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Sample records for irradiation induced improvement

  1. Irradiation induced improvement in crystallinity of epitaxially grown Ag thin films on Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    Takahiro, Katsumi; Nagata, Shinji; Yamaguchi, Sadae [Tohoku Univ., Sendai (Japan). Inst. for Materials Research

    1997-03-01

    We report the improvement in crystallinity of epitaxially grown Ag films on Si(100) substrates with ion irradiation. The irradiation of 0.5 MeV Si ions to 2x10{sup 16}/cm{sup 2} at 200degC, for example, reduces the channeling minimum yield from 60% to 6% at Ag surface. The improvement originates from the decrease of mosaic spread in the Ag thin film. In our experiments, ion energy, ion species and irradiation temperature have been varied. The better crystallinity is obtained as the higher concentration of defect is generated. The mechanism involved in the irradiation induced improvement is discussed. (author)

  2. Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

    International Nuclear Information System (INIS)

    Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

    2004-01-01

    Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed

  3. Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

    Energy Technology Data Exchange (ETDEWEB)

    Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

    2004-08-01

    Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed.

  4. Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements.

    Science.gov (United States)

    Peng, Bei; Locascio, Mark; Zapol, Peter; Li, Shuyou; Mielke, Steven L; Schatz, George C; Espinosa, Horacio D

    2008-10-01

    The excellent mechanical properties of carbon nanotubes are being exploited in a growing number of applications from ballistic armour to nanoelectronics. However, measurements of these properties have not achieved the values predicted by theory due to a combination of artifacts introduced during sample preparation and inadequate measurements. Here we report multiwalled carbon nanotubes with a mean fracture strength >100 GPa, which exceeds earlier observations by a factor of approximately three. These results are in excellent agreement with quantum-mechanical estimates for nanotubes containing only an occasional vacancy defect, and are approximately 80% of the values expected for defect-free tubes. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging was used to directly determine the number of fractured shells and the chirality of the outer shell. Electron irradiation at 200 keV for 10, 100 and 1,800 s led to improvements in the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. Computer simulations also illustrate the effects of various irradiation-induced crosslinking defects on load sharing between the shells.

  5. Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements.

    Energy Technology Data Exchange (ETDEWEB)

    Peng, B.; Locascio, M.; Zapol, P.; Li, S.; Mielke, S. L.; Schatz, G. C.; Espinosa, H. D.; Northwestern Univ.

    2008-01-01

    The excellent mechanical properties of carbon nanotubes are being exploited in a growing number of applications from ballistic armour to nanoelectronics. However, measurements of these properties have not achieved the values predicted by theory due to a combination of artifacts introduced during sample preparation and inadequate measurements. Here we report multiwalled carbon nanotubes with a mean fracture strength >100 GPa, which exceeds earlier observations by a factor of approximately three. These results are in excellent agreement with quantum-mechanical estimates for nanotubes containing only an occasional vacancy defect, and are {approx}80% of the values expected for defect-free tubes. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging was used to directly determine the number of fractured shells and the chirality of the outer shell. Electron irradiation at 200 keV for 10, 100 and 1,800 s led to improvements in the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. Computer simulations also illustrate the effects of various irradiation-induced crosslinking defects on load sharing between the shells.

  6. Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements

    International Nuclear Information System (INIS)

    Peng, B.; Locascio, M.; Zapol, P.; Li, S.; Mielke, S.L.; Schatz, G.C.; Espinosa, H.D.

    2008-01-01

    The excellent mechanical properties of carbon nanotubes are being exploited in a growing number of applications from ballistic armour to nanoelectronics. However, measurements of these properties have not achieved the values predicted by theory due to a combination of artifacts introduced during sample preparation and inadequate measurements. Here we report multiwalled carbon nanotubes with a mean fracture strength >100 GPa, which exceeds earlier observations by a factor of approximately three. These results are in excellent agreement with quantum-mechanical estimates for nanotubes containing only an occasional vacancy defect, and are ∼80% of the values expected for defect-free tubes. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging was used to directly determine the number of fractured shells and the chirality of the outer shell. Electron irradiation at 200 keV for 10, 100 and 1,800 s led to improvements in the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. Computer simulations also illustrate the effects of various irradiation-induced crosslinking defects on load sharing between the shells.

  7. Structural and optical properties improvements of PVP/gelatin blends induced by neutron irradiation

    Science.gov (United States)

    Basha, Mohammad Ahmad-Fouad; Hassan, Mohamed Ahmed

    2018-05-01

    Blends of polyvinylpyrrolidone and gelatin were prepared in three different concentrations to study the modifications in their structural and optical properties induced by neutron irradiations with different neutron fluence values from 108 up to 1011 neutron/cm2. X-ray spectroscopy revealed that the irradiation has induced a recrystallization phenomenon in the studied blends and the crystallinity index increased by increasing the neutron fluence due to the breaking of the crystallites. Fourier-transform infrared spectroscopy came to confirm the existence of interactions between interchain groups and a higher compatibility for the irradiated blends. The irradiation induced defects inside the material were responsible for the change in their optical and structural properties. The creation of free radicals or ions inside the conduction bands has led to the increase in the number of carriers on localized states; this has caused the increase in optical conductivity of the irradiated blends as a result of decreasing the energy gaps by increasing the neutron fluence. Results may widen the applications of the gelatin based blends to include optoelectronic devices, organic light emitting devices, solar selective and anti-reflectance bio-coatings, optical organic glass and lenses.

  8. Irradiation-Induced Nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Birtcher, R.C.; Ewing, R.C.; Matzke, Hj.; Meldrum, A.; Newcomer, P.P.; Wang, L.M.; Wang, S.X.; Weber, W.J.

    1999-08-09

    This paper summarizes the results of the studies of the irradiation-induced formation of nanostructures, where the injected interstitials from the source of irradiation are not major components of the nanophase. This phenomena has been observed by in situ transmission electron microscopy (TEM) in a number of intermetallic compounds and ceramics during high-energy electron or ion irradiations when the ions completely penetrate through the specimen. Beginning with single crystals, electron or ion irradiation in a certain temperature range may result in nanostructures composed of amorphous domains and nanocrystals with either the original composition and crystal structure or new nanophases formed by decomposition of the target material. The phenomenon has also been observed in natural materials which have suffered irradiation from the decay of constituent radioactive elements and in nuclear reactor fuels which have been irradiated by fission neutrons and other fission products. The mechanisms involved in the process of this nanophase formation are discussed in terms of the evolution of displacement cascades, radiation-induced defect accumulation, radiation-induced segregation and phase decomposition, as well as the competition between irradiation-induced amorphization and recrystallization.

  9. Radiation effects on polymer materials. Ionizing radiation induces degradation or improvement? (2) Gas evolution by irradiation

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo

    2005-01-01

    The present article reviews gas evolution from organic polymers induced by ionizing radiations, focusing on gamma-ray irradiation of PE (polyethylene) and PP (polypropylene)-model compounds at temperatures from -77 to 55degC. In the polyolefins, the main gas evolved by irradiation is hydrogen with G-value of 3-4 at room temperatures and G(H 2 ) is 1.8 at 77K. For PE, G(H 2 ) is higher for the low-density PE than for higher-density PE. For the halogenated polymers as PVC, etc., evolved gas is hydrogen halogenated: G(HCl)=6.8 for PVC. For the case where the irradiation is accompanied with the oxidation of polymers, the de-oxygenation and formation of carboxylic radicals are remarkably high and known to emit a bad smell which depends on the thickness of oxidized layers. In conclusion, the gas evolution can be estimated by considering the molecular structure of polymer materials. (S.Ohno)

  10. Laser irradiation-induced laminated graphene/MoS2 composites with synergistically improved tribological properties

    Science.gov (United States)

    Luo, Ting; Chen, Xinchun; Li, Peisheng; Wang, Ping; Li, Cuncheng; Cao, Bingqiang; Luo, Jianbin; Yang, Shikuan

    2018-06-01

    Engineering lubricant additives that have extraordinary friction reduction and anti-wear performance is critical to almost any modern mechanical machines. Here, we demonstrate the fabrication of laminated lubricant additives that can combine the advantages of zero-dimensional nanospheres and two-dimensional nanosheets. A simple in situ laser irradiation method is developed to prepare the laminated composite structure composed of ideally ultrasmooth MoS2 sub-microspheres embedded within multiple layers of graphene. These ultrasmooth MoS2 spheres within the laminated structure can change sliding friction into rolling friction under strong shear force created by moving contact surfaces to significantly reduce the friction. Meantime, the graphene layers can behave as ‘protection pads’ to efficiently avoid the formation of scars on the metal-to-metal contact surfaces. Overall, the laminated composites as lubricant additives synergistically improve the friction reduction and anti-wear properties. Additionally, due to the unique loosely packed laminated structure, the composites can stably disperse in the lubricant for more than 15 d and work under high temperatures without being oxidized. Such constructed laminated composites with outstanding tribological properties by an in situ laser irradiation method supply a new concept in designing lubricant additives that can combine the advantages of 0D and 2D structures.

  11. Hypoxia-Inducible Factor Pathway Inhibition Resolves Tumor Hypoxia and Improves Local Tumor Control After Single-Dose Irradiation

    International Nuclear Information System (INIS)

    Helbig, Linda; Koi, Lydia; Brüchner, Kerstin; Gurtner, Kristin; Hess-Stumpp, Holger; Unterschemmann, Kerstin; Pruschy, Martin

    2014-01-01

    Purpose: To study the effects of BAY-84-7296, a novel orally bioavailable inhibitor of mitochondrial complex I and hypoxia-inducible factor 1 (HIF-1) activity, on hypoxia, microenvironment, and radiation response of tumors. Methods and Materials: UT-SCC-5 and UT-SCC-14 human squamous cell carcinomas were transplanted subcutaneously in nude mice. When tumors reached 4 mm in diameter BAY-84-7296 (Bayer Pharma AG) or carrier was daily administered to the animals. At 7 mm tumors were either excised for Western blot and immunohistologic investigations or were irradiated with single doses. After irradiation animals were randomized to receive BAY-84-7296 maintenance or carrier. Local tumor control was evaluated 150 days after irradiation, and the dose to control 50% of tumors (TCD 50 ) was calculated. Results: BAY-84-7296 decreased nuclear HIF-1α expression. Daily administration of inhibitor for approximately 2 weeks resulted in a marked decrease of pimonidazole hypoxic fraction in UT-SCC-5 (0.5% vs 21%, P 50 , with an enhancement ratio of 1.37 (95% confidence interval [CI] 1.13-1.72) in UT-SCC-5 and of 1.55 (95% CI 1.26-1.94) in UT-SCC-14. BAY-84-7296 maintenance after irradiation did not further decrease TCD 50 . Conclusions: BAY-84-7296 resulted in a marked decrease in tumor hypoxia and substantially reduced radioresistance of tumor cells with the capacity to cause a local recurrence after irradiation. The data suggest that reduction of cellular hypoxia tolerance by BAY-84-7296 may represent the primary biological mechanism underlying the observed enhancement of radiation response. Whether this mechanism contributes to the improved outcome of fractionated chemoradiation therapy warrants further investigation

  12. Gamma knife irradiation of injured sciatic nerve induces histological and behavioral improvement in the rat neuropathic pain model.

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    Yuki Yagasaki

    Full Text Available We examined the effects of gamma knife (GK irradiation on injured nerves using a rat partial sciatic nerve ligation (PSL model. GK irradiation was performed at one week after ligation and nerve preparations were made three weeks after ligation. GK irradiation is known to induce immune responses such as glial cell activation in the central nervous system. Thus, we determined the effects of GK irradiation on macrophages using immunoblot and histochemical analyses. Expression of Iba-1 protein, a macrophage marker, was further increased in GK-treated injured nerves as compared with non-irradiated injured nerves. Immunohistochemical study of Iba-1 in GK-irradiated injured sciatic nerves demonstrated Iba-1 positive macrophage accumulation to be enhanced in areas distal to the ligation point. In the same area, myelin debris was also more efficiently removed by GK-irradiation. Myelin debris clearance by macrophages is thought to contribute to a permissive environment for axon growth. In the immunoblot study, GK irradiation significantly increased expressions of βIII-tubulin protein and myelin protein zero, which are markers of axon regeneration and re-myelination, respectively. Toluidine blue staining revealed the re-myelinated fiber diameter to be larger at proximal sites and that the re-myelinated fiber number was increased at distal sites in GK-irradiated injured nerves as compared with non-irradiated injured nerves. These results suggest that GK irradiation of injured nerves facilitates regeneration and re-myelination. In a behavior study, early alleviation of allodynia was observed with GK irradiation in PSL rats. When GK-induced alleviation of allodynia was initially detected, the expression of glial cell line-derived neurotrophic factor (GDNF, a potent analgesic factor, was significantly increased by GK irradiation. These results suggested that GK irradiation alleviates allodynia via increased GDNF. This study provides novel evidence that GK

  13. Improvement effect of gamma-irradiated complex leaf extract of date plum, persimmon and mulberry on UVB-induced skin damage

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Won; Cho, Byoung Ok; Che, Denis Nchang; Shin, Jae Young; Fang, Chong Zhou; Jang, Seon Il [Jeonju University, Jeonju (Korea, Republic of)

    2016-11-15

    This study was conducted to evaluate the improvement effect of gamma-irradiated complex leaf extract of Date Plum, Persimmon and Mulberry (γ-DPME) on UVB induced skin damage. The samples were gamma irradiated at doses of 10 kGy. γ-DPME treatment tended to decrease UVB-induced immune cell infiltration and erthyderma index than the groups treated with non-gamma-irradiated DPME (n-DPME) and L-ascobic acid (AA). In addition, γ-DPME treatment significantly decreased skin thickness, melanin index and mast cell infiltration in UVB-irradiated skin. Moreover, γ-DPME treatment significantly decreased the compound 48/80-induced scratching behavior and immune cell infiltration than n-DPME group. These results show that gamma irradiation can be used to increase the physiological activities of DPME.

  14. Improving bambara groundnut productivity using gamma irradiation ...

    African Journals Online (AJOL)

    In recent times efforts are being made to improve the productivity of bambara groundnut. Studies were initiated (i) to characterise and evaluate landraces and to select superior ones for irradiation, (ii) to induce genetic variation through gamma irradiation and (iii) to use biotechnological approaches to shorten the generation ...

  15. Hypoxia-Inducible Factor Pathway Inhibition Resolves Tumor Hypoxia and Improves Local Tumor Control After Single-Dose Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Helbig, Linda [OncoRay–National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Koi, Lydia [OncoRay–National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Deutsches Konsortium für Translationale Krebsforschung, Site Dresden, Dresden (Germany); Brüchner, Kerstin [Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Institute of Radiooncology Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Gurtner, Kristin [Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden (Germany); Hess-Stumpp, Holger; Unterschemmann, Kerstin [Global Drug Discovery, Bayer Pharma, Berlin (Germany); Pruschy, Martin [Radiation Oncology, University of Zurich, Zurich (Switzerland); and others

    2014-01-01

    Purpose: To study the effects of BAY-84-7296, a novel orally bioavailable inhibitor of mitochondrial complex I and hypoxia-inducible factor 1 (HIF-1) activity, on hypoxia, microenvironment, and radiation response of tumors. Methods and Materials: UT-SCC-5 and UT-SCC-14 human squamous cell carcinomas were transplanted subcutaneously in nude mice. When tumors reached 4 mm in diameter BAY-84-7296 (Bayer Pharma AG) or carrier was daily administered to the animals. At 7 mm tumors were either excised for Western blot and immunohistologic investigations or were irradiated with single doses. After irradiation animals were randomized to receive BAY-84-7296 maintenance or carrier. Local tumor control was evaluated 150 days after irradiation, and the dose to control 50% of tumors (TCD{sub 50}) was calculated. Results: BAY-84-7296 decreased nuclear HIF-1α expression. Daily administration of inhibitor for approximately 2 weeks resulted in a marked decrease of pimonidazole hypoxic fraction in UT-SCC-5 (0.5% vs 21%, P<.0001) and in UT-SCC-14 (0.3% vs 19%, P<.0001). This decrease was accompanied by a significant increase in fraction of perfused vessels in UT-SCC-14 but not in UT-SCC-5. Bromodeoxyuridine and Ki67 labeling indices were significantly reduced only in UT-SCC-5. No significant changes were observed in vascular area or necrosis. BAY-84-7296 before single-dose irradiation significantly decreased TCD{sub 50}, with an enhancement ratio of 1.37 (95% confidence interval [CI] 1.13-1.72) in UT-SCC-5 and of 1.55 (95% CI 1.26-1.94) in UT-SCC-14. BAY-84-7296 maintenance after irradiation did not further decrease TCD{sub 50}. Conclusions: BAY-84-7296 resulted in a marked decrease in tumor hypoxia and substantially reduced radioresistance of tumor cells with the capacity to cause a local recurrence after irradiation. The data suggest that reduction of cellular hypoxia tolerance by BAY-84-7296 may represent the primary biological mechanism underlying the observed enhancement of

  16. Improvement of garlic (Allium Sativum L.) resistance to white rot and storability using gamma irradiation induced mutations

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Mirali, N.; Arabi, M. I. E.

    2001-01-01

    A mutation program was conducted to improve garlic (Allium sativum) resistance to white rot (Sclerotium cepivorum) and to improve its storability under natural conditions. Cloves of two local garlic cultivars (Kisswany and Yabroudy) were irradiated with gamma ray doses 4, 5, 6, and 7 gray. The cloves were then planted in the field and plants were advanced for 4 generations in order to isolate mutations in stable form. The results indicated that the cultivar Yabroudy was more sensitive to gamma irradiation than Kisswany. Rate of morphological mutants increased with increasing gamma ray dosage. Selection pressure against white rot disease was applied starting in the second generation by adding infected garlic leaves to the soil. In the third and fourth generations, however, full selection pressure was applied by inoculating the cloves with the fungus sclerotia and planting them in a soil previously planted with infected garlic plants. healthy garlic bulbs were harvested and stored under natural conditions and then planted to obtain the next generation. By the end of the fourth generation, we have been able to improve garlic resistance to white rot disease and its storability. Twenty four mutant lines from each garlic cultivar have been selected. Out of the selected lines, twelve lines from cultivar Kisswany had only 3% infection percentage as compared to 29% in the control, and twelve lines from cultivar Yabroudy had less than 5% infection percentage as compared to 20% in the control. Also, we have been able to improve storability under natural conditions. Weight loss during storage decreased from 8.25% in the control to only 4% in some Kisswany lines and from 10% to 3% in some Yabroudy lines. However, we have not been able to increase the bulb weight over the control but the weights of the selected lines were comparable to those of the control. (author)

  17. Improvement of irradiation facilities performance in JMTR

    International Nuclear Information System (INIS)

    Kanno, Masaru; Sakurai, Susumu; Honma, Kenzo; Sagawa, Hisashi; Nakazaki, Chousaburo

    1999-01-01

    Various kinds of irradiation facilities are installed in the JMTR for the purpose of irradiation tests on fuels and materials and of producing radioisotopes. The irradiation facilities have been improved so far at every opportunity of new irradiation requirements and of renewing them which reached the design lifetime. Of these irradiation facilities, improvements of the power ramping test facility (BOCA/OSF-1 facility) and the hydraulic rabbit No.2 (HR-2 facility) are described here. (author)

  18. Irradiation induced effects in zirconium (A review)

    International Nuclear Information System (INIS)

    Madden, P.K.

    1975-06-01

    Irradiation creep in zirconium and its alloys is comprehensively discussed. The main theories are outlined and the gaps between them and the observed creep behaviour, indicated. Although irradiation induced point defects play an important role, effects due to irradiation induced dislocation loops seem insignificant. The experimental results suggest that microstructural variations due to prior cold-working or hydrogen injection perturb the irradiation growth and the irradiation creep of zircaloy. Further investigations into these areas are required. One disadvantage of creep experiments lies in their duration. The possibility of accelerated experiments using ion implantation or electron irradiation is examined in the final section, and its possible advantages and disadvantages are outlined. (author)

  19. Improving smoked herring quality by gamma irradiation

    International Nuclear Information System (INIS)

    Zahran, D.A.; Abd El-Wahab, S.A.; Hendy, B.A.

    2009-01-01

    Smoked herring which is a highly purchasable product in Egypt, was exposed to different gamma irradiation doses (1.5,3.0 and 5.0 kGy) and stored at environmental temperature (12± 2 deg C) until spoilage of the control. Microbiological, chemical and sensory analyses were performed throughout storage to monitor the quality attributes. It is worthy to mention that irradiation reduced the population of bacteria and the effect was more pronounced at the highest dose used (5.0 kGy). At the same time 1.5 kGy completely eliminated staphylococcus aureus (coagulase + ve) and coliforms. By chemical analysis, there was significant decrease in average moisture content by different gamma irradiation doses and storage. Although the average thiobarbituric acid reactive substances (TBARS) increased slightly by γ-irradiation, this increase was highly significant by storage . At the same time there was a significant (p< 0.05)decrease in the average trimethylamine (TMA) value of all irradiated samples compared with unirradiated control, this value increased significantly by storage. interestingly, the average histamine value decreased significantly in all irradiated samples. The sensory analysis revealed a highly significant difference in the average acceptability scores between different irradiation doses used and also by storage. Therefore it could be concluded that the quality of smoked herring during storage at environmental temperature (12 ± 2 deg C) could be improved by using 5.0 kGy γ -irradiation

  20. Studies on the improvement of irradiation process

    International Nuclear Information System (INIS)

    Kim, Ki Yup; Pyun, Hyung Chick; Yoon, Byung Mok; Nho, Young Chang; Lee, Young Keun; Park, Soon Chul; Na, Bong Joo; Yoo, Young Soo

    1991-01-01

    On the basis of analysis and examination for efficient maintenance and operation of the facility, the method of improving irradiation process was discussed so that we may extend the applicability of irradiation technique to various materials and accelerate nation-wide propagation of radiation processing technology. Preparations have been made for transfer, installation, and operation of the irradiation facilities in radiation application building which will be completed at the headquarter site by the end of 1992. The qualification testing apparatus for nuclear power station cables was conceptually designed to investigate the degradation behavior of the cables under a simulated LOCA(Loss of Coolant Accident) environments. (Author)

  1. Free radicals induced archive paper by irradiation

    International Nuclear Information System (INIS)

    Cutrubinis, M.; Moise, I.V.; Negut, C.D.; Georgescu, R.; Suvaila, R.; Virgolici, M.; Manea, M.M.

    2011-01-01

    Complete text of publication follows. Irradiation of archive paper (document archives of institutions, companies etc. and library or museum collections of books and documents) can solve the problems related to the bio-deterioration and bio-contamination of paper and sometimes save valuable cultural heritage paper items. For valuable paper items care should be taken to the degradation induced instantly by the ionising radiation to the cellulosic support and also to the long term post-irradiation effects. The free radicals formed due to the irradiation treatment could contribute to instant degradation of paper. Part of them are also trapped for months and years after irradiation and they could be related to the post-irradiation effects in paper items. In this study, different sorts of cellulosic support samples (soft wood and hard wood cellulose, contemporary paper, paper from archives and from collections etc.) have been irradiated with dosis up to 100 kGy and the radiation induced free radicals have been measured by ESR spectrometry. The ESR signals have shown the type and quantity of radiation induced free radicals. Their study can be used for a realistic estimation of the degradative effect of the ionising radiation treatment of archive paper.

  2. Analysis of radicals induced in irradiated foods

    International Nuclear Information System (INIS)

    Kishida, Keigo; Kaimori, Yoshihiko; Kawamura, Shoei; Sakamoto, Yuhki; Nakamura, Hideo; Ukai, Mitsuko; Kikuchi, Masahiro; Shimoyama, Yuhei; Kobayashi, Yasuhiko

    2012-01-01

    By electron spin resonance (ESR) spectroscopy, we revealed free radicals in γ-ray irradiated foods; black pepper, green coffee bean and ginseng. We also analyzed the decay behavior of radiation induced free radicals during storage of irradiated foods. The ESR spectrum of experimental irradiated foods consists of a sextet signal centered at g=2.0 and a singlet signal at the same g-value position and a singlet signal at g=4.0. The singlet signal at g=2.0 is originated from organic free radicals and its peak intensity showed the dependence of γ-ray irradiation dose levels. The signal intensity was decreased during storage. Only after 3 hours of radiation treatment the peak intensity was decreased fast and after that the intensity was decreased slowly. The relaxation times, T 1 and T 2 , of radiation induced free radicals showed the variations before and after irradiation. During long time storage period it was shown that T 1 was increased and T 2 was decreased. By analysis of decay process using the simulation methods based on the theory of reaction speed, it is considered that at least two kinds of radicals were induced in irradiated foods during long time storage. (author)

  3. Improvement of rice starch by gamma irradiation

    International Nuclear Information System (INIS)

    Duan Zhiying; Wu Dianxing; Shen Shengquan; Han Juanying; Xia Yingwu

    2003-01-01

    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, physico-chemical properties and starch granule structure. Four major parameters of RVA profile, peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV) and consistence viscosity (CSV) 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 alkali spreading value (ASV) were detected after irradiation, but the peak time (PKT) were reduced with the dose level. Gel consistency (GC) were significantly increased in the tested cultivars, especially in the high AAC Indica rice, suggesting that it is promising to use gamma irradiation to improve eating and cooking quality of rice

  4. Irradiation-induced amorphization process in graphite

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Hiroaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-04-01

    Effects of the element process of irradiation damage on irradiation-induced amorphization processes of graphite was studied. High orientation thermal decomposed graphite was cut about 100 nm width and used as samples. The irradiation experiments are carried out under the conditions of electronic energy of 100-400 KeV, ion energy of 200-600 KeV, ionic species Xe, Ar, Ne, C and He and the irradiation temperature at from room temperature to 900 K. The critical dose ({phi}a) increases exponentially with increasing irradiation temperature. The displacement threshold energy of graphite on c-axis direction was 27 eV and {phi}a{sup e} = 0.5 dpa. dpa is the average number of displacement to atom. The critical dose of ion irradiation ({phi}a{sup i}) was 0.2 dpa at room temperature, and amorphous graphite was produced by less than half of dose of electronic irradiation. Amorphization of graphite depending upon temperature is discussed. (S.Y.)

  5. Preliminary examination of induced radioactivity in pepper by 10 MeV electron irradiation

    International Nuclear Information System (INIS)

    Katayama, Tadashi; Furuta, Masakazu; Sibata, Setsuko; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Toratani, Hirokazu; Takeda, Atsuhiko.

    1991-01-01

    β-ray measurement was performed on 10 MeV electron-irradiated black pepper and white pepper with liquid scintillation counter in order to reconfirm the wholesomeness of irradiated foods and present unambiguous data to general consumers concerning about the induced radioactivity in the irradiated foods. In irradiated black pepper no radioactivity other than from natural source, un-irradiated one, was detected. But in irradiated white pepper, it was suggested that induced radioactivity might be detected if the detection method was more improved. (author)

  6. Antitumor bystander effect induced by radiation-inducible target gene therapy combined with α particle irradiation

    International Nuclear Information System (INIS)

    Liu Hui; Jin Chufeng; Wu Yican; Ge Shenfang; Wu Lijun; FDS Team

    2012-01-01

    In this work, we investigated the bystander effect of the tumor and normal cells surrounding the target region caused by radiation-inducible target gene therapy combined with α-particle irradiation. The receptor tumor cell A549 and normal cell MRC-5 were co-cultured with the donor cells irradiated to 0.5 Gy or the non-irradiated donor cells, and their survival and apoptosis fractions were evaluated. The results showed that the combined treatment of Ad-ET and particle irradiation could induce synergistic antitumor effect on A549 tumor cell, and the survival fraction of receptor cells co-cultured with the irradiated cells decreased by 6%, compared with receptor cells co-cultured with non-irradiated cells, and the apoptosis fraction increased in the same circumstance, but no difference was observed with the normal cells. This study demonstrates that Ad-ET combined with α-particle irradiation can significantly cause the bystander effect on neighboring tumor cells by inhibiting cell growth and inducing apoptosis, without obvious toxicity to normal cells. This suggests that combining radiation-inducible TRAIL gene therapy and irradiation may improve tumor treatment efficacy by specifically targeting tumor cells and even involving the neighboring tumor cells. (authors)

  7. Gastroprotective effect of kefir on ulcer induced in irradiated rats.

    Science.gov (United States)

    Fahmy, Hanan A; Ismail, Amel F M

    2015-03-01

    The current study was designed to investigate the protective effect of kefir milk on ethanol-induced gastric ulcers in γ-irradiated rats. The results of the present study revealed that treatment with γ-irradiation and/or ethanol showed a significant increase in ulcers number, total acidity, peptic, H(+)K(+)ATPase, MMP-2 and MMP-9 activities and MDA level, which were accompanied by a significant decrease in the mucus content, the stomach GSH level, the GSH-Px activity and DNA damage. Pre-treatment with kefir milk exert significant improvement in all the tested parameters. Kefir milk exerts comparable effect to that of the antiulcer drug ranitidine. In conclusion, the present study revealed that oral administration of kefir milk prevents ethanol-induced gastric ulcer in γ-irradiated rats that could attribute to its antioxidant, anti-apoptotic and radio-protective activities. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Chemical reactions induced by fast neutron irradiation

    International Nuclear Information System (INIS)

    Katsumura, Y.

    1989-01-01

    Here, several studies on fast neutron irradiation effects carried out at the reactor 'YAYOI' are presented. Some indicate a significant difference in the effect from those by γ-ray irradiation but others do not, and the difference changes from subject to subject which we observed. In general, chemical reactions induced by fast neutron irradiation expand in space and time, and there are many aspects. In the time region just after the deposition of neutron energy in the system, intermediates are formed densely and locally reflecting high LET of fast neutrons and, with time, successive reactions proceed parallel to dissipation of localized energy and to diffusion of the intermediates. Finally the reactions are completed in longer time region. If we pick up the effects which reserve the locality of the initial processes, a significant different effect between in fast neutron radiolysis and in γ-ray radiolysis would be derived. If we observe the products generated after dissipation and diffusion in longer time region, a clear difference would not be observed. Therefore, in order to understand the fast neutron irradiation effects, it is necessary to know the fundamental processes of the reactions induced by radiations. (author)

  9. Curcuma sparganifolia Improvement Through Gamma Irradiation

    International Nuclear Information System (INIS)

    Krasaechai, A.

    1990-01-01

    The studies of Curcuma sparganifolia improvement through irradiation using gamma rays from 40 Gy to inhibit sprouting of the rhizomes were conducted. Various effects of gamma rays on growth and development were observed in 11 parameters. Colour mutation of flowers and braces were not found except in 1 plant which showed deeper brats colour. Leaf chimera was observed but the characters for commercialization were not achieved

  10. Electron-irradiation-induced phase transformation in alumina

    International Nuclear Information System (INIS)

    Chen, C.L.; Arakawa, K.; Lee, J.-G.; Mori, H.

    2010-01-01

    In this study, electron-irradiation-induced phase transformations between alumina polymorphs were investigated by high-resolution transmission electron microscopy. It was found that the electron-irradiation-induced α → κ' phase transformation occurred in the alumina under 100 keV electron irradiation. It is likely that the knock-on collision between incident electrons and Al 3+ cations is responsible for the occurrence of electron-irradiation-induced phase transformation from α-alumina to κ'-alumina.

  11. Study on the improvement of irradiation process

    International Nuclear Information System (INIS)

    Jin, Joon Ha; Yoon, Byung Mok; Kim, Ki Yup; Nho, Young Chang; Lee, Young Keun; Park, Soon Chul; Na, Bong Joo; Yoo, Young Soo

    1993-02-01

    The source operation system, carrier systems, safety systems and all other miscellaneous systems were installed for the High Intensity Co-60 Gamma Irradiation Facility. The Co-60 Source(72,800 Ci) was installed on the source rack by Canadian engineers and the facility was approved to be safe after some test operations. The acceleration tube, transformer, main control panel and high voltage cable were installed in the Electron Accelerator Facility. All parts of the accelerator were inspected and repaired. The Low Intensity Co-60 Gamma Irradiator in Seoul was dismantled for moving to Taejon and source operation and safety systems were prepared for the new facility. During the installations, old parts and equipments of each irradiation facility were replaced and many improvement were made on the systems by installing the irradiation tables and experimental holes, movements of control and machine room and ventilation fans to each reasonable position, and installation of additional fire alarm system and cable terminal box. The knowledge and experiences obtained during the installations will be very helpful for the operation and maintenance of the facilities in the future. The facilities will be utilized for the various researches and application fields such as polymer, food agriculture, biology, equipment qualification, etc. (Author)

  12. Effect of irradiation-induced defects on fusion reactor ceramics

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1986-01-01

    Structural, thermal, and electrical properties critical to performance of ceramics in a fusion environment can be profoundly altered by irradiation effects. Neutron damage may cause swelling, reduction of thermal conductivity, increase in dielectric loss, and either reduction or enhancement of strength depending on the crystal structure and defect content of the material. Absorption of ionizing energy inevitably leads to degradation of insulating properties, but these changes can be reduced by alterations in structural or compositional makeup. Assessment of the irradiation response of candidate ceramics Al 2 O 3 , MgAl 2 O 4 , SiC and Si 3 N 4 shows that each may find use in advanced fusion devices. The present understanding of irradiation-induced defects in ceramics, while far from complete, nevertheless points the way to methods for developing improved materials for fusion applications

  13. Improvement of carbon fibre surface properties using electron beam irradiation

    International Nuclear Information System (INIS)

    Eddy Segura Pino; Luci Diva Brocardo Machado; Claudia Giovedi

    2006-01-01

    Carbon fiber-reinforced advance composites have been used for structural applications, mainly due to their mechanical properties, and additional features such as high strength-to-weight ratio, stiffness-to-weight ratio, corrosion resistance and wear properties. The main factor for a good mechanical performance of carbon fiber-reinforced composite is the interfacial interaction between the components that are fiber and polymeric matrix. The greatest challenge is to improve adhesion between components having elasticity modulus which differ by orders of magnitude and furthermore they are immiscible in each other. Another important factor is the sizing material on the carbon fiber, which protects the carbon fiber filaments and must be compatible with the matrix material in order to improve the adhesion process. The interaction of ionizing radiation from electron beam can induce in the irradiated material the formation of very active centers and free radicals. Further evolution of these active species can significantly modify structure and properties not only in the irradiated polymeric matrix but also on the fiber surface. So that, fiber and matrix play an important role in the production of chemical bonds, which promote better adhesion between both materials improving the composite mechanical performance. The aim of this work was to improve the surface properties of the carbon fiber surface using ionizing radiation from an electron beam in order to obtain improvement of the adhesion properties in the resulted composite. Commercial carbon fiber roving of high tensile strength with 12 000 filaments named 12 k, and sizing material of epoxy resin modified by ester groups was studied. EB irradiation has been carried out at the Institute for Nuclear and Energy Research (IPEN) facilities using a 1.5 MeV 37.5 kW Dynamitron electron accelerator model JOB-188. Rovings of carbon fibers with 1.78 g cm -3 density and 0.13 mm thickness were irradiated with 0.555 MeV, 6.43 mA and

  14. Grain weight improvement in wheat through irradiation

    International Nuclear Information System (INIS)

    Rasal, P.N.; Gadekar, D.A.; Gavhane, V.N.; Bhoite, K.D.

    2006-01-01

    T. aestivum wheat variety NIAW 34 was developed by Agricultural Research Station, Niphad, and was released by Central Varietal Release Committee, for cultivation under irrigated late sown conditions of Peninsular Zone. The grains of NIAW 34 are medium sized with 40g 1000 grain weight. However, in market the bold sized grains (above 40g 1000 grain weight) are preferred by the traders and consumers. To overcome this lacuna, grains of wheat variety NIAW 34 were irradiated to exploit the possibilities of improvement in test weight. The material was irradiated with 15 and 20 kr dose of gamma rays. In M2 generation, mutants for various morphological characters were observed. The plants showing vigorous growth habit and desirable morphological characters were selected. These selected plants were studied for grain characters after harvest. On the basis of improved test weight as compared to parental line, selections were effected. The material was advanced to M6 generation and found stable for character of interest. The material selected comprised of total 10 lines showing improved test weight having range of 42-46 g i.e. increase of 4-6 g over the parental line NIAW 34. The lines selected are being evaluated in yield evaluation trials during Rabi 2006-07. Amongst the doses used, frequency of desired mutants was higher in treatment, of 15 kr

  15. Gamma Irradiation Induced Degradation of Orange Peels

    Directory of Open Access Journals (Sweden)

    Jaime Saucedo Luna

    2012-08-01

    Full Text Available In this study, gamma irradiation induced degradation of orange peels (OP was investigated. The lignocellulosic biomass degradation was carried out at doses of 0 (control, 600, 1800 and 3500 kGy using a Co-60 gamma radiation source. The samples were tested for total and reducing sugars. The concentrations of total sugars ranged from 0.530 g∙g−1 in control sample to 0.382 g∙g−1 of dry weight in the sample which received the highest radiation dose. The reducing sugars content varying from 0.018 to 0.184 g∙g−1 of dry weight with the largest rise occurring in the sample irradiated at 3500 kGy. The concentrations of sucrose, glucose and fructose were determined. The changes generated in physico-chemical properties were determined by Fourier Transform Infrared Spectroscopy (FTIR and termogravimetric analysis (TG-DTG. The results show that OP was affected, but not significantly, which suggests that lignocellulose and sugars profiles were partially degraded after gamma irradiation.

  16. Irradiation induced precipitation: a thermodynamical approach

    International Nuclear Information System (INIS)

    Bocquet, J.-L.; Martin, Georges.

    1979-02-01

    A binary alloy (A, B) under steady state irradiation is considered as a ternary alloy (A, B, defects) in constrained equilibrium (the constraint represented by the irradiation consists in maintaining a given supersaturation of point defects). All possible two-body interactions (attractive, repulsive) have been checked between the solvent A, the solute B, and the defects C. The conditions of an irradiation corresponds to a low point-defect concentration; the only cases of interest are those where such a low concentration makes new phases precipitate, which are richer in solute than the initial solid-solution. Radiation induced precipitation is expected to occur under the following necessary conditions: - when the binary alloy (A, B) shows ordering or is ideal, a necessary condition is that the binary solute-defects must show ordering. - when the binary alloy (A, B) shows clustering, a necessary condition is that the temperature must be close to the critical mixing temperature Tsub(AB)sup(D). The physical significance of these conditions is discussed [fr

  17. Mutation induced with ion beam irradiation in rose

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H. E-mail: yhiroya@nias.affrc.go.jp; Nagatomi, S.; Morishita, T.; Degi, K.; Tanaka, A.; Shikazono, N.; Hase, Y

    2003-05-01

    The effects of mutation induction by ion beam irradiation on axillary buds in rose were investigated. Axillary buds were irradiated with carbon and helium ion beams, and the solid mutants emerged after irradiation by repeated cutting back. In helium ion irradiation, mutations were observed in plants derived from 9 buds among 56 irradiated buds in 'Orange Rosamini' and in plants derived from 10 buds among 61 irradiated buds in 'Red Minimo'. In carbon ion, mutations were observed in plants derived from 12 buds among 88 irradiated buds in 'Orange Rosamini'. Mutations were induced not only in higher doses but also in lower doses, with which physiological effect by irradiation was hardly observed. Irradiation with both ion beams induced mutants in the number of petals, in flower size, in flower shape and in flower color in each cultivar.

  18. Improvement of physical properties of soyabeans by gamma irradiation

    International Nuclear Information System (INIS)

    Byun, M.-W.; Kwon, J.-H.; Mori, Tomohiko

    1993-01-01

    Physical properties of gamma-irradiated soybeans were evaluated at different temperatures by determining water absorption pattern and cooking characteristics of the sample. Irradiation at 2.5-10 kGy caused the reduction of soaking time in soybeans by 2-5 hours and the increase of hydration capacity by 10-20%, respectively, compared to the non-irradiated control at 20 o C. The activation energy for water absorption was lower in irradiated soybeans than in the non-irradiated control. Irradiation at 2.5-10 kGy caused the reduction of cooking time in soybeans by 30-60% compared to the non-irradiated control and the cooking rate constant of irradiated samples was higher about 2 times than that of the non-irradiated control. The irradiation efficacy on physical quality improvement was also recognized in the stored soybeans for one year at room temperature. (author)

  19. Improved calculation of displacements per atom cross section in solids by gamma and electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Piñera, Ibrahin, E-mail: ipinera@ceaden.edu.cu [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, CEADEN, 30 St. 502, Playa 11300, Havana (Cuba); Cruz, Carlos M.; Leyva, Antonio; Abreu, Yamiel; Cabal, Ana E. [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, CEADEN, 30 St. 502, Playa 11300, Havana (Cuba); Espen, Piet Van; Remortel, Nick Van [University of Antwerp, CGB, Groenenborgerlaan 171, 2020 Antwerpen (Belgium)

    2014-11-15

    Highlights: • We present a calculation procedure for dpa cross section in solids under irradiation. • Improvement about 10–90% for the gamma irradiation induced dpa cross section. • Improvement about 5–50% for the electron irradiation induced dpa cross section. • More precise results (20–70%) for thin samples irradiated with electrons. - Abstract: Several authors had estimated the displacements per atom cross sections under different approximations and models, including most of the main gamma- and electron-material interaction processes. These previous works used numerical approximation formulas which are applicable for limited energy ranges. We proposed the Monte Carlo assisted Classical Method (MCCM), which relates the established theories about atom displacements to the electron and positron secondary fluence distributions calculated from the Monte Carlo simulation. In this study the MCCM procedure is adapted in order to estimate the displacements per atom cross sections for gamma and electron irradiation. The results obtained through this procedure are compared with previous theoretical calculations. An improvement in about 10–90% for the gamma irradiation induced dpa cross section is observed in our results on regard to the previous evaluations for the studied incident energies. On the other hand, the dpa cross section values produced by irradiation with electrons are improved by our calculations in about 5–50% when compared with the theoretical approximations. When thin samples are irradiated with electrons, more precise results are obtained through the MCCM (in about 20–70%) with respect to the previous studies.

  20. Edaravone protects human peripheral blood lymphocytes from γ-irradiation-induced apoptosis and DNA damage.

    Science.gov (United States)

    Chen, Liming; Liu, Yinghui; Dong, Liangliang; Chu, Xiaoxia

    2015-03-01

    Radiation-induced cellular injury is attributed primarily to the harmful effects of free radicals, which play a key role in irradiation-induced apoptosis. In this study, we investigated the radioprotective efficacy of edaravone, a licensed clinical drug and a powerful free radical scavenger that has been tested against γ-irradiation-induced cellular damage in cultured human peripheral blood lymphocytes in studies of various diseases. Edaravone was pre-incubated with lymphocytes for 2 h prior to γ-irradiation. It was found that pretreatment with edaravone increased cell viability and inhibited generation of γ-radiation-induced reactive oxygen species (ROS) in lymphocytes exposed to 3 Gy γ-radiation. In addition, γ-radiation decreased antioxidant enzymatic activity, such as superoxide dismutase and glutathione peroxidase, as well as the level of reduced glutathione. Conversely, treatment with 100 μM edaravone prior to irradiation improved antioxidant enzyme activity and increased reduced glutathione levels in irradiated lymphocytes. Importantly, we also report that edaravone reduced γ-irradiation-induced apoptosis through downregulation of Bax, upregulation of Bcl-2, and consequent reduction of the Bax:Bcl-2 ratio. The current study shows edaravone to be an effective radioprotector against γ-irradiation-induced cellular damage in lymphocytes in vitro. Finally, edaravone pretreatment significantly reduced DNA damage in γ-irradiated lymphocytes, as measured by comet assay (% tail DNA, tail length, tail moment, and olive tail moment) (p edaravone offers protection from radiation-induced cytogenetic alterations.

  1. X-irradiation-induced emesis in Suncus murinus

    International Nuclear Information System (INIS)

    Torii, Yoshifumi; Saito, Hiroshi; Matsuki, Norio; Shikita, Mikio.

    1993-01-01

    X-irradiation-induced emesis was investigated in Suncus murinus, a house musk shrew. Whole body X-irradiation caused emesis, and the calculated ED 50 value that induced emesis in 50% of animals was 429 cGy. At the irradiation dose of 800 cGy all the animals vomited 10.0±2.4 times with a latency of 20.0±2.9 min. The emetogenic effect of X-irradiation was dependent on the part of the body exposed. Abdominal X-irradiation at 1000 cGy caused emesis in all animals studied, whereas the same dose to the head had no emetogenic effect. We investigated several prophylactic methods against X-irradiation-induced emesis. Surgical vagotomy completely inhibited the emesis induced by 800 cGy X-irradiation. Emesis was also prevented by the subcutaneous administration of tropisetron (ICS 205-930, a selective serotonergic 5-HT 3 receptor antagonist) with an ID 50 value of 29 μg/kg. These results suggest that (1) suncus is a useful experimental animal for the study of radiation-induced emesis and the development of prophylactic drugs, (2) serotonin plays an important role in X-irradiation-induced emesis, and (3) X-irradiation-induced emesis is very similar to that caused by cancer chemotherapeutic agents. (author)

  2. Irradiation creep due to SIPA-induced growth

    International Nuclear Information System (INIS)

    Woo, C.H.

    1980-01-01

    An additional contribution to irradiation creep resulting from the stress-induced preferred adsorption (SIPA) effect is described - SIPA-induced growth (SIG). The mechanism of SIG is discussed and an expression for its contribution to irradiation creep developed. It is shown that SIG is very significant in comparison with SIPA. Enhancement of creep by swelling may also occur. (U.K.)

  3. Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells

    International Nuclear Information System (INIS)

    Hino, Mizuki; Tajika, Yuki; Hamada, Nobuyuki

    2010-01-01

    Autophagy is one of the major processes involved in the degradation of intracellular materials. Here, we examined the potential impact of heavy ion irradiation on the induction of autophagy in irradiated C2C12 mouse myoblasts and their non-targeted bystander cells. In irradiated cells, ultrastructural analysis revealed the accumulation of autophagic structures at various stages of autophagy (id est (i.e.) phagophores, autophagosomes and autolysosomes) within 20 min after irradiation. Multivesicular bodies (MVBs) and autolysosomes containing MVBs (amphisomes) were also observed. Heavy ion irradiation increased the staining of microtubule-associated protein 1 light chain 3 and LysoTracker Red (LTR). Such enhanced staining was suppressed by an autophagy inhibitor 3-methyladenine. In addition to irradiated cells, bystander cells were also positive with LTR staining. Altogether, these results suggest that heavy ion irradiation induces autophagy not only in irradiated myoblasts but also in their bystander cells. (author)

  4. The improvement of corn starch isolation process by gamma irradiation

    International Nuclear Information System (INIS)

    Byun, M.W.; Kang, I.J.; Kwon, J.H.; Lee, S.J.; Kim, S.K.

    1995-01-01

    Gamma irradiation was applied to non-glutinous and glutinous corns for improving starch isolation process. No significant changes in proximate composition of corn grains were observed by gamma irradiation. Irradiation at 1 and 5 kGy was effective for sterilizing all contaminated microorganisms of non-glutinous and glutinous corns, respectively. The moisture-uptake rate constants were increased in proportional to the steeping temperature and applied irradiation dose level. The irradiation efficacy on water absorption properties was also recognized in the corns stored for six months at room temperature. The combined use of gamma irradiation with sulfur dioxide solution was very effective for reducing steeping time. The starch yield gradually increased as irradiation dose levels increased. At 2 kGy, the sarch yield of non-glutinous and glutinous corns increased by 38% and 27%, respectively. No significant difference in Hunter's color value was observed between the starches isolated from nonirradiated and irradiated corn grains

  5. Renal effects of renal x irradiation and induced autoallergic glomerulonephritis

    International Nuclear Information System (INIS)

    Rappaport, D.S.; Casarett, G.W.

    1979-01-01

    This study was conducted to determine what influence a single large x-ray exposure of kidney has on the development and course of an experimental autoallergic glomerulonephritis (EAG) in rats. EAG was induced in female Sprague-Dawley rats by immunization with Bordetella pertussis vaccine and homogenate of homologous kidney tissue and Freund's complete adjuvant. Progressive arteriolonephrosclerosis (ANS) was observed in right (irradiated) kidneys following unilateral renal irradiation (1500 rad). Rats were either immunized, sham-immunized, irradiated, sham-irradiated, or both immunized and irradiated. Light and immunofluorescent microscopic observation, urine protein content, and kidney weights were evaluated. In immunized-irradiated animals the effects of irradiation and immunization were largely additive. Immunization did not considerably influence the development and course of ANS and irradiation did not considerably influence the development and course of EAG

  6. An ESR study of radicals induced in irradiated fresh mango

    International Nuclear Information System (INIS)

    Kikuchi, Masahiro; Hussain, Mohammed S.; Morishita, Norio; Kobayashi, Yasuhiko; Ukai, Mitsuko; Shimoyama, Yuhei

    2009-01-01

    An electron spin resonance (ESR) spectroscopic study was performed on the radicals induced irradiated fresh mangoes. Fresh Philippine mangoes were irradiated by the γ-rays, lyophilized and powdered. The ESR spectrum of the dry specimen showed a strong main peak at g=2.004 and a pair of peaks at both magnetic fields of the main peak. The main peak detected from flesh and skin specimens faded away in a few days after the irradiation. On the other hand, the side peaks showed a well-defined dose response even 9 days after the irradiation. The side-peak is a useful mean to define the irradiation on fresh mangoes. (author)

  7. Improving Quality of Yoghurt By Irradiation

    International Nuclear Information System (INIS)

    Sallam, E.M.; Nasr, E.H.; Shawki, H.A.

    2012-01-01

    This investigation was carried out to study the possibility to utilize gamma irradiation to activate starter culture during incubation period and prolong the shelf-life of yoghurt. Starter culture of yoghurt was subjected to gamma irradiation with 10, 15, 20, 25, 30, 35, 40 and 45 Gy to activate the starter then yoghurt was made. Effect of irradiation dose on titratable acidity and the sensory evaluation of all samples were evaluated during incubation period. The obtained results indicated that the irradiation doses 30, 35 and 40 Gy activated the starter and caused significant decreased of incubation period from 4 h to 3.5 h while irradiation doses that less than 30 Gy and more than 40 Gy did not significantly effect. Yoghurt samples were subjected to gamma irradiation with 1.5, 2.5 and 3.5 kGy to prolong the shelf-life of yoghurt samples. The sensory, microbial and chemical properties of yoghurt samples were evaluated during cold storage. The obtained results indicated that the counts of total viable bacteria, molds and yeasts were decreased by applying gamma irradiation. Irradiation treatment caused significant decrease in acidity. The overall acceptability scores, total solid and ph value of all treatments were gradually decreased as the storage period proceeded while total nitrogen of all treatments was not affected. In addition, treatments of yoghurt with 1.5, 2.5 and 3.5 kGy prolonged the shelf-life to 20, 28 and 36 days as compared to 12 days for control treatment

  8. Irradiation-enhanced and-induced mass transport

    International Nuclear Information System (INIS)

    Rehn, L.E.

    1989-01-01

    Irradiation can be used to enhance diffusion, that is, to increase the rate at which equilibrium is attained, as well as to induce nonequilibrium changes. The main factors influencing whether irradiation will drive a material toward or away from equilibrium are the initial specimen microstructure and geometry, irradiation temperature, and primary recoil spectrum. This paper summarizes known effects of irradiation temperature and primary recoil spectrum on mass transport during irradiation. In comparison to either electron or heavy-ion irradiation, it is concluded that relatively low-energy, light-ion bombardment at intermediate temperatures offers the greatest potential to enhance the rate at which equilibrium is attained. The greatest departures from equilibrium can be expected from irradiation with similar particles at very low temperatures

  9. Irradiation creep induced anisotropy in a/2 dislocation populations

    International Nuclear Information System (INIS)

    Gelles, D.S.

    1984-05-01

    The contribution of anisotropy in Burgers vector distribution to irradiation creep behavior has been largely ignored in irradiation creep models. However, findings on Frank loops suggest that it may be very important. Procedures are defined to identify the orientations of a/2 Burgers vectors for dislocations in face-centered cubic crystals. By means of these procedures the anisotropy in Burgers vector populations was determined for three Nimonic PE16 pressurized tube specimens irradiated under stress. Considerable anisotropy in Burgers vector population develops during irradiation creep. It is inferred that dislocation motion during irradiation creep is restricted primarily to a climb of a/2 dislocations on 100 planes. Effect of these results on irradiation creep modeling and deformation induced irradiation growth is considered

  10. Bilateral streptococcal corneoscleritis complicating β irradiation induced scleral necrosis

    International Nuclear Information System (INIS)

    Moriarty, A.P.; Crawford, G.J.; McAllister, I.L.; Constable, I.J.

    1993-01-01

    Bacterial corneoscleritis may complicate scleral necrosis induced by β irradiation following pterygium removal. Previous cases have been unilateral. The authors report a case of severe bilateral corneoscleritis caused by Streptococcus pneumoniae. (author)

  11. Pathogenesis of irradiation-induced cognitive dysfunction

    International Nuclear Information System (INIS)

    Abayomi, O.K.

    1996-01-01

    Neurocognitive dysfunction is a common sequela of cranial irradiation that is especially severe in young children. The underlying mechanisms of this disorder have not been described. The present review describes the role of the hippocampus and the anatomically related cortex in memory function and its marked susceptibility to ischemic and hypoxic injury. Based on studies of animal models of human amnesia and histopathological findings in the irradiated brain, the neurocognitive sequela of cranial irradiation can be seen to be mediated through vascular injury, resulting in ischemia and hypoxia in the hippocampal region. Recognition of the site and mechanisms of this injury may lead to the development of techniques to minimize the risks. (orig.)

  12. Pathogenesis of irradiation-induced cognitive dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Abayomi, O.K. [Howard Univ. Hospital, Washington, DC (United States). Dept. of Radiation Oncology

    1996-12-31

    Neurocognitive dysfunction is a common sequela of cranial irradiation that is especially severe in young children. The underlying mechanisms of this disorder have not been described. The present review describes the role of the hippocampus and the anatomically related cortex in memory function and its marked susceptibility to ischemic and hypoxic injury. Based on studies of animal models of human amnesia and histopathological findings in the irradiated brain, the neurocognitive sequela of cranial irradiation can be seen to be mediated through vascular injury, resulting in ischemia and hypoxia in the hippocampal region. Recognition of the site and mechanisms of this injury may lead to the development of techniques to minimize the risks. (orig.).

  13. A case of dysphagia induced by irradiation to the neck

    International Nuclear Information System (INIS)

    Ito, Hiroyuki; Kubota, Akira; Moriyama, Hiroshi.

    1995-01-01

    This report deals with a case of dysphagia induced by the irradiation of a malignant lymphoma of the neck. The patient was a 55-year-old male with dysphagia who had undergone irradiation to the neck for a malignant lymphoma ten years previously. The dysphagia that had gradually worsened in ten years made him enable to eat and drink orally. He often contracted by pneumonia. On first examination, atrophic changes were observed in the soft palates, and the epiglottis, and the improvement of the tongue was bilaterally impaired. These findings were diagnosed as the causes of the dysphagia. A barium study showed that the movement of the tongue and the pharynx were impaired. The barium was aspirated. A plain X-ray film of the mandible showed ostitis. The impairment of the tongue movement was due to bilateral hypopharyngeal nerve palsies induced by the irradiation. Laryngeal suspension and cricopharyngeal myotomy were not suitable because they could have aggravated the radiation necrosis of the thyroid cartilage which will be expected in the future. A total laryngectomy, which sacrifies the phonation, was out of the question, because the patient's dysarthria was not so hard to understand. He was instructed in the self-insertion of a feeding tube to get enough nutrition, the physical therapy of the lung with the aid of his wife to prevent aspiration pneumonia. The loss of phonation lowers the QOL of such patients. In the cases with dysphagia which do not recover with surgical treatments, rehabilitation should mainly stress the conservation of phonation and the prevention of pneumonia to maintain the higher QOL of patients. (author)

  14. Polymerization of sodium methacrylate induced by irradiation

    International Nuclear Information System (INIS)

    Galvan S, A.

    1998-01-01

    This work has two objectives, first: it is pretended to localize the lines of carbon links in its IR spectra, and second: following the polymerization of sodium methacrylate according to that it is irradiated with gamma rays. (Author)

  15. Structural changes induced by electron irradiation

    International Nuclear Information System (INIS)

    Koike, J.; Pedraza, D.F.

    1993-01-01

    Highly oriented pyrolytic graphite was irradiated at room temperature with 300 kV electrons. Transmission electron microscopy and electron energy loss spectroscopy were employed to study the structural changes produced by irradiation. The occurrence of a continuous ring intensity in the selected area diffraction (SAD) pattern obtained on a specimen irradiated with the electron beam parallel to the c-crystallographic axis indicated that microstructural changes had occurred. However, from the SAD pattern obtained for the specimens tilted relative to the irradiation direction, it was found that up to a fluence of 1.1x10 27 e/m 2 graphite remained crystalline. An SAD pattern of a specimen irradiated with the electron beam perpendicular to the c-axis confirmed the persistence of crystalline order. High resolution electron microscopy showed that ordering along the c-axis direction remained. A density reduction of 8.9% due to irradiation was determined from the plasmon frequency shift. A qualitative model is proposed to explain these observations. A new determination of the threshold displacement energy, Ed, of carbon atoms in graphite was done by examining the appearance of a continuous ring in the SAD pattern at various electron energies. A value of 30 eV was obtained whether the incident electron beam was parallel or perpendicular to the c-axis, demonstrating that Ed is independent of the displacement direction

  16. Renal effects of renal x irradiation and induced autoallergic glomerulonephritis

    International Nuclear Information System (INIS)

    Rappaport, D.S.

    1977-01-01

    This study was conducted to determine what, if any, influence a single large x-ray exposure of kidney has on the development and course of an experimental autoallergic glomerulonephritis (EAG) in rats. The EAG was induced by immunization with B. pertussis vaccine and homogenate of homologous kidney tissue and Freund's complete adjuvant. Rats were either immunized, sham-immunized, irradiated (1500 R to right kidney temporarily exteriorized), sham-irradiated, or both immunized and irradiated. Immunized-irradiated animals were irradiated either 4 or 2 weeks prior to, concurrently with, or 1 or 2 weeks after immunization, and were sacrificed at 2, 4, 6, 10, or 14 weeks post-immunization. Immunized-only and sham-immunized-only animals were sacrificed at corresponding post-immunization times, and irradiated-only and sham-irradiated-only animals were sacrificed at corresponding post-irradiation times. Progressive arteriolonephrosclerosis (ANA) was observed in right (irradiated) kidneys following x irradiation. The experimental autoallergic glomerulonephritis (EAG) was observed in both kidneys following immunization. The histopathological changes associated with EAG were distinct from those associated with ANS

  17. Electron irradiation-induced defects in {beta}-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Oshima, Ryuichiro [Osaka Prefectural Univ., Sakai (Japan). Reseach Inst. for Advanced Science and Technology

    1996-04-01

    To add information of point defects in cubic crystal SiC, polycrystal {beta}-SiC on the market was used as sample and irradiated by neutron and electron. In situ observation of neutron and electron irradiation-induced defects in {beta}-SiC were carried out by ultra high-voltage electronic microscope (UHVEM) and ordinary electronic microscope. The obtained results show that the electron irradiation-induced secondary defects are micro defects less than 20 nm at about 1273K, the density of defects is from 2x10{sup 17} to 1x10{sup 18}/cc, the secondary defects may be hole type at high temperature and the preexistant defects control nuclear formation of irradiation-induced defects, effective sink. (S.Y.)

  18. Estimation of γ irradiation induced genetic damage by Ames test

    International Nuclear Information System (INIS)

    Hosoda, Eiko

    1999-01-01

    Mutation by 60 Co γ irradiation was studied in five different histidine-requiring auxotrophs of Salmonella typhimurium. The strains TA98 (sensitive to frameshift) and TA100 (sensitive to base-pair substitution) were irradiated (10-84 Gy and 45-317 Gy, respectively) and revertants were counted. TA98 exhibited radiation-induced revertants, 2.8 fold of spontaneous revertants, although no significant increase was detected in TA100. Then, three other frameshift-sensitive strains TA1537, TA1538 and TA94 were irradiated in a dose of 61-167 Gy. Only in TA94, revertants increased 3.5 fold. Since spontaneous revertants are known to be independent of cell density, a decrease of bacterial number by γ irradiation was confirmed not to affect the induced revertants by dilution test. Thus the standard Ames Salmonella assay identified γ irradiation was confirmed not to affect the induced revertants by dilution test. Thus the standard Ames Salmonella assay identified γ irradiation as a mutagenetic agent. The mutagenicity of dinitropyrene, a mutagen widely existing in food, and dismutagenicity of boiling water insoluble fraction of Hizikia fusiforme, edible marine alga, were tested on γ induced revertant formation in TA98 and TA94. Dinitropyrene synergistically increased γ induced revertants and Hizikia insoluble fraction reduced the synergistic effect of dinitropyrene dependently on the concentration. (author)

  19. Survivin and chromosome instability induced by X-irradiation

    International Nuclear Information System (INIS)

    Shen Bo; Ju Guizhi; Liu Yang

    2006-01-01

    Objective: To explore the biological effect of survivin on chromosome instability induced by X-ray irradiation. Methods: Immunocytochemistry was used to detect the expression of sutvivin in HeLa cells. Carrier pSUPER-SVV was transfected into HeLa cells to interfere the expression of survivin. Flow cytometry assay was applied to detect the occurrence of polyploid at 0 h, 4 h, 12 h, and 48 h after the HeLa cells transfected with pSUPER-SVV and irradiated with 4 Gy X-rays irradiation, and compared with the group irradiated with 4 Gy X-rays but no transfection. Results: The expression of survivin was down-regulated by transfecting with small hair RNA, its depression rate was estimated to be about 32.16% at 48 h after transfection. The occurrence of polyploid giant cells was higher in the 4 Gy X-ray irradiated group at 48 h after the irradiation than the control groups (P<0.001). Being expression of survivin interfered, the occurrence at 12 h or 48 h after irradiation, however, was about two times higher than that in the control group. Conclusion: X-ray irradiation can induce chromosome instability in HeLa cells and the effect could be enhanced by interfering the expression of surviving. It was suggested that survivin plays an important role in maintaining the stability of chromosome. (authors)

  20. Irradiation strongly reduces tumorigenesis of human induced pluripotent stem cells

    International Nuclear Information System (INIS)

    Inui, Shoki; Minami, Kazumasa; Ito, Emiko; Imaizumi, Hiromasa; Mori, Seiji; Koizumi, Masahiko; Fukushima, Satsuki; Miyagawa, Shigeru; Sawa, Yoshiki; Matsuura, Nariaki

    2017-01-01

    Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Since the main purpose of this study was to explore the prevention of tumor formation in human iPS (hiPS) cells, we tested the effects of irradiation on tumor-associated factors such as radiosensitivity, pluripotency and cell death in hiPS cells. The irradiated hiPS cells showed much higher radiosensitivity, because the survival fraction of hiPS cells irradiated with 2 Gy was < 10%, and there was no change of pluripotency. Irradiation with 2 and 4 Gy caused substantial cell death, which was mostly the result of apoptosis. Irradiation with 2 Gy was detrimental enough to cause loss of proliferation capability and trigger substantial cell death in vitro. The hiPS cells irradiated with 2 Gy were injected into NOG mice (NOD/Shi-scid, IL-2 Rγnull) for the analysis of tumor formation. The group of mice into which hiPS cells irradiated with 2 Gy was transplanted showed significant suppression of tumor formation in comparison with that of the group into which non-irradiated hiPS cells were transplanted. It can be presumed that this diminished rate of tumor formation was due to loss of proliferation and cell death caused by irradiation. Our findings suggest that tumor formation following cell therapy or organ transplantation induced by hiPS cells may be prevented by irradiation.

