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Sample records for chronic irradiation studies

  1. Study of splenic irradiation in chronic lymphocytic leukemia

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    Guiney, M.J.; Liew, K.H.; Quong, G.G.; Cooper, I.A.

    1989-01-01

    A retrospective study was performed to assess the effect of splenic irradiation (SI) on splenomegaly, splenic pain, anemia, and thrombocytopenia in patients with chronic lymphocytic leukemia. Twenty-two patients received 32 courses of SI. Of 31 courses of SI given for splenomegaly there were 19 responders (61%). Ten courses of SI were given for splenic pain resulting in partial relief of pain in 4 courses and complete relief in 4 courses. Only 4 of 16 courses given for anemia resulted in elevations of hemoglobin of 2 g/dL or more. Of the 14 courses of SI given for thrombocytopenia there were only 2 responses with platelet counts decreasing further in another 9 courses. The median duration of response was 14 months (range: 3-116 months). There was no dose-response relationship detected for SI in CLL. Treatment related toxicity was hematologic and secondary to leucopenia and thrombocytopenia. We recommend the use of small fraction sizes of 25 cGy to 50 cGy and close monitoring of hematological parameters. Splenic irradiation effectively palliates splenomegaly and reduces spleen size in CLL. It was of limited value in correcting anemia and thrombocytopenia in this patient population.

  2. Comparison of total body irradiation vs chlorambucil and prednisone for remission induction of active chronic lymphocytic leukemia: an ECOG study. Part I: total body irradiation-response

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    Rubin, P.I. (Univ. of Rochester Cancer Center, NY); Bennett, J.M.; Begg, C.; Bozdech, M.J.; Silber, R.

    1981-12-01

    Twenty-six evaluable patients were entered into two fractionated total body irradiation (TBI) programs; 11 patients received a course of 150 rad TBI (x 3 if tolerated) and 15 patients received a lower dose course of 50 rad (x 3 if tolerated). Complete remissions (CR) were not produced by either course; however, the higher dose course (Plan I) yielded a partial response (PR) rate of 73%, while the lower dose course yielded a PR of 47%. Although fraction size seemed trivial in both TBI plans, an unexpected high degree of hematologic toxicity was encountered, and was parallel to the response rates: in Plan I 73% of patients experienced severe to life-threatening depression of platelets or granulocytes, whereas in Plan II this rate was 47%. This was of short duration with rapid return of blood counts to normal levels. One death can be attributed to TBI. The chemotherapy arm of the study demonstrated superiority in terms of complete responses. Twenty-three percent of patients treated by cholrambucil and prednisone attained CR, in contrast to 0% of TBI patients. PR for chemotherapy was similar to that obtained with TBI. Chemotherapy also proved superior in terms of overall response rate, number of patients in remission, and in the median duration of response, but not in the median duration of survival. Fractional TBI techniques for active chronic lymphocytic leukemia (CLL) should be interrupted when the platelet count dips below 100,000 and the granulocyte count is lower than 2,000. Future studies should combine TBI radiation therapy and chemotherapy.

  3. Effect of total lymphoid irradiation in chronic progressive multiple sclerosis

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    Cook, S.D.; Devereux, C.; Troiano, R.; Hafstein, M.P.; Zito, G.; Hernandez, E.; Lavenhar, M.; Vidaver, R.; Dowling, P.C.

    1986-06-21

    Total lymphoid irradiation (TLI; 1980 cGy) or sham irradiation was given to 40 patients with chronic progressive multiple sclerosis (MS) in a prospective, randomised, double-blind study. During mean follow-up of 21 months, MS patients treated with TLI has less functional decline than sham-irradiated MS patients (p<0.01). A significant relation was noted between absolute blood lymphocyte counts in the first year after TLI and subsequent course, patients with higher lymphocyte counts generally having a worse prognosis (p<0.01). TLI was well tolerated and associated with only mild short-term, and to date, long-term side-effects.

  4. Splenic irradiation before hematopoietic stem cell transplantation for chronic myeloid leukemia: long-term follow-up of a prospective randomized study.

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    Gratwohl, Alois; Iacobelli, Simona; Bootsman, Natalia; van Biezen, Anja; Baldomero, Helen; Arcese, William; Arnold, Renate; Bron, Dominique; Cordonnier, Catherine; Ernst, Peter; Ferrant, Augustin; Frassoni, Francesco; Gahrton, Gösta; Richard, Carlos; Kolb, Hans Jochem; Link, Hartmut; Niederwieser, Dietger; Ruutu, Tapani; Schattenberg, Anton; Schmitz, Norbert; Torres-Gomez, Antonio; Zwaan, Ferry; Apperley, Jane; Olavarria, Eduardo; Kröger, Nicolaus

    2016-05-01

    In the context of discussions on the reproducibility of clinical studies, we reanalyzed a prospective randomized study on the role of splenic irradiation as adjunct to the conditioning for hematopoietic stem cell transplantation (HSCT) for chronic myeloid leukemia (CML). Between 1986 and 1989, a total of 229 patients with CML were randomized; of these, 225 (98 %; 112 with, 113 without splenic irradiation) could be identified in the database and their survival updated. Results confirmed the early findings with no significant differences in all measured endpoints (overall survival at 25 years: 42.7 %, 32.0-52.4 % vs 52.9 %, 43.2-62.6 %; p = 0.355, log rank test). Additional splenic irradiation failed to reduce relapse incidence. It did not increase non-relapse mortality nor the risk of late secondary malignancies. Comforting are the long-term results from this predefined consecutive cohort of patients: more than 60 % were alive at plus 25 years when they were transplanted with a low European Society for Blood and Marrow Transplantation (EBMT) risk sore. This needs to be considered today when treatment options are discussed for patients who failed initial tyrosine kinase inhibitor therapy and have an available low risk HLA-identical donor.

  5. Pathological consequences of chronic low daily dose gamma irradiation

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

    2000-07-01

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

  6. Rituximab, fludarabine, and total body irradiation as conditioning regimen before allogeneic hematopoietic stem cell transplantation for advanced chronic lymphocytic leukemia: long-term prospective multicenter study.

    Science.gov (United States)

    Michallet, Mauricette; Socié, Gerard; Mohty, Mohamad; Sobh, Mohamad; Bay, Jacques-O; Morisset, Stéphane; Labussière-Wallet, Hélène; Tabrizi, Reza; Milpied, Noel; Bordigoni, Pierre; El-Cheikh, Jean; Blaise, Didier

    2013-02-01

    To evaluate the efficacy and toxicity of reduced-intensity conditioning (RIC) combining fludarabine, low-dose total body irradiation (TBI) and rituximab before allogeneic hematopoietic stem cell transplantation (allo-HSCT) from human leucocyte antigen (HLA) identical siblings, we conducted a prospective study in patients ≤65 years old with advanced chronic lymphocytic leukemia (CLL) stage B or C in response after a salvage treatment. Conditioning included rituximab (375 mg/m² on day 5), fludarabine (30 mg/m² from day 4 to day 2), TBI (2 Gy on day 0), and rituximab (500 mg/m² on days 1 and 8). Forty patients were included, 34 (85%) were male with a median age of 54 years (range, 35-65 years), 38 (95%) were in B stage, and 2 were in stage C; only 7 patients (17%) were in complete response. Seven (17%) patients did not receive rituximab. Thirty-nine (98%) patients engrafted, 17 patients developed acute graft-versus-host disease (GVHD) grade ≥II with a cumulative incidence at 3 months of 44% (36-52) with a significant protective effect of rituximab (p = 0.02). The cumulative incidence of chronic GVHD was 29% (21-36) at 12 months for both limited and extensive forms. The median overall survival was not reached with 5-years probability of 55% (41-74). The multivariate analysis showed a positive effect of rituximab on overall survival and event-free survival (hazard ratio [HR] = 0.1 [0-0.6], p = 0.02; and HR = 0.1 [0-0.4], p = 0.035, respectively). The association of fludarabine, TBI, and rituximab is feasible, well tolerated, and allows better outcomes in advanced CLL.

  7. Comparison of total body irradiation vs chlorambucil and prednisone for remission induction of active chronic lymphocytic leukemia: an ECOG study. Part I: total body irradiation-response and toxicity

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    Rubin, P. (Univ. of Rochester, NY); Bennent, J.M.; Begg, C.; Bozdech, M.J.; Silber, R.

    1981-12-01

    Twenty-six evaluable patients were entered into two fractionated total body irradiation (TBI) programs; 11 patients received a course of 150 rad TBI (x 3 if tolerated) and 15 patients received a lower dose course of 50 rad (x 3 if tolerated). Complete remissions (CR) were not produced by either course; however, the higher dose course (Plan I) yielded a partial response (PR) rate of 73%, while the lower dose course yielded a PR of 47%. Although fraction size seemed trivial in both TBI plans, an unexpected high degree of hematologic toxicity was encountered, and was parallel to the response rates: in Plan I 73% of patients experienced severe to life-threatening depression of platelets, or granulocytes, whereas in Plan II this rate was 47%. This was of short duration with rapid return of blood counts to normal levels. One death can be attributed to TBI. The chemotherapy arm of the study demonstrated superiority in terms of complete responses. Twenty-three percent of patients treated by cholrambucil and prednisone attained CR, in contrast to 0% of TBI patients. PR for chemotherapy was similar to that obtained with TBI. Chemotherapy also proved superior in terms of overall response rate, number of patients in remission, and in the median duration of response, but not in the median duration of survival. Fractional TBI techniques for active chronic lymphocytic leukemia (CLL) should be interrupted when the platelet count dips below 100,000 and the granulocyte count is lower than 2,000. Future studies should continue TBI radiation therapy and chemotherapy.

  8. Mediastinal irradiation for chronic lymphocytic leukemia

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    Sawitskii, A.; Rai, K.R.; Aral, I.; Silver, R.T.; Glicksman, A.S.; Carey, R.W.; Scialla, S.; Cornell, C.J. Jr.; Seligman, B.; Shapiro, L.

    1976-12-01

    Thirty-one patients with chronic lymphocytic leukemia were treated with mediastinal radiation. In none of the patients was complete remission achieved; either partial remission or clinical improvement was achieved in 52 percent, but the duration of response was short. The response rate was 77 percent for the patients receiving a total radiation dose greater than 3,000 rads and 45 percent for those receiving less than 3,000 rads. Severe life-threatening toxicity was noted in 11 patients and seven of these patients died; two patients died with progressive disease. Severe toxicity was manifested by one or more of the following: bone marrow aplasia, pancytopenia, gram-negative sepsis, generalized herpes zoster and severe esophagitis. Neither the total dose of radiation nor the dose per week correlated with the severity of reaction or death.

  9. Hematopoietic tissue repair under chronic low daily dose irradiation

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    Seed, T.M.

    1994-12-01

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

  10. Chronic oxidative stress after irradiation: an unproven hypothesis

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    Cohen, Samuel R; Cohen, Eric P

    2012-01-01

    Injury and organ failure after irradiation of late-responding tissues is a substantial problem in radiation oncology and a major threat after accidental or belligerent exposures. The mechanisms of injury may include death of clonogens, vascular injury, activation of cytokine networks, and/or chronic oxidative stress. Knowledge of mechanisms may guide optimal use of mitigators. The hypothesis of chronic oxidative stress as a mechanism of late radiation injury has received much attention. We review herein the published evidence for chronic oxidative stress in vivo, and for use of antioxidants as mitigators of normal tissue radiation injury. We conclude that there is only indirect evidence for chronic oxidative stress after irradiation, and there are only limited published reports of mitigation by antioxidants. We did not find a differentiation of persistent markers of oxidative stress from an ongoing production of oxygen radicals. It is thus unproven that chronic oxidative stress plays a major role in causing radiation injury and organ failure in late-responding tissues. Further investigation is justified, to identify persistent oxidative stress and to identify optimal mitigators of radiation injury. PMID:23245910

  11. Modeling analysis of the lymphocytopoiesis dynamics in chronically irradiated residents of Techa riverside villages

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    Smirnova, Olga A. [Federal State Unitary Enterprise Research and Technical Center of Radiation-Chemical Safety and Hygiene, Moscow (Russian Federation); Akleyev, Alexander V. [Urals Research Center for Radiation Medicine (URCRM), Chelyabinsk (Russian Federation); Chelyabinsk State University, Chelyabinsk (Russian Federation); Dimov, Georgy P. [Urals Research Center for Radiation Medicine (URCRM), Chelyabinsk (Russian Federation)

    2014-08-15

    A biologically motivated dynamical model of the lymphocytopoietic system in irradiated humans is applied here to analyze the data obtained under hematological examinations of residents of Techa riverside villages. Those people were exposed to chronic irradiation with varying dose rates, due to the radioactive contamination of the river basin by the Mayak Production Association. Modeling studies revealed the relationship between the dynamics of the lymphocytopoietic system in the examined individuals and the variation of dose rate over the considered period of time. It is found that the developed model is capable of reproducing the decreased level of blood lymphocyte concentration observed during the period of maximum radiation exposure, the recovery processes in the system observed during the period of decreasing dose rate, as well as the enhanced mitotic activity of bone marrow precursor cells in this hematopoietic lineage observed during the entire period under consideration. Mechanisms of these effects of chronic irradiation on the human lymphocytopoietic system are elucidated based on the applied model. The results obtained demonstrate the efficiency of the developed model in the analysis, investigation, and prediction of effects of chronic irradiation with varying dose rate on the human lymphocytopoietic system. In particular, the developed model can be used for predicting any radiation injury of this vital system in people exposed to chronic irradiation due to environmental radiological events, such as anthropogenic radiation accidents or radiological terroristic attacks. (orig.)

  12. Effects of He-Ne laser acupuncture-point irradiation on serology hepatitis virus markers in chronic hepatitis B

    Science.gov (United States)

    Wang, Yue-lan; Huang, Bing-chen; Ni, Liu-da

    1993-03-01

    For most of the patients with chronic hepatitis B the immunologic function is deficient. Immunopotentiation and immunoregulation can be used as effective treatments. Laser irradiation can potentiate the cellular immune function of the human body and has good effects on improving clinical symptoms, cutting short the process of diseases, and promoting HBsAg negative change. Thereby we have a randomized opportunity to study the effect of He-Ne laser acupoint irradiation on serological HBV markers (HBVM) in chronic hepatitis B (CHB).

  13. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

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    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

  14. Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts.

    Science.gov (United States)

    Wirohadidjojo, Yohanes Widodo; Budiyanto, Arief; Soebono, Hardyanto

    2016-09-01

    To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.

  15. Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts

    Science.gov (United States)

    Budiyanto, Arief; Soebono, Hardyanto

    2016-01-01

    To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm-2) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined. PMID:27401663

  16. Lipid composition of liver microsomes and mitochondria after acute and chronic {gamma}-irradiation of rats

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    Markevich, L.N.; Kolomiitseva, I.K. [Institute of Cell Biophysics, Moscow (Russian Federation)

    1994-07-01

    Acute {gamma}-irradiation of rats at doses of 100 and 270 Gy stimulates lipid synthesis and changes the lipid composition of liver cell organelles. The content of cholesterol and cholesterol esters in microsomes increased at 100 Gy and decreased at 270 Gy, with total phospholipid content remaining unchanged. The lipid content in mitochondria decreased considerably 1 h after irradiation at 270 Gy. This change was significantly less pronounced 47 h later. Under chronic {gamma}-irradiation (0.129 Gy/day), cholesterol and cardiolipin in mitochondria increased. The changes in lipid content caused by acute irradiation are presumed to be related to activated synthesis of lipids in the liver. The modification of the lipid content of mitochondria observed in chronically irradiated rats may indicate that energy-metabolizing liver cell systems are involved in the adaptation to irradiation.

  17. Study of irradiation creep of vanadium alloys

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    Tsai, H.; Strain, R.V.; Smith, D.L. [Argonne National Lab., IL (United States)] [and others

    1997-08-01

    Thin-wall tubing was produced from the 832665 (500 kg) heat of V-4 wt.% Cr-4 wt.% Ti to study its irradiation creep behavior. The specimens, in the form of pressurized capsules, were irradiated in Advanced Test Reactor and High Flux Isotope Reactor experiments (ATR-A1 and HFIR RB-12J, respectively). The ATR-A1 irradiation has been completed and specimens from it will soon be available for postirradiation examination. The RB-12J irradiation is not yet complete.

  18. Case of chronic myelocytic leukemia in myeloblastic crisis with eosinophilia after splenic irradiation

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    Mimura, Kazuo; Otsuka, Teruhisa; Niho, Yoshiyuki; Nagasawa, Kohei; Okamura, Seiichi

    1985-02-01

    We report herein a patient with myeloblastic transformation of chronic myelocytic leukemia (CML) with eosinophilia after splenic irradiation following chemotherapy. When splenic irradiation of 50 rads per day was given, eosinophils in the peripheral blood increased gradually to more than 70% of the white blood cells, whereas before splenic irradiation they comprised only 1%. Bone marrow aspiration also showed marked eosinophilia after the irradiation. To our knowledge, eosinophilia over 70% both in the peripheral blood and in the bone marrow of patients with myeloblastic transformation of CML has not been reported. (author).

  19. Study of rice. gamma. -irradiation

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    Lien, J.J.; Chau, R.S.; Chen, S.C.; Chu, S.L.; Fu, Y.K.; Fang, C.K.; Fu, Y.H.

    1981-03-01

    The purpose of this experiment was to investigate whether the /sup 60/Co gamma-irradiated milled rice packed in economic and practical sealed bags could be preserved in common granaries in Taiwan for more than one year rather than slightly over one month without quality deterioration. As a result of this experiment we found that during the preservation of over a period of 18 months, the contents, such as moisture, ash, protein and fiber, of Tainan-5 Bon-Lai (Japonica Type) rice irradiated with 20 and 40 krad doses were quite stable, whereas reducing sugar showed slight fluctuations but did not vary significantly either. The fat, vitamin B/sub 1/ and niacin contents were found being reduced, while the increase in fatty acid content was an inevitable phenomenon along with the proceeding of the preservation.

  20. INTRACELLULAR COPPER ACCUMULATION ENHANCES THE GROWTH OF KINEOCOCCUS RADIOTOLERANS DURING CHRONIC IRRADIATION

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    Bagwell, C; Charles Milliken, C

    2007-07-24

    The actinobacteria Kineococcus radiotolerans is highly resistant to ionizing radiation, desiccation, and oxidative stress; though the underlying biochemical mechanisms are unknown. The purpose of this study was to explore a possible linkage between the uptake of transition metals and extreme resistance to ionizing radiation and oxidative stress. The effects of 6 different divalent cationic metals on growth were examined in the absence of ionizing radiation. None of the metals tested were stimulatory, though cobalt was inhibitory to growth. In contrast, copper supplementation dramatically increased cell growth during chronic irradiation. K. radiotolerans exhibited specific uptake and intracellular accumulation of copper compared to only a weak response to both iron and manganese supplementation. Copper accumulation sensitized cells to hydrogen peroxide. Acute irradiation induced DNA damage was similar between the copper-loaded culture as the age-synchronized no copper control culture, though low molecular weight DNA was more persistent during post-irradiation recovery in the Cu-loaded culture. Still, the estimated times for genome restoration differed by only 1 hr between treatments. While we cannot discount the possibility that copper fulfills an unexpectedly important biochemical role in a radioactive environment; K. radiotolerans has a high capacity for intracellular copper sequestration, and presumably efficiently coordinated oxidative stress defenses and detoxification systems, which confers cross-protection from the damaging affects ionizing radiation.

  1. Employment of whole-body. gamma. -irradiation in chronic lymphoid leukemia and malignant lymphomas

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    Danilova, N.B.; Baranov, A.E.; Khrushchev, V.G.; Grammatikati, V.S.; Murav' eva, L.I.; Strashnenko, E.S.

    1982-11-01

    There are presented data showing that whole-body therapeutic ..gamma..-irradiation is an effective method of treatment of chronic lymphoid leukosis and lymphomas. Rapid lymphopenic effect, satisfactory diminution of lymph nodes and spleen sizes testify to the effect. The necessity of further investigation of the treatment method is underlined. It is of interest to trace the fate of lymphocyte subpopulations in the course and after treatment. The urgency of working out a most rational scheme for whole-body therapeutic irradiation and for investigating indications for local irradiation of various groups of lymphatic nodes is indicated.

  2. [Ecological and genetic monitoring of muridae from populations undergone to the chronic irradiation].

    Science.gov (United States)

    Taskaev, A I; Bashlykova, L A; Zaĭnullin, V G

    2010-01-01

    In work the data of long-term researches of consequences of chronic irradiation and radioactive pollution on a population of muridaea living in a zone of failure on the Chernobyl atomic power station and in territory of Northern radioecological station are resulted. It is shown, that chronic influence by investigated factors leads to authentically significant change of size of the genetic load determined on a level cytogenetic damages, intensity of reproduction, fertility.

  3. Acute and chronic response of articular cartilage to Ho:YAG laser irradiation

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    Trauner, Kenneth B.; Nishioka, Norman S.; Flotte, Thomas J.; Patel, Dinesh K.

    1992-06-01

    A Ho:YAG laser system operating at a wavelength of 2.1 microns has recently been introduced for use in arthroscopic surgery. The acceptability of this new tool will be determined not only by its ability to resect tissue, but also by its long term effects on articular surfaces. In order to investigate these issues further, we performed two studies to evaluate the acute and chronic effects of the laser on cartilaginous tissue. We evaluated the acute, in vitro effects of 2.1 micron laser irradiation on articular and fibrocartilage. This included the measurement of ablation efficiency, ablation threshold and thermal damage in both meniscus and articular cartilage. To document the chronic effects on articular cartilage in vivo, we next performed a ten week healing study. Eight sheep weighing 30 - 40 kg underwent bilateral arthrotomy procedures. Multiple full thickness and partial thickness defects were created. Animals were sacrificed at 0, 2, 4, and 10 weeks. The healing study demonstrated: (1) no healing of full or partial thickness defects at 10 weeks with hyaline cartilage; (2) fibrocartilaginous granulation tissue filling full thickness defects at two and four weeks, but no longer evident at ten weeks; (3) chondrocyte necrosis extending to greater than 900 microns distal to ablation craters at four weeks with no evidence of repair at later dates; and (4) chondrocyte hyperplasia at the borders of the damage zone at two weeks but no longer evident at later sacrifice dates.

  4. The studies of irradiation hardening of stainless steel reactor internals under proton and xenon irradiation

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    Xu, Chaoliang; Zhang, Lu; Qian, Wangjie; Mei, Jinna; Liu, Xiang Bing [Suzhou Nuclear Power Research Institute, Suzuhou (China)

    2016-06-15

    Specimens of stainless steel reactor internals were irradiated with 240 keV protons and 6 MeV Xe ions at room temperature. Nanoindentation constant stiffness measurement tests were carried out to study the hardness variations. An irradiation hardening effect was observed in proton- and Xe-irradiated specimens and more irradiation damage causes a larger hardness increment. The Nix-Gao model was used to extract the bulk-equivalent hardness of irradiation-damaged region and critical indentation depth. A different hardening level under H and Xe irradiation was obtained and the discrepancies of displacement damage rate and ion species may be the probable reasons. It was observed that the hardness of Xe-irradiated specimens saturate at about 2 displacement/atom (dpa), whereas in the case of proton irradiation, the saturation hardness may be more than 7 dpa. This discrepancy may be due to the different damage distributions.

  5. Effects of Linear-Polarized Near-Infrared Light Irradiation on Chronic Pain

    Directory of Open Access Journals (Sweden)

    Dong Huang

    2012-01-01

    Full Text Available In order to study the efficacy of linear-polarized near-infrared light irradiation (LPNIR on relieving chronic pain in conjunction with nerve block (NB or local block (LB, a 3-week prospective, randomized, double-blind, controlled study was conducted to evaluate the pre- and post-therapy pain intensity. Visual analogue scales (VASs were measured in all patients before and 6 months after therapy visiting the pain clinic during the period of August 2007 to January 2008. A total of 52 patients with either shoulder periarthritis or myofascial pain syndrome or lateral epicondylitis were randomly assigned into two groups by drawing lots. Patients in Group I were treated with NB or LB plus LPNIR; Group II patients, for their part, were treated with the same procedures as in Group I, but not using LPNIR. In both groups, the pain intensity (VAS score decreased significantly immediately after therapy as compared to therapy. There was a significant difference between the test and control groups immediately after therapy (P<0.05, while no effect 6 months later. No side effects were observed. It is concluded that LPNIR is an effective and safe modality to treat various chronic pains, which has synergic effects with NB or LB.

  6. Effects of linear-polarized near-infrared light irradiation on chronic pain.

    Science.gov (United States)

    Huang, Dong; Gu, Yong-Hong; Liao, Qin; Yan, Xue-Bin; Zhu, Shai-Hong; Gao, Chang-Qing

    2012-01-01

    In order to study the efficacy of linear-polarized near-infrared light irradiation (LPNIR) on relieving chronic pain in conjunction with nerve block (NB) or local block (LB), a 3-week prospective, randomized, double-blind, controlled study was conducted to evaluate the pre- and post-therapy pain intensity. Visual analogue scales (VASs) were measured in all patients before and 6 months after therapy visiting the pain clinic during the period of August 2007 to January 2008. A total of 52 patients with either shoulder periarthritis or myofascial pain syndrome or lateral epicondylitis were randomly assigned into two groups by drawing lots. Patients in Group I were treated with NB or LB plus LPNIR; Group II patients, for their part, were treated with the same procedures as in Group I, but not using LPNIR. In both groups, the pain intensity (VAS score) decreased significantly immediately after therapy as compared to therapy. There was a significant difference between the test and control groups immediately after therapy (P < 0.05), while no effect 6 months later. No side effects were observed. It is concluded that LPNIR is an effective and safe modality to treat various chronic pains, which has synergic effects with NB or LB.

  7. Late results of mucosal proctectomy and colo-anal sleeve anastomosis for chronic irradiation rectal injury

    Energy Technology Data Exchange (ETDEWEB)

    Browning, G.G.P.; Varma, J.S.; Smith, A.N.; Small, W.P.; Duncan, W.

    1987-01-01

    Ten patients with severe chronic irradiation injury to the rectum were treated by mucosal proctectomy and colo-anal sleeve anastomosis. The indications were: recurrent rectal bleeding (five), stricture (three), fistula (one) and intractable pain (one). Overall follow-up has ranged from 8 to 77 months (mean 40 months). In the present survivors (n=7) the follow-up ranges from 18 to 77 months (mean 52 months). Six patients have been followed up for more than 3 years and four for more than 5 years. There was no operative mortality. Three anastomotic strictures occurred but the protecting stoma could be closed in all but one patient. Continence was acceptable although urgency and frequency of defaecation were troublesome symptoms. The operation is recommended for life-threatening, haemorrhagic chronic irradiation injury to the rectum.

  8. Quantitative Modeling of Microbial Population Responses to Chronic Irradiation Combined with Other Stressors

    OpenAIRE

    Igor Shuryak; Ekaterina Dadachova

    2016-01-01

    Microbial population responses to combined effects of chronic irradiation and other stressors (chemical contaminants, other sub-optimal conditions) are important for ecosystem functioning and bioremediation in radionuclide-contaminated areas. Quantitative mathematical modeling can improve our understanding of these phenomena. To identify general patterns of microbial responses to multiple stressors in radioactive environments, we analyzed three data sets on: (1) bacteria isolated from soil co...

  9. [Dynamics of ultrastructural morphology of the nucleolar apparatus in bovine preimplantation embryos collected in an area of chronic irradiation].

    Science.gov (United States)

    Pivko, J; Baran, V; Grafenau, P; Kopecný, V; Pelechatyj, N S; Bondarcuk, V N; Kozuch, A J; Kovalcik, L M

    1997-02-01

    Ultrastructural morphology and immunoelectron microscopy of the nucleus and nucleologenesis in early preimplantation cow embryos were applied in an attempt to demonstrate a possible radiation injury to that early stage of development due to chronical irradiation of the animals in the Tchernobyl area. Mostly eight cell embryos as well as morulae were collected from superovulated cows which were previously constantly kept in zones of different levels of radioactive irradiation. In addition to the normometric status of reproductive organs in no case was it possible to detect an apparent deviation in the nuclear morphology or in the process of nucleologenesis as compared to the physiological situation (Kopecný et al., 1989b, 1991, 1996). This observation was supported by an immunoelectron microscope study of DNA association and penetration in the differentiated nucleolus in the late 8-cell stage. These observations show that the otherwise demonstrated radiation injury localized in the genome does not probably influence markedly the early events of the developing embryo and that the aberrant cytoplasmic command of the nuclear events known in other types of oocyte/early cow embryo impairment (review Kopecný and Nicmann, 1993; Kanka et al. 1991; Pavlok et al., 1993) is not seen in early embryos collected from chronically irradiated animals.

  10. A novel ATM/TP53/p21-mediated checkpoint only activated by chronic γ-irradiation.

    Directory of Open Access Journals (Sweden)

    Lili Cao

    Full Text Available Different levels or types of DNA damage activate distinct signaling pathways that elicit various cellular responses, including cell-cycle arrest, DNA repair, senescence, and apoptosis. Whereas a range of DNA-damage responses have been characterized, mechanisms underlying subsequent cell-fate decision remain elusive. Here we exposed cultured cells and mice to different doses and dose rates of γ-irradiation, which revealed cell-type-specific sensitivities to chronic, but not acute, γ-irradiation. Among tested cell types, human fibroblasts were associated with the highest levels of growth inhibition in response to chronic γ-irradiation. In this context, fibroblasts exhibited a reversible G1 cell-cycle arrest or an irreversible senescence-like growth arrest, depending on the irradiation dose rate or the rate of DNA damage. Remarkably, when the same dose of γ-irradiation was delivered chronically or acutely, chronic delivery induced considerably more cellular senescence. A similar effect was observed with primary cells isolated from irradiated mice. We demonstrate a critical role for the ataxia telangiectasia mutated (ATM/tumor protein p53 (TP53/p21 pathway in regulating DNA-damage-associated cell fate. Indeed, blocking the ATM/TP53/p21 pathway deregulated DNA damage responses, leading to micronucleus formation in chronically irradiated cells. Together these results provide insights into the mechanisms governing cell-fate determination in response to different rates of DNA damage.

  11. Effects of He-Ne laser irradiation on chronic atrophic gastritis in rats

    Institute of Scientific and Technical Information of China (English)

    Xue-Hui Shao; Yue-Ping Yang; Jie Dai; Jing-Fang Wu; Ai-Hua Bo

    2005-01-01

    AIM: To study the effects of He-Ne laser irradiation on experimental chronic atrophic gastritis (CAG) in rats.METHODS: Sixty-three male adult Wistar rats were randomly divided into five groups including normal control group, model control group and three different dosages He-Ne laser groups. The chronic atrophic gastritis (CAG)model in rats was made by pouring medicine which was a kind of mixed liquor including 2% sodium salicylate and 30% alcohol down the throat for 8 wk to stimulate rat gastric mucosa, combining with irregular fasting and compulsive sporting as pathogenic factors; 3.36, 4.80, and 6.24J/cm2doses of He-Ne laser were used, respectively for three different treatment groups, once a day for 20 d. The pH value of diluted gastric acid was determined by acidimeter,the histopathological changes such as the inflammatory degrees in gastric mucosa, the morphology and structure of parietal cells were observed, and the thickness of mucosa was measured by micrometer under optical microscope.RESULTS: In model control group, the secretion of gastric acid was little, pathologic morphological changes in gastric mucosa such as thinner mucous, atrophic glands, notable inflammatory infiltration were found. After 3.36 J/cm2 dose of He-Ne laser treatment for 20 d, the secretion of gastric acid was increased (P<0.05), the thickness of gastric mucosa was significantly thicker than that in model control group (P<0.01), the gastric mucosal inflammation cells were decreased (P<0.05). Morphology, structure and volume of the parietal cells all recuperated or were closed to normal.CONCLUSION: 3.36J/cm2 dose of He-Ne laser has a significant effect on CAG in rats.

  12. CHRONIC FOLLICULITIS- A CLINICOEPIDEMIOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    Balachandran Parapattu Kunjukunju

    2017-04-01

    Full Text Available BACKGROUND Chronic folliculitis is a chronic infection of the hair follicles predominantly seen on legs. The main features of the disease are follicular pustules, perifolliculitis, cutaneous oedema, crusting, scaling, atrophy, loss of hair and follicular scarring. In spite of treatment, the condition progresses till loss of all hair from the affected area. MATERIALS AND METHODS This is a cross-sectional descriptive study of seventy five patients with chronic folliculitis who attended the Outpatient Department of Dermatology and Venereology, Government Medical College, Kottayam, Kerala. After getting the informed written consent, they were enrolled in the study. Aim of the study is to find out the clinical and demographic profile, aetiology and treatment response. RESULTS Out of the 75 patients studied, 57 (76% were males and 18 (24% were females. Maximum age group affected were in the 21-40 years (60%. Out of 75 patients studied, 58.7% were manual labourers. Initial site of involvement was lower limb in 86.7% patients. Involvement of legs seen in all patients in the course of the disease. Oil application, working with wet soil, soap application and rubbing are the common precipitating factors noted in the study. Staphylococci was the commonest aetiological agent seen in 57 (76% patients. CONCLUSION We conclude that chronic folliculitis is mainly a disease of males affecting mainly to the manual labourers, chronic folliculitis is a disease refractory to treatment.

  13. Studies of defects on ion irradiated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Lai, P.F.; Prawer, S.; Spargo, A.E.C.; Bursill, L.A. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  14. Histological and physiological studies on rat heart following irradiation with single doses of X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Yeung, T.K.; Hopewell, J.W.

    1986-01-01

    In the first 6 months after x-irradiation, most rats appeared normal, gaining weight after initial growth delay. Their general condition then declined, death occurring from about 230 days post-irradiation. Mean survival was dose-dependent, ranging from 550 +-12 days to 260 +- 13 days after 20 Gy and 50 Gy respectively. At post-mortem, 70% of irradiated animals had slight pleural effusions and 38% ascites. Early myocardial injury, indicated by T-wave abnormalities, were observed 2 months post-irradiation, consistent with observed degenerative changes seen in the myocardium, but the difference between cardiac output values measured in irradiated and control animals was very small. About 7 months after irradiation, ECG studies showed onset of arrhythmia. Histologically, in addition to chronic myocardial changes, lesions were observed in the larger vessel walls. Measurements of 'equivalent heart muscle wall thickness' showed a dose-dependent decline in irradiated animals after this. Histological and physiological changes were reflected by substantial reduction in cardiac output values in irradiated animals.

  15. Light microscopic and autoradiographic study of non-irradiated and irradiated ocular wounds

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarthy, U.; Gardiner, T.A.; Archer, D.B.; Maguire, C.J. (Queen' s Univ., Belfast, Northern Ireland (UK). Dept. of Opthalmology; Royal Victoria Hospital, Belfast, Northern Ireland (UK). Eye and Ear Clinic)

    1989-01-01

    Focal gamma irradiation was used to limit the intraocular extension of scar tissue which typically occurs after posterior perforating injury to the eye. Standard posterior perforating injuries were created in the right eye of forty-eight rabbits, half of which had the site of perforation focally irradiated using a Cobalt 60 ophthalmic plaque. Non-irradiated wounds healed with profuse formation of highly cellular and vascularised granulation tissue which invaded the vitreous to form contractile vitreo-retinal membranes. In irradiated eyes vitreo-retinal membrane formation was infrequent; the wounds showing only sparse granulation tissue with little or no extension into the vitreous cavity. Autoradiographic studies carried out in a second group of 40 animals showed that the episclera was the main source of the proliferating fibroblasts, and call counts confirmed that the inflammatory and repair responses in irradiated wounds were both delayed and attenuated. (author).

  16. High Levels of Dietary Supplement Vitamins A, C and E are Absorbed in the Small Intestine and Protect Nutrient Transport Against Chronic Gamma Irradiation

    Science.gov (United States)

    Azzam, Edouard I.; Ferraris, Ronaldo P.; Howell, Roger W.

    2015-01-01

    We examined nutrient transport in the intestines of mice exposed to chronic low-LET 137Cs gamma rays. The mice were whole-body irradiated for 3 days at dose rates of 0, 0.13 and 0.20 Gy/h, for total dose delivery of 0, 9.6 or 14.4 Gy, respectively. The mice were fed either a control diet or a diet supplemented with high levels of vitamins A, C and E. Our results showed that nutrient transport was perturbed by the chronic irradiation conditions. However, no apparent alteration of the macroscopic intestinal structures of the small intestine were observed up to day 10 after initiating irradiation. Jejunal fructose uptake measured in vitro was strongly affected by the chronic irradiation, whereas uptake of proline, carnosine and the bile acid taurocholate in the ileum was less affected. D-glucose transport did not appear to be inhibited significantly by either 9.6 or 14.4 Gy exposure. In the 14.4 Gy irradiated groups, the diet supplemented with high levels of vitamins A, C and E increased intestinal transport of fructose compared to the control diet (day 10; t test, P = 0.032), which correlated with elevated levels of vitamins A, C and E in the plasma and jejunal enterocytes. Our earlier studies with mice exposed acutely to 137Cs gamma rays demonstrated significant protection for transport of fructose, glucose, proline and carnosine. Taken together, these results suggest that high levels of vitamins A, C and E dietary supplements help preserve intestinal nutrient transport when intestines are irradiated chronically or acutely with low-LET gamma rays. PMID:26484399

  17. High Levels of Dietary Supplement Vitamins A, C and E are Absorbed in the Small Intestine and Protect Nutrient Transport Against Chronic Gamma Irradiation.

    Science.gov (United States)

    Roche, Marjolaine; Neti, Prasad V S V; Kemp, Francis W; Azzam, Edouard I; Ferraris, Ronaldo P; Howell, Roger W

    2015-11-01

    We examined nutrient transport in the intestines of mice exposed to chronic low-LET 137Cs gamma rays. The mice were whole-body irradiated for 3 days at dose rates of 0, 0.13 and 0.20 Gy/h, for total dose delivery of 0, 9.6 or 14.4 Gy, respectively. The mice were fed either a control diet or a diet supplemented with high levels of vitamins A, C and E. Our results showed that nutrient transport was perturbed by the chronic irradiation conditions. However, no apparent alteration of the macroscopic intestinal structures of the small intestine were observed up to day 10 after initiating irradiation. Jejunal fructose uptake measured in vitro was strongly affected by the chronic irradiation, whereas uptake of proline, carnosine and the bile acid taurocholate in the ileum was less affected. D-glucose transport did not appear to be inhibited significantly by either 9.6 or 14.4 Gy exposure. In the 14.4 Gy irradiated groups, the diet supplemented with high levels of vitamins A, C and E increased intestinal transport of fructose compared to the control diet (day 10; t test, P = 0.032), which correlated with elevated levels of vitamins A, C and E in the plasma and jejunal enterocytes. Our earlier studies with mice exposed acutely to 137Cs gamma rays demonstrated significant protection for transport of fructose, glucose, proline and carnosine. Taken together, these results suggest that high levels of vitamins A, C and E dietary supplements help preserve intestinal nutrient transport when intestines are irradiated chronically or acutely with low-LET gamma rays.

  18. [Intravenous laser irradiation of blood for the combined treatment of patients presenting with chronic sensorineural hearing loss].

    Science.gov (United States)

    2011-01-01

    A method for the treatment of chronic sensorineural hearing loss (CSNHL) is proposed that includes administration of trental followed by intravenous laser irradiation of blood (IVLBI). The study included 81 patients at the age from 20 to more than 60 years presenting with CSNHL. They were allocated to three groups; the patients in group 1 (n=32) were given trental intravenously followed by intravenous laser irradiation of blood, those of group 2 (n=24) were treated with IVLBI alone while patients of group 3 (n=25) received "traditional" treatment. Audiometric examination and rheoencephalography were carried out before and after therapy. The hearing improved to 18-20 dB in group 1, to 10-15 dB in group 2, and to 10 dB in group 3. The improvement of rheoencephalographic characteristics was documented in the patients of all groups but was especially pronounced in group 1. It is concluded that the proposed method significantly increases the efficiency of treatment of chronic sensorineural hearing loss.

  19. Selective brain responses to acute and chronic low-dose X-ray irradiation in males and females.

    Science.gov (United States)

    Silasi, Greg; Diaz-Heijtz, Rochellys; Besplug, Jill; Rodriguez-Juarez, Rocio; Titov, Viktor; Kolb, Bryan; Kovalchuk, Olga

    2004-12-24

    Radiation exposure is known to have profound effects on the brain, leading to precursor cell dysfunction and debilitating cognitive declines [Nat. Med. 8 (2002) 955]. Although a plethora of data exist on the effects of high radiation doses, the effects of low-dose irradiation, such as ones received during repetitive diagnostic and therapeutic exposures, are still under-investigated [Am. J. Otolaryngol. 23 (2002) 215; Proc. Natl. Acad. Sci. USA 97 (2000) 889; Curr. Opin. Neurol. 16 (2003) 129]. Furthermore, most studies of the biological effects of ionizing radiation have been performed using a single acute dose, while clinically and environmentally relevant exposures occur predominantly under chronic/repetitive conditions. Here, we have used a mouse model to compare the effects of chronic/repetitive and acute low-dose radiation (LDR) exposure (0.5Gy) to ionizing radiation on the brain in vivo. We examined the LDR effects on p42/44 MAPK (ERK1/ERK2), CaMKII, and AKT signaling-the interconnected pathways that have been previously shown to be crucial for neuronal survival upon irradiation. We report perturbations in ERK1/2, AKT, and CREB upon acute and chronic/repetitive low-dose exposure in the hippocampus and frontal cortex of mice. These studies were paralleled by the analysis of radiation effects on neurogenesis and cellular proliferation. Repetitive exposure had a much more pronounced effect on cellular signaling and neurogenesis than acute exposure. These results suggest that studies of single acute exposures might be limited in terms of their predictive value. We also present the first evidence of sex differences in radiation-induced signaling in the hippocampus and frontal cortex. We show the role of estrogens in brain radiation responses and discuss the implications of the observed changes.

  20. Assessment of testicular function after acute and chronic irradiation: Further evidence for an influence of late spermatids on Sertoli cell function in the adult rat

    Energy Technology Data Exchange (ETDEWEB)

    Pineau, C.; Velez de la Calle, J.F.; Pinon-Lataillade, G.; Jegou, B.

    1989-06-01

    To study cell to cell communications within the testis of adult Sprague-Dawley rats, we used acute whole body neutron plus gamma-irradiation over 7-121 days postirradiation and chronic whole body gamma-irradiation over 14-84 days of irradiation and 7-86 days postirradiation. Neither irradiation protocol had an effect on the body weight of the animals. Neutron plus gamma-rays induced dramatic damages to spermatogonia, preleptotene spermatocytes, spermatozoa, and, to a lesser extent, pachytene spermatocytes. In contrast, gamma-rays induced a selective destruction of spermatogonia. Subsequently, in both experiments a maturation-depletion process led to a marked decrease in all germ cell types. A complete or near complete recovery of the different germ cell types and spermatozoa took place during the two postirradiation periods. Under both irradiation protocols Sertoli cells number was unchanged. Androgen-binding protein and FSH levels were normal in spite of the disappearance of most germ cells from spermatogonia to early spermatids. However, the decline of androgen-binding protein as well as the rise of FSH and their subsequent recovery were highly correlated to the number of late spermatids and spermatozoa. Moreover, it appeared that spermatocytes may also interfere with the production of inhibin (Exp B). With neither irradiation was Leydig cell function altered, except in Exp B in which elevated LH levels were temporarily observed. Correlation analysis suggested a relationship between preleptotene spermatocytes and Leydig cell function. In conclusion, this study establishes that chronic gamma-irradiation is particularly useful in the study of intratesticular paracrine regulation in vivo and provides further support to the concept that late spermatids play a major role in controlling some aspects of Sertoli cell function in the adult rat.

  1. Effect of a vitamin D{sub 3}-based nutritional supplement ('Videchol') on carbohydrate metabolism of rats following chronic low dose-rate irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Starikovich, L.S.; Vernikovska, Ya.I.; Vigovska, T.V.; Veliky, M.M. [Lviv Ivan Franko National University, Department of Biochemistry, Lviv (Ukraine); Becerril Aragon, G.A. [Lviv Ivan Franko National University, Department of Biochemistry, Lviv (Ukraine)]. E-mail: gabriel_aragon@mail.ru

    2001-09-01

    In this study we evaluated the effects of the administration of a vitamin D{sub 3} preparation 'Videchol' to chronically irradiated rats (1 cGy day{sup -1}) by the assessment of the activities of several glycolytic enzymes: lactic dehydrogenase (LDH) (EC 1.1.1.28), pyruvate kinase (PK) (EC 2.7.1.40) and hexokinase (HK) (EC 2.7.1.1), in populations of erythroid and myeloid bone marrow cells. Videchol treatment of irradiated rats led to the normalisation of HK and LDH activity at cumulative doses of around 30 cGy in granulocyte-monocyte cells and to normalisation of LDH and PK activities in erythroid cells starting at 20 cGy in comparison with irradiated rats who did not receive Videchol. The reaction kinetic parameters of LDH in erythrocytes changed according to the redistribution pattern of the isozymes throughout the different stages of the experiment. The administration of Videchol to irradiated rats led to a rearrangement of the LDH isozymes ratio characterised by kinetic properties more comparable to those of the controls. Thus, vitamin D{sub 3} appears to induce a normalisation of carbohydrate metabolism in rats chronically irradiated with low dose-rate ionising radiation. (author)

  2. EPR study on gamma-irradiated fruits dehydrated via osmosis

    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; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2007-06-15

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and {gamma}-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas {gamma}-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  3. Clinicomicrobiological study of chronic paronychia

    Directory of Open Access Journals (Sweden)

    Guha P

    1992-01-01

    Full Text Available A total of 261 digits affected in 100 patients of chronic paronychia were studied for clinical features. The bacteriological and mycological flora have been examined in 25 cases of the above 100 cases which were most severely affected. Aerobic bacteria were found in all cases. Staphylococcus aureus was seen in 60 percent. Klebsiella in 16 percent, Escherichia coli in 12 percent, Pseudomonas aeruginosa in 12 percent, Proteus mirabillis in 8 percent, Staphylococcus epidermidis in 4 percent and Streptococcus viridans in 4 percent. Culture for fungus revealed Candida albicans in 64 percent and other species such as C. krusei, C. stellatoides, C. viswanathi, C. parapsilosis and C. tropicalis were present in 1 case each. No fungus was detected in 4 cases(16percent. The present investigation was designed to compare the bacterial and mycotic flora of the nail folds of patients of chronic paronychia with that of western countries.

  4. Antinociceptive effect of linear polarized 0.6 to 1.6 microm irradiation of lumbar sympathetic ganglia in chronic constriction injury rats.

    Science.gov (United States)

    Muneshige, Hiroshi; Toda, Katsuhiro; Ma, Dianli; Kimura, Hiroaki; Asou, Tomohiro; Ikuta, Yoshikazu

    2006-01-01

    Linear polarized near-infrared light created with linear polarized near-infrared light therapy equipment (Super Lizer HA-550, Tokyo Iken Co, Ltd, Tokyo, Japan) has been used for the treatment of various painful disorders in Japan. Irradiation near the stellate ganglion with a Super Lizer (ISGL) is an especially notable therapeutic method used with stellate ganglion block (SGB) or substitutes for SGB. ISGL is a safe, simple, well-tolerated, and effective treatment. We examined the effects of irradiation with a Super Lizer applied to an area near the lumbar sympathetic ganglia on the ligated side in a chronic constriction injury (CCI) model, which is believed to be an animal model of complex regional pain syndrome (CRPS). Rats showing thermal hyperalgesia in a radiant heat test 1 wk postoperatively were used in Experiments 1 and 2: (1) Thermal hyperalgesia of irradiation group (n = 11) was less than that of the control or nonirradiation (n = 11) group at 1, 3, and 8 h after irradiation; however, the effect disappeared 12 h after irradiation. (2) Daily irradiation (n = 16) and 1 wk (n = 14) from 7 days after nerve ligation significantly shortened the interval from thermal hyperalgesia until recovery. Rats showing mechanical hyperalgesia in the von Frey hair test 1 wk postoperatively were used in Experiment 3: 1 wk irradiation beginning 7 days after nerve ligation (n = 9) did not promote the recovery from mechanical hyperalgesia. We speculate that repeated ISGL may be more effective than a single ISGL in alleviating pain in CRPS patients. We cannot explain the discrepancy between the results obtained in Experiments 2 and 3. We believe the results of this study are relevant to the effect of ISGL for patients with upper-limb CRPS: irradiation near the lumbar sympathetic ganglia of the rat is effective for thermal but not mechanical pain in CCI.

  5. Study of the conductivity of irradiated dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.V.; Ivanov, N.V.; Shelenin, A.V.

    1977-01-01

    The processes of ionization of air, metals and dielectrics arising from Gamma irradiation are analyzed. The effect of these processes on the measurement of the electrical conductivity of the dielectrics which are irradiated is evaluated. The maximum current which can be carried by an ionized gas is proportional to the radiation dose, gas pressure and reciprocal gas temperature. It is much more difficult to define the voltage developing between the two metal objects exposed to ionizing radiation due to such factors as the variation in resistance with dose, difficulty in defining the coefficient characterizing the accumulated charge, which depends on the nature of the metal, its shape, thickness and many other factors. Results of a simple calculation are presented in tabular form for aluminum. In some cases the voltage which develops is proportional to dose, in other cases--to the square root of dose, in still other cases--somewhere in between. 3 tables, 6 references.

  6. Effects of a turmeric extract (Curcuma longa) on chronic ultraviolet B irradiation-induced skin damage in melanin-possessing hairless mice.

    Science.gov (United States)

    Sumiyoshi, Maho; Kimura, Yoshiyuki

    2009-12-01

    Turmeric (the rhizomes of Curcuma longa L., Zingiberacease) is widely used as a dietary pigment and spice, and has been traditionally used for the treatment of inflammation, skin wounds and hepatic disorders in Ayurvedic, Unani and Chinese medicine. Although the topical application or oral administration of turmeric is used to improve skin trouble, there is no evidence to support this effect. The aim of this study was to clarify whether turmeric prevents chronic ultraviolet B (UVB)-irradiated skin damage. We examined the effects of a turmeric extract on skin damage including changes in skin thickness and elasticity, pigmentation and wrinkling caused by long-term, low-dose ultraviolet B irradiation in melanin-possessing hairless mice. The extract (at 300 or 1000 mg/kg, twice daily) prevented an increase in skin thickness and a reduction in skin elasticity induced by chronic UVB exposure. It also prevented the formation of wrinkles and melanin (at 1000 mg/kg, twice daily) as well as increases in the diameter and length of skin blood vessels and in the expression of matrix metalloproteinase-2 (MMP-2). Prevention of UVB-induced skin aging by turmeric may be due to the inhibition of increases in MMP-2 expression caused by chronic irradiation.

