which is related to the presence of unavoidable trace iron impurities. FT/IR spectra were used to identify the main building structural groups present in the studied lithium phosphate glass. The same spectroscopic reutilized techniques were reutilized to identify the induced defects generated after successive gamma irradiation and the influence of molybdenum ions on the irradiation process. Experimental results indicate that molybdenum ions occupy two valences: Mo 5+ and Mo 3+ with the first in dominant percent. The change in the UV, visible and infrared spectral data are discussed in relation to the change in the state of molybdenum ions with glass composition or dopant concentration or network structure evolution caused by the change in glass constituents.

  5. Effect of radiation on solid paracetamol: ESR identification and dosimetric features of gamma-irradiated paracetamol

    NASA Astrophysics Data System (ADS)

    Polat, M.; Korkmaz, M.

    2006-01-01

    In the present work, electron spin resonance (ESR) identification of gamma-irradiated paracetamol and its potential use as a normal and/or accidental dosimetric material were investigated in the dose range of 2.5-25 kGy. Both unirradiated paracetamol and mechanically ground vermidon samples exhibited a weak single resonance line at g = 2.0049 +/- 0.0006 and had Delta H-pp = 0.6 +/- 0.02 mT. Gamma irradiation produced an increase in signal intensity with a small hyperfine splitting in both paracetamol and vermidon and many weak resonance lines on both sides of a central line in the case of vermidon. Dose-response curves associated with central line of paracetamol and vermidon were found to follow polynomial and linear function, respectively. Simulation calculations based on the room temperature ESR intensity data of the paracetamol sample irradiated at 10 kGy were performed to determine the structure and spectral parameters of the radiation-induced radical species involved in the formation of the experimental ESR spectrum of paracetamol.

  6. Effect of gamma-irradiation on the molecular properties of myoglobin.

    PubMed

    Lee, Yongwoo; Song, Kyung Bin

    2002-11-30

    To elucidate the effect of gamma-irradiation on the molecular properties of myoglobin, the secondary and tertiary structures, as well as the molecular weight size of the protein, were examined after irradiation at various irradiation doses. Gamma-irradiation of myoglobin solutions caused the disruption of the ordered structure of the protein molecules, as well as degradation, crosslinking, and aggregation of the polypeptide chains. A SDSPAGE study indicated that irradiation caused initial fragmentation of the proteins and subsequent aggregation, due to cross-linking of the protein molecules. The effect of irradiation on the protein was more significant at lower protein concentrations. Ascorbic acid protected against the degradation and aggregation of proteins by scavenging oxygen radicals that are produced by irradiation. A circular dichroism study showed that an increase of the irradiation decreased the alpha-helical content of myoglobin with a concurrent increase of the aperiodic structure content. Fluorescence spectroscopy indicated that irradiation increased the emission intensity that was excited at 280 nm.

  7. [Comparative protective action of radiorotectors and shielding in gamma-irradiated mice].

    PubMed

    Shashkov, V S; Karsanova, S K; Iasnetsov, V V

    2007-01-01

    Experiments with male mice were performed to evaluate comparative effectiveness of radioprotectors cystamine, aminoethyl isothiuronium, mexamine and indralin against minimal absolutely lethal gamma-doses (9 Gy). The best protective effect was demonstrated by indralin at a dose of 75 mg/kg. Supportive data were received in experiments with rats. The radioprotective action of indralin consists mainly in quite successful preservation of the blood-forming components, i.e. the pool of stem cells in the marrow and spleen. Gamma-irradiation at superlethal doses (10 Gy and higher) weakens significantly or fully neutralizes these protectors in rodents. Shielding of radiosensitive organs with the help of lead and plastics proved to be a good protection of animals from minimal lethal gamma-doses. However, the superlethal doses of gamma-irradiation penetrated the shielding materials and disabled them to a large and full extent. Evaluation of effectiveness of the combined protection against superlethal gamma-doses by pharmaceutical agents and shielding revealed a potentiating effect. For instance, mexamine and shielding of the abdomen together increased survivability of rats to 76.7%. An even stronger effect was noted when shielding was combined with indraline which raised survivability to 100%. It should be emphasized that this combination is effective against superlethal gamma-doses that usually unassailable to radioprotectors and shielding.

  8. Preparation of low molecular weight fucoidan by gamma-irradiation and its anticancer activity.

    PubMed

    Choi, Jong-il; Kim, Hyun-Joo

    2013-09-12

    Fucoidan is a marine sulfated polysaccharide with a wide variety of biological activities. Recently, it has been reported that low molecular weight fucoidan has the enhanced antioxidant and anticoagulative activities. However, degradation techniques such as enzymolysis and acid hydrolysis for obtaining low molecular weight fucoidan, have the disadvantages such as narrow substrate specificity and unfavorable hydrolysis of side groups, respectively. In this study, low molecular weight fucoidan was prepared by gamma-irradiation. When fucoidan was gamma-irradiated, the molecular weight rapidly dropped to 38 kDa when the sample was irradiated at 10 kGy, then gradually dropped to 7 kDa without the significant elimination of the sulfate groups. Low molecular weight fucoidan had higher cytotoxicity than native fucoidan in cancer cells, such as AGS, MCF-7, and HepG-2. In addition, low molecular weight fucoidan showed higher inhibitory activity of cell transformation, which resulted in higher anticarcinogenicity. This result suggests that low molecular weight fucoidan with enhanced biological activities can be produced by a simple irradiation method without changing the functional groups.

  9. Effect of hydrogen uptake on the electrochemical corrosion of N18 zircaloy under gamma irradiation

    NASA Astrophysics Data System (ADS)

    Xin, Z. Y.; Ling, Y. H.; Bai, Y. K.; Zeng, C.; Wang, S.; Clara, J. C.

    2016-12-01

    It has been well recognized that dramatic hydrogen uptake occurred in zircaloy after kinetic transition and porous structure was observed subsequently due to phase transformation of tetragonal to monoclinic zirconia. Therefore, how hydrogen solute and gamma-induced capillary-embedded hydrolysis influence the corrosion of zircaloy is an intriguing issue. In this work, the effect of hydrogen uptake and gamma irradiation on corrosion of N18 zircaloy was studied. Raman spectra and atomic force microscopy (AFM) were employed to analyse phase structure and surface morphology. Potentiodynamic polarization and electrochemical impedance spectroscopy were utilized to qualitatively evaluate the electron transfer properties of the oxide film formed on the zircaloy surface after corrosion. The depth profile and surface chemical states of involving elements were analysed by auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), respectively. It was found that hydrogen permeation can decline the integrity and impedance semicircle of the oxide films, the more the hydrogen uptake is; the smaller magnitude of impedance will be. In view of the gamma irradiation, it is demonstrated that it promotes the corrosion rate slightly. Based on the irradiation theory and existing phenomena, the underlying mechanism is proposed.

  10. Formation of an 8-hydroxyguanine moiety in deoxyribonucleic acid on gamma-irradiation in aqueous solution

    SciTech Connect

    Dizdaroglu, M.

    1985-07-30

    Isolation and characterization of a novel radiation-induced product, i.e., the 8-hydroxyguanine residue, produced in deoxyribonucleic acid (DNA), 2'-deoxyguanosine, and 2'-deoxyguanosine 5'-monophosphate by gamma-irradiation in aqueous solution, are described. For this purpose, gamma-irradiated DNA was first hydrolyzed with a mixture of four enzymes, i.e., DNase I, spleen and snake venom exonucleases, and alkaline phosphatase. Analysis of the resulting mixture by capillary gas chromatography-mass spectrometry after trimethylsilylation revealed the presence of a product, which was identified as 8-hydroxy-2'-deoxyguanosine on the basis of the typical fragment ions of its trimethylsilyl (Me3Si) derivative. This product was then isolated by using reversed-phase high-performance liquid chromatography. The UV and proton nuclear magnetic resonance spectra taken from the isolated product confirmed the structure suggested by the mass spectrum of its Me3Si derivative. The yield of 8-hydroxyguanine was also measured. Its mechanism of formation is believed to involve OH radical addition to the C-8 position of guanine followed by oxidation of the radical adduct.

  11. Gamma irradiation effect on the chemical composition and the antioxidant activity of Ipomoea batatas L.

    NASA Astrophysics Data System (ADS)

    Tahir, D.; Halide, H.; Wahab, A. W.; Kurniawan, D.

    2014-09-01

    The chemical composition and antioxidant activity of Ipomoea batatas L. (sweet potato) were studied by x-ray fluorescence (XRF) spectroscopy, Fourier transform infrared spectroscopy, and by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity. The irradiation treatment was performed by using Cs-137 as a gamma sources in experimental equipment. Treatment by irradiation emerges as a possible conservation technique that has been tested successfully in several food products. The amount of chemical composition was changed and resulting new chemical for absorbed dose 40 mSv. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by DPPH radical scavenging capacity. The antioxidant activity of Ipomoea batatas L. extract was dramatically increased in the non-irradiated sample to the sample irradiated at 40 mSv. These results indicate that gamma irradiation of Ipomoea batatas L. extract can enhance its antioxidant activity through the formation of a new chemical compound. Based on these results, increased antioxidant activity of Ipomoea batatas L. extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

  12. Influence of gamma irradiation in the antioxidant potential of chestnuts (Castanea sativa Mill.) fruits and skins.

    PubMed

    Antonio, Amilcar L; Fernandes, Angela; Barreira, João C M; Bento, Albino; Botelho, M Luisa; Ferreira, Isabel C F R

    2011-09-01

    As seasonal products chestnuts have to be post-harvest treated to increase their shelf-life. The most common preservation method for chestnuts is the chemical fumigation with methyl bromide, a toxic agent that is under strictly Montreal Protocol due to its adverse effects on human health and environment. Food irradiation is a possible feasible alternative to substitute the traditional quarantine chemical fumigation treatment. This preliminary study evaluated the influence of gamma irradiation in the antioxidant potential of chestnut fruits and skins, through several chemical and biochemical parameters. The bioactive compounds (phenolics and flavonoids) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, reducing power and inhibition of β-carotene bleaching capacity were determined. The obtained results seem to indicate that the storage favoured chestnuts antioxidant potential. Furthermore, the application of gamma irradiation also seems to be advantageous for antioxidant activity, independently of the dose used (0.27 ± 0.04 kGy or 0.54 ± 0.04 kGy).

  13. Reaction of glass during gamma irradiation in a saturated tuff environment. Part 1. SRL 165 glass

    SciTech Connect

    Bates, J.K.; Fischer, D.F.; Gerding, T.J.

    1986-02-01

    The influence of gamma irradiation on the reaction of actinide-doped borosilicate glass (SRL 165) in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The following conclusions were reached. The reaction of, and subsequent actinide release from, the glass depends on the dynamic interaction between radiolysis effects, which cause the solution pH to become more acidic; glass reaction, which drives the pH more basic; and test component interactions that may extract glass components from solution. The use of large gamma irradiation dose rates to accelerate reactions that may occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons between the present results and data obtained by reacting similar glasses using MCC-1 and NNWSI rock cup procedures indicate that the irradiation conditions used in the present experiments do not dramatically influence the reaction rate of the glass. 8 figs., 9 tabs.

  14. Effect of gamma irradiation on cell lysis and polyhydroxyalkanoate produced by Bacillus flexus

    NASA Astrophysics Data System (ADS)

    Divyashree, M. S.; Shamala, T. R.

    2009-02-01

    Bacillus flexus cultivated on sucrose and sucrose with plant oil such as castor oil produced polyhydroxybutyrate (PHB), a homopolymer of polyhydroxyalkanoate (PHA) and PHA copolymer (containing hydroxybutyrate and hexanoate), respectively. Gamma irradiation of these cells (5-40 kGy) resulted in cell damage and aided in the isolation of 45% and 54% PHA on biomass weight, correspondingly. Molecular weight of PHB increased from 1.5×10 5 to 1.9×10 5 after irradiation (10 kGy), with marginal increase of tensile strength from 18 to 20 MPa. At the same irradiation dosage, PHA copolymer showed higher molecular weight increase from 1.7×10 5 to 2.3×10 5 and tensile strength from 20 to 35 MPa. GC, GC-MS, FTIR and 1H NMR were used for the characterization of PHA. Gamma irradiation seems to be a novel technique, to induce cross-linking and molecular weight increase of PHA copolymer and aid in easy extractability of intracellular PHA, simultaneously.

  15. Comparison of Free and Immobilized L-asparaginase Synthesized by Gamma-Irradiated Penicillium cyclopium.

    PubMed

    El-Refai, Heba A; Shafei, Mona S; Mostafa, Hanan; El-Refai, Abdel-Monem H; Araby, Eman M; El-Beih, Fawkia M; Easa, Saadia M; Gomaa, Sanaa K

    2016-01-01

    Gamma irradiation is used on Penicillium cyclopium in order to obtain mutant cells of high L-asparaginase productivity. Using gamma irradiation dose of 4 KGy, P. cyclopium cells yielded L-asparaginase with extracellular enzyme activity of 210.8 ± 3 U/ml, and specific activity of 752.5 ± 1.5 U/mg protein, which are 1.75 and 1.53 times, respectively, the activity of the wild strain. The enzyme was partially purified by 40-60% acetone precipitation. L-asparaginase was immobilized onto Amberlite IR-120 by ionic binding. Both free and immobilized enzymes exhibited maximum activity at pH 8 and 40 degrees C. The immobilization process improved the enzyme thermal stability significantly. The immobilized enzyme remained 100% active at temperatures up to 60 degrees C, while the free asparaginase was less tolerant to high temperatures. The immobilized enzyme was more stable at pH 9.0 for 50 min, retaining 70% of its relative activity. The maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) of the free form were significantly changed after immobilization. The K(m) value for immobilized L-asparaginase was about 1.3 times higher than that of free enzyme. The ions K+, Ba2+ and Na+ showed stimulatory effect on enzyme activity with percentages of 110%, 109% and 106% respectively.

  16. Effect of gamma irradiation on MnO2/Ag2O hydrogen getter

    NASA Astrophysics Data System (ADS)

    Chlique, Christophe; Lambertin, David; Galliez, Kévin; Labed, Véronique; Dannoux-Papin, Adeline; Jobic, Stéphane; Deniard, Philippe; Leoni, Elisa

    2015-03-01

    This study aims to show the stability of γ-MnO2/Ag2O hydrogen getter under gamma irradiation in order to be suitable for decreasing the hydrogen risk during the nuclear waste transportation. The chemical and the structural properties of the getter were barely unchanged for irradiated doses up to 4 MGy. The pair distribution function (PDF) analysis showed that the γ-MnO2, which can be describe as an intergrowth of the ramsdellite phase (R-MnO2) and the pyrolusite phase (β-MnO2), had the same intergrowth rate (around 60% for β-MnO2 and 40% for R-MnO2) after irradiation and the silver containing promoter was also unchanged. The getter remains therefore efficient for hydrogen trapping. Furthermore, γ-MnO2/Ag2O was tested in a closed environment in the presence of hydrogen released by organic technological waste radiolysis, such as polyvinyl chloride, ion exchange resins, polyethylene and silicone. Over 80% of the hydrogen, generated by organic radiolysis, was trapped under a 1.5 MGy gamma irradiation.

  17. Developmental inhibition of gamma irradiation on the peach fruit moth Carposina sasakii (Lepidoptera: Carposinidae)

    NASA Astrophysics Data System (ADS)

    Ryu, Jihoon; Ahn, Jun-Young; Sik Lee, Seung; Lee, Ju-Woon; Lee, Kyeong-Yeoll

    2015-01-01

    Ionizing irradiation is a useful technique for disinfestation under plant quarantine as well as post-harvest management. Effects of gamma irradiation treatment were tested on different developmental events of Carposina sasakii, which is a serious pest of various orchard crops. Apple fruits infested by C. sasakii were irradiated by gamma rays ranging from 0 to 300 Gy. Inhibition rates were determined on behavioral events related to development, including larval exit from apples, cocoon formation, adult eclosion, and oviposition. Failure rates of all these developmental events increased with increasing doses of irradiation. Rates of larval exit from apples and cocoon formation decreased to 13.2% and 1.7%, respectively, at 300 Gy. However, the adult eclosion rate decreased to 5.4% at 100 Gy and was completely inhibited at doses greater than 150 Gy. LD99 values for the inhibition of cocoon formation and adult emergence was estimated into 313.4 and 191.0 Gy. Furthermore, adults developed from irradiated larvae completely failed to lay eggs. Thus, irradiation of infested apples at doses of 200 Gy and higher completely inhibited the next generation of C. sasakii. Our results suggest that gamma irradiation treatment would be a promising technique for the control of C. sasakii.

  18. Restricting the ageing degradation of the mechanical properties of gamma irradiated UHMWPE using MWCNTs.

    PubMed

    Rama Sreekanth, P S; Kanagaraj, S

    2013-05-01

    Property degradation of the medical grade polymers after gamma irradiation is the primary concern that limits longevity of them. Though the conventional antioxidant material helps to reduce the degradation but it limits the degree of crosslinking of the polymer. The objective of the present work is to study the influence of multi walled carbon nanotubes (MWCNTs) on restricting the degradation of mechanical properties of medical grade ultra high molecular weight polyethylene (UHMWPE) after its irradiation. UHMWPE was reinforced by chemically treated MWCNTs at different concentrations such as 0.5, 1.0, 1.5, and 2.0 wt%. The test samples were then subjected to Co⁶⁰ gamma irradiation with an integral dose of 25, 50, 75 and 100 kGy in air. The mechanical properties of irradiated samples were evaluated within 10 days, 60 and 120 days after irradiation. It was observed that the mechanical properties of virgin UHMWPE and nanocomposites were enhanced immediately after irradiation but they were found to be reduced at later stages. It was also observed that the presence of MWCNTs limited the ageing degradation of the mechanical properties of UHMWPE. Raman spectroscopic and TEM studies confirmed the formation of irradiation induced defects on the MWCNTs. Electron spin resonance studies showed that the relative radical intensity of virgin UHWMPE was reduced significantly with an increase of MWCNTs concentration confirming the radical scavenging ability of them. It is concluded that MWCNTs restricted the ageing degradation of irradiated UHMWPE.

  19. Effect of gamma irradiation on microbial load and sensory characteristics of aniseed (Pimpinella anisum).

    PubMed

    Al-Bachir, M

    2007-07-01

    Seeds of anise (Pimpinella anisum) were exposed to doses of 0, 5, 10, 15 and 20kGy in a (60)Co package irradiator. Irradiated and unirradiated samples were stored at room temperature. Microbial populations on seeds, total and inorganic soluble solids in water extract and sensory properties of the latter were evaluated after 0, 6 and 12 months of storage. Results indicated that gamma irradiation reduced the aerobic plate counts of aniseed. Immediately after irradiation, the total soluble solids in an extract of irradiated seeds were greater than those of unirradiated ones. The total soluble solids in an extract of irradiated and un-irradiated seeds increased after 6 and 12 months of storage. There were no significant differences (p>0.05) in inorganic soluble solids between the water extract of irradiated and unirradiated aniseeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of aniseed water extract tested immediately after irradiation; however, after 12 months of storage, no significant differences (p>0.05) were found in color, taste or flavor between extract of irradiated and unirradiated seeds.

  20. Effect of gamma irradiation on chemical composition, antimicrobial and antioxidant activities of Thymus vulgaris and Mentha pulegium essential oils

    NASA Astrophysics Data System (ADS)

    Zantar, Said; Haouzi, Rachid; Chabbi, Mohamed; Laglaoui, Amin; Mouhib, Mohammed; Mohammed Boujnah; Bakkali, Mohammed; Zerrouk, Mounir Hassani

    2015-10-01

    The effects of gamma irradiation doses (10, 20 and 30 kGy) on chemical composition, antimicrobial and antioxidant activities of Thymus vulgaris and Mentha pulegium essential oils (EOs) have been studied. The chromatographic analysis showed that the studied EOs were constituted mainly by carvacrol for T. vulgaris and pulegone for M. pulegium. Gamma irradiation on the studied doses, affects quantitatively and not qualitatively some components of the investigated oils. This effect was dose dependent. While the antioxidant activity remains stable at any dose applied for the plants studied, the antimicrobial activity increased in the irradiated samples for gram negative bacteria and did not change for gram+bacteria. This study supports that gamma irradiation employed at sterilizing doses did not compromise the biological activities of medicinal and aromatic plants.

  1. Effects of gamma irradiation on chemical composition and antioxidant potential of processed samples of the wild mushroom Macrolepiota procera.

    PubMed

    Fernandes, Ângela; Barreira, João C M; Antonio, Amilcar L; Oliveira, M Beatriz P P; Martins, Anabela; Ferreira, Isabel C F R

    2014-04-15

    It was previously demonstrated that gamma irradiation was the processing technology with the highest capacity to maintain the chemical profile of fresh Macrolepiota procera wild mushroom, when compared to freeze-dried or oven-dried samples. Herein, it was aimed to evaluate gamma irradiation effects on processed samples. Chemical composition and antioxidant potential of irradiated (0.5 and 1 kGy) fresh, frozen and dried samples were determined by chromatographic techniques and in vitro assays, respectively. M. procera irradiation attenuated the effects caused by oven-drying or freezing; combining freeze treatment with 0.5 kGy dose preserved total tocopherols. Rather than a conservation methodology, gamma irradiation might act as a useful adjuvant to other conservation techniques (e.g., freezing or oven-drying).

  2. Application of gamma irradiation for aging control and improvement of shelf-life of kimchi, korean salted and fermented vegetables

    NASA Astrophysics Data System (ADS)

    Song, Hyun-Pa; Kim, Dong-Ho; Yook, Hong-Sun; Kim, Kyung-Soo; Kwon, Joong-Ho; Byun, Myung-Woo

    2004-09-01

    This study was carried out to evaluate the application of food irradiation as a method for extending shelf life of Kimchi. Gamma irradiation up to 10 kGy in the early stage of Kimchi fermentation had a dose-dependent effect on the inactivation of fermentative microbes, lowering the lactate dehydrogenase (LDH) activity and delaying acidification. Although gamma irradiation on the mid-fermentation stage of Kimchi inactivated the fermentative microbes effectively, LDH activity remained high and acidification continued. Kimchi irradiated at 10 kGy had lower scores in acceptability than those of control, 2.5 and 5 kGy irradiated. Therefore, gamma irradiation upto 5 kGy in the early fermentation stage is recommended for aging control and the improvement of shelf life of Kimchi.

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

    NASA Astrophysics Data System (ADS)

    Bhatti, Ijaz Ahmad; Adeel, Shahid; Fazal-ur-Rehman; Irshad, Misbah; Abbas, Muhammad

    2012-07-01

    The dyeing behaviour of mercerized and gamma irradiated cotton fabric using stilbene based direct dye has been investigated. The fabric was treated with different concentrations of alkali to optimize the mercerization. The optimum mercerized cotton fabric was irradiated to absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. Dyeing was performed using irradiated and un-irradiated cotton with dye solutions. The dyeing parameters such as temperature, time of dyeing, pH of dyeing solutions and salt concentration were optimized. The colour strength values of dyed fabrics were evaluated by comparing irradiated and un-irradiated cotton in CIE Lab system using Spectra flash SF650. Methods suggested by International Standard Organization (ISO) were employed to study the effect of gamma irradiation on the colourfastness properties of dyed fabric. It was found that mercerized and irradiated cotton have not only improved the colour strength but enhanced the rating of fastness properties also.

  4. Sensitization of the apoptotic effect of gamma-irradiation in genistein-pretreated CaSki cervical cancer cells.

    PubMed

    Shin, Jang-In; Shim, Jung-Hyun; Kim, Ki-Hong; Choi, Hee-Sook; Kim, Jae-Wha; Lee, Hee-Gu; Kim, Bo-Yeon; Park, Sue-Nie; Park, Ok-Jin; Yoon, Do-Young

    2008-03-01

    Radiotherapy is currently applied in the treatment of human cancers. We studied whether genistein would enhance the radiosensitivity and explored its precise molecular mechanism in cervical cancer cells. After co-treatment with genistein and irradiation, the viability, cell cycle analysis, and apoptosis signaling cascades were elucidated in CaSki cells. The viability was decreased by co-treatment with genistein and irradiation compared with irradiation treatment alone. Treatment with only gamma-irradiation led to cell cycle arrest at the G1 phase. On the other hand, co-treatment with genistein and gamma-irradiation caused a decrease in the G1 phase and a concomitant increase up to 56% in the number of G2 phase. In addition, cotreatment increased the expression of p53 and p21, and Cdc2- tyr-15-p, supporting the occurrence of G2/M arrest. In general, apoptosis signaling cascades were activated by the following events: release of cytochrome c, upregulation of Bax, downregulation of Bcl-2, and activation of caspase-3 and -8 in the treatment of genistein and irradiation. Apparently, co-treatment downregulated the transcripts of E6*I, E6*II, and E7. Genistein also stimulated irradiation-induced intracellular reactive oxygene, species (ROS) production, and co-treatment-induced apoptosis was inhibited by the antioxidant N-acetylcysteine, suggesting that apoptosis has occurred through the increase in ROS by genistein and gamma-irradiation in cervical cancer cells. Gamma-irradiation increased cyclooxygenase-1 (COX-2) expression, whereas the combination with genistein and gamma-irradiation almost completely prevented irradiation-induced COX-2 expression and PGE2 production. Co-treatment with genistein and gamma-irradiation inhibited proliferation through G2/M arrest and induced apoptosis via ROS modulation in the CaSki cancer cells.

  5. Low-Dose Gamma Irradiation of Decellularized Heart Valves Results in Tissue Injury in Vitro and in Vivo

    PubMed Central

    Helder, Meghana R. K.; Hennessy, Ryan S.; Spoon, Daniel B.; Tefft, Brandon J.; Witt, Tyra A.; Marler, Ronald J.; Pislaru, Sorin V.; Simari, Robert D.; Stulak, John M.; Lerman, Amir

    2017-01-01

    Background Decellularized heart valves are emerging as a potential alternative to current bioprostheses for valve replacement. While techniques of decellularization have been thoroughly examined, terminal sterilization techniques have not received the same scrutiny. Methods This study evaluated low dose gamma irradiation as a sterilization method for decellularized heart valves. Incubation of valves and transmission electron microscopy evaluation after different doses of gamma irradiation were used to determine the optimal dose of gamma irradiation. Quantitative evaluation of mechanical properties was done by tensile mechanical testing of isolated cusps. Sterilize decellularized heart valves were tested in a sheep model (n=3, 1 1,500 Gy and 2 3,000 Gy) of pulmonary valve replacement. Results Valves sterilized with gamma radiation between 1,000 Gy and 3,000 Gy were found to be optimal with in-vitro testing. However, with in-vivo showed deteriorating valve function within 2 months. On explant the valve with 1,500 Gy gamma irradiation showed signs of endocarditis with neutrophils on hematoxylin and eosin staining, positive gram stain resembling streptococcus infection. The 3,000 Gy valves had no evidence of infection, but the hematoxylin and eosin staining showed evidence of wound remodeling with macrophages and fibroblasts. Tensile strength testing showed decreased strength (0 Gy-2.53±0.98 MPa, 1,500 Gy-2.03±1.23 MPa, 3,000 Gy-1.26±0.90 MPa) with increasing levels of irradiation. Conclusions Low dose gamma irradiation does not maintain the mechanical integrity of valves and the balance between sterilization and damage may not be able to be achieved with gamma irradiation. Other methods of terminal sterilization must be pursued and evaluated. PMID:26453425

  6. Proteins Associated with Adaptation of Cultured Tobacco Cells to NaCl 1

    PubMed Central

    Singh, Narendra K.; Handa, Avtar K.; Hasegawa, Paul M.; Bressan, Ray A.

    1985-01-01

    Cultured tobacco cells (Nicotiana tabacum L. cv Wisconsin 38) adapted to grow in medium containing high levels of NaCl or polyethylene glycol (PEG) produce several new or enhanced polypeptide bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The intensities of some of the polypeptide bands (molecular weights of 58, 37, 35.5, 34, 26, 21, 19.5, and 18 kilodaltons) increase with increasing levels of NaCl adaptation, while the intensities of other polypeptide bands (54, 52, 17.5, and 16.5 kilodaltons) are reduced. Enhanced levels of 43- and 26-kilodalton polypeptides are present in both NaCl and PEG-induced water stress adapted cells but are not detectable in unadapted cells. In addition, PEG adapted cells have enhanced levels of 29-, 17.5-, 16.5-, and 11-kilodalton polypeptides and reduced levels of 58-, 54-, 52-, 37-, 35.5-, 34-, 21-, 19.5-, and 18-kilodalton polypeptide bands. Synthesis of 26-kilodalton polypeptide(s) occurs at two different periods during culture growth of NaCl adapted cells. Unadapted cells also incorporate 35S into a 26-kilodalton polypeptide during the later stage of culture growth beginning at midlog phase. The 26-kilodalton polypeptides from adapted and unadapted cells have similar partial proteolysis peptide maps and are immunologically cross-reactive. During adaptation to NaCl, unadapted cells synthesize and accumulate a major 26-kilodalton polypeptide, and the beginning of synthesis corresponds to the period of osmotic adjustment and culture growth. From our results, we suggest an involvement of the 26-kilodalton polypeptide in the adaptation of cultured tobacco cells to NaCl and water stress. Images Fig. 1 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 PMID:16664357

  7. Effect of gamma irradiation on physical characteristics of Jordanian durum wheat and quality of semolina and lasagna products

    NASA Astrophysics Data System (ADS)

    Azzeh, F. S.; Amr, A. S.

    2009-09-01

    This study was conducted to determine the effect of using varying gamma irradiation doses on the physiochemical and rheological properties of semolina and its products. Ash, protein and water content were not influenced with gamma irradiation, while falling number and fungi counts decreased with increasing irradiation dose. Irradiation adversely affected wet gluten at 5 kGy dose. Dough stability was deteriorated vigorously with increasing irradiation dose. Sensory evaluation showed that lasagna produced from 0.25- and 1 kGy-irradiated semolina did not show any significant differences as compared with the control sample.

  8. Hepatic progenitor cell lines from allyl alcohol-treated adult rats are derived from gamma-irradiated mouse STO cells.

    PubMed

    Zhang, Mingjun; Sell, Stewart; Leffert, Hyam L

    2003-01-01

    In attempts to recharacterize several markers of putative rat liver progenitor cells, single-stage reverse transcription-polymerase chain reaction (RT-PCR) analyses failed to confirm the reported immunochemical detection of albumin, alpha(1)-fetoprotein, and cytochrome P450-1A2 in the clonal line, 3(8)#21, and the cloned derivative, 3(8)#21-EGFP (enhanced green fluorescent protein). Undetectable expression occurred whether or not both lines were cultured on or off feeder layers of gamma-irradiated mouse embryonic STO (SIM [Sandoz inbred Swiss mouse] thioguanine-resistant ouabain-resistant) cells. PCR amplification of liver progenitor cell chromosomal (rat and mouse Pigr, rat INS1, mouse INS2) and mitochondrial (rat and mouse COX1) genes revealed only mouse sequences. Further analyses of rat and mouse COX1 sequences in cells from untampered storage vials of all 11 reported liver progenitor cell lines and strains revealed only mouse sequences. In addition, uniquely similar metaphase spreads were observed in STO, 3(8)#21, and 3(8)#21-EGFP cells. The combined results suggest that the previously reported "rat" liver progenitor cell lines were most likely generated during early derivation in cell culture from gamma-radiation-resistant or ineffectively irradiated mouse STO cells used as the feeder layers. These findings reveal new types of artifacts encountered in cocultures of tissue progenitor cells and feeder layer cell lines, and they sound a cautionary note: phenotypic and genotypic properties of feeder layers should be well-characterized before and during coculture with newly derived stem cells and clonal derivatives.

  9. Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere.

    PubMed

    Mallikharjuna Rao, K L N; Siva Raju, K; Ravisankar, H

    2016-01-01

    Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30°C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco.

  10. Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere

    PubMed Central

    Mallikharjuna Rao, K.L.N.; Siva Raju, K.; Ravisankar, H.

    2016-01-01

    Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30 °C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco. PMID:26887223

  11. Biochemical Basis of Resistance of Tobacco Callus Tissue Cultures to Hydroxyphenylethylamines.

    PubMed Central

    Negrel, J.; Javelle, F.; Paynot, M.

    1993-01-01

    It has been reported that hydroxyphenylethylamines, such as tyramine and octopamine, are toxic to tobacco (Nicotiana tabacum L.) callus cultures grown in the presence of auxins, whereas calli grown in the presence of cytokinins and crown gall cultures are resistant to these amines (P. Christou and K.A. Barton [1989] Plant Physiol 89: 564-568). In an attempt to understand the underlying mechanism of this resistance, we compared the fates of tyramine in tyramine-sensitive and tyramine-resistant tobacco tissue cultures (cv Xanthi nc). The very rapid formation of black-colored oxidation products from tyramine in sensitive tissues suggested that the toxicity might be caused by the oxidation of tyramine by phenol oxidases present in the tissues or released into the medium after subculture. This was confirmed through many indirect procedures (effect of exogenously added tyrosinase, induction of polyphenol oxidase [PPO] activity by auxin, etc.). The study of tyramine structure-activity relationships further suggested that the toxicity of tyramine might be due to the formation of indolequinones after oxidation by PPO. Subculture of calli grown on 2,4-dichlorophenoxyacetic acid in a medium containing benzyladenine triggered a slow decrease in PPO activity and dramatic increases in peroxidase and tyramine hydroxycinnamoyl transferase (THT) activities. THT was undetectable in calli grown on 2,4-dichlorophenoxyacetic acid but very active in tyramine-resistant crown gall cultures. Moreover, when [3H]tyramine was fed in vivo to tyramine-resistant tissues, it was rapidly integrated into cell walls in the wound periderm formed at the periphery of the calli. Both the conjugation of tyramine and its integration into cell walls could compete with the formation of toxic quinones and therefore play a part in the resistance. Thus, it seems likely that the control of the toxicity of hydroxyphenylethylamines by cytokinins results primarily from changes in the metabolism and the

  12. Metabolic Study of Breast MCF-7 Tumor Spheroids after Gamma Irradiation by 1H NMR Spectroscopy and Microimaging

    PubMed Central

    Palma, Alessandra; Grande, Sveva; Luciani, Anna Maria; Mlynárik, Vladimír; Guidoni, Laura; Viti, Vincenza; Rosi, Antonella

    2016-01-01

    Multicellular tumor spheroids are an important model system to investigate the response of tumor cells to radio- and chemotherapy. They share more properties with the original tumor than cells cultured as 2D monolayers do, which helps distinguish the intrinsic properties of monolayer cells from those induced during cell aggregation in 3D spheroids. The paper investigates some metabolic aspects of small tumor spheroids of breast cancer and their originating MCF-7 cells, grown as monolayer, by means of high–resolution (HR) 1H NMR spectroscopy and MR microimaging before and after gamma irradiation. The spectra of spheroids were characterized by higher intensity of mobile lipids, mostly neutral lipids, and glutamine (Gln) signals with respect to their monolayer cells counterpart, mainly owing to the lower oxygen supply in spheroids. Morphological changes of small spheroids after gamma-ray irradiation, such as loss of their regular shape, were observed by MR microimaging. Lipid signal intensity increased after irradiation, as evidenced in both MR localized spectra of the single spheroid and in HR NMR spectra of spheroid suspensions. Furthermore, the intense Gln signal from spectra of irradiated spheroids remained unchanged, while the low Gln signal observed in monolayer cells increased after irradiation. Similar results were observed in cells grown in hypoxic conditions. The different behavior of Gln in 2D monolayers and in 3D spheroids supports the hypothesis that a lower oxygen supply induces both an upregulation of Gln synthetase and a downregulation of glutaminases with the consequent increase in Gln content, as already observed under hypoxic conditions. The data herein indicate that 1H NMR spectroscopy can be a useful tool for monitoring cell response to different constraints. The use of spheroid suspensions seems to be a feasible alternative to localized spectroscopy since similar effects were found after radiation treatment. PMID:27200293

  13. Response of thyroid follicular cells to gamma irradiation compared to proton irradiation. I. Initial characterization of DNA damage, micronucleus formation, apoptosis, cell survival, and cell cycle phase redistribution

    NASA Technical Reports Server (NTRS)

    Green, L. M.; Murray, D. K.; Bant, A. M.; Kazarians, G.; Moyers, M. F.; Nelson, G. A.; Tran, D. T.

    2001-01-01

    The RBE of protons has been assumed to be equivalent to that of photons. The objective of this study was to determine whether radiation-induced DNA and chromosome damage, apoptosis, cell killing and cell cycling in organized epithelial cells was influenced by radiation quality. Thyroid-stimulating hormone-dependent Fischer rat thyroid cells, established as follicles, were exposed to gamma rays or proton beams delivered acutely over a range of physical doses. Gamma-irradiated cells were able to repair DNA damage relatively rapidly so that by 1 h postirradiation they had approximately 20% fewer exposed 3' ends than their counterparts that had been irradiated with proton beams. The persistence of free ends of DNA in the samples irradiated with the proton beam implies that either more initial breaks or a quantitatively different type of damage had occurred. These results were further supported by an increased frequency of chromosomal damage as measured by the presence of micronuclei. Proton-beam irradiation induced micronuclei at a rate of 2.4% per gray, which at 12 Gy translated to 40% more micronuclei than in comparable gamma-irradiated cultures. The higher rate of micronucleus formation and the presence of larger micronuclei in proton-irradiated cells was further evidence that a qualitatively more severe class of damage had been induced than was induced by gamma rays. Differences in the type of damage produced were detected in the apoptosis assay, wherein a significant lag in the induction of apoptosis occurred after gamma irradiation that did not occur with protons. The more immediate expression of apoptotic cells in the cultures irradiated with the proton beam suggests that the damage inflicted was more severe. Alternatively, the cell cycle checkpoint mechanisms required for recovery from such damage might not have been invoked. Differences based on radiation quality were also evident in the alpha components of cell survival curves (0.05 Gy(-1) for gamma rays, 0

  14. Enhancement of enzymatic hydrolysis of wheat straw by gamma irradiation-alkaline pretreatment

    NASA Astrophysics Data System (ADS)

    Yin, Yanan; Wang, Jianlong

    2016-06-01

    Pretreatment of wheat straw with gamma irradiation and NaOH was performed to enhance the enzymatic hydrolysis of wheat straw for production of reducing sugar. The results showed that the irradiation of wheat straw at 50 kGy decreased the yield of reducing sugar, however, the reducing sugar yield increased with increasing dose from 50 kGy to 400 kGy. The irradiation of wheat straw at 100 kGy can significantly decrease NaOH consumption and treatment time. The reducing sugar yield could reach 72.67% after irradiation at 100 kGy and 2% NaOH treatment for 1 h. The combined pretreatment of wheat straw by gamma radiation and NaOH immersion can increase the solubilization of hemicellulose and lignin as well as the accessible surface area for enzyme molecules.

  15. Sensory acceptability of squid rings gamma irradiated for shelf-life extension

    NASA Astrophysics Data System (ADS)

    Tomac, Alejandra; Cova, María C.; Narvaiz, Patricia; Yeannes, María I.

    2017-01-01

    The feasibility of extending the shelf-life of a squid product by gamma irradiation was analyzed. Illex argentinus rings were irradiated at 4 and 8 kGy; and stored at 4±1 °C during 77 days. No mesophilic bacteria, enterobacteriaceae and coliforms were detected in irradiated rings during storage. Psychrotrophic bacteria were significantly reduced by irradiation; their counts were fitted to a growth model which was further used for shelf-life estimations: 3 and 27 days for 0 and 4 kGy, respectively. Initially, non-irradiated as well as irradiated rings had very good sensory scores. The overall acceptability of 4 and 8 kGy rings did not decrease during 27 and 64 days, respectively, while control samples spoiled after 3 days. A radiation dose range for squid rings preservation was defined, which attained the technological shelf-life extension objective, without impairing sensory quality.

  16. Molecular weight changes induced in an anionic polydimethylsiloxane by gamma irradiation in vacuum

    NASA Astrophysics Data System (ADS)

    Satti, Angel J.; Andreucetti, Noemí A.; Ciolino, Andrés E.; Vitale, Cristian; Sarmoria, Claudia; Vallés, Enrique M.

    2010-11-01

    An anionic almost monodisperse linear polydimethylsiloxane (PDMS) was subjected to gamma irradiation under vacuum at room temperature. The molecular weight changes induced by the radiation process have been investigated using size exclusion chromatography (SEC) with refraction index (RI) and multi angle laser light scattering (MALLS) detectors, to obtain the number and weight average molecular weights of the irradiated samples. The analysis of the data indicates that crosslinking reactions predominated over scission reactions. The results obtained by an SEC-RI have confirmed the presence of small, but measurable amounts of scission. A previously developed mathematical model of the irradiation process that accounts for simultaneous scission and crosslinking and allows for both H- and Y-crosslinks, fitted well the measured molecular weight data. This prediction is in accordance with the experimental data obtained by 29Si-Nuclear Magnetic Resonance spectroscopy (NMR) and previously reported data for commercial linear PDMS ( Satti et al., 2008).

  17. Gamma irradiation induced disintegration of waste activated sludge for biological hydrogen production

    NASA Astrophysics Data System (ADS)

    Yin, Yanan; Wang, Jianlong

    2016-04-01

    In this paper, gamma irradiation was applied for the disintegration and dissolution of waste activated sludge produced during the biological wastewater treatment, and the solubilized sludge was used as substrate for bio-hydrogen production. The experimental results showed that the solubilization of waste activated sludge was 53.7% at 20 kGy and pH=12, and the SCOD, polysaccharides, protein, TN and TP contents in the irradiated sludge solutions was 3789.6 mg/L, 268.3 mg/L, 1881.5 mg/L, 132.3 mg/L and 80.4 mg/L, respectively. The irradiated sludge was used for fermentative hydrogen production, and the hydrogen yield was 10.5±0.7 mL/g SCODconsumed. It can be concluded that the irradiated waste activated sludge could be used as a low-cost substrate for fermentative hydrogen production.