  1. DNA damage induced by radionuclide internal irradiation

    International Nuclear Information System (INIS)

    Cui Fengmei; Zhao Jingyong; Hong Chengjiao; Lao Qinhua; Wang Liuyi; Yang Shuqin

    2004-01-01

    Objective: To study the DNA damage of peripheral blood mononuclear cell (PBMC) in rats exposed to radionuclide internal irradiation. Methods: The radionuclides were injected into the rats and single cell get electrophoresis (SCGE) was performed to detect the length of DNA migration in the rat PBMC. Results: DNA migration in the rat PBMC increased with accumulative dose or dose-rate. It showed good relationship of dose vs. response and of dose-rate vs. response, both relationship could be described as linear models. Conclusion: Radionuclide internal irradiation could cause DNA damage in rat PBMC. (authors)

  2. Strain Improvement of Fungi by Induced Mutation through Gamma Irradiation and Selection for Animal Feed Enzymes Production and its Fermentation Process

    International Nuclear Information System (INIS)

    Konsue, Parichart; Piadang, Nattayana; Kitpreechavanich, Vichien

    2006-09-01

    Ten from eighty-nine strains of thermophilic fungi Thermomyces lanuginosus produced high level insoluble xylan degrading enzyme when cultured in submerge condition using untreated corncob as a substrate. Strain of T. lanuginosus THKU56 produced high level of insoluble xylan degrading enzyme with the most stable which was remained 28.2 and 58.9 % after treated at pH 3.5 and 70 o C for 1 h, respectively. To improve xylanase production, the strain was subjected to mutate using gamma ray at 0.4 - 1.6 kGy. The result showed the mutant strains produced insoluble xylanase activity lesser than wild type. Thus wild type strain THKU56 was then selected as potent strains for enzyme production and medium optimization was investigated using a central composite design. The four components, corncobs, yeast extract, KH 2 PO 4 and Tween 8 0, were parameters of this study. It was found that corncobs and yeast extract were discovered to affect on the xylanase production. The optimal concentration of the active nutrients for xylanase production were 41 g/l of corncobs and 24 g/l of yeast extract, which gave a predicted yield of 526.7 units/ml after 5 days culture at a temperature of 50 o C. The xylanase activity obtained from the experiment was 541 units/ml that was close to the predicted value

  3. Pregnancy complicating irradiation-induced constrictive pericarditis

    Energy Technology Data Exchange (ETDEWEB)

    Bakri, Younes N.; Martan, Ahmed; Amri, Aladin (King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Obstetrics and Gynecology); Amri, M. (King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Cardiovascular Diseases)

    1992-01-01

    A case is reported of a 24 year-old primigravida who had severe effusive constrictive pericarditis secondary to mediastinal irradiation following chemotherapy for Hodgkins disease. Pregnancy was threatened by serious maternal cardiovascular complications and a non-viable fetus was born spontaneously and prematurely. Patient was completely asymptomatic before pregnancy. (au).

  4. Characterization of irradiation induced deep and shallow impurities

    Science.gov (United States)

    Treberspurg, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Krammer, Manfred; Valentan, Manfred

    2013-12-01

    Silicon Detectors close to the interaction point of the High Luminosity Large Hardron Collider (HL-LHC) have to withstand a harsh irradiation environment. In order to evaluate the behaviour of shallow and deep defects, induced by neutron irradiation, spreading resistance resistivity measurements and capacitance voltage measurements have been performed. These measurements, deliver information about the profile of shallow impurities after irradiation as well as indications of deep defects in the Space Charge Region (SCR) and the Electrical Neutral Bulk (ENB). By considering the theoretical background of the measurement both kinds of defects can be investigated independently from each other.

  5. Characterization of irradiation induced deep and shallow impurities

    Energy Technology Data Exchange (ETDEWEB)

    Treberspurg, Wolfgang, E-mail: wolfgang.treberspurg@oeaw.ac.at; Bergauer, Thomas; Dragicevic, Marko; Krammer, Manfred; Valentan, Manfred

    2013-12-21

    Silicon Detectors close to the interaction point of the High Luminosity Large Hardron Collider (HL-LHC) have to withstand a harsh irradiation environment. In order to evaluate the behaviour of shallow and deep defects, induced by neutron irradiation, spreading resistance resistivity measurements and capacitance voltage measurements have been performed. These measurements, deliver information about the profile of shallow impurities after irradiation as well as indications of deep defects in the Space Charge Region (SCR) and the Electrical Neutral Bulk (ENB). By considering the theoretical background of the measurement both kinds of defects can be investigated independently from each other.

  6. Characterization of irradiation induced deep and shallow impurities

    International Nuclear Information System (INIS)

    Treberspurg, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Krammer, Manfred; Valentan, Manfred

    2013-01-01

    Silicon Detectors close to the interaction point of the High Luminosity Large Hardron Collider (HL-LHC) have to withstand a harsh irradiation environment. In order to evaluate the behaviour of shallow and deep defects, induced by neutron irradiation, spreading resistance resistivity measurements and capacitance voltage measurements have been performed. These measurements, deliver information about the profile of shallow impurities after irradiation as well as indications of deep defects in the Space Charge Region (SCR) and the Electrical Neutral Bulk (ENB). By considering the theoretical background of the measurement both kinds of defects can be investigated independently from each other

  7. Improvement and utilization of irradiation capsule technology in HANARO

    International Nuclear Information System (INIS)

    Choo, Kee-Nam; Cho, Man-Soon; Kim, Bong-Goo; Lee, Cheol-Yong; Yang, Sung-Woo; Shin, Yoon-Taek; Park, Seng-Jae; Jung, Hoan-Sung

    2012-01-01

    Several improvements of irradiation capsule technology regarding irradiation test parameters, such as temperature and neutron flux/fluence, and regarding instrumentation have progressed at HANARO since the last KAERI-JAERI joint seminar held in 2008. The standard HANARO capsule technology that was developed for use in a commercial power plant temperature of about 300degC was improved to apply to a temperature range of 100-1000degC for the irradiation test of materials of new research reactors and future nuclear systems. Low-flux and long-term irradiation technologies have been developed at HANARO. As a beginning step of the localization of capsule instrumentation technology, the irradiation performance of a domestically produced thermocouple and LVDT will be examined at HANARO. The accuracy of an evaluation of neutron fluence and precise welding technology are also being examined at HANARO. Based on these accumulated capsule technologies, a HANARO irradiation capsule system is being actively utilized for the national R and D programme on commercial nuclear reactors and nuclear fuel cycle technology in Korea. HANARO has recently started the irradiation support of R and D relevant to future nuclear systems including SMART, VHTR, and SFR, and HANARO is preparing new support relevant to new research and Fusion reactors. (author)

  8. Neutron irradiation induced amorphization of silicon carbide

    International Nuclear Information System (INIS)

    Snead, L.L.; Hay, J.C.

    1998-01-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 x 10 25 n/m 2 . Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (-10.8%), elastic modulus as measured using a nanoindentation technique (-45%), hardness as measured by nanoindentation (-45%), and standard Vickers hardness (-24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C

  9. Effect of irradiation on analgesia induced by morphine and endorphin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Lee, Byoung Hun; Hyun, Soung Hee; Chung, Ki Myung [KAERI, Daejeon (Korea, Republic of)

    2003-07-01

    Morphine and endorphin administered intracerebroventricularly (i.c.v.) produce analgesia by activating different descending pain inhibitory systems. Gamma irradiation attenuates the acute analgesic action of i.c.v. injected morphine in mice. This study was done to investigate the effect of-irradiation on the analgesia produced by i.c.v. injected morphine and endorphin in male ICR mice. In one group, mice were exposed to whole-body irradiation at a dose of 5 Gy from a {sup 60}Co source and the analgesic effects were tested 5, 30, 60, 90 and 180 min after irradiation using the acetic acid-induced writhing test. The analgesic effect was produced time-dependently and reached its maximum at 90 min after irradiation. Thus, time was fixed in the following studies. In another group, mice were irradiated with 5 Gy and tested 90 minutes later for analgesia produced by i.c.v. administration of morphine or endorphin. Irradiation significantly potentiated the analgesia produced by endorphin. However, the antinociception produced by morphine was not affected by irradiation. These results support the hypothesis that morphine and endorphin administered supraspinally produce antinocieception by different neuronal mechanisms.

  10. Effect of irradiation on analgesia induced by morphine and endorphin

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Lee, Byoung Hun; Hyun, Soung Hee; Chung, Ki Myung

    2003-01-01

    Morphine and endorphin administered intracerebroventricularly (i.c.v.) produce analgesia by activating different descending pain inhibitory systems. Gamma irradiation attenuates the acute analgesic action of i.c.v. injected morphine in mice. This study was done to investigate the effect of-irradiation on the analgesia produced by i.c.v. injected morphine and endorphin in male ICR mice. In one group, mice were exposed to whole-body irradiation at a dose of 5 Gy from a 60 Co source and the analgesic effects were tested 5, 30, 60, 90 and 180 min after irradiation using the acetic acid-induced writhing test. The analgesic effect was produced time-dependently and reached its maximum at 90 min after irradiation. Thus, time was fixed in the following studies. In another group, mice were irradiated with 5 Gy and tested 90 minutes later for analgesia produced by i.c.v. administration of morphine or endorphin. Irradiation significantly potentiated the analgesia produced by endorphin. However, the antinociception produced by morphine was not affected by irradiation. These results support the hypothesis that morphine and endorphin administered supraspinally produce antinocieception by different neuronal mechanisms

  11. Radiation-induced aperiodicity in irradiated ceramics

    International Nuclear Information System (INIS)

    Hobbs, L.W.

    1993-02-01

    The experimental program is designed to reveal details of the metamict (amorphization, or crystal-to-glass) transformation in irradiated ceramics (silica compounds, less-connected lead phosphates). The silica compounds were amorphized using electrons, neutrons, and ions, while the phosphates were amorphized using ions (primarily) and neutrons. Energy-filtered electron microdiffraction, high-resoltuion transmission electron microscopy, and high-performance liquid-phase chromatography are being used

  12. Residual stress improvement mechanism on metal material by underwater laser irradiation

    International Nuclear Information System (INIS)

    Sano, Yuji; Yoda, Masaki; Mukai, Naruhiko; Obata, Minoru; Kanno, Masanori

    2000-01-01

    Residual stress improvement technology for component surface by underwater pulsed laser irradiation has been developed as a method of preventing stress corrosion cracking (SCC) of core components in nuclear reactors. In order to optimize the laser irradiation conditions based on a complete understanding of the mechanism, the propagation of a shock wave induced by the impulse of laser irradiation and the dynamic response of the irradiated material were analyzed through time-dependent elasto-plastic calculations with a finite element program. The calculated results are compared with the measured results obtained by experiments in which laser pulses with an energy of 200 mJ are focused to a diameter of 0.8 mm on a water-immersed test piece of 20% cold-worked Type 304 austenitic stainless steel to simulate neutron irradiation hardening. A residual compressive stress, which is nearly equivalent to the yield stress of the processed material, remains on the material surface after passage of the shock wave with enough amplitude to induce a permanent strain. Multiple irradiation of laser pulses extends the stress-improved depth to about 1 mm, which would be the limit corresponding to the three-dimensional dispersion effect of the shock wave. (author)

  13. Radiation-induced cancer of the esophagus after postoperative irradiation for breast cancer

    International Nuclear Information System (INIS)

    Ito, Ichiro; Miyaishi, Kazuo; Mitsuhashi, Norio; Ito, Jun; Inoue, Tomio

    1978-01-01

    Two cases of radiation-induced cancer of the esophagus after postoperative irradiation for breast cancer were reported. Latent period of case 1 (cervical esophagus) was 12 years, and case 2 (middle thoracic esophagus) was 16 years. Radiographically the lesions were both serrated, and histologically, case 1 was ''poorly differentiated'' and case 2 was ''moderately differentiated'' squamous cell carcinoma. Histological types of basic breast cancer were both papillotubular carcinomas. Previous irradiation doses were 4180 rads for case 1 and 1860 rads for case 2. The esophageal cancers were remarkably improved by radiation therapy. It should be emphasized that radiation therapy is useful for the radiation-induced cancer of the esophagus. (author)

  14. Study of irradiation induced defects in silicon

    International Nuclear Information System (INIS)

    Pal, Gayatri; Sebastian, K.C.; Somayajulu, D.R.S.; Chintalapudi, S.N.

    2000-01-01

    Pure high resistivity (6000 ohm-cm) silicon wafers were recoil implanted with 1.8 MeV 111 In ions. As-irradiated wafers showed a 13 MHz quadrupole interaction frequency, which was not observed earlier. The annealing behaviour of these defects in the implanted wafers was studied between room temperature and 1073 K. At different annealing temperatures two more interaction frequencies corresponding to defect complexes D2 and D3 are observed. Even though the experimental conditions were different, these are identical to the earlier reported ones. Based on an empirical point charge model calculation, an attempt is made to identify the configuration of these defect complexes. (author)

  15. Gamma irradiation induced variabilities in Canavalia virosa

    International Nuclear Information System (INIS)

    Rodrigues, B.F.

    1993-01-01

    Dry seeds of Canavalia virosa were treated with seven different doses viz., 4,8,12,16,24,32 and 36 Krad of gamma irradiation. Percent germination increased in 4 and 8 Krad treatment, while, a gradual decrease was observed from 12 to 32 Krad treatments. Seedling measurements taken at the end of 15 days showed increase in 4 and 8 Krad over control, while 12 to 32 Krad treatments showed gradual decrease, plants treated with 4 Krad showed maximum survival percentage at maturity, while a gradual decrease was observed in 12 to 32 Krad treated plants. The treatment of 36 Krad was lethal. (author). 6 refs., 2 tabs

  16. Irradiation induced crystalline to amorphous transition

    International Nuclear Information System (INIS)

    Bourgoin, J.

    1980-01-01

    Irradiation of a crystalline solid with energetic heavy particles results in cascades of defects which, with increasing dose, overlap and form a continuous disordered layer. In semiconductors the physical properties of such disordered layers are found to be similar to those of amorphous layers produced by evaporation. It is shown in the case of silicon, that the transition from a disordered crystalline (X) layer to an amorphous (α) layer occurs when the Gibbs energy of the X phase and of the defects it contains becomes larger than the Gibbs energy of the α phase. (author)

  17. Improvement in properties of plastic teeth by electron beam irradiation

    International Nuclear Information System (INIS)

    Sano, Yuko; Ishikawa, Shun-ichi; Seguchi, Tadao

    2011-01-01

    Improvement of the comfort and esthetics of artificial plastic teeth is desirable for the recently increasing numbers of elderly in society. Plastic teeth made of polycarbonate (PC) were modified by electron beam (EB) irradiation under specific conditions, and the change in the chemical properties of the PC was investigated. The water absorption, glucose attachment, level of bis-phenol-A (BPA) extraction, maltose adhesion, and mucin adhesion on the PC teeth were measured before and after EB irradiation. EB irradiation to a dose of 3.5 kGy at 150 o C in a nitrogen gas atmosphere reduced the water absorption by 20%, glucose absorption by 40%, maltose adhesion by 20%, and the amount of various amino acids, formed as the hydrolysis products of mucin, adhering on the PC teeth were reduced by 60-99%. The BPA content was lower than the detection limit for analysis of both the original and the EB irradiated PC teeth. - Highlights: → Radiation improvement of polycarbonate for plastic teeth by EB irradiation 3.5 kGy at 150 o C in inert gas. → Water and glucose absorption and maltose adhesion on PC teeth were much reduced. → Bis-phenol-A content from PC teeth was lower than the detection limit after irradiation.

  18. A history of study on safety of irradiated foods (3). Induced radioactivity in irradiated foods

    International Nuclear Information System (INIS)

    Miyahara, Makoto

    2006-01-01

    Food irradiation can induce a small amount of radioactivity in the foods. The principal mechanisms of the nuclear reactions are (n, γ), (γ, n), (γ, γ'). The resulting nuclear products were found in irradiated foods were Na-24, P-32, Ca-45, C-11, N-13, and O-15 in the food irradiated by 24 MeV electron beam. The total radioactivity is less than 1/1000 of those of K-40 in the case of electron beams below 10 MeV or X rays below 5 MeV. Package materials affected neutron flux in the foods and enhanced the radioactivity. Electron beam machine produces neutrons and increases the flux in food. IAEA recommend to reduce neutron production in the facility. The safety of irradiated food in the radioactivity field still needs more progress. (author)

  19. Improvement in the textural qualities of irradiated legumes

    International Nuclear Information System (INIS)

    Nene, S.P.; Vakil, U.K.; Sreenivasan, A.

    1975-01-01

    The potential for use of gamma radiation processing to improve texture, hydration and cooking quality of pulses, particularly red gram, has been examined. The textural changes in irradiated pulses in terms of softening is measured by a texturometer, Radiation (1 Mrad) processing of pulses resulted in reduction of cooking time varying from 8 to 39%, red gram showing the maximum reduction. Initial higher hydration rate on soaking and cooking, stabilized on prolonged cooking and resulted in better and uniform texture of irradiated red gram. In the uncooked, irradiated (1 Mrad) sample, destruction of riboflavin was negligible, whereas thiamine and niacin showed about 7% loss. However, the vitamins were retained better in the samples irradiated and then cooked, compared to the corresponding control ones. (F.J.)

  20. Improvement in the textural qualities of irradiated legumes

    Energy Technology Data Exchange (ETDEWEB)

    Nene, S P; Vakil, U K; Sreenivasan, A [Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.

    1975-01-01

    The potential for use of gamma radiation processing to improve texture, hydration and cooking quality of pulses, particularly red gram, has been examined. The textural changes in irradiated pulses in terms of softening is measured by a texturometer, Radiation (1 Mrad) processing of pulses resulted in reduction of cooking time varying from 8 to 39%, red gram showing the maximum reduction. Initial higher hydration rate on soaking and cooking, stabilized on prolonged cooking and resulted in better and uniform texture of irradiated red gram. In the uncooked, irradiated (1 Mrad) sample, destruction of riboflavin was negligible, whereas thiamine and niacin showed about 7% loss. However, the vitamins were retained better in the samples irradiated and then cooked, compared to the corresponding control ones.

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

    CERN Document Server

    Daum, E

    2000-01-01

    The accelerator-based intense D-Li neutron source International Fusion Materials Irradiation Facility (IFMIF) provides very suitable irradiation conditions for fusion materials development with the attractive option of accelerated irradiations. Investigations show that a neutron moderator made of tungsten and placed in the IFMIF test cell can further improve the irradiation conditions. The moderator softens the IFMIF neutron spectrum by enhancing the fraction of low energy neutrons. For displacement damage, the ratio of point defects to cascades is more DEMO relevant and for tritium production in Li-based breeding ceramic materials it leads to a preferred production via the sup 6 Li(n,t) sup 4 He channel as it occurs in a DEMO breeding blanket.

  2. Branch formation induced by microbeam irradiation of Adiantum protonemata

    International Nuclear Information System (INIS)

    Wada, M.

    1998-01-01

    Branches were induced in centrifuged Adiantum protonemal cells by partial irradiation with polarized red light. Nuclear behavior and microtubule pattern change during branch formation were investigated. A branch formed at any part where a red microbeam was focused along a long apical cell. The nucleus moved towards the irradiated area and remained there until a branch developed. The pattern of microtubules changed from parallel to oblique at the irradiated area and then a transverse arrangement of microtubules appeared on both sides of the area. It appeared as if the nucleus was suspended between two microtubule rings. This nuclear behavior and the changes in microtubule pattern were different from those observed during branch formation under whole cell irradiation. From the results of this work we suggest that there is an importance for precise control of experimental conditions

  3. Electron irradiation induced nanocrystal formation in Cu-borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Sabri, Mohammed Mohammed; Möbus, Günter, E-mail: g.moebus@sheffield.ac.uk [University of Sheffield, Department of Materials Science and Engineering (United Kingdom)

    2016-03-15

    Nanoscale writing of Cu nanoparticles in glasses is introduced using focused electron irradiation by transmission electron microscopy. Two types of copper borosilicate glasses, one with high and another with low Cu loading, have been tested at energies of 200–300 keV, and formation of Cu nanoparticles in a variety of shapes and sizes using different irradiation conditions is achieved. Electron energy loss spectroscopy analysis, combined with high-resolution transmission electron microscopy imaging, confirmed the irradiation-induced precipitated nanoparticles as metallic, while furnace annealing of the glass triggered dendrite-shaped particles of copper oxide. Unusual patterns of nanoparticle rings and chains under focused electron beam irradiation are also presented. Conclusively, electron beam patterning of Cu-loaded glasses is a promising alternative route to well-established femtosecond laser photoreduction of Cu ions in glass.

  4. Irradiation of Ananas comosus: shelf life improvement, nutritional quality and assessment of genotoxicity

    International Nuclear Information System (INIS)

    Susheela, K.; Damayanti, M.; Sharma, G.J.

    1997-01-01

    The effect of gamma radiation in improving the shelf life of three-quarter ripe and fully ripe pineapple fruit by reducing the incidence of fungal infection, predominantly caused by Ceratocystis paradoxa, is described. Ananas comosus irradiated at 50, 100 and 150 Gy and stored at 25-29°C with 90-97% relative humidity maintained their texture better than the controls. The maximum tolerable dose was about 250 Gy. There was, no significant loss of sugar and ascorbic acid contents in fruit irradiated at the optimum dose, i.e. 150 Gy. At the same time, the irradiated pineapple fruit (250 Gy) did not induce any harmful genotoxic effect on rats fed daily with the irradiated pineapples for 30 days

  5. The protective effect of Sambucus ebulus against lung toxicity induced by gamma irradiation in mice

    Directory of Open Access Journals (Sweden)

    Mohammad Karami

    2015-01-01

    Full Text Available The aim of present study was to investigate the potential antioxidant and lung protective activities of Sambucus ebulus (SE against toxicity induced by gamma irradiation. Hydroalcoholic extract of SE (20, 50 and 100 mg/kg was studied for its lung protective activity. Phenol and flavonoid contents of SE were determined. Male C57 mice were divided into ten groups with five mice per group. Only the first and second groups (as negative control received intraperitoneally normal saline fluid. Groups 3 to 5 received only SE extract at doses of 20 mg/kg, 50 mg/kg and 100 mg/kg intraperitoneally; three groups were repeatedly injected for 15 days as chronic group. Groups 6 to 8 received a single-dose of gamma irradiation just 2 hours before irradiation as acute group. The ninth and tenth groups (as positive control received only gamma rays. Animal was exposed whole-body to 6 Gy gamma radiation. After irradiation, tissue sections of lung parenchyma were examined by light microscope for any histopathologic changes. SE at doses 50 and 100 mg/kg improved markedly histopathological changes induced by gamma irradiation in lung. Lung protective effect of SE could be due to attention of lipid peroxidation. Our study demonstrated that SE as a natural product has a protective effect against lung toxicity induced by   gamma irradiation in animal.

  6. Irradiation spectrum and ionization-induced diffusion effects in ceramics

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-08-01

    There are two main components to the irradiation spectrum which need to be considered in radiation effects studies on nonmetals, namely the primary knock-on atom energy spectrum and ionizing radiation. The published low-temperature studies on Al{sub 2}O{sub 3} and MgO suggest that the defect production is nearly independent of the average primary knock-on atom energy, in sharp contrast to the situation for metals. On the other hand, ionizing radiation has been shown to exert a pronounced influence on the microstructural evolution of both semiconductors and insulators under certain conditions. Recent work on the microstructure of ion-irradiated ceramics is summarized, which provides evidence for significant ionization-induced diffusion. Polycrystalline samples of MgO, Al{sub 2}O{sub 3}, and MgAl{sub 2}O{sub 4} were irradiated with various ions ranging from 1 MeV H{sup +} to 4 MeV Zr{sup +} ions at temperatures between 25 and 650{degrees}C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructural of the irradiated specimens. Dislocation loop nucleation was effectively suppressed in specimens irradiated with light ions, whereas the growth rate of dislocation loops was enhanced. The sensitivity to irradiation spectrum is attributed to ionization-induced diffusion. The interstitial migration energies in MgAl{sub 2}O{sub 4} and Al{sub 2}O{sub 3} are estimated to be {le}0.4 eV and {le}0.8 eV, respectively for irradiation conditions where ionization-induced diffusion effects are expected to be negligible.

  7. Irradiation deformation due to SIPA induced dislocation anisotropy

    International Nuclear Information System (INIS)

    Woo, CH.

    1980-02-01

    A contribution to irradiation deformation resulting from the stress-induced preferred adsorption (SIPA) effect is considered. SIPA causes a variation of the growth rates of irradiation-generated dislocation loops, according to the alignment of their Burgers vectors with respect to the applied stress. A prolinged period under an applied stress then creates an anisotropic dislocation structure in which the majority of dislocations have their Burgers vectors in alignment with the stress. In the presence of 'neutral' sinks, the resulting anisotropic dislocation structure causes plastic deformation similar to the way in which irradiation growth occurs in zirconium. This mechanism is called SIPA-induced growth (SIG). We have shown that SIG is very significant in comparison to SIPA, except when little or no loop growth has occurred during the period the stress is applied. This report contains the detailed formulation and derivation of the formulae for the evaluation of the contribution due to SIG. (auth)

  8. Irradiation-induced stress relaxation of Eurofer97 steel

    International Nuclear Information System (INIS)

    Luzginova, N.V.; Jong, M.; Rensman, J.W.; Hegeman, J.B.J.; Laan, J.G. van der

    2011-01-01

    The irradiation-induced stress relaxation behavior of Eurofer97 at 300 deg. C up to 3.4 dpa and under pre-stress loads typical for the ITER applications is investigated. The bolt specimens are pre-loaded from 30% to 90% of the yield strength. To verify the results obtained with the pre-stressed bolts, bent strips were investigated as well. The strips are bent into a pre-defined radius in order to achieve similar pre-stress levels. The irradiation-induced stress relaxation is found to be independent of the pre-stress level. 10-12% of the stress relaxation in Eurofer97 may be reached after a dose of 0.1 dpa, and after an irradiation dose of 2.7 dpa 42-47% of the original pre-stress is retained.

  9. Irradiation-induced tumours of the head and neck

    Energy Technology Data Exchange (ETDEWEB)

    Aanesen, J P; Olofsson, J [Linkoepings Hoegskola (Sweden)

    1979-09-01

    Though irradiation-induced tumours are uncommon, they represent a well defined entity. At this Hospital, 14 irradiation-induced head and neck tumours were encountered in 11 patients over a 10-year period. The irradiation had been given for tuberculous lymphadenitis in 6 of the patients, for lupus vulgaris in one, and thyrotoxicosis in another; the other 3 patients had received radiotherapy for malignant tumours. The interval between the treatment and the diagnosis of the tumour disease ranged from 9 to 48 years (mean 32). Three of the patients had multiple tumours. In view of the risk of cancer-albeit a small one-associated with radiological diagnosis and radiotherapy, these should be performed only on strict indications, expecially in young patients.

  10. Improving quality of some types of cheese by gamma irradiation

    International Nuclear Information System (INIS)

    Sallam, E.M.E.A

    2010-01-01

    The use of ionizing radiation as a food preservation technique has been recognized for many years as a means to reduce food losses, improve food safety, and extend shelf life. Furthermore, irradiation can be an effective way of reducing the incidence of food borne disease and treating a variety of potential problems in food supplies. The treatment of food with ionizing radiation is one of the most thoroughly researched techniques available to the food processing industry. In view of the afore mentioned the objective of this study were to study the effect of irradiation time and dose on Ras cheese quality, investigate the effect of irradiation after ripening on cheese quality and possibility of prolonging the shelf-life of Ras cheese, study the effect of irradiation dose on Kareish cheese quality and its shelf- life and to monitor the chemical, microbiological and sensory changes during ripening and storage of Ras and Kareish cheeses .The results of this study will be presented in three parts: Part I: Effect of irradiation dose and time on some properties of Ras cheese:Part II: Effect of irradiation on some properties during storage of ripened Ras cheese.Part III: Effect of irradiation on the quality and shelf-life of Kareish cheese: It could be concluded that irradiation caused a significant reduction of cheese ripening indices, and count of total viable,proteolytic, lipolytic bacteria and mould and yeast. Using irradiation doses of 3 and 4 kGy were able to stop the ripening factors and these safety dose were used to prevent the ripened Ras cheese irradiation of ripened Ras cheese has been prolonged the shelf-life of Ras cheese to about 32 months compared with control cheese, which showed only 18 months. The obtained results revealed that the best irradiation treatment was at the end of ripening period. Also safety irradiation of Kareish cheese has been prolonged the shelf-life of Kareish cheese to about 54 days compared with 12 days only control cheese.

  11. Five cases of squamous cell carcinoma induced by irradiation

    International Nuclear Information System (INIS)

    Omoto, Kayo; Tani, Tasaburo; Nagata, Hiroyuki; Kohda, Mamoru; Ueki, Hiroaki

    1985-01-01

    Five cases of squamous cell carcinoma (skin) induced by irradiation are reported. Three cases had been given radiotherapy for benign skin disorders, tinea pedis, lichen Vidal, and dermatitis papillaris capillitis. The other two cases were medical doctors who had developed carcinoma as the result of advanced radiodermatitis. (author)

  12. Improvement of carbon fiber surface properties using electron beam irradiation

    International Nuclear Information System (INIS)

    Pino, E.S.; Machado, L.D.B.; Giovedi, C.

    2007-01-01

    Carbon fiber-reinforced advance composites have been used for structural applications, mainly on account of their mechanical properties. The main factor for a good mechanical performance of carbon fiber-reinforced composite is the interfacial interaction between its components, which are carbon fiber and polymeric matrix. The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite. EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests. Experimental results showed that EB irradiation improved the tensile strength of carbon fiber samples. The maximum value in tensile strength was reached using doses of about 250 kGy. After breakage, the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated. SEM micrographs showed modifications on the carbon fiber surface. (authors)

  13. Fundamental Studies of Irradiation-Induced Modifications in Microstructural Evolution and Mechanical Properties of Advanced Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Stubbins, James; Heuser, Brent; Hosemann, Peter; Liu, Xiang

    2018-04-24

    temperature shift) is needed to determine the onset of accelerated void swelling (possibly at lower dose). Nanoindentation measurements show that the irradiation hardening decreases with increasing temperature. Microstructure-property correlation shows that the measured hardening at low dose ( 5 dpa) was mostly contributed by Frank loops at temperatures above 400° and network dislocations at 300°. T91 and G92 are both Fe–9Cr ferritic/martensitic alloy. G92 is optimized composition and heat treatment for improved performance in nuclear applications. The chromium content of T91 and G92 is close to the – 0 phase boundary. Irradiation hardening in ion-irradiated T91 and G92 is largely due to dislocation loops and network dislocations. The dislocation structure evolution was characterized by TEM during in situ 1 MeV Kr++ irradiation at 300, 400, and 500°. At 500°, the loop density at 1–3 dpa is significantly lower and the loops are dominantly h100i type. The loops at 400° are a mixture of h100i loops and h111i loops. The changes in yield strength were calculated at different doses and temperatures based on the microstructure observations. Nanoindentation measurements on bulk-irradiated specimens show that T91 and G92 have similar hardening behavior. The temperature dependence and dose dependence shown by nanoindentation measurements are consistent with the typical hardening behavior of neutron-irradiated F/M steels. In summary, radiation-induced microstructural and mechanical property modifications in proposed advanced structural alloys were systematically investigated in this program. The results and discussions advance the understanding of the material performance under extreme irradiation environment. The results of our accelerated ion beam irradiation also serve as critical reference for further neutron irradiation campaigns. Based on current findings, we are making several recommendations for future irradiation studies of A709 and G92 in the following section.

  14. Damage induced in semiconductors by swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Levalois, M.; Marie, P.

    1999-01-01

    The behaviour of semiconductors under swift heavy ion irradiation is different from that of metals or insulators: no spectacular effect induced by the inelastic energy loss has been reported in these materials. We present here a review of irradiation effects in the usual semiconductors (silicon, germanium and gallium arsenide). The damage is investigated by means of electrical measurements. The usual mechanisms of point defect creation can account for the experimental results. Besides, some results obtained on the wide gap semiconductor silicon carbide are reported. Concerning the irradiation effects induced by heavy ions in particle detectors, based on silicon substrate, we show that the deterioration of the detector performances can be explained from the knowledge of the substrate properties which are strongly perturbed after high doses of irradiation. Finally, some future ways of investigation are proposed. The silicon substrate is a good example to compare the irradiation effects with different particles such as electrons, neutrons and heavy ions. It is then necessary to use parameters which account for the local energy deposition, in order to describe the damage in the material

  15. Irradiation induced precipitation in tungsten based, W-Re alloys

    Science.gov (United States)

    Williams, R. K.; Wiffen, F. W.; Bentley, J.; Stiegler, J. O.

    1983-03-01

    Tungsten-base alloys containing 5, 11, and 25 pct Re were irradiated in the EBR-II reactor. Irradiation temperatures ranged from 600 to 1500 °C. All compositions were irradiated to fluences in the range 4.3 to 6.1 X 1025 n/m2 (E > 0.1 MeV), and three 25 pct Re samples were also irradiated to 3.7 X 1026 n/m2 at temperatures 700 to 900 °C. Postirradiation examination included measurement of electrical resistivity at room temperature and lower temperatures, X-ray diffraction, optical metallography, microprobe analysis, and transmission electron microscopy. Irradiation induced resistivity decreases observed in most of the samples suggested second-phase precipitation. Complete results confirmed the precipitate formation in all samples, in disagreement with existing phase diagrams for the W-Re system. Electron diffraction showed the precipitates to be consistent with the cubic, Re-rich X-phase and inconsistent with the σ-phase. Large variations in precipitate morphology and distribution were observed between the different compositions and irradiation conditions. For the 5 and 11 pct Re-alloys, spherically symmetric strain fields surrounded the equiaxed precipitate particles, and were observed even where no particles were visible. These strain fields are believed to arise from local Re enrichment. Thermoelectric data show that the precipitation can lead to decalibration of W/Re thermocouples.

  16. Modulatory Role of Aloe vera on Gamma Irradiation Induced Histological Changes in Different Tissues of Rats

    International Nuclear Information System (INIS)

    Rezk, R.G.

    2005-01-01

    Aloe Vera is known for its wide medicinal properties. This study was performed to evaluate the role of Aloe vera (Aloe barbadensis Miller) in the amelioration of the histological disorders that occurr in different tissues of albino rats exposed to 7 Gy whole body gamma irradiation, delivered as a single dose. Aloe vera (leaf juice filtrate) was supplemented daily to rats (0.25 ml/kg b wt/day) by gavage, 5 days before irradiation and 10 days after irradiation. Experimental investigations performed 7 and 10 days after exposure to radiation showed that Aloe vera treatment has significantly improved the radiation-induced inflammation, haemorrhage, widening and dilated blood vessela, necrosis, atrophy sloughing in liver, spleen and small intestine (jejenum) tissues of irradiated rats. It is concluded that the synergistic relationship between the elements found in the leaf of Aloe vera could be a useful adjunct for maintaining the integrity of histological architecture

  17. Investigations of Atomic Transport Induced by Heavy Ion Irradiation

    Science.gov (United States)

    Banwell, Thomas Clyde

    The mechanisms of atomic transport induced by ion irradiation generally fall into the categories of anisotropic or isotropic processes. Typical examples of these are recoil implantation and cascade mixing, respectively. We have measured the interaction of these processes in the mixing of Ti/SiO(,2)/Si, Cr/SiO(,2)/Si and Ni/SiO(,2)/Si multi-layers irradiated with Xe at fluences of 0.01 - 10 x 10('15)cm('-2). The fluence dependence of net metal transport into the underlying layers was measured with different thicknesses of SiO(,2) and different sample temperatures during irradiation (-196 to 500C). There is a linear dependence at low fluences. At high fluences, a square-root behavior predominates. For thin SiO(,2) layers (primary recoils is quite pronounced since the gross mixing is small. A significant correlation exists between the mixing and the energy deposited through elastic collisions F(,D ). Several models are examined in an attempt to describe the transport process in Ni/SiO(,2). It is likely that injection of Ni by secondary recoil implantation is primarily responsible for getting Ni into the SiO(,2). Secondary recoil injection is thought to scale with F(,D). Trends in the mixing rates indicate that the dominant mechanism for Ti and Cr could be the same as for Ni. The processes of atomic transport and phase formation clearly fail to be separable at higher temperatures. A positive correlation with chemical reactivity emerges at higher irradiation temperatures. The temperature at which rapid mixing occurs is not much below that for spontaneous thermal reaction. Less Ni is retained in the SiO(,2) at high irradiation temperatures. Ni incorporated in the SiO(,2) by low temperature irradiation is not expelled during a consecutive high temperature irradiation. The Ni remains trapped within larger clusters during a sequential 500C irradiation. (Abstract shortened with permission of author.).

  18. Analysis of radicals induced in irradiated cereal flour using ESR

    International Nuclear Information System (INIS)

    Kawamura, Shoei; Kishita, Keigo; Ukai, Mitsuko; Kikuchi, Masahiro; Kobayashi, Yasuhiko

    2013-01-01

    Using electron spin resonance (ESR) spectroscopy, we revealed radicals induced in cereal flour irradiated with gamma-ray or electron beam. Sample was wheat and rice. We detected a broad singlet signal at g = 2.0. It consists of a singlet signal and a triplet signal. It suggested that the singlet signal is originated from organic free radicals and the triplet signal is from 14 N. There were no differences of ESR spectra between irradiated wheat flour and rice flour. The signal intensity of radiation induced radical was tend to increase following with the increase of radiation dose level. After radiation treatment, relaxation time of radiation induced radical was changed during storage. T 1 was decreased and T 2 was increased. In this study, the relaxation time is calculated using the parameters obtained from the ESR signal. It is necessary to analyze the relaxation time directly with pulsed ESR spectroscopy in future. (author)

  19. SHI induced irradiation effect on Mo/Si interface

    International Nuclear Information System (INIS)

    Agarwal, Garima; Agarwal, Shivani; Jain, Rajkumar; Lal, Chhagan; Jain, I.P.; Kabiraj, D.; Pandey, Akhilesh

    2006-01-01

    Present parametric study investigates the characteristics of SHI induced mixed molybdenum silicide film with various ion fluences. The deposition of molybdenum thin films onto the Silicon substrate was performed using e-beam evaporation, while the heavy Au ion irradiation with energy 120 MeV was subsequently applied to form molybdenum silicide. The samples have been characterized by grazing incidence X-ray diffraction (GIXRD) for the identification of phase formation at the interface. Formation of t-Mo 5 Si 3 mixed molybdenum silicide was observed on increasing the ion irradiation fluences. (author)

  20. Safety protection and technical improvement of 60Co irradiation facilities

    International Nuclear Information System (INIS)

    Zhou Yongxing; Liang Cannan

    1993-01-01

    To ensure personal safety, some improvements has been made in the design of 60 Co irradiation compartment. The shielding door was interlocked while the 60 Co source to be lifted to the irradiation position or lowered to the shielded position. A universal change-over switch was used to cut the power supply when the source moved beyond the limits. Both γ-ray alarm and a closed-TV system were adopted. The electromagnetic attraction method was employed to shift the 60 Co source from the Pb container to the source pipe

  1. Improvement of microbiological qualities of namphrik by gamma irradiation

    International Nuclear Information System (INIS)

    Chahorm, K; Neramitmansook, N; Kongsang, N; Ko, J

    2017-01-01

    Twenty samples of Namphrik from commercial markets were evaluated the microbiological qualities. It was found that 15 samples did not meet Thai Community Product Standard. The total plate count (TPC) in 15 samples were higher than the maximum limits (1.60x10 4 – 4.4x10 5 CFU/g). In addition, the other pathogens were higher than the maximum limits such as B. cereus in 11 samples (2.10x10 3 – 6.10x10 4 CFU/g) S. aureus in 2 samples (15 – 40 CFU/g) Clostridium perfringens in 4 samples (1.00x10 2 – 8.8x10 3 CFU/g) and yeast and mold in 9 samples (3.00 x10 2 – 9.00x10 3 CFU/g). To reduce TPC and pathogenic bacteria, the gamma irradiation were applied at 3.28- 4.43 kGy. The results indicated that the irradiation can reduce the TPC around 1.2 – 3.9 log cycles and eliminate pathogens bacteria in the product to make all of 15 samples qualified to the standard. The sensory evaluation was conducted in Namphrik Narok by using difference from control test to determine whether the consumers can differentiate between the non-irradiated and irradiated. The result showed that the consumers can significantly differentiate the color, odor and flavor (p<0.05). However, the preference test showed that there was no significant preferences at p>0.05. Both non-irradiated and irradiated were scored at 6.4 (slightly to moderately preference). Thus the gamma irradiation can be used as a tool to improve the microbiological qualities of the Namphrik Narok product without effecting the consumer preference. (paper)

  2. Improvement of microbiological qualities of namphrik by gamma irradiation

    Science.gov (United States)

    Chahorm, K.; Neramitmansook, N.; Kongsang, N.; Ko, J.

    2017-06-01

    Twenty samples of Namphrik from commercial markets were evaluated the microbiological qualities. It was found that 15 samples did not meet Thai Community Product Standard. The total plate count (TPC) in 15 samples were higher than the maximum limits (1.60x104 - 4.4x105 CFU/g). In addition, the other pathogens were higher than the maximum limits such as B. cereus in 11 samples (2.10x103 - 6.10x104 CFU/g) S. aureus in 2 samples (15 - 40 CFU/g) Clostridium perfringens in 4 samples (1.00x102 - 8.8x103 CFU/g) and yeast&mold in 9 samples (3.00 x102 - 9.00x103 CFU/g). To reduce TPC and pathogenic bacteria, the gamma irradiation were applied at 3.28- 4.43 kGy. The results indicated that the irradiation can reduce the TPC around 1.2 - 3.9 log cycles and eliminate pathogens bacteria in the product to make all of 15 samples qualified to the standard. The sensory evaluation was conducted in Namphrik Narok by using difference from control test to determine whether the consumers can differentiate between the non-irradiated and irradiated. The result showed that the consumers can significantly differentiate the color, odor and flavor (p0.05. Both non-irradiated and irradiated were scored at 6.4 (slightly to moderately preference). Thus the gamma irradiation can be used as a tool to improve the microbiological qualities of the Namphrik Narok product without effecting the consumer preference.

  3. Enlargement of induced variations by combined method of chronic irradiations with callus culture in sugarcane

    International Nuclear Information System (INIS)

    Nagatomi, Shigeki

    1993-01-01

    The present study was conducted to elucidate the effects of gamma ray irradiation and callus culture upon induced variation of the regeneratives. The populations regenerated from young leaf tissue of chronic irradiated plnats grown under a gamma field receiving a total dose of 300 and 100 Gy, showed rather wider variation on quantitative characters than plants from populations of the non-irradiated. This variation extended in both negative and positive directions. Analysis of variance also revealed that variation and heritability in broad sense of most agronomic characters increased significantly among the subclones as the irradiation done rose. Principal component analysis also indicated that the subclones from the irradiated population were more variable than the non-irradiated. Such variation with higher heritability could be transmitted to the following generations by clonal propagation and utilized as genetic sources in mutation breeding. The combined method with chronic irradiation followed by tissue culture is evaluated as an effective method of widening mutation spectrum and increasing mutation frequency in regenerated plants. In addition, this method is valid to improve any crop species which can regenerate plants through callus culture. (author)

  4. Evaluation of Chemical Changes in Some Soybean Mutants Induced by Gamma Irradiation

    International Nuclear Information System (INIS)

    Abd-Elkalik, K.; Mekkawy, S.H.; El-Demerdash, H.M.

    2010-01-01

    The Egyptian soybean cultivar Giza-22 was used to induce genetic variability by using gamma rays at dose levels of 100, 150 and 200 Gy. Sixteen mutants (including parental cultivar) were evaluated in M3 generation for their agronomic traits and chemical analysis was done in seeds of M3 generation. Four mutants A21 (150 Gy), A22, A23 and A24 (200 Gy) showed superiority in their agronomic traits compared with parental cultivar. The results of chemical analysis of seeds of M3 generation showed that, oil and energy contents were unaffected by irradiation treatments while protein contents were significantly increased at doses 150 and 200 Gy. Phenolic and tannin contents in seeds of M3 generation showed no significant changes in their percentages due to irradiation treatments. Gamma irradiation significantly increased in linoleic acid content in most of the mutants compared with the control (Giza-22), whereas, there were decreases in linolenic acid content. Investigation of amino acid composition of mutants of M3 generation revealed significant increases in the essential amino acids in most mutants induced by gamma irradiation at 150 and 200 Gy. It could be suggested that the use of gamma irradiation can induce an improvement of the oil and protein composition in soybean

  5. Gamma irradiation-induced variation in carrots (Daucus carota L.)

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Simon, P.W.

    1996-01-01

    Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue cultures, were exposed to low doses of gamma irradiation. Higher doses reduced M1 plant size by 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M2 families. Less variation was observed in total carotene content and none was seen in sugar type (reducing vs. non reducing sugars). Induced variation in root color and root shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M2 somaclonal variation. Average root weight of M2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment

  6. Gamma irradiation induced variation in carrots (Daucus Carota L.)

    International Nuclear Information System (INIS)

    Al-Safady, B.; Simon, P.W.

    1999-01-01

    Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M 1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue culture, were exposed to low doses of gamma irradiation. Higher doses reduced M 1 plant size by > 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M 1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M 2 families. Less variation was observed in total carotene content and none was seen in sugar type [reducing vs. non reducing sugars]. Induced variation in root color and rot shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M 2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M 2 somaclonal variation. Average root weight of M 2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment (Author)

  7. Cell death induced by gamma irradiation of developing skeletal muscle

    International Nuclear Information System (INIS)

    Olive, M.; Blanco, R.; Rivera, R.; Cinos, C.; Ferrer, I.

    1995-01-01

    Newborn Sprague-Dawley rats were exposed to a single dose of 2 Gy gamma rays and killed from 6 h to 5 d later. Increased numbers of dying cells, characterised by their extreme chromatin condensation and often nuclear fragmentation were seen in skeletal muscle 6 h after irradiation. Dying cells decreased to nearly normal values 48 h later. In situ labelling of nuclear DNA fragmentation identified individual cells bearing fragmented DNA. The effects of gamma rays were suppressed following cycloheximide i.p. at a dose of 1 μg/g body weight given at the time of irradiation. Taken together, the present morphological and pharmacological results suggest that gamma ray induced cell death in skeletal muscle is apoptotic, and that the process is associated with protein synthesis. Finally, proliferating cell nuclear antigen-immunoreactive cells, which were abundant in control rats, decreased in number 48 h after irradiation. However, a marked increase significantly above normal age values was observed at the 5th day, thus suggesting that regeneration occurs following irradiation-induced cell death in developing muscle. (author)

  8. Elemental process of amorphization induced by electron irradiation in Si

    International Nuclear Information System (INIS)

    Yamasaki, Jun; Takeda, Seiji; Tsuda, Kenji

    2002-01-01

    We recently found that amorphization is induced in Si by electron irradiation. Examining the amorphization systematically, we have established the diagram of steady states under electron irradiation, either amorphous Si (a-Si) or crystalline Si (c-Si) as a function of incident electron energy, electron dose, and irradiation temperature. Utilizing transmission electron microscopy, electron energy filtered diffraction and electron energy-loss spectroscopy, we have characterized the atomic structure, the electronic structure, and the thermal stability of a-Si induced by electron irradiation. Based on the experimental data, we have also concluded that the amorphization is caused by the accumulation of not point defects but small cascade damages. Analyzing the change in the intensity of halo diffraction rings during amorphization, we have clarified that the smallest cascade damage that contributes to amorphization includes only about four Si atoms. This presumably supports the amorphization mechanism that four self-interstitial atoms form the quasistable structure I4 in c-Si and it becomes an amorphous embryo

  9. Erlotinib-induced rash spares previously irradiated skin

    International Nuclear Information System (INIS)

    Lips, Irene M.; Vonk, Ernest J.A.; Koster, Mariska E.Y.; Houwing, Ronald H.

    2011-01-01

    Erlotinib is an epidermal growth factor receptor inhibitor prescribed to patients with locally advanced or metastasized non-small cell lung carcinoma after failure of at least one earlier chemotherapy treatment. Approximately 75% of the patients treated with erlotinib develop acneiform skin rashes. A patient treated with erlotinib 3 months after finishing concomitant treatment with chemotherapy and radiotherapy for non-small cell lung cancer is presented. Unexpectedly, the part of the skin that had been included in his previously radiotherapy field was completely spared from the erlotinib-induced acneiform skin rash. The exact mechanism of erlotinib-induced rash sparing in previously irradiated skin is unclear. The underlying mechanism of this phenomenon needs to be explored further, because the number of patients being treated with a combination of both therapeutic modalities is increasing. The therapeutic effect of erlotinib in the area of the previously irradiated lesion should be assessed. (orig.)

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

    International Nuclear Information System (INIS)

    Hong Chengjiao; Zhang Junning; Zhu Shoupeng

    2001-01-01

    Apoptosis in tumor cells induced by radionuclides is likely the most effective way to cure cancer. In order to explore the possibility in clinic application, the characteristics and mechanism of apoptosis induced by internal irradiation were investigated. The apoptosis and expressions of bcl-2mRNA, bcl-2 and bax of K 562 cells following internal exposure with different accumulated absorbed doses of strontium-89 were studied. 6 h after irradiation, the characteristics of apoptosis and necrosis appeared in K 562 cells. The apoptosis and necrosis enhanced with the prolongation of internally contaminated time at 6 h, 9 h, 12 h, 24 h and 48 h. The expressions of bcl-2mRNA decreased at 12 h, most remarkably at 24 h. The expressions of bcl-2 decreased after irradiation whereas bax had no obvious changes. The results suggest that the apoptosis induced by internal exposure may be regulated by lower expressions of bcl-2mRNA and bcl-2, lower bcl-2/bax value

  11. Improvement of Protein Digestibility in Jatropha curcas Seed Cakes by Gamma Irradiation

    International Nuclear Information System (INIS)

    Sudprasert, Wanwisa; Pakkong, Pannee; Thiengtham, Jamroen; Chandang, Pipatpong

    2011-06-01

    Full text: The effect of gamma radiation on protein digestibility of Jatropha curcas press cake was investigated using in vitro digestibility technique. Six varieties of Jatropha curcas seeds were subjected to cobalt-60 gamma radiation at doses of 10-100 kGy. All treated seeds were defatted by screw press. In vitro protein digest abilities in defatted seeds were assayed using trinitrobenzene sulphonic acid (TNBS) method, by which the contents of alpha amino induced from the function of enzymes were determined using L-alanine as a reference standard. It was found that irradiation treatment at 60 kGy significantly increased the protein digestibility by 15-92%. Also, the results showed that moisture, crude protein, fat and ash contents were unchanged by irradiation, whereas fiber was significantly decreased (p < 0.05). Therefore, irradiation could serve as a possible processing method for protein utilization improvement in defatted Jatropha curcas seeds before using as a protein supplement in animal feed

  12. Using gamma irradiation to improve sterile turf and forage bermudagrasses

    International Nuclear Information System (INIS)

    Burton, G.W.; Georgia Univ., Tifton

    1976-01-01

    The widely-used Tif-series of turf bermudagrasses - Tifgreen, Tifway, and Tifdwarf - are vegetatively propagated sterile triploids that cannot be improved by conventional breeding methods. Dormant stolons, washed free of soil and cut into one-or two-node sections were treated with varying dosages of EMS (ethyl methane sulfonate) and gamma irradiation ranging from 7 to 12 kR. EMS failed to produce noticeable variants but gamma irradiation from a Cobalt 60 source created 158 mutants. These mutants differed in many characters such as leaf size, hairiness, stem diameter, internode length, basic plant color, herbicide tolerance, spreading rate, and nematode resistance. Attempts to improve the winterhardiness of tetraploid sterile Coastcross-1 forage bermudagrass by exposing over 1,400,000 sprigs (vegetative stems) to 7 kR of gamma rays gave chlorophyll deficient mutants but progress in increasing winterhardiness has not been established. (author)

  13. Improvement of neutron irradiation field of research reactors for BNCT

    International Nuclear Information System (INIS)

    Aizawa, Otohiko

    1992-01-01

    The modification of research reactors for an improvement of the irradiation field for BNCT has been investigated in comparison with the field characteristics of the 'old' configuration at the Musashi reactor. The new point of this study is that the evaluation has been done by using an arrangement including both the facility structure and a whole-body phantom, and also by considering the whole-body absorbed dose. (author)

  14. The application of irradiation techniques for food preservation and process improvement -Studies on application of radiation and radioisotopes-

    International Nuclear Information System (INIS)

    Byeon, Myeong Uh; Cho, Han Ok; Yang, Jae Seung; Cho, Seong Ki; Kang, Il Joon

    1994-07-01

    With the increased consumption of processed food, quality control techniques are inevitably required in the food industry for its mass production and distribution. Recently, there has been a growing interest in the use of irradiation for solving the infrastructural problems in the food industry by developing viable alternatives to conventional technology and by improving the quality of processed foods. Even though food irradiation technology has been commercialized in 25 countries, and 18 items of irradiated foods have been approved for human consumption domestically, infrastructural studies are needed for the practical application of this technology. In order to enlarge the utilization of irradiation technology in solving the infrastructural problems of the food industry, this project was designed to investigate the efficacy of gamma irradiation for improving the process and physical properties of dried foods (corn and soybean), for preserving the reserved foods for emergency (red pepper) and for producing natural products (red polyketied pigment) using microbial immobilization with radiation-induced polymer

  15. Improving the efficiency of CDTN's Gamma Irradiation Laboratory with additional designed turntables

    International Nuclear Information System (INIS)

    Silva, Luiz Leite da; Albino, Sergio Celeghini; Candido, Marcos Antonio; Grossi, Pablo Andrade; Correa, Ricardo Ferracini; Pinto, Fausto Carvalho

    2007-01-01

    The Gamma Irradiation Laboratory (LIG) of CDTN was originally supplied with four turntables. Operating with this configuration was a loss of time and irradiation volume, what induced the Irradiator's staff creating an optimisation production program. Firstly, the staff requests the Gamma Irradiator Manufacturer a quotation for new turntables, but the price was very high. Secondly, the CDTN Design Group was invited to develop new LIG turntables. The groups worked together and found a very good solution. The new turntables are much cheaper and their rotating plate diameters are increased in 5 cm and four of them were made to attend the LIG demand. They have been in operation without significant problems for 1.5 years and absorbed an estimated dose of 7 MGy. This fact confirms the design and materials good quality. Operating with the eight turntables was possible to improve the LIG irradiation capacity in six times in weigh and in volume. Irradiation time is reduced; nowadays doses up to 5 KGy can be done in the same day. For irradiation doses greater than 5 KGy, the process was speeded up by positioning the new turntables in the spaces between the original ones. With this operational configuration the samples receive the dose escaped in those spaces. Calculation of the new dose necessary for the sample is done and it is repositioned in the internals turntables to finish the irradiation process. With this technique the samples do not need to wait so much on the line. The scope of the research program includes day and night operation. Continuously operating in association with the four new turntables enhanced the original operational capacity of the LIG fifteen times. The objectives of this work are to present the developed turntables characteristics and the results acquired. (author)

  16. Potential for improvement in estimation of solar diffuse irradiance

    International Nuclear Information System (INIS)

    Muneer, T.; Munawwar, S.

    2006-01-01

    Most of the meteorological stations around the world measure global irradiation and provide information on weather elements. Diffuse radiation measurement, however, is unavailable for many of those sites. This accentuates the need to estimate it whereupon it can be used for the simulation of solar applications. This paper explores the role of synoptic information, e.g. sunshine fraction, cloud cover and air mass on the basic k-k t relationship for nine sites across the globe. The influence on the k-k t regressions is studied qualitatively, and the inclusion of these parameters is suggested based on that. Thus, it is recommended to use the complementary data usually provided with the database apart from the global irradiation in order to estimate the diffuse irradiation more accurately. It was found by analysing each synoptic parameter individually that while the sunshine fraction showed a strong bearing, it was followed closely by cloud cover. Air mass, on the other hand, was found to be a weak parameter for general estimation of diffuse radiation. It was concluded that air mass if coupled with other synoptic parameters might improve the estimation accuracy, but it does not show much promise on its own when used with the global irradiation

  17. improving the hygienic quality of quail carcasses by gamma irradiation

    International Nuclear Information System (INIS)

    Nasr, E.H.A.

    2002-01-01

    this investigation aimed to use gamma irradiation doses as compared to chemical preservative sodium tripolyphosphate (stpp) for increasing the shelf-life and improving the hygienic quality of quail carcasses during cold and frozen storage. one hundred quail carcasses were examined for the presence of salmonella. the examination illustrated that 70 carcasses from all examined carcasses were positive for salmonella. therefore, the contaminated quail carcasses were gamma irradiated at 2,4,6 and 8 kGy doses and soaking in 3% stpp and the effect of these treatments on the organoleptic, microbiological aspects and chemical properties during cold (4±1 o C) and frozen storage (-18 o C) of samples under investigation were evaluated .the results indicated that, the chemical composition of samples did not alter by gamma irradiation and soaking in STPP treatments. furthermore, treatments had no deleterious effects on the organoleptic properties of quail samples. irradiation of samples at doses of 2,4,6 and 8 kGy or soaking in STPP greatly reduced its microbial count and prolonged its shelf- life for 12,15,21,24 and 9 days at 4±1 o C, respectively against only 6 days for control samples

  18. Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, D.H.; Chen, H.C.; Lei, G.H.; Huang, H.F.; Zhang, W.; Wang, C.B. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, L., E-mail: yanlong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Fu, D.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Tang, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2017-06-15

    The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness. - Highlights: •Irradiation Swelling: The irradiation induced volumetric swelling increases with ion dose. •Irradiation Hardening: The irradiation hardening initiates below 1 dpa, then saturates with higher ion dose (1–10 dpa). •Irradiation Mechanism: The irradiation phenomena are ascribed to the microstructural evolution of the irradiation defects.

  19. Deuterium ion irradiation induced precipitation in Fe–Cr alloy: Characterization and effects on irradiation behavior

    International Nuclear Information System (INIS)

    Liu, P.P.; Yu, R.; Zhu, Y.M.; Zhao, M.Z.; Bai, J.W.; Wan, F.R.; Zhan, Q.

    2015-01-01

    Highlights: • A new phase precipitated in Fe–Cr alloy after deuterium ion irradiation at 773 K. • B2 structure was proposed for the Cr-rich new phase. • Strain fields around the precipitate have been measured by GPA. • The precipitate decrease growth rate of dislocation loop under electron irradiation. - Abstract: A new phase was found to precipitate in a Fe–Cr model alloy after 58 keV deuterium ion irradiation at 773 K. The nanoscale radiation-induced precipitate was studied systematically using high resolution transmission electron microscopy (HRTEM), image simulation and in-situ ultrahigh voltage transmission electron microscopy (HVEM). B2 structure is proposed for the new Cr-rich phase, which adopts a cube-on-cube orientation relationship with regard to the Fe matrix. Geometric phase analysis (GPA) was employed to measure the strain fields around the precipitate and this was used to explain its characteristic 1-dimensional elongation along the 〈1 0 0〉 Fe direction. The precipitate was stable under subsequent electron irradiation at different temperatures. We suggest that the precipitate with a high interface-to-volume ratio enhances the radiation resistance of the material. The reason for this is the presence of a large number of interfaces between the precipitate and the matrix, which may greatly reduce the concentration of point defects around the dislocation loops. This leads to a significant decrease in the growth rate

  20. Surface modification of ceramic materials induced by irradiation of high power pulsed ICP

    International Nuclear Information System (INIS)

    Ishigaki, Takamasa; Okada, Nobuhiro; Ohashi, Naoki; Haneda, Hajime

    2003-01-01

    Newly developed pulse-modulated high-power inductively coupled plasma [ICP] is expected to offer the unique physico-chemical condition, such as the increased concentration of chemically reactive species, as well as the appropriate heat flux for materials processing. Two kinds of oxide materials, titanium and zinc oxide, were placed at the downstream of Ar-H 2 ICP and irradiated in the plasma of continuous [CN] and pulse-modulated [PM] modes. The CN-ICP irradiation at the position close to the plasma tail gave rise to the thermal reduction of oxides. In the PM-ICP irradiation, the degree of thermal reduction depended on the lower power level during pulse-off time, as well as the total electric power. Irradiation in PM-ICP led to the increased formation of oxygen vacancies in titanium dioxide. In the case of zinc oxide, the UV emission efficiency was improved by PM-ICP irradiation, while the green emission became predominant by CN-ICP irradiation at the appropriate position. Induced effects in the two oxides by PM-ICP would be related to the high concentration of hydrogen radicals in the plasma. (author)

  1. Irradiation-induced patterning in dilute Cu–Fe alloys

    International Nuclear Information System (INIS)

    Stumphy, B.; Chee, S.W.; Vo, N.Q.; Averback, R.S.; Bellon, P.; Ghafari, M.

    2014-01-01

    Compositional patterning in dilute Cu 1−x Fe x (x ≈ 12%) induced by 1.8 MeV Kr + irradiation was studied as a function of temperature using atom probe tomography. Irradiation near room temperature led to homogenization of the sample, whereas irradiation at 300 °C and above led to precipitation and macroscopic coarsening. Between these two temperatures the irradiated alloys formed steady state patterns of composition where precipitates grew to a fixed size. The size in this regime increased somewhat with temperature. It was also observed that the steady state concentrations of Fe in Cu matrix and Cu in the Fe precipitates both greatly exceeded their equilibrium solubilities, with the degree of supersaturation in each phase decreasing with increasing temperature. In the macroscopic coarsening regime, the Fe-rich precipitates showed indications of a “cherry-pit” structure, with Cu precipitates forming within the Fe precipitates. In the patterning regime, interfaces between Fe-rich precipitates and the Cu-rich matrix were irregular and diffuse

  2. Irradiation induced creep in whiskers of NaCl

    International Nuclear Information System (INIS)

    Khan, J.A.A.