  7. Quantitative Modeling of Microbial Population Responses to Chronic Irradiation Combined with Other Stressors.

    Science.gov (United States)

    Shuryak, Igor; Dadachova, Ekaterina

    2016-01-01

    Microbial population responses to combined effects of chronic irradiation and other stressors (chemical contaminants, other sub-optimal conditions) are important for ecosystem functioning and bioremediation in radionuclide-contaminated areas. Quantitative mathematical modeling can improve our understanding of these phenomena. To identify general patterns of microbial responses to multiple stressors in radioactive environments, we analyzed three data sets on: (1) bacteria isolated from soil contaminated by nuclear waste at the Hanford site (USA); (2) fungi isolated from the Chernobyl nuclear-power plant (Ukraine) buildings after the accident; (3) yeast subjected to continuous γ-irradiation in the laboratory, where radiation dose rate and cell removal rate were independently varied. We applied generalized linear mixed-effects models to describe the first two data sets, whereas the third data set was amenable to mechanistic modeling using differential equations. Machine learning and information-theoretic approaches were used to select the best-supported formalism(s) among biologically-plausible alternatives. Our analysis suggests the following: (1) Both radionuclides and co-occurring chemical contaminants (e.g. NO2) are important for explaining microbial responses to radioactive contamination. (2) Radionuclides may produce non-monotonic dose responses: stimulation of microbial growth at low concentrations vs. inhibition at higher ones. (3) The extinction-defining critical radiation dose rate is dramatically lowered by additional stressors. (4) Reproduction suppression by radiation can be more important for determining the critical dose rate, than radiation-induced cell mortality. In conclusion, the modeling approaches used here on three diverse data sets provide insight into explaining and predicting multi-stressor effects on microbial communities: (1) the most severe effects (e.g. extinction) on microbial populations may occur when unfavorable environmental

  8. Modelling population-level consequences of chronic external gamma irradiation in aquatic invertebrates under laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lance, Emilie [Laboratoire de modelisation pour l' expertise environnementale (LM2E) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Alonzo, Frederic, E-mail: frederic.alonzo@irsn.fr [Laboratoire d' ecotoxicologie des radionucleides (LECO) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Garcia-Sanchez, Laurent [Laboratoire de biogeochimie, biodisponibilite et transferts des radionucleides (L2BT) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Beaugelin-Seiller, Karine; Garnier-Laplace, Jacqueline [Laboratoire de modelisation pour l' expertise environnementale (LM2E) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France)

    2012-07-01

    We modelled population-level consequences of chronic external gamma irradiation in aquatic invertebrates under laboratory conditions. We used Leslie matrices to combine life-history characteristics (duration of life stages, survival and fecundity rates) and dose rate-response curves for hatching, survival and reproduction fitted on effect data from the FREDERICA database. Changes in net reproductive rate R{sub 0} (offspring per individual) and asymptotic population growth rate {lambda} (dimensionless) were calculated over a range of dose rates in two marine polychaetes (Neanthes arenaceodentata and Ophryotrocha diadema) and a freshwater gastropod (Physa heterostropha). Sensitivities in R{sub 0} and {lambda} to changes in life-history traits were analysed in each species. Results showed that fecundity has the strongest influence on R{sub 0}. A delay in age at first reproduction is most critical for {lambda} independent of the species. Fast growing species were proportionally more sensitive to changes in individual endpoints than slow growing species. Reduction of 10% in population {lambda} were predicted at dose rates of 6918, 5012 and 74,131 {mu}Gy{center_dot}h{sup -1} in N. arenaceodentata, O. diadema and P. heterostropha respectively, resulting from a combination of strong effects on several individual endpoints in each species. These observations made 10%-reduction in {lambda} a poor criterion for population protection. The lowest significant changes in R{sub 0} and {lambda} were respectively predicted at a same dose rate of 1412 {mu}Gy h{sup -1} in N. arenaceodentata, at 760 and 716 {mu}Gy h{sup -1} in O. diadema and at 12,767 and 13,759 {mu}Gy h{sup -1} in P. heterostropha. These values resulted from a combination of slight but significant changes in several measured endpoints and were lower than effective dose rates calculated for the individual level in O. diadema and P. heterostropha. The relevance of the experimental dataset (external irradiation rather

  9. Studies on irradiation stability of polystyrene by NMR

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xin; SUN Wan-Fu; XIE Cheng-Xi

    2004-01-01

    The irradiation stability of polystyrene (PS) was studied by 13C and 1H NMR spectra, Nuclear Overhauser Relaxation (NOE) and 13C NMR spin-lattice relaxation time (T1). The results indicate that 13C and 1H NMR chemical shifts, NOE and T1 were almost invariant with the increase of irradiation dose. This shows that polystyrene is particularly stable within 2.5 kGy doses and the mechanism of its stability is discussed.

  10. Study on process control and acceptability of irradiated seasonings

    Science.gov (United States)

    Qixun, Chen; Peishu, Xu; Hao, Chen; Lihua, Chen; Shaobin, Dong

    1993-07-01

    This paper studied the process control and quality control of irradiated seasonings for commercial purpose, market test and consumers' acceptability. The results showed that the rate of relative deviation of dose was less than 2 and the uniformity was better than 1.31 and the number of microbes decreased by 3-4 orders of magnitude after treatment with 8kGy. No pathogenic bacteria were discovered and sensary evaluation as well as quality analysis were not changed. 110 tons of irradiated seasonings have been supplied to domestic markets and stores since 1990. The statistic data of 2045 consumers investigated showed that 67% of consumers heard about food irradiation. 72% of persons and 67% of families were willing to buy irradiated seasonings. This research is a program supported by IAEA and UNDP.

  11. Study of silicon strain gauges under electron irradiation

    Directory of Open Access Journals (Sweden)

    Liakh-Kaguj N. S.

    2010-02-01

    Full Text Available The characteristics of semiconductor strain gauges based on boron doped р-type silicon whiskers under high energy electron irradiation were studied. Strain gauges were irradiated at room temperature by electrons with energies 4,2—14 MeV and different doses 5·1016—1·1018 el/cm2. The main parameters of irradiated strain gauges: resistance, its temperature dependence and resistance change vs strain at –196…+100°C and –269…+20°C temperature ranges were measured. There are determined the values of electron irradiation energy and dose at which the radiation stability of strain gauges could be ensured.

  12. Study of TL response in heavily irradiated rock salt

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, X.; Dies, X. (Univ. Politecnica de Catalunya, Barcelona (Spain). Inst. de Tecniques Energetiques); Cuevas, C. de las (Barcelona Univ. (Spain))

    1993-01-01

    Within the framework of the CEC R and D Programme ''Management and Storage of Radioactive Waste'', the study of the generation of radiation damage in heavily irradiated rock salt is being carried out. This work describes the experiments carried out for the validation of the TL techniques, in the assessment of the phenomena related to the energy absorbed by the rock salt, due to the high levels of irradiation. The samples analysed are natural rock salt coming from the Sallent mine (Spain). The chemical composition of the rocks is, in all cases, higher than 90% NaCl, having small amounts of SO[sub 4], Mg, K, Br and Sr as major impurities. A first set of irradiations was performed at the laboratory with a source of [sup 137]Cs. The doses reached were lower than 20Gy. A second set of irradiations was performed at an industrial facility with a source of [sup 60]Co, achieving doses up to 2.5 MGy. Afterwards the irradiated samples were analysed with TL and optical absorption techniques. The results have facilitated a study of the glow curves, their evolution in time and the influence of the chemical composition, the absorbed dose, and the absorbed dose rate. These experiments have increased knowledge of the behaviour of heavily irradiated rock salt. (Author).

  13. [Histopathologic study of chronic sinusitis].

    Science.gov (United States)

    Wayoff, M; Parache, R M; Bodelet, B; Gazel, P

    1983-01-01

    The conventional histopathology of the sinus is a criterium for the therapeutic indication, since it is possible to distinguish between granulomatous chronic sinusitis, chronic sinusitis with oedema and nasal polyposis. Each one of these clinical pictures has his own etiology and requires a specific therapeutic approach.

  14. Mortality theory used to predict the life-span shortening caused by chronic internal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Panteleev, L.I.; Shvedov, V.L. (Institut Biofiziki, Moscow (USSR))

    In experiments on albino rats received strontium 90 in daily doses of 1.85 to 185 kBq/day the regularities of death were studied. It was shown that death of animals exposed to chronic internal radiation followed the Gomperz B. mortality law.

  15. Experimental study of the intraoperative irradiation for liver cancer

    Energy Technology Data Exchange (ETDEWEB)

    Arii, S.; Takasan, H.; Takahashi, S. (Kyoto Univ. (Japan). Faculty of Medicine)

    1981-07-01

    The resectability rate of the liver cancer is very low. Especially, hepatoma is apt to combine cirrhosis and its curability is poor as compared with malignant neoplasma of other organs. Therefore, the development of more effective adjuvant therapy for liver cancer is desirable. We studied the possibility of intraoperative radiotherapy with electron beams of Betatron. At first, we examined the influence of 5000 rad irradiation to approximately 1/2 area of the liver on the aspect of the serological liver function and histology using the domestic rabbits. Following this experiment, we used V x 2 carcinoma transplanted into the livers of the rabbits as the simulation model of the human liver tumors and examined the effect of irradiation to the tumor and its surrounding liver tissue. Results 1. The rabbits irradiated with 5000 rad to approximately 1/2 area of the liver intraoperatively grew healthily without severe dysfunction of the liver. 2. On the histological examination, degeneration and necrosis of the parenchymal cells appeared at the small parts of the irradiated area at the earlier periods of irradiation, but the necrotic regions did not get wider in range. Subsequently, liver fibrosis progressed gradually. 3. Irradiation to the rabbits transplanted V x 2 carcinoma resulted in the prolongation of the life spans and the diminution of the tumors.

  16. Endocrine function and reproductive impairment in an irradiated population of the lizard Uta stansburiana. [Effects of chronic, low-level /sup 137/Cs. gamma. irradiation underfield conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, A.K. (Univ. of California, Berkeley); Licht, P.; Nagy, K.A.; Medica, P.A.

    1978-12-01

    Gonadal changes in lizards (Uta stansburiana) exposed to chronic low levels of ..gamma.. radiation (1.5 to 10 R/day) under field conditions are described, and attempts to evaluate endocrine involvement in these changes are made. Reproductive impairment in irradiated males was demonstrated during the breeding season by reduced testes weights and by seminiferous tubules devoid of germ cells. Ultrastructural morphology of Leydig cells, plasma testosterone levels, and developed accessory sex structures indicatedd normal steroidogenesis in such males; cytology of the pituitary gonadotropes and pituitary gonadotropin content indicated normal gonadotropin levels. These findings suggest that low levels of radiation affect the spermatogenic process directly, rather than through damage to the pituitary. Comparable irradiation caused complete resorption of ovarian tissue in some female Uta. The oviducts were atrophic and the pituitary gonadotropes hyperactive. Resemblance of gonadotropes to those of castrated animals and reduced pituitary hormone content suggests elevated levels of gonadotropin production, probably due to the absence of ovarian steroid feedback in affected animals. The continued mitotic activity of oogonia in adult reptiles and their limited number contributed to the vulnerability of germinal tissue in irradiated female lizards. Destruction of the germ cells was accompanied by resorption of all ovarian tissue including steroidogenic elements. Thus, in females as in males, radiation appears to damage gametogenesis rather than pituitary function.

  17. Chronic adventitial inflammation, vasa vasorum expansion, and 5-lipoxygenase up-regulation in irradiated arteries from cancer survivors

    Science.gov (United States)

    Halle, Martin; Christersdottir, Tinna; Bäck, Magnus

    2016-01-01

    Radiation-induced cardiovascular disease is an emerging problem in a steadily increasing population of survivors of cancer. However, the underlying biology is poorly described, and the late onset, which occurs several years after exposure, precludes adequate investigations in animal and cell culture models. We investigated the role of the 5-lipoxygenase (5-LO)/leukotriene pathway in radiation-induced vascular changes. Use of paired samples of irradiated arteries and nonirradiated internal control arteries from the same patient that were harvested during surgery for cancer reconstruction ≤10 yr after radiotherapy provides a unique human model of chronic radiation–induced vascular changes. Immunohistochemical stainings and perioperative inspection revealed an adventitial inflammatory response, with vasa vasorum expansion and chronic infiltration of CD68+ macrophages. These macrophages stained positive for the leukotriene-forming enzyme 5-LO. Messenger RNA levels of 5-LO and leukotriene B4 receptor 1 were increased in irradiated arterial segments compared with control vessels. These results point to targeting the 5-LO/leukotriene pathway as a therapeutic adjunct to prevent late adverse vascular effects of radiotherapy.—Halle, M., Christersdottir, T., Bäck, M. Chronic adventitial inflammation, vasa vasorum expansion, and 5-lipoxygenase up-regulation in irradiated arteries from cancer survivors. PMID:27530979

  18. Paramecium tetraurelia growth stimulation under low-level chronic irradiation: investigations on a possible mechanism. [/sup 60/Co

    Energy Technology Data Exchange (ETDEWEB)

    Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Dupouy, D.; Planel, H.

    1982-12-01

    Experiments were carried out to demonstrate the effects of low-level chronic irradiation on Paramecium tetraurelia proliferation. Biological effects were strongly dependent on the bacterial density of culture medium and more exactly on the catalase content of the medium. Significant growth stimulation was found under /sup 60/Co chronic irradiation at a dose rate of 2 rad/year when paramecia were grown in a medium containing a high bacterial concentration (2.5 x 10/sup 2/ cells/m) or supplemented with catalase (300 U/ml). In a medium with a low bacterial density (1 x 10/sup 6/ cell/ml) or supplemented with a catalase activity inhibitor, growth simulation was preceded by a transitory inhibiting effect which could be correlated with extracellularly radioproduced H/sub 2/O/sub 2/. H/sub 2/O/sub 2/ addition appeared to be able to simulate the biological effects of chronic irradiation. A possible mechanism is discussed.We proposed that the stimulating effects were the result of intracellular enzymatic scavenging of radioproduced H/sub 2/O/sub 2/.

  19. Quantitative Modeling of Microbial Population Responses to Chronic Irradiation Combined with Other Stressors.

    Directory of Open Access Journals (Sweden)

    Igor Shuryak

    Full Text Available Microbial population responses to combined effects of chronic irradiation and other stressors (chemical contaminants, other sub-optimal conditions are important for ecosystem functioning and bioremediation in radionuclide-contaminated areas. Quantitative mathematical modeling can improve our understanding of these phenomena. To identify general patterns of microbial responses to multiple stressors in radioactive environments, we analyzed three data sets on: (1 bacteria isolated from soil contaminated by nuclear waste at the Hanford site (USA; (2 fungi isolated from the Chernobyl nuclear-power plant (Ukraine buildings after the accident; (3 yeast subjected to continuous γ-irradiation in the laboratory, where radiation dose rate and cell removal rate were independently varied. We applied generalized linear mixed-effects models to describe the first two data sets, whereas the third data set was amenable to mechanistic modeling using differential equations. Machine learning and information-theoretic approaches were used to select the best-supported formalism(s among biologically-plausible alternatives. Our analysis suggests the following: (1 Both radionuclides and co-occurring chemical contaminants (e.g. NO2 are important for explaining microbial responses to radioactive contamination. (2 Radionuclides may produce non-monotonic dose responses: stimulation of microbial growth at low concentrations vs. inhibition at higher ones. (3 The extinction-defining critical radiation dose rate is dramatically lowered by additional stressors. (4 Reproduction suppression by radiation can be more important for determining the critical dose rate, than radiation-induced cell mortality. In conclusion, the modeling approaches used here on three diverse data sets provide insight into explaining and predicting multi-stressor effects on microbial communities: (1 the most severe effects (e.g. extinction on microbial populations may occur when unfavorable environmental

  20. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    Science.gov (United States)

    Kulriya, P. K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A. K.; Avasthi, D. K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd2Ti2O7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd2Ti2O7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd2Ti2O7 is readily amorphized at an ion fluence 6 × 1012 ions/cm2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 1013 ions/cm2. The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures.

  1. Morphological study of borosilicate glass surface irradiated by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T. S.; Du, X.; Yuan, W.; Duan, B. H.; D. Zhang, J.; Chen, L.; Peng, H. B.; Yang, D.; Zhang, G. F.; Zhu, Z. H.

    2016-11-01

    Borosilicate glass is a candidate material for radiation waste formation and other optical applications in various fields. To understand the radiation effect of borosilicate glass, heavy ion (Arq+, Krq+ and Xeq+) irradiations were used to simulate the alpha and recoiled nuclei irradiations in this study. The surface morphology of glass has been compared to ion irradiation doses and ion energies. The surface topography evolution of irradiated samples is characterized by optical microscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS). Micro-bumps are observed on the sample surface after irradiationwith 5 MeV Xeq+ over 5 × 1013 ions·cm-2. The size and density of the bumps increaseswith increasing irradiation dose. At a lowdose, bumps are on the nanometer (nm) scale and rather rare.While the dose is higher than 9 × 1015 ions·cm-2, the size of bumps is on the scale of a few microns, and the density is saturated. However, the height of the bumps increases froma fewnmto over 150nmwith further irradiation. The distribution of micro-bumps is nearly homogeneous. The bumps are condensed and swell up, and there is no crystallized structure according to the TEMdiffraction pattern. Elementmigration and concentrations are observedwith SIMS imaging. The arrayed micro-bumps are a new finding, and they might be used to change the surface properties. Bump formation is caused by phase separation, and volume swelling is induced by ion irradiation.

  2. Irradiation damage studies of high power accelerator materials

    Energy Technology Data Exchange (ETDEWEB)

    Simos, N. [Brookhaven National Laboratory, Upton, NY 11973 (United States)], E-mail: simos@bnl.gov; Kirk, H.G.; Thieberger, P.; Ludewig, H.; Conor, J.O.; Mausner, L. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Trung, P.-T. [SUNY Stony Brook, Stony Brook, NY 11794 (United States); McDonald, K.T. [Princeton University, Princeton, NJ 08544 (United States); Yoshimura, K. [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Bennett, J.R.J. [Rutherford Appleton Laboratory, CCLRC, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)

    2008-06-30

    High-performance production targets and other critical accelerator components intercepting intense, energetic proton beams are essential as the accelerator community envisions the next generation, multi-MW accelerators. Materials that have served the nuclear sector well may not be suitable to play such a role which demands that the material comprising the beam-intercepting element must, in addition to the long exposure which leads to accumulated irradiation damage, also endure short exposure that manifests itself as thermo-mechanical shock. The ability of materials to resist irradiation-induced degradation of its properties that control shock and fatigue is of primary interest. The need for such materials that extend beyond resistance to the neutron-driven irradiation damage of reactor components has led to an extensive search and experimentation with new alloys and composites. These new high-performance materials, which appear to possess the right combination of mechanical and physical properties, are explored through a multi-phased experimental study at Brookhaven National Laboratory (BNL). This study, which brings together the interest in accelerator targets of different facilities around the world, seeks to simulate conditions of both short and long exposure to proton beams to assess the survivability potential of these new alloys and composite materials. While thermo-mechanical shock effects have been studied in the early stages of this comprehensive effort, it is irradiation damage that is currently the focus of the study and results to-date are presented in this paper along with the status and objectives of on-going studies. Of special interest are results depicting damage reversal through post-irradiation annealing in some of the materials. High fluences of 200 and/or 117 MeV protons provided by the BNL Linac beam that serves the Isotope Production Facility were used to assess irradiation damage in these new composites and alloys.

  3. [Features of behavioral reactions of chronically irradiated mice in the raised crosswise labyrinth with various genetically determined radiosensitivity and possibilities of their modification by the fungal biopolymer complex].

    Science.gov (United States)

    Seniuk, O F; Gorovoĭ, L F; Kovalev, V A; Palamar, L A; Krul', N I; Zhidkov, A V; Chemerskiĭ, G F; Kireev, S I; Khatuntseva, I V

    2013-01-01

    Structural elements of the central nervous system--neurons, along with the higher neuroendocrine structures and the hypothalamus centres, show high sensitivity to a chronic action of low doses of ionizing radiation (IR) in view of their extreme enrichment by phospholipids and intensive supply by oxygen, creating favorable conditions for the development of oxidizing stress. Stressful influences cause negative emotions in the behaviour of animals manifested as fear or uneasiness. The study represents the results of comparative research into the behavioral reactions characterized by uneasiness in the Balb/c and C57bl/6 mice exposed to a chronic irradiation at low doses. The chitin-melanin-glucan complex from fungi Fomes fomentarius (ChMG) was approved as an adaptive agent. It has been shown that under identical conditions, deposition levels of radionuclides 137Cs and 90Sr are raised in mice with IR hypersensitivity--line Balb/c, in comparison with less radio sensitive mice--line C57bl/6. Simultaneously, Balb/c mice were observed to exhibit the signs of a more anxious behaviour in the new environment. Chronic external and internal radiation exposure to rare ionizing radiation at low doses promotes strengthening of anxiety and phobic reactions in mice with IR hypersensitivity. The use of ChMG in animals neutralized the increase in anxiety and phobic reactions after a prolonged irradiation, thus indicating the presence in ChMG of the anxiolitic activity along with the above mentioned powerful radiosorbent, antioxidant, gene protective and immunomodulatory properties.

  4. Radioisotope tracer study in a sludge hygienization research irradiator (SHRI).

    Science.gov (United States)

    Pant, H J; Thýn, J; Zitný, R; Bhatt, B C

    2001-01-01

    A radioisotope tracer study has been carried out in a batch type sludge hygienization research irradiator with flow from top to bottom, the objective being to measure flow rate, circulation and mixing times and to investigate the hydrodynamic behaviour of the irradiator for identifying the cause(s) of malfunction. A stimulus-response technique with NH4(82)Br as a tracer was used to measure the above parameters. Experiments were carried out at three different flow rates, i.e 1.0, 0.64 and 0.33 m3/min. Three combined models based on a set of differential equations are proposed and used to simulate the measured tracer concentration curves. The obtained parameters were used to estimate dead volume and analyse hydrodynamic behaviour of the irradiator. The nonlinear regression problem of model parameter estimation was solved using the Marquardt-Levenberg method. The measured flow rate was found to be in good agreement with the values shown by the flow meter. The circulation times were found to be half of the mixing times. A simple approach for estimation of dose based on a known vertical dose-rate profile inside the irradiator is presented. About one-fourth of the volume of the irradiator was found to be dead at lower flow rates and this decreased with increase in flow rate. At higher flow rates, a semi stagnant volume was found with slow exchange of flow between the active and dead volumes.

  5. Radioisotope tracer study in a sludge hygienization research irradiator (SHRI)

    Energy Technology Data Exchange (ETDEWEB)

    Pant, H.J. E-mail: hjpant@aspsara.barc.ernet.in; Thyn, J.; Zitny, R.; Bhatt, B.C

    2001-01-15

    A radioisotope tracer study has been carried out in a batch type sludge hygienization research irradiator with flow from top to bottom, the objective being to measure flow rate, circulation and mixing times and to investigate the hydrodynamic behaviour of the irradiator for identifying the cause(s) of malfunction. A stimulus-response technique with NH{sup 82}{sub 4}Br as a tracer was used to measure the above parameters. Experiments were carried out at three different flow rates, i.e 1.0, 0.64 and 0.33 m{sup 3}/min. Three combined models based on a set of differential equations are proposed and used to simulate the measured tracer concentration curves. The obtained parameters were used to estimate dead volume and analyse hydrodynamic behaviour of the irradiator. The nonlinear regression problem of model parameter estimation was solved using the Marquardt-Levenberg method. The measured flow rate was found to be in good agreement with the values shown by the flow meter. The circulation times were found to be half of the mixing times. A simple approach for estimation of dose based on a known vertical dose-rate profile inside the irradiator is presented. About one-fourth of the volume of the irradiator was found to be dead at lower flow rates and this decreased with increase in flow rate. At higher flow rates, a semi stagnant volume was found with slow exchange of flow between the active and dead volumes.

  6. EPR study on tomatoes before and after gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Georgieva, L.; Tzvetkova, E. [Institute of Cryobiology and Food Technology, 1162 Sofia (Bulgaria); Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)], E-mail: ndyepr@bas.bg

    2009-09-15

    The results from the EPR studies on fresh, air-dried and lyophilized tomato samples before and after gamma-irradiation are reported. Before irradiation fresh and air-dried tomatoes exhibit one singlet EPR line characterized with common g-factor of 2.0048{+-}0.0005, whereas freeze-dried tomato does not show any EPR spectrum. After irradiation, a typical 'cellulose-like' triplet EPR spectrum appears in all samples, attributed to cellulose free radicals, generated by gamma-irradiation. It consists of intense central line with g=2.0048{+-}0.0005 and two weak satellite lines separated ca. 3 mT left and right of it. In air-dried and lyophilized tomatoes the 'cellulose-like' EPR spectrum is superimposed by an additional partly resolved carbohydrate spectrum. Fading measurements of the radiation-induced EPR signals indicate that the intensity of the EPR spectra of air-dried and freeze-dried tomato are reduced to about 50% after 50 days, whereas those of fresh irradiated tomatoes kept at 4 {sup o}C fade completely in 15 days. The reported results unambiguously show that the presence of two satellite lines in the EPR 'cellulose-like' spectra of tomato samples can be used for identification of radiation processing.

  7. Light scattering studies of irradiated {kappa}- and {iota}-carrageenan

    Energy Technology Data Exchange (ETDEWEB)

    Abad, L.V. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan) and Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines)]. E-mail: lvabad@pnri.dost.gov.ph; Nasimova, I.R. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Physics Department, Moscow State University, Moscow 119992 (Russian Federation); Aranilla, C.T. [Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines); Shibayama, M. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan)]. E-mail: sibayama@issp.u-tokyo.ac.jp

    2005-05-01

    The relationships between the molecular weight (Mw) and the characteristic decay time distribution function G({gamma}) of irradiated kappa ({kappa}-) and iota ({iota}-) carrageenan were studied by static and dynamic light scattering (DLS). Mw and the characteristic decay time ({gamma}{sup -1}) are both steep decreasing exponential function with radiation dose. The dynamic behavior of irradiated {iota}-carrageenan was compared to irradiated {kappa}-carrageenan by DLS. The intensity correlation function of both carrageenans shifted towards shorter relaxation times with increasing radiation dose. Irradiated {iota}-carrageenan like {kappa}-carrageenan exhibits power law behavior at 0-50 kGy (at 0.05-0.1M KCl) indicating similar gelation behaviors. The temperature at which transition from coil to helix takes place (conformational transition temperature) decreases with increasing irradiation dose. A new faster relaxation mode appears at around 0.1-1 ms for both carrageenans between 100 and 150 kGy. Maximum peak height for this mode is at 100 kGy which corresponds to the optimum biological activity of {kappa}- and {iota}-carrageenan.

  8. An assessment of the solar irradiance record for climate studies

    Directory of Open Access Journals (Sweden)

    Kopp Greg

    2014-04-01

    Full Text Available Total solar irradiance, the spatially and spectrally integrated radiant output from the Sun at a mean Sun-Earth distance of 1 astronomical unit, provides nearly all the energy driving the Earth’s climate system. Variations in this energy, particularly over long time scales, contribute to changes in Earth’s climate and have been linked to historical glaciation and inter-glacial periods as well as having a small effect on more recent global warming. Accurate measurements of solar irradiances require measurements above the Earth’s atmosphere. The total solar irradiance spaceborne record began in 1978 and has been uninterrupted since, with over a dozen instruments contributing to the present solar climate data record. I assess the required and achieved accuracies of this record with a focus on its value for climate studies.

  9. Study of the degradation behaviour of dimethoate under microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei [College of Chemistry and Chemical Engineering, Liaoning University, Shenyang 110036 (China)], E-mail: zhanglei63@126.com; Guo Xingjia; Yan Fei; Su Mingming; Li Ying [College of Chemistry and Chemical Engineering, Liaoning University, Shenyang 110036 (China)

    2007-11-19

    In this work, the degradation of dimethoate under microwave irradiation assisted advanced oxidation processes (MW/oxidants) were studied. The efficiencies of the degradation of dimethoate in dilute aqueous solutions for a variety of oxidants with or without MW irradiation were compared. The results showed that the synergistic effects between MW and K{sub 2}S{sub 2}O{sub 8} had high degradation efficiency for dimethoate. Simultaneously, UV/TiO{sub 2}/K{sub 2}S{sub 2}O{sub 8} photocatalytic oxidation degradation of dimethoate was investigated. The experimental results indicated that the method of microwave degradation of organic pollutants in the presence of oxidant could reduce reaction time and improve product yield. Microwave irradiation was an advisable choice for treating organic wastewaters and has a widely application perspective for non- or low-transparent and fuscous dye wastewaters.

  10. Theoretical study of irradiation effects in close binaries

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao M.

    2009-01-01

    Full Text Available The effect of irradiation is studied in a close binary system assuming that the secondary component is a point source, moving in a circular orbit. The irradiation effects are calculated on the atmosphere of the primary component in a 3-dimensional Cartesian coordinate geometry. In treating the reflection effect theoretically, the total radiation (ST is obtained as the sum of the radiation of 1 the effect of irradiation on the primary component which is calculated by using one dimensional rod model (Sr and 2 the self radiation of the primary component which is calculated by using the solution of radiative transfer equation in spherical symmetry (Ss. The radiation field is estimated along the line of sight of the observer at infinity. It is shown how the radiation field changes depending on the position of the secondary component.

  11. Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: a prospective randomized clinical study.

    Science.gov (United States)

    Sun, Kang; Tian, Shaoqi; Zhang, Jihua; Xia, Changsuo; Zhang, Cailong; Yu, Tengbo

    2009-05-01

    The effect of using gamma irradiation to sterilize bone-patellar tendon-bone (BPTB) allograft on the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with irradiated allograft remains controversial. Our study was aimed to analyze the clinical outcomes of arthroscopic ACL reconstruction with irradiated BPTB allograft compared with non-irradiated allograft and autograft. All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 Mrad of irradiation prior to distribution. A total of 102 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into three groups. The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months follow-up (range 24-47 months) patients were evaluated by the same observer according to objective and subjective clinical evaluations. Of these patients, 99 (autograft 33, non-irradiated allograft 34, irradiated allograft 32) were available for full evaluation. When compared the irradiated allograft group to non-irradiated allograft group or autograft group at 31 months follow-up by the Lachman test, ADT, pivot shift test and KT-2000 arthrometer testing, statistically significant differences were found. Most importantly, 87.8% of patients in the Auto group, 85.3% in the Non-Ir-Auto group and just only 31.3% in the Ir-Allo group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%) and non-irradiated allograft (8.8%). The anterior and rotational stability decreased significantly in the irradiated allograft group. According to the overall IKDC, functional, subjective evaluations and activity level testing, no statistically significant differences were found between the three groups. However, there was a trend that the functional and

  12. Neutron irradiation study of silicon photomultipliers from different vendors

    Science.gov (United States)

    Kushpil, V.; Mikhaylov, V.; Kugler, A.; Kushpil, S.; Ladygin, V. P.; Reznikov, S. G.; Svoboda, O.; Tlustý, P.

    2017-02-01

    We present recent results on the investigation of the KETEK, ZECOTEK, HAMAMATSU and SENSL SiPM properties after irradiation by the 6-35 MeV neutrons. The typical neutron fluence was about 1012 n /cm2. The changing of the internal structure of the irradiated SiPMs was studied by the measuring of the C-V and C-f characteristics. We have observed the strong influence of the SiPM manufacturing technology on their radiation hardness. The application of the obtained results to the development of the readout electronics is discussed.

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

    Science.gov (United States)

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

    2013-02-01

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

  14. Study of neutron irradiated silicon counters with a fast amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Bates, S.; Munday, D.J.; Parker, M.A.; Anghinolfi, F.; Chilingarov, A.; Ciasnohova, A.; Glaser, M.; Jarron, P.; Lemeilleur, F.; Santiard, J.C.; Goessling, C.; Lisowski, B.; Pilath, S.; Rolf, A.; Bonino, R.; Clark, A.G.; Kambara, H.; Wu, X.; Fretwurst, E.; Lindstroem, G.; Schulz, T.; Moorhead, G.F.; Taylor, G.N.; Tovey, S.N.; Hawkings, R.; Weidberg, A.; Teiger, J. (Cavendish Lab., Univ. of Cambridge (United Kingdom) CERN, Geneva (Switzerland) Inst. fuer Physik, Univ. Dortmund (Germany) DPNC, Geneva Univ. (Switzerland) 1. Inst. fuer Experimentalphysik, Univ. Hamburg (Germany) School of Physics, Univ. of Melbourne, Parkville, Victoria (Australia) Dept. of Nuclear Physics, Oxford Univ. (United Kingdom) Centre d' Etudes Nucleaires de Saclay, 91 Gif-sur-Yvette (France)); RD2 Collaboration

    1993-12-15

    Silicon detectors have been irradiated with fluences of up to 2.7x10[sup 13] neutrons/cm[sup 2], and have been subsequently studied using low-noise preamplifiers with a peaking time of about 15 ns. The detector response to minimum ionizing particles was found to be close to that of non-irradiated detectors. The short integration time of the preamplifier makes the shot noise due to the detector dark current tolerable up to at least 15 [mu]A/channel. (orig.)

  15. ESR STUDY OF FREE RADICALS IN IRRADIATED POLYAMIDE- 1010

    Institute of Scientific and Technical Information of China (English)

    ZHOU Maotang; ZHANG Lihua; LIU Yayan; CHEN Donglin

    1993-01-01

    Polyamide-1010 samples were irradiated in vacuum at room temperature by Cobalt-60γ-rays. The free radicals formed in irradiation were studied by means of electron spin resonance (ESR)techniques. The ESR spectra consisted of a quartet and a superimposed singlet whichwere attributed to radical - CO - NH - CH - CH2 and - CH2 - C = O, respectively. The effects of temperature and crystallinity on the radicals were discussed and the mechanism for the production and decay of the radicals was also proposed.

  16. Does total body irradiation conditioning improve outcomes of myeloablative human leukocyte antigen-identical sibling transplantations for chronic lymphocytic leukemia?

    Science.gov (United States)

    Sabloff, Mitchell; Sobecks, Ronald M; Ahn, Kwang Woo; Zhu, Xiaochun; de Lima, Marcos; Brown, Jennifer R; Inamoto, Yoshihiro; Holland, H Kent; Aljurf, Mahmoud D; Laughlin, Mary J; Kamble, Rammurti T; Hsu, Jack W; Wirk, Baldeep M; Seftel, Matthew; Lewis, Ian D; Arora, Mukta; Alyea, Edwin P; Kalaycio, Matt E; Cortes, Jorge; Maziarz, Richard T; Gale, Robert Peter; Saber, Wael

    2014-03-01

    An allogeneic hematopoietic cell transplantation from an HLA-identical donor after high-dose (myeloablative) pretransplantation conditioning is an effective therapy for some people with chronic lymphocytic leukemia (CLL). Because CLL is a highly radiosensitive cancer, we hypothesized that total body irradiation (TBI) conditioning regimens may be associated with better outcomes than those without TBI. To answer this, we analyzed data from 180 subjects with CLL receiving myeloablative doses of TBI (n = 126) or not (n = 54), who received transplants from an HLA-identical sibling donor between 1995 and 2007 and reported to the Center for International Blood & Marrow Transplant Research. At 5 years, treatment-related mortality was 48% (95% confidence interval [CI], 39% to 57%) versus 50% (95% CI, 36% to 64%); P = NS. Relapse rates were 17% (95% CI, 11% to 25%) versus 22% (95% CI, 11% to 35%); P = NS. Five-year progression-free survival and overall survival were 34% (95% CI, 26% to 43%) versus 28% (95% CI, 15% to 42%); P = NS and 42% (95% CI, 33% to 51%) versus 33% (95% CI, 19% to 48%); P = NS, respectively. The single most common cause of death in both cohorts was recurrent/progressive CLL. No variable tested in the multivariate analysis was found to significantly affect these outcomes, including having failed fludarabine. Within the limitations of this study, we found no difference in HLA-identical sibling transplantation outcomes between myeloablative TBI and chemotherapy pretransplantation conditioning in persons with CLL.

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

    Science.gov (United States)

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

    2014-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Aleksieva, K., E-mail: katerina_bas@abv.b [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Lagunov, O. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Yordanov, N.D. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2011-06-15

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

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

    Science.gov (United States)

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

    2011-06-01

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

  20. Damage studies on tungsten due to helium ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, N.J.; Buzarbaruah, N.; Mohanty, S.R., E-mail: smrutirm@yahoo.com

    2014-09-15

    Highlights: • Used plasma focus helium ion source to study radiation induced damage on tungsten. • Surface analyses confirm formation of micro-crack, bubbles, blisters, pinholes, etc. • XRD patterns confirm development of compressive stress due to thermal load. • Reduction in hardness value is observed in the case of exposed sample. - Abstract: Energetic and high fluence helium ions emitted in a plasma focus device have been used successfully to study the radiation induced damage on tungsten. The reference and irradiated samples were characterized by optical microscopy, field emission scanning electron microscopy, X-ray diffraction and by hardness testers. The micrographs of the irradiated samples at lower magnification show uniform mesh of cracks of micrometer width. However at higher magnification, various types of crystalline defects such as voids, pinholes, bubbles, blisters and microcracks are distinctly noticed. The prominent peaks in X-ray diffraction spectrum of irradiated samples are seen shifted toward higher Bragg angles, thus indicating accumulation of compressive stress due to the heat load delivered by helium ions. A marginal reduction in hardness of the irradiated sample is also noticed.

  1. Spectroscopic and thermal studies of 8 MeV electron beam irradiated HPMC films

    Energy Technology Data Exchange (ETDEWEB)

    Sangappa [Department of Studies in Physics, Mangalore University, Mangalagangotri 574 199 (India)], E-mail: syhalabhavi@yahoo.co.in; Asha, S. [Department of Studies in Physics, Mangalore University, Mangalagangotri 574 199 (India); Demappa, T. [Department of Studies in Polymer Science, University of Mysore, Sir M.V.P.G. Center, Mandya 571 402 (India); Sanjeev, Ganesh [Microtron Centre, Mangalore University, Mangalagangotri 574 199 (India); Parameswara, P.; Somashekar, R. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2009-07-01

    Radiation-induced changes in hydroxypropyl methylcellulose (HPMC) films under electron irradiation were investigated and correlated with dose. Polymer samples were irradiated in air at room temperature by an electron beam accelerator in the range of 0-100 kGy. Various properties of the irradiated films were studied using a Ultraviolet-Visible spectrophotometer and Fourier transform infrared spectroscopy and thermogravimetric analysis. Electron irradiation was found to induce changes in the physical, chemical and thermal properties, depending on the irradiation dose.

  2. Radioprotection by WR-2721 against long-term chronic damage to the rat parotid gland. [Local x irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sodicoff, M.; Conger, A.D.; Pratt, N.E.; Trepper, P.

    1978-10-01

    WR-2721 protected against the acute phase of radiation damage which is manifest during the first week after irradiation, though recovery occurred both in the presence and absence of such protection. The drug also protected against the chronic phase damage which appeared later (60 to 90 days postirradiation), with dose modification factors of 2.3 for gland weight, 3.2 for amylase, and 2.0 for total gland amylase, and roentgen increases ranging from 1.7 to 4.9 kR.

  3. Early reduction of microglia activation by irradiation in a model of chronic glaucoma.

    Directory of Open Access Journals (Sweden)

    Alejandra Bosco

    Full Text Available Glaucoma is a neurodegenerative disease that results in the progressive decline and ultimate death of retinal ganglion cells (RGCs. While multiple risk factors are associated with glaucoma, the mechanisms leading to onset and progression of the disease remain unknown. Molecular analysis in various glaucoma models has revealed involvement of non-neuronal cell populations, including astrocytes, Mueller glia and microglia, at early stages of glaucoma. High-dose irradiation was reported to have a significant long-term protective effect in the DBA/2J (D2 mouse model of glaucoma, although the cellular and molecular basis for this effect remains unclear. In particular, the acute effects of irradiation on specific cell populations, including non-neuronal cells, in the D2 retina and nerve have not been assessed. Here we report that irradiation induces transient reduction in proliferating microglia within the optic nerve head and glial lamina within the first week post-irradiation. This was accompanied by reduced microglial activation, with no effect on astrocyte gliosis in those regions. At later stages we confirm that early high-dose irradiation of the mouse head results in improvement of axonal structural integrity and anterograde transport function, without reduction of intraocular pressure. Thus reduced microglial activation induced by irradiation at early stages is associated with reduced optic nerve and retinal neurodegeneration in the D2 mouse model of glaucoma.

  4. Superoxide dismutase mimic, MnTE-2-PyP5+ ameliorates acute and chronic proctitis following focal proton irradiation of the rat rectum

    Directory of Open Access Journals (Sweden)

    John O. Archambeau

    2013-01-01

    Full Text Available Radiation proctitis, an inflammation and damage to the lower part of colon, is a common adverse event of the radiotherapy of tumors in the abdominal and pelvic region (colon, prostate, cervical. Several Mn(III porphyrin-based superoxide dismutase mimics have been synthesized and successfully evaluated in preclinical models as radioprotectants. Here we report for the first time the remarkable rectal radioprotection of frequently explored Mn(III meso-tetrakis(N-ethylpyridinium-2-ylporphyrin, MnTE-2-PyP5+. A batch prepared in compliance with good manufacturing practice (GMP, which has good safety/toxicity profile, was used for this study. MnTE-2-PyP5+ was given subcutaneously at 5 mg/kg, either 1 h before or 1 h after irradiation, with additional drug administered at weekly intervals thereafter. MnTE-2-PyP5+ ameliorated both acute and chronic radiation proctitis in male Sprague-Dawley rats irradiated with 20–30 Gy protons delivered to 2.5 cm span of rectum using spread-out Bragg peak of a proton treatment beam. Focal irradiation of the rectum produced acute proctitis, which healed, followed by chronic rectal dilation and symptomatic proctitis. MnTE-2-PyP5+ protected rectal mucosa from radiation-induced crypt loss measured 10 days post-irradiation. Significant effects were observed with both pre- and post-treatment regimens. However, only MnTE-2-PyP5+ pre-treatment, but not post-treatment, prevented the development of rectal dilation, indicating that proper dosing regimen is critical for radioprotection. The pre-treatment also prevented or delayed the development of chronic proctitis depending on the radiation dose. Further work aimed at developing MnTE-2-PyP5+ and similar drugs as adjunctive agents for radiotherapy of pelvic tumors is warranted. The present study substantiates the prospects of employing this and similar analogs in preserving normal tissue during cancer radiation as well as any other radiation exposure.

  5. a Study of Stress Relaxation Rate in Un-Irradiated and Neutron-Irradiated Stainless Steel

    Science.gov (United States)

    Ghauri, I. M.; Afzal, Naveed; Zyrek, N. A.

    Stress relaxation rate in un-irradiated and neutron-irradiated 303 stainless steel was investigated at room temperature. The specimens were exposed to 100 mC, Ra-Be neutron source of continuous energy 2-12 MeV for a period ranging from 4 to 16 days. The tensile deformation of the specimens was carried out using a Universal Testing Machine at 300 K. During the deformation, straining was frequently interrupted by arresting the cross head to observe stress relaxation at fixed load. Stress relaxation rate, s, was found to be stress dependent i.e. it increased with increasing stress levels σ0 both in un-irradiated and irradiated specimens, however the rate was lower in irradiated specimens than those of un-irradiated ones. A further decrease in s was observed with increase in exposure time. The experiential decrease in the relaxation rate in irradiated specimens is ascribed to strong interaction of glide dislocations with radiation induced defects. The activation energy for the movement of dislocations was found to be higher in irradiated specimens as compared with the un-irradiated ones.

  6. Structural changes in irradiated steels. An example of industrial studies

    Energy Technology Data Exchange (ETDEWEB)

    May, R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Miloudi, S. [Electricite de France (France)

    1997-04-01

    The security of nuclear reactors depends on knowledge about the degradation of some of their components by neutron irradiation. It is anticipated in the design of power reactors so as to ensure their safe operation. The long-time behaviour of reactor components is investigated. These studies serve to verify that the predictions concerning mechanical properties of reactors hold, but also to better understand the processes leading to degradation in order to find means for safely increasing the lifetimes of power plants. (author).

  7. Study of neutron irradiated structures of ammonothermal GaN

    Science.gov (United States)

    Gaubas, E.; Ceponis, T.; Deveikis, L.; Meskauskaite, D.; Miasojedovas, S.; Mickevicius, J.; Pavlov, J.; Pukas, K.; Vaitkus, J.; Velicka, M.; Zajac, M.; Kucharski, R.

    2017-04-01

    Study of the radiation damage in GaN-based materials becomes an important aspect for possible application of the GaN detectors in the harsh radiation environment at the Large Hadron Collider and at other particle acceleration facilities. Intentionally doped and semi-insulating bulk ammonothermal GaN materials were studied to reveal the dominant defects introduced by reactor neutron irradiations. These radiation defects have been identified by combining electron spin resonance and transmission spectroscopy techniques. Characteristics of carrier lifetime dependence on neutron irradiation fluence were examined. Variations of the response of the capacitor-type sensors with neutron irradiation fluence have been correlated with the carrier lifetime changes. The measurements of the photoconductivity and photoluminescence transients have been used to study the variation of the parameters of radiative and non-radiative recombination. The examined characteristics indicate that AT GaN as a particle sensing material is radiation hard up to high hadron fluences  ⩾1016 cm‑2.

  8. Immunological studies in chronic atrophic gastritis and chronic (superficial) gastritis.

    Science.gov (United States)

    Fung, W P; Rigby, R J; Trenchev, P; Matz, L R

    1978-01-01

    Detection of autoantibodies, HLA typing and immunofluorescence studies on gastric biopsies were carried out in subjects with histologically proven chronic atrophic gastritis (CAG) and chronic superficial gastritis (CG). All were seronegative for parietal cell antibody and did not have pernicious anemia. Except for positive antismooth muscle and antimitochrondrial antibodies in one patient with CAG, autoantibodies (antinuclear, smooth muscle, mitochrondrial, parietal cell) were absent in patients with CAG and CG. Immunofluorescence studies showed that Ig-G and IgA were presented in the lamina propria of all cases with CAG or CG and of subjects with normal gastric histology. Ig-M was seen less often, in about half the cases. Complement C3 was an uncommon finding, being positive in only one case with CAG and one case with CG and in none of the cases with normal gastric histology. Fibrinogen was more commonly seen in patients with CG (5/5 cases) than in those with CAG (3/11 cases). Fibrinogen was found in one case with normal gastric histology. The most consistent fluorescence was obtained with antiparietal cell antiserum. All subjects with CAG showed negative or weak staining only. In contrast, subjects with CG and normal gastric histology had strong specific fluorescence. An increased frequency of HLA-A1 plus HLA-B8 was found in subjects with CAG (20.7% in controls; 40% in CAG).

  9. Short-term solar irradiance and irradiation forecasts via different time series techniques: A preliminary study

    CERN Document Server

    Join, Cédric; Fliess, Michel; Muselli, Marc; Nivet, Marie Laure; Paoli, Christophe; Chaxel, Frédéric

    2014-01-01

    This communication is devoted to solar irradiance and irradiation short-term forecasts, which are useful for electricity production. Several different time series approaches are employed. Our results and the corresponding numerical simulations show that techniques which do not need a large amount of historical data behave better than those which need them, especially when those data are quite noisy.

  10. Study of of epoxy polymers aging under irradiation; Etude du vieillissement sous irradiation de polymeres epoxy

    Energy Technology Data Exchange (ETDEWEB)

    Longieras, N

    2004-01-01

    This work concerns the mechanisms of aging under irradiation of epoxy polymers. As epoxy network are insoluble, physicochemical characterisation is difficult to achieve and the interpretation is complex. Thus, we investigated first the degradation of a linear phenoxy polymer which contains DGEBA moiety as a repeat unit. Results obtained on this polymer were then used to study the more complex DGEBA/TETA network. In order to assess the role of oxygen on the aging mechanism, both radiolysis under helium and radio-oxidation under pure oxygen were carried out. The study of radiolysis under helium of phenoxy polymer shows a chain scission mechanism. This result was confirmed by the increase of molecular mobility measured by T{sub 2} and T{sub 1{rho}} NMR relaxation times. Identification of the degradation products were carried out using NMR and FTIR spectrometries. From the quantitative correlation of the whole experimental results, it was possible to determine the main polymer degradation mechanism: each chain scission is followed by the formation of two phenolic terminations, a loss of the intermediate aliphatic chain and the formation of acetone and isopropanol. Radio-oxidation displays a sharp degradation profile of oxidation products including formiate, ester and carboxylic acid groups. Like phenoxy polymer, DGEBA/TETA exhibits a chain scission mechanism. This result was confirmed by a net increase of NMR relaxation times. Dipolar spectra measured from 2DWISE solid state NMR two-dimensional sequence indicate that chain scission occur mainly at methylene amine site. Phenolic termination and acetone are not produced during aging of DGEBA/TETA network as in phenoxy polymer but new products are identified such as unsaturation, isopropyl alcohol, aldehyde, ketone, methide with two hetero-atom. Oxygen effect during irradiation leads mainly to amide formation and to carboxylic acid and ester. (author)

  11. Charge collection efficiency studies with irradiated silicon detectors

    CERN Document Server

    Allport, P P; Casse, G; Greenall, A; Jackson, J N; Turner, P R

    2003-01-01

    Small area (1x1 cm sup 2) microstrip detectors, made with a p sup + -n diode structure on FZ silicon substrates, both with and without oxygen enrichment, have been irradiated with 24 GeV/c protons to fluences of 1.9, 2.9 and 5.1x10 sup 1 sup 4 p/cm sup 2. Their charge collection properties have been studied using a sup 1 sup 0 sup 6 Ru beta-source with a wide bandwidth current amplifier and compared with those for a non-irradiated device. The integrated charge collected at different times (10, 25, 40 and 80 ns) has been used to estimate the effect of ballistic deficit. Predictions for the reduction in charge collection efficiency expected at fluences as high as 10 sup 1 sup 5 cm sup - sup 2 are presented using a parameterization described in earlier work which also fits this data well.

  12. Theoretical Study of Irradiation Effects in Close Binaries

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao, M.

    2009-06-01

    Full Text Available The effect of irradiation is studied in a close binary systemassuming that the secondary component is a point source, moving in a circularorbit. The irradiation effects are calculatedon the atmosphere of the primary component in a 3-dimensional Cartesiancoordinate geometry. In treating the reflection effect theoretically, the totalradiation $(S_mathrm{T}$ is obtained as the sum of the radiation of 1 the effect ofirradiation on the primary component which is calculated by using onedimensional rod model $(S_mathrm{r}$ and 2 the self radiation of the primarycomponent which is calculated by using the solution of radiative transferequation in spherical symmetry $(S_mathrm{s}$. The radiation field is estimated alongthe line of sight of the observer at infinity. It is shown how the radiationfield changes depending on the position of the secondary component.

  13. Post irradiation examinations for IASCC study at JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Takashi; Miwa, Yukio; Tsuji, Hirokazu; Nakajima, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-09-01

    At the Japan Atomic Energy Research Institute (JAERI), a research program on the irradiation assisted stress corrosion cracking (IASCC) was initiated in 1989. Its objective is to investigate the synergistic effects of high temperature water and neutron radiation on the austenitic stainless steel for core internals of both the light water reactors (LWRs) and water-cooled fusion reactor, i.e., the international thermonuclear experimental reactor (ITER). IASCC has been recently recognized as one of the key issues for the integrity of core-internals of aging LWRs including both BWR and PWR. Majorities of experimental data on IASCC have been obtained through the post irradiation examinations (PIEs) such as the slow strain rate testing (SSRT) in high temperature water. This paper presents the outline and requirements for the PIEs conducted for IASCC study. (author)

  14. An IR study of pure and ion irradiated frozen formamide

    CERN Document Server

    Brucato, J R; Strazzulla, G; Baratta, Giuseppa A.; Brucato, John R.; Strazzulla, Giovanni

    2006-01-01

    Context. The chemical evolution of formamide (HCONH2), a molecule of astrobiological interest that has been tentatively identified in interstellar ices and in cometary coma, has been studied in laboratory under simulated astrophysical conditions such as ion irradiation at low temperature. Aims. To evaluate the abundances of formamide observed in space or in laboratory, the integrated absorbances for all the principal IR features of frozen amorphous pure formamide deposited at 20 K were measured. Further evidence that energetic processing of ices occurring in space is extremely relevant both to astrochemistry and to astrobiology has been found, showing that new molecular species are synthesized by ion irradiation at a low temperature. Methods. Pure formamide were deposited at 20 K and IR transmission spectra measured for different ice thicknesses. The ice thickness was derived by looking at the interference pattern (intensity versus time) of a He-Ne laser beam reflected at an angle of 45 deg by the vacuum-film...

  15. Study of irradiation effects in non-metallic conductors

    Energy Technology Data Exchange (ETDEWEB)

    Atobe, Kozo; Fukuoka, Noboru; Honda, Makoto; Kondo, Tadashi; Morishima, Kouichi [Naruto Univ. of Education, Naruto, Tokushima (Japan). Faculty of Science; Okada, Moritami; Nakagawa, Masuo

    1998-01-01

    The production of point defects induced by reactor and the thermal behavior of defects in sintered AlN and c-BN have been investigated using the optical absorption and electron spin resonance (ESR) methods. The absorption band at 370 nm (AlN) and the structureless absorption over the visible region are observed. These specimens also show ESR signals with g-value 2.007 (AlN), 2.006 (BN), which are probably caused by N vacancies with a trapped electron. In addition to these experiments, the difference of the photoluminescence(PL) lines on neutron irradiated CZ-Si and FZ-Si has been also studied. The models of the defect associated with neutron irradiation are discussed. (author)

  16. External irradiation models for intracranial 9L glioma studies

    Directory of Open Access Journals (Sweden)

    Feuvret Loïc

    2010-11-01

    Full Text Available Abstract Purpose Radiotherapy has been shown to be an effective for the treatment human glioma and consists of 30 fractions of 2 Gy each for 6-7 weeks in the tumor volume with margins. However. in preclinical studies, many different radiation schedules are used. The main purpose of this work was to review the relevant literature and to propose an external whole-brain irradiation (WBI protocol for a rat 9L glioma model. Materials and methods 9L cells were implanted in the striatum of twenty 344-Fisher rats to induce a brain tumor. On day 8, animals were randomized in two groups: an untreated group and an irradiated group with three fractions of 6 Gy at day 8, 11 and 14. Survival and toxicity were assessed. Results Irradiated rats had significantly a longer survival (p = 0.01. No deaths occurred due to the treatment. Toxicities of reduced weight and alopecia were increased during the radiation period but no serious morbidity or mortality was observed. Moreover, abnormalities disappeared the week following the end of the therapeutic schedule. Conclusions Delivering 18 Gy in 3 fractions of 6 Gy every 3 days, with mild anaesthesia, is safe, easy to reproduce and allows for standardisation in preclinical studies of different treatment regimens glioma rat model.

  17. Psychological Characteristics of Chronic Depression : A Longitudinal Cohort Study

    NARCIS (Netherlands)

    Wiersma, Jenneke E.; van Oppen, Patricia; van Schaik, Digna J. F.; van der Does, A. J. Willem; Beekman, Aartjan T. E.; Penninx, Brenda W. J. H.