  18. {gamma} Irradiation-induced degradation of organochlorinated pollutants in fatty esters and in Cod

    SciTech Connect

    Lepine, F.L.; Brochu, F.; Milot, S.

    1995-02-01

    The {gamma} irradiation-induced degradation of 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (DDT), 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (DDD), and 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) dissolved in methyl myristate and methyl oleate was studied. DDT and DDE produced DDD and 2,2-bis(4-chlorophenyl)chloroethylene (DDMU) respectively, in agreement with a previous study performed with aliphatic solvents. The degradation of these two former compounds was larger in methyl myristate than in methyl oleate and addition products between methyl myristate and the organochlorines were found. While DDD, DDE, and many PCB congeners in a cod sample were not measurably degraded at 15 KGy, DDT underwent 30% degradation. 9 refs., 1 fig., 2 tabs.

  19. Gamma irradiation assisted fungal degradation of the polypropylene/biomass composites

    NASA Astrophysics Data System (ADS)

    Butnaru, Elena; Darie-Niţă, Raluca Nicoleta; Zaharescu, Traian; Balaeş, Tiberius; Tănase, Cătălin; Hitruc, Gabriela; Doroftei, Florica; Vasile, Cornelia

    2016-08-01

    White-rot fungus Bjerkandera adusta has been tested for its ability to degrade some biocomposites materials based on polypropylene and biomass (Eucalyptus globulus, pine cones, and Brassica rapa). γ-irradiation was applied to initiate the degradation of relatively inert polypropylene matrix. The degradation process has been studied by scanning electron microscopy, atomic force microscopy, infrared spectroscopy, contact angle measurements, rheological and chemiluminescence tests. These analyses showed that the polypropylene/biomass composites properties are worsen under the action of the selected microorganism. The formation of cracks and scrap particles over the entire matrix surface and the decrease of the complex viscosity values, as well as the dynamic moduli of gamma irradiated PP/biomass composite and exposed to Bjerkandera adusta fungus, indicate fungal efficiency in composite degradation.

  20. Attempted protection of spermatogenesis from single doses of gamma-irradiation in the androgen pretreated rat.

    PubMed

    Schlappack, O K; Delic, J I; Harwood, J R; Stanley, J A

    1987-01-01

    Spermatogenic stem-cell survival after gamma-irradiation has been investigated in the adult Wistar rat. Single doses of 4.5 and 9 Gy gamma-rays were administered to the testes of rats who received arachis oil (0.1 ml/100 g body weight) or testosterone enanthate (240 micrograms/100 g body weight) subcutaneously three times weekly for 6 weeks prior to radiation and during the week in which the radiations were given. A mean percentage of regenerating seminiferous tubule cross-sections of 32.45% and 7.26% was found in the testes of androgen-pretreated rats at 8 weeks after 4.5 and 9 Gy, respectively. Similar values (33.4% and 6.2%) were obtained in arachis oil-pretreated controls. We therefore conclude that protection of rat spermatogenesis from single doses of gamma-rays cannot be achieved by androgen pretreatment.

  1. Kinetics of hardness evolution during annealing of gamma-irradiated polycarbonate

    SciTech Connect

    Yeh, S. H.; Chen, P. Y.; Lee, Sanboh; Harmon, Julie

    2012-12-01

    This study focuses on the evolution in microhardness values that accompany isothermal annealing in gamma-irradiated polycarbonate (PC). Hardness increases with increasing annealing time, temperature, and gamma radiation dose. A model composed of a mixture of first and zero order structure relaxation is proposed to interpret the hardness data. The rate constant data fit the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The extent of structural relaxation that controls the hardness in post-annealed PC increases with increasing annealing temperature and dose. The model demonstrates that hardness evolution in PC is an endothermic process. By contrast, when the model is applied to irradiated poly(methyl methacrylate) and hydroxyethyl methacrylate copolymer, hardness evolution is an exothermic process.

  2. Effect of gamma irradiation on physico-mechanical properties of spice packaging films

    NASA Astrophysics Data System (ADS)

    Mizani, Maryam; Sheikh, Nasrin; Ebrahimi, Samad N.; Gerami, Abas; Tavakoli, Farnaz A.

    2009-09-01

    Physico-mechanical properties of two types of laminated films, commercially used for spice packaging, are investigated after gamma irradiation at 8, 10 and 15 kGy. Data showed that polyethylene terephthalate/polyethylene terephthalate/linear low density polyethylene (PET/PET/LLDPE) was more resistant to radiation compared to biaxially oriented polypropylene/cast polypropylene (BOPP/CPP) and its barrier properties slightly improved up to 15 kGy. Oxygen transmission rate of BOPP/CPP was increased by 25%, and the melting peak temperature was decreased by 3.9% at 15 kGy, which may lead to oxidation of packaged spices and loss of their aroma/flavour, respectively.

  3. Effect of gamma-irradiation on the lipid profile of nutmeg (Myristica fragrans Houtt.).

    PubMed

    Niyas, Zareena; Variyar, Prasad S; Gholap, Achyut S; Sharma, Arun

    2003-10-22

    The effect of gamma-irradiation on the lipid constituents of nutmeg (Myristica fragrans) was examined at radiation doses between 2.5 and 10 kGy. The fatty acid composition of the triacylglycerol, the major lipid component, was found to be made up of myristic (90%), palmitic (6%), lauric (3%), petroselinic (0.13%), and stearic acids (0.5%) as determined by gas chromatography-mass spectrometry. A dose-dependent decrease in the triacylglycerol content and a concomitant increase in free fatty acids characterized the lipid profile of the irradiated spice. This suggested a breakdown of acylglycerols during radiation processing, resulting in the release of free fatty acids. These changes were found to be significant at doses above 5 kGy. The impact of the above changes on the flavor of the spice is discussed. These studies suggest that radiation processing of nutmeg should be limited to a dose of 5 kGy.

  4. EPR study of gamma irradiated DL-methionine sulfone single crystals

    NASA Astrophysics Data System (ADS)

    Karabulut, Bünyamin; Yıldırım, İlkay

    2015-12-01

    Electron paramagnetic resonance (EPR) study of gamma irradiated dl-2-amino-4-(Methylsulfonyl) butyric acid (dl-methionine sulfone, hereafter dl-ABA) single crystals and powder was performed at room temperature. It has been found that this compound indicates the existence of C. O2- and N. H2 radicals after γ-irradiation. While g and hyperfine splitting values for the N. H2 radical were observed, for the C. O2- radical, only the g factor was measured. The EPR spectra have shown that N. H2 radical has two groups each having two distinct sites and C. O2- radical has one site. The principal g and hyperfine values for all sites were analyzed.

  5. Combined effects of gamma-irradiation and modified atmosphere packaging on quality of some spices.

    PubMed

    Kirkin, Celale; Mitrevski, Blagoj; Gunes, Gurbuz; Marriott, Philip J

    2014-07-01

    Thyme (Thymus vidgaris L.), rosemary (Rosmarinus officinalis L.), black pepper (Piper nigrum L.) and cumin (Cuminum cyminum L.) in ground form were packaged in either air or 100% N2 and γ-irradiated at 3 different irradiation levels (7kGy, 12kGy, 17kGy). Total viable bacterial count, yeast and mould count, colour, essential oil yield and essential oil composition were determined. Microbial load was not detectable after 12kGy irradiation of all samples. Irradiation resulted in significant changes in colour values of rosemary and black pepper. The discolouration of the irradiated black pepper was lower in modified atmosphere packaging (MAP) compared to air packaging. Essential oil yield of irradiated black pepper and cumin was lower in air packaging compared to MAP. Gamma-irradiation generally decreased monoterpenes and increased oxygenated compounds, but the effect was lower in MAP. Overall, spices should be irradiated under an O2-free atmosphere to minimise quality deterioration.

  6. Facile Synthesis of Silver Nanoparticles Under {gamma}-Irradiation: Effect of Chitosan Concentration

    SciTech Connect

    Huang, N. M.; Radiman, S.; Ahmad, A.; Idris, H.; Lim, H. N.; Khiew, P. S.; Chiu, W. S.; Tan, T. K.

    2009-06-01

    In the present study, a biopolymer, low molecular weight chitosan had been utilized as a 'green' stabilizing agent for the synthesis of silver nanoparticles under {gamma}-irradiation. The as-synthesized silver nanoparticles have particle diameters in the range of 5 nm-30 nm depending on the percentage of chitosan used (0.1 wt%, 0.5 wt%, 1.0 wt% and 2.0 wt%). It was found that the yield of the silver nanoparticles was in accordance with the concentration of chitosan presence in the solution due to the reduction by the chitosan radical during irradiation. The highly stable chitosan encapsulated silver nanoparticles were characterized using transmission electron microscopy (TEM), UV-Visible spectrophotometer (UV-VIS) and X-ray diffraction spectroscopy (XRD)

  7. Influence of {gamma} irradiation on the optical and mechanical properties of langasite

    SciTech Connect

    Burkov, V. I.; Pisarevskii, Yu. V. Sizova, N. L.; Fedotov, E. V.; Mill', B. V.

    2007-07-15

    The optical (transmission and circular dichroism) spectra and mechanical (Vickers microhardness and fracture toughness K{sub 1c}) properties of langasite La{sub 3}Ga{sub 5}SiO{sub 14} crystals have been studied after {gamma} irradiation and exposure for a month. It is shown that, as a result of irradiation crystals become more transparent in the range 310-640 nm, nonstructural defects with the energies of excited states in the range 2.06-4.13 eV decay and new structural defects with the excited-state energies in the range 4.14-5.00 eV are formed. Irradiation does not lead to a change in microhardness, while the coefficient K{sub 1c} increases from 0.32 to 0.36 MPa m{sup 1/2}.

  8. Antioxidant activities of fucoidan degraded by gamma irradiation and acidic hydrolysis

    NASA Astrophysics Data System (ADS)

    Lim, Sangyong; Choi, Jong-il; Park, Hyun

    2015-04-01

    Low molecular weight fucoidan, prepared by radical degradation using gamma ray was investigated for its antioxidant activities with different assay methods. As the molecular weight of fucoidan decreased with a higher absorbed dose, ferric-reducing antioxidant power values increased, but β-carotene bleaching inhibition did not change significantly. The antioxidant activity of acid-degraded fucoidan was also examined to investigate the effect of different degradation methods. At the same molecular weight, fucoidan degraded by gamma irradiation showed higher 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity than that observed with the acidic method. This result reveals that in addition to molecular weight, the degradation method affects the antioxidant activity of fucoidan.

  9. Gamma-irradiation tests of IR optical fibres for ITER thermography--a case study

    SciTech Connect

    Reichle, R.; Pocheau, C.; Jouve, M.

    2008-03-12

    In the course of the development of a concept for a spectrally resolving infrared thermography diagnostic for the ITER divertor we have tested 3 types of infrared (IR) fibres in Co{sup 60} irradiation facilities under {gamma} irradiation. The fibres were ZrF{sub 4} (and HfF{sub 4}) fibres from different manufacturers, hollow fibres (silica capillaries with internal Ag/AgJ coating) and a sapphire fibre. For the IR range, only the latter fibre type encourages to go further for neutron tests in a reactor. If one restricted the interest onto the near infrared range, high purity core silica fibres could be used. This study might be seen as a typical example of the relation between diagnostic development for a nuclear environment and irradiation experiments.

  10. Influence of gamma irradiation on structural, thermal and antibacterial properties of HPMC/ZnO nanocomposites

    NASA Astrophysics Data System (ADS)

    Rao, B. Lakshmeesha; Madhukumar, R.; Latha, S.; Shetty, G. Rajesha; Shivananda, C. S.; Chandra, K. Sharath; Sangappa, Y.

    2016-05-01

    This work was carried out to evaluate the effect of gamma irradiation on the structural, thermal and antibacterial properties of HPMC/ZnO nanocomposite films exposed to Cobalt-60 (Average energy: 1.25MeV). The X-ray diffraction study revealed that the crystallite size (L in Å) decreased as irradiation dose increased. The crystallinity (Xc) of the nanocomposites initially increased and at higher doses it was decreased. The thermal stability of the nanocomposites increased up to 50 kGy and after that decreased as the irradiation dose increased. But, HPMC/ZnO nanocomposite films, showed a promising range of antimicrobial activity against tested micro-organisms making nanocomposites suitable for food packing and other biomedical applications.

  11. Improvement of plant parameters of the ROBO gamma irradiation facility due to design modification

    NASA Astrophysics Data System (ADS)

    Kovacs, A.; Moussa, A.; Othman, I.; Del Valle Odar, C.; Seminario, A.; Linares, M.; Huamanlazo, P.; Aymar, J.; Chu, R.

    1998-06-01

    Two industrial scale, "ROBO" type 60Co gamma irradiation facilities have recently been put into operation in Syria and Peru, and the dosimetry commissioning of both plants have been carried out to determine dose distribution within products and to calculate plant parameters such as efficiency, dose uniformity ratio and throughput. There are some design modifications between the two plants in connection with the location of the carriers with respect to the source plaque and also to each other. The effect of these construction modifications on the plant parameters is discussed in the analysis of the dose distribution data measured in the carriers with depth and height among the four irradiation rows on both sides of the source plaque. The plant parameters were also calculated for different product densities using the technical data of the facilities, and the calculated and measured results were compared to each other.

  12. TL and ESR based identification of gamma-irradiated frozen fish using different hydrolysis techniques

    NASA Astrophysics Data System (ADS)

    Ahn, Jae-Jun; Akram, Kashif; Shahbaz, Hafiz Muhammad; Kwon, Joong-Ho

    2014-12-01

    Frozen fish fillets (walleye Pollack and Japanese Spanish mackerel) were selected as samples for irradiation (0-10 kGy) detection trials using different hydrolysis methods. Photostimulated luminescence (PSL)-based screening analysis for gamma-irradiated frozen fillets showed low sensitivity due to limited silicate mineral contents on the samples. Same limitations were found in the thermoluminescence (TL) analysis on mineral samples isolated by density separation method. However, acid (HCl) and alkali (KOH) hydrolysis methods were effective in getting enough minerals to carry out TL analysis, which was reconfirmed through the normalization step by calculating the TL ratios (TL1/TL2). For improved electron spin resonance (ESR) analysis, alkali and enzyme (alcalase) hydrolysis methods were compared in separating minute-bone fractions. The enzymatic method provided more clear radiation-specific hydroxyapatite radicals than that of the alkaline method. Different hydrolysis methods could extend the application of TL and ESR techniques in identifying the irradiation history of frozen fish fillets.

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

    NASA Astrophysics Data System (ADS)

    Al-Bachir, M.; Al-Adawi, M. A.; Al-Kaid, A.

    2004-03-01

    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.

  14. Lymphoid cell kinetics under continuous low dose-rate gamma irradiation: A comparison study

    NASA Technical Reports Server (NTRS)

    Foster, B. R.

    1975-01-01

    A comparison study was conducted of the effects of continuous low dose-rate gamma irradiation on cell population kinetics of lymphoid tissue (white pulp) of the mouse spleen with findings as they relate to the mouse thymus. Experimental techniques employed included autoradiography and specific labeling with tritiated thymidine (TdR-(h-3)). The problem studied involved the mechanism of cell proliferation of lymphoid tissue of the mouse spleen and thymus under the stress of continuous irradiation at a dose rate of 10 roentgens (R) per day for 105 days (15 weeks). The aim was to determine whether or not a steady state or near-steady state of cell population could be established for this period of time, and what compensatory mechanisms of cell population were involved.

  15. ESR study of some gamma irradiated amino acids and condensed 1,4-dihydropyridines

    NASA Astrophysics Data System (ADS)

    Aydın, Murat; Şimşek, Rahime; Gündüz, Miyase Gözde; Şafak, Cihat; Osmanoğlu, Y. Emre

    2013-03-01

    L-alanine methyl ester hydrochloride, 2-aminoisobutyric acid and some condensed 1,4-dihydropyridine derivatives (Compounds R1-R4) were gamma irradiated, the induced free radicals was investigated at room temperature by electron spin resonance techniques. The observed paramagnetic species of amino acids compounds were attributed to the CH3ĊHCOOCH3 and (CH3)2ĊCOOH radicals, respectively. The observed spectra of the 1,4-dihydropyridine derivatives interpreted in terms of some type of amine radical fragments. The spectra were computer simulated and the g values of the radicals and the hyperfine structure constants of the unpaired electron with nearby protons and 14N nucleus were determined. In this study, the observed paramagnetic species were found to be stable at room temperature more than 2 months.

  16. 3-D nasal cultures: Systems toxicological assessment of a candidate modified-risk tobacco product.

    PubMed

    Iskandar, Anita R; Mathis, Carole; Martin, Florian; Leroy, Patrice; Sewer, Alain; Majeed, Shoaib; Kuehn, Diana; Trivedi, Keyur; Grandolfo, Davide; Cabanski, Maciej; Guedj, Emmanuel; Merg, Celine; Frentzel, Stefan; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

    2017-01-01

    In vitro toxicology approaches have evolved from a focus on molecular changes within a cell to understanding of toxicity-related mechanisms in systems that can mimic the in vivo environment. The recent development of three dimensional (3-D) organotypic nasal epithelial culture models offers a physiologically robust system for studying the effects of exposure through inhalation. Exposure to cigarette smoke (CS) is associated with nasal inflammation; thus, the nasal epithelium is relevant for evaluating the pathophysiological impact of CS exposure. The present study investigated further the application of in vitro human 3-D nasal epithelial culture models for toxicological assessment of inhalation exposure. Aligned with 3Rs strategy, this study aimed to explore the relevance of a human 3-D nasal culture model to assess the toxicological impact of aerosols generated from a candidate modified risk tobacco product (cMRTP), the Tobacco Heating System (THS) 2.2, as compared with smoke generated from reference cigarette 3R4F. A series of experimental repetitions, where multiple concentrations of THS2.2 aerosol and 3R4F smoke were applied, were conducted to obtain reproducible measurements to understand the cellular/molecular changes that occur following exposure. In agreement with "Toxicity Testing in the 21st Century - a Vision and a Strategy", this study implemented a systems toxicology approach and found that for all tested concentrations the impact of 3R4F smoke was substantially greater than that of THS2.2 aerosol in terms of cytotoxicity levels, alterations in tissue morphology, secretion of pro-inflammatory mediators, impaired ciliary function, and increased perturbed transcriptomes and miRNA expression profiles.

  17. Stimulatory Effects of Gamma Irradiation on Phytochemical Properties, Mitotic Behaviour, and Nutritional Composition of Sainfoin (Onobrychis viciifolia Scop.)

    PubMed Central

    Mat Taha, Rosna; Lay, Ma Ma; Khalili, Mahsa

    2014-01-01

    Sainfoin (Onobrychis viciifolia Scop. Syn. Onobrychis sativa L.) is a bloat-safe forage crop with high levels of tannins, which is renowned for its medicinal qualities in grazing animals. Mutagenesis technique was applied to investigate the influence of gamma irradiation at 30, 60, 90, and 120 Gy on mitotic behavior, in vitro growth factors, phytochemical and nutritional constituents of sainfoin. Although a percentage of plant necrosis and non-growing seed were enhanced by irradiation increment, the germination speed was significantly decreased. It was observed that gamma irradiated seeds had higher value of crude protein and dry matter digestibility compared to control seeds. Toxicity of copper was reduced in sainfoin irradiated seeds at different doses of gamma rays. Anthocyanin content also decreased in inverse proportion to irradiation intensity. Accumulation of phenolic and flavonoid compounds was enhanced by gamma irradiation exposure in leaf cells. HPLC profiles differed in peak areas of the two important alkaloids, Berberine and Sanguinarine, in 120 Gy irradiated seeds compared to control seeds. There were positive correlations between irradiation dose and some abnormality divisions such as laggard chromosome, micronucleus, binucleated cells, chromosome bridge, and cytomixis. In reality, radiocytological evaluation was proven to be essential in deducing the effectiveness of gamma irradiation to induce somaclonal variation in sainfoin. PMID:25147870

  18. Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy.

    PubMed

    Jovanović, Svetlana P; Syrgiannis, Zois; Marković, Zoran M; Bonasera, Aurelio; Kepić, Dejan P; Budimir, Milica D; Milivojević, Dušan D; Spasojević, Vuk D; Dramićanin, Miroslav D; Pavlović, Vladimir B; Todorović Marković, Biljana M

    2015-11-25

    Herein, the ability of gamma irradiation to enhance the photoluminescence properties of graphene quantum dots (GQDs) was investigated. Different doses of γ-irradiation were used on GQDs to examine the way in which their structure and optical properties can be affected. The photoluminescence quantum yield was increased six times for the GQDs irradiated with high doses compared to the nonirradiated material. Both photoluminescence lifetime and values of optical band gap were increased with the dose of applied gamma irradiation. In addition, the exploitation of the gamma-irradiated GQDs as photosensitizers was examined by monitoring the production of singlet oxygen under UV illumination. The main outcome was that the GQDs irradiated at lower doses act as better photoproducers than the ones irradiated at higher doses. These results corroborate that the structural changes caused by gamma irradiation have a direct impact on GQD ability to produce singlet oxygen and their photostability under prolonged UV illumination. This makes low-dose irradiated GQDs promising candidates for photodynamic therapy.

  19. Optical study of gamma irradiated sodium metaphosphate glasses containing divalent metal oxide MO (ZnO or CdO)

    NASA Astrophysics Data System (ADS)

    Nabhan, E.; Abd-Allah, W. M.; Ezz-El-Din, F. M.

    Sodium metaphosphate glasses containing divalent metal oxide, ZnO or CdO with composition 50 P2O5 - (50 - x) Na2O - x MO (ZnO, or CdO) where x = 0, 10, 20 (mol%) were prepared by conventional melt method. UV/visible spectroscopy and FTIR spectroscopy are measured before and after exposing to successive gamma irradiation doses (5-80 kGy). The optical absorption spectra results of the samples before irradiation reveal a strong UV absorption band at (∼230 nm) which is related to unavoided iron impurities. The effects of gamma irradiation on the optical spectral properties of the various glasses have been compared. From the optical absorption spectral data, the optical band gap is evaluated. The main structural groups and the influence of both divalent metal oxide and gamma irradiation effect on the structural vibrational groups are realized through IR spectroscopy. The FTIR spectra of γ-irradiated samples are characterized by the stability of the number and position for the main characteristic band of phosphate groups. To better understood the structural changes during γ-irradiation, a deconvolution of FTIR spectra in the range 650-1450 cm-1 is made. The FTIR deconvolution results found evidence that, the changes occurring after gamma irradiation have been related to irradiation induced structural defects and compositional changes.

  20. Gamma irradiation as a biological decontaminant and its effect on common fingermark detection techniques and DNA profiling.

    PubMed

    Hoile, Rebecca; Banos, Connie; Colella, Michael; Walsh, Simon J; Roux, Claude

    2010-01-01

    The use of disease-causing organisms and their toxins against the civilian population has defined bioterrorism and opened forensic science up to the challenges of processing contaminated evidence. This study sought to determine the use of gamma irradiation as an effective biological decontaminant and its effect on the recovery of latent fingermarks from both porous and nonporous items. Test items were contaminated with viable spores marked with latent prints and then decontaminated using a cobalt 60 gamma irradiator. Fingermark detection was the focus with standard methods including 1,2-indanedione, ninhydrin, diazafluoren-9-one, and physical developer used during this study. DNA recovery using 20% Chelex extraction and quantitative real-time polymerase chain reaction was also explored. Gamma irradiation proved effective as a bacterial decontaminant with D-values ranging from 458 to 500 Gy for nonporous items and 797-808 Gy for porous ones. The results demonstrated the successful recovery of latent marks and DNA establishing gamma irradiation as a viable decontamination option.

  1. Effect of gamma irradiation on Schottky-contacted vertically aligned ZnO nanorod-based hydrogen sensor

    NASA Astrophysics Data System (ADS)

    Ranwa, Sapana; Singh Barala, Surendra; Fanetti, Mattia; Kumar, Mahesh

    2016-08-01

    We report the impact of gamma irradiation on the performance of a gold Schottky-contacted ZnO nanorod-based hydrogen sensor. RF-sputtered vertically aligned highly c-axis-oriented ZnO NRs were grown on Si(100) substrate. X-ray diffraction shows no significant change in crystal structure at low gamma doses from 1 to 5 kGy. As gamma irradiation doses increase to 10 kGy, the single crystalline ZnO structure converts to polycrystalline. The photoluminescence spectra also shows suppression of the near-band emission peak and the huge wide-band spectrum indicates the generation of structural defects at high gamma doses. At 1 kGy, the hydrogen sensor response was enhanced from 67% to 77% for 1% hydrogen in pure argon at a 150 °C operating temperature. However, at 10 kGy, the relative response decreases to 33.5%. High gamma irradiation causes displacement damage and defects in ZnO NRs, and as a result, degrades the sensor’s performance as a result. Low gamma irradiation doses activate the ZnO NR surface through ionization, which enhances the sensor performance. The relative response of the hydrogen sensor was enhanced by ∼14.9% with respect to pristine ZnO using 1 kGy gamma ray treatment.

  2. Effects of gamma irradiation on physicochemical properties, antioxidant and microbial activities of sour cherry juice

    NASA Astrophysics Data System (ADS)

    Arjeh, Edris; Barzegar, Mohsen; Ali Sahari, Mohammad

    2015-09-01

    Recently, due to the beneficial effects of bioactive compounds, demand for minimally processed fruits and fruit juices has increased rapidly in the world. In this study, sour cherry juice (SCJ) was exposed to gamma irradiation at 0.0, 0.5, 1.5, 3.0, 4.5, and 6.0 kGy and then stored at 4 °C for 60 days. Total soluble solids (TSS), total acidity (TA), color, total phenolic content (TPC), total monomeric anthocyanin content (TMC), antioxidant activity, organic acid profile, and microbial analysis were evaluated at regular intervals during the storage. Results indicated that irradiation did not have any significant effect on TSS, while level of TA increased significantly at the dose of 6 kGy (p<0.05). Furthermore, irradiation treatment and storage time led to a significant increase in L* and b* values and a decrease in a* values. Total monomeric anthocyanin content of the irradiated SCJ was lower than that of the non-irradiated one (24% at 3.0 kGy) and also changed toward a more negative direction during the storage (63% at 3.0 kGy for 60 days). There was a significant decrease in the antioxidant activity (DPPH radical scavenging and FRAP assay) in both irradiated and stored SCJs. After irradiation (0-6 kGy), the results showed that the concentration of malic and oxalic acid significantly increased; but, the concentration of ascorbic, citric, fumaric, and succinic acids significantly decreased. Gamma irradiation with doses of ≥3 kGy resulted in overall reduction in microbial loads. Based on the results obtained from the changes of physicochemical properties, antioxidant activity, and microbial analysis, irradiation of SCJ at doses of higher than 3.0 kGy is not recommended.

  3. Royal jelly modulates oxidative stress and tissue injury in gamma irradiated male Wister Albino rats

    PubMed Central

    Azab, Khaled Shaaban; Bashandy, Mohamed; Salem, Mahmoud; Ahmed, Osama; Tawfik, Zaki; Helal, Hamed

    2011-01-01

    Background: Royal jelly is a nutritive secretion produced by the worker bees, rich in proteins, carbohydrates, vitamins and minerals. Aim: The present study was designed to determine the possible protective effects of royal jelly against radiation induced oxidative stress, hematological, biochemical and histological alterations in male Wister albino rats. Materials and Methods: Male Wister albino rats were exposed to a fractionated dose of gamma radiation (2 Gy every 3 days up to 8 Gy total doses). Royal jelly was administrated (g/Kg/day) by gavages 14 days before exposure to the 1st radiation fraction and the treatment was continued for 15 days after the 1st irradiation fraction till the end of the experiment. The rats were sacrificed 3rd, equivalent to 3rd post 2nd irradiation fraction, and equivalent to 3rd day post last irradiation fraction. Results: In the present study, gamma- irradiation induced hematological, biochemical and histological effects in male Wister albino rats. In royal jelly treated irradiated group, there was a noticeable decrease recorded in thiobarbituric reactive substances concentration when compared to γ-irradiated group. Also, the serum nitric oxide concentration was significantly improved. The administration of royal jelly to irradiated rats according to the current experimental design significantly ameliorates the changes induced in serum lipid profile. Moreover, in royal jelly treated irradiated group, there was a noticeable amelioration recorded in all hematological parameters along the three experimental intervals. The microscopic examination of cardiac muscle of royal jelly treated irradiated rats demonstrated structural amelioration, improved nuclei and normal features of capillaries and veins in endomysium when compared to gamma-irradiated rats. Conclusion: It was suggested that the biochemical, hematological and histological amelioration observed in royal jelly (g/Kg/day) treated irradiated rats might be due to the antioxidant

  4. Chemical, sensory and microbiological changes of gamma irradiated coconut cream powder

    NASA Astrophysics Data System (ADS)

    Yusof, Norimah; Ramli, Ros Anita Ahmad; Ali, Foziah

    2007-11-01

    A study was carried out to determine optimum decontamination dose for a locally manufactured coconut cream powder. Samples were gamma irradiated (0-15 kGy) and ageing process was achieved using GEER oven at 60 °C for 7 days, which is equivalent to one-year storage at room temperature. Iodine value (IV), ranging from 4.8 to 6.4, was not affected by radiation doses and storage, however peroxide value and thiobarbituric acid (TBA) generally increased with radiation doses. In most samples, peroxide value (meq/kg) reduced after storage, whilst the TBA (mg malonaldehyde/kg), indicator for product quality, slightly increased. The sensory evaluation conducted using 25 taste panellists indicated that scores on odour, creamy taste and overall acceptance for all irradiated samples at more than 5 kGy were significantly lower ( P<0.05) than the control. However, the panellists could not detect any significant differences among the irradiation doses ( P>0.05). All stored products were significantly different in colour, creamy taste, odour and overall acceptance ( P<0.05) when compared to the non-stored non-irradiated control. Microbiological count of the samples prior to irradiation was in the range of 1×10 2-1.7×10 3 cfu/g with no detection of Salmonella sp. and Escherichia coli. No microbial colonies were detected after irradiation. Based on the TBA and overall sensory acceptance, gamma irradiation of 5 kGy was found to be the optimum dose and lower doses can be considered to decontaminate coconut cream powder.

  5. Gamma Irradiation of Active Self-healing PLGA Microspheres for Efficient Aqueous Encapsulation of Vaccine Antigens

    PubMed Central

    Desai, Kashappa-Goud H.; Kadous, Samer; Schwendeman, Steven P.

    2013-01-01

    Purpose To investigate the effect of γ-irradiation of poly(lactic-co-glycolic acid) (PLGA)/Al(OH)3/0 or 5 wt% diethyl phthalate (DEP) microspheres for active self-healing encapsulation of vaccine antigens. Methods Microspheres were irradiated with 60Co at 2.5 and 1.8 MRad and 0.37 and 0.20 MRad/h. Encapsulation of tetanus toxoid (TT) was achieved by mixing Al(OH)3-PLGA microspheres with TT solution at 10-38°C. Electron paramagnetic resonance (EPR) spectroscopy was used to examine free radical formation. Glass transition temperature (Tg) and molecular weight of PLGA was measured by differential scanning calorimetry and gel permeation chromatography, respectively. Loading and release of TT were examined by modified Bradford, amino acid analysis, and ELISA assays. Results EPR spectroscopy results indicated absence of free radicals in PLGA microspheres after γ-irradiation. Antigen-sorbing capacity, encapsulation efficiency, and Tg of the polymer were also not adversely affected. When DEP-loaded microspheres were irradiated at 0.2 MRad/h, some PLGA pores healed during irradiation and PLGA healing during encapsulation was suppressed. The molecular weight of PLGA was slightly reduced when DEP-loaded microspheres were irradiated at the same dose rate. These trends were not observed at 0.37 MRad/h. Gamma irradiation slightly increased TT initial burst release. Apart from the slightly higher polymer molecular weight decline caused by higher irradiation dose in case of DEP-loaded microspheres, the small increase in total irradiation dose from 1.8 to 2.5 MRad had insignificant effect on the polymer and microspheres properties analyzed. Conclusion Gamma irradiation is a plausible approach to provide a terminally sterilized, self-healing encapsulation PLGA excipient for vaccine delivery. PMID:23515830

  6. Dystrophic changes in extraocular muscles after gamma irradiation in mdx:utrophin(+/-) mice.

    PubMed

    McDonald, Abby A; Kunz, Matthew D; McLoon, Linda K

    2014-01-01

    Extraocular muscles (EOM) have a strikingly different disease profile than limb skeletal muscles. It has long been known that they are spared in Duchenne (DMD) and other forms of muscular dystrophy. Despite many studies, the cause for this sparing is not understood. We have proposed that differences in myogenic precursor cell properties in EOM maintain normal morphology over the lifetime of individuals with DMD due to either greater proliferative potential or greater resistance to injury. This hypothesis was tested by exposing wild type and mdx:utrophin(+/-) (het) mouse EOM and limb skeletal muscles to 18 Gy gamma irradiation, a dose known to inhibit satellite cell proliferation in limb muscles. As expected, over time het limb skeletal muscles displayed reduced central nucleation mirrored by a reduction in Pax7-positive cells, demonstrating a significant loss in regenerative potential. In contrast, in the first month post-irradiation in the het EOM, myofiber cross-sectional areas first decreased, then increased, but ultimately returned to normal compared to non-irradiated het EOM. Central nucleation significantly increased in the first post-irradiation month, resembling the dystrophic limb phenotype. This correlated with decreased EECD34 stem cells and a concomitant increase and subsequent return to normalcy of both Pax7 and Pitx2-positive cell density. By two months, normal het EOM morphology returned. It appears that irradiation disrupts the normal method of EOM remodeling, which react paradoxically to produce increased numbers of myogenic precursor cells. This suggests that the EOM contain myogenic precursor cell types resistant to 18 Gy gamma irradiation, allowing return to normal morphology 2 months post-irradiation. This supports our hypothesis that ongoing proliferation of specialized regenerative populations in the het EOM actively maintains normal EOM morphology in DMD. Ongoing studies are working to define the differences in the myogenic precursor cells

  7. Assessment of Cultivation Factors that Affect Biomass and Geraniol Production in Transgenic Tobacco Cell Suspension Cultures

    PubMed Central

    Vasilev, Nikolay; Schmitz, Christian; Grömping, Ulrike; Fischer, Rainer; Schillberg, Stefan

    2014-01-01

    A large-scale statistical experimental design was used to determine essential cultivation parameters that affect biomass accumulation and geraniol production in transgenic tobacco (Nicotiana tabacum cv. Samsun NN) cell suspension cultures. The carbohydrate source played a major role in determining the geraniol yield and factors such as filling volume, inoculum size and light were less important. Sucrose, filling volume and inoculum size had a positive effect on geraniol yield by boosting growth of plant cell cultures whereas illumination of the cultures stimulated the geraniol biosynthesis. We also found that the carbohydrates sucrose and mannitol showed polarizing effects on biomass and geraniol accumulation. Factors such as shaking frequency, the presence of conditioned medium and solubilizers had minor influence on both plant cell growth and geraniol content. When cells were cultivated under the screened conditions for all the investigated factors, the cultures produced ∼5.2 mg/l geraniol after 12 days of cultivation in shaking flasks which is comparable to the yield obtained in microbial expression systems. Our data suggest that industrial experimental designs based on orthogonal arrays are suitable for the selection of initial cultivation parameters prior to the essential medium optimization steps. Such designs are particularly beneficial in the early optimization steps when many factors must be screened, increasing the statistical power of the experiments without increasing the demand on time and resources. PMID:25117009

  8. Evaluation of the Effect of a Gamma Irradiated DBM-Pluronic F127 Composite on Bone Regeneration in Wistar Rat

    PubMed Central

    Canciani, Barbara; Losi, Paola; Tripodi, Maria; Burchielli, Silvia; Ottoni, Priscilla; Salvadori, Piero Antonio; Soldani, Giorgio

    2015-01-01

    Demineralized bone matrix (DBM) is widely used for bone regeneration. Since DBM is prepared in powder form its handling properties are not optimal and limit the clinical use of this material. Various synthetic and biological carriers have been used to enhance the DBM handling. In this study we evaluated the effect of gamma irradiation on the physical-chemical properties of Pluronic and on bone morphogenetic proteins (BMPs) amount in DBM samples. In vivo studies were carried out to investigate the effect on bone regeneration of a gamma irradiated DBM-Pluronic F127 (DBM-PF127) composite implanted in the femur of rats. Gamma irradiation effects (25 kGy) on physical-chemical properties of Pluronic F127 were investigated by rheological and infrared analysis. The BMP-2/BMP-7 amount after DBM irradiation was evaluated by ELISA. Bone regeneration capacity of DBM-PF127 containing 40% (w/w) of DBM was investigated in transcortical holes created in the femoral diaphysis of Wistar rat. Bone porosity, repaired bone volume and tissue organization were evaluated at 15, 30 and 90 days by Micro-CT and histological analysis. The results showed that gamma irradiation did not induce significant modification on physical-chemical properties of Pluronic, while a decrease in BMP-2/BMP-7 amount was evidenced in sterilized DBM. Micro-CT and histological evaluation at day 15 post-implantation revealed an interconnected trabeculae network in medullar cavity and cellular infiltration and vascularization of DBM-PF127 residue. In contrast a large rate of not connected trabeculae was observed in Pluronic filled and unfilled defects. At 30 and 90 days the DBM-PF127 samples shown comparable results in term of density and thickness of the new formed tissue respect to unfilled defect. In conclusion a gamma irradiated DBM-PF127 composite, although it may have undergone a significant decrease in the concentration of BMPs, was able to maintains bone regeneration capability. PMID:25897753

  9. Bioconversion of the antihistaminc drug loratadine by tobacco cell suspension cultures expressing human cytochrome P450 3A4.

    PubMed

    Warzecha, Heribert; Ferme, Daniela; Peer, Markus; Frank, Andreas; Unger, Matthias

    2010-03-01

    In this study we have expanded the metabolic potential of plant cell suspension cultures by introducing active human cytochrome P450 monooxygenase 3A4 into tobacco cells. Exogenously supplied loratadine was metabolized in a 3A4-specific manner, showing the capacity of this system for the generation of metabolites.

  10. Response of tobacco tissue cultures growing in contact with lunar fines.

    NASA Technical Reports Server (NTRS)

    Weete, J. D.; Walkinshaw, C. H.; Laseter, J. L.

    1973-01-01

    During the quarantine periods following each Apollo mission to the moon, various biological systems were placed in the presence of lunar material to determine if pathogenic agents were present. Although no detrimental effects resulted, various responses by the several plant systems tested were noted. One such response was the increased pigmentation observed in the callus tissue cultures of tobacco. Further investigations revealed that these tissues grown in the presence of lunar material resulted in as much as a 35% increase in total pigments while differences in fatty acid and sterol concentrations were also noted when compared to the controls. It is believed that these changes brought about by the lunar material can be attributed to a change in the nutritional environment caused by its dissolution.

  11. Drying and irradiation of calf and horse serum. I. Influence on the growth of cell cultures and mycoplasmas.

    PubMed

    Veber, P; Jurmanová, K; Lesko, J; Hána, L

    1975-05-01

    Gamma-irradiation of liquid and dried calf sera with 2.5 Mrads did not affect their capacity to promote the growth of chick embryo, L cell and human embryonic lung cell cultures. Drying and gamma-irradiation of horsesera did not affect their capacity to support the growth of 3 mycoplasma of the species Acholeplasma laidawii and Mycoplasma bovigenitalium.

  12. Evaluation of Parameters in the Isolation of Viable Protoplasts from Cultured Tobacco Cells 1

    PubMed Central

    Uchimiya, Hirofumi; Murashige, Toshio

    1974-01-01

    A systematic evaluation disclosed the following conditions to be optimum for the isolation of viable protoplasts from cultured cells of Nicotiana tabacum L. `Bright Yellow' grown in liquid suspensions: (a) the cell culture in the early phase of cell number increase, (b) an enzyme mixture of 1% cellulase “Onozuka” and 0.2% Macerozyme, (c) an enzyme solution pH of 4.7 or 5.7, (d) a 2- to 3-hr incubation period, (e) 5 ml of enzyme solution per 500 mg cells and contained in a 50-ml Delong flask, (f) agitation on a gyrotory shaker at 50 rpm, and (g) 0.3 to 0.8 m mannitol as osmoticum in the cell enzyme mixture. The incubation temperature may be varied from 22 to 37 C. The procedure enabled 30% of the tobacco cells to form protoplasts, 80% of which regenerated cell walls in 4 days and 40% resumed cell division activity when returned to cell culture medium. Images PMID:16659004

  13. Salicylic Acid induces cyanide-resistant respiration in tobacco cell-suspension cultures.

    PubMed

    Kapulnik, Y; Yalpani, N; Raskin, I

    1992-12-01

    Cyanide-resistant, alternative respiration in Nicotiana tabacum L. cv Xanthi-nc was analyzed in liquid suspension cultures using O(2) uptake and calorimetric measurements. In young cultures (4-8 d after transfer), cyanide inhibited O(2) uptake by up to 40% as compared to controls. Application of 20 mum salicylic acid (SA) to young cells increased cyanide-resistant O(2) uptake within 2 h. Development of KCN resistance did not affect total O(2) uptake, but was accompanied by a 60% increase in the rate of heat evolution from cells as measured by calorimetry. This stimulation of heat evolution by SA was not significantly affected by 1 mm cyanide, but was reduced by 10 mm salicylhydroxamic acid (SHAM), an inhibitor of cyanide-resistant respiration. Treatment of SA-induced or uninduced cells with a combination of cyanide and SHAM blocked most of the O(2) consumption and heat evolution. Fifty percent of the applied SA was taken up within 10 min, with most of the intracellular SA metabolized in 2 h. 2,6-Dihydroxybenzoic and 4-hydroxybenzoic acids also induced cyanide-resistant respiration. These data indicate that in tobacco cell-suspension culture, SA induces the activity and the capacity of cyanide-resistant respiration without affecting the capacity of the cytochrome c respiration pathway.