    1977-09-01

    Whiskers of NaCl have been grown and irradiated under flexion by X-rays (approximately 2x10 7 R/h) at room temperature and the residual curvature measured. Complete recovery of the initial form of the whisker within an hour's annealing at 400 0 C proves clearly that the observed deformation (creep) is due to the presence of dislocation loops. The choice of NaCl extremely simplifies the experiment and its interpretation since X-rays create point defects one by one. Moreover, this mode of irradiation, at room temperature, produces a very simple situation: perfect interstitial dislocation loops and immobile point defects which are little influenced by the applied stress. The flexion leads to a stress system which hardly differs from an uniaxial stress. One can study separately the preferential nucleation of dislocation loops and their differential growth by carrying out an irradiation under stress followed by an irradiation without stress and vice versa. It is shown that the induced creep is mostly due to the preferential nucleation of dislocation loops and is little affected by the differential growth of these loops. The nucleation period of the loops is very short: a dose of approximately 10 -5 d.p.a. is largely sufficient for the quasi completion of dislocation loops in a crystal having an impurity concentration of approximately 10 -3 [fr

  3. Minocycline ameliorates cognitive impairment induced by whole-brain irradiation: an animal study

    International Nuclear Information System (INIS)

    Zhang, Liyuan; Li, Kun; Sun, Rui; Zhang, Yuan; Ji, JianFeng; Huang, Peigeng; Yang, Hongying; Tian, Ye

    2014-01-01

    It has been long recognized that cranial irradiation used for the treatment of primary and metastatic brain tumor often causes neurological side-effects such as intellectual impairment, memory loss and dementia, especially in children patients. Our previous study has demonstrated that whole-brain irradiation (WBI) can cause cognitive decline in rats. Minocycline is an antibiotic that has shown neuroprotective properties in a variety of experimental models of neurological diseases. However, whether minocycline can ameliorate cognitive impairment induced by ionizing radiation (IR) has not been tested. Thus this study aimed to demonstrate the potential implication of minocycline in the treatment of WBI-induced cognitive deficits by using a rat model. Sprague Dawley rats were cranial irradiated with electron beams delivered by a linear accelerator with a single dose of 20 Gy. Minocycline was administered via oral gavages directly into the stomach before and after irradiation. The open field test was used to assess the anxiety level of rats. The Morris water maze (MWM) was used to assess the spatial learning and memory of rats. The level of apoptosis in hippocampal neurons was measured using immunohistochemistry for caspase-3 and relative markers for mature neurons (NeuN) or for newborn neurons (Doublecortin (DCX)). Neurogenesis was determined by BrdU incorporation method. Neither WBI nor minocycline affected the locomotor activity and anxiety level of rats. However, compared with the sham-irradiated controls, WBI caused a significant loss of learning and memory manifest as longer latency to reach the hidden platform in the MWM task. Minocycline intervention significantly improved the memory retention of irradiated rats. Although minocycline did not rescue neurogenesis deficit caused by WBI 2 months post-IR, it did significantly decreased WBI-induced apoptosis in the DCX positive neurons, thereby resulting in less newborn neuron depletion 12 h after irradiation

  4. Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces

    International Nuclear Information System (INIS)

    Kang, M.; Wu, J. H.; Chen, H. Y.; Thornton, K.; Goldman, R. S.; Sofferman, D. L.; Beskin, I.

    2013-01-01

    We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport

  5. Consequences of the improvement of fast reactor material behavior under irradiation on fuel element performance

    International Nuclear Information System (INIS)

    Leclere, J.; Dupouy, J.M.; Marcon, J.P.

    1979-01-01

    The most important problems in fast reactor fuel element come from the excessive swelling of the structural materials used. The limitations of irradiation time for a given reactor result from the cladding or hexagonal wrapper deformations. Irradiation creep plays a major role, either in inducing additional deformations, or in providing possible ways of accommodation of bending stresses. Progress has been made in designing swelling resistant and/or low irradiation creep modulus materials. For instance in FRANCE, annealed 316 SS has been eliminated from pin and subassembly, and replaced by cold worked 316; we are now considering introduction of stabilizing elements in 316 SS as a further improvement and studying different alloys (nickel alloys, or ferritic steels). It has to be checked that the improvement of irradiation characteristic is not counterbalanced by losses on other properties (embrittlement for instance). Considering that pushing off or eliminating a limit may lead to the onset of a new one, it is porposed to make a review of the consequences of substantial improvement of structural material behavior

  6. Partial characterization of bacteriocin induced by irradiated and non-irradiated strain of yersinia enterocolitical

    International Nuclear Information System (INIS)

    Awny, N.M.

    1991-01-01

    Twenty isolates of yersinia enterocolitica were tested for the inhibition of the growth of different strains of yersinia. The screening tests revealed three possible bacteriocinogenic strains. One of them was selected for additional studies after it was shown that its inhibitory substances differed in their activity spectra. The gamma irradiated strain lost the ability to produce bacteriocin at 0.6 kGy level. Crude preparation of bacteriocin obtained from the wild strain were not affected by chloroform or other organic solvents but inactivated by trypsin and heating at 80 C for 45 min. Bacteriocin induced by irradiated strain was easily inactivated by thermal treatment. Exposure of agar fragments containing the inhibitory active component to a pH value ranging between 2 to 11 did not affect bactericidal activity.4 tab

  7. Effects of mecobalamin on testicular dysfunction induced by X-ray irradiation in mice

    International Nuclear Information System (INIS)

    Oshio, Shigeru; Yazaki, Tsunetada; Umeda, Takashi; Ozaki, Satoru; Ohkawa, Isao; Tajima, Tetsuya; Yamada, Takeshi; Mohri, Hideo.

    1991-01-01

    Experimental testicular dysfunction was produced by X-ray irradiation to the testes in mice. Mecobalamin (CH 3 -B 12 ) was orally administered at a daily dose of 0.01, 0.1 or 1 mg/kg six times a week for 8 weeks from the next day after the irradiation. The control mice received physiological saline in the same manner. On 4th- and 6th-week after the irradiation, the weights of testes and epididymides were decreased, although those of the body and accessory sex glands (seminal vesicle, coagulating gland and prostate) were nearly equal to those of non-irradiated mice. At the same time, the diameter of seminiferous tubules decreased and sperm parameters (sperm count, sperm motility and sperm abnormality) deteriorated. When CH 3 -B 12 (1 mg/kg) was administered, the diameter of seminiferous tubules increased and sperm parameters improved as compared to those of the control. The results indicate that CH 3 -B 12 improved the experimental testicular dysfunction in mice induced by the irradiation. These results suggest that CH 3 -B 12 might accelerate testicular function. (author)

  8. Irradiation-induced segregation in multi-component alloys

    International Nuclear Information System (INIS)

    Chen, I.W.

    1983-01-01

    A unified analysis of irradiation-induced segregation in multi-component alloys is developed using the formulation of irreversible thermodynamics. Three distinct mechanisms for segregation, namely the inverse Kirkendall effect, the vacancy-wind effect, and the solute drag of interstitials, are identified. In particular, the inverse Kirkendall effect due to interstitials arises only if a solute-interstitial interaction or a mutual conversion among interstitials via lattice atom intermediaries operates simultaneously. In the limit of fast conversion a para-equilibrium state may be reached between interstitials and lattice atoms, and the interstitial mechanism becomes formally analogous to the vacancy mechanism. Although the past treatment of rate phenomena in this field was apparently limited to the latter case, the importance of the consideration of separate chemical potentials for interstitials of different species, in segregation and other irradiation effects, is emphasized. (orig.)

  9. Improvement of boiling heat transfer by radiation induced boiling enhancement

    International Nuclear Information System (INIS)

    Imai, Yasuyuki; Okamoto, Koji; Madarame, Haruki; Takamasa, Tomoji

    2003-01-01

    For nuclear reactor systems, the critical heat flux (CHF) data is very important because it limits reactor efficiency. Improvement of CHF requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. In our previous study, we confirmed that the surface wettability changed significantly or that highly hydrophilic conditions were achieved, after irradiation of 60 Co gamma ray, by the Radiation Induced Surface Activation (RISA) phenomenon. To delineate the effect of RISA on boiling phenomena, surface wettability in a high-temperature environment and critical heat flux (CHF) of metal oxides irradiated by gamma rays were investigated. A CHF experiment in the pool boiling condition was carried out under atmospheric pressure. The heating test section made of titanium was 0.2 mm in thickness, 3 mm in height, and 60 mm in length. Oxidation of the surface was carried out by plasma jetting for 40 seconds. The test section was irradiated by 60 Co gamma ray with predetermined radiation intensity and period. The CHF of oxidized titanium was improved up to 100 percent after 800 kGy 60 Co gamma ray irradiation. We call this effect Radiation Induced Boiling Enhancement (RIBE). Before we conducted the CHF experiment, contact angles of the test pieces were measured to show the relationship between wettability and CHF. The CHF in the present experiment increases will surface wettability in the same manner as shown by Liaw and Dhir's results. (author)

  10. Improvement of boiling heat transfer by radiation induced boiling enhancement

    International Nuclear Information System (INIS)

    Imai, Y.; Okamoto, K.; Madarame, H.; Takamasa, T.

    2003-01-01

    For nuclear reactor systems, the Critical Heat Flux (CHF) data is very important because it limits reactor efficiency. Improvement of CHF requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. In our previous study, we confirmed that the surface wettability changed significantly or that highly hydrophilic conditions were achieved, after irradiation of 60Co gamma ray, by the Radiation Induced Surface Activation (RISA) phenomenon. To delineate the effect of RISA on boiling phenomena, surface wettability in a high-temperature environment and Critical Heat Flux (CHF) of metal oxides irradiated by gamma rays were investigated. A CHF experiment in the pool boiling condition was carried out under atmospheric pressure. The heating test section made of titanium was 0.2mm in thickness, 3mm in height, and 60mm in length. Oxidation of the surfaces was carried out by plasma jetting for 40 seconds. The test section was irradiated by 60Co gamma ray with predetermined radiation intensity and period. The CHF of oxidized titanium was improved up to 100 percent after 800kGy 60Co gamma ray irradiation. We call this effect Radiation Induced Boiling Enhancement (RIBE). Before we conducted the CHF experiment, contact angles of the test pieces were measured to show the relationship between wettability and CHF. The CHF in the present experiment increases with surface wettability in the same manner as shown by Liaw and Dhir's results

  11. Ion irradiation-induced precipitation of Cr23C6 at dislocation loops in austenitic steel

    International Nuclear Information System (INIS)

    Jin, Shuoxue; Guo, Liping; Luo, Fengfeng; Yao, Zhongwen; Ma, Shuli; Tang, Rui

    2013-01-01

    The irradiation-induced precipitates in argon ion-irradiated austenitic stainless steel at 550 °C were examined via transmission electron microscopy. The selected-area electron diffraction patterns of precipitates indicated unambiguously that the precipitates were Cr 23 C 6 carbides. It was observed directly for the first time that irradiation-induced Cr 23 C 6 precipitates formed at dislocation loops in austenitic stainless steel, and coarsened with increasing irradiation dose.

  12. Study of cancer-specific chimeric promoters induced by irradiation

    International Nuclear Information System (INIS)

    Xiong Jie; Zhou Yunfeng; Sun Wenjie; Wang Weifeng; Liao Zhengkai; Zhou Fuxiang; Xie Conghua

    2010-01-01

    Objective: To combine the radio-inducible CArG element with cancer-specific human telomerase reverse transcriptase (hTERT) gene promoter, and to construct the novel chimeric promoters. Methods: The synthetic hTERT promoters containing different number of radio-inducible CArG elements were constructed, and the activities of the promoters in the cancer cells (HeLa, A549, and MHCC97 cells) and nomal cells (hEL cells) were detected by using luciferase-reporter assays after the treatment of irradiation (a single or fractionated irradiation dose). Results: Synthetic promoter containing 6 repeated CArG units was better in radio-inducibility than any other promoters containing different number of CArG units, and nearly maximum levels obtained at 4-6 Gy. The very low activities of the chimeric promoters could be detected in normal hEL cells. A similar level of reporter gene expression was observed after 3 fractionated doses of 2 Gy compared with a single dose of 6 Gy in cancer cells. Conclusions: The cancer-specific chimeric promoter containing 6 CArG elements showes the best radio-response, and the chimeric promoter system has the potential in cancer gene therapy. (authors)

  13. EFFICIENCY OF BORAGE SEEDS OIL AGAINST GAMMA IRRADIATION-INDUCED HEPATOTOXICITY IN MALE RATS: POSSIBLE ANTIOXIDANT ACTIVITY.

    Science.gov (United States)

    Khattab, Hala A H; Abdallah, Inas Z A; Yousef, Fatimah M; Huwait, Etimad A

    2017-01-01

    Borage ( Borago officinal L.) is an annual herbaceous plant of great interest because its oil contains a high percentage of γ-linolenic acid (GLA). The present work was carried out to detect fatty acids composition of the oil extracted from borage seeds (BO) and its potential effectiveness against γ-irradiation- induced hepatotoxicity in male rats. GC-MS analysis of fatty acids methyl esters of BO was performed to identify fatty acids composition. Sixty rats were divided into five groups (12 rats each): Control, irradiated; rats were exposed to (6.5 Gy) of whole body γ-radiation, BO (50 mg/kg b.wt), irradiated BO post-treated and irradiated BO prepost-treated. Six rats from each group were sacrificed at two time intervals 7 and 15 days post-irradiation. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT) levels, lipids profile, as well as serum and hepatic reduced glutathione (GSH) and lipid peroxide (malondialdehyde) (MDA) levels were assessed. Histopathological examination of liver sections were also carried out. The results showed that the high contents of BO extracted by cold pressing, were linoleic acid (34.23%) and GLA (24.79%). Also, oral administration of BO significantly improved serum levels of liver enzymes, lipids profile, as well as serum and hepatic GSH and MDA levels (p<0.001) as compared with irradiated rats after 15 days post irradiation. Moreover, it exerted marked amelioration against irradiation-induced histopathological changes in liver tissues. The improvement was more pronounced in irradiated BO prepost-treated group than irradiated BO post-treated. BO has a beneficial role in reducing hepatotoxicity and oxidative stress induced by radiation exposure. Therefore, BO may be used as a beneficial supplement for patients during radiotherapy treatment.

  14. Sustained improvement of intractable rheumatoid arthritis after total lymphoid irradiation

    International Nuclear Information System (INIS)

    Field, E.H.; Strober, S.; Hoppe, R.T.

    1983-01-01

    Total lymphoid irradiation (TLI) was administered to 11 patients who had intractable rheumatoid arthritis that was unresponsive to conventional medical therapy, including aspirin, multiple nonsteroidal antiinflammatory drugs, gold salts, and D-penicillamine. Total lymphoid irradiation was given as an alternative to cytotoxic drugs such as azathioprine and cyclophosphamide. After radiotherapy, 9 of the 11 patients showed a marked improvement in clinical disease activity as measured by morning stiffness, joint tenderness, joint swelling, and overall functional abilities. The mean improvement of disease activity in all patients ranged from 40-70 percent and has persisted throughout a 13-28 month followup period. This improvement permitted the mean daily steroid dose to be reduced by 54%. Complications included severe fatigue and other constitutional symptoms during radiotherapy, development of Felty's syndrome in 1 patient, and an exacerbation of rheumatoid lung disease in another. After therapy, all patients exhibited a profound T lymphocytopenia, and a reversal in their T suppressor/cytotoxic cell to helper cell ratio. The proliferative responses of peripheral blood mononuclear cells to phytohemagglutinin, concanavalin A, and allogeneic leukocytes (mixed leukocyte reaction) were markedly reduced, as was in vitro immunoglobulin synthesis after stimulation with pokeweed mitogen. Alterations in T cell numbers and function persisted during the entire followup period, except that the mixed leukocyte reaction showed a tendency to return to normal values

  15. Preliminary examination of induced radio activity in pepper by 10 MeV electron irradiation

    International Nuclear Information System (INIS)

    Furuta, Masakazu; Katayama, Tadashi; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Toratani, Hirokazu; Takeda, Atsuhiko

    1989-01-01

    β-ray measurement was performed on 10 MeV electron-irradiated black pepper and white pepper in order to reconfirm the wholesomeness of irradiated food and present unambiguous data to general consumers concerning about the induced radioactivity in the irradiated foods. From elemental composition of the samples and investigation of photonuclear reactions, several β-emmitters were listed up. But no radioactivity other than from natural sources was detected in the irradiated sample by β-ray counting with 2 π gass flow counter, suggesting that the induced β-emmitters in the irradiated sample was below the detection limit of its induced radioactivity. (author)

  16. Studies on safety and efficacy of gamma-irradiated ginseng -Development of irradiation techniques for quality improvement of ginseng products-

    International Nuclear Information System (INIS)

    Cho, Han Ok; Byun, Myung Woo; Cho, Sung Kee; Kand, Il Joon; Yook, Hong Sun

    1995-02-01

    Gamma irradiation was applied to red ginseng powder for improving microbiological and physicochemical quality. Irradiation at 5-10 kGy was effective for sterilizing all contaminated microorganisms of red ginseng powder. At the dose levels, major physicochemical properties (saponin, amino acids, sugars, proximate composition, color, pH, acidity, hydrogen donating activity, fatty acids and minerals) were not changed by gamma irradiation upto 10 kGy. Based upon the results, it is concluded that gamma irradiation can effectively improve the microbiological quality of red ginseng powders without significant unfavorable changes. Therefore, it is suggested that irradiation technology is a viable alternative method to other sanitary process containing chemical fumigant and will be useful for the improvement of the quality of red ginseng powders and their products. 5 figs, 18 tabs, 92 refs. (Author)

  17. Studies on safety and efficacy of gamma-irradiated ginseng -Development of irradiation techniques for quality improvement of ginseng products-

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Han Ok; Byun, Myung Woo; Cho, Sung Kee; Kand, Il Joon; Yook, Hong Sun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    Gamma irradiation was applied to red ginseng powder for improving microbiological and physicochemical quality. Irradiation at 5-10 kGy was effective for sterilizing all contaminated microorganisms of red ginseng powder. At the dose levels, major physicochemical properties (saponin, amino acids, sugars, proximate composition, color, pH, acidity, hydrogen donating activity, fatty acids and minerals) were not changed by gamma irradiation upto 10 kGy. Based upon the results, it is concluded that gamma irradiation can effectively improve the microbiological quality of red ginseng powders without significant unfavorable changes. Therefore, it is suggested that irradiation technology is a viable alternative method to other sanitary process containing chemical fumigant and will be useful for the improvement of the quality of red ginseng powders and their products. 5 figs, 18 tabs, 92 refs. (Author).

  18. Effect of quercetin on paracetamole-induced liver disjunction in irradiated rats

    International Nuclear Information System (INIS)

    Hedayat, I.S.

    2005-01-01

    Nowadays, increasing attention has been given to the role of free radicals generated through oxidation stress. Persons subjected to radiation, such as radiotherapy, consuming analgesic drugs such as paracetamole which accumulates at relatively high concentration in liver, are in need to be investigated to explore the synergetic effects of these stresses. Many radical scavengers, interestingly naturally occurring antioxidants, have been found to be effective in inhibiting the oxidative damage Quercetin, the well known phenolic compound widely present in the plant kingdom, has been investigated for its possible protection effect against gamma irradiation and paracetamole-induced hepatic damage. Data revealed serious effects of oral administration of sublethal dose of paracetamole (500 mg/kg) and/or exposure to 6 Gy whole body gamma irradiation on liver. This damage is reflected by increased hepatic levels of MDA, carbonyl content and ALT activity, associated by decrease in hepatic SOD, catalase and GSH when compared with respective control values. The combination of quercetin with paracetamole and/or gamma irradiation have clearly reduced liver damage. It was noticed that the restoration of peroxides and carbonyls rates has occurred. Quercetin seems to act by activation of the turnover of SOD, catalase and GSH and permitting the capitation of reactive metabolites of paracetamole as well as its ability in quenching free radicals induced by exposure of rats to gamma irradiation, thus improving regeneration in the biological tissues

  19. The effect of mesenchymal stem cells on the p53 methylation in irradiation-induced thymoma in C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Hai B Zheng

    2015-01-01

    Conclusion: MSCs decrease the incidence of irradiation-induced thymoma, which may be mediated by improving thymus microenvironment and changing the methylation of p53 promoter, and subsequently maintaining genome′s stability.

  20. On the analogy between thermally and irradiation induced creep

    International Nuclear Information System (INIS)

    Cozzarelli, F.A.; Huang, S.

    1977-01-01

    Employing an analogy between thermally induced and irradiation induced creep, physical arguments are used first to deduce a one-dimensional constitutive relation for metals under stress in a high temperature and high neutron flux field. This constitutive relation contains modified superposition integrals in which the temperature and flux dependence of the material parameters is included via the use of two reduced time scales; linear elastic, thermal expansion and swelling terms are also included. A systematic development based on thermodynamics, with the stress, temperature increment and defect density increment as independent variables in the Gibbs free energy, is then employed to obtain general three-dimensional memory integrals for strain; the entropy and coupled energy equation are also obtained. Modified superposition integrals similar to those previously obtained by physical argument are then obtained by substituting special functions into the results of the thermodynamic analysis, and the special case of an isotropic stress power law is examined in detail. (Auth.)

  1. Surgical treatment of 2 cases of irradiation induced constrictive pericarditis

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, Hiroshi; Takahashi, Wataru; Yoshii, Shinpei [Yamanashi Medical Univ., Tamaho (Japan)] (and others)

    1999-11-01

    A 72-years-old man underwent radiation therapy (62 Gy) for esophageal carcinoma. Twelve months later, symptoms of heart failure such as syncope, cough and hepatomegaly manifested. On catheter study, a dip and plateau pattern of right ventricular pressure curve was evident. Pericardiectomy without extracorporeal circulation was performed. Operative findings and pathological results were compatible with radiation-induced constrictive pericarditis. He recovered from the heart failure, and has been doing well 3 months after the surgery. A 54-years-old man underwent thymectomy for malignant thymoma. He underwent a radiation therapy (52 Gy) postoperatively. After 12 months from the irradiation, syncope and dyspnea manifested. On catheter study, a dip and plateau pattern of right ventricular pressure curve was observed. Pericardiectomy with extracorporeal circulation was performed. He recovered from the heart failure after pericardiectomy, however he died of radiation-induced pneumonitis 6 months later. (author)

  2. Deuterium ion irradiation induced blister formation and destruction

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jaemin; Kim, Nam-Kyun; Kim, Hyun-Su; Jin, Younggil; Roh, Ki-Baek; Kim, Gon-Ho, E-mail: ghkim@snu.ac.kr

    2016-11-01

    Highlights: • The areal number density of blisters on the grain with (1 1 1) plane orientation increased with increasing ion fluence. • No more blisters were created above the temperature about 900 K due to high thermal mobility of ions and inactivity of traps. • The destruction of blister at the boundary induced by sputtering is proposed. • The blisters were destructed at the position about the boundary by high sputtering yield of oblique incident ions and thin thickness due to plastic deformation at the boundary. - Abstract: The blisters formation and destruction induced by the deuterium ions on a polycrystalline tungsten were investigated with varying irradiation deuterium ion fluence from 3.04 × 10{sup 23} to 1.84 × 10{sup 25} D m{sup −2} s{sup −1} and an fixed irradiated ion energy of 100 eV in an electron cyclotron resonance plasma source, which was similar to the far-scrape off layer region in the nuclear fusion reactors. Target temperature was monitored during the irradiation. Most of blisters formed easily on the grain with (1 1 1) plane orientation which had about 250 nm in diameter. In addition, the areal number density of blisters increased with increasing the ion fluence under the surface temperature reaching to about 900 K. When the fluence exceeded 4.6 × 10{sup 24} D m{sup −2}, the areal number density of the blister decreased. It could be explained that the destruction of the blister was initiated by erosion at the boundary region where the thickness of blister lid was thin and the sputtering yield was high by oblique incident ions, resulting in remaining the lid open, e.g., un-eroded center dome. It is possible to work as a tungsten dust formation from the plasma facing divertor material at far-SOL region of fusion reactor.

  3. Beam-induced temperature changes in HVEM irradiations

    International Nuclear Information System (INIS)

    Garner, F.A.; Thomas, L.E.; Gelles, D.S.

    1975-01-01

    The peak value of the temperature distribution induced by energy loss of 1.0 MeV electrons in traversing a typical HVEM irradiation specimen can be very substantial. The origin and various features of this distribution were analyzed for a variety of specimen geometries. The major parametric dependencies are shown to be relatively independent of specimen geometry, however, and allow the definition of a scaling relationship that can be employed to predict temperature rises in materials that cannot be measured directly. The use of this scaling relationship requires that the experimenter minimize perturbations of the heat flow due to proximity of the central hole in the specimen. An experimental method of determining directly the magnitude and distribution of beam-induced temperature profiles was developed which utilizes the order-disorder transformation in Fe 3 Al and Cu 3 Au. Scaling of experimentally determined temperature changes leads to more realistic estimates of the total temperature rise than are currently available in various literature tabulations. The factors which determine the optimum selection of irradiation parameters for a given experiment are also discussed

  4. Irradiation induced surface segregation in concentrated alloys: a contribution

    International Nuclear Information System (INIS)

    Grandjean, Y.

    1996-01-01

    A new computer modelization of irradiation induced surface segregation is presented together with some experimental determinations in binary and ternary alloys. The model we propose handles the alloy thermodynamics and kinetics at the same level of sophistication. Diffusion is described at the atomistic level and proceeds vis the jumps of point defects (vacancies, dumb-bell interstitials): the various jump frequencies depend on the local composition in a manner consistent with the thermodynamics of the alloy. For application to specific alloys, we have chosen the simplest statistical approximation: pair interactions in the Bragg Williams approximation. For a system which exhibits the thermodynamics and kinetics features of Ni-Cu alloys, the model generates the behaviour parameters (flux and temperature) and of alloy composition. Quantitative agreement with the published experimental results (two compositions, three temperatures) is obtained with a single set of parameters. Modelling austenitic steels used in nuclear industry requires taking into account the contribution of dumbbells to mass transport. The effects of this latter contribution are studied on a model of Ni-Fe. Interstitial trapping on dilute impurities is shown to delay or even suppress the irradiation induced segregation. Such an effect is indeed observed in the experiments we report on Fe 50 Ni 50 and Fe 49 Ni 50 Hf 1 alloys. (author)

  5. Ordering of pentacene in organic thin film transistors induced by irradiation of infrared light

    International Nuclear Information System (INIS)

    Wang, C. H.; Chen, S. W.; Hwang, J.

    2009-01-01

    The device performances of pentacene-based organic thin film transistors (OTFTs) were greatly improved by irradiation of infrared light. The field effect mobility and maximum drain current increase from 0.20±0.01 to 0.57±0.02 cm 2 /V s and 1.14x10 -5 to 4.91x10 -5 A, respectively. The (001) peak of the pentacene 'thin film' phase increases in intensity by 4.5 times after infrared irradiation at 50 W for 2 h. Two types of crystal orientations, i.e., 'crystal I' (2θ=5.91 deg.) and 'crystal II' (2θ=5.84 deg.), coexist in the pentacene. The improvement of the characteristics of OTFTs is attributed to crystallization and crystal reorientation induced by infrared light.

  6. STI571 (Gleevec) improves tumor growth delay and survival in irradiated mouse models of glioblastoma

    International Nuclear Information System (INIS)

    Geng Ling; Shinohara, Eric T.; Kim, Dong; Tan Jiahuai; Osusky, Kate; Shyr, Yu; Hallahan, Dennis E.

    2006-01-01

    Purpose: Glioblastoma multiforme (GBM) is a devastating brain neoplasm that is essentially incurable. Although radiation therapy prolongs survival, GBMs progress within areas of irradiation. Recent studies in invertebrates have shown that STI571 (Gleevec; Novartis, East Hanover, NJ) enhances the cytotoxicity of ionizing radiation. In the present study, the effectiveness of STI571 in combination with radiation was studied in mouse models of GBM. Methods and Materials: Murine GL261 and human D54 GBM cell lines formed tumors in brains and hind limbs of C57BL6 and nude mice, respectively. GL261 and D54 cells were treated with 5 μmol/L of STI571 for 1 h and/or irradiated with 3 Gy. Protein was analyzed by Western immunoblots probed with antibodies to caspase 3, cleaved caspase 3, phospho-Akt, Akt, and platelet-derived growth factor receptor (PDGFR) α and β. Tumor volumes were assessed in mice bearing GL261 or D54 tumors treated with 21 Gy administered in seven fractionated doses. Histologic sections from STI571-treated mice were stained with phospho-Akt and phospho-PDGFR β antibodies. Kaplan-Meier survival curves were used to study the response of mice bearing intracranial implants of GL261. Results: STI571 penetrated the blood-brain barrier, which resulted in a reduction in phospho-PDGFR in GBM. STI571-induced apoptosis in GBM was significantly enhanced by irradiation. STI571 combined with irradiation induced caspase 3 cleavage in GBM cells. Glioblastoma multiforme response to therapy correlated with an increase in tumor growth delay and survival when STI571 was administered in conjunction with daily irradiation. Conclusion: These findings suggest that STI571 has the potential to augment radiotherapy and thereby improve median survival

  7. γIrradiation induced formation of PCB-solvent adducts in aliphatic solvents

    International Nuclear Information System (INIS)

    Lepine, F.; Milot, S.; Gagne, N.

    1990-01-01

    γIrradiation induced formation of PCB-solvent adducts was investigated as a model for PCB residues in irradiated food. Formation of cyclohexyl adducts of PCBs was found to be significant when pure PCB congeners and Aroclor mixture were irradiated in cyclohexane and cyclohexene. Reaction pathways were investigated, and the effects of oxygen and electron scavenger were studied

  8. Radiation induced improvement of superconducting properties of HTSC materials (Review)

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Kirk, M.A.

    2002-01-01

    The aim of this paper is to demonstrate unique opportunities for significant improvement of superconducting properties of YBaCuO single crystals, ceramics, films and tapes by means of different irradiation. It was found (about 200 papers) that irradiation with moderate doses of high energy particles (electron, protons, neutrons, ions) results in significant enhancement of magnetization and Jc at high magnetic fields (1-5 T). So called flux pinning centers responsible for such enhancement are still a subject for study. Most researches ascribe the stronger pinners to linear and columnar defects, and weaker ones to point defects. Several researches reported also about small increase of the critical temperature Tc after ionizing irradiation (X- or gamma-rays). All these data are related to improvement of Jc in bulk - intragranular critical current, which is much higher than the real intragranular transport critical current Ic limited by weak intergrain contacts. Much less studied is the effect of irradiation on the intragranular critical current and conductivity. Several authors found some increase of current carrying ability of YBaCuO ceramics, crystals and films after X-ray , gamma-ray, oxygen plasma, electron and proton irradiations. However there was not mentioned direct correlation between the radiation induced changes in the Tc, Jc, Ic and the normal state resistivity. Only a few papers are devoted to synthesis or sintering the particular texture ensuring enhancement of the intergranular contacts by minimizing both off-plan and in-plan grain misorientation. The transport Ic at 77 K and the normal state resistivity correlated well each to other and with the c-axis-texturing degree of the YBaCuO ceramics. Our latest experiment on proton irradiation at elevated temperatures of the coated conductors (the second generation of HTSC tapes) demonstrated a noticeable increase of the transport (intergranular) Ic at 77 K and a significant decrease of the normal state

  9. Radiation-induced organogenesis: effects of irradiated medium and its components on tobacco tissue culture

    International Nuclear Information System (INIS)

    Degani, N.

    1975-01-01

    Gamma irradiated medium induces the formation of buds in non-irradiated dark growth tobacco callus (Nicotiana tabacum Var. Wisconsin No.38). Experiments were conducted to determine the component(s) of the medium that is effective in this radiation-induced organogenesis. Fraction of medium were irradiated singly and in combination, then combined with non-irradiated fractions to form the complete growth medium. The results showed that irradiated indoleacetic acid (IAA) was not the effective component in the induction of organogensis. Omission of IAA from the medium resulted in the formation of buds, as expected. Irradiated myo-inositol induced organogenesis more consistently than the other irradiated components. The age of the inoculum tissue and its passage number from the tobacco stem affected the potency of the tobacco callus to organise. (author)

  10. Development of new techniques of using irradiation in the genetic improvement of warm season grasses and an assessment of the genetic and cytogenetic effects. Progress report, November 1, 1977--October 31, 1978

    International Nuclear Information System (INIS)

    Hanna, W.W.; Burton, G.W.

    1978-05-01

    Progress is reported on plant breeding programs for the genetic improvement of warm season grasses using irradiation as a tool. Data are included from studies on alteration of the protein quantity and quality in pearl millet grain by irradiation and mutation breeding; the effects of nitrogen and genotype on pearl millet grain; the effects of seed size on quality in pearl millet; irradiation breeding of sterile triploid turf Bermuda grasses; irradiation breeding of sterile coastcross-1, a forage grass, to increase winter hardiness; use of irradiation to induce resistance to rust disease; and an economic assessment of irradiation-induced mutants for plant breeding programs

  11. Structural changes and tribological performance of thermosetting polyimide induced by proton and electron irradiation

    International Nuclear Information System (INIS)

    Lv, Mei; Wang, Yanming; Wang, Qihua; Wang, Tingmei; Liang, Yongmin

    2015-01-01

    The structural changes and tribological performance of thermosetting polyimide were investigated by electron, proton or both combined irradiations at 25 keV in a ground-based simulation facility. Three forms of irradiations could lead to the formation of the carbonized layer on the polymer surface that could increase the hardness and adhesive force of the material. Proton irradiation induced more extensive changes in structure and friction behavior than electron irradiation by reason of the higher linear energy transfer value, and combined irradiation resulted in the largest impact, but which was less than the sum of the radiation effects of electron and proton. Moreover, the experimental results indicated that the changes in friction behavior are closely related with the carbonized layer, which was easily worn out in friction process and could introduce a shift from adhesion wear to three-body abrasive wear that reduced the wear rate and the friction coefficient. The friction process of irradiated samples could be divided into the initial stage and the steady stage. Three forms of irradiations all induced the high friction coefficient in the initial stage and the low friction coefficient in the steady stage, and the wear rate of the irradiated samples decreased in the order: electron irradiation>proton irradiation>combined irradiation. - Highlights: • Proton irradiation induced more extensive changes in structure and friction behavior than electron irradiation. • The effect of combined irradiation was less than that of the sum of electron and proton irradiation. • Three forms of irradiations all induced the high initial friction coefficient and the low steady-stage friction coefficient. • The initial friction stage means a fast-wearing adhesive process while the steady-state of the system is a three-body abrasion

  12. Glucidic and lipidic metabolic changes in rats induced by irradiation and the effect of adrenalectomy

    Energy Technology Data Exchange (ETDEWEB)

    Groza, P; Ghizari, E; Butculescu, I; Ciontescu, L; Ciuntu, L

    1975-01-01

    In experiments on X-irradiated rats (1000 R) the hepatic glycogen, total lipids, phospholipids content, and plasma glucose, cholesterol and beta-lipoprotein concentration were determined in intact and adrenalectomized animals. It was confirmed that irradiation produces a hepatic glycogen and blood glucose increased concentration. The glucidic metabolic response on irradiation is diminished by adrenalectomy. The adrenalectomy-induced modifications in the lipid metabolism of irradiated rats are more inconstant, which corresponds with its relative independence from glucocorticoid hormones.

  13. Fatigue behavior of Type 316 stainless steel following neutron irradiation inducing helium

    International Nuclear Information System (INIS)

    Grossbeck, M.L.; Liu, K.C.

    1980-01-01

    Since a tokamak reactor operates in a cyclic mode, thermal stresses will result in fatigue in structural components, especially in the first wall and blanket. There has been limited work on fatigue in irradiated alloys but none on irradiated materials containing significant amounts of irradiation-induced helium. To provide scoping data and to study the effects of irradiation on fatigue behavior, 20%-cold-worked type 316 stainless steel from the MFE reference heat was studied

  14. CR-39 as induced track detector in reactor: irradiation effect

    International Nuclear Information System (INIS)

    Zylberberg, H.

    1989-07-01

    A systematic study about reactor's neutrons radiation effect and gamma radiation effect on the properties of CR-39 that are significant for its use as induced fission track detector is showed. The following studies deserved attention: kinetics of the fission track chemical development; efficiency to register and to develop fission track; losses of developable tracks; variation in the number of developable tracks and variation in the visible and ultraviolet radiation spectrum. The dissertation is organized in seven specific chapters: solid state nuclear tracks (SSNT); CR-39 as SSNT; objectives and problems presentation; preparation and characterization of CR-39 as SSNT; gamma irradiation effect on the properties of CR-39 as SSNT; reactor neutron irradiation effect on the properties of CR-39 as SSNT and, results discussions and conclusions. The main work contributions are the use of CR-39 in the determination of fissionable nuclide as thorium and uranium in solid and liquid samples; gamma radiation damage on CR-39 as well as the reactor's neutron damage on CR-39. (B.C.A.) 62 refs, 53 figs, 21 tabs

  15. Irradiation-induced dimensional changes of poorly crystalline carbons

    International Nuclear Information System (INIS)

    Bullock, R.E.

    1979-01-01

    Data are presented on irradiation-induced changes of poorly crystalline carbons at high temperatures(>900 0 C). The materials surveyed include: (1) carbon fibers, (2) glassy carbons, (3) carbonaceous matrix materials for HTGR fuel rods and (4) pyrocarbons. The materials are listed in order of increasing stability, with maximum strains ranging from more than 50% for fibers to less than 10% for pyrocarbons. Dimensional changes of highly anisotropic carbon fibers appear to be sensitive to irradiation temperature, as slightly anisotropic pyrocarbons are, whereas temperature seems to have little influence on the behavior of isotropic glassy carbons over the range from 600 to 1350 0 C. Dimensional changes for graphite-filled matrix materials were roughly isotropic on the average and did not seem to be strongly temperature dependent for the lower fluences investigated. Increased graphite filler lowered volumetric dimensional changes of the matrix in agreement with a rule-of-mixtures relationship between change components for the filler and the less-stable binder phases. Instabilities of all of the poorly crystalline materials were generally greater than those for more crystalline carbons under the same conditions, including highly orientated graphites that approximate single-crystal behavior. (author)

  16. Clustered DNA damage induced by proton and heavy ion irradiation

    International Nuclear Information System (INIS)

    Davidkova, M.; Pachnerova Brabcova, K; Stepan, V.; Vysin, L.; Sihver, L.; Incerti, S.

    2014-01-01

    Ionizing radiation induces in DNA strand breaks, damaged bases and modified sugars, which accumulate with increasing density of ionizations in charged particle tracks. Compared to isolated DNA damage sites, the biological toxicity of damage clusters can be for living cells more severe. We investigated the clustered DNA damage induced by protons (30 MeV) and high LET radiation (C 290 MeV/u and Fe 500 MeV/u) in pBR322 plasmid DNA. To distinguish between direct and indirect pathways of radiation damage, the plasmid was irradiated in pure water or in aqueous solution of one of the three scavengers (coumarin-3-carboxylic acid, dimethylsulfoxide, and glycylglycine). The goal of the contribution is the analysis of determined types of DNA damage in dependence on radiation quality and related contribution of direct and indirect radiation effects. The yield of double strand breaks (DSB) induced in the DNA plasmid-scavenger system by heavy ion radiation was found to decrease with increasing scavenging capacity due to reaction with hydroxyl radical, linearly with high correlation coefficients. The yield of non-DSB clusters was found to occur twice as much as the DSB. Their decrease with increasing scavenging capacity had lower linear correlation coefficients. This indicates that the yield of non-DSB clusters depends on more factors, which are likely connected to the chemical properties of individual scavengers. (authors)

  17. Heart malformation induced by ionizing irradiation in rat embryo

    International Nuclear Information System (INIS)

    Higo, Hiromi; Satow, Yukio; Lee, Juing-Yi; Higo, Ken-ichi

    1986-01-01

    Proteins were extracted from morphologically abnormal heart induced by gamma-irradiation, and fractionated into the soluble and the insoluble (''muscle structural proteins'') fractions. Protein compositions of these fractions were examined by O'Farrell's two-dimensional polyacrylamide gel electrophoresis, and also by non-equilibrium pH gradient electrophoresis. The protein patterns thus obtained were then compared with those of the normal heart. Among about 450 major protein species observed, no significant difference was detected between normal and abnormal hearts as to the intensity and the location of the protein spots. Several minor protein species were found varying among the samples examined, but their relevance to the heart malformation are not clear at present. (author)

  18. Irradiation-induced creep in graphite: a review

    International Nuclear Information System (INIS)

    Price, R.J.

    1981-08-01

    Data on irradiation-induced creep in graphite published since 1972 are reviewed. Sources include restrained shrinkage tests conducted at Petten, the Netherlands, tensile creep experiments with continuous strain registration at Petten and Grenoble, France, and controlled load tests with out-of-reactor strain measurement performed at Oak Ridge National Laboratory, Petten, and in the United Kingdom. The data provide reasonable confirmation of the linear viscoelastic creep model with a recoverable transient strain component followed by a steady-state strain component, except that the steady-state creep coefficient must be treated as a function of neutron fluence and is higher for tensile loading than for compressive loading. The total transient creep strain is approximately equal to the preceding elastic strain. No temperature dependence of the transient creep parameters has been demonstrated. The initial steady-state creep coefficient is inversely proportional to the unirradiated Young modulus

  19. Studies on the graphite rupture under irradiation induced strains

    International Nuclear Information System (INIS)

    Jouquet, G.; Berthion, Y.; L'Homme, A.

    1980-01-01

    Following the RMG experiments (failure of graphite by mechanical effect, i.e. under very high temperature gradient) an experimental program called RWG (Failure of Graphite by WIGNER effect) was initiated in 75 at C.E.A. 3 experiments have been already performed in the OSIRIS reactor at Saclay: RWG 01, 02 and 03. A 4th one, RWG04, is scheduled for the end of 79, may be in collaboration with GERMANY. The aim of the RWG experiments is to induce internal stresses in graphite blocks by irradiation at high temperature which would lead or not to their failure so one could bracket, as tightly as possible, the critical value for failure onset in given experimental conditions

  20. Effectiveness of trimethylopropane trimethacrylate for the electron-beam-irradiation-induced cross-linking of polylactic acid

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Hon-Meng [Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur (Malaysia); Bee, Soo-Tueen, E-mail: beest@utar.edu.my [Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur (Malaysia); Ratnam, C.T. [Radiation Processing Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Sin, Lee Tin; Phang, Yee-Yao; Tee, Tiam-Ting [Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur (Malaysia); Rahmat, A.R. [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2014-01-15

    Highlights: • Investigation of trimethylopropane trimethacrylate (TMPTMA) on electron beam irradiated PLA. • Irradiated PLA blends were weakened by incorporation of high amount of TMPTMA. • TMPTMA interacts with polymer free radicals to build crosslinking network. -- Abstract: The purpose of this research was to investigate the effects of various loading levels of trimethylopropane trimethacrylate (TMPTMA) on the properties of polylactic acid (PLA) cross-linked via electron-beam irradiation. PLA was compounded with 3–5 wt.% of TMPTMA to induce cross-linking upon subjection to electron-beam irradiation doses of 25–250 kGy. The physical properties of the PLA samples were characterised by means of X-ray diffraction, gel fraction and scanning electron microscopy analyses on fractured surfaces after tensile tests. The presence of TMPTMA in PLA was found to effectively increase the crystallite size and gel fraction. However, higher loading levels of TMPTMA could compromise the properties of the PLA/TMPTMA samples, indicating that a larger amount of monomer free radicals might promote degradation within the substantially cross-linked amorphous phase. Irradiation-induced cross-linking in the samples could improve the cross-linking density while decreasing the elongation and interfering with the crystallisation. These effects are caused by the intensive irradiation-induced chain scission that is responsible for the deterioration of the mechanical and crystalline properties of the samples.

  1. Effectiveness of trimethylopropane trimethacrylate for the electron-beam-irradiation-induced cross-linking of polylactic acid

    International Nuclear Information System (INIS)

    Ng, Hon-Meng; Bee, Soo-Tueen; Ratnam, C.T.; Sin, Lee Tin; Phang, Yee-Yao; Tee, Tiam-Ting; Rahmat, A.R.

    2014-01-01

    Highlights: • Investigation of trimethylopropane trimethacrylate (TMPTMA) on electron beam irradiated PLA. • Irradiated PLA blends were weakened by incorporation of high amount of TMPTMA. • TMPTMA interacts with polymer free radicals to build crosslinking network. -- Abstract: The purpose of this research was to investigate the effects of various loading levels of trimethylopropane trimethacrylate (TMPTMA) on the properties of polylactic acid (PLA) cross-linked via electron-beam irradiation. PLA was compounded with 3–5 wt.% of TMPTMA to induce cross-linking upon subjection to electron-beam irradiation doses of 25–250 kGy. The physical properties of the PLA samples were characterised by means of X-ray diffraction, gel fraction and scanning electron microscopy analyses on fractured surfaces after tensile tests. The presence of TMPTMA in PLA was found to effectively increase the crystallite size and gel fraction. However, higher loading levels of TMPTMA could compromise the properties of the PLA/TMPTMA samples, indicating that a larger amount of monomer free radicals might promote degradation within the substantially cross-linked amorphous phase. Irradiation-induced cross-linking in the samples could improve the cross-linking density while decreasing the elongation and interfering with the crystallisation. These effects are caused by the intensive irradiation-induced chain scission that is responsible for the deterioration of the mechanical and crystalline properties of the samples

  2. Effect of irradiation on the dental pulp tissues in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Kang, Ho Duk; Hwang, Eui Hwan; Lee, Sang Rae

    2005-01-01

    To observe the histological changes in the pulp tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups : control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. In the diabetes group, capillary dilatation was observed. However, there was no obvious morphologic alteration of the odontoblasts. In the irradiation group, generalized necrosis of the dental pulp tissues was observed. Vacuolation of the odontoblasts and dilatation of the capillaries were noted in the early experimental phases. In the diabetes-irradiation group, generalized degeneration of the dental pulp tissues was observed. Vacuolation of the dental pulp cells and the odontoblasts was noted in the late experimental phases. This experiment suggest that dilatation of the capillaries in the dental pulp tissue is induced by diabetic state, and generalized degeneration of the dental pulp tissues is induced by irradiation of the diabetic group.

  3. Risk factors of conventional irradiation-induced lower cranial neuropathy in patients with nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Pan Jianji; Hong Jinsheng; Zhang Yu

    2006-01-01

    Objective: To study the risk factors of radiation-induced lower cranial neuropathy (RILCN) after conventional radiotherapy in patients with nasopharyngeal carcinoma, and to improve the radiotherapeutic planning. Methods: A hundred cases received radical radiotherapy of nasopharyngeal carcinoma and 200 individual matched controls on sex, age and time to start the radiotherapy were studied. Conditional logistic regression model was used to analyze 13 risk factors related to development of RILCN. Results: Conditional logistic regression analysis revealed that cigarette smoking, irradiation scheme, radiation close to the superior neck, neck fibrosis and acute radiation-related dermatitis of neck were risk factors of RILCN, their relative risks were 4.594, 2.629, 1.072, 4.141 and 2.531, respectively. Among three external irradiation schemes, it is found that pre-auricular portal plus whole neck tangential portal irradiation had the highest risk of RILCN. Conclusions: The study suggested that the irradiation scheme of pre-auricular portal plus whole neck tangential portal should be no longer used. (authors)

  4. In situ transmission electron microscope studies of ion irradiation-induced and irradiation-enhanced phase changes

    International Nuclear Information System (INIS)

    Allen, C.W.

    1992-01-01

    Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing transmission electron microscopes (TEM) have been performed for several decades, involving irradiation-induced and irradiation-enhanced microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact; the development of TEM specimen holder sin which specimen temperature can be controlled in the range 10-2200 K and the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes and presents two case studies involving in situ experiments performed in an HVEM to illustrate the strategies of such an approach of the materials research of irradiation effects

  5. Irradiation-induced precipitates in a neutron irradiated 304 stainless steel studied by three-dimensional atom probe

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, T., E-mail: ttoyama@imr.tohoku.ac.jp [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Narita-cho 2145-2, Oarai, Ibaraki 311-1313 (Japan); Nozawa, Y. [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Narita-cho 2145-2, Oarai, Ibaraki 311-1313 (Japan); Van Renterghem, W. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, 2400 Mol (Belgium); Matsukawa, Y.; Hatakeyama, M.; Nagai, Y. [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Narita-cho 2145-2, Oarai, Ibaraki 311-1313 (Japan); Al Mazouzi, A. [EDF R and D, Avenue des Renardieres Ecuelles, 77818 Moret sur Loing Cedex (France); Van Dyck, S. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, 2400 Mol (Belgium)

    2011-11-15

    Highlights: > Irradiation-induced precipitates in a 304 stainless steel were investigated by three-dimensional atom probe. > The precipitates were found to be {gamma}' precipitates (Ni{sub 3}Si). > Post-irradiation annealing was performed to discuss the contribution of the precipitates to irradiation-hardening. - Abstract: Irradiation-induced precipitates in a 304 stainless steel, neutron-irradiated to a dose of 24 dpa at 300 deg. C in the fuel wrapper plates of a commercial pressurized water reactor, were investigated by laser-assisted three-dimensional atom probe. A high number density of 4 x 10{sup 23} m{sup -3} of Ni-Si rich precipitates was observed, which is one order of magnitude higher than that of Frank loops. The average diameter was {approx}10 nm and the average chemical composition was 40% Ni, 14% Si, 11% Cr and 32% Fe in atomic percent. Over a range of Si concentrations, the ratio of Ni to Si was {approx}3, close to that of {gamma}' precipitate (Ni{sub 3}Si). In some precipitates, Mn enrichment inside the precipitate and P segregation at the interface were observed. Post-irradiation annealing was performed to discuss the contribution of the precipitates to irradiation-hardening.

  6. Hepatocyte transplantation improves early survival after partial hepatic resection and irradiation

    International Nuclear Information System (INIS)

    Guha, C.; Sharma, A.; Alfieri, A.; Guha, U.; Sokhi, R.; Gagandeep, S.; Gupta, S.; Vikram, B.; RoyChowdhury, J.

    1997-01-01

    Purpose: Radiation therapy (RT) is limited in its role as an adjuvant therapy of intrahepatic malignancies because of lower tolerance of human liver to irradiation (TD (5(5)) -TD (50(5)) ∼ 30-40 Gy). Although, surgical resection of primary or metastatic hepatic tumors has been shown to prolong survival, it is often limited by the presence of residual disease. RT could potentially improve survival of patients with positive surgical margins. However, radiation damage to the liver may be enhanced by hepatocellular proliferation induced by partial hepatic (PH) resection. We hypothesize that hepatocyte transplantation would be able to provide metabolic support and modulate the development of radiation-induced liver disease post-resection. The present study was designed to test the potential of hepatocyte transplantation in modifying the outcome of hepatocellular damage induced by PH and RT. Methods: Adult male Fischer 344 rats (Charles River) received hepatic irradiation of 50 Gy in a single fraction, after surgical exposure and shielding of the stomach and intestine, using a 320 MGC Philips orthovoltage unit. Immediately following irradiation, a two-third partial hepatectomy was performed. Four days post-radiation, the treatment group was injected with 5 x 10 6 syngeneic hepatocytes into the splenic pulp after a left subcostal incision, which allows homogeneous liver engraftment of the transplanted hepatocytes. Hematoxylin and eosin stains of liver biopsies, performed at various time points (3 days, 1, 2, 3 weeks or, anytime when animals died) were used for histologic evaluation. Time-adjusted survival was calculated from the date of irradiation by the product-limit Kaplan-Meier method, adjusting the denominator at every time point for the number of rats at risk. Results: Eight weeks after RT, 30% (n = 11) of the control animals (PH + 50 Gy) were alive compared to 100% (n = 9) of the transplant recipients (p <0.05). The median survival of the control group was 15

  7. Radiation-induced neuropathies: collateral damage of improved cancer prognosis

    International Nuclear Information System (INIS)

    Pradat, Pierre-Francois; Maisonobe, Thierry; Psimaras, Dimitri; Lenglet, Timothee; Porcher, Raphael; Lefaix, J.L.; Delenian, S.

    2012-01-01

    Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system. Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation. The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and

  8. Induced mutations for crop improvement

    International Nuclear Information System (INIS)

    Micke, A.; Donini, B.; Maluszynski, M.

    1990-01-01

    Mutation induction has become an established tool in plant breeding to supplement existing germ plasma and to improve cultivars in certain specific traits. Hundreds of improved varieties have been released to farmers for many different crop species, demonstrating the economic value of the technology. Limitations arise mainly from the large mutagenized populations to be screened and from the unsatisfactory selection methods. Both limitations may be eased to some extent by advances in techniques of plant in-vitro culture. (author). Refs, 1 fig., 7 tabs

  9. Temperature annealing of tracks induced by ion irradiation of graphite

    International Nuclear Information System (INIS)

    Liu, J.; Yao, H.J.; Sun, Y.M.; Duan, J.L.; Hou, M.D.; Mo, D.; Wang, Z.G.; Jin, Y.F.; Abe, H.; Li, Z.C.; Sekimura, N.

    2006-01-01

    Highly oriented pyrolytic graphite (HOPG) samples were irradiated by Xe ions of initial kinetic energy of 3 MeV/u. The irradiations were performed at temperatures of 500 and 800 K. Scanning tunneling microscopy (STM) images show that the tracks occasionally have elongated structures under high-temperature irradiation. The track creation yield at 800 K is by three orders of magnitude smaller compared to that obtained during room-temperature irradiation. STM and Raman spectra show that amorphization occurs in graphite samples irradiated at 500 K to higher fluences, but not at 800 K. The obtained experimental results clearly reveal that the irradiation under high temperature causes track annealing

  10. Correlation of simulated TEM images with irradiation induced damage

    International Nuclear Information System (INIS)

    Schaeublin, R.; Almeida, P. de; Almazouzi, A.; Victoria, M.

    2000-01-01

    Crystal damage induced by irradiation is investigated using transmission electron microscopy (TEM) coupled to molecular dynamics (MD) calculations. The displacement cascades are simulated for energies ranging from 10 to 50 keV in Al, Ni and Cu and for times of up to a few tens of picoseconds. Samples are then used to perform simulations of the TEM images that one could observe experimentally. Diffraction contrast is simulated using a method based on the multislice technique. It appears that the cascade induced damage in Al imaged in weak beam exhibits little contrast, which is too low to be experimentally visible, while in Ni and Cu a good contrast is observed. The number of visible clusters is always lower than the actual one. Conversely, high resolution TEM (HRTEM) imaging allows most of the defects contained in the sample to be observed, although experimental difficulties arise due to the low contrast intensity of the smallest defects. Single point defects give rise in HTREM to a contrast that is similar to that of cavities. TEM imaging of the defects is discussed in relation to the actual size of the defects and to the number of clusters deduced from MD simulations

  11. Photodynamic therapy improves the ultraviolet-irradiated hairless mice skin

    Science.gov (United States)

    Jorge, Ana Elisa S.; Hamblin, Michael R.; Parizotto, Nivaldo A.; Kurachi, Cristina; Bagnato, Vanderlei S.

    2014-03-01

    Chronic exposure to ultraviolet (UV) sunlight causes premature skin aging. In light of this fact, photodynamic therapy (PDT) is an emerging modality for treating cancer and other skin conditions, however its response on photoaged skin has not been fully illustrated by means of histopathology. For this reason, the aim of this study was analyze whether PDT can play a role on a mouse model of photoaging. Hence, SKH-1 hairless mice were randomly allocated in two groups, UV and UV/PDT. The mice were daily exposed to an UV light source (280-400 nm: peak at 350 nm) for 8 weeks followed by a single PDT session using 20% 5-aminolevulinic acid (ALA) topically. After the proper photosensitizer accumulation within the tissue, a non-coherent red (635 nm) light was performed and, after 14 days, skin samples were excised and processed for light microscopy, and their sections were stained with hematoxylin-eosin (HE) and Masson's Trichrome. As a result, we observed a substantial epidermal thickening and an improvement in dermal collagen density by deposition of new collagen fibers on UV/PDT group. These findings strongly indicate epidermal and dermal restoration, and consequently skin restoration. In conclusion, this study provides suitable evidences that PDT improves the UV-irradiated hairless mice skin, supporting this technique as an efficient treatment for photoaged skin.

  12. Compact Flyeye concentrator with improved irradiance uniformity on solar cell

    Science.gov (United States)

    Zhuang, Zhenfeng; Yu, Feihong

    2013-08-01

    A Flyeye concentrator with improved irradiance distribution on the solar cell in a concentrator photovoltaic system is proposed. This Flyeye concentrator is composed of four surfaces: a refractive surface, mirror surface, freeform surface, and transmissive surface. Based on the principles of geometrical optics, the contours of the proposed Flyeye concentrator are calculated according to Fermat's principle, the edge-ray principle, and the ray reversibility principle without solving partial differential equations or using an optimization algorithm, therefore a slope angle control method is used to construct the freeform surface. The solid model is established by applying a symmetry of revolution around the optical axis. Additionally, the optical performance for the Flyeye concentrator is simulated and analyzed by Monte-Carlo method. Results show that the Flyeye concentrator optical efficiency of >96.2% is achievable with 1333× concentration ratio and ±1.3 deg acceptance angle, and 1.3 low aspect ratio (average thickness to entry aperture diameter ratio). Moreover, comparing the Flyeye concentrator specification to that of the Köhler concentrator and the traditional Fresnel-type concentrator, results indicate that this concentrator has the advantages of improved uniformity, reduced thickness, and increased tolerance to the incident sunlight.

  13. Effect of microstructure on radiation induced segregation and depletion in ion irradiated SS316 steel

    International Nuclear Information System (INIS)

    Jin, Hyung Ha; Kwon, Sang Chul; Kwon, Jun Hyun

    2011-01-01

    Irradiation assisted stress corrosion cracking (IASCC), void swelling and irradiation induced hardening are caused by change of characteristics of material by neutron irradiation, stress state of material and environmental situation. It has been known that chemical compositions varies at grain boundary (GB) significantly with fluence level and the depletion of Cr element at GB has been considered as one of important factors causing material degradation, especially, IASCC in austenitic stainless steel. However, experimental results of IASCC under PWR condition were directly not connected with Cr depletion phenomenon by neutron irradiation. Because the mechanism of IASCC under PWR has not yet been clearly understood in spite of many energetic researches, fundamental researches about radiation induced segregation and depletion in irradiated austenitic stainless steels have been attracted again. In this work, an effect of residual microstructure on radiation induced segregation and depletion of alloy elements at GB was investigated in ion irradiated SS316 steel using transmission electron microscope (TEM) with energy dispersive spectrometer (EDS)

  14. Efficiency of borage seeds oil against gamma irradiation-induced ...

    African Journals Online (AJOL)

    Sixty rats were divided into five groups (12 rats each): Control, irradiated; rats were exposed to (6.5 Gy) of whole body γ-radiation, BO (50 mg/kg b.wt), irradiated BO post-treated and irradiated BO prepost-treated. Six rats from each group were sacrificed at two time intervals 7 and 15 days post-irradiation. Serum aspartate ...

  15. Combination processes for improving storage of irradiated potatoes

    International Nuclear Information System (INIS)

    Shirsat, S.G.; Thomas, P.; Nair, P.M.

    1990-01-01

    Various combined treatments of harvested potatoes to reduce microbial spoilage of irradiated potatoes in storage were studied. Treatments studied were irradiation in conjunction with hot water dip, cold or hot salicylic acid dip, dusting with salicylic acid powder, and sodium hypochlorite wash followed by storage in well aerated containers. Microbial spoilage in irradiated potatoes was found to be greatly reduced by storage at 10deg or 15degC in well aerated containers. (M.G.B.). 9 refs., 1 tab

  16. Improvement of polyethylene by irradiation in artificial joints

    International Nuclear Information System (INIS)

    Oonishi, H.; Takayama, Y.

    1992-01-01

    The decrease in socket thickness of several total hip prostheses was measured on X-ray film. The following prostheses were compared: (1) SOM ''28 mm metal head and an ultra-high-molecular-weight-polyethylene (UHMWPE) socket irradiated with 10 8 rad of γ-radiation'', (2) T-28 ''28 mm metal head and a UHMWPE socket not irradiated'', (3) Bioceram ''28 mm alumina head and UHMWPE not irradiated'' and (4) irradiated Bioceram ''28 mm alumina head and UHMWPE socket irradiated with 10 8 rad of γ-radiation''. The average steady state wear rate of SOM, T-28, Bioceram and irradiated Bioceram were 0.076, 0.247, 0.098 and 0.072 mm/year, respectively. The weight bearing portion of the irradiated socket presented a clearly-outlined and irregular pattern of about 0.1 μm thickness having a smooth ripple surface. The scratch and holding phenomenon characteristic of non-irradiated sockets was not observed at all. In our experimental tests using an IS sliding wear test machine, the wear measured as decrease of thickness was smallest at 10 8 rad, although there was an increase in the coefficient of friction. Our experimental and clinical findings suggest that the best total hip prosthesis at present is one with an alumina head and a UHMWPE socket irradiated with 10 8 rad of γ-radiation. (author)

  17. Improved SAFARI-1 research reactor irradiation position modeling in OSCAR-3 code system

    International Nuclear Information System (INIS)

    Moloko, L. E.; Belal, M. G. A. H.

    2009-01-01

    The demand on the availability of irradiation positions in the SAFARI-1 reactor is continuously increasing due to the commercial pressure to produce isotopes more efficiently. This calls for calculational techniques and modeling methods to be improved regularly to optimize irradiation services. The irradiation position models are improved using the OSCAR-3 code system, and results are compared to experimental measurements. It is concluded that the irradiation position models are essential if realistic core follow and reload studies are to be performed and most importantly, for the realization of improved agreement between experimental data and calculated results. (authors)

  18. Improvement of radiation response characteristic on CdTe detectors using fast neutron irradiation

    International Nuclear Information System (INIS)

    Miyamaru, Hiroyuki; Takahashi, Akito; Iida, Toshiyuki

    1999-01-01

    The treatment of fast neutron pre-irradiation was applied to a CdTe radiation detector in order to improve radiation response characteristic. Electron transport property of the detector was changed by the irradiation effect to suppress pulse amplitude fluctuation in risetime. Spectroscopic performance of the pre-irradiated detector was compared with the original. Additionally, the pre-irradiated detector was employed with a detection system using electrical signal processing of risetime discrimination (RTD). Pulse height spectra of 241 Am, 133 Ba, and 137 Cs gamma rays were measured to examine the change of the detector performance. The experimental results indicated that response characteristic for high-energy photons was improved by the pre-irradiation. The combination of the pre-irradiated detector and the RTD processing was found to provide further enhancement of the energy resolution. Application of fast neutron irradiation effect to the CdTe detector was demonstrated. (author)

  19. Initial decay process of radicals induced in irradiated food

    International Nuclear Information System (INIS)

    Kaimori, Yoshihiko; Sakamoto, Yuki; Nakamura, Hideo; Ukai, Mitsuko; Kikuchi, Masahiro; Shimoyama, Yuhei; Kobayashi, Yasuhiko; Kameya, Hiromi

    2011-01-01

    In order to determine radial decay behaviors of γ-irradiated food, we analyzed radicals in the food using ESR. We detected the ESR signal of specimens just several minutes after irradiation. The singlet signal intensity at g=2.0, originated from organic free radicals was increased as followed by the increasing radiation dose. Singlet signal intensity that increased by γ-irradiation was decreased with time. The phenomena of decay of the ESR singlet signal showed two phase that are rapid decay and slow decay. It was suggested that those two phase decay is due to at least the two radical species. Also we concluded that after three hours of radiation treatment long life radical as ESR signal intensity was detected in irradiated specimen; black pepper, green coffee bean and ginseng, showed the same decay phenomena. But the signal intensity of irradiated black pepper was three times larger than that of irradiated green coffee bean and irradiated ginseng. (author)

  20. Modulation of Immune Disorders Induced-Arthritis in γ- Irradiated Rats

    International Nuclear Information System (INIS)

    Thabet, N.M.S.