    Background: Few studies have investigated the importance of psychological characteristics for chronicity of depression. Knowledge about psychological differences between chronically depressed persons and nonchronically depressed persons may help to improve treatment of chronic depression. This is

  18. Transcending chronic liver disease: a qualitative study.

    Science.gov (United States)

    Wainwright, S P

    1997-01-01

    This study explores and describes experiences of chronic liver disease from the patient's perspective. No qualitative research studies appear to have examined the experiences of these patients. In-depth focused interviews and grounded theory data collection and data analysis methods were used. A two-stage theoretical framework (becoming ill, and not living) of the experience of transcending chronic liver disease is presented. Sociological and psychological literature on common sense models of health and illness are briefly reviewed. Several suggestions for further research are made. The way in which this qualitative research study is leading to a quantitative and qualitative appraisal of the psychological adjustment in end-stage chronic liver disease patients is outlined.

  19. Results of long-term genetic monitoring of animal populations chronically irradiated in the radiocontaminated areas

    Energy Technology Data Exchange (ETDEWEB)

    Goncharova, R.; Riabokon, N. [Institute of Genetics and Cytology, National Academy of Sciences of Belarus, Minsk (Belarus)

    1998-03-01

    The artificial geochemical land where all organisms lived and will live under the conditions of increased level of radiation was set up due to the Chernobyl disaster in 1986. An urgent necessity for studying the various biological effects of chronic influence of low intensity radiation on both individual organisms and populations arose. Combined cytogenetic and radioecological investigations in wild populations of terrestrial small mammals (bank vole = Clethrionomys glareolus, Schreber and yellow-necked mouse = Apodemus flavicollus, Melchior) and in laboratory mice have been carried out by our laboratory since 1986. Our test organisms have contacted closely with low intensity radiation in the radiocontaminated areas of Belarus and absorbed low whole-body dose. We study the following problems: dynamics of radionuclide concentration in wild populations of small rodents; dynamics of mutation process in somatic and germ cells over many generations as well as embryonal lethality; dynamics of population density, age and sex structure of mammalian populations. The large part of results obtained are presented here. (J.P.N.)

  20. Treatment of Chronic Diarrhea with Point-irradiation of He-Ne Laser in 50 Cases

    Institute of Scientific and Technical Information of China (English)

    WU Tong-fa; SHI Bing-pei

    2003-01-01

    To treat 50 cases of chronic diarrhea by laser point-radiation on Shenque (CV 8 ), Tianshu (ST25), Zusanli (ST 36) and Point Anti-diarrhea with low power He-Ne laser. The total effective rate was 96%.

  1. Study of color centers induced by PIXE irradiation

    CERN Document Server

    Absil, J; Strivay, D; Oger, C; Weber, G

    2002-01-01

    The particle induced X-ray emission method is perfectly adapted to the study, by external beam, of art objects (like paintings) and allows non-destructive analysis of the atomic composition of the target. However, a strange phenomenon occurs during irradiation on some pigments: dark brownish stains appear, and this could be due to the formation of color centers. In fact, these darkening spots progressively fade out and disappear after a few weeks. Heat and UV light accelerate the decreasing process. The aim of this study is to understand the physical processes of the stain creation and to find a way to make stains disappear, avoiding any damage for the painting.

  2. Study of color centers induced by PIXE irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Absil, J.; Garnir, H.-P.; Strivay, D.; Oger, C.; Weber, G. E-mail: g.weber@ulg.ac.be

    2002-12-01

    The particle induced X-ray emission method is perfectly adapted to the study, by external beam, of art objects (like paintings) and allows non-destructive analysis of the atomic composition of the target. However, a strange phenomenon occurs during irradiation on some pigments: dark brownish stains appear, and this could be due to the formation of color centers. In fact, these darkening spots progressively fade out and disappear after a few weeks. Heat and UV light accelerate the decreasing process. The aim of this study is to understand the physical processes of the stain creation and to find a way to make stains disappear, avoiding any damage for the painting.

  3. EELS study on BST thin film under electron beam irradiation

    Institute of Scientific and Technical Information of China (English)

    RAO Jie; ZHU Jing

    2004-01-01

    It was found that BST thin film was damaged by the irradiation of high density electron beam (the current density was about 2 nA/cm2). In-situ and real time EELS showed that the intensity ratio of Ti to O edge and the distance between Ti and O edge changed. It indicated that the film lost oxygen and thus the oxidation states of positive ions lowered. EELS study with high spatial resolution proved that compared with the inner of columnar grains, the grain boundaries with special structure and chemical environment were the main passageway of oxygen loss.

  4. EPR studies of gamma-irradiated taurine single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bulut, A. E-mail: abulut@samsun.omu.edu.tr; Karabulut, B.; Tapramaz, R.; Koeksal, F

    2000-04-01

    An EPR study of gamma-irradiated taurine [C{sub 2}H{sub 7}NO{sub 3}S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of {sup 32}SO{sup -}{sub 2} and {sup 33}SO{sup -}{sub 2} radicals. The hyperfine values of {sup 33}SO{sup -}{sub 2} radical were used to obtain O-S-O bond angle for both sites.

  5. The type 2 diabetes drug liraglutide reduces chronic inflammation induced by irradiation in the mouse brain.

    Science.gov (United States)

    Parthsarathy, Vadivel; Hölscher, Christian

    2013-01-30

    Chronic inflammation in the brain is found in a range of neurodegenerative diseases such as Parkinson's or Alzheimer's disease. We have recently shown that analogues of the glucagon-like polypeptide 1 (GLP-1) such as liraglutide have potent neuroprotective properties in a mouse model of Alzheimer's disease. We also found a reduction of activated microglia in the brain. This finding suggests that GLP-1 analogues such as liraglutide have anti-inflammatory properties. To further characterise this property, we tested the effects of liraglutide on the chronic inflammation response induced by exposure of the brain to 6 Gy (X-ray). Animals were injected i.p. with 25 nmol/kg once daily for 30 days. Brains were analysed for cytokine levels, activated microglia and astrocyte levels, and nitrite levels as a measure for nitric oxide production and protein expression of iNOS. Exposure of the brain to 6 Gy induced a pronounced chronic inflammation response in the brain. The activated microglia load in the cortex and dentate gyrus region of hippocampus (Pbrains of animals treated with liraglutide. The results demonstrate that liraglutide is effective in reducing a number of parameters linked to the chronic inflammation response. Liraglutide or similar GLP-1 analogues may be a suitable treatment for reducing the chronic inflammatory response in the brain found in several neurodegenerative conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. [Radiation situation prognosis for deep space: reactions of water and living systems to chronic low-dose ionizing irradiation].

    Science.gov (United States)

    Ushakov, I B; Tsetlin, V V; Moisa, S S

    2013-01-01

    The authors review the findings of researches into the effects of low-dose ionizing irradiation on diverse biological objects (embryonic Japanese quails, Aspergillus niger, Spirostomum ambiguum Ehrbg., mesenchymal stem cells from mouse marrow, dry higher plants seeds, blood lymphocytes from pilots and cosmonauts). Model experiments with chronic exposure to ionizing radiation doses comparable with the measurements inside orbital vehicles and estimations for trips through the interplanetary space resulted in morphological disorders (embryonic Japanese quails, Aspergillus niger), radiation hormesis (Aspergillus niger, MSCs from mouse marrow), increase in the seed germination rate, inhibition of Spirostomum spontaneous activity, DNA damages, chromosomal aberrations, and increase of the blood lymphocytes reactivity to additional radiation loading. These facts give grounds to assume that the crucial factor in the radiation outcomes is changes in liquid medium. In other words, during extended orbiting within the magnetosphere region and interplanetary missions ionizing radiation affects primarily liquids of organism and, secondarily, its morphofunctional structures.

  7. [Ultrastructural study of chronic gastritis].

    Science.gov (United States)

    Jorge, A D; Picatoste, R; del Valle, A; Díaz Flores, L

    1977-06-01

    A study of gastric biopsies with optical and electronical microscope from patients with gastritis in different stages of evolution was realized. The ultraestructural results consist in phenomenal alterations at the epitelium level, apparition of bodies of mielinic aspects in the inside of the Oxintcs cells, reduction of the number of this and the peptic cells and even the disappearance of the last. There is an increase of the mucous cells with mitotic changes, notable hyperplasia of the arget cells and intestinal metaplasia in the advanced cases. In the stroma is demonstrative the infiltration of plasmatic cells having a endoplasmatic reticule in different stages of activity, linphocytes and macrophagous full of primary and secondary lysosomas. A very important fact is the increase of the argentofilous cells and its probably relation with the appearing of the gastritis. The presence of the plasma cells and lynphocyts mark the role that takes the immunitary reaction in this process.

  8. LNL irradiation facilities for radiation damage studies on electronic devices

    Science.gov (United States)

    Bisello, D.; Candelori, A.; Giubilato, P.; Mattiazzo, S.; Pantano, D.; Silvestrin, L.; Tessaro, M.; Wyss, J.

    2016-11-01

    In this paper we will review the wide range of irradiation facilities installed at the INFN Legnaro National Laboratories and routinely used for radiation damage studies on silicon detectors, electronic components and systems. The SIRAD irradiation facility, dedicated to Single Event Effect (SEE) and bulk damage studies, is installed at the 14MV Tandem XTU accelerator and can deliver ion beams from H up to Au in the energy range from 28MeV to 300MeV. An Ion Electron Emission Microscope, also installed at SIRAD, allows SEE testing with micrometric sensitivity. For total dose tests, two facilities are presently available: an X-rays source and a 60Co γ -ray source. The 7MV Van de Graaff CN accelerator provides 1H beams in the energy range 2-7MeV and currents up to few μA for both total dose and bulk damage studies. At this facility, very high dose rates (up to ˜ 100 krad/s (SiO2)) can be achieved. Finally, also neutron beams are available, produced at the CN accelerator, by the reaction d + Be ⇒ n + B.

  9. Proliferative effect of green light emitting diode irradiation on chicken fibroblasts in hyperglycaemic circumstances: a preliminary in vitro study

    Science.gov (United States)

    Vinck, Elke; Cagnie, Barbara; Declercq, Heidi; Cornelissen, Ria; Cambier, Dirk

    2004-09-01

    A reduced mortality due to hyperglycaemia was noted since the development of insulin treatment for type I diabetes and various oral hypoglycaemic agents for type II diabetes. Nevertheless the chronic metabolic disorder, Diabetes Mellitus, remains an important cause of morbidity and mortality due to a series of common secondary metabolic complications. Patients with diabetes have an increased tendency to develop infections of the skin. Healing of skin lesions in diabetics evolves often relatively slow and the lesions tend to be more severe than in non-diabetics. Endeavouring to accelerate the healing process of skin lesions in diabetic patients, this preliminary in vitro study investigates the efficacy of green Light Emitting Diode (LED) irradiation on fibroblast proliferation of cells in hyperglycaemic circumstances. In an attempt to imitate the diabetic environment, embryonic chicken fibroblasts were cultured in hyperglycaemic medium (30.000mg Glucose per litre Hanks Medium). LED irradiation was performed three consecutive days with a wavelength of 540 nm and a power output of 10 mW, at 0,6 cm distance from the fibroblasts. Each treatment lasted 3 minutes, resulting in a surface energy density of 0,2 J/cm2. Statistical analysis revealed that LED irradiation at the applied parameters induced a higher rate of proliferation in hyperglycaemic circumstances after irradiation than in the same circumstances without irradiation. Regarding these results the effectiveness of green LED irradiation on cells in hyperglycaemic circumstances is proven. To ensure the effectiveness and to evaluate the value of LED irradiation in vivo, further research is required.

  10. Morphological studies on the healing process of tooth extraction wounds in whole body irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Yoichiro (Hokkaido Univ., Sapporo (Japan). School of Dentistry)

    1991-06-01

    The present studies were performed to investigate the healing process of the tooth extraction wound in whole body irradiated rats and to clarify the effect of irradiation on bone metabolism. One hundred and seven Wistar rats of about 100 g body weight were used and divided into 3 groups. Whole body irradiated rats were given single exposure with a dose of 8 Gy. The region of the left upper molars of local irradiated rats as controls, was exposed to 8 Gy. On the 7th day after irradiation, the left upper first molar of each rat was extracted. The rats were sacrificed at intervals of 1 to 14 days after extraction. Non-irradiated rats were sacrificed at the same intervals after extraction. The maxillary bone including the extraction wound was evaluated, histologically, histometrically and ultrastructurally. From the histological and histometrical findings, the difference of the healing process between non-irradiated rats and locally irradiated rats is not significant. In whole body irradiated rats, the healing process especially in the socket was disturbed. The osteoblastic new bone formation following production of granulation tissue was interfered with. Ultrastructurally, the cytoplasmic organellae were poorly developed in the osteoblast and osteoid formation was reduced in the socket. But periosteal new bone formation was the same as that of the locally irradiated rats. In whole body irradiated rats, the osteoclasts in the interradicular alveolar bone were decreased and have smaller nuclei, compared with non-irradiated and locally irradiated rats. Histometrically, the amount of bone loss was decreased in whole body irradiated rats. Ultrastructurally, the cyoplasmic organellae and ruffled border were poorly developed in the osteoclasts of whole body irradiated rats. The findings suggested that irradiation induced cytological changes not only in osteoblasts but in osteoclasts and these changes resulted in the delayed healing of extraction wound. (author) 106 refs.

  11. Kr ion irradiation study of the depleted-uranium alloys

    Science.gov (United States)

    Gan, J.; Keiser, D. D.; Miller, B. D.; Kirk, M. A.; Rest, J.; Allen, T. R.; Wachs, D. M.

    2010-12-01

    Fuel development for the reduced enrichment research and test reactor (RERTR) program is tasked with the development of new low enrichment uranium nuclear fuels that can be employed to replace existing high enrichment uranium fuels currently used in some research reactors throughout the world. For dispersion type fuels, radiation stability of the fuel-cladding interaction product has a strong impact on fuel performance. Three depleted-uranium alloys are cast for the radiation stability studies of the fuel-cladding interaction product using Kr ion irradiation to investigate radiation damage from fission products. SEM analysis indicates the presence of the phases of interest: U(Al, Si) 3, (U, Mo)(Al, Si) 3, UMo 2Al 20, U 6Mo 4Al 43 and UAl 4. Irradiations of TEM disc samples were conducted with 500 keV Kr ions at 200 °C to ion doses up to 2.5 × 10 19 ions/m 2 (˜10 dpa) with an Kr ion flux of 10 16 ions/m 2/s (˜4.0 × 10 -3 dpa/s). Microstructural evolution of the phases relevant to fuel-cladding interaction products was investigated using transmission electron microscopy.

  12. A study of SiC decomposition under laser irradiation

    Science.gov (United States)

    Adelmann, B.; Hellmann, R.

    2017-06-01

    In this experimental study we investigate the laser induced thermal decomposition of 4H-Sic under ambient conditions using fiber laser. Using a unique two-color pyrometer setup, we measure the temporal evolution of the temperature in the irradiated zone and determine the decomposition rate for various laser power levels. We find that the temporal evolution of the temperature in the irradiated area exhibits an initial heating phase up to about 1300 K, being characterized by an unaffected SiC surface. Upon an expeditious temperature increase, a decomposition phase follows with temperatures above 1700 K, being accompanied by carbonization of the SiC surface. The decomposed volume depends linearly on the duration of the decomposition phase and increases linearly with laser power. The temperature evaluation of the decomposition speed reveals an Arrhenius-type behavior allowing the calculation of the activation energy for the decomposition under ambient conditions to 613 kJ/mol in the temperature range between 2140 and 2420 K.

  13. Glycoalkaloids and phenolic compounds in gamma irradiated potatoes; a food irradiation study on radiation induced stress in vegetable products

    NARCIS (Netherlands)

    Bergers, W.W.A.

    1980-01-01

    Irradiation is a recent preservation method. With the aid of ionizing radiation microorganisms in food can be killed or specific physiological processes in vegetable products can be influenced.

    In order to study the effects of metabolic radiation stress on quantitative chemical changes in

  14. Quantitative computed tomography bone mineral density measurements in irradiated and non-irradiated minipig alveolar bone: an experimental study.

    NARCIS (Netherlands)

    Verdonck, H.W.; Meijer, G.J.; Nieman, F.H.; Stoll, C.; Riediger, D.; Baat, C. de

    2008-01-01

    OBJECTIVE: The objective of this study was to analyse the effect of irradiation on bone mineral density (BMD). MATERIALS AND METHODS: All maxillary and mandibular pre-molars and molars of six minipigs were extracted. After a 3-month healing period, the maxilla and mandibles of three minipigs receive

  15. Glycoalkaloids and phenolic compounds in gamma irradiated potatoes (a food irradiation study on radiation-induced stress in vegetable products)

    NARCIS (Netherlands)

    Bergers, W.W.A.

    1980-01-01

    Irradiation is a recent preservation method. With the aid of ionizing radiation microorganisms in food can be killed or specific physiological processes in vegetable products can be influenced.In order to study the effects of metabolic radiation stress on quantitative chemical changes in vegetable p

  16. Performance studies under high irradiation of resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

    CERN Document Server

    Sidiropoulou, Ourania; Bortfeldt, J; Farina, E; Iengo, P; Longo, L; Sidiropoulou, O; Wotschack, J

    2017-01-01

    Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term age- ing study. The chambers under study have an active area of 10 x 10 cm 2 , a strip pitch of 400 m m , an ampli- fication gap of 128 m m , and a drift gap of 5 mm. The results on the detector performance as a function of the photon flux up to 44 MHz/cm 2 will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.

  17. In vitro studies of different irradiation conditions for Photodynamic inactivation of Helicobacter pylori.

    Science.gov (United States)

    Simon, C; Mohrbacher, C; Hüttenberger, D; Bauer-Marschall, I; Krickhahn, C; Stachon, A; Foth, H-J

    2014-12-01

    Helicobacter pylori (HP) infections are considered to be the main cause for chronic gastritis and gastric ulcers, whereby more than half of the world's population is nowadays infected. The increased use of antibiotics is leading to an enhanced resistance. Photodynamic inactivation of bacteria seems to be a potential alternative for antibiotic therapies. In our study we used the photosensitizer Chlorin e6 (Ce6) in combination with red light-emitting diodes to inactivate HP in vitro. Ce6 uptake is determined by spectroscopy. Furthermore diverse experiments of different concentrations in the range of 0-100 μM of the photosensitizer and exposure times up to 300 s are carried out in order to find optimal irradiation parameters (wavelength: 660 nm, power density: 9 mW/cm(2), absorbed dose: up to 2.7 J/cm(2)). The data show a significant reduction after already a few seconds of illumination, even with a low Ce6 concentration in the sub-μM-region. At a concentration of 100 μM a nearly total inactivation (6-log10-reduction) of HP was achieved within 60s of irradiation.

  18. Optical studies of neutron-irradiated lithium hydride single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Oparin, D.V.; Pilipenko, G.I.; Tyutyunnik, O.I.; Gavrilov, F.F.; Sulimov, E.M. (Ural' skij Politekhnicheskij Inst., Sverdlovsk (USSR))

    1984-09-01

    Lithium hydride single crystals irradiated with neutrons were studied by the optical method. Wide bands belonging to the large F-aggregate and quasimetallic F-centres and to the metallic lithium colloids were discovered in the absorption spectra at room temperature. The small Fsub(n)-centres and molecular lithium centres were detected at 77 K. From the electron-vibrational structure of the absorption spectra of these centres the energies of acoustic phonons in X, W, L points of the Brillouin zone of lithium hydride have been found out: TA(L)-235 cm/sup -1/, TA(X)-27g cm/sup -1/, TA(W)-327 cm/sup -1/, LA(W)-384 cm/sup -1/, LA(X)-426 cm/sup -1/.

  19. Proton irradiation studies on Al and Al5083 alloy

    Science.gov (United States)

    Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

    2017-10-01

    The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

  20. p53-Dependent Senescence in Mesenchymal Stem Cells under Chronic Normoxia Is Potentiated by Low-Dose γ-Irradiation

    Directory of Open Access Journals (Sweden)

    Ines Höfig

    2016-01-01

    Full Text Available Mesenchymal stem cells (MSCs are a source of adult multipotent cells important in tissue regeneration. Murine MSCs are known to proliferate poorly in vitro under normoxia. The aim of this study is to analyze the interaction of nonphysiological high oxygen and low-dose γ-irradiation onto growth, senescence, and DNA damage. Tri-potent bone marrow-derived MSCs from p53 wildtype and p53−/− mice were cultured under either 21% or 2% O2. Long-term observations revealed a decreasing ability of wildtype mMSCs to proliferate and form colonies under extended culture in normoxia. This was accompanied by increased senescence under normoxia but not associated with telomere shortening. After low-dose γ-irradiation, the normoxic wildtype cells further increased the level of senescence. The number of radiation-induced γH2AX DNA repair foci was higher in mMSCs kept under normoxia but not in p53−/− cells. P53-deficient MSCs additionally showed higher clonogeneity, lower senescence levels, and fewer γH2AX repair foci per cell as compared to their p53 wildtype counterparts irrespective of oxygen levels. These results reveal that oxygen levels together with γ-irradiation and p53 status are interconnected factors modulating growth capacity of BM MSCs in long-term culture. These efforts help to better understand and optimize handling of MSCs prior to their therapeutic use.

  1. Pristine and γ-irradiated halloysite reinforced epoxy nanocomposites - Insight study

    Science.gov (United States)

    Saif, Muhammad Jawwad; Naveed, Muhammad; Zia, Khalid Mahmood; Asif, Muhammad

    2016-10-01

    The present study focuses on development of epoxy system reinforced with naturally occurring halloysite nanotubes (HNTs). A comparative study is presented describing the performance of pristine and γ-irradiated HNTs in an epoxy matrix. The γ-irradiation treatment was used for structural modification of natural pristine HNTs under air sealed environment at different absorbed doses and subsequently these irradiated HNTs were incorporated in epoxy resin with various wt% loadings. The consequences of γ-irradiation on HNTs were studied by FTIR and X-ray diffraction analysis (XRD) in terms of changes in functional groups and crystalline characteristics. An improvement is observed in mechanical properties and crack resistance of composites reinforced with γ-irradiated HNTs. The irradiated HNTs imparted an improved flexural and tensile strength/modulus along with better thermal performance.

  2. Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

    2008-04-15

    This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions.

  3. Long-Term Effects of Exposure to Ionizing Irradiation on Periodontal Health Status – The Tinea capitis Cohort Study

    Science.gov (United States)

    Sadetzki, Siegal; Chetrit, Angela; Sgan-Cohen, Harold D.; Mann, Jonathan; Amitai, Tova; Even-Nir, Hadas; Vered, Yuval

    2015-01-01

    Studies among long-term survivors of childhood cancer who had received high-dose irradiation therapy of 4–60 Gy, demonstrated acute and chronic dental effects, including periodontal diseases. However, the possible effects of low to moderate doses of radiation on dental health are sparse. The aim of this study is to investigate the association between childhood exposure to low–moderate doses of ionizing radiation and periodontal health following 50 years since exposure. The study population included 253 irradiated subjects (treated for Tinea capitis in the 1950s) and, 162 non-irradiated subjects. The estimated dose to the teeth was 0.2–0.4 Gy. Dental examination was performed according to the community periodontal index (CPI). Socioeconomic and health behavior variables were obtained through a personal questionnaire. Periodontal disease was operationally defined as “deep periodontal pockets.” A multivariate logistic regression model was used for the association of irradiation status and other independent variables with periodontal status. The results showed that among the irradiated subjects, 23%, (95% CI 18–28%) demonstrated complete edentulousness or insufficient teeth for CPI scoring as compared to 13% (95% CI 8–19%) among the non-irradiated subjects (p = 0.01). Periodontal disease was detected among 54% of the irradiated subjects as compared to 40% of the non-irradiated (p = 0.008). Controlling for education and smoking, the ORs for the association between radiation and periodontal disease were 1.61 (95% CI 1.01–2.57) and 1.95 (95% CI 1.1–3.5) for ever never and per 1 Gy absorbed in the salivary gland, respectively. In line with other studies, a protective effect for periodontal diseases among those with high education and an increased risk for ever smokers were observed. In conclusion, childhood exposure to low-moderate doses of ionizing radiation might be associated with later outcomes of dental health. The results add

  4. Long term effects of exposure to ionizing irradiation on periodontal health status – the Tinea Capitis cohort study

    Directory of Open Access Journals (Sweden)

    Siegal eSadetzki

    2015-10-01

    Full Text Available Studies among long term survivors of childhood cancer who had received high dose irradiation therapy of 4-60 Gy, demonstrated acute and chronic dental effects including periodontal diseases. However, the possible effects of low to moderate doses of radiation on dental health are sparse. The aim of this study is to investigate the association between childhood exposure to low-moderate doses of ionizing radiation and periodontal health following 50 years from the exposure. The study population included 253 irradiated subjects (treated for Tinea Capitis in the 1950s and, 162 non-irradiated subjects, treated for Tinea Capitis in the 1950s. The estimated dose to the teeth was 0.2-0.4Gy. Dental examination was performed according to the Community Periodontal Index (CPI. Socio-economic and health behavior variables were obtained through a personal questionnaire. Periodontal disease was operationally defined as deep periodontal pockets. A multivariate logistic regression model was used for the association of irradiation status and other independent variables with periodontal status.The results showed that among the irradiated subjects, 23% (95% CI 18%-28% demonstrated complete edentulousness or insufficient teeth for CPI scoring as compared to 13% (95% CI 8%-19% among the non-irradiated subjects (p=0.01. Periodontal disease was detected among 54% of the irradiated subjects as compared to 40% of the non-irradiated (p=0.008. Controlling for education and smoking, the ORs for the association between radiation and periodontal disease were 1.61 (95% CI 1.01-2.57 and 1.95 (95% CI 1.1-3.5 for ever never and per 1 Gy absorbed in the salivary gland, respectively. In line with other studies, a protective effect for periodontal diseases among those with high education and an increased risk for ever smokers were observed. In conclusion, childhood exposure to low-moderate doses of ionizing radiation might be associated with later outcomes of dental health. The

  5. A comparative study of the hydrolysis of gamma irradiated lignocelluloses

    Directory of Open Access Journals (Sweden)

    E. Betiku

    2009-06-01

    Full Text Available The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis and softwood (Triplochiton scleroxylon were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p < 0.05, hardwood was hydrolysed significantly better compared to the softwood.

  6. Study of dose-response and radical decay curves of gamma irradiated norfloxacin using EPR spectroscopy

    Science.gov (United States)

    Sütçü, Kerem; Osmanoǧlu, Yunus Emre

    2017-02-01

    In this study, Electron Paramagnetic Resonance (EPR) spectra of unirradiated and γ-irradiated at doses of 1, 5, 10, 12 and 15 kGy norfloxacin (NOF) were investigated. Before irradiation no EPR signal were observed. After irradiation a weak singlet signal at g = 2.0039 were obtained at room temperature. In order to describe the variation of EPR signal intensity with absorbed radiation dose, several mathematical equations were tried. Increasing irradiation dose up to 15 kGy has increased the signal intensity of the central signal however, no significant changes were observed in g spectroscopic splitting factor. The stability of signal intensity of irradiated NOF was studied over a storage period of 200 days. According to analyses conducted, EPR spectroscopy can be used to distinguish irradiated and unirradiated samples from each other.

  7. DSC studies of retrogradation and amylose lipid complex transition taking place in gamma irradiated wheat starch

    Science.gov (United States)

    Cieśla, K.; Eliasson, A. C.

    2007-12-01

    The effect of gamma irradiation ( 60Co) with doses of 5-30 kGy on the amylose-lipid complex transition and retrogradation occurring in gels containing ca. 50% and ca. 20% wheat starch was studied by differential scanning calorimetry (DSC) during heating-cooling-heating cycles (up to three cycles). Transition of the amylose-lipid complex occurs in all the irradiated samples at a lower temperature as compared to the non-irradiated starch. That effect was larger when the radiation dose was higher. A further thermal treatment causes a decrease of the transition temperature in the irradiated samples, with no effect or increase of that temperature observed for the non-irradiated ones. Irradiation hinders retrogradation taking place in 50% gels but facilitates the process occurring in 20% gels. The differences between the irradiated and the non-irradiated samples are more evident in the every next heating or cooling cycle as well as after storage and in the case of ca. 50% suspensions as compared to ca. 20% suspensions. The results point out to the deterioration of the structure of the complexes formed in the irradiated starch as compared to the non-irradiated one.

  8. Systematic Study of the PbWO4 Crystal Short Term Instalibity Under Irradiation

    CERN Document Server

    Annenkov, Alexander; Chipaux, Rémi; Drobychev, Gleb; Fedorov, Andrey; Géléoc, Marie; Golubev, Nikolai; Korzhik, Mikhail; Lecoq, Paul; Ligun, A B; Missevitch, Oleg; Pavlenko, V B; Peigneux, Jean-Pierre; Singovsky, Alexander

    1997-01-01

    The effect of the irradiation on the lead tungstate ( PWO) scintillator properties has been studied at different irradiation facilities. Lead tungstate crystals grown with the tuning of oxides content in the melt to the stoichiometry of pure sheelite or sheelite-like type crystals and doped with heterovalent, trivalent and pentavalent impurities have been studied in order to optimize their resistance to irradiation. A combination of a selective cleaning of raw materials, a tuning of the melt from crystallization to crystallisation, and a destruction or compensation of the point structure defects has been used to minimize the short-term instability of PWO parameters under irradiation.

  9. [Application of the Gompertz mortality law to the prognosis of lifespan shortening due to chronic internal irradiation].

    Science.gov (United States)

    Panteleev, L I; Shvedov, V L

    1984-01-01

    In experiments on albino rats received strontium 90 in daily doses of 1.85 to 185 kBq/day the regularities of death were studied. It was shown that death of animals exposed to chronic internal radiation followed the Gomperz B. mortality law.

  10. Study of Mutagenic Effects of M1 Generation of Maize Seeds Irradiated by Heavy Ions

    Institute of Scientific and Technical Information of China (English)

    LUOHong-bing; ZHAOKui; GUOJi-yu; SUILi; NIMei-nan; MEIJun-ping; LUXiu-qin; ZHOUPing; KONGFu-quan; ZHANGGen-fa

    2003-01-01

    In order to study M1 biological effects induced by heavy ion irradiation on maize seeds, the embryos of dry maize seeds are irradiated with 7Li and 12C ions. The experiment is performed at the heavy ion scanning tube of the HI-13 tandem accelerator. The beam goes through a thickness of 25μm. Then the maize seeds are irradiated in the air uniformly.

  11. Study of the Effect of Swelling on Irradiation Assisted Stress Corrosion Cracking

    Energy Technology Data Exchange (ETDEWEB)

    Teysseyre, Sebastien Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    This report describes the methodology used to study the effect of swelling on the crack growth rate of an irradiation-assisted stress corrosion crack that is propagating in highly irradiated stainless steel 304 material irradiated to 33 dpa in the Experimental Breeder Reactor-II. The material selection, specimens design, experimental apparatus and processes are described. The results of the current test are presented.

  12. Study on some chemical changes in irradiated pepper and parsley

    Energy Technology Data Exchange (ETDEWEB)

    Josimovic, L. (Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia))

    1983-05-01

    The effect of ionizing radiation on some water soluble components (carbohydrates, carbonyl compounds) of pepper and parsley, as well as on piperine in pepper and chlorophyll in parsley has been investigated. The irradiation of parsley with doses as high as 5 Mrad does not bring about any distinct qualitative and quantitative changes. In irradiated pepper qualitative changes were also not observed, but quantitative changes were measured even for doses lower than 1 Mrad. However, piperine in pepper is quite resistant against radiation.

  13. Irradiation of carbon nanotubes with carbon projectiles: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Cristian D. [Departamento de Fisica Aplicada, Universidad de Alicante, 03080 Alicante (Spain); Heredia-Avalos, Santiago; Moreno-Marin, Juan Carlos [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, 03080 Alicante (Spain)

    2013-04-15

    The irradiation of carbon based nanostructures with ions and electrons has been shown to be an appropriate tool to tailor their properties. The defects induced in the nanostructures during irradiation are able to modify their mechanical and electronic properties. Here we simulate the irradiation of carbon nanotubes with carbon ions using a molecular dynamics code. We use the Tersoff potential joined smoothly to the Universal Ziegler-Biersack-Littmark potential at short distances. We study the number of defects produced after irradiation with a single carbon ion finding a saturation with its energy at {proportional_to} 3 keV. We observe, after continuum irradiation with low energy ions, the formation of bumps in the irradiated region. For larger energy ions we find that the diameter of the nanotube shrinks as shown in previous works. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Mechanical properties of irradiated nanowires – A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, Emilio [Grupo de NanoMateriales, Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla, 653 Santiago (Chile); Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile); Tramontina, Diego [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, 5500 Mendoza (Argentina); Instituto de Bioingeniería, Universidad de Mendoza, 5500 Mendoza (Argentina); Gutiérrez, Gonzalo, E-mail: gonzalo@fisica.ciencias.uchile.cl [Grupo de NanoMateriales, Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla, 653 Santiago (Chile); Bringa, Eduardo [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, 5500 Mendoza (Argentina)

    2015-12-15

    In this work we study, by means of molecular dynamics simulation, the change in the mechanical properties of a gold nanowire with pre-existing radiation damage. The gold nanowire is used as a simple model for a nanofoam, made of connected nanowires. Radiation damage by keV ions leads to the formation of a stacking fault tetrahedron (SFT), and this defect leads to a reduced plastic threshold, as expected, when the nanowire is subjected to tension. We quantify dislocation and twin density during the deformation, and find that the early activation of the SFT as a dislocation source leads to reduced dislocation densities compared to the case without radiation damage. In addition, we observed a total destruction of the SFT, as opposed to a recent simulation study where it was postulated that SFTs might act as self-generating dislocation sources. The flow stress at large deformation is also found to be slightly larger for the irradiated case, in agreement with recent experiments. - Highlights: • Stacking Fault Tetrahedra (SFT) formation proceeds by cascades, containing typically a vacancy cluster and interstitials. • Applied tension leads to the destruction of the SFT, in contrast to a recently reported case of a SFT which soften the NW. • After the initial dislocation activity, strength is controlled by a few surviving dislocations.

  15. LPI studies with grazing incidence irradiation at the Nike laser

    Science.gov (United States)

    Weaver, J.; Kehne, D.; Schmitt, A.; Obenschain, S.; Serlin, V.; Oh, J.; Lehmberg, R.; Seely, J.

    2013-10-01

    Studies of laser plasma instabilities (LPI) at the Nike laser facility at NRL have previously concentrated on planar targets irradiated with their surface normal aligned to the central axis of the laser. Shots with planar targets rotated up 60° to the laser have shown changes in thresholds for the two-plasmon decay instability and stimulated Raman scattering near the quarter critical region. In the case of rotated low-Z targets, spectra were observed to shift to lower wavelength and were substantially stronger in the visible and ultraviolet spectral ranges. The low-Z target data show growth at an incident intensity slightly below (~30%) the threshold values observed at normal incidence. A rapid rise in signal level over the same laser intensities was also observed in the hard x-ray data which serve as an overall indicator of LPI activity. Shots with rotated planar high-Z targets showed that the visible and ultraviolet emissions dropped significantly when compared to low-Z targets in the same geometry. This presentation will include results from upcoming experiments to determine the LPI signal for low-Z, high-Z, and high-Z coated targets at lower laser intensities for several angles of target rotation. Shots with widely separated laser beams are also planned to explore cross beam energy transport at Nike. Work supported by DoE/NNSA.

  16. Virus inactivation studies using ion beams, electron and gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Smolko, Eduardo E. [Laboratorio de Polimeros, Grupo Aplicaciones Industriales, Unidad de Aplicaciones Tecnologicas y Agropecuarias, Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Pbro. Juan Gonzalez y Aragon 15, C.P. B1802AYA Ezeiza, Buenos Aires (Argentina)]. E-mail: smolko@cae.cnea.gov.ar; Lombardo, Jorge H. [Biotech S.A., C.P. 1754 Buenos Aires (Argentina)

    2005-07-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle ({alpha}, d and ss) and {gamma} irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D{sub 37} dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule.

  17. Virus inactivation studies using ion beams, electron and gamma irradiation

    Science.gov (United States)

    Smolko, Eduardo E.; Lombardo, Jorge H.

    2005-07-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle (α, d and ß) and γ irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D37 dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule.

  18. Chronic UVA (365-nm) irradiation induced scratching in hairless mice: dose-time dependency and the effect of ketanserin

    Energy Technology Data Exchange (ETDEWEB)

    Laat, J.M.T. de; Groenendijk, M.; Vloten, W.A. van; Gruijl, F.R. de [Univ. Hospital Utrecht, Dept. of Dermatology (Netherlands); Seite, S. [L`Oreal-Centre de Recherche Charles Zviak, Recherche Avancee Biologie (France)

    1997-12-31

    In a study on the dose-response relationship for longwave UVA (UVA1; 340-400 nm) carcinogenesis in hairless mice scratch marks appeared after months of daily exposure as an unwanted side effect. Tumor induction in the highest of the 4 tested dose groups (receiving a daily dose of 430 kJ/m{sup 2} of 365-nm radiation) could not be determined because extensive scarification occurred prior to the development of any tumors. The induction of scratch marks could be scored and quantified in all 4 dose groups tested. The UVA1 dose-dependencies for the induction of tumors and scratch marks were compared. We found that the induction of scratch marks depended mainly on the cumulative UVA1 exposure, whereas tumor induction showed a lesser dose-dependency. An attempt was made to prevent the apparent pruritogenic effect of UVA1 irradiation and to understand its mechanism. The influence of ketanserin, a serotonin/histamine antagonist, on the UVA1 induction of scratch marks was tested in groups of 8 mice daily irradiated with 430 kJ/m{sup 2}. No difference was found between treated and untreated animals. Histological examination of skin biopsies from irradiated mice from the 430-kJ/m{sup 2} dose group from the UVA1 carcinogenic experiment, showed no changes in numbers of mast cells or other inflammatory features when compared to skin biopsies from unirradiated control mice. This indicated that UVA1-induced scratching is not mediated through mast cell release of serotonin and/or histamine. An adequate therapeutic treatment which can prevent UVA1-induced scratching would enable us to test tumor induction with UVA1 over a larger dose range, and may provide additional insight in how this radiation damages the skin. It remains conjectural whether there exists and analogous UVA-induced pruritus in human skin. (au) 26 refs.

  19. The irradiation studies on diamond-like carbon films

    CERN Document Server

    LiuGuIang; Xie Er Qin

    2002-01-01

    Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (r.f.) plasma deposition method. gamma-ray, ultraviolet (UV) ray and neutron beam were used to irradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were used to characterize the changing characteristics of SP sup 3 C-H bond and hydrogen content in the films due to the irradiations. It showed that, the damage degrees of the gamma-ray, UV ray and neutron beam on the SP sup 3 C-H bonds are different. Among them, the damage of gamma-ray on the SP sup 3 C-H bond is the weakest. When the irradiation dose of gamma-ray reaches 10x10 sup 4 Gy, the SP sup 3 C-H bond reduces about 50% in number. The square resistance of the films is reduced due to the irradiation of UV ray and this is caused by severe oxidation of the films. Compared with that of the as-deposited one, the IR transmittance of the films irradiated by both gamma-ray and neutron beam is increased to some extent. By using the results on optical...

  20. Positron annihilation Doppler broadening spectroscopy study on Fe-ion irradiated NHS steel

    Science.gov (United States)

    Zhu, Huiping; Wang, Zhiguang; Gao, Xing; Cui, Minghuan; Li, Bingsheng; Sun, Jianrong; Yao, Cunfeng; Wei, Kongfang; Shen, Tielong; Pang, Lilong; Zhu, Yabin; Li, Yuanfei; Wang, Ji; Song, Peng; Zhang, Peng; Cao, Xingzhong

    2015-02-01

    In order to study the evolution of irradiation-induced vacancy-type defects at different irradiation fluences and temperatures, a new type of ferritic/martensitic (F/M) steel named NHS (Novel High Silicon) was irradiated by 3.25 MeV Fe-ion at room temperature and 723 K to fluences of 4.3 × 1015 and 1.7 × 1016 ions/cm2. After irradiation, vacancy-type defects were investigated with variable-energy positron beam Doppler broadening spectra. Energetic Fe-ions produced a large number of vacancy-type defects in the NHS steel, but one single main type of vacancy-type defect was observed in both unirradiated and irradiated samples. The concentration of vacancy-type defects decreased with increasing temperature. With the increase of irradiation fluence, the concentration of vacancy-type defects increased in the sample irradiated at RT, whereas for the sample irradiated at 723 K, it decreased. The enhanced recombination between vacancies and excess interstitial Fe atoms from deeper layers, and high diffusion rate of self-interstitial atoms further improved by diffusion via grain boundary and dislocations at high temperature, are thought to be the main reasons for the reversed trend of vacancy-type defects between the samples irradiated at RT and 723 K.

  1. Small-angle neutron scattering study on irradiated kappa carrageenan

    Energy Technology Data Exchange (ETDEWEB)

    Abad, Lucille [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan) and Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines) and Advanced Science Research Center, Japan Atomic Energy Research Institute, 2-4 Shirane Shirakata, Tokai, Ibaraki 319-1195 (Japan)]. E-mail: lvabad@pnri.dost.gov.ph; Okabe, Satoshi [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Koizumi, Satoshi [Advanced Science Research Center, Japan Atomic Energy Research Institute, 2-4 Shirane Shirakata, Tokai, Ibaraki 319-1195 (Japan); Shibayama, Mitsuhiro [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan)]. E-mail: sibayama@issp.u-tokyo.ac.jp

    2006-05-31

    The structure of gamma-ray-irradiated {kappa}-carrageenan in aqueous solutions was investigated in terms of small-angle neutron scattering. The scattered intensity, I(q), of non-irradiated {kappa}-carrageenan solutions (5 wt%) was well described with an Ornstein-Zernike (OZ)-type function with the correlation length of 85 A, indicating that the {kappa}-carrageenan solution behaves just as a polymer solution in the semi-dilute regime. By increasing the irradiation dose (100 kGy), I(q) changed to a power-law function with the scattering exponent of -1.84. Further increase in dose results in a recovery of OZ-type function. This indicates that a progressive cleavage of {kappa}-carrageenan chains takes place randomly, leading to a self-similar structure at 100 kGy. This is followed by further segmentation of {kappa}-carrageenan chains.

  2. Detection of irradiated chestnuts: preliminary study using three analytical techniques

    Science.gov (United States)

    Mangiacotti, Michele; Chiaravalle, Antonio Eugenio; Marchesani, Giuliana; De Sio, Antonio; Boniglia, Concetta; Bortolin, Emanuela; Onori, Sandro

    2009-07-01

    Irradiation of chestnuts has recently been considered as an alternative treatment to fumigation to reduce the considerable amount of the product normally lost during post-harvest period. The treatment is allowed in countries such as Korea and, in view of a possible extension to European countries, to permit the legal controls as required by the directive 1999/2/EC [ European Parliament and Council Directive, 1999/2/EC, on the approximation of the laws of the Member States concerning foods and food ingredients treated with ionising radiation. Official Journal of the European Communities. L 66/16 of 13.3.1999] and meet consumer consensus, reliable methods for detecting irradiated chestnuts have to be proposed. The aim of the present work was to test the efficacy of the European Standard EN 13751, EN 1788, EN 1787 and EN 13708 in detecting irradiated chestnuts. For this purpose, six sets of "Montella" chestnuts, a typical Italian variety recognized as a PGI (protected geographical indication), non-irradiated and irradiated at different doses in the 0.1-1 kGy range, were analysed by thermoluminescence (TL), photo-stimulated luminescence (PSL) (screening and calibrated PSL) and ESR techniques. PSL and TL analysis results revealed the low luminescence sensitivity of the chestnuts. Nevertheless, PSL screening data were in the intermediate band above the negative threshold (at all doses except at the lowest one) and TL analysis led to correct positive classifications even at the lowest dose tested (0.15 Gy). On the contrary, no radio-induced ESR signal could be registered with the irradiated samples of chestnut shell or pulp.

  3. Detection of irradiated chestnuts: preliminary study using three analytical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mangiacotti, Michele [Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Foggia (Italy)], E-mail: izsfgchimica@infinito.it; Chiaravalle, Antonio Eugenio; Marchesani, Giuliana [Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Foggia (Italy); De Sio, Antonio [La Dolce Irpinia Srl - Montella (AV) (Italy); Boniglia, Concetta [Department of Public Veterinary Health and Food Safety, Istituto Superiore di Sanita, Rome (Italy); Bortolin, Emanuela; Onori, Sandro [Department of Technology and Health, Istituto Superiore di Sanita, Rome (Italy)

    2009-07-15

    Irradiation of chestnuts has recently been considered as an alternative treatment to fumigation to reduce the considerable amount of the product normally lost during post-harvest period. The treatment is allowed in countries such as Korea and, in view of a possible extension to European countries, to permit the legal controls as required by the directive 1999/2/EC [/2/EC, on the approximation of the laws of the Member States concerning foods and food ingredients treated with ionising radiation. Official Journal of the European Communities. L 66/16 of 13.3.1999] and meet consumer consensus, reliable methods for detecting irradiated chestnuts have to be proposed. The aim of the present work was to test the efficacy of the European Standard EN 13751, EN 1788, EN 1787 and EN 13708 in detecting irradiated chestnuts. For this purpose, six sets of 'Montella' chestnuts, a typical Italian variety recognized as a PGI (protected geographical indication), non-irradiated and irradiated at different doses in the 0.1-1 kGy range, were analysed by thermoluminescence (TL), photo-stimulated luminescence (PSL) (screening and calibrated PSL) and ESR techniques. PSL and TL analysis results revealed the low luminescence sensitivity of the chestnuts. Nevertheless, PSL screening data were in the intermediate band above the negative threshold (at all doses except at the lowest one) and TL analysis led to correct positive classifications even at the lowest dose tested (0.15 Gy). On the contrary, no radio-induced ESR signal could be registered with the irradiated samples of chestnut shell or pulp.

  4. Irradiation of Polystyrene and Polypropylene to study NIH 3T3 fibroblasts adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Arbeitman, C.R. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Grosso, M.F. del, E-mail: delgrosso@tandar.cnea.gov.a [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina); Ibanez, I. [Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina); Gerencia de Aplicaciones Tecnologicas de la Energia Nuclear, Dpto. de Radiobiologia, TANDAR-CNEA (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina); Escuela de Ciencia y Tecnologia, UNSAM (Argentina); Duran, H. [Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina); Gerencia de Aplicaciones Tecnologicas de la Energia Nuclear, Dpto. de Radiobiologia, TANDAR-CNEA (Argentina); Escuela de Ciencia y Tecnologia, UNSAM (Argentina); Chappa, V.C. [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina); Mazzei, R. [U.A. Tecnologicas y Agropecuarias, CNEA, Dpto. Ing. Quimica, UTN FRBA, Bs. As. (Argentina); Behar, M. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

    2010-10-01

    When polymers are irradiated with heavy ions new chemical groups are created in a few microns of the material. The irradiation changed the polarity and wettability on the surface so that could enhance the biocompatibility of the modified polymer. The study of chemistry and nanoscale topography of the biomaterial is important in determining its potential applications in medicine and biotechnology, because their strong influence on cell function, adhesion and proliferation. In this study, thin films of Polystyrene and Polypropylene samples were modified by irradiation with low energy ion beams (30-150 keV) and swift heavy ions both with various fluences and energies. The changes were evaluated with different methods. Adhesion of NIH 3T3 fibroblasts onto unirradiated and irradiated surfaces has been studied by in vitro techniques. The correlations between physicochemical properties as a function of different irradiations parameters were compared with cell adhesion on the modified polymer surface.

  5. Studies on the safety and consumer acceptance of gamma irradiated meats

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Il Jun [Hallym University, Kangwon (Korea); Lee, Cherl Ho [Korea University, Seoul (Korea); Kim, Jung Hee [Seoul Women' s University, Seoul (Korea)

    1999-04-01

    Gamma irradiation was applied to beefs (0-5 kGy) and porks (0-30 kGy) for evaluation of their possible genotoxicity, acute toxicity and four-week oral toxicity. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535, TA1537. Clastogenic effects of the irradiated samples tested were not shown in vivo mouse micronucleus assay. In an acute toxicity test, the maximal dose of 5,000 mg/kg did not change any toxic parameter examined in this study. In four-week oral toxicity study, no significant differences were found between the control and treatment groups. In the study of rat hepatocarcinogenesis, the consumption of gamma irradiated beef and pork not only does not affect the formation of lipid peroxide and membrane stability but also has a possibility to inhibit hepatocarcinogenesis. Also, the consumption of {gamma} - irradiated beef and pork does not affect antioxidative defense system. In the study of the biological safety of korean red pepper, no difference was found on microbial growth between pepper extract alone or irradiated pepper extract. In the preservation study of korean traditional rice-cake(garedok), irradiation dose below 10kGy had no influence on typical sensory characteristics. The shelf-life in rice-cakes with different conditions was the longest on 10kGy treatment than 5kGy. In investigation of the consumer attitude toward irradiated foods, the main reason for the concern about irradiated foods is that compounds in the products formed by irradiation. Therefore, regulatory authorities must be encouraged to permit the sale of irradiated items when wholesomeness is established. (author). 94 refs.,31 figs., 62 tabs.

  6. Study on antibacterial activity of hydrogel from irradiated silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Bunnak, J.; Chaisupakitsin, M. [King Mongkut' s Institute of Technology Lardkrabang, Bangkok (Thailand)

    2001-03-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N{sub 2} atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  7. [Study on the absolute spectral irradiation calibration method for far ultraviolet spectrometer in remote sensing].

    Science.gov (United States)

    Yu, Lei; Lin, Guan-Yu; Chen, Bin

    2013-01-01

    The present paper studied spectral irradiation responsivities calibration method which can be applied to the far ultraviolet spectrometer for upper atmosphere remote sensing. It is difficult to realize the calibration for far ultraviolet spectrometer for many reasons. Standard instruments for far ultraviolet waveband calibration are few, the degree of the vacuum experiment system is required to be high, the stabilities of the experiment are hardly maintained, and the limitation of the far ultraviolet waveband makes traditional diffuser and the integrating sphere radiance calibration method difficult to be used. To solve these problems, a new absolute spectral irradiance calibration method was studied, which can be applied to the far ultraviolet calibration. We build a corresponding special vacuum experiment system to verify the calibration method. The light source system consists of a calibrated deuterium lamp, a vacuum ultraviolet monochromater and a collimating system. We used the calibrated detector to obtain the irradiance responsivities of it. The three instruments compose the calibration irradiance source. We used the "calibration irradiance source" to illuminate the spectrometer prototype and obtained the spectral irradiance responsivities. It realized the absolute spectral irradiance calibration for the far ultraviolet spectrometer utilizing the calibrated detector. The absolute uncertainty of the calibration is 7.7%. The method is significant for the ground irradiation calibration of the far ultraviolet spectrometer in upper atmosphere remote sensing.

  8. High resolution X-ray diffraction studies on unirradiated and irradiated strontium hexaferrite crystals

    Indian Academy of Sciences (India)

    Balwinder Kaur; Monita Bhat; F Licci; Ravi Kumar; K K Bamzai; P N Kotru

    2012-04-01

    High-resolution X-ray diffraction technique, employing a three-crystal monochromator–collimator combination is used to study the irradiation induced defects in flux grown Sr-hexaferrite crystals irradiated with 50 MeV Li3+ ion beams at room temperature with a fluence value of 1 × 1014 ions/cm2. The diffraction curves of the irradiated crystals suggest the possibility of creation of low angle grain boundaries and other point/clusters of defects causing amorphization in the irradiated crystals. The perfection of the irradiated and unirradiated (0001) cleaved surfaces of the crystals is studied using the bulk method of X-ray topography. The topographs supplement the findings suggestive of modifications in the crystalline quality of SrFe12O19 on irradiation with SHI of Li3+. Etching of the (0001) cleaved surfaces in H3PO4 at 120°C suggests that the dissolution characteristics of the surfaces get affected on irradiation with SHI of Li3+, besides supporting the findings of HRXRD and X-ray topography regarding modifications in the perfection of SrFe12O19 on irradiation.

  9. Spectroscopic study of energetic helium-ion irradiation effects on nuclear graphite tiles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Wan; Lee, K.W. [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Choi, D.M.; Noh, S.J.; Kim, H.S. [Department of Applied Physics, Dankook University, Yongin 448-701 (Korea, Republic of); Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of)

    2016-02-01

    Highlights: • Energetic helium-ion irradiation on nuclear graphite tiles studied for plasma facing components. • XPS reveals recrystallization at low dose irradiation and DLC sites at higher doses. • Raman spectroscopy reveals increasing diamond-like defects and structural deformation. • Average inter-defect distance obtained as a function of irradiation dose from Raman intensities. - Abstract: Helium ion-irradiation effects on the nuclear graphite tiles were studied in order to understand the structural modifications and damages that can be produced by fusion reaction in tokamaks. The surface morphological changes due to increasing dose of the irradiation were examined by the field-effect scanning electron microscopy, and X-ray photoelectron spectroscopy elucidated the changes in the shallow surface bonding configurations caused by the energetic irradiation. Raman spectroscopy revealed the structural defects and diamond-like carbon sites that increased with increasing irradiation dose, and the average inter-defect distance was found from the Raman peak intensities as a function of the irradiation dose.