  14. Effect of gamma irradiation on the pigments and the biological activities of methanolic extracts from leaves of centipedegrass (Eremochloa ophiuroides Munro)

    NASA Astrophysics Data System (ADS)

    Lee, Eun Mi; Lee, Seung Sik; Bai, Hyoung-Woo; Cho, Jae-Young; Kim, Tae Hoon; Chung, Byung Yeoup

    2013-10-01

    Extracts from centipedegrass (Eremochloa ophiuroides Munro) have been previously identified as having beneficial effects medically and cosmetically. In this study, the effects of gamma irradiation on pigment removal and biological activities of centipedegrass extracts to promote industrial application were investigated. The methanolic extracts were exposed to gamma irradiation at dose ranging from 2 to 20 kGy. The major pigments of centipedegrass extracts, cyanidin-3-O-glucoside and cyanidin-3-O-(6″-malonyl-)glucoside, were found to be effectively removed by gamma irradiation above 10 kGy. Although the reddish-orange color of the cyanidins was markedly decreased by gamma irradiation, the biological activities were relatively unaffected. The biological activities such as 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, inhibition of tyrosinase activity, and inhibition of elastase activity in methanolic extracts were modulated from 50.5% to 70.2%, from 50.9% to 65.8% and from 65.6% to 94.0%, respectively. Surprisingly, the biological activities have the highest activities after 6-8 kGy of gamma irradiation. These results indicate that despite pigment degradation, biological activities were maintained or increased by gamma irradiation. Based on these results, gamma irradiation may be a useful tool to remove the undesirable reddish-orange color present in centipedegrass without any loss of biological activities, thereby promoting its utility in industrial applications such as manufacturing of cosmetic products.

  15. Effect of gamma irradiation on the change of solubility and anti-inflammation activity of chrysin in macrophage cells and LPS-injected endotoxemic mice

    NASA Astrophysics Data System (ADS)

    Byun, Eui-Baek; Jang, Beom-Su; Byun, Eui-Hong; Sung, Nak-Yun

    2016-10-01

    This study evaluated the changes of solubility and anti-inflammatory properties of structurally modified gamma-irradiated chrysin. Chrysin was irradiated at various doses for a physical analysis and determining any structural changes and solubility. As shown through the physical analysis, the main peak of the chrysin was decreased as the irradiation dose increased, and it was concomitant with the appearance of several new peaks, which were highly increased in 50 kGy gamma-irradiated chrysin. The solubility was markedly increased in the gamma-irradiated groups. As shown through a physiological analysis, both gamma-irradiated- (15-50 kGy) and intact-chrysin (0 kGy) did not exert cytotoxicity to bone-marrow derived macrophages. The treatment of LPS-stimulated macrophages with 50 kGy gamma-irradiated chrysin resulted in a dose-dependent decrease in pro-inflammatory mediators, such as iNOS-mediated NO, PGE2, COX-2, and cell surface marker (CD80 and CD86), as well as pro-inflammatory cytokines (TNF-α and IL-6), when compared to the intact-chrysin treated group. Mechanically, we found that the inhibition of these pro-inflammatory mediators induced by gamma-irradiated chrysin occurred through an inhibition of MAPKs (ERK1/2 and p38) and the NF-κB signaling pathways. Furthermore, the anti-inflammatory activity remained in the LPS-injected animal model. In this model, gamma-irradiated chrysin treatment highly increased the mouse survival, and significantly decreased the serum cytokine (TNF-α, IL-6 and IL-1β) levels. From these findings, the anti-inflammatory action by gamma-irradiated chrysin may be closely mediated with structural modification. It seems likely that gamma irradiation can be an effective tool for improvement of the physical and physiological properties of polyphenols.

  16. Hesperidin a flavanoglycone protects against gamma-irradiation induced hepatocellular damage and oxidative stress in Sprague-Dawley rats.

    PubMed

    Pradeep, Kannampalli; Park, Sang Hyun; Ko, Kyong Cheol

    2008-06-10

    Oxidative stress plays a pivotal role in the pathogenesis and progression of gamma-irradiation induced cellular damage and the administration of dietary antioxidants has been suggested to protect against the subsequent tissue damage. Here, we present the data to explore the hepatoprotective and antioxidant effect of hesperidin, a naturally occurring citrus flavanoglycone, against gamma-irradiation induced oxidative damage in the liver of rats. Healthy male Sprague-Dawley rats were exposed to gamma-irradiation (1 Gy, 3 Gy and 5 Gy) and were administered hesperidin (50 mg/kg and 100 mg/kg, b.w, orally) for 7 days post irradiation. The changes in body weight, liver weight, spleen index, serum and liver aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (gamma-GT) and serum ceruloplasmin levels were determined along with differences in the liver histopathology. Liver thiobarbuturic acid reactive substance as an index for lipid peroxidation and the levels of enzymatic antioxidants like superoxide dismutase, catalase, glutathione peroxidase and the status of non-enzymatic antioxidants as an index for oxidative stress were also determined. Exposure to gamma-irradiation resulted in hepatocellular damage in a dose-dependent manner, featuring a significantly decreased body weight and liver weight and higher levels of serum AST, ALT, ALP, LDH and gamma-GT levels and a simultaneous decrease in their levels in the liver tissue. Oxidative stress was evidenced by elevated levels of lipid peroxidation and a decrease in the levels of key enzymatic and non-enzymatic antioxidants in the liver. However, the gamma-irradiation induced toxic effects were dramatically and dose-dependently inhibited by hesperidin treatment as observed by the restoration in the altered levels of the marker enzymes, lipid peroxidation, enzymatic and non-enzymatic antioxidants. The results of the biochemical

  17. The Effect of Gamma Irradiation on the Electrical Properties of the Epoxy Resins.

    NASA Astrophysics Data System (ADS)

    Gedeon, Sa'ad S.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis is concerned primarily with the curing of epoxy resin and the effect of gamma-irradiation on the electrical properties of epoxy resin systems. The particular systems examined were a diglycidyl ether of bisphenol A (DGEBA, Ciba Geigy MY750) epoxy resin cured using one of two hardeners. These were a hydroxyalkylated polyamine (Ciba Geigy HY956) and a dodecenyl-succinicanhydride (DDSA) with an accelerator of benzyldimethylamine. Different methods of examining the curing of the epoxy resin system have been carried out including differential scanning calorimetry (DSC), infrared spectroscopy (I.R.), dielectric measurements, volume resistivity measurements and thermally stimulated discharge current. The results of dielectric relaxation measurements obtained during the curing of the epoxy resin system were interpreted on the basis of a model considering the growing polymer molecules to be in solution, the solvent being the unreacted monomer and hardener. The investigation of the effect of gamma-irradiation on the electrical properties (conduction mechanism and dielectric behaviour) of the epoxy resin system was achieved by examining the electrical properties of the fully cured epoxy resin system before and after irradiation and the results compared. To establish the electrical properties of the fully cured epoxy resin system before and after irradiation, a series of experiments which provide information about the conduction mechanism, the dielectric properties, the infrared spectra (I.R.) and the glass transition temperature (Tg) obtained from (DSC) measurements were carried out. For the epoxy resin system MY750/HY956, it was found that the D.C. conductivity, dissipation factor and capacitance values increase, whereas the glass transition temperature (Tg) and the activation energy, E, obtained from D.C. measurements decreased for the irradiated samples. Furthermore, a modification

  18. Acid-growth response and alpha-expansins in suspension cultures of bright yellow 2 tobacco

    NASA Technical Reports Server (NTRS)

    Link, B. M.; Cosgrove, D. J.

    1998-01-01

    The possibility that Bright Yellow 2 (BY2) tobacco (Nicotiana tabacum L.) suspension-cultured cells possess an expansin-mediated acid-growth mechanism was examined by multiple approaches. BY2 cells grew three times faster upon treatment with fusicoccin, which induces an acidification of the cell wall. Exogenous expansins likewise stimulated BY2 cell growth 3-fold. Protein extracted from BY2 cell walls possessed the expansin-like ability to induce extension of isolated walls. In western-blot analysis of BY2 wall protein, one band of 29 kD was recognized by anti-expansin antibody. Six different classes of alpha-expansin mRNA were identified in a BY2 cDNA library. Northern-blot analysis indicated moderate to low abundance of multiple alpha-expansin mRNAs in BY2 cells. From these results we conclude that BY2 suspension-cultured cells have the necessary components for expansin-mediated cell wall enlargement.

  19. Copper elicits an increase in cytosolic free calcium in cultured tobacco cells.

    PubMed

    Inoue, Hiroki; Kudo, Tomoko; Kamada, Hiroshi; Kimura, Makoto; Yamaguchi, Isamu; Hamamoto, Hiroshi

    2005-12-01

    At concentrations greater than 0.1 mM, CuSO(4) provoked a rapid and sustained increase in the cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)), in tobacco suspension culture cells expressing apoaequorin, a Ca(2+)-sensitive photoprotein. The increase was suppressed by treatment with LaCl(3), indicating that the increase is due to an influx of Ca(2+) from the apoplast through plasma membrane Ca(2+) channels. Although stimulation of H(2)O(2) production upon the CuSO(4) treatment (0.1 mM) was observed, treatment with catalase did not inhibit the increase in [Ca(2+)](cyt), and treatment with H(2)O(2) dose-dependently suppressed or delayed the increase. These results suggested that active oxygen species generated through copper-mediated reactions, or copper-mediated oxidative damages to plasma membrane, are not responsible for the increase. Treatment with sulfhydryl reagents, which alkylate or oxidize thiol groups, or acidification of the culture medium suppressed the increase in [Ca(2+)](cyt). These results demonstrated that copper causes an influx of Ca(2+) through plasma membrane Ca(2+) channels, and that plasma membrane thiol groups play an important role in activating the Ca(2+) channels.

  20. Microbial decontamination by low dose gamma irradiation and its impact on the physico-chemical quality of peppermint (Mentha piperita)

    NASA Astrophysics Data System (ADS)

    Machhour, Hasna; El Hadrami, Ismail; Imziln, Boujamaa; Mouhib, Mohamed; Mahrouz, Mostafa

    2011-04-01

    Peppermint was inoculated with Escherichia coli and its decontamination was carried out by gamma irradiation at low irradiation doses (0.5, 1.0 and 2.66 kGy). The efficiency of this decontamination method was evaluated and its impact on the quality parameters of peppermint, such as the color and ash content, as well as the effect on fingerprint components such as phenols and essential oils, was studied. Gas chromatography coupled to mass spectrometry (GC/MS) and High Performance Liquid Chromatography (HPLC) were used to characterize essential oils and phenolic compounds, respectively. The results indicated a complete decontamination of peppermint after the low dose gamma irradiation without a significant loss in quality attributes.

  1. Assessing the effects of gamma irradiation and storage time in energetic value and in major individual nutrients of chestnuts.

    PubMed

    Fernandes, Angela; Barreira, João C M; Antonio, Amilcar L; Bento, Albino; Luisa Botelho, M; Ferreira, Isabel C F R

    2011-09-01

    Chestnut (Castanea sativa Miller) is an important food resource all over the world. In the present study, it is intended to evaluate if the application of gamma irradiation doses ≤ 3 kGy maintain chestnuts chemical and nutritional profiles unaffected. Furthermore, possible interactions among irradiation dose and storage time were accessed using linear discriminate analysis (LDA). The nutritional composition was evaluated through determination of proteins, fat, ash, carbohydrates and energetic value. The chemical composition was focused in the main nutrients found in chestnuts: sugars - sucrose, fatty acids - palmitic, oleic, linoleic and linolenic acids, tocopherols - γ-tocopherol. The obtained results seem to indicate that the irradiation treatment did not affect the nutritional and chemical quality of chestnut fruits. Otherwise, storage time exerted more evident influence in those parameters. The application of gamma irradiation emerges as a promising technology for chestnuts chemical quality, but food safety issues have to be evaluated in order to recommend its application as a useful conservation alternative.

  2. Effect of gamma irradiation on the vitamins, phytochemicals, antimicrobial and antioxidant properties of Ziziphus mauritiana Lam. leaves

    NASA Astrophysics Data System (ADS)

    Khattak, Khanzadi Fatima; Rahman, Taj Ur

    2016-10-01

    Plant based food products and medicines are given more consideration for their efficacy, safety and synergistic effects. Radiation processing has been valuably used for microbial decontamination and value addition of the plant materials. The current study is about the effect of gamma irradiation on the quality attributes of Ziziphus mauritiana Lam. leaves. The leaves of the plant were irradiated at the dose levels of 2.5, 5.0, 7.5, 10.0 and 12.5 kGy. The irradiated and control samples were evaluated for vitamin, phytochemicals, antibacterial and DPPH scavenging activities. The results showed that gamma irradiation doses up to 12.5 kGy enhanced the levels of certain phytochemicals and augmented the biological activities.

  3. Characterization and antioxidant properties of alcoholic extracts from gamma irradiated κ-carrageenan

    NASA Astrophysics Data System (ADS)

    Relleve, Lorna; Abad, Lucille

    2015-07-01

    Different extracts from unirradiated and gamma irradiated κ-carrageenan (solid and 1% w/v aqueous solution) were obtained with isopropyl alcohol (IPA) at concentrations of 40%, 60% and 80% v/v at room temperature. Physical and chemical properties of the different IPA extracts were analyzed by GPC, UV, and FT-IR. The extracts consisted of low molecular weight fragments with an average molecular weight (Mw) ranging from 2300 Da to 5000 Da. UV analyses of extracts from irradiated carrageenan showed varying maximum absorptions in the range of 265-280 nm. FT-IR spectra of all extracts from irradiated carrageenan showed all the important functional groups of carrageenan in the fingerprint region (4000-600 cm-1) and additional carbonyl C=O and C=C double bond peaks. Antioxidant properties of the different extracts were investigated using reducing power assay. The reducing power of extracts from the irradiated solution follows the order of 80%>60%>40% while no trend was observed for all extracts from irradiated solid κ-carrageenan.

  4. Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

    NASA Astrophysics Data System (ADS)

    Seo, Hye-Young; Kim, Jun-Hyoung; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kwon, Joog-Ho; Kim, Kyong-Su

    2007-11-01

    The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, α-pinene, camphene, α-limonene, β-eudesmol, α-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as β-eudesmol, α-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.

  5. Gamma irradiation of peanut kernel to control mold growth and to diminish aflatoxin contamination

    NASA Astrophysics Data System (ADS)

    Y.-Y. Chiou, R.

    1996-09-01

    Peanut kernel inoculated with Aspergillus parasiticus conidia were gamma irradiated with 0, 2.5, 5.0 and 10 kGy using Co60. Levels higher than 2.5 kGy were effective in retarding the outgrowth of A. parasiticus and reducing the population of natural mold contaminants. However, complete elimination of these molds was not achieved even at the dose of 10 kGy. After 4 wk incubation of the inoculated kernels in a humidified condition, aflatoxins produced by the surviving A. parasiticus were 69.12, 2.42, 57.36 and 22.28 μ/g, corresponding to the original irradiation levels. Peroxide content of peanut oils prepared from the irradiated peanuts increased with increased irradiation dosage. After storage, at each irradiation level, peroxide content in peanuts stored at -14°C was lower than that in peanuts stored at an ambient temperature. TBA values and CDHP contents of the oil increased with increased irradiation dosage and changed slightly after storage. However, fatty acid contents of the peanut oil varied in a limited range as affected by the irradiation dosage and storage temperature. The SDS-PAGE protein pattern of peanuts revealed no noticeable variation of protein subunits resulting from irradiation and storage.

  6. Physicochemical and thermal properties of gamma-irradiated sago (Metroxylon sagu) starch

    NASA Astrophysics Data System (ADS)

    Othman, Zainon; Hassan, Osman; Hashim, Kamaruddin

    2015-04-01

    Sago (Metroxylon sagu) starch was exposed to gamma-irradiation in air at doses 6, 10 and 25 kGy. Subsequent changes in the physicochemical and thermal properties were measured. The apparent amylose content and swelling power of irradiated sago starch was significantly reduced while reducing sugars and starch solubility were significantly increased due to degradation. X-ray diffraction studies showed that radiation did not affect the crystalline type but induced a decrease in the degree of crystallinity, indicating the destruction of the ordered distribution of neighboring polysaccharide chains in the starch granules, in particular of the amylopectin component, which is responsible for starch crystallinity. Differential scanning calorimetry (DSC) of irradiated sago starch showed a small but significant increase in the onset and peak transition temperatures at 10 and 25 kGy dose; the conclusion temperature and gelatinization enthalpy was not affected. SEM and particle size analysis produced no evidence of physical damage to sago starch up to 25 kGy dose radiation treatment since the granular appearance and size distribution was retained.

  7. Low dose gamma irradiation enhances defined signaling components of intercellular reactive oxygen-mediated apoptosis induction

    NASA Astrophysics Data System (ADS)

    Bauer, G.

    2011-01-01

    Transformed cells are selectively removed by intercellular ROS-mediated induction of apoptosis. Signaling is based on the HOCl and the NO/peroxynitrite pathway (major pathways) and the nitryl chloride and the metal-catalyzed Haber-Weiss pathway (minor pathways). During tumor progression, resistance against intercellular induction of apoptosis is acquired through expression of membrane-associated catalase. Low dose radiation of nontransformed cells has been shown to enhance intercellular induction of apoptosis. The present study was performed to define the signaling components which are modulated by low dose gamma irradiation. Low dose radiation induced the release of peroxidase from nontransformed, transformed and tumor cells. Extracellular superoxide anion generation was strongly enhanced in the case of transformed cells and tumor cells, but not in nontransformed cells. Enhancement of peroxidase release and superoxide anion generation either increased intercellular induction of apoptosis of transformed cells, or caused a partial protection under specific signaling conditions. In tumor cells, low dose radiation enhanced the production of major signaling components, but this had no effect on apoptosis induction, due to the strong resistance mechanism of tumor cells. Our data specify the nature of low dose radiation-induced effects on specific signaling components of intercellular induction of apoptosis at defined stages of multistep carcinogenesis.

  8. Modulatory effects of new curcumin analogues on gamma-irradiation - Induced nephrotoxicity in rats.

    PubMed

    Ismail, Amel F M; Zaher, Nashwa H; El-Hossary, Ebaa M; El-Gazzar, Marwa G

    2016-12-25

    In the present study, a new series of 2-amino-pyran-3-carbonitrile derivatives of curcumin 2-7 have been synthesized via one-pot simple and efficient protocol, involving the reaction of curcumin 1 with substituted-benzylidene-malononitrile to modify the 1,3-diketone moiety. The structures of the synthesized compounds 2-7 were elucidated by microanalytical and spectral data, which were found consistent with the assigned structures. The nephroprotective mechanism of these new curcumin analogues was evaluated on the post-gamma-irradiation (7 Gy) - induced nephrotoxicity in rats. Activation of Nrf2 by these curcumin analogues is responsible for the amendment of the antioxidant status, impairment of NF-κB signal, thus attenuate the nephrotoxicity induced post-γ-irradiation exposure. 4-Chloro-phenyl curcumin analogue 7 showed the most potent activity. In conclusion, the results of the present study demonstrate a promising role of these new curcumin analogues to attenuate the early symptoms of nephrotoxicity induced by γ-irradiation in rats via activation of Nrf2 gene expression. These new curcumin analogues need further toxicological investigations to assess their therapeutic index.

  9. Whole-Genome Sequencing in Microbial Forensic Analysis of Gamma-Irradiated Microbial Materials.

    PubMed

    Broomall, Stacey M; Ait Ichou, Mohamed; Krepps, Michael D; Johnsky, Lauren A; Karavis, Mark A; Hubbard, Kyle S; Insalaco, Joseph M; Betters, Janet L; Redmond, Brady W; Rivers, Bryan A; Liem, Alvin T; Hill, Jessica M; Fochler, Edward T; Roth, Pierce A; Rosenzweig, C Nicole; Skowronski, Evan W; Gibbons, Henry S

    2015-11-13

    Effective microbial forensic analysis of materials used in a potential biological attack requires robust methods of morphological and genetic characterization of the attack materials in order to enable the attribution of the materials to potential sources and to exclude other potential sources. The genetic homogeneity and potential intersample variability of many of the category A to C bioterrorism agents offer a particular challenge to the generation of attributive signatures, potentially requiring whole-genome or proteomic approaches to be utilized. Currently, irradiation of mail is standard practice at several government facilities judged to be at particularly high risk. Thus, initial forensic signatures would need to be recovered from inactivated (nonviable) material. In the study described in this report, we determined the effects of high-dose gamma irradiation on forensic markers of bacterial biothreat agent surrogate organisms with a particular emphasis on the suitability of genomic DNA (gDNA) recovered from such sources as a template for whole-genome analysis. While irradiation of spores and vegetative cells affected the retention of Gram and spore stains and sheared gDNA into small fragments, we found that irradiated material could be utilized to generate accurate whole-genome sequence data on the Illumina and Roche 454 sequencing platforms.

  10. Effect of gamma irradiation on the nutritional quality of Agaricus bisporus strains cultivated in different composts.

    PubMed

    Andrade, Meire C N; Jesus, João P F; Vieira, Fabrício R; Viana, Sthefany R F; Spoto, Marta H F; Minhoni, Marli T A

    2014-05-14

    The effect of irradiation doses (0, 125, 250 and 500 Gy) on the nutritional quality of A. bisporus mushrooms (strains ABI-07/06, ABI-05/03 and PB-1) cultivated in composts based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) was evaluated. The experimental design was 4 x 3 x 2 factorial scheme (irradiation doses x strains x composts), with 24 treatments, consisting of two repetitions each, totaling 48 experimental units (samples of mushrooms). The samples were irradiated in Cobalt-60 irradiator, model Gammacell 220 kGy, with dose rate of 0.740 kGy h-1, according to the treatments proposed. Subsequently, the control (unirradiated) and the other treatments were maintained at 4±1°C and 90% RH in a climatic chamber for carrying out the chemical analysis of the mushrooms on the 1st and 14th day of storage. It was found that all A. bisporus strains evaluated were food with excellent nutritional value, because they presented high protein and fiber contents and low ethereal extract content; the chemical characterization of the mushrooms was influenced by the compost type in which they were cultivated; gamma irradiation influenced the chemical composition of mushrooms.

  11. Effect of gamma irradiation on the wear behaviour of human tooth enamel

    NASA Astrophysics Data System (ADS)

    Qing, Ping; Huang, Shengbin; Gao, Shanshan; Qian, Linmao; Yu, Haiyang

    2015-06-01

    Radiotherapy is a frequently used treatment for oral cancer. Extensive research has been conducted to detect the mechanical properties of dental hard tissues after irradiation at the macroscale. However, little is known about the influence of irradiation on the tribological properties of enamel at the micro- or nanoscale. Therefore, this study aimed to investigate the effect of gamma irradiation on the wear behaviour of human tooth enamel in relation to prism orientation. Nanoscratch tests, surface profilometer and scanning electron microscope (SEM) analysis were used to evaluate the friction behaviour of enamel slabs before and after treatment with identical irradiation procedures. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were performed to analyse the changes in crystallography and chemical composition induced by irradiation. Surface microhardness (SMH) alteration was also evaluated. The results showed that irradiation resulted in different scratch morphologies, friction coefficients and remnant depth and width at different loads. An inferior nanoscratch resistance was observed independent of prism orientation. Moreover, the variation of wear behaviours was closely related to changes in the crystallography, chemical composition and SMH of the enamel. Together, these measures indicated that irradiation had a direct deleterious effect on the wear behaviour of human tooth enamel.

  12. Inactivation of Enterobacter sakazakii of dehydrated infant formula by gamma-irradiation

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Woon; Oh, Sang-Hee; Byun, Eui-Baek; Kim, Jae-Hun; Kim, Jang-Ho; Woon, Jae-Ho; Byun, Myung-Woo

    2007-11-01

    Enterobacter sakazakii has been implicated as a causal organism in a severe form of neonatal meningitis, with reported mortality rates of 20%. The population at greatest risk is immunocompromised infants of any age. Dried infant formula has been identified as a potential source of the organism in both outbreaks and sporadic cases. The objective of this study was to investigate theirradiation effect of the inactivation on E. sakazakii (ATCC 29544) of a dehydrated infant formula. The D10-values were 0.22-0.27 and 0.76 kGy for broth and dehydrated infant formula, respectively. The irradiation at 5.0 kGy was able to completely eliminate the E. sakazakii inoculated at 8.0 to 9.0 log CFU g -1 onto a dehydrated infant formula. There was no regrowth for all samples during the time they were stored at 10 °C for 6 h after rehydration. The present results indicated that a gamma-irradiation could potentially be used to inactivate E. sakazakii in a dehydrated powdered infant formula.

  13. Phototherapeutic Effect of Low-Level Laser on Thyroid Gland of Gamma-Irradiated Rats.

    PubMed

    Morcos, Nadia; Omran, Manar; Ghanem, Hala; Elahdal, Mahmoud; Kamel, Nashwa; Attia, Elbatoul

    2015-01-01

    One inescapable feature of life on the earth is exposure to ionizing radiation. The thyroid gland is one of the most sensitive organs to gamma-radiation and endocrine disrupters. Low-level laser therapy (LLLT) has been used to stimulate tissue repair, and reduce inflammation. The aim of this study was to gauge the value of using Helium-Neon laser to repair the damaged tissues of thyroid gland after gamma-irradiation. Albino rats were used in this study (144 rats), divided into control, gamma, laser, and gamma plus laser-irradiated groups, each group was divided into six subgroups according to time of treatment (total six sessions). Rats were irradiated once with gamma radiation (6 Gy), and an external dose of laser (Wavelength 632.8 nm, 12 mW, CW, Illuminated area 5.73 cm(2), 2.1 mW cm(-2) 120 s, 1.4 J, 0.252 J cm(-2)) twice weekly localized on thyroid region of the neck, for a total of six sessions. Animals were sacrificed after each session. Analysis included thyroid function, oxidative stress markers, liver function and blood picture. Results revealed improvement in thyroid function, liver function and antioxidant levels, and the blood cells count after LLLT.

  14. Modification of the microstructure of the films formed by gamma irradiated starch examined by SEM

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Sartowska, B.

    2016-01-01

    The paper concerns the effect of gamma irradiation carried out for starch on the microstructure of the films prepared using the starch and its composition with sodium laurate (NaLau) and cetyltrimethylammonium bromide (CTAB) studied by scanning electron microscopy (SEM). Potato starch was irradiated with 60Co gamma rays applying a dose of 30 kGy. Films were prepared by the solution casting method with the addition of 30 wt% glycerol as a plasticizer. Films containing NaLau and CTAB were prepared after performing the procedure, leading to starch-surfactant complexes. Mechanical tests and wetting angle measurements were performed for the films. SEM observations were carried out for the surfaces, fractures and/or sections of the films subjected to chemical fixation and for the dried films. The films obtained using irradiated starch are characterized by a smoother and more homogeneous structure as compared to those based on the non-irradiated starch. Besides, a number of small precipitates were observed on the films surfaces after drying and the number of those precipitates seemed to be higher after irradiation. The results can be related to differences in the microstructure of gels formed on the intermediate step of the films preparation and to the presence of two phases in the system and might serve for explanation of the radiation induced improvement of the hydrophilic/hydrophobic properties, a modification of the mechanical properties of the films, as well as for the changes of those properties resulting after storage.

  15. Effect of gamma irradiation on the friction and wear of ultrahigh molecular weight polyethylene

    NASA Technical Reports Server (NTRS)

    Jones, W. R.; Hady, W. F.; Crugnola, A.

    1981-01-01

    The effect of sterilization gamma irradiation on the friction and wear properties of ultrahigh molecular weight polyethylene (UHMWPE) sliding against stainless steel 316L in dry air at 23 C is investigated, the results to be used in the development of artificial joints which are to surgically replace diseased human joints. A pin-on-disk sliding friction apparatus is used, a constant sliding speed in the range 0.061-0.27 m/s is maintained, a normal load of 1 kgf is applied with dead weight, and the irradiation dose levels are: 0, 2.5, and 5.0 Mrad. Wear and friction data and conditions for each of the ten tests are summarized, and include: (1) wear volume as a function of the sliding distance for the irradiation levels, (2) incremental wear rate, and (3) coefficient of friction as a function of the sliding distance. It is shown that (1) the friction and wear properties of UHMWPE are not significantly changed by the irradiation doses of 2.5 and 5.0 Mrad, (2) the irradiation increases the amount of insoluble gel as well as the amount of low molecular weight material, and (3) after run-in the wear rate is either steady or gradually decreases as a function of the sliding distance.

  16. Whole-Genome Sequencing in Microbial Forensic Analysis of Gamma-Irradiated Microbial Materials

    PubMed Central

    Broomall, Stacey M.; Ait Ichou, Mohamed; Krepps, Michael D.; Johnsky, Lauren A.; Karavis, Mark A.; Hubbard, Kyle S.; Insalaco, Joseph M.; Betters, Janet L.; Redmond, Brady W.; Rivers, Bryan A.; Liem, Alvin T.; Hill, Jessica M.; Fochler, Edward T.; Roth, Pierce A.; Rosenzweig, C. Nicole; Skowronski, Evan W.

    2015-01-01

    Effective microbial forensic analysis of materials used in a potential biological attack requires robust methods of morphological and genetic characterization of the attack materials in order to enable the attribution of the materials to potential sources and to exclude other potential sources. The genetic homogeneity and potential intersample variability of many of the category A to C bioterrorism agents offer a particular challenge to the generation of attributive signatures, potentially requiring whole-genome or proteomic approaches to be utilized. Currently, irradiation of mail is standard practice at several government facilities judged to be at particularly high risk. Thus, initial forensic signatures would need to be recovered from inactivated (nonviable) material. In the study described in this report, we determined the effects of high-dose gamma irradiation on forensic markers of bacterial biothreat agent surrogate organisms with a particular emphasis on the suitability of genomic DNA (gDNA) recovered from such sources as a template for whole-genome analysis. While irradiation of spores and vegetative cells affected the retention of Gram and spore stains and sheared gDNA into small fragments, we found that irradiated material could be utilized to generate accurate whole-genome sequence data on the Illumina and Roche 454 sequencing platforms. PMID:26567301

  17. Hematopoietic responses under protracted exposures to low daily dose gamma irradiation.

    PubMed

    Seed, T M; Fritz, T E; Tolle, D V; Jackson, W E

    2002-01-01

    In attempting to evaluate the possible health consequences of chronic ionizing radiation exposure during extended space travel (e.g., Mars Mission), ground-based experimental studies of the clinical and pathological responses of canines under low daily doses of 60Co gamma irradiation (0.3-26.3 cGy d-1) have been examined. Specific reference was given to responses of the blood forming system. Results suggest that the daily dose rate of 7.5 cGy d-1 represents a threshold below which the hematopoietic system can retain either partial or full trilineal cell-producing capacity (erythropoiesis, myelopoiesis, and megakaryopoiesis) for extended periods of exposure (>1 yr). Trilineal capacity was fully retained for several years of exposure at the lowest dose-rate tested (0.3 cGy d-1) but was completely lost within several hundred days at the highest dose-rate (26.3 cGy d-1). Retention of hematopoietic capacity under chronic exposure has been demonstrated to be mediated by hematopoietic progenitors with acquired radioresistance and repair functions, altered cytogenetics, and cell-cycle characteristics. Radiological, biological, and temporal parameters responsible for these vital acquisitions by hematopoietic progenitors have been partially characterized. These parameters, along with threshold responses, are described and discussed in relation to potential health risks of the space traveler under chronic stress of low-dose irradiation.

  18. Effects of gamma irradiation on chemical, microbial quality and shelf life of shrimp

    NASA Astrophysics Data System (ADS)

    Hocaoğlu, Aslı; Sükrü Demirci, Ahmet; Gümüs, Tuncay; Demirci, Mehmet

    2012-12-01

    In the present study the combined effect of gamma irradiation (1, 3 and 5 kGy) and storage at two temperatures: refrigeration (+4 °C) and frozen (-18 °C), on the shelf-life extension of fresh shrimp meat was investigated. The study was based on microbiological and physicochemical changes occuring in the shrimp samples. Total volatile base nitrogen values and trimethylamine values for irradiated shrimp samples were significantly lower than non-irradiated samples at both storage temperatures, and the rate of decrease was more pronounced in samples irradiated at the higher dose (p<0.05). Thiobarbituric acid values for irradiated shrimp samples were significantly higher than non-irradiated samples at both storage temperatures (p<0.05). pH values of shrimp samples were affected significantly by both irradiating dose and storage temperatures (p<0.05). Microbial counts for non-irradiated shrimp samples were higher than the respective irradiated samples at both storage temperatures (p<0.05). The results revealed that irradiation at high dose (5 kGy) might enhance lipid oxidation, although the growth of microorganisms and protein oxidation was inhibited.

  19. Effect of gamma irradiation on microbial decontamination, and chemical and sensory characteristic of lycium fruit

    NASA Astrophysics Data System (ADS)

    Wen, Hsiao-Wei; Chung, Hsiao-Ping; Chou, Fong-In; Lin, I.-hsin; Hsieh, Po-Chow

    2006-05-01

    Lycium fruit, popular traditional Chinese medicine and food supplement generally is ingested uncooked, was exposed to several doses of gamma irradiation (0-14 kGy) to evaluate decontamination efficiency, changes in chemical composition, and changes in sensory characteristic. In this study, lycium fruit specimens contained microbial counts of 3.1×10 3-1.7×10 5 CFU/g and 14 kGy was sufficient for microbial decontamination. Before irradiation, the main microbe isolated from lycium fruit was identified as a strain of yeast, Cryptococcus laurentii. After 10 kGy of irradiation, a Gram-positive spore-forming bacterium, Bacillus cereus, was the only survivor. The first 90% reduction (LD 90) of C. laurentii and B. cereus was approximately 0.6 and 6.5 kGy, respectively, the D 10 doses of C. laurentii and B. cereus was approximately 0.6 and 1.7 kGy, respectively. After 14 kGy irradiation, except the vitamin C content, other chemical composition (e.g., crude protein, β-carotene, riboflavin, fructose, etc.) and the sensory characteristic of lycium fruit specimens did not have significant changes. In conclusion, 14 kGy is the optimal decontamination dose for lycium fruit for retention of its sensory quality and extension of shelf life.

  20. Antioxidant Capacities and Total Phenolic Contents Enhancement with Acute Gamma Irradiation in Curcuma alismatifolia (Zingiberaceae) Leaves

    PubMed Central

    Taheri, Sima; Abdullah, Thohirah Lee; Karimi, Ehsan; Oskoueian, Ehsan; Ebrahimi, Mahdi

    2014-01-01

    The present study was conducted in order to assess the effect of various doses of acute gamma irradiation (0, 10, 15, and 20 Gy) on the improvement of bioactive compounds and their antioxidant properties of Curcuma alismatifolia var. Sweet pink. The high performance liquid chromatography (HPLC) and gas chromatography (GC) analysis uncovered that various types of phenolic, flavonoid compounds, and fatty acids gradually altered in response to radiation doses. On the other hand, antioxidant activities determined by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), ferric reduction, antioxidant power (FRAP), and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay showed a higher irradiation level significantly increased the antioxidant properties. This study revealed an efficient effect of varying levels of gamma radiation, based on the pharmaceutical demand to enhance the accumulation and distribution of bioactive compounds such as phenolic and flavonoid compounds, fatty acids, as well as their antioxidant activities in the leaves of C. alismatifolia var. Sweet pink. PMID:25056545

  1. Metal adsorption of gamma-irradiated carboxymethyl cellulose/polyethylene oxide blend films

    NASA Astrophysics Data System (ADS)

    El-Naggar, Amal A.; Magida, M. M.; Ibrahim, Sayeda M.

    2016-03-01

    Blend films of different ratios of carboxymethyl cellulose (CMC)/polyethylene oxide (PEO) were prepared by the solution casting method. To investigate the effect of irradiation on all properties of prepared blend, it was exposed to different gamma irradiation doses (10, 20, and 30 kGy). Physical properties such as gel fraction (GF) (%) and swelling (SW) (%) were investigated. It was found that the GF (%) increases with increasing irradiation dose up to 20 kGy, while SW (%) decreases with an increase in the irradiation doses for all blend compositions. Moreover, the structural and mechanical properties of the prepared films were studied. The results of the mechanical properties obtained showed that there is an improvement in these properties with an increase in both CMC and irradiation dose up to 20 kGy. The efficiency of metal ions uptake was measured using a UV spectrophotometer. The prepared films showed good tendency to absorb and release metal ions from aqueous media. Thus, the CMC/PEO film can be used in agricultural domain.

  2. Effect of gamma irradiation on hyaluronic acid and dipalmitoylphosphatidylcholine (DPPC) interaction

    NASA Astrophysics Data System (ADS)

    Ahmad, Ainee Fatimah; Mohd, Hur Munawar Kabir; bin Ayob, Muhammad Taqiyuddin Mawardi; Rosli, Nur Ratasha Alia Md; Mohamed, Faizal; Radiman, Shahidan; Rahman, Irman Abdul

    2014-09-01

    DPPC lipids are the major component constituting the biological membrane, and their importances in various physiological functions are well documented. Hyaluronic acid (HA) in the synovial joint fluid functions as a lubricant, shock absorber and a nutrient carrier. Gamma irradiation has also been found to be effective in depolymerizing and cleaving molecular chains related to free radicals, thus extends with changes in chemical composition as well as its physiological functions. This research are conducted to investigate the hyaluronic acid (HA) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) interaction in form of vesicles and its effect to gamma radiation. The size of DPPC vesicles formed via gentle hydration method is between 100 to 200 nm in diameter. HA (0.1, 0.5 and 1.0 mg/ml) was added into the vesicles and characterized by using TEM to determine vesicle size distributions, fusion and rupture of DPPC structure. The results demonstrated that the size of the vesicles approximately between 200 to 300 nm which caused by vesicles fusion with HA and formed even larger vesicles. After being irradiated by 0 to 200 Gy, the size of vesicles decreased as HA was degraded. To elucidate the mechanism of these effects, FTIR spectra were carried out and have shown that at absorption bands at 1700-1750 cm-1 due to formation of carboxylic acid and leads to alteration of HA structure.

  3. Effect of. gamma. -irradiated DNA on the activity of DNA polymerase. [/sup 60/Co

    SciTech Connect

    Leadon, S.A.; Ward, J.F.

    1981-06-01

    A cell-free assay was developed to measure the effect of ..gamma..-irradiated DNA template on the ability of DNA polymerase to copy unirradiated template. Doses as low as 1 krad were able to decrease (approx. 15%) the activity of both bacterial and mammalian DNA polymerases in the assay. The percentage of polymerase activity decreased as the dose received by the template increased. The reduction in DNA polymerase activity was shown to be due to an inhibition of the enzyme by the irradiated DNA. Irradiated poly(dA-dT) was more effective in reducing polymerase activity than calf thymus DNA. Thus the polymerase-inhibition site(s) appears to be associated with base damage, specifically adenine or thymine. Using a free-radical scavenger, OH radicals were found to be involved in producing the damage sites. The interaction between irradiated DNA and DNA polymerase was found to be specific for the enzyme and not for other proteins present in the assay. The inhibition of DNA polymerase occurred prior to or during the initiation of DNA synthesis rather than after initiation of synthesis, i.e., during elongation.

  4. Degradation of poly(bisphenol- a-epichlorohydrin) by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Özdemir, Tonguç; Usanmaz, Ali

    2008-06-01

    In this study, radiation stability of poly(bisphenol- a-epichlorohydrin) (PBEH) was studied via gamma irradiations at two different dose rates of 1540 and 82.8 Gy/h, in order to understand the possible use of PBEH in radioactive waste management as a solidifying agent. The total dose of irradiation was up to 2150 kGy. Degradation nature was tested by studying the changes in mechanical and thermal properties with the change of dose rate and total dose of irradiation. Tensile strength at yield was increased first then decreased when irradiated, while toughness decreased. The half value dose (HVD) of elongation was found as 29 kGy at dose rate of 1540 Gy/h. The non-irradiated PBEH was transparent, and the color changed to yellow with irradiation. Mechanical tests showed that PBEH has high radiation stability although there were some structural changes. It was seen that PBEH is a candidate polymer to be used in the immobilization of radioactive waste regarding radiation stability.

  5. Antioxidant capacities and total phenolic contents increase with gamma irradiation in two types of Malaysian honey.

    PubMed

    Hussein, Saba Zuhair; Yusoff, Kamaruddin Mohd; Makpol, Suzana; Yusof, Yasmin Anum Mohd

    2011-07-27

    Two types of monofloral Malaysian honey (Gelam and Nenas) were analyzed to determine their antioxidant activities and total phenolic and flavonoid contents, with and without gamma irradiation. Our results showed that both types of honey can scavenge free radicals and exhibit high antioxidant-reducing power; however, Gelam honey exhibited higher antioxidant activity (p < 0.05) than Nenas honey, which is in good correlation (r = 0.9899) with its phenolic contents. Interestingly, we also noted that both irradiated honeys have higher antioxidant activities and total phenolic and flavonoid contents compared to nonirradiated honeys by Folin-Ciocalteu and UV-spectrophotometry methods, respectively. However, HPLC analysis for phenolic compounds showed insignificant increase between irradiated and nonirradiated honeys. The phenolic compounds such as: caffeic acid, chlorogenic acid, ellagic acid, p- coumaric acid, quercetin and hesperetin as indicated by HPLC method were found to be higher in Gelam honey versus Nenas honey. In conclusion, irradiation of honey causes enhanced antioxidant activities and flavonoid compounds.