    2013-01-01

    This study was to evaluate the antioxidant and anti-inflammatory capability of a laboratory preparation mixture Nano Selenium-lovastatin (Lov-Se) against oxidative stress and inflammatory cascade in irradiated and/or adjuvant arthritic rats. The experimental animals were divided into: adjuvant free groups and adjuvant induced groups. Rats were exposed to whole body γ-radiation (2 Gy every 3 days up to total dose of 8 Gy) and received oral administration of 1 ml Lov-Se mixture (≈ 20 mg kg - 1 Lov and 0.1 mg kg - 1 day - 1 Se) for 14 successive days. Animal model of arthritis was organized by subcutaneous injection of complete freund’s adjuvant. The antioxidant parameters (heart GSH-Px, CAT, SOD, XDH, GSH and blood Se), and oxidant markers (heart XO, NO, protein carbonyls and TBARS) and Also, the inflammatory molecules (serum TNF-α, CRP and RF) were determined. In irradiated Lov-Se rats, the results obtained reveals that, TBARS, protein carbonyl, TNF-α, CRP levels, and XO, CAT and SOD activities were significantly ameliorated as compared to irradiated rats. Also, heart GSH, NO levels, XDH, GSH-Px activities and blood Se level were significantly improved. In addition, the administration of Lov-Se to the arthritic and arthritic irradiated rats ameliorates the disturbance occurs in oxidative stress, inflammatory cascades and antioxidant indicators when compared to control rats. In conclusion, the proper administration of Lov-Se mixture might reduce the radiation-induced heart injury via amending the antioxidant molecules and decreasing lipid and protein oxidation. Also, it could be suggested that Lov-Se mixture might posses a considerable anti-inflammatory properties

  1. Induced mutants for cereal grain protein improvement

    International Nuclear Information System (INIS)

    1982-01-01

    Out of 17 papers and one summary presented, six dealing with the genetic improvement of seed protein using ionizing radiations fall within the INIS subject scope. Other topics discussed were non-radiation induced mutants used for cereal grain protein improvement

  2. Improving restorer line of hybrid rice by irradiation

    International Nuclear Information System (INIS)

    Guo Guangrong; Yi Weiping; Liu Wuquan

    1995-03-01

    The work for improving restorer line of hybrid rice has been done. The results showed the radiosensitivity of foreign varieties overtakes Chinese ones at average level. Because of their different blood relationship, there are various situation on foreign varieties, i.e. varieties from IR system are not sensitive, Shui-yun system are second and Miyang system are sensitive. The radiosensitivity for restorer lines of hybrid F 0 overtakes one for F 1 . According to this results. We have put forward the point of view 'Multi-gene type blend system'. M 2 mutant frequency of restorer line was investigated. The results showed: there was a little difference between the total mutant frequencies from the different varieties. But, there may be difference in some characters by over thirty times between them. So a problem, worthy to be further studied is proposed that do the differences of radiosensitivity between varieties relate to the mutant frequency of these characters? Various mutants were obtained by irradiation treatment, among which a few mutants changed to maintainer line because losing restorer genes, other more mutants still were restorer lines. New combinations developed by these new mutant restorer lines have strong heterosis. The optimum combinations have been utilized in rice production. (7 tabs.)

  3. Tangential breast irradiation - rationale and methods for improving dosimetry

    International Nuclear Information System (INIS)

    Neal, A.J.; Mayles, W.P.M.; Yarnold, J.R.

    1994-01-01

    In recent years there have been great advances and innovations in all technical aspects of radiotherapy, including three dimensional (3D) computer planning, patient immobilization, radiation delivery and treatment verification. Despite this progress, the technique of tangential breast irradiation has changed little over this period and has not exploited these advances. There is increasing evidence that dose inhomogeneity within the breast is greater than at other anatomical sites, especially in women with large breasts. This paper is a review of the factors contributing to poor dosimetry in the breast, the clinical consequences of an inhomogeneous dose distribution, and how breast dosimetry could be improved by considering each of the stages from planning to accurate treatment delivery. It also highlights the particular problem of women with large breasts who may be more likely to have a poorer outcome after a fractionated course of radiotherapy than women with small/medium-sized breasts, and supports the clinical impression that such women are also more likely to have greater inhomogenicity when 3D treatment plans are examined. Preliminary data from our current computed tomography (CT) planning study are presented to support these observations. (author)

  4. Potential of irradiation technology for improved shellfish sanitation

    International Nuclear Information System (INIS)

    Mallett, J.C.; Beghian, L.E.; Metcalf, T.G.; Kaylor, J.D.

    1991-01-01

    Ionizing radiation is shown capable of serving as an effective sanitizing treatment improving the sanitary quality of shellfish and providing an increased margin of safety for shellfish consumers. 60Co irradiation of the hard-shelled clam, Mercenaria mercenaria, and the oyster, Crassostrea virginica, significantly reduced virus carriage numbers without unduly affecting shellfish survival rates or desirable organoleptic qualities. A D10 value of 2 kGy was determined for depletion of hepatitis A virus in clams and oysters as measured by in situ hybridization fluorescent foci and cytopathology enumeration methods. A D10 value of 2.4 kGy was determined for depletion of rotavirus SA11 in clams and oysters as measured by a plaque forming unit enumeration method. Study results showed ionizing radiation capable of providing an extra, highly effective safeguard of shellfish sanitary quality when combined with traditional depuration treatment. Data drawn from other studies is introduced which shows D10 values as low as 1.0 kGy effectively eliminate Vibrio cholerae, and V. parahemolyticus, from shellfish

  5. Identification of irradiation treatment in processed food. Pt. 2. Evaluation of a SPE-method for analyzing irradiation induced hydrocarbons

    International Nuclear Information System (INIS)

    Hartmann, M.; Ammon, J.; Berg, H.

    1996-01-01

    This paper deals with a solid phase extraction (SPE) method for the isolation of irradiation induced hydrocarbons which can replace the column chromatography described in the paragraph 35 LMBG (German Food Law) procedure L06.00-37. Using this new method, only a tenth of solvents and column material is necessary. The SPE method was a good as LC-LC-GC/FID or LC-LC-GC/MS in analyzing new or complex matrices like paprika or salmon. Additionally, it is fast, cheap and easy to perform. As far as we know, the detection of irradiation traetment in paprika powder by analyzing irradiation induced hydrocarbons has not been described before. The new method is a good alternative for the commonly used thermoluminescence procedure. (orig.) [de

  6. Effect of irradiation on the acinar cells of submandibular gland in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Lee, Seung Hyun; Hwang, Eui Hwan; Lee, Sang Rae

    2003-01-01

    To observe the histologic changes and clusterin expression in the acinar cells of the submandibular gland in streptozotocin-induced diabetic rat following irradiation. Mature Sprague-Dawley rats were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the Sprague-Dawley rats by injecting streptozotocin, while the control rats were injected with citrate buffer only. After 5 days, rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy to the head and neck region. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the submandibular gland were sectioned and observed using histologic and immunohistochemical methods. Morphologic change of acinar cells was remarkable in the diabetic group, but was not observed in the diabetic-irradiated group. Necrotic tissues were observed in the diabetic-irradiated group. Coloring of toluidine blue stain was most increased at 14 days in the diabetic group, however there were no significant change throughout the period of the experiment in the diabetic-irradiated group. Expression of clusterin was most significant at 14 days in the diabetic group, but gradually decreased with time after 7 days in the diabetic-irradiated group. Degeneration of clusterin was observed in the diabetic-irradiated group. This experiment suggests that the acinar cells of submandibular gland in rats are physiologically apoptosis by the induction of diabetes, but that the apoptosis is inhibited and the acinar cells necrotized after irradiation.

  7. Craniospinal axis irradiation: an improved electron technique for irradiation of the spinal axis

    International Nuclear Information System (INIS)

    Chun Li; Vijayakumar, S.; Myrianthopoulos, L.C.; Kuchnir, F.T.; Muller-Runkel, R.

    1994-01-01

    The authors review dosimetric features of craniospinal axis irradiation in the areas of matching cranial and spinal fields, with reference to normal structures within the spinal field. The implications of the use of photon or electron modalities for the spinal port were evaluated. A novel method of matching the cranial photon and the spinal electron fields involving a computer-aided junction design is presented, involving moving the photon beam in three steps to degrade its penumbra to match that of the electron field. Thermoluminescent dosimetry in a Rando phantom and computed tomography-based dose-volume histogram study for an illustrative paediatric case were used to compare dose to normal structures within the spinal field. Results show that the use of electrons for the spinal field leads to better sparing of deep seated normal structures. For bone marrow, the use of a customized bolus for the spinal field results in an improved dose distribution, making electrons potentially superior to photons for radiobiological reasons. (author)

  8. An improved technique for breast cancer irradiation including the locoregional lymph nodes

    NARCIS (Netherlands)

    Hurkmans, C. W.; Saarnak, A. E.; Pieters, B. R.; Borger, J. H.; Bruinvis, I. A.

    2000-01-01

    PURPOSE: To find an irradiation technique for locoregional irradiation of breast cancer patients which, compared with a standard technique, improves the dose distribution to the internal mammary-medial supraclavicular (IM-MS) lymph nodes. The improved technique is intended to minimize the lung dose

  9. Irradiation-induced microchemical changes in highly irradiated 316 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K., E-mail: fujiik@inss.co.jp; Fukuya, K.

    2016-02-15

    Cold-worked 316 stainless steel specimens irradiated to 74 dpa in a pressurized water reactor (PWR) were analyzed by atom probe tomography (APT) to extend knowledge of solute clusters and segregation at higher doses. The analyses confirmed that those clusters mainly enriched in Ni–Si or Ni–Si–Mn were formed at high number density. The clusters were divided into three types based on their size and Mn content; small Ni–Si clusters (3–4 nm in diameter), and large Ni–Si and Ni–Si–Mn clusters (8–10 nm in diameter). The total cluster number density was 7.7 × 10{sup 23} m{sup −3}. The fraction of large clusters was almost 1/10 of the total density. The average composition (in at%) for small clusters was: Fe, 54; Cr, 12; Mn, 1; Ni, 22; Si, 11; Mo, 1, and for large clusters it was: Fe, 44; Cr, 9; Mn, 2; Ni, 29; Si, 14; Mo,1. It was likely that some of the Ni–Si clusters correspond to γ′ phase precipitates while the Ni–Si–Mn clusters were precursors of G phase precipitates. The APT analyses at grain boundaries confirmed enrichment of Ni, Si, P and Cu and depletion of Fe, Cr, Mo and Mn. The segregation behavior was consistent with previous knowledge of radiation induced segregation.

  10. Irradiation-induced microchemical changes in highly irradiated 316 stainless steel

    International Nuclear Information System (INIS)

    Fujii, K.; Fukuya, K.

    2016-01-01

    Cold-worked 316 stainless steel specimens irradiated to 74 dpa in a pressurized water reactor (PWR) were analyzed by atom probe tomography (APT) to extend knowledge of solute clusters and segregation at higher doses. The analyses confirmed that those clusters mainly enriched in Ni–Si or Ni–Si–Mn were formed at high number density. The clusters were divided into three types based on their size and Mn content; small Ni–Si clusters (3–4 nm in diameter), and large Ni–Si and Ni–Si–Mn clusters (8–10 nm in diameter). The total cluster number density was 7.7 × 10"2"3 m"−"3. The fraction of large clusters was almost 1/10 of the total density. The average composition (in at%) for small clusters was: Fe, 54; Cr, 12; Mn, 1; Ni, 22; Si, 11; Mo, 1, and for large clusters it was: Fe, 44; Cr, 9; Mn, 2; Ni, 29; Si, 14; Mo,1. It was likely that some of the Ni–Si clusters correspond to γ′ phase precipitates while the Ni–Si–Mn clusters were precursors of G phase precipitates. The APT analyses at grain boundaries confirmed enrichment of Ni, Si, P and Cu and depletion of Fe, Cr, Mo and Mn. The segregation behavior was consistent with previous knowledge of radiation induced segregation.

  11. Improvement of colour strength and colourfastness properties of gamma irradiated cotton using reactive black-5

    International Nuclear Information System (INIS)

    Ahmad Bhatti, Ijaz; Adeel, Shahid; Nadeem, Raziya; Asghar, Toheed

    2012-01-01

    The dyeing behaviour of gamma irradiated cotton fabric using Reactive Black-5 dye powder has been investigated. The mercerized, bleached and plain weaved cotton fabric was irradiated to different absorbed doses of 100, 200, 300, 400, 500 and 600 Gy using Co-60 gamma irradiator. Dyeing was performed using irradiated and un-irradiated cotton with dye solutions. The dyeing parameters such as temperature of dyeing, time of dyeing and pH of dyeing solutions were optimised. 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 Organisation (ISO) were employed to study the effect of gamma irradiation on the colourfastness properties of dyed fabric. It is found that gamma irradiated cotton dyed with Reactive Black-5 has not only improved the colour strength but also enhanced the rating of fastness properties. - Highlights: ► Optimum absorbed dose for cotton is 500 Gy using un-irradiated Reactive Black-5. ► Optimum dyeing conditions: 60 °C, 30 min and dyeing pH is10. ► At optimum conditions colour strength and fastness properties are enhanced. ► Gamma irradiation can improve dyeing characters of other dyed fabrics.

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

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Xiao Dong

    1999-01-01

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

  13. Compositional changes in industrial hemp biomass (Cannabis sativa L.) induced by electron beam irradiation Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Yong Joo [Department of Biobased Materials, College of Agriculture and Life Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Shin, Soo-Jeong [Department of Wood and Paper Science, College of Agriculture and Life Science, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)

    2011-07-15

    The effects of electron beam irradiation on chemical decomposition of industrial hemp biomass were evaluated at doses of 150, 300, and 450 kGy. The quantity of decomposed components was indirectly estimated by measuring changes in alkaline extraction. The more severe degradation of structural components induced by higher irradiation doses resulted in larger amounts of alkaline extract. Carbohydrate compositional analysis using {sup 1}H-NMR spectroscopy was applied to quantitatively investigate changes in the polysaccharides of the industrial hemp. The xylose peak intensity in the NMR spectra decreased with increasing electron irradiation dose, indicating that xylan was more sensitive to electron beam irradiation than cellulose. -- Highlights: {yields} The more severe degradation of structural components induced by higher irradiation. {yields} Carbohydrate analysis was applied to quantitatively investigate changes in the industrial hemp. {yields} Xylan was more sensitive to electron beam irradiation than cellulose.

  14. Compositional changes in industrial hemp biomass (Cannabis sativa L.) induced by electron beam irradiation Pretreatment

    International Nuclear Information System (INIS)

    Sung, Yong Joo; Shin, Soo-Jeong

    2011-01-01

    The effects of electron beam irradiation on chemical decomposition of industrial hemp biomass were evaluated at doses of 150, 300, and 450 kGy. The quantity of decomposed components was indirectly estimated by measuring changes in alkaline extraction. The more severe degradation of structural components induced by higher irradiation doses resulted in larger amounts of alkaline extract. Carbohydrate compositional analysis using 1 H-NMR spectroscopy was applied to quantitatively investigate changes in the polysaccharides of the industrial hemp. The xylose peak intensity in the NMR spectra decreased with increasing electron irradiation dose, indicating that xylan was more sensitive to electron beam irradiation than cellulose. -- Highlights: → The more severe degradation of structural components induced by higher irradiation. → Carbohydrate analysis was applied to quantitatively investigate changes in the industrial hemp. → Xylan was more sensitive to electron beam irradiation than cellulose.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  16. Study on silk yellowing induced by gamma-irradiation

    International Nuclear Information System (INIS)

    Tsukada, Masuhiro; Aoki, Akira

    1985-01-01

    The changes in the yellow color of silk threads with total dose of irradiation applied were described and studied by a colorimetric method and by monochrome photography. The change into a yellow color of the specimen in the course of irradiation was clearly detected in photographs using filters, 2B and SC 56 under light conditions at the wavelength of 366 nm. The b/L value measured by colorimetry in undegummed and degummed silk fibers sharply increased in the early stage of irradiation. Yellow color indices (b/L) of the specimen subjected to gamma-irradiation continued to increase and the yellow color of the silk threads became more pronounced above a total dose of irradiation of 21 Mrad. The b/L value of the undegummed silk fiber which had deen irradiated was about 2 times that of the degummed silk fiber. (author)

  17. Effect of irradiation on unscheduled DNA synthesis induced by 4-nitroquinoline in tracheal epithelium of rats

    International Nuclear Information System (INIS)

    Hahn, F.F.; Kennedy, R.; Brooks, A.L.

    1986-01-01

    Unscheduled DNA synthesis (UDS) was determined in rat epithelium by autoradiographic techniques to determine the influence of prior irradiation on the ability of the cells to repair mutagenic damage induced by 4-nitroquionoline (4NQO). UDS was stimulated by in vitro exposure to 4NPO. However, prior whole-body irradiation of rats with either 50 or 300 rad did not alter the UDS induced by 4NQO. The results of this study do not support the hypothesis that irradiation can induce DNA repair enzymes in respiratory tract epithelium. 5 references, 3 figures

  18. Effect of melatonin and time of administration on irradiation-induced damage to rat testes

    Directory of Open Access Journals (Sweden)

    G. Take

    2009-07-01

    Full Text Available The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol or melatonin administered 24 h before (10 mg/kg, immediately before (20 mg/kg and 24 h after irradiation (10 mg/kg, all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05. Melatonin-treated groups showed less apoptosis as indicated by a considerable decrease in caspace-3 immunoreactivity (P < 0.05. Electron microscopic examination showed that all spermatogenic cells, especially primary spermatocytes, displayed prominent degeneration in the groups submitted to total body and abdominopelvic irradiation. However, melatonin administration considerably inhibited these degenerative changes, especially in rats who received abdominopelvic irradiation. Total body and abdominopelvic irradiation induced identical apoptosis and testicular damage. Chronobiological assessment revealed that biologic rhythm does not alter the inductive effect of irradiation. These data indicate that melatonin protects against total body and abdominopelvic irradiation. Melatonin was more effective in the evening abdominopelvic irradiation and melatonin-treated group than in the total body irradiation and melatonin-treated group.

  19. Experimental and numerical investigations of shock and shear wave propagation induced by femtosecond laser irradiation in epoxy resins

    International Nuclear Information System (INIS)

    Ecault, Romain; Touchard, Fabienne; Boustie, Michel; Berthe, Laurent; Lescoute, Emilien; Sollier, Arnaud; Voillaume, Hubert

    2015-01-01

    In this work, original shock experiments are presented. Laser-induced shock and shear wave propagations have been observed in an epoxy resin, in the case of femtosecond laser irradiation. A specific time-resolved shadowgraphy setup has been developed using the photoelasticimetry principle to enhance the shear wave observation. Shear waves have been observed in epoxy resin after laser irradiation. Their propagation has been quantified in comparison with the main shock propagation. A discussion, hinging on numerical results, is finally given to improve understanding of the phenomenon. (paper)

  20. Degradation mechanism of polyurethane foam induced by electron beam irradiation

    International Nuclear Information System (INIS)

    Huang Wei; Fu Yibei; Bian Zhishang; He Meiying

    2002-01-01

    The degradation mechanism of irradiated polyurethane foam has been studied in detail. The changes of chemical structure and micro-phase separation have been determined by DTG. The gas products from irradiated samples are analyzed quantitatively and qualitatively by GC. The degradation mechanism of irradiated polyurethane foam has been deduced according to the experimental results. It provides some basis of the application on the polyurethane in the radiation field

  1. Induced effect of irradiated exogenous DNA on wheat

    International Nuclear Information System (INIS)

    Li Zhongjie; Sun Guangzu; Wang Guangjin

    1996-01-01

    Irradiated exogenous DNA introduced into wheat can give rise to break of DNA-chain and damage of part of alkali radicals. Introducing exogenous DNA irradiated by γ rays could increase Do fructification rate and decrease seed size and plumpness. These tendencies became obvious with dose increase. In comparison with control DNA, introducing DNA irradiated could raise evidently mutagenic effect of pollen tube pathway technique

  2. Gamma irradiation induced ultrastructural changes in Paracoccidioides brasiliensis yeast cells

    International Nuclear Information System (INIS)

    Demicheli, Marina C.; Andrade, Antero S.R.; Goes, Alfredo Miranda

    2007-01-01

    Paracoccidioides brasiliensis is a thermally dimorphic fungus agent of paracoccidioidomycosis, a deep-seated systemic infection of humans with high prevalence in Latin America. Up to the moment no vaccine has still been reported. Ionizing radiation can be used to attenuate pathogens for vaccine development and we have successfully attenuated yeast cells of P. brasiliensis by gamma irradiation. The aim of the present study was to examine at ultrastructural level the effects of gamma irradiation attenuation on the morphology of P. brasiliensis yeast cells. P. brasiliensis (strain Pb-18) cultures were irradiated with a dose of 6.5 kGy. The irradiated cells were examined by scanning and also transmission electron microscopy. When examined two hours after the irradiation by scanning electron microscopy the 6.5 kGy irradiated cells presented deep folds or were collapsed. These lesions were reversible since examined 48 hours after irradiation the yeast have recovered the usual morphology. The transmission electron microscopy showed that the irradiated cells plasma membrane and cell wall were intact and preserved. Remarkable changes were found in the nucleus that was frequently in a very electrodense form. A extensive DNA fragmentation was produced by the gamma irradiation treatment. (author)

  3. Brain anomalies induced by gamma irradiation in prenatal period

    International Nuclear Information System (INIS)

    Schmidt, S.L.

    1992-01-01

    Gamma irradiation has been utilized in order to produce cortical and callosal abnormalities. We have also checked for the presence of the aberrant longitudinal bundle in the brains of mice born acallosal due to prenatal irradiation is also checked. Pregnant mice were exposed to gamma irradiation from a 6 0 Co source at 16, 17 and 19 days of gestational age (E 16, E 17 and E 19) with total doses of 2 Gy and 3 Gy. At 60 days postnatal the offspring of irradiated animals were intra cardiac perfused, the brains were removed from the cranio and cut into coronal or para sagittal sections. (author)

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

    International Nuclear Information System (INIS)

    Zhao Yujie; Su Liaoyuan; Zou Huawei; Kong Xiangrong

    1999-01-01

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

  5. Beta-irradiation used for systemic radioimmunotherapy induces apoptosis and activates apoptosis pathways in leukaemia cells

    International Nuclear Information System (INIS)

    Friesen, Claudia; Lubatschofski, Annelie; Debatin, Klaus-Michael; Kotzerke, Joerg; Buchmann, Inga; Reske, Sven N.

    2003-01-01

    Beta-irradiation used for systemic radioimmunotherapy (RIT) is a promising treatment approach for high-risk leukaemia and lymphoma. In bone marrow-selective radioimmunotherapy, beta-irradiation is applied using iodine-131, yttrium-90 or rhenium-188 labelled radioimmunoconjugates. However, the mechanisms by which beta-irradiation induces cell death are not understood at the molecular level. Here, we report that beta-irradiation induced apoptosis and activated apoptosis pathways in leukaemia cells depending on doses, time points and dose rates. After beta-irradiation, upregulation of CD95 ligand and CD95 receptor was detected and activation of caspases resulting in apoptosis was found. These effects were completely blocked by the broad-range caspase inhibitor zVAD-fmk. In addition, irradiation-mediated mitochondrial damage resulted in perturbation of mitochondrial membrane potential, caspase-9 activation and cytochrome c release. Bax, a death-promoting protein, was upregulated and Bcl-x L , a death-inhibiting protein, was downregulated. We also found higher apoptosis rates and earlier activation of apoptosis pathways after gamma-irradiation in comparison to beta-irradiation at the same dose rate. Furthermore, irradiation-resistant cells were cross-resistant to CD95 and CD95-resistant cells were cross-resistant to irradiation, indicating that CD95 and irradiation used, at least in part, identical effector pathways. These findings demonstrate that beta-irradiation induces apoptosis and activates apoptosis pathways in leukaemia cells using both mitochondrial and death receptor pathways. Understanding the timing, sequence and molecular pathways of beta-irradiation-mediated apoptosis may allow rational adjustment of chemo- and radiotherapeutic strategies. (orig.)

  6. Effect of Bifidobacterium breve B-3 on skin photoaging induced by chronic UV irradiation in mice.

    Science.gov (United States)

    Satoh, T; Murata, M; Iwabuchi, N; Odamaki, T; Wakabayashi, H; Yamauchi, K; Abe, F; Xiao, J Z

    2015-01-01

    Probiotics have been shown to have a preventative effect on skin photoaging induced by short term UV irradiation, however, the underlying mechanisms and the effect of probiotics on skin photoaging induced by chronic UV irradiation remain unclear. In this study, we investigated the effect of Bifidobacterium breve B-3 on skin photoaging induced by chronic UV irradiation in hairless mice. Mice were irradiated with UVB three times weekly and orally administered B. breve B-3 (2×10(9) cfu/mouse /day) for 7 weeks. Nonirradiated mice and UVB-irradiated mice without probiotic treatment were used as controls. B. breve B-3 significantly suppressed the changes of transepidermal water loss, skin hydration, epidermal thickening and attenuated the damage to the tight junction structure and basement membrane induced by chronic UVB irradiation. Administration of B. breve B-3 tended to suppress the UV-induced interleukin-1β production in skin (P=0.09). These results suggest that B. breve B-3 could potentially be used to prevent photoaging induced by chronic UV irradiation.

  7. The Role of Yeast Beta Glucan on Blood Coagulation in Streptozotocin-Induced Diabetes and Irradiated Rats

    International Nuclear Information System (INIS)

    El-Kashoury, M.M.A.; Abdel Fattah, S.M.; Ramadan, L.A.; El-Denshary, E.S.

    2016-01-01

    Clotting abnormalities are observed after exposure to ionizing radiation as well as in diabetes melittus. The objective of this study is to elucidate the role of yeast beta glucan (YBG) in the modulation of some biochemical variations observed in γ-irradiated, diabetic and diabeticγγ-irradiated rats. Gamma-irradiation was performed through the whole body exposure of rats to 6 Gy administered in four fractions of 1.5 Gy two times per week for two weeks. Diabetes was induced by a single intraperitoneal injection of streptozotocin (55 mg/kg body weight). YBG was given orally to male albino rats (1 g/kg body weight) for two weeks post irradiation and/or induction of diabetes. Animals were divided into 4 main groups: 1- control, 2- γ-irradiated, 3- diabetic and 4- diabetic-γ-irradiated rats. Each group was subdivided into 2 subgroups (a) untreated and (b) treated. The 3rd and 14th day, after the last dose of radiation in the irradiated groups and after the induction of diabetes in diabetic groups, were chosen to evaluate the effect of oral YBG in irradiated and/or diabetic rats. The results revealed that the body weight decreased significantly in irradiated, diabetic and diabetic–irradiated rats. The loss of weight was accompanied by a reduction in the pancreas weight. Glucose concentration was significantly increased in diabetic group at the two time intervals. It is worth noting that, radiation ameliorated blood glucose level in diabetic-γ-irradiated group. Radiation exposure and/or diabetes caused an oxidative stress manifested by a significant increase of malondialdhyde (MDA) accompanied by a significant decrease in glutathione (GSH) level. This oxidative stress caused disturbances in the measured clotting parameters by enhancing platelet aggregation (PA) induced by arachidonic acid and increased thrombin level as concluded from the significant shortening of prothrombin time (PT) and activated partial thromboplastin time (APTT). Also, exposure to radiation

  8. Improvement of life time of SCC in type 304 stainless steel by ultrasound irradiation

    International Nuclear Information System (INIS)

    Tokiwai, Moriyasu; Kimura, Hideo

    1985-01-01

    It is well known that the susceptibility to stress corrosion cracking (SCC) is controled by compressive stress such as shot-peening treatment. In this study, the effects of ultrasound irradiation to type 304 stainless upon SCC were investigated. The main findings are as follows; (1) Ultrasound irradiation produces the high level compressive stress on the surface of metals. This compressive stress was induced by the cavitation phenomenon. (2) In U-bent specimen, the initial tensile stress was mitigated and converted to compressive stress by ultrasound irradiation. (3) Type 304 stainless steel was subjected to SCC test using sodium thyosulfate solution. It was definitely demonstrated that the ultrasound irradiation was effective for the mitigation of SCC life time. (4) Ultrasound irradiation time was one of the most important factors in irradiation conditions. (author)

  9. Analysis of irradiation processes for laser-induced periodic surface structures

    NARCIS (Netherlands)

    Eichstädt, J.; Huis In 't Veld, A.J.

    2013-01-01

    The influence of errors on the irradiation process for laser-induced periodic surface structures (LIPSS) was studied theoretically with energy density simulations. Therefore an irradiation model has been extended by a selection of technical variations. The influence of errors has been found in a

  10. Irradiation-induced growth of zircaloy and its effects on the mechanical design of fuel assemblies

    International Nuclear Information System (INIS)

    Yao Pu

    1991-01-01

    Zircaloy growth could be induced due to irradiation. The ammount of growth is described as a function of texture, irradiation temperature, fast neutron fluence and the reduction of cold work, and it should be given great attention in the mechanical design of fuel assemblies

  11. Influence of irradiation upon neonative tolerance state induced in rabbit

    International Nuclear Information System (INIS)

    Servant, P.; Marquer, C.

    An attempt was made to determine the effect of whole-body irradiation on the establishment of a state of tolerance in new-born rabbits by the intraperitoneal injection of 1mg of human serum albumin. Simultaneous irradiation (doses of 200, 150, 100 rads) and antigen injections inhibited the establishment of this tolerance [fr

  12. Induced defects in neutron irradiated GaN single crystals

    International Nuclear Information System (INIS)

    Park, I. W.; Koh, E. K.; Kim, Y. M.; Choh, S. H.; Park, S. S.; Kim, B. G.; Sohn, J. M.

    2005-01-01

    The local structure of defects in undoped, Si-doped, and neutron irradiated free standing GaN bulk crystals, grown by hydride vapor phase epitaxy, has been investigated by employing Raman scattering and cathodoluminescence. The GaN samples were irradiated to a dose of 2 x 10 17 neutrons in an atomic reactor at Korea Atomic Energy Research Institute. There was no appreciable change in the Raman spectra for undoped GaN samples before and after neutron irradiation. However, a forbidden transition, A 1 (TO) mode, appeared for a neutron irradiated Si-doped GaN crystal. Cathodoluminescence spectrum for the neutron irradiated Si-doped GaN crystal became much more broadened than that for the unirradiated one. The experimental results reveal the generation of defects with locally deformed structure in the wurtzite Si-doped GaN single crystal

  13. Effect of irradiation on the periodontal tissues in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Park, Dong Sin; Hwang, Eui Hwan; Lee, Sang Rae

    2005-01-01

    To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups; control, diabetes, irradiation, and diabetes - irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes - irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes- irradiation group, osteoblastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

  14. Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Kwangwon [Eulji Univ. Hospital, Daejeon (Korea, Republic of); Kwon, Jungkee [Chonbuk National Univ., Jeonju (Korea, Republic of); Kim, Taewoon [Jeonbuk Technopark, Jeonju (Korea, Republic of)

    2012-03-15

    This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage.

  15. Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

    International Nuclear Information System (INIS)

    Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon; Lee, Kwangwon; Kwon, Jungkee; Kim, Taewoon

    2012-01-01

    This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage

  16. Field- and irradiation-induced phenomena in memristive nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Mikhaylov, A.N.; Gryaznov, E.G.; Belov, A.I.; Korolev, D.S.; Sharapov, A.N.; Guseinov, D.V.; Tetelbaum, D.I.; Tikhov, S.V.; Malekhonova, N.V.; Bobrov, A.I.; Pavlov, D.A.; Gerasimova, S.A.; Kazantsev, V.B.; Agudov, N.V.; Dubkov, A.A. [Lobachevsky University, Nizhny Novgorod (Russian Federation); Rosario, C.M.M.; Sobolev, N.A. [Departamento de Fisica and I3N, Universidade de Aveiro (Portugal); Spagnolo, B. [Dipartimento di Fisica e Chimica, Universita di Palermo, Group of Interdisciplinary Theoretical Physics (Italy); CNISM, Unita di Palermo (Italy)

    2016-12-15

    The breakthrough in electronics and information technology is anticipated by the development of emerging memory and logic devices, artificial neural networks and brain-inspired systems on the basis of memristive nanomaterials represented, in a particular case, by a simple 'metal-insulator-metal' (MIM) thin-film structure. The present article is focused on the comparative analysis of MIM devices based on oxides with dominating ionic (ZrO{sub x}, HfO{sub x}) and covalent (SiO{sub x}, GeO{sub x}) bonding of various composition and geometry deposited by magnetron sputtering. The studied memristive devices demonstrate reproducible change in their resistance (resistive switching - RS) originated from the formation and rupture of conductive pathways (filaments) in oxide films due to the electric-field-driven migration of oxygen vacancies and / or mobile oxygen ions. It is shown that, for both ionic and covalent oxides under study, the RS behaviour depends only weakly on the oxide film composition and thickness, device geometry (down to a device size of about 20 x 20 μm{sup 2}). The devices under study are found to be tolerant to ion irradiation that reproduces the effect of extreme fluences of high-energy protons and fast neutrons. This common behaviour of RS is explained by the localized nature of the redox processes in a nanoscale switching oxide volume. Adaptive (synaptic) change of resistive states of memristive devices is demonstrated under the action of single or repeated electrical pulses, as well as in a simple model of coupled (synchronized) neuron-like generators. It is concluded that the noise-induced phenomena cannot be neglected in the consideration of a memristive device as a nonlinear system. The dynamic response of a memristive device to periodic signals of complex waveform can be predicted and tailored from the viewpoint of stochastic resonance concept. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Field- and irradiation-induced phenomena in memristive nanomaterials

    International Nuclear Information System (INIS)

    Mikhaylov, A.N.; Gryaznov, E.G.; Belov, A.I.; Korolev, D.S.; Sharapov, A.N.; Guseinov, D.V.; Tetelbaum, D.I.; Tikhov, S.V.; Malekhonova, N.V.; Bobrov, A.I.; Pavlov, D.A.; Gerasimova, S.A.; Kazantsev, V.B.; Agudov, N.V.; Dubkov, A.A.; Rosario, C.M.M.; Sobolev, N.A.; Spagnolo, B.

    2016-01-01

    The breakthrough in electronics and information technology is anticipated by the development of emerging memory and logic devices, artificial neural networks and brain-inspired systems on the basis of memristive nanomaterials represented, in a particular case, by a simple 'metal-insulator-metal' (MIM) thin-film structure. The present article is focused on the comparative analysis of MIM devices based on oxides with dominating ionic (ZrO_x, HfO_x) and covalent (SiO_x, GeO_x) bonding of various composition and geometry deposited by magnetron sputtering. The studied memristive devices demonstrate reproducible change in their resistance (resistive switching - RS) originated from the formation and rupture of conductive pathways (filaments) in oxide films due to the electric-field-driven migration of oxygen vacancies and / or mobile oxygen ions. It is shown that, for both ionic and covalent oxides under study, the RS behaviour depends only weakly on the oxide film composition and thickness, device geometry (down to a device size of about 20 x 20 μm"2). The devices under study are found to be tolerant to ion irradiation that reproduces the effect of extreme fluences of high-energy protons and fast neutrons. This common behaviour of RS is explained by the localized nature of the redox processes in a nanoscale switching oxide volume. Adaptive (synaptic) change of resistive states of memristive devices is demonstrated under the action of single or repeated electrical pulses, as well as in a simple model of coupled (synchronized) neuron-like generators. It is concluded that the noise-induced phenomena cannot be neglected in the consideration of a memristive device as a nonlinear system. The dynamic response of a memristive device to periodic signals of complex waveform can be predicted and tailored from the viewpoint of stochastic resonance concept. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Foeniculum vulgare Mill. Essential Oil Attenuates some Biochemical Disorders Induced by ?-irradiation in Male Rats

    International Nuclear Information System (INIS)

    Nada, A.S.; Amin, N.E.; Ahmed, O.M.; Abdel-Reheim, E.S.; Ali, M.M.

    2011-01-01

    This study was conducted to evaluate the modulating efficacy of prolonged oral administration of Foeniculum vulgare Mill. essential oil (FEO) against gamma-rays-induced biochemical changes in rats. To achieve the ultimate goal of this study, 32 rats were used, divided into 4 groups. Control group, Irradiated group with a single dose (6.5 Gy), and sacrificed after 7 days of irradiation, group 3 received FEO (250 mg/kg b.wt) for 28 successive days by gavages and group 4 received treatment of FEO for 21 days, then was exposed to gamma-rays (6.5 Gy), followed by treatment with FEO 7 days later to be 28 days. Animals were sacrificed at the end of the experiment. Transaminases (AST, ALT), alkaline phosphatase (ALP) and total bilirubin, lipids (cholesterol, triglycerides), proteins profile (total protein, albumin, globulin, and A/G ratio) as well as levels of urea, creatinine and testosterone were determined in serum. Rats exposed to gamma-rays exhibited a profound elevation of AST, ALP, bilirubin, urea and creatinine levels and lipid abnormalities. Noticeable drop in serum total protein, albumin and testosterone levels were recorded. Rats treated with FEO before and after whole body gamma-rays showed significant modulation in AST and ALT, ALP, bilirubin, urea, creatinine and lipids and noticeable improvement in the protein profile levels. It could be concluded that FEO has a beneficial protective potentials against radiation-induced some oxidative stress and biochemical perturbations

  19. Influence of Magnolol on the bystander effect induced by alpha-particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wong, T.P.W.; Law, Y.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Tse, A.K.W.; Fong, W.F. [Research and Development Division, School of Chinese Medicine, Hong Kong Baptist University, Baptist University Road, Kowloon Tong (Hong Kong); Yu, K.N. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)], E-mail: peter.yu@cityu.edu.hk

    2010-04-15

    In this work, the influence of Magnolol on the bystander effect in alpha-particle irradiated Chinese hamster ovary (CHO) cells was examined. The bystander effect was studied through medium transfer experiments. Cytokinesis-block micronucleus (CBMN) assay was performed to quantify the chromosome damage induced by alpha-particle irradiation. Our results showed that the alpha-particle induced micronuclei (MN) frequencies were suppressed with the presence of Magnolol.

  20. Inhomogeneous strain induced by fast neutron irradiation in NaKSO/sub 4/ crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, S.H.; Kassem, M.E.; El-Khatib, A.; El-Gamal, M.A.; El-Wahidy, E.F.

    1987-11-01

    The paper reports the effect of fast neutron irradiation on the thermal properties of NaKSO/sub 4/ crystals in the temperature range 400-475 K. Results are presented for the thermal expansion, tensile strain and specific heat of NaKSO/sub 4/, as a function of neutron irradiation dose. All these results revealed an inhomogeneous strain induced by the radiation. It is suggested that this induced inhomogeneous strain could be used to detect neutron exposure doses.

  1. Inhomogeneous strain induced by fast neutron irradiation in NaKSO4 crystals

    International Nuclear Information System (INIS)

    Kandil, S.H.; Kassem, M.E.; El-Khatib, A.; El-Gamal, M.A.; El-Wahidy, E.F.

    1987-01-01

    The paper reports the effect of fast neutron irradiation on the thermal properties of NaKSO 4 crystals in the temperature range 400-475 K. Results are presented for the thermal expansion, tensile strain and specific heat of NaKSO 4 , as a function of neutron irradiation dose. All these results revealed an inhomogeneous strain induced by the radiation. It is suggested that this induced inhomogeneous strain could be used to detect neutron exposure doses. (UK)

  2. Thermal Effects Induced by Laser Irradiation of Solids

    International Nuclear Information System (INIS)

    Galovic, S.

    2004-01-01

    A part of incident energy is absorbed within the irradiated sample when a solid is exposed to the influence of laser radiation, to more general electromagnetic radiation within the wide range of wavelengths (from microwaves, to infrared radiation to X-rays), or to the energy of particle beams (electronic, protonic, or ionic). The absorption process signifies a highly selective excitation of the electronic state of atoms or molecules, followed by thermal and non-thermal de-excitation processes. Non-radiation de-excitation-relaxation processes induce direct sample heating. In addition, a great number of non-thermal processes (e.g., photoluminescence, photochemistry, photovoltage) may also induce heat generation as a secondary process. This method of producing heat is called the photothermal effect.The photothermal effect and subsequent propagation of thermal waves on the surface and in the volume of the solid absorbing the exciting beam may produce the following: variations in the temperature on the surfaces of the sample; deformation and displacement of surfaces; secondary infrared radiation (photothermal radiation); the formation of the gradient of the refractivity index; changes in coefficients of reflection and absorbtion; the generation of sound (photoacoustic generation), etc. These phenomena may be used in the investigation and measurement of various material properties since the profile and magnitude of the generated signal depend upon the nature of material absorbing radiation. A series of non-destructive spectroscopic, microscopic and defectoscopic detecting techniques, called photothermal methods, is developed on the basis of the above-mentioned phenomena.This paper outlines the interaction between the intensity modulated laser beam and solids, and presents a mathematical model of generated thermal sources. Generalized models for a photothermal response of optically excited materials have been obtained, including thermal memory influence on the propagation

  3. Polymerization of calcium caseinates solutions induced by gamma irradiation

    International Nuclear Information System (INIS)

    Lacroix, M.; Jobin, M.; Mezgheni, E.; Srour, M.; Boileau, S.

    1998-01-01

    Solutions of calcium caseinate (5%) combined with propylene glycol (PG) or triethylene glycol(TEG) (0, 2.5% and 5%) and used for the development of edible films and coatings, were irradiated at doses between 0 to 128 kGy. Solutions were chromatographed through toyopearl HW 55F resin to observe the effect of irradiation on cross-link reactions. In unirradiated calcium caseinate solutions, two peaks could be observed (fractions 30 and 37) while samples irradiated at 64 kGy and 128 kGy showed one shifted peak at fraction 32 and 29 respectively. No effect of the plasticizers was observed. According to proteins standards of knowed molecular weights, the molecular weight of calcium caseinate increased approximately 10 times when irradiated at 128 kGy and 5 times when irradiated at 64 kGy. The physico-chemical properties of bio-films prepared with the irradiated solutions, demonstrated that tensile strength at break increased with increase of irradiation dose. A maximum dose was obtained at 16 kGy

  4. Intestinal metaplasia induced by x-irradiation in rat

    International Nuclear Information System (INIS)

    Watanabe, Hiromitsu; Terada, Yoritaka; Fujii, Isao; Yamamoto, Yukiko; Takizawa, Shoichi

    1978-01-01

    Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation. (Ueda, J.)

  5. Intestinal metaplasia induced by x-irradiation in rat

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H; Terada, Y; Fujii, I; Yamamoto, Y; Takizawa, S [Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology

    1978-04-01

    Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation.

  6. Improving the determination of irradiation efficacy by the identification of surviving bacteria from irradiated spices

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko; Matsushima, Masako; Hironiwa, Takayuki; Takekawa, Tetsuya; Miyahara, Makoto

    2009-01-01

    The identification of the surviving bacteria isolated from 5 kinds of irradiated spices (all-spice, oregano, sage, paprika and black pepper) was carried out to know whether these bacteria were marker organisms to determine the efficacy of the irradiation treatment. Except in paprika, B.megaterium was detected. In allspice, paprika and black pepper B.pumilus was detected. B.cereus was detected in allspice, oregano and black pepper. Gram negative bacteria such as Methylobacterium and Enterobacter genus were also detected in oregano, sage and paprika. These bacteria were strongly resistant to radiation, and can be used as marker organisms for the determination of the efficacy of the irradiation treatment of spices. (author)

  7. Esterification of jatropha oil via ultrasonic irradiation with auto-induced temperature-rise effect

    International Nuclear Information System (INIS)

    Andrade-Tacca, Cesar Augusto; Chang, Chia-Chi; Chen, Yi-Hung; Manh, Do-Van; Chang, Ching-Yuan; Ji, Dar-Ren; Tseng, Jyi-Yeong; Shie, Je-Lueng

    2014-01-01

    Auto-induced temperature-rise effects of ultrasonic irradiation (UI) on the esterification performance of jatropha oil (JO) were studied. Comparisons with other methods of mechanical mixing (MM) and hand shaking mixing were made. Major system parameters examined include: esterification time (t E ), settling time (t S ) after esterification and temperature. Properties of acid value (AV), iodine value (IV), kinematic viscosity (KV) and density of JO and ester product were measured. The esterification conversion efficiencies (η) were determined and assessed. Sulfuric acid was used to catalyze the esterification using methyl alcohol. For esterification without temperature control, η at t E  = 10 and 30 min for UI of 56.73 and 83.23% are much higher than those for MM of 36.76 and 42.48%, respectively. At t E  = 10 min, the jatropha oil esters produced via UI and MM respectively possess AV of 15.82 and 23.12 mg KOH/g, IV of 111.49 and 113.22 g I 2 /100 g, KV of 22.41 and 22.51 mm 2 /s and density of 913.8 and 913.58 kg/m 3 , showing that UI is much better than MM in enhancing the reduction of AV. The t E exhibits more vigorous effect on AV for UI than MM. The UI offers auto-induced temperature-rise, improving the mixing and esterification extents. - Highlights: • Esterification of jatropha oil is pronounced under ultrasonic irradiation (UI). • UI can auto-induce temperature rise. • The induced temperature rise assists the mixing of UI in enhancing esterification. • UI offers better esterification than mechanical mixing with external heating. • An 83.23% reduction of FFA in jatropha-ester is achievable via UI in 30 min

  8. Validation of software components for the prediction of irradiation-induced damage of RPV steel

    International Nuclear Information System (INIS)

    Bergner, Frank; Birkenheuer, Uwe; Ulbricht, Andreas

    2010-04-01

    The modelling of irradiation-induced damage of RPV steels from primary cascades up to the change of mechanical properties bridging length scales from the atomic level up to the macro-scale and time scales up to years contributes essentially to an improved understanding of the phenomenon of neutron embrittlement. In future modelling may become a constituent of the procedure to evaluate RPV safety. The selected two-step approach is based upon the coupling of a rate-theory module aimed at simulating the evolution of the size distribution of defect-solute clusters with a hardening module aimed at predicting the yield stress increase. The scope of the investigation consists in the development and validation of corresponding numerical tools. In order to validate these tools, the output of representative simulations is compared with results from small-angle neutron scattering experiments and tensile tests performed for neutron-irradiated RPV steels. Using the developed rate-theory module it is possible to simulate the evolution of size, concentration and composition of mixed Cu-vacancy clusters over the relevant ranges of size up to 10.000 atoms and time up to tens of years. The connection between the rate-theory model and hardening is based upon both the mean spacing and the strength of obstacles for dislocation glide. As a result of the validation procedure of the numerical tools, we have found that essential trends of the irradiation-induced yield stress increase of Cu-bearing and low-Cu RPV steels are displayed correctly. First ideas on how to take into account the effect of Ni on both cluster evolution and hardening are worked out.

  9. Temper embrittlement, irradiation induced phosphorus segregation and implications for post-irradiation annealing of reactor pressure vessels

    International Nuclear Information System (INIS)

    McElroy, R.J.; English, C.A.; Foreman, A.J.; Gage, G.; Hyde, J.M.; Ray, P.H.N.; Vatter, I.A.

    1999-01-01

    Three steels designated JPB, JPC and JPG from the IAEA Phase 3 Programme containing two copper and phosphorus levels were pre- and post-irradiation Charpy and hardness tested in the as-received (AR), 1200 C/0.5h heat treated (HT) and heat treated and 450 C/2000h aged (HTA) conditions. The HT condition was designed to simulate coarse grained heat-affected zones (HAZ's) and showed a marked sensitivity to thermal ageing in all three alloys. Embrittlement after thermal ageing was greater in the higher phosphorus alloys JPB and JPG. Charpy shifts due to thermal ageing of between 118 and 209 C were observed and accompanied by pronounced intergranular fracture, due to phosphorus segregation. The irradiation embrittlement response was complex. The low copper alloys, JPC and JPB, in the HT and HTA condition exhibited significant irradiation induced Charpy shift but very low or even negative hardness changes indicating non-hardening embrittlement. The higher copper alloy, JPG, also exhibited irradiation hardening in line with its copper content. Fractographic and microchemical studies indicated irradiation induced phosphorus segregation and a transition from cleavage to intergranular failure at grain boundary phosphorus concentrations above a critical level. The enhanced grain boundary phosphorus level increased with dose in agreement with a kinetic segregation model developed at Harwell. The relevance of the thermal ageing studies to RPV Annealing for Plant-Life Extension was identified early in the program. It is of concern that annealing of RPV's has been performed, or is proposed, at temperatures in the range 425--475 C for periods of about 1 week (168h). Much attention has been given to the use of in-situ hardness measurements and machining miniature Charpy and tensile specimens from belt-line plate and weld materials. However, HAZ's, often containing higher phosphorus levels than the present materials, have largely been ignored. A post-irradiation annealing (PIA

  10. Contribution of caspase-3 differs by p53 status in apoptosis induced by X-irradiation

    International Nuclear Information System (INIS)

    Kobayashi, Daisuke; Tokino, Takashi; Watanabe, Naoki

    2001-01-01

    We investigated the effect of p53 status on involvement of caspase-3 activation in cell death induced by X-irradiation, using rat embryonic fibroblasts (REFs) transduced with a temperature-sensitive mutant (mt) p53 gene. Cells with wild-type (wt) p53 showed greater resistance to X-irradiation than cells with mt p53. In cells with wt p53, X-irradiation-induced apoptosis was not inhibited by the caspase-3 inhibitor acetyl-L-aspartyl-L-methionyl-L-glutaminyl-L-aspartyl-aldehyde (Ac-DMQD-CHO) and caspase-3 activity was not elevated following X-irradiation, although induction of p53 and p21/WAF-1 protein was observed. In contrast, irradiated cells with mt p53 showed 89% inhibition of cell death with Ac-DMQD-CHO and 98% inhibition with the antioxidant N-acetyl-L-cysteine (NAC). In cells with mt p53, caspase-3 activity was increased approximately 5 times beyond baseline activity at 24 h after irradiation. This increase was almost completely inhibited by NAC. However, inhibition of caspase-3 by Ac-DMQD-CHO failed to decrease production of reactive oxygen species by cells with mt p53. Differential involvement of caspase-3 is a reason for differences in sensitivity to X-irradiation in cells with different p53 status. Caspase-3 activation appears to occur downstream from generation of reactive oxygen species occurring independently of wt p53 during X-irradiation-induced cell death. (author)

  11. Protection from radiation induced changes in liver and serum transaminase of whole body gamma irradiated rats

    International Nuclear Information System (INIS)

    Elkashef, H.S.; Roushdy, H.M.; Saada, H.N.; Abdelsamie, M.

    1986-01-01

    Whole body gamma irradiation of rats with a dose of 5.5 Gy induced significant changes in the activity of liver and serum transaminase. The results indicated that this radiation dose caused a significant increase in the activity of serum Got and GPT on the third and seventh days after irradiation. This was followed by significant decreases on the fourteenth post-irradiation day. The activity of Got returned to is control activity, while the activity of GPT was significantly above the control on the twenty ones post-irradiation day. The activity of Got, in the liver of irradiated rats was elevated during the post-irradiation days, but on the twenty one day activity was about the normal value. The activity of liver GPT firstly decreased and then increased very much but attained the control level on the fourteenth after irradiation. The intraperitoneal injection of testosterone-vitamin E mixture 10 days before whole body gamma irradiation caused complete recovery for the activity of liver and serum Got. No indication of remarkable recovery in the case of GPT activity was recorded either in liver or in serum of irradiated rats. The applied mixture could protect against radiation induced changes in Got activity of liver and serum but could not protect or ameliorate the changes which occurred in the activity of GPT of the two tissues. 2 tab

  12. Effect of gamma-irradiation pretreatment on improvement of anaerobic digestive characteristic of sludge

    International Nuclear Information System (INIS)

    Mou Yanyan; Yuan Shoujun; Yu Xin; Zheng Zheng; Cui Lei; Zhao Yongfu

    2005-01-01

    A comparative study was made about main anaerobic digestive characteristics of sludge which was subjected to a 60 Co gamma-irradiation pretreatment. The results showed the gamma-irradiation pretreatment can clearly improve anaerobic digestibility of sludge and pick up the anaerobic digestion speed of sludge. (authors)

  13. Swift heavy ion irradiation induced modification of structure and ...

    Indian Academy of Sciences (India)

    1Department of Physics, Salipur College, Salipur 754 103, India. 2Department of ... Ion irradiation; nanoparticles; atomic force microscopy; BiFeO3. 1. Introduction .... and to understand their possible origin, a study on power spectral density ...

  14. Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

    International Nuclear Information System (INIS)

    Jeong, Rae Dong

    2017-01-01

    Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit

  15. Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Rae Dong [Dept. of Applied Biology, Institute of Environmentally Friendly Agriculture, Chonnam National University, Gwangju (Korea, Republic of)

    2017-06-15

    Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit.

  16. Protective role of acetylsalicylic acid (Aspirin) against gamma irradiation-induced ophthalmic and histological changes in rat's eye

    International Nuclear Information System (INIS)

    Naguib, N. I.; Abd El Maguid, A.

    2007-01-01

    Radiation generates a variety of free radicals during the exposure of biological tissues through radiolysis of water. These free radicals are highly reactive and cause oxidative damage to biological molecules. This study examined the protective ability of aspirin against radiation-induced ophthalmic and histological disorders in the eye of rats exposed to 6.5 Gy single dose of gamma irradiation, Acetylsalicylic acid was given daily to rats in drinking water (2.5 g/ L) 1 week pre-irradiation, during irradiation and 9 weeks post-irradiation. Experimental investigations showed that irradiation caused cataract formation. Irradiation also caused histopathological changes in the retina of the eyes described as focal degeneration and necrosis of the inner and outer nuclear layers, vacuolation of ganglionic cell layer as well as necrosis of retinal inner and outer segments of the rods and cones. The cornea revealed vacuolation of stratified epithelial layer, edema in substantia propria with dispersion of the connective tissue as well as presence of extravasated red blood cells as a result of exposure to radiation. The lens became homogenous and oesinophilic due to radiation exposure. The eye tissues of rats .that received acetylsalicylic acid supplement showed slight improvement of radiation-induced histological damage in the eyes and it also delayed the onset of cataract formation. According to the results obtained it could be concluded that oral administration of aspirin gave only a slight, nonsignificant reduction of eye radiation injury after exposure to single dose of gamma irradiation (6.5 Gy). The anatomy, physiology and biochemistry of the visual system make the eye uniquely vulnerable to damage from injurious agents, physical and chemical. Although many studies were conducted on a broad range of agents, the majority of all efforts are directed at deleterious effect of radiation on the eye tissues, and

  17. γ-Irradiation-induced radiolysis of inulin in aqueous solutions

    International Nuclear Information System (INIS)

    Tsyba, I.A.; Revina, A.A.; Shostenko, A.G.

    1997-01-01

    Radiochemical transformations of inulin in aqueous solutions, in air, in the presence of inert gases, helium, nitrogen and in nitrous oxide exposed to various doses of 60 Co γ-irradiation were investigated. It was shown that interactions in inulin with OH radicals are principally responsible for radiolytic decomposition of inulin. The data on radiolysis of more simple model systems were used to make available decomposition spectra of γ-irradiated aerated aqueous solution of inulin. 9 refs., 6 figs

  18. Irradiation-induced precipitation in Ni--Si alloys

    International Nuclear Information System (INIS)

    Barbu, A.; Ardell, A.J.

    1975-07-01

    The microstructures of Ni + ion-irradiated Ni--Si solid-solution alloys, containing 2, 4, 6 and 8 at. percent Si were investigated as a function of dose, dose-rate, and temperature. Results of transmission electron microscopy and other data show the precipitation of γ' (Ni 3 Si) in all samples irradiated at 500 0 C. Characteristics of the precipitates are described and a mechanism for their formation is suggested. (U.S.)

  19. Colorectal irradiation induced immune response: 'toll like receptors' therapeutic manipulation

    International Nuclear Information System (INIS)

    Lacave-Lapalun, Jean-Victor

    2013-01-01

    Exposure of the abdomino-pelvic sphere to ionizing radiation is associated with a high incidence of complications. Radiation therapy may cause short and / or long-term harmful effects. In the most severe cases and in the absence of heavy treatments, the appearance of ulcers may induce the death of patients. Clinical trials are being conducted with Mesenchymal Stem Cells (MSC) to cure theses complications. Others studies indicate that the injection of bacterial motifs limits the radiotoxicity in the intestine. They stimulate receptors (Toll-Like- Receptors (TLR)) located on the surface of epithelial and intestinal immune cells. The first aim of this doctoral work is to characterize the effects of TLR stimulation on immunity and tissue repair using a model of localized colorectal irradiation at 20 Gy (acute effects of radiotherapy) on a rat. The thesis then aims to potentiate the effects of the MSC treatment when adding TLR ligands upon localized colorectal irradiation at 27 Gy (accidental complications). This work, using a 20 Gy exposure, show that TLR stimulation improves homeostasis (normalization of T cells, induction of regulatory T cells (Treg) and macrophages 'anti-inflammatory' M2). On the 27 Gy colorectal model, the injection of TLR ligand before CSM transplant improves the immune climate by reducing pro-inflammatory cytokines and inducting Treg and M2 cells. These modulations could contribute to improving the implantation and effectiveness of CSM. The observations have all shown that the stimulation of immunity is an approach to minimize radiation-induced lesions. (author) [fr

  20. Radiation-induced epigenetic alterations after low and high LET irradiations

    International Nuclear Information System (INIS)

    Aypar, Umut; Morgan, William F.; Baulch, Janet E.

    2011-01-01

    Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding radiation-induced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET X-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NFκB), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. We demonstrate that miRNA expression levels can be altered after X-ray irradiation and that these miRNA are involved in chromatin remodeling and DNA methylation. A higher incidence of epigenetic changes was observed after exposure to X-rays than Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This distinction is apparent at miRNA analyses at which only three miRNA involved in two major pathways were altered after high LET irradiations while six miRNA involved in five major pathways were altered after low LET irradiations. This study also shows that the irradiated cells acquire epigenetic changes suggesting that epigenetic aberrations may arise in the

  1. Radiation-induced epigenetic alterations after low and high LET irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Aypar, Umut, E-mail: uaypa001@umaryland.edu [Department of Radiation Oncology, Radiation Oncology Research Laboratory, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Morgan, William F. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Baulch, Janet E. [Department of Radiation Oncology, Radiation Oncology Research Laboratory, University of Maryland School of Medicine, Baltimore, MD 21201 (United States)

    2011-02-10

    Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding radiation-induced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET X-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NF{kappa}B), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. We demonstrate that miRNA expression levels can be altered after X-ray irradiation and that these miRNA are involved in chromatin remodeling and DNA methylation. A higher incidence of epigenetic changes was observed after exposure to X-rays than Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This distinction is apparent at miRNA analyses at which only three miRNA involved in two major pathways were altered after high LET irradiations while six miRNA involved in five major pathways were altered after low LET irradiations. This study also shows that the irradiated cells acquire epigenetic changes suggesting that epigenetic aberrations may arise

  2. Improvement of foaming ability of egg white product by irradiation and its application

    Science.gov (United States)

    Song, Hyun-Pa; Kim, Binna; Choe, Jun-Ho; Jung, Samooel; Kim, Kyong-Su; Kim, Dong-Ho; Jo, Cheorun

    2009-03-01

    To investigate the enhancement of foaming abilities of liquid egg white (LEW) and egg white powder (EWP) by irradiation and its application for bakery product, LEW and EWP were irradiated at 0, 1, 2, and 5 kGy by Co-60 gamma ray. There was no pH change found among treatments in both LEW and EWP. The viscosity of LEW decreased significantly by irradiation ( Pcake baked with irradiated LEW were significantly higher than those of unirradiated control ( Pcake were greater at 2 kGy only than those of control. A significant decrease in hardness, chewiness, and gumminess values and an increase in Hunter L* value were observed in the angel cakes prepared from irradiated egg white products ( P<0.05). Results indicated that irradiation of egg white could offer advantages in increasing foaming ability and improving quality of final bakery products.

  3. Surface modification and adhesion improvement of PTFE film by ion beam irradiation

    International Nuclear Information System (INIS)

    Lee, S.W.; Hong, J.W.; Wye, M.Y.; Kim, J.H.; Kang, H.J.; Lee, Y.S.

    2004-01-01

    The polytetrafluoroethylene (PTFE) surfaces, modified by 1 kV Ar + or O 2 + ion beam irradiation, was investigated with in-situ X-ray photoelectron spectroscopy (XPS), scanning electron micrographs (SEM), atomic force microscopy (AFM) measurements. The surface of PTFE films modified by Ar + ion irradiation was carbonized and the surface roughness increased with increasing ion doses. The surface of PTFE films modified by both Ar + ion in O 2 atmosphere and O 2 + ion irradiation formed the oxygen function group on PTFE surface, and the surface roughness change was relatively small. The adhesion improvement in Ar + ion irradiated PTFE surface is attributed to mechanical interlocking due to the surface roughness and -CF-radical, but that in Ar + ion irradiation in an O 2 atmosphere was contributed by the C-O complex and -CF-radical with mechanical interlocking. The C-O complex and -CF-radical in O 2 + ion irradiated surface contributed to the adhesion

  4. Uranium doping and neutron irradiation of Bi-2223 superconduction tapes for improved critical current density

    International Nuclear Information System (INIS)

    Moss, S.D.; Wang, W.G.; Dou, S.X.; Weinstein, R.

    1998-01-01

    It is demonstrated that a combination of neutron irradiation with uranium doping introduce fission tracks through a Bi-2223 tape which act as effective pinning centres, leading to a substantial increase in critical current. Preliminary data suggests that the combination of uranium doping and neutron irradiation produces improved flux pinning in Bi-2223 tapes over neutron irradiation alone. Before irradiation, SEM, DTA and XRD analyses were performed on the tapes. Both before and after irradiation the trapped maximum magnetic flux was measured at 77K. Before neutron irradiation, uranium doping has no effect on critical current. Preliminary SEM data suggested that the uranium is homogeneously distributed throughout the oxide core of the tape. The presence of 2212 and other secondary phases in the doped tapes suggest further refinement of the sintering procedure is necessary. (authors)

  5. Heavy-ion irradiation induced diamond formation in carbonaceous materials

    International Nuclear Information System (INIS)

    Daulton, T. L.

    1999-01-01

    The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond

  6. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Science.gov (United States)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  7. Spontaneous and x-irradiation induced carcinomas of small intestine in Wistar-Furth rats

    Energy Technology Data Exchange (ETDEWEB)

    Maeura, Y; Kosaki, G; Kitamura, H [Osaka Univ. (Japan). Faculty of Medicine; Nagatomo, T

    1980-04-01

    Spontaneous carcinoma of the small intestine in Wistar-Furth (WF) rats and carcinoma of the small intestine induced by local x-ray irradiation to the abdomen of WF rats without carcinoma were observed, and x-ray sensitivity of the small intestine mucosa was reported. Out of 19 rats with spontaneous carcinoma of the small intestine, 18 also had carcinoma of the colon, and 4 also had gastric cancer. They already had spontaneous carcinoma of the small intestine within 2 weeks after their birth, and the ratio of female and male was 13 : 6. Histological type of this carcinoma in all 19 rats was highly differentiated adenocarcinoma, and small intestine epithelium around carcinoma presented atypical epithelium. As to mice without carcinoma, x-ray, 1,000 R, 1,500 R, and 2,000 R, was irradiated to the abdomen of Sprague-Dawley (SD) and WF rats. In the irradiation with 1,000 R, carcinogenesis was not found in rats of both strains. In the irradiation with 1,500 R, carcinogenesis was hardly found, but in the irradiation with 2,000 R, carcinoma of small intestine occurred in 5 of 17 rats 15 weeks after the irradiation, 9 of 19 rats 25 weeks after the irradiation, and 9 of 14 rats 35 weeks after the irradiation. Histological type of carcinoma in irradiated rats was highly differentiated adenocarcinoma. The incidence of carcinoma in irradiated rats was higher in WF rats than SD rats through the course after the irradiation, which suggested that x-ray sensitivity of WF rats was higher than that of SD rats. Therefore, carcinoma of the small intestine in irradiated mice seemed to be induced by x-ray.