  10. Design study of water chemistry control system for IASCC irradiation test

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Yuichiro; Ide, Hiroshi; Nabeya, Hideaki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-02-01

    In relation to the aging of Light Water Reactor (LWR), the Irradiation Assisted Stress Corrosion Cracking (IASCC) has been regarded as a significant and urgent issue for the reliability of in-core components of LWR, and the irradiation research on the IASCC is now under schedule. With the progress of the irradiation research on reactor materials, well-controlled environment conditions during irradiation testing are required. Especially for irradiation testing of IASCC studies, water chemistry control is essential in addition to the control of neutron fluence and irradiation temperature. According to these requirements, at the Japan Atomic Energy Research Institute (JAERI), an irradiation testing facility that simulates in-core environment of Boiling Water Reactor (BWR) has been designed to be installed in the Japan Materials Testing Reactor (JMTR). This facility is composed of the Saturated Temperature Capsules (SATCAP) that are installed into the JMTR's core to irradiate material specimens, the Water Control Unit that is able to supply high-temperature and high-pressure chemical controlled water to SATCAP, and other components. This report describes the design study of water chemistry control system of the Water Control Unit. The design work has been performed in the fiscal year 1999. (author)

  11. Chronic pain and pain medication use in chronic obstructive pulmonary disease. A cross-sectional study.

    Science.gov (United States)

    Roberts, Melissa H; Mapel, Douglas W; Hartry, Ann; Von Worley, Ann; Thomson, Heather

    2013-08-01

    Pain is a common problem for patients with chronic obstructive pulmonary disease (COPD). However, pain is minimally discussed in COPD management guidelines. The objective of this study was to describe chronic pain prevalence among patients with COPD compared with similar patients with other chronic diseases in a managed care population in the southwestern United States (age ≥ 40 yr). Using data for the period January 1, 2006 through December 31, 2010, patients with COPD were matched to two control subjects without COPD but with another chronic illness based on age, sex, insurance, and healthcare encounter type. Odds ratios (OR) for evidence of chronic pain were estimated using conditional logistic regression. Pulmonary function data for 200 randomly selected patients with COPD were abstracted. Retrospectively analyzed recurrent pain-related utilization (diagnoses and treatment) was considered evidence of chronic pain. The study sample comprised 7,952 patients with COPD (mean age, 69 yr; 42% male) and 15,904 patients with other chronic diseases (non-COPD). Patients with COPD compared with non-COPD patients had a higher percentage of chronic pain (59.8 vs. 51.7%; P pain-related medications (41.2 vs. 31.5%; P Hispanic ethnicity, and comorbidities, patients with COPD had higher odds of chronic pain (OR, 1.56; 95% confidence interval [CI], 1.43-1.71), chronic use of pain-related medications (OR, 1.60; 95% CI, 1.46-1.74), and chronic use of short-acting or long-acting opioids (OR, 1.74; 95% CI, 1.57-1.92). Chronic pain and opioid use are prevalent among adults with COPD. This finding was not explained by the burden of comorbidity.

  12. Status of Chronic Oxidation Studies of Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mee, Robert W. [Univ. of Tennessee, Knoxville, TN (United States)

    2016-05-01

    Graphite will undergo extremely slow, but continuous oxidation by traces of moisture that will be present, albeit at very low levels, in the helium coolant of HTGR. This chronic oxidation may cause degradation of mechanical strength and thermal properties of graphite components if a porous oxidation layer penetrates deep enough in the bulk of graphite components during the lifetime of the reactor. The current research on graphite chronic oxidation is motivated by the acute need to understand the behavior of each graphite grade during prolonged exposure to high temperature chemical attack by moisture. The goal is to provide the elements needed to develop predictive models for long-time oxidation behavior of graphite components in the cooling helium of HTGR. The tasks derived from this goal are: (1) Oxidation rate measurements in order to determine and validate a comprehensive kinetic model suitable for prediction of intrinsic oxidation rates as a function of temperature and oxidant gas composition; (2) Characterization of effective diffusivity of water vapor in the graphite pore system in order to account for the in-pore transport of moisture; and (3) Development and validation of a predictive model for the penetration depth of the oxidized layer, in order to assess the risk of oxidation caused damage of particular graphite grades after prolonged exposure to the environment of helium coolant in HTGR. The most important and most time consuming of these tasks is the measurement of oxidation rates in accelerated oxidation tests (but still under kinetic control) and the development of a reliable kinetic model. This report summarizes the status of chronic oxidation studies on graphite, and then focuses on model development activities, progress of kinetic measurements, validation of results, and improvement of the kinetic models. Analysis of current and past results obtained with three grades of showed that the classical Langmuir-Hinshelwood model cannot reproduce all

  13. FTIR study of silicon carbide amorphization by heavy ion irradiations

    Science.gov (United States)

    Costantini, Jean-Marc; Miro, Sandrine; Pluchery, Olivier

    2017-03-01

    We have measured at room temperature (RT) the Fourier-transform infra-red (FTIR) absorption spectra of ion-irradiated thin epitaxial films of cubic silicon carbide (3C–SiC) with 1.1 µm thickness on a 500 µm thick (1 0 0) silicon wafer substrate. Irradiations were carried out at RT with 2.3 MeV 28Si+ ions and 3.0 MeV 84Kr+ ions for various fluences in order to induce amorphization of the SiC film. Ion projected ranges were adjusted to be slightly larger than the film thickness so that the whole SiC layers were homogeneously damaged. FTIR spectra of virgin and irradiated samples were recorded for various incidence angles from normal incidence to Brewster’s angle. We show that the amorphization process in ion-irradiated 3C–SiC films can be monitored non-destructively by FTIR absorption spectroscopy without any major interference of the substrate. The compared evolutions of TO and LO peaks upon ion irradiation yield valuable information on the damage process. Complementary test experiments were also performed on virgin silicon nitride (Si3N4) self-standing films for similar conditions. Asymmetrical shapes were found for TO peaks of SiC, whereas Gaussian profiles are found for LO peaks. Skewed Gaussian profiles, with a standard deviation depending on wave number, were used to fit asymmetrical peaks for both materials. A new methodology for following the amorphization process is proposed on the basis of the evolution of fitted IR absorption peak parameters with ion fluence. Results are discussed with respect to Rutherford backscattering spectrometry channeling and Raman spectroscopy analysis.

  14. Reliability studies on NPN RF power transistors under swift heavy ion irradiation

    Science.gov (United States)

    Pushpa, N.; Praveen, K. C.; Gnana Prakash, A. P.; Naik, P. S.; Cressler, John D.; Gupta, S. K.; Revannasiddaiah, D.

    2012-02-01

    NPN RF power transistors were irradiated with 140 MeV Si 10+ ions, 100 MeV F 8+ ions, 50 MeV Li 3+ ions and Co-60 gamma radiation in the dose range from 100 krad to 100 Mrad. The transistor characteristics are studied before and after irradiation from which the parameters such as Gummel characteristics, excess base current (Δ IB = IBpost - IBpre), dc current gain ( hFE), transconductance ( gm) and collector-saturation current ( ICSat) are determined. The degradation observed in the electrical characteristics is almost the same for different types of ion irradiated NPN RF power transistors with similar total doses although there is a large difference in the linear energy transfer (LET) of the ions. Further, it was observed more degradation in DC I- V characteristics of ion irradiated devices than the Co-60 gamma irradiated devices for higher doses.

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

    Science.gov (United States)

    Al-Bachir, Mahfouz

    2015-01-15

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

  16. Study on shelf life extension of papayas irradiated by /sup 60/Co gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Chang, M.S.; Chen, M.D.; Lin, C.T.; Fu, Y.K.

    1984-11-01

    Papayas are one of the main fresh fruits in Taiwan area. Papaya fruits were treated with hot water to pasteurize peels followed by /sup 60/Co gamma-ray irradiation to extend the ripening time. The purpose of synergetic methods is to extend the shelf life of papaya fruits. This experiment was carried out by seven treatments, which were: (1) control group, (2) hot water treatment only, (3) hot water treatment with a 25 krad ..gamma..-irradiation, (4) hot water treatment with a 50 krad ..gamma..-irradiation, (5) hot water treatment with a 75 krad ..gamma..-irradiation, (6) 75 krad ..gamma..-irradiation only, and (7) hot water treatment with a 100 krad ..gamma..-irradiation. The items of observation were: surface yellowing, surface decaying, quality of texture, and length of period lasted after irradiation for 50% marketable papayas. The results of this study showed that a shelf-life extension of six days could be obtained for papayas subjected to hot water (50 to 55/sup 0/C) treatment and a 100 krad irradiation. 3 refs., 2 figs., 2 tabs.

  17. Depth profile study on Raman spectra of high-energy-electron-irradiated hydrogenated amorphous silicon films

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    According to the different penetration depths for the incident lights of 472 nm and 532 nm in hydrogenated amorphous silicon (a-Si:H) thin films, the depth profile study on Raman spectra of a-Si:H films was carried out. The network ordering evolution in the near surface and interior region of the unirradiated and irradiated a-Si:H films was investigated. The results show that there is a structural improvement in the shortand intermediate-range order towards the surface of the unirradiated a-Si:H films. The amorphous silicon network in the near and interior region becomes more disordered on the shortand intermediate-range scales after being irradiated with high energy electrons. However, the surface of the irradiated films becomes more disordered in comparison with their interior region, indicating that the created defects caused by electron irradiation are concentrated in the near surface of the irradiated films. Annealing eliminates the irradiation effects on a-Si:H thin films and the structural order of the irradiated films is similar to that of the unirradiated ones after being annealed. There exists a structural improvement in the shortand intermediate-range order towards the surface of the irradiated a-Si:H films after being annealed.

  18. [Somnoplasty: treatment of chronic snoring using radiofrequency irradiation of the palate].

    Science.gov (United States)

    Galindo Campillo, A N; García Simal, M; Navarro Cunchillos, M; Toledano Muñoz, A

    2003-12-01

    The goal of this study is to evaluate the efficacy and the safety of tissue reduction of the palate by means of radiofrequency for the treatment of snoring. Fifty-three patients were evaluated. Eight of them (15%) met criteria for mild OSAS. All of them underwent RF energy treatment with several ablation sites and the mean total energy administered was about 2500 J per treatment session. 40 patients (75%) underwent an additional RF treatment and the energy administered in the second session was the same as in the first one. We evaluated postoperative pain, snoring and the satisfaction of the patient and his enviroment. After a mean follow-up of 20 months no adverse effect was reported. The success diminishes with time as happens other surgical procedures (UPPP or LAUP) but the absence of serious adverse side-effects and the minimal postoperative pain support the use of RF as an effective procedure for reducing snoring.

  19. Positron annihilation Doppler broadening spectroscopy study on Fe-ion irradiated NHS steel

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Huiping [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Zhiguang, E-mail: zhgwang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Gao, Xing; Cui, Minghuan; Li, Bingsheng; Sun, Jianrong; Yao, Cunfeng; Wei, Kongfang; Shen, Tielong; Pang, Lilong; Zhu, Yabin [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Li, Yuanfei; Wang, Ji [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); University of Lanzhou, Lanzhou 730000 (China); Song, Peng [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Peng; Cao, Xingzhong [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-02-01

    Highlights: • NHS steel was irradiated by 3.25 MeV Fe ions to different fluences at room temperature and 723 K. • The evolution of vacancy type defects is studied through positron annihilation spectroscopy. • The concentration gradient of SIA can induce the decrease of S value with increasing fluence at high temperature. - Abstract: In order to study the evolution of irradiation-induced vacancy-type defects at different irradiation fluences and temperatures, a new type of ferritic/martensitic (F/M) steel named NHS (Novel High Silicon) was irradiated by 3.25 MeV Fe-ion at room temperature and 723 K to fluences of 4.3 × 10{sup 15} and 1.7 × 10{sup 16} ions/cm{sup 2}. After irradiation, vacancy-type defects were investigated with variable-energy positron beam Doppler broadening spectra. Energetic Fe-ions produced a large number of vacancy-type defects in the NHS steel, but one single main type of vacancy-type defect was observed in both unirradiated and irradiated samples. The concentration of vacancy-type defects decreased with increasing temperature. With the increase of irradiation fluence, the concentration of vacancy-type defects increased in the sample irradiated at RT, whereas for the sample irradiated at 723 K, it decreased. The enhanced recombination between vacancies and excess interstitial Fe atoms from deeper layers, and high diffusion rate of self-interstitial atoms further improved by diffusion via grain boundary and dislocations at high temperature, are thought to be the main reasons for the reversed trend of vacancy-type defects between the samples irradiated at RT and 723 K.

  20. 3D detectors at ITC-irst: first irradiation studies

    Energy Technology Data Exchange (ETDEWEB)

    Ronchin, S.; Boscardin, M. [ITC-irst Microsystems Division, via Sommarive, 18 - 38050 Povo di Trento (Italy); Bosisio, L. [INFN and Department of Physics, University of Trieste, via A. Valerio, 2 - 34127 Trieste (Italy); Cindro, V. [Jozef Stefan Institute and University of Ljubljana, Jamova 39, Si-1000, Ljubljana (Slovenia); Dalla Betta, G.-F. [INFN and Department of ICT, University of Trento, via Sommarive, 14 - 38050 Povo di Trento (Italy); Piemonte, C.; Pozza, A. [ITC-irst Microsystems Division, via Sommarive, 18 - 38050 Povo di Trento (Italy); Zoboli, A. [INFN and Department of ICT, University of Trento, via Sommarive, 14 - 38050 Povo di Trento (Italy); Zorzi, N. [ITC-irst Microsystems Division, via Sommarive, 18 - 38050 Povo di Trento (Italy)

    2007-10-15

    In the past two years, we have developed 3D detector technologies at ITC-irst (Trento, Italy). We have proposed a new 3D architecture, having columnar electrodes of one doping type only, allowing for a simplified fabrication process. In this paper, we report on preliminary results from the electrical characterization of devices irradiated with neutrons, showing that low depletion voltage values can be achieved even after very large fluences.

  1. An irradiation facility with a vertical beam for radiobiological studies

    CERN Document Server

    Besserer, J; Dellert, M; Gahn, C; Moosburger, M; Pemler, P; Quicken, P; Distel, L; Schuessler, H

    1999-01-01

    A vertical beam facility for radiobiological experiments was designed and constructed at the Munich Tandem-Accelerator Laboratory. The main part of the facility is a 90 deg. dipole magnet bending the beam of protons or heavy particles into a vertical upward direction, which is advantageous for wet-cell irradiation. After collimation the beam is spread out passively by thin scattering foils and dynamically by magnetic coils. A homogeneity of the radiation field better than +-5% has been achieved over the diameter of the exit window of 60 mm. The dose rate can be widely adjusted from single particles to more than 10 sup 1 sup 0 particles (i.e. hundreds of Grays) per second. The dose measurement is based on single-particle counting and on standard dosimeters. The detector system for dosimetry and irradiation control is described. In a first radiobiological experiment the cell survival of chinese hamster cells was measured after irradiation with 22.7 MeV protons and compared with the X-ray result.

  2. A facility for studying irradiation accelerated corrosion in high temperature water

    Science.gov (United States)

    Raiman, Stephen S.; Flick, Alexander; Toader, Ovidiu; Wang, Peng; Samad, Nassim A.; Jiao, Zhijie; Was, Gary S.

    2014-08-01

    A facility for the study of irradiation accelerated corrosion in high temperature water using in situ proton irradiation has been developed and validated. A specially designed beamline and flowing-water corrosion cell added to the 1.7 MV tandem accelerator at the Michigan Ion Beam Laboratory provide the capability to study the simultaneous effects of displacement damage and radiolysis on corrosion. A thin sample serves as both a “window” into the corrosion cell through which the proton beam passes completely, and the sample for assessing irradiation accelerated corrosion. The facility was tested by irradiating stainless steel samples at beam current densities between 0.5 and 10 μA/cm2 in 130 °C and 320 °C deaerated water, and 320 °C water with 3 wppm H2. Increases in the conductivity and dissolved oxygen content of the water varied with the proton beam current, suggesting that proton irradiation was accelerating the corrosion of the sample. Conductivity increases were greatest at 320 °C, while DO increases were highest at 130 °C. The addition of 3 wppm H2 suppressed DO below detectable levels. The facility will enable future studies into the effect of irradiation on corrosion in high temperature water with in situ proton irradiation.

  3. High-temperature annealing of proton irradiated beryllium - A dilatometry-based study

    Science.gov (United States)

    Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit; Savkliyildiz, Ilyas

    2016-08-01

    Ssbnd 200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 1020 cm-2 peak fluence and irradiation temperatures in the range of 100-200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation 4He and 3H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

  4. Studies on chemical radioprotectors against X-irradiation used by soft X-ray accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Shinoda, Masato [Hoshi Univ., Tokyo (Japan). Faculty of Pharmaceutical Sciences

    1995-01-01

    This review describes the modes of mice radiation injuries induced by soft X-irradiation under various conditions and the protective effects of several kinds of substances on these injuries. The models of radiation injuries in this study were bone marrow death after lethal irradiation, skin damage induced by irradiation with long length soft X-ray and leukocytopenia in the peripheral blood after sublethal irradiation. Two bioassay methods were established for the survival effect on the lethal irradiation and protective potency on the skin damage induced by soft X-irradiation. The protective potencies of various sulfur compounds, related compounds of ferulic acid, nucleic acid constitutional compounds, crude drugs and chinese traditional medicines were determined and then many effective drugs were recognized. Effective components in the methanol extracts of Cnidii Rhizoma and Aloe arborescens recognized as radioprotectable were fractionated. As a result of these studies, it was observed that the active principles in Cnidii Rhizoma were identified as ferulic acid and adenosine. The scavenge action of active oxygens, a protective effect on the damages of deoxyribonucleic acid and superoxide dismutase by in vitro soft X-irradiation were evaluated as radiation protective mechanisms. (author).

  5. [Correction of free-radical processes in patients with chronic brain ischemia with intravenous laser irradiation of blood].

    Science.gov (United States)

    Karneev, A N; Solov'eva, E Iu; Fedin, A I

    2007-01-01

    We examined lipid peroxidation (LPO) in 130 patients with chronic brain ischemia (CBI). Primary and secondary LPO products, oxidative and antioxidative enzymes were studied in the course of therapy with antioxidant drug cytoflavin and intravenous laser radiation of blood (ILRB). The latter proved to have a normalizing action on LPO and antioxidant defense. With progression of CBI, effects of ILRB on enzymatic activity weakens due to depletion of endogenic antioxidants. This necessitates administration of exogenic antioxidants (cytoflavin) for complex correction of free radical processes. This conclusion allows recommending combined schemes of therapy for patients with CBI stage II and III.

  6. Postoperative irradiation after implant placement: A pilot study for prosthetic reconstruction

    Science.gov (United States)

    Keum, Ki Chang; Kim, Jun Won; Shim, June-Sung; Jung, Han-Sung; Park, Kyeong-Mee

    2016-01-01

    PURPOSE On maxillofacial tumor patients, oral implant placement prior to postoperative radiotherapy can shorten the period of prosthetic reconstruction. There is still lack of research on effects of post-implant radiotherapy such as healing process or loading time, which is important for prosthodontic treatment planning. Therefore, this study evaluated the effects of post-implant local irradiation on the osseointegration of implants during different healing stages. MATERIALS AND METHODS Custom-made implants were placed bilaterally on maxillary posterior edentulous area 4 weeks after extraction of the maxillary first molars in Forty-eight Sprague-Dawley rats. Experimental group (exp.) received radiation after implant surgery and the other group (control) didn't. Each group was divided into three sub-groups according to the healing time (2, 4, and 8 week) from implant placement. The exp. group 1, 2 received 15-Gy radiation 1 day after implant placement (immediate irradiation). The exp. group 3 received 15-Gy radiation 4 weeks after implant placement (delayed irradiation). RESULTS The bone mineral density (BMD) was significantly lower in the immediate irradiation groups. BMD was similar in the delayed irradiation group and the control group. The irradiated groups exhibited a lower bone-to-implant contact ratio, although the difference was not statistically significant. The irradiated groups also exhibited a significantly lower bone volume and higher empty lacuna count than the control groups. No implant failure due to local irradiation was found in this study. CONCLUSION Within the limits of this study, the timing of local irradiation critically influences the bone healing mechanism, which is related to loading time of prostheses. PMID:27826386

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

    OpenAIRE

    2016-01-01

    Effective inactivation of biosafety level 4 (BSL-4) pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common...

  8. DLTS Studies of high-temperature electron irradiated Cz n-Si

    Science.gov (United States)

    Neimash, V.; Kras'ko, M.; Kraitchinskii, A.; Voytovych, V.; Tishchenko, V.; Simoen, E.; Rafi, J. M.; Claeys, C.; Versluys, J.; de Gryse, O.; Clauws, P.

    2004-02-01

    This paper reports on a Deep Level Transient Spectroscopy (DLTS) study of both oxygen-related thermal donors (OTDs) and radiation-induced defects (RDs) formed in high-temperature 1 MeV electron irradiated n-type Czochralski silicon. The heating of Si samples is done in-situ by the electron beam. The formation of deep levels is studied on both heat-treated and irradiated at high temperature sides of samples. The interaction between OTDs and RDs is investigated.

  9. Irradiation-induced disorder in high- Tc cuprates: electronic band structure study

    Science.gov (United States)

    Vobornik, I.; Quitmann, C.; Zacchigna, M.; Zwick, F.; Grioni, M.; Karkin, A.; Kelley, R. J.; Onellion, M.; Margaritondo, G.

    1998-05-01

    We used thermal neutron irradiation to produce disorder in Bi-2212 single crystals ( TC=85 K), at a constant carrier density. The irradiated samples were insulators. High-temperature superconductivity with a lower TC than prior to irradiation could be restored by a low-temperature annealing. We performed angle-resolved photoemission investigation on both unannealed (insulating) and annealed (superconducting) samples in order to study the corresponding changes in electronic structure. We observed a strong suppression of the spectral weight near the Fermi energy with increasing disorder. Our results demonstrate that effects related to disorder cannot be neglected in the interpretation of the spectral properties of cuprates.

  10. Alveolar wound healing after x-irradiation: a histologic, radiographic, and histometric study

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmotti, M.B.; Ubios, A.M.; Cabrini, R.L.

    1986-12-01

    Healing of extraction wounds in rats following cephalic irradiation was studied by histologic, radiographic, and histometric methods 14 days after tooth extraction. Irradiation was given at 0, 3, and 7 days after surgery in doses of either 15, 20, or 30 Gy. No significant differences were seen with the different doses given seven days post-extraction. However, socket healing was delayed when irradiation was given immediately and three days after extraction. On the basis of these observations, it is recommended that radiation not begin until at least one week after the extraction of teeth.

  11. An Experimental Study on the Effects of Co-60 Irradiation on the Rat Tongue Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seon Kee; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1990-02-15

    It is known that radiation therapy is a kind of treatment choices of the maxillofacial tumors. This study is designed to investigate the effects of irradiation on rat's tongue tissues as functional tissues which relate to taste, mastication, and pronunciation. 88 rats (Sprague Dawley branch, male) were divided into control group of 4 and experimental group of 84. Experimental group was singly exposed to Co-60 irradiation with 8, 13, 18 Gy in the head and neck region. Animals were sacrificed on 1 hour, 3 hours, 6 hours, 1 day, 3 days, 7 days, and 28 days after the irradiation. The specimens were observed by histopathological examination employing H-E stain and Van-Gieson stain. The results were follows; 1. The tongue tissue were severely swollen on the 1 hour after irradiation, but gradually decreased in course of time. 2. The basal cells of epithelium of tongue proliferated at initial stage of irradiation, but gradually decreased. The Keratin layer were gradually increased. 4. The tissue changes after irradiation were gradually increased by the degree of irradiation.

  12. A study on proton irradiation effects of home-made solar cell for space use

    CERN Document Server

    Wang Rong; Zhang Xin Hui; Guo Zeng Liang; Zhai Zuo Xu

    2001-01-01

    The proton irradiation effects of Si solar cell and GaAs/Ge solar cell for space use are studied. The cells are irradiated by protons with an energy of 10 MeV at fluences ranging from 1 x 10 sup 9 to 5 x 10 sup 1 sup 3 cm sup - sup 2 , and then photovoltaic properties are measured at AMO. It is shown that the degradation of electric performances of two kinds of solar cells is different as proton irradiation fluence increases. The electric parameters I sub s sub c and P sub m sub a sub x of GaAs/Ge solar cell degrade slower than that of Si solar cell under 3 x 10 sup 1 sup 2 cm sup - sup 2 , but degrade rapidly above 3 x 10 sup 1 sup 2 cm sup - sup 2 , and the irradiation tolerance of GaAs/Ge solar cell is better than that of Si solar cell. The degradation of the performance is related to proton irradiation-induced defects E sub c -0.41 eV in irradiated GaAs/Ge cell, and E sub v + 0.14 eV and E sub v + 0.43 eV in irradiated Si cell

  13. Er:YAG laser irradiation to control the progression of enamel erosion: an in situ study.

    Science.gov (United States)

    Scatolin, R S; Colucci, V; Lepri, T P; Alexandria, A K; Maia, L C; Galo, R; Borsatto, M C; Corona, S A M

    2015-07-01

    This in situ study evaluated the effect of Er:YAG laser irradiation in controlling the progression of enamel erosion-like lesions. Fifty-six enamel slabs (330 KHN ± 10 %) with one fourth of the surface covered with resin composite (control area) were submitted to initial erosion-like lesion formation with citric acid. The slabs were divided into two groups: irradiated with Er:YAG laser and non-irradiated. Fourteen volunteers used an intraoral palatal appliance containing two slabs, in two phases of 5 days each. During the intraoral phase, in a crossed-over design, half of the volunteers immersed the appliance in citric acid while the other half used deionized water, both for 5 min, three times per day. Enamel wear was determined by an optical 3D profilometer. ANOVA revealed that when deionized water was used as immersion solution during the intraoral phase, lower values of wear were showed when compared with the groups that were eroded with citric acid, whether irradiated or non-irradiated with Er:YAG laser. When erosion with citric acid was performed, Er:YAG laser was not able to reduce enamel wear. Small changes on enamel surface were observed when it was irradiated with Er:YAG laser. It may be concluded that Er:YAG laser irradiation did not reduce the progression of erosive lesions on enamel submitted to in situ erosion with citric acid.

  14. In situ study of defect accumulation in zirconium under heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Idrees, Y. [Department of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada K7L 3N6 (Canada); Yao, Z., E-mail: yaoz@me.queensu.ca [Department of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada K7L 3N6 (Canada); Kirk, M.A. [Material Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Daymond, M.R. [Department of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada K7L 3N6 (Canada)

    2013-02-15

    In this study, we report direct observations on heavy ion (Kr{sup 2+}) irradiation induced changes in microstructures of pure Zr at different temperatures using intermediate voltage electron microscopy. Thin TEM foils were irradiated with 1 MeV Kr{sup 2+} ions. Materials have been irradiated to different damage levels ranging from 0.008 dpa to 1 dpa at different temperatures ranging from 300 °C to 500 °C. We particularly concentrate on yield of small defects directly occurring from cascade collapse at very low doses, and their evolution as the dose increases. In situ observation of growth and evolution of these small defects into complex defect structures at high dose has been carried out. Irradiation of materials at different temperatures provided an opportunity to investigate the temperature dependence of defect accumulation in Zr during irradiation. The differences in defect structures, defect densities, and therefore dynamic growth have been discussed in detail as a function of irradiation parameters (dose, temperature). Interaction of irradiation induced defects with existing microstructure and other defects is discussed.

  15. A study of the photodegradation of leukotriene B sub 4 by ultraviolet irradiation (UVB, UVA)

    Energy Technology Data Exchange (ETDEWEB)

    Millar, B.; Green, C.; Ferguson, J.; Raffle, E.J.; Macleod, T.M. (Ninewells Hospital and Medical School, Dundee (UK))

    1989-02-01

    In view of the presence of the polymorphonuclear leukocyte (PMN) chemoattractant Leukotriene B{sub 4} (LTB{sub 4}) in surface scale of the psoriatic lesion and the known therapeutic effect of phototherapy in psoriasis, the photostability of LTB{sub 4} was investigated. LTB{sub 4} was irradiated with UVB (290-320 nm) from 100-1500 mJ cm{sup -2} and UVA (320-400 nm) from 5-40 J cm{sup -2}. Topical application of UVB irradiated LTB{sub 4} to forearm skin of normal volunteers showed marked reduction in cutaneous erythema, paralleled by reduced transepidermal PMN migration compared with sites of application of unirradiated and UVA irradiated LTB{sub 4}. High performance liquid chromatography (HPLC) demonstrated a dose-dependent photodegradation of LTB{sub 4} by UVB irradiation. UVA irradiation produced no such effect. The wavelengths responsible lie within the absorption spectrum of LTB{sub 4}. In vitro chemotaxis studies, using an under agarose technique, showed a statistically significant reduction in the migration of PMN from psoriatic and non-psoriatic subjects to the UVB irradiated LTB{sub 4} compared with unirradiated LTB{sub 4}, whilst UVA irradiated LTB{sub 4} produced a normal PMN chemotactic response. (author).

  16. Mechanistical Studies on the Irradiation of Methanol in Extraterrestrial Ices

    Science.gov (United States)

    Bennett, Chris J.; Chen, Shih-Hua; Sun, Bing-Jian; Chang, Agnes H. H.; Kaiser, Ralf I.

    2007-05-01

    Pure ices of amorphous methanol, CH3OH(X1A'), were irradiated at 11 K by 5 keV electrons at 100 nA for 1 hr. These energetic electrons simulate electronic energy transfer processes that occur as interstellar ices, comets, and icy solar system bodies are subjected to irradiation from MeV ions and secondary electrons produced in this process. The results were analyzed quantitatively via absorption-reflection-absorption Fourier transform infrared (FTIR) spectroscopy, with the identification of new species aided by high-level electronic structure calculations. The unimolecular decomposition of methanol was found to proceed via the formation of (1) the hydroxymethyl radical, CH2OH(X2A''), and atomic hydrogen, H(2S1/2), (2) the methoxy radical, CH3O(X2A'), plus atomic hydrogen, (3) formaldehyde, H2CO(X1A1) plus molecular hydrogen, H2(X1Σ+g), and (4) the formation of methane, CH4(X1A1), together with atomic oxygen, O(1D). The accessibility of the last channel indicates that the reverse process, oxygen addition into methane to form methanol, should also be feasible. A kinetic model is presented for the decomposition of methanol into these species, as well as the formyl radical, HCO(X2A'), and carbon monoxide, CO(X1Σ+). During the subsequent warming up of the sample, radicals previously generated within the matrix were mobilized and found to recombine to form methyl formate, CH3OCHO(X1A'), glycolaldehyde, CH2OHCHO(X1A'), and ethylene glycol, HOCH 2CH2OH(X1A). Upper limits for the production of these species by the recombination of neighboring radicals produced during irradiation as well as during the warm-up procedure are presented. The generation of these molecules by irradiation of ices in the solid state and their subsequent sublimation into the gas phase can help explain their high abundances as observed toward hot molecular cores and underlines their importance in astrobiology.

  17. Role of chronic toxicology studies in revealing new toxicities.

    Science.gov (United States)

    Galijatovic-Idrizbegovic, Alema; Miller, Judith E; Cornell, Wendy D; Butler, James A; Wollenberg, Gordon K; Sistare, Frank D; DeGeorge, Joseph J

    2016-12-01

    Chronic (>3 months) preclinical toxicology studies are conducted to support the safe conduct of clinical trials exceeding 3 months in duration. We have conducted a review of 32 chronic toxicology studies in non-rodents (22 studies in dogs and 10 in non-human primates) and 27 chronic toxicology studies in rats dosed with Merck compounds to determine the frequency at which additional target organ toxicities are observed in chronic toxicology studies as compared to subchronic studies of 3 months in duration. Our review shows that majority of the findings are observed in the subchronic studies since additional target organs were not observed in 24 chronic non rodent studies and in 21 chronic rodent studies. However, 6 studies in non rodents and 6 studies in rodents yielded new findings that were not seen in studies of 3-month or shorter duration. For 3 compounds the new safety findings did contribute to termination of clinical development plans. Although the incidence of compound termination associated with chronic toxicology study observations is low (∼10%), the observations made in these studies can be important for evaluating human safety risk.

  18. Study on Tribological Properties of Irradiated Crosslinking UHMWPE Nano-Composite

    Institute of Scientific and Technical Information of China (English)

    Lei Xiong; Dang-sheng Xiong; Jia-bo Jin

    2009-01-01

    Ultra High Molecular Weight Polyethylene (UHMWPE) has been widely used as a bearing material for artificial joint replacement over forty years. It is usually crosslinked by gamma rays irradiation before its implantation into human body. In this study, UHMWPE and UHMWPE/nano-hydroxyapatite (n-HA) composite were prepared by vacuum hot-pressing method. The prepared materials were irradiated by gamma rays in vacuum and molten heat treated in vacuum just after irradiation. The effect of filling n-HA with gamma irradiation on tribological properties of UHMWPE was investigated by using friction and wear experimental machine (model MM-200) under deionized water lubrication. Micro-morphology of wom surface was observed by metallographic microscope. Contact angle and hardness of the materials were also measured. The results show that contact angle and hardness are changed by filling n-HA and gamma irradiation. Friction coefficient and wear rate under deionized water lubrication are reduced by filling n-HA. While friction coefficient is increased and wear rate is reduced significantly by gamma irradiation. The worn surface of unfilled material is mainly characterized as adhesive wear and abrasive wear, and that of n-HA filled material is mainly characterized as abrasive wear. After gamma irradiation, the degrees of adhesive and abrasive wear for unfilled material and abrasive wear of n-HA filled material are significantly reduced. Unfilled and filled materials after irradiation are mainly shown as slight fatigue wear. The results indicate that UHMWPE and UHMWPE/n-HA irradiated at the dose of 150 kGy can be used as bearing materials in artificial joints for its excellent wear resistance compared to original UHMWPE.

  19. XPS STUDY ON DNA DAMAGE BY LOW-ENERGY ELECTRON IRRADIATION

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Hyung Ah; Cho, Hyuck [Chungnam National University, Physics Department, Daejeon (Korea, Republic of)

    2011-12-15

    After the first report that electrons with sub-ionization energy of DNA could cause single strand breaks or double strand breaks to DNA, there have been various studies to investigate the mechanisms of DNA damage by low-energy electrons. In this paper, we examined the possibility of using X-ray photoelectron spectroscopy (XPS) to analyze the dissociation patterns of the molecular bonds by electron irradiation on DNA thin films and tried to establish the method as a general tool for studying the radiation damage of biomolecules by low energy electrons. For the experiment, pBR322 plasmid DNA solution was formed into the films on tantalum plates by lyophilization and was irradiated by 5-eV electrons. Un-irradiated and irradiated DNA films were compared and analyzed using the XPS technique.

  20. Scrotal Irradiation in Primary Testicular Lymphoma: Review of the Literature and In Silico Planning Comparative Study

    Energy Technology Data Exchange (ETDEWEB)

    Brouwer, Charlotte L., E-mail: c.l.brouwer@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Wiesendanger, Esther M.; Hulst, Peter C. van der [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Imhoff, Gustaaf W. van [Department of Hematology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Langendijk, Johannes A.; Beijert, Max [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

    2013-02-01

    We examined adjuvant irradiation of the scrotum in primary testicular lymphoma (PTL) by means of a literature review in MEDLINE, a telephone survey among Dutch institutes, and an in silico planning comparative study on scrotal irradiation in PTL. We did not find any uniform adjuvant irradiation technique assuring a safe planning target volume (PTV) coverage in published reports, and the definition of the clinical target volume is unclear. Histopathologic studies of PTL show a high invasion rate of the tunica albuginea, the epididymis, and the spermatic cord. In retrospective studies, a prescribed dose of at least 30 Gy involving the scrotum is associated with best survival. The majority of Dutch institutes irradiate the whole scrotum without using a planning computed tomography scan, with a single electron beam and a total dose of 30 Gy. The in silico planning comparative study showed that all evaluated approaches met a D{sub 95%} scrotal dose of at least 85% of the prescription dose, without exceeding the dose limits of critical organs. Photon irradiation with 2 oblique beams using wedges resulted in the best PTV coverage, with a mean value of 95% of the prescribed dose, with lowest maximum dose. Adjuvant photon or electron irradiation of the whole scrotum including the contralateral testicle with a minimum dose of 30 Gy is recommended in PTL. Computed tomography-based radiation therapy treatment planning with proper patient positioning and position verification guarantees optimal dose coverage.

  1. Irradiation of left breast and cardiac risk: fundamentals for a prospective study; Irradiation du sein gauche et risque cardiaque: bases pour une etude prospective

    Energy Technology Data Exchange (ETDEWEB)

    Untereiner, M.; Frederick, B.; Burie, D.; Philippi, S.; Joseph, S.; Harzee, L.; Hoziel, D.; Eschenbrenner, A.; Meyer, P. [Centre Francois-Baclesse, Esch-sur-Alzette (Luxembourg); Gibeau, L.; Laurent-Daniel, F.; Libert, S.; Fressancourt, C. [Centre Gray, 59 - Maubeuge (France)

    2010-10-15

    As the delineation of the anterior interventricular artery and of the heart is to be taken into account during irradiations of the left beast, in order to limit cardiotoxicity, the authors discuss the results of previous studies which highlighted this risk, and notably in a retrospective assessment of dose-volume histograms of the anterior interventricular artery and of the heart which concerned 162 left breast irradiations. This last study allowed cardiac tolerance thresholds to be defined. Short communication

  2. Studies on the ability of irradiated Escherichia coli bacteria to reactivate X-ray inactivated bacteriophages

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, W.

    1980-01-01

    The Weigle Reactivation phenomenon ie. the observation that low UV-flow irradiated bacteria increase the survival rate of UV-irradiated phages has not, to date, been studied with other forms of irradiation as inducers. In the studies reported here lambda-phages and E. coli cells in LB-medium were treated with X-rays. Host cells treated with an X-ray dose from 85 to 765 Gy showed a reactivation factor of 1.3 to 3.0 for X-ray inactivated phages. The capacity of the bacteria for phage reproduction did not appear to be markedly diminished. A reactivation factor of 1.3 only was found for X-irradiated phages when host cells were treated with UV-irradiation. The low Weigle reactivation of X-ray treated phages compared to UV-treatment was found to be due to a diminished absorption capacity, as demonstrated by the determination of free non-absorbed phages by filtration of radioactive-labelled phage-host-complexes. Reactivation studies on X-irradiated phages with various host bacteria of different radiation sensitivities confirm this finding.

  3. An experimental study on photothermal damage to tissue: the role of irradiance and wavelength

    Science.gov (United States)

    Yildiz, F.; Gulsoy, M.; Cilesiz, I.

    2016-09-01

    Laser exposure time and irradiance are crucial parameters governing the process of thermal damage. The goal of our in vitro study was to study and determine optimal parameters for the onset of coagulation and carbonization at three different wavelengths (980, 1070 and 1940 nm). We also compared photothermal effects at these three wavelengths by varying laser exposure time and irradiance. Fresh bovine liver specimens were used for experimentation. The onset of thermal damage at different irradiances and for different exposure time was studied macroscopically and histologically. Photothermal damage or lesion volume generally decreased with irradiance and increasing exposure time. We observed an exponential and linear relationship between irradiance and exposure time for specific thermal endpoints. These specific endpoints were the onset of (i) coagulation, and (ii) carbonization. The time interval or difference between these specific endpoints termed as Δt (t carbonization  -  t coagulation) (s) was also determined. This relation between irradiance and exposure time will make possible the pre-estimation of thermal tissue lesion volume before operation, and photothermal therapy may thus be performed with minimum side effects on liver tissue.

  4. Irradiation effect on antifungal potential Myristica fragrans (nutmeg) essential oil, a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Renato C.; Fanaro, Gustavo B.; Koike, Amanda C.R.; Villavicencio, Anna Lucia C.H., E-mail: gbfanaro@ipen.b, E-mail: amandaramos@usp.b, E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The Myristica fragrans (nutmeg) is any of several species of trees in genus Myristica. The most important commercial species is Myristica fragrans, an evergreen tree indigenous to the Banda Islands in the Moluccas of Indonesia, or Spice Islands. Widely used as a food condiment and flavoring, used in perfumery and medicine. The nutmeg has many biological properties as analgesic, antiseptic, antispasmodic, aphrodisiac, astringent, carminative, haemostatic, insecticidal and parasiticide. Previous research has revealed interesting antimicrobial effect of nutmeg essential oil. Spices irradiation is a worldwide process used and this technique is an effective pathogenic microorganisms control providing consumers food security. By the fact nutmeg not only used in food, but also as an essential oil raw material this study investigated the nutmeg different irradiation doses influence on the possible antimicrobial potential oil. The aim of this study was evaluate the antifungal potential oil from unirradiated and irradiated nutmeg in the fungus Guignardia citricarpa that causes serious damage in orange plantations. The Myristica fragrans samples were irradiated in {sup 60}Co irradiator at doses of 5.0 and 10.0 kGy. The oil was used in 50 and 100% of concentration (irradiated and not irradiated). The essential oil in high concentration could be a good substitute for the pesticides used to control the fungus Guignardia citricarpa, the nutmeg irradiation treatment with the doses 5.0 and 10.0 kGy did not changed the results in the essential oil effectiveness. It is clear that is necessary others studies with others doses to verify the radiation ionizing influence in the essential oil activity and the oil application efficiency in the field against the fungus. (author)

  5. Magnetization studies of YBa 2Cu 3O 7-x irradiated by fast neutrons

    Science.gov (United States)

    Wisniewski, A.; Baran, M.; Przysłupski, P.; Szymczak, H.; Pajaczkowska, A.; Pytel, B.; Pytel, K.

    1988-02-01

    Studies of the effect of fast neutron damage on the magnetic hysteresis of YBa 2Cu 3O 7-x ceramic samples subjected to fluence of neutrons of 2∗10 16 n/cm 2 up to 6∗10 17 n/cm 2 have been performed. irradiation up to dose of 1∗10 17 did not cause any change in the critical temperature. However it causes a strong increase of the magnetic hysteresis which is presumably connected with the creation of defects. The critical current density at 77 K in H = 10 k0e for the sample irradiated with the dose 1∗10 17 n/cm 2 was estimated to be 520 A/cm 2 as compared to 29 A/cm 2 for the reference non-irradiated sample, non-irradiated sample.

  6. Photoacoustic spectroscopy applied to the study of the influence of laser irradiation on corn seeds

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Aguilar, C.; Michtchenko, A. [Instituto Politecnico Nacional (Mexico); Carballo, A. [Colegio de Postgraduados, Programa de Semillas (IREGEP) (Mexico); Cruz-Orea, A. [Centro de Investigacion y de Estudios Avanzados-IPN (Mexico); Ivanov, R. [Universidad Autonoma de Zacatecas, Unidad Academia de Fisica (Mexico); San Martin Martinez, E. [Centro de Investigacion en ciencia Aplicada y Tecnologia Avanzada-IPN (Mexico)

    2005-06-01

    In the present study we were interested in the effects of low intensity laser irradiation on hybrid corn seeds CL{sub 1} x CL{sub 4} when these seeds were exposed to different laser intensities and irradiation times. In order to observe qualitative differences in chlorophyll a and b optical absorption spectra of seedling's leaves, whose seeds were irradiated and non irradiated, were obtained by using photoacoustic spectroscopy (PAS). A randomized complete blocks experimental design with three replications was used. The experimental unit included 10 seeds, from which we randomly choose three seedlings. The variance analysis (ANOVA) for both chlorophylls revealed significant (P < 0.05) differences among treatments. (authors)

  7. Defect Kinetics and Magnetic Studies of Ion-Irradiated FePt Nanoparticles

    Science.gov (United States)

    Seetala, Naidu V.

    2009-03-01

    We have used 300 keV Al+-irradiation and 1 MeV proton-irradiation to obtain vacancy-migration enhanced phase transformation of FePt nanoparticles at lower temperatures (˜200° C). SRIM-2006 computer code was used to estimate the irradiation parameters and the defect concentrations. Low temperature annealing showed promising results, but further annealing at higher temperatures gave detrimental effects due to lattice strain produced by larger defect clusters. These effects are more prominent in proton-irradiation and the effects of vacancy clusters seem to remain stronger even at higher temperatures. The magnetization results indicate dissociation of vacancy clusters above 600° C. The magnetization studies of 700° C and 800° C annealed particles aged for one year at room temperature showed defect strain release over time.

  8. Spectroscopic studies of UV irradiated erythrosine B thin films prepared by spin coating technique.

    Science.gov (United States)

    Zeyada, H M; El-Mallah, H M; Atwee, T; El-Damhogi, D G

    2017-05-15

    The spectroscopic studies of erythrosine B thin films manufactured by the spin coating technique have been presented. The spectra of infrared absorption allow characterization of vibrational modes for erythrosine B in powder form, pristine and UV irradiated thin films. The absorption spectra recorded in UV-vis-NIR for pristine films of erythrosine B display two main bands. UV irradiation on erythrosine B films decreased absorbance over the spectra. Indirect allowed transition with optical energy gap of 2.57eV is observed in pristine films. UV irradiation introduced structural defects and decreased optical band gap. Some of the optical absorption parameters and their relation to UV irradiation times, namely molar extinction coefficient (ε), electronic dipole strength (q(2)), and oscillator strength (f), of the principal optical transitions have also been evaluated.

  9. Correlation between electron-irradiation defects and applied stress in graphene: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Kida, Shogo; Yamamoto, Masaya; Kawata, Hiroaki; Hirai, Yoshihiko; Yasuda, Masaaki, E-mail: yasuda@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Tada, Kazuhiro [Department of Electrical and Control Systems Engineering, National Institute of Technology, Toyama College, Toyama 939-8630 (Japan)

    2015-09-15

    Molecular dynamics (MD) simulations are performed to study the correlation between electron irradiation defects and applied stress in graphene. The electron irradiation effect is introduced by the binary collision model in the MD simulation. By applying a tensile stress to graphene, the number of adatom-vacancy (AV) and Stone–Wales (SW) defects increase under electron irradiation, while the number of single-vacancy defects is not noticeably affected by the applied stress. Both the activation and formation energies of an AV defect and the activation energy of an SW defect decrease when a tensile stress is applied to graphene. Applying tensile stress also relaxes the compression stress associated with SW defect formation. These effects induced by the applied stress cause the increase in AV and SW defect formation under electron irradiation.

  10. Studies on mechanical, thermal and morphological properties of irradiated recycled polyamide and waste rubber powder blends

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Medhat M., E-mail: medhat_smh@yahoo.co [National Center for Radiation Research and Technology, Nasr City, Cairo 11731 (Egypt); Badway, Nagwa A.; Gamal, Azza M. [Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo (Egypt); Elnaggar, Mona Y.; Hegazy, El-Sayed A. [National Center for Radiation Research and Technology, Nasr City, Cairo 11731 (Egypt)

    2010-05-01

    The aim of this article was to show the effect of gamma irradiation on mechanical and thermal properties of recycled polyamide (rPA) copolymer blended with different content of waste rubber powder (WRP). In order to study the structural modifications of prepared blends have been subjected to irradiation doses up to 200 kGy were applied to all samples. Non-irradiated blends were used as control samples. Mechanical properties, namely, tensile strength (TS), elastic modulus, elongation at break and hardness have been followed up as a function of irradiation dose and degree of loading with rubber content. Furthermore, the influence of radiation dose in the thermal parameters, melting temperature, heat of fusion, DELTAH{sub f} of the recycled PA and its blend with waste rubber powder (WRP) was also investigated.

  11. Presentation of chronic daily headache : A clinical study

    NARCIS (Netherlands)

    Spierings, E L H; Schroevers, M.; Honkoop, P.C.; Sorbi, M.

    1998-01-01

    We studied the presentation of chronic daily headache in 258 patients from a private headache practice, 50 men and 208 women. Chronic daily headache was defined as headaches, occurring at least 5 days per week for at least 1 year. Seventy-seven percent of the patients experienced the onset of headac

  12. Presentation of chronic daily headache : A clinical study

    NARCIS (Netherlands)

    Spierings, E L H; Schroevers, M.; Honkoop, P.C.; Sorbi, M.

    1998-01-01

    We studied the presentation of chronic daily headache in 258 patients from a private headache practice, 50 men and 208 women. Chronic daily headache was defined as headaches, occurring at least 5 days per week for at least 1 year. Seventy-seven percent of the patients experienced the onset of headac

  13. Development of chronic daily headache : A clinical study

    NARCIS (Netherlands)

    Spierings, E.L.H.; Schroevers, M.; Honkoop, P.C.; Sorbi, M.

    1998-01-01

    We studied the development of chronic daily headache in 258 headache practice patients, 50 men and 208 women. Chronic daily headache was defined as headaches occurring at least 5 days per week for at least 1 year. Twenty-two percent of the patients had daily headaches from the onset, and 78% initial

  14. Microstructural study of irradiated isotopically tailored F82H steel

    Energy Technology Data Exchange (ETDEWEB)

    Wakai, E. E-mail: wakai@realab01.tokai.jaeri.go.jp; Miwa, Y.; Hashimoto, N.; Robertson, J.P.; Klueh, R.L.; Shiba, K.; Abiko, K.; Furuno, S.; Jitsukawa, S

    2002-12-01

    The synergistic effect of displacement damage and hydrogen or helium atoms on microstructures in F82H steel irradiated at 250-400 deg. C to 2.8-51 dpa in HFIR has been examined using isotopes of {sup 54}Fe or {sup 10}B. Hydrogen atoms increased slightly the formation of dislocation loops and changed the Burgers vector for some parts of dislocation loops, and they also affected on the formation of cavity at 250 deg. C to 2.8 dpa. Helium atoms also influenced them at around 300 deg. C, and the effect of helium atoms was enhanced at 400 deg. C. Furthermore, the relations between microstructures and radiation-hardening or ductile to brittle transition temperature (DBTT) shift in F82H steel were discussed. The cause of the shift increase of DBTT is thought to be due to the hardening of dislocation loops and the formation of {alpha}{sup '}-precipitates on dislocation loops.

  15. Safety Irradiation Parameters of Nd:YAP Laser Beam for Endodontic Treatments: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    A. Namour

    2016-01-01

    Full Text Available Objective. Nd:YAP laser has several potentialities of clinical applications in endodontics. The aim of our study is to determine the safety range of irradiation parameters during endodontic application of Nd:YAP laser that can be used without damaging and overheating the periodontal tissue. Material and Methods. Twenty-seven caries-free single-rooted extracted human teeth were used. Crowns were sectioned to obtain 11 mm root canal length. Temperature increases at root surfaces were measured by a thermocouple during Nd:YAP laser irradiation of root canals at different energy densities. Canal irradiation was accomplished with a circular and retrograde movement from the apex until the cervical part of the canal during 10 seconds with an axial speed of 1 mm/s. Each irradiation was done in a canal irrigated continuously with 2.25% NaOCl solution. Results. Periodontal temperature increase depends on the value of energy density. Means and standard deviations of temperature increases at root surfaces were below 10°C (safe threshold level when the average energy densities delivered per second were equal to or below 4981 J/cm2 and 9554 J/cm2, respectively, for irradiations using a fiber diameter of 320 μm and 200 μm. Conclusions. Within the limitations of this study and under specific irradiation conditions, Nd:YAP laser beam may be considered harmless for periodontal tissues during endodontic applications.

  16. Safety Irradiation Parameters of Nd:YAP Laser Beam for Endodontic Treatments: An In Vitro Study

    Science.gov (United States)

    Namour, A.; Geerts, S.; Zeinoun, T.; De Moor, R.; Nammour, S.

    2016-01-01

    Objective. Nd:YAP laser has several potentialities of clinical applications in endodontics. The aim of our study is to determine the safety range of irradiation parameters during endodontic application of Nd:YAP laser that can be used without damaging and overheating the periodontal tissue. Material and Methods. Twenty-seven caries-free single-rooted extracted human teeth were used. Crowns were sectioned to obtain 11 mm root canal length. Temperature increases at root surfaces were measured by a thermocouple during Nd:YAP laser irradiation of root canals at different energy densities. Canal irradiation was accomplished with a circular and retrograde movement from the apex until the cervical part of the canal during 10 seconds with an axial speed of 1 mm/s. Each irradiation was done in a canal irrigated continuously with 2.25% NaOCl solution. Results. Periodontal temperature increase depends on the value of energy density. Means and standard deviations of temperature increases at root surfaces were below 10°C (safe threshold level) when the average energy densities delivered per second were equal to or below 4981 J/cm2 and 9554 J/cm2, respectively, for irradiations using a fiber diameter of 320 μm and 200 μm. Conclusions. Within the limitations of this study and under specific irradiation conditions, Nd:YAP laser beam may be considered harmless for periodontal tissues during endodontic applications. PMID:27376084

  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. Experimental studies of chronic pneumonia of sheep.