  6. Gamma-irradiation effect on a commercial composite anticorrosive pigment and acidity-to-alkalinity conversion

    NASA Astrophysics Data System (ADS)

    Song, Weiqiang; Niu, Kaihui; Wu, Longchao

    2016-05-01

    A commercial composite anticorrosive pigment based on aluminum dihydrogen tripolyphosphate was studied after exposure to gamma irradiation (Co60, 0, 20, 50, 100 and 150 kGy) using FTIR, XRD, TGA and acid-base titration technologies. Although the FTIR spectra showed that the effect of the irradiation on functional groups in the pigments was not obvious, the decrease in the crystal lattice parameters of the irradiated pigments was observed in the XRD spectra compared to the non-irradiated sample. But the extent of the lattice parameter decrease monotonically with the increase of absorbed dose from 20 to 150 kGy, which was attributed to the decomposition of water and the simultaneous occurrence of lattice damage when the pigments were exposed to gamma rays. Of particular significance was the displayed basicity of the aqueous solutions of the irradiated pigments compared to the acidity of the solution of the non-irradiated pigment, which was attributed to the decomposition of P-OH groups (combined water).

  7. DSC studies of retrogradation and amylose lipid complex transition taking place in gamma irradiated wheat starch

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Eliasson, A. C.

    2007-12-01

    The effect of gamma irradiation ( 60Co) with doses of 5-30 kGy on the amylose-lipid complex transition and retrogradation occurring in gels containing ca. 50% and ca. 20% wheat starch was studied by differential scanning calorimetry (DSC) during heating-cooling-heating cycles (up to three cycles). Transition of the amylose-lipid complex occurs in all the irradiated samples at a lower temperature as compared to the non-irradiated starch. That effect was larger when the radiation dose was higher. A further thermal treatment causes a decrease of the transition temperature in the irradiated samples, with no effect or increase of that temperature observed for the non-irradiated ones. Irradiation hinders retrogradation taking place in 50% gels but facilitates the process occurring in 20% gels. The differences between the irradiated and the non-irradiated samples are more evident in the every next heating or cooling cycle as well as after storage and in the case of ca. 50% suspensions as compared to ca. 20% suspensions. The results point out to the deterioration of the structure of the complexes formed in the irradiated starch as compared to the non-irradiated one.

  8. Application of gamma irradiation for inactivation of three pathogenic bacteria inoculated into meatballs

    NASA Astrophysics Data System (ADS)

    Gumus, Tuncay; Şukru Demirci, A.; Murat Velioglu, H.; Velioglu, Serap D.; Yilmaz, Ismail; Sagdic, Osman

    2008-09-01

    In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157:H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples were inoculated with pathogens and irradiated at the absorbed doses of 1, 2.2, 3.2, 4.5 and 5.2 kGy. E. coli O157:H7 count in 1 kGy irradiated meatballs stored in the refrigerator for 7 days was detected to be 4 log cfu/g lower than the count in nonirradiated samples ( p<0.05). S. aureus counts were decreased to 4 log cfu/g after being exposed to irradiation at a dose of 1 kGy. Although it was ineffective on elimination of S. typhimurium, irradiation at a dose of 3.2 kGy reduced E. coli O157:H7 and S. aureus counts under detectable values in the meatballs. However, none of the test organisms were detected in the samples after irradiation with 4.5 kGy doses.

  9. Effect of gamma irradiation on the wear behaviour of human tooth enamel

    PubMed Central

    Qing, Ping; Huang, Shengbin; Gao, ShanShan; Qian, LinMao; Yu, HaiYang

    2015-01-01

    Radiotherapy is a frequently used treatment for oral cancer. Extensive research has been conducted to detect the mechanical properties of dental hard tissues after irradiation at the macroscale. However, little is known about the influence of irradiation on the tribological properties of enamel at the micro- or nanoscale. Therefore, this study aimed to investigate the effect of gamma irradiation on the wear behaviour of human tooth enamel in relation to prism orientation. Nanoscratch tests, surface profilometer and scanning electron microscope (SEM) analysis were used to evaluate the friction behaviour of enamel slabs before and after treatment with identical irradiation procedures. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were performed to analyse the changes in crystallography and chemical composition induced by irradiation. Surface microhardness (SMH) alteration was also evaluated. The results showed that irradiation resulted in different scratch morphologies, friction coefficients and remnant depth and width at different loads. An inferior nanoscratch resistance was observed independent of prism orientation. Moreover, the variation of wear behaviours was closely related to changes in the crystallography, chemical composition and SMH of the enamel. Together, these measures indicated that irradiation had a direct deleterious effect on the wear behaviour of human tooth enamel. PMID:26099692

  10. Effect of cement kiln dust and gamma irradiation on the ultrasonic parameters of HMO borate glasses

    NASA Astrophysics Data System (ADS)

    Abd elfadeel, G.; Saddeek, Yasser B.; Mohamed, Gehan Y.; Mostafa, A. M. A.; Shokry Hassan, H.

    2017-03-01

    Glass samples with the chemical formula x CKD-(100 - x) (5Na2O-65 B2O3-9 Bi2O3-21PbO), (0 ⩽ x ⩽ 32 mol%) were prepared. The density and the ultrasonic estimations of the investigated glasses were analyzed at room temperature before and after the impact of two dosages of gamma irradiation to study the effect of both CKD and gamma radiation. It was found that the density, and the ultrasonic parameters are sensitive to the variety of the content of CKD and the effect of γ-radiation. Replacement of oxides with higher atomic weights such as Bi2O3 and PbO by CKD decreases the density. Analysis of the behavior of the ultrasonic parameters demonstrates that creation of CaO6 and SiO4 on one hand and an alternate transformation between BO4 and BO3 structural units, on the other hand, affect the increase of the ultrasonic velocities and the elastic moduli. Moreover, the density and the ultrasonic parameters decrease somewhat with the increase of the doses of γ-irradiation. The variations of the previous physical parameters can be referred to the creation of radiation imperfections, which occupied the voids inside the glass structure.

  11. Hemopathologic consequences of protracted gamma irradiation: alterations in granulocyte reserves and granulocyte mobilization

    SciTech Connect

    Seed, T.M.; Cullen, S.M.; Kaspar, L.V.; Tolle, D.V.; Fritz, T.E.

    1980-07-01

    Aplastic anemia and myelogenous leukemia are prominent pathologic effects in beagles exposed to continuous, daily, low-dose gamma irradiation. In the present work, granulocyte reserves and related mobilization functions have been sequentially assessed by the endotoxin stress assay during the preclinical and clinical phases of these hemopoietic disorders. Characteristic patterns of granulocyte reserve mobilization are described that reflect given stages of pathologic progression. For radiation-induced leukemia, a five-stage pattern has been proposed. In contrast, a simple pattern of progressive, time-dependent contraction of granulocyte reserves and mobilization capacity was noted in the development of terminal aplastic anemia. Early preclinical phases of radiation-induced leukemia appear to involve an extensive depletion of the granulocyte reserves (phase I) during the first approx. 200 days of exposure followed by a partial renewal of the reserves and associated mobilization functions between approx. 200 and 400 days (phase II). Sustained, subnormal granulocyte mobilizations (phase III) following endotoxin stress typify the responses of dogs during the intermediate phase, whereas late preclinical, preleukemic stages (phase IV) are characterized by a further expansion of the reserves and in the mobilization capacities, particularly of the less mature granulocytes. Such late alterations in the pattern of granulocyte mobilization, together with other noted cellular aberrancies in the peripheral blood and marrow, appear to indicate leukemia (phase V) onset.

  12. Raman spectroscopy of 2-hydroxyethyl methacrylate-acrylamide copolymer using gamma irradiation for crosslinking

    SciTech Connect

    Goheen, Steven C.; Saunders, Rachel M.; Davis, Rachel M.; Harvey, Scott D.; Olsen, Peter C.

    2006-02-18

    A copolymer hydrogel was made by mixing acrylamide and 2-hydroxyethyl methacrylate monomers in water and polymerizing with gamma irradiation. The progress of polymerization and the vibrational structure of the hydrogel was examined using Raman spectroscopy. Raman spectra indicated that the co-polymer has a molecular structure different from polyacrylamide or the individual monomers. The Raman data also indicate the presence of crosslinking at the C=O, NH2 and OH side chains. The spectra further suggest the continuous lengthening of the backbone of the polymers with increasing gamma dose. This is shown as the increase in C-C modes as C=C vibrations decrease. Raman spectra changed most dramatically as the monomer mixture became a gel at a dose of approximately 320 Gy. Spectral differences were subtler with doses exceeding 640 Gy, although chain lengthening continued beyond 1500 Gy. Potential applications of the copolymer hydrogel include reconstructive tissue as well as a standard material for radiation protection dosimetry. Results are discussed in relation to other potential applications of this polymer and dose-dependent changes in the Raman spectrum.

  13. Gamma Irradiation Facility at Sandia National Laboratories, Albuquerque, New Mexico. Final environmental assessment

    SciTech Connect

    1995-11-01

    The US Department of Energy (DOE) has prepared an environmental assessment (EA) on the proposed construction and operation of a new Gamma Irradiation Facility (GIF) at Sandia National Laboratories/New Mexico (SNL/NM). This facility is needed to: enhance capabilities to assure technical excellence in nuclear weapon radiation environments testing, component development, and certification; comply with all applicable ES and H safeguards, standards, policies, and regulations; reduce personnel radiological exposure to comply with ALARA limits in accordance with DOE orders and standards; consolidate major gamma ray sources into a central, secured area; and reduce operational risks associated with operation of the GIF and LICA in their present locations. This proposed action provides for the design, construction, and operation of a new GIF located within TA V and the removal of the existing GIF and Low Intensity Cobalt Array (LICA). The proposed action includes potential demolition of the gamma shield walls and removal of equipment in the existing GIF and LICA. The shielding pool used by the existing GIF will remain as part of the ACRR facility. Transportation of the existing {sup 60}Co sources from the existing LICA and GIF to the new facility is also included in the proposed action. Relocation of the gamma sources to the new GIF will be accomplished by similar techniques to those used to install the sources originally.

  14. Suitability of gamma irradiated chitosan based membranes as matrix in drug release system.

    PubMed

    Casimiro, M H; Gil, M H; Leal, J P

    2010-08-16

    To test the possibility of obtain a material simultaneously biocompatible and microbiologically safe to be used as wound dressing material and as a matrix for drug release system, membranes with different initial contents in chitosan and 2-hydroxyethyl methacrylate (HEMA) have been prepared by gamma irradiation from a (60)Co source. The antimicrobial activity of obtained membranes against several reference strains was evaluated after inoculation. Sub-lethal gamma radiation doses were also applied in artificially contaminated membranes and the D(values) of microorganisms in use were determined in order to predict which radiation dose could guarantee membranes microbiological safety. In vitro haemolysis tests were also performed using drug loaded membranes irradiated at different doses. Results point out that those membranes naturally exhibit antimicrobial properties. Also show that, over the studied range values, drug loaded irradiated membranes display a non-significant level of haemolysis. These features show that the application of prepared membranes as a transdermal drug release system "ready to use" is viable.

  15. Effect of gamma irradiation on hyaluronic acid and dipalmitoylphosphatidylcholine (DPPC) interaction

    SciTech Connect

    Ahmad, Ainee Fatimah; Mohd, Hur Munawar Kabir; Taqiyuddin Mawardi bin Ayob, Muhammad; Rosli, Nur Ratasha Alia Md; Mohamed, Faizal; Radiman, Shahidan; Rahman, Irman Abdul

    2014-09-03

    DPPC lipids are the major component constituting the biological membrane, and their importances in various physiological functions are well documented. Hyaluronic acid (HA) in the synovial joint fluid functions as a lubricant, shock absorber and a nutrient carrier. Gamma irradiation has also been found to be effective in depolymerizing and cleaving molecular chains related to free radicals, thus extends with changes in chemical composition as well as its physiological functions. This research are conducted to investigate the hyaluronic acid (HA) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) interaction in form of vesicles and its effect to gamma radiation. The size of DPPC vesicles formed via gentle hydration method is between 100 to 200 nm in diameter. HA (0.1, 0.5 and 1.0 mg/ml) was added into the vesicles and characterized by using TEM to determine vesicle size distributions, fusion and rupture of DPPC structure. The results demonstrated that the size of the vesicles approximately between 200 to 300 nm which caused by vesicles fusion with HA and formed even larger vesicles. After being irradiated by 0 to 200 Gy, the size of vesicles decreased as HA was degraded. To elucidate the mechanism of these effects, FTIR spectra were carried out and have shown that at absorption bands at 1700–1750 cm{sup −1} due to formation of carboxylic acid and leads to alteration of HA structure.

  16. Genistein nanoparticles protect mouse hematopoietic system and prevent proinflammatory factors after gamma irradiation.

    PubMed

    Ha, Cam T; Li, Xiang-Hong; Fu, Dadin; Xiao, Mang; Landauer, Michael R

    2013-09-01

    Previous studies demonstrated that genistein protects mice from radiation-induced bone marrow failure. To overcome genistein's extremely low water solubility, a nanoparticle suspension of genistein has been formulated for more rapid dissolution. In the current study, we evaluated the radioprotective effects of a nanoparticle formulation of genistein on survival and hematopoietic recovery in mice exposed to total-body gamma irradiation. A single intramuscular injection of a saline-based genistein nanosuspension (150 mg/kg) administered to CD2F1 mice 24 h before 9.25 Gy (60)Co radiation exposure resulted in a 30-day survival rate of 95% compared to 25% in vehicle-treated animals. In mice irradiated at 7 Gy, the genistein nanosuspension increased mouse bone marrow cellularity from approximately 2.9% (vehicle treated) to 28.3% on day 7 postirradiation. Flow cytometry analysis demonstrated decreased radiation-induced hematopoietic stem and progenitor cell (HSPC, Lineage(-)/cKit(+)) death from 77.0% (vehicle) to 43.9% (genistein nanosuspension) with a significant recovery of clonogenicity 7 days after irradiation. The genistein nanosuspension also attenuated the radiation-induced elevation of proinflammatory factors interleukin 1 beta (IL-1β), IL-6 and cyclooxygenase-2 (COX-2) in mouse bone marrow and spleen, which may contribute to protecting HSPCs.

  17. Effect of gamma irradiation on the wear behaviour of human tooth enamel.

    PubMed

    Qing, Ping; Huang, Shengbin; Gao, ShanShan; Qian, LinMao; Yu, HaiYang

    2015-06-23

    Radiotherapy is a frequently used treatment for oral cancer. Extensive research has been conducted to detect the mechanical properties of dental hard tissues after irradiation at the macroscale. However, little is known about the influence of irradiation on the tribological properties of enamel at the micro- or nanoscale. Therefore, this study aimed to investigate the effect of gamma irradiation on the wear behaviour of human tooth enamel in relation to prism orientation. Nanoscratch tests, surface profilometer and scanning electron microscope (SEM) analysis were used to evaluate the friction behaviour of enamel slabs before and after treatment with identical irradiation procedures. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were performed to analyse the changes in crystallography and chemical composition induced by irradiation. Surface microhardness (SMH) alteration was also evaluated. The results showed that irradiation resulted in different scratch morphologies, friction coefficients and remnant depth and width at different loads. An inferior nanoscratch resistance was observed independent of prism orientation. Moreover, the variation of wear behaviours was closely related to changes in the crystallography, chemical composition and SMH of the enamel. Together, these measures indicated that irradiation had a direct deleterious effect on the wear behaviour of human tooth enamel.

  18. A Quantitative Proteomic Analysis of Urine from Gamma-Irradiated Non-Human Primates

    PubMed Central

    Byrum, Stephanie D; Burdine, Marie S; Orr, Lisa; Moreland, Linley; Mackintosh, Samuel G; Authier, Simon; Pouliot, Mylene; Hauer-Jensen, Martin; Tackett, Alan J

    2016-01-01

    The molecular effects of total body gamma-irradiation exposure are of critical importance as large populations of people could be exposed either by terrorists, nuclear blast, or medical therapy. In this study, we aimed to identify changes in the urine proteome using a non-human primate model system, Rhesus macaque, in order to characterize effects of acute radiation syndrome following whole body irradiation (Co-60) at 6.7 Gy and 7.4 Gy with a twelve day observation period. The urine proteome is potentially a valuable and non-invasive diagnostic for radiation exposure. Using high-resolution mass spectrometry, we identified 2346 proteins in the urine proteome. We show proteins involved in disease, cell adhesion, and metabolic pathway were significantly changed upon exposure to differing levels and durations of radiation exposure. Cell damage increased at a faster rate at 7.4 Gy compared with 6.7 Gy exposures. We report sets of proteins that are putative biomarkers of time- and dose-dependent radiation exposure. The proteomic study presented here is a comprehensive analysis of the urine proteome following radiation exposure. PMID:26962295

  19. Manufacture of ice cream with improved microbiological safety by using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Woon; Kim, Hyun-Joo; Yoon, Yohan; Kim, Jae-Hun; Ham, Jun-Sang; Byun, Myung-Woo; Baek, Min; Jo, Cheorun; Shin, Myung-Gon

    2009-07-01

    Children suffered from leukemia want to eat delicious dishes, such as cake and ice cream. However, it is very difficult to serve these foods to immune-compromised patients without application of any adequate sanitary measures. This study was conducted to evaluate application of irradiation to frozen ready-to-eat food, ice cream. Three ice creams with flavors of vanilla, chocolate and strawberry were manufactured and gamma irradiated at the absorbed doses of 1, 3, and 5 kGy at -70 °C. Total microflora and coliform bacteria were determined, and Listeria spp., Escherichia coli and Salmonella spp. were also tested by the use of API 20E Kit. Aerobic bacteria, yeast/mold and coliforms were contaminated in the levels of 2.3 to 3.3, 2.3 to 2.7 and 1.7 to 2.4 log CFU/g, respectively. In samples irradiated at 5 kGy, the growth of any microorganisms could not be observed. Listeria spp. and E. coli were detected at non-irradiated samples, but S. spp. was not existed. D10 values of L. ivanovii and E. coli were 0.75 and 0.31 kGy, respectively, in ice cream. From these results, irradiation technology can reduce the risk by the food-borne pathogens of ice cream.

  20. Comparative effects of gamma irradiation and phosphine fumigation on the quality of white ginseng

    NASA Astrophysics Data System (ADS)

    Kwon, J.-H. J.-H.; Byun, M.-W. M.-W.; Kim, K.-S. K.-S.; Kang, I.-J. I.-J.

    2000-03-01

    The hygienic, physicochemical, and organoleptic qualities of white ginseng were monitored during 6 months under accelerated conditions (40°C, 90% r.h.) by observing its microbial populations, disinfestation, and some quality attributes following either gamma irradiation at 2.5-10 kGy or commercial phosphine (PH 3) fumigation. In a comparative study, both treatments were found to be effective for disinfecting the stored samples. Phosphine showed no appreciable decontaminating effects on microorganisms contaminated including coliforms, while 5 kGy irradiation was sufficient to control all microorganisms related to the quality of the packed samples. Irradiation at 5 kGy caused negligible changes in physicochemical attributes of the samples, such as ginsenosides, amino acids, fatty acids, and organoleptic properties, whereas phosphine fumigation was found detrimental to sensory flavor ( P<0.01). Quality deterioration occurred in the commercially-packed samples was in the following order: the control, 10 kGy-, phosphine-, and 2.5-5 kGy-treated samples. Accordingly, irradiation at <5 kGy was found to be an effective alternative to phosphine fumigation for white ginseng.

  1. Effect of gamma irradiation on mechanical, thermal and rheological behavior of HDPE filled with seaweed residues

    NASA Astrophysics Data System (ADS)

    Cataño, L.; Albano, C.; Karam, A.; Domínguez, N.; Sánchez, Y.; González, J.

    2005-07-01

    The present work shows the results obtained during the investigation of the influence of gamma irradiation on mechanical, thermal and rheological properties of high-density polyethylene (HDPE) filled with seaweed residues (SR). The SR used was located on Venezuelan coastlines and they are composed mainly by CaCO3 in aragonite phase. The HDPE was extruded along with the filler at different compositions (20, 30 and 40 wt.%). The composites were exposed to a 60Co source irradiated at 25 and 100 kGy. From the obtained results, it was noticed that Young modulus remained constant with filler content. Moreover, the influence of filler content was found to be more prominent on properties like tensile stress and elongation at break. On the other hand, thermal analysis showed that filler content had no significant influence on thermal stability. Still, it is necessary to point out that low radiation doses improved thermal stability of the composites. From rheological studies it was observed a decreasing of melt flow index (MFI) by increasing the SR amount and radiation. Therefore, was determinate that high filler content composites are the best choice to be considered for biomedical and industrial applications.

  2. Gamma Irradiation and Oxidative Degradation of a Silica-Filled Silicone Elastomer

    DOE PAGES

    Labouriau, Andrea; Cady, Carl Mcelhinney; Gill, John T.; ...

    2015-03-21

    The radiation oxidative degradation of a commonly used silica-filled silicone elastomer DC745 was investigated by a series of experimental techniques. This elastomer is known to be chemically and thermally stable, but insufficient data exist on the radiation resistance. In the present work, gamma doses up to 200 kGy were applied under air at RT and 1Gy/s. Radiation chemical changes were investigated by NMR, FT-IR, Raman, and mass spectroscopy. DSC and TGA experiments probed thermal transitions and thermal stability changes with exposure dose. SEM probed variations on the surface of the elastomer, and solvent swelling methods were used to investigate changesmore » in the polymer network properties. Electron paramagnetic resonance was employed to detect and identify free radicals. Uniaxial compression load tests at variable temperatures were performed to assess changes in the material’s mechanical response as a function of radiation dose. Results demonstrate that, with increasing exposure, DC745 undergoes changes in chemistry that lead to an increase in thermal stability and cross-link density, formation of free radical species, decrease in heat of fusion and increase in stiffness at low temperatures. Taken together, these results indicate that oxidative cross-linking is the dominant radiolysis mechanism that occurs when this material is exposed to gamma irradiation in air at high dose rates.« less

  3. Competitiveness of gamma irradiation with fumigation for chestnuts associated with quarantine and quality security

    NASA Astrophysics Data System (ADS)

    Kwon, Joong-Ho; Kwon, Yong-Jung; Byun, Myung-Woo; Kim, Kyong-Su

    2004-09-01

    Comparative effects of gamma irradiation and methyl bromide (MeBr) fumigation were determined for fresh chestnut on mortality of pests and quality stability. Chestnut was exposed to both irradiation at 0-10 kGy and MeBr fumigation in commercial conditions, and then subjected to the corresponding study during storage at 5°C for 6 months. Pests with quarantine importance for chestnut were found Curculio sikkimensis Heller and Dichocrocis punctiferalis Guenee, which showed 100% mortality by MeBr at the 3rd day after fumigation and by irradiation at 0.5 kGy in about 4 weeks. Sprouting was controlled for 6 months with treatments of 0.25 kGy or more and of MeBr, but rotting rate dramatically increased from 2 months after fumigation. Irradiation over 1 kGy as well as fumigation significantly caused changes in the color of stored chestnut. Considering the cumulative mortality of chestnut pests, irradiation at the range of 0.5 kGy is recommendable as one of alternatives to MeBr fumigation for both quarantine and sprout control purposes.

  4. Kinetics of the radiation-induced radicals in gamma irradiated solid cefazolin sodium

    NASA Astrophysics Data System (ADS)

    Yurus, S.; Korkmaz, M.

    2005-01-01

    Room and high temperature kinetic and spectroscopic features of the radical species produced in gamma irradiated cefazolin sodium (here after CS) were investigated in detail using electron spin resonance (ESR) spectroscopy to determine the feasibility of its sterilization by radiation and to explore the dosimetric properties of this semi-synthetic representative of cephalosporins. Irradiated CS exhibits an unresolved ESR doublet as other cephalosporins reported up to date. Signal intensity data derived from microwave saturation, dose-response, decays at room and at high temperature studies were analysed assuming a model of two radical species giving rise to doublet and singlet ESR signals. Spectroscopic parameters of these species were determined through spectrum simulation calculations. Decay parameters calculated from annealing studies at seven different temperatures were used to calculate the activation energies of the contributing species. Radiosensitivity of CS to gamma rays was found to be relatively low in the dose range of 0-25 kGy. This conclusion was considered as an indication of the feasibility of radiosterilization of CS by gamma radiation. Five different functions were tried to explore dose-response data of CS in the dose range of 0-25 kGy and it was concluded that a function comprising a linear and a quadratic terms of applied dose describes best experimental results.

  5. Structural and optical modifications in gamma-irradiated polyimide/silica nanocomposite

    NASA Astrophysics Data System (ADS)

    Nouh, S. A.; Tommalieh, M. J.; El-Shamy, N. T.

    2015-06-01

    The structural and optical properties of thin films of polyimide composites with nanosilica particle content of 15 wt%, prepared via sol-gel process, were studied as a function of the gamma dose. The resultant effect of gamma irradiation on the properties of polyimide/silica nanocomposite has been investigated using X-ray diffraction and UV spectroscopy. Absorption and reflectance spectra were collected by a spectrophotometer giving UV-radiation of wavelength range 200-800 nm. The optical data obtained were analyzed and the calculated values of the optical energy gap exhibited gamma dose dependence. The direct optical energy gap for the nonirradiated polyimide/silica nanocomposite is about 2.41 eV, and increases to a value of 2.65 eV when irradiated with gamma doses up to 300 kGy. It was found that the calculated refractive index of the polyamide/silica increases with the gamma dose in the range 50-300 kGy.

  6. Effect of gamma irradiation on the antimicrobial and free radical scavenging activities of Glycyrrhiza glabra root

    NASA Astrophysics Data System (ADS)

    Fatima Khattak, Khanzadi; James Simpson, Thomas

    2010-04-01

    The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in samples treated with 20 and 25 kGy doses. The DPPH scavenging activity significantly ( p<0.05) increased in all irradiated samples of the plant.

  7. Effect of gamma irradiation and cooking on cowpea bean grains ( Vigna unguiculata L. Walp)

    NASA Astrophysics Data System (ADS)

    Lima, Keila dos Santos Cople; Souza, Luciana Boher e.; Godoy, Ronoel Luiz de Oliveira; França, Tanos Celmar Costa; Lima, Antônio Luís dos Santos

    2011-09-01

    Leguminous plants are important sources of proteins, vitamins, carbohydrates, fibers and minerals. However, some of their non-nutritive elements can present undesirable side effects like flatulence provoked by the anaerobic fermentation of oligosaccharides, such as raffinose and stachyose, in the gut. A way to avoid this inconvenience, without any change in the nutritional value and post-harvesting losses, is an irradiation process. Here, we evaluated the effects of gamma irradiation on the amino acids, thiamine and oligosaccharide contents and on the fungi and their toxin percentages in cowpea bean ( Vigna unguiculata L. Walp) samples. For irradiation doses of 0.0, 0.5, 1.0, 2.5, 5.0 and 10.0 kGy the results showed no significant differences in content for the uncooked samples. However, the combination of irradiation and cooking processes reduced the non-nutritive factors responsible for flatulence. Irradiation also significantly reduced the presence of Aspergillus, Penicilium, Rhizopus and Fusarium fungi and was shown to be efficient in grain conservation for a storage time of 6 months.

  8. Environmental stress cracking in gamma-irradiated polycarbonate - A diffusion approach

    NASA Astrophysics Data System (ADS)

    Silva, Pietro Paolo J. C. de O.; Araújo, Patricia L. B.; da Silveira, Leopoldo B. B.; Araújo, Elmo S.

    2017-01-01

    Polycarbonate (PC) is an engineering polymer which presents interesting properties. This material has been also used in medical devices, which is frequently exposed to gamma radiosterilization and to chemical agents. This may produce significant changes in polymer structure, leading to failure in service. The present work brings about a new approach on environmental stress cracking (ESC) processes elucidation in 100 kGy gamma-irradiated PC, by evaluating the diffusion process of methanol or 2-propanol in test specimens and determining the diffusion parameters on solvent-irradiated polymer systems. A comparison of diffusion parameters for both solvents indicated that methanol has a considerable ESC action on PC, with diffusion parameter of 7.5×10-14±1% m2 s-1 for non-irradiated PC and 7.8×10-14±2.8% m2 s-1 for PC irradiated at 100 kGy. In contrast, 2-propanol did not act as an ESC agent, as it did promote neither swelling nor cracks in the test specimens. These results were confirmed by visual analysis and optical microscopy. Unexpectedly, structural damages evidenced in tensile strength tests suggested that 2-propanol is as aggressive as methanol chemical for PC. Moreover, although some manufacturers indicate the use of 2-propanol as a cleaning product for PC artifacts, such use should be avoided in parts under mechanical stress.

  9. Elimination of coliforms and Salmonella spp. in sheep meat by gamma irradiation treatment

    PubMed Central

    Henriques, Luciana Salles Vasconcelos; da Costa Henry, Fábio; Barbosa, João Batista; Ladeira, Silvania Alves; de Faria Pereira, Silvia Menezes; da Silva Antonio, Isabela Maria; Teixeira, Gina Nunes; Martins, Meire Lelis Leal; de Carvalho Vital, Helio; dos Prazeres Rodrigues, Dália; dos Reis, Eliane Moura Falavina

    2013-01-01

    This study aimed at evaluating the bacteriological effects of the treatment of sheep meat contaminated with total coliforms, coliforms at 45 °C and Salmonella spp. by using irradiation at doses of 3 kGy and 5 kGy. Thirty sheep meat samples were collected from animals located in Rio de Janeiro State, Brazil, and then grouped in three lots including 10 samples: non-irradiated (control); irradiated with 3 kGy; and irradiated with 5 kGy. Exposure to gamma radiation in a 137Cs source-driven irradiating facility was perfomed at the Nuclear Defense Section of the Brazilian Army Technological Center (CTEx) in Rio de Janeiro. The samples were kept under freezing temperature (−18 °C) until the analyses, which occurred in two and four months after irradiation. The results were interpreted by comparison with the standards of the current legislation and demonstrated that non-irradiated samples were outside the parameters established by law for all groups of bacteria studied. Gamma irradiation was effective in inactivating those microorganisms at both doses tested and the optimal dose was achieved at 3 kGy. The results have shown not only the need for sanitary conditions improvements in slaughter and processing of sheep meat but also the irradiation effectiveness to eliminate coliform bacteria and Salmonella spp. PMID:24688504

  10. Elimination of coliforms and Salmonella spp. in sheep meat by gamma irradiation treatment.

    PubMed

    Henriques, Luciana Salles Vasconcelos; da Costa Henry, Fábio; Barbosa, João Batista; Ladeira, Silvania Alves; de Faria Pereira, Silvia Menezes; da Silva Antonio, Isabela Maria; Teixeira, Gina Nunes; Martins, Meire Lelis Leal; de Carvalho Vital, Helio; dos Prazeres Rodrigues, Dália; dos Reis, Eliane Moura Falavina

    2013-12-01

    This study aimed at evaluating the bacteriological effects of the treatment of sheep meat contaminated with total coliforms, coliforms at 45 °C and Salmonella spp. by using irradiation at doses of 3 kGy and 5 kGy. Thirty sheep meat samples were collected from animals located in Rio de Janeiro State, Brazil, and then grouped in three lots including 10 samples: non-irradiated (control); irradiated with 3 kGy; and irradiated with 5 kGy. Exposure to gamma radiation in a (137)Cs source-driven irradiating facility was performed at the Nuclear Defense Section of the Brazilian Army Technological Center (CTEx) in Rio de Janeiro. The samples were kept under freezing temperature (-18 °C) until the analyses, which occurred in two and four months after irradiation. The results were interpreted by comparison with the standards of the current legislation and demonstrated that non-irradiated samples were outside the parameters established by law for all groups of bacteria studied. Gamma irradiation was effective in inactivating those microorganisms at both doses tested and the optimal dose was achieved at 3 kGy. The results have shown not only the need for sanitary conditions improvements in slaughter and processing of sheep meat but also the irradiation effectiveness to eliminate coliform bacteria and Salmonella spp.

  11. Gamma Irradiation and Oxidative Degradation of a Silica-Filled Silicone Elastomer

    SciTech Connect

    Labouriau, Andrea; Cady, Carl Mcelhinney; Gill, John T.; Stull, Jamie Ann; Ortiz-Acosta, Denisse; Henderson, Kevin C.; Hartung, Vaughn; Quintana, Adam; Celina, Mathew C.

    2015-03-21

    The radiation oxidative degradation of a commonly used silica-filled silicone elastomer DC745 was investigated by a series of experimental techniques. This elastomer is known to be chemically and thermally stable, but insufficient data exist on the radiation resistance. In the present work, gamma doses up to 200 kGy were applied under air at RT and 1Gy/s. Radiation chemical changes were investigated by NMR, FT-IR, Raman, and mass spectroscopy. DSC and TGA experiments probed thermal transitions and thermal stability changes with exposure dose. SEM probed variations on the surface of the elastomer, and solvent swelling methods were used to investigate changes in the polymer network properties. Electron paramagnetic resonance was employed to detect and identify free radicals. Uniaxial compression load tests at variable temperatures were performed to assess changes in the material’s mechanical response as a function of radiation dose. Results demonstrate that, with increasing exposure, DC745 undergoes changes in chemistry that lead to an increase in thermal stability and cross-link density, formation of free radical species, decrease in heat of fusion and increase in stiffness at low temperatures. Taken together, these results indicate that oxidative cross-linking is the dominant radiolysis mechanism that occurs when this material is exposed to gamma irradiation in air at high dose rates.

  12. Identification of Novel Genes Affected by Gamma Irradiation Using a Gene-Trapped Library of Human Mammary Epithelial Cells

    DTIC Science & Technology

    2005-04-01

    Chromosomal and chromatid analysis was performed on the DREV 1 knockdown MCF10A cells to access cel l survival following ionizing radiation treatment...statement of work as well as their response to ionizing radiation . 14 . SUBJECT TERMS 15 . NUMBER OF PAGE S 3 0 Gamma Irradiation, gene trapping...line with and without ionizing radiation treatment . We felt that it was important t o analyze the identified gene expression levels following IR

  13. The change in dielectric constant, AC conductivity and optical band gaps of polymer electrolyte film: Gamma irradiation

    SciTech Connect

    Raghu, S. Subramanya, K. Sharanappa, C. Mini, V. Archana, K. Sanjeev, Ganesh Devendrappa, H.

    2014-04-24

    The effects of gamma (γ) irradiation on dielectric and optical properties of polymer electrolyte film were investigated. The dielectric constant and ac conductivity increases with γ dose. Also optical band gap decreased from 4.23 to 3.78ev after irradiation. A large dependence of the polymer properties on the irradiation dose was noticed. This suggests that there is a possibility of improving polymer electrolyte properties on gamma irradiation.

  14. Performance studies under high irradiation and ageing properties of resistive bulk Micromegas chambers at the new CERN Gamma Irradiation Facility

    NASA Astrophysics Data System (ADS)

    Sidiropoulou, O.; Gonzalez, B. Alvarez; Bianco, M.; Farina, E. M.; Iengo, P.; Longo, L.; Pfeiffer, D.; Wotschack, J.

    2017-02-01

    Resistive bulk Micromegas chambers, produced at CERN, have been installed at the new CERN Gamma Irradiation Facility (GIF++) in order to study the effects of ageing and to evaluate the detector behaviour under high irradiation. The chambers have an active area of 10×10 cm2, strip pitch of 400 μm and an amplification gap of 128 μm. We present the detector performance as a function of the background rate of up to 20 MHz/cm2.

  15. High-level production of human interleukin-10 fusions in tobacco cell suspension cultures

    PubMed Central

    Kaldis, Angelo; Ahmad, Adil; Reid, Alexandra; McGarvey, Brian; Brandle, Jim; Ma, Shengwu; Jevnikar, Anthony; Kohalmi, Susanne E; Menassa, Rima

    2013-01-01

    The production of pharmaceutical proteins in plants has made much progress in recent years with the development of transient expression systems, transplastomic technology and humanizing glycosylation patterns in plants. However, the first therapeutic proteins approved for administration to humans and animals were made in plant cell suspensions for reasons of containment, rapid scale-up and lack of toxic contaminants. In this study, we have investigated the production of human interleukin-10 (IL-10) in tobacco BY-2 cell suspension and evaluated the effect of an elastin-like polypeptide tag (ELP) and a green fluorescent protein (GFP) tag on IL-10 accumulation. We report the highest accumulation levels of hIL-10 obtained with any stable plant expression system using the ELP fusion strategy. Although IL-10-ELP has cytokine activity, its activity is reduced compared to unfused IL-10, likely caused by interference of ELP with folding of IL-10. Green fluorescent protein has no effect on IL-10 accumulation, but examining the trafficking of IL-10-GFP over the cell culture cycle revealed fluorescence in the vacuole during the stationary phase of the culture growth cycle. Analysis of isolated vacuoles indicated that GFP alone is found in vacuoles, while the full-size fusion remains in the whole-cell extract. This indicates that GFP is cleaved off prior to its trafficking to the vacuole. On the other hand, IL-10-GFP-ELP remains mostly in the ER and accumulates to high levels. Protein bodies were observed at the end of the culture cycle and are thought to arise as a consequence of high levels of accumulation in the ER. PMID:23297698

  16. Effect of Magnetic Nanoparticles on Tobacco BY-2 Cell Suspension Culture

    PubMed Central

    Krystofova, Olga; Sochor, Jiri; Zitka, Ondrej; Babula, Petr; Kudrle, Vit; Adam, Vojtech; Kizek, Rene

    2012-01-01

    Nanomaterials are structures whose exceptionality is based on their large surface, which is closely connected with reactivity and modification possibilities. Due to these properties nanomaterials are used in textile industry (antibacterial textiles with silver nanoparticles), electronics (high-resolution imaging, logical circuits on the molecular level) and medicine. Medicine represents one of the most important fields of application of nanomaterials. They are investigated in connection with targeted therapy (infectious diseases, malignant diseases) or imaging (contrast agents). Nanomaterials including nanoparticles have a great application potential in the targeted transport of pharmaceuticals. However, there are some negative properties of nanoparticles, which must be carefully solved, as hydrophobic properties leading to instability in aqueous environment, and especially their possible toxicity. Data about toxicity of nanomaterials are still scarce. Due to this fact, in this work we focused on studying of the effect of magnetic nanoparticles (NPs) and modified magnetic nanoparticles (MNPs) on tobacco BY-2 plant cell suspension culture. We aimed at examining the effect of NPs and MNPs on growth, proteosynthesis—total protein content, thiols—reduced (GSH) and oxidized (GSSG) glutathione, phytochelatins PC2-5, glutathione S-transferase (GST) activity and antioxidant activity of BY-2 cells. Whereas the effect of NPs and MNPs on growth of cell suspension culture was only moderate, significant changes were detected in all other biochemical parameters. Significant changes in protein content, phytochelatins levels and GST activity were observed in BY-2 cells treated with MNPs nanoparticles treatment. Changes were also clearly evident in the case of application of NPs. Our results demonstrate the ability of MNPs to negatively affect metabolism and induce biosynthesis of protective compounds in a plant cell model represented by BY-2 cell suspension culture. The

  17. Effect of annealing on electronic carrier transport properties of gamma-irradiated AlGaN/GaN high electron mobility transistors

    NASA Astrophysics Data System (ADS)

    Yadav, Anupama; Schwarz, Casey; Shatkhin, Max; Wang, Luther; Flitsiyan, Elena; Chernyak, Leonid; Liu, Lu; Hwang, Ya; Ren, Fan; Pearton, Stephen; Department of Physics, University of Central Florida Collaboration; Department of Chemical Engineering, University of Florida Collaboration; Department of Materials Science; Engineering, University of Florida Collaboration

    2014-03-01

    AlGaN/GaN High Electron Mobility Transistors were irradiated with 60Co gamma-ray doses from 100Gy to 1000Gy, in order to analyze the effects of irradiation on the devices' transport properties. Temperature dependent Electron Beam Induced Current (EBIC) measurements, conducted on the devices before and after exposure to gamma-irradiation, allowed for the obtaining of activation energy related to radiation-induced defects due to nitrogen vacancies. Later, the devices were annealed at 200o C for 25 minutes. All the measurements were performed again to study the effect of annealing on the gamma-irradiated devices. Annealing of gamma-irradiated transistors shows that partial recovery of device performance is possible at this temperature. DC current-voltage measurements were also conducted on the transistors to assess the impact of gamma-irradiation and annealing on transfer, gate and drain characteristics.

  18. Effect of STI-571 (imatinib mesylate) in combination with retinoic acid and {gamma}-irradiation on viability of neuroblastoma cells

    SciTech Connect

    Roessler, Jochen . E-mail: jochen.roessler@uniklinik-freiburg.de; Zambrzycka, Izabella; Lagodny, Jeanette; Kontny, Udo; Niemeyer, Charlotte Marie

    2006-04-21

    Neuroblastoma (NB) expresses the tyrosine kinase receptors c-Kit, PDGFR-{alpha} and -{beta}-targets for STI-571.We investigated a possible combination therapy of STI-571 with retinoic acid (RA) and {gamma}-irradiation on NB cell viability in vitro. Expression of tyrosine kinase receptors and their ligands was examined in 6 NB cell lines by RT-PCR and FACS. The effect on cell viability was determined by MTT assay. Cell viability of all 6 NB cell lines was significantly inhibited after treatment with 20 {mu}M STI-571 for 72 h, two cell lines responding already to 10 {mu}M. Cell lines responded irrespective of their mRNA status or cell surface expression of c-Kit, PDGFR-{alpha} and -{beta}. Co-incubation with 9-cis RA sensitized cells to the inhibitory effects of STI-571. However, pre-treatment with 9-cis RA resulted in resistance of NB cell lines to STI-571 and {gamma}-irradiation. Treatment of NB with STI-571 in combination with 9-cis RA might be a therapeutic strategy for patients in consolidation therapy who have completed {gamma}-irradiation therapy.