  8. Improved irradiation tolerance of reactive gas pulse sputtered TiN coatings with a hybrid architecture of multilayered and compositionally graded structures

    Science.gov (United States)

    Liang, Wei; Yang, Jijun; Zhang, Feifei; Lu, Chenyang; Wang, Lumin; Liao, Jiali; Yang, Yuanyou; Liu, Ning

    2018-04-01

    This study investigates the improved irradiation tolerance of reactive gas pulse (RGP) sputtered TiN coatings which has hybrid architecture of multilayered and compositionally graded structures. The multilayered RGP-TiN coating is composed of hexagonal close-packed Ti phase and face-centred cubic TiN phase sublayers, where the former sublayer has a compositionally graded structure and the latter one maintains constant stoichiometric atomic ratio of Ti:N. After 100 keV He ion irradiation, the RGP-TiN coating exhibits improved irradiation resistance compared with its single layered (SL) counterpart. The size and density of He bubbles are smaller in the RGP-TiN coating than in the SL-TiN coating. The irradiation-induced surface blistering of the coatings shows a similar tendency. Meanwhile, the irradiation hardening and adhesion strength of the RGP-TiN coatings were not greatly affected by He irradiation. Moreover, the irradiation damage tolerance of the coatings can be well tuned by changing the undulation period number of N2 gas flow rate. Detailed analysis suggested that this improved irradiation tolerance could be related to the combined contribution of the multilayered and compositionally graded structures.

  9. Evaluation of induced radioactivity in 10 MeV-electron irradiated spices, (1)

    International Nuclear Information System (INIS)

    Furuta, Masakazu; Katayama, Tadashi; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Shibata, Setsuko; Toratani, Hirokazu; Takeda, Atsuhiko.

    1994-01-01

    Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by γ-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H 50 according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from 40 K contained in the samples. (author)

  10. Modelling irradiation-induced softening in BCC iron by crystal plasticity approach

    International Nuclear Information System (INIS)

    Xiao, Xiazi; Terentyev, Dmitry; Yu, Long; Song, Dingkun; Bakaev, A.; Duan, Huiling

    2015-01-01

    Crystal plasticity model (CPM) for BCC iron to account for radiation-induced strain softening is proposed. CPM is based on the plastically-driven and thermally-activated removal of dislocation loops. Atomistic simulations are applied to parameterize dislocation-defect interactions. Combining experimental microstructures, defect-hardening/absorption rules from atomistic simulations, and CPM fitted to properties of non-irradiated iron, the model achieves a good agreement with experimental data regarding radiation-induced strain softening and flow stress increase under neutron irradiation. - Highlights: • A stress- and thermal-activated defect absorption model is proposed for the dislocation-loop interaction. • A temperature-dependent plasticity theory is proposed for the irradiation-induced strain softening of irradiated BCC metals. • The numerical results of the model match with the corresponding experimental data.

  11. A small angle neutron study of irradiation induced microstructures in Cr-Mo-V WWER steels

    International Nuclear Information System (INIS)

    Levit, Vladimir I.; Santos, Ari S.; Louzada, Ana R.R.; Silveira, Cristina M.; Vaniel, Ana Paula H.; Odette, George R.; Mader, Eric

    2000-01-01

    Small angle neutron scattering (SANS) has proven to be a very effective technique for characterizing the ultrafine (∼1 nm) irradiation induced microstructures which are responsible for hardening and the concomitant embrittlement of reactor pressure vessel steels. SANS measurement were carried out on three irradiated and unirradiated weld materials of WWER- type on 8 m instrument at the National Institute of Standards and Technology, Washington, USA. Small (r m < 1 nm) irradiation induced features were found for all three materials. Were found volume fractions, number densities and ratios of magnetic to nuclear scattering. Some analyses of the irradiation induced precipitation nature and possible chemical composition were made by comparison of the results with other reactor materials SANS and Atom Probe Field Ion Microscopy data. (author)

  12. Modelling irradiation-induced softening in BCC iron by crystal plasticity approach

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Xiazi [State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871 (China); CAPT, HEDPS and IFSA Collaborative Innovation Center of MoE, Peking University, Beijing 100871 (China); Terentyev, Dmitry, E-mail: dterenty@SCKCEN.BE [Structural Material Group, Institute of Nuclear Materials Science, SCK-CEN, Mol (Belgium); Yu, Long; Song, Dingkun [State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871 (China); Bakaev, A. [Structural Material Group, Institute of Nuclear Materials Science, SCK-CEN, Mol (Belgium); Duan, Huiling, E-mail: hlduan@pku.edu.cn [State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871 (China); CAPT, HEDPS and IFSA Collaborative Innovation Center of MoE, Peking University, Beijing 100871 (China)

    2015-11-15

    Crystal plasticity model (CPM) for BCC iron to account for radiation-induced strain softening is proposed. CPM is based on the plastically-driven and thermally-activated removal of dislocation loops. Atomistic simulations are applied to parameterize dislocation-defect interactions. Combining experimental microstructures, defect-hardening/absorption rules from atomistic simulations, and CPM fitted to properties of non-irradiated iron, the model achieves a good agreement with experimental data regarding radiation-induced strain softening and flow stress increase under neutron irradiation. - Highlights: • A stress- and thermal-activated defect absorption model is proposed for the dislocation-loop interaction. • A temperature-dependent plasticity theory is proposed for the irradiation-induced strain softening of irradiated BCC metals. • The numerical results of the model match with the corresponding experimental data.

  13. The irradiation induced creep of graphite under accelerated damage produced by boron doping

    International Nuclear Information System (INIS)

    Brocklehurst, J.E.

    1975-01-01

    The presence of boron enhances fast neutron irradiation damage in graphite by providing nucleation sites for interstitial loop formation. Doping with 11 B casues an increase in the irradiation induced macroscopic dimensional changes, which have been shown to result from an acceleration in the differential crystal growth rate for a given carbon atom displacement rate. Models of irradiation induced creep in graphite have centred around those in which creep is induced by internal stresses due to the anisotopic crystal growth, and those in which creep is activated by atomic displacements. A creep test on boron doped graphite has been performed in an attempt to establish which of these mechanisms is the determining factor. An isotropic nuclear graphite was doped to a 11 B concentration of 0.27 wt.%. The irradiation induced volume shrinkage rate at 750 0 C increased by a factor of 3 over that of the virgin graphite, in agreement with predictions from the earlier work, but the total creep strains were comparable in both doped and virgin samples. This observation supports the view that irradiation induced creep is dependent only on the carbon atom displacement rate and not on the internal stress level determined by the differential crystal growth rate. The implications of this result on the irradiation behaviour of graphite containing significant concentrations of boron are briefly discussed. (author)

  14. Search for the lowest irradiation dose from literatures on radiation-induced breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

    1975-12-01

    A survey of past case reports concerning radiation-induced breast cancer was carried out in order to find the lowest irradiation dose. The search of literature published since 1951 revealed 10 cases of radiation-induced breast cancer. Only 5 cases had precise descriptions of the irradiation dose. The lowest irradiation dose was estimated at 1470 rads in the case of external X-ray irradiation for tuberous angioma. All of cases of radiation-induced breast cancer had received radiation for the treatment of nonmalignant tumors, such as pulmonary tuberculosis, mastitis, and tuberous angioma. There also were three statistical studies. The first concerned atomic bomb survivors, the second, pulmoanry tuberculous patients subjected to frequent fluoroscopies, and the third, patients of acute post partum mastitis. These statistical studies had revealed a significant increase in the incidence of breast cancer in the irradiated group, but there was little information about the lowest irradiation dose. It was noticed that radiation-induced breast cancer was more numerous in the upper inner quadrant of the breast. Most histopathological findings of radiation-induced breast cancer involved duct cell carcinoma. The latent period was about 15 years.

  15. The application of irradiation techniques for food preservation and processing improvement

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Myung Woo; Cho, Han Ok; Jo, Sung Ki; Yook, Hong Sun; Kwon, Oh Jin; Yang, Jae Seung; Kim, Sung; Im, Sung Il

    1997-09-01

    This project has intended to develop alternative techniques to be used in food industry for food processing and utilization by safe irradiation methods. For improvement of rheology and processing in corn starch by irradiation, the production of modified starch with low viscosity as well as with excellent viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added inorganic peroxides to starch. Also, this project was developed the improvement methods of hygienic quality and long-term storage of dried red pepper by gamma irradiation. And, in Korean medicinal plants, 10 kGy gamma irradiation was effective for improving sanitary quality and increasing extraction yield of major components. For the sanitization of health and convenience foods, gamma irradiation was more effective than ozone treatment in decontamination of microorganisms, with minimal effect on the physicochemical properties analysed. In evaluation of wholesomeness, gamma-irradiated the Korean medicinal plants could be safe on the genotoxic point of view. And, thirteen groups of irradiated foods approved for human consumption from Korea Ministry of Health and Welfare. (author). 81 refs., 74 tabs.

  16. The application of irradiation techniques for food preservation and processing improvement

    International Nuclear Information System (INIS)

    Byun, Myung Woo; Cho, Han Ok; Jo, Sung Ki; Yook, Hong Sun; Kwon, Oh Jin; Yang, Jae Seung; Kim, Sung; Im, Sung Il.

    1997-09-01

    This project has intended to develop alternative techniques to be used in food industry for food processing and utilization by safe irradiation methods. For improvement of rheology and processing in corn starch by irradiation, the production of modified starch with low viscosity as well as with excellent viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added inorganic peroxides to starch. Also, this project was developed the improvement methods of hygienic quality and long-term storage of dried red pepper by gamma irradiation. And, in Korean medicinal plants, 10 kGy gamma irradiation was effective for improving sanitary quality and increasing extraction yield of major components. For the sanitization of health and convenience foods, gamma irradiation was more effective than ozone treatment in decontamination of microorganisms, with minimal effect on the physicochemical properties analysed. In evaluation of wholesomeness, gamma-irradiated the Korean medicinal plants could be safe on the genotoxic point of view. And, thirteen groups of irradiated foods approved for human consumption from Korea Ministry of Health and Welfare. (author). 81 refs., 74 tabs

  17. An improved approach to identify irradiated dog feed by electron paramagnetic resonance study and thermoluminescence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, Bhaskar, E-mail: bhaskar_sanyal@rediffmail.co [Food Technology Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India); Chawla, S.P.; Sharma, Arun [Food Technology Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    2011-05-15

    In the present study, probably for the first time, a detailed analysis of the radiation induced radical species and thermoluminescence measurements of irradiated dog feed are reported. The EPR spectrum of non-irradiated ready-to-eat dog feed was characterized by singlet g=2.0047{+-}0.0003. Irradiated samples exhibited a complex EPR spectrum. During high power (50.0 mW) EPR spectroscopy, a visible change in the shape of the EPR spectrum was observed and characterized by EPR spectrum simulation technique. An axially symmetric anisotropic signal with g{sub ||}=2.0028 and g{sub perpendicular}=1.9976 was identified. However, a negligible change in the matrix of irradiated edible dog chew was observed using EPR spectroscopy. Therefore, thermoluminescence study of the isolated minerals from dog chew was carried out. The composition of the poly-minerals was studied using SEM and EDX analysis and a complete verdict on identification of irradiation is proposed.

  18. An improved approach to identify irradiated dog feed by electron paramagnetic resonance study and thermoluminescence measurements

    International Nuclear Information System (INIS)

    Sanyal, Bhaskar; Chawla, S.P.; Sharma, Arun

    2011-01-01

    In the present study, probably for the first time, a detailed analysis of the radiation induced radical species and thermoluminescence measurements of irradiated dog feed are reported. The EPR spectrum of non-irradiated ready-to-eat dog feed was characterized by singlet g=2.0047±0.0003. Irradiated samples exhibited a complex EPR spectrum. During high power (50.0 mW) EPR spectroscopy, a visible change in the shape of the EPR spectrum was observed and characterized by EPR spectrum simulation technique. An axially symmetric anisotropic signal with g || =2.0028 and g perpendicular =1.9976 was identified. However, a negligible change in the matrix of irradiated edible dog chew was observed using EPR spectroscopy. Therefore, thermoluminescence study of the isolated minerals from dog chew was carried out. The composition of the poly-minerals was studied using SEM and EDX analysis and a complete verdict on identification of irradiation is proposed.

  19. Studies of soy sauce sterilization and its special flavour improvement by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Yang Jingtian; Jin Xinhua; Gu Guoxing; Yun Guichun

    1988-01-01

    Experimental studies for sterilizing 12 kinds of soy sauce with gamma-ray irradiation showed that both sterilization and improvements in flavour and quality of soy sauce were obtained simultaneously. (author)

  20. Development of Ice Cream with Improved Microbiological Safety and Acceptable Organoleptic Quality Using Irradiation

    International Nuclear Information System (INIS)

    Kim, H.J.; Byun, M.W.; Ham, J.S.; Jeong, S.G.; Ahn, J.N.; Jang, A.; Jo, C.

    2007-01-01

    To develop the manufacturing method of ice cream with microbiologically safe and proper sensory quality using irradiation for sensitive consumer, 3 different flavors, which were resistant to their flavors against irradiation, were selected and used for ice cream manufacturing to reduce the irradiation-induced off-flavor problem. The general composition was not different among treatments. Total aerobic bacteria were detected as 2.38, 1.23, 1.38, and 1.15 log CFU/g level in ice cream with control (no flavor added), spearmint, mint, and citrus flavor, respectively

  1. Pathological study about two autopsy cases of bilateral irradiation pneumonitis induced by unilateral irradiation

    International Nuclear Information System (INIS)

    Yamauchi, Noriko; Tajima, Yo; Iio, Masaaki; Oshima, Takeo; Iino, Koichi.

    1978-01-01

    The first case is a 73-year-old man with left lung cancer. Seven days after completion of radiotherapy 7,000 rad, a chest roentgenogram showed diffuse bilateral pneumonia. The second case is a 61-year-old woman with right lung cancer and about one month after completion of radiotherapy 2,600 rad, a chest roentgenogram showed bilateral pneumonia. Pathological findings, all lobes of both lungs of these cases showed acute interstitial pneumonitis. The pathogenesis of irradiation pneumonitis is poorly understood. Several investigators thought that the pathogenesis of irradiation pneumonitis was caused by autoimmune mechanism, they carried out sero-pathological studies and demonstrated the bilateral pneumonia caused by unilateral irradiation. (author)

  2. Correlation of yield strength with irradiation-induced microstructure in AISI 316 stainless steel

    International Nuclear Information System (INIS)

    Simons, R.L.; Hulbert, L.A.

    1985-10-01

    Improvements in the correlation of radiation-induced change in yield strength in AISI 316 stainless steel with microstructure were made by re-examining the role of short-range obstacles. Effects due to the size of the obstacles relative to their spacing and shape of the obstacles were applied. The concept of shearing the precipitates instead of bowing around them was used to explain the effects of precipitate hardening. It is concluded that large changes in yield strength may be produced in high swelling materials. Voids will dominate the hardening at high dpa. The increase in hardening will depend on the diameter of the voids even though the swelling in the material is the same. Precipitate hardening at high fluence (>15 dpa) make a significant contribution for irradiation temperatures above 500 0 C

  3. Gamma ray irradiation to roots of tea-plants and induced mutant system

    International Nuclear Information System (INIS)

    Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa

    1990-01-01

    In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.)

  4. Gamma ray irradiation to roots of tea-plants and induced mutant system

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa (National Research Inst. of Vegetables, Ornamental Plants and Tea, Ano, Mie (Japan))

    1990-11-01

    In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.).

  5. Martensitic transformation induced by irradiation and deformation in stainless steels

    International Nuclear Information System (INIS)

    Maksimkin, O.P.

    1997-01-01

    In the present work the peculiarities of martensite γ → α , (γ → ε → α , ) transformation in the steels with a low stacking fault energy (12Cr18Ni10T, Cr15AG14) irradiated by neutrons, α-particles and electrons (pulse and stationary) and then deformed with the various strain rates in the temperature range - 20 - 1000 C are considered. It is established by the electron-microscope research that the phase γ → α ' transition in irradiated and deformed steels is observed on the definite stage of evolution of the dislocation structure (after the cell formation) and the martensite formation preferentially occurs on a stacking fault aggregation. The regularities of the irradiation by high energy particles effect on the formation parameters and martensite α , -phase accumulation kinetics ones and also their role in forming of the strength and ductile properties in steels are analysed. (A.A.D.)

  6. Femtosecond laser irradiation-induced infrared absorption on silicon surfaces

    Directory of Open Access Journals (Sweden)

    Qinghua Zhu

    2015-04-01

    Full Text Available The near-infrared (NIR absorption below band gap energy of crystalline silicon is significantly increased after the silicon is irradiated with femtosecond laser pulses at a simple experimental condition. The absorption increase in the NIR range primarily depends on the femtosecond laser pulse energy, pulse number, and pulse duration. The Raman spectroscopy analysis shows that after the laser irradiation, the silicon surface consists of silicon nanostructure and amorphous silicon. The femtosecond laser irradiation leads to the formation of a composite of nanocrystalline, amorphous, and the crystal silicon substrate surface with microstructures. The composite has an optical absorption enhancement at visible wavelengths as well as at NIR wavelength. The composite may be useful for an NIR detector, for example, for gas sensing because of its large surface area.

  7. The relaxation phenomena of radicals induced in irradiated fresh mangoes

    International Nuclear Information System (INIS)

    Kikuchi, Masahiro; Morishita, Norio; Kobayashi, Yasuhiko; Ogawa, Hideyuki; Shimoyama, Yuhei; Ukai, Mitsuko

    2009-01-01

    Using the γ-irradiated fresh mangoes followed by freeze-drying and powderization, electron spin resonance spectrometry of specimens was performed. As a result, a strong single peak in the flesh, the pericarp and the seed was observed at g=2.004 and attributed to organic free radicals. When relaxation times of the peak was calculated using the method of Lund et al., T 2 showed dose responses according to increasing doses while T 1 was almost constant. Dose responsibility of the relaxation time T 2 obtained from flesh specimens of the mangoes could be measured regardless of the preservation period of 1 to 9 days following γ-irradiation. Therefore, there might be possible to detect the irradiation treatment of fresh mangoes using relaxation time T 2 . (author)

  8. Sub-micron indent induced plastic deformation in copper and irradiated steel

    International Nuclear Information System (INIS)

    Robertson, Ch.

    1998-09-01

    In this work we aim to study the indent induced plastic deformation. For this purpose, we have developed a new approach, whereby the indentation curves provides the mechanical behaviour, while the deformation mechanisms are observed thanks to Transmission Electron Microscopy (TEM). In order to better understand how an indent induced dislocation microstructure forms, numerical modeling of the indentation process at the scale of discrete dislocations has been worked out as well. Validation of this modeling has been performed through direct comparison of the computed microstructures with TEM micrographs of actual indents in pure Cu [001]. Irradiation induced modifications of mechanical behaviour of ion irradiated 316L have been investigated, thanks to the mentioned approach. An important hardening effect was reported from indentation data (about 50%), on helium irradiated 316L steel. TEM observations of the damage zone clearly show that this behaviour is associated with the presence of He bubbles. TEM observations of the indent induced plastic zone also showed that the extent of the plastic zone is strongly correlated with hardness, that is to say: harder materials gets a smaller plastic zone. These results thus clearly established that the selected procedure can reveal any irradiation induced hardening in sub-micron thick ion irradiated layers. The behaviour of krypton irradiated 316L steel is somewhat more puzzling. In one hand indeed, a strong correlation between the defect cluster size and densities on the irradiation temperature is observed in the 350 deg C -600 deg C range, thanks to TEM observations of the damage zone. On the other hand, irradiation induced hardening reported from indentation data is relatively small (about 10%) and shows no dependence upon the irradiation temperature (within the mentioned range). In addition, it has been shown that the reported hardening vanishes following appropriate post-irradiation annealing, although most of the TEM

  9. Study on improving antioxidant and antibacterial activities of silk fibroin by irradiation treatment

    International Nuclear Information System (INIS)

    Tran Bang Diep; Nguyen Van Binh; Hoang Phuong Thao; Hoang Dang Sang; Nguyen Thuy Huong Trang

    2014-01-01

    The silk fibroin solutions were prepared in solvent system of CaCl 2 . CH 3 CH 2 OH. H 2 O (mole ratio = 1:2:8) followed dialysis against deionized water. The 3% silk fibroin solutions were irradiated under gamma Co-60 source with dose ranging from 0 to 50 kGy at Hanoi Irradiation Centre and bioactivities of the irradiated silk fibroin solutions were investigated with different radiation doses. The results indicated that the antioxidant and antibacterial activities of fibroin were much improved by gamma irradiation. Maximum value of DPPH radical scavenging activity was 70.4% for the solution of silk fibroin irradiated at 10 kGy. Silk fibroin solutions irradiated at doses higher than 10 kGy also exhibited rather high antibacterial activity against E. coli and S. aureus. In order to estimate the applicability of our irradiated fibroin, the silk fibroin solutions were lyophilized to obtain a pure fibroin powder, then their bio-activities were compared with those of commercial silk fibroin (Proteines De Soie/ Zijdeproteine, Bioflore, Canada). Our fibroin powder revealed higher antioxidant and antibacterial activities. The amino acid compositions of our irradiated fibroin were also higher than that of the commercial product. Thus, the irradiated silk fibroin can be used for further application in cosmetic and other related fields. (author)

  10. In-beam PET measurement of $^{7}Li^{3+}$ irradiation induced $\\beta^+}$-activity

    CERN Document Server

    Priegnitz, M; Parodi, K; Sommerer, F; Fiedler, F; Enghardt, W

    2008-01-01

    At present positron emission tomography (PET) is the only feasible method of an in situ and non-invasive monitoring of patient irradiation with ions. At the experimental carbon ion treatment facility of the Gesellschaft für Schwerionenforschung (GSI) Darmstadt an in-beam PET scanner has been integrated into the treatment site and lead to a considerable quality improvement of the therapy. Since ions other than carbon are expected to come into operation in future patient treatment facilities, it is highly desirable to extend in-beam PET also to other therapeutic relevant ions, e.g. 7Li. Therefore, by means of the in-beam PET scanner at GSI the β+-activity induced by 7Li3+ ions has been investigated for the first time. Targets of PMMA, water, graphite and polyethylene were irradiated with monoenergetic, pencil-like beams of 7Li3+ with energies between 129.1 A MeV and 205.3 A MeV and intensities ranging from 3.0 × 107 to 1.9 × 108 ions s−1. This paper presents the measured β+-activity profiles as well as d...

  11. Radiation-Induced Mutation and Crop Improvement

    International Nuclear Information System (INIS)

    Lee, Y. I.; Song, H. S.; Kim, J. S.; Shin, I. C.; Lee, S. J.

    1987-01-01

    Radiation induced mutations have not only been used directly as a cultivar in crop plants, but also indirectly as a genetic resource that is essential to conventional plant breeding. M 1 plant survivals of three rice cultivars treated with gamma rays of 200-350 Gy varied from 30-40%. The survival of the Sawing variety was less sensitive to radiation, but its fertility was more sensitive in comparison with Seomjin and Sponging. Various dwarf or semi-dwarf mutants and early=matured mutants have been selected in the M 2 and M 3 generations of the three rice cultivars irradiated with gamma rays. Other desirable mutants also have been selected, such as high-yielding, high-tailoring and disease-resistant. The genetic nature of most of the selected short calm and earliness mutants was fixed in M 2 or M 3 generations. Dwarfism of IEAR 308 and Monogynol 10 were found to have a single recessive gene. However, the dwarf of IEAR 308 has a recessive deficit phenomenon. The highest genetic heritability of plant height was observed in the cross combination of Monogynol 10 Χ Pawling

  12. Irradiation-induced motor disorder of the oesophagus

    International Nuclear Information System (INIS)

    Thorpe, J.A.C.; Oakland, C.; Adams, I.P.; Matthews, H.R.

    1982-01-01

    This case report describes the late development of an achalasia-like disturbance of oesophageal motility following irradiation to the neck for a pharyngeal lymphosarcoma. The radiological, manometric and endoscopic findings are recorded as well as laboratory investigations showing evidence of complete vagal denervation. (author)

  13. Irradiation-induced amorphization in split-dislocation cores

    International Nuclear Information System (INIS)

    Ovid'ko, I.A.; Rejzis, A.B.

    1999-01-01

    The model describing special splitting of lattice and grain-boundary dislocations as one of the micromechanisms of solid-phase amorphization in irradiated crystals is proposed. Calculation of energy characteristics of the process of dislocations special splitting is carried out [ru

  14. Swift heavy ion irradiation induced modification of structure

    Indian Academy of Sciences (India)

    AFM analysis indicated that the pristine film consists of agglomerated grains with diffuse grain boundary. Irradiation led to reduced agglomeration of the grains with the formation of sharper grain boundaries. The rms roughness (rms) estimated from AFM analysis increased from 6.2 in pristine film to 12.7 nm when the film ...

  15. Irradiation-induced motor disorder of the oesophagus

    Energy Technology Data Exchange (ETDEWEB)

    Thorpe, J.A.C.; Oakland, C.; Adams, I.P.; Matthews, H.R. (East Birmingham Hospital (UK); Birmingham General Hospital (UK))

    1982-08-01

    This case report describes the late development of an achalasia-like disturbance of oesophageal motility following irradiation to the neck for a pharyngeal lymphosarcoma. The radiological, manometric and endoscopic findings are recorded as well as laboratory investigations showing evidence of complete vagal denervation.

  16. Breeding value of wheat mutants induced by gamma irradiation

    International Nuclear Information System (INIS)

    Szilagyi, Gy.

    1979-01-01

    The combined use of the irradiation techniques available in Hungary and a number of other breeding methods has resulted in the production at Martonvasar of a new wheat variety, Martonvasari 8. It has valuable agronomic characteristics for commercial production and it will no doubt be of good service in the coming years in the development of Hungarian agricultural production. (author)

  17. Irradiation-induced microstructural changes in alloy X-750

    International Nuclear Information System (INIS)

    Kenik, E.A.

    1997-01-01

    Alloy X-750 is a nickel base alloy that is often used in nuclear power systems for it's excellent corrosion resistance and mechanical properties. The present study examines the microstructure and composition profiles in a heat of Alloy X-750 before and after neutron irradiation

  18. Induced protein polymorphisms and nutritional quality of gamma irradiation mutants of sorghum

    Energy Technology Data Exchange (ETDEWEB)

    Mehlo, Luke, E-mail: LMehlo@csir.co.za [CSIR Biosciences, Meiring Naude Road, P.O. Box 395, Pretoria 0001 (South Africa); Mbambo, Zodwa [CSIR Biosciences, Meiring Naude Road, P.O. Box 395, Pretoria 0001 (South Africa); Microbiology Discipline, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Private Bag X54001, Durban 4000 (South Africa); Bado, Souleymane [Plant Breeding and Genetics Laboratory – Joint FAO/IAEA Agriculture and Biotechnology Laboratory, International Atomic Energy Agency Laboratories, A-2444 Seibersdorf (Austria); Lin, Johnson [Microbiology Discipline, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Private Bag X54001, Durban 4000 (South Africa); Moagi, Sydwell M.; Buthelezi, Sindisiwe; Stoychev, Stoyan; Chikwamba, Rachel [CSIR Biosciences, Meiring Naude Road, P.O. Box 395, Pretoria 0001 (South Africa)

    2013-09-15

    Highlights: • We analyse kafirin protein polymorphisms induced by gamma irradiation in sorghum. • One mutant with suppressed kafirins in the endosperm accumulated them in the germ. • Kafirin polymorphisms were associated with high levels of free amino acids. • Nutritional value of sorghum can be improved significantly by induced mutations. - Abstract: Physical and biochemical analysis of protein polymorphisms in seed storage proteins of a mutant population of sorghum revealed a mutant with redirected accumulation of kafirin proteins in the germ. The change in storage proteins was accompanied by an unusually high level accumulation of free lysine and other essential amino acids in the endosperm. This mutant further displayed a significant suppression in the synthesis and accumulation of the 27 kDa γ-, 24 kDa α-A1 and the 22 kDa α-A2 kafirins in the endosperm. The suppression of kafirins was counteracted by an upsurge in the synthesis and accumulation of albumins, globulins and other proteins. The data collectively suggest that sorghum has huge genetic potential for nutritional biofortification and that induced mutations can be used as an effective tool in achieving premium nutrition in staple cereals.

  19. Induced protein polymorphisms and nutritional quality of gamma irradiation mutants of sorghum

    International Nuclear Information System (INIS)

    Mehlo, Luke; Mbambo, Zodwa; Bado, Souleymane; Lin, Johnson; Moagi, Sydwell M.; Buthelezi, Sindisiwe; Stoychev, Stoyan; Chikwamba, Rachel

    2013-01-01

    Highlights: • We analyse kafirin protein polymorphisms induced by gamma irradiation in sorghum. • One mutant with suppressed kafirins in the endosperm accumulated them in the germ. • Kafirin polymorphisms were associated with high levels of free amino acids. • Nutritional value of sorghum can be improved significantly by induced mutations. - Abstract: Physical and biochemical analysis of protein polymorphisms in seed storage proteins of a mutant population of sorghum revealed a mutant with redirected accumulation of kafirin proteins in the germ. The change in storage proteins was accompanied by an unusually high level accumulation of free lysine and other essential amino acids in the endosperm. This mutant further displayed a significant suppression in the synthesis and accumulation of the 27 kDa γ-, 24 kDa α-A1 and the 22 kDa α-A2 kafirins in the endosperm. The suppression of kafirins was counteracted by an upsurge in the synthesis and accumulation of albumins, globulins and other proteins. The data collectively suggest that sorghum has huge genetic potential for nutritional biofortification and that induced mutations can be used as an effective tool in achieving premium nutrition in staple cereals

  20. In vivo UVB irradiation induces clustering of Fas (CD95) on human epidermal cells

    DEFF Research Database (Denmark)

    Bang, Bo; Gniadecki, Robert; Larsen, Jørgen K

    2003-01-01

    In vitro studies with human cell lines have demonstrated that the death receptor Fas plays a role in ultraviolet (UV)-induced apoptosis. The purpose of the present study was to investigate the relation between Fas expression and apoptosis as well as clustering of Fas in human epidermis after...... a single dose of UVB irradiation. Normal healthy individuals were irradiated with three minimal erythema doses (MED) of UVB on forearm or buttock skin. Suction blisters from unirradiated and irradiated skin were raised, and Fas, FasL, and apoptosis of epidermal cells quantified by flow cytometry....... Clustering of Fas was from skin biopsied. Soluble FasL in suction blister fluid was quantified by ELISA. Flow cytometric analysis demonstrated increased expression intensity of Fas after irradiation, with 1.6-,2.2- and 2.7-fold increased median expression at 24, 48 and 72 h after irradiation, respectively (n...

  1. Influence of ion beam irradiation induced defects on the structural, optical and electrical properties of tellurium nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Narinder [Department of Physics, Chaudhary Devi Lal University, Sirsa, 125055 (India); Department of Physics, Haryana College of Technology & Management, Kaithal, 136027 (India); Kumar, Rajesh [Department of Physics, RN College of Engineering & Technology, Madlauda, 132104 (India); Kumar, Sushil, E-mail: sushil_phys@rediffmail.com [Department of Physics, Chaudhary Devi Lal University, Sirsa, 125055 (India); Chakarvarti, S.K. [Research and Development, Manav Rachana International University, Faridabad, 121001 (India)

    2016-11-01

    In this study, tellurium nanowires were electrodeposited into the polymer membranes from aqueous acidic bath containing HTeO{sub 2}{sup +} ions. The field emission scanning electron microscopy (FESEM) images confirmed the formation of uniform and straight nanowires. The influence of 110 MeV Ni{sup 8+} ion irradiation induced defects on the structural, optical and electrical properties of as–deposited tellurium nanowires were examined using X-ray diffraction (XRD), UV–visible absorption spectroscopy and current–voltage (I–V) measurements. The XRD data depicted the hexagonal phase of tellurium nanowires and further revealed a variation in the intensity of diffraction peaks of ion irradiated nanowires. Williamson–Hall (WH) analysis is used for convoluting the size and microstrain contributions to the width of diffraction peaks. Tellurium nanowires exhibited a distinct absorbance band in the visible region at 686 nm, while this was absent in bulk tellurium. Electrical properties of nanowires are explored on the basis of I–V curves, which revealed a significant increase in the electrical conductivity of irradiated nanowires. A possible mechanism for the enhanced electrical conductivity is the increase in carrier concentration due to thermally excited defects. The defects produced by ion irradiation play a vital role in modifying the properties of semiconducting nanowires. - Highlights: • 110 MeV Ni{sup 8+} ion beam induced changes in tellurium nanowires have been examined. • Nanowires were prepared using template electrodeposition method. • Irradiation improved the electrical conductivity of tellurium nanowires. • Mechanism for enhanced electrical conductivity of irradiated nanowires was discussed.

  2. Atom probe study of the microstructural evolution induced by irradiation in Fe-Cu ferritic alloys and pressure vessel steels

    International Nuclear Information System (INIS)

    Pareige, P.

    1996-04-01

    Pressure vessel steels used in pressurized water reactors are low alloyed ferritic steels. They may be prone to hardening and embrittlement under neutron irradiation. The changes in mechanical properties are generally supposed to result from the formation of point defects, dislocation loops, voids and/or copper rich clusters. However, the real nature of the irradiation induced-damage in these steels has not been clearly identified yet. In order to improve our vision of this damage, we have characterized the microstructure of several steels and model alloys irradiated with electrons and neutrons. The study was performed with conventional and tomographic atom probes. The well known importance of the effects of copper upon pressure vessel steel embrittlement has led us to study Fe-Cu binary alloys. We have considered chemical aging as well as aging under electron and neutron irradiations. The resulting effects depend on whether electron or neutron irradiations ar used for thus. We carried out both kinds of irradiation concurrently so as to compare their effects. We have more particularly considered alloys with a low copper supersaturation representative of that met with the French vessel alloys (0.1% Cu). Then, we have examined steels used on French nuclear reactor pressure vessels. To characterize the microstructure of CHOOZ A steel and its evolution when exposed to neutrons, we have studied samples from the reactor surveillance program. The results achieved, especially the characterization of neutron-induced defects have been compared with those for another steel from the surveillance program of Dampierre 2. All the experiment results obtained on model and industrial steels have allowed us to consider an explanation of the way how the defects appear and grow, and to propose reasons for their influence upon steel embrittlement. (author). 3 appends

  3. Utilization of induced mutation techniques in rice improvement in the Philippines

    International Nuclear Information System (INIS)

    Asencion, A.B.; Santos, I.S.; Barrida, A.C.; Medina, F.I.S. III

    2001-01-01

    Rice is one of the most important food crops in the Philippines, as such, efforts have been made consistently to improve the varieties released to the farmers for planting. Both conventional and induced mutation techniques were utilized to solve some of the problems. Varieties with improved qualities, resistance to pests and diseases, reduced height, early maturity and non-photoperiod sensitive were developed using either physical or chemical mutagen. Other methods were also tried to enhance variability like combination of gamma irradiation and biotechnology. Irradiation of F1 seeds was also initiated including the use of mutants in crosses to transfer their improved mutated characters. Promising selections were already tested and six lines from the F1 irradiation out-yielded both C4-63G and IR 1561-288-3, their parents. (author)

  4. Utilization of induced mutation techniques in rice improvement in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Asencion, A.B.; Santos, I.S.; Barrida, A.C.; Medina, F.I.S. III [Philippine Nuclear Research Institute, Atomic Research Center (Philippines)

    2001-03-01

    Rice is one of the most important food crops in the Philippines, as such, efforts have been made consistently to improve the varieties released to the farmers for planting. Both conventional and induced mutation techniques were utilized to solve some of the problems. Varieties with improved qualities, resistance to pests and diseases, reduced height, early maturity and non-photoperiod sensitive were developed using either physical or chemical mutagen. Other methods were also tried to enhance variability like combination of gamma irradiation and biotechnology. Irradiation of F1 seeds was also initiated including the use of mutants in crosses to transfer their improved mutated characters. Promising selections were already tested and six lines from the F1 irradiation out-yielded both C4-63G and IR 1561-288-3, their parents. (author)

  5. Irradiation-induced mutation experiments with eiploid and tetraploid tomato plants

    International Nuclear Information System (INIS)

    Boda, J.

    1979-01-01

    Tomato mutation experiments are described. The tomatoes used in the experiment were the diploid Reziszta and its autotetraploid variety. The experimental plants were exposed to an irradiation of 5000 rsd for 1-2 days, and after transplantation into the gamma field, to chronic irradiation during the whole growing season. The chronic treatment heavily reduced fertility in the generations of tetraploid tomato plants. Recurrent treatment of tetraploid led to further deterioration in fertility. Several berries were formed with few seeds or with no seeds at all. After three irradiations, the chlorophyll mutation frequency increased in the diploid and tetraploid tomato plants. For diploids, treatment applied at the seedling stage gave a lower chlorophyll mutation frequency. With tetraploids the same treatment induced similar chlorophyll mutation frequency. As regards to phenotypic variability of quantitative characteristics in diploid and tetraploid tomatoes, the single and repeated chronic irradiation induced no increase in the variability of properties like flowering time, weight, height etc. (author)

  6. Study on DNA Damage Induced by Neon Beam Irradiation in Saccharomyces Cerevisiae

    International Nuclear Information System (INIS)

    Lu Dong; Li Wenjian; Wu Xin; Wang Jufang; Ma Shuang; Liu Qingfang; He Jinyu; Jing Xigang; Ding Nan; Dai Zhongying; Zhou Jianping

    2010-01-01

    Yeast strain Saccharomyces cerevisiae was irradiated with different doses of 85 MeV/u 20 Ne 10+ to investigate DNA damage induced by heavy ion beam in eukaryotic microorganism. The survival rate, DNA double strand breaks (DSBs) and DNA polymorphic were tested after irradiation. The results showed that there were substantial differences in DNA between the control and irradiated samples. At the dose of 40 Gy, the yeast cell survival rate approached 50%, DNA double-strand breaks were barely detectable, and significant DNA polymorphism was observed. The alcohol dehydrogenase II gene was amplified and sequenced. It was observed that base changes in the mutant were mainly transversions of T→G and T→C. It can be concluded that heavy ion beam irradiation can lead to change in single gene and may be an effective way to induce mutation.

  7. Evaluation of induced radioactivity in 10 MeV-Electron irradiated spices, (2)

    International Nuclear Information System (INIS)

    Katayama, Tadashi; Furuta, Masakazu; Shibata, Setsuko; Matsunami, Tadao; Ito, Norio; Mizohata, Akira; Toratani, Hirokazu; Takeda, Atsuhiko.

    1994-01-01

    In order to check radioactivity of beta-emmitters produced by (γ, n) reactions which could occur at energies up to 10 MeV, black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy. Beta-rays were counted using a 2π gas flow counter and a liquid scintillation counter. Any induced radioactivity could not be detected in irradiated samples. When inorganic compounds containing the nuclides in the list were artificially added in the samples and were irradiated, the β-activities were detected. From the amount of observed radioactivities of β-emmitters produced in the compounds as photonuclear products, it is concluded that the induced radioactivity in natural samples by 10 MeV-electron irradiation were far smaller than natural radioactivity from 40 K contained in the samples and, hence, its biological effects should be negligible. (author)

  8. Protective effects of nelumbo nucifera against {gamma}-irradiation-induced lipid peroxidation in mice urine

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Il Yun; Park, Yong Dae; Jin, Caang Hyun; Choi, Dae Seong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Hyo Jung [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

    2009-12-15

    The radioprotective effect of isoquercitrin-abundant fraction (IAF) of N. nucifera Gaertn. Ieaf extract against {gamma}-irradiation-induced oxidative stress was evaluated by the lipid peroxidation-derived aldehydes (LPDAs) as a marker for oxidative risk in mice urine, and the DNA damage using comet assay in RAW 264.7 cells. Mice that were treated with IAF (50 mg/kg) and {gamma}-irradiation showed considerably decreased LPDA levels relative to those that had received {gamma}-irradiation alone. Furthermore, pretreatment with IAF resulted in a significant decrease in the amount of DNA damage in cells. It is demonstrated that pretreatment with IAF of N. nucifera Gaertn. gives protection against irradiation-induced cellular damage.

  9. Study on DNA Damage Induced by Neon Beam Irradiation in Saccharomyces Cerevisiae

    Science.gov (United States)

    Lu, Dong; Li, Wenjian; Wu, Xin; Wang, Jufang; Ma, Shuang; Liu, Qingfang; He, Jinyu; Jing, Xigang; Ding, Nan; Dai, Zhongying; Zhou, Jianping

    2010-12-01

    Yeast strain Saccharomyces cerevisiae was irradiated with different doses of 85 MeV/u 20Ne10+ to investigate DNA damage induced by heavy ion beam in eukaryotic microorganism. The survival rate, DNA double strand breaks (DSBs) and DNA polymorphic were tested after irradiation. The results showed that there were substantial differences in DNA between the control and irradiated samples. At the dose of 40 Gy, the yeast cell survival rate approached 50%, DNA double-strand breaks were barely detectable, and significant DNA polymorphism was observed. The alcohol dehydrogenase II gene was amplified and sequenced. It was observed that base changes in the mutant were mainly transversions of T→G and T→C. It can be concluded that heavy ion beam irradiation can lead to change in single gene and may be an effective way to induce mutation.

  10. Irradiation-induced permeability in pyrocarbon coatings. Final report of work conducted under PWS FD-12

    International Nuclear Information System (INIS)

    Kania, M.J.; Thiele, B.A.; Homan, F.J.

    1982-10-01

    Two US irradiation experiments were planned to provide information to supplement data from the German program on irradiation-induced permeability in pyrocarbon coatings. Hopefully, the data from both programs could be combined to define the onset of neutron-induced permeability in a variety of Biso coatings produced with different process variables (coating temperature, coating gases, and coating rates). The effort was not successful. None of the preirradiation characterization procedures were able to adequately predict irradiation performance. A large amount of within-batch scatter was observed in the fission gas and cesium release data along with significant within-batch variation in coating properties. Additional preirradiation characterization might result in a procedure that could successfully predict irradiation performance, but little can be done about the within-batch variation in coating properties. This variation is probably the result of random movement of particles within the coating furnace during pyrocarbon deposition. 19 figures, 4 tables

  11. Effect of irradiation on the temporomandibular joint in streptozotocin-induced diabetic rat

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Ki Dong; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    2004-06-15

    To investigate the histopathological changes in the temporomandibular joint in streptozotocin-induced diabetic rat following irradiation. Sprague-Dawley rats weighing about 250 gm were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control group were injected with citrate buffer only. After 5 days, the head and neck region of the rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the temporomandibular joint were sectioned and observed using a histopathological method. In the diabetic group, severe bone resorption in the mandibular condyle was observed throughout the period of experiment. Necrosis of bone marrow and trabeculae was observed at 28 days after diabetic state. Atrophy and fibrosis in the retrodiscal tissue was gradually progressed during the time of the experiment. In the diabetic-irradiated group, severe bone resorption in the mandibular condyle was observed during the early experimental phases, but regeneration of bone marrow was initiated at 14 days after diabetic state and irradiation. Also, calcification of abnormal trabeculae was observed at 28 days after diabetic state and irradiation. The retrodiscal tissue was degenerated in the early experimental phases, but it had been gradually regenerated during the experimental time. This experiment suggests that bone resorption and degeneration in the mandibular condyle are caused by the induction of diabetes, and abnormal bone formation is induced after irradiation in diabetic state.

  12. Evaluation of radio-protective effect of melatonin on whole body irradiation induced liver tissue damage.

    Science.gov (United States)

    Shirazi, Alireza; Mihandoost, Ehsan; Ghobadi, Ghazale; Mohseni, Mehran; Ghazi-Khansari, Mahmoud

    2013-01-01

    Ionizing radiation interacts with biological systems to induce excessive fluxes of free radicals that attack various cellular components. Melatonin has been shown to be a direct free radical scavenger and indirect antioxidant via its stimulatory actions on the antioxidant system.The aim of this study was to evaluate the antioxidant role of melatonin against radiation-induced oxidative injury to the rat liver after whole body irradiation. In this experimental study,thirty-two rats were divided into four groups. Group 1 was the control group, group 2 only received melatonin (30 mg/kg on the first day and 30 mg/kg on the following days), group 3 only received whole body gamma irradiation of 10 Gy, and group 4 received 30 mg/kg melatonin 30 minutes prior to radiation plus whole body irradiation of 10 Gy plus 30 mg/kg melatonin daily through intraperitoneal (IP) injection for three days after irradiation. Three days after irradiation, all rats were sacrificed and their livers were excised to measure the biochemical parameters malondialdehyde (MDA) and glutathione (GSH). Each data point represents mean ± standard error on the mean (SEM) of at least eight animals per group. A one-way analysis of variance (ANOVA) was performed to compare different groups, followed by Tukey's multiple comparison tests (p<0.05). The results demonstrated that whole body irradiation induced liver tissue damage by increasing MDA levels and decreasing GSH levels. Hepatic MDA levels in irradiated rats that were treated with melatonin (30 mg/kg) were significantly decreased, while GSH levels were significantly increased, when compared to either of the control groups or the melatonin only group. The data suggest that administration of melatonin before and after irradiation may reduce liver damage caused by gamma irradiation.

  13. Effect of irradiation on the temporomandibular joint in streptozotocin-induced diabetic rat

    International Nuclear Information System (INIS)

    Ahn, Ki Dong; Hwang, Eui Hwan; Lee, Sang Rae

    2004-01-01

    To investigate the histopathological changes in the temporomandibular joint in streptozotocin-induced diabetic rat following irradiation. Sprague-Dawley rats weighing about 250 gm were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control group were injected with citrate buffer only. After 5 days, the head and neck region of the rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the temporomandibular joint were sectioned and observed using a histopathological method. In the diabetic group, severe bone resorption in the mandibular condyle was observed throughout the period of experiment. Necrosis of bone marrow and trabeculae was observed at 28 days after diabetic state. Atrophy and fibrosis in the retrodiscal tissue was gradually progressed during the time of the experiment. In the diabetic-irradiated group, severe bone resorption in the mandibular condyle was observed during the early experimental phases, but regeneration of bone marrow was initiated at 14 days after diabetic state and irradiation. Also, calcification of abnormal trabeculae was observed at 28 days after diabetic state and irradiation. The retrodiscal tissue was degenerated in the early experimental phases, but it had been gradually regenerated during the experimental time. This experiment suggests that bone resorption and degeneration in the mandibular condyle are caused by the induction of diabetes, and abnormal bone formation is induced after irradiation in diabetic state.

  14. Improved growth response to GH treatment in irradiated children

    International Nuclear Information System (INIS)

    Lannering, B.; Albertsson-Wikland, K.

    1989-01-01

    The growth response to two years of GH treatment was studied in fifteen children after radiotherapy for a cranial tumour. The growth response was compared to that of short children (-2 SD) and that of children with idiopathic growth hormone deficiency (GHD) of similar ages. All children were treated with hGH 0.1 IU/kg/day s.c.; which is a higher dose and frequency than previously reported for irradiated children. On this protocol the growth rate increased 5.0 +- 0.5 cm/y (mean +- SEM) the first year and 3.8 +- 0.7 cm/y the second year compared to the growth rate the year before GH-treatment. Although the net gain in growth was higher than previously reported, the first year growth response was significantly reduced (p less than 0.05) compared to that of GHD-children (7.6 +- 0.5 cm/y) but exceeded (p less than 0.05) that of short children (3.4 +- 0.3 cm/y). The median spontaneous 24 h-GH secretion was 209 mU/l in the short children, 52 mU/l in the irradiated children and 16 mU/l in the idiopathic GHD children. Thus the growth increment varied inversely to the spontaneous GH secretion observed in the three groups

  15. Irradiation-induced creep in metallic nanolaminates characterized by In situ TEM pillar nanocompression

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, Shen J., E-mail: sdillon@illinois.edu [Department of Materials Science and Engineering, University of Illinois Urbana-Champagin, Urbana, IL 61801 (United States); Bufford, Daniel C. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Jawaharram, Gowtham S.; Liu, Xuying; Lear, Calvin [Department of Materials Science and Engineering, University of Illinois Urbana-Champagin, Urbana, IL 61801 (United States); Hattar, Khalid [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Averback, Robert S. [Department of Materials Science and Engineering, University of Illinois Urbana-Champagin, Urbana, IL 61801 (United States)

    2017-07-15

    This work reports on irradiation-induced creep (IIC) measured on nanolaminate (Cu-W and Ni-Ag) and nanocrystalline alloys (Cu-W) at room temperature using a combination of heavy ion irradiation and nanopillar compression performed concurrently in situ in a transmission electron microscope. Appreciable IIC is observed in multilayers with 50 nm layer thicknesses at high stress, ≈½ the yield strength, but not in multilayers with only 5 nm layer thicknesses.

  16. The genetic effects induced by an irradiation in low doses at Drosophila melanogaster

    International Nuclear Information System (INIS)

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

    2006-01-01

    The review generalizes the results obtained in researches of genetic radiation effects for Drosophila melanogaster from contamination regions near the Chernobylsk NPP. The results of laboratory investigations of low dose irradiation effects on genotype variability and lifetime of Drosophila are presented too. It supposed that the main effect of low dose irradiation is caused by the induced genetic instability against the background of which the realization of different-directed radiobiological reactions is possible [ru

  17. Inhomogeneous strain induced by fast neutron irradiation in NaKSO4 crystals

    International Nuclear Information System (INIS)

    Kandil, S.H.; El Gamal, M.A.; El Khatib, A.; El Wahidy, E.F.

    1987-06-01

    The effect of fast neutron irradiation on the thermal properties of NaKSO 4 crystals was studied around the phase transition temperature T c =453 K. The thermal expansion coefficient as well as the phase transition temperature were found to be dependent upon the irradiation dose. The specific heat, C p , showed multiple peaks in the phase transition temperature region. An explanation of this behaviour was based on the induced inhomogeneous strain in the crystal casued by the neutron irradiation process. (author). 10 refs, 3 figs

  18. Caffeine-induced hematological changes after whole-body irradiation in rat

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Ji Hyang; Yoon Yong Dal [Hanyang University, Seoul (Korea, Republic of)

    2004-07-01

    Recent research indicated dietary antioxidants were useful radioprotectors to protect organisms against radiation-induced tissue lethality and other deleterious effects. Radioprotective effects of vitamin C have been demonstrated in certain cells and animals, which would result from scavenging free radicals. Moreover, the previous studies indicated that caffeine had been shown to potently act the radioprotector in irradiated mice. However it is not clear exactly about effects of caffeine treatments chronically after irradiation. So the present studies were designed to identify the hematological effect of caffeine treatments chronically one month after whole-body gamma irradiation.

  19. Influence of catechins on bystander responses in CHO cells induced by alpha-particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Law, Y.L.; Wong, T.P.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Yu, K.N. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)], E-mail: peter.yu@cityu.edu.hk

    2010-04-15

    In this work, we studied alpha-particle induced and medium-mediated bystander effects in Chinese hamster ovary (CHO) cells through micronucleus (MN) assay. We showed that signal transduction from irradiated cells to bystander cells occur within a short time after irradiation. We then studied the effects of ROS (reactive oxygen species)-scavenging catechins in the medium before irradiation. We observed decreases in the percentage of bystander cells with MN formation and thus proved the protection effect of catechins on bystander cells from radiation.

  20. Decrease of glucose-induced insulin secretion of rat pancreatic islets after irradiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Heinzmann, D; Nadrowitz, R; Besch, W; Schmidt, W; Hahn, H J [Zentralinstitut fuer Diabetes, Karlsburg (German Democratic Republic); Ernst-Moritz-Arndt-Universitaet, Greifswald (German Democratic Republic). Radiologische Klinik)

    1983-01-01

    In vitro irradiation of rat pancreatic islets up to a dose of 2.5 Gy did neither alter glucose- nor isobutylmethyl xanthine (IBMX)-induced insulin secretion. Insulin as well as glucagon content of irradiated islets corresponded to that of the control tissue. So it was in islets irradiated with 25 Gy which were characterized by a decreased insulin secretion in the presence of glucose and IBMX, respectively. There was no indication of an enhanced hormone output in the radiation medium and it is to be suggested that higher radiation doses affect the insulin release of pancreatic islets in vitro. This must be taken into consideration for radioimmunosuppression experiments.

  1. Elevated sodium chloride concentrations enhance the bystander effects induced by low dose alpha-particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Han Wei; Zhu Lingyan; Jiang Erkang; Wang Jun; Chen Shaopeng; Bao Linzhi; Zhao Ye; Xu An; Yu Zengliang [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wu Lijun [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)], E-mail: ljw@ipp.ac.cn

    2007-11-01

    Previous studies have shown that high NaCl can be genotoxic, either alone or combined with irradiation. However, little is known about the relationship between environmental NaCl at elevated conditions and radiation-induced bystander effects (RIBE). RIBE, which has been considered as non-targeted bystander responses, has been demonstrated to occur widely in various cell lines. In the present study, RIBE under the elevated NaCl culture condition was assessed in AG 1522 cells by both the induction of {gamma}-H2AX, a reliable marker of DNA double-strand break (DSB) for the early process (<1 h post irradiation), and the generation of micronuclei (MN), a sensitive marker for relative long process of RIBE. Our results showed that in the absence of irradiation, NaCl at elevated concentration such as 8.0, 9.0 and 10.0 g/L did not significantly increase the frequency of {gamma}-H2AX foci-positive cells and the number of foci per positive cell comparing with that NaCl at a normal concentration (6.8 g/L). However, with 0.2 cGy {alpha}-particle irradiation, the induced fraction of {gamma}-H2AX foci-positive cells and the number of induced {gamma}-H2AX foci per positive cell were significantly increased in both irradiated and adjacent non-irradiated regions. Similarly, the induction of MN by 0.2 cGy {alpha}-particle irradiation also increased with the elevated NaCl concentrations. With N{sup G}-methyl-L-arginine, an inhibitor of nitric oxide synthase, the induced fraction of foci-positive cells was effectively inhibited both in 0.2 cGy {alpha}-particle irradiated and adjacent non-irradiated regions under either normal or elevated NaCl conditions. These results suggested that the cultures with elevated NaCl medium magnified the damage effects induced by the low dose {alpha}-particle irradiation and nitric oxide generated by irradiation was also very important in this process.

  2. Electronic excitation induced modifications in elongated iron nanoparticle encapsulated multiwalled carbon nanotubes under ion irradiation

    Science.gov (United States)

    Saikiran, V.; Bazylewski, P.; Sameera, I.; Bhatia, Ravi; Pathak, A. P.; Prasad, V.; Chang, G. S.

    2018-05-01

    Multi-wall carbon nanotubes (MWCNT) filled with Fe nanorods were shown to have contracted and deformed under heavy ion irradiation. In this study, 120 MeV Ag and 80 MeV Ni ion irradiation was performed to study the deformation and defects induced in iron filled MWCNT under heavy ion irradiation. The structural modifications induced due to electronic excitation by ion irradiation were investigated employing high-resolution transmission electron microscopy, micro-Raman scattering experiments, and synchrotron-based X-ray absorption and emission spectroscopy. We understand that the ion irradiation causes modifications in the Fe nanorods which result in compressions and expansions of the nanotubes, and in turn leads to the buckling of MWCNT. The G band of the Raman spectra shifts slightly towards higher wavenumber and the shoulder G‧ band enhances with the increase of ion irradiation fluence, where the buckling wavelength depends on the radius 'r' of the nanotubes as exp[(r)0.5]. The intensity ratio of the D to G Raman modes initially decreases at the lowest fluence, and then it increases with the increase in ion fluence. The electron diffraction pattern and the high resolution images clearly show the presence of ion induced defects on the walls of the tube and encapsulated iron nanorods.

  3. A phase field model for segregation and precipitation induced by irradiation in alloys

    Science.gov (United States)

    Badillo, A.; Bellon, P.; Averback, R. S.

    2015-04-01

    A phase field model is introduced to model the evolution of multicomponent alloys under irradiation, including radiation-induced segregation and precipitation. The thermodynamic and kinetic components of this model are derived using a mean-field model. The mobility coefficient and the contribution of chemical heterogeneity to free energy are rescaled by the cell size used in the phase field model, yielding microstructural evolutions that are independent of the cell size. A new treatment is proposed for point defect clusters, using a mixed discrete-continuous approach to capture the stochastic character of defect cluster production in displacement cascades, while retaining the efficient modeling of the fate of these clusters using diffusion equations. The model is tested on unary and binary alloy systems using two-dimensional simulations. In a unary system, the evolution of point defects under irradiation is studied in the presence of defect clusters, either pre-existing ones or those created by irradiation, and compared with rate theory calculations. Binary alloys with zero and positive heats of mixing are then studied to investigate the effect of point defect clustering on radiation-induced segregation and precipitation in undersaturated solid solutions. Lastly, irradiation conditions and alloy parameters leading to irradiation-induced homogeneous precipitation are investigated. The results are discussed in the context of experimental results reported for Ni-Si and Al-Zn undersaturated solid solutions subjected to irradiation.

  4. A phase field model for segregation and precipitation induced by irradiation in alloys

    International Nuclear Information System (INIS)

    Badillo, A; Bellon, P; Averback, R S

    2015-01-01

    A phase field model is introduced to model the evolution of multicomponent alloys under irradiation, including radiation-induced segregation and precipitation. The thermodynamic and kinetic components of this model are derived using a mean-field model. The mobility coefficient and the contribution of chemical heterogeneity to free energy are rescaled by the cell size used in the phase field model, yielding microstructural evolutions that are independent of the cell size. A new treatment is proposed for point defect clusters, using a mixed discrete-continuous approach to capture the stochastic character of defect cluster production in displacement cascades, while retaining the efficient modeling of the fate of these clusters using diffusion equations. The model is tested on unary and binary alloy systems using two-dimensional simulations. In a unary system, the evolution of point defects under irradiation is studied in the presence of defect clusters, either pre-existing ones or those created by irradiation, and compared with rate theory calculations. Binary alloys with zero and positive heats of mixing are then studied to investigate the effect of point defect clustering on radiation-induced segregation and precipitation in undersaturated solid solutions. Lastly, irradiation conditions and alloy parameters leading to irradiation-induced homogeneous precipitation are investigated. The results are discussed in the context of experimental results reported for Ni–Si and Al–Zn undersaturated solid solutions subjected to irradiation. (paper)

  5. Roles of acid sphingomyelinase activation in neuronal cells apoptosis induced by microwave irradiation

    International Nuclear Information System (INIS)

    Zhang Lei; Xu Shangcheng; Zhang Guangbin; Yu Zhengping

    2009-01-01

    The present study is to examine the effect of microwave on acid sphingomyelinase (ASM) activity and expression, and to explore the role of ASM activation in neuronal cells apoptosis induced by microwave irradiation. Primary cultured hippocampal neurons were irradiated by 30 W/cm 2 microwave for 10 min, and ASM activity assay was used to investigate ASM activity alteration. RT-PCR and western blot were used to detect ASM mRNA and protein expression respectively. Apoptosis was observed by Hoechst 33342 fluorescence staining. ASM specific inhibitor imipramine was applied to inhibit ASM activation. It has been found that apoptosis rate of primary cultured hippocampal neurons increased significantly after microwave irradiation. ASM was activated while ASM mRNA and protein expression were upregulated in neurons after microwave irradiation. Pretreatment with imipramine could reverse neuronal apoptosis induced by microwave irradiation. Results show that microwave irradiation causes increment of ASM activation and expression and ASM activation is involved in microwave induced neuronal apoptosis. (authors)

  6. Improvement of foaming ability of egg white product by irradiation and its application

    International Nuclear Information System (INIS)

    Song, Hyun-Pa; Kim, Binna; Choe, Jun-Ho; Jung, Samooel; Kim, Kyong-Su; Kim, Dong-Ho; Jo, Cheorun

    2009-01-01

    To investigate the enhancement of foaming abilities of liquid egg white (LEW) and egg white powder (EWP) by irradiation and its application for bakery product, LEW and EWP were irradiated at 0, 1, 2, and 5 kGy by Co-60 gamma ray. There was no pH change found among treatments in both LEW and EWP. The viscosity of LEW decreased significantly by irradiation (P<0.05), whereas that of EWP was not affected by irradiation. The foaming ability of LEW and EWP was significantly increased by irradiation as a dose-dependent manner (P<0.05). The volume and the height of angel cake baked with irradiated LEW were significantly higher than those of unirradiated control (P<0.05). For EWP, the volume and the height of angel cake were greater at 2 kGy only than those of control. A significant decrease in hardness, chewiness, and gumminess values and an increase in Hunter L* value were observed in the angel cakes prepared from irradiated egg white products (P<0.05). Results indicated that irradiation of egg white could offer advantages in increasing foaming ability and improving quality of final bakery products

  7. Shelf-life extension and improvement of the microbiological quality of smoked salmon by irradiation

    International Nuclear Information System (INIS)

    Hammond, A.A.I.; El-Mongy, T.M.

    1992-01-01

    Cold-smoked salmon locally available was irradiated at 2 and 4 kGy. Irradiated and unirradiated samples were stored at refrigeration temperature (2-3 degrees C). Microbiological and sensory qualities were studied immediately after irradiation and during storage. Irradiation at 2 kGy caused a great reduction in all the tested microbial population, thus improving the hygienic quality of smoked salmon to meet the microbiological limits for the top-grade quality. Moreover, irradiated samples at 4 kGy were free from coliform bacteria, fecal streptococci and Staph. aureus over the entire storage period. Unirradiated samples reached the maximum accepted mesophilic plate count after only one month of storage, while those irradiated at 2 and 4 kGy reached this level after 3 and 4 months, respectively. No differences in sensory qualities were found by the taste panel between unirradiated samples and those irradiated at 2 kGy, but they observed a distinct loss in normal cherry red color of the samples irradiated at 4 kGy

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    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.

  9. Irradiation-induced hypoxia in bones and soft tissues: an experimental study

    International Nuclear Information System (INIS)

    Aitasalo, K.; Aro, H.

    1986-01-01

    Bone marrow and subcutaneous tissue pO 2 and pCO 2 were measured by means of implanted tissue tonometers in irradiated and nonirradiated rabbit hind limbs. The x-ray dose was 500, 1000, 1500, 2000, and 3000 rads. Tissue gas tensions were measured 1 day and 5 and 11 weeks after radiation. The pCO 2 changes in both tissues were slight but not statistically significant. The subcutaneous tissue pO 2 decreased during the acute phase of irradiation injury, and the effect of irradiation was dose-dependent. Later on, irradiation had no significant effects on the subcutaneous pO 2 , although light microscopy of the affected tissues showed fibrosis and blood vessel changes. The response of the subcutaneous pO 2 to systemic hyperoxia also increased in the chronic phase of irradiation injury as a sign of improved microcirculation. The bone marrow showed a high radiosensitivity. Irradiation caused a rapid dose-dependent decrease of the marrow pO 2 , and the marrow pO 2 decreased with time during the chronic phase of irradiation injury. The marrow pO 2 responded slowly and marginally to an increment of arterial pO 2 during breathing 100% oxygen as further evidence of impaired vascular pattern. The results showed that irradiation causes only a transient impairment of tissue perfusion in the skin. However, irradiation-damaged marrow was characterized by progressive tissue hypoxia

  10. Post-factum detection of radiation treatment in processed food by analysis of radiation-induced hydrocarbons. Pt. 1. Applying the method L 06.00-37 defined in Para. 35 LMBG (German Act on Food Irradiation) to processed food

    International Nuclear Information System (INIS)

    Hartmann, M.; Ammon, J.; Berg, H.

    1995-01-01

    The German official method L 06.00-37 (Para. 35 German Act on Food Irradiation) is used for the identification of irradiated fat-containing food by GC-analysis of radiation-induced hydrocarbons. Simple modifications in sample preparation allow a distinctive improvement in detection possibilities and detection limits as well. The applicability of the modified method for the detection of irradiated ingredients in model-like processed food is shown. An identification of only 3% (irradiated fat to total fat ratio) irradiated ingredient (1,5 kGy) in processed food was possible. Additionally, the kind of irradiated ingredient could be identified by the pattern of radiation induced hydrocarbons. Their concentrations are corresponding with the fatty acid composition of the irradiated compound. (orig.) [de

  11. Use of induced mutations for potato improvement

    International Nuclear Information System (INIS)

    Kishore, H.; Das, B.; Subramanyam, K.N.; Chandra, R.; Upadhya, M.D.