    Science.gov (United States)

    Gilmour, J S; Jones, G E; Rae, A G

    1979-01-01

    Strains of Mycoplasma ovipneumoniae and Pasteurella haemolytica isolated from sheep affected with chronic pneumonia were inoculated by endobronchial route to conventionally-reared and SPF (Specific Pathogen-Free) lambs. Changes resembling those of the naturally-occurring disease were produced in most lambs given the organisms in combination and in some given M. ovipneumoniae alone. Similar but less extensive changes were seen in SPF lambs and fewer animals were affected. Different strains of M. ovipneumoniae did not affect the extent of changes produced in SPF lambs. M. ovipneumoniae became established in the lungs of both types of sheep; P. haemolytica did so less readily. It was concluded that chronic pneumonia may be reproduced in conventional animals by combined inoculation of M. ovipneumoniae and P. haemolytica. Age and status of immunity to mycoplasmas may account for the different responses of conventional and SPF lambs.

  19. [Clinicopathological study of chronic kidney diseases (CKD)].

    Science.gov (United States)

    Yoshida, Haruyoshi

    2012-02-01

    up-to-date information and techniques in clinical nephrology. From this hospital, I published a paper in Kidney International entitled, "Mesangiolytic glomerulopathy in severe congestive heart failure", based on the autopsy cases collected at the Pathology Department. This paper became a milestone in starting to study the role of chronic hypoxia in CKD. In 1999, I was elected as a professor of the Department of Clinical Laboratories, Faculty of Medicine, University of Fukui. In Fukui, I could extend my hypoxia study to cellular levels and diabetic mouse experiments in collaboration with Dr. Kimura, Dr. Li, Dr. Takahashi and many other doctors and technicians. When overviewing my research history, I realize that I was fortunate to be involved at the starting point of every laboratory with energetic mood and that I was supported and helped by many people.

  20. A small animal image guided irradiation system study using 3D dosimeters

    Science.gov (United States)

    Qian, Xin; Admovics, John; Wuu, Cheng-Shie

    2015-01-01

    In a high resolution image-guided small animal irradiation platform, a cone beam computed tomography (CBCT) is integrated with an irradiation unit for precise targeting. Precise quality assurance is essential for both imaging and irradiation components. The conventional commissioning techniques with films face major challenges due to alignment uncertainty and labour intensive film preparation and scanning. In addition, due to the novel design of this platform the mouse stage rotation for CBCT imaging is perpendicular to the gantry rotation for irradiation. Because these two rotations are associated with different mechanical systems, discrepancy between rotation isocenters exists. In order to deliver x-ray precisely, it is essential to verify coincidence of the imaging and the irradiation isocenters. A 3D PRESAGE dosimeter can provide an excellent tool for checking dosimetry and verifying coincidence of irradiation and imaging coordinates in one system. Dosimetric measurements were performed to obtain beam profiles and percent depth dose (PDD). Isocentricity and coincidence of the mouse stage and gantry rotations were evaluated with starshots acquired using PRESAGE dosimeters. A single PRESAGE dosimeter can provide 3 -D information in both geometric and dosimetric uncertainty, which is crucial for translational studies.

  1. Optical and rheological study of gamma irradiated rare-earth nanoparticle based ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Nibedita [Nanoscience and Soft Matter Laboratory, Department of Physics, Tezpur University, PO Napaam, Tezpur 784 028, Assam (India); Mohanta, Dambarudhar, E-mail: best@tezu.ernet.in [Nanoscience and Soft Matter Laboratory, Department of Physics, Tezpur University, PO Napaam, Tezpur 784 028, Assam (India); Department of Physics, School of Engineering and Applied Sciences, Harvard University, MA 02138 (United States); Saha, Abhijit [UGC-DAE Consortium for Scientific Research, Kolkata Centre, III/LB-8 Bidhannagar, Kolkata 700 098 (India)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Gd{sub 2}O{sub 3} nanoparticle based ferrofluids have been produced with ethanol as carrier medium. Black-Right-Pointing-Pointer PL emission show improvement in defect related emission with {gamma}-irradiation dose. Black-Right-Pointing-Pointer The ferrofluids show shear thinning behavior with bi-exponential decay characteristics. Black-Right-Pointing-Pointer Fast and slow components are found to increase with irradiation dose. - Abstract: The present work reports on the optical and rheological properties of unexposed and gamma irradiated rare-earth (RE) oxide nanoparticle-based ferrofluids (FF). The ferrofluids were prepared by dispersing surfactant coated gadolinium oxide (Gd{sub 2}O{sub 3}) nanoparticles in ethanol medium and later on subjected to energetic gamma irradiation (1.25 MeV) at select doses. As predicted from transmission electron microscopy and X-ray diffraction (XRD) studies, the synthesized nanoparticles are of {approx}7 nm size which crystallize into cubic crystal structure. The photoluminescence response reveals creation of defect states on nanoparticle surfaces when FFs are subjected to gamma irradiation. Whereas, rheology measurements showed unusual shear thinning behavior of the ferrofluids. The flow behavior of all the samples can be correlated to the bi-exponential decay curve fitting which reveals that decay phenomenon is governed by two independent mechanism: fast and slow events. The variation of the decay parameter with irradiation dose is attributed to the creation of point defects and weakening of inter nanoparticle bonding.

  2. GC-FID and NMR Spectroscopic Studies on Gamma Irradiated Walnut Lipids

    Directory of Open Access Journals (Sweden)

    Vassilia J. Sinanoglou

    2015-01-01

    Full Text Available Walnuts have an excellent fatty acid profile, beneficial for coronary heart diseases. A diet rich in walnuts has shown to decrease the total and LDL cholesterol levels as well as lipoprotein levels. In this study, the effects of different doses of γ-irradiation and different packaging conditions on proximate composition and fatty acid profile of walnuts (Juglans regia L. were investigated merging data from different spectroscopic techniques. Walnuts moisture, ash, fat, and protein content as well as fatty acid profile were evaluated immediately after irradiation. GC-FID results showed that SFA increased and MUFA and PUFA decreased with the increase of irradiation dose. Moreover, MUFA/SFA and PUFA/SFA ratios decreased P<0.05 compared to control samples. Furthermore, NMR spectroscopy was implemented to examine possible discrimination patterns based on irradiation dose and packaging. This approach revealed the role of PUFA decrease with the parallel increase of irradiation dose while indicating the protective role of vacuum and MAP compared to air packaging. In conclusion, at irradiation doses of up to 5 kGy, the walnuts retained the nutritional benefits of its fatty acids, in particular MUFA and PUFA. Concerning the different types of packaging, greater stability in the nuts was observed using MAP packaging.

  3. A model system and technique to study the effects of ultrasound irradiation on embryonic development.

    Science.gov (United States)

    Rosenthal, M S; Yip, Y P; Capriotti, C; Yip, J W

    1991-08-01

    To study the effects of ultrasound on development it is important to have a system which provides reliable results. We have designed a system which allows for reproducible irradiations of chick embryos in ovo. The irradiation system includes a heated sonation tank with ultrasound absorbers and a PC/AT computer-based data acquisition system for on-line monitoring of irradiations. The ultrasound detection microprobe and irradiation transducers were calibrated against an NBS traceable balance meter. An acoustic spacer was utilized to provide a more uniform profile of the irradiation beam. At the position of the embryo the ultrasound field geometry was determined. To maintain the chick embryo in its natural physiological state while minimizing ultrasonic reflections and standing-wave generation, two diametrically opposed windows were made in the eggshell along the ultrasound pathway and covered with polyethylene membranes. Using this irradiation system at intensity levels as high as 1.1 W/cm2 (spatial average, temporal average) for 10 min, the temperature rise is minimal.

  4. A preliminary study on anti-irradiation performance of epoxy shape memory polymer

    Science.gov (United States)

    Wu, Xuelian; Liu, Yanju; Leng, Jinsong

    2009-07-01

    As a new class of smart material, shape memory polymer (SMP) receives more and more attention. In this paper, in addition to the fabrication of a new type of epoxy SMP, the thermo-mechanical properties of the polymer with/without gamma irradiation were investigated and compared systematically. The radiation source is Co-60 and the total dosage of radiation is 1×104Gy. Changes of network structures of the polymer were investigated by Fourier Transform Infrared (FTIR) spectroscopy. The influence of gamma irradiation on thermo and mechanical properties of the polymer were investigated by Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA) and tensile test, respectively. Furthermore, shape recovery behaviors of the polymer before/after the irradiation were compared too. Results show that the epoxy SMP possesses good chemical stability, glass transition temperature (Tg) determined by DSC decreased by 7°C after the irradiation. The gamma radiation has a slight influence on storage modulus, loss modulus and tan delta, respectively. No considerable change was found both in tensile strength and elongation at break after the gamma radiation. Finally, the shape recovery ratio of the polymer is near 100% with and without the gamma irradiation. Based on the above results, it can be demonstrated that the epoxy SMP prepared in the study possesses not only good thermo-mechanical properties but unique anti irradiation performance. The epoxy SMP shows potential for application of aerospace fields.

  5. Effect of total lymphoid irradiation on functional status in chronic multiple sclerosis: importance of lymphopenia early after treatment--the pros

    Energy Technology Data Exchange (ETDEWEB)

    Devereux, C.; Troiano, R.; Zito, G.; Devereux, R.B.; Kopecky, K.J.; Friedman, R.; Dowling, P.C.; Hafstein, M.P.; Rohowsky-Kochan, C.; Cook, S.D.

    1988-07-01

    To determine whether immunosuppression by total lymphoid irradiation (TLI) slowed deterioration of chronic progressive multiple sclerosis (MS), functional impairment score and blood lymphocyte counts were compared at 6-month intervals through 4 years following treatment of MS patients by either TLI (n = 27) or sham irradiation (n = 21). At each interval, 20 to 30% fewer TLI-treated patients had deteriorated (p less than 0.05 at 6, 12, and 18 months), and the difference in mean functional impairment score between groups became progressively greater (p less than 0.01 at 42 and 48 months). Benefit accrued principally to the 17 TLI-treated patients with absolute blood lymphocyte counts less than 900/mm3 3 months after treatment, whose mean functional impairment score remained within 0.6 units of baseline (p = NS), whereas the ten TLI patients with higher post-treatment lymphocyte counts had progressive deterioration (p less than 0.05 to p less than 0.001 versus TLI-treated patients with lower lymphocyte counts at all intervals except 30 months) and had deteriorated by more than 5 functional scale units by 42 and 48 months. Side effects were minor and complications rare in TLI-treated patients, but one TLI-treated patient developed staphylococcal sepsis. Thus, TLI slows deterioration of chronic progressive MS, with what appears to be enduring benefit through 4 years compartmented to patients with greater induced lymphopenia. Modification of lymphoid irradiation regimens to increase the proportion of MS patients who achieve a favorable degree of lymphopenia and to avert functional hyposplenism may further improve the benefit/risk ratio.

  6. Psychoneuroendocrinological studies on chronic stress and depression.

    Science.gov (United States)

    Tafet, Gustavo E; Smolovich, Jaime

    2004-12-01

    The adaptive response to stress is characterized by activation of neural and neuroendocrine cascades mediated mainly by the noradrenergic/sympathetic and limbic-hypothalamic-pituitary-adrenal (HPA) systems, respectively. Chronic psychosocial stress has long been associated with the origin and development of depression, where increased levels of cortisol have been observed in both conditions. In this regard, increased levels of cortisol could be directly involved in the mood changes observed in depression, and direct connections between these and alterations of the serotonergic neurotransmission have been also proposed. Therefore, we investigated the potential link between alterations of the limbic-HPA system with the serotonergic hypothesis of depression at both the molecular and clinical levels. Our findings support the notion that chronic psychosocial stress may lead to depression in certain individuals depending on the psychobiological background and their particular psychological resources. Therefore, certain interventions aimed at normalization of the HPA system could potentially prevent the development of depression in chronically stressed subjects. This would be possible through either pharmacological interventions or psychotherapeutic strategies, such as cognitive therapy, aimed at improving resilience and controllability in stressful situations.

  7. 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.

  8. Studies on irradiation effects on rat salivary glands; Morphological and functional changes after sup 60 Co. gamma. irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Saotome, Hitoshi (Meikai Univ., Sakado, Saitama (Japan). School of Dentistry)

    1991-07-01

    Following {sup 60}Co {gamma} irradiation (17.82 Gy) given as a single dose, time, dose and fractionation factor (TDF) 100, to the head and neck area of rats, the major salivary glands were examined at 1, 2, 3, 5, 7, 14, 21, 28 and 49 days for evidence of microscopic and ultrastructural damage as well as for changes in various enzymes. In addition, parotid salivary function assessed in terms of flow rate, total salivary protein, and secretion of {alpha}-amylase activity was also determined. In the early stage after {sup 60}Co {gamma}-irradiation 17.82 Gy (TDF 100), systemic effects, body weight loss, and dehydration were observed, and the animals tended to recover from these effects within 1 or 2 weeks. Regarding the irradiation effect on the salivary glands, the parotid gland was showed severe damage; the submandibular, moderate; and the sublingual, slight. Also the effects remained longer in the parotid. Proliferation of granular convoluted tubule cells was retarded by irradiation. The total protein in the parotid gland was decreased after irradiation, whereas the submandibular and sublingual were showed slight or no change. The amount of activity of {alpha}-amylase and of alkaline phosphatase activity in the parotid gland, and that of acid phosphatase and {beta}-D-glucuronidase in all glands, was dependent on the degree of morphological damage observed following irradiation. The salivary flow rate in the parotid gland was depressed 7 days after irradiation to approximately 1/7 of normal, and recovery was noted by 49 days post irradiation. The total protein and {alpha}-amylase activity in the parotid saliva were decreased within several days after irradiation, but had recovered to normal levels. (author).

  9. Study of boron carbide evolution under neutron irradiation; Contribution a l'etude de l'evolution du carbure de bore sous irradiation neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Simeone, D. [CEA/Saclay, Dept. de Mecanique et de Technologie (DMT), 91 - Gif-sur-Yvette (France)]|[Universite Blaise Pascal, Clermont-Ferrand II, (CNRS), 63 - Aubiere (France)

    1999-07-01

    Owing to its high neutron efficiency, boron carbide (B{sub 4}C) is used as a neutron absorber in control rods of nuclear plants. Its behaviour under irradiation has been extensively studied for many years. It now seems clear that brittleness of the material induced by the {sup 10}B(n,{alpha}){sup 7}Li capture reaction is due to penny shaped helium bubbles associated to a high strain field around them. However, no model explains the behaviour of the material under neutron irradiation. In order to build such a model, this work uses different techniques: nuclear microprobe X-ray diffraction profile analysis and Raman and Nuclear Magnetic Resonance Spectroscopy to present an evolution model of B{sub 4}C under neutron irradiation. The use of nuclear reactions produced by a nuclear microprobe such as the {sup 7}Li(p,p'{gamma}){sup 7}Li reaction, allows to measure lithium profile in B{sub 4}C pellets irradiated either in Pressurised Water Reactors or in Fast Breeder Reactors. Examining such profiles enables us to describe the migration of lithium atoms out of B{sub 4}C materials under neutron irradiation. The analysis of X-ray diffraction profiles of irradiated B{sub 4}C samples allows us to quantify the concentrations of helium bubbles as well as the strain fields around such bubbles.Furthermore Raman spectroscopy studies of different B{sub 4}C samples lead us to propose that under neutron irradiation. the CBC linear chain disappears. Such a vanishing of this CBC chain. validated by NMR analysis, may explain the penny shaped of helium bubbles inside irradiated B{sub 4}C. (author)

  10. Spectroscopic study of fast-neutron-irradiated chromatin

    Energy Technology Data Exchange (ETDEWEB)

    Radu, L. [V. Babes National Inst., Dept. of Molecular Genetics, Bucharest (Romania)]. E-mail: serbanradu@pcnet.ro; Gazdaru, D. [Bucharest Univ., Dept. of Biophysics, Physics Faculty, Bucharest (Romania); Constantinescu, B. [H. Hulubei National Inst., Dept. of Cyclotron, Bucharest (Romania)

    2004-02-01

    The effects produced by fast neutrons (0-100 Gy) on chromatin structure were analyzed by (i) [{sup 1}H]-NMR spectroscopy, (ii) time resolved spectroscopy, and (iii) fluorescence resonance energy transfer (FRET). Two types of chromatin were tested: (i) a chromatin from a normal tissue (liver of Wistar rats) and (ii) a chromatin from a tumoral tissue (Guerin limphotrope epithelioma, a rat solid tumor). The fast-neutron action on chromatin determines greater values of the [{sup 1}H]-NMR transverse relaxation time, indicating a more injured structure. Time-resolved fluorescence measurements show that the relative contribution of the excited state lifetime of bound ethidium bromide to chromatin DNA diminishes with increasing irradiation doses. This reflects the damage that occurs in DNA structure: production of single- and double-strand breaks due to sugar and base modifications. By the FRET method, the distance between dansyl chloride and acridine orange coupled at chromatin was determined. This distance increases upon fast-neutron action. The radiosensitivity of the tumor tissue chromatin seems higher than that of the normal tissue chromatin, probably because of its higher (loose) euchromatin/(compact) heterochromatin ratio. As the values of the physical parameters analyzed are specific for a determined dose, the establishment of these parameters may constitute a criterion for the microdosimetry of chromatin radiolesions produced by fast neutrons. (author)

  11. Rheological study of polypropylene irradiated with polyfunctional monomers

    Science.gov (United States)

    Otaguro, H.; Rogero, S. O.; Yoshiga, A.; Lima, L. F. C. P.; Parra, D. F.; Artel, B. W. H.; Lugão, A. B.

    2007-12-01

    The aim of this paper is to investigate the rheological properties of polypropylene (PP) modified by ionization radiation (gamma rays) in the presence of two different monomers. The samples were mixed in a twin-screw extruder with ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TMPTMA) with concentration in the range of 0.5-5.0 mmol. After that, they were irradiated with 20 kGy dose of gamma radiation. The structural modification of polypropylene was analyzed in the melt state by measuring melt flow rate (MFR), η* (complex viscosity) and G' (storage modulus) in the angular frequency range of 10 -1 to 3 × 10 2 rad s -1. From the oscillatory rheology data, one could obtain the values of η0 (zero shear viscosity) that would be related to the molar mass. All results were discussed with respect to the crosslinking and degradation process that occur in the post-reactor treatment to produce controlled rheology polypropylene. The resulting polymeric materials were submitted the cytotoxicity in vitro test by neutral red uptake methodology with NCTC L 929 cell line from American Type Culture Collection bank. All modified PP samples presented no cytotoxicity.

  12. A pilot study of accelerated irradiation for brain metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Michinao; Tokuuye, Koichi; Akine, Yasuyuki; Akimoto, Tetsuo; Ogino, Takashi; Tsukiyama, Iwao; Ono, Ryosuke; Egawa, Sunao (National Cancer Center, Tokyo (Japan). Hospital)

    1992-12-01

    Twenty-eight patients with brain metastases received brain radiotherapy with a total dose of 48 Gy, at 2 Gy per fraction, twice a day with a minimum interfractional period of 4 hours, and 5 days per week. This was intended to shorten the treatment period without increasing the morbidity, since most of these patients had a limited survival expectancy. Twenty-six of the 28 patients completed the radiotherapy. Three of the 26 patients experienced nausea and/or vomiting during the treatment. Radiotherapy was interrupted in two patients: one developed hemiplegia, and the other somnolence, both of which resulted from the progressive intracerebral disease. This radiotherapy regimen appears to be comparable to the conventional scheme in alleviation of symptoms. No patient needed interruption of the planned course of treatment because of acute irradiation toxicity. Based on these results, a multi-institutional randomized trial has been initiated to compare the twice-a-day and once-a-day radiotherapy schemes on patients with brain metastases. (author).

  13. STUDY OF RAY IRRADIATION ON DIAMOND-LIKE CARBON FILMS

    Institute of Scientific and Technical Information of China (English)

    G.A.Liu; T.M.Wang; E.Q.Xie

    2002-01-01

    Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (rf) plasma deposition method, γ-ray, ultraviolet (UV) ray were used toirradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were usedto characterize the changing characteristics of SP3 C-H bond and hydrogen content inthe films due to the irradiations. The results show that, the damage degrees induced bythe UV ray on the SP3 C-H bonds are much stronger than that by the γ-ray. When theirradiation dose of γ-ray reaches 10× 104Gy, the SP3 C-H bond reduces about 50% innumber. The square electrical resistance of the films is reduced due to the irradiationof UV ray and this is caused by severe oxidation of the films. By using the results onoptical gap of the films and the fully constrained network theory, the hydrogen contentin the as-deposited films is estimated to be 10-25at.%.

  14. Effect of chronic fractionated low-dose gamma irradiation on division potential of human embryonic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami; Suzuki, Masao; Suzuki, Keiji; Watanabe, Kimiko (Yokohama City Univ. (Japan). Faculty of Medicine); Nakano, Kazushiro

    1991-12-01

    We investigated the in vitro phenotypic transformation of human embryo (HE) cells that were repeatedly irradiated (7.5 cGy once a week) throughout their life-span. Irradiation was repeated until the cells had accumulated 195 cGy (equivalent to the 26th passage). Samples of cells were assayed for survival by colony formation, as well as for mutation at the hypoxanthine guanine phosphoribosyl transferase (HGPRT) locus and for transformation by focus formation. The life-span (mean number of population doublings) of multiply irradiated cells with a total dose of 97.5 cGy was slightly but significantly prolonged over that of controls. After HE cells had accumulated 195 cGy, the maximum number of divisions increased to 130-160% of the number in non-irradiated control cells. Transformed foci were not observed until cells had accumulated 97.5 cGy, and then increased with the increasing accumulation of radiation. However, no cells showed immortality or expressed a malignant phenotype in vitro. (author).

  15. Studies of material properties under irradiation at BNL Linear Isotope Producer (BLIP)

    CERN Document Server

    Simos, N; Ludewig, H; Mokhov, N; Hurh, P; Misek, J

    2012-01-01

    Effects of proton beams irradiating materials considered for targets in high-power accelerator experiments have been under study using the Brookhaven National Laboratory's (BNL) 200 MeV Linac. The primary objectives of the study that includes a wide array of materials and alloys ranging between low and high-Z are to (a) observe changes in physio-mechanical properties which are important in maintaining high-power target functionality, (b) identify possible limits of proton flux or fluence above which certain material seize to maintain integrity, (c) study the role of material operating temperature in inducing or maintaining radiation damage reversal, and (d) correlate radiation damage effects of different species such as energetic protons and neutrons on materials by utilizing reactor and particle accelerator experience data. These objectives are specifically being addressed in the latest material irradiation study linked to the Long Baseline Neutrino Experiment (LBNE). Observations on irradiation effects on m...

  16. Chronic urticaria. Clinical and pathogenetic studies in 141 patients

    NARCIS (Netherlands)

    Doeglas, Hendrik Maarten George

    1975-01-01

    This study describes a combined clinical, laboratory and experimental approach of the problems of 141 patients with chronic urticaria, collected over a three-year period in a Dermatology department. ... Zie: Summary

  17. Association between erectile dysfunction and chronic periodontitis: A clinical study

    Directory of Open Access Journals (Sweden)

    Ranjit Singh Uppal

    2014-01-01

    Conclusion: It may be concluded that chronic periodontitis and ED are associated with each other. However, further large scale studies with confounder analysis and longitudinal follow-up are warranted to explore the link between these two diseases.

  18. Chronic urticaria. Clinical and pathogenetic studies in 141 patients

    NARCIS (Netherlands)

    Doeglas, Hendrik Maarten George

    1975-01-01

    This study describes a combined clinical, laboratory and experimental approach of the problems of 141 patients with chronic urticaria, collected over a three-year period in a Dermatology department. ... Zie: Summary

  19. Study of dpa distributions in electron irradiated YBCO slabs through MCCM algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Pinera, Ibrahin, E-mail: ipinera@ceaden.edu.cu [Radiation Damage Laboratory, Department of Physics, Center of Technological Applications and Nuclear Developments, CEADEN, Playa 11300, P.O. Box 6122, Havana City (Cuba); Cruz, Carlos M. [Radiation Damage Laboratory, Department of Physics, Center of Technological Applications and Nuclear Developments, CEADEN, Playa 11300, P.O. Box 6122, Havana City (Cuba); Espen, Piet Van [Micro and Trace Analysis Centre, Department of Chemistry, University of Antwerp, Wilrijk 2610, Antwerp (Belgium); Abreu, Yamiel; Leyva, Antonio [Radiation Damage Laboratory, Department of Physics, Center of Technological Applications and Nuclear Developments, CEADEN, Playa 11300, P.O. Box 6122, Havana City (Cuba)

    2012-03-01

    The Monte Carlo assisted Classical Method (MCCM) consists on a calculation procedure for determining the displacements per atom (dpa) distribution in solid materials. This algorithm allows studying the gamma and electron irradiation damage in different materials. It is based on the electrons elastic scattering classic theories and the use of Monte Carlo simulation for the physical processes involved. The present study deals with the Monte Carlo simulation of electron irradiation effects on YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) slabs using the MCNPX code system. Displacements per atom distributions are obtained through the MCCM for electron irradiation up to 10 MeV. In-depth dpa profiles for electrons and positrons are obtained and analysed. Also, dpa contributions from each atomic specie in the material are calculated. It was found that the dpa distribution is more homogeneous in the material volume when increasing energy of incident electrons. Also, the dpa produced by positrons has no relevance when irradiating with electrons, in contrast with previous similar gamma irradiation studies. All the results are presented and discussed in this contribution.

  20. Chronic irradiation of Scots pine trees (Pinus sylvestris) in the Chernobyl exclusion zone: dosimetry and radiobiological effects.

    Science.gov (United States)

    Yoschenko, Vasyl I; Kashparov, Valery A; Melnychuk, Maxim D; Levchuk, Svjatoslav E; Bondar, Yulia O; Lazarev, Mykola; Yoschenko, Maria I; Farfán, Eduardo B; Jannik, G Timothy

    2011-10-01

    To identify effects of chronic internal and external radiation exposure for components of terrestrial ecosystems, a comprehensive study of Scots pine trees in the Chernobyl Exclusion Zone was performed. The experimental plan included over 1,100 young trees (up to 20 y old) selected from areas with varying levels of radioactive contamination. These pine trees were planted after the 1986 Chernobyl Nuclear Power Plant accident mainly to prevent radionuclide resuspension and soil erosion. For each tree, the major morphological parameters and radioactive contamination values were identified. Cytological analyses were performed for selected trees representing all dose rate ranges. A specially developed dosimetric model capable of taking into account radiation from the incorporated radionuclides in the trees was developed for the apical meristem. The calculated dose rates for the trees in the study varied within three orders of magnitude, from close to background values in the control area (about 5 mGy y(-1)) to approximately 7 Gy y(-1) in the Red Forest area located in the immediate vicinity of the Chernobyl Nuclear Power Plant site. Dose rate/effect relationships for morphological changes and cytogenetic defects were identified, and correlations for radiation effects occurring on the morphological and cellular level were established.

  1. CHRONIC IRRADIATION OF SCOTS PINE TREES (PINUS SYLVESTRIS) IN THE CHERNOBYL EXCLUSION ZONE: DOSIMETRY AND RADIOBIOLOGICAL EFFECTS

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Jannik, T.

    2011-10-01

    To identify effects of chronic internal and external radiation exposure for components of terrestrial ecosystems, a comprehensive study of Scots pine trees in the Chernobyl Exclusion Zone was performed. The experimental plan included over 1,100 young trees (up to 20 years old) selected from areas with varying levels of radioactive contamination. These pine trees were planted after the 1986 Chernobyl Nuclear Power Plant accident mainly to prevent radionuclide resuspension and soil erosion. For each tree, the major morphological parameters and radioactive contamination values were identified. Cytological analyses were performed for selected trees representing all dose rate ranges. A specially developed dosimetric model capable of taking into account radiation from the incorporated radionuclides in the trees was developed for the apical meristem. The calculated dose rates for the trees in the study varied within three orders of magnitude, from close to background values in the control area (about 5 mGy y{sup -1}) to approximately 7 Gy y{sup -1} in the Red Forest area located in the immediate vicinity of the Chernobyl Nuclear Power Plant site. Dose rate/effect relationships for morphological changes and cytogenetic defects were identified and correlations for radiation effects occurring on the morphological and cellular level were established.

  2. Comparison of outcomes of allogeneic transplantation for chronic myeloid leukemia with cyclophosphamide in combination with intravenous busulfan, oral busulfan, or total body irradiation.

    Science.gov (United States)

    Copelan, Edward A; Avalos, Belinda R; Ahn, Kwang Woo; Zhu, Xiaochun; Gale, Robert Peter; Grunwald, Michael R; Hamadani, Mehdi; Hamilton, Betty K; Hale, Gregory A; Marks, David I; Waller, Edmund K; Savani, Bipin N; Costa, Luciano J; Ramanathan, Muthalagu; Cahn, Jean-Yves; Khoury, H Jean; Weisdorf, Daniel J; Inamoto, Yoshihiro; Kamble, Rammurti T; Schouten, Harry C; Wirk, Baldeep; Litzow, Mark R; Aljurf, Mahmoud D; van Besien, Koen W; Ustun, Celalettin; Bolwell, Brian J; Bredeson, Christopher N; Fasan, Omotayo; Ghosh, Nilanjan; Horowitz, Mary M; Arora, Mukta; Szer, Jeffrey; Loren, Alison W; Alyea, Edwin P; Cortes, Jorge; Maziarz, Richard T; Kalaycio, Matt E; Saber, Wael

    2015-03-01

    Cyclophosphamide (Cy) in combination with busulfan (Bu) or total body irradiation (TBI) is the most commonly used myeloablative conditioning regimen in patients with chronic myeloid leukemia (CML). We used data from the Center for International Bone Marrow Transplantation Research to compare outcomes in adults who underwent hematopoietic cell transplantation for CML in first chronic phase after myeloablative conditioning with Cy in combination with TBI, oral Bu, or intravenous (i.v.) Bu. Four hundred thirty-eight adults received human leukocyte antigen (HLA)-matched sibling grafts and 235 received well-matched grafts from unrelated donors (URD) from 2000 through 2006. Important differences existed between the groups in distribution of donor relation, exposure to tyrosine kinase inhibitors, and year of transplantation. In multivariate analysis, relapse occurred less frequently among patients receiving i.v. Bu compared with TBI (relative risk [RR], .36; P = .022) or oral Bu (RR, .39; P = .028), but nonrelapse mortality and survival were similar. A significant interaction was detected between donor relation and the main effect in leukemia-free survival (LFS). Among recipients of HLA-identical sibling grafts, but not URD grafts, LFS was better in patients receiving i.v. Bu (RR, .53; P = .025) or oral Bu (RR, .64; P = .017) compared with TBI. In CML in first chronic phase, Cy in combination with i.v. Bu was associated with less relapse than TBI or oral Bu. LFS was better after i.v. or oral Bu compared with TBI.

  3. Effects of far-infrared irradiation on myofascial neck pain: a randomized, double-blind, placebo-controlled pilot study.

    Science.gov (United States)

    Lai, Chien-Hung; Leung, Ting-Kai; Peng, Chih-Wei; Chang, Kwang-Hwa; Lai, Ming-Jun; Lai, Wen-Fu; Chen, Shih-Ching

    2014-02-01

    The objective of this study was to determine the relative efficacy of irradiation using a device containing a far-infrared emitting ceramic powder (cFIR) for the management of chronic myofascial neck pain compared with a control treatment. This was a randomized, double-blind, placebo-controlled pilot study. The study comprised 48 patients with chronic, myofascial neck pain. Patients were randomly assigned to the experimental group or the control (sham-treatment) group. The patients in the experimental group wore a cFIR neck device for 1 week, and the control group wore an inert neck device for 1 week. Quantitative measurements based on a visual analogue scale (VAS) scoring of pain, a sleep quality assessment, pressure-pain threshold (PPT) testing, muscle tone and compliance analysis, and skin temperature analysis were obtained. Both the experimental and control groups demonstrated significant improvement in pain scores. However, no statistically significant difference in the pain scores was observed between the experimental and control groups. Significant decreases in muscle stiffness in the upper regions of the trapezius muscles were reported in the experimental group after 1 week of treatment. Short-term treatment using the cFIR neck device partly reduced muscle stiffness. Although the differences in the VAS and PPT scores for the experimental and control groups were not statistically significant, the improvement in muscle stiffness in the experimental group warrants further investigation of the long-term effects of cFIR treatment for pain management.

  4. Multifrequency EPR study on freeze-dried fruits before and after X-ray irradiation

    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; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimitrova, A. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Georgieva, L. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Tzvetkova, E. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria)

    2006-09-15

    X-, K- and Q-band EPR studies on lyophilized whole pulp parts of blue plum, apricot, peach, melon as well as achens and pulp separately of strawberry before and after X-ray irradiation are reported. Before irradiation all samples show in X band a weak singlet EPR line with g=2.0030+/-0.0005, except melon, which is EPR silent. Immediately after irradiation all samples exhibit complex fruit-depending spectra, which decay with time and change to give, in ca. 50days, an asymmetric singlet EPR line with g=2.0041+/-0.0005. Only apricot pulp gave a typical ''sugar-like'' EPR spectrum. Singlet EPR lines recorded after irradiation in X -band are K- and Q-band resolved as typical anisotropic EPR spectra with g{sub ||}=2.0023+/-0.0003 and g{sub -}bar =2.0041+/-0.0005. In addition, K- and Q-band EPR spectra of all samples show a superposition with the six EPR lines of Mn{sup 2+} naturally present in the fruits. The saturation behavior of the EPR spectra of achens of lyophilized and fresh strawberry is also studied. The differences in g factors of samples before and after X-ray irradiation might be used for the identification of radiation processing of fruits in the case of pulp and the differences in the EPR saturation behavior might be used for the achens of strawberry.

  5. Low-temperature positron-lifetime studies of proton-irradiated silicon

    DEFF Research Database (Denmark)

    Mäkinen, S.; Rajainmäki, H.; Linderoth, Søren

    1990-01-01

    The positron-lifetime technique has been used to identify defects created in high-purity single-crystal silicon by irradiation with 12-MeV protons at 15 K, and the evolution of the defects has been studied by subsequent annealings between 20 and 650 K. Two clear annealing steps were seen in the s......The positron-lifetime technique has been used to identify defects created in high-purity single-crystal silicon by irradiation with 12-MeV protons at 15 K, and the evolution of the defects has been studied by subsequent annealings between 20 and 650 K. Two clear annealing steps were seen...

  6. ESR and optical absorption studies of gamma- and electron-irradiated sugar crystals

    Energy Technology Data Exchange (ETDEWEB)

    Flores, J.C.; Cabrera, B.E.; Calderon, T.; Munoz, P.E.; Adem, E.; Hernandez, A.J.; Boldu, J.L.; Ovalle M.P.; Murrieta, S.H. E-mail: murrieta@fenix.ifisicacu.unam.mx

    2000-05-15

    Electron spin resonance (ESR) studies of the free radicals induced in gamma- or electron-irradiated sugar crystals were performed. The number of radicals increases linearly, pointing out that this material can be used as a dosimeter. The optical absorption studies show the presence of several distinctive bands in the infrared and UV region, whose intensity changes with the irradiation dose. An interpretation of these results in terms of the formation of free radicals and possible crosslinking along the sugar molecular chains is presented.

  7. DLTS Studies of high-temperature electron irradiated Cz n-Si

    Energy Technology Data Exchange (ETDEWEB)

    Neimash, V.; Kras' ko, M.; Kraitchinskii, A.; Voytovych, V.; Tishchenko, V. [Institute of Physics NANU, 46 Nauki Av., Kiev (Ukraine); Simoen, E.; Rafi, J.M. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Claeys, C. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); E.E. Dept., KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven (Belgium); Versluys, J.; De Gryse, O.; Clauws, P. [Dept. Solid-State Sciences, Ghent University, Krijgslaan 281 S1, B-9000 Gent (Belgium)

    2004-02-01

    This paper reports on a Deep Level Transient Spectroscopy (DLTS) study of both oxygen-related thermal donors (OTDs) and radiation-induced defects (RDs) formed in high-temperature 1 MeV electron irradiated n-type Czochralski silicon. The heating of Si samples is done in-situ by the electron beam. The formation of deep levels is studied on both heat-treated and irradiated at high temperature sides of samples. The interaction between OTDs and RDs is investigated. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Pterygium excision with or without postoperative irradiation, a double-blind study

    Energy Technology Data Exchange (ETDEWEB)

    de Keizer, R.J.W. (Amsterdam Univ. (Netherlands). Academisch Ziekenhuis)

    1982-01-29

    A double-blind study (covering 40 months) of 40 eyes with a pterygium which had not previously been operated on, was carried out to study the effect of post-operative irradiation. Nineteen eyes were treated by the 'bare sclera' operation technique only and in 13 cases (68%) a recurrence occurred within 4 months. In 18 eyes from the group of patients treated with Sr 90 irradiation on the 1st, 7th and 14th postoperative day (maximum 3 x 1000 rad) no recurrences were seen. Patients with a recurrent pterygium and diplopia, symblepharon, visual disturbances (growth over the pupil or severe astigmatism) or many previous operations, were treated by lamellar keratoplasty (Dake, 1980). The recurrences without these complications were treated with success by the 'bare sclera' technique and postoperative irradiation. Complications did not occur in any of the series.

  9. Simulation study of irradiated Si sensors equipped with metal- overhang for applications in LHC environment

    CERN Document Server

    Chatterji, Sudeep; Bhardwaj, Ashutosh; Srivastava-Ajay, K; Kumar, Ashish; Jha, Manoj Kumar; Shivpuri, R K; Khanna, S L

    2004-01-01

    The performance of metal-overhang (MO) equipped silicon micro-strip sensors, after irradiation for the preshower detector to be used in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC), CERN, has been studied through simulations. Detailed calculations using Hamburg model have allowed the parameterization of these effects and helped to simulate the operation scenario of MO equipped sensors over ten years of LHC operation. The utility of overhanging metal extension as junction termination technique after space charge sign inversion (SCSI) has been explored in detail for the first time in this work. Several interesting results like a shift in the optimal oxide thickness in MO equipped structures after irradiation have been reported. The comparison of dielectric and semi-insulator passivated MO equipped structures after irradiation has been studied. Also, the impact of various crucial geometrical parameters like device depth (W//N), width of back N **+ layer used for ohmic contact (W/...

  10. Determination of cell survival after irradiation via clonogenic assay versus multiple MTT Assay - A comparative study

    Directory of Open Access Journals (Sweden)

    Buch Karl

    2012-01-01

    Full Text Available Abstract For studying proliferation and determination of survival of cancer cells after irradiation, the multiple MTT assay, based on the reduction of a yellow water soluble tetrazolium salt to a purple water insoluble formazan dye by living cells was modified from a single-point towards a proliferation assay. This assay can be performed with a large number of samples in short time using multi-well-plates, assays can be performed semi-automatically with a microplate reader. Survival, the calculated parameter in this assay, is determined mathematically. Exponential growth in both control and irradiated groups was proven as the underlying basis of the applicability of the multiple MTT assay. The equivalence to a clonogenic survival assay with its disadvantages such as time consumption was proven in two setups including plating of cells before and after irradiation. Three cell lines (A 549, LN 229 and F 98 were included in the experiment to study its principal and general applicability.

  11. Study of the irradiation effect on zirconolite and monazite-brabandite matrices: comparison of the damages induced by the auto irradiation and the external irradiation; Etude du comportement sous irradiation des matrices zirconolite et monazite-brabantite: comparaison des dommages induits par l auto irradiation et l irradiation externe

    Energy Technology Data Exchange (ETDEWEB)

    Picot, V. [CEA Centre de Marcoule BP17171 - 30207 Bagnols sur Ceze Cedex (France); Blondiaux, G. [CNRS/CERI, 3A rue de la Ferollerie 45071 Orleans Cedex 2 (France); Deschanels, X.; Peuget, S.; Fillet, C. [CEA/DEN Centre de Marcoule BP17171 - 30207 Bagnols sur Ceze Cedex (France); Glorieux, B. [CNRS/PROMES 7, rue du Four Solaire 66120 Font Romeu Odeillo (France); Loubet, J.L.; Pavan, S. [LTDS, UMR CNRS 5513, Ecole Centrale de Lyon 36 avenue Guy de Collongue 69134 Ecully Cedex (France); Henry, S. [CSNSM/IN2P3, Universite Paris-Sud 11, 91405 Orsay cedex (France)

    2006-07-01

    Two ceramics, the zirconolite matrix and the solid solution monazite-brabantite have been studied for the conditioning of minor actinides. Under the effects of irradiation damages due to {alpha} disintegrations, important changes of macroscopic and mechanical properties of matrices have been revealed. The doping of the matrices with short living actinides and the external irradiation of inactive materials by heavy and light ions are two techniques which have been used for simulating the effects of {alpha} disintegrations. The comparison of the obtained results on doped and ions implanted materials have allowed to dissociate the effects of the nuclear interactions (elastic collisions) of the electronic interactions (inelastic collisions) due to {alpha} disintegrations. The results have shown that the swelling and hardness variations of a zirconolite matrix doped with plutonium 238 are due to the nuclear interactions of the {alpha} disintegrations. (O.M.)

  12. Reliability studies on NPN RF power transistors under swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pushpa, N.; Praveen, K.C. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta 30308 (United States); Gupta, S.K. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Revannasiddaiah, D. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2012-02-15

    NPN RF power transistors were irradiated with 140 MeV Si{sup 10+} ions, 100 MeV F{sup 8+} ions, 50 MeV Li{sup 3+} ions and Co-60 gamma radiation in the dose range from 100 krad to 100 Mrad. The transistor characteristics are studied before and after irradiation from which the parameters such as Gummel characteristics, excess base current ({Delta}I{sub B} = I{sub Bpost} - I{sub Bpre}), dc current gain (h{sub FE}), transconductance (g{sub m}) and collector-saturation current (I{sub CSat}) are determined. The degradation observed in the electrical characteristics is almost the same for different types of ion irradiated NPN RF power transistors with similar total doses although there is a large difference in the linear energy transfer (LET) of the ions. Further, it was observed more degradation in DC I-V characteristics of ion irradiated devices than the Co-60 gamma irradiated devices for higher doses.

  13. Defects and texture studies on polish and electron irradiated copper foils

    Energy Technology Data Exchange (ETDEWEB)

    Garcia S, F.; Barragan V, A.; Cabral P, A.; Tavera D, L.; Nieto, M.; Adem, E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Applied and basic research on the irradiation-induced defects on metals and alloys has attracted the attention of many researches and the number of published articles is large (1-4). In copper can be distinguished two main temperature ranges to produce characteristic interstitial and vacancies (Frenkel pairs). When electron irradiation is carried out at the low temperature range ({<=} 300 K) Frenkel pairs are created where vacancies are immobile and the interstitial are mobile, forming interstitial clusters. However, when electron irradiation is carried out at the high temperature range ({>=} 350 K) interstitial and vacancies are both mobile (1,2,5). In this latter case the vacancy interstitial mutual annihilation becomes effective due to their high mobility, but other stable defects may be produced. It is also well known that by mechanical polishing, electrochemical polishing, sputtering, radiation damage, annealing among others, the surface of metal specimens may be modified. Several techniques have been used to follow the polishing and irradiation-induced damage in copper and other metals and alloys. Positron annihilation spectroscopy (PAS), High voltage electron microscopy (HVEM), Resistivity as a function of fluence, X-ray diffraction (XRD) measurements are among others used to these purposes. Particularly, PAS is one of these techniques that is only sensitive to free volume vacancies, being of paramount importance in studies of point defects. Within this area, preliminary PAS and XRD results on the characterization of the electron irradiation-induced defects and the polishing induced deformation on copper are presented. (Author)

  14. Studies of electron-beam irradiation on ethylene-styrene interpolymers

    CERN Document Server

    Liu, I C

    2002-01-01

    Electron-beam irradiation-induced structural and properties changes on ethylene-styrene interpolymers (ESI) have been studied at electron doses ranging from 0 to 200 kGy. The amounts of species generated by irradiation such as hydroxyls, hydroperoxides, carbonyls and unsaturated double bonds have been analyzed using ATR-FTIR. While the structural changes are minimal for ESI69 comprising 69 wt.% styrene regardless of the dose level, the changes for ESI40 comprising 40 wt.% styrene are dose dependent and reaches a maximum at a dose of 100 kGy. Gel permeation chromatography analysis indicates that macromolecular chain scission occurs at low irradiation dose and crosslinking dominates at high irradiation doses. The average molecular weights between crosslinks, M sub C 's, have been calculated using the Flory-Rehner equation based on data collected from solvent extraction experiments. The M sub C 's of ESI40 samples are much smaller than those of ESI69 samples. Irradiated ESI samples have higher glass transition t...

  15. Degradation and annealing studies on gamma rays irradiated COTS PPD CISs at different dose rates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zujun, E-mail: wangzujun@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Ma, Yingwu [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Liu, Jing [School of Materials Science and Engineering, Xiangtan University, Xiangtan, 411105 Hunan (China); Xue, Yuan; He, Baoping; Yao, Zhibin; Huang, Shaoyan; Liu, Minbo; Sheng, Jiangkun [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China)

    2016-06-01

    The degradation and annealing studies on Colbalt-60 gamma-rays irradiated commercial-off-the-shelf (COTS) pinned photodiode (PPD) CMOS image sensors (CISs) at the various dose rates are presented. The irradiation experiments of COTS PPD CISs are carried out at 0.3, 3.0 and 30.0 rad(Si)/s. The COTS PPD CISs are manufactured using a standard 0.18-μm CMOS technology with four-transistor pixel PPD architecture. The behavior of the tested CISs shows a remarkable degradation after irradiation and differs in the dose rates. The dark current, dark signal non-uniformity (DSNU), random noise, saturation output, signal to noise ratio (SNR), and dynamic range (DR) versus the total ionizing dose (TID) at the various dose rates are investigated. The tendency of dark current, DSNU, and random noise increase and saturation output, SNR, and DR to decrease at 3.0 rad(Si)/s are far greater than those at 0.3 and 30.0 rad(Si)/s. The damage mechanisms caused by TID irradiation at the various dose rates are also analyzed. The annealing tests are carried out at room temperature with unbiased conditions after irradiation.

  16. Study of optical properties of swift heavy ion irradiated gallium antimonide

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, S.K. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India)]. E-mail: skdubey@physics.mu.ac.in; Dubey, R.L. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India); Yadav, A.D. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India); Jadhav, V. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India); Rao, T.K. Gundu [Regional Sophisticated Instrumentation Centre, IIT Bombay, Mumbai 400 076 (India); Mohanty, T. [Nuclear Science Centre, New Delhi 110 067 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi 110 067 (India)

    2006-03-15

    Gallium antimonide (GaSb) which is a narrow band gap compound semiconductor has received attention because of its potential applications in optoelectronic devices. In the present work, p-type GaSb wafers of <1 0 0> orientation were irradiated with 70 MeV {sup 56}Fe ions at fluences varying from 1 x 10{sup 12} to 1 x 10{sup 14} ions cm{sup -2}. Mid-infrared and Far-infrared Fourier Transform (FT) measurements were carried out to investigate the optical properties of as irradiated and vacuum annealed samples. Mid-infrared Fourier Transform study revealed that the optical absorption of the irradiated samples increases with increasing ion fluence due to increase in irradiation-induced defects. The band gap energy determined from the infrared spectra was found to change from 0.65 to 0.62 eV while for non-irradiated GaSb wafer the corresponding estimate was 0.67 eV. The density of the carrier estimated from the plasma frequency ({omega} {sub p}) was found to vary from 2.05 x 10{sup 18} to 1.9 x 10{sup 18} cm{sup -3}. The samples annealed in vacuum (10{sup -6} mb) over the temperature range 100-600 deg. C showed the significant damage recovery.

  17. Electron spin resonance studies on PS, PP and PS/PP blends under gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Jacobo E-mail: reyesj@camelot.rect.ucv.ve; Albano, Carmen E-mail: calbano@ivic.vealbanoc@camelot.rect.ucv.ve; Claro, Marjorie; Moronta, Delfin

    2003-06-01

    Electron spin resonance studies on polystyrene (PS), polypropylene (PP) and on 80/20 PS/PP blends with and without compatibilizer (block SBS), at 7.5 wt%, irradiated with gamma rays from a {sup 60}Co source at a dose rate of 4.8 kGy/h and at integral irradiation doses of 10, 25, 50, 60, 70, 400, 800 and 1300 kGy in the presence of air and at room temperature are reported. Dependence of resonance line width, Hpp, resonance line shapes, K, and resonance line intensity, Ipp, on the integral dose of irradiation is investigated. Nature of free radicals after 10 days of air storage is discussed.

  18. Structural study and preliminary biological evaluation on the collagen hydrogel crosslinked by γ-irradiation.

    Science.gov (United States)

    Zhang, Xiangmei; Xu, Ling; Huang, Xin; Wei, Shicheng; Zhai, Maolin

    2012-11-01

    Under γ-irradiation, concentrated collagen solutions yielded collagen hydrogels and liquid products. The molecular structure of collagen hydrogels and the source of the liquid products were studied. Furthermore, preliminary biological properties of the hydrogels were investigated. The results revealed that crosslinking occurred to form collagen hydrogel and the crosslinking density increased with the increasing of the absorbed dose, and the collagen hydrogels showed enhanced mechanical properties. Meanwhile, collagen underwent radiation degradation and water was squeezed out from hydrogel by contraction of hydrogel, yielding liquid products. Collagen hydrogels induced by γ-irradiation maintained the backbone structure of collagen, and tyrosine partially involved in crosslinking. The irradiated collagen hydrogels have higher denatured temperature, can promote fibroblasts proliferation, and their degradation rate in vivo depended on the absorbed dose. The comprehensive results suggested that the collagen hydrogels prepared by radiation crosslinking preserved the triple helical conformation, possessed improved thermal stability and mechanical properties, excellent biocompatibility, which is expected to favor its application as biomaterials.

  19. 1H NMR Study of Polyvinylalcohol Irradiated by Ultra-violet

    Institute of Scientific and Technical Information of China (English)

    Xiu Ling YAN; Wan Fu SUN; Jun TANG; Xin ZHAO

    2005-01-01

    The effect of Ultra-violet light on the structure and motion of the polyvinyl alcohol(PVA) chains was studied by 1H NMR, spin-lattice relaxation and IR spectroscopy. The results indicated that with the increase of irradiation time, the intensity of the polymer hydroxyl proton peaks decreased and finally vanished, which suggested the self-condensation between the hydroxyl groups proceeded. No methyl proton peaks appeared in the spectra after irradiation shows that there is no cleavage of polymer chain. The longer the irradiation time is, the wider the proton peak of the residual water of the solvent is and it shifted toward low field. This result implies that the hydrogen bonds formed between the polymer and the residual water. The absorption peak of hydroxyl group of the polymer moves toward the lower wave number in the IR spectrum that showed the existence of the hydrogen bonds between the PVA macromolecules.

  20. Study on damage of K9 glass under 248nm ultraviolet pulsed laser irradiation

    Science.gov (United States)

    Wang, Xi; Fang, Xiaodong

    2015-04-01

    The damage of K9 glass under 248nm ultraviolet pulsed laser irradiation was studied. The laser pulse energy was kept within the range of 60mJ to 160mJ, and the repetition rate was adjusted within the range of 1Hz to 40Hz. The damage morphologies of single-pulse and multi-pulse laser irradiation were characterized by optical microscope, and the damage mechanism was discussed. The experimental results indicated that the damage of K9 glass irradiated by 248nm ultraviolet laser mainly followed the thermal-mechanical coupling mechanism and the damage threshold of K9 glass was 2.8J/cm2. The intensity of damage area increased gradually with the increase of the laser pulse number. It was shown that accumulation effect of laser induced damage to K9 glass was obvious.

  1. Positron annihilation study of Fe-ion irradiated reactor pressure vessel model alloys

    Science.gov (United States)

    Chen, L.; Li, Z. C.; Schut, H.; Sekimura, N.

    2016-01-01

    The degradation of reactor pressure vessel steels under irradiation, which results from the hardening and embrittlement caused by a high number density of nanometer scale damage, is of increasingly crucial concern for safe nuclear power plant operation and possible reactor lifetime prolongation. In this paper, the radiation damage in model alloys with increasing chemical complexity (Fe, Fe-Cu, Fe-Cu-Si, Fe-Cu-Ni and Fe-Cu-Ni-Mn) has been studied by Positron Annihilation Doppler Broadening spectroscopy after 1.5 MeV Fe-ion implantation at room temperature or high temperature (290 oC). It is found that the room temperature irradiation generally leads to the formation of vacancy-type defects in the Fe matrix. The high temperature irradiation exhibits an additional annealing effect for the radiation damage. Besides the Cu-rich clusters observed by the positron probe, the results show formation of vacancy-Mn complexes for implantation at low temperatures.