  19. Influence of triallyl cyanurate as co-agent on gamma irradiation cured high density polyethylene/reclaimed tire rubber blend

    NASA Astrophysics Data System (ADS)

    Mali, Manoj N.; Arakh, Amar A.; Dubey, K. A.; Mhaske, S. T.

    2017-02-01

    Utilization of waste from tire industry as reclaimed tire rubber (RTR) by formation of blends with high density polyethylene (HDPE) is great area to be focused. Enhancement of properties by the addition of triallyl cyanurate (TAC) as a co-agent with 1%, 3% and 5% to blend of HDPE 50 wt% and RTR 50 wt% in presence of gamma irradiation curing were investigated. Specifically, mechanical and thermal properties were studied as a function of amount of TAC and gamma irradiation dose in range of 50-200 kGy. The resultant blends were evaluated for the values of impact strength, gel content, thermal stability, tensile properties, rheological properties and morphological properties with increasing irradiation dosage and TAC loading. The mechanical properties tensile strength, hardness, impact strength of blend containing 3% of TAC were substantially increased with increasing irradiation dosage up to 150 KGy. Rheological analysis has shown increase in viscosity with increase in TAC loading up to 3% and 150 KGy irradiation dosages. 3% loading of TAC lead to better set of properties with150 KGy gamma irradiation dosage.

  20. Influence of gamma irradiation on uranium determination by Arsenazo III in the presence of Fe(II)/Fe(III).

    PubMed

    Zheng, Zhong; Kang, Mingliang; Wang, Chunli; Liu, Chunli; Grambow, Bernd; Duro, Lara; Suzuki-Muresan, Tomo

    2014-07-01

    Arsenazo III is a widely used reagent for the concentration measurement of uranium and other actinides in aqueous samples. This study indicates that, for routine aqueous samples, due to the strong complexing ability with Arsenazo III, Fe(III) can significantly decrease the UV-Vis absorbance of the U(VI)-Arsenazo III complex, whereas the influence of Fe(II) on the absorbance is negligible. However, when Fe(II) is present in a gamma-irradiated U(VI) aqueous sample, it can give rise to the Fenton reaction, which produces oxidizing radicals that decompose the subsequently added Arsenazo III, leading to a sharp decrease in the absorbance of the U(VI)-Arsenazo III complex. The decrease in absorbance depends on the iron content and irradiation dose. Furthermore, the oxidizing radicals from the Fenton reaction induced by gamma irradiation can be continually produced. Even if the irradiated solution has been aged for more than one month in the absence of light at room temperature and without the exclusion of oxygen, the reactivity of the radicals did not decrease toward the subsequently added Arsenazo III. This finding demonstrates that the presence of Fe(II) in gamma-irradiated U(VI) aqueous samples can lead to incorrect U(VI) measurement using the Arsenazo III method, and a new method needs to be developed for the quantitative determination of U(VI) in the presence of gamma radiation and ferrous iron.

  1. Optical and FT Infrared spectral studies of vanadium ions in cadmium borate glass and effects of gamma irradiation.

    PubMed

    AbdelAziz, T D; EzzElDin, F M; El Batal, H A; Abdelghany, A M

    2014-10-15

    Combined optical and infrared absorption spectra of V2O5-doped cadmium borate glasses were investigated before and after gamma irradiation with a dose of 8 Mrad (=8×10(4) Gy). The undoped base cadmium borate glass reveals a spectrum consisting of strong charge transfer UV absorption bands which are related to the presence of unavoidable contaminated trace iron impurities (mainly Fe(3+)). The V2O5-doped glasses reveal an extra band at 380nm and the high V2O5-content glass also shows a further band at about 420nm. The observed optical spectrum indicates the presence of vanadium ions mainly in the pentavalent state (d(0) configuration). The surplus band at 420nm shows that some trivalent vanadium ions are identified at high V2O5 content. The optical spectra of the glasses after gamma irradiation show small decrease of the intensity of the UV absorption which are interpreted by assuming the transformation of some Fe(3+) ions by photochemical reactions with the presence of high content (45mol%) of heavy massive CdO causing some shielding behavior. FT infrared absorption spectra of the glasses show vibrational bands due to collective presence of triangular and tetrahedral borate groups in their specific wavenumbers. The FTIR spectra are observed to be slightly affected by both the V2O5-dopants being present in modifying low percent or gamma irradiation due to the presence of high content heavy CdO.

  2. Effect of gamma irradiation on microbial load, physicochemical and sensory characteristics of soybeans (Glycine max L. Merrill)

    NASA Astrophysics Data System (ADS)

    Yun, Juan; Li, Xihong; Fan, Xuetong; Tang, Yao; Xiao, Yao; Wan, Sen

    2012-08-01

    Gamma irradiation is highly effective in inactivating microorganisms in various foods and offers a safe alternative method of food decontamination. In the present study, soybeans (Glycine max L. Merrill) were treated with 0, 1.0, 3.0, 5.0 and 10.0 KGy of gamma irradiation. Microbial populations on soybeans, isoflavone, tocopherol contents, raffinose family oligosaccharides, color and sensory properties were evaluated as a function of irradiation dose. The results indicated that gamma irradiation reduced aerobic bacterial and fungal load. Irradiation at the doses applied did not cause any significant change (p>0.05) in the contents of isoflavone of soybeans, but decreased tocopherol contents. The content of key flatulence-producing raffinose family oligosaccharides in irradiated soybeans (10.0 kGy) decreased by 82.1% compared to the control. Sensory analysis showed that the odor of the soybeans was organoleptically acceptable at doses up to 5.0 kGy and no significant differences were observed between irradiated and nonirradiated samples in flavor, texture and color after irradiation.

  3. Structural and optical analysis of 60Co gamma-irradiated thin films of polycrystalline Ga10Se85Sn5

    NASA Astrophysics Data System (ADS)

    Ahmad, Shabir; Asokan, K.; Shahid Khan, Mohd.; Zulfequar, M.

    2015-12-01

    The present study focuses on the effects of gamma irradiation on structural and optical properties of polycrystalline Ga10Se85Sn5 thin films with a thickness of ∼300 nm deposited by the thermal evaporation technique on cleaned glass substrates. X-ray diffraction patterns of the investigated thin films show that crystallite growth occurs in the orthorhombic phase structure. The surface study carried out by using the scanning electron microscope (SEM) confirms that the grain size increases with gamma irradiation. The optical parameters were estimated from optical transmission spectra data measured from a UV-vis-spectrophotometer in the wavelength range of 200-1100 nm. The refractive index dispersion data of the investigated thin films follow the single oscillator model. The estimated values of static refractive index n0, oscillator strength Ed, zero frequency dielectric constant ε0, optical conductivity σoptical and the dissipation factor increases after irradiation, while the single oscillator energy Eo decreases after irradiation. It was found that the value of the optical band gap of the investigated thin films decreases and the corresponding absorption coefficient increases continuously with an increase in the dose of gamma irradiation. This post irradiation changes in the values of optical band gap and absorption coefficient were interpreted in terms of the bond distribution model.

  4. Gamma irradiation resistance of early age Ba(OH)2-Na2SO4-slag cementitious grouts

    NASA Astrophysics Data System (ADS)

    Mobasher, Neda; Bernal, Susan A.; Kinoshita, Hajime; Provis, John L.

    2016-12-01

    The gamma irradiation resistance of early age Ba(OH)2-Na2SO4-slag cementitious grouts, formulated for the immobilisation of sulfate bearing nuclear waste, was assessed. The observable crystalline phases were not modified upon heating (50 °C) or upon gamma irradiation up to a total dose of 2.9 MGy over 256 h, but the compressive strengths of the irradiated samples increased significantly. 27Al and 29Si MAS NMR spectroscopy showed that the main binding phase, a calcium aluminosilicate hydrate (C-A-S-H) type gel, had a more ordered and polymerised structure upon heating and irradiation compared to that identified in reference samples. This is associated with a higher degree of reaction of the slag. Samples formulated with the waste simulant Na2SO4, but without Ba(OH)2, became porous and cracked upon heating and irradiation, but still retained their compressive strength. The Ba(OH)2-Na2SO4-slag grouts evaluated in this work withstand gamma irradiation without showing identifiable damage, and are thus a technically feasible solution for immobilisation of sulfate-bearing nuclear wastes.

  5. The anti-oxidative properties of alpha-tocopherol in gamma-irradiated UHMWPE with respect to fatigue and oxidation resistance.

    PubMed

    Shibata, Nobuyuki; Tomita, Naohide

    2005-10-01

    Although addition of an antioxidant (alpha-tocopherol) is reported to prevent delamination in ultrahigh molecular weight polyethylene (UHMWPE) knee components, contribution of alpha-tocopherol as an antioxidant to the improvement of long-term fatigue performance of UHMWPE is an unknown mechanism. To solve this problem, bi-directional sliding fatigue tests were performed for gamma-irradiated (25 kGy), gamma-irradiated (25 kGy) with 0.3 wt% alpha-tocopherol added, and gamma-irradiated (25 kGy) with 0.3 wt% tocopheryl acetate added UHMWPE specimens. Internal defect initiation was quantified with scanning acoustic tomography (SAT). Also, oxidation index and crystallinity were obtained from infrared absorption spectra measured using Fourier transform infrared (FT-IR) microscopy. Only gamma-irradiated UHMWPE specimens resulted in severe fatigue fractures. alpha-Tocopherol-added UHMWPE specimens showed significantly lower projected area ratio of defects (1.80+/-0.82) than did gamma-irradiated (7.0+/-2.29) and tocopheryl acetate-added ones (8.50+/-2.01). The oxidation index of gamma-irradiated UHMWPE specimens (0.111+/-0.0052) was extremely higher compared to those of doped ones; 0.0179+/-0.0026 and 0.0144+/-0.0069 for alpha-tocopherol-added and tocopheryl acetate-added ones, respectively. The crystallinity of gamma-irradiated UHMWPE specimens (57.5+/-1.16) was lower compared to those of doped ones; 60.3+/-0.72 and 60.4+/-1.38 for alpha-tocopherol-added and tocopheryl acetate-added ones, respectively. The incorporation of alpha-tocopherol significantly improves the long-term fatigue performance of gamma-irradiated UHMWPE with oxidation stability. Also, the addition of alpha-tocopherol controls macromolecular structures resulting in the improvement of fatigue performance of UHMWPE.

  6. Tobacco use and secondhand smoke exposure during pregnancy in low- and middle-income countries: the need for social and cultural research.

    PubMed

    Nichter, Mimi; Greaves, Lorraine; Bloch, Michele; Paglia, Michael; Scarinci, Isabel; Tolosa, Jorge E; Novotny, Thomas E

    2010-01-01

    Tobacco use is a leading cause of death and of poor pregnancy outcome in many countries. While tobacco use is decreasing in many high-income countries, it is increasing in many low- and middle-income countries (LMICs), where by the year 2030, 80% of deaths caused by tobacco use are expected to occur. In many LMICs, few women smoke tobacco, but strong evidence indicates this is changing; increased tobacco smoking by pregnant women will worsen pregnancy outcomes, especially in resource-poor settings, and threatens to undermine or reverse hard-won gains in maternal and child health. To date, little research has focused on preventing pregnant women's tobacco use and secondhand smoke (SHS) exposure in LMICs. Research on social and cultural influences on pregnant women's tobacco use will greatly facilitate the design and implementation of effective prevention programs and policies, including the adaptation of successful strategies used in high-income countries. This paper describes pregnant women's tobacco use and SHS exposure and the social and cultural influences on pregnant women's tobacco exposure; it also presents a research agenda put forward by an international workgroup convened to make recommendations in this area.

  7. Culture change in addictions treatment: a targeted training and technical assistance initiative affects tobacco-related attitudes and beliefs in addiction treatment settings.

    PubMed

    Perka, Edward J

    2011-11-01

    Targeted training and technical assistance can have a major impact on the attitudes and beliefs of addiction service providers with respect to the treatment of tobacco dependency. Major gains have been made with the general public since the mid-1960s with respect to the reduction of tobacco use behavior and tobacco-related diseases. Tobacco use continues to be a major public health problem, and tobacco control initiatives are significantly affecting public attitudes and norms regarding tobacco use. There is, however, a specific population that has not benefited from these gains and, in fact, has been encouraged to continue smoking rather than make an attempt to quit. Individuals with a substance use disorder and/or mental health disorder have a much higher percentage of tobacco use than the general population, resulting in major health disparities. The addiction treatment and recovery community has lagged behind the general public in addressing tobacco use. New York State's project, "Integrating Tobacco Use Interventions Into Chemical Dependence Services," is a model that demonstrates how innovative regulations, and training and technical assistance developed specifically for addiction service providers, can initiate culture change with respect to tobacco use within addiction treatment settings, resulting in improved treatment outcomes and longer term stable recovery.

  8. Effect of gamma irradiation on physicochemical, functional and pasting properties of some locally-produced rice (Oryza spp) cultivars in Ghana

    NASA Astrophysics Data System (ADS)

    Ocloo, Fidelis C. K.; Owureku-Asare, Mavis; Agyei-Amponsah, Joyce; Agbemavor, Wisdom S. K.; Egblewogbe, Martin N. Y. H.; Apea-Bah, Franklin B.; Sarfo, Adjoa; Apatey, John; Doku, Henry; Ofori-Appiah, Dora; Ayeh, Ernestina

    2017-01-01

    Rice (Oryza sativa L.) is a staple crop in Ghana and much of West Africa, where it serves as an important convenience food for urban consumers. The objective of this study was to determine the effect of gamma irradiation as insect disinfestation technique on some physicochemical, functional and pasting properties of selected locally-produced rice cultivars in Ghana. Four local rice cultivars and an imported (commercial) type were purchased, cleaned and irradiated at doses of 0.0, 0.25, 0.50, 0.75, 1.0 and 1.5 kGy. The irradiated rice cultivars were milled and their physicochemical, functional and pasting properties determined. There were reductions in pH and swelling power, as well as increase in solubility of rice cultivars after gamma irradiation. Gamma irradiation did not change the XRD pattern of the rice cultivars. Gamma irradiation significantly (P<0.05) decreased peak time for BAL and VNT rice cultivars. Gamma irradiation significantly (P<0.05) decreased PV, HPV, BDV, FV and SBV for all the rice cultivars. This study shows that flours from gamma irradiated rice cultivars have potential in food formulations that require low viscosity.

  9. Gamma-irradiation aggravates stress concentration along subsurface grain boundary of ultra-high molecular weight polyethylene (UHMWPE) under sliding fatigue environment.

    PubMed

    Shibata, Nobuyuki; Tomita, Naohide; Ikeuchi, Ken

    2003-01-01

    Numerical simulations were carried out using a DEM-based model under a sliding fatigue environment to investigate the influences of differences of mechanical properties between intra-granular portions and inter-granular portions on local stress-strain fields and to determine the effect of gamma-irradiative degradation of UHMWPE components on delamination. The predicted stress fields in the gamma-irradiated UHMWPE component were highly nonuniform and were quite different from those predicted in the non-irradiated UHMWPE component. The stress distributions were intensely affected by the structural inhomogeneousness of networked grain boundaries. Marked stress concentrations were observed along subsurface grain boundaries in the gamma-irradiated UHMWPE. The gamma-irradiated UHMWPE showed a steep increase in the maximum equivalent stresses for an increase in the number of sliding. As the number of sliding increased, moreover, the region where the maximum equivalent stress was observed, moved deep into the specimen. These findings suggest that fatigue damage with plastic deformation proceeds mainly at a subsurface region in the gamma-irradiated UHMWPE and at a superficial region in the non-irradiated one. Therefore, gamma-irradiation is an important factor in accelerating fatigue crack initiation resulting in delamination.

  10. Early steps in the oxidative burst induced by cadmium in cultured tobacco cells (BY-2 line).

    PubMed

    Olmos, Enrique; Martínez-Solano, Juan R; Piqueras, Abel; Hellín, Eladio

    2003-01-01

    The rapid generation of H(2)O(2) by Cd(2+)-treated plant cells was investigated in cultured tobacco (Nicotiana tabacum L.) BY-2 cells. The starting point for the generation of H(2)O(2) has been located at the cell plasma membrane using cytochemical methods. Treatment of the cells with diphenyleneiodonium (DPI) and imidazol, both inhibitors of the neutrophil NADPH oxidase, prevented the generation of H(2)O(2) induced by Cd(2+). These data suggest the involvement of an NADPH oxidase-like enzyme leading to H(2)O(2) production through O(2)(*-) dismutation by superoxide dismutase enzymes. To investigate the implication of Ca(2+) channels in a Cd(2+)-induced oxidative burst, different inhibitors of Ca(2+) channels were used. Only La(3+) totally inhibited the generation of H(2)O(2) induced by Cd(2+). However, verapamil and nifedipine, inhibitors of Ca(2+) channels, were not effective. Calmodulin or a Ca(2+)-dependent protein kinase is also implicated in the signal transduction sequence, based on the results obtained with two types of calmodulin antagonists, fluphenazine and N-(-6-amino-hexyl)-5-chloro-1-naphthalenesulphonamide (W-7) and staurosporine, an inhibitor of protein kinases. However, neomycin, an inhibitor of the phosphoinositide cycle, did not inhibit the generation of H(2)O(2) induced by Cd(2+), suggesting mainly an induction of the oxidative burst mediated by calmodulin and/or calmodulin-dependent proteins.

  11. Osmotic Adjustment of Cultured Tobacco Cells (Nicotiana tabacum var. Samsum) Grown on Sodium Chloride 1

    PubMed Central

    Heyser, James W.; Nabors, Murray W.

    1981-01-01

    Tobacco cell cultures (var. Samsum) were grown on increasing levels of NaCl to select variants for increased salt tolerance. The osmotic adjustment of NaCl-adapted and nonadapted cell lines was studied. Both cell lines were grown on modified Linsmaier and Skoog medium with or without NaCl. Few differences were found in the response of adapted and nonadapted lines to NaCl. The concentrations of sugars, Na+, Cl−, and NO3− were identical in the cells and medium. Potassium and amino acids were accumulated by the cells. All of the above solutes accounted for 80 to 90% of the osmotic potential for both cell lines when grown on basal medium with or without NaCl. The osmotic potential of growing cells was always 1 to 3 bars more negative than that of the medium. During the first 10 days culture, the cells hydrolyzed the 117 millimolar sucrose present in the fresh media, and the media became more negative by 3 bars. Growing cells absorbed and metabolized the sugars, NH4+, and NO3− during the next 25 days, and the osmotic potential of the media and cells became less negative. The addition of 130 millimolar NaCl made the media and cells osmotically more negative by 6 bars throughout the growth cycle, as compared with cells growing on basal medium. The efflux of cellular solutes during distilled H2O washes was resolved into two components. The fast component (0.6 to 1.7 minutes half-time) included solutes of the free space and cytoplasm, whereas the slow component (1.6 to 4.9 hours half-time) represented the vacuolar solutes. Sodium and Cl− were present in the vacuole. No differences were observed in the solute efflux between the adapted and nonadapted cell lines. PMID:16661743

  12. Hodgkin-Huxley analysis of whole-cell outward rectifying K(+)-currents in protoplasts from tobacco cell suspension cultures.

    PubMed

    Van Duijn, B

    1993-02-01

    The voltage and time dependence of outward-rectifying K+ currents (IK,out) measured in protoplasts from tobacco cell suspension cultures in the whole-cell configuration of the patch-clamp technique are quantitatively analyzed. The voltage and time dependence was described according to the Hodgkin and Huxley model for IK,out currents in the squid giant axon, and to allow comparison, in analogy with the quantitative analysis of IK,out currents in Vicia faba guard cell protoplasts as described by Schroeder (J. Membrane Biol., 107:229-235, 1989). The IK,out from tobacco could be described by a similar model as the IK,out from guard cell protoplasts (i.e., sigmoid activation time course, activation variable raised to second power, single exponential deactivating tail currents, absence of inactivation). However, in contrast to guard cells, both the activation and deactivation time constants were strongly voltage dependent in tobacco protoplasts. The voltage dependence of the transition rates for channel opening and channel closing was slightly asymmetrical and inverse to the asymmetry found in guard cells. The data presented show that the voltage-dependent kinetic properties of the IK,out conductance of tobacco protoplasts are different from these properties in guard cell protoplasts. This analysis provides a basis for the study of IK,out conductance function and modulation.

  13. Bystander responses in low dose irradiated cells treated with plasma from gamma irradiated blood

    NASA Astrophysics Data System (ADS)

    Acheva, A.; Georgieva, R.; Rupova, I.; Boteva, R.; Lyng, F.

    2008-02-01

    There are two specific low-dose radiation-induced responses that have been the focus of radiobiologists' interest in recent years. These are the bystander effect in non-irradiated cells and the adaptive response to a challenge dose after prior low dose irradiation. In the present study we have investigated if plasma from irradiated blood can act as a 'challenge dose' on low dose irradiated reporter epithelial cells (HaCaT cell line). The main aim was to evaluate the overall effect of low dose irradiation (0.05 Gy) of reporter cells and the influence of bystander factors in plasma from 0.5 Gy gamma irradiated blood on these cells. The effects were estimated by clonogenic survival of the reporter cells. We also investigated the involvement of reactive oxygen species (ROS) as potential factors involved in the bystander signaling. Calcium fluxes and mitochondrial membrane potential (MMP) depolarization were also examined as a marker for initiation of apoptosis in the reporter cells. The results show that there are large individual differences in the production of bystander effects and adaptive responses between different donors. These may be due to the specific composition of the donor plasma. The observed effects generally could be divided into two groups: adaptive responses and additive effects. ROS appeared to be involved in the responses of the low dose pretreated reporter cells. In all cases there was a significant decrease in MMP which may be an early event in the apoptotic process. Calcium signaling also appeared to be involved in triggering apoptosis in the low dose pretreated reporter cells. The heterogeneity of the bystander responses makes them difficult to be modulated for medical uses. Specific plasma characteristics that cause these large differences in the responses would need to be identified to make them useful for radiotherapy.

  14. Evaluation of embryo quality after concurrent use of ovarian stimulating hormones and gamma irradiation

    PubMed Central

    Dehghan, Tahere; Mozdarani, Hossein; Khoradmehr, Arezoo; Kalantar, Seyed Mehdi; Bakhshandeh, Mohsen; Bouzarjomehri, Fathollah; Kalantar, Seyed Milad; Sepehr Javan, Morteza

    2014-01-01

    Background: Radiotherapy has many side effects on fertilization in young women. Radiation can lead to ovarian failure in women who underwent abdomen or pelvic radiotherapy. Objective: This study helps us to investigate ovarian response of NMRI female mice to ovarian stimulating hormones (PMSG, HCG) after whole-body gamma irradiation. Materials and Methods: 45 pregnant mice were divided into two groups of control and experimental. The experimental group was classified into three sub-groups: Irradiation group (2 or 4Gy),Superovulation group (10 or 15IU),and superovulation and gamma-radiation group (2Gy & 10IU, 2Gy & 15IU, 4Gy & 10IU,4Gy & 15IU). Female mice were killed and embryos were removed from oviduct .The number of embryos cells counted and the quality of them was evaluated in each group. Kruskal-Wallis test and Mann-Whitney test were used to analyze the data. Results: There was a significant difference in the number of 2-4 cells grade D embryos in 2Gy & 15IU group compared with control and 2Gy groups (p=0.01), and the number of embryos in 4Gy group was more than in 10IU and 15IU (p=0.03) and 2Gy & 15IU groups (p=0.01). It was more significantly embryos in 4Gy & 15IU group compared to 2Gy & 15IU group (p=0.01).In addition There were no significant differences in the number of 2-4 cells grades A, B and C embryos and also number of 4-8 cells grades A, B and C, D embryos in groups. Conclusion: The concurrent use of ovulation stimulating hormones and gamma rays ameliorates this problem of drastic decrease in number of living embryos due to whole-body irradiation. PMID:25408708

  15. Gamma irradiation-induced oxidative stress and developmental impairment in the hermaphroditic fish, Kryptolebias marmoratus embryo.

    PubMed

    Rhee, Jae-Sung; Kim, Bo-Mi; Kang, Chang-Mo; Lee, Young-Mi; Lee, Jae-Seong

    2012-08-01

    This study investigated the effects of gamma radiation on the early developmental stages in hermaphroditic fish embryos of Kryptolebias marmoratus. The authors measured reactive oxygen species (ROS) level and antioxidant enzyme activities with the endpoint hatching rate after gamma irradiation of different embryonic stages. Then, the transcriptional changes of antioxidant enzyme-coding genes were evaluated by quantitative real-time reverse transcription polymerase chain reaction in response to gamma radiation on embryonic stages. Gamma radiation inhibited hatching rate and caused developmental impairment in a dose-dependent manner. Embryos showed tolerances in a developmental stage-dependent manner, indicating that early embryonic stages were more sensitive to the negative effects of gamma radiation than were later stages. After 5 Gy rate of radiation, the ROS level increased significantly at embryonic stages 2, 3, and 4 with a significant induction of all antioxidant enzyme activities. The expressions of glutathione S-transferase isoforms, catalase, superoxide dismutase (Mn-SOD, Cu/Zn-SOD), glutathione reductase, and glutathione peroxidase mRNA were upregulated in a dose-and-developmental stage-dependent manner. This finding indicates that gamma radiation can induce oxidative stress and subsequently modulates the expression of antioxidant enzyme-coding genes as one of the defense mechanisms. Interestingly, embryonic stage 1 exposed to gamma radiation showed a decreased expression in most antioxidant enzyme-coding genes, suggesting that this is also related to a lower hatching rate and developmental impairment. The results of this study provide a better understanding of the molecular mode of action of gamma radiation in aquatic organisms.

  16. Mining gene expression data for pollutants (dioxin, toluene, formaldehyde) and low dose of gamma-irradiation.

    PubMed

    Moskalev, Alexey; Shaposhnikov, Mikhail; Snezhkina, Anastasia; Kogan, Valeria; Plyusnina, Ekaterina; Peregudova, Darya; Melnikova, Nataliya; Uroshlev, Leonid; Mylnikov, Sergey; Dmitriev, Alexey; Plusnin, Sergey; Fedichev, Peter; Kudryavtseva, Anna

    2014-01-01

    (dioxin, toluene), low dose of gamma-irradiation and common molecular pathways for different kind of stressors.

  17. Fatty acid profile of gamma-irradiated and cooked African oil bean seed (Pentaclethra macrophylla Benth)

    PubMed Central

    Olotu, Ifeoluwa; Enujiugha, Victor; Obadina, Adewale; Owolabi, Kikelomo

    2014-01-01

    The safety and shelf-life of food products can be, respectively, ensured and extended with important food-processing technologies such as irradiation. The joint effect of cooking and 10 kGy gamma irradiation on the fatty acid composition of the oil of Pentaclethra macrophylla Benth was evaluated. Oils from the raw seed, cooked seeds, irradiated seeds (10 kGy), cooked, and irradiated seeds (10 kGy) were extracted and analyzed for their fatty acid content. An omega-6-fatty acid (linoleic acid) was the principal unsaturated fatty acid in the bean seed oil (24.6%). Cooking significantly (P < 0.05) increased Erucic acid by 3.3% and Linolenic acid by 23.0%. Combined treatment significantly (P < 0.05) increased C18:2, C6:0, C20:2, C18:3, C20:3, C24:0, and C22:6 being linoleic, caproic, eicosadienoic, linolenic, eicosatrienoic, ligoceric, and docosahexaenoic acid, respectively, and this increase made the oil sample to have the highest total fatty acid content (154.9%), unsaturated to saturated fatty acid ratio (109.6), and unsaturated fatty acid content (153.9%). 10 kGy irradiation induces the formation of C20:5 (eicosapentaenoic), while cooking induced the formation of C20:4 (arachidic acid), C22:6 (Heneicosanoic acid), and C22:2 (docosadienoic acid). Combined 10 kGy cooking and irradiation increased the susceptibility of the oil of the African oil bean to rancidity. PMID:25493197

  18. Characterization and dosimetry of a practical X-ray alternative to self-shielded gamma irradiators

    NASA Astrophysics Data System (ADS)

    Mehta, Kishor; Parker, Andrew

    2011-01-01

    The Insect Pest Control Laboratory of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture recently purchased an X-ray irradiator as part of their programme to develop the sterile insect technique (SIT). It is a self-contained type with a maximum X-ray beam energy of 150 keV using a newly developed 4 π X-ray tube to provide a very uniform dose to the product. This paper describes the results of our characterization study, which includes determination of dose rate in the centre of a canister as well as establishing absorbed dose distribution in the canister. The irradiation geometry consists of five canisters rotating around an X-ray tube—the volume of each canister being 3.5 l. The dose rate at the maximum allowed power of the tube (about 6.75 kW) in the centre of a canister filled with insects (or a simulated product) is about 14 Gy min -1. The dose uniformity ratio is about 1.3. The dose rate was measured using a Farmer type 0.18-cm 3 ionization chamber calibrated at the relevant low photon energies. Routine absorbed dose measurement and absorbed dose mapping can be performed using a Gafchromic® film dosimetry system. The radiation response of Gafchromic film is almost independent of X-ray energy in the range 100-150 keV, but is very sensitive to the surrounding material with which it is in immediate contact. It is important, therefore, to ensure that all absorbed dose measurements are performed under identical conditions to those used for the calibration of the dosimetry system. Our study indicates that this X-ray irradiator provides a practical alternative to self-shielded gamma irradiators for SIT programmes. Food and Agriculture Organization/International Atomic Energy Agency.

  19. EPR spectra induced by gamma-irradiation of some dry medical herbs

    NASA Astrophysics Data System (ADS)

    Yordanov, N. D.; Lagunov, O.; Dimov, K.

    2009-04-01

    The radiation-induced EPR spectra in some medical herbs are reported. The samples studied are: (i) leaves of nettle, common balm, peppermint and thyme; (ii) stalks of common balm, thyme, milfoil, yarrow and marigold; (iii) blossoms of yarrow and marigold; (iv) blossoms and leaves of hawthorn and tutsan; and (v) roots of common valerian, nettle, elecampane (black and white), restharrows and carlina. Before irradiation all samples exhibit one weak anisotropic singlet EPR line with effective g-value of 2.0050±0.0002. The radiation-induced spectra fall into three groups. EPR spectra of irradiated blossoms of yarrow and marigold, stalks of common balm, thyme, tutsan and yarrow as well as roots of common valerian, nettle and elecampane (black and white) show "cellulose-like" EPR spectrum typical for irradiated plants. It is characterized by one intense central line with g=2.0050±0.0005 and two weak satellite lines situated ca. 30 G left and right to it. EPR spectra of gamma-irradiated restharrows and carlina are complex. They may be represented by one triplet corresponding to the "cellulose-like" EPR spectrum, one relatively intense singlet, situated in the center of the spectrum, and five weak additional satellite lines left and right to the center. The last spectrum was assigned as "carbohydrate-like" type. Only one intense EPR singlet with g=2.0048±0.0005 was recorded after irradiation of leaves of nettle and common balm. The lifetime of the radiation-induced EPR spectra was followed for a period of 3 months.

  20. Gamma irradiation of the fetus damages the developing hemopoietic microenvironment rather than the hemopoietic progenitor cells

    SciTech Connect

    Yang, F.T.; Lord, B.I.; Hendry, J.H.

    1995-03-01

    Hemopoiesis is the product of two components: the hemopoietic tissue and the regulatory stromal microenvironment in which it resides. Plutonium-239, incorporated during fetal development in mice, is known to cause deficient hemopoiesis. A predetermined equivalent {gamma}-ray dose has now been used in combination with cross-transplantation experiments to separate these two components and define where the damage arises. It was confirmed that 1.8 Gy {gamma} irradiation at midterm gestation caused a 40% reduction in the hemopoietic stem (spleen colony-forming) cell population of their offspring which persisted to at least 24 weeks of age. Spleen colony formation after sublethal doses of {gamma} rays reflected this reduced complement of endogenous stem cells. The regulatory hemopoietic microenvironment, measured as fibroblastoid colony-forming cells, was similarly depleted. Normal growth of the CFU-S population after transplantation into standard recipients showed that the quality of the stem cell population in the offspring of irradiated mothers was not affected. By contrast, when used as recipients of a bone marrow transplant from either normal or irradiated offspring, the offspring of irradiated mothers were unable to support normal growth: there was a twofold difference in the number of CFU-S per femur for at least 100 days after transplantation. There were 70% fewer CFU-F in the femur 1 month after bone marrow transplantation when the offspring of irradiated mothers were used as transplant recipients compared to when normal offspring were used. This not only confirmed their reduced capacity to host normal stem cells but also indicated that CFU-F in the transplant were unable to compensate for the poor microenvironment in the irradiated offspring hosts. It is concluded that irradiation at midterm gestation damages the developing regulatory microenvironment but not the hemopoietic stem cell population that it hosts. 12 refs., 1 fig., 4 tabs.

  1. Effects of gamma irradiation on the grape vine moth, Lobesia botrana, eggs

    NASA Astrophysics Data System (ADS)

    Mansour, M.; Al-Attar, J.

    2012-11-01

    Eggs of the grape vine moth, Lobesia botrana (Denis and Schiffermuller), ranging in age from 1-24 to 73-96 h, were exposed, at 24 h intervals, to gamma radiation ranging from 25-600 Gy. The effects of gamma radiation on egg hatch, pupation, adult emergence, sex ratio and rate of development were examined. Results showed that the radiosensitivity of the grape vine moth eggs decreased with increasing age and increased with increasing radiation dose. Egg hatch in 1-24 h old eggs was significantly affected at 25 Gy and completely prevented at 100 Gy. At the age of 25-48 h, radiation sensitivity was only a little lower; egg hatch at 100 Gy was <1% and at 125 Gy no egg hatch was observed. Egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; egg hatch was 66% at 100 Gy, and 500 Gy did not completely stop egg hatch (<1%). Eggs irradiated a few hours before egg hatch (73-96 h old) were the most resistant; 150 Gy had no significant effect on egg hatch and at 600 Gy over 33% of the eggs hatched. When pupation or adult emergence was used as a criterion for measuring effectiveness, however, the effects of gamma radiation were very severe. In the most resistant age group (73-96 h old), 150 Gy completely prevented pupation and adult emergence and all larvae resulting from eggs irradiated <49 h old died before pupation. In addition, the rate of development of immature stages resulting from irradiated eggs was negatively affected and sex ratio was skewed in favor of males.

  2. Dental hygiene students' perceptions of a cultural competence component in a tobacco dependence education curriculum: a pilot study.

    PubMed

    Doucette, Heather J; Maillet, Peggy J; Brillant, Martha G; Tax, Cara L

    2015-06-01

    First Nations and Inuit peoples have tobacco use rates three times that of the Canadian national average. Providing tobacco dependence education (TDE) requires an understanding of the factors surrounding tobacco use that are culturally specific to this population. The aim of this pilot study was to evaluate the effectiveness of a new cultural competence component for Canadian First Nations and Inuit peoples in a TDE curriculum at Dalhousie University School of Dental Hygiene, Halifax, Nova Scotia, Canada. In 2011, the TDE curriculum was revised to include a First Nations and Inuit people's cultural component. A 32-question survey was developed for the study, with questions divided into four subscales regarding students' perceived knowledge, skills, comfort level, and attitudes about working with this population. Responses from students in two succeeding years were compared: the first cohort had not participated in the revised curriculum (56% response rate), and the second cohort had (63% response rate). The results showed an overall improvement in the subscales evaluated and a significant (p=0.002) improvement in the knowledge subscale of the students who received the new TDE curriculum, specifically regarding knowledge about sociocultural characteristics, health risks, and cultural healing traditions of First Nations and Inuit people. Although the results indicated an increase in the knowledge of the culture of First Nations and Inuit peoples, it is unclear whether the students felt better prepared to provide TDE to this population. For future research, the investigators would examine what learning experiences and further changes to the curriculum could be provided to facilitate the level of preparedness to successfully deliver TDE.

  3. Intracellular concentrations and metabolism of carbon compounds in tobacco callus cultures: Effects of light and auxin

    SciTech Connect

    Lawyer, A.L.; Grady, K.L.; Bassham, J.A.

    1981-10-01

    Callus cultures derived from pith tissue of Nicotiana tobacum were grown on two media either under continuous illumination or in complete darkness. The first medium limited greening ability of callus grown in the light (3 milligrams per liter naphthalene acetic acid, 0.3 milligram per liter 2-isopentenylaminopurine, Murashige and Skoog salts, and 2% sucrose). The second medium encouraged chlorophyll synthesis (greening) though not shoot formation (0.3 milligram per liter naphthalene acetic acid; 0.3 milligrams per liter 2-isopentylaminopurine). To measure intracellular concentrations, calli were grown for 15 days on these standard media containing (U-/sup 14/C)sucrose. The dry weight proportions of the calli (as a fraction of fresh weight) and many metabolite concentrations nearly doubled in light-grown cells compared to dark-grown cells and increase 30 to 40% on low-auxin media relative to high-auxin media. Glutamine concentrations (from 4 to 26 millimolar) were very high, probably due to the NH/sub 3/ content of the media. Proline concentrations were 20-fold higher in calli grown on low-auxin media in the light (green cells), possibly a stress response to high osmotic potentials in these cells. To analyze sucrose metabolism, callus cells were allowed to take up 0.2% (weight per volume) (U-/sup 14/C)sucrose for up to 90 minutes. In callus tissues and in pith sections from stems of tobacco plants, sucrose was primarily metabolized through invertase activity, producing equal amounts of labeling glucose and fructose. Respiration of /sup 14/CO/sub 2/ followed the labeling patterns of tricarboxylic acid cycle intermediates. Photorespiration activity was low.

  4. Construction of a cytogenetic dose-response curve for low-dose range gamma-irradiation in human peripheral blood lymphocytes using three-color FISH.

    PubMed

    Suto, Yumiko; Akiyama, Miho; Noda, Takashi; Hirai, Momoki

    2015-12-01

    In order to estimate biological doses after low-dose ionizing radiation exposure, fluorescence in situ hybridization (FISH) using three differentially colored chromosome painting probes was employed to detect exchange-type chromosome aberrations. A reference dose response curve was constructed using blood samples from a female donor whose lymphocytes consistently exhibited a low frequency of cells at the second mitosis under routine culture conditions. Aberration yields were studied for a total of about 155 thousand metaphases obtained from seven dose-points of gamma irradiations (0, 50, 100, 150, 200, 250 and 300mGy). In situ hybridization was performed using commercially available painting probes for chromosomes 1, 2 and 4. With the aid of an automated image-capturing method, exchange-type aberrations involving painted chromosomes were detected with considerable accuracy and speed. The results on the exchange-type aberrations (dicentrics plus translocations) at the seven dose-points showed a good fit to the linear-quadratic model (y=0.0023+0.0015x+0.0819x(2), P=0.83). A blind test proved the reproducibility of the reference dose-response relationship. In the control experiments using blood samples from another donor, the estimated doses calculated on the basis of the present reference curve were proved to be in good agreement with the actual physical doses applied. The present dose-response curve may serve as a means to assess the individual differences in cytogenetical radio-sensitivities.

  5. Identification of the novel lesion 8,5'-cyclo-2'-deoxyguanosine in DNA isolated from. gamma. -irradiated human cells

    SciTech Connect

    Dizdaroglu, M.; Dirksen, M.L.; Simic, M.G.; Robbins, J.H.

    1986-05-01

    The authors used capillary gas chromatography (GC)-mass spectrometry (MS) to detect damage in DNA from ..gamma..-irradiated viable cells. Epstein-Barr virus-transformed peripheral blood B-lymphocytes (lines GM 130 and RB 4580) were ..gamma..-irradiated at 0/sup 0/C at 1 to 10 krad (8.2 krad/min). The cells were immediately lysed with sodium dodecyl sulfate and incubated with proteinase K. The DNA was isolated by phenol-chloroform extractions, ethanol precipitations, and RNase A digestion. The DNA was hydrolyzed to 2'-deoxyribonucleosides with a mixture of DNase I, venom and spleen exonucleases, and alkaline phosphatase. The hydrolysate was dried, trimethylsilylated, and analyzed by GC-MS with selected-ion monitoring. Chromatographic retention time and mass spectrum were determined for a trimethylsilylated sample of authentic 8,5'-cyclo-2'-deoxyguanosine (8,5'-cyclo-dGuo). DNA from ..gamma..-irradiated cells gave the characteristic ions of this compound with proper relative intensities. Formation of 8,5'-cyclo-dGuo was dose-dependent. It was detectable in ca. 0.05 mg of DNA from cells irradiated at doses as low as 1 krad. The (5'R)- and the (5'S)-epimer of 8,5'-cyclo-dGuo were observed in a ratio of 1 to 3. The formation of 8,5'-cyclo-dGuo is believed to involve hydrogen atom abstraction from the carbon-5' of 2'-deoxyribose by radiation-generated OH radicals followed by intramolecular cyclization between carbon-5' and carbon-8 and subsequent oxidation of the resulting nitrogen-7 radical.