    1975-01-01

    The investigations aim at the utilization of induced mutations for potato improvement. The effect of γ-rays was tested on selfed seeds and hybrid seeds as well as on tubers of several potato varieties. Chemical mutagens have been successfully employed to produce daylength neutral clones. An attempt to induce resistance against Pseudomonas solanacearum did not give conclusive results. Potato improvement in relation of yield and other characters of economic significance like maturity and attributes of tubers has been handicapped by several technical considerations world over. The crux of the problem lies in the narrow genetic base (variability) for potato breeders to work with. The use of mutation breeding, therefore, offers a good tool for this. Improvement by mutation breeding for the quantitative characters besides the resistance to disease and pest has been demonstrated in other crops like white mustard variety Primex (Anderson and Olsson, 1954), barley (Gustafsson, 1965) and peanut (Gregory, 1956). Keeping these in view and the success we had in isolating photoperiod insensitive types (Upadhaya et al, 1973, 1974) study was enlarged to use mutagens to increase as wide a spectrum as possible of the variability for quantative and qualitative characters. (author)

  12. Electron-irradiation-induced crystallization of amorphous orthophosphates

    International Nuclear Information System (INIS)

    Meldrum, A.; Ewing, R.C.; Boatner, L.A.

    1996-12-01

    Amorphous LaPO 4 , EuPO 4 , GdPO 4 , ScPO 4 , and fluorapatite [Ca 5 (PO 4 ) 3 F] were irradiated by electron beam in a TEM. Irradiations were done at -150 to 300 C, 80 to 200 keV, and current densities from 0.3 to 16 A/cm 2 . In all cases, the materials crystallized to form a randomly oriented polycrystalline assemblage. Crystallization is driven dominantly by inelastic processes, although ballistic collisions with target nuclei can be important above 175 keV, particularly in apatite. Using a high current density, crystallization is so fast that continuous lines of crystallites can be ''drawn'' on the amorphous matrix

  13. Ion-irradiation-induced defects in bundles of carbon nanotubes

    International Nuclear Information System (INIS)

    Salonen, E.; Krasheninnikov, A.V.; Nordlund, K.

    2002-01-01

    We study the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this, we employ empirical potential molecular dynamics and simulate ion impact events over an energy range of 100-1000 eV. We show that the most common defects produced at all energies are vacancies on nanotube walls, which at low temperatures are metastable but long-lived defects. We further calculate the spatial distribution of the defects, which proved to be highly non-uniform. We also show that ion irradiation gives rise to the formations of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling bond saturation. The number of inter-tube links, as well as the overall damage, linearly grows with the energy of incident ions

  14. Radiation induced coloring of glasses measured during and after electron irradiation

    International Nuclear Information System (INIS)

    Swyler, K.J.; Hardy, W.H. II; Levy, P.W.

    1975-01-01

    The growth of color centers during irradiation, and the decay after irradiation, were studied in two glasses using recently developed equipment for making optical absorption and luminescence measurements during and after electron irradiation. The glasses studied were NBS 710, a soda-lime silicate glass, and NBS 711, a lead silicate glass. Both glasses exhibit similar coloring characteristics. The radiation-induced absorption spectra consists of a weak gaussian shaped band in the visible, a stronger gaussian band in the ultraviolet, and a band edge ''shift'' which may be accurately approximated by a third gaussian band. For all absorption bands, the color center vs dose (or irradiation time) curves can be accurately resolved into two saturating exponential and one linear component. The decay curves obtained after the irradiation is terminated can be accurately expressed by three exponential components. Coloring and decay curves made at different dose rates indicate that the processes responsible for decay after irradiation and electron hole recombination during irradiation play important roles in determining the rate and extent of coloring. Results are qualitatively in agreement with some very simple kinetic treatments for color center formation. In some, but not all, respects the quantitative agreement is also good. Lastly, the results indicate that it is necessary to make measurements during irradiation to establish the formation kinetics of color centers that are unstable at the bombardment temperature. (U.S.)

  15. The spreading of focal brain edema induced by ultraviolet irradiation

    International Nuclear Information System (INIS)

    Ferszt, R.; Neu, S.; Cervos-Navarro, J.; Sperner, J.

    1978-01-01

    Focal brain edema limited to one cerebral hemisphere was produced by ultraviolet irradiation of the exposed cortex. Tissue water content was determined by the gravimetric method which allows microsampling. Therefore, the spread of edema around the small necrotic area be mapped more precisely than by determination of dry weight which calls for larger samples. As early as 30 min after irradiation, hyperemia and swelling of the brain are observed under the operating microscope. This correlates with venous stasis, hyperemia, and broadened perivascular spaces around venules and large capillaries accompanied by a marked rise in the specific weigth of the tissue. After 4h an edema front can be observed spreading from the perinerotic zone in which there is a marked rise in endothelial cell vesicular activity. Edema reaches maximum levels in the deep white matter at 48h post irradiation with normalisation of the tissue water content after 96h. The velocity at which the edema front spreads from the cortex to the periventricular area lies in the range of 0.25mm/h. Edema reabsorption coincides with signs of retrograde micropinocytosis in endothelial cells. (orig./AJ) [de

  16. Gamma irradiation induced effects of butyl rubber based damping material

    Science.gov (United States)

    Chen, Hong-Bing; Wang, Pu-Cheng; Liu, Bo; Zhang, Feng-Shun; Ao, Yin-Yong

    2018-04-01

    The effects of gamma irradiation on the butyl rubber based damping material (BRP) at various doses in nitrogen were investigated in this study. The results show that irradiation leads to radiolysis of BRP, with extractives increasing from 14.9 ± 0.8% of control to 37.2 ± 1.2% of sample irradiated at 350 kGy, while the swelling ratio increasing from 294 ± 3% to 766 ± 4%. The further investigation of the extractives with FTIR shows that the newly generated extractives are organic compounds containing C-H and C˭C bonds, with molecular weight ranging from 26,500 to 46,300. SEM characterization shows smoother surface with holes disappearing with increasing absorbed doses, consistent with "softer" material because of radiolysis. Dynamic mechanical study of BRP show that tan δ first slightly then obviously increases with increasing absorbed dose, while storage modulus slightly decreases. The tensile testing shows that the tensile strength decreases while the elongation at break increases with increasing dose. The positron annihilation lifetime spectroscopy show no obvious relations between free volume parameters and the damping properties, indicating the complicated influencing factors of damping properties.

  17. Spreading of focal brain edema induced by ultraviolet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ferszt, R; Neu, S; Cervos-Navarro, J; Sperner, J [Freie Univ. Berlin (Germany, F.R.). Inst. fuer Neuropathologie

    1978-01-01

    Focal brain edema limited to one cerebral hemisphere was produced by ultraviolet irradiation of the exposed cortex. Tissue water content was determined by the gravimetric method which allows microsampling. Therefore, the spread of edema around the small necrotic area be mapped more precisely than by determination of dry weight which calls for larger samples. As early as 30 min after irradiation, hyperemia and swelling of the brain are observed under the operating microscope. This correlates with venous stasis, hyperemia, and broadened perivascular spaces around venules and large capillaries accompanied by a marked rise in the specific weigth of the tissue. After 4h an edema front can be observed spreading from the perinerotic zone in which there is a marked rise in endothelial cell vesicular activity. Edema reaches maximum levels in the deep white matter at 48h post irradiation with normalisation of the tissue water content after 96h. The velocity at which the edema front spreads from the cortex to the periventricular area lies in the range of 0.25mm/h. Edema reabsorption coincides with signs of retrograde micropinocytosis in endothelial cells.

  18. Structural and defects induced phenomena in γ-rays irradiated 6H-SiC

    International Nuclear Information System (INIS)

    Sibuyi, P.; Ngom, B.D.; Kotsedi, L.

    2016-01-01

    Damages and/or defects induced by γ-rays irradiation on 6H-SiC single crystals in channeled configuration towards 〈006〉/〈0012〉 crystallographic directions are reported in the range of 0–1200 kGy. Atomic force microscopy, X-rays diffraction, Raman and photoluminescence investigations were used to obtain a comprehensive set of informations on the nature and population distribution of the induced defects. Primarily, there was no carbon clusterization upon γ-rays irradiation and hence no formation of others SiC polytypes. In contrast, the γ-rays irradiation has induced an increase of the surface roughness at higher doses, which indicates a structural degradation. Larger doses induced an emergence of deeper shallow traps at energies greater than 350 meV below the bandgap. - Highlights: • No formation of others SiC polytypes. • The gamma rays irradiation has induced a slight surface amorphization. • A re-crystallization at lower and higher doses is noticed. • Larger doses induced a substantial internal stress.

  19. Apoptosis of nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation

    International Nuclear Information System (INIS)

    Liang Ke; He Shaoqin; Feng Yan; Tang Jinhua; Feng Qinfu; Shen Yu; Yin Weibo; Xu Guozhen; Liu Xinfan; Wang Luhua; Gao Li

    1999-01-01

    Objective: To study the apoptotic response of the nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation. Methods: CNE-2 cells were cultured as usual. Using the techniques of DNA agarose gel electrophoresis and DNA special fluorescent staining, the status of apoptosis in CNE-2 cells after neutron irradiation was detected. Results: It was shown that the apoptosis can be induced in CNE-2 cell after neutron radiation. Six hrs, after different doses of neutron (0/0.667/1.333/2.000/2.667/3.333 Gy) and X-ray 0/2/4/6/8/10 Gy) irradiation the apoptotic rates were 2.4%, 6.3%, 7.1%, 9.5%, 13.5%, 14.6% and 2.4%, 3.8%, 5.7%, 7.8%, 10.4%, 11.7%, respectively; at 48 hrs they were 18.3%, 21.5%, 22.8%, 29.3%, 34.2% and 13.7%, 17.6%, 21.3%, 25.6%, 28.9%, respectively. At 10 hrs after neutron irradiation the DNA ladder of apoptosis could be detected between 0.667-3.333 Gy doses in CNE-2 cells by DNA agarose gel electrophoresis. Conclusion: Neutron radiation can induce apoptosis in tumor cells. Compared with the X-ray, neutron induces apoptosis in larger extent than X-ray in the same condition; meanwhile, apoptosis after irradiation is dose and time dependent

  20. Radiation-Induced Epigenetic Alterations after Low and High LET Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Aypar, Umut; Morgan, William F.; Baulch, Janet E.

    2011-02-01

    Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding the delayed, non-targeted effects of radiation including radiationinduced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET x-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NFκB), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. MiRNA shown to be altered in expression level after x-ray irradiation are involved in chromatin remodeling and DNA methylation. Different and higher incidence of epigenetic changes were observed after exposure to low LET x-rays than high LET Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This study also shows that the irradiated cells acquire epigenetic changes even though they are chromosomally stable suggesting that epigenetic aberrations may arise in the cell without initiating RIGI.

  1. Detection of radiation-induced hydrocarbons in baked sponge cake prepared with irradiated liquid egg

    International Nuclear Information System (INIS)

    Schulzki, G.; Spiegelberg, A.; Boegl, K.W.; Schreiber, G.A.

    1995-01-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg. (Author)

  2. Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg

    Science.gov (United States)

    Schulzki, G.; Spiegelberg, A.; Bögl, K. W.; Schreiber, G. A.

    1995-02-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg.

  3. Cyclophosphamide-induced cardiomyopathy in a patient with seminoma and a history of mediastinal irradiation

    International Nuclear Information System (INIS)

    Kamezaki, Kenjirou; Fukuda, Takahiro; Makino, Shigeyoshi; Harada, Mine

    2005-01-01

    A 17-year-old man with mediastinal seminoma was treated with chemotherapy and mediastinal irradiation therapy. Then he received high-dose chemotherapy containing cyclophosphamide (CY) followed by autologous peripheral blood stem cell transplantation. He suffered from CY-induced cardiomyopathy beginning six days after the administration of high-dose CY. The predictable factors associated with the onset of CY-induced cardiomyopathy are not precisely known. It is suggested that the history of mediastinal irradiation was responsible for the onset of cardiomyopathy. (author)

  4. High-dose radiation-induced meningioma following prophylactic cranial irradiation for acute lymphoblastic leukaemia

    International Nuclear Information System (INIS)

    Matsuda, Ryosuke; Nikaido, Yuji; Yamada, Tomonori; Mishima, Hideaki; Tamaki, Ryo

    2005-01-01

    A 12 year-old girl was treated with prophylactic cranial irradiation for acute lymphoblastic leukaemia (ALL). At the age of 39, she was admitted to our hospital for status epilepticus. Computed tomography demonstrated two, enhancing bilateral sided intracranial tumors. After surgery, this patient presented meningiomas which histologically, were of the meningothelial type. The high cure rate in childhood ALL, attributable to aggressive chemotherapy and prophylactic cranial irradiation, is capable of inducing secondary brain tumor. Twelve cases of high-dose radiation-induced meningioma following ALL are also reviewed. (author)

  5. High-dose radiation-induced meningioma following prophylactic cranial irradiation for acute lymphoblastic leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Ryosuke; Nikaido, Yuji; Yamada, Tomonori; Mishima, Hideaki; Tamaki, Ryo [National Hospital Organization Osaka Minami Medical Center, Kawachinagano (Japan)

    2005-03-01

    A 12 year-old girl was treated with prophylactic cranial irradiation for acute lymphoblastic leukaemia (ALL). At the age of 39, she was admitted to our hospital for status epilepticus. Computed tomography demonstrated two, enhancing bilateral sided intracranial tumors. After surgery, this patient presented meningiomas which histologically, were of the meningothelial type. The high cure rate in childhood ALL, attributable to aggressive chemotherapy and prophylactic cranial irradiation, is capable of inducing secondary brain tumor. Twelve cases of high-dose radiation-induced meningioma following ALL are also reviewed. (author)

  6. External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio

    International Nuclear Information System (INIS)

    Gagnaire, B.; Cavalié, I.; Pereira, S.; Floriani, M.; Dubourg, N.; Camilleri, V.; Adam-Guillermin, C.

    2015-01-01

    Highlights: • The present study aimed to evaluate the effects of gamma rays on zebrafish larvae. • Different techniques were used: gene expression, biochemistry, microscopy and macroscopical observations. • The results showed that gamma irradiation can alter embryo-larval development at several levels of organization. - Abstract: In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

  7. External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Gagnaire, B., E-mail: beatrice.gagnaire@irsn.fr [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Cavalié, I. [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Pereira, S. [Neolys Diagnostics, Lyon 69373 (France); Floriani, M.; Dubourg, N.; Camilleri, V.; Adam-Guillermin, C. [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France)

    2015-12-15

    Highlights: • The present study aimed to evaluate the effects of gamma rays on zebrafish larvae. • Different techniques were used: gene expression, biochemistry, microscopy and macroscopical observations. • The results showed that gamma irradiation can alter embryo-larval development at several levels of organization. - Abstract: In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

  8. Time-effect relationship of immunological adaptive response induced by low dose X-irradiation in mice

    International Nuclear Information System (INIS)

    Zhao Yong; Gong Shouliang; Liu Shuzheng

    1995-01-01

    Kunming mice irradiated with whole-body X-rays were used to observe time-effect relationship of immunological adaptive response induced by ionizing radiation. The results showed that pre-irradiation dose of 75 mGy X-rays with the intervals of 6-48 h between pre-irradiation and challenge irradiation could induce immunological adaptive response in the spontaneous proliferation of thymocytes and the responses of splenocytes to Con A and LPS in mice at 18-24 h after challenge irradiation with 1.5-2.0 Gy X-rays

  9. Protective effect of Hippophae rhamnoides leaf extract on gamma irradiation induced clastogenecity in mice

    International Nuclear Information System (INIS)

    Tyagi, Anuradha; Prasad, Jagdish; Bala, Madhu

    2012-01-01

    Hippophae rhamnoides (sea buckthorn) is a plant belonging to Elaeagnaceae family and is distributed worldwide. It has variety of uses from nutritional food to pharmacological application. The study was aimed to analyse the extract from Hippophae rhamnoides leaves for their possible protective effects against the whole body 60 Co-a-irradiation. The study was performed on six groups of male mice i.e. untreated group, H. rhamnoides extract group, irradiated (2Gy), irradiated (3Gy), H. rhamnoides and irradiated (2Gy) and H. rhamnoides and irradiated (3Gy). In each group micronucleus test was performed utilising bone marrow and peripheral blood. The mice were sacrificed 30 hrs after treatment and analysed for the presence of micronuclei. In the present study, there was no significant increase in the frequency of either micronucleated polychromatic erythrocytes (MNPCEs) or normochromatic erythrocytes (NCE) in H. rhamnoides extract treated group over the negative control group of animals, indicating its non-clastogenic and non-toxic activity in the erythropoietic system. H. rhamnoides extract showed good anti-clastogenic activity against the a-irradiation induced clastogenecity in both the tissues i.e. bone marrow and peripheral blood by reducing the frequency of micronuclei. Also the administration of H. rhamnoides extract along with irradiation was slightly able to increase the frequency of PCE in bone marrow as well as in peripheral blood in comparison to the irradiated group (2Gy and 3Gy) indicating its ability to reduce the toxicity caused by irradiation in the erythropoietic system. Thus the results indicate the non-clastogenic effect of H. rhamnoides leaf extract and significant protective activity against 60 Co-a-irradiation suggesting its pharmacological significance for development of radioprotector. (author)

  10. Carbon nanotubes polymerization induced by self-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Cassio Stein [Faculdade de Fisica, Pontificia Univ. Catolica do Rio Grande do Sul (PUCRS), Porto Alegre (Brazil)

    2008-07-01

    Full text: We discuss our recent results on the formation of cross-links between neighboring carbon nanotubes within a bundle. Classical molecular dynamics was used to follow the evolution of the system when it is bombarded by low-energy carbon atoms. We show that it is possible to polymerize carbon nanotubes through irradiation and discuss the most common types of defects produced. Cross-links are created mainly in the direction perpendicular to the surface, and for higher energies, defects are created deeper in the rope. The final defects geometries may provide a realistic input to electronic density first principle calculations. (author)

  11. Carbon nanotubes polymerization induced by self-irradiation

    International Nuclear Information System (INIS)

    Moura, Cassio Stein

    2008-01-01

    Full text: We discuss our recent results on the formation of cross-links between neighboring carbon nanotubes within a bundle. Classical molecular dynamics was used to follow the evolution of the system when it is bombarded by low-energy carbon atoms. We show that it is possible to polymerize carbon nanotubes through irradiation and discuss the most common types of defects produced. Cross-links are created mainly in the direction perpendicular to the surface, and for higher energies, defects are created deeper in the rope. The final defects geometries may provide a realistic input to electronic density first principle calculations. (author)

  12. Switching the uniaxial magnetic anisotropy by ion irradiation induced compensation

    Science.gov (United States)

    Yuan, Ye; Amarouche, Teyri; Xu, Chi; Rushforth, Andrew; Böttger, Roman; Edmonds, Kevin; Campion, Richard; Gallagher, Bryan; Helm, Manfred; Jürgen von Bardeleben, Hans; Zhou, Shengqiang

    2018-04-01

    In the present work, the uniaxial magnetic anisotropy of GaMnAsP is modified by helium ion irradiation. According to the micro-magnetic parameters, e.g. resonance fields and anisotropy constants deduced from ferromagnetic resonance measurements, a rotation of the magnetic easy axis from out-of-plane [0 0 1] to in-plane [1 0 0] direction is achieved. From the application point of view, our work presents a novel avenue in modifying the uniaxial magnetic anisotropy in GaMnAsP with the possibility of lateral patterning by using lithography or focused ion beam.

  13. Studies on safety and efficacy of gamma-irradiated ginseng -Development of irradiation techniques for quality improvement of ginseng products

    International Nuclear Information System (INIS)

    Cho, Han Ok; Byeon, Meong Uh; Yang, Jae Seung; Cho, Seong Ki; Kang, Il Joon

    1993-10-01

    The fourth year research program on Korean ginseng was carried out in order to improve in the microbiological quality and physical properties of red ginseng and its processing by application of irradiation technology. The quality of red ginseng and their products were strictly controlled by government invested Korean Tobacco Ginseng Co., but there is a need of alternative technology for decontaminating and disinfestating in view of supplying stable raw material and securing the hygienic production because the use of food fumigants and preservatives has been restricted due to their harmful effects on human and environment. It is desirable that the limited moisture content of red ginseng product should be increased, considering the economic and physical properties of its products, by application of irradiation technology for sterilization of prepackaged red ginseng products. Red ginseng products were irradiated at dose of 0, 5, 7.5, 10 kGy respectively, following moisture content of sample were increased up to 14%, 16%, 18% and 20% by keeping at humidity controlled desiccator. Each sample stored at ambient temperature (20 deg C, 70% RH) and accelerated storage condition (40 deg C, 90% RH) were used for the evaluation of microbiological quality, TBA value, color difference measurement, hydrogen donating activity, HPLC pattern and content of saponins, change of fatty acids and characteristics of moisture absorption

  14. Activation of 45-MeV proton irradiation and proton-induced neutron irradiation in polymers

    International Nuclear Information System (INIS)

    Ra, Se-Jin; Kim, Kye-Ryung; Jung, Myung-Hwan; Yang, Tae-Keon

    2010-01-01

    During beam irradiation experiments with more than a few MeV energetic protons, the sample activation problem can be very severe because it causes many kinds of additional problems for the post-processing of the samples, such as time loss, inconvenience of sample handling, personal radiation safety, etc. The most serious problem is that immediate treatment of the sample is impossible in some experiments, such as nano-particle synthesizing. To solve these problems, we studied why the samples are activated and how the level of the activation can be reduced. It is known that the main reasons of activation are nuclear reactions with elements of the target material by primary protons and secondary produced neutrons. Even though the irradiation conditions are same, the level of the activation can be different depending on the target materials. For the nanoparticle synthesizing experiments, the target materials can be defined as the container and the sample itself. The reduction of the activation from the container is easier than the reduction from the sample. Therefore, we tried to reduce the activation level by changing the container materials. In this paper, the results are displayed for some candidate container materials, such as polymethyl methacrylate, polystyrene, Glass, etc., with 45-MeV and 10-nA proton beams. As a result, PS is the most suitable material for the container because of its relatively low level of the activation by protons. Also the contribution of secondary produced neutrons to the activation is negligible.

  15. Modeling of cavity swelling-induced embrittlement in irradiated austenitic stainless steels

    International Nuclear Information System (INIS)

    Han, X.

    2012-01-01

    During long-time neutron irradiation occurred in Pressurized Water Reactors (PWRs), significant changes of the mechanical behavior of materials used in reactor core internals (made of 300 series austenitic stainless steels) are observed, including irradiation induced hardening and softening, loss of ductility and toughness. So far, much effect has been made to identify radiation effects on material microstructure evolution (dislocations, Frank loops, cavities, segregation, etc.). The irradiation-induced cavity swelling, considered as a potential factor limiting the reactor lifetime, could change the mechanical properties of materials (plasticity, toughness, etc.), even lead to a structure distortion because of the dimensional modifications between different components. The principal aim of the present PhD work is to study qualitatively the influence of cavity swelling on the mechanical behaviors of irradiated materials. A micromechanical constitutive model based on dislocation and irradiation defect (Frank loops) density evolution has been developed and implemented into ZeBuLoN and Cast3M finite element codes to adapt the large deformation framework. 3D FE analysis is performed to compute the mechanical properties of a polycrystalline aggregate. Furthermore, homogenization technique is applied to develop a Gurson-type model. Unit cell simulations are used to study the mechanical behavior of porous single crystals, by accounting for various effects of stress triaxiality, of void volume fraction and of crystallographic orientation, in order to study void effect on the irradiated material plasticity and roughness at polycrystalline scale. (author) [fr

  16. Blue light irradiation-induced oxidative stress in vivo via ROS generation in rat gingival tissue.

    Science.gov (United States)

    Yoshida, Ayaka; Shiotsu-Ogura, Yukako; Wada-Takahashi, Satoko; Takahashi, Shun-suke; Toyama, Toshizo; Yoshino, Fumihiko

    2015-10-01

    It has been reported that oxidative stress with reactive oxygen species (ROS) generation is induced by blue light irradiation to a living body. Only limited research has been reported in dental field on the dangers of blue light, mostly focusing on cytotoxicity associated with heat injury of dental pulp. We thus performed an in vivo study on oral tissue exposed to blue light. ROS generated upon blue light irradiation of flavin adenine dinucleotide were measured by electron spin resonance spectroscopy. After blue light irradiation, the palatal gingiva of Wistar rats were isolated. Collected samples were subjected to biochemical analysis of lipid peroxidation and glutathione. Singlet oxygen was generated by blue light irradiation, but was significantly quenched in an N-acetyl-L-cysteine (NAC) concentration-dependent manner. Blue light significantly accelerated oxidative stress and increased the oxidized glutathione levels in gingival tissue. These effects were also inhibited by NAC pre-administration. The results suggest that blue light irradiation at clinical levels of tooth bleaching treatment may enhance lipid peroxidation by the induction of oxidative stress and the consumption of a significant amount of intracellular glutathione. In addition, NAC might be an effective supplement for the protection of oral tissues against blue light irradiation-induced oxidative damage. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Radioprotective effects of chlorogenic acid against mortality induced by gamma irradiation in mice

    International Nuclear Information System (INIS)

    Seyed Jalal Hosseinimehr; Amirhossein Ahmadi; Shahram Akhlaghpoor; Tehran University of Medical Sciences, Tehran

    2007-01-01

    Complete text of publication follows. The radioprotective effects of the naturally occurring compound chlorogenic acid has been investigated against mortality induced by gamma irradiation in mice. Chlorogenic acid administrated at single doses of 100, 200 and 400 mg/kg 1 and 24 h prior to lethal dose of gamma irradiation (8.5 Gy). At 30 days after treatment, the percentage of animal survival in each group was: control, 20%; 100 mg/kg, 20% and 15%; 200 mg/kg, 45% and 15%; 400 mg/kg, 25% and 35% for 1 h and 24 h treatment prior gamma irradiation, respectively. Percentage of survival increased in animal treated with this agent at 200 mg/kg at 1 h statistically compared with irradiated alone group. Other doses of chlorogenic acid have not showed any enhanced survival at 1 and 24 h before irradiation. Chlorogenic acid exhibited concentration-dependent activity on 1, 1-diphenyl 2-picrylhydrazyl free radical to show strong antioxidant activity. It appeared that chlorogenic acid with antioxidant activity reduced mortality induced by gamma irradiation.

  18. The Potential Therapeutic Effect of Curcumin on the Adjuvant-induced Arthritis in Irradiated Rats

    International Nuclear Information System (INIS)

    El-Ghazaly, M.A.; Nada, A.S.; Hegazy, M.E.; Kenawy, S.A.

    2010-01-01

    Naturalistic that provide medical or health benefits, including prevention and treatment of diseases. They may be advantageous in inflammation and exposure to radiation. The study was conducted to investigate curcumin potential to modulate, counteract or prevent the inflammatory response induced in arthritic irradiated and non-irradiated rats using the adjuvant-induced arthritis model. Diclofenac was used as a reference standard non-steroidal anti-inflammatory drug (NSAID). Results indicated that exposure of rats to single dose of gamma-radiation (6 Gy) before induction of inflammation increased production of prostaglandin E2 (PGE2), tumour necrosis factor-gamma (TNF-gamma) and malondialdehyde (MDA) levels in serum. Blood glutathione (GSH) was shown to be reduced in irradiated animals. Curcumin suppressed the elevated levels of TNF-gamma, PGE2 and MDA and was able to restore blood GSH level. Reduction in liver contents of copper (Cu), zinc (Zn), selenium (Se) and iron (Fe) was recorded in animals irradiated before induction of inflammation. In addition, curcumin restored the hepatic contents of these trace elements. The present results suggest that irradiation of rats caused marked changes in the inflammatory response, while curcumin suppressed the inflammatory response in both irradiated and normal rats

  19. X-irradiation-induced nuclear lesions in cultured mammaliam cells: an ultrastructural analysis

    International Nuclear Information System (INIS)

    Barham, S.S.; Walters, R.A.

    1978-01-01

    Electron-dense chromatin aggregates, hereafter referred to as lesions, have been characterized morphologically within interphase nuclei of Chinese hamster cells (line CHO) after a single acute exposure to 400, 800, 1200, or 2000 rad of x irradiation. At all doses studied, lesions were observed only after termination of radiation-induced division delay. Cell profiles were scored by electron microscopy for the presence or absence of nuclear lesions at various times after irradiation. The mitotic fraction from each irradiated population was also scored for each sample by light and electron microscopy. From these data and from simultaneous cell-density counts for each sample, it is apparent that postirradiation cell division is a prerequisite to formation of interphase nuclear lesions. Irradiated cell populations blocked in mitosis by Colcemid beyond the normal period of postirradiation division-delay failed to display nuclear lesions until after Colcemid was removed and cell division was completed. Enzyme digestions of isolated nuclei from irradiated cells with DNase I, RNase A, and Pronase suggest that the nuclear lesions are comprised primarily of chromatin. Nucleolar lesions, as well as various aberrant morphological forms of nucleoli, were also observed in cell populations after the onset of postirradiation cell division during the first 72 hr following exposure to irradiation. Delayed radiation-induced ultrastructural alterations of the nucleus included the formation of cytoplasmic invaginations into the nuclear space and inclusions of membranes within nuclei

  20. Possible radiation induced cancer of the thoracic esophagus after postoperative irradiation for the breast cancer

    International Nuclear Information System (INIS)

    Ueda, Mamoru; Matsubara, Toshiki; Kasumi, Fujio; Nishi, Mitsumasa; Kajitani, Tamaki

    1991-01-01

    We report 11 patients with cancer of the thoracic esophagus developing after postoperative irradiation therapy for breast cancer. Irradiation was done immediately after mastectomy in these patients and the irradiation field included the unilateral or bilateral parasternal region. They received a total dose ranging from 35 Gy to 60 Gy and the dose received to the thoracic esophagus was estimated from 10 Gy to 48 Gy. All cancer sites were involved in the irradiation field. The latent intervals of 10 patients from radiation to the manifest of cancer ranged from 10 to 19 years. Among 4777 women undergoing mastectomy for breast cancer between 1946 and 1980 in our hospital, 8 women (0.17%) developed cancer of the thoracic esophagus, whereas 5 (0.335%) out of 1534 women treated with mastectomy and radiotherapy with Linac between 1964 and 1980 developed cancer of the thoracic esophagus. Higher incidence of esophageal cancer in patients treated with surgery and radiation suggests that these cancers might be induced by radiation. Eight patients had esophagectomy and 4 patients of them received postoperative irradiation. They have survived from 9 months to 13 years. Two patients were controlled well by the irradiation alone. It is interesting that radiation therapy is sensitive to the possible radiation induced cancer of the thoracic esophagus. Follow up study should be directed to the possible development of second malignancy in patients who survive for a long time after radiation therapy. (author)

  1. Improving the microbial safety and quality of quail carcasses by gamma irradiation

    International Nuclear Information System (INIS)

    Rady, A.H.; Khalaf, H.H.; Afifi, E.A.; Nasr, E.H.

    2002-01-01

    This investigation aims to study the possibility of using gamma irradiation for improving the microbial safety quality of quail carcasses. One hundred quail carcasses were examined for the presence of salmonella. The examination illustrated that 70 carcasses from all examined carcasses were positive for salmonella. therefore, the contaminated quail carcasses were gamma irradiated at 2, 4 and 6 kGy doses and the effects of these treatments on the microbiological aspects and chemical properties of samples under investigation were evaluated. The results indicated that, the chemical composition of samples did not alter by gamma irradiation treatment. Furthermore, irradiation of samples at doses of 2, 4 and kGy greatly reduced its microbial count. Moreover, irradiation doses of 2 and 4 kGy completely destroyed salmonella and enterococcus faecalis, respectively. In addition, the acid value, peroxide value and thiobarbituric acid value were increased after irradiation. On the other hand, irradiation treatment had no real effects on the total volatile basic nitrogen content and amino acid composition of samples under investigation

  2. Induced mutation In Nelumbo nucifera Gaertn. by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lama, Sainiya; Aeksomtramaet, Ladda; Kanchanapoom, Kamnoon [Department of Biology, Faculty of Science, Prince of Songkla University, Songkhla (Thailand)

    2005-10-15

    Lotus (Nelumbo nucifera Gaertn.) seeds were exposed to different levels of Gamma irradiation at 0, 2, 4, 6, 8 and 10 Kilo rad. The exposed embryos were cultured on solid M S medium supplemented with 2 mg/l B A and overlaid with a liquid M S medium without growth regulators for 1 month. It was found that 50% growth reduction (GR50) was at 6 Kilo rad. The plant lets were subcultured twice every 2 months then they were transferred to solid M S medium supplemented with 4 mg/l NAA and overlaid with M S medium without growth regulators for root induction. The results revealed that plant lets in the control treatment (not exposed to Gamma irradiation) had the highest shoot growth and adventitious root formation. Plant lets at 2-Kilo rad treatment showed the second highest growth. The plant lets at 4-Kilo rad treatment did not exhibit adventitious root formation and had abnormal characteristics. Treatments at 6-10 Kilo rad inhibited the growth of the plant lets.

  3. Induced mutation In Nelumbo nucifera Gaertn. by gamma irradiation

    International Nuclear Information System (INIS)

    Lama, Sainiya; Aeksomtramaet, Ladda; Kanchanapoom, Kamnoon

    2005-10-01

    Lotus (Nelumbo nucifera Gaertn.) seeds were exposed to different levels of Gamma irradiation at 0, 2, 4, 6, 8 and 10 Kilo rad. The exposed embryos were cultured on solid M S medium supplemented with 2 mg/l B A and overlaid with a liquid M S medium without growth regulators for 1 month. It was found that 50% growth reduction (GR50) was at 6 Kilo rad. The plant lets were subcultured twice every 2 months then they were transferred to solid M S medium supplemented with 4 mg/l NAA and overlaid with M S medium without growth regulators for root induction. The results revealed that plant lets in the control treatment (not exposed to Gamma irradiation) had the highest shoot growth and adventitious root formation. Plant lets at 2-Kilo rad treatment showed the second highest growth. The plant lets at 4-Kilo rad treatment did not exhibit adventitious root formation and had abnormal characteristics. Treatments at 6-10 Kilo rad inhibited the growth of the plant lets

  4. Induced parthenocarpy with pollen irradiated with gamma rays

    International Nuclear Information System (INIS)

    Dryanovska, O.

    1975-01-01

    The results of serial experiments carried out during 1971-1974 using different vegetable crops for the purpose of obtaining parthenocarpous fruits with pollen irradiated with gamma rays are summed. Different varieties of tomatoes, cucumbers and sugar melons are used. The pollen was irradiated on the day on which it was collected with 1 to 500 kR (1500-1000 R/min) with immediate pollination of the respective flowers. The pollination of the flower was conducted with or without castration and with or without isolation depending on the varieties and the conditions of cultivating the plants. The fruits thus obtained were normal in size and shape and contained degenerated seed (flakes) witout cavities. Degustations in all cases established a fuller and richer taste in comparison with the control fruits. Biochemical indices for the same tomatoes varieties (sugars, vitamin C, acidity, dry substance determined refractometrically) show that the quality of the experimental fruits is better than the control ones. (A.B.)

  5. Characterization of color centers in quartz induced by gamma irradiation

    International Nuclear Information System (INIS)

    Guttler, Rainer A.S.

    2009-01-01

    The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with much colored commercial varieties. Quartz occurs in Brazil mainly in two geological environments, called pegmatitic and hydrothermal. The detailed mechanism of color center formation of these two types of quartz will be investigated by spectroscopic and chemical analysis. Until yet, it can be shown that due to chemical differences of the nature of mineral forming fluids, the two types behave differently. All quartzes contain mainly traces of Iron, Aluminum, Lithium and some amounts of Water. The quartz of hydrothermal origin incorporated much structurally bound water, and despite some similarities with the chemical composition of pegmatitic quartz, this high water content is the reason for the formation of Silanol radicals, giving the green color to the quartz. The main difference in chemical composition of pegmatitic quartz is the presence of higher amounts of Al and Li , responsible for the brownish and yellowish colors formed by irradiation. Since each pegmatite is different, the quartz will behave differently. This explains the formation of the famous 'Green Gold' of quartz from Sao Jose da Safira , and the more yellowish, Citrine type, color of quartz from the Coluna deposit, near Itamarandiba, Minas Gerais. (author)

  6. Induced Mutation in Yellow Lotus by Gamma Irradiation

    International Nuclear Information System (INIS)

    Puripunyavanich, Vichai; Boonsirichai, Kanokporn

    2006-01-01

    Rhizomes of American yellow lotus were irradiated at eht dosed of 0, 10, 20 and 30 Gy, 10 rhizomes per treatment. They were planted in nursery pots. Unirradiated rhizomes gave out new shoots within 3-4 days. The survival rates of the 10, 20 and 30 Gy irradiated rhizomes at one month after transplanted were 80%, 30% and 10%, respectively. The radiation dose that resulted in a 50% death rate (LD 5 0) was approximately 17 Gy. The surviving plant lets were transplanted and grown in pots as the Agricultural Occupation Promotion and Development Center in Chiangmai and Chiangrai for three years. Normally, American yellow lotus does not flower in Thailand. However, a mutant was found to bear flower in Thailand. The mutant flower appeared a little different from the wild-type flower. The tip of its petals was more rounded than the pointy wild-type tip. The mutant will be propagated for clonal production or for use as a par net in breeding crosses with Thai white and pink lotuses

  7. Characterization of color centers in quartz induced by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Guttler, Rainer A.S., E-mail: rainersg@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias; Enokihara, Cyro T.; Rela, Paulo R., E-mail: prela@ipen.b, E-mail: cteiti@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with much colored commercial varieties. Quartz occurs in Brazil mainly in two geological environments, called pegmatitic and hydrothermal. The detailed mechanism of color center formation of these two types of quartz will be investigated by spectroscopic and chemical analysis. Until yet, it can be shown that due to chemical differences of the nature of mineral forming fluids, the two types behave differently. All quartzes contain mainly traces of Iron, Aluminum, Lithium and some amounts of Water. The quartz of hydrothermal origin incorporated much structurally bound water, and despite some similarities with the chemical composition of pegmatitic quartz, this high water content is the reason for the formation of Silanol radicals, giving the green color to the quartz. The main difference in chemical composition of pegmatitic quartz is the presence of higher amounts of Al and Li , responsible for the brownish and yellowish colors formed by irradiation. Since each pegmatite is different, the quartz will behave differently. This explains the formation of the famous 'Green Gold' of quartz from Sao Jose da Safira , and the more yellowish, Citrine type, color of quartz from the Coluna deposit, near Itamarandiba, Minas Gerais. (author)

  8. γ - irradiation induced effect on the optical parameters of Cu10 Se90 thin films

    International Nuclear Information System (INIS)

    Abu EL-Fadl, A.; Hafiz, M. M.; Aashour, A.S.; Wakaad, M.M.

    2007-01-01

    The optical constants of Cu 10 SE 90 Chalcogenide films successfully deposited by evaporation coating technique have been measured. The absorption coefficient (a) for the as-deposited or after being γ-irradiation at various doses have been computed in the spectral wavelength range 400-900 nm from the transmittance (T) and reflectance (R) measurements of normally-incident light. Both irradiated and as-prepared films showed direct transition. The direct optical band gaps of the films were found to decrease from 2.017 for as prepared to 1.941 eV for γ-irradiation at 190 kGy doses. The width of the tails of localized states E e were calculated and found to be increasing after γ-irradiation. The effects of the γ-irradiation on the refractive index n and extinction coefficient k were studied. Other optical parameters (ε I , ε 2 were calculated at different γ-irradiation doses the obtained values of both ε 1 and ε 2 were found to be incident light and γ-doses dependent. The effect of γ-irradiation on the high-frequency dielectric constant (ε ∞ ) and carrier concentration (N/m * ) is also studied. The change on the degree of disorder as will as the radiation-induced defect changes applied to explain the radiation effects on nature of optical properties Cu 10 SE 90 glasses

  9. Fission gas induced deformation model for FRAP-T6 and NSRR irradiated fuel test simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Takehiko; Sasajima, Hideo; Fuketa, Toyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Hosoyamada, Ryuji; Mori, Yukihide

    1996-11-01

    Pulse irradiation tests of irradiated fuels under simulated reactivity initiated accidents (RIAs) have been carried out at the Nuclear Safety Research Reactor (NSRR). Larger cladding diameter increase was observed in the irradiated fuel tests than in the previous fresh fuel tests. A fission gas induced cladding deformation model was developed and installed in a fuel behavior analysis code, FRAP-T6. The irradiated fuel tests were analyzed with the model in combination with modified material properties and fuel cracking models. In Test JM-4, where the cladding temperature rose to higher temperatures and grain boundary separation by the pulse irradiation was significant, the fission gas model described the cladding deformation reasonably well. The fuel had relatively flat radial power distribution and the grain boundary gas from the whole radius was calculated to contribute to the deformation. On the other hand, the power density in the irradiated LWR fuel rods in the pulse irradiation tests was remarkably higher at the fuel periphery than the center. A fuel thermal expansion model, GAPCON, which took account of the effect of fuel cracking by the temperature profile, was found to reproduce well the LWR fuel behavior with the fission gas deformation model. This report present details of the models and their NSRR test simulations. (author)

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

    Science.gov (United States)

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

    2017-02-01

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

  11. Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations

    Directory of Open Access Journals (Sweden)

    Martin Hofmann

    2014-01-01

    Full Text Available High resolution global irradiance time series are needed for accurate simulations of photovoltaic (PV systems, since the typical volatile PV power output induced by fast irradiance changes cannot be simulated properly with commonly available hourly averages of global irradiance. We present a two-step algorithm that is capable of synthesizing one-minute global irradiance time series based on hourly averaged datasets. The algorithm is initialized by deriving characteristic transition probability matrices (TPM for different weather conditions (cloudless, broken clouds and overcast from a large number of high resolution measurements. Once initialized, the algorithm is location-independent and capable of synthesizing one-minute values based on hourly averaged global irradiance of any desired location. The one-minute time series are derived by discrete-time Markov chains based on a TPM that matches the weather condition of the input dataset. One-minute time series generated with the presented algorithm are compared with measured high resolution data and show a better agreement compared to two existing synthesizing algorithms in terms of temporal variability and characteristic frequency distributions of global irradiance and clearness index values. A comparison based on measurements performed in Lindenberg, Germany, and Carpentras, France, shows a reduction of the frequency distribution root mean square errors of more than 60% compared to the two existing synthesizing algorithms.

  12. Contribution to the investigation of phase transitions induced by irradiation in insulating crystalline ceramics

    International Nuclear Information System (INIS)

    Simeone, D.

    2003-01-01

    The author gives a rather detailed overview of his research activities on the behaviour of ceramics subjected to irradiations by charged or not-charged particles. He reports the development of a new application of low incidence X ray diffraction to assess the evolutions within irradiated solids. Coupling this technique with Raman spectroscopy studies enabled the monitoring of order parameter evolution in these solids. He shows that, in some oxides, irradiation effects entail order-disorder type transitions and, more surprisingly, displacive phase transitions. From this experimental work, he developed a modelling of these phase transitions induced by irradiation. Quantitative data obtained on the evolutions of order parameters enabled these phase transitions to be explained within the frame of the thermodynamics of off-equilibrium phenomena

  13. Low-energy electron irradiation induced top-surface nanocrystallization of amorphous carbon film

    Science.gov (United States)

    Chen, Cheng; Fan, Xue; Diao, Dongfeng

    2016-10-01

    We report a low-energy electron irradiation method to nanocrystallize the top-surface of amorphous carbon film in electron cyclotron resonance plasma system. The nanostructure evolution of the carbon film as a function of electron irradiation density and time was examined by transmission electron microscope (TEM) and Raman spectroscopy. The results showed that the electron irradiation gave rise to the formation of sp2 nanocrystallites in the film top-surface within 4 nm thickness. The formation of sp2 nanocrystallite was ascribed to the inelastic electron scattering in the top-surface of carbon film. The frictional property of low-energy electron irradiated film was measured by a pin-on-disk tribometer. The sp2 nanocrystallized top-surface induced a lower friction coefficient than that of the original pure amorphous film. This method enables a convenient nanocrystallization of amorphous surface.

  14. Ion irradiation-induced diffusion in bixbyite-fluorite related oxides: Dislocations and phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Rolly, Gaboriaud, E-mail: Rolly.gaboriaud@univ-poitiers.fr [Institut Pprime, CNRS-University of Poitiers, SP2MI-BP 30179, 86962 Chasseneuil-Futuroscope (France); Fabien, Paumier [Institut Pprime, CNRS-University of Poitiers, SP2MI-BP 30179, 86962 Chasseneuil-Futuroscope (France); Bertrand, Lacroix [CSIC – University of Sevilla, Avenida Américo Vespucio, 49, 41092 Sevilla (Spain)

    2014-05-01

    Ion-irradiation induced diffusion and the phase transformation of a bixbyite-fluorite related rare earth oxide thin films are studied. This work is focused on yttrium sesquioxide, Y{sub 2}O{sub 3}, thin films deposited on Si (1 0 0) substrates using the ion beam sputtering technique (IBS). As-deposited samples were annealed ant then irradiated at cryogenic temperature (80 K) with 260 keV Xe{sup 2+} at different fluences. The irradiated thin oxide films are characterized by X-ray diffraction. A cubic to monoclinic phase transformation was observed. Analysis of this phenomenon is done in terms of residual stresses. Stress measurements as a function of irradiation fluences were realised using the XRD-sin{sup 2}ψ method. Stress evolution and kinetic of the phase transformation are compared and leads to the role-played by the nucleation of point and extended defects.

  15. Method for determining correction factors induced by irradiation of ionization chamber cables in large radiation field

    International Nuclear Information System (INIS)

    Rodrigues, L.L.C.

    1988-01-01

    A simple method was developed to be suggested to hospital physicists in order to be followed during large radiation field dosimetry, to evaluate the effects of cables, connectors and extension cables irradiation and to determine correction factors for each system or geometry. All quality control tests were performed according to the International Electrotechnical Commission for three clinical dosimeters. Photon and electron irradiation effects for cables, connectors and extention cables were investigated under different experimental conditions by means of measurements of chamber sensitivity to a standard radiation source of 90 Sr. The radiation induced leakage current was also measured for cables, connectors and extension cables irradiated by photons and electrons. All measurements were performed at standard dosimetry conditions. Finally, measurements were performed in large fields. Cable factors and leakage factors were determined by the relation between chamber responses for irradiated and unirradiated cables. (author) [pt

  16. Decrease of glucose-induced insulin secretion of pancreatic rat islets after irradiation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Heinzmann, D; Nadrowitz, R; Besch, W; Schmidt, W; Hahn, H J

    1983-01-01

    Irradiation of pancreatic rat islets up to a dose of 2.5 Gy did neither alter glucose-nor IBMX-induced insulin secretion studied in vitro. The insulin as well as glucagon content of irradiated islets were similar as in the control tissue. This was also true in islets irradiated with 25 Gy which were characterized by a decreased insulin secretion in the presence of glucose and IBMX, respectively. Since we did not find indications of an enhanced hormone output in the radiation medium, we want to suggest that higher irradiation doses affect insulin release of pancreatic islets in vitro. This observation has to be taken into account for application of radioimmunosuppression for transplantation.

  17. Reaction mechanism of hydroxymaleimide induced by γ-irradiation in alcohol solvents

    International Nuclear Information System (INIS)

    Nakagawa, Seiko

    2010-01-01

    Methanol and 2-propanol solutions of hydroxymaleimide were irradiated with γ-ray and mechanism of its γ-irradiation-induced reactions was investigated through final-product analyses using high performance liquid chromatography (HPLC) coupled with mass spectroscopy. An addition reaction of a solvent radical toward hydroxymaleimide was dominant among its oxygen-free γ-irradiation-induced reactions in its alcohol solutions while it is known that electron attachment toward hydroxyphthalimide or hydroxysuccinimide is dominant among their γ-irradiation-induced reactions. The radical adduct abstracts hydrogen from solvent molecule to re-produce a solvent radical. Therefore, the degradation efficiency of hydroxymaleimide was more than ten times larger than that of hydroxyphthalimide and hydroxysuccinimide. Dimer was also produced through electron attachment process in the solutions of hydroxymaleimide. In addition, it was found that the degradation efficiency increased with decrease in dose rate. An additional reaction of a solvent radical toward hydroxymaleimide competes with a radical-radical recombination. The latter was reduced, with the former leading to efficient degradation of hydroxymaleimide increased by irradiation at lower dose rate. On the contrary, the production yield of the adduct radical as well as the degradation efficiency of hydroxymaleimide was inhibited in the presence of oxygen.

  18. Reaction mechanism of hydroxymaleimide induced by γ-irradiation in alcohol solvents

    International Nuclear Information System (INIS)

    Nakagawa, Seiko

    2010-01-01

    Methanol and 2-propanol solutions of hydroxymaleimide were irradiated with γ-ray and mechanism of its γ-irradiation-induced reactions was investigated through final-product analyses using high performance liquid chromatography (HPLC) coupled with mass spectroscopy. An addition reaction of a solvent radical toward hydroxymaleimide was dominant among its oxygen-free γ-irradiation-induced reactions in its alcohol solutions while it is known that electron attachment toward hydroxyphthalimide or hydroxysuccinimide is dominant among their γ-irradiation-induced reactions. The radical adduct abstracts hydrogen from solvent molecule to re-produce a solvent radical. Therefore, the degradation efficiency of hydroxymaleimide was more than 10 times larger than that of hydroxyphthalimide and hydroxysuccinimide. Dimer was also produced through electron attachment process in the solutions of hydroxymaleimide. In addition, it was found that the degradation efficiency increased with decreasing the dose rate. An addition reaction of a solvent radical toward hydroxymaleimide competes with a radical-radical recombination. The latter was reduced and the former leading to efficient degradation of hydroxymaleimide increased by irradiation at lower dose rate. On the contrary, the production yield of the adduct radical as well as the degradation efficiency of hydroxymaleimide was inhibited in the presence of oxygen.

  19. Elevated sodium chloride concentrations enhance the bystander effects induced by low dose alpha-particle irradiation

    International Nuclear Information System (INIS)

    Han Wei; Zhu Lingyan; Jiang Erkang; Wang Jun; Chen Shaopeng; Bao Linzhi; Zhao Ye; Xu An; Yu Zengliang; Wu Lijun

    2007-01-01

    Previous studies have shown that high NaCl can be genotoxic, either alone or combined with irradiation. However, little is known about the relationship between environmental NaCl at elevated conditions and radiation-induced bystander effects (RIBE). RIBE, which has been considered as non-targeted bystander responses, has been demonstrated to occur widely in various cell lines. In the present study, RIBE under the elevated NaCl culture condition was assessed in AG 1522 cells by both the induction of γ-H2AX, a reliable marker of DNA double-strand break (DSB) for the early process ( G -methyl-L-arginine, an inhibitor of nitric oxide synthase, the induced fraction of foci-positive cells was effectively inhibited both in 0.2 cGy α-particle irradiated and adjacent non-irradiated regions under either normal or elevated NaCl conditions. These results suggested that the cultures with elevated NaCl medium magnified the damage effects induced by the low dose α-particle irradiation and nitric oxide generated by irradiation was also very important in this process

  20. Study on apoptosis of prostate cancer cell induced by 125I seed irradiation

    International Nuclear Information System (INIS)

    Liao Anyan; Wang Junjie; Wang Jidong; Zhuang Hongqing; Zhao Yong

    2007-01-01

    Objective: To explore the mechanism of apoptosis induced by 125 I seed irradiation on PC3 cells. Methods: Human prostate cancer cell line PC3 was treated by irradiation of 125 I (2.77 cGy/h) with various dose. Agarose gel electrophoresis of DNA and flows cytometry were used to detect the apoptosis of PC3 cells and indirect immunofluorescence assay was used to detect the expression of Bcl-2. The activity of Caspase-3 was measured by Caspase Colorimetric Assay Kits. Results: Apoptosis of PC3 cells could be efficiently induced by 125 I seed irradiation. The apoptotic peaks were found by flow cytometry and DNA ladder appeared on 1.8% agarose gel. The activity of Caspase-3 on PC3 cells treated by 125 I seed irradiation was not changed significantly. Bcl-2 gene expression was down-regulated with the sample concentration increased. Conclusion: 125 I irradiation can induce the apoptosis of PC3 cells and the mechanism of apoptosis is related with down regulation of Bcl-2 gene expression and is not related with Caspase-3 activity. (authors)

  1. Viscous surface flow induced on Ti-based bulk metallic glass by heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kun [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Hu, Zheng [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Science and Technology on Vehicle Transmission Laboratory, China North Vehicle Research Institute, Beijing 100072 (China); Li, Fengjiang [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Wei, Bingchen, E-mail: weibc@imech.ac.cn [Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

    2016-12-30

    Highlights: • Obvious smoothing and roughening phases on the Ti-based MG surface resulted, which correspond respectively to the normal and off-normal incidence angles. • Atomic force microscopy confirms two types of periodic ripples distributed evenly over the rough surface. • The irradiation-induced viscosity of MG is about 4×10{sup 12} Pa·s, which accords with the theoretical prediction for metallic glasses close to glass transition temperature. • Surface-confined viscous flow plays a dominant quantitative role, which is due to radiation-induced softening of the low-viscosity surface layer. - Abstract: Ti-based bulk metallic glass was irradiated by a 20 MeV Cl{sup 4+} ion beam under liquid-nitrogen cooling, which produced remarkable surface smoothing and roughening that respectively correspond to normal and off-normal incidence angles of irradiation. Atomic force microscopy confirms two types of periodic ripples distributed evenly over the rough glass surface. In terms of mechanism, irradiation-induced viscosity agrees with the theoretical prediction for metallic glasses near glass transition temperature. Here, a model is introduced, based on relaxation of confined viscous flow with a thin liquid-like layer, that explains both surface smoothing and ripple formation. This study demonstrates that bulk metallic glass has high morphological instability and low viscosity under ion irradiation, which assets can pave new paths for metallic glass applications.

  2. Improvement of biological properties of titanium by anodic oxidation and ultraviolet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Baoe [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Li, Ying [Stomatological Hospital, Tianjin Medical University, Tianjin 300070 (China); Li, Jun [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Fu, Xiaolong; Li, Changyi [Stomatological Hospital, Tianjin Medical University, Tianjin 300070 (China); Wang, Hongshui [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Liu, Shimin [Business School, Tianjin University of Commerce, Tianjin 300134 (China); Guo, Litong [China University of Mining and Technology, Xuzhou 221116 (China); Xin, Shigang [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Liang, Chunyong, E-mail: liangchunyong@126.com [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Li, Haipeng, E-mail: lhpcx@163.com [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China)

    2014-07-01

    Anodic oxidation was applied to produce a homogeneous and uniform array of nanotubes of about 70 nm on the titanium (Ti) surface, and then, the nanotubes were irradiated by ultraviolet. The bioactivity of the Ti surface was evaluated by simulated body fluid soaking test. The biocompatibility was investigated by in vitro cell culture test. The results showed that bone-like apatite was formed on the anodic oxidized and UV irradiated Ti surface, but not on the as-polished Ti surface after immersion in simulated body fluid for two weeks. Cells cultured on the anodic oxidized Ti surface showed enhanced cell adhesion and proliferation, also presented an up-regulated gene expression of osteogenic markers OPG, compared to those cultured on the as-polished Ti surface. After UV irradiation, the cell behaviors were further improved, indicating better biocompatibility of Ti surface. Based on these results, it can be concluded that anodic oxidation improved the biological properties (bioactivity and biocompatibility) of Ti surface, while UV irradiation improved the biocompatibility to a better extent. The improved biological properties were attributed to the nanostructures as well as the enhanced hydrophilicity. Therefore, anodic oxidation combined with UV irradiation can be used to enhance the biological properties of Ti-based implants.

  3. Convoluted dislocation loops induced by helium irradiation in reduced-activation martensitic steel and their impact on mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Fengfeng [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Yao, Z. [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, Canada K7L 3N6 (Canada); Guo, Liping, E-mail: guolp@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Suo, Jinping [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Wen, Yongming [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory, School of Physics and Technology, Wuhan University, Wuhan 430072 (China)

    2014-06-01

    Helium irradiation induced dislocation loops in reduced-activation martensitic steels were investigated using transmission electron microscopy. The specimens were irradiated with 100 keV helium ions to 0.8 dpa at 350 °C. Unexpectedly, very large dislocation loops were found, significantly larger than that induced by other types of irradiations under the same dose. Moreover, the large loops were convoluted and formed interesting flower-like shape. The large loops were determined as interstitial type. Loops with the Burgers vectors of b=〈100〉 were only observed. Furthermore, irradiation induced hardening caused by these large loops was observed using the nano-indentation technique.

  4. Improving enzymatic hydrolysis of industrial hemp (Cannabis sativa L.) by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Soo-Jeong [Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Sung, Yong Joo [KT and G Central Research Institute, 302 Shinseong-Dong, Yuseong-Gu, Daejeon 305-805 (Korea, Republic of)], E-mail: yosung17@yahoo.co.kr

    2008-09-15

    The electron beam irradiation was applied as a pretreatment of the enzymatic hydrolysis of hemp biomass with doses of 150, 300 and 450 kGy. The higher irradiation dose resulted in the more extraction with hot-water extraction or 1% sodium hydroxide solution extraction. The higher solubility of the treated sample was originated from the chains scission during irradiation, which was indirectly demonstrated by the increase of carbonyl groups as shown in diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) spectra. The changes in the micro-structure of hemp resulted in the better response to enzymatic hydrolysis with commercial cellulases (Celluclast 1.5L and Novozym 342). The improvement in enzymatic hydrolysis by the irradiation was more evident in the hydrolysis of the xylan than in that of the cellulose.

  5. Improving enzymatic hydrolysis of industrial hemp (Cannabis sativa L.) by electron beam irradiation

    International Nuclear Information System (INIS)

    Shin, Soo-Jeong; Sung, Yong Joo

    2008-01-01

    The electron beam irradiation was applied as a pretreatment of the enzymatic hydrolysis of hemp biomass with doses of 150, 300 and 450 kGy. The higher irradiation dose resulted in the more extraction with hot-water extraction or 1% sodium hydroxide solution extraction. The higher solubility of the treated sample was originated from the chains scission during irradiation, which was indirectly demonstrated by the increase of carbonyl groups as shown in diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) spectra. The changes in the micro-structure of hemp resulted in the better response to enzymatic hydrolysis with commercial cellulases (Celluclast 1.5L and Novozym 342). The improvement in enzymatic hydrolysis by the irradiation was more evident in the hydrolysis of the xylan than in that of the cellulose

  6. Improving enzymatic hydrolysis of industrial hemp ( Cannabis sativa L.) by electron beam irradiation

    Science.gov (United States)

    Shin, Soo-Jeong; Sung, Yong Joo

    2008-09-01

    The electron beam irradiation was applied as a pretreatment of the enzymatic hydrolysis of hemp biomass with doses of 150, 300 and 450 kGy. The higher irradiation dose resulted in the more extraction with hot-water extraction or 1% sodium hydroxide solution extraction. The higher solubility of the treated sample was originated from the chains scission during irradiation, which was indirectly demonstrated by the increase of carbonyl groups as shown in diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) spectra. The changes in the micro-structure of hemp resulted in the better response to enzymatic hydrolysis with commercial cellulases (Celluclast 1.5L and Novozym 342). The improvement in enzymatic hydrolysis by the irradiation was more evident in the hydrolysis of the xylan than in that of the cellulose.

  7. Irradiation induced tensile property change of SA 508 Cl.3 reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Chi, Se-Hwan; Hong, Jun-Hwa; Kuk, Il-Hiun

    1998-01-01

    Irradiation induced tensile property change of four kinds of reactor pressure vessel steels manufactured by different steel refining process was compared based on the differences in the unirradiated and irradiated microstructure. Microvickers hardness, indentation, and miniature tensile specimen tests were conducted for mechanical property measurement and optical microscope (OM) and transmission electron microscope (TEM) were used for microstructural characterization. Specimens were 2 irradiated to a neutron fluence of 2.7x10 19 n/cm 2 (E ≥ 1 MeV) at 288 deg. C. Investigation on the unirradiated microstructures showed largely a same microstructure in that tempered acicular bainite and ferrite with bainitic phase prevailing in the unirradiated condition. Band-shaped segregations were also clearly observed except a kind of materials. A large difference in the unirradiated microstructure appeared in the grain size and carbide microstructure. Of carbide microstructures, noticeable differences were observed in the size and distribution of cementite, and bainitic lath microstructures. No noticeable changes were observed in the optical and thin film TEM microstructures after irradiation. Complicated microstructural. state of heat treated bainitic low alloy microstructure prevents easy quantification of microstructural changes due to irradiation. Apparent differences, however, were observed in the results of mechanical testing. Results of tensile testing and hardness measurement show that a steel refined by vacuum carbon deoxidation(VCD) method exhibits the highest radiation hardening behavior. Some of mechanical testing results on irradiated materials were possible to understand based on the initial microstructure, but further investigations using a wide array of sophisticated tools (for example, SANS, APFIM) are required to understand and characterize irradiation induced defects that are responsible for irradiation hardening behavior but are not revealed by

  8. Improving the lipid stability and sensory characteristics of irradiated minced beef by using natural herbal extracts

    International Nuclear Information System (INIS)

    Mansour, H. A.; Moliarned, H.M.; El-Niely, H.F.G.