  2. The optimization study of Bonner sphere in the epi-thermal neutron irradiation field for BNCT.

    Science.gov (United States)

    Ueda, H; Tanaka, H; Maruhashi, A; Ono, K; Sakurai, Y

    2011-12-01

    The optimization study on the Bonner sphere in the epi-thermal neutron irradiation field for BNCT was done for the moderator material, moderator size, and activation foils as a neutron detector in the sphere. The saturated activity for the activation foil was obtained from the calculated response, and the effective energy range for each Bonner sphere was determined from the saturated activity. We can see that boric acid solution moderator is suitable for the spectrum measurement of a epi-thermal neutron irradiation field.

  3. Study of the spatial distribution of the absorbed dose in blood volumes irradiated using a teletherapy unit

    Energy Technology Data Exchange (ETDEWEB)

    Goes, E.G., E-mail: eggoes@terra.com.b [Regional Blood Center of Ribeirao Preto, Ribeirao Preto, SP (Brazil); Nicolucci, P.; Nali, I.C. [Physics and Mathematics Department, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Pela, C.A.; Bruco, J.L. [Physics and Mathematics Department, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Center of Instrumentation, Dosimetry and Radioprotection, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Borges, J.C. [Center of Instrumentation, Dosimetry and Radioprotection, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Covas, D.T. [Regional Blood Center of Ribeirao Preto, Ribeirao Preto, SP (Brazil); Center for Cell-Based Therapy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP (Brazil)

    2010-06-15

    Blood irradiation can be performed using a dedicated blood irradiator or a teletherapy unit. A thermal device providing appropriate storage conditions during blood components irradiation with a teletherapy unit has been recently proposed. However, the most appropriated volume of the thermal device was not indicated. The goal of this study was to indicate the most appropriated blood volume for irradiation using a teletherapy unit in order to minimize both the dose heterogeneity in the volume and the blood irradiation time using these equipments. Theoretical and experimental methods were used to study the dose distribution in the blood volume irradiated using a linear accelerator and a cobalt-60 therapy machine. The calculation of absorbed doses in the middle plane of cylindrical acrylic volumes was accomplished by a treatment planning system. Experimentally, we also used cylindrical acrylic phantoms and thermoluminescent dosimeters to confirm the calculated doses. The data obtained were represented by isodose curves. We observed that an irradiation volume should have a height of 28 cm and a diameter of 28 cm and a height of 35 cm and a diameter of 35 cm, when the irradiation is to be performed by a linear accelerator and a cobalt-60 teletherapy unit, respectively. Calculated values of relative doses varied from 93% to 100% in the smaller volume, and from 66% to 100% in the largest one. A difference of 5.0%, approximately, was observed between calculated and experimental data. The size of these volumes permits the irradiation of blood bags in only one bath without compromising the homogeneity of the absorbed dose over the irradiated volume. Thus, these irradiation volumes can be recommend to minimize the irradiation time when a teletherapy unit is used to irradiate blood.

  4. Study of the spatial distribution of the absorbed dose in blood volumes irradiated using a teletherapy unit

    Science.gov (United States)

    Góes, E. G.; Nicolucci, P.; Nali, I. C.; Pelá, C. A.; Bruço, J. L.; Borges, J. C.; Covas, D. T.

    2010-06-01

    Blood irradiation can be performed using a dedicated blood irradiator or a teletherapy unit. A thermal device providing appropriate storage conditions during blood components irradiation with a teletherapy unit has been recently proposed. However, the most appropriated volume of the thermal device was not indicated. The goal of this study was to indicate the most appropriated blood volume for irradiation using a teletherapy unit in order to minimize both the dose heterogeneity in the volume and the blood irradiation time using these equipments. Theoretical and experimental methods were used to study the dose distribution in the blood volume irradiated using a linear accelerator and a cobalt-60 therapy machine. The calculation of absorbed doses in the middle plane of cylindrical acrylic volumes was accomplished by a treatment planning system. Experimentally, we also used cylindrical acrylic phantoms and thermoluminescent dosimeters to confirm the calculated doses. The data obtained were represented by isodose curves. We observed that an irradiation volume should have a height of 28 cm and a diameter of 28 cm and a height of 35 cm and a diameter of 35 cm, when the irradiation is to be performed by a linear accelerator and a cobalt-60 teletherapy unit, respectively. Calculated values of relative doses varied from 93% to 100% in the smaller volume, and from 66% to 100% in the largest one. A difference of 5.0%, approximately, was observed between calculated and experimental data. The size of these volumes permits the irradiation of blood bags in only one bath without compromising the homogeneity of the absorbed dose over the irradiated volume. Thus, these irradiation volumes can be recommend to minimize the irradiation time when a teletherapy unit is used to irradiate blood.

  5. DSC studies of retrogradation and amylose-lipid complex transition taking place in gamma irradiated wheat starch

    Energy Technology Data Exchange (ETDEWEB)

    Ciesla, K. [Institute of Nuclear Chemistry and Technology, Dorodna 16 str., 03-195 Warsaw (Poland)], E-mail: kciesla@orange.ichtj.waw.pl; Eliasson, A.C. [Department of Food Technology Engineering and Nutrition, Division of Food Technology, University of Lund, P.O. Box 124, S-221 00 Lund (Sweden)

    2007-12-15

    The effect of gamma irradiation ({sup 60}Co) with doses of 5-30 kGy on the amylose-lipid complex transition and retrogradation occurring in gels containing ca. 50% and ca. 20% wheat starch was studied by differential scanning calorimetry (DSC) during heating-cooling-heating cycles (up to three cycles). Transition of the amylose-lipid complex occurs in all the irradiated samples at a lower temperature as compared to the non-irradiated starch. That effect was larger when the radiation dose was higher. A further thermal treatment causes a decrease of the transition temperature in the irradiated samples, with no effect or increase of that temperature observed for the non-irradiated ones. Irradiation hinders retrogradation taking place in 50% gels but facilitates the process occurring in 20% gels. The differences between the irradiated and the non-irradiated samples are more evident in the every next heating or cooling cycle as well as after storage and in the case of ca. 50% suspensions as compared to ca. 20% suspensions. The results point out to the deterioration of the structure of the complexes formed in the irradiated starch as compared to the non-irradiated one.

  6. Chronic effects of light irradiated from LED on the growth performance and endocrine properties of barfin flounder Verasper moseri.

    Science.gov (United States)

    Takahashi, Akiyoshi; Kasagi, Satoshi; Murakami, Naoto; Furufuji, Sumihisa; Kikuchi, Shigeto; Mizusawa, Kanta; Andoh, Tadashi

    2016-06-01

    We investigated the effects of specific wavelengths of light on the growth of barfin flounder. The fish, reared in white tanks in a dark room, were irradiated with light from light-emitting diodes (LEDs) with peak wavelengths of 464nm (blue), 518nm (green), and 635nm (red) under a controlled photoperiod (10.5:13.5, light-dark cycle; 06:00-16:30, light). Fish were reared for four weeks in three independent experiments at three different water temperatures (averages of 14.9°C, 8.6°C, and 6.6°C). The fish irradiated with blue and green light had higher specific growth rates (% body weight⋅day(-1)) than fish irradiated with red light. Notably, green light had the greatest effect on growth among the three light wavelengths at 6.6°C. In the brains of fish reared at 6.6°C, the amounts of melanin-concentrating hormone 1 mRNA under green light were lower than those under red light, and amounts of proopiomelanocortin-C mRNA under blue and green light were higher than those under red light. No differences were observed for other neuropeptides tested. In the pituitary, no difference was observed in growth hormone mRNA content. In plasma, higher levels of insulin and insulin-like growth factor-I were observed in fish under green light than those of fish under red light. These results suggest that the endocrine systems of barfin flounder are modulated by a specific wavelength of light that stimulates somatic growth.

  7. Relapse Analysis of Irradiated Patients Within the HD15 Trial of the German Hodgkin Study Group

    Energy Technology Data Exchange (ETDEWEB)

    Kriz, Jan; Reinartz, Gabriele [Department of Radiation Oncology, University of Münster, Münster (Germany); Dietlein, Markus; Kobe, Carsten; Kuhnert, Georg [Department of Nuclear Medicine, University of Cologne, Cologne (Germany); Haverkamp, Heinz [First Department of Internal Medicine, University of Cologne, Cologne (Germany); Haverkamp, Uwe [Department of Radiation Oncology, University of Münster, Münster (Germany); Engenhart-Cabillic, Rita [Department of Radiation Oncology, University of Marburg, Marburg (Germany); Herfarth, Klaus [Department of Radiation Oncology, University Heidelberg, Heidelberg (Germany); Lukas, Peter [Department of Radiation Oncology, University of Innsbruck, Innsbruck (Austria); Schmidberger, Heinz [Department of Radiation Oncology, University of Mainz, Mainz (Germany); Staar, Susanne [Department of Radiation Oncology, Klinikum Bremen-Mitte, Bremen (Germany); Hegerfeld, Kira [Department of Radiation Oncology, University of Münster, Münster (Germany); Baues, Christian [Department of Radiation Oncology, University of Cologne, Cologne (Germany); Engert, Andreas [First Department of Internal Medicine, University of Cologne, Cologne (Germany); Eich, Hans Theodor, E-mail: hans.eich@ukmuenster.de [Department of Radiation Oncology, University of Münster, Münster (Germany)

    2015-05-01

    Purpose: To determine, in the setting of advanced-stage of Hodgkin lymphoma (HL), whether relapses occur in the irradiated planning target volume and whether the definition of local radiation therapy (RT) used by the German Hodgkin Study Group (GHSG) is adequate, because there is no harmonization of field and volume definitions among the large cooperative groups in the treatment of advanced-stage HL. Methods and Materials: All patients with residual disease of ≥2.5 cm after multiagent chemotherapy (CTX) were evaluated using additional positron emission tomography (PET), and those with a PET-positive result were irradiated with 30 Gy to the site of residual disease. We re-evaluated all sites of disease before and after CTX, as well as the PET-positive residual tumor that was treated in all relapsed patients. Documentation of radiation therapy (RT), treatment planning procedures, and portal images were carefully analyzed and compared with the centrally recommended RT prescription. The irradiated sites were compared with sites of relapse using follow-up computed tomography scans. Results: A total of 2126 patients were enrolled, and 225 patients (11%) received RT. Radiation therapy documents of 152 irradiated patients (68%) were analyzed, with 28 irradiated patients (11%) relapsing subsequently. Eleven patients (39%) had an in-field relapse, 7 patients (25%) relapsed outside the irradiated volume, and an additional 10 patients (36%) showed mixed in- and out-field relapses. Of 123 patients, 20 (16%) with adequately performed RT relapsed, compared with 7 of 29 patients (24%) with inadequate RT. Conclusions: The frequency and pattern of relapses suggest that local RT to PET-positive residual disease is sufficient for patients in advanced-stage HL. Insufficient safety margins of local RT may contribute to in-field relapses.

  8. Irradiation study of UV Silicon Photomultipliers for the Mu2e calorimeter

    Science.gov (United States)

    Baccaro, S.; Cemmi, A.; Cordelli, M.; Diociaiuti, E.; Donghia, R.; Ferrari, A.; Giovannella, S.; Loreti, S.; Miscetti, S.; Müller, S.; Pillon, M.; Sarra, I.

    2017-02-01

    The Mu2e calorimeter is composed of 1400 un-doped CsI crystals, coupled to large area UV extended Silicon Photomultipliers (SiPMs), arranged in two annular disks. This calorimeter has to provide precise information on energy, timing and position resolutions. It should also be fast enough to handle the high rate background and it must operate and survive in the high radiation environment. Simulation studies estimated that, in the highest irradiated regions, each photo-sensor will absorb a dose of 20 krad and will be exposed to a neutron fluency of 5.5×1011n1 MeV/cm2 in three years of running, with a safety factor of 3 included. At the end of 2015, we have concluded an irradiation campaign at the Frascati Neutron Generator (FNG, Frascati, Italy) measuring the response of two different 16 array models from Hamamatsu, which differ for the protection windows and a SiPM from FBK. In 2016, we have carried out two additional irradiation campaigns with neutrons and photons at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR, Dresden, Germany) and at the Calliope gamma irradiation facility at ENEA-Casaccia, respectively. A negligible increment of the leakage current and no gain change have been observed with the dose irradiation. On the other hand, at the end of the neutron irradiation, the gain does not show large changes whilst the leakage current increases by around a factor of 2000. In these conditions, the too high leakage current makes problematic to bias the SiPMs, thus requiring to cool them down to a running temperature of ~0oC.

  9. Proton irradiation induced defects in GaN: Rutherford backscattering and thermally stimulated current studies

    Science.gov (United States)

    Nakamura, T.; Nishikata, N.; Kamioka, K.; Kuriyama, K.; Kushida, K.

    2016-03-01

    The proton irradiation induced defects in GaN are studied by combining elastic recoil detection analysis (ERDA), thermally stimulated current (TSC), and Rutherford backscattering spectroscopy (RBS) measurements. The proton irradiation (peak concentration: 1.0 × 1015 cm-2) into GaN films with a thickness of 3 μm is performed using a 500 keV implanter. The proton concentration by a TRIM simulation is maximum at 3600 nm in depth, which means that the proton beam almost passes through the GaN film. The carrier concentration decreases three orders of magnitude to 1015 cm-3 by the proton irradiation, suggesting the existence of the proton irradiation-induced defects. The ERDA measurements using the 1.5 MeV helium beam can evaluate hydrogen from the surface to ∼300 nm. The hydrogen concentration at ∼220 nm is ∼8.3 × 1013 cm-2 and ∼1.0 × 1014 cm-2 for un-irradiated and as-irradiated samples, respectively, suggesting that electrical properties are almost not affected by hydrogen. TSC measurements show a broad spectrum at around 110 K which can be divided into three traps, P1 (ionization energy 173 meV), P2 (251 meV), and P3 (330 meV). The peak intensity of P1 is much larger than that of P2 and P3. These traps are related to the N vacancy and/or complex involving N vacancy (P1), neutral Ga vacancy (VGa) (P2), and complex involving VGa (P3). The Ga displacement concentration evaluated by RBS measurements is 1.75 × 1019 cm-3 corresponding to 1/1000 of the Ga concentration in GaN. The observed Ga displacement may be origins of P2 and P3 traps.

  10. Possible Biomarkers of Chronic Stress Induced Exhaustion - A Longitudinal Study.

    Directory of Open Access Journals (Sweden)

    Johanna Wallensten

    Full Text Available Vascular endothelial growth factor (VEGF, epidermal growth factor (EGF and monocyte chemotactic protein-1 (MCP-1 have previously been suggested to be potential biomarkers for chronic stress induced exhaustion. The knowledge about VEGF has increased during the last decades and supports the contention that VEGF plays an important role in stress and depression. There is scarce knowledge on the possible relationship of EGF and MCP-1 in chronic stress and depression. This study further examines the role of VEGF, EGF and MCP-1 in women with chronic stress induced exhaustion and healthy women during a follow-up period of two years.Blood samples were collected from 105 women with chronic stress induced exhaustion on at least 50% sick leave for at least three months, at inclusion (T0, after 12 months (T12 and after 24 months (T24. Blood samples were collected at inclusion (T0 in 116 physically and psychiatrically healthy women. The plasma levels of VEGF, EGF and MCP-1 were analyzed using Biochip Array Technology. Women with chronic stress induced exhaustion had significantly higher plasma levels of VEGF and EGF compared to healthy women at baseline, T12 and at T24. There was no significant difference in plasma levels of MCP-1. Plasma levels of VEGF and EGF decreased significantly in women with chronic stress induced exhaustion during the two years follow-up.The replicated findings of elevated levels of VEGF and EGF in women with chronic stress induced exhaustion and decreasing plasma levels of VEGF and EGF during the two years follow-up add important knowledge to the pathophysiology of chronic stress induced exhaustion.

  11. A study of chronic fatigue in Norwegian cervical cancer survivors.

    Science.gov (United States)

    Steen, Rita; Dahl, Alv A; Hess, Siri Lothe; Kiserud, Cecilie E

    2017-09-01

    Chronic fatigue after treatment is a common adverse event in cancer patients, but there are few studies in long-term survivors of cervical cancer. The aim of this investigation was to explore the prevalence of chronic fatigue and its association with various clinical and treatment-related factors in a population-based cohort of Norwegian cervical cancer survivors treated by any modality. All patients, treated for cervical cancer from 2000 through 2007 in the Health Region of South-Eastern Norway, cancer-free, alive and aged ≤75years by the end 2013 (n=822) received a questionnaire covering chronic fatigue and other clinical variables. 461 of 822 survivors (56%) completed the questionnaire and 382 entered the analyses. Chronic fatigue was reported by 23% (95% confidence interval 19%-27%) with a median age of 52years (range 32-75) at survey, 11years (range 7-15) after diagnosis. Among survivors treated by minimal invasive- or radical surgery, 19% had chronic fatigue, while the prevalence was 28% in those treated with radiation and concomitant chemotherapy (chemoradiation). The chronic fatigue group reported significantly more cardiovascular disease, obesity, less physical activity, more treatment-related symptom experience, more menopausal symptoms, higher levels of anxiety and depressive symptoms, and poorer quality of life than the non-fatigued group. In multivariate analysis only increased level of depression and poorer global quality of life were significantly associated with chronic fatigue. Chronic fatigue was reported by 23% of long-term survivors after cervical cancer at a mean of 11years after treatment. Some of the associated factors are amenable to prevention and/or treatment and should be subjects of attention at follow-up. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Revising the negative meaning of chronic pain - A phenomenological study.

    Science.gov (United States)

    Ojala, Tapio; Häkkinen, Arja; Karppinen, Jaro; Sipilä, Kirsi; Suutama, Timo; Piirainen, Arja

    2015-06-01

    Chronic pain may disable the body, depress the mind and ruin the quality of life. The aim of this study was to use the participants' personal experiences to explore the meaning of the experience of chronic pain and to find successful ways to manage chronic pain. Thirty-four participants with chronic pain were interviewed. The transcribed interviews were analysed using Giorgi's phenomenological method consisting of four phases: (1) reading the transcriptions several times, (2) discriminating meaning units, (3) collecting meaning units into groups and (4) the synthesis. The participants stated that the key to managing chronic pain was to reconsider the individual meaning of the experience of pain. As a result of the interviews, seven subthemes were found based on the 'Negativity of chronic pain', namely, 'State of reflection', 'Reconsidering values', 'Acceptance of pain', 'Support network', 'Altered self', 'Joys in life' and 'Pain dissociation'. Pain is an aversive sensation, which leads to the conclusion that the meaning of the experience is also negative, but it can be reversed. In clinical practice, the focus should be on revising the subjective meaning of pain in order to manage pain and to restore positivity in personal life. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. A study on the irradiation embrittlement and recovery characteristics of light water reactor pressure vessel steels

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Se Hwan; Hong, Jun Hwa; Lee, Bong Sang; Oh, Jong Myung; Song, Sook Hyang; Milan, Brumovsky [NRI Czech (Czech Republic)

    1999-03-01

    The neutron irradiation embrittlement phenomenon of light water RPV steels greatly affects the life span for safe operation of a reactor. Reliable evaluation and prediction of the embrittlement of RPV steels, especially of aged reactors, are of importance to the safe operation of a reactor. In addition, the thermal recovery of embrittled RPV has been recognized as an option for life extension. This study aimed to tracer/refine available technologies for embrittlement characterization and prediction, to prepare relevant materials for several domestic RPV steels of the embrittlement and recovery, and to find out possible remedy for steel property betterment. Small specimen test techniques, magnetic measurement techniques, and the Meechan and Brinkmann's recovery curve analysis method were examined/applied as the evaluation techniques. Results revealed a high irradiation sensitivity in YG 3 RPV steel. Further extended study may be urgently needed. Both the small specimen test technique for the direct determination of fracture toughness, and the magnetic measurement technique for embrittlement evaluation appeared to be continued for the technical improvement and data base preparation. Manufacturing process relevant to the heat treatment appeared to be improved in lowering the irradiation sensitivity of the steel. Further study is needed especially in applying the present techniques to the new structural materials under new irradiation environment of advanced reactors. (author)

  14. Preliminary feasibility study on production of cobalt-60 source for industrial irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Po Kook; Park, Kyung Bae; Ahn, Yun Soo; Lee, Jong Tai; Kim, Hark Rho

    1999-05-01

    As there is a high possible demand of industrial Co-60 source in the world market, feasibility study of a project was performed to produce and to export Co-60 sources, utilizing KEPCO's Wolsung NPP for irradiation of cobalt and KAERI's hot-cells for fabrication of cobalt sources. Main concerns of the study were to understand irradiation and fabrication (encapsulation) processes and to examine related technologies, required facilities and equipment. In particular, it was examined intensively if it would be possible to modify facilities around the reactor vessel of Wolsung NPP tp substantiate the related licensing in order to irradiate cobalt in the reactor. It is expected that once, if cooperation scheme with MDS Nordion of Canada is established, main issues such as modification of facilities, related licensing, raw material procurement and technology transfer for high quality product will be solved. In order to review overall feasibility of the project, present status and prospect of the world market was surveyed and various usages of cobalt sources were reviewed with emphasis on possible demand increase per usage. Food poisoning accidents are prevailing worldwide and food irradiation with cobalt sources is considered as a promising measure to prevent them and may bring forth high increase of cobalt sources demand in the world market. Preliminary economic feasibility was studied in conservation, evaluating roughly the investment and the operating cost based on materials from various information sources. (author)

  15. Graft irradiation in the treatment of acute rejection of renal transplants: a randomized study

    Energy Technology Data Exchange (ETDEWEB)

    Pilepich, M.V.; Anderson, C.B.; Etheredge, E.E.; Sicard, G.A.; Melzer, J.S.; Blum, J.

    1982-05-01

    A randomized study of graft irradiation in the treatment of acute rejection of renal transplants was conducted from 1978 to 1981. Patients developing clinical signs of an acute graft rejection received customary antirejection treatment in the form of intravenous administration of high-dose (1 gm per day) of methylprednisolone. They were at the same time randomized to either receive therapeutic irradiation (175 rad every other day to a total of 525 rad) or sham irradiation. Neither the patient nor the Transplant Service surgeons knew at any time whether the radiation treatment had been given. Eighty-three rejection episodes occurring in 64 grafts were entered into the study. Acute rejection was reversed in 84.5% of grafts in the control and 75% in the treated group. The incidence of recurrent rejection was higher in the treated group (66 vs. 46%) and graft survival was lower (22% vs. 54%). The study failed to demonstrate a beneficial effect of graft irradiation in the treatment of acute renal allograft rejection, when used in conjunction with high dose steriods.

  16. Studies on effects of ionizing irradiation to structural modification of Carbohydrate-complex under each radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Lim, S. T.; Lee, J. H.; Kim, H. N.; Baik, B. Y.; Lee, S. Y

    2009-02-15

    The structural changes of starches were occurred by irradiation. Purposes of this study were to reveal the mechanism of irradiation with gamma ray effects on the structural changes of starches. As the irradiation dose increased, molecular weight of starch molecules and viscosity of starches decreased. However, crystalline structure didn't affected by irradiation. Under the low moisture contents(5%), structural changes(molecular degradation and reduction of digestibility) were severe. At pH 8 or 5% salt concentration, reduction of molecular weight, viscosity, gelation and retrogradation rate were examined. Cross linked starches exhibited the pasting properties and increasing viscosity in proportional to irradiation dose. No changes on crystalline region in starches could be confirmed by results of melting enthalpy. It could be suggested the novel starches which were resistant starches having pasting properties were produced by irradiation.

  17. Effects of polypeptide from Chlamys farreri on amino acid content in guinea pig skin irradiated by chronic ultraviolet A and B

    Institute of Scientific and Technical Information of China (English)

    YU Guoying; CAO Pengli; GUO Kun; WANG Yuejun; SUN Mi; WANG Chunbo

    2004-01-01

    We examined the effects of polypeptide from Chlamys farreri (PCF) on the amount of hydroxyproline in guinea pig skin irradiated by chronic ultraviolet A (UVA) and ultraviolet B (UVB) radiation. PCF was applied locally before repeated exposure of guinea pig to UVA and UVB. The contents of hydroxyproline and other amino acids in guinea pig skin were determined by automatic amino acid analyzer. Our results showed that: (1) long-time UVA and UVB radiation can reduce dramatically the amounts of hydroxyproline, aspartic acid, threonine, glycine, phenylalanine and lysine in guinea pig skin in comparison with the control group (P < 0.05); (2) Compared with model group, pre-treatment with 5 % and 20 % PCF prior to UVA and UVB radiation can inhibit the decline of amino acids content in guinea pig skin in a dose-dependent manner (P < 0.05). As the decrease of hydroxyproline, glycine and lysine contents in the skin directly reflexes type I collagen degeneration, our results indicated that the chronic application of PCF can protect skin type I collagen against UV radiation, and thus protect skin from photoaging.

  18. Irradiation-induced defects in InN and GaN studied with positron annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Reurings, Floris; Tuomisto, Filip [Department of Applied Physics, Aalto University, Espoo (Finland); Egger, Werner; Loewe, Benjamin [Institut fuer Angewandte Physik und Messtechnik, Universitaet der Bundeswehr Muenchen, Neubiberg (Germany); Ravelli, Luca [Dipartimento di Fisica, Universita degli studi di Trento, Povo (Italy); Sojak, Stanislav [Department of Nuclear Physics and Technology, Slovak University of Technology in Bratislava (Slovakia); Liliental-Weber, Zuzanna; Jones, Rebecca E.; Yu, Kin M.; Walukiewicz, Wladek [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Schaff, William J. [Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY (United States)

    2010-05-15

    We use positron annihilation to study 2-MeV {sup 4}He{sup +} irradiated and subsequently rapid-thermal-annealed InN grown by molecular-beam epitaxy and GaN grown by metal-organic chemical-vapour deposition. The irradiation fluences were in the range 5 x 10{sup 14}-2 x 10{sup 16}cm{sup -2}. In vacancies are introduced in the irradiation at a low rate of 100 cm{sup -1}, with their concentration saturating in the mid-10{sup 17} cm{sup -3} range at an irradiation fluence of 2 x 10{sup 15} cm{sup -2}. The annealing, performed at temperatures between 425 and 475 C, is observed to result in an inhomogeneous redistribution of the In vacancies. The behaviour is opposite to GaN, where Ga vacancies are introduced at a much higher rate of 3600 cm{sup -1} showing no detectable saturation. About half of the Ga vacancies are found to recover in the annealing, in agreement with previous studies, while the remaining Ga vacancies undergo no spatial redistribution. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  19. In-situ Study of Nanostructure and Electrical Resistance of Nanocluster Films Irradiated with Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Weilin; Sundararajan, Jennifer A.; Varga, Tamas; Bowden, Mark E.; Qiang, You; McCloy, John S.; Henager, Charles H.; Montgomery, Robert O.

    2014-08-11

    An in-situ study is reported on the structural evolution in nanocluster films under He+ ion irradiation using an advanced helium ion microscope. The films consist of loosely interconnected nanoclusters of magnetite or iron-magnetite (Fe-Fe3O4) core-shells. The nanostructure is observed to undergo dramatic changes under ion-beam irradiation, featuring grain growth, phase transition, particle aggregation, and formation of nanowire-like network and nano-pores. Studies based on ion irradiation, thermal annealing and election irradiation have indicated that the major structural evolution is activated by elastic nuclear collisions, while both electronic and thermal processes can play a significant role once the evolution starts. The electrical resistance of the Fe-Fe3O4 films measured in situ exhibits a super-exponential decay with dose. The behavior suggests that the nanocluster films possess an intrinsic merit for development of an advanced online monitor for neutron radiation with both high detection sensitivity and long-term applicability, which can enhance safety measures in many nuclear operations.

  20. Ultrasonic study of point defects in electron-irradiated p-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, W.L.

    1987-01-01

    The mechanisms of interaction of ultrasonic waves with point defects in crystals are reviewed, and a perturbation approach is introduced that leads to general expressions for the resonance and relaxation strengths in terms of matrix elements of the ultrasonic perturbation. These expressions provide the basis for a discussion of the polarization dependence of resonance and relaxation. Selection rules for cubic crystals are presented. An exploratory ultrasonic study is performed on electron-irradiated B-doped and Al-doped silicon. Neutral substitutional boron is detected before irradiation, as expected from previous ultrasonic studies on unirradiated silicon. This defect produces both resonance and relaxation. Similar effects are observed for substitutional aluminum. After irradiation, a relaxation is observed when the sample is exposed to 0.18-0.39 eV light. By comparison with previous EPR results, this relaxation is identified as the singly positively charged state of the vacancy, V/sup +/. Preliminary results on the relaxation time and strength of V/sup +/ suggest that it may have several populated vibronic levels. Another relaxation is observed in irradiated Al-doped silicon when the sample is exposed to white light. From its annealing behavior and dopant dependence, it is identified as a nonequilibrium charge state of interstitial aluminum.

  1. Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

    1998-05-01

    The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

  2. [Chronic prostatitis/chronic pelvic pain syndrome. Influence of osteopathic treatment - a randomized controlled study].

    Science.gov (United States)

    Marx, S; Cimniak, U; Beckert, R; Schwerla, F; Resch, K L

    2009-11-01

    Prostatitis is the most common urological disease in males under [corrected] the age of 50 years old. As bacteria are detected in only prostatitis. The symptoms of this problem complex, often described as chronic prostatitis and chronic pelvic pain syndrome (CP-CPPS), seem to be multifactorial so that an improvement can only rarely be achieved with conventional forms of therapy. The aim of this study was to investigate whether osteopathic treatment can influence the symptoms of CP-CPPS (randomized controlled study, 5 sessions, follow-up after 6 weeks and 1.5 years without treatment). The study was carried out in a practice for osteopathy. Patients were recruited by referral from urologists, newspaper articles and lectures on the topic. A total of 35 males with medically diagnosed CP-CPPS aged 29-70 years old took part in the study. Of the patients 20 were allocated to the treatment group and 15 to the placebo group whereby 2 patients had to retire from the study prematurely. Patients in the treatment group received 5 osteopathic treatment sessions separated by 1 week at the beginning and by up to 3 weeks at the end (total period 8 weeks). The osteopathic dysfunctions of the patients were treated according to the principles of osteopathy. The placebo treatment in the control group consisted of a training program with simple gymnastic and physiotherapeutic exercises. Improvements of the complaints by urination (LUTS), chronic pelvic pain (CPPS) and quality of life (QOL) were measured using the questionnaires for international prostate symptom score (IPSS), the National Institutes of Health chronic prostatitis symptom index (NIH-CPSI) and the quality of life index (QOL). Comparison of the results from the osteopathy and placebo groups revealed statistically significant differences in favor of the osteopathy group (ppatients should be carried out to substantiate these results.

  3. Association of chronic mucus hypersecretion with FEV1 decline and chronic obstructive pulmonary disease morbidity. Copenhagen City Heart Study Group

    DEFF Research Database (Denmark)

    Vestbo, J; Prescott, E; Lange, P

    1996-01-01

    The aim of this study was to examine the association between chronic mucus hypersecretion, and FEV1 decline, and subsequent hospitalization from chronic obstructive pulmonary disease (COPD). We used data from The Copenhagen City Heart Study on 5,354 women and 4,081 men 30 to 79 yr of age with ass......The aim of this study was to examine the association between chronic mucus hypersecretion, and FEV1 decline, and subsequent hospitalization from chronic obstructive pulmonary disease (COPD). We used data from The Copenhagen City Heart Study on 5,354 women and 4,081 men 30 to 79 yr of age...

  4. Determinants of depression in chronic stroke : A prospective cohort study

    NARCIS (Netherlands)

    van de Port, Ingrid G. L.; Kwakkel, Gert; Bruin, Margje; Lindeman, Eline

    2007-01-01

    Purpose. The aim of the study was to identify factors that are significantly related to depression in chronic stroke patients. Methods. Prospective cohort study of stroke patients admitted for rehabilitation. A total of 165 first ever stroke patients over 18 years of age were assessed at one and thr

  5. HAPD time-resolution study under single-photon irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, S.; Akatsu, M.; Enari, Y.; Fujimoto, K.; Higashino, Y.; Hirose, M.; Hokuue, T.; Inami, K.; Ishikawa, A.; Matsumoto, T.; Misono, K.; Ohshima, T. E-mail: ohshima@hepl.phys.nagoya-u.ac.jp; Sugi, A.; Sugiyama, A.; Suzuki, S.; Tomoto, M

    2001-05-01

    We have studied the timing property of a Hybrid Avalanche PhotoDiode, Hamamatsu R7110U-07, and attained a time resolution of {sigma}{sub t}{approx}150 ps for single photons and {<=}100 ps for a few photons under certain conditions of photocathode voltage and diode reverse bias voltage. Relation between the achievable timing resolution and a multiplication gain is discussed, especially in realizing {sigma}{sub t}{<=}100 ps for single photons.

  6. Study on Fractionated Total Body Irradiation before Hematopoietic Stem Cell Transplantation

    Institute of Scientific and Technical Information of China (English)

    Tong Fang; Bo Liu; Hong Gao

    2009-01-01

    OBJECTIVE To observe the dose and the complications from total body irradiation before hematopoietic stem cell transplantation.METHODS This study involved 312 patients with total body irradiation before hematopoietic stem cell transplantation. They were entered into the treated research from May 1999 to October 2005. All patients had Received the irradiation from 60Co of an absorbed dose rate of (5.2 ± 1.13) cGy/min. The total dose of TBI was 7~12 Gy, 1 f/d × 2 d. A high-dose rate group (≥ 10 Gy) included 139 cases and a low-dose rate group (< 10 Gy) included 173 cases.RESULTS The probability of acute gastrointestinal reactions in the high-dose rate group was more compared with that in the low-dose rate group. The differences for other reactions, such as hematopoietic reconstitution and graft survival rate, between the two groups were insignificant.CONCLUSION Using fractional total body irradiation at a dose rate of 5 cGy/min, with a total dose of 7~12 Gy, 1 f/d x 2 d, with the lung receiving under 7.5 Gy is a safe and effective pretreatment for hematopoietic stem cell transplantation.

  7. A magnetic resonance imaging study on changes in rat mandibular bone marrow and pulp tissue after high-dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wan; Lee, Byung Do [Dept. of Oral and Maxillofacial Radiology and Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Lee, Kang Kyoo [Dept. of Radiation Oncology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju (Korea, Republic of)

    2014-03-15

    This study was designed to evaluate whether magnetic resonance imaging (MRI) is appropriate for detecting early changes in the mandibular bone marrow and pulp tissue of rats after high-dose irradiation. The right mandibles of Sprague-Dawley rats were irradiated with 10 Gy (Group 1, n=5) and 20 Gy (Group 2, n=5). Five non-irradiated animals were used as controls. The MR images of rat mandibles were obtained before irradiation and once a week until week 4 after irradiation. From the MR images, the signal intensity (SI) of the mandibular bone marrow and pulp tissue of the incisor was interpreted. The MR images were compared with the histopathologic findings. The SI of the mandibular bone marrow had decreased on T2-weighted MR images. There was little difference between Groups 1 and 2. The SI of the irradiated groups appeared to be lower than that of the control group. The histopathologic findings showed that the trabecular bone in the irradiated group had increased. The SI of the irradiated pulp tissue had decreased on T2-weighted MR images. However, the SI of the MR images in Group 2 was high in the atrophic pulp of the incisor apex at week 2 after irradiation. These patterns seen on MRI in rat bone marrow and pulp tissue were consistent with histopathologic findings. They may be useful to assess radiogenic sclerotic changes in rat mandibular bone marrow.

  8. Fludarabine Phosphate and Total-Body Irradiation Before Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Chronic Lymphocytic Leukemia or Small Lymphocytic Leukemia

    Science.gov (United States)

    2016-07-18

    B-Cell Prolymphocytic Leukemia; Chronic Lymphocytic Leukemia; Prolymphocytic Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; T-Cell Prolymphocytic Leukemia

  9. Viscosity changes in hyaluronic acid: Irradiation and rheological studies

    Energy Technology Data Exchange (ETDEWEB)

    Daar, Eman [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: e.daar@surrey.ac.uk; King, L.; Nisbet, A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Thorpe, R.B. [Fluids and Systems Centre, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2010-04-15

    Hyaluronic acid (HA) is a significant component of the extracellular matrix (ECM), particular interest being shown herein in synovial fluid. The present study aims to investigate the degrading effects of X-ray radiation on HA at radiotherapy doses. Measurements of viscosity and shear stresses on HA solutions have been made at different shear rates using various types of viscometer for different concentrations in the range 0.01-1% w/v of HA. The HA has been subjected to doses of 6 MV photon radiation ranging from 0 to 20 Gy, the major emphasis being on doses below 5 Gy. It is found that there is a dose-dependent relationship between viscosity and shear rate, viscosity reducing with radiation dose, this being related to polymer scissions via the action of radiation-induced free radicals. The dependency appears to become weaker at higher concentrations, possibly due to the contribution to viscosity from polymer entanglement becoming dominant over that from mean molecular weight. Present results, for HA solutions in the concentration range 0.01% to 1% w/v, show reduced viscosity with dose over the range 0-4 Gy, the latter covering the dose regime of interest in fractionated radiotherapy. The work also shows agreement with previous Raman microspectrometry findings by others, the possible bond alterations being defined by comparison with available published data.

  10. Study of the degradation process of polyimide induced by high energetic ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Severin, Daniel

    2008-09-19

    The dissertation focuses on the radiation hardness of Kapton under extreme radiation environment conditions. To study ion-beam induced modifications, Kapton foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (e.g. Ti, Mo, Au, and U) within a large fluence regime (1 x 10{sup 10}-5 x 10{sup 12} ions/cm{sup 2}). The irradiated Kapton foils were analysed by means of infrared and UV/Vis spectroscopy, tensile strength measurement, mass loss analysis, and dielectric relaxation spectroscopy. For testing the radiation stability of Kapton at the cryogenic operation temperature (5-10 K) of the superconducting magnets, additional irradiation experiments were performed at the Grand Accelerateur National d' Ions Lourds (GANIL, France) focusing on the online analysis of the outgassing process of small volatile degradation fragments. The investigations of the electrical properties analysed by dielectric relaxation spectroscopy exhibit a different trend: high fluence irradiations with light ions (e.g. Ti) lead to a slight increase of the conductivity, whereas heavy ions (e.g. Sm, Au) cause a drastic change already in the fluence regime of nonoverlapping tracks (5 x 10{sup 10} ions/cm{sup 2}). Online analysis of the outgassing process during irradiation at cryogenic temperatures shows the release of a variety of small gaseous molecules (e.g. CO, CO{sub 2}, and short hydro carbons). Also a small amount of large polymer fragments is identified. The results allow the following conclusions which are of special interest for the application of Kapton as insulating material in a high-energetic particle radiation environment. a) The material degradation measured with the optical spectroscopy and tensile strength tests are scalable with the dose deposited by the ions. The high correlation of the results allows the prediction of the mechanical degradation with the simple and non-destructive infrared spectroscopy. The degradation curve points to a

  11. EELS study on BST thin film under electron beam irradiation

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    [11]Yoshiya, M., Tanaka, I., Kaneko, K. et al., First principles calculation of chemical shifts in ELNES/NEXAFS of titanium oxides, J. Phys.: Condens. Matter., 1999, 11: 3217 -3228.[12]Egerton, R. F., Electron Energy-Loss Spectroscopy in the Electron Microscope, New York: Plenum Press,www.scichina.com1996, 245-300.[13]Smyth, D. M., Harmer, M. P., Peng, P., Defect chemistry of relaxor ferroelectrics and the implications for dielectric degradation, J. Am. Ceram. Soc., 1989, 72 (12): 2276-2278.[14]Chan, N. H., Sharma, R. K., Smyth, D. M., Nonstoichiometry in undoped BaTiO3, J. Am. Ceram. Soc., 1981,64 (9): 556-562.[15]Leapman, R. D., Grunes, L. A., Fejes, P. L., Study of the L23 edges in the 3d transition metals and their oxides by electron-energy-loss spectroscopy with comparisons to theory, Phys. Rev. B, 1982, 26: 614-435.[16]Otten, M. T., Buseck, P. R., The oxidation state of Ti in hornblende and biotite determined by electron energy-loss spectroscopy, with inferences regarding the Ti substitution, Phys. Chem. Miner., 1987, 14:45 -51.[17]Sankararaman, M., Perry, D., Valence determination of titanium and iron using electron energy loss spectroscopy, J. Mater. Sci., 1992, 27: 2731-2733.[18]Lusvardi, V. S., Barteau, M. A., Chen, J. G. et al., An NEXAFS investigation of the reduction and reoxidation of TiO2 (001), Surf. Sci., 1998, 397: 237-250.[1]Kingon, A. I., Streiffer, S. K., Basceri, C. et al., High-permittivity perovskite thin films for dynamic random-access memories, MRS Bull., 1996, 21: 46-52.[2]Kingon, A. I., Maria, J. P., Streiffer, S. K., Alternative dielectrics to silicon dioxide for memory and logic devices, Nature (London), 2000, 406: 1032-1038.[3]Stemmer, S., Hoche, T., Keding, R. et al., Oxidation states of titanium in bulk barium titanates and in (100) fiber-textured (BaxSr1- x)Ti1+ yO3+ z thin films, Appl. Phys. Lett., 2001, 79:3149-3151.[4]Stemmer, S., Streiffer, S. K., Browning, N. D. et al., Grain

  12. Comparative study on sulphur reduction from heavy petroleum - Solvent extraction and microwave irradiation approach

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, Abdullahi Dyadya; Isah, Abubakar Garba; Umaru, Musa; Ahmed, Shehu [Department of Chemical Engineering, Federal University of Technology, P.M.B 65, Minna (Nigeria); Abdullahi, Yababa Nma [National Petroleum Investment Management Services (Nigeria National Petroleum Corporation), Lagos (Nigeria)

    2012-07-01

    Sulphur- containing compounds in heavy crude oils are undesirable in refining process as they affect the quality of the final product, cause catalyst poisoning and deactivation in catalytic converters as well as causing corrosion problems in oil pipelines, pumps and refining equipment aside environmental pollution from their combustion and high processing cost. Sulphur reduction has being studied using microwave irradiation set at 300W for 10 and 15minutes and oxidative- solvent extraction method using n- heptane and methanol by 1:1, 1:2 and 1:3 crude- solvent ratios after being oxidized with hydrogen peroxide, H2O2 oxidants. Percentage sulphur removal with n- heptane solvent by 1:1 and 1:2 are 81.73 and 85.47%; but extraction using methanol by different observed ratios gave less sulphur reduction. Indeed when microwave irradiated at 300W for 10 and 15minutes, 53.68 and 78.45% reduction were achieved. This indicates that microwave irradiation had caused oxidation by air in the oven cavity and results to formation of alkyl radicals and sulphoxide from sulphur compound in the petroleum. The prevailing sulphur found in the crude going by FT-IR results is sulphides which oxidized to sulphoxide or sulphones. It is clear that sulphur extraction with heptane is more efficient than microwave irradiation but economically due to demands for solvent and its industrial usage microwave irradiation can serve as alternative substitute for sulphur reduction in petroleum. Sulphur reduction by microwave radiation should be up- scaled from laboratory to a pilot plant without involving extraction column in the refining.

  13. Comparative study on sulphur reduction from heavy petroleum - Solvent extraction and microwave irradiation approach

    Directory of Open Access Journals (Sweden)

    Abdullahi Dyadya Mohammed, Abubakar Garba Isah, Musa Umaru, Shehu Ahmed, Yababa Nma Abdullahi

    2012-01-01

    Full Text Available Sulphur- containing compounds in heavy crude oils are undesirable in refining process as they affect the quality of the final product, cause catalyst poisoning and deactivation in catalytic converters as well as causing corrosion problems in oil pipelines, pumps and refining equipment aside environmental pollution from their combustion and high processing cost. Sulphur reduction has being studied using microwave irradiation set at 300W for 10 and 15minutes and oxidative- solvent extraction method using n- heptane and methanol by 1:1, 1:2 and 1:3 crude- solvent ratios after being oxidized with hydrogen peroxide, H2O2 oxidants. Percentage sulphur removal with n- heptane solvent by 1:1 and 1:2 are 81.73 and 85.47%; but extraction using methanol by different observed ratios gave less sulphur reduction. Indeed when microwave irradiated at 300W for 10 and 15minutes, 53.68 and 78.45% reduction were achieved. This indicates that microwave irradiation had caused oxidation by air in the oven cavity and results to formation of alkyl radicals and sulphoxide from sulphur compound in the petroleum. The prevailing sulphur found in the crude going by FT-IR results is sulphides which oxidized to sulphoxide or sulphones. It is clear that sulphur extraction with heptane is more efficient than microwave irradiation but economically due to demands for solvent and its industrial usage microwave irradiation can serve as alternative substitute for sulphur reduction in petroleum. Sulphur reduction by microwave radiation should be up- scaled from laboratory to a pilot plant without involving extraction column in the refining.

  14. Morphometric Study of the Irradiation Effect on the Cartilage Formation in the Rat Mandibular Condyle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Hwa; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1999-02-15

    This study was undertaken to quantitatively estimate the degree of the damage and recovery of the irradiated rat condylar cartilage using the Image Analyzer. Experimental animals were 16 male rats of the Sprague-Dawley strain at the age of 20 day irradiated with the dose of 10 Gy in their head and neck region. Four rats were sacrificed at the each of the following time intervals - 1, 4, 7 and 14 days, respectively. The same number of control group animals were sacrificed at the each age of 21, 24, 27 and 34 days, respectively. The specimens were stained with 0.5% toluidine blue and examined with light microscope. The condylar cartilage was divided into 4 zones; fibrous zone, proliferating zone, upper hypertrophic zone, and lower hypertrophic zone. And then, the proliferating zone was subdivided into 2 layers - upper and lower layer, and upper and lower hypertrophic zone were subdivided into three layers, respectively - upper, middle and lower layer. With the aid of Image Analyzer, morphometric analysis was performed. The thickness, the numerical density of cells, the cell area density, the extracellular matrix area density, the mean area of single cell, the mean area of extracellular matrix per single cell were measured and analysed. In the experimental group, the thickness of the fibrous zone was slightly increased and that of the proliferating zone and the upper and the lower hypertrophic zone was markedly decreased. With time, the thickness of the fibrous zone was gradually increased and that of the proliferating zone and the upper and the lower hypertrophic zone was steadily in the decreased state. The numerical density of cells of the proliferating zone was increased on post-irradiated 1 day, but decreased after post-irradiated 4 day, and that of the upper hypertrophic zone was decreased. The numerical density of cells of the lower hypertrophic zone was decreased in the early stage and then was decreased or not significantly different from that of the control

  15. In situ heavy ion irradiation studies of nanopore shrinkage and enhanced radiation tolerance of nanoporous Au

    Science.gov (United States)

    Li, Jin; Fan, C.; Ding, J.; Xue, S.; Chen, Y.; Li, Q.; Wang, H.; Zhang, X.

    2017-01-01

    High energy particle radiations induce severe microstructural damage in metallic materials. Nanoporous materials with a giant surface-to-volume ratio may alleviate radiation damage in irradiated metallic materials as free surface are defect sinks. Here we show, by using in situ Kr ion irradiation in a transmission electron microscope at room temperature, that nanoporous Au indeed has significantly improved radiation tolerance comparing with coarse-grained, fully dense Au. In situ studies show that nanopores can absorb and eliminate a large number of radiation-induced defect clusters. Meanwhile, nanopores shrink (self-heal) during radiation, and their shrinkage rate is pore size dependent. Furthermore, the in situ studies show dose-rate-dependent diffusivity of defect clusters. This study sheds light on the design of radiation-tolerant nanoporous metallic materials for advanced nuclear reactor applications.

  16. Ferritin and iron studies in anaemia and chronic disease.

    Science.gov (United States)

    Peng, Ying Y; Uprichard, James

    2017-01-01

    Anaemia is a condition in which the number of red cells necessary to meet the body's physiological requirements is insufficient. Iron deficiency anaemia and the anaemia of chronic disease are the two most common causes of anaemia worldwide;(1) iron homeostasis plays a pivotal role in the pathogenesis of both diseases. An understanding of how iron studies can be used to distinguish between these diseases is therefore essential not only for diagnosis but also in guiding management. This review will primarily focus on iron deficiency anaemia and anaemia of chronic disease; however, iron overload in anaemia will also be briefly discussed.

  17. Brain shrinkage in chronic alcoholics: a pathological study.

    Science.gov (United States)

    Harper, C G; Kril, J J; Holloway, R L

    1985-02-16

    A quantitative neuropathological necropsy study of 22 control and 22 chronic alcoholic subjects showed a statistically significant loss of brain tissue in the chronic alcoholic group. The loss of tissue appeared to be from the white matter of the cerebral hemispheres rather than the cerebral cortex. This may reflect a primary alteration in the composition or structure of the white matter or it may be secondary to loss of nerve cells from the cortex with subsequent degeneration of the axons in the white matter. Further morphometric analyses including cortical neuronal counts will be necessary to clarify this issue.

  18. Dutch transmural nurse clinics for chronic patients: a descriptive study.

    NARCIS (Netherlands)

    Temmink, D.; Francke, A.L.; Kerkstra, A.; Huyer Abu-Saad, H.

    2000-01-01

    'Transmural care' can be defined as patient-tailored care provided on the basis of close collaboration and joint responsibility between hospitals and home care organizations. One form of transmural care is transmural nurse clinics for chronically ill. This study describes 62 transmural nurse clinics

  19. Effects of post-irradiation annealing and re-irradiation on microstructure in surveillance test specimens of the Loviisa-1 reactor studied by atom probe tomography and positron annihilation

    Science.gov (United States)

    Toyama, T.; Kuramoto, A.; Nagai, Y.; Inoue, K.; Nozawa, Y.; Shimizu, Y.; Matsukawa, Y.; Hasegawa, M.; Valo, M.

    2014-06-01

    This paper presents a microstructural study of a surveillance test specimen from the Loviisa-1 reactor in Finland, which is a Russian-type pressurized water reactor (VVER-440), after initial irradiation to a neutron fluence of 2.5 × 1019 n/cm2 (E > 1 MeV), post-irradiation annealing at 475 °C for 100 h and re-irradiation to three different fluences up to 2.7 × 1019 n/cm2. Atom probe tomography (APT) and positron annihilation spectroscopy (PAS) were used to characterize the test specimens. APT results showed the formation of Cu-rich solute clusters (SCs) during the initial irradiation and their subsequent coarsening during annealing. After re-irradiation, a small number of SCs formed once again. The hardening due to the SCs was estimated using the Russell-Brown model based on the APT results, and was in good agreement with the measured hardening after the initial irradiation and post-irradiation annealing. In contrast, during the first-step of re-irradiation, the estimated hardening due to the SCs was smaller than the measured hardening. This suggested that the hardening after re-irradiation was due to some microstructure other than the observed SCs. This difference was attributed to newly-formed matrix defects during re-irradiation, which was supported by the PAS results. However in subsequent steps of re-irradiation, the hardening was almost constant.

  20. Exploratory study of the prognostic value of microenvironmental parameters during fractionated irradiation in human squamous cell carcinoma xenografts.

    Science.gov (United States)

    Yaromina, Ala; Kroeber, Theresa; Meinzer, Andreas; Boeke, Simon; Thames, Howard; Baumann, Michael; Zips, Daniel

    2011-07-15

    To explore the prognostic value of microenvironmental parameters for local tumor control determined before and during fractionated irradiation. Six human squamous cell carcinoma (hSCC) lines were transplanted subcutaneously into the right hind leg of nude mice. Tumors were irradiated with 30 fractions within 6 weeks. Local tumor control was determined 120 days after irradiation. Radiation response was quantified as dose to cure 50% of tumors (TCD(50)). In parallel, untreated and irradiated tumors were excised after injection of pimonidazole (hypoxia marker) and Hoechst 33342 (perfusion marker) for histological evaluation. Pimonidazole hypoxia decreased during fractionated irradiation in the majority of tumor lines. Fraction of perfused vessels and vascular area showed modest changes during fractionated irradiation. Histological parameters before treatment and after three and five fractions did not significantly correlate with TCD(50) after irradiation with 30 fractions within 6 weeks (p > 0.05). Hypoxic volume and perfused vessels after 10 fractions showed a significant association with local tumor control after fractionated irradiation (p = 0.018 and p = 0.019, respectively). None of these parameters remained statistically significant when the p value was adjusted for multiple comparisons. The results from this exploratory study suggest that determination of microenvironmental parameters during treatment provides better prognostic information for the outcome after fractionated radiotherapy than pretreatment parameters, which warrants further investigation and confirmation in experimental and clinical studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Luminescence, optical and laser Raman scattering studies on γ -irradiated terbium-doped potassium iodide crystals

    Science.gov (United States)

    Bangaru, S.

    2011-02-01

    This paper reports the thermoluminescence (TL), optical absorption and other laser Raman scattering studies performed on terbium-doped KI crystals γ-irradiated at room temperature. Photoluminescence studies confirm the presence of terbium ions in the KI matrix in their trivalent form. Formation of V3- and Z1-centres on F-bleaching of γ-irradiated crystals was observed. The characteristic emission due to Tb3+ ions in the spectral distribution under optically stimulated emission and TL emission confirms the participation of the Tb3+ ions in the recombination process. The Raman bands were identified as the totally symmetric vibration modes of f.c.c. species KI:Tb3+.