  6. Influence of gamma irradiation on polymerization of pyrrole and glucose oxidase immobilization onto poly (pyrrole)/poly (vinyl alcohol) matrix

    NASA Astrophysics Data System (ADS)

    Idris, Sarada; Bakar, Ahmad Ashrif A.; Ratnam, Chantara Thevy; Kamaruddin, Nur Hasiba; Shaari, Sahbudin

    2017-04-01

    This paper describes the immobilization of glucose oxidase, GOx onto polymer matrix comprising of poly(pyrrole), PPy and poly(vinyl alcohol), PVA using gamma irradiation technique. Py/PVA-GOx film was prepared by spreading PVA:GOx, 1:1 solution onto dried pyrrole film and exposed to gamma irradiation from cobalt 60 source at doses ranging from 0 to 60 kGy. The films were subjected to structural and morphological analyses by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Field emission scanning electron microscope (FESEM) and Atomic-force microscopy (AFM) techniques. Similar studies were also made on pristine pyrrole film which served as control. The SEM and FTIR spectra of Py/PVA-GOx film revealed that pyrrole has been successfully polymerized through irradiation-induced reactions. The results on the morphological properties of the samples characterize using FESEM, SEM and AFM further confirmed the occurrence of radiation-induced modification of Py/PVA-GOx film. The FTIR spectra showed the existence of intermolecular interaction between polymer matrix and GOx indicating that GOx had been successfully immobilized onto Ppy/PVA matrix by radiation-induced reactions. Results revealed that radiation induced reactions such as polymerization of pyrrole, crosslinking of PVA, grafting between the adjacent PVA and pyrrole molecules as well as immobilization of GOx onto Ppy/PVA matrix occurred simultaneously upon gamma irradiation. The optimum dose for GOx immobilization in the polymer matrix found to be 40 kGy. Therefore it is clear that this irradiation technique offered a simple single process to produce Py/PVA-GOx film without additional crosslinking and polymerization agents.

  7. Effect of gamma irradiation on the structural and magnetic properties of Co–Zn spinel ferrite nanoparticles

    SciTech Connect

    Raut, Anil V.; Kurmude, D.V.; Shengule, D.R.; Jadhav, K.M.

    2015-03-15

    Highlights: • Co–Zn ferrite nanoparticles were examined before and after γ-irradiation. • Single phase cubic spinel structure of Co–Zn was confirmed by XRD data. • The grain size was reported in the range of 52–62 nm after γ-irradiation. • Ms, Hc, n{sub B} were reported to be increased after gamma irradiation. - Abstract: In this work, the structural and magnetic properties of Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (0.0 ≤ x ≤ 1.0) ferrite nanoparticles were studied before and after gamma irradiation. The as-synthesized samples of Co–Zn ferrite nanoparticles prepared by sol–gel auto-combustion technique were analysed by XRD which suggested the single phase; cubic spinel structure of the material. Crystal defects produced in the spinel lattice were studied before and after Co{sup 60} γ-irradiation in a gamma cell with a dose rate of 0.1 Mrad/h in order to report the changes in structural and magnetic properties of the Co–Zn ferrite nanoparticles. The average crystallite size (t), lattice parameter (α) and other structural parameters of gamma-irradiated and un-irradiated Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} spinel ferrite system was calculated from XRD data. The morphological characterizations were performed using scanning electron microscopy (SEM). The magnetic properties were measured using pulse field hysteresis loop tracer by applying magnetic field of 1000 Oe, and the analysis of data obtained revealed that the magnetic property such as saturation magnetization (Ms), coecivity (Hc), magneton number (n{sub B}) etc. magnetic parameters were increased after irradiation.

  8. Gamma irradiation alters fatigue-crack behavior and fracture toughness in 1900H and GUR 1050 UHMWPE.

    PubMed

    Cole, Jantzen C; Lemons, Jack E; Eberhardt, Alan W

    2002-01-01

    Pitting and delamination remain causative factors of polyethylene failure in total knee replacement. Gamma irradiation induces cross linking in ultra-high-molecular-weight polyethylene, which has been shown to improve wear resistance. Irradiation may reduce fracture toughness and fatigue strength, however, and the effects of irradiation are dependent upon the resin, processing technique, and radiation dose. The effects of varying levels of gamma irradiation (0, 33, 66, and 100 kGy) on the fracture toughness and fatigue-crack resistance of UHMWPE, isostatically molded from 1900H and GUR 1050 resins, were examined. Paris law regressions were performed to quantify fatigue-crack propagation rates as functions of change in stress intensity, and J-integral methods were used to quantify the elastic-plastic fracture toughness. The results indicated that gamma irradiation reduced the resistance of both materials to fatigue-crack growth, and that the reductions were radiation dosage and resin dependent. Irradiation at any level was detrimental to the fracture toughness of the 1900H specimens. Irradiation at 33 kGy increased fracture toughness for the GUR 1050 specimens, and substantial reductions were observed only at the highest irradiation level. Scanning electron microscopy of the fracture surface revealed diamond-like fracture patterns of the nonirradiated specimens indicative of ductile, multilevel fracture. Pronounced striations were apparent on these fracture surfaces, oriented perpendicular to the direction of crack growth. The striations appeared as folds in surface layers of the GUR 1050 specimens. At the highest irradiation levels, the striations were nearly eliminated on the fracture surfaces of the 1900H specimens, and were markedly less severe for the GUR 1050. These results demonstrated that at higher irradiation levels the materials became more brittle in fatigue, with less ductile folding and tearing of the fracture surfaces.

  9. Gamma-irradiated cross-linked LDPE foams: Characteristics and properties

    NASA Astrophysics Data System (ADS)

    Cardoso, E. C. L.; Scagliusi, S. R.; Parra, D. F.; Lugão, A. B.

    2013-03-01

    Foamed polymers are future materials, as they are increasingly considered "green materials" due to their interesting properties at very low consumption of raw materials. They can be used to improve appearance of insulation structures, thermal and acoustic insulation, core materials for sandwich panels, fabrication of furniture and flotation materials or to reduce costs involving materials. Low-density polyethylene is widely used because of its excellent properties, such as softness, elasticity, processibility and insulation. In general, cross-linking is often applied to improve the thermal and mechanical properties of polyethylene products, due to the formation of a three-dimensional network. In particular for the production of PE foams, cross-linking is applied prior the expansion to control bubble formation, cell characteristics and final properties of the foam. However, the usual production process of PE foams is a process in which a gaseous blowing agent is injected into a melted thermoplastic polymer, under pressure, to form a solution between blowing agent and melted polymer. An extrusion system is provided for foaming the polymer, supplied to an extruder and moving through a rotating screw. The pressure must be high enough to keep the gas blowing agent (or foaming agent) in the solution with the melt. The foaming agent is then diffused and dissolved in the molten material to form a single-phase solution. In the present work carbon dioxide was used as the bowing agent, a chemically stable and non-toxic gas, with good diffusion coefficient; gas pressure used varied within a 20-40 bar range. Some requirements for physical foaming are required, as low friction heat generation, homogeneous melt temperature distribution, melt temperature at die exit just above crystallization temperature (die) and high melt strength during expansion. This work studied foams properties gamma-irradiated within 0, 10, 15, 20, 25, and 30 kGy, from a LDPE exhibiting 2.6 g/10 min Melt

  10. Gene Expression Changes in Mouse Intestinal Tissue Following Whole-Body Proton or Gamma-Irradiation

    NASA Technical Reports Server (NTRS)

    Purgason, Ashley; Zhang, Ye; Mangala, Lingegowda; Nie, Ying; Gridley, Daila; Hamilton, Stanley R.; Seidel, Derek V.; Wu, Honglu

    2014-01-01

    Crew members face potential consequences following exposure to the space radiation environment including acute radiation syndrome and cancer. The space radiation environment is ample with protons, and numerous studies have been devoted to the understanding of the health consequences of proton exposures. In this project, C57BL/6 mice underwent whole-body exposure to 250 MeV of protons at doses of 0, 0.1, 0.5, 2 and 6 Gy and the gastrointestinal (GI) tract of each animal was dissected four hours post-irradiation. Standard H&E staining methods to screen for morphologic changes in the tissue showed an increase in apoptotic lesions for even the lowest dose of 0.1 Gy, and the percentage of apoptotic cells increased with increasing dose. Results of gene expression changes showed consistent up- or down- regulation, up to 10 fold, of a number of genes across exposure doses that may play a role in proton-induced oxidative stress including Gpx2. A separate study in C57BL/6 mice using the same four hour time point but whole-body gamma-irradiation showed damage to the small intestine with lesions appearing at the smallest dose of 0.05 Gy and increasing with increasing absorbed dose. Expressions of genes associated with oxidative stress processes were analyzed at four hours and twenty-four hours after exposure to gamma rays. We saw a much greater number of genes with significant up- or down-regulation twenty-four hours post-exposure as compared to the four hour time point. At both four hours and twenty-four hours post-exposure, Duox1 and Mpo underwent up-regulation for the highest dose of 6 Gy. Both protons and gamma rays lead to significant variation in gene expressions and these changes may provide insight into the mechanism of injury seen in the GI tract following radiation exposure. We have also completed experiments using a BALB/c mouse model undergoing whole-body exposure to protons. Doses of 0, 0.1, 1 and 2 Gy were used and results will be compared to the work mentioned

  11. Effects of low-level gamma irradiation on the characteristics of fermented pork sausage during storage

    NASA Astrophysics Data System (ADS)

    Kim, I. S.; Jo, C.; Lee, K. H.; Lee, E. J.; Ahn, D. U.; Kang, S. N.

    2012-04-01

    The effect of gamma irradiation (0.5, 1, 2, and 4 kGy) on the quality of vacuum-packaged dry fermented sausages during refrigerated storage was evaluated. At Day 0 of irradiation, the pH, redness (CIE a*), yellowness (CIE b*), 2-thiobarbituric acid-reactive substances (TBARS) and volatile basic nitrogen (VBN) values of samples irradiated at 2 and 4 kGy were higher (p<0.05), but the CIE L* values (lightness) were lower than those of the non-irradiated control (p<0.05). At<1 kGy irradiation, however, the pH, CIE L*, CIE a* and CIE b*-value of samples were not significantly influenced by irradiation. The CIE a*, and CIE b*-values of samples irradiated at 2 and 4 kGy decreased with the increase of storage time. The VBN, TBARS, and CIE L*-values of samples irradiated at 4 kGy were not changed significantly during refrigerated storage for 90 days (p>0.05). The total plate counts (TPC) and lactic acid bacteria (LAB) in the samples irradiated at 4 kGy were significantly lower (p<0.01) than those with lower irradiation doses. At the end of storage, the TPC, coliform, and LAB in the samples were not increased after irradiation at 1, 0.5 and 1 kGy, respectively. TPC and LAB were not detected in samples irradiated at 4 kGy at Day 90. In addition, no coliform bacteria were found in samples irradiated at 1 kGy during refrigerated storage. Sensory evaluation indicated that the rancid flavor of samples irradiated at 4 kGy was significantly higher, but aroma and taste scores were lower than those of the control at Day 3 of storage. Irradiation of dry fermented sausages at 2 kGy was the best conditions to prolong the shelf-life and decrease the rancid flavor without significant quality deterioration.

  12. Effect of gamma irradiation on the expressed proteins in the foodborne pathogen Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Trudeau, Karine; Dang Vu, Khanh; Shareck, François; Lacroix, Monique

    2012-08-01

    A capillary electrophoresis method with UV detection was developed to analyze protein composition of the foodborne pathogen Staphylococcus aureus. Bacterial samples containing 109 CFU/ml, obtained after two cycles of incubations of 24 h, were gamma irradiated at different doses of 1.2, 3.5 and 2.9 kGy to respectively create damage cells, to kill cells and to provoke viable but non cultivable cells (VBNC). It was observed that an irradiation at a sensitive dose of 1.2 kGy caused a significantly increase in the protein with molecular weight (MW) of 17.7 kDa (from 0.61% to 1.2%). This treatment also caused decreases in the expressed proteins with the MWs of 16.3 kDa (from 6.2% to 5.3%) and of 23.4 kDa (from 4.0% to 2.30%). Irradiation at a VBCN dose of 2.9 kGy caused increases in expressed proteins with the MWs of 17.7 kDa (from 0.61% to 3.43%), 18.7 kDa (from 1.04% to 4.30%), 19.5 kDa (from 0.71% to 2.30%), 21.1 kDa (from 1.20% to 3.80%). Moreover, this treatment (2.9 kGy) also caused significantly decreases (P≤0.05) in the expressed proteins with the MW of 30.7 kDa (from 8.6% to 5.15%), 36.3 kDa (from 3.1% to 2.7%) and 40.5 kDa (from 11.3% to 8.5%). Finally, for the irradiation at a lethal dose of 3.5 kGy, it can be found that the expressed proteins with the MW of 17.7 kDa, 18.7 kDa and 19.5 kDa were increased less than that of expressed proteins at the VCNC dose (2.9 kGy) and these might be the very important proteins which are responsible for the survival of the S. aureus. Further, there were also the decreases in expressed proteins with the MW of 30.7 kDa, 36.3 kDa and 75.1 kDa at this dose of treatment (3.5 kGy) which can be expected that these proteins are seriously affected at high dose of γ-irradiation treatment.

  13. Alpha particles are extremely damaging to developing hemopoiesis compared to gamma irradiation

    SciTech Connect

    Tie-Nan Jiang ); Lord, B.I.; Hendry, J.H. )

    1994-03-01

    Estimates of risk of stochastic effects from contamination with [alpha]-particle-emitting radionuclides are based on equivalent doses which take into account the RBE of the high-LET radiation. It is assumed that the RBEs for deterministic effects are considerably less than those for stochastic effects. However, the offspring of mice injected with 30 Bq g[sup [minus]1] [sup 239]Pu at 13 days gestation develop a persistent deficit in hemopoietic stem cells which is primarily the result of damage to their regulatory microenvironment. Their spatial distribution in the marrow is also perturbed, and recent observations on those mice suggested a considerably higher factor than 20. To define a more realistic RBE for hemopoiesis, the effects of external [gamma] irradiation during the fetal development period have been compared directly with those of [sup 239]Pu incorporated via placental transfer on the development of hemopoietic tissue. Pregnant mice were irradiated with [sup 60]Co [gamma] rays (a) continuously from day 13 of gestation to birth at 0.15 or 0.6 Gy/day; (b) six repeated acute doses (0.6 Gy/min) at 0.1 or 0.3 Gy from day 13 of gestation; (c) one acute dose of 0.6 or 1.8 Gy on day 15 of gestation. The spatial distribution of hemopoietic stem cells in 8-week-old offspring was then determined and compared to that resulting from [alpha]-particle irradiation. In each case, the higher dose was required to match the results for [alpha] particles, suggesting an RBE for developing hemopoiesis of 250-360 compared to a continuous [gamma]-ray dose and a rather lower value of 130-180 compared to a single acute dose of [gamma] rays. This contrasts greatly to values for direct irradiation of the stem cells but argues that the effective RBE, measured for long-term effects in vivo, is the more realistic. It is concluded that an all-embracing factor can be grossly misleading and can greatly underestimate the risks of exposure to [alpha] particles. 21 refs., 3 figs., 1 tab.

  14. The effects of gamma irradiation on the vitamin E content and sensory qualities of pecan nuts ( Carya illinoensis)

    NASA Astrophysics Data System (ADS)

    Taipina, Magda S.; Lamardo, Leda C. A.; Rodas, Maria A. B.; del Mastro, Nelida L.

    2009-07-01

    Pecan nuts ( Carya illinoensis) were treated with gamma irradiation and evaluated for changes in vitamin E content and sensory properties. Irradiation at 1 and 3 kGy resulted in no changes in vitamin E content measured as α-tocopherol equivalents by a colorimetric method. A trained sensory panel found that irradiation at 1 kGy produced no significant changes in appearance, aroma, texture and flavor attributes. The vitamin E content of irradiated pecan nuts remained stable, but from the point of view of sensory quality a dose of merely 1 kGy can be considered as recommendable.

  15. [Dominant lethality and translocations in the sex cells of male rats under low-intensity gamma irradiation].

    PubMed

    Baev, I A; Rupova, I M

    1978-11-01

    Adult male rats were given 1300 rad of chronic gamma-irradiation (0.08 rad/min) Dominant lethal rates were found to be high (ranging from 48 to 75%) in irradiated postmeiotic cells and clearly lower (6.8%) in spermatogonia. The chromosome aberration (reciprocal translocation) yields observed with 1300 rad chronic irradiation were comparatively low, averaging 1.6%. Spermatogonia irradiation at low dose rate resulted in a smaller effect as compared to the genetic effects of a single acute exposure.

  16. Effect of gamma irradiation on some physicochemical properties and bioactive compounds of jujube (Ziziphus jujuba var vulgaris) fruit

    NASA Astrophysics Data System (ADS)

    Najafabadi, Najmeh Shams; Sahari, Mohammad Ali; Barzegar, Mohsen; Esfahani, Zohreh Hamidi

    2017-01-01

    Interest in the protection of bioactive compounds and a safe alternative method for preservation of processed fruits and fruit juices has recently increased significantly throughout the world. There is a distinct lack of information on the profile of bioactive compounds in jujube fruit (e.g. organic acids, anthocyanins, and water-soluble vitamins) and their changes during processing (e.g. gamma irradiation). Therefore, in this study, the effect of gamma irradiation at different doses (0.0, 0.5, 1.0, 2.5 and 5.0 kGy) on some physicochemical properties and the bioactive compounds of jujube fruit was investigated. The total soluble solids (TSSs) values remained unaffected at various doses, while the level of total acidity (TA) showed a slight increase at doses ≥ 2.5 kGy (p ≤ 0.05). Irradiation up to 2.5 kGy caused a significant increase in the total monomeric anthocyanin and the total phenolic content (about 12% and 6%, respectively), but a significant decrease was observed in both parameters immediately after irradiation at 5 kGy. Moreover, irradiation treatment caused a significant decrease in L* value and a significant increase in a* and b* values (P ≤ 0.05); however, changes of color were slight until the dose of 5 kGy. Gamma irradiation up to 2.5 kGy had no significant effect on the concentration of malic, citric and succinic acids, while the level of ascorbic acid decreased significantly at all irradiation doses (0-5 kGy). Cyanidin-3, 5-diglucoside was determined as the major anthocyanin in the jujube fruit studied (about 68%), which was reduced significantly when 5 kGy of irradiation was applied (degradation percentage: 27%). The results demonstrated that vitamins C, B2 and B1 are the most water-soluble vitamins in jujube fruit, respectively. Vitamins C and B1 content significantly decreased at all applied doses (0-5 kGy), whereas B2 content at doses ≤ 2.5 kGy was not significantly affected. The results of this study indicate that gamma irradiation at

  17. Efficacy of the inactivation of bacterial spores in white petrolatum and a hydrophilic ointment by gamma irradiation.

    PubMed

    Oie, S H; Fystro, D

    1975-10-01

    To evaluate the possibilities of using gamma irradiation for the sterilization of ointments, the effect of irradiation on spores of Bacillus pumilus and Bacillus sphaericus in dry material and in two different kinds of ointments was studied. The results indicate that for sterilization purposes irradiation was less effective in white petrolatum as compared to irradiation in the dry state. No such protective effect was found in a hydrophilic ointment. Accordingly, the sterilization dose needed for the sterilization of an ointment can be decided upon only after inactivation experiments with suitable test organisms in the actual preparation.

  18. High-yield secretion of recombinant proteins expressed in tobacco cell culture with a designer glycopeptide tag: Process development.

    PubMed

    Zhang, Ningning; Gonzalez, Maria; Savary, Brett; Xu, Jianfeng

    2016-03-01

    Low-yield protein production remains the most significant economic hurdle with plant cell culture technology. Fusions of recombinant proteins with hydroxyproline-O-glycosylated designer glycopeptide tags have consistently boosted secreted protein yields. This prompted us to study the process development of this technology aiming to achieve productivity levels necessary for commercial viability. We used a tobacco BY-2 cell culture expressing EGFP as fusion with a glycopeptide tag comprised of 32 repeat of "Ser-Pro" dipeptide, or (SP)32 , to study cell growth and protein secretion, culture scale-up, and establishment of perfusion cultures for continuous production. The BY-2 cells accumulated low levels of cell biomass (~7.5 g DW/L) in Schenk & Hildebrandt medium, but secreted high yields of (SP)32 -tagged EGFP (125 mg/L). Protein productivity of the cell culture has been stable for 6.0 years. The BY-2 cells cultured in a 5-L bioreactor similarly produced high secreted protein yield at 131 mg/L. Successful operation of a cell perfusion culture for 30 days was achieved under the perfusion rate of 0.25 and 0.5 day(-1) , generating a protein volumetric productivity of 17.6 and 28.9 mg/day/L, respectively. This research demonstrates the great potential of the designer glycopeptide technology for use in commercial production of valuable proteins with plant cell cultures.

  19. Evaluation of an air-liquid interface cell culture model for studies on the inflammatory and cytotoxic responses to tobacco smoke aerosols.

    PubMed

    Azzopardi, David; Haswell, Linsey E; Foss-Smith, Geoff; Hewitt, Katherine; Asquith, Nathan; Corke, Sarah; Phillips, Gary

    2015-10-01

    In vitro toxicological studies for tobacco product assessment have traditionally been undertaken using the particulate phase of tobacco smoke. However, this does not truly reflect exposure conditions that occur in smokers. Thus in vitro cell culture systems are required in which cells are exposed to tobacco whole smoke (WS) at the air-liquid interface (ALI). In this study bronchial epithelial cells were cultured on semi-permeable membranes, transitioned to the ALI and the robustness and sensitivity of the cells to tobacco WS and vapour phase (VP) assessed. Although no effect of air exposure was observed on cell viability, IL-6 and IL-8 release was increased. Exposure to WS resulted in a significant dose dependent decrease in cell viability and a significant non-dose dependent increase in inflammatory mediator secretion. The VP was found to contribute approximately 90% of the total cytotoxicity derived from WS. The cell culture system was also able to differentiate between two smoking regimens and was sensitive to passage number with increased inflammatory mediator secretion and lower cell viability observed in cell cultures of low passage number following WS exposure. This simple cell culture system may facilitate studies on the toxicological impact of future tobacco products and nicotine delivery devices.

  20. Effects of gamma irradiation on microbial safety and quality of stir fry chicken dices with hot chili during storage

    NASA Astrophysics Data System (ADS)

    Chen, Qian; Cao, Mei; Chen, Hao; Gao, Peng; Fu, Yi; Liu, Mianxue; Wang, Yan; Huang, Min

    2016-10-01

    The purpose of this study was to investigate effects of irradiation with different doses on microbial safety, sensory quality and protein content of ready-to-eat stir fry chicken dices with hot chili (FCC) during one year storage. Fresh chicken meat was cut into small dices and fried at approximately 180 °C for 10 min for preparation of FCC samples. The samples were vacuum-packaged and gamma irradiated at 10, 20, 30 and 40 kGy. The results suggest that irradiation with the doses of 10 and 20 kGy could ensure microbiological safety of the samples without deterioration of sensory quality. Microbial counts, sensory qualities and protein contents of the samples were investigated during one year storage. No viable cells were observed and the samples were completely sterilized. Sensory qualities showed no significant difference after irradiated at the doses of 10 and 20 kGy during the storage period. Protein contents were also not affected by irradiation at the same doses. Our results indicate that gamma irradiation of 10 and 20 kGy are effective to maintain shelf stability of ready-to-eat FCC products with microbial safety, sensory quality and nutritional value.

  1. Ameliorative effect of septilin, an ayurvedic preparation against gamma-irradiation-induced oxidative stress and tissue injury in rats.

    PubMed

    Mansour, Heba Hosny; Ismael, Naglaa El-Sayed Rifaat; Hafez, Hafez Farouk

    2014-04-01

    Ionizing radiation is known to induce multiple organ dysfunctions directly related to an increase of cellular oxidative stress, due to overproduction of reactive oxygen species (ROS). This study was aimed to investigate the effect of septilin (an ayurvedic poly-herbal formulation containing the principal herbs, namely Commiphora wightii, Trinospora cordifolia, Rubia cardifolia, Emblica officinalis, Saussurea lappa and Glycyrrhiza glabra) against whole body gamma-irradiation-induced oxidative damage in hepatic and brain tissues in rats. Administration of septilin for 5 days (100 mg/kg) prior to radiation resulted in a significant increase in both superoxide dismutase (SOD) activity and total glutathione (GSH) level in hepatic and brain tissues, while serum high-density lipoprotein-cholesterol (HDL) was reduced by gamma-irradiation. Also, septilin resulted in a significant decrease in NO(x), nitric oxide and malondialdehyde (MDA) levels in hepatic and brain tissues and a significant decrease in serum triglycerides, low-density lipoprotein-cholesterol (LDL) and total cholesterol levels and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels and alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) activities, as well as serum tumor necrosis factor-alpha (TNF-alpha), compared to irradiated group. In conclusion, data obtained from this study indicated that septilin exhibited potential antioxidant activity and showed radioprotective effect against gamma-radiation by preventing oxidative stress and scavenging free radicals.

  2. Gamma-Irradiated Influenza A Virus Provides Adjuvant Activity to a Co-Administered Poorly Immunogenic SFV Vaccine in Mice

    PubMed Central

    Babb, Rachelle; Chan, Jennifer; Khairat, Jasmine E.; Furuya, Yoichi; Alsharifi, Mohammed

    2014-01-01

    Many currently available inactivated vaccines require “adjuvants” to maximize the protective immune responses generated against the antigens of interest. Recent studies in mice with gamma-irradiated influenza A virus (γ-FLU) have shown its superior efficacy compared to other forms of inactivated FLU vaccines and its ability to induce both potent interferon type-I (IFN-I) responses and the IFN-I-associated partial lymphocyte activation. Commonly, IFN-I responses induced by adjuvants, combined in vaccine preparations, have been shown to effectively enhance the immunogenicity of the antigens of interest. Therefore, we investigated the potential adjuvant activity of γ-FLU and the possible effect on antibody responses against co-administrated antigens, using gamma-irradiated Semliki Forest virus (γ-SFV) as the experimental vaccine in mice. Our data show that co-vaccination with γ-FLU and γ-SFV resulted in enhanced SFV-specific antibody responses in terms of increased titers by sixfold and greater neutralization efficacy, when compared to vaccination with γ-SFV alone. This study provides promising evidence related to the possible use of γ-FLU as an adjuvant to poorly immunogenic vaccines without compromising the vaccine efficacy of γ-FLU. PMID:24959166

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

    PubMed

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

    2015-08-26

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

  4. EPR studies of free radicals decay and survival in gamma irradiated aminoglycoside antibiotics: sisomicin, tobramycin and paromomycin.

    PubMed

    Wilczyński, Sławomir; Pilawa, Barbara; Koprowski, Robert; Wróbel, Zygmunt; Ptaszkiewicz, Marta; Swakoń, Jan; Olko, Paweł

    2012-02-14

    Radiation sterilization technology is more actively used now that any time because of its many advantages. Gamma radiation has high penetrating power, relatively low chemical reactivity and causes small temperature rise. But on the other hand radiosterilization can lead to radiolytic products appearing, in example free radicals. Free radicals in radiative sterilized sisomicin, tobramycin and paromomycin were studied by electron paramagnetic resonance (EPR) spectroscopy. Dose of gamma irradiation of 25kGy was used. Concentrations and properties of free radicals in irradiated antibiotics were studied. EPR spectra were recorded for samples stored in air and argon. For gamma irradiated antibiotics strong EPR lines were recorded. One- and two-exponential functions were fitted to experimental points during testing and researching of time influence of the antibiotics storage to studied parameters of EPR lines. Our study of free radicals in radiosterilized antibiotics indicates the need for characterization of medicinal substances prior to sterilization process using EPR values. We propose the concentration of free radicals and other spectroscopic parameters as useful factors to select the optimal type of sterilization for the individual drug. The important parameters are i.a. the τ time constants and K constants of exponential functions. Time constants τ give us information about the speed of free radicals concentration decrease in radiated medicinal substances. The constant K(0) shows the free radicals concentration in irradiated medicament after long time of storage.

  5. Combined effects of gamma irradiation and modified atmosphere packaging on bacterial resistance in grated carrots ( Daucus carota)

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Lafortune, R.

    2004-09-01

    The present study was conducted to evaluate the efficiency of gamma irradiation combined with modified atmosphere packaging as an alternative treatment to ensure the innocuity and the shelf life extension of pre-cured vegetables. Grated carrots were inoculated with Escherichia coli (10 6 CFU/g) and packed under air or under MAP condition (60% O 2, 30% CO 2 and 10% N 2). The packages were then, gamma irradiated at doses from 0.15 to 0.9 kGy and stored at 4±1°C. E. coli counts were periodically evaluated during 50 days of storage. Results showed that at day 1, an irradiation treatment at a dose of 0.15 kGy reduced by 3 and 4 log the microbial level representing a level of 3 and 2 log CFU/g when samples were irradiated under air and under MAP respectively. However, a level of 3 log CFU/g was detected in both treated samples after 7 days of storage. When samples were irradiated at doses ⩾0.3 kGy no E.coli were detected during the whole storage in samples treated under MAP. However, when samples were treated under air, a level of 1-2 log CFU/g of E.coli was detected after 5 days of storage.

  6. Effects of gamma irradiation on the radiation-resistant bacteria and polyphenol oxidase activity in fresh kale juice

    NASA Astrophysics Data System (ADS)

    Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Yun, Hyejeong; Chung, Jinwoo

    2007-07-01

    Gamma radiation was performed to prolong the shelf life of natural kale juice. The total aerobic bacteria in fresh kale juice, prepared by a general kitchen process, was detected in the range of 10 6 cfu/ml, and about 10 2 cfu/ml of the bacteria survived in the juice in spite of gamma irradiation treatment with a dose of 5 kGy. Two typical radiation-resistant bacteria, Bacillus megaterium and Exiguobacterium acetylicum were isolated and identified from the 5 kGy-irradiated kale juices. The D10 values of the vegetative cell and endospore of the B. megaterium in peptone water were 0.63±0.05 and 1.52±0.05 kGy, respectively. The D10 value of the E. acetylicum was calculated as 0.65±0.06 kGy. In the inoculation test, the growth of the surviving B. megaterium and E. acetylicum in the 3-5 kGy-irradiated kale juice retarded and/or decreased significantly during a 3 d post-irradiation storage period. However, there were no significant differences in the residual polyphenol oxidase activity and browning index between the nonirradiated control and the gamma irradiated kale juice during a post-irradiation period.

  7. Graphene scavenges free radicals to synergistically enhance structural properties in a gamma-irradiated polyethylene composite through enhanced interfacial interactions.

    PubMed

    Kolanthai, Elayaraja; Bose, Suryasarathi; Bhagyashree, K S; Bhat, S V; Asokan, K; Kanjilal, D; Chatterjee, Kaushik

    2015-09-21

    A unique strategy for scavenging free radicals in situ on exposure to gamma irradiation in polyethylene (PE) nanocomposites is presented. Blends of ultra-high molecular weight PE and linear low-density PE (PEB) and their nanocomposites with graphene (GPEB) were prepared by melt mixing to develop materials for biomedical implants. The effect of gamma irradiation on the microstructure and mechanical properties was systematically investigated. The neat blend and the nanocomposite were subjected to gamma-ray irradiation in order to improve the interfacial adhesion between PE and graphene sheets. Structural and thermal characterization revealed that irradiation induced crosslinking and increased the crystallinity of the polymer blend. The presence of graphene further enhanced the crystallinity via crosslinks between the polymer matrix and the filler on irradiation. Graphene was found to scavenge free radicals as confirmed by electron paramagnetic resonance spectroscopy. Irradiation of graphene-containing polymer composites resulted in the largest increase in modulus and hardness compared to either irradiation or addition of graphene to PEB alone. This study provides new insight into the role of graphene in polymer matrices during irradiation and suggests that irradiated graphene-polymer composites could emerge as promising materials for use as articulating surfaces in biomedical implants.

  8. Pulse radiolysis and 77 K matrix. gamma. irradiation of dimethyl truxinates and trans-methyl cinnamate in 2-methyltetrahydrofuran

    SciTech Connect

    Takamuku, S.; Kigawa, H.; Suematsu, H.; Susumu, T.; Tsumori, K.; Sakurai, H.

    1982-05-13

    One-electron reduction of dimethyl ..mu..-truxinate (..mu..-DMT), dimethyl ..beta..-truxinate (..beta..-DMT), and dimethyl ..cap alpha..-truxillate (..cap alpha..-DMT) has been investigated by pulse radiolysis and 77 K matrix ..gamma.. irradiation of the 2-methyltetrahydrofuran solutions. Cycloreversion of the radical anions formed by an electron attachment to these cyclobutanes was observed in all cases, even at 77 K. The orientation of the cycloreversion was dependent on the stereochemistry of the cyclobutanes, and the selectivity was reasonably explained by a so-called cis effect; the best possible release of steric hindrance decides the primary step of the reaction. In 77 K matrix ..gamma.. irradiation of ..cap alpha..-DMT, an intense IR absorption was found after the photobleaching of trapped electrons with light > 690 nm. In other DMTs, the IR absorption band was not observed while the cycloreversion of DMT by mobile electrons occurred. Thus, the IR band in the case of ..cap alpha..-DMT was assigned to an associated dimer anion due to the interaction between the radical anion and the neutral molecule pair of trans-methyl cinnamate orginally formed by the cycloreversion of ..cap alpha..-DMT. The dimer anion was presumed to be oriented in a head-to-tail structure in a solvent cage on the basis of the original configuration of ..cap alpha..-DMT.

  9. Infrared and UV-visible spectroscopic studies of gamma-irradiated Sb2O3-B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Marzouk, Samir Y.; Elbatal, Fatma H.

    2014-04-01

    Glasses from the binary Sb2O3-B2O3 system were prepared in the compositional range 90-30 Sb2O3 mol%. UV-visible spectroscopic measurements were carried out in the range 190-1100 nm before and after successive gamma rays irradiation (1, 3, 4 Mrad). Infrared absorption of the samples was measured by the KBr technique in the range 4000-400 cm-1 and the same measurements were repeated after gamma irradiation with 4 kGy. Experimental results indicate that antimony borate glasses reveal quite shielding behavior towards gamma rays irradiation as observed with heavy metal cations bearing glasses such as Bi3+ and Pb2+. Infrared absorption spectra reveal characteristic absorption bands specific for the glass-forming borate units and Sb-O units. Glasses containing high antimony oxide content can thus be recommended as promising radiation-shielding material because they show resistant to gamma irradiation due to the presence of high percent of heavy metal oxide (Sb2O3).

  10. A novel hydrogel of poloxamer 407 and chitosan obtained by gamma irradiation exhibits physicochemical properties for wound management.

    PubMed

    Leyva-Gómez, Gerardo; Santillan-Reyes, Erika; Lima, E; Madrid-Martínez, Abigail; Krötzsch, E; Quintanar-Guerrero, D; Garciadiego-Cázares, David; Martínez-Jiménez, Alejandro; Hernández Morales, M; Ortega-Peña, Silvestre; Contreras-Figueroa, M E; Cortina-Ramírez, G E; Abarca-Buis, René Fernando

    2017-05-01

    Application of polymers cross-linked by gamma irradiation on cutaneous wounds has resulted in the improvement of healing. Chitosan (CH) and poloxamer 407 (P407)-based hydrogels confer different advantages in wound management. To combine the properties of both compounds, a gamma-irradiated mixture of 0.75/25% (w/w) CH and P407, respectively, was obtained (CH-P), and several physical, chemical, and biological analyses were performed. Notably, gamma radiation induced changes in the mixture's thermal behavior, viscosity, and swelling, and exhibited stability at neutral pH. The thermal reversibility provided by P407 and the bacteriostatic effect of CH were maintained. Mice full-thickness wounds treated with CH-P diminished the wound area during the first days. Consequently, with this treatment, increased levels of macrophages, α-SMA, and collagen deposition in wounds were observed, indicating a more mature scar tissue. In conclusion, the new hydrogel CH-P, at physiologic pH, combined the beneficial characteristics of both polymers and produced new properties for wound management.

  11. Structural and optical properties of CuO in zinc phosphate glasses and effects of gamma irradiation

    NASA Astrophysics Data System (ADS)

    Ouis, M. A.; ElBatal, H. A.; Abdelghany, A. M.; Hammad, Ahmed H.

    2016-01-01

    Collective optical and infrared measurements have been employed to investigate the state of increasing copper ions in host 0.5ZnO-0.5P2O5 glass composition. The same spectral measurements were repeated after gamma irradiation with a dose of 20 and 80 KGy. Optical absorption spectra reveal strong UV absorption due to trace ferric ions present as unavoidable impurities within the chemicals used in the preparation of the glasses. Copper containing glasses show an additional broad visible-near infrared band due to distorted octahedrally coordinated Cu2+ ions which at high CuO contents exhibit splitting to several component absorption peaks. Gamma irradiation causes several variations between the response of the base host zinc phosphate glass and effect of increasing CuO. These changes are correlated with both the formation of induced defects through suggested photochemical reactions in the UV region and some shielding effects with increasing CuO in the visible-near infrared spectrum. Infrared absorption spectra reveal repetitive vibrational bands due to phosphate groups mainly from metaphosphate units and the spectra show some variations with the increase of CuO content visualize by the increase of the intensity of the mid broad band extending in the range 800-1500 cm-1.

  12. Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation

    SciTech Connect

    Tostar, Sandra; Stenvall, Erik; Boldizar, Antal; Foreman, Mark R. St. J.

    2013-06-15

    Highlights: • We have proposed a method to recover antimony from electronic plastics. • The most efficient acid solution was sodium hydrogen tartrate in dimethyl sulfoxide. • Gamma irradiation did not influence the antimony leaching ability. - Abstract: There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5 M) dissolved in either dimethyl sulfoxide or water (at ca. 23 °C and heated to ca. 105 °C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed.

  13. Effects of gamma irradiation on the initial mechanical and material properties of goat bone-patellar tendon-bone allografts

    SciTech Connect

    Gibbons, M.J.; Butler, D.L.; Grood, E.S.; Bylski-Austrow, D.I.; Levy, M.S.; Noyes, F.R. )

    1991-03-01

    The effects of {sup 60}Co gamma irradiation on the initial mechanical properties of the composite bone-patellar tendon-bone unit (CU) and the tendon midsubstance (TM) were studied. Frozen specimens were exposed to either 2 or 3 Mrad of gamma irradiation. Paired frozen specimens served as intraanimal controls. Treatment effects on the CU were assessed using four mechanical parameters. Effects on the TM were assessed using four material parameters measured using an optical surface-strain analysis system. The maximum force and strain energy to maximum force of the composite unit were significantly reduced 27% and 40%, respectively, after 3 Mrad of irradiation (p less than .05). Mechanical properties of the CU were not significantly altered, however, following 2 Mrad of irradiation. Based on individual paired contrasts between treatment and control, significant differences were also found in the material properties of the tendon midsubstance. The maximum stress, maximum strain, and strain energy density to maximum stress were significantly reduced following 3 Mrad, but not 2 Mrad, of irradiation. The results provide important time zero material property data, which will be useful for later anterior cruciate ligament reconstruction studies using irradiated allograft patellar tendons in the goat model and other animal models as well.

  14. Changes in antigenicity of porcine serum albumin in gamma-irradiated sausage extract by treatment with pepsin and trypsin

    NASA Astrophysics Data System (ADS)

    Kim, Koth-Bong-Woo-Ri; Song, Eu-Jin; Lee, So-Young; Park, Jin-Gyu; Lee, Ju-Woon; Byun, Myung-Woo; Ahn, Dong-Hyun

    2011-11-01

    Pork is known as an allergenic food with porcine serum albumin (PSA, 66 kDa) representing the major allergen. This study was conducted to investigate the change in antigenicity of PSA in gamma-irradiated sausage extract treated with pepsin and trypsin. Sausage products (A and B) were irradiated at 1, 3, 10, and 20 kGy. After irradiation, sausage proteins were extracted and digested with pepsin (1:200, 30 min) and trypsin (1:300, 5, 30, 60, 90, and 120 min). The binding ability of PSA in extracts of the irradiated sausages (A and B) decreased by over 3 kGy relative to the binding ability of PSA in extracts of intact sausages and showed no notable differences when the dose of radiation ranged from 3 to 20 kGy. After treatment with pepsin and trypsin, the binding ability of PSA in extracts of the irradiated sausages was decreased more relative to that of intact sausages and showed no significant differences when the period of trypsin treatment is increased or when the dose of irradiation is increased. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results indicated that there was no visible change in the intensity of the PSA band in extracts of the irradiated sausages. After pepsin and trypsin treatment, the intensity of PSA band faded with increasing doses of irradiation. In conclusion, antigenicity of PSA in pork sausages could be reduced by gamma irradiation.

  15. Effects of sterilizing gamma irradiation on bloodspot newborn screening tests and whole blood cyclosporine and tacrolimus measurements.

    PubMed

    Stickle, Douglas F; McKenzie, David A; Landmark, James D; Pirruccello, Samuel J; Post, Gregory R; Iwen, Peter C; Thompson, Robert B; Hinrichs, Steven H

    2003-02-01

    Sterilizing irradiation of the US mail has been proposed as a method to prevent delivery of viable anthrax spores. Because newborn screening samples (bloodspots) and cyclosporine and tacrolimus specimens (whole blood) are delivered routinely through the mail, we studied whether sterilizing gamma irradiation could affect these test results. Specimens were exposed to 18 kGy gamma irradiation (100 hours x 18,000 rad/h), a "kill dose" for Bacillus pumilus spore strips. Irradiation had no significant effect on whole blood cyclosporine or tacrolimus results, but it had a degradative effect on bloodspot phenylalanine, hemoglobins, biotinidase, galactose-1-phosphate uridyltransferase, thyroxine, and thyrotropin. Such irradiation potentially could cause false-negative results for the detection of phenylketonuria and likely would lead to an increase in secondary testing for hemoglobin variants, but it is unlikely to lead to false-negative or false-positive results for the remaining newborn screening tests. These experiments cannot rule out possible greater effects by larger doses or other types of irradiation.