    2007-01-01

    The objective of the present work was to use natural herbal extracts to minimize lipid oxidation and improve the sensory characteristics of irradiated minced beef. Beef longissimus dorsi were minced, mixed with herbal extracts as appropriate and packed in polyethylene bags (50 g each). There were four treatment groups: (1) untreated controls, (2) irradiated with cobalt-60 gamma-rays to either 2 or 4.5 kGy, (3) addition of extracts of one of marjoram, rosemary or sage to a final concentration of 0.04 % (v/w), (4) combination treatment with either 2 or 4.5 kGy irradiation, plus herbal extract at 0.04 % (v/w) added pre-irradiation. Aerobically packaged samples were then placed into storage at 5 degree C. At specified time intervals samples were withdrawn to be analyzed for thiobarbituric acid reactive substances (TEARS), sensory characteristics and psychrotrophic bacterial counts, Results demonstrated a significant benefit of the addition of herbal extracts to the minced beef prior to irradiation. All three extracts generally lowered the TBARS values in both control and irradiated samples, with marjoram being the most effective, followed by sage and rosemary in that order of efficacy. As regards radiation effected off-odour, all three extracts generally lowered the off-odour score, with marjoram and sage being most effective, and rosemary being somewhat less so. All three extracts protected against radiation effected colour loss. Addition of herbal extracts prior to irradiation resulted in significant increase (p< 0.05) in the acceptability scores for all irradiated samples in the post-irradiation period, with rosemary being somewhat less effective than sage and marjoram. Addition of herbal extracts alone to the minced meat did not affect the psychrotrophic bacterial counts of treated samples. The combination treatment with herbal extracts plus

  9. Recovery Profiles of T-Cell Subsets Following Low-Dose Total Body Irradiation and Improvement With Cinnamon

    International Nuclear Information System (INIS)

    Zheng, Xiaodan; Guo, Yuqi; Wang, Lei; Zhang, Honghai; Wang, Shaobo; Wang, Li; An, Lei; Zhou, Xianbin; Li, Xia; Yao, Chengfang

    2015-01-01

    Purpose: Inefficient T-cell reconstitution from x-ray–induced immune damage reduces antitumor response. To understand the profile of T-cell reconstitution after irradiation will overcome the barrier of antitumor immunity. This study aimed to identify the recovery profile of T-cell subsets following x-ray irradiation and to highlight the role of cinnamon on efficient T-cell restoration postexposure in the antitumor response. Methods and Materials: CD3"+, CD8"+, and CD4"+ T cells and Th1, Th2, Th17, and regulatory T (Treg) cells were evaluated at different time points after single low-dose total body irradiation (SLTBI) with or without cinnamon treatments. T-bet, GATA3, RORγt, and Foxp3 signaling specific for Th1, Th2, Th17, and Treg were also analyzed by RT-PCR assay. The effects of cinnamon on efficient T-cell subset reconstitution was confirmed in a lung melanoma model in irradiated mice. Results: Reconstitution of CD4"+ T cells was delayed more than that of CD8"+ T cells in T-cell restoration after SLTBI. The production of IFNγ by Th1 or Tc1 cells was sharply decreased and was accompanied by reduced T-bet mRNA, even when total T-cell numbers had recovered; the frequencies of Th17 and Treg cells and their specific transcription factors (RORγt and Foxp3, respectively) were obviously increased. Irradiation-induced inefficient T-cell reconstitution impaired the antitumor capacities in the lung melanoma model. Pretreatment with cinnamon in irradiated mice accelerated the generation of Th1 and reduced the differentiation of Treg cells by activating T-bet and limiting transcriptions of Foxp3. Improvement resulting from cinnamon pretreatment on the efficient T-cell recovery profile from SLTBI promoted antitumor immunity in the lung melanoma model. Conclusions: T-cell reconstitution from SLTBI was characterized by impaired Th1 and elevated Th17 and Treg cells. Cinnamon effectively improved the imbalance of T-cell subsets by promoting the proliferation of Th1 and

  10. Recovery Profiles of T-Cell Subsets Following Low-Dose Total Body Irradiation and Improvement With Cinnamon

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xiaodan [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); School of Medicine and Life Science, University of Jinan-Shandong Academy of Medical Science, Jinan (China); Guo, Yuqi [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); Wang, Lei [Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan (China); Zhang, Honghai [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); Wang, Shaobo [Shandong University, Jinan (China); Wang, Li [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); An, Lei [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); School of Medicine and Life Science, University of Jinan-Shandong Academy of Medical Science, Jinan (China); Zhou, Xianbin; Li, Xia [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China); Yao, Chengfang, E-mail: yaocf9941@163.com [Key Laboratory for Tumor Immunology and Traditional Chinese Medicine Immunology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan (China)

    2015-12-01

    Purpose: Inefficient T-cell reconstitution from x-ray–induced immune damage reduces antitumor response. To understand the profile of T-cell reconstitution after irradiation will overcome the barrier of antitumor immunity. This study aimed to identify the recovery profile of T-cell subsets following x-ray irradiation and to highlight the role of cinnamon on efficient T-cell restoration postexposure in the antitumor response. Methods and Materials: CD3{sup +}, CD8{sup +}, and CD4{sup +} T cells and Th1, Th2, Th17, and regulatory T (Treg) cells were evaluated at different time points after single low-dose total body irradiation (SLTBI) with or without cinnamon treatments. T-bet, GATA3, RORγt, and Foxp3 signaling specific for Th1, Th2, Th17, and Treg were also analyzed by RT-PCR assay. The effects of cinnamon on efficient T-cell subset reconstitution was confirmed in a lung melanoma model in irradiated mice. Results: Reconstitution of CD4{sup +} T cells was delayed more than that of CD8{sup +} T cells in T-cell restoration after SLTBI. The production of IFNγ by Th1 or Tc1 cells was sharply decreased and was accompanied by reduced T-bet mRNA, even when total T-cell numbers had recovered; the frequencies of Th17 and Treg cells and their specific transcription factors (RORγt and Foxp3, respectively) were obviously increased. Irradiation-induced inefficient T-cell reconstitution impaired the antitumor capacities in the lung melanoma model. Pretreatment with cinnamon in irradiated mice accelerated the generation of Th1 and reduced the differentiation of Treg cells by activating T-bet and limiting transcriptions of Foxp3. Improvement resulting from cinnamon pretreatment on the efficient T-cell recovery profile from SLTBI promoted antitumor immunity in the lung melanoma model. Conclusions: T-cell reconstitution from SLTBI was characterized by impaired Th1 and elevated Th17 and Treg cells. Cinnamon effectively improved the imbalance of T-cell subsets by promoting the

  11. A 3D-RBS study of irradiation-induced deformation and masking properties of ordered colloidal nanoparticulate masks

    International Nuclear Information System (INIS)

    Zolnai, Z.; Deak, A.; Nagy, N.; Toth, A.L.; Kotai, E.; Battistig, G.

    2010-01-01

    The 500 keV Xe 2+ irradiation-induced anisotropic deformation of ordered colloidal silica nanoparticulate masks is followed using 2 MeV 4 He + Rutherford Backscattering Spectrometry (RBS) with different measurement geometries and the improved data analysis capabilities of the RBS-MAST spectrum simulation code. The three-dimensional (3D) geometrical transformation from spherical to oblate ellipsoidal and polygonal shape and the decrease of the mask's hole size is described. The masking properties of the silica monolayer and the depth distribution of Xe in the underlying Si substrate vs. the irradiated Xe 2+ fluence are discussed. Field Emission Scanning Electron Microscopy (FESEM) is applied as complementary characterization tool. Our results give contribution to clarify the impact of ion-nanoparticle interactions on the potentials and limits of nanosphere lithography. We also show the capability of the conventional RBS technique to characterize laterally ordered submicron-sized three-dimensional structures.

  12. Failure of irradiated beef and ham to induce genetic aberrations of Drosophila

    International Nuclear Information System (INIS)

    Mittler, S.

    1979-01-01

    Ham that had been irradiated by electrons and beef which had been exposed to gamma rays from 60 Co were fed to Drosophila melanogaster to determine whether meat sterilized by these methods would induce genetic aberrations. The results showed that for yB/sc 8 y + Y males, fed on irradiated ham or beef, thermally preserved beef or frozen beef for their entire larval life, there was no significant increase in the loss of X or Y chromosomes or non-disjunction of these chromosomes; there was also no significant increase in any of the broods. Similarly for the Oregon R males, there was no significant increase in yield of sex-linked recessive lethals. Thus feeding of irradiated ham and beef to Drosophila males did not induce significant increases in genetic aberrations. The present findings are discussed in relation to the conflicting results of previous studies. (U.K.)

  13. Changes in the surface electronic states of semiconductor fine particles induced by high energy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamaki, Tetsuya; Asai, Keisuke; Ishigure, Kenkichi [Tokyo Univ. (Japan); Shibata, Hiromi

    1997-03-01

    The changes in the surface electronic states of Q-sized semiconductor particles in Langmuir-Blodgett (LB) films, induced by high energy ion irradiation, were examined by observation of ion induced emission and photoluminescence (PL). Various emission bands attributed to different defect sites in the band gap were observed at the initial irradiation stage. As the dose increased, the emissions via the trapping sites decreased in intensity while the band-edge emission developed. This suggests that the ion irradiation would remove almost all the trapping sites in the band gap. The low energy emissions, which show a multiexponential decay, were due to a donor-acceptor recombination between the deeply trapped carriers. It was found that the processes of formation, reaction, and stabilization of the trapping sites would predominantly occur under the photooxidizing conditions. (author)

  14. Schisandrin B protects against solar irradiation-induced oxidative injury in BJ human fibroblasts.

    Science.gov (United States)

    Chiu, Po Yee; Lam, Philip Y; Yan, Chung Wai; Ko, Kam Ming

    2011-06-01

    The effects of schisandrin B (Sch B) and its analogs on solar irradiation-induced oxidative injury were examined in BJ human fibroblasts. Sch B and schisandrin C (Sch C) increased cellular reduced glutathione (GSH) level and protected against solar irradiation-induced oxidative injury. The photoprotection was paralleled by decreases in the elastases-type protease activity and matrix-metalloproteinases-1 expression in solar-irradiated fibroblasts. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production. The results suggest that by virtue of its pro-oxidant action and the subsequent glutathione antioxidant response, Sch B or Sch C may offer the prospect of preventing skin photo-aging. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    International Nuclear Information System (INIS)

    Liu Hanzhou; Yu Ming; Deng Bo; Li Linfan; Jiang Haiqing; Li Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA). - Highlights: → Acrylonitrile is grafted onto pre-irradiated polyethylene (PE) nonwoven fabrics. → Emulsion system is applied, for the graft polymerization avoids organic solvent. → Kinetic of the pre-irradiation induced graft polymerization is studied. → Optimal condition is determined at the temperature below the b.p. of acrylonitrile.

  16. Induced variation in potato dry rot fusarium roseum by ultraviolet irradiation

    International Nuclear Information System (INIS)

    Lee, C.U.

    1979-01-01

    Variations were readily induced in Fusarium roseum isolated from decayed potato tubers by subjecting its conidia to ultraviolet irradiation. The dosage that resulted in complete absence of developing colonies in five minutes of irradiation did not cause the mortality of conidia for the initial one minute. Eighty eight precent of conidia were killed in three minutes. Approximately 90% of the conidia showed resistance to lethality for the initial two minutes whereas 10% began to show resistance after three minutes of the irradiation. The maximum 42% of color variation was obtained among the surviving conidia. Varients in both decreased and increased pathogenicity were induced in 8% among the color variants. Variations occurred in such other characteristics as growth rate, rigidity of mycelium, and conidia formation. (author)

  17. Ag induced suppression of irradiation response in YBCO/Ag composite thin films

    International Nuclear Information System (INIS)

    Behera, D.; Mohanty, T.; Mohanta, D.; Patnaik, K.; Mishra, N.C.; Senapati, L.; Kanjilal, D.; Mehta, G.K.; Pinto, R.

    1999-01-01

    Practical application of cuprate superconductors in radiation environment demands that these systems remain insensitive to the irradiation induced defects. The cuprate superconductors however are many orders of magnitude more sensitive than the conventional low T c superconductors. To suppress the irradiation sensitivity of cuprates we consider a crystal engineering approach where metal ions as Ag is made to occupy inter and intra-granular sites of YBa 2 Cu 3 O 7 thin films. We show that superconducting and normal state properties of YBCO/Ag composite thin films prepared by laser ablation remain unchanged under 140 MeV Si ion irradiation up to fluence of 8 x 10 14 ions/cm 2 . The inter- and intra-granular occupancy of Ag is shown to induce microstructural modifications and rigidity to the CuO chains respectively which in turn lead to the radiation insensitivity of the composite films. (author)

  18. Insulating Behavior in Graphene with Irradiation-induced Lattice Defects

    Science.gov (United States)

    Chen, Jian-Hao; Williams, Ellen; Fuhrer, Michael

    2010-03-01

    We irradiated cleaned graphene on silicon dioxide in ultra-high vacuum with low energy inert gas ions to produce lattice defects [1], and investigated in detail the transition from metallic to insulating temperature dependence of the conductivity as a function of defect density. We measured the low field magnetoresistance and temperature-dependent resistivity in situ and find that weak localization can only account for a small correction of the resistivity increase with decreasing temperature. We will discuss possible origins of the insulating temperature dependent resistivity in defected graphene in light of our recent experiments. [4pt] [1] Jian-Hao Chen, W. G. Cullen, C. Jang, M. S. Fuhrer, E. D. Williams, PRL 102, 236805 (2009)

  19. Stability of thermally induced copper precipitates under neutron irradiation

    International Nuclear Information System (INIS)

    Phythian, W.J.; Dumbill, S.; Brown, P.; Sinclair, R.

    1993-01-01

    Model Fe 1.3%Cu and Fe 1.3%Cu 1.1%Ni alloys have been thermally aged at 550 C for 2 hours (peak) and 10 hours prior to irradiation at 288 C to a dose of 5.10 22 n/m 2 . Results of a microstructural investigation using dedicated field emission gun scanning transmission electron microscopy (FEGSTEM) and small angle neutron scattering (SANS) to assess precipitate stability in the binary alloy, are presented. These data are then used to predict a hardness change as a result of copper precipitation for comparison with the measured values obtained using standard 5 kg Vickers hardness tests on the SANS samples. Implications of these data to the re-embrittlement of the RPV by subsequent copper precipitation is discussed. (authors). 16 refs., 5 figs., 5 tabs

  20. Biopolymer nanostructures induced by plasma irradiation and metal sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Juřík, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Malinský, P.; Macková, A. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Prague 25068 (Czech Republic); Faculty of Science, J.E. Purkyně University, Ústí nad Labem (Czech Republic); Kasálková, N. Slepičková; Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2014-08-01

    Modification based on polymer surface exposure to plasma treatment exhibits an easy and cheap technique for polymer surface nanostructuring. The influence of argon plasma treatment on biopolymer poly(L-lactide acid (PLLA) will be presented in this paper. The combination of Ar{sup +} ion irradiation, consequent sputter metallization (platinum) and thermal annealing of polymer surface will be summarized. The surface morphology was studied using atomic force microscopy. The Rutherford Backscattering Spectroscopy and X-ray Photoelectron Spectroscopy were used as analytical methods. The combination of plasma treatment with consequent thermal annealing and/or metal sputtering led to the change of surface morphology and its elemental ratio. The surface roughness and composition has been strongly influenced by the modification parameters and metal layer thickness. By plasma treatment of polymer surface combined with consequent annealing or metal deposition can be prepared materials applicable both in tissue engineering as cell carriers, but also in integrated circuit manufacturing.

  1. Stability of thermally induced copper precipitates under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Phythian, W J; Dumbill, S; Brown, P; Sinclair, R [AEA Technology, Harwell (United Kingdom)

    1994-12-31

    Model Fe 1.3%Cu and Fe 1.3%Cu 1.1%Ni alloys have been thermally aged at 550 C for 2 hours (peak) and 10 hours prior to irradiation at 288 C to a dose of 5.10{sup 22} n/m{sup 2}. Results of a microstructural investigation using dedicated field emission gun scanning transmission electron microscopy (FEGSTEM) and small angle neutron scattering (SANS) to assess precipitate stability in the binary alloy, are presented. These data are then used to predict a hardness change as a result of copper precipitation for comparison with the measured values obtained using standard 5 kg Vickers hardness tests on the SANS samples. Implications of these data to the re-embrittlement of the RPV by subsequent copper precipitation is discussed. (authors). 16 refs., 5 figs., 5 tabs.

  2. Carbon ion irradiation induced surface modification of polypropylene

    International Nuclear Information System (INIS)

    Saha, A.; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N.

    2001-01-01

    Polypropylene was irradiated with 12 C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x10 13 -5x10 14 ions/cm 2 using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 μm) were observed, but at higher fluence (1x10 14 ions/cm 2 ) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed

  3. Carbon ion irradiation induced surface modification of polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Saha, A. E-mail: abhijit@alpha.iuc.res.in; Chakraborty, V.; Dutta, R.K.; Chintalapudi, S.N

    2001-12-01

    Polypropylene was irradiated with {sup 12}C ions of 3.6 and 5.4 MeV energies in the fluence range of 5x10{sup 13}-5x10{sup 14} ions/cm{sup 2} using 3 MV tandem accelerator. Ion penetration was limited to a few microns and surface modifications were investigated by scanning electron microscopy. At the lowest ion fluence only blister formation of various sizes (1-6 {mu}m) were observed, but at higher fluence (1x10{sup 14} ions/cm{sup 2}) a three-dimensional network structure was found to form. A gradual degradation in the network structure was observed with further increase in the ion fluence. The dose dependence of the changes on surface morphology of polypropylene is discussed.

  4. Surgical management of irradiation-induced small bowel damage

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.T.; Seski, J.C.; Copeland, L.J.; Gershenson, D.M.; Edwards, C.L.; Herson, J.

    1985-04-01

    Seventy-seven patients, presenting with radiation small bowel injuries at the University of Texas M. D. Anderson Hospital and Tumor Institute at Houston between 1962 and 1978, were analyzed retrospectively. The patients were divided into two categories: bowel bypass without resection, and resection of irradiated bowel. Each group was then analyzed for its short- and long-term complications. Ileocolectomy with end-to-end anastomosis was the surgical procedure of choice in those people undergoing resection. There was no difference in short-term complications noted between the two groups. The long-term complications of fistula formation and continued small bowel necrosis could be prevented by resection, as a primary procedure. The surgical details of ileocolectomy with end-to-end anastomosis are presented, along with an analysis of the complications encountered in both groups.

  5. Surgical management of irradiation-induced small bowel damage

    International Nuclear Information System (INIS)

    Smith, S.T.; Seski, J.C.; Copeland, L.J.; Gershenson, D.M.; Edwards, C.L.; Herson, J.

    1985-01-01

    Seventy-seven patients, presenting with radiation small bowel injuries at the University of Texas M. D. Anderson Hospital and Tumor Institute at Houston between 1962 and 1978, were analyzed retrospectively. The patients were divided into two categories: bowel bypass without resection, and resection of irradiated bowel. Each group was then analyzed for its short- and long-term complications. Ileocolectomy with end-to-end anastomosis was the surgical procedure of choice in those people undergoing resection. There was no difference in short-term complications noted between the two groups. The long-term complications of fistula formation and continued small bowel necrosis could be prevented by resection, as a primary procedure. The surgical details of ileocolectomy with end-to-end anastomosis are presented, along with an analysis of the complications encountered in both groups

  6. Surface amorphization in Al2O3 induced by swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Okubo, N.; Ishikawa, N.; Sataka, M.; Jitsukawa, S.

    2013-01-01

    Microstructure in single crystalline Al 2 O 3 developed during irradiation by swift heavy ions has been investigated. The specimens were irradiated by Xe ions with energies from 70 to 160 MeV at ambient temperature. The fluences were in the range from 1.0 × 10 13 to 1.0 × 10 15 ions/cm 2 . After irradiations, X-ray diffractometry (XRD) measurements and cross sectional transmission electron microscope (TEM) observations were conducted. The XRD results indicate that in the initial stage of amorphization in single crystalline Al 2 O 3 , high-density S e causes the formation of new planes and disordering. The new distorted lattice planes formed in the early stage of irradiation around the fluence of 5.0 × 10 13 ions/cm 2 for single crystalline Al 2 O 3 irradiated with 160 MeV-Xe ions. Energy dependence on structural modification was also examined in single crystalline Al 2 O 3 irradiated by swift heavy ions. The XRD results indicate that the swift heavy ion irradiation causes the lattice expansion and the structural modification leading to amorphization progresses above the energy around 100 MeV in this XRD study. The TEM observations demonstrated that amorphization was induced in surface region in single crystalline Al 2 O 3 irradiated by swift heavy ions above the fluence expected from the results of XRD. Obvious boundary was observed in the cross sectional TEM images. The crystal structure of surface region above the boundary was identified to be amorphous and deeper region to be single crystal. The threshold fluence of amorphization was found to be around 1.0 × 10 14 ions/cm 2 in the case over 80 MeV swift heavy ion irradiation and the fluence did not depend on the crystal structures

  7. Surface amorphization in Al2O3 induced by swift heavy ion irradiation

    Science.gov (United States)

    Okubo, N.; Ishikawa, N.; Sataka, M.; Jitsukawa, S.

    2013-11-01

    Microstructure in single crystalline Al2O3 developed during irradiation by swift heavy ions has been investigated. The specimens were irradiated by Xe ions with energies from 70 to 160 MeV at ambient temperature. The fluences were in the range from 1.0 × 1013 to 1.0 × 1015 ions/cm2. After irradiations, X-ray diffractometry (XRD) measurements and cross sectional transmission electron microscope (TEM) observations were conducted. The XRD results indicate that in the initial stage of amorphization in single crystalline Al2O3, high-density Se causes the formation of new planes and disordering. The new distorted lattice planes formed in the early stage of irradiation around the fluence of 5.0 × 1013 ions/cm2 for single crystalline Al2O3 irradiated with 160 MeV-Xe ions. Energy dependence on structural modification was also examined in single crystalline Al2O3 irradiated by swift heavy ions. The XRD results indicate that the swift heavy ion irradiation causes the lattice expansion and the structural modification leading to amorphization progresses above the energy around 100 MeV in this XRD study. The TEM observations demonstrated that amorphization was induced in surface region in single crystalline Al2O3 irradiated by swift heavy ions above the fluence expected from the results of XRD. Obvious boundary was observed in the cross sectional TEM images. The crystal structure of surface region above the boundary was identified to be amorphous and deeper region to be single crystal. The threshold fluence of amorphization was found to be around 1.0 × 1014 ions/cm2 in the case over 80 MeV swift heavy ion irradiation and the fluence did not depend on the crystal structures.

  8. Apoptosis-promoted tumorigenesis: γ-irradiation-induced thymic lymphomagenesis requires Puma-driven leukocyte death

    OpenAIRE

    Michalak, Ewa M.; Vandenberg, Cassandra J.; Delbridge, Alex R.D.; Wu, Li; Scott, Clare L.; Adams, Jerry M.; Strasser, Andreas

    2010-01-01

    Although tumor development requires impaired apoptosis, we describe a novel paradigm of apoptosis-dependent tumorigenesis. Because DNA damage triggers apoptosis through p53-mediated induction of BH3-only proteins Puma and Noxa, we explored their roles in γ-radiation-induced thymic lymphomagenesis. Surprisingly, whereas Noxa loss accelerated it, Puma loss ablated tumorigenesis. Tumor suppression by Puma deficiency reflected its protection of leukocytes from γ-irradiation-induced death, because...

  9. Coordination defects in vitreous As2S3 induced by γ-irradiation

    International Nuclear Information System (INIS)

    Shpotyuk, O.; Balitska, V.

    1997-01-01

    Destruction-polymerization transformations in vitreous As 2 S 3 , associated with coordination defects formation process induced by γ-irradiation, were studied by the IR Fourier Spectroscopy method in the region of 400-100 cm -1 . All topological variants of these processes, statistically possible in the investigated samples, were taken into account for physical consideration of the real structural changes. (author)

  10. A case of irradiation-induced malignant fibrous histiocytoma after an operation for rectal cancer

    International Nuclear Information System (INIS)

    Tahara, Hiroyuki; Kuroda, Yoshinori; Kuranishi, Fumito; Toyota, Kazuhiro; Nakahara Masahiro

    2004-01-01

    We recently observed a case of presumed irradiation-induced malignant fibrous histiocytoma (MFH), which developed 11 years after postoperative chemoradiotherapy for residual rectal cancer. A 65-year-old female underwent chemoradiotherapy for the residual tumor on the sacrum after abdominoperineal resection for rectal cancer in 1991. She showed no evidence of local recurrence or distant metastasis. Biopsy and MRI in 2002 suggested a retroperitoneal malignant tumor associated with invasion of the uterus and the sacrum, and the patient subsequently underwent surgery. Histopathologically the tumor was MFH. This case was considered to be an irradiation-induced secondary malignant tumor, according to the criteria developed by Arlen et al. In elderly patients and cases that underwent chemoradiotherapy, the latency period of irradiation-induced secondary malignant tumor tends to be shorter. If the progress of postoperative adjuvant chemotherapy increases the number of long-term surviving cases in the future, the incidence of irradiation-induced secondary malignant tumor will increase. It is therefore necessary to survey these cases over a longer period of time after surgery. (author)

  11. Screening and identification of respiration deficiency mutants of yeasts (Saccharomyces Cerevisiae) induced by heavy ion irradiation

    International Nuclear Information System (INIS)

    Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei; Zhang Hong

    2006-01-01

    A screen of respiration deficiency mutants of Saccharomyces Cerevisiae induced by 5.19 MeV/u 22 Ne 5- ion irradiation is studied. Some respiration deficiency mutants, which are white colony phenotype in the selective culture of TTC medium, are obtained. The mutants are effectively identified by means of a new and simplified restriction analysis method. (authors)

  12. Flux pinning by heavy-ion-irradiation induced linear defects in YBa2Cu3O7 epitaxial films

    International Nuclear Information System (INIS)

    Budhani, R.C.; Zhu, Y.; Suenaga, M.

    1992-01-01

    We report some transport measurements carried out to study flux pinning by heavy-ion-irradiation induced linear defects in Y 1 Ba 2 Cu 3 O 7 films. Our results show that in these in situ deposited films containing a large concentration of defects frozen-in at the time of film growth, a marginal enhancement in critical current density occurs when the density of linear defects 10 /cm 2 , and their diameter of the order of coherence length. This criterion is satisfied by Ag +21 ions. The damage due to Au +24 ions is much too severe to improve the J c

  13. Yield improvement in barley by using gamma-irradiation

    International Nuclear Information System (INIS)

    Benamer, Ibrahim Mohammed

    1990-01-01

    Breeding work for barley improvement in Libya is very rare. All varieties grown here are foreign varieties. Yield per hectare is low compared with other countries having similar climatic conditions. Productivity, lodging, disease resistance, drought and salt tolerance are the main characteristics that need to be improved. A mutation breeding programme for barley improvement was initiated at the Tajoura Nuclear Research Centre in 1983-1984. The objectives of this programme are the development of new lines that could be used directly or indirectly in the development of new varieties. The locally adapted barley (Hordeum vulgare L.) variety ''California Mariout'' was used as a parent material. Grains with 14% moisture were exposed to 200 Gy gamma-ray from 60 Co source at the Centre. Three experiments were conducted during 1986-1989. From the first experiment (1986-1987), 62 mutant lines were evaluated. From the second and third experiments (1987-1989), only seven mutant lines were evaluated. In the 1988-1989 experiment, the crop was irrigated and fertilised with 0, 100 and 200 kgN/ha. Lodging score was low in 0 kgN/ha and increased significantly by the increase in N level. None of the mutant lines more lodging resistant than the parent or the control. However, yield differences were significant and the application of 100 kgN/ha increased the grain yield

  14. Dosimetric improvements following 3D planning of tangential breast irradiation

    International Nuclear Information System (INIS)

    Aref, Amr; Thornton, Dale; Youssef, Emad; He, Tony; Tekyi-Mensah, Samuel; Denton, Lori; Ezzell, Gary

    2000-01-01

    Purpose: To evaluate the dosimetric difference between a simple radiation therapy plan utilizing a single contour and a more complex three-dimensional (3D) plan utilizing multiple contours, lung inhomogeneity correction, and dose-based compensators. Methods and Materials: This is a study of the radiation therapy (RT) plans of 85 patients with early breast cancer. All patients were considered for breast-conserving management and treated by conventional tangential fields technique. Two plans were generated for each patient. The first RT plan was based on a single contour taken at the central axis and utilized two wedges. The second RT plan was generated by using the 3D planning system to design dose-based compensators after lung inhomogeneity correction had been made. The endpoints of the study were the comparison between the volumes receiving greater than 105% and greater than 110% of the reference dose, as well as the magnitude of the treated volume maximum dose. Dosimetric improvement was defined to be of significant value if the volume receiving > 105% of one plan was reduced by at least 50% with the absolute difference between the volumes being 5% or greater. The dosimetric improvements in 49 3D plans (58%) were considered of significant value. Patients' field separation and breast size did not predict the magnitude of improvement in dosimetry. Conclusion: Dose-based compensator plans significantly reduced the volumes receiving > 105%, >110%, and volume maximum dose.

  15. A case of congestive heart failure induced by therapeutic irradiation

    International Nuclear Information System (INIS)

    Kushigami, Motohiko; Suruda, Hidetoshi; Mizukoshi, Masato; Umemoto, Masaaki; Fujiwara, Setsuko; Yamamoto, Katsuhiro; Ueno, Yuji; Nishio, Ichiro; Masuyama, Yoshiaki

    1985-01-01

    Valvular insufficiency in radiation-induced heart disease is very rare. We described a patient, 53 years old woman, who developed congestive heart failure 2.5 years later following radiotherapy for esophageal carcinoma. The findings on examinations including cardiac catheterization revealed pericarditis with effusion, mitral and tricuspid valve insufficiency and pulmonary infarction. (author)

  16. Case of congestive heart failure induced by therapeutic irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kushigami, Motohiko; Suruda, Hidetoshi; Mizukoshi, Masato; Umemoto, Masaaki; Fujiwara, Setsuko; Yamamoto, Katsuhiro; Ueno, Yuji; Nishio, Ichiro; Masuyama, Yoshiaki

    1985-02-01

    Valvular insufficiency in radiation-induced heart disease is very rare. We described a patient, 53 years old woman, who developed congestive heart failure 2.5 years later following radiotherapy for esophageal carcinoma. The findings on examinations including cardiac catheterization revealed pericarditis with effusion, mitral and tricuspid valve insufficiency and pulmonary infarction. (author).

  17. Man bhawan - new chrysanthemum cultivar induced by gamma irradiation

    International Nuclear Information System (INIS)

    Datta, S.K.

    1987-01-01

    Attempts were made to find out the biochemical difference between two gamma ray induced chrysanthemum cultivars, 'Flirt' and 'Man Bhawan' by thin layer chromatographic and spectrophotometric analysis of pigments. The analysis were done from florets extracts of original cv., 'Flirt' and mutant 'Man Bhawan' at full bloom stage and also at fading of 'Man Bhawan'. (author)

  18. High-dose irradiation induces cell cycle arrest, apoptosis, and developmental defects during Drosophila oogenesis.

    Directory of Open Access Journals (Sweden)

    Hee Jin Shim

    Full Text Available Ionizing radiation (IR treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis.

  19. Color improvement by irradiation of Curcuma aromatica extract for industrial application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Kyung [Radiation Food Science and Biotechnology Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup 580-185 (Korea, Republic of); Jo, Cheorun [Radiation Food Science and Biotechnology Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup 580-185 (Korea, Republic of); Hwang, Han Joon [Graduate School of Biotechnology, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Park, Hyun Jin [Graduate School of Biotechnology, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Kim, Young Ji [Division of Food Beverage and Culinary Arts, Younganm College of Science and Technology, Daegu 705-703 (Korea, Republic of); Byun, Myung Woo [Radiation Food Science and Biotechnology Team, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup 580-185 (Korea, Republic of)]. E-mail: mwbyun@kaeri.re.kr

    2006-03-15

    Curcuma species are medicinal herbs with various pharmacological activities. They have a characteristic yellow color and contain curcuminoids which are natural antioxidants. In this study, Curcuma aromatica (Canada) and Curcuma longa (CL) extracts were gamma-irradiated for improving the color, and the irradiation effects on the curcuminoids contents in CA and CL extracts were determined in order to evaluate if CA can replace CL on the market, where the price of CA is 70% lower than the price of CL. The Hunter color L*-values were increased significantly in all the samples with increasing dose, while the a*-values and b*-values decreased, which implies that the color of the CA and CL extracts changed from dark yellow to brighter yellow. Curcuminoids contents of all the samples were evaluated, and CA contains more curcuminoids than CL. These results indicated that irradiation improved the properties of CA for possible industrial use in manufacturing food and cosmetic industrial products.

  20. Color improvement by irradiation of Curcuma aromatica extract for industrial application

    International Nuclear Information System (INIS)

    Kim, Jae Kyung; Jo, Cheorun; Hwang, Han Joon; Park, Hyun Jin; Kim, Young Ji; Byun, Myung Woo

    2006-01-01

    Curcuma species are medicinal herbs with various pharmacological activities. They have a characteristic yellow color and contain curcuminoids which are natural antioxidants. In this study, Curcuma aromatica (Canada) and Curcuma longa (CL) extracts were gamma-irradiated for improving the color, and the irradiation effects on the curcuminoids contents in CA and CL extracts were determined in order to evaluate if CA can replace CL on the market, where the price of CA is 70% lower than the price of CL. The Hunter color L*-values were increased significantly in all the samples with increasing dose, while the a*-values and b*-values decreased, which implies that the color of the CA and CL extracts changed from dark yellow to brighter yellow. Curcuminoids contents of all the samples were evaluated, and CA contains more curcuminoids than CL. These results indicated that irradiation improved the properties of CA for possible industrial use in manufacturing food and cosmetic industrial products

  1. Color improvement by irradiation of Curcuma aromatica extract for industrial application

    Science.gov (United States)

    Kim, Jae Kyung; Jo, Cheorun; Hwang, Han Joon; Park, Hyun Jin; Kim, Young Ji; Byun, Myung Woo

    2006-03-01

    Curcuma species are medicinal herbs with various pharmacological activities. They have a characteristic yellow color and contain curcuminoids which are natural antioxidants. In this study, Curcuma aromatica (CA) and Curcuma longa (CL) extracts were gamma-irradiated for improving the color, and the irradiation effects on the curcuminoids contents in CA and CL extracts were determined in order to evaluate if CA can replace CL on the market, where the price of CA is 70% lower than the price of CL. The Hunter color L*-values were increased significantly in all the samples with increasing dose, while the a*-values and b*-values decreased, which implies that the color of the CA and CL extracts changed from dark yellow to brighter yellow. Curcuminoids contents of all the samples were evaluated, and CA contains more curcuminoids than CL. These results indicated that irradiation improved the properties of CA for possible industrial use in manufacturing food and cosmetic industrial products.

  2. Use of irradiation in combination with other treatments to improve the quality of precooked meals

    International Nuclear Information System (INIS)

    Desmonts, M.H.; Pierrat, N.; Ingersheim, A.; Strasser, A.; Hasselmann, C.

    1998-01-01

    Two different studies on the improvement in quality of precooked meals are presented. The microbiological, nutritional and organoleptic qualities of air packed, electron beam irradiated salmon pats were examined during a 42 day storage period at refrigeration temperature. The vitamin contents, although diminished, especially for retinol and α-tocopherol, were still appreciable. No lipid oxidation was detected. Under French legislation, the shelf-life of fresh precooked dishes should not exceed 6 days. In contrast, salmon pats irradiated at 2.5 and 6 kGy had a shelf-life of 11 and 23 days, respectively, at 4 deg. C. Electron beam irradiated precooked meals destined for immunosuppressed patients were also studied. The effects of low temperature (-40 deg. C) electron beam irradiation at doses ranging between 12 and 40 kGy, combined with vacuum packaging, on the bacteriological (sterility), nutritional (lipid oxidation, vitamin losses) and organoleptic qualities of selected precooked meals were investigated. All the meals remained sterile, even after 11 months of storage at 4 deg. C. Strict hygienic conditions were maintained during their preparation. The irradiated meals, which consisted of duck with orange sauce, chicken, salmon and while fish, fried potatoes, stuffed pancakes, rice with currants, and mashed potatoes and carrots, all showed good organoleptic qualities. Off-odour and off-flavour were detected only in the irradiated fried potatoes, which were rejected because of their soft texture. It is suggested that those meals that are organoleptically better than autoclaved foods could be proposed for immunosuppressed patients. (author)

  3. Improving the Hygienic Quality and Shelf-Life of Minced Common Carp Fish by Gamma Irradiation

    International Nuclear Information System (INIS)

    El-Khawas, Kh.H.; Fawzia, M.; El-Nashaby; Abd El-daim, M.H.

    1999-01-01

    This investigation aimed to improve the hygienic quality and extend cold storage life of minced carp fish by gamma irradiation. The frozen samples were gamma irradiation at 0, 2, 4 and 6 kGy doses and the effects of these treatments on the chemical properties, microbiological aspects and sensory properties were studied post treatments and during cold storage. Irradiation of samples at doses of 2, 4 and 6 kGy greatly reduced its microbial counts and prolonged its shelf-life for 2, 4, and 6 weeks at 4 ±degree, respectively against only 3 days for control samples. Moreover, 4 kGy dose completely destroyed Staph aureus. The chemical composition of samples did not alter neither by γirradiation treatments nor by cold storage. Furthermore, irradiation treatments had no effects on pH-value, TVBN and TMA contents, while a gradual increase in these chemical quality indexes was observed during cold storage. However, both irradiation treatments and cold storage increased the TBA value

  4. Fe+ ion irradiation induced changes in structural and magnetic properties of iron films

    Directory of Open Access Journals (Sweden)

    K. Papamihail

    2016-12-01

    Full Text Available 490keV Fe+ ion irradiation of 200nm thick Fe films was found to induce both structural and magnetic changes. Both, the lattice constant and the grain size increase as a function of dose and both properties follow the same power law. Irradiation induces a depth dependent magnetic profile consisting of two sublayers. The top Fe sublayer has a magnetic moment higher than that of the Fe before the irradiation whereas the bottom sublayer lower. The two sublayers are connected with the effects of Fe+ irradiation, i.e. the top sublayer with the depth in which mainly radiation damage occurs whereas the bottom one with the implantation of impinging Fe+ ions. The magnetic moments of the two sublayers have a non-monotonous variation with irradiation dose depicting a maximum for the top sublayer and a minimum for the bottom one at 96.2 dpa (‘displacements per atom’. The magnetic moment enhancement/reduction is discussed in relation with the atomic volume variation in the case of atom displacements and/or implantation effects.

  5. Improvement of wood quality used in Syria by irradiation polymerization

    International Nuclear Information System (INIS)

    Bakarji, E. H.

    2002-06-01

    Wood plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, and with Okoume (aucoumea klaineana pierre) imported to Syria in large quantities. Three monomer systems; acrylamide, butylmethacrylate, and styrene were used. polymerization was induced at various radiation doses (10, 20, and 30 kGy) to study the role of radiation doses using a 60 Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength or tensile strength of the obtained wood polymer composites (WPC) were studied. The effect of the additives, sulfuric acid (H + ), N-vinyl pyrrolidone (NVP), trimethyolpropane triacrylate (TMPTA), urea (U), lithium nitrate (LiNo 3 ), copper sulfate (CuSO 4 ) and co-additives on monomer system polymerization were also investigated. Methanol, water and water/methanol mixtures were used as the swelling agents. In general, the use of additives and co-additives brought about an enhancement of tensile strength or compression strength and polymer loading of the composites. In some cases, additives also lowered the monomer concentration and the gamma radiation dose required for polymerization (author)

  6. Various categories of defects after surface alloying induced by high current pulsed electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Dian [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Tang, Guangze, E-mail: oaktang@hit.edu.cn [School of Material Science & Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Xinxin [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Gu, Le [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Sun, Mingren [School of Material Science & Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2015-10-01

    Highlights: • Four kinds of defects are found during surface alloying by high current electron beam. • Exploring the mechanism how these defects appear after irradiation. • Increasing pulsing cycles will help to get good surface quality. • Choosing proper energy density will increase surface quality. - Abstract: High current pulsed electron beam (HCPEB) is an attractive advanced materials processing method which could highly increase the mechanical properties and corrosion resistance. However, how to eliminate different kinds of defects during irradiation by HCPEB especially in condition of adding new elements is a challenging task. In the present research, the titanium and TaNb-TiW composite films was deposited on the carburizing steel (SAE9310 steel) by DC magnetron sputtering before irradiation. The process of surface alloying was induced by HCPEB with pulse duration of 2.5 μs and energy density ranging from 3 to 9 J/cm{sup 2}. Investigation of the microstructure indicated that there were several forms of defects after irradiation, such as surface unwetting, surface eruption, micro-cracks and layering. How the defects formed was explained by the results of electron microscopy and energy dispersive spectroscopy. The results also revealed that proper energy density (∼6 J/cm{sup 2}) and multi-number of irradiation (≥50 times) contributed to high quality of alloyed layers after irradiation.

  7. Effect of immunomodifier on radiation-induced antitumor immunity following local irradiation to tumor, 2

    International Nuclear Information System (INIS)

    Mukae, Shiro; Norimura, Toshiyuki; Tsuchiya, Takehiko

    1988-01-01

    This study was carried out to clarify whether or not the antitumor cell-mediated immunity of host is more effectively induced by the combined use of mouse interferon-α/β (MuIFN-α/β) with local irradiation than by simple local irradiation to tumor. C3H/He female mice, MM46 tumor cells and mouse interferon-α/β (MuIFN-α/β) were used in the experiment. Antitumor activity in mice was evaluated by the inhibition of tumor growth and mean survival days after treatment. Spleen cell killing activity to MM46 tumor cells was measured to evaluate the antitumor activity in vitro. In the case of single use of MuIFN-α/β, tumor growth was more rapid than in the non-treated group (control) in vivo. The mean survival days were also reduced. There was no siginificant difference in tumor growth inhibition between combined therapy using X-irradiation and MuIFN-α/β, and single therapy by local irradiation. However, in the case of administration of MuIFN-α/β after irradiation, the mean survival days was significantly increased compared with the group receiving X-ray irradiation only. (author)

  8. Resistance to reinfection in rats induced by irradiated metacercariae of Clonorchis sinensis

    Directory of Open Access Journals (Sweden)

    Fu Shi Quan

    2005-08-01

    Full Text Available A study was made to observe the association between the resistance to reinfection induced by irradiated metacercariae (MC of Clonorchis sinensis and antigen specific Th1- and Th2-type cytokine productions in rats. Rats were infected with 20 MC of C. sinensis, previously exposed to a single dose of gamma irradiation, which varied from 0 to 100 Gy. All of them, single dose of 12 Gy showed higher IgG antibody titer with lowest worm recovery. Thus, 50 MC were used to challenge infection in rats previously infected with 20 MC irradiated at 12 Gy and the highest resistance to challenge infection was observed. The results of lymphocyte proliferation with specific antigen, ES Ag were shown no difference of proliferative responses as compared with primary and challenge infection at 12 Gy irradiation dose. In the case of cytokines production were observed that interferon (IFN-gamma and interlukin (IL-2 were significantly enhanced, while IL-4 and IL-10 was almost unchanged to make comparison between primary and secondary infection at 12 Gy irradiation dose. In conclusion, the single dose of 12 Gy could be adopted for induction of the highest resistance to challenge infection. Up-regulation of Th1 type cytokines, IFN-gamma and IL-2 may be affected to develop vaccine by irradiated MC.

  9. Continuous in-situ measurements of fission fragment irradiation induced void swelling in Ni

    International Nuclear Information System (INIS)

    Lefakis, H.

    1980-01-01

    A novel simulation technique has been developed to study the early stages of irradiation induced void formation in metals. The technique makes use of fission fragment irradiation produced by doping with 235 U and irradiating in a thermal neutron flux under highly controlled irradiation-environmental conditions. Employment of a computer and a high temperature radiation resistant LVDT resulted in a high volumetric sensitivity and the production of continuous, in-situ void swelling data for bulk specimens. Results for Ni, used as a test-metal served to corroborate the technique in a number of ways including comparisons with (a) reactor data, (b) direct post-irradiation specimen length measurements and (c) TEM examinations of irradiated samples. The technique has several unique advantages and, in conjunction with other conventional methods, it offers the possibility of detailed evaluation of void nucleation and growth theories. In view of the present results no definitive answer may be given on the issue of the incubation period while checks with two theoretical models have yielded an order-of-magnitude agreement

  10. Analysis of behavioural changes induced by prenatal irradiation

    International Nuclear Information System (INIS)

    Bornhausen, M.

    1986-01-01

    Two experiments were carried out to detect an impairment of central nervous system functions after prenatal exposure to ionizing radiation. Groups of rats (Wistar) were either irradiated in-utero on the 13th day of gestation with doses of 0.15, 0.30, 0.60 or 0,90 Gy or on days 11, 13 or 16 p.c. with a dose of 0.60 Gy (Cs 137, 1.0 Gy/min). When adult all animals were confronted with a series of standardized tests of operant, instrumental behaviour in which they were required to press a lever for food reward. The contingencies of reinforcement and the data collection from 10 simultaneously operating test chambers were controlled by a microcomputer. The behavioural performance of each exposure group (n=10) and its course during the tests were expressed as percentages of reinforced lever presses/session and compared to other biological, especially weight changes. The analysis of the experimental data obtained so far indicate that the observed performance deficits depended more on the exposure date than on the exposure dose. (orig.)

  11. Irradiation induced tensile property change of SA 508 Cl. 3 reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Chi, Se Hwan; Hong, Jun Hwa; Kuk, Il Hiun

    1998-01-01

    Irradiation induced tensile property change of four kinds of reactor pressure vessel steels manufactured by different steel refining process was compared based on the differences in the miniature tensile specimen tests were conducted for mechanical property measurement and optical microscope (OM) and transmission electron microscope (TEM) were used for microstructural characterization. Specimens were irradiated to a neutron fluence of 2.7 x 10 19 n/cm 2 (E ≥ 1 MeV) at 288 deg C. Investigation on the unirradiated microstructures showed largely a same microstructure in that tempered acicular bainite and ferrite with bainitic phase prevailing in the unirradiated condition. Ban-shaped segregations were also clearly observed except a kind of materials. A large difference in the unirradiated microstructure appeared in the grain size and carbide microstructure. Of carbide microstructures, noticeable differences were observed in the size and distribution of cementite, and bainitic lath microstructures. No noticeable changes were observed in the optical and thin film TEM microstructures after irradiation. Complicated microstructural state of heat treated bainitic low alloy microstructure prevents easy quantification of microstructural changes due to irradiation. Apparent differences, however, were observed in the results of mechanical testing. Results of tensile testing and hardness measurement show that a steel refined by vacuum carbon deoxidation (VCD) method exhibits the highest radiation hardening behavior. Some of mechanical testing results on irradiated materials were possible to understand based on the initial microstructure, but further investigations using a wide array of sophisticated tools (for example, SANS, APFIM) are required to understand and characterize irradiation induced defects that are responsible for irradiation hardening behavior but are not revealed by conventional TEM. (author)

  12. Gamma radiation induced mutant for improved yield components in sunflower

    International Nuclear Information System (INIS)

    Elangovan, M.

    2001-01-01

    Sunflower has become an important oilseed in the Indian vegetable oil pool following its introduction from Russia in 1969. It can be used for all quality products useful to humans. The need for genetic variability and new useful gene sources has necessitated that sunflower breeders and geneticists utilize a wide range of germplasm in their breeding programmes. The induction of mutations in sunflower by physical and chemical mutagens has been practiced quite intensively in the last two decades. The results recorded to date suggest that utilization of mutagenesis could be a great advantage in improving the sunflower crop. An induced mutation programme was undertaken to generate variability in the variety 'Morden' using gamma rays. The certified and genetically pure seeds were irradiated with 50, 100, and 150 Gy gamma rays and used for further studies. Selection in M 2 generations, raised from different treatments, revealed the presence of an erectophylly leaf mutant from 50 Gy treatment. The isolated mutant showed improved yield components like head diameter, 100- seed weight and yield per plant. The mutant was a plant with short petiole length and erect leaves. This type of leaf get sunlight throughout the day. From morning to afternoon, the first half of the leaf gets sunlight, and from afternoon to evening the second half of the leaf gets sunlight. As a result of getting sunlight the whole day, the plant had more photosynthetic products and grew vigorously. Plant height, head diameter and 100-seed weight had direct effect on seed yield, and the number of leaves and stem diameter influenced the seed yield indirectly. In the M 3 generation, the mutant showed an almost two-fold increase over the parent variety for all investigated characters, except that of the yield per plant where there was a three-fold increase. The present investigation has shown that there are remarkable possibilities of increasing the yield components in sunflower by induced mutations

  13. The impact of irradiation induced specimen charging on microanalysis in a scanning electron microscope

    International Nuclear Information System (INIS)

    Stevens-Kalceff, M.A.

    2003-01-01

    Full text: It is necessary to assess and characterize the perturbing influences of experimental probes on the specimens under investigation. The significant influence of electron beam irradiation on poorly conducting materials has been assessed by a combination of specialized analytical scanning electron and scanning probe microscopy techniques including Cathodoluminescence Microanalysis and Kelvin Probe Microscopy. These techniques enable the defect structure and the residual charging of materials to be characterized at high spatial resolution. Cathodoluminescence is the non-incandescent emission of light resulting from the electron irradiation. CL microscopy and spectroscopy in a Scanning Electron Microscope (SEM) enables high spatial resolution and high sensitivity detection of defects in poorly conducting materials. Local variations in the distribution of defects can be non-destructively characterized with high spatial (lateral and depth) resolution by adjusting electron beam parameters to select the specimen micro-volume of interest. Kelvin Probe Microscopy (KPM) is a Scanning Probe Microscopy technique in which long-range Coulomb forces between a conductive atomic force probe and the specimen enable the surface potential to be characterized with high spatial resolution. A combination of Kelvin Probe Microscopy (KPM) and Cathodoluminescence (CL) microanalysis has been used to characterize ultra pure silicon dioxide exposed to electron irradiation in a Scanning Electron Microscope. Silicon dioxide is an excellent model specimen with which to investigate charging induced effects. It is a very poor electrical conductor, homogeneous and electron irradiation produces easily identifiable surface modification which enables irradiated regions to be easily and unambiguously located. A conductive grounded coating is typically applied to poorly conducting specimens prior to investigation in an SEM to prevent deflection of the electron beam and surface charging, however

  14. Caffeine and Aspirin Protecting Albino Rats A gainst Biochemical and Histological Disorders Induced by Whole Body Gamma Irradiation

    International Nuclear Information System (INIS)

    Abd El-Rahman, N.A.; Sherif, N.H.

    2015-01-01

    increase in the content of thiobarbituric acid reactive substances (TBARS) associated with a significant decrease in glutathione (GSH) content, superoxide dismutase (SOD), and catalase (CAT) activities indicating oxidative stress. In addition, radiation caused inflammatory, fibrotic and cellular damage to the intestine and stomach. A demonstration of caffeine and aspirin resulted in significant improvement in hepatic and renal functions associated with reduction in oxidative stress and amelioration of the histological changes caused by gamma irradiation. It could be concluded that the antioxidant properties of caffeine and aspirin might modulate γ-radiation-induced oxidative stress and histological disorders

  15. Incidence and nature of tumors induced in Sprague-Dawley rats by gamma-irradiation

    International Nuclear Information System (INIS)

    Gross, L.; Dreyfuss, Y.; Faraggiana, T.

    1988-01-01

    In our previous studies carried out on inbred rats of the Sprague-Dawley strain, the tumor incidence was increased following irradiation (150 rads, 5 times, at weekly intervals), from 22 to 93% in females and from 5 to 59% in males. Experiments here reported suggest that 2 consecutive total-body gamma-irradiations of 150 rads each are sufficient to induce in rats the development of tumors, some malignant; 18 of 19 females (94.7%) developed tumors at an average age of 11.4 mo, and seven of the 14 males in this group (50%) developed tumors at an average age of 10.4 mo. In the second group, which received 3 consecutive gamma-irradiations, 20 of 23 females (86.9%) and 5 of 13 males (38.4%) developed tumors at average ages of 9.1 and 7.5 mo, respectively. In the third group, among rats which received 4 consecutive gamma-irradiations, 17 of 19 females (89.4%) and 4 of 12 males (33.3%) developed tumors at average ages of 9.4 and 10.5 mo, respectively. The etiology of tumors either developing spontaneously or induced by irradiation in rats remains to be clarified. Our attempts to detect virus particles by electron microscopy in such tumors or lymphomas have not been successful. As a working hypothesis, we are tempted to theorize that tumors or lymphomas developing spontaneously or induced by gamma irradiation in rats are caused by latent viral agents which are integrated into the cell genome and are cell associated, i.e., not separable from the rat tumor cells by conventional methods thus far used

  16. Ultrasonic irradiation and its application for improving the corrosion resistance of phosphate coatings on aluminum alloys.

    Science.gov (United States)

    Sheng, Minqi; Wang, Chao; Zhong, Qingdong; Wei, Yinyin; Wang, Yi

    2010-01-01

    In this paper, ultrasonic irradiation was utilized for improving the corrosion resistance of phosphate coatings on aluminum alloys. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The effect of ultrasonic irradiation on the corrosion resistance of phosphate coatings was investigated by polarization curves and electrochemical impedance spectroscopy (EIS). Various effects of the addition of Nd(2)O(3) in phosphating bath on the performance of the coatings were also investigated. Results show that the composition of phosphate coating were Zn(3)(PO(4))(2).4H(2)O(hopeite) and Zn crystals. The phosphate coatings became denser with fewer microscopic holes by utilizing ultrasonic irradiation treatment. The addition of Nd(2)O(3) reduced the crystallinity of the coatings, with the additional result that the crystallites were increasingly nubby and spherical. The corrosion resistance of the coatings was also significantly improved by ultrasonic irradiation treatment; both the anodic and cathodic processes of corrosion taking place on the aluminum alloy substrate were suppressed consequently. In addition, the electrochemical impedance of the coatings was also increased by utilizing ultrasonic irradiation treatment compared with traditional treatment.

  17. Improved Extraction and Quality Characterization of Water-Soluble Polysaccharide from Gamma-Irradiated Lentinus edodes.

    Science.gov (United States)

    Akram, Kashif; Shahbaz, Hafiz Muhammad; Kim, Gui-Ran; Farooq, Umar; Kwon, Joong-Ho

    2017-02-01

    Gamma irradiation was applied to the improved extraction of water-soluble polysaccharides (WSPs) from dried Lentinus edodes. Irradiation provided a dose-dependent increase in extraction yield (0 kGy, 2.01%; 7.5 kGy, 4.03%; 15 kGy, 7.17%) and purity (0 kGy, 78.8%; 7.5 kGy, 83.1%; 15 kGy, 85.6%) of the WSPs from hot-water extraction. The effect of irradiation was evident in the degraded microstructures and reduced molecular weights of the WSPs. However, nuclear magnetic resonance, Fourier-transform infrared, and X-ray diffraction spectroscopic analyses provided comparable structures of WSPs from nonirradiated and irradiated samples. UV-visible spectra showed a dose-dependent decline in intensity, but an improvement in thermal properties of the WSPs from the irradiated mushroom samples was observed. © 2017 Institute of Food Technologists®.

  18. Genomic instability induced by 137Cs γ-ray irradiation in CHL surviving cells

    International Nuclear Information System (INIS)

    Yue Jingyin; Liu Bingchen; Wu Hongying; Zhou Jiwen; Mu Chuanjie

    1999-01-01

    Objective: To study in parallel several possible manifestations of instability of surviving CHL cells after irradiation, namely the frequencies of mutation at locus, micronuclei and apoptosis. Methods: The frequencies of mutation at HGPRT locus, micronuclei and apoptosis were assayed at various times in surviving cells irradiated with γ-rays. Results: The surviving cells showed a persistently increased frequency of mutation at the HGPRT locus after irradiation until 53 days. Mutant fraction as high as 10 -4 was scored, tens of times higher than those assayed in control cells studied in parallel. The frequency of bi nucleated cells with micronuclei determined within 24 hours after irradiation increased with dose and reached a peak value of (26.58 +- 2.48)% at 3 Gy, decreasing at higher doses to a plateau around 20%. The micronucleus frequency decreased steeply to about (14.47 +- 2.39)% within the first 3 days post-irradiation, and fluctuated at around 10% up to 56 days post-irradiation. The delayed efficiency of irradiated cells was significantly decreased. The frequency of apoptosis peaked about (24.90 +- 4.72)% at 10 Gy 48 h post-irradiation (γ-ray dose between 3-10 Gy) and then decreased to about 12% within 3 days. It was significantly higher than in control cells until 14 days. Conclusions: It shows that genomic instability induced by radiation can be transmitted to the progeny of surviving cells and may take many forms of expression such as lethal mutation, chromosome aberrations, gene mutation, etc

  19. Modifications induced by gamma irradiation to Makrofol polymer nuclear track detector

    Directory of Open Access Journals (Sweden)

    A. Tayel

    2015-03-01

    Full Text Available The aim of the present study was extended from obtaining information about the interaction of gamma rays with Makrofol DE 7-2 track detector to introduce the basis that can be used in concerning simple sensor for gamma irradiation and bio-engineering applications. Makrofol polymer samples were irradiated with 1.25 MeV 60Co gamma radiations at doses ranging from 20 to 1000 kG y. The modifications of irradiated samples so induced were analyzed using UV–vis spectrometry, photoluminescence spectroscopy, and the measurements of Vickers’ hardness. Moreover, the change in wettability of irradiated Makrofol was investigated by the contact angle determination of the distilled water. UV–vis spectroscopy shows a noticeable decrease in the energy band gap due to gamma irradiation. This decrease could be attributed to the appearance of a shift to UV spectra toward higher wavelength region after irradiation. Photoluminescence spectra reveal a remarkable change in the integrated photoluminescence intensity with increasing gamma doses, which may be resulted from some matrix disorder through the creation of some defected states in the irradiated polymer. The hardness was found to increase from 4.78 MPa for the unirradiated sample to 23.67 MPa for the highest gamma dose. The contact angle investigations show that the wettability of the modified samples increases with increasing the gamma doses. The result obtained from present investigation furnishes evidence that the gamma irradiations are a successful technique to modify the Makrofol DE 7-2 polymer properties to use it in suitable applications.

  20. Search for the lowest irradiation dose from literatures on radiation-induced cancer in gastrointestinal tract

    International Nuclear Information System (INIS)

    Yoshizawa, Yasuo; Kusama, Tomoko

    1976-01-01

    A survey of past case reports about radiation-induced cancer in the gastrointestinal tract was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1923 revealed 80 cases of radiation-induced large intestine cancer and one case of stomach cancer. The cases of radiation-induced cancer in the large intestine had received radiation for the treatment of non-malignant conditions, fibroma, ovarial cyste, myoma, endometritis and duodenal ulcer. The lowest irradiation dose was estimated at 460 rads. Adenocarcinoma was the histopathological finding in all cases of radiation-induced cancer in the caecum, colon and rectum, and squamous cell carcinoma in the cases of anal cancer. The latent period ranged from 1 to 31 years, with the average of 13.6 years. There were some reports of statistical studies of radiation-induced stomach cancer. Three groups were the subjects of these studies. The first group was composed of atomic bomb survivors, the second of patients who had undergone radiation treatment for ankylosing spondilitis, and the third of duodenal ulcer patients subjected to radiation treatment for the purpose of suppressing gastric acid secretion. These statistical studies showed no significant increase of the incidence of stomach cancer in the irradiated groups. (auth.)

  1. Ultraviolet B irradiation of human leukaemia HL-60 cells in vitro induces apoptosis

    International Nuclear Information System (INIS)

    Martin, S.J.; Cotter, T.G.

    1991-01-01

    UV radiation is known to be a potent agent for the induction of programmed cell death (apoptosis) in human skin. However, the mechanistic aspects of UV-induced apoptosis remain ill-defined. In this study the effects of varying periods of UV-irradiation on the human leukaemia HL-60 cell line and on five other human cell lines were investigated.HL-60 cells were found to rapidly undergo apoptosis en masse after short periods of UV-irradiation whereas prolonged exposure of these cells to this form of radiation induced a more rapid form of cell death which was suggestive of necrosis, the pathological mode of cell death. UV-induced apoptosis in cell lines was characterized by morphological changes as well as DNA fragmentation into unit multiples of ∼ 200 bp, which was indicative of endogenous endonuclease activation. This DNA fragmentation pattern was not detected in cells immediately after UV-irradiation, and was therefore not the result of direct UV-induced DNA damage. UV-induced apoptosis of the HL-60 cell line was found to require extracellular calcium and to be inhibited in a dose-dependent way by zinc added to the culture medium. (author)

  2. Search for the lowest irradiation dose from literatures on radiation-induced cancer in gastrointestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

    1976-05-01

    A survey of past case reports about radiation-induced cancer in the gastrointestinal tract was carried out with the main object of finding the lowest irradiation dose. Search of the literature published since 1923 revealed 80 cases of radiation-induced large intestine cancer and one case of stomach cancer. The cases of radiation-induced cancer in the large intestine had received radiation for the treatment of non-malignant conditions, fibroma, ovarial cyste, myoma, endometritis and duodenal ulcer. The lowest irradiation dose was estimated at 460 rads. Adenocarcinoma was the histopathological finding in all cases of radiation-induced cancer in the caecum, colon and rectum, and squamous cell carcinoma in the cases of anal cancer. The latent period ranged from 1 to 31 years, with the average of 13.6 years. There were some reports of statistical studies of radiation-induced stomach cancer. Three groups were the subjects of these studies. The first group was composed of atomic bomb survivors, the second of patients who had undergone radiation treatment for ankylosing spondilitis, and the third of duodenal ulcer patients subjected to radiation treatment for the purpose of suppressing gastric acid secretion. These statistical studies showed no significant increase of the incidence of stomach cancer in the irradiated groups.

  3. Inhibition of IL-1 activity induced with allogeneic transfusion of UV-irradiated blood

    International Nuclear Information System (INIS)

    Horvat, B.; Poljak-Blazi, M.; Hadija, M.

    1991-01-01

    Treatment with UV-irradiated donor-specific blood transfusion is known to induce specific unresponsiveness in recipient animals and prolong allograft survival. Mixed lymphocyte response in transfused mice was decreased towards spleen cells of the blood donor strain, but was not altered to third-party cells. Sera from treated mice showed significantly lower interleukin-1 (IL-1) activity, which was increased with higher dilutions of sera, indicating the presence of IL-1 inhibitor. Furthermore, sera decreased rIL-1-induced cell proliferation in dose-dependent manner, while the response to rIL-2 neither depended on the concentration of sera, nor differed between non-treated controls and treated mice. These results indicate that UV-irradiated allogeneic blood transfusion could induce an inhibitor, specifically directed to IL-1 activity, which may be involved in the generation of immunological unresponsiveness in treated animals. (author)

  4. Radiation retinopathy caused by low dose irradiation and antithyroid drug-induced systemic vasculitis

    International Nuclear Information System (INIS)

    Sonoda, Koh-hei; Ishibashi, Tatsuro

    2005-01-01

    We report on a patient with Graves' disease with radiation retinopathy caused by low-dose irradiation and antithyroid drug-induced antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. A 38-year-old woman with Graves' disease presented with bilateral blurred vision, micro-aneurysms, telangiectasia, and macular edema. The patient was examined by ophthalmoscopy and fluorescein angiography, and radiation retinopathy was diagnosed. The patient had been treated with low-dose irradiation for her Graves' ophthalmopathy a few years earlier. She also had ANCA-positive vasculitis induced by the antithyroid drug (propylthiouracil, PTU) that had been prescribed for her at that time. Because of multiple avascular areas on both retinas, she was treated by intensive retinal photocoagulation to control progressive retinopathy. The radiation doses used to treat Graves' disease ophthalmopathy are low. Nevertheless, there is still a risk of radiation retinopathy developing in patients with PTU-induced ANCA-positive vasculitis. (author)

  5. A study of the effect of propolis against gastric ulcers induced in gamma -irradiated rats

    International Nuclear Information System (INIS)

    Abd El-Aziz, R.R

    2009-01-01

    The anti-ulcerogenic activity of propolis or bee glue, a natural product from honey bees, was investigated against indomethacin -induced gastric ulcers in non- irradiated and irradiated rats, and the effects were compared with those of the proton pump inhibitor lansoprazole, as a reference anti-ulcerogenic drug. Indomethacin-induced gastric ulcer was used in this study as a model of experimentally induced gastric ulceration. The anti-ulcerogenic, antisecretory and cytoprotective activities of 13% aqueous propolis extract (APE) were assessed. Gastric contents of animals were sampled for the measurement of free acidity, acid output, mucin and pepsin concentrations in the gastric juice. The stomach was examined macroscopically for the determination of the ulcer index. PGE 2 was assayed in the gastric mucosa, while the pro-inflammatory cytokines TNF-α and IL-1β as well as the oxidative stress marker MDA were determined in the plasma.

  6. Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Katayama, Tadashi; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1993-10-01

    In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (J.P.N.).

  7. Persistent genetic instability induced by synergistic interaction between x-irradiation and 6-thioguanine

    International Nuclear Information System (INIS)

    Grosovsky, A.J.; Nelson, S.L.; Smith, L.E.