  2. CCE measurements and annealing studies on proton-irradiated p-type MCz silicon diodes

    CERN Document Server

    Hoedlmoser, H; Köhler, M; Nordlund, H

    2007-01-01

    Magnetic Czochralski (MCz) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of p-type MCz Silicon diodes irradiated with protons up to a fluence of has been performed by means of Charge Collection Efficiency (CCE) measurements as well as standard CV/IV characterizations. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. A subsequent annealing study of the irradiated detectors shows an increase in effective doping concentration and a decrease in the leakage current, whereas the CCE remains basically unchanged. Two different series of detectors have been compared differing in the implantation dose of p-spray isolation as well as effective doping concentration (Neff) of the p-type bulk presumably due to a difference in thermal donor (TD) activation during processing. The series with the higher concentration of TDs shows a delayed reverse annealing of Neff after irradia...

  3. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis,modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC).The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000- 30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.

  4. A Position Annihilation Study of Defect Recovery in Electron-Irradiated alpha-Zr

    DEFF Research Database (Denmark)

    Hood, G. M.; Eldrup, Morten Mostgaard; Mogensen, O. E.

    1977-01-01

    The presence of vacancy defects in α-Zr, irradiated at 320 > T > 290 K with 1.5 MeV electrons, has been indicated by positron annihilation measurements. It was found that positron lifetimes associated with annihilation in well-annealed α-Zr, fell in the range 173 to 181 psec, with no obvious...... dependence on the sample purity or grain size (down to 10 microns). After irradiation, however, the mean lifetime increase-associated with defect trapping-was found to be bigger for lower purity Zr, a result that was emphasized in a multicomponent analysis. Isochronal annealing studies on the less pure Zr...... showed nearly continuous recovery up to 550 K, while other specimens exhibited no measurable recovery below 450 K. Potential effects of particular impurities are considered in terms of their interstitial/substitutional nature, inferred from tracer diffusion studies....

  5. Study of y-irradiated benzothiazole-doped polyvinyl chloride by positron annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Misheva, M. [Faculty of Physics, Sofia Univ. (Bulgaria); Djourelov, N. [Inst. of Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Sertova, N.; Petkov, I.; Deligeorgiev, T. [Faculty of Chemistry, Sofia Univ. (Bulgaria)

    2001-07-01

    Poly(vinyl chloride) (PVC) films containing different (0 / 4) weight percentage of 2-aryl substituted benzothiazole (BT) are studied by positron lifetime and Doppler broadening of annihilation line measurements. The effects of gamma-irradiation dose and of BT contents on positron annihilation parameters are studied. The positron lifetimes and intensities depend on irradiation dose only for BT-doped films. The ortho-positronium intensities for pure and doped PVC decrease with dose increasing in a similar way. The influence of doping is significant only at first doping with 0.125 wt% BT and is weak afterwards. Some of the observed changes of the parameters are explained by the protonation of BT and its conversion into [BTH{sup +}.Cl{sup -}] complexes by the interaction with hydrogen chloride - a product of PVC photodegradation. (orig.)

  6. Retinopathy and Chronic Kidney Disease in the Chronic Renal Insufficiency Cohort Study (CRIC)

    Science.gov (United States)

    Grunwald, Juan E.; Alexander, Judith; Ying, Gui-Shuang; Maguire, Maureen; Daniel, Ebenezer; Whittock-Martin, Revell; Parker, Candace; McWilliams, Kathleen; Lo, Joan C.; Go, Alan; Townsend, Raymond; Gadegbeku, Crystal A.; Lash, James P.; Fink, Jeffrey C.; Rahman, Mahboob; Feldman, Harold; Kusek, John W.; Xie, Dawei; Jaar, Bernard G.

    2013-01-01

    Objectives Retinal vascular and anatomic abnormalities caused by diabetes, hypertension, and other conditions can be observed directly in the ocular fundus and may reflect severity of chronic renal insufficiency. The purpose of this study was to investigate the association between retinopathy and chronic kidney disease (CKD). Methods In this observational, cross-sectional study, 2605 participants of the Chronic Renal Insufficiency Cohort (CRIC) study, a multi-center study of CKD, were offered participation. Non-mydriatic fundus photographs of the disc and macula in both eyes were obtained in 1936 of these subjects. Photographs were reviewed in a masked fashion at a central photograph reading center using standard protocols. Presence and severity of retinopathy (diabetic, hypertensive or other) and vessel diameter caliber were assessed by trained graders and a retinal specialist using protocols developed for large epidemiologic studies. Kidney function measurements and information on traditional and non-traditional risk factors for decreased kidney function were obtained from the CRIC study. Results Greater severity of retinopathy was associated with lower estimated glomerular filtration rate (eGFR) after adjustment for traditional and non-traditional risk factors. Presence of vascular abnormalities usually associated with hypertension was also associated with lower eGFR. We found no strong direct relationship between eGFR and average arteriolar or venular calibers. Conclusions Our findings show a strong association between severity of retinopathy and its features and level of kidney function after adjustment for traditional and non-traditional risk factors for CKD, suggesting that retinovascular pathology reflects renal disease. PMID:22965589

  7. Qigong ameliorates symptoms of chronic fatigue: a pilot uncontrolled study.

    Science.gov (United States)

    Craske, Naropa J Mike; Turner, Warren; Zammit-Maempe, Joseph; Lee, Myeong Soo

    2009-06-01

    Traditional Chinese Medicine practitioners consider that chronic fatigue reflects a disharmony and depletion in the supply of qi in the body. Qigong is one of the traditional complementary interventions used to strengthen qi through self-practice, and to manage the state of qi to prevent and cure disease. The aim of this study is to assess whether qigong could be used to manage the symptoms of chronic fatigue. Eighteen Caucasian, British female participants were recruited, taught a qigong routine during weekly classes over 6 months, and asked to practice it daily for 15 min. Participants completed the core set of the RAND Medical Outcomes Study questionnaire (RAND MOS) and a sleep diary during the 2-week baseline control period, and at 3 and 6 months following the start of the trial. The qigong intervention resulted in significant changes in sleep rate score and in the following subscales of the RAND MOS: SF36 Vitality, Sleep Problems, Social Activity, Social Activity Limitation due to Health, Health Distress, Mental Health Index and Psychological Well-being. Qigong seems to improve factors related to chronic fatigue such as sleep, pain, mental attitude and general mobility after 3 and 6 months. Qigong's positive effects indicate that it represents a potentially safe method of treatment for chronic fatigued patients. However, we cannot completely discount the possible influence of placebo effects, and more objective clinical measures are needed to reproduce our findings with long-term follow-up in a randomized, controlled study involving a larger number of subjects.

  8. Studies on irradiated silicon sensors for the CMS tracker at the HL-LHC

    Energy Technology Data Exchange (ETDEWEB)

    Nuernberg, Andreas

    2014-02-14

    For the high luminosity phase of the LHC at CERN, the strip tracker of the CMS Experiment will be replaced due to higher demands on track density, track trigger and radiation damage. To study these aspects, more than 40 different silicon sensors were irradiated. Besides lab measurements, tests in an electron beam and Lorentz angle measurements were performed. A simulation model, which is capable to predict the charge distribution after a particle hit has been developed from these measurements.

  9. Electron spin resonance study of γ-irradiated Anatolian chickpea (Cicer arietinum L.)

    Science.gov (United States)

    Ayda, Canan; Engin, B. I. R. O. L.; Polat, Mustafa; Aydin, Talat

    In this study, an electron spin resonance (ESR) investigation on γ-irradiated chickpea cultivated in Turkey is reported in detail. ESR spectra of unirradiated (control) chickpea were composed of an equally spaced sextet originating from the presence of Mn2+ ions and a single weak resonance signal both centered at gD2.0054±0.0006. Although irradiation was found to have no effect on the Mn2+ signals, it caused a noteworthy increase in free radical signal intensity of chickpea in the studied dose range of (0.1-4.5 kGy). In addition, the ESR spectrum of irradiated chickpea recorded at low scan range (10 mT) showed that there were more than one radical species, having different spectral features, contributing to the central resonance signal. From this point of view, we focussed on the free radical signal in the present study. The area under the ESR absorption curve which is related to the free radical concentration was determined from the experimental spectra recorded throughout the study, and its variation with microwave power, radiation dose, storage time and temperature was investigated in detail. Free radical concentration was observed to decay very fast within the first 15 days after the irradiation cessation and little thereafter. At the end of the storage period (60 days), the free radical concentration is still higher than that of the control (unirradiated) sample. The decay of free radical concentration at room and high temperatures were described well by the sum of three second-order decay functions representing three different radical species (A, B and C). The activation energies of these radicals, evaluated by Arrhenius analysis, are in the order EC>EB>EA. Simulation calculations have shown that three radical species (A, B and C) of different spectral parameters were found to best explain the experimental values.

  10. Irradiation of plexiglas with heavy Gev ions: a study of destruction products

    Energy Technology Data Exchange (ETDEWEB)

    Fink, D. [Hahn-Meitner-Institut Berlin GmbH (Germany); Moeckel, H.J. [Hahn-Meitner-Institut Berlin GmbH (Germany); Melzer, H. [Hahn-Meitner-Institut Berlin GmbH (Germany); Klett, R. [Hahn-Meitner-Institut Berlin GmbH (Germany); Cardoso, J. [Univ. Autonoma Metropolitana-Iztapalapa, Mexico (Mexico). Dept. de Fisica; Montiel, R. [Univ. Autonoma Metropolitana-Iztapalapa, Mexico (Mexico). Dept. de Fisica; Vazquez, H. [Univ. Autonoma Metropolitana-Iztapalapa, Mexico (Mexico). Dept. de Fisica; Hosoi, F. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Omichi, H. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Wang, L. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Chadderton, L.T. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences]|[CSIRO, Canberra, ACT (Australia). Div. of Appl. Phys.

    1997-01-01

    Examinations were performed on GeV-ion irradiated plexiglas. The radiochemical reaction products are studied by FTIR and UV spectrometry as a function of their depth of origin, and some of the possible radiochemical reaction mechanisms are examined in detail. The radiochemistry of commercial plexiglas is found to differ somewhat from the one of pure PMMA. No hint for ion-induced buckminsterfullerene formation could be found. (orig.). With 7 figs., 1 tab.

  11. Review on Clinical and Mechanism Studies of Moxibustion Therapy for Chronic Gastritis

    Institute of Scientific and Technical Information of China (English)

    Zhu Hui-wen; Ruan Chun-xun; Cao Shu-fei; Wu Huan-gan; Li Jing

    2014-01-01

    By computer research, the literature of clinical and experimental studies on moxibustion therapy for chronic gastritis in the recent fifteen years was collected, sorted and analyzed, in order to understand the general situation about the clinical and experimental studies on moxibustion therapy for chronic gastritis, summarize the regularity of moxibustion therapy for chronic gastritis, so as to guide the treatment of chronic gastritis.

  12. THE STUDY OF SELF-ATTITUDE OF YOUNGER ADOLESCENTS WITH CHRONIC DISEASES (CASE STUDY OF PATIENTS WITH CHRONIC GLOMERULONEPHRITIS

    Directory of Open Access Journals (Sweden)

    T. V. Sviridova

    2013-01-01

    Full Text Available In order to study self-attitude of younger adolescents with chronic diseases, we examined 86 children with chronic glomerulonephritis and 78 conditionally healthy peers. The average disease duration was 3.5 years. The authors revealed that the level of integral self-attitude, its components (self-esteem, autogenic sympathy, self-interest, expected positive attitude and sets on internal actions towards one’s ego (self-confidence, attitude of other people, self-acceptance, self-interest of younger adolescents with chronic diseases is significantly lower than in healthy peers. Special social situation arising in connection with the disease leads to distorted development of the personality. The adolescent’s personality becomes even more vulnerable to stressful situations, social and psychological deadaptation.

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

    Science.gov (United States)

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

    2016-07-22

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

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

    Directory of Open Access Journals (Sweden)

    Adam J. Hume

    2016-07-01

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

  15. Aortic PWV in Chronic Kidney Disease: A CRIC Ancillary Study

    Science.gov (United States)

    Townsend, Raymond R.; Wimmer, Neil J.; Chirinos, Julio A.; Parsa, Afshin; Weir, Matthew; Perumal, Kalyani; Lash, James P.; Chen, Jing; Steigerwalt, Susan P.; Flack, John; Go, Alan S.; Rafey, Mohammed; Rahman, Mahboob; Sheridan, Angela; Gadegbeku, Crystal A.; Robinson, Nancy A.; Joffe, Marshall

    2009-01-01

    Background Aortic PWV is a measure of arterial stiffness and has proved useful in predicting cardiovascular morbidity and mortality in several populations of patients, including the healthy elderly, hypertensives and those with end stage renal disease receiving hemodialysis. Little data exist characterizing aortic stiffness in patients with chronic kidney disease who are not receiving dialysis, and in particular the effect of reduced kidney function on aortic PWV. Methods We performed measurements of aortic PWV in a cross-sectional cohort of participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study to determine factors which predict increased aortic PWV in chronic kidney disease. Results PWV measurements were obtained in 2564 participants. The tertiles of aortic PWV (adjusted for waist circumference) were 10.2 m/sec with an overall mean (± S.D.) value of 9.48 ± 3.03 m/sec [95% CI = 9.35–9.61 m/sec]. Multivariable regression identified significant independent positive associations of age, blood glucose concentrations, race, waist circumference, mean arterial blood pressure, gender, and presence of diabetes with aortic PWV and a significant negative association with the level of kidney function. Conclusions The large size of this unique cohort, and the targeted enrollment of chronic kidney disease participants provides an ideal situation to study the role of reduced kidney function as a determinant of arterial stiffness. Arterial stiffness may be a significant component of the enhanced cardiovascular risk associated with kidney failure. PMID:20019670

  16. In vitro and in vivo studies on the cytotoxicity of irradiated silk fibroin against mouse melanoma tumor cell

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Eui-Baek [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Division of Bioresources and Biosciences, Faculty of Agriculture, Graduate school of Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Sung, Nak-Yun [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kwon, Sun-Kyu [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Graduate school of Food and Biotechnology, Korea University, Jochiwon 339-800 (Korea, Republic of); Song, Beom-Seok; Kim, Jae-Hun; Choi, Jong-il [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Hwang, Han-Joon [Graduate school of Food and Biotechnology, Korea University, Jochiwon 339-800 (Korea, Republic of); Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Lee, Ju-Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    The physicochemical properties of proteins can be altered by irradiation. But, it is rarely that the researches on the functional properties of irradiated proteins have been reported. Fibroin is a fibrous protein derived from silkworm Bombyx mori and has been suggested as a biomaterial for biomedical application. Therefore, fibroin was selected as a model protein and was examined with the irradiation effects on the cytotoxicity of fibroin on tumor cell. The cytotoxicity of fibroin against mouse melanoma cell (B16BL6) showed a significant increase dependent upon the increase of irradiation dose. And also, the splenocyte proliferation activities of fibroin were increased by gamma irradiation. In addition, the oral administration of irradiated fibroin significantly increased the inhibition rate of tumor growth in tumor-bearing mouse model. The reason might be due to the change of protein structure by gamma irradiation and is being studied. From these result, it could be concluded that the irradiated fibroin might be a potential candidate as a valuable product in food and medical industry.

  17. An electron paramagnetic resonance study of PP and PP/SBS blends irradiated with gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Pedro E-mail: silva@ivic.ve; Albano, Carmen; Perera, Rosestela; Gonzalez, Jeanette; Ichazo, Miren

    2004-11-01

    Electron paramagnetic resonance (EPR) measurements of Polypropylene (PP) and its blends with a Styrene-Butadiene-Styrene (SBS) copolymer in 10, 20, 30 and 40 wt.% of SBS were carried out. The samples were irradiated in the 0{<=}D{<=}100 kGy range at a dose rate of 4.8 kGy/h. Typical spectra indicative of the formation of peroxy and alkyl radicals were obtained. The dynamics of formation and recombination of radicals in these samples could be explained using a mixed zero and first order generation-recombination fit of the total spin concentration as a function of the integral dose. The time dependence of the spin concentration was studied assuming a mixed first order fit in the decay process. The parameters obtained from the fitting are interpreted in terms of the rate of formation of free radicals at the irradiation time and in terms of the decay time of the total free radical concentration.

  18. Studies of irradiated AMS H35 CMOS detectors for the ATLAS tracker upgrade

    Science.gov (United States)

    Cavallaro, E.; Casanova, R.; Förster, F.; Grinstein, S.; Lange, J.; Kramberger, G.; Mandić, I.; Puigdengoles, C.; Terzo, S.

    2017-01-01

    Silicon detectors based on the HV-CMOS technology are being investigated as possible candidate for the outer layers of the ATLAS pixel detector for the High Luminosity LHC. In this framework the H35Demo ASIC has been produced in the 350 nm AMS technology (H35). The H35Demo chip has a large area (18.49 × 24.40 mm2) and includes four different pixel matrices and three test structures. In this paper the radiation hardness properties, in particular the evolution of the depletion region with fluence is studied using edge-TCT on test structures. Measurements on the test structures from chips with different substrate resistivity are shown for non irradiated and irradiated devices up to a cumulative fluence of 2 ṡ 1015 1 MeV neq / cm2.

  19. Studies of irradiated AMS H35 CMOS detectors for the ATLAS tracker upgrade

    CERN Document Server

    Cavallaro, Emanuele; Förster, Fabian; Grinstein, Sebastinan; Lange, Jörn; Kramberger, Gregor; Mandić, Igor; Puigdengoles, Carles; Terzo, Stefano

    2016-01-01

    Silicon detectors based on the HV-CMOS technology are being investigated as possible candidate for the outer layers of the ATLAS pixel detector for the High Luminosity LHC. In this framework the H35Demo ASIC has been produced in the 350 nm AMS technology (H35). The H35Demo chip has a large area ($18.49 \\times 24.40 \\, \\mathrm{mm^2}$) and includes four different pixel matrices and three test structures. In this paper the radiation hardness properties, in particular the evolution of the depletion region with fluence is studied using edge-TCT on test structures. Measurements on the test structures from chips with different substrate resistivity are shown for non irradiated and irradiated devices up to a cumulative fluence of $2 \\cdot 10^{15} \\, \\mathrm{1\\,MeV\\, n_{eq} / cm^{2}}$.

  20. Photoluminescence and Raman studies in swift heavy ion irradiated polycrystalline aluminum oxide

    Indian Academy of Sciences (India)

    K R Nagabhushana; B N Lakshminarasappa; Fouran Singh

    2009-10-01

    Polycrystalline aluminum oxide is synthesized by combustion technique and XRD studies of the sample revealed the -phase. The synthesized sample is irradiated with 120 MeV swift Au9+ ions for the fluence in the range from 1 × 1011 to 1 × 1013 ions cm-2. A broad photoluminescence (PL) emission with peak at ∼447 nm and two sharp emissions with peak at ∼ 679 and ∼ 695 nm are observed in pristine when sample was excited with 326 nm. However, in the irradiated samples the PL intensity at ∼ 447, 679 and 695 nm decreases with increase in ion fluence. The -Al2O3 gives rise to seven Raman modes with Raman intensity with peaks at ∼ 253, 396, 417, 546, 630, 842, 867 cm-1 observed in pristine. The intensity of these modes decreases with increase in ion fluence. However, the Raman modes observed at lower fluences are found to disappear at higher fluence.

  1. Study of TileCal scintillators irradiation using the Minimum Bias integrators

    CERN Document Server

    Fischer, Cora; The ATLAS collaboration

    2016-01-01

    The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the LHC. It provides precise energy measurements of hadrons, jets, taus and missing transverse energy. The monitoring and calibration of the calorimeter response at each stage of the signal development is done by a movable Cs$^{137}$ radioactive source, a laser calibration system and a charge injection system. Moreover, during LHC data taking, an integrator based readout provides the signals coming from inelastic proton-proton collisions at predominantly low momentum transfer (minimum bias events) and allows to monitor the instantaneous ATLAS luminosity as well as the response of calorimeter cells. The integrator currents have been used to detect and quantify the effect of TileCal scintillators irradiation using the data taken in 2012 and 2015 that corresponds to about 22\\;fb$^{-1}$ and 4\\;fb$^{-1}$ of integrated luminosity. Finally, the response variation for an irradiated cell has been studied combining the informa...

  2. Capacitance and conductance studies on silicon solar cells subjected to 8 MeV electron irradiations

    Science.gov (United States)

    Sathyanarayana Bhat, P.; Rao, Asha; Sanjeev, Ganesh; Usha, G.; Priya, G. Krishna; Sankaran, M.; Puthanveettil, Suresh E.

    2015-06-01

    The space grade silicon solar cells were irradiated with 8 MeV electrons with doses ranging from 5-100 k Gy. Capacitance and conductance measurements were carried out in order to investigate the anomalous degradation of the cells in the radiation harsh environments and the results are presented in this paper. Detailed and systematic analysis of the frequency-dependent capacitance and conductance measurements were performed to extract the information about the interface trap states. The small increase in density of interface states was observed from the conductance-frequency measurements. The reduction in carrier concentration upon electron irradiation is due to the trapping of charge carriers by the radiation induced trap centres. The Drive Level Capacitance Profiling (DLCP) technique has been applied to study the properties of defects in silicon solar cells. A small variation in responding state densities with measuring frequency was observed and the defect densities are in the range 1015 -1016 cm-3.

  3. An experimental study on the motion of water droplets in oil under ultrasonic irradiation.

    Science.gov (United States)

    Luo, Xiaoming; He, Limin; Wang, Hongping; Yan, Haipeng; Qin, Yahua

    2016-01-01

    The motion of a single water droplet in oil under ultrasonic irradiation is investigated with high-speed photography in this paper. First, we described the trajectory of water droplet in oil under ultrasonic irradiation. Results indicate that in acoustic field the motion of water droplet subjected to intermittent positive and negative ultrasonic pressure shows obvious quasi-sinusoidal oscillation. Afterwards, the influence of major parameters on the motion characteristics of water droplet was studied, such as acoustic intensity, ultrasonic frequency, continuous phase viscosity, interfacial tension, and droplet diameter, etc. It is found that when the acoustic intensity and frequency are 4.89 W cm(-2) and 20 kHz respectively, which are the critical conditions, the droplet varying from 250 to 300 μm in lower viscous oil has the largest oscillation amplitude and highest oscillation frequency.

  4. Study on Plasmid and Damage Induced by Low-energy Neon Ion Irradiation

    Institute of Scientific and Technical Information of China (English)

    MaQiufeng; WangXiao; JinGenming; LiWenjian; DangBingrong; XieHongmei; ZhouLibin; MaoShuhong

    2003-01-01

    DNA is considered to be the most important and sensitive target in biological systems. Beside base damage, DNA strand breaks are the major lesion in the genome due to exposure to ionizing radiation. Mutation can be introduced to DNA as a result of enzymatic processing of DNA lesions or post-irradiation replication. However, the mechanisms of radiation-induced mutations are not well clarified at the molecular level. A good way to approach the mechanism is to irradiate the plasmid DNA of heavy ion, then transfect the DNA to host cells to determine the mutation spectra. So to study the effect of heavy ions on the simple plasmid DNA is even predominant or more feasible.

  5. STUDY STRUCTURE OF THREE-COMPONENT POLYMERIC MATERIAL UNDER INFLUENCE OF γ-IRRADIATION

    Directory of Open Access Journals (Sweden)

    V. T. Tarasyuk

    2017-01-01

    Full Text Available The polymer material (РА/РЕ/Eva with a width of 55 μm was studied. Sterilization was carried out on the unit GU–200 at doses from 3 to 18 kGy in the Research Institute of Technical Physics and Automation, Rosatom, Moscow, Russia. The structure of the polymermaterial samples was studied by IR spectroscopy before and after irradiation in a range of 400–5000 сm–1. According to the results of the analysis of the IR spectrum structure, the changes in the structure were insignificant upon irradiation at doses up to 6 kGy. Upon irradiation at doses from 9 kGy and higher, an increase in quantity of ester groups (2340 сm–1 and insignificant increase in other functional groups were observed, which can suggest a simultaneous process of intra-molecular cross-linking with the intermediatestage of cross-linking occurring with formation of vinylene groups. This causes destruction of a polymer material and radiation oxidation. These disorders can lead to changes in physico-mechanical and barrier parameters of a polymer material, which can be notably reflected in the shelf life of agricultural products.

  6. ENDOR and ELDOR studies of x-irradiated polycrystalline dipeptides, myosin, and actomyosin

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, J.S. (Univ. of Alabama, Tuscaloosa); Dickinson, A.C.; Kispert, L.D.

    1979-12-27

    ENDOR and ELDOR studies have been carried out for nine dipeptide powders as well as powders of myosin and actomyosin x ray irradiated at 77/sup 0/K in an attempt to characterize the final radical stable upon annealing between 183 and 260/sup 0/K. The dipeptides studied were glycylglycine, L-alanylglycine, glycyl-L-alanine, L-alanyl-L-alanine, glycyl-L-aspartic acid, glycyl-L-glutamic acid, glycyl-L-methionine, glycyl-L-serine, and L-lysyl-L-lysine. Nitrogen ENDOR spectra have been observed between 1 and 8 MHz for each powder and the nitrogen hyperfine and quadrupole tensor has been estimated. Analysis of the ENDOR, ELDOR, and ESR spectra indicates at least one of the final radicals in the dipeptide powders (except Gly-Gly, and possibly Gly-Glu, Gly-Ser) to be the decarboxylation product NH/sub 2/CHRCONHCHR' rather than just the abstraction type (NH/sub 3//sup +/-CHRONHCR'COO/sup -/) previously identified in irradiated dipeptide ices. A decarboxylation type radical is also present as a final radical in the irradiated myosin and actomyosin.

  7. Monte Carlo study of secondary electron production from gold nanoparticle in proton beam irradiation

    Directory of Open Access Journals (Sweden)

    Jeff Gao

    2014-03-01

    Full Text Available Purpose: In this study, we examined some characteristics of secondary electrons produced by gold nanoparticle (NP during proton beam irradiation.Method: By using the Geant4 Monte Carlo simulation toolkit, we simulated the NP at the range from radius (r of 17.5 nm, 25 nm, 35 nm to r = 50 nm. The proton beam energies used were 20MeV, 50MeV, and 100MeV. Findings on secondary electron production and their average kinetic energy  are presented in this paper. Results: Firstly, for NP with a finite size, the secondary electron production increase with decreasing incident proton beam energy and secondary buildup existed outside NP. Secondly, the average kinetic energy of secondary electrons produced by a gold NP increased with incident proton beam energy. Thirdly, the larger the NP size, the more the secondary electron production.Conclusion: Collectively, our results suggest that apart from biological uptake efficiency, we should take the secondary electron production effect into   account when considering the potential use of NPs in proton beam irradiation.-----------------------------------------------Cite this article as: Gao J, Zheng Y. Monte Carlo study of secondary electron production from gold nanoparticle in proton beam irradiation. Int J  Cancer Ther Oncol 2014; 2(2:02025.DOI: http://dx.doi.org/10.14319/ijcto.0202.5

  8. Studies on the irradiation of toxins of Clostridium botulinum and Staphylococcus aureus

    Energy Technology Data Exchange (ETDEWEB)

    Rose, S.A.; Bailey, N.E.; Stringer, M.F. (Campden Food and Drink Research Association, Chipping Campden (UK)); Modi, N.K.; Tranter, H.S. (Porton International plc., London (UK)); Hambleton, P. (Centre for Applied Microbiological Research, Porton Down (UK))

    1988-10-01

    The effects of irradiation of Clostridium botulinum neurotoxin type A (BNTA) and staphylococcal enterotoxin A (SEA) in gelatin phosphate buffer and cooked mince beef slurries were investigated. Estimation of toxins by immunoassays showed that in buffer, toxins were destroyed by irradiation at 8.0 kGy; in mince slurries however, 45% of BTNA and 27-34% of SEA remained after this level of irradiation. At 23.7 kGy, over twice the dose of irradiation proposed for legal acceptance in the UK, 15% of BNTA and 16-26% of SEA still remained. Increasing concentrations of mince conferred increased protection against the effect of irradiation on both toxins. The biological activity of BNTA was more sensitive to irradiation than the immunological activity. Staphylococcal enterotoxin was more resistant to irradiation than BNTA. Irradiation should therefore only be used in conjunction with good manufacturing practices to prevent microbial proliferation and toxin production prior to irradiation. (author).

  9. Studies on the irradiation of toxins of Clostridium botulinum and Staphylococcus aureus

    Energy Technology Data Exchange (ETDEWEB)

    Rose, S.A.; Bailey, N.E.; Stringer, M.F. (Campden Food and Drink Research Association, Chipping Campden (UK)); Modi, N.K.; Tranter, H.S. (Centre for Applied Micobiological Research, Porton Down, (UK)); Hambleton, P. (Porton International plc, London (UK))

    1989-09-01

    The effects of irradiation of Clostridium botulinum neutotoxin type A (BNTA) and staphylococcal enterotoxin A (SEA) in gelatin phosphate buffer and cooked mince beef slurries were investigated. Estimation of toxins by immunoassays showed that in buffer, toxins were destroyed by irradiation at 8.0 kGy; in mince slurries however, 45% of BTNA and 27-34% of SEA remained after this level of irradiation. At 23.7 kGy, over twice the dose of irradiation proposed for legal acceptance in the UK, 15% of BNTA and 16-26% of SEA still remained. Increasing concentrations of mince conferred increased protection against the effect of irradiation on both toxins. The biological activity of BNTA was more sensitive to irradiation than the immunological activity. Staphylococcal enterotoxin was more resistant to irradiation than BNTA. Irradiation should therefore only be used in conjunction with good manufacturing practices to prevent microbial proliferation and toxin production prior to irradiation. (author).

  10. SERS study of transformation of phenylalanine to tyrosine under particle irradiation

    Science.gov (United States)

    Zhang, Jingjing; Huang, Qing; Yao, Guohua; Ke, Zhigang; Zhang, Hong; Lu, Yilin

    2014-08-01

    Surface enhanced Raman scattering or spectroscopy (SERS) is a very powerful analytical tool which has been widely applied in many scientific research and application fields. It is therefore also very intriguing for us to introduce SERS technique in the radiobiological research, where in many cases only a very few of biomolecules are subjected to changes which however can lead to significant biological effects. The radiation induced biochemical reactions are normally very sophisticated with different substances produced in the system, so currently it is still a big challenge for SERS to analyze such a mixture system which contains multiple analytes. In this context, this work aimed to establish and consolidate the feasibility of SERS as an effective tool in radiation chemistry, and this purpose, we employed SERS as a sensitive probe to a known process, namely, the oxidation of phenylalanine (Phe) under particle irradiation, where the energetic particles were obtained from either plasma discharge or electron-beam. During the irradiation, three types of tyrosine (Tyr), namely, p-Tyr, m-Tyr and o-Tyr were produced, and all these tyrosine isomers together with Phe could be identified and measured based on the SERS spectral analysis of the corresponding enhanced characteristic signals, namely, 1002 cm-1 for Phe, 1161 cm-1 for p-Tyr, 990 cm-1 for m-Tyr, and 970 cm-1 for o-Tyr, respectively. The estimation of the quantities of different tyrosine isomers were also given and verified by conventional method such as high performance liquid chromatography (HPLC). As for comparison of different ways of particle irradiation, our results also indicated that electron-beam irradiation was more efficient for converting Phe into Tyr than plasma discharge treatment, confirming the role of hydroxyl radicals in the Phe-Tyr conformation. Therefore, our work has not only demonstrated that SERS can be successfully applied in the radiobiological study, but also given insights into the

  11. Primary experimental studies on mid-infrared FEL irradiation on dental substances at BFEL

    CERN Document Server

    Biao, Z J; Gao Xue Ju; He Wei; Huang Yu Ying; Li Yong Gui; LiuNianQing; Wang Min Kai; Wu Gan; Yan Xue Pin; Zhang Guo Qing

    2001-01-01

    A free electron laser (FEL) with its characteristics of wide wavelength tunability, ultrashort pulse time structure, and high peak power density is predominantly superior to all other conventional lasers in applications. Several experimental studies on mid-infrared FEL irradiation on dental enamel and dentine were performed at the Beijing FEL. Experimental aims were to investigate changes in the hardness, ratios of P to Ca and Cs before and after irradiation on samples with a characteristic absorption wavelength of 9.66 mu m, in the colors of these sample surfaces after irradiation with different wavelengths around the peak wavelength. The time dependence of temperature of the dentine sample was measured with its ps pulse effects compared to that with a continuous CO sub 2 laser. FTIR absorption spectra in the range of 2.5-15.4 mu m for samples of these hard dental substances and pure hydroxyapatite were first examined to decide their chemical components and absorption maximums. Primary experimental results w...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

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

    Directory of Open Access Journals (Sweden)

    P. C. Lucas de Oliveira

    2007-01-01

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

  14. Organics produced by irradiation of frozen and liquid HCN solutions: implications for chemical evolution studies.

    Science.gov (United States)

    Colín-García, M; Negrón-Mendoza, A; Ramos-Bernal, S

    2009-04-01

    Hydrogen cyanide (HCN), an important precursor of organic compounds, is widely present in extraterrestrial environments. HCN is also readily synthesized in prebiotic simulation experiments. To gain insight into the radiation chemistry of one of the most important and highly versatile constituents of cometary ices, we examined the behavior of over-irradiated frozen and liquid HCN solutions under ionizing radiation. The samples were exposed to gamma radiation at a dose range from 0 up to 419 kGy. Ultraviolet spectroscopy and gas chromatography were used to follow the process. The analyses confirmed that gamma-ray irradiation of liquid HCN solutions generates several organic products. Many of them are essential to life; we verified the presence of carboxylic acids (some of them members of the Krebs cycle) as well as free amino acids and urea. These are the first studies to reveal the presence of these compounds in experiments performed at low temperatures and bulk irradiation. Organic material was produced even at low temperatures and low radiation doses. This work strongly supports the presumption that, as a parent molecule, HCN played a central essential role in the process of chemical evolution on early Earth, comets, and other extraterrestrial environments.

  15. ESR and TL studies of irradiated Anatolian laurel leaf (Laurus nobilis L.)

    Science.gov (United States)

    Tepe Çam, Semra; Aydaş, Canan; Engin, Birol; Rabia Yüce, Ülkü; Aydın, Talat; Polat, Mustafa

    2012-06-01

    Laurel leaf (Laurus nobilis L.) samples that originated from Turkey were analyzed by electron spin resonance (ESR) and thermoluminescence (TL) techniques before and after γ-irradiation. Unirradiated (control) laurel leaf samples exhibit a weak ESR singlet centered at g=2.0020. Besides this central signal were two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. The dose-response curve of the radiation-induced ESR signal at g=2.0187 (the left satellite signal) was found to be described well by a power function. Variation of the left satellite ESR signal intensity of irradiated samples at room temperature with time in a long term showed that cellulosic free radicals responsible for the ESR spectrum of laurel leaves were not stable but detectable even after 100 days. Annealing studies at four different temperatures were used to determine the kinetic behavior and activation energy of the radiation-induced cellulosic free radicals responsible from the left satellite signal (g=2.0187) in laurel leaves. TL measurements of the polymineral dust isolated from the laurel leaf samples allowed distinguishing between irradiated and unirradiated samples.

  16. Study on containerisation of irradiated fuel at JRC ISPRA for medium/long-term storage

    Energy Technology Data Exchange (ETDEWEB)

    Bertelli, S.; Bielli, G.; Covini, R.

    2001-07-01

    During the last 40 years big amounts of wastes arising from past experiments have been generated at JRC Ispra. These wastes are now stored on site in unconditioned form and must be characterised and re-conditioned to ensure their acceptance by future repositories. Among the several types of wastes produced, spent fuel has a great importance in JRC waste management. In fact, there are more than the tons of irradiated material, varying widely from commercial to experimental fuel elements or pins, in form of oxides and metal fuel, with very different geometry, dry and wet stored. The biggest part of it can be considered as unirradiated, according to the IAEA regulations (ST-1, 1996), while a relatively small amount (nearly 720 kg U total) are to be considered as irradiated and treated accordingly. Studies on the most suitable solutions for medium/long term storage for such irradiated experimental fuel are being performed, taking into account two main options, containerisation of the nuclear materials, as it is, in suitable casks or reprocessing. The technical aspects of the project for containerisation are here discussed. (Author)

  17. Organics Produced by Irradiation of Frozen and Liquid HCN Solutions: Implications for Chemical Evolution Studies

    Science.gov (United States)

    Colín-García, M.; Negrón-Mendoza, A.; Ramos-Bernal, S.

    2009-04-01

    Hydrogen cyanide (HCN), an important precursor of organic compounds, is widely present in extraterrestrial environments. HCN is also readily synthesized in prebiotic simulation experiments. To gain insight into the radiation chemistry of one of the most important and highly versatile constituents of cometary ices, we examined the behavior of over-irradiated frozen and liquid HCN solutions under ionizing radiation. The samples were exposed to gamma radiation at a dose range from 0 up to 419 kGy. Ultraviolet spectroscopy and gas chromatography were used to follow the process. The analyses confirmed that gamma-ray irradiation of liquid HCN solutions generates several organic products. Many of them are essential to life; we verified the presence of carboxylic acids (some of them members of the Krebs cycle) as well as free amino acids and urea. These are the first studies to reveal the presence of these compounds in experiments performed at low temperatures and bulk irradiation. Organic material was produced even at low temperatures and low radiation doses. This work strongly supports the presumption that, as a parent molecule, HCN played a central essential role in the process of chemical evolution on early Earth, comets, and other extraterrestrial environments.

  18. Sensory dynamics of intense microwave irradiation: A comparative study of aversive behaviors by mice and rats

    Energy Technology Data Exchange (ETDEWEB)

    Justesen, D.R.

    1981-10-01

    The results of two experiments are reported, the first on 24 mice and 14 rats, all experimentally naive, that were observed for evidence of adventitious escape from faradic shock or from a potentially lethal, 2450-MHz microwave field in a multi-mode cavity. All of ten rats irradiated at a whole-body-averaged dose rate of 60 mW/g convulsed and expired, presumably from radiation-induced hyperpyrexia. Eight of ten mice irradiated at 60 mW/g survived the four sessions of irradiation, but reliable evidence of escape learning was not observed. The data of the second experiment, which was a pilot study of four rats with an extensive history of exposure to intense but intermittently applied microwave fields, revealed that the animals learned to thermoregulate behaviorally by locomoting in and out of the safe-area circle. A strong relation between dose rate (30, 60, and 120 mW/g) and proportion of time spent in the safe area was observed (r = .97). Post-exposure means of colonic temperature during three sets of sessions under the different rates of energy dosing were highly stable and averaged 39.6 deg C.

  19. Chronic bronchitis in the iron and steel industry: prevalence study.

    Science.gov (United States)

    Scotti, P G; Arossa, W; Bugiani, M; Nicoli, E

    1989-01-01

    The paper reports the results of a prevalence study on functional impairment and chronic bronchitis in 733 foundry workers and in a control group of 1041 workers not exposed to the specific risks of the iron and steel industry. This study is the first part of a longitudinal study lasting 5 years within the framework of the Fourth Research Programme of the European Coal and Steel Community. Data on microclimate and particulate pollution for the various departments showed uniformly cold and damp conditions. Concentrations of pollutants were generally below the current T.L.V.'s. The subjects were subdivided into groups according to age, smoking and length of exposure. All the subjects were administered the "E.C.S.C. Questionnaire for the study of chronic bronchitis and pulmonary emphysema" and underwent a chest X-ray and spirometry to measure FVC, FEV1 and Vmax 50. The prevalence of functional impairment and chronic bronchitis was higher in the foundry workers than in the group of non-exposed workers. A statistical standardization was made of the effect of age and smoking thus accentuating the effect of exposure. The results are compared with the data obtained by other epidemiologic studies on working populations exposed to a similar risk.

  20. A spectroscopic study of dyes decomposition by irradiated nanocrystalline TiO2

    Science.gov (United States)

    Rosu, M. C.; Suciu, R. C.; Kasco, I.; Dreve, S. V.; Indrea, E.; Silipas, T. D.

    2009-08-01

    The photocatalytic activity of the TiO2 films prepared by wet-chemical techniques and deposited on the ITO glass was tested by examining the decomposition of violet gentian (VG), methylen blue (MB) and methyl green (MG) aqueous solutions under UV light illumination. The photodegradation processes of dyes have been studied using UV-VIS spectrophotometry and spectrofluorimetry. The comparative results of the present study demonstrate the capability of UV irradiation of the TiO2/ITO photocatalytic system to degrade studied organic dyes from aqueous solutions.

  1. Acupuncture and Immune Function in Chronic Prostatitis/Chronic Pelvic Pain Syndrome: A Randomized, Controlled Study

    Science.gov (United States)

    Lee, Shaun Wen Huey; Liong, Men Long; Yuen, Kah Hay; Krieger, John N

    2014-01-01

    Objective The immune system has been implicated as one mechanism underlying the benefits of acupuncture therapy. Evidence suggests that acupuncture can ameliorate symptoms of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), but the association between clinical response and the immune system has not been investigated. Design/Setting We investigated 12 CP/CPPS patients participating in a prospective randomized clinical trial comparing acupuncture versus sham acupuncture for effects on cellular immunity. Blood samples were taken before the first needling and after the last of 20 treatment sessions (week 10). Patients also completed questionnaires examining their CP/CPPS symptoms and mood status at the baseline and end of study visits. Results At the end of study 8 of 12 participants (67%) were classified as treatment responders, 4 participants each from the acupuncture and sham groups. The acupuncture group averaged a 5% increase in natural killer cell levels compared to corresponding sham (-13%; p=0.03). Similarly, patients randomized to acupuncture reported a reduction in other white blood cell parameters examined, supporting the possibility that immunity might be important in the pathophysiology of CP/CPPS. Conclusions The specific effect of acupuncture on CP/CPPS remains unclear. Further research is warranted to examine the mechanisms by which acupuncture therapy may improve clinical symptoms in patients with CP/CPPS. PMID:25453515

  2. Chronic lymphocytic leukaemia: case control epidemiological study in Yorkshire.

    OpenAIRE

    Cartwright, R. A.; Bernard, S.M.; Bird, C. C.; Darwin, C. M.; O'Brien, C; Richards, I D; Roberts, B; McKinney, P A

    1987-01-01

    This is the second report of a large case control study of lymphoma/leukaemia occurring in Yorkshire during 1979-84, and deals with chronic lymphocytic leukaemia presenting either in its haematological (CLL) or more solid lymphomatous (malignant lymphoma-lymphocytic or MLL) forms. In all, 330 cases and 561 controls were interviewed. The results support the concept that CLL/MLL is a condition of multiple aetiologies with evidence for genetic predisposition through an excess of family cases, im...

  3. Iron deficiency in chronic systolic heart failure(indic study

    Directory of Open Access Journals (Sweden)

    Sunil Verma

    2016-01-01

    Full Text Available Background: Chronic systolic heart failure (HF is characterized by the left ventricular dysfunction, exercise intolerance and is associated with neurohormonal activation that affects several organs such as kidney and skeletal muscle. Anemia is common in HF and may worsen symptoms. Iron deficiency (ID is also common in HF patients with or without anemia. Iron is the key cofactor in oxidative metabolism in skeletal muscle and the Krebs cycle. There is a paucity of data regarding iron metabolism in chronic systolic HF in India. Methods: IroN Deficiency In CHF study (INDIC is an observational study that investigated forty chronic heart failure patients for the presence of ID. Serum ferritin (micrograms per liter, serum iron (micrograms per liter, total iron binding capacity (micrograms per liter, transferring (milligrams per deciliter, and transferrin saturation were measured to assess iron status. Results: There were 67.5% (27/40 patients who had ID with a mean serum ferritin level of 76.4 μg/L. Of the 27 iron deficient patients, 22 (55% had an absolute ID, and 5 had a functional ID. Eight out of 27 of the iron deficient patients were anemic (20% of the total cohort, 30% of the iron deficient patients. Anemia was seen in 6 other patients, which was possibly anemia of chronic disease. There was a trend for more advanced New York Heart Association (NYHA class (NYHA III and NYHA IV patients with ID (37.4% vs. 30.77%, P = 0.697. Conclusion: In our study, ID was very common, affecting more than half of the patients with systolic HF. Absolute ID was the most common cause of ID and patients with ID had a tendency to have advanced NYHA class. Our study also demonstrated that ID can occur in the absence of anemia (iron depletion.

  4. THE STUDY OF HEART MUSCLE IN CHRONIC ALCOHOLICS

    Directory of Open Access Journals (Sweden)

    Girish M

    2016-09-01

    Full Text Available BACKGROUND Alcohol affects many organs, especially the liver, pancreas and brain. Although, the beneficial effects of mild or moderate ethanol consumption have been implied with respect to coronary artery disease, excessive ethanol consumption can result in Alcoholic Heart Muscle Disease (AHMD. AIMS Alcohol consumption, mainly arrack, is common social problem in Mangalore. This study has been undertaken to assess the effects of alcohol on cardiovascular system. MATERIALS AND METHODS Thirty patient with history of consumption of about 6 units of alcohol per day for at least 5 days a week for at least 5 years who were admitted to Government Wenlock Hospital, Attavar K.M.C. and University Medical Centre, Mangalore, were selected as case and studied. RESULTS Alcohol intake is predominantly observed in males, majority of alcoholic had high blood pressure, serum levels of CPK-MB and LDH are elevated in chronic alcoholic patients, left ventricular hypertrophy, premature ventricular contraction and sinus tachycardia were common findings in the electrocardiograms of chronic alcoholic patients and development of alcoholic heart muscle disease is directly proportional to the quantity and duration of alcohol intake. CONCLUSION Overall, the present study has found high morbidity from chronic alcohol consumption highlighting the need for preventive measures to tackle this preventable hazard.

  5. Shielding design studies for a neutron irradiator system based on a 252Cf source.

    Science.gov (United States)

    da Silva, A X; Crispim, V R

    2001-01-01

    This study aims to investigate a shielding design against neutrons and gamma rays from a source of 252Cf, using Monte Carlo simulation. The shielding materials studied were borated polyethylene, borated-lead polyethylene and stainless steel. The Monte Carlo code MCNP4B was used to design shielding for 252Cf based neutron irradiator systems. By normalising the dose equivalent rate values presented to the neutron production rate of the source, the resulting calculations are independent of the intensity of the actual 252Cf source. The results show that the total dose equivalent rates were reduced significantly by the shielding system optimisation.

  6. Development of food preservation and processing techniques by radiation - Studies on the safety and consumer acceptance of gamma irradiated meats

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Il Jun; Lee, Young Jin; Lee, Young Sook; Kim, Ha Kyung [Hallym University, Chunchon (Korea)

    2000-04-01

    Gamma irradiation was applied to chickens for evaluation of their possible genotoxicity, acute toxicity, four-week oral toxicity and nutritional safety. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535, TA1537. Clastogenic effects of the irradiated samples tested were not shown in vivo mouse micronucleus assay and in chromosomal aberration tests with CHL cells. In an acute toxicity test, the maximal dose of 5,000 mg/kg did not change any toxic parameter examined in this study. In four-week oral toxicity study, appearance, behavior, mortality, food and water consumption of mouse of treated groups were not affected during the experimental periods(four-weeks). In urine analysis, in hematological examination as well as in serum biochemical experiment, no significant differences were found between the control and treatment groups. Although minor changes in some hematological and biochemical parameters were observed, they were in the normal range and were not dose dependent. In nutritional safety, the proximate composition of foods were not significantly changed by irradiation dose. No significant difference in the components of fatty acids were observed by gamma irradiation. In general, the amount of released free amino acid was not significantly changed by gamma irradiation. There was no difference in total amino acid content between non irradiated and irradiated samples. The SDS electrophoresis patterns of samples were not significantly different between nonirradiated and irradiated samples. The major mineral compositions of chicken were phosphorus, potassium, sodium, magnesium. The content of mineral was not significantly changed by gamma irradiation. 58 refs., 11 figs., 16 tabs. (Author)

  7. Qigong Ameliorates Symptoms of Chronic Fatigue: A Pilot Uncontrolled Study

    Directory of Open Access Journals (Sweden)

    Naropa J. Mike Craske

    2009-01-01

    Full Text Available Traditional Chinese Medicine practitioners consider that chronic fatigue reflects a disharmony and depletion in the supply of qi in the body. Qigong is one of the traditional complementary interventions used to strengthen qi through self-practice, and to manage the state of qi to prevent and cure disease. The aim of this study is to assess whether qigong could be used to manage the symptoms of chronic fatigue. Eighteen Caucasian, British female participants were recruited, taught a qigong routine during weekly classes over 6 months, and asked to practice it daily for 15 min. Participants completed the core set of the RAND Medical Outcomes Study questionnaire (RAND MOS and a sleep diary during the 2-week baseline control period, and at 3 and 6 months following the start of the trial. The qigong intervention resulted in significant changes in sleep rate score and in the following subscales of the RAND MOS: SF36 Vitality, Sleep Problems, Social Activity, Social Activity Limitation due to Health, Health Distress, Mental Health Index and Psychological Well-being. Qigong seems to improve factors related to chronic fatigue such as sleep, pain, mental attitude and general mobility after 3 and 6 months. Qigong's positive effects indicate that it represents a potentially safe method of treatment for chronic fatigued patients. However, we cannot completely discount the possible influence of placebo effects, and more objective clinical measures are needed to reproduce our findings with long-term follow-up in a randomized, controlled study involving a larger number of subjects.

  8. Study and simulation of irradiated zirconium alloys fracture under type RIA accidental loading conditions; Comprehension et modelisation de la rupture d'alliages de zirconium irradies en conditions accidentelles de type RIA

    Energy Technology Data Exchange (ETDEWEB)

    Le Saux, M. [CEA Saclay, Dept. des Materiaux pour le Nucleaire (DEN/DANS/DMN/SEMI), 91 - Gif-sur-Yvette (France)

    2008-07-01

    The thesis aims to study and simulate the mechanical behavior under Reactivity Initiated Accident loading conditions, of the Zircaloy 4 fuel claddings, irradiated or not. It also aims to characterize and simulate the behavior and the fracture under RIA loading conditions of hydrided Zircaloy 4 non irradiated. This study proposes an experimental approach and a simulation. (A.L.B.)

  9. A Model for Precise and Uniform Pelvic- and Limb-Sparing Abdominal Irradiation to Study the Radiation-Induced Gastrointestinal Syndrome in Mice Using Small Animal Irradiation Systems

    Science.gov (United States)

    Brodin, N. Patrik; Velcich, Anna; Guha, Chandan

    2017-01-01

    Background and Purpose: Currently, no readily available mitigators exist for acute abdominal radiation injury. Here, we present an animal model for precise and homogenous limb-sparing abdominal irradiation (LSAIR) to study the radiation-induced gastrointestinal syndrome (RIGS). Materials and Methods: The LSAIR technique was developed using the small animal radiation research platform (SARRP) with image guidance capabilities. We delivered LSAIR at doses between 14 and 18 Gy on 8- to 10-week-old male C57BL/6 mice. Histological analysis was performed to confirm that the observed mortality was due to acute abdominal radiation injury. Results: A steep dose–response relationship was found for survival, with no deaths seen at doses below 16 Gy and 100% mortality at above 17 Gy. All deaths occurred between 6 and 10 days after irradiation, consistent with the onset of RIGS. This was further confirmed by histological analysis showing clear differences in the number of regenerative intestinal crypts between animals receiving sublethal (14 Gy) and 100% lethal (18 Gy) radiation. Conclusion: The developed LSAIR technique provides uniform dose delivery with a clear dose response, consistent with acute abdominal radiation injury on histological examination. This model can provide a useful tool for researchers investigating the development of mitigators for accidental or clinical high-dose abdominal irradiation. PMID:28203121

  10. A Pilot Study of Mindfulness Meditation for Pediatric Chronic Pain

    Directory of Open Access Journals (Sweden)

    Lynn C. Waelde

    2017-04-01

    Full Text Available Despite advances in psychological interventions for pediatric chronic pain, there has been little research examining mindfulness meditation for these conditions. This study presents data from a pilot clinical trial of a six-week manualized mindfulness meditation intervention offered to 20 adolescents aged 13–17 years. Measures of pain intensity, functional disability, depression and parent worry about their child’s pain were obtained at baseline and post-treatment. Results indicated no significant changes in pain or depression, however functional disability and frequency of pain functioning complaints improved with small effect sizes. Parents’ worry about child’s pain significantly decreased with a large effect size. Participants rated intervention components positively and most teens suggested that the number of sessions be increased. Three case examples illustrate mindfulness meditation effects and precautions. Mindfulness meditation shows promise as a feasible and acceptable intervention for youth with chronic pain. Future research should optimize intervention components and determine treatment efficacy.