  16. Determination of the changes of antifungal properties of Satureja hortensis, Thymus vulgaris and Thymbra spicata exposed to gamma irradiation

    NASA Astrophysics Data System (ADS)

    Gumus, Tuncay

    2010-01-01

    In this research, changes in the antifungal activity of the extract of Satureja hortensis, Thymus vulgaris and Thymbra spicata exposed to gamma irradiation against two aflatoxigenic moulds Aspergillus parasiticus NRRL 2999 and 465 were investigated. The samples of dry plant leaf powder were irradiated with doses of 1.2, 3.0, 5.1 kGy. While the antifungal activity of S. hortensis with 0 and 1.2 kGy dose irradiation against A. parasiticus NRRL 2999 was found to be similar, it decreased with 3.0 and 5.1 kGy irradiation doses ( P<0.05). On the contrary, antifungal activity of T. spicata increased until 3.0 kGy and then it decreased with 5.1 kGy irradiation dose ( P<0.05). For T. vulgaris, an increase of irradiation dose resulted in a decrease of antifungal activity against aflatoxigenic moulds. This research shows that antifungal properties of some spices can be changed by gamma irradiation.

  17. Gamma irradiation of sorghum flour: Effects on microbial inactivation, amylase activity, fermentability, viscosity and starch granule structure

    NASA Astrophysics Data System (ADS)

    Mukisa, Ivan M.; Muyanja, Charles M. B. K.; Byaruhanga, Yusuf B.; Schüller, Reidar B.; Langsrud, Thor; Narvhus, Judith A.

    2012-03-01

    Malted and un-malted sorghum ( Sorghum bicolor (L.) Moench) flour was gamma irradiated with a dose of 10 kGy and then re-irradiated with 25 kGy. The effects of irradiation on microbial decontamination, amylase activity, fermentability (using an amylolytic L. plantarum MNC 21 strain), starch granule structure and viscosity were determined. Standard methods were used during determinations. The 10 kGy dose had no effect on microbial load of un-malted flour but reduced that of malted flour by 3 log cycles. Re-irradiation resulted in complete decontamination. Irradiation of malt caused a significant ( p<0.05) reduction in alpha and beta amylase activity (22% and 32%, respectively). Irradiation of un-malted flour increased the rates of utilization of glucose and maltose by 53% and 100%, respectively, during fermentation. However, microbial growth, rate of lactic acid production, final lactic acid concentration and pH were not affected. Starch granules appeared normal externally even after re-irradiation, however, granules ruptured and dissolved easily after hydration and gelatinization. Production of high dry matter density porridge (200 g dry matter/L) with a viscosity of 3500 cP was achieved by irradiation of un-malted flout at 10 kGy. Gamma irradiation can be used to decontaminate flours and could be utilized to produce weaning porridge from sorghum.

  18. Luminescence properties and compositions of contaminating inorganic minerals separated from gamma-irradiated fresh and white ginsengs from different areas

    PubMed Central

    Ahn, Jae-Jun; Akram, Kashif; Jeong, Mi-Seon; Kwak, Ji-Young; Park, Eun-Joo; Kwon, Joong-Ho

    2013-01-01

    Gamma-irradiation (0-7 kGy) of ginseng is permitted in Korea for the purpose of microbial decontamination; with strict labeling, traceability and monitoring requirements. An identification study was conducted to determine the photostimulated-luminescence (PSL) and thermoluminescence (TL) properties of gamma-irradiated fresh and white ginsengs cultivated in different areas. Dosedependent PSL-based screening was possible for white ginseng samples; however, inappropriate results from non-irradiated fresh ginseng samples were obtained, showing intermediate (700 to 5,000) or positive (T2 >5,000, irradiated) PSL counts due to the abundance of minerals on the surfaces of the samples. TL analysis of separated minerals from all non-irradiated samples gave TL glow curves of low intensity with a maximum peak after 300℃. However, well-defined irradiation-specific (high intensity with a maximum peak at about 200℃) glow curves were observed for all the irradiated samples, regardless of their type and origins. TL ratios (first glow curve /second glow curve) were also determined to confirm the irradiated (>0.1) and non-irradiated (<0.1) results. SEM-EDX (scanning electron microscope-energy dispersive X-ray) and XRD (X-ray diffraction) spectroscopic analyses showed that feldspar and quartz minerals were the main source for the typical radiation-specific luminescence properties. PMID:24235863

  19. Inactivation of contaminated fungi and antioxidant effects of peach ( Prunus persica L. Batsch cv Dangeumdo) by 0.5-2 kGy gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kim, Kyoung-Hee; Kim, Mi-Seon; Kim, Hong-Gi; Yook, Hong-Sun

    2010-04-01

    The effect of gamma irradiation (0.5-2 kGy) on the physicochemical properties of peaches was investigated during a 6-day storage at 20±3 °C. Gamma irradiation is able to inactivate the four pathogens, namely Botrytis cinerea, Penicillium expansum, Rhizopus stolonifer var. stolonifer and Monilinia fructicola in peaches. Hardness significantly decreased with the increment of irradiation dose level whereas soluble solid and total polyphenol contents increased with increment of irradiation dose level. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the irradiated peach was higher than that of control, and its activity increased with increment of irradiation dose level. These results suggest that gamma irradiation of peaches improved antioxidant activity, but dramatically affects the hardness throughout the entire storage time.

  20. Tobacco-Control Policies in Tobacco-Growing States: Where Tobacco Was King

    PubMed Central

    Fallin, Amanda; Glantz, Stanton A

    2015-01-01

    Context The 5 major tobacco-growing states (Kentucky, North Carolina, South Carolina, Tennessee, and Virginia) are disproportionately affected by the tobacco epidemic, with higher rates of smoking and smoking-induced disease. These states also have fewer smoke-free laws and lower tobacco taxes, 2 evidence-based policies that reduce tobacco use. Historically, the tobacco farmers and hospitality associations allied with the tobacco companies to oppose these policies. Methods This research is based on 5 detailed case studies of these states, which included key informant interviews, previously secret tobacco industry documents (available at http://legacy.library.ucsf.edu), and media articles. This was supplemented with additional tobacco document and media searches specifically for this article. Findings The tobacco companies were particularly concerned about blocking tobacco-control policies in the tobacco-growing states by promoting a pro-tobacco culture, beginning in the late 1960s. Nevertheless, since 2003, there has been rapid progress in the tobacco-growing states’ passage of smoke-free laws. This progress came after the alliance between the tobacco companies and the tobacco farmers fractured and hospitality organizations stopped opposing smoke-free laws. In addition, infrastructure built by National Cancer Institute research projects (COMMIT and ASSIST) led to long-standing tobacco-control coalitions that capitalized on these changes. Although tobacco production has dramatically fallen in these states, pro-tobacco sentiment still hinders tobacco-control policies in the major tobacco-growing states. Conclusions The environment has changed in the tobacco-growing states, following a fracture of the alliance between the tobacco companies and their former allies (tobacco growers and hospitality organizations). To continue this progress, health advocates should educate the public and policymakers on the changing reality in the tobacco-growing states, notably the

  1. Evaluation of the potential of hexamethylenetetramine, compared with tirapazamine, as a combined agent with {gamma}-irradiation and cisplatin treatment in vivo.

    PubMed

    Masunaga, S; Tano, K; Watanabe, M; Kashino, G; Suzuki, M; Kinashi, Y; Ono, K; Nakamura, J

    2009-05-01

    The purpose of this investigation was to compare the effect on intratumour quiescent (Q) cells in vivo of hexamethylenetetramine (HMTA) or tirapazamine (TPZ) in combination with gamma-irradiation and cisplatin treatment. Squamous cell carcinoma (SCC) VII tumour-bearing mice were administered 5-bromo-2'-deoxyuridine (BrdU) continuously to label all intratumour proliferating (P) cells. The mice then received HMTA or TPZ intraperitoneally or continuously with or without gamma-irradiation or cisplatin treatment. Other tumour-bearing mice received HMTA or TPZ intraperitoneally immediately after gamma-irradiation. Immediately after gamma-irradiation or cisplatin treatment following HMTA or TPZ, or 24 h after gamma-irradiation followed by HMTA or TPZ, the response of Q cells was assessed in terms of the micronucleus frequency using immunofluorescence staining for BrdU. The response of all tumour cells (P + Q) was determined from the BrdU-non-treated tumours. HMTA was more toxic to the subset of Q cells than to the population of tumour cells as a whole, similar to the findings for TPZ. The radiosensitising effect of HMTA was similar to that of TPZ in both all cells and Q cells. The recovery-inhibiting effect of HMTA was reliable, but not as great as that of TPZ. The cisplatin sensitivity-enhancing effect of HMTA was similar to or slightly greater than that of TPZ. Continuous administration of both HMTA and TPZ resulted in higher radiosensitivity- and cisplatin sensitivity-enhancing effects than did a single i.p. administration. We concluded that, in terms of the total tumour cell killing effect, including killing of Q cells, gamma-irradiation and cisplatin treatment combined with continuous HMTA administration is a promising strategy given that HMTA is used in clinics.

  2. Effects of gamma irradiation on the biomechanical properties of peroneus tendons

    PubMed Central

    Aguila, Christopher M; Delcroix, Gaëtan J-R; Kaimrajh, David N; Milne, Edward L; Temple, H Thomas; Latta, Loren L

    2016-01-01

    PB and PL tendons. Only the PB structural stiffness was affected by irradiation. Thus, sterilizing allografts at 1.5–2.5 Mrad of gamma irradiation does not cause major alterations in the tendons’ biomechanical properties while still providing a suitable amount of sterilization for anterior cruciate ligament reconstruction. PMID:27695371

  3. Tissue culture specificity of the tobacco ASA2 promoter driving hpt as a selectable marker for soybean transformation selection.

    PubMed

    Zernova, Olga; Zhong, Wei; Zhang, Xing-Hai; Widholm, Jack

    2008-11-01

    This study was carried out to determine if the tobacco anthranilate synthase ASA2 2.3 kb promoter drives tissue culture specific expression and if it is strong enough to drive hpt (hygromycin phosphotransferase) gene expression at a level sufficient to allow selection of transformed soybean embryogenic culture lines. A number of transformed cell lines were selected showing that the promoter was strong enough. Northern blot analysis of plant tissues did not detect hpt mRNA in the untransformed control or in the ASA2-hpt plants except in developing seeds while hpt mRNA was detected in all tissues of the CaMV35S-hpt positive control line plants. However, when the more sensitive RT-PCR assay was used all tissues of the ASA2-hpt plants except roots and mature seeds were found to contain detectable hpt mRNA. Embryogenic tissue cultures initiated from the ASA2-hpt plants contained hpt mRNA detectable by both northern and RT-PCR analysis and the cultures were hygromycin resistant. Friable callus initiated from leaves of ASA2-hpt plants did in some cases contain hpt mRNA that was only barely detectable by northern hybridization even though the callus was very hygromycin resistant. Thus the ASA2 promoter is strong enough to drive sufficient hpt expression in soybean embryogenic cultures for hygromycin selection and only very low levels of expression were found in most plant tissues with none in mature seeds.

  4. Effect of 2,4-Dichlorophenoxyacetic Acid on Glucosylation of Scopoletin to Scopolin in Tobacco Tissue Culture

    PubMed Central

    Hino, Fumitsugu; Okazaki, Mitsuo; Miura, Yoshiharu

    1982-01-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) stimulated the formation of scopoletin and scopolin in tobacco (Nicotiana tabacum L. `Bright Yellow') cell culture. It especially stimulated the uptake of scopoletin from culture medium into the cells and the glucosylation of scopoletin to its monoglucoside, scopolin. This phenomenon is peculiar to 2,4-D, in contrast to other plant hormones. 2,4-D (1 μg/ml) stimulated the glucosylation of scopoletin to scopolin by enhancing UDP-glucose:scopoletin glucosyltransferase (SGTase) activity. The enhancement of SGTase activity caused by treatment with 2,4-D was observed when the syntheses of RNA and protein were inhibited by either actinomycin-D and/or cycloheximide. However, the stimulatory effect of 2,4-D was inhibited by treatment with dinitrophenol. Furthermore, SGTase with or without treatment by 2,4-D in vivo for 24 hours, was isolated from cultured tobacco cells. The enzymes were purified about 200-fold by precipitation with (NH4)2SO4 and chromatography with Sephadex G-100, DEAE-cellulose, and hydroxyapatite. The specific activity of 2,4-D-treated SGTase was 10 times higher than that of untreated SGTase even in the purified fraction, which showed one protein band under electrophoresis. These results suggest that the enhancement of SGTase activity by 2,4-D is due to the energy-dependent activation of the enzyme already present, but not due to the de novo synthesis of the enzyme. Images PMID:16662301

  5. Characterization and identification of gamma-irradiated sauces by electron spin resonance spectroscopy using different sample pretreatments.

    PubMed

    Akram, Kashif; Ahn, Jae-Jun; Kwon, Joong-Ho

    2013-06-01

    Tomato ketchup, barbeque sauce, sweet chili sauce, and spaghetti sauce were gamma irradiated at 0, 1, 5, and 10 kGy. Electron spin resonance (ESR) technique was used to characterize the irradiated sauces, targeting radiation-induced cellulose radicals and using a modified sample pretreatment method. The samples were first washed with water, and then the residues were extracted with alcohol. The non-irradiated sauces exhibited the single central signal, whose intensity showed a significant increase on irradiation. The ESR spectra from the radiation-induced cellulose radicals, with two side peaks (g=2.02012 and g=1.98516) equally spaced (± 3 mT) from the central signal, were also observed in the irradiated sauces. The improvements in the central (natural) and radiation-induced (two side peaks corresponding to the cellulose radicals) signal intensities were obvious, when compared with routine freeze-drying and alcoholic-extraction techniques.

  6. Evaluation of gamma irradiation and frozen storage on microbial load and physico-chemical quality of turkey breast meat

    NASA Astrophysics Data System (ADS)

    Jouki, M.

    2013-04-01

    In this study we evaluated the effects of gamma irradiation at doses of 0.0, 0.5, 2.0 and 4.0 kGy and frozen storage as a combination process on improvement of turkey breast meat shelf life. The samples were stored at -18 °C and were undergone microbial, chemical and sensory evaluation at 2-month intervals. However, 4 kGy dose reduced the counts of mesophilic bacteria and coliform by more than 5 log units, while Salmonella was not detected. Irradiation of samples significantly increased peroxide value but had no significant effect on total volatile nitrogen contents, while storage significantly increased the peroxide value and total volatile nitrogen.

  7. Qualitative and Quantitative Assessment of Sewage Sludge by Gamma Irradiation with Pasteurization as a Tool for Hygienization

    NASA Astrophysics Data System (ADS)

    Priyadarshini, J.; Roy, P. K.; Mazumdar, A.

    2014-01-01

    In this research work, management of sewage sludge disposal on agricultural soils is addressed. The increasing amount of sewage sludge and more legislative regulation of its disposal have stimulated the need for developing new technologies to recycle sewage sludge efficiently. The research was structured along two main avenues, namely, the efficacy of the irradiation process for removing enteric pathogenic microorganisms and the potential of irradiated sludge as a soil amendment. This study investigated how application of irradiation with heat treatment reduced pathogens in sewage sludge. Raw and pasteurised Sewage sludge was treated at different dose treatment of 1.5, 3 and 5 kilogray (kGy) gamma irradiation individually and for 3 kGy sufficiency was achieved. Decrease in irradiation dose from 5 to 3 kGy was observed for pasteurised sludge resulting in saving of radiation energy. The presence of heavy metals in untreated sewage sludge has raised concerns, which decreases after irradiation.

  8. Effect of gamma irradiation on physicochemical properties of commercial poly(lactic acid) clamshell for food packaging

    NASA Astrophysics Data System (ADS)

    Madera-Santana, Tomás J.; Meléndrez, R.; González-García, Gerardo; Quintana-Owen, Patricia; Pillai, Suresh D.

    2016-06-01

    Poly(lactic acid) (PLA) is a well-known biodegradable polymer with strong potential application in food packaging industry. In this paper, samples of PLA clamshell for tomatoes packaging were exposed with 60CO γ-ray's source (1.33 MeV) at different dose levels (0, 10, 60, 150, 300, and 600 kGy), at room temperature and in presence of air. The physicochemical properties of neat PLA and sample exposed to gamma irradiation were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and tensile measurements. Results show as the dose increases, the molecular weight (Mw), melting temperature (Tm), tensile strength and elongation at break decreased. However, the tensile modulus increased with increasing doses. The surface of PLA clamshells was degraded (scratches and minor cracks) when samples were exposed to doses greater than 60 kGy.

  9. Removal of reactive dyes from textile wastewater by immobilized chitosan upon grafted Jute fibers with acrylic acid by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Hassan, Mahmoud S.

    2015-10-01

    Jute fibers were grafted with acrylic acid by gamma irradiation technique. Chitosan was immobilized upon the grafted Jute fibers to be used as an adsorbent for waste reactive dye. The treated Jute fibers were characterized by using of Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of Jute treatment on its thermal stability by using thermogravimetric analysis (TGA) and its mechanical properties were investigated. The adsorption isotherm and the different factors affecting the dye adsorption such as pH and contact time were also studied. It was found that the dye adsorption was enhanced in the low pH range and increased with increasing of the contact time, regardless of temperature change.

  10. Fracture resistance behaviour of gamma-irradiation sterilized cortical bone protected with a ribose pre-treatment

    NASA Astrophysics Data System (ADS)

    Woodside, Carman Mitchell

    Structural bone allograft reconstructions are often implemented to repair large skeletal defects. To ensure the biological safety of the patient, allograft material is routinely sterilized with gamma-irradiation prior to implantation. The sterilization process damages the tissue, specifically the collagen protein network, leading to severe losses in the mechanical properties of the bone. Our lab has begun developing a ribose pre-treatment that can protect bone from these harmful effects. The goals of the present study were to develop a method to measure the fracture toughness of bone, an important clinical failure mode, and implement it to determine the effectiveness of the ribose pre-treatment on fracture toughness. We have shown that the ribose pre-treatment is successful at protecting some of the original fracture toughness of sterilized bone, and that the connectivity of the collagen network is an important contributor to the fracture resistance of bone.

  11. Evaluating structural and microstructural changes of PDMS-SiO2 hybrid materials after sterilization by gamma irradiation.

    PubMed

    Almeida, J Carlos; Lancastre, Joana; Vaz Fernandes, M Helena; Margaça, Fernanda M A; Ferreira, Luís; Miranda Salvado, Isabel M

    2015-03-01

    PDMS-SiO2 hybrid materials obtained by sol-gel process have been extensively studied over the past years due to its promising biomedical applications namely as bone substitutes, catheters, and drug delivery devices. Regardless of the intended biomedical application, all these materials should go through a sterilization process before interfacing with a living structure. However, it is unclear whether they undergo structural and microstructural changes when subjected to sterilization by gamma irradiation. This paper addresses this issue by showing that a sol-gel processed biomaterial based on the PDMS-CaO-SiO2 hybrid system suffers only small structural changes when submitted to a radiation dose of 25kGy, the dose usually recommended to achieve a Sterility Assurance Level of 10(-6) when the natural contamination level and microorganism types cannot be calculated. The characterization was assessed by FT-IR, (29)Si-{(1)H} CP-MAS, thermal analysis (DTG), and SEM.

  12. The gamma-irradiation of aqueous hydrogen cyanide in the presence of ferrocyanide or ferricyanide: implications to prebiotic chemistry.

    PubMed

    Navarro-González, R; Negrón-Mendoza, A; Aguirre-Calderón, M E; Ponnamperuma, C

    1989-01-01

    The gamma-irradiation of 0.1 M, O2-free, aqueous HCN was studied in the presence of ferrocyanide or ferricyanide in the concentration range 10(-3) - 10(-5) M. This study was carried out in order to get an insight into the possible role that cyanocomplexes of iron may have played in promoting prebiotic syntheses via the free-radical oligomerization of HCN. It was found that ferrocyanide or ferricyanide have no effect on the irradiation of 0.1 M HCN solutions at concentrations < or = 10(-4) M. At high concentrations, 10(-3) M, they lead to a marked decrease in the conversion of HCN. There was no significant difference due to the oxidation state of iron used, particularly at high doses > or = 100 kGy.

  13. The effect of continuous low dose-rate gamma irradiation on cell population kinetics of lymphoid tissue

    NASA Technical Reports Server (NTRS)

    Foster, B. R.

    1974-01-01

    Cellular response and cell population kinetics were studied during lymphopoiesis in the thymus of the mouse under continuous gamma irradiation using autoradiographic techniques and specific labeling with tritiated thymidine. On the basis of tissue weights, it is concluded that the response of both the thymus and spleen to continuous low dose-rate irradiation is multiphasic. That is, alternating periods of steady state growth, followed by collapse, which in turn is followed by another period of homeostasis. Since there are two populations of lymphocytes - short lived and long-lived, it may be that different phases of steady state growth are mediated by different lymphocytes. The spleen is affected to a greater extent with shorter periods of steady-state growth than exhibited by the thymus.

  14. Efficacy of integrated treatment of UV light and low dose gamma irradiation on Escherichia coli O157:H7 and Salmonella enterica on grape tomatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficacy of integrated treatment of UVC and low dose Gamma irradiation to inactivate mixed Strains of Escherichia coli O157:H7 and Salmonella enterica inoculated on whole Grape tomatoes was evaluated. A mixed bacterial cocktail composed of a three strain mixture of E. coli O157:H7 (C9490, E02128 an...

  15. Effects of lactic acid fermentation and gamma irradiation of barley on antinutrient contents and nutrient digestibility in mink (Mustela vison) with and without dietary enzyme supplement.

    PubMed

    Skrede, Anders; Sahlstrøm, Stefan; Ahlstrøm, Oystein; Connor, Kirsti Hjelme; Skrede, Grete

    2007-06-01

    The experiment was conducted to study the effects of fermentation of barley, using two different strains of lactic acid bacteria, a Lactobacillus plantarum/pentosus strain isolated from spontaneously fermented rye sourdough (AD2) and a starch-degrading Lactobacillus plantarum (AM4), on contents of mixed-linked (1 --> 3) (1 --> 4)-beta-glucans, alpha-amylase inhibitor activity, inositol phosphates, and apparent digestibility of macronutrients in mink. Effects of fermentation were compared with effects of gamma irradiation (gamma-irradiation: 60Co gamma-rays at 25 kGy). The diets were fed to mink with and without a supplementary enzyme preparation. Both lactic acid fermentation and gamma-irradiation followed by soaking and incubation, reduced concentrations of soluble beta-glucans, phytate and alpha-amylase inhibitor activity. Dietary enzyme supplementation increased significantly digestibility of crude protein, fat, starch and crude carbohydrate (CHO). Fermentation of the barley increased digestibility of starch and CHO. Fermentation with lactic acid bacteria AD2 resulted in higher starch and CHO digestibility than strain AM4, and had greater effect than gamma-irradiation, soaking and incubation. The highest digestibility of starch and CHO was obtained after AD2 fermentation followed by enzyme supplementation. It is concluded that both lactic acid fermentation of barley and enzyme supplementation have positive nutritional implications in the mink by limiting the effects of antinutrients and improving digestibility and energy utilization.

  16. Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

    NASA Astrophysics Data System (ADS)

    Parra, Duclerc F.; Rodrigues, Juliana A. F. R.; Lugão, Ademar B.

    2005-07-01

    Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60Co source. Samples were melted at 200 °C and quenched to 0 °C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N2 atmosphere, heating from -50 to 200 °C (10 °C min-1), cooling from 200 to -50 °C (10 °C min-1); and heating from -50 to 200 °C (10 °C min-1). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy.

  17. Influence of CuO content on the structure of lithium fluoroborate glasses: Spectral and gamma irradiation studies.

    PubMed

    Abdelghany, A M; ElBatal, H A; EzzElDin, F M

    2015-10-05

    Glasses of lithium fluoroborate of the composition LiF 15%-B2O3 85% with increasing CuO as added dopant were prepared and characterized by combined optical and FTIR spectroscopy before and after gamma irradiation. The optical spectrum of the undoped glass reveals strong UV absorption with two distinct peaks at about 235 and 310 nm and with no visible bands. This strong UV absorption is related to the presence of unavoidable trace iron impurity (Fe(3+)) within the materials used for the preparation of this glass. After irradiation, the spectrum of the undoped glass shows a decrease of the intensity of the UV bands together with the resolution of an induced visible broad band centered at about 520 nm. The CuO doped glasses reveal the same UV absorption beside a very broad visible band centered at 780 nm and this band shows extension and splitting to several component peaks with higher CuO contents. Upon gamma irradiation, the spectra of all CuO-doped glasses reveal pronounced decrease of their intensities. The response of irradiation on the studied glasses is correlated with suggested photochemical reactions together with some shielding effect of the copper ions. The observed visible band is related to the presence of copper as distorted octahedral Cu(2+) ions. Infrared absorption spectra of the prepared glasses show repetitive characteristic triangular and tetrahedral borate units similar to that published from alkali or alkaline earth oxides B2O3 glasses. A suggested formation of (BO3/2F) tetrahedral units is advanced through action of LiF on B2O3 and these suggested units showing the same position and number as BO4 tetrahedra.

  18. The effect of Cinnamaldehyde on mucositis and salivary antioxidant capacity in gamma-irradiated rats (a preliminary study)

    PubMed Central

    2012-01-01

    Background and purpose of the study The aim of this study was to investigate the effect of cinnamaldehyde on mucositis and salivary total antioxidant capacity in gamma-irradiated rats. Methods The study was conducted on 28 male Wistar rats, 7–11 weeks of age and 160 ± 20 g body weight, divided into four groups of seven rats each. The first group receiving normal saline (S), the second group receiving saline and gamma radiation (SR), the third group receiving 50 mg/kg cinnamaldehyde 98% (C), and the fourth group receiving 50 mg/kg cinnamaldehyde 98% and gamma radiation (CR). SR and CR groups were exposed to 15 Gy gamma irradiation for 7 min and 39 s. Rats were intraperitoneally injected each day during the 10-day period of the experiment, and their tongues and lips were examined to assess the incidence and severity of mucositis. The saliva samples were taken from the animals three times on day zero, six, and ten. Results The mean mucositis incidence appeared to be delayed in the CR than the SR group (P = 0.024), and the severity was significantly higher in the SR compared to the CR group;the difference was statistically significant on the second day (P = 0.027). In the evaluation of salivary antioxidant capacity, salivary antioxidant concentration was significantly higher in the C than the S, SR, and CR groups on the tenth day of the experiment (p <0.05). Conclusion The clinical effects in the CR group seem to be due to antioxidant, anti-bacterial and anti-inflammatory effects of cinnamaldehyde; this conclusion, however, requires further investigations. Delayed antioxidant effect in the CR group was evident in ip cinnamaldehyde injection, the exact mechanism is not clear. PMID:23351595

  19. UV-visible and infrared spectroscopy of gamma-irradiated lithium diborate glasses containing SeO 2

    NASA Astrophysics Data System (ADS)

    ElBatal, F. H.; Marzouk, S. Y.; Ezz-ElDin, F. M.

    2011-02-01

    UV-visible spectroscopic studies of a base lithium diborate glass together with samples containing SeO 2 substituting B 2O 3 have been measured before and after successive gamma irradiation. The optical absorption spectra of the base and SeO 2-containing samples show charge transfer UV absorption bands which are related to the unavoidable contamination with trace iron impurities [mainly Fe 3+ ions] within the raw materials used for the preparation of such glasses. The progressive introduction of SeO 2 causes some changes in the intensity of the two UV bands which are identified at 235 and 285 nm instead of the three peaks already observed in the base glass at 235, 275, 310 nm. Gamma irradiation produces induced bands which are assumed to be generated from the intrinsic defects in the lithium diborate base glass together with the sharing of trace iron impurities through suggested photochemical reactions. The UV induced bands are observed to be highly intensified showing continuous growth with progressive irradiation and are identified at about 230, 285 and 310 nm together with a further induced broad visible band centered at about 550 nm. Infrared absorption measurements of the base lithium diborate glass reveal characteristic bands due to stretching and bending vibrations of both BO 3 and BO 4 units together with the far-infrared bands due to the modifier Li + ions. The introduction of SeO 2 causes some changes in the IR spectra due either to the sharing of SeO 3 units and/or the polymerization of the borate network.

  20. Influence of gamma irradiation on productivity indices of the edible Emperor moth caterpillar, Cirina forda (Lepidoptera: Saturniidae).

    PubMed

    Odeyemi, M O; Fasoranti, J O; Ande, A T; Olayemi, I K

    2013-08-01

    This study was aimed at generating baseline information for sustainable genetic improvement of Cirana forda larvae for entomophagy, through the use of gamma irradiation. Eggs of C. forda were irradiated with increasing doses of gamma rays from 0 to 200 Gy and raised through larval instal stages under laboratory conditions. The Body Weight (BW) and Head Capsule Width (HCW) of the larval instar stages were monitored as indices of productivity. Successful larval emergence was recorded for all irradiation doses tested and BW of the 1st and 2nd instar larvae were not significantly (p > 0.05) different between the control and treated groups (range = 0.021 +/- 0.003 g/larva in the 200 Gy treatment to 0.028 +/- 0.003 g/larva in the control group and 0.105 +/- 0.003 g/larva in 20 Gy treatment to 0.172 +/- 0.009 g/larva in the control group, respectively). On the other hand, BW during the 3rd and 4th larval instars were significantly (p < 0.05) lower among the irradiated treatments than control. Pattern of distribution of HCW was different from that of BW; as HCW increased with irradiation dose from 10-50 Gy during the 3rd and 4th larval instars. Also, HCW during the 5th instar larvae among the irradiated treatments (range = 5.256 +/- 0.012 to 5.662 +/- 0.026 mm) were not higher than that of the 6th instar in the control group (6.065 +/- 0.010 mm). These results suggest promising potentials of the use of gamma irradiation in sustainably improving the productivity of C. forda larvae for entomophagy.

  1. The generation of oxidation products of benzo(a)pyrene by lipid peroxidation: a study using gamma-irradiation

    SciTech Connect

    Gower, J.D.; Wills, E.D.

    1984-09-01

    The role which active oxygen and radicals generated by the peroxidation of unsaturated fatty acids could play in the oxidation of benzo(a)pyrene has been studied using gamma-irradiation. Irradiation of benzo(a)pyrene resulted in the formation of benzo(a)pyrene 1,6-, 3,6- and 6,12-quinones and other more polar products which were analysed by h.p.l.c. OH. radicals are believed to be involved in this oxidation. The presence of polyunsaturated fatty acids and polyunsaturated lipids stimulated the formation of benzo(a)pyrene products following gamma-irradiation. Oxidation of benzo(a)pyrene also occurred over a period of days in the presence of autoxidising mackerel oil. The rate of benzo(a)pyrene oxidation was related to the extent of lipid peroxidation as determined by malonaldehyde formation. Malonaldehyde production as a result of peroxidising lipids was inhibited by benzo(a)pyrene which suggested that benzo(a)pyrene reacted directly with lipid peroxy radicals or hydroperoxides generated in the process of lipid peroxidation. These results demonstrate that oxidation products of the peroxidation of lipids and fatty acids are able to react directly with benzo(a)pyrene to form products including benzo(a)pyrene quinones without the presence of enzymes such as the cytochrome P-450 mixed function oxidase system and prostaglandin synthetase. It is possible that benzo(a)pyrene may be activated by these types of reactions in vivo or in vitro when benzo(a)pyrene is in contact with polyunsaturated lipids in foodstuffs or the intestinal lumen and peroxidation of unsaturated fats may play an important role in human carcinogenesis.

  2. Regulation of immune responses in SJL and F1 hybrid mice by gamma-irradiated syngeneic lymphoma cells

    SciTech Connect

    Katz, I.R.; Nagase, F.; Bell, M.K.; Ponzio, N.M.; Thorbecke, G.J.

    1984-01-01

    Syngeneic mixed lymphocyte-stimulating la+ lymphomas of SJL mice (reticulum cell sarcoma(s) (RCS)) were found to modulate immune responses in vivo. Simultaneous injection of 2 X 10(7) gamma-irradiated or glutaraldehyde-fixed RCS cells with the antigen sheep red blood cells (SRBC) or 2,4,6-trinitrophenol (TNP)-Ficoll markedly suppressed the subsequent plaque-forming cell response in the spleen. The suppression of the anti-SRBC response was prevented by pretreatment of the mice with cyclophosphamide, whereas the suppression of the anti-TNP-Ficoll response was not affected. RCS injection induced high interferon serum titers within 24 hours after injection, which were not prevented by pretreatment with cyclophosphamide. Injection of gamma-irradiated RCS cells (gamma-RCS) or RCS cell extract 2 days prior to antigen enhanced the anti-SRBC but markedly suppressed the anti- TNP-Ficoll response. Injection of RCS both on day -2 and day 0 enhanced the anti-SRBC response. SJL mice 8-9 months of age showed much less or no suppression when gamma-RCS cells were injected on day 0. Certain F1 hybrids of SJL also showed the gamma-RCS-induced suppression of the anti-SRBC response. Suppression was seen in SJL X BALB.B but not in SJL X BALB/c mice and in SJL X A.TH but not in SJL X A.TL mice, suggesting an I-region effect. F1 hybrids of SJL by B10 background mice showed no significant suppression. Enhancement of the anti-SRBC response by prior injection of gamma-RCS was seen in all F1 hybrid mice examined.

  3. Inactivation of Escherichia coli O157:H7, salmonellae, and Campylobacter jejuni in raw ground beef by gamma irradiation.

    PubMed Central

    Clavero, M R; Monk, J D; Beuchat, L R; Doyle, M P; Brackett, R E

    1994-01-01

    Raw ground beef patties inoculated with stationary-phase cells of Escherichia coli O157:H7, salmonellae, or Campylobacter jejuni were subjected to gamma irradiation (60Co) treatment, with doses ranging from 0 to 2.52 kGy. The influence of two levels of fat (8 to 14% [low fat] and 27 to 28% [high fat]) and temperature (frozen [-17 to -15 degrees C] and refrigerated [3 to 5 degrees C]) on the inactivation of each pathogen by irradiation was investigated. In ascending order of irradiation resistance, the D10 values ranged from 0.175 to 0.235 kGy (C. jejuni), from 0.241 to 0.307 kGy (E. coli O157:H7), and from 0.618 to 0.800 kGy (salmonellae). Statistical analysis revealed that E. coli O157:H7 had a significantly (P < 0.05) higher D10 value when irradiated at -17 to -15 degrees C than when irradiated at 3 to 5 degrees C. Regardless of the temperature during irradiation, the level of fat did not have a significant effect on the D10 value. Salmonellae behaved like E. coli O157:H7 in low-fat beef, but temperature did not have a significant effect when the pathogen was irradiated in high-fat ground beef. Significantly higher D10 values were calculated for C. jejuni irradiated in frozen than in refrigerated low-fat beef. C. jejuni was more resistant to irradiation in low-fat beef than in high-fat beef when treatment was at -17 to -15 degrees C. Regardless of the fat level and temperature during inactivation, these pathogens were highly sensitive to gamma irradiation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8031098

  4. Bioconversion of lutein using a microbial mixture--maximizing the production of tobacco aroma compounds by manipulation of culture medium.

    PubMed

    Rodríguez-Bustamante, Eduardo; Maldonado-Robledo, Gabriela; Ortiz, Marco Antonio; Díaz-Avalos, Carlos; Sanchez, Sergio

    2005-08-01

    The generation of aroma compounds by carotenoid cleavage in the 9-10 position was studied, due to the importance of these compounds in the flavor and fragrance industry. The bioconversion of the carotenoid lutein to C(13) norisoprenoids utilizing a microbial mixture composed of Trichosporon asahii and Paenibacillus amylolyticus was carried out by a fermentation process. Applying an experimental design methodology, the effects of nutritional factors on the production of aroma compounds present in the tobacco profile were studied. After an assessment of the significance of each nutritional factor, the levels of the variables yielding the maximum response were calculated. Glucose, tryptone, and yeast extract exerted a strong negative effect over the objective function, with glucose being the strongest. Lutein possessed a positive effect over the tobacco aroma production, while sodium chloride and trace elements showed no influence over the process. The yield attained after culture medium manipulation was almost ten-fold higher, compared with the base medium; and the aroma mixture was characterized as: 7,8-dihydro-beta-ionol (95.2%), 7,8-dihydro-beta-ionone (3.7%), and beta-ionone (1.1%).

  5. Study of the dual effect of gamma irradiation and strontium substitution on bioactivity, cytotoxicity and antimicrobial properties of 45S5 bioglass.

    PubMed

    Farag, M M; Abd-Allah, W M; Ahmed, Hanaa Y A

    2017-02-10

    In this work, we studied simultaneous effect of gamma irradiation and SrO substitution for Na2 O on bioactivity, cytotoxicity and antimicrobial properties of 45S5 glass. Gamma irradiation was mainly introduced in this work as an effective sterilizing technique, improvement of bulk properties and surface modification of glass. Where, gamma irradiation is considered a modifier for glass network due to generation of defects resulted from this irradiation. Furthermore, SrO was introduced into the glass structure in place of Na2 O in order to reduce a probable toxic effect of Na2 O for surrounding tissue by decreasing its percentage. Where, Sr(2+) is characterized by its antibacterial properties, as well as, it induces formation of bone tissue and inhibits its resorption. The cell viability was studied for selected samples using Vero cells. As well as, antimicrobial activity was evaluated against Bacillus subtilis, Staphylococcus pneumonia and Escherichia coliand Pseudomonas aeruginosa bacteria. The results showed that substitution of Na2 O by SrO in glass composition decreased the glass dissolution in SBF. However, the glass dissolution increased after irradiation of such glass due to generation of nonbridgingoxygens (NBOs) throughout glass network by gamma irradiation, and this effect was more obvious for Sr-contained glass. On the other hand, two selected Sr-containing glasses (gamma irradiated at 0 and 25 kGy) showed a good ability to stimulate cell proliferation of normal fibroblast cells, as well as, they represented a potential ability to inhibit the growth of or kill bacteria, which is considered an important issue commonly found in a clinical situation. This article is protected by copyright. All rights reserved.

  6. Effect of combination treatment of gamma irradiation and ascorbic acid on physicochemical and microbial quality of minimally processed eggplant (Solanum melongena L.)

    NASA Astrophysics Data System (ADS)

    Hussain, Peerzada R.; Omeera, A.; Suradkar, Prashant P.; Dar, Mohd A.

    2014-10-01

    Gamma irradiation alone and in combination with ascorbic acid was tested for preventing the surface browning and maintaining the quality attributes of minimally processed eggplant. Eggplant samples after preparation were subjected to treatment of gamma irradiation in the dose range of 0.25-1.0 kGy and to combination treatments of ascorbic acid dip at a concentration of 2.0% w/v and gamma irradiation (dose range 0.5-2.0 kGy) followed by storage at 3±1 °C, RH 80%. Studies revealed inverse correlation (r=-0.93) between the polyphenol oxidase (PPO) activity, browning index and the treatments of ascorbic acid and gamma irradiation. Combinatory treatment of 2.0% w/v ascorbic acid and 1.0 kGy gamma irradiation proved to be significantly (p≤0.05) effective in inhibiting the PPO activity, preventing the surface browning and maintaining the creamy white color and other quality attributes of minimally processed eggplant up to 6 days of refrigerated storage. Sensory evaluation revealed that control and 0.25 kGy irradiated samples were unacceptable only after 3 days of storage. Samples irradiated at 0.5 kGy and 0.75 kGy were unacceptable after 6 days of storage. Microbial analysis revealed that radiation processing of minimally processed eggplant at 1.0 kGy with and without ascorbic acid resulted in around 1 and 1.5 log reduction in yeast and mold count as well as bacterial count just after treatment and 6 days of storage therefore, enhances the microbial safety.

  7. Ties That Work: The Interaction between Group Assignment Method and a Culturally-Relevant Curriculum in the Context of Middle School Anti-Tobacco Program

    ERIC Educational Resources Information Center

    Carolan, Brian V.; Unger, Jennifer B.; Johnson, C. Anderson; Valente, Thomas W.

    2007-01-01

    Peer-led programs that employ classroom-based group exercises have been shown to be the most effective in preventing adolescent tobacco use. In addition, health promotion programs that include cultural referents have also been shown to be advantageous. The purpose of this study was to test the interaction between the method by which leaders and…

  8. Fusion of mitochondria in tobacco suspension cultured cells is dependent on the cellular ATP level but not on actin polymerization.

    PubMed

    Wakamatsu, Kairo; Fujimoto, Masaru; Nakazono, Mikio; Arimura, Shin-ichi; Tsutsumi, Nobuhiro

    2010-10-01

    Mitochondria in plant cells undergo fusion and fission frequently. Although the mechanisms and proteins of mitochondrial fusion are well known in yeast and mammalian cells, they remain poorly understood in plant cells. To clarify the physiological requirements for plant mitochondrial fusion, we investigated the fusion frequency of mitochondria in tobacco cultured cells using the photoconvertible fluorescent protein Kaede and some physiological inhibitors. The latter included two uncouplers, 2,4-dinitrophenol (DNP) and carbonyl cyanide m-chlorophenylhydrazone (CCCP), an inhibitor of mitochondrial ATP synthase, oligomycin, and an actin polymerization inhibitor, latrunculin B (Lat B). The frequency of mitochondrial fusion was clearly reduced by DNP, CCCP and oligomycin, but not by Lat B, although Lat B severely inhibited mitochondrial movement. Moreover, DNP, CCCP and oligomycin evidently lowered the cellular ATP levels. These results indicate that plant mitochondrial fusion depends on the cellular ATP level, but not on actin polymerization.

  9. Aluminium reduces sugar uptake in tobacco cell cultures: a potential cause of inhibited elongation but not of toxicity.