    1995-01-01

    Clonal karyotypic analysis was performed using G-banding on four groups of clones derived from TK6 human lymphoblasts: 25 HPRT - total gene deletion mutants induced by exposure to 2 Gy of x-rays; 8 spontaneous HPRT - total gene deletion mutants; 25 clones irradiated with 2 Gy, not selected with 6-thioguanine. Ten to twenty metaphases were examined for each clone. Extensive karyotypic heterogeneity was observed among x-ray induced HPRT - mutants involving translocations, deletions, duplications and aneuploidy; recovery of chromosomal aberrations and karyotypic heterogeneity was greater than the additive effects of clones treated with x-irradiation or 6-thioguanine alone. This synergistic interaction between x-irradiation and 6-thioguanine was observed despite a 7 day phenotypic expression interval between exposure to the two agents. Thus, x-irradiated TK6 cells appear to be persistently hypersensitive to the induction of genetic instability. Several mutants appeared to exhibit evidence of clonal evolution since aberrant chromosomes observed in one metaphase, were found to be further modified in other metaphases. In order to determine if genetic instability, identified by clonal karyotypic heterogeneity, affected specific locus mutation rates, we utilized the heterozygous thymidine kinase (tk) locus as a genetic marker. Four x-ray induced HPRT - mutants with extensive karyotypic heterogeneity, exhibited mutation rates at tk ranging from 5 to 8 fold higher than the parental TK6 cells. Further analysis, using fractionated low dose radiation exposure, is currently in progress

  8. Detection of irradiation induced modifications in foodstuff DNA using 32p post-labelling

    International Nuclear Information System (INIS)

    Hoey, B.M.; Swallow, A.J.; Margison, G.P.

    1991-01-01

    DNA post-labelling has been used successfully to detect damage to DNA caused by a range of damaging agents. The assay results in a fingerprint of changes induced in DNA which might, in principle, be useful as a test for the detection of the irradiation of foods. The authors present their DNA extraction and 32 p post-labelling methods from chicken or cooked prawn samples and their analysis method (High Performance liquid chromatography). It's hoped that these results could form the basis of a test to detect if foods have been irradiated

  9. DLTS and capacitance transients study of defects induced by neutron irradiation in MOS structures CCD process

    International Nuclear Information System (INIS)

    Ahaitouf, A.; Losson, E.; Charles, J.P.

    1999-01-01

    The aim of this paper is to study neutron irradiation effects on PMOS capacitors and NMOSFETs transistors. The characterization of induced defects was made by capacitance transients C(t) measurements, DLTS spectroscopy, and optical DLTS (ODLTS). DLTS spectra present three peaks due to deep levels created in the semiconductor and two peaks due to minority carrier generation. Two levels are reported in the literature. Two other minority carrier traps have been observed on ODLTS spectra after irradiation. This can explain the decrease of the minority carrier generation lifetime observed by capacitance transients measurements. (authors)

  10. What can we learn from Raman Spectroscopy on irradiation-induced defects in UO2?

    International Nuclear Information System (INIS)

    Desgranges, L.; Martin, Ph.; Simon, P.; Guimbretiere, G.; Baldinozzi, G.

    2014-01-01

    Recent results on irradiated UO 2 by Raman spectroscopy evidenced Raman lines that are characteristic of irradiation-induced defects. Three main mechanisms are identified to explain their origin: resonant Raman, formation of new molecular entities, or breakdown in symmetry. Arguments are given to consider breakdown in symmetry as the predominant mechanism. A tentative description of the defects at the origin of this symmetry breakdown is proposed in terms of coordination polyhedrons of uranium. This discussion led us to consider that the Raman defect modes could be related to area with different stoichiometry. (authors)

  11. Heat-shock-induced enhanced reactivation of UV-irradiated Herpesvirus

    Energy Technology Data Exchange (ETDEWEB)

    Yager, J.D.; Zurlo, J.; Penn, A.L.

    1985-09-01

    The objective of this study was to compare the ability of heat shock (HS) with that of another type of cellular stress, UV irradiation, to cause the induction of enhanced viral reactivation, a process that may represent an SOS-type repair process in mammalian cells. These results indicate that, like UV irradiation, HS at levels inhibitory to cell growth induced enhanced viral reactivation in Vero cells. The results also suggest that at least two proteins in the HS protein family are not necessary for this response to occur. (Auth.). 27 refs.; 5 figs.

  12. Defects in CdSe thin films, induced by high energy electron irradiation

    International Nuclear Information System (INIS)

    Ion, L.; Antohe, S.; Tutuc, D.; Antohe, V.A.; Tazlaoanu, C.

    2004-01-01

    Defects induced in CdSe thin films by high energy electron irradiation are investigated by means of thermally stimulated currents (TSC) spectroscopy. Films were obtained by vacuum deposition from a single source and irradiated with a 5 x 10 13 electrons/cm 2 s -1 beam of 6-MeV energy. It was found that electrical properties of the films are controlled by a deep donor state, located at 0.38 eV below the bottom edge of the conduction band. Parameters of the traps responsible for the recorded TSC peaks were determined. (authors)

  13. Radiation induced chimeric rearrangement flower structure of Rhododendron simsii Planch. (Azaleaindica L. ) Use of recurrent irradiation

    Energy Technology Data Exchange (ETDEWEB)

    de Loose, R [IWONL (IRSIA) Irradiation Laboratory, Institute of Ornamental Plant Growing, Melle (Belgium)

    1979-02-01

    A radiation-induced chimeric flower colour sport of vegetatively propagated Rhododendron simsii Planch was recurrently irradiated (up to three times in three consecutive years) with soft X-rays (50kV-30mA), as compared to a single treatment. Because of the low true flower colour mutation frequency the efficiency of the different radiation treatments was compared on the basis of the number of chimeric rearrangements in flower structure i.e. the flower colour change from red with broad white edge towards either homogeneous carminered or white. It is quite clear that recurrent irradiation with appropiate doses is most efficient.

  14. Modeling of radiation-induced charge trapping in MOS devices under ionizing irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Petukhov, M. A., E-mail: m.a.petukhov@gmail.com; Ryazanov, A. I. [National Research Center Kurchatov Institute (Russian Federation)

    2016-12-15

    The numerical model of the radiation-induced charge trapping process in the oxide layer of a MOS device under ionizing irradiation is developed; the model includes carrier transport, hole capture by traps in different states, recombination of free electrons and trapped holes, kinetics of hydrogen ions which can be accumulated in the material during transistor manufacture, and accumulation and charging of interface states. Modeling of n-channel MOSFET behavior under 1 MeV photon irradiation is performed. The obtained dose dependences of the threshold voltage shift and its contributions from trapped holes and interface states are in good agreement with experimental data.

  15. Improvement of mungbean by X-ray and thermal neutron irradiation

    International Nuclear Information System (INIS)

    Kwon, S.H.; Oh, J.H.

    1983-01-01

    With the aim of improving yield, resistance to Cercospora leaf spot and pod shattering, mungbean varieties Kyunggi No. 5 and M-317 were irradiated with X-rays and thermal neutrons. High yielding mutant lines are generally characterized by a higher number of pods per plant. Better Cercospora resistance appears often associated with later maturity. Satisfactory shattering resistance was not yet obtained. (author)

  16. Hydrophilicity improvement of polyethersulfone membranes by grafting methacrylic acid with γ-ray irradiation

    International Nuclear Information System (INIS)

    Li Jing; Hou Zhengchi; Xie Leidong; Zhang Fengying; Deng Bo

    2005-01-01

    Grafting methyacrylic acid onto poly(ether sulfone) membranes was realized by means of simultaneous irradiation in liquids. The modified membranes with different grafting ratios were obtained by changing the concentration of methyacrylic acid. It was shown that the grafting ratio increased lineally as the monomer concentration was less than 10% and hydrophilicity of the membranes was improved with increasing grafting ratios. (authors)

  17. Irradiation for quality improvement, microbial safety and phytosanitation of fresh produce

    Science.gov (United States)

    In this book we pull together research, technological advances and current trends from many disciplines to provide a single comprehensive source of information on the many uses of irradiation to improve the safety and supply of fruits and vegetables. Part 1 of the book focuses on the potential of io...

  18. A study on the improvement of radiation-induced oxidation resistance for polypropylene and PVC materials

    International Nuclear Information System (INIS)

    Park, K. Z.; Jeong, K. S.; Cho, S. H.; Cho, Y. H.; Seok, H. C.

    2002-01-01

    The object of this project is to improve the stability and the economics by reducing the radiation-induced oxidation as a factor of degradation of polymer materials used under the radiation environment. In order to attain the objective of this study and to check the effect of diamond-like carbon (DLC) coating on the anti-oxidation reaction, polymer specimens such as Polyproplyene, PVC coating DLC thin layer were exposed to high level gamma radiation, and their irradiation effects were investigated. A plasma-enhanced chemical vapor deposition method was adopted in fabricating a DLC thin film on the polymer specimens, which were irradiated with the non-DLC film deposited specimens under the gamma radiation emitted from Co-60 source from 1 x 10 5 to 1 x 10 8 rads exposure. According to the characterization of irradiated specimens from the elapsed time of minimum 4 hours to a maximum of 105 days after the irradiation, the DLC deposition on the polymer surface was revealed to contribute to the improvement on the resistance of the radiation-induced oxidation in this study

  19. Improvement of Pure Poly aromatic Hydrocarbon Degrading Bacteria Using Gamma Irradiation

    International Nuclear Information System (INIS)

    Abd El-Daem, G.A.N.A.; Tarrad, M.M.

    2013-01-01

    The main goal of this study is to obtain a potent polycyclic aromatic hydrocarbons (PAHs) biodegrading bacteria to be used for bio augmentation purpose which is considered a promising strategy for the cleanup of contaminated sites. Among 10 selected potent PAHs degrading bacteria isolated from Suez Gulf water (after enrichments on phenanthrene as a sole source of carbon and energy). Isolate HD20 was selected due to its fast and remarkable abilities to breakdown phenanthrene . In a trial to improve the biodegradation potentials of the most potent isolate (Had) identified as Stenotrophomonas maltophilia, low doses of gamma irradiation were used to activate the organism. To determine the radiation response of S. maltophilia, 24 hours culture was exposed in saline solution in a triplicate glass vials separately to increasing doses of gamma irradiation, 0.25, 0.5, 1.0, 1.5, 2.0 and 2.5 kGy. The dose response curve revealed the linear death of bacterial cells with increasing irradiation dose, The D10 value of S. maltophilia was found to be 0.3 kGy. For PAHs biodegradation enhancement, the organism was irradiated at low doses of gamma irradiation, 0.2, 0.4, 0.5, 0.6 and 0.7 kGy. The grown colonies exhibited a morphological differences from the non irradiated Stenotrophomonas maltophilia on Tryptone-glucose-yeast extract (TGY) plates. All of them showed a creamy rough appearance and a loss of the known yellow colour of the original isolate. The single selected irradiated colonies as well as the whole irradiated mixture of cells irradiated at different doses were tested separately in fertilized marine microcosms containing 200 ppm of phenanthrene as a model of PAH and the degradation rates of polyaromatic hydrocarbons were monitored by the determination of the residual phenanthrene up to one week . The biodegradation potentials of irradiated and non irradiated S. maltophilia was compared with that of the natural Suez Gulf microbial communities. The irradiated culture of S

  20. Ageing effects in As10Se90 chalcogenide glasses induced by gamma-irradiation

    International Nuclear Information System (INIS)

    Golovchak, R.; Shpotyuk, O.; Shpotyuk, M.; Gorecki, Cz.; Kozdras, A.

    2005-01-01

    The peculiarities of gamma-induced (Co 60 source, 1.85 MGy absorbed dose) ageing phenomena in As 10 Se 90 chalcogenide glasses are investigated for the first time. The analogy between the observed radiation-induced ageing and the thermally induced one in vitreous selenium is emphasized. Like to thermal treatment, gamma-irradiation leads to an increase in the glass transition temperature and the relaxation rate towards a thermodynamic equilibrium of supercooled liquid, the value of this increase being greater in the case of radiation influence

  1. Membrane damage induced in cultured human skin fibroblasts by UVA irradiation

    International Nuclear Information System (INIS)

    Gaboriau, F.; Morliere, P.; Marquis, I.; Moysan, A.; Geze, M.; Dubertret, L.

    1993-01-01

    Irradiation of cultured human skin fibroblasts with ultraviolet light from 320 to 400 nm (UVA) leads to a decrease in the membrane fluidity exemplified by an enhanced fluorescence anisotropy of the lipophilic fluorescent probe 1-[4-trimethylamino)-phenyl]-6-phenylhexa-1,3,5-triene. This UVA-induced decrease in fluidity is associated with lactate dehydrogenase leakage in the supernatant. Vitamin E, an inhibitor of lipid peroxidation, exerts a protective effect on both phenomena. Therefore, this UVA-induced damage in membrane properties may be related to lipid peroxidation processes. Moreover, exponentially growing cells are more sensitive to these UVA-induced alterations than confluent cells. (Author)

  2. Irradiation-induced precipitation and solute segregation in alloys. Fourth annual progress report, February 1, 1981-March 31, 1982

    International Nuclear Information System (INIS)

    Ardell, A.J.

    1982-04-01

    The studies of irradiation-induced solute segregation (IISS) and irradiation-induced precipitation (IIP) in Ni-Si and Pd-Fe alloys have been completed. Progress is reported for several other projects: irradiation damage in binary Pd-Cr, -Mn and -V alloys (15 at. %); IIP in Pd-Mo and Pd-W alloys; IIP in Pd-25 at. % Cr alloy; and irradiation damage effects in proton-bombarded metallic glasses (Ni-65 Zr, 40 Fe 40 Ni 14 P6B). 27 figures

  3. Yield Improvement in barley by using gamma irradiation

    International Nuclear Information System (INIS)

    Ben-Amer, Ibrahim Mohammed

    1993-01-01

    Sixty two mutant lines in the M4 generation were studies for one year for yield components (heads per plant kernals per head and kernal weight). Four mutant lines out yielded the parent but the differences being significant only with the mutant 2-6-26. This is mainly due to significant increase in number of beads per plant. Yield per plant was correlated with number of heads per plant. In a 2-year field experiment, mutant 2-6-26 out yielded the parent variety, the difference being significant only in one experiment (1988-89). The increase in nitrogen rate from 0 to 100 kg/ha increased yield significantly. mutant 2-6-26 produced 415 g grains/m 2 in the 1987-88 experiment; in 1988-89 experiment, its yields were 426, 610 and 594 g grains/m 2 for the 0, 100 and 200 kg N/ha respectively. The differences in kernal weight were highly significant only in 1988-89 experiment. Lodging was low in 1987-88 experiment due to moisture stress. In 1988-89 experiment, Lodging increased with the increase in N application rate. None of the mutant lines showed any improvement in the resistance to lodging. Mutant 2-6-26 is very promising. It will be evaluated in large yield-trials at different locations in the country. (author)

  4. Effect of salt-inducible kinase 2 on checkpoint in response to γ-ray irradiation

    International Nuclear Information System (INIS)

    Yin Jiaojiao; Zhou Lijun; Wang Yu; Liu Xiaodan; Gu Yongqing; Zhou Pingkun

    2014-01-01

    Objective: To investigate the effect of salt-induced kinase 2 (SIK2) in the G_2/M checkpoint in response to ionizing radiation and the possible mechanism. Methods: HeLa cells were irradiated with "6"0Co γ-rays. The cell model of knockdown SIK2 expression was constrcuted by transfecting HeLa cells with a pSicoR-based lentivirus vector of expressing SIK2 shRNA by lipofectamin 2000. Western blot and flow cytometry were performed to measure the changes of SIK2 protein level and cell cycle distribution. The phosphorylated histone protein H3 on Ser 10 was used as a molecular marker of mitotic cells for detecting the function of G2/M checkpoint. Results: The expression level of SIK2 protein increased in HeLa cells after "6"0Co γ-ray irradiation. A cell model of knockdown SIK2 expression was successfully generated by transfecting the specific shRNA against SIK2. Depression of SIK2 significantly increased the cellular sensitivity at 1, 2, 4, 6 Gy post-irradiation (t = -3.445, -2.581, -3.251, -2.553, P < 0.05), and led cells to release earlier from the G_2/M boundary arrest compared to control cells at 5, 6 h post-irradiation(t = 4.341, 6.500, P < 0.05). Western blot analysis indicated that the irradiation-induced phosphorylated CHK2/T68 in SIK2 knock-down cells was earlier than that in control cells. Conclusions: salt-induced kinase 2 (SIK2) participates in the regulation of G_2/M checkpoint induced by ionizing radiation and affects cellular radiosensitivity. (authors)

  5. Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

    International Nuclear Information System (INIS)

    Yu, H.; Yao, Z.; Kirk, M.A.; Daymond, M.R.

    2015-01-01

    In situ heavy ion irradiation with 1 MeV Kr"2"+ was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 "oC or 450 "oC. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 "oC irradiation but not at 450 "oC. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2 and both present in β-Zr under room temperature irradiation. (author)

  6. Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, H.; Yao, Z., E-mail: 12hy1@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada); Kirk, M.A. [Argonne National Laboratory, Materials Science Division, Argonne, IL (United States); Daymond, M.R. [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

    2015-07-01

    In situ heavy ion irradiation with 1 MeV Kr{sup 2+} was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 {sup o}C or 450 {sup o}C. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 {sup o}C irradiation but not at 450 {sup o}C. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2<111> and <001> both present in β-Zr under room temperature irradiation. (author)

  7. Temperature dependence of ion irradiation induced amorphization of zirconolite

    International Nuclear Information System (INIS)

    Smith, K. L.; Blackford, M. G.; Lumpkin, G. R.; Zaluzec, N. J.

    1999-01-01

    Zirconolite is one of the major host phases for actinides in various wasteforms for immobilizing high level radioactive waste (HLW). Over time, zirconolite's crystalline matrix is damaged by α-particles and energetic recoil nuclei recoil resulting from α-decay events. The cumulative damage caused by these particles results in amorphization. Data from natural zirconolites suggest that radiation damage anneals over geologic time and is dependant on the thermal history of the material. Proposed HLW containment strategies rely on both a suitable wasteform and geologic isolation. Depending on the waste loading, depth of burial, and the repository-specific geothermal gradient, burial could result in a wasteform being exposed to temperatures of between 100--450 C. Consequently, it is important to assess the effect of temperature on radiation damage in synthetic zirconolite. Zirconolite containing wasteforms are likely to be hot pressed at or below 1,473 K (1,200 C) and/or sintered at or below 1,623 K (1,350 C). Zirconolite fabricated at temperatures below 1,523 K (1,250 C) contains many stacking faults. As there have been various attempts to link radiation resistance to structure, the authors decided it was also pertinent to assess the role of stacking faults in radiation resistance. In this study, they simulate α-decay damage in two zirconolite samples by irradiating them with 1.5 MeV Kr + ions using the High Voltage Electron Microscope-Tandem User Facility (HTUF) at Argonne National Laboratory (ANL) and measure the critical dose for amorphization (D c ) at several temperatures between 20 and 773 K. One of the samples has a high degree of crystallographic perfection, the other contains many stacking faults on the unit cell scale. Previous authors proposed a model for estimating the activation energy of self annealing in zirconolite and for predicting the critical dose for amorphization at any temperature. The authors discuss their results and earlier published data in

  8. Study on antitussive effects of eprazinone dihydrochloride on radiation induced inflammation of upper respiratory tract due to postoperative irradiation of breast cancer

    International Nuclear Information System (INIS)

    Taoya, Koichiro

    1977-01-01

    Discussion was made of antitussive effects of Eprazinone hydrochloride (Resplen) on radiation induced inflammation of the upper respiratory tract in 15 cases irradiated after an operation of breast cancer. Depth dose at 3 cm was 200 rads/day, and 5000 rad/25 times/5 weeks was irradiated with telecobalt. Mainly abnormal sensation and pain in the throat and cough appeared and patients complained of suffering from a common cold, because a part of irradiation field included the throat, trachea, and esophagus. At the same time as manifestation of symptoms, 120 mg/day of Eprazinone Dihydrochloride was administered. In 8 cases, other drugs were added to, or irradiation schedule was changed because the symptoms were not improved or were exaggerated. The symptoms disappeared up to 5000 rad irradiation in one case, up to 4000 - 5000 rad irradiation in 4 cases, and up to 4000 rad irradiation in 2 cases. It is impossible to decide effective rate of this drug because of shortage of clinical cases, but it is suggested that there is a significance to increase cases treated successively with this drug in future. (Tsunoda, M.)

  9. Study on antitussive effects of Eprazinone dihydrochloride on radiation--induced inflammation of upper respiratory tract due to postoperative irradiation of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Taoya, K [National Hospital of Yokohama (Japan)

    1977-04-01

    Discussion was made of the antitussive effects of Eprazinone hydrochloride (Resplen) on radiation-induced inflammation of the upper respiratory tract in 15 cases irradiated after an operation of breast cancer. Depth dose at 3 cm was 200 rads/day, and 5000 rad/25 times/5 weeks was irradiated with telecobalt. Mainly abnormal sensation and pain in the throat and cough appeared and patients complained of suffering from a common cold, because a part of irradiation field included the throat, trachea, and esophagus. At the same time as manifestation of symptoms, 120 mg/day of Eprazinone Dihydrochloride was administered. In 8 cases, other drugs were added to, or irradiation schedule was changed because the symptoms were not improved or were exaggerated. The symptoms disappeared up to 5000 rad irradiation in one case, up to 4000 to 5000 rad irradiation in 4 cases, and up to 4000 rad irradiation in 2 cases. It is impossible to decide effective rate of this drug because of shortage of clinical cases, but it is suggested that there is a significance to increase cases treated successively with this drug in future.

  10. Induced mutations for improvement of grain legume production

    International Nuclear Information System (INIS)

    1980-11-01

    After an introduction on plant science research in Malaysia concerning crop breeding, 22 research reports are presented, 17 of which are analyzed individually and constitute separate INIS references. The remaining 5 were essentially concerned with only future applications of nuclear technology: a paper by V.L. Chopra (India) on mutation breeding for partial disease resistance of wheat; by H.H. Hoppe (Federal Republic of Germany) on mechanisms of resistance against Uromyces in Phaseolus vulgaris; by I.S. Santos (Philippines) on induction evaluation and utilization of beneficial mutations in the winged bean (Psophocarpus tetragonolobus), where gamma rays and fast neutrons will be used as well as other mutagens; by F. Saccardo (Italy) on breeding for disease resistance in peas and other vegetables (short communication only); and by E. Balazs and I. Sziraki (Hungary) on in vitro studies on virus resistance of legumes, including virus-host interaction studies involving gamma irradiation (short communication only). The conclusions and recommendations of the Regional Seminar on Induced Mutations for the Improvement of Grain Legumes in S.E. Asia 1975 (IAEA-203, 1977) were considered and generally endorsed, with some clarification. Conclusions and recommendations are given on p.121-126

  11. Early life hormetic treatments decrease irradiation-induced oxidative damage, increase longevity, and enhance sexual performance during old age in the Caribbean fruit fly

    International Nuclear Information System (INIS)

    López-Martínez, Giancarlo; Hahn, Daniel A.

    2014-01-01

    Early life events can have dramatic consequences on performance later in life. Exposure to stressors at a young age affects development, the rate of aging, risk of disease, and overall lifespan. In spite of this, mild stress exposure early in life can have beneficial effects on performance later in life. These positive effects of mild stress are referred to as physiological conditioning hormesis. In our current study we used anoxia conditioning hormesis as a pretreatment to reduce oxidative stress and improve organismal performance, lifespan, and healthspan of Caribbean fruit flies. We used gamma irradiation to induce mild oxidative damage in a low-dose experiment, and massive oxidative damage in a separate high-dose experiment, in pharate adult fruit flies just prior to adult emergence. Irradiation-induced oxidative stress leads to reduced adult emergence, flight ability, mating performance, and lifespan. We used a hormetic approach, one hour of exposure to anoxia plus irradiation in anoxia, to lower post-irradiation oxidative damage. We have previously shown that this anoxic-conditioning treatment elevates total antioxidant capacity and lowers post-irradiation oxidative damage to lipids and proteins. In this study, conditioned flies had lower mortality rates and longer lifespan compared to those irradiated without hormetic conditioning. As a metric of healthspan, we tracked mating both at a young age (10 d) and old age (30 d). We found that anoxia-conditioned male flies were more competitive at young ages when compared to unconditioned irradiation stressed male flies, and that the positive effects of anoxic conditioning hormesis on mating success were even more pronounced in older males. Our data shows that physiological conditioning hormesis at a young age, not only improves immediate metrics of organismal performance (emergence, flight, mating), but the beneficial effects also carry into old age by reducing late life oxidative damage and improving lifespan and

  12. Studies on γ-irradiation-induced-degradation of chloramphenicol in aqueous solution

    International Nuclear Information System (INIS)

    Xie Fang; Ha Yiming; Wang Feng; Zhou Hongjie

    2008-01-01

    The irradiation-induced degradation of chloramphenicol by γ-rays in aqueous solution was studied and the radiolytical products were determined. The relationship among degradation rate, absorbed dose and initial concentration have been explored by comparing the position of maximum absorption peaks of chloramphenicol be- fore and after irradiation using high performance liquid chromatography. The identification of radiolytical products has been conducted using liquid chromatography tandem mass spectrometry. It has been found that the relationship among C/C 0 , absorbed dose and initial concentration can be fit with index curve. After irradiation, more than 30 radiolytical products with stable absorption below 278nm could be determined. 8 major radiolytical products with [M-H] - 353, 337, 335(A), 335(B), 319, 289, 127, 166, which are detected in several different conditions, have been picked up. Their possible structures are deducted. (authors)

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

    International Nuclear Information System (INIS)

    Satti, Angel J.; Andreucetti, Noemi A.; Ciolino, Andres E.; Vitale, Cristian; Sarmoria, Claudia; Valles, Enrique M.

    2010-01-01

    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 29 Si-Nuclear Magnetic Resonance spectroscopy (NMR) and previously reported data for commercial linear PDMS ().

  14. Transmission electron microscope study of neutron irradiation-induced defects in silicon

    International Nuclear Information System (INIS)

    Oshima, Ryuichiro; Kawano, Tetsuya; Fujimoto, Ryoji

    1994-01-01

    Commercial Czochralski-grown silicon (Cz-Si) and float-zone silicon (Fz-Si) wafers were irradiated with fission neutrons at various fluences from 10 19 to 10 22 n/cm 2 at temperatures ranging from 473 K to 1043 K. The irradiation induced defect structures were examined by transmission electron microscopy and ultra high voltage electron microscopy, which were compared with Marlowe code computer simulation results. It was concluded that the vacancy-type damage structure formed at 473 K were initiated from collapse of vacancy-rich regions of cascades, while interstitial type defect clusters formed by irradiation above 673 K were associated with interstitial oxygen atoms and free interstitials which diffused out of the cascades. Complex defect structures were identified to consist of {113} and {111} planar faults by the parallel beam illumination diffraction analysis. (author)

  15. Meiotic chromosomal translocations in male mice induced by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Savkovic, N.; Pecevski; Vuksanovic, L.; Radivojevic, D.; Alavantic, D.

    1983-01-01

    The dose-response curve for reciprocal translocations induced by acute exposure of spermatogonial stem cells to X-rays in treated mice and their F-1 sons was examined. Male mice were totally irradiated with doses of 1Gy;5x1Gy and 5Gy. The obtained results show that frequency of the chromosomal translocations in directly treated animals is dose dependent. The percentage of animals irradiated with 1Gy which had the chromosomal translocations was 60, while this percentage in animals irradiated with single and fractionated dose of 5Gy was 100. The frequency of chromosomal translocations varies from 1.5% to 8.0%. Multivalent configurations in F-1 males were observed after exposure to 5Gy only. The incidence of F-1 translocated males was 17.5%.

  16. Magnetic circular dichroism study of electron-irradiation induced defects in InP

    International Nuclear Information System (INIS)

    Gislason, H.P.

    1989-01-01

    A strong magnetic circular dichroism (MCD) absorption band centered at 1.07 eV in electron irradiated InP is reported. Temperature and magnetic field dependence of the signal reveal that the centre giving rise to this band is a spin triplet. By simulating neutral and reverse bias conditions of junction measurements through a careful choice of irradiation dose and starting material, the MCD band is shown to have an annealing behaviour closely resembling that of the majority carrier traps which control the Fermi level position in n- and p-type InP. The 1.07 eV MCD band represents the first magneto-optical signal connected with this family of complex irradiation-induced defects in InP. (author) 19 refs., 5 figs., 1 tab

  17. Effects of X-irradiation on axonal sprouting induced by botulinum toxin

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, S; Duchen, L W [National Hospital, London (UK); Hornsey, S [Hammersmith Hospital, London (UK). M.R.C. Cyclotron Unit

    1982-01-01

    The effect of X-irradiation on axonal sprouting of motor nerves induced by botulinum toxin was examined. Muscles of one leg in the mouse were X-irradiated (15Gy) prior to the injection of a locally paralysing dose of botulinum toxin. It was found that axonal sprouting occurred as expected, but the sprouts remained unmyelinated and many degenerated. Fewer new end-plates were formed, muscles remained more severely atrophied and supersensitive to acetylcholine and recovery of neuromuscular transmission was greatly delayed when compared with the effects of botulinum toxin alone. X-irradiation did not prevent sprouting but, probably by impairing Schwann cell proliferation, altered axon-Schwann cell relationships and prevented the maturation of newly-formed axons and the differentiation of new end-plates.

  18. The irradiation induced creep in fuel compact materials for H.T.R. applications

    International Nuclear Information System (INIS)

    Veringa, H.; Blackstone, R.; Loelgen, R.

    1976-01-01

    Restrained shrinkage experiments up to 3 x 10 21 ncm -2 (DNE) in the temperature range of 600-1,200 0 C on three different dummy coated particle fuel compact materials were performed in the High Flux Reactor at Petten, the Netherlands. The data were evaluated to obtain the steady state irradiation creep coefficient of the compacts. It was found that for the materials investigated, the creep coefficient is temperature-dependent, but no clear relationship to the Young's modulus could be established. Under certain conditions, this irradiation-induced plasticity influences the elastic properties, while also the creep coefficient increases. This effect coincides with the formation and further opening of cracks due to stresses caused by irradiation shrinkage of the matrix material. (orig.) [de

  19. Changes in grain boundary composition induced by neutron irradiation of austenitic stainless steels

    International Nuclear Information System (INIS)

    Asano, K.; Nakata, K.; Fukuya, K.; Kodama, M.

    1992-01-01

    The radiation induced segregation of solutes to the grain boundary in austenitic stainless steels were studied. Type 304 and type 316 steel samples neutron irradiated at 561K up to 9.2x10 25 n/m 2 were obtained and minute compositional profiles across grain boundaries were examined using an analytical scanning transmission electron microscope equipped with a field emission electron gun. Chromium was slightly enriched at grain boundaries at the lowest irradiation dose but decreased with increasing fluence. Higher fluence irradiation resulted in depletion in chromium and molybdenum, and enrichment in nickel, silicon and phosphorus. These changes in grain boundary chemistry were limited within about 5nm of the boundary. Significant depletion of chromium and enrichment of impurities on the grain boundary occurred at fluences roughly coincidental with that of SCC susceptibility change obtained from another project

  20. Irradiation-induced dimensional changes of fuel compacts and graphite sleeves of OGL-1 fuel assemblies

    International Nuclear Information System (INIS)

    Hayashi, Kimio; Minato, Kazuo; Kobayashi, Fumiaki; Tobita, Tsutomu; Kikuchi, Teruo; Kurobane, Shiro; Adachi, Mamoru; Fukuda, Kousaku

    1988-06-01

    Experimental data are summarized on irradiation-induced dimensional changes of fuel compacts and graphite sleeves of the first to ninth OGL-1 fuel assemblies. The range of fast-neutron fluence is up to 4 x 10 24 n/m 2 (E > 0.18 MeV); and that of irradiation temperature is 900 - 1400 deg C for fuel compacts and 800 - 1050 deg C for graphite sleeves. The dimensional change of the fuel compacts was shrinkage under these test conditions, and the shrinkage fraction increased almost linearly with fast-neutron fluence. The shrinkage fraction of the fuel compacts was larger by 20 % in the axial direction than in the radial direction. Influence of the irradiation temperature on the dimensional-change behavior of the fuel compacts was not observed clearly; presumably the influence was hidden by scatter of the data because of low level of the fast-neutron fluence and the resultant small dimensional changes. (author)

  1. On some paramagnetic species induced in natural calcites by β and γ-rays irradiations

    International Nuclear Information System (INIS)

    Rossi, A.; Danon, J.

    1985-01-01

    The ESR absorption lines of calcite speleothems are studied both as monocrystals and powders, after energetic β-rays or γ-rays irradiation. Both Kinds of irradiation produce same lines. Angular variation studies of monocrystals revealed four induced paramagnetic species stable at room temperature. Three of these were attributed to CO 3 sup(---) group, CO 2 sup(-) groups with axial and orthorhombic symetry and a fourth one could be due to the CO 3 sup(-) group. Powder spectra show that these lines, are activated by irradiation in all speleothems we studied and can be present either in natural ESR spectra. Their relationships to the lines usually considered for ESR dating are discussed. (Author) [pt

  2. Phenomenological understanding of dewetting and embedding of noble metal nanoparticles in thin films induced by ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai, E-mail: jai.gupta1983@gmail.com [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Chemical Physics of Materials, Université Libre de Bruxelles, Campus de la Plaine, CP 243, B-1050 Bruxelles (Belgium); Tripathi, A. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India); Gautam, Sanjeev; Chae, K.H.; Song, Jonghan [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Rigato, V. [INFN Laboratori Nazionali di Legnaro, Via Romea. 4, 35020 Legnaro, Padova (Italy); Tripathi, Jalaj [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Asokan, K. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India)

    2014-10-15

    The present experimental work provides the phenomenological approach to understand the dewetting in thin noble metal films with subsequent formation of nanoparticles (NPs) and embedding of NPs induced by ion irradiation. Au/polyethyleneterepthlate (PET) bilayers were irradiated with 150 keV Ar ions at varying fluences and were studied using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (X-TEM). Thin Au film begins to dewet from the substrate after irradiation and subsequent irradiation results in spherical nanoparticles on the surface that at a fluence of 5 × 10{sup 16} ions/cm{sup 2} become embedded into the substrate. In addition to dewetting in thin films, synthesis and embedding of metal NPs by ion irradiation, the present article explores fundamental thermodynamic principles that govern these events systematically under the effect of irradiation. The results are explained on the basis of ion induced sputtering, thermal spike inducing local melting and of thermodynamic driving forces by minimization of the system free energy where contributions of surface and interfacial energies are considered with subsequent ion induced viscous flow in substrate. - Highlights: • Phenomenological interpretation of dewetting and embedding of metal NPs in thin film. • Exploring fundamental thermodynamic principles under influence of ion irradiation. • Ion induced surface/interface microstructural changes using SEM/X-TEM. • Ion induced sputtering, thermal spike induced local melting. • Thermodynamic driving forces relate to surface and interfacial energies.

  3. Molecular mechanisms of induced mutagenesis. Replication in vivo of bacteriophage phiX174 single-stranded, ultraviolet light-irradiated DNA in intact and irradiated host cells

    Energy Technology Data Exchange (ETDEWEB)

    Caillet-Fauquet, P; Defais, M; Radman, M [Brussels Univ. (Belgium)

    1977-11-25

    Genetic analysis has revealed that radiation and many chemical mutagens induce in bacteria an error-prone DNA repair process which is responsible for their mutagenic effect. The biochemical mechanism of this inducible error-prone repair has been studied by analysis of the first round of DNA synthesis on ultraviolet light-irradiated phiX174 DNA in both intact and ultraviolet light-irradiated host cells. Intracellular phiX174 DNA was extracted, subjected to isopycnic CsCl density-gradient analysis, hydroxylapatite chromatography and digestion by single-strand-specific endonuclease S/sub 1/. Ultraviolet light-induced photolesions in viral DNA cause a permanent blockage of DNA synthesis in intact Escherichia coli cells. However, when host cells were irradiated and incubated to induce fully the error-prone repair system, a significant fraction of irradiated phiX174 DNA molecules can be fully replicated. Thus, inducible error-prone repair in E.coli is manifested by an increased capacity for DNA synthesis on damaged phiX174 DNA. Chloramphenicol (100 ..mu.. g/ml), which is an inhibitor of the inducible error-prone DNA repair, is also an inhibitor of this particular inducible DNA synthesis.

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

    International Nuclear Information System (INIS)

    Gurtner, Kristin; Hessel, Franziska; Eicheler, Wolfgang; Dörfler, Annegret; Zips, Daniel; Heider, Karl-Heinz; Krause, Mechthild; Baumann, Michael

    2012-01-01

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

  5. γ-irradiation induced zinc ferrites and their enhanced room-temperature ammonia gas sensing properties

    Science.gov (United States)

    Raut, S. D.; Awasarmol, V. V.; Ghule, B. G.; Shaikh, S. F.; Gore, S. K.; Sharma, R. P.; Pawar, P. P.; Mane, R. S.

    2018-03-01

    Zinc ferrite (ZnFe2O4) nanoparticles (NPs), synthesized using a facile and cost-effective sol-gel auto-combustion method, were irradiated with 2 and 5 kGy γ-doses using 60Co as a radioactive source. Effect of γ-irradiation on the structure, morphology, pore-size and pore-volume and room-temperature (300 K) gas sensor performance has been measured and reported. Both as-synthesized and γ-irradiated ZnFe2O4 NPs reveal remarkable gas sensor activity to ammonia in contrast to methanol, ethanol, acetone and toluene volatile organic gases. The responses of pristine, 2 and 5 kGy γ-irradiated ZnFe2O4 NPs are respectively 55%, 66% and 81% @100 ppm concentration of ammonia, signifying an importance of γ-irradiation for enhancing the sensitivity, selectivity and stability of ZnFe2O4 NPs as ammonia gas sensors. Thereby, due to increase in surface area and crystallinity on γ-doses, the γ-irradiation improves the room-temperature ammonia gas sensing performance of ZnFe2O4.

  6. A comparative study of total body irradiation as a method of inducing granulocyte depletion in mice

    International Nuclear Information System (INIS)

    Bogman, M.J.J.T.; Cornelissen, I.M.H.A.; Berden, J.H.M.; Jong, J. de; Koene, R.A.P.

    1984-01-01

    Since conventional methods of inducing depletion of polymorphonuclear granulocytes (PMNs) in mice, such as treatment with cytostatic drugs and anti-PMN sera, proved to be insufficient to induce a stable PMN depletion for several days, and were accompanied by considerable toxic side effects, we induced neutrophil depletion in mice by total body irradiation (TBI) in a single dose of 6.0 Gy (600 rads.) at a dose rate of 0.20 Gy/min. This treatment reduced the number of PMNs in the peripheral circulation to values below 150/μl from day 3-10 after irradiation. The number of lymphocytes fell simultaneously. Platelet counts remained above 60% of normal values during the first 7 days after irradiation. Complement levels were not significantly affected by TBI. The results show that TBI of 6.0 Gy induces pronounced and stable PMN depletion in mice for at least 7 days. Furthermore, under an aseptic regimen the mice can be kept in good condition and losses are less than 5%. (Auth.)

  7. Search for the lowest irradiation dose from literatures on radiation-induced cancer in uterus

    International Nuclear Information System (INIS)

    Yoshizawa, Yasuo; Kusama, Tomoko

    1975-01-01

    A survey of past case reports on radiation-induced cancer of the uterus was carried out with the main object of finding the lowest irradiation dose. Search of literature published since 1912 revealed 548 cases of radiation-induced cancer of the uterus. All of these cases of radiation-induced cancer had received radiation for the treatment of non-malignant disease. The primary gynecological conditions which were the object of radiation therapy were functional bleeding, endometrial hyperplasia, myoma, endometritis, and polyps. The lowest irradiation dose was estimated at 1000-1450 rad in the case of external X-ray irradiation, and 100 mg.hr for intrauterine radium therapy, which corresponds to 100-1000 rad. It was noted that were more cases of corpus cancer than cervical cancer. Histopathological findings of radiation-induced uterine cancer were carcinoma, sarcoma, and mixed mesodermal tumors. The latent period was distributed in the range of 1 to 40 years, with the average of 10.1 years. (auth.)

  8. Ovarian carcinoma: improved survival following abdominopelvic irradiation in patients with a completed pelvic operation

    International Nuclear Information System (INIS)

    Dembo, A.J.; Bush, R.S.; Beale, F.A.; Bean, H.A.; Pringle, J.F.; Sturgeon, J.; Reid, J.G.

    1979-01-01

    A prospective, stratified, randomized study of 190 postoperative ovarian carcinoma patients with Stages IB, II, and III (asymptomatic) presentations is reported. The median time of follow-up was 52 months. Patients in whom bilateral salpingo-oophorectomy and hysterectomy (BSOH) could not be completed because of extensive pelvic tumor had a poor prognosis which did not differ for any of the therapies tested. When BSOH was completed, pelvic plus abdominopelvic irradiation (P + AB) with no diaphragmatic shielding significantly improved patient survival rate and long-term control of occult upper abdominal disease in approximately 25% more patients than pelvic irradiation alone or followed by adjuvant daily chlorambucil therapy. The effectiveness of P + AB in BSOH-completed patients was independent of stage or tumor grade and was most clearly appreciated in patients with all gross tumor removed. Chlorambucil added to pelvic irradiation delayed the time to treatment failure without reducing the number of treatment failures

  9. Kinetics of radiation-induced structural alterations in electron-irradiated polymer-based composites

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Potanin, A.S.; Koztaeva, U.P.

    2002-01-01

    Complete text of publication follows. In our previous studies measurements of internal friction temperature dependence were used for characterization of thermally activated and radiation-induced structural evolution in different types of polymer-based composites. This paper supplements these measurements with kinetic studies of internal friction (IF) parameters and EPR signals in a glass-cloth epoxy-filled laminate ST-ETF after electron irradiation up to doses of 1-10 MGy. Experiment have shown that the lifetime of free radicals in this composite considerably exceeds the characteristic time of molecular structural rearrangement due to scission and cross-linking after irradiation, as determined from IF measurements. This result is explained by slow proceeding of sterically hindered disproportionation reactions that stabilize the end groups of the macro-chain disrupt during irradiation and finally fix the act of scission. A mathematical model is formulated for description of structural evolution and alterations of IF parameters in polymer-based composites during and after electron irradiation. The description is based on the track model of radiation damage in polymers and phenomenological theory of radiation-induced structural transformations. General description does not give details of radiation-chemical conversion in different structural components of composites but indicates the direction of their structural evolution. In the model considered a composite material was divided into three parts (binder, filler, and a boundary layer). It was supposed that after primary distribution of radiation energy radiation-chemical conversion proceeds independently in each of these regions. It was also suggested that all the radical reactions were of the second order. On the example of glass-cloth laminate ST-ETF it is shown that this model allows to describe alterations in composite structural characteristics during irradiation and in the course of their self-organization after

  10. Biochemical and topological analysis of bovine sperm cells induced by low power laser irradiation

    Science.gov (United States)

    Dreyer, T. R.; Siqueira, A. F. P.; Magrini, T. D.; Fiorito, P. A.; Assumpção, M. E. O. A.; Nichi, M.; Martinho, H. S.; Milazzotto, M. P.

    2011-07-01

    Low-level laser irradiation (LLLI) increases ATP production and energy supply to the cell which could increase sperm motility, acrossomal reaction and consequently the fertilizing potential. The aim of this study was to characterize the biochemical and topological changes induced by low power laser irradiation on bull sperm cells. Post-thawing sperm were irradiated with a 633nm laser with fluence rates of 30, 150 and 300mJ.cm-2 (power of 5mW for 1, 5 and 10minutes, respectively); 45, 230, and 450mJ.cm-2 (7.5mW for 1, 5 and 10 minutes); and 60, 300 and 600mJ.cm-2 (10mW for 1, 5 and 10 minutes). Biochemical and metabolical changes were analyzed by FTIR and flow cytometry; oxygen reactive species production was assessed by TBARS and the morphological changes were evaluated by AFM. Motility had no difference among times or powers of irradiation. Increasing in ROS generation was observed with power of 5mW compared to 7.5 and 10mW, and with 10min of irradiation in comparison with 5 and 1min of irradiation. This higher ROS generation was related to an increase in acrossomal and plasma membrane damage. FTIR results showed that the amount of lipids was inversely proportional to the quantity of ROS generated. AFM images showed morphological differences in plasma/acrossomal membrane, mainly on the equatorial region. We conclude that LLLI is an effective method to induce changes on sperm cell metabolism but more studies are necessary to establish an optimal dose to increase the fertility potential of these cells.

  11. Antioxidant Activity of Cabbage and/or Carrot Against Oxidative Stress Induced by Gamma Irradiation in Male Albino Rats

    International Nuclear Information System (INIS)

    Hamza, R.G.; Mahmoud, K.A.

    2011-01-01

    Several studies indicated that diets rich in fruits and vegetables are protective against diseases, and populations that consume such diets have higher plasma antioxidants and exhibit lower risk of cancer and cardiovascular diseases. Vegetable is considered major dietary source of fibers and antioxidants such as polyphenols, flavonoids and carotenoids that can protect against different dietary disorders. The present study was carried out to investigate the potential protective effects of cabbage and/or carrot against oxidative stress induced by gamma irradiation in male albino rats. Chemical composition and phenolic contents in cabbage and carrot were determined. Male albino rats were exposed to 5 Gy (single dose with rate 0.46 Gy/min) of whole body gamma irradiation. Thirty five rats were randomly divided into five groups as follow: group 1: control (rats fed on balanced diet for 6 weeks), group 2: irradiated (rats were exposed to whole gamma irradiation and fed on balanced diet for 6 weeks) and groups 3, 4 and 5: irradiated rats fed on balanced diet and received cabbage 15%, carrot 15% and a combination of cabbage and carrot, respectively. The results obtained revealed that the administration of cabbage and/or carrot diet significantly reduced the changes induced by gamma irradiation in the serum level of glucose and liver function parameters; serum aminotransferases (AST, ALT), alkaline phosphatase (ALP), total protein and albumin. In addition, significant improvements were observed in the serum levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C). Significant enhancement in hepatic antioxidant enzymes; superoxide dismutase (SOD) and catalase (CAT), was observed. The levels of reduced glutathione (GSH) associated with remarkable decrease in the level of lipid peroxidation (TBARS) were observed. Accordingly, it could be concluded that consumption of cabbage and/or carrot

  12. Use of irradiation to improve the safety and quality of Thai prepared meal

    Energy Technology Data Exchange (ETDEWEB)

    Noomhorm, A [Food Engineering and Bioprocess Technology, Asian Institute of Technology (Thailand)

    2002-07-01

    There is a dynamic growth of market for chilled prepared meals in Thailand because of the growth of food services in supermarkets and convenient stores. However, the shelf life of this food is short furthermore it is implicated in a number of serious foodborne disease outbreaks. Irradiation could provide a potential to improve the microbiological safety and extend the shelf life of chilled prepared meals. It is possibly used alone or together with chilling. With the combination of irradiation and chilling, frozen condition could be replaced resulting to saving in energy and cost. However, there is a limitation of information about the application of irradiation on chilled prepared meals. Also, information relevant to the application of food safety control system like Hazard Analysis and Critical Control Point (HACCP) should be gathered to ensure more safety of the irradiated prepared meals. For Thai dishes, they are normally composed of herb and spicy with different types of meat. All dishes are eaten along with rice. Both Thai aromatic rice and herb are susceptible to deterioration in quality by processing factors. Therefore, the study of the effect of irradiation on Thai dishes, which compose of these two components, is necessary.

  13. Accuracy improvement of irradiation data by combining ground and satellite measurements

    Energy Technology Data Exchange (ETDEWEB)

    Betcke, J. [Energy and Semiconductor Research Laboratory, Carl von Ossietzky University, Oldenburg (Germany); Beyer, H.G. [Department of Electrical Engineering, University of Applied Science (F.H.) Magdeburg-Stendal, Magdeburg (Germany)

    2004-07-01

    Accurate and site-specific irradiation data are essential input for optimal planning, monitoring and operation of solar energy technologies. A concrete example is the performance check of grid connected PV systems with the PVSAT-2 procedure. This procedure detects system faults in an early stage by a daily comparison of an individual reference yield with the actual yield. Calculation of the reference yield requires hourly irradiation data with a known accuracy. A field test of the predecessing PVSAT-1 procedure showed that the accuracy of the irradiation input is the determining factor for the overall accuracy of the yield calculation. In this paper we will investigate if it is possible to improve the accuracy of sitespeci.c irradiation data by combining accurate localised pyranometer data with semi-continuous satellite data.We will therefore introduce the ''Kriging of Differences'' data fusion method. Kriging of Differences also offers the possibility to estimate it's own accuracy. The obtainable accuracy gain and the effectiveness of the accuracy prediction will be investigated by validation on monthly and daily irradiation datasets. Results will be compared with the Heliosat method and interpolation of ground data. (orig.)

  14. Improvement of conventional parameters of actual industrial effluent by electron beam irradiation

    International Nuclear Information System (INIS)

    Duarte, C.L.; Sampa, M.H.O.; Rela, P.R.; Silveira, C.G.

    1998-01-01

    The ordinary process to treat wastewater from the dye, textile, chemical, pharmaceutical and paper mill industries do not degrade easily the coloured substances and organic compounds. A study on the improvement of this treatment using high energy electron irradiation was carried out. Experiments were conducted using samples from the public Wastewater Treatment Plant (WTP) that receives about 80% of wastewater from industrial sources and 20% from domestic sources. A large amount of industrial wastewater comes from chemical and textile industries, which change everyday the quality, quantity and colour these characteristics depend on for the production line of each particular industry. Samples from WTP influent and effluent were collected every 15 days and irradiated in a batch system; the delivered doses were 3.0 kGy, 4.0 kGy, 6.0 kGy, 8.0 kGy and 10.0 kGy. For the non-irradiated and irradiated samples the following parameters were analyzed: chemical oxygen demand (COD), fixed and volatile total solids and fixed and volatile suspended solids, absorption spectrum (300-700nm) and gas chromatography. For samples from effluent irradiated with 3.0 kGy dose, the COD value presented a reduction average of 45%, and this result was fixed for higher doses, however the COD of influent sample did not show significant change for all the delivered doses

  15. A study on the improvement of microbiological quality of bromelain by gamma-irradiation

    International Nuclear Information System (INIS)

    Prachasitthisak, Yuthapong; Pringsulaka, Vachira

    2000-01-01

    Sixty bromelain samples produced from Great Food ( Biochem) company and Hong Mao Biochemical company were investigated for microbiological quality. It was found that bromelain quality of both companies did not meet the microbiological standard of the buyers. The total viable microbial counts found in bromelain samples were higher than 5,000 cells per gram. Besides, microorganisms used as hygenic indicator of foods such as coliforms and Escherichia coli were found in some samples. The irradiation effect at the doses of 2, 4, 6, 8 and 10 kGy on microbiological quality and enzyme activity of bromelain were also studied. It was found that irradiation with 4-6 kGy resulted in 1-4 log cycles and 2-5 log cycles reduction of the total viable microbial counts of Great Food and Hong Mao samples, respectively. No coliforms, E. coli. Salmonella and staph. aureus were found in any irradiated sample at the dose of 6 kGy. In addition, irradiation with 6 kGy resulted in average percentage lost of enzyme activity of Great Food and Hong Mao samples were 10.4 and 6.2, respectively. It could be concluded that irradiation with 6 kGy appeared to sufficient for the improvement of microbiological quality of bromelain

  16. Final report of the HFIR [High Flux Isotope Reactor] irradiation facilities improvement project

    International Nuclear Information System (INIS)

    Montgomery, B.H.; Thoms, K.R.; West, C.D.

    1987-09-01

    The High-Flux Isotope Reactor (HFIR) has outstanding neutronics characteristics for materials irradiation, but some relatively minor aspects of its mechanical design severely limited its usefulness for that purpose. In particular, though the flux trap region in the center of the annular fuel elements has a very high neutron flux, it had no provision for instrumentation access to irradiation capsules. The irradiation positions in the beryllium reflector outside the fuel elements also have a high flux; however, although instrumented, they were too small and too few to replace the facilities of a materials testing reactor. To address these drawbacks, the HFIR Irradiation Facilities Improvement Project consisted of modifications to the reactor vessel cover, internal structures, and reflector. Two instrumented facilities were provided in the flux trap region, and the number of materials irradiation positions in the removable beryllium (RB) was increased from four to eight, each with almost twice the available experimental space of the previous ones. The instrumented target facilities were completed in August 1986, and the RB facilities were completed in June 1987

  17. UV irradiation improves the bond strength of resin cement to fiber posts.

    Science.gov (United States)

    Zhong, Bo; Zhang, Yong; Zhou, Jianfeng; Chen, Li; Li, Deli; Tan, Jianguo

    2011-01-01

    The purpose is to evaluate the effect of UV irradiation on the bond strength between epoxy-based glass fiber posts and resin cement. Twelve epoxy-based glass fiber posts were randomly divided into three groups. Group 1 (Cont.): No surface treatment. Group 2 (Low-UV): UV irradiation was conducted from a distance of 10 cm for 10 min. Group 3 (High-UV): UV irradiation was conducted from a distance of 1 cm for 3 min. A resin cement (CLEARFIL SA LUTING) was used for the post cementation to form resin slabs which contained fiber posts in the center. Microtensile bond strengths were tested and the mean bond strengths (MPa) were 18.81 for Cont. group, 23.65 for Low-UV group, 34.75 for High-UV group. UV irradiation had a significant effect on the bond strength (pUV irradiation demonstrates its capability to improve the bond strength between epoxy-based glass fiber posts and resin cement.

  18. Improved crystallinity and dynamic mechanical properties of reclaimed waste tire rubber/EVA blends under the influence of electron beam irradiation

    Science.gov (United States)

    Ramarad, Suganti; Ratnam, Chantara T.; Khalid, Mohammad; Chuah, Abdullah Luqman; Hanson, Svenja

    2017-01-01

    Dependence on automobiles has led to a huge amount of waste tires produced annually around the globe. In this study, the feasibility of recycling these waste tires by blending reclaimed waste tire rubber (RTR) with poly(ethylene-co-vinyl acetate) (EVA) and electron beam irradiation was studied. The RTR/EVA blends containing 100-0 wt% of RTR were prepared in the internal mixer followed by electron beam (EB) irradiation with doses ranging from 50 to 200 kGy. The processing torques, calorimetric and dynamic mechanical properties of the blends were studied. Blends were found to have lower processing torque indicating easier processability of RTR/EVA blends compared to EVA. RTR domains were found to be dispersed in EVA matrix, whereas, irradiation improved the dispersion of RTR into smaller domains in EVA matrix. Results showed the addition of EVA improves the efficiency of irradiation induced crosslink formation and dynamic mechanical properties of the blends at the expense of the calorimetric properties. Storage and loss modulus of 50 wt% RTR blend was higher than RTR and EVA, suggesting partial miscibility of the blend. Whereas, electron beam irradiation improved the calorimetric properties and dynamic mechanical properties of the blends through redistribution of RTR in smaller domain sizes within EVA.

  19. Does laser diode irradiation improve the degree of conversion of simplified dentin bonding systems?

    Directory of Open Access Journals (Sweden)

    Leticia Ferreira de Freitas BRIANEZZI

    Full Text Available Abstract Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC, water sorption (WS, and water solubility (WSB of these bonding systems in an attempt to improve their physico-mechanical resistance. Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU]. Square-shaped specimens were prepared and assigned into 4 groups (n=5: SB and SU (control groups – no laser irradiation and SB-L and SU-L [SB and SU laser (L – irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5 of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10 were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm, irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2. Results Laser irradiation immediately before photopolymerization increased the DC (% of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3, only the dentin bonding system (DBS was a significant factor (pSU. Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.

  20. High resolution laser beam induced current images under trichromatic laser radiation: approximation to the solar irradiation.

    Science.gov (United States)

    Navas, F J; Alcántara, R; Fernández-Lorenzo, C; Martín-Calleja, J

    2010-03-01

    A laser beam induced current (LBIC) map of a photoactive surface is a very useful tool when it is necessary to study the spatial variability of properties such as photoconverter efficiency or factors connected with the recombination of carriers. Obtaining high spatial resolution LBIC maps involves irradiating the photoactive surface with a photonic beam with Gaussian power distribution and with a low dispersion coefficient. Laser emission fulfils these characteristics, but against it is the fact that it is highly monochromatic and therefore has a spectral distribution different to solar emissions. This work presents an instrumental system and procedure to obtain high spatial resolution LBIC maps in conditions approximating solar irradiation. The methodology developed consists of a trichromatic irradiation system based on three sources of laser excitation with emission in the red, green, and blue zones of the electromagnetic spectrum. The relative irradiation powers are determined by either solar spectrum distribution or Planck's emission formula which provides information approximate to the behavior of the system if it were under solar irradiation. In turn, an algorithm and a procedure have been developed to be able to form images based on the scans performed by the three lasers, providing information about the photoconverter efficiency of photovoltaic devices under the irradiation conditions used. This system has been checked with three photosensitive devices based on three different technologies: a commercial silicon photodiode, a commercial photoresistor, and a dye-sensitized solar cell. These devices make it possible to check how the superficial quantum efficiency has areas dependent upon the excitation wavelength while it has been possible to measure global incident photon-to-current efficiency values approximating those that would be obtained under irradiation conditions with sunlight.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong [University of South China, Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, Hengyang, Hunan Province (China)

    2016-11-15

    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. (orig.)

  4. EPR spectra induced by gamma-irradiation of some dry medical herbs

    Science.gov (United States)

    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.

  5. EPR spectra induced by gamma-irradiation of some dry medical herbs

    International Nuclear Information System (INIS)

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

    2009-01-01

    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

  6. A reevaluation of X-irradiation-induced phocomelia and proximodistal limb patterning.

    Science.gov (United States)

    Galloway, Jenna L; Delgado, Irene; Ros, Maria A; Tabin, Clifford J

    2009-07-16

    Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a marked increase in incidence in the early 1960s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation. Both X-irradiation and thalidomide-induced phocomelia have been interpreted as patterning defects in the context of the progress zone model, which states that a cell's proximodistal identity is determined by the length of time spent in a distal limb region termed the 'progress zone'. Indeed, studies of X-irradiation-induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the progress zone model. Here, using a combination of molecular analysis and lineage tracing in chick, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. Because skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the aetiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that proximodistal patterning is unaffected after X-irradiation does not support the predictions of the progress zone model.

  7. A Reevaluation of X-Irradiation Induced Phocomelia and Proximodistal Limb Patterning

    Science.gov (United States)

    Galloway, Jenna L.; Delgado, Irene; Ros, Maria A.; Tabin, Clifford J.

    2009-01-01

    Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a dramatic increase in incidence in the early 1960’s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative1, 2. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation3-5. Both X-irradiation5 and thalidomide-induced phocomelia5, 6 have been interpreted as patterning defects in the context of the Progress Zone Model, which states that a cell’s proximodistal (PD) identity is determined by the length of time spent in a distal limb region termed the “Progress Zone” 7. Indeed, studies of X-irradiation induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the Progress Zone Model. Here, using a combination of molecular analysis and lineage tracing, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. As skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the etiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that PD patterning is unaffected following X-irradiation does not support the predictions of the Progress Zone

  8. EPR spectra induced by gamma-irradiation of some dry medical herbs

    Energy Technology Data Exchange (ETDEWEB)

    Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)], E-mail: ndyepr@bas.bg; Lagunov, O. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food technology, 1162 Sofia (Bulgaria)

    2009-04-15

    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.

  9. Structural modifications induced by ion irradiation and temperature in boron carbide B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Victor, G., E-mail: g.victor@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pipon, Y.; Bérerd, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); CEA-DEN, Saclay, 91191 Gif-sur-Yvette (France); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Djourelov, N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee blvd, BG-1784 Sofia (Bulgaria); ELI-NP, IFIN-HH, 30 Reactorului Str, MG-6 Bucharest-Magurele (Romania); Miro, S. [CEA-DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Baillet, J. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pradeilles, N.; Rapaud, O.; Maître, A. [SPCTS, UMR CNRS 7315, Centre Européen de la céramique, University of Limoges (France); Gosset, D. [CEA, Saclay, DMN-SRMA-LA2M, 91191 Gif-sur-Yvette (France)

    2015-12-15

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B{sub 4}C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B{sub 4}C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (S{sub e} ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B{sub 4}C structure under irradiation.

  10. Structural modifications induced by ion irradiation and temperature in boron carbide B4C

    Science.gov (United States)

    Victor, G.; Pipon, Y.; Bérerd, N.; Toulhoat, N.; Moncoffre, N.; Djourelov, N.; Miro, S.; Baillet, J.; Pradeilles, N.; Rapaud, O.; Maître, A.; Gosset, D.

    2015-12-01

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B4C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B4C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (Se ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B4C structure under irradiation.

  11. γ-irradiation-induced mortality: protective effect of protease inhibitors in chickens and mice

    International Nuclear Information System (INIS)

    Palladino, M.A.; Galton, J.E.; Troll, W.; Thorbecke, G.J.

    1982-01-01

    Chickens (Gallus domesticus) were protected from the acute γ-irradiation-induced mortality (within 24 hours) by the proteolytic enzyme inhibitors, soy-bean trypsin inhibitor (SBTI), lima bean inhibitor (LBTI), antipain, α-N-benzoyl-L-arginine ethyl ester HCl (BAEE), trasylol, and leupeptin. Several other enzyme inhibitors, p-tosyl-L-arginine methyl ester HCl (TAME), α-tosyl-lysyl-chloromethyl ketone HCl (TLCK) and epsilon-amino caproic acid (EACA), did not protect. EACA even increased the mortality caused by γ-irradiation. The pattern of protective enzyme inhibitors suggests involvement of a kallikrein-like enzyme. SBTI and antipain also protected against low range lethal γ-irradiation exposures, 690 R in BALB/c and 880 R in SJL/J mice. It is suggested that enhanced vascular permeability, which in chickens is known to be the cause of the irradiation mortality during the first 24 hours, may also contribute to the mortality in mice during the first week after irradiation. (author)

  12. Role of carnitine in ameliorating the lead and / or irradiation induced toxicity in male albino rats

    International Nuclear Information System (INIS)

    El-Sayed, N.M.

    2005-01-01

    This work: aimed to investigate the protective effect of carnitine (3-hydroxy-4-N-trimethyl amino butyric acid) on the contents of total protein, albumin, glucose and lipid peroxides as malonaldehyde (MDA) in serum, in addition to liver glycogen and lipid peroxides content 1, 2, 4 weeks after exposure of rats to a collective dose of 4 Gy whole body gamma irradiation and / or lead treatment. Adult male rats received lead (50 mg/kg body weight) and / or exposed to fractionated dose (4 Gy) of gamma irradiation delivered as 0.5 Gy twice weekly for four weeks. Results of the present study revealed that fractionated whole body gamma irradiation and / or lead administration induced cellular damage manifested by a significant decrease in serum total protein and albumin, and a significant increase in serum glucose and MDA content as well as significant increase in liver glycogen and MDA. Administration of carnitine (200 mg/kg b.wt.) before lead and / or gamma irradiation, has significantly ameliorated the observed changes, indicating the prophylactic action of carnitine on lead and / or irradiation toxicity

  13. Irradiation-induced structure and property changes in tokamak plasma-facing, carbon-carbon composites

    International Nuclear Information System (INIS)

    Burchell, T.D.