    PubMed

    Abdel-Basset, Refat; Ozuka, Shotaro; Demiral, Tijen; Furuichi, Takuya; Sawatani, Ikuo; Baskin, Tobias I; Matsumoto, Hideaki; Yamamoto, Yoko

    2010-06-01

    Aluminium is well known to inhibit plant elongation, but the role in this inhibition played by water relations remains unclear. To investigate this, tobacco (Nicotiana tabacum L.) suspension-cultured cells (line SL) was used, treating them with aluminium (50 microM) in a medium containing calcium, sucrose, and MES (pH 5.0). Over an 18 h treatment period, aluminium inhibited the increase in fresh weight almost completely and decreased cellular osmolality and internal soluble sugar content substantially; however, aluminium did not affect the concentrations of major inorganic ions. In aluminium-treated cultures, fresh weight, soluble sugar content, and osmolality decreased over the first 6 h and remained constant thereafter, contrasting with their continued increases in the untreated cultures. The rate of sucrose uptake, measured by radio-tracer, was reduced by approximately 60% within 3 h of treatment. Aluminium also inhibited glucose uptake. In an aluminium-tolerant cell line (ALT301) isogenic to SL, all of the above-mentioned changes in water relations occurred and tolerance emerged only after 6 h and appeared to involve the suppression of reactive oxygen species. Further separating the effects of aluminium on elongation and cell survival, sucrose starvation for 18 h inhibited elongation and caused similar changes in cellular osmolality but stimulated the production of neither reactive oxygen species nor callose and did not cause cell death. We propose that the inhibition of sucrose uptake is a mechanism whereby aluminium inhibits elongation, but does not account for the induction of cell death.

  10. A Comparison of Molecular and Histopathological Changes in Mouse Intestinal Tissue Following Whole-Body Proton- or Gamma-Irradiation

    NASA Technical Reports Server (NTRS)

    Purgason, Ashley; Mangala, Lingegowda; Zhang, Ye; Hamilton, Stanley; Wu, Honglu

    2010-01-01

    There are many consequences following exposure to the space radiation environment which can adversely affect the health of a crew member. Acute radiation syndrome (ARS) involving nausea and vomiting, damage to radio-sensitive tissue such as the blood forming organs and gastrointestinal tract, and cancer are some of these negative effects. The space radiation environment is ample with protons and contains gamma rays as well. Little knowledge exists to this point, however, regarding the effects of protons on mammalian systems; conversely several studies have been performed observing the effects of gamma rays on different animal models. For the research presented here, we wish to compare our previous work looking at whole-body exposure to protons using a mouse model to our studies of mice experiencing whole-body exposure to gamma rays as part of the radio-adaptive response. Radio-adaptation is a well-documented phenomenon in which cells exposed to a priming low dose of radiation prior to a higher dose display a reduction in endpoints like chromosomal aberrations, cell death, micronucleus formation, and more when compared to their counterparts receiving high dose-irradiation only. Our group has recently completed a radio-adaptive experiment with C57BL/6 mice. For both this study and the preceding proton research, the gastrointestinal tract of each animal was dissected four hours post-irradiation and the isolated small intestinal tissue was fixed in formalin for histopathological examination or snap-frozen in liquid nitrogen for RNA isolation. Histopathologic observation of the tissue using standard H&E staining methods to screen for morphologic changes showed an increase in apoptotic lesions for even the lowest doses of 0.1 Gy of protons and 0.05 Gy of gamma rays, and the percentage of apoptotic cells increased with increasing dose. A smaller percentage of crypts showed 3 or more apoptotic lesions in animals that received 6 Gy of gamma-irradiation compared to mice

  11. Biochemical and Immunocytochemical Characterization of Two Types of Myosins in Cultured Tobacco Bright Yellow-2 Cells1

    PubMed Central

    Yokota, Etsuo; Yukawa, Chiharu; Muto, Shoshi; Sonobe, Seiji; Shimmen, Teruo

    1999-01-01

    We have isolated a myosin (referred to as 170-kD myosin) from lily pollen tubes, which consists of 170-kD heavy chain and calmodulin (CaM) light chain and is responsible for cytoplasmic streaming. A 170-kD polypeptide that has similar antigenicity to the 170-kD myosin heavy chain of lily pollen tubes was also present in cultured tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells, and possessed the ability to interact with F-actin in an ATP-dependent manner. In addition to this myosin, we identified biochemically another kind of myosin in BY-2 cells. This myosin consisted of a CaM light chain and a 175-kD heavy chain with antigenicity different from the 170-kD myosin heavy chain. In the present study, we referred to this myosin as 175-kD myosin. This myosin was able to translocate rhodamine-phalloidin (RP)-labeled F-actin at an average velocity of about 9 μm/s in the motility assay in vitro. In contrast, the sliding velocity of RP-labeled F-actin translocated by fractions containing the 170-kD myosin was 3 to 4 μm/s. The velocity of cytoplasmic streaming in living BY-2 cells ranged from 2 to 9 μm/s. The motile activity of 175-kD myosin in vitro was inhibited by Ca2+ at concentrations higher than 10−6 m. Immunoblot analyses using an antiserum against the heavy chain of 170- or 175-kD myosin revealed that in tobacco plants, the 175-kD myosin was expressed in leaf, stem, and root, but not in germinating pollen, while 170-kD myosin was present in all of these plant parts and in germinating pollen. These results suggest that the two types of myosins, 170 and 175 kD, presumably participate in cytoplasmic streaming in BY-2 cells and other somatic cells of tobacco plants. PMID:10517844

  12. Free radical scavenging and radioprotective activity of dehydrozingerone against whole body gamma irradiation in Swiss albino mice.

    PubMed

    Parihar, Vipan Kumar; Dhawan, Jatin; Kumar, Suryakant; Manjula, S N; Subramanian, G; Unnikrishnan, M K; Rao, C Mallikarjuna

    2007-10-20

    Dehydrozingerone (DZ) was explored for in vitro-in vivo antioxidant potential and in vivo radioprotective activity against whole body gamma irradiation in Swiss albino mice. DZ scavenged the ABTS (2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (1, 1-dipehnyl-2-picrylhydrazyl) free radicals at room temp. DZ reduced Fe (III) to Fe (II) at pH 7.4 and scavenged the NADH/phenazine methosulfate generated superoxide radical in cell free system. DZ also scavenged the nitric oxide radical generated by sodium nitroprusside. To evaluate the radioprotective activity, mice were exposed to whole body gamma irradiation 30 min after the drug treatment at a dose rate of 1.66 Gy/min. Pretreatment with DZ 75, 100 and 125 mg/kg, i.p. reduced the radiation induced mortality and increased the mean survival times (MSTs). An i.p. dose of DZ 100 mg/kg was found the most effective dose in preventing radiation sickness and increasing the MST. Pretreatment DZ100 mg/kg maintained the spleen index (spleen weight/body weight x 100) and stimulates the endogenous spleen colony forming units (CFU). Pretreatment with DZ100 mg/kg maintained the villus height close to normal, prevents mucosal erosion and basement membrane damage in irradiated mice jejunum. However, no significant reductions in dead, inflammatory and mitotic cells were observed in DZ pretreated mice, but there was an increased in crypt cells proliferation and regeneration. Pretreatment with DZ100 mg/kg significantly elevated the endogenous antioxidant enzymes (GSH, GST and SOD) in mice at 2, 4 and 8 h post sham irradiation. Radiation induced fall in endogenous antioxidant enzymes was significantly prevented by DZ pretreatment. Pretreatment with DZ 75 and 100 mg/kg reduced the radiation induced micronucleated polychromatic erythrocytes (MPCE) and normochromatic erythrocytes (MNCE) in mice bone marrow. DZ also maintained the polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) ratio (P/N ratio) in

  13. Changes in compartments of hemospoietic and stromal marrow progenitor cells after continuous low dose gamma-irradiation

    NASA Astrophysics Data System (ADS)

    Domaratskaya, E.; Starostin, V.

    The low dose continuous gamma-irradiation chosen corresponded with that affected the organisms onboard a spacecraft (Mitrikas, Tsetlin, 2000). F1 (CBAxC57Bl/6) male and female mice were used at 3 4 months of age. Experimental mice were- irradiated during 10 days to a total dose of 15 mGy (Co60 gamma-sources, mean dose rate of 1.5-2.0 mGy/day). Another group of intact mice served as control. Younger and advanced hemopoietic progenitors measured at day 11 (i.e. CFU -S-11) and day 7 (i.e. CFU-S-7), respectively, after transplantation of test donor cells were assayed by the method of Till and McCulloch (1961). Stromal changes were evaluated by estimation of in vitro fibroblastic colony-forming units (CFU -F ) content and by the ability of ectopically grafted (under renal capsule) stroma to regenerate the new bone marrow organ. CFU-S-11 number increased of 40% as compared with control and almost 2-fold higher than that of CFU-S-7. The CFU-F content increased almost of 3-fold. Size of ectopic marrow transplants was estimated at day 70 following grafting by counting myelokariocyte and CFU -S number that repopulated the newly formed bone marrow organ. It was found more than 2-fold increase of myelokariocytes in transplants produced by marrow stroma of irradiated donors. CFU -S contents in transplants increased strikingly in comparison to control level. CFU-S-7 and CFU-S-11 increased of 7.5- and of 3.7-fold, respectively, i.e. the rate of advanced CFU - S predominated. It should be noted a good correlation between number of stromal progenitor cells (CFU-F) and ectopic transplant sizes evaluated as myelokaryocyte counts when irradiated donors used. In the same time, if sizes of transplants was measured as CFU-S-7 and CFU - S-11 numbers, their increases were more pronounced. Therefore, continuous low dose gamma- irradiation augments significantly both hemopoietic and stromal progenitor cell number in bone marrow. Additionally, the ratio of distinct CFU -S subpopulations

  14. Comparison between Biosynthesis of ent-Kaurene in Germinating Tomato Seeds and Cell Suspension Cultures of Tomato and Tobacco

    PubMed Central

    Yafin, Yitshak; Shechter, Ishaiahu

    1975-01-01

    Biosynthesis of ent-kaurene was investigated in extracts of cell suspension cultures derived from tobacco callus (Nicotiana tabacum L.), tomato callus (Solanum lycopersicum L.), and in germinating tomato seeds. Incubation of extracts derived from the two cell cultures with either isopentenyl pyrophosphate-14C or with 14C-labeled mevalonate, followed by alkaline phosphatase hydrolysis, resulted in the formation of trans-geranylgeraniol-14C and trans-farnesol-14C. The corresponding pyrophosphates of trans-geranyl-geraniol-14C and trans-farnesol-14C were also detected. No detectable amount of ent-kaurene-14C was produced by these enzymatic preparations when trans-geranylgeranyl-14C pyrophosphate served as substrate. However, copalyl-14C pyrophosphate served as a substrate for the production of ent-kaurene. Cell-free extracts derived from germinating tomato seeds catalyzed the formation of ent-kaurene-14C from mevalonate-14C, isopentenyl-14C pyrophosphate, trans-geranylgeranyl-14C pyrophosphate, and copalyl-14C pyrophosphate. PMID:16659368

  15. Effect of gamma irradiation on nutritional components and Cry1Ab protein in the transgenic rice with a synthetic cry1Ab gene from Bacillus thuringiensis

    NASA Astrophysics Data System (ADS)

    Wu, Dianxing; Ye, Qingfu; Wang, Zhonghua; Xia, Yingwu

    2004-01-01

    The effects of gamma irradiation on the transgenic rice containing a synthetic cry1Ab gene from Bacillus thuringiensis were investigated. There was almost no difference in the content of the major nutritional components, i.e. crude protein, crude lipid, eight essential amino acids and total ash between the irradiated grains and the non-irradiated transgenic rice. However, the amounts of Cry1Ab protein and apparent amylose in the irradiated transgenic rice were reduced significantly by the doses higher than 200 Gy. In vivo observation showed that Cry1Ab protein contents also decreased in the fresh leaf tissues of survival seedlings after irradiation with 200 Gy or higher doses and showed inhibition of seedling growth. The results indicate that gamma irradiation might improve the quality of transgenic rice due to removal of the toxic Cry1Ab protein.

  16. EPR investigation of gamma-irradiated L-citrulline, α-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine

    NASA Astrophysics Data System (ADS)

    Osmanoğlu, Y. Emre; Sütçü, Kerem; Başkan, M. Halim

    2017-02-01

    The spectroscopic parameters of the paramagnetic species produced in gamma-irradiated L-citrulline, α-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine were investigated at room temperature at a dose of 20 kGy by using EPR technique. The paramagnetic species were attributed to NH2CONH(CH2)3ĊNH2COOH, HOCH2ĊCH3COOH and HOĊHCCH3NH2COOH, CH3CH3ĊCHNH2COOH and SHCH2ĊNHCOCH3COOH radicals, respectively. EPR data of the unpaired electron with the environmental protons and 14N nucleus were used to characterize the contributing radicals produced in gamma irradiated compounds. In this paper, the stability of these compounds at room temperature after irradiation was also studied.

  17. Comparison of the immunological responses and efficacy of gamma-irradiated V3526 vaccine formulations against subcutaneous and aerosol challenge with Venezuelan equine encephalitis virus subtype IAB.

    PubMed

    Martin, Shannon S; Bakken, Russell R; Lind, Cathleen M; Garcia, Patricia; Jenkins, Erin; Glass, Pamela J; Parker, Michael D; Hart, Mary Kate; Fine, Donald L

    2010-01-22

    We recently developed a gamma-irradiation method to inactivate V3526, a live-attenuated Venezuelan equine encephalitis virus (VEEV) vaccine candidate. Dosage and schedule studies were conducted to evaluate the immunogenicity and efficacy of gamma-irradiated V3526 (gV3526). Subcutaneous (SC) and low dosage intramuscular (IM) administration of gV3526 were highly effective in protecting mice against a SC challenge with VEEV IA/B Trinidad Donkey strain, but not against an equivalent aerosol challenge. More robust immune responses and increased protective efficacy were noted when the IM dosage of gV3526 was increased. IM administration of gV3526 formulated with either CpG or CpG plus Alhydrogel further augmented the immune response in mice and resulted in 100% protection against aerosol challenge.

  18. The influence of nano silica particles on gamma-irradiation ageing of elastomers based on chlorosulphonated polyethylene and acrylonitrile butadiene rubber

    NASA Astrophysics Data System (ADS)

    Marković, G.; Marinović-Cincović, M.; Tanasić, Lj.; Jovanović, V.; Samaržija-Jovanović, S.; Vukić, N.; Budinski-Simendić, J.

    2011-12-01

    The goal of this work was to study gamma irradiation ageing of rubber blends based on acrylonitrile butadiene rubber (NBR) and chlorosulphonated polyethylene rubber (CSM) reinforced by silica nano particles. The NBR/CSM compounds (50: 50, w/w) filled with different content of filler (0-100 phr) were crosslinked by sulfur. The vulcanization characteristics were assessed using the rheometer with an oscillating disk. The vulcanizates were prepared in a hydraulic press. The obtained materials were exposed to the different irradiation doses (100, 200, 300 and 400 kGy). The mechanical properties (hardness, modulus at 100% elongation, tensile strength and elongation at break) and swelling numbers were assessed before and after gamma irradiation ageing.

  19. Effects of environment and gamma irradiation on the mechanical properties of high density polyethylene. [Construction material for LLW high-integrity containers

    SciTech Connect

    Soo, P.; Arora, H.; Swyler, K.J.; Becker, W.; Sobel, E.

    1986-03-01

    An evaluation was made of the effects of environment and gamma irradiation on the short-term tensile and creep properties of Marlex CL-100, a highly cross-linked high-density polyethylene. This material is being considered as a constructional material for a low-level radioactive waste high-integrity container. It was found that the chemical environments studied could be beneficial or detrimental to strength and ductility depending on the type of mechanical property test and the nature of the exposure of the polyethylene to the chemical environment. Gamma irradiation to a sufficiently high dose prior to tensile or creep testing increased the strength and decreased the ductility. In-test irradiation, however, could increase or decrease the creep rate depending on the dose rate and applied stress.

  20. Mycotoxin contamination of animal feedingstuff: detoxification by gamma-irradiation and reduction of aflatoxins and ochratoxin A concentrations.

    PubMed

    Di Stefano, Vita; Pitonzo, Rosa; Cicero, Nicola; D'Oca, Maria Cristina

    2014-01-01

    Mycotoxins are fungal secondary metabolites identified in many agricultural products screened for toxigenic moulds. They have been reported to be carcinogenic, teratogenic, tremorogenic, haemorrhagic and dermatitic to a wide range of organisms. With the increasing stringent regulations for mycotoxins imposed by importing countries such as those of the European Union, many cereals that are not safe for human consumption are used in formulations intended for animal feed. Gamma-rays are reported in the scientific literature to destroy ochratoxin A and aflatoxin in food crops and feed. The present study provides preliminary data for establishing the effect of dose of gamma-irradiation, ranging from 0 to 15 kGy, on aflatoxins and ochratoxin A reduction in commercial animal feed. The mycotoxin levels were determined by means of immunoaffinity clean-up (IAC) and HPLC with fluorescence detection (HPLC-FLD). The maximum reductions found at 15 kGy were 23.9%, 18.2%, 11.0%, 21.1% and 13.6% for ochratoxin A, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂, respectively. Results showed that the gamma-rays even at 15 kGy were not effective in the complete destruction of ochratoxin A and aflatoxins in the tested feed.

  1. Effect of gamma irradiation on the flavour and flatulence causing oligosaccharides from broad bean ( Vicia Faba L.

    NASA Astrophysics Data System (ADS)

    Jaddou, H.; Mhaisen, M. T.; Al-Adamy, L. Z.; Naji, E. Z.

    Effect of gamma - irradiation ( 2.5-10 KGy ) on the flavour and flatulence causing oligosaccharides of broad bean were investigated. The method used for the cooked flavour analysis involved low temperature distillation. Gaschromatography was used to separate the flavour extracts into their various constituents. The major volatile free fatty acids isolated are C16, C18, C18:1, and C20. Identification of the major peaks from the non-acid fraction were carried out. Identified peaks were hydrocarbones, alcohols, ketones, aldehydes and phenoles. Most of the compounds found to increase with increase in radiation dose. On the other hand, sensory evaluation tests indicated no changes in broad bean flavour quality after irradiation. Sugars were also analysed by gas chromatographic method after TMS-ether derivation. Fructose, ∞ and β -glucose, sucrose, raffinose and stachyose were the major sugars present. The gas - forming oligosaccharides were found to decrease with increase in dose applied. On the other hand, other sugars found to increase with increase in radiation dose.

  2. Genomic inversion caused by gamma irradiation contributes to downregulation of a WBC11 homolog in bloomless sorghum.

    PubMed

    Mizuno, Hiroshi; Kawahigashi, Hiroyuki; Ogata, Jun; Minami, Hiroshi; Kanamori, Hiroyuki; Nakagawa, Hitoshi; Matsumoto, Takashi

    2013-06-01

    Epicuticular wax (bloom) plays important roles in protecting the tissues of sorghum (Sorghum bicolor (L.) Moench) plants from abiotic stresses. However, reducing wax content provides resistance to greenbug and sheath blight-a useful trait in agricultural crops. We generated a sorghum bloomless (bm) mutant by gamma irradiation. One bm population segregated for individuals with and without epicuticular wax at a frequency of 72:22, suggesting that the bm mutation was under the control of a single recessive nuclear gene. Genes differentially expressed in the wild-type and the bm mutant were identified by RNA-seq technology. Of the 31 downregulated genes, Sb06g023280 was the most differentially expressed and was similar to WBC11, which encodes an ABC transporter responsible for wax secretion in Arabidopsis. An inversion of about 1.4 Mb was present in the region upstream of the Sb06g023280 gene in the bm mutant; it is likely that this inversion changed the promoter sequence of the Sb06g023280 gene. Using genomic PCR, we confirmed that six independent F2 bm mutant-phenotype plants carried the same inversion. Therefore, we concluded that the inversion involving the Sb06g023280 gene inhibited wax secretion in the bloomless sorghum.

  3. Transient restoration of gene rearrangement at multiple T cell receptor loci in gamma-irradiated scid mice

    PubMed Central

    1996-01-01

    The developmental arrest of thymocytes from scid mice, deficient in variable, (diversity), and joining, or V(D)J recombination, can be overcome by sublethal gamma-irradiation. Since previous studies focused on restoration of rearrangement of the T cell receptor (TCR) beta locus, productive rearrangement of which is selected for, we sought to examine to what extent locus specificity and cellular selection contributed to the observed effects. We report here that irradiation of newborn scid mice induces normal V-D-J rearrangements of the TCR delta locus, which like TCR beta, is also actively rearranged in CD(4-)CD(8-) (double negative) thymocytes. In contrast, no complete V-J alpha rearrangements were detected. Instead, we detected substantial levels of hairpin-terminated coding ends at the 5' end of the J alpha locus, demonstrating that TCR alpha rearrangements manifest the effects of the scid mutation. Irradiation, therefore, transiently compensates for the effects of the scid mutation in a locus-nonspecific manner in thymocytes, resulting in a burst of normal TCR beta and delta rearrangements. Irradiation also allows the development of cells that can initiate but fail to complete V(D)J recombination events at the TCR alpha locus, which is normally inaccessible in scid thymocytes. PMID:8760795

  4. Microbial quality evaluation and effective decontamination of nutraceutically valued lotus seeds by electron beams and gamma irradiation

    NASA Astrophysics Data System (ADS)

    Bhat, Rajeev; Sridhar, K. R.; Karim, A. A.

    2010-09-01

    Lotus seeds are nutraceutically valued natural plant produce, which succumbs to microbial contamination, predominantly to toxigenic moulds. Results of the present study revealed seed coat portion to harbor higher proportion of microbial load, particularly fungi than cotyledon portion. Among the mycotoxins analyzed, aflatoxins (B 1, B 2, G 1 and G 2) were below detectable limits, while the seeds were devoid of Ochratoxin-A (OTA). Application of different doses of electron beam and gamma irradiation (0, 2.5, 5, 7.5, 10, 15 and 30 kGy) for decontamination purpose revealed significant dose-dependent decrease in the fungal contaminants ( P<0.05). However, the contaminant yeasts could survive up to 10 kGy dose, which could be completely eliminated at 15 kGy. From the results obtained, a dose range between 10 and 15 kGy is recommended for complete decontamination, as these doses have also been shown earlier to have minimal effects on nutritional and functional properties of lotus seeds.

  5. [Changes in functional activity of the synthetic apparatus of rat thymocytes under acute and chronic gamma-irradiation].

    PubMed

    Sergievich, L A; Karnaukhova, N A

    2002-01-01

    The changes in functional activity of rat thymocyte synthetic apparatus (synthetic activity) under acute (7.5 Gy) and continuous (dose rates 14.4 and 0.43 cGy/day) gamma-irradiation were studied by the fluorescent microspectral analysis. It has been shown that after the acute irradiation the changes in synthetic activity occurred in three main stages. The stages reflect the depression and activation of synthetic processes that is due to interphase and reproductive cell death and urgent recovery of thymus cellularity and secondary repopulating. Under continuous irradiation with a dose rate 14.4 cGy/day in long-term period both the decrease of thymocyte synthetic activity (in most animals) and activation (in the animals with pronounced symptoms of radiation damage) were observed. This reflects the depression processes in immune system and augmentation of immunoreactivity due to mass antigen influence of transformed cells and infectious agents on thymocytes. Under low dose ionizing irradiation (dose rate 0.43 cGy/day) the undulating changes in synthetic processes in thymus cells were observed. This depends on the recurrence of depression and recovery processes in the blood-forming tissue.

  6. Degradation of a monoazo dye Alizarin Yellow GG in aqueous solutions by gamma irradiation: Decolorization and biodegradability enhancement

    NASA Astrophysics Data System (ADS)

    Sun, Weihua; Chen, Lujun; Tian, Jinping; Wang, Jianlong; He, Shijun

    2013-02-01

    The irradiation-induced degradation of an azo dye, Alizarin Yellow GG (AY-GG), was investigated in aqueous solution under gamma irradiation using a 60Cobalt source at a dose rate of 113 Gy/min. The decolorization percentage of AY-GG reached 65% when its initial concentration was 100 mg/l and the absorbed dose was 9 kGy. The decolorization process could be described by first-order kinetic equation. In addition, specific oxygen uptake rate (SOUR, mg O2 (g MLVSS)-1 h-1) of activated sludge using the irradiated azo dye solutions was 8.1 mg O2 (g MLVSS)-1 h-1 after 9 kGy irradiation, indicating that the biodegradability of AY-GG could be enhanced by 30%. However, toxic intermediates including heterocyclic aromatic amines and cyanides were detected during the irradiation process, which inhibited the complete biological degradation of azo dye. Fortunately, the inhibition could be eliminated by further irradiation. The azo dye solution became amenable to biodegradation and can be further treated by biological treatment process.

  7. Quantitative aspects of ESR and spin trapping of hydroxyl radicals and hydrogen atoms in gamma-irradiated aqueous solutions.

    PubMed

    Carmichael, A J; Makino, K; Riesz, P

    1984-11-01

    The efficiency of 5,5-dimethylpyrroline-1-N-oxide (DMPO) and alpha-(4-pyridyl-1-oxide)-N-tert.-butylnitrone (POBN) to spin trap hydroxyl radicals and hydrogen atoms, respectively, was studied in gamma-irradiated solutions where the radical yields are accurately known. The effects of dose, spin trap concentration, and pH and of the stability of the spin adducts on the spin-trapping efficiency were investigated. In degassed or N2-saturated solutions the spin-trapping efficiencies were 35% for DMPO and hydroxyl radicals and 14% for POBN and hydrogen atoms. The low spin-trapping efficiencies were shown not to be due to the instability of the DMPO-OH and POBN-H spin adducts or to the effects of H2O2 or O2. The low spin-trapping efficiency of DMPO may be explained by the reaction of hydroxyl radicals to abstract hydrogen from the DMPO molecule to produce carbon radicals as well as addition to the N = C double bond to form nitroxide radicals. For POBN the low spin-trapping efficiency for hydrogen atoms is explained in terms of addition reactions of hydrogen atoms to the aromatic ring and the pyridinium and nitrone oxygens.

  8. gamma. -irradiated sewage solids in diets for sheep: nutritive evaluations and long-term assessments of possible toxicants

    SciTech Connect

    Sanson, D.W.

    1983-01-01

    Air-dried solids from primary (undigested) sewage sludge were collected at Las Cruces, New Mexico (a non-industrial town with population about 50,000). Bagged sewage solids were ..gamma..-irradiated (1 megarad dosage) to kill parasites and pathogenic organisms and evaluated as prospective feedstuffs for sheep. Pelleted, complete diets for gestating-lactating fine-wool ewes and for their growing-finishing lambs were formulated to be isonitrogenous with either 3.5% cottonseed meal (conventional diet) or 7% sewage solids (experimental diet). Digestibility of organic matter and crude protein, and biological value of nitrogen, did not differ (P > .05) between diets, as determined with wethers. Wether lambs fed to slaughter with conventional or experimental diets did not differ (P > .05) in rate of gain, carcass characteristics, element concentrations in blood and serum chemistry profiles, although liver Cu and kidney Pb levels were increased (P < .05) about 1.6-fold by sewage solids. Element contents of spleen and muscles did not differ (P > .05) due to diets. These studies confirm previous research at New Mexico State University which indicates that dried solids from municipal (primary) sludge provide nutritive benefits to sheep with risks of toxicity and heavy metal accumulation that appear tolerable where managed properly.

  9. Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation.

    PubMed

    Tostar, Sandra; Stenvall, Erik; Boldizar, Antal; Foreman, Mark R St J

    2013-06-01

    There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5M) dissolved in either dimethyl sulfoxide or water (at ca. 23°C and heated to ca. 105°C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed.

  10. Optimization of Pan Bread Prepared with Ramie Powder and Preservation of Optimized Pan Bread Treated by Gamma Irradiation during Storage

    PubMed Central

    Lee, Heejeong; Joo, Nami

    2012-01-01

    This study was conducted to develop an optimal composite recipe for pan bread with ramie powder that has high sensory approval with all age groups and to estimate the DPPH radical scavenging activity and the pan bread shelf life after gamma irradiation. The sensory evaluation results showed significant differences in flavor (p<0.05), appearance (p<0.01), color (p<0.01), moistness (p<0.01), and overall quality (p<0.05) based on the amount of ramie powder added. As a result, the optimum formulations by numerical and graphical methods were calculated to be as follows: ramie powder 2.76 g (0.92%) and water 184.7 mL. Optimized pan bread with ramie powder and white pan bread were irradiated with gamma-rays at doses of 0, 10, 15, and 20 kGy. The total bacterial growth increased with the longer storage time and the least amount of ramie powder added. Consequently, these results suggest that the addition of ramie powder to pan bread provides added value to the bread in terms of increased shelf life. PMID:24471063

  11. Gamma irradiation induces acetylcholine-evoked, endothelium-independent relaxation and activatesk-channels of isolated pulmonary artery of rats

    SciTech Connect

    Eder, Veronique . E-mail: eder@med.univ-tours.fr; Gautier, Mathieu; Boissiere, Julien; Girardin, Catherine; Rebocho, Manuel; Bonnet, Pierre

    2004-12-01

    Purpose: To test the effects of irradiation (R*) on the pulmonary artery (PA). Methods and materials: Isolated PA rings were submitted to gamma irradiation (cesium, 8 Gy/min{sup -1}) at doses of 20 Gy-140 Gy. Rings were placed in an organ chamber, contracted with serotonin (10{sup -4} M 5-hydroxytryptamine [5-HT]), then exposed to acetylcholine (ACh) in incremental concentrations. Smooth muscle cell (SMC) membrane potential was measured with microelectrodes. Results: A high dose of irradiation (60 Gy) increased 5HT contraction by 20%, whereas lower (20 Gy) doses slightly decreased it compared with control. In the absence of the endothelium, 5-HT precontracted rings exposed to 20 Gy irradiation developed a dose-dependent relaxation induced by acetylcholine (EI-ACh) with maximal relaxation of 60 {+-} 17% (n = 13). This was totally blocked by L-NAME (10{sup -4} M), partly by 7-nitro indazole; it was abolished by hypoxia and iberiotoxin, decreased by tetra-ethyl-ammonium, and not affected by free radical scavengers. In irradiated rings, hypoxia induced a slight contraction which was never observed in control rings. No differences in SMC membrane potential were observed between irradiated and nonirradiated PA rings. Conclusion: Irradiation mediates endothelium independent relaxation by a mechanism involving the nitric oxide pathway and K-channels.

  12. Crosslinking of poly(L-lactide) nanofibers with triallyl isocyanutrate by gamma-irradiation for tissue engineering application.

    PubMed

    He, Chuanglong; Feng, Wei; Cao, Lijun; Fan, Linpeng

    2011-12-15

    The radiation crosslinked poly(L-lactide) (PLLA) electrospun nanofibers have been developed with improved thermal stability and mechanical properties. Trially isocyanurate (TAIC) were added into PLLA solution at different weight ratios (1, 3, and 5%) and electrospun into nanofibrous mats, the mats were then irradiated by gamma ray at different radiation doses (5, 10, and 25 kGy) to crosslink the PLLA chains. Their surface morphology, thermal properties, mechanical properties, and biodegradation properties were investigated and compared before and after gamma irradiation. Furthermore, the in vitro biocompatibilities were also evaluated by using mouse L929 fibroblasts. The results indicated that the efficient crosslinking networks can be generated when the TAIC content is higher than 3%. The thermal stability and tensile mechanical properties were significantly increased at higher irradiation dose of 10 and 25 kGy. However, radiation dose at 25 kGy have an adverse effect on the thermal stability of crosslinked samples due to thermal degradation induced by irradiation, the crosslinked samples irradiated at 10 kGy exhibited the best enzymatic degradation. The in vitro results also revealed that the crosslinked PLLA/TAIC composite nanofibers did not induce cytotoxic effects and are suitable for cell growth. Therefore, the crosslinked PLLA nanofibers are one of the promising materials for future tissue engineering applications.

  13. Reduction of the IgE-binding ability and maintenance of immunogenicity of gamma-irradiated Dermatophagoides farinae

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Woon; Seo, Ji-Hyun; Kim, Jae-Hun; Lee, Soo-Young; Park, Joong-Won; Byun, Myung-Woo

    2007-11-01

    House dust mites, Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus, are major allergens in the most common indoor allergen and are important risk factor for asthma. The modified antigen has been studied to treat allergic disorder. This study was carried out to measure possibility of modified allergen using gamma irradiation to treat allergy such as asthma. DF solutions (2 mg/ml) as target allergen were irradiated with Co-60 at 50 and 100 kGy. Conformational alternation of irradiated DF was observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Levels of anti-irradiated DF mouse IgGs (sub-isotypes) against intact DF were measured similar to that of anti-intact DF IgGs. The binding abilities of house dust mite-allergic patients' IgE were reduced depending on radiation dose, and irradiation could inhibit the binding ability of patients' IgE more than 40%. This study has shown that the binding ability of IgE was reduced by conformational alteration by irradiation and the irradiated DF had epitopes capable to induce immunogeniciy.

  14. The role of meiotic cohesin REC8 in chromosome segregation in {gamma} irradiation-induced endopolyploid tumour cells

    SciTech Connect

    Erenpreisa, Jekaterina; Cragg, Mark S.; Salmina, Kristine; Hausmann, Michael; Scherthan, Harry

    2009-09-10

    Escape from mitotic catastrophe and generation of endopolyploid tumour cells (ETCs) represents a potential survival strategy of tumour cells in response to genotoxic treatments. ETCs that resume the mitotic cell cycle have reduced ploidy and are often resistant to these treatments. In search for a mechanism for genome reduction, we previously observed that ETCs express meiotic proteins among which REC8 (a meiotic cohesin component) is of particular interest, since it favours reductional cell division in meiosis. In the present investigation, we induced endopolyploidy in p53-dysfunctional human tumour cell lines (Namalwa, WI-L2-NS, HeLa) by gamma irradiation, and analysed the sub-cellular localisation of REC8 in the resulting ETCs. We observed by RT-PCR and Western blot that REC8 is constitutively expressed in these tumour cells, along with SGOL1 and SGOL2, and that REC8 becomes modified after irradiation. REC8 localised to paired sister centromeres in ETCs, the former co-segregating to opposite poles. Furthermore, REC8 localised to the centrosome of interphase ETCs and to the astral poles in anaphase cells where it colocalised with the microtubule-associated protein NuMA. Altogether, our observations indicate that radiation-induced ETCs express features of meiotic cell divisions and that these may facilitate chromosome segregation and genome reduction.

  15. Developmental disturbance of rat cerebral cortex following prenatal low-dose gamma-irradiation: a quantitative study

    SciTech Connect

    Fukui, Y.; Hoshino, K.; Hayasaka, I.; Inouye, M.; Kameyama, Y. )

    1991-06-01

    Pregnant rats were exposed to a single whole-body gamma-irradiation on Day 15 of gestation at a dose of 0.27, 0.48, 1.00, or 1.46 Gy. They were allowed to give birth and the offspring were killed at 6 or 12 weeks of age for microscopic and electron microscopic examinations of the cerebrum. Their body weight, brain weight, cortical thickness, and numerical densities of whole cells and synapses in somatosensory cortex were examined. Growth of the dendritic arborization of layer V pyramidal cells was also examined quantitatively with Golgi-Cox specimens. A significant dose-related reduction in brain weight was found in all irradiated groups. Neither gross malformation nor abnormality of cortical architecture was observed in the groups exposed to 0.27 Gy. A significant change was found in thickness of cortex in the groups exposed to 0.48 Gy or more. Cell packing density increased significantly in the group exposed to 1.00 Gy. Significant reduction in the number of intersections of dendrites with the zonal boundaries were found in the groups exposed to 0.27 Gy or more. There was no difference in the numerical density of synapses in layer I between the control and irradiated groups. These results suggested that doses as low as 0.27 Gy could cause a morphologically discernible change in the mammalian cerebrum.

  16. Treatment of opium alkaloid containing wastewater in sequencing batch reactor (SBR)—Effect of gamma irradiation

    NASA Astrophysics Data System (ADS)

    Bural, Cavit B.; Demirer, Goksel N.; Kantoglu, Omer; Dilek, Filiz B.

    2010-04-01

    Aerobic biological treatment of opium alkaloid containing wastewater as well as the effect of gamma irradiation as pre-treatment was investigated. Biodegradability of raw wastewater was assessed in aerobic batch reactors and was found highly biodegradable (83-90% degradation). The effect of irradiation (40 and 140 kGy) on biodegradability was also evaluated in terms of BOD 5/COD values and results revealed that irradiation imparted no further enhancement in the biodegradability. Despite the highly biodegradable nature of wastewater, further experiments in sequencing batch reactors (SBR) revealed that the treatment operation was not possible due to sludge settleability problem observed beyond an influent COD value of 2000 mg dm -3. Possible reasons for this problem were investigated, and the high molecular weight, large size and aromatic structure of the organic pollutants present in wastewater was thought to contribute to poor settleability. Initial efforts to solve this problem by modifying the operational conditions, such as SRT reduction, failed. However, further operational modifications including addition of phosphate buffer cured the settleability problem and influent COD was increased up to 5000 mg dm -3. Significant COD removal efficiencies (>70%) were obtained in both SBRs fed with original and irradiated wastewaters (by 40 kGy). However, pre-irradiated wastewater provided complete thebain removal and a better settling sludge, which was thought due to degradation of complex structure by radiation application. Degradation of the structure was observed by GC/MS analyses and enhancement in filterability tests.

  17. The effect of gamma irradiation on the stability and hygienic quality of semi-dried Pacific saury ( Cololabis seira) flesh

    NASA Astrophysics Data System (ADS)

    Lee, Ju.-Woon; Cho, Kyung.-Hwan; Yook, Hong.-Sun; Jo, Cheorun; Kim, Dong.-Ho; Byun, Myung.-Woo

    2002-07-01

    This study was carried out to investigate the effects of gamma irradiation on the improvement of hygienic quality and the extension of shelf life of Kwamegi prepared from semi-dried Pacific saury ( Cololabis seira) flesh. Commercial Kwamegi was purchased from a domestic market, vacuum-packaged, and irradiated to doses of 0, 3, 5, 7 or 10 kGy. Non-irradiated Kwamegi rapidly deteriorated during storage at 5°C, and some bacteria presumed as Salmonella and/or Shigella species were detected using selective medium. However, the total viable cells and presumptive pathogens were reduced with increased radiation dose, and a dose level of 7-10 kGy was considered to be an optimum and effective dose for the preservation of Kwamegi. Thiobarbituric acid values did not differ, regardless of irradiation dose and storage time. Sensory evaluation results were not different in all samples immediately after irradiation. After 60-day storage, the sensory quality of irradiated Kwamegi was adequate; however the quality of the control deteriorated.

  18. Food intake and growth of burro foals after 250 roentgens of cobalt-60 whole-body gamma irradiation.

    PubMed

    Knapka, J J; Brown, D G; Barth, K M

    1968-10-01

    Possible late effects of sublethal levels of whole-body gamma irradiation on growth of burro foals were studied. Two trials included 31 nonirradiated foals and 32 foals that were exposed to 250 R of 60Co gamma radiation during their fourth month of life. The foals were weaned 90 days postirradiation and allotted into treatment groups based on radiation treatment, weight, sex, and size. Each group was then randomly selected to be fed a ration containing either 9 %, 14 %, or 18 % crude protein in the first trial and either 9 % or 18 % in the second trial. The length of these trials was 364 days. Criteria used to evaluate the treatments included feed consumption, body weight gains, feed efficiency, increase in height, and increase in heart girth. Least-squares analysis of these data indicated that radiation had no significant effect on any of the traits tested. There was a consistent though nonsignificant trend for irradiated foals to be less efficient in feed utilization than their nonirradiated counterparts.

  19. Swelling and drug release behavior of poly(2-hydroxyethyl methacrylate/itaconic acid) copolymeric hydrogels obtained by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Tomić, S. Lj.; Mićić, M. M.; Filipović, J. M.; Suljovrujić, E. H.

    2007-05-01

    The new copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were prepared by gamma irradiation, in order to examine the potential use of these hydrogels in controlled drug release systems. The influence of IA content in the gel on the swelling characteristics and the releasing behavior of hydrogels, and the effect of different drugs, theophylline (TPH) and fenethylline hydrochloride (FE), on the releasing behavior of P(HEMA/IA) matrix were investigated in vitro. The diffusion exponents for swelling and drug release indicate that the mechanisms of buffer uptake and drug release are governed by Fickian diffusion. The swelling kinetics and, therefore, the release rate depends on the matrix swelling degree. The drug release was faster for copolymeric hydrogels with a higher content of itaconic acid. Furthermore, the drug release for TPH as model drug was faster due to a smaller molecular size and a weaker interaction of the TPH molecules with(in) the P(HEMA/IA) copolymeric networks.

  20. EPR study of free radicals in non- and gamma-irradiated nutritive supplements containing anthocyanins concentrate from lyophilized red wine

    NASA Astrophysics Data System (ADS)

    Mladenova, Ralitsa B.; Firzov, Cyril; Yordanov, Nicola D.

    2010-09-01

    Nutritive supplements Enoviton, Enoviton C and Enoviton CE containing standardized anthocyanins from lyophilized red wine, vitamins (some of them) and excipients were investigated by EPR spectrometry before and after gamma-irradiation. Non-irradiated samples exhibit one singlet line with g=2.0039±0.0002, most probably due to free radicals from anthocyanins. After irradiation with 10 kGy gamma-rays, tablets of Еnoviton, Еnoviton С and Еnoviton СЕ, all exhibit complex EPR signals centered at a g-value of g=2.0034. The EPR spectrum of irradiated Enoviton is different from that of Еnoviton С or Еnoviton СЕ due to the overlap of the spectra of microcrystalline cellulose and the background singlet spectrum present in all tablets with the EPR resonance due to irradiated ascorbic acid (in Еnoviton С and Еnoviton СЕ). Gamma-induced free radicals exhibit long time stability—for a six months period the intensity of central peak decrease with 30-40%.