  11. Irradiated T. cruzi and resistant consomic animals can be useful in Chagas disease studies

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Viviane Liotti; Passos, Luiz Augusto Correa; Salgado, Andreia Ruis [Universidade Estadual de Campinas, SP (Brazil). Centro Multidisciplinar para a Investigacao Biologica (CEMIB/UNICAMP)], e-mail: viviliotti@cemib.unicamp.br; Spencer, Patrick Jack; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Human Chagas disease is considered the most significant parasitic disease in Latin America. It is estimated that 16-18 million people are infected by T. cruzi. As a consequence, approximately 50,000 deaths occur every year. The acute infection usually goes unrecognized and enters into a chronic stage that persists throughout the host's life span. However, roughly 30% of infected individuals eventually will develop disease with an array of possible manifestations affecting the heart, the digestive tract, and/or the peripheral nervous system. This disease is commonly modeled in inbred mice even though mouse strains used to simulate experimental infection vary considerably. In this way, Wrightsman and Trischmann showed that chromosome 17 was directly involved in a T. cruzi resistance, showing the influence of host's genetic constitution on disease severity. Additionally, in 2003, Passos and Graefe, working separately, quantified parasite burdens in resistant and susceptible strains and applied a backcross strategy to map the genomic loci linked to susceptibility and resistance in inbred mice. The genomes of the animals were scanned with microsatellite markers and the results found by these authors showed that the resistance mechanism is polygenic and is under the control of a complex network. In the particular case of Y strain, in vivo assays indicated that survival was related to the chromosomes 7,11,14,17 and 19. In order to evaluate the influence of each isolated chromosome as well as their interactions, we employed susceptible isogenic mice to construct consomic lineages for each one of those chromosomes. The consomic strains were injected with irradiated and native forms of Y strain T. cruzi, and the infectivity parameters were evaluated by quantitative methods. Radiation caused inability of trypanosomes to infect and kill mice, when these parasites were irradiated with 1 kGy of gamma rays from a {sup 60}Co source. In this experiment we used 10{sup 1

  12. Study on long-term irradiation aging of electrical cables (The VEILLE program)

    Energy Technology Data Exchange (ETDEWEB)

    Carlin, F.; Attal, M.; Gaussens, G. [and others

    1995-04-01

    The VEILLE program (French acronym for study on long-term irradiation aging of electrical cables) was implemented in 1988 by the Institute of Protection and Nuclear Safety (IPSN) in collaboration with the US Nuclear Regulatory Commission (NRC) for a period of six years. It is intended to validate the assumptions put forward as regards aging of electrical cables and to develop criteria for early detection of degradation likely to lead to functional failures. The tests were carried out partly at the Sandia National Laboratories in the United States, partly in France in the CIS bio international Laboratories at the Saclay Nuclear Research Centre. The study focused on the radiation effects from cobalt 60 on electrical cables made up of various polymers for two temperatures and at various dose rates. Other tests were also performed using a device laid under water in the OSIRIS reactor pool at Saclay to test cables under irradiation and temperature conditions close to those found in nuclear power plant operation. Subsequently the aged cables were subjected to containment accident conditions (irradiation and thermodynamic profile) in order to show any degradation due to aging. The study showed the significant effect of radiation doses on EPR and EPDM cable insulations as well as synergy between radiation dose rates and temperature on the mechanical properties of the Hypalon sheath. Correlation between the mechanical properties and the function of cables is difficult to establish as electrical characteristics are preserved whatever the type of mechanical degradation observed. Finally, the performance of electrical cables after an accident remains a key criterion to define the materials likely to be used when manufacturing cables intended to ensure safety functions.

  13. Positron study of steel NF 709 after irradiation and thermal strain

    Science.gov (United States)

    Veternikova, J.; Degmova, J.; Simko, F.; Pekarcikova, M.; Sojak, S.; Slugen, V.

    2015-12-01

    New improved austenitic steel NF 709 was studied in term of thermal and radiation stability in consideration of its application as structural material for the newest generation of nuclear reactors - Generation IV. Samples of steel NF 709 were exposed to two strains: annealing at 1000 °C in argon atmosphere and simulated irradiation performed by helium ion implantation. Changes of the microstructure after the experimental strains were observed by positron annihilation techniques. The microstructure after both treatments indicated growing of vacancy defects; although these changes were small or in the range of error bar. Thus, material NF 709 can be considered as well resistant to these applied strains.

  14. Chlorophyll bleaching by UV-irradiation in vitro and in situ: Absorption and fluorescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Zvezdanovic, Jelena [Faculty of Technology, University of Nish, Bulevar oslobodjenja 124, 16000 Leskovac (Serbia)], E-mail: jelite74@yahoo.com; Cvetic, Tijana [Faculty of Biology, University of Belgrade, Takovska 43, Belgrade 11000 (Serbia); Veljovic-Jovanovic, Sonja [Center for Multidisciplinary Studies, University of Belgrade, Kneza Viseslava la, Belgrade 11030 (Serbia); Markovic, Dejan [Faculty of Technology, University of Nish, Bulevar oslobodjenja 124, 16000 Leskovac (Serbia)], E-mail: dejan_markovic57@yahoo.com

    2009-01-15

    Chlorophyll bleaching by UV-irradiation has been studied by absorbance and fluorescence spectroscopy in extracts containing mixtures of photosynthetic pigments, in acetone and n-hexane solutions, and in aqueous thylakoid suspensions. Chlorophyll undergoes destruction (bleaching) accompanied by fluorescent transient formation obeying first-order kinetics. The bleaching is governed by UV-photon energy input, as well as by different chlorophyll molecular organizations in solvents of different polarities (in vitro), and in thylakoids (in situ). UV-C-induced bleaching of chlorophylls in thylakoids is probably caused by different mechanisms compared to UV-A- and UV-B-induced bleaching.

  15. Dielectric relaxation study of gamma irradiated oriented low-density polyethylene

    CERN Document Server

    Suljovrujic, E; Kostoski, D

    2003-01-01

    The influence of drawing, gamma irradiation and accelerated aging on the dielectric relaxation of low-density polyethylene has been studied using dielectric loss tangent measurements in the temperature range from 25 to 325 K and in the frequency range from 10 sup 3 to 10 sup 6 Hz. The intensity, position and activation energy of the gamma- and beta-dielectric relaxations were found to be strongly dependent upon the changes in the microstructure of the amorphous phase induced by uniaxial orientation, oxidation and crosslinking.

  16. Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

    2012-04-01

    The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

  17. In Situ Studies on the Irradiation-Induced Twin Boundary-Defect Interactions in Cu

    Science.gov (United States)

    Fan, C.; Li, Jin; Fan, Zhe; Wang, H.; Zhang, X.

    2017-08-01

    Polycrystalline Cu films with nanoscale annealing twins are subjected to in situ Kr++ ion irradiation at room temperature inside a transmission electron microscope up to a dose of 1 displacement-per-atom. Radiation induces prominent migration of incoherent twin boundaries. Depending on twin thickness, three types of twin boundary evolutions are observed, including rapid detwinning, gradual detwinning, and self-healing. The mechanism of twin thickness-dependent evolution of microstructures is discussed. This study provides further evidence on twin boundary-defect interactions and may assist the design of radiation-tolerant twinned metallic materials.

  18. Neutron beam irradiation study of workload dependence of SER in a microprocessor

    Energy Technology Data Exchange (ETDEWEB)

    Michalak, Sarah E [Los Alamos National Laboratory; Graves, Todd L [Los Alamos National Laboratory; Hong, Ted [STANFORD; Ackaret, Jerry [IBM; Sonny, Rao [IBM; Subhasish, Mitra [STANFORD; Pia, Sanda [IBM

    2009-01-01

    It is known that workloads are an important factor in soft error rates (SER), but it is proving difficult to find differentiating workloads for microprocessors. We have performed neutron beam irradiation studies of a commercial microprocessor under a wide variety of workload conditions from idle, performing no operations, to very busy workloads resembling real HPC, graphics, and business applications. There is evidence that the mean times to first indication of failure, MTFIF defined in Section II, may be different for some of the applications.

  19. Depletion analysis and sensitivity study of PHENIX fuel-irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, D.; Kallfelz, J.M.; White, J.R.

    1981-01-01

    The experimental results are in the form of various U and Pu atom density ratios (R/sub E/) and burnup (BU) values. The results were for samples irradiated during the first three cycles in the central zone of PHENIX. The time-dependent sensitivity study was performed with the depletion generalized perturbation code DEPTH-CHARGE, to investigate the sensitivity of R/sub E/ to cross sections and to absolute flux level changes. The depletion analysis was performed using ENDS/B-IV data, an (R-Z) model, and the VENTURE Code system. 2 tables.

  20. Doppler ultrasound study and venous mapping in chronic venous insufficiency.

    Science.gov (United States)

    García Carriazo, M; Gómez de las Heras, C; Mármol Vázquez, P; Ramos Solís, M F

    2016-01-01

    Chronic venous insufficiency of the lower limbs is very prevalent. In recent decades, Doppler ultrasound has become the method of choice to study this condition, and it is considered essential when surgery is indicated. This article aims to establish a method for the examination, including venous mapping and preoperative marking. To this end, we review the venous anatomy of the lower limbs and the pathophysiology of chronic venous insufficiency and explain the basic hemodynamic concepts and the terminology required to elaborate a radiological report that will enable appropriate treatment planning and communication with other specialists. We briefly explain the CHIVA (the acronym for the French term "cure conservatrice et hémodynamique de l'insuffisance veineuse en ambulatoire"=conservative hemodynamic treatment for chronic venous insufficiency) strategy, a minimally invasive surgical strategy that aims to restore correct venous hemodynamics without resecting the saphenous vein. Copyright © 2015 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  1. A DESCRIPTIVE STUDY OF FUNGAL INFECTIONS IN CHRONICALLY DISCHARGING EARS

    Directory of Open Access Journals (Sweden)

    Sujatha

    2015-08-01

    Full Text Available BACKGROUND : Chronic Suppurative Otitis Media (CSOM is a disease of multiple aetiology and well known for its persis tence and recurrence inspite of treatment and are the bearbug of otologist, paediatrician and general practitioner. One of the reason s for the refractoriness to treatment and chronicity is coexist ing fungal infection of the ear. OBJECTIVES: Are to find out the prevalence of fungal infections in chronic discharging ears and to identify and isolate the type of fungus prevalent in these ears . MATERIALS AND METHOD S: Tertiary care hospital level descrip tive study was conducted in 50 cases of CSOM with actively discharging ears for a period of one year starting from February 2013. For all the cases aural swabs were collected from the diseased ear and were used for direct microscopic examination in potassi um hydroxide wet mount. Ear swab was cultured on Sabouraud’s dextrose agar plate for fungal cultures. The patient characteristics were prospectively recorded and results were analysed. CONCLUSION : There is high prevalence of coexisting fungal infection in actively discharging ears of CSOM patients

  2. A pharmacokinetic study of roxatidine acetate in chronic renal failure.

    Science.gov (United States)

    Lameire, N; Rosenkranz, B; Maass, L; Brockmeier, D

    1988-01-01

    The pharmacokinetics of a single oral dose of roxatidine acetate 150 mg were studied in 31 patients with varying degrees of chronic renal failure. The patients were divided into 5 groups according to their creatinine clearance (Clcr): controls (Clcr 94.5 +/- 13.9 ml/min; n = 6); mild chronic renal failure (Clcr 47 +/- 6 ml/min; n = 4); moderate chronic renal failure (Clcr 27.3 +/- 3.1 ml/min; n = 4); severe chronic renal failure (Clcr 12.8 +/- 1.4 ml/min; n = 5) and uraemia (Clcr 6.6 +/- 0.6 ml/min; n = 12). Serum and urine samples were analysed with capillary gas chromatography to measure the salt of the desacetyl metabolite of roxatidine acetate (roxatidine). The terminal half-life was 6.02 +/- 0.31 hours in controls and 7.35 +/- 0.57, 9.3 +/- 0.83, 14.6 +/- 3.7 and 18.10 +/- 2.77 hours, respectively, in the 4 other groups, with progressively decreasing creatinine clearance. Maximum serum concentration and time to maximum serum concentration rose from 816 +/- 75 ng/ml and 2.08 +/- 0.22 hours, respectively, in controls to 1364.7 +/- 156 ng/ml and 4.05 +/- 0.47 hours, respectively, in uraemic patients. Relative total clearance progressively decreased with decreasing glomerular filtration rate (GFR) [from 353.6 +/- 26 ml/min in controls to 90.31 +/- 12.2 ml/min in patients with uraemia]. Renal clearance decreased from a control of 243.9 +/- 56 ml/min to 12.32 +/- 0.18 ml/min in uraemic patients. A linear correlation between creatinine clearance and both relative total clearance and renal drug clearance was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Preliminary studies of the rubber from unserviceable tires irradiated by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Clecia M.; Silva, Leonardo G. Andrade e, E-mail: blgasilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Nowadays there is a growth in the developing processes for modification of polymers with ionizing radiation (gamma rays, electron beam) for several industrial applications. An option is ionizing radiation process due to their capacity of inducing crosslinking and scission on a wide range of polymeric materials without initiators or chemicals products. This method has significant advantages on economical and ecological fields, when compared to chemical, thermal and mechanical process. The rubber recycling has been extensively discussed, mainly related to tire. There are reports with data about production and consumption of rubber and unserviceable tire. There is very few information about the destination of others rubber items, incineration and landfill are the main methods for elimination of unserviceable tire, however those methods are not environmentally friendly. It is necessary to study better and effective methods to recycle and to give value to rubber residue. This work is about the use of ionizing radiation for the recovery and/or reuse and processing rubber of unserviceable tire. The samples were irradiated with 200, 400 and 600 kGy radiation dose, 22.39 kGy/s dose rates, at room temperature and in the presence of air using an 1.5 MeV electron beam accelerator. The irradiated and non-irradiated samples were studied by thermogravimetry (TG). The analyses were performed from room temperature up to 600 deg C, heating rate of 10 deg C/min in the presence of nitrogen (N{sub 2}) and air. By this technique it was possible to observe the effects of the radiation dose on the weight loss. (author)

  4. The medical management of high risk individuals. Experiences with persons exposed to chronic internal irradiation; Ueber den aerztlichen Umgang mit Hochrisikopersonen. Erfahrungen bei Personen mit chronischer interner Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Kaick, G. van; Delorme, S. [Deutsches Krebsforschungszentrum, E010 - Radiologie, Heidelberg (Germany)

    2011-12-15

    The medical management and counseling of persons at high risk due to exposure to chemicals or radiation or due to personal disposition, present an additional challenge for physicians and especially radiologists involved. This article is based on own experiences with patients who had been exposed to Thorotrast. They had been injected with the contrast medium Thorotrast, which was in use world-wide until around 1950. Thorotrast caused a chronic alpha irradiation mainly of the liver (up to 0.4 Gy/a), spleen (1.2 Gy/a) and bone marrow (0.1 Gy/a). For the Thorotrast patients and their physicians the most worrying problem was the risk of primary malignant liver tumors which occurred in more than 20% of the exposed persons, i.e. 100 times more frequently than in a non-exposed control group. The medical and especially radiological experiences with the management of these patients summarize a general aspect of the problem and can be referred to when managing other high risk groups. (orig.) [German] Die aerztliche Fuehrung von Personen, die noch nicht erkrankt sind, aber ein deutlich hoeheres Risiko fuer bestimmte Tumorerkrankungen aufgrund exogener oder endogener Ursachen haben, stellt den Arzt und speziell den diagnostischen Radiologen vor neue Herausforderungen. Dem Beitrag zugrunde liegen die Erfahrungen bei der Betreuung und Beratung so genannter Thorotrastpatienten, d. h. Personen, die nach lange zurueckliegender (vor 1950) intravasaler Injektion eines weltweit eingesetzten Roentgenkontrastmittels zeitlebens einer Alphastrahlung v. a. der Leber (bis 0,4 Gy/a), der Milz (1,2 Gy/a) und des Knochenmarks (0,1 Gy/a) ausgesetzt waren. Fuer die Thorotrastpatienten und die Aerzte stand im Vordergrund die Sorge der Entstehung primaerer, maligner Lebertumoren, die bei mehr als 20% der Betroffenen und damit im Vergleich zu einer Kontrollgruppe 100-fach haeufiger auftraten. Die allgemeinen aerztlichen und speziell radiologischen Erfahrungen sind grundsaetzlicher Art und lassen

  5. Comparative study on the effect of electron beam irradiation on the physical properties of ethylene-vinyl acetate copolymer composites

    Science.gov (United States)

    Wang, Bibo; Hong, Ningning; Shi, Yongqian; Wang, Biao; Sheng, Haibo; Song, Lei; Tang, Qinbo; Hu, Yuan

    2014-04-01

    Ethylene-vinyl acetate copolymer (EVA) flame retarded by a combination of cellulose acetate butyrate (CAB) microencapsulated ammonium polyphosphate (MCAPP) and polyamide-6 (PA-6) have been crosslinked by high energy electron beam irradiation. The effect of high energy electron beam irradiation on the crosslinking degree, mechanical, electrical and thermal properties of EVA/MCAPP/PA-6 cable material was studied by gel content, heat extention test, mechanical test, dynamic mechanical analysis, high-insulation resistance meter and thermogravimetric analysis. The gel content and heat extention test results showed that the EVA/MCAPP/PA-6 composites can be easily crosslinked by electron beam irradiation. The tensile strength of EVA composites was drastically increased from 16.2 to maximum 26.2 MPa as the electron beam irradiation dose increases from 0 to 160 kGy. The volatilized products of EVA/MCAPP/PA-6 composites were analyzed and compared by thermogravimetric analysis/infrared spectrometry (TG-FTIR).

  6. A STUDY ON MECHANICAL PROPERTIES OF γ-RAY IRRADIATED HDPE FILLED WITH SERICITE-TRIDYMITE-CRISTOBALITE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The effect of γ-ray irradiation on the mechanical properties of high density polyethylene(HDPE) filled with sericite-tridymite-cristobalite(STC) was studied. The experimental results show that γ-ray irradiation can improve the affinity between HDPE and STC, and the dispersion of STC in HDPE matrix. Compared with HDPE/STC (80/20)blend, the yield stress and impact strength of irradiated HDPE (10kGy)/STC (80/20) blend are increased from 22.8 MPa and 70J/m to 28.5 MPa and 144J/m. The yield stress and impact strength of HDPE/irradiated HDPE/STC (48/32/20) are 27.8MPa and 210J/m,respectively.

  7. [Study of the effects of gamma-irradiation of common wheat F1 seeds using gliadins as genetic markers].

    Science.gov (United States)

    Kozub, N O; Sozinov, I O; Blium, Ia B; Sozinov, O O

    2013-01-01

    Effects of irradiation of dry F1 seeds with gamma rays in the dose of 200 Gy were studied. Hybrids between near-isogenic lines on the basis of the variety Bezostaya 1 served as the material of investigation. Irradiation markedly reduced productivity traits of F1 plants and did not affect the survival of F1 plants under the given growth conditions. A significant relative increase in the frequency of pollen grains with the 1BL/1RS translocation that formed F2 seeds in comparison with the control was one of the effects of irradiation of F1 seeds. Irradiation with gamma-rays induced mutations at gliadin loci with the frequency of 7,4 % (at 0,5 % in the control).

  8. DSC studies of gamma irradiation influence on gelatinisation and amylose-lipid complex transition occurring in wheat starch

    Science.gov (United States)

    Cieśla, K.; Eliasson, A.-C.

    2003-12-01

    Differential scanning calorimetry studies are presented dealing with the influence of gamma irradiation (carried out in the solid state) on the structure of amylose-lipid complex in wheat starch . Suspensions of the control and the wheat starch irradiated with a 30 kGy gamma rays (characterised by starch-to-water ratio of 1:1 and ca. 1:4) were examined during several courses of heating and cooling at rates of 2.5 and 10°C min -1. Differences were observed between enthalpy and temperature of gelatinisation and amylose-lipid complex transition as well as retrogradation taking place in the suspensions and gels of the control and the irradiated starch. The influence of the preceding heating and cooling on further transformations of the amylose-lipid complex differs for the control and the irradiated samples.

  9. Electron Paramagnetic Resonance Study of Defects in γ-irradiated Marine Mussel (Mytilus galloprovincialis) and Scallop (Pecten jacobaeus) Shells

    Science.gov (United States)

    Köseoğlu, R.; Köksal, F.; Birey, M.

    2004-11-01

    EPR studies have been performed on some gamma-irradiated marine mussels (Mytilus galloprovincialis) and scallops (Pecten jacobaeus) from the families of Mytilidae and Pectinidae, respectively. Before γ-irradiation, the EPR lines of Mytilus galloprovincialis indicated the existence of Mn2+ ions, which were not observed in the powders of scallop shells. γ -irradiation induced defects in powders of Mytilus galloprovincialis shells, were attributed to orthorhombic CO-3 , axial CO3-3 , orthorhombic CO-2 , freely rotating CO-2 , freely rotating SO-2 , axial SO-3 , isotropic PO2-4 and organic free radicals. γ -irradiation induced defects in powders of Pecten jacobaeus shells were attributed to orthorhombic CO-3 , axial CO3-3 , orthorhombic CO-2 , freely rotating CO-2 , freely rotating SO-2 , and axial SO-3 free radicals. The EPR parameters of the free radicals were compared with literature data on similar defects

  10. Studies on enhancing the keeping quality of peach (Prunus persica Bausch) Cv. Elberta by gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, P.R.; Meena, R.S.; Dar, M.A. [Nuclear Research Laboratory, Bhabha Atomic Research Centre, Zakura, Srinagar-190006 (India); Wani, A.M. [Nuclear Research Laboratory, Bhabha Atomic Research Centre, Zakura, Srinagar-190006 (India)], E-mail: alimwani@yahoo.co.uk

    2008-04-15

    The effect of gamma-irradiation on keeping quality of peach fruit was studied. The fruit, after harvesting at proper maturity stage, was irradiated in the dose range of 1.0-2.0 kGy, stored under ambient (temp. 25{+-}2 deg. C, RH 70%) and refrigerated (temp. 3{+-}1 deg. C, RH 80%) conditions and evaluated periodically for firmness, total soluble solids (TSS), anthocyanins, water-soluble pectic fractions, loss in weight and decay percentage. The anthocyanin evaluation of the fruits revealed that irradiation enhanced the colour development under both the storage conditions. The gamma-irradiation dose range of 1.2-1.4 kGy proved effective in maintaining higher TSS concentration, reducing weight loss and significantly (p{<=}0.05) delaying the decaying of the fruit by 6 days under ambient conditions and by 20 days under refrigerated storage conditions.

  11. Methylation changes in muscle and liver tissues of male and female mice exposed to acute and chronic low-dose X-ray-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, Olga; Burke, Paula; Besplug, Jill; Slovack, Mark; Filkowski, Jody; Pogribny, Igor

    2004-04-14

    The biological and genetic effects of chronic low-dose radiation (LDR) exposure and its relationship to carcinogenesis have received a lot of attention in the recent years. For example, radiation-induced genome instability, which is thought to be a precursor of tumorogenesis, was shown to have a transgenerational nature. This indicates a possible involvement of epigenetic mechanisms in LDR-induced genome instability. Genomic DNA methylation is one of the most important epigenetic mechanisms. Existing data on radiation effects on DNA methylation patterns is limited, and no one has specifically studied the effects of the LDR. We report the first study of the effects of whole-body LDR exposure on global genome methylation in muscle and liver tissues of male and female mice. In parallel, we evaluated changes in promoter methylation and expression of the tumor suppressor gene p16{sup INKa} and DNA repair gene O{sup 6}-methylguanine-DNA methyltransferase (MGMT). We observed different patterns of radiation-induced global genome DNA methylation in the liver and muscle of exposed males and females. We also found sex and tissue-specific differences in p16{sup INKa} promoter methylation upon LDR exposure. In male liver tissue, p16{sup INKa} promoter methylation was more pronounced than in female tissue. In contrast, no significant radiation-induced changes in p16{sup INKa} promoter methylation were noted in the muscle tissue of exposed males and females. Radiation also did not significantly affect methylation status of MGMT promoter. We also observed substantial sex differences in acute and chronic radiation-induced expression of p16{sup INKa} and MGMT genes. Another important outcome of our study was the fact that chronic low-dose radiation exposure proved to be a more potent inducer of epigenetic effects than the acute exposure. This supports previous findings that chronic exposure leads to greater genome destabilization than acute exposure.

  12. Study of the influence of homologous serum globulin preparations on the intestinal automicroflora in irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Pinegin, B.V.; Klemparskaya, N.N.; Mal' tsev, V.N.; Korshunov, G.A.; Shal' nova, G.A.; Kuz' mina, T.D.

    1984-09-01

    In spite of considerable experience of practical use of serum globulin preparations, their effect on automicroflora wasn't studied. The favorable effect of therapeutic injection of homologous serum globulin preparations on automicroflora of small and large intestine of mices was established for the model of acute radiation sickness caused by /sup 60/Co irradiation with 700 R dose. The effect of injecting two types of globulin preparations was studied: ones prepared of blood of intact and hemostimulated mices (to increase the content of normal antitissue antibodies in the serum). Besides the general globulin fraction isolated by ammonium sulfate precipitation a study was made on the effect of purified IgG and IgM preparations. Threefold subcutaneous or intraperitoneal globulin in ection of 1 ..mu..g dose in a mice prevented after 2, 24, 48 h after irradiation the development of bacteriosis, typical for radiation injury - decreased accumulation of putrefactive bacteria and reduced the suppression of lactobacilli content. Globulin preparations and fractions of hemostimulated mice serum, enriched by normal antitissue antibodies are the most effective ones.

  13. Neuro-immune response and sleep studies after whole body irradiation with high-LET particles

    Energy Technology Data Exchange (ETDEWEB)

    Marquette, C.; Bertho, J.M.; Wysoki, J.; Maubert, C.; Gerbin, R.; Aigueperse, J. [IRSN, F-92260 Fontenay Aux Roses, (France); Mathieu, J.; Galonnier, M.; Clarencon, D. [CRSSA, Dept Radiobiol and Radiopathol, F-38700 La Tronche, (France); Balanzat, E. [CEA, DSM, CIRIL, Ganil, Caen, (France)

    2009-07-01

    In order to investigate the biological effects of galactic rays on astronaut cerebral functions after space flight, mice were exposed to different heavy ions (HZE) in whole-body conditions at doses comparable to the galactic flux: {sup 12}C, {sup 16}O and {sup 20}Ne (95 MeV/u, at 42-76 mGy). Animals were also exposed to 42 mGy of {sup 60}Co radiation for comparison with HZE. The neuro-immune response, evaluated by interleukin-I (IL-1) measurement, showed that this cytokine was produced 3 h after irradiation by {sup 16}O or {sup 60}Co. In contrast, neither {sup 12}C (56.7 mGy) nor {sup 20}Ne (76 mGy) induced IL-1 production. However, immunohistochemical staining of {sup 12}C-irradiated mouse brain tissue showed 2 months later a marked inflammatory reaction in the hippocampus and a diffuse response in parenchyma. Sleep studies were realized before and after exposure to 42 mGy of {sup 16}O and 76 mGy of {sup 20}Ne: only the {sup 20}Ne radiation displayed a small effect. A slight decrease in paradoxical sleep, corresponding to a reduction in the number of episodes of paradoxical sleep, was manifested between 8 and 22 days after exposure. Exposure to {sup 12}C and {sup 16}O induced no changes either in cellularity of spleen or thymus, or in caspase 3 activity (as much as four months after irradiation). Taken together, these data indicate that the CNS could be sensitive to heavy ions and that responses to HZE impact depend on the nature of the particle, the dose threshold and the time delay to develop biological processes. Differences in responses to different HZE highlight the complex biological phenomena to which astronauts are submitted during space flight. (authors)

  14. I- V and deep level transient spectroscopy studies on 60 MeV oxygen ion irradiated NPN transistors

    Science.gov (United States)

    Gnana Prakash, A. P.; Ke, S. C.; Siddappa, K.

    2004-02-01

    NPN transistors have been irradiated by 60 MeV oxygen ions in a fluence ranging from 5 × 10 10 to 1 × 10 13 ions/cm 2. The DC current gain ( hFE), excess base current ( ΔI B=I B post -I B pre ), excess collector current ( ΔI C=I C post -I C pre ) and collector saturation current (I C Sat ) of the ion irradiated transistors were studied systematically. The hFE of the transistors were found to be decreased drastically after ion irradiation. A significant increase has been observed in the collector current ( IC) along with the increase in the base current ( IB) after ion irradiation. The I C Sat of the ion irradiated transistors were also decreased significantly after irradiation. The radiation induced trap levels in the collector base depletion region of NPN transistors were studied by deep level transient spectroscopy technique and different types of trap levels were observed. The results obtained on the activation energy, density of trap levels, apparent capture cross section, introduction rate and space charge layer lifetime of different defects for different total fluence are presented and discussed.

  15. The study of the carriers’ transport mechanism of GaAs/Ge solar cells based on irradiation damage model

    Energy Technology Data Exchange (ETDEWEB)

    Yanhui, Sheng [Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Jianmin, Hu, E-mail: hujianmin@foxmail.com [Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Jiahong, Qi [Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Yueyuan, Wang, E-mail: yywang72@foxmail.com [Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Yiyong, Wu [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Jianwen, Xu [Shanghai Institute of Space Power Sources, Shanghai 200233 (China)

    2015-10-01

    Based on the irradiation damage model of solar cells, the irradiation damage mechanism of space solar cells from the aspect of the carriers’ transport is studied. The basic rules of electrical parameter degradation of GaAs/Ge solar cells under different energy proton and electron irradiation are obtained through the ground-accelerated equivalent simulation test for space-charged particles. The open-circuit voltage degradation curves of the solar cells are fitted nonlinearly by its mathematical model. The change laws of damage coefficient of majority carriers’ removal rate with the incident proton and electron energy are given. The damage coefficient of GaAs/Ge solar cells first increases and then decreases with increasing incident proton energy, and it reaches a maximum at 100 keV proton irradiation. In addition, the damage coefficient increases with increasing incident electron energy. The studies show that open-circuit voltage degradation is closely related to the removal effect of the majority carriers under charged particle irradiation. The results have important significance to reveal the irradiation damage mechanism of the space solar cells.

  16. Studies of defects and annealing behavior of silicon irradiated with 70 MeV {sup 56}Fe ions

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, S.K. [Department of Physics, University of Mumbai, Vidyanagari Campus, Mumbai 400 098 (India)]. E-mail: skdubey@physics.mu.ac.in; Yadav, A.D. [Department of Physics, University of Mumbai, Vidyanagari Campus, Mumbai 400 098 (India); Kamalapurkar, B.K. [Department of Physics, University of Mumbai, Vidyanagari Campus, Mumbai 400 098 (India); Gundu Rao, T.K. [Regional Sophisticated Instrumentation Centre, Indian Institute of Technology, Mumbai 400 076 (India); Gokhale, M. [Tata Institute of Fundamental Research, Mumbai 400 005 (India); Mohanty, T. [Nuclear Science Centre, New Delhi 110 067 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi 110 067 (India)

    2006-03-15

    The effects of 70 MeV irradiation of iron ions in p-type silicon at fluences between 1 x 10{sup 12} and 5 x 10{sup 14} ions cm{sup -2} were investigated by high resolution X-ray diffraction (HRXRD), electron spin resonance (ESR) and current-voltage measurements. The irradiated samples were isochronally annealed in nitrogen ambient up to 973 K for 2 min using the rapid thermal annealing (RTA) system. The screw dislocation density of the annealed sample (5 x 10{sup 14} ions cm{sup -2}) estimated at each stage of annealing from the broadening of the HRXRD peak was observed to change from 8.70 x 10{sup 7} to 1.58 x 10{sup 7} cm{sup -2} with increasing temperatures. The strain and stress parameters estimated at each stage of annealing using the FWHM of {omega}-scan clearly indicate relative trend towards the un-irradiated silicon sample. The electron spin resonance studies indicate the presence of the dangling bond state of silicon (Si{identical_to}Si) and complex defects. The annealing at 873 K was found to be sufficient for complete removal of the defect centers induced due to irradiation. The I-V studies performed on the irradiated samples before and after annealing indicate that the defects created as a consequence of irradiation trap the charge carriers.

  17. Effect of phosphorus on vacancy-type defect behaviour in electron-irradiated Ni studied by positron annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Druzhkov, A.P., E-mail: druzhkov@imp.uran.ru; Danilov, S.E.; Perminov, D.A.; Arbuzov, V.L.

    2015-02-15

    Very dilute Ni–P system (containing 50–240 appm phosphorus) irradiated by 5 MeV electrons at various temperatures (270–543 K) was studied by positron annihilation spectroscopy (PAS) and the electrical resistivity measurements. Under irradiation at 270 K (below stage III in Ni), the accumulation of the monovacancies in the Ni–P system is 1.5–2.0 times greater than that in pure Ni irradiated in the same conditions. This fact attests to the strong interaction between P atoms and self-interstitial atoms (SIAs). As a result of the non-mobile SIA–P complexes formation, the mutual recombination of point defects is suppressed and the vacancy accumulation is, respectively, enhanced. During post-irradiation annealing, the vacancy migration induces the transport process of the phosphorus atoms and leads to the formation of the vacancy clusters decorated with P atoms. The annealing behaviour of the defect structures in Ni–P systems after irradiation at enhanced temperatures was also studied. The influence of phosphorus on the formation and further evolution of the vacancy aggregates decrease with increasing of the irradiation temperature.

  18. X-ray diffraction studies of 145MeV proton-irradiated AlBeMet 162

    Directory of Open Access Journals (Sweden)

    Mohamed Elbakhshwan

    2016-08-01

    Full Text Available AlBeMet 162 (Materion Co., formerly Brush Wellman has been irradiated with 145MeV protons up to 1.2×1020cm−2 fluence, with irradiation temperatures in the range of 100–220°C. Macroscopic post-irradiation evaluation on the evolution of mechanical and thermal properties was integrated with a comprehensive X-ray- diffraction study using high-energy monochromatic and polychromatic X-ray beams, which offered a microscopic view of the irradiation damage effects on AlBeMet. The study confirmed the stability of the metal–matrix composite, its resistance to proton damage, and the continuing separation of the two distinct phases, fcc aluminum and hcp beryllium, following irradiation. Furthermore, based on the absence of inter-planar distance change during proton irradiation, it was confirmed that the stacking faults and clusters on the Al (111 planes are stable, and thus can migrate from the cascade region and be absorbed at various sinks. XRD analysis of the unirradiated AlBeMet 162 showed clear change in the texture of the fcc phase with orientation especially in the Al (111 reflection which exhibits a “non-perfect” six-fold symmetry, implying lack of isotropy in the composite.

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

    Science.gov (United States)

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

    2016-07-01

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

  20. Hepatitis-related stigma in chronic patients: A qualitative study.

    Science.gov (United States)

    HassanpourDehkordi, Ali; Mohammadi, Nooredin; NikbakhatNasrabadi, Alireza

    2016-02-01

    Hepatitis is one of health problems throughout the world. It has numerous consequences on patients' life. Stigma, depression, social marginalization and financial problems are some of the challenges in these patients. The purpose of this qualitative study was to examine hepatitis-related stigma and discrimination in patients living with chronic hepatitis in Iranian society. This present study was designed as a qualitative method, and this article shows up the results of a qualitative research study undertaken with patients living with hepatitis in Iran. The study uses a content analysis method. A purposive sample of 18 patients was chosen. Data were collected through a semi-structured interview and field note that the researchers will take during participants' observation. Data analysis process was performed on the texts which were generated from verbatim transcripts of the participants interviews. Participants were between 18 and 61 years old. The main theme, Stigma, emerged from three themes during the process data analysis in this study. These themes were including fear to lose of family and social support, fear to present in public and fear of transmission. This research indicates that stigma presents major challenges not only for patients living with chronic hepatitis but also for nurses, other healthcare practitioners, family and social networks, institutions and society. The researcher suggests that interventions to reduce or eliminate stigma should require individual, structural, cultural thought, society and systemic changes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Comparative study by IBIC of Si and SiC diodes irradiated with high energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Lopez, J., E-mail: fjgl@us.es [Dpto. Física Atómica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); CNA (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, 41092 Sevilla (Spain); Jimenez-Ramos, M.C.; Rodriguez-Ramos, M. [CNA (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, 41092 Sevilla (Spain); Ceballos, J. [Institute of Microelectronics of Seville, IMSE-CNM (CSIC/University of Seville), Seville 41092 (Spain); Linez, F. [Department of Applied Physics, Aalto University, 02150 Espoo (Finland); Raisanen, J. [Department of Physics, University of Helsinki, Helsinki 00014 (Finland)

    2016-04-01

    The transport properties of a series of Si and SiC diodes have been studied using the Ion Beam Induced Charge (IBIC) technique. Structural defects were induced into the samples during the irradiation with 17 MeV protons. The experimental values of the charge collection efficiency (CCE) vs bias voltages have been analyzed using a modified drift-diffusion model, which takes into account the recombination of carriers in the neutral and depletion regions. From these simulations, we have obtained the values of the carrier’s lifetime for pristine and irradiated diodes, which are found to degrade faster in the case of the SiC samples. However, the decrease of the CCE at high bias voltages is more important for the Si detectors, indicative of the lower radiation hardness of this material compared to SiC. The nature of the proton-induced defects on Si wafers has been studied by Positron Annihilation Spectroscopy (PAS) and Doppler Broadening Spectroscopy (DBS). The results suggest that the main defect detected by the positrons in p-type samples is the divacancy while for n-type at least a fraction of the positron annihilate in another defect. The concentration of defects is much lower than the number of vacancies predicted by SRIM.

  2. Data Fitting to Study Ablated Hard Dental Tissues by Nanosecond Laser Irradiation.

    Directory of Open Access Journals (Sweden)

    Y Al-Hadeethi

    Full Text Available Laser ablation of dental hard tissues is one of the most important laser applications in dentistry. Many works have reported the interaction of laser radiations with tooth material to optimize laser parameters such as wavelength, energy density, etc. This work has focused on determining the relationship between energy density and ablation thresholds using pulsed, 5 nanosecond, neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12 (Nd:YAG laser at 1064 nanometer. For enamel and dentin tissues, the ablations have been performed using laser-induced breakdown spectroscopy (LIBS technique. The ablation thresholds and relationship between energy densities and peak areas of calcium lines, which appeared in LIBS, were determined using data fitting. Furthermore, the morphological changes were studied using Scanning Electron Microscope (SEM. Moreover, the chemical stability of the tooth material after ablation has been studied using Energy-Dispersive X-Ray Spectroscopy (EDX. The differences between carbon atomic % of non-irradiated and irradiated samples were tested using statistical t-test. Results revealed that the best fitting between energy densities and peak areas of calcium lines were exponential and linear for enamel and dentin, respectively. In addition, the ablation threshold of Nd:YAG lasers in enamel was higher than that of dentin. The morphology of the surrounded ablated region of enamel showed thermal damages. For enamel, the EDX quantitative analysis showed that the atomic % of carbon increased significantly when laser energy density increased.

  3. Thermoluminescence studies on γ-irradiated CaF2:Dy:Pb:Na single crystals

    Institute of Scientific and Technical Information of China (English)

    S. Masilla Moses Kennedy

    2009-01-01

    Thermoluminescence (TL) glow, thermoluminescence emission (TLE) and thermal decay (TD) of optical absorption (OA) bands were studied on γ-irradiated CaF2:Dy (0.010at.%):Pb (0.188at.%):Na (0.026at.%) single crystals (hereafter called crystal-I). The TL glow ex-hibited four glow peaks in the temperature region 300-600 K. The TL response with dose was studied up to ~7.5 kGy. The total glow showed linear, supra linear and exponential growth with dose. The TLE showed bands characteristic of Dy3+ ions (around 1.65, 1.87, 2.18 and 2.63 eV) and sodium associated (SA) colour centres (CCs) such as MNa (around 1.67 eV) and XNa (a new SA CC, with an emission band around 2.63 eV). The OA bands of MNa CC around 3.23 and 2.07 eV were found to decrease with temperature almost in accordance with the TL glow. The R+A centre absorption around 2.48 eV was found to grow with temperature initially and then decayed. The formation/growth of the CCs R+A and XNa might be from the conversion of the irradiation produced CC MNa- An attempt was made to explain the TL mechanism in the present system.

  4. Controlled study of lactoperoxidase gel on oral flora and saliva in irradiated patients with oral cancer.

    Science.gov (United States)

    Nagy, Katalin; Urban, Edit; Fazekas, Olga; Thurzo, Laszlo; Nagy, Elisabeth

    2007-09-01

    The aim of this study was to determine if radiotherapy induces hyposalivation altering oral microbial flora. The purpose of this placebo-controlled, single-blind study was to determine beneficial effects of a saliva substitute and an oral hygiene product on irradiated patients with oropharyngeal cancer. Eighteen patients were assigned to the test group (Biotène Oral Balance gel [Lacléde Incorporated Healthcare Products, Gardena, CA] and toothpaste used daily), and another 18 were put on a conventional daily regimen (carboxymethylcellulose gel and Oral-B toothpaste [Laclede Pharmaceuticals, Gardena, CA]). Cultures for identifying and quantitating microorganisms, whole unstimulated saliva, and visual analog measurements for comfort were obtained before mucositis occurred and after treatment. Daily use of Biotène products enhanced control of microbial flora, improved salivary flow, and increased oral comfort as compared with control subjects. Four weeks after mucositis, some aerobic isolates disappeared in the test group; periodontal-associated bacteria were markedly decreased in the test group; and candidal species were significantly lowered in the test group. Although baseline saliva was lower in the test group (P = 0.001), after 4 weeks, no difference between groups existed; comfort was greater in the test group (P = 0.007). Use of enzyme-engineered Biotène products that assist in control of the oral microbial flora as well as supporting oral comfort through lubrication appear to be useful aids for irradiated patients with oropharyngeal cancer.

  5. Chronic pain in multiple sclerosis: A 10-year longitudinal study.

    Science.gov (United States)

    Young, Jamie; Amatya, Bhasker; Galea, Mary P; Khan, Fary

    2017-07-01

    Pain is a common symptom associated with multiple sclerosis (MS), and has lasting effects on an individual's functional capacity and quality of life. A wide range of prevalence rates of pain (between 23% and 90%)have been reported in MS and this is mainly due to the methodological differences amongst the studies such as variability in patient sources, method of sampling and the definition of pain used. Chronic pain in MS, defined as pain lasting for greater than 3-6 months, can have a significant impact on their biopsychosocial health, including negative impact on activities of daily living, relationships and social participation. The long-term course of MS-related pain and its impact in an Australian cohort over a 7-year period has been investigated earlier. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period. This was a prospective longitudinal study conducted at the Rehabilitation Department of Royal Melbourne Hospital (RMH), a tertiary referral hospital in Victoria and Australia. The source of participants was from the RMH MS database and contains detailed MS patient information including demographic data, diagnosis details (using McDonald's criteria), pain characteristics. Structured face-face interviews and validated measures were used, which include the visual analogue scale (VAS); chronic pain grade (CPG); the assessment of quality of life (AQoL) and the carer strain index (CSI). The mean age of the participants (n=70) was 55.3 years and majority (70%) were female. The mean age of the participants (n=70) was 55.3 years and majority (70%) were female. The findings show that over time (10 years), participants report having greater bilateral bodily pain and greater description of pain as 'worse

  6. Irradiation Defects in Silicon Crystal

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The application of irradiation in silicon crystal is introduced.The defects caused by irradiation are reviewed and some major ways of studying defects in irradiated silicon are summarized.Furthermore the problems in the investigation of irradiated silicon are discussed as well as its properties.

  7. The effect of irradiation on the intracellular transportation of the parotid gland acinar cells in the mouse. Localization of monosaccharides studied by electron microscopic autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Hajime (Nippon Dental Univ., Tokyo (Japan))

    1994-06-01

    The present study was designed to investigate the effects of radiation on the ability to ingest monosaccharides and intracellular transportation in the parotid gland in mice. The submandibular regions, including the parotid gland, was exposed to 10 Gy of X-rays. Three days after irradiation, the localization of reducing silver grains in organelles was determined, using electron microscopic autoradiography with H-3 labeled galactosamine, glucosamine, fucose, and mannose. In the non-irradiated group, the proportion of reducing silver grains in the acinar cells began to increase 15 min after administration of monosaccharides, reached a peak at 180 min, and thereafter decreased. Similar findings were observed in the irradiated group, although the values were lower than the non-irradiated group. The proportion of reducing silver grains in the endoplasmic reticulum reached a peak at 15 min in both the non-irradiated and irradiated groups, and gradually decreased until 120 min. Thereafter, it became almost constant and low, but the proportion in the irradiated group was slightly higher than in the non-irradiated group. The proportion of reducing silver grains in the Golgi apparatus was maximum at 60 min in the non-irradiated group, and gradually decreased until 360 min. A similar tendency was seen in the irradiated group, although its variation was not so marked as in the non-irradiated group. The proportion of reducing silver grains in the condensing vacuoles was maximum at 120 min, and thereafter, it decreased; the decrease was only slight in the irradiated group. The proportion of reducing silver grains in secretory granules increased with time in both the non-irradiated and irradiated groups, although this was only slight in the irradiated group, and reached a peak at 360 min. Transportation of monosaccharides in an acinar cell was found to be delayed by irradiation. (N.K.).

  8. Chronic lymphocytic leukaemia: case control epidemiological study in Yorkshire.

    Science.gov (United States)

    Cartwright, R A; Bernard, S M; Bird, C C; Darwin, C M; O'Brien, C; Richards, I D; Roberts, B; McKinney, P A

    1987-07-01

    This is the second report of a large case control study of lymphoma/leukaemia occurring in Yorkshire during 1979-84, and deals with chronic lymphocytic leukaemia presenting either in its haematological (CLL) or more solid lymphomatous (malignant lymphoma-lymphocytic or MLL) forms. In all, 330 cases and 561 controls were interviewed. The results support the concept that CLL/MLL is a condition of multiple aetiologies with evidence for genetic predisposition through an excess of family cases, immune perturbation demonstrated by excessive previous skin diseases and phenylbutazone use, and viral involvement shown by links with infectious diseases and multiple sclerosis.

  9. Chronic myeloproliferative neoplasms and subsequent cancer risk: a Danish population-based cohort study

    DEFF Research Database (Denmark)

    Frederiksen, Henrik Kronholm; Farkas, Dóra Körmendiné; Christiansen, Christian Fynbo

    2011-01-01

    Patients with chronic myeloproliferative neoplasms, including essential thrombocythemia (ET), polycythemia vera (PV), and chronic myeloid leukemia (CML), are at increased risk of new hematologic malignancies, but their risk of nonhematologic malignancies remains unknown. In the present study, we ...

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

    Science.gov (United States)

    Stalin, A; Broos, K V; Sadiq Bukhari, A; Syed Mohamed, H E; Singhal, R K; Venu-Babu, P

    2013-11-15

    This study was framed to investigate the (60)Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD50 value of (60)Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3,000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of the organs it is felt could affect the vital physiological functions such as respiration, osmotic and ionic regulation in gills and muscles; absorption, storage and secretion of the hepatopancreas which in turn could adversely affect the growth and survival of freshwater prawn M. rosenbergii.

  11. Study on food preservation by irradiation of agricultural and marine products from Cheju island

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Kim, S.H.; Choung, C.C.; Cho, H.O. (Jeju Univ. (Republic of Korea))

    1984-01-01

    Salted dry yellow sea bream were vaccum packed in a plastic bags and irradiated at differents levels (0,0.5,1.0,1.5, and 2.0 Mrad) using sup(60)Co source. The irradiated samples were stored at room temperature 5degC. Physical and chemical properties were examined during storage. The total bacterial count was depressed according to level of irradiation applied. It was noted that cold storage after irradiation was more effective than room temperature. TMA contents slowly increased with higher dosage rates up to 1.5 Mrad but there was a gradual decrease of TMA at the 2.0 Mrad level. It was observed that there was a rapid decrease of TMAO 20 days after irradiation irrespective of storage temperature. The reduction of total nitrogen content was highest in the control but to a lesser degree when irradiation was applied. VBN content increased in all treatments 30 days after irradiation but it was also noted that there was a tendency toward depression of VBN by irradiation. The shelf life of salted dry sea bream was extended by 20 days with irradiation plus room temperature, and by 40 days with irradiation plus cold storage. To extend shelf life of salted dry sea bream, the most effective dosage rate was 1.0 Mrad based on tenderness, bacterial count and rancidity.

  12. A study on the best irradiation dose of X-ray for Hep-2 cells by Fourier transform infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Renming Liu; Weiyue Tang; Guangshui Zhang; Fengqiu Zhang; Xinhui Yan

    2008-01-01

    Fourier transform infrared spectroscopy (FTIR) was employed to study the human epidermis larynx carcinoma cell lines (Hep-2) which were irradiated by different doses of X-ray.The results show that (1) the irradiation of X-ray damages the structure of the CH3 groups of the thymine in DNA,which restrains the reproduction of Hep-2 cells effectively,(2) the 8 Gy dose of X-ray irradiation changes the framework and the relative contents of some proteins,lipids and the nucleic acid molecules intercellular in the greatest degree,and (3) the 8 Gy dose of X-ray irradiation is the best irradiation dose for lowering the degree of the cancerization of Hep-2 cells according to the criteria for the degree of the cancerization reported recently.Meanwhile,the apoptosis of these cells were detected by using flow cytometry (FCM) primarily.It shows that the apoptotic ratio of the Hep-2 cells depends on the irradiation dose to some extent,but is not linearly.And the apoptotic ratio of the 12 Gy dose group is the maximum (20.36%),but the apoptotic ratios of the 2 to 8 Gy dose groups change little.

  13. Potential of recycling gamma-irradiated sewage sludge for use as a fertilizer: a study on chickpea (Cicer arietinum).

    Science.gov (United States)

    Pandya, G A; Sachidanand, S; Modi, V V

    1989-01-01

    The effects of gamma-irradiated sludge on the growth and yield of chickpea (Cicer arietinum) in pot cultures have been studied. Compared to plants grown only in soil, root length, fresh weight and dry weight of plants grown in soil supplemented with unirradiated sludge were found to be significantly reduced. This inhibition in growth was found to be nullified when plants were grown in soil supplemented with gamma-irradiated sludge, suggesting that gamma radiation induced inactivation of toxic substance(s) in sludge. The protein content of plants grown in soil supplemented with irradiated sludge was also found to be significantly increased compared to those grown with unirradiated or no sludge, after 45 days. There was no significant effect of gamma irradiated sludge on shoot length, total soluble sugars, starch content and yield of chickpea plants. The results obtained suggest that the sludge tested, and obtained from the digester of a conventional domestic sewage treatment plant, is inhibitory to several growth parameters. Gamma irradiation of sewage resulted in removal of this inhibition. This suggests a possibility of beneficial and safe recycling of gamma-irradiated sludge for agricultural uses.

  14. Effect of Ultraviolet Irradiation of the Implant Surface on Progression of Periimplantitis--A Pilot Study in Dogs.

    Science.gov (United States)

    Ishii, Kouken; Matsuo, Masato; Hoshi, Noriyuki; Takahashi, Shun-Suke; Kawamata, Ryota; Kimoto, Katsuhiko

    2016-02-01

    The objective of this study was to investigate morphologically the progression of periimplantitis around an ultraviolet (UV)-light-irradiated implant in dogs. Pure titanium implants (3.3 mm in diameter and 8 mm long) were placed into dog jawbone bilaterally. Implants on one side were irradiated with UV light for 15 minutes using a photodevice immediately before placement (UV group), whereas those on the other side were not irradiated (non-UV group). Osseointegration was confirmed 90 days after implant placement by radiography. Experimental periimplantitis was induced by the application of dental floss over 90 days. Clinical and radiographic examination and micro-computed tomography (micro-CT) were performed after 90 and 180 days, and bone resorption was measured. The bone-implant interface in tissue sections was examined by light microscopy. Bone resorption around the UV-irradiated implant was less pronounced than around the non-UV-irradiated implant in the ligature-induced periimplantitis model. Tissue section images revealed no contact and partial destruction at the bone-implant interface. Within the limitations of this preliminary investigation, it is suggested that UV-light-irradiated implants suppress spontaneous progression of periimplantitis.

  15. {sup 197}Au irradiation study of phase-change memory cell with GeSbTe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Liangcai; Song, Zhitang; Lian, Jie; Rao, Feng; Liu, Bo; Song, Sannian; Liu, Weili; Feng, Songlin [State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Zhou, Xilin; Liu, Xuyan [State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100080 (China)

    2010-10-15

    A {sup 197}Au ion source was used to irradiate a Ge{sub 2}Sb{sub 2}Te{sub 5}-alloy-based phase-change memory (PCM) cell to study the ion-irradiation effect on the properties of the cell. The PCM devices with the tungsten (W) heating electrode of 260 nm diameter were fabricated by 0.18 {mu}m complementary metal-oxide-semiconductor (CMOS) technology. Four different doses (10{sup 10}, 10{sup 11}, 10{sup 12}, and 5 x 10{sup 12} ions/cm{sup 2}, respectively) were applied to irradiate the PCM cell. The samples before and after irradiation were characterized by current-voltage and resistance measurements at room temperature. It is found that the cell properties (resistance value of the amorphous and crystalline states, threshold voltage, and current for phase transition, etc.) have hardly changed, even for the sample irradiated up to 10{sup 12} ions/cm{sup 2} dose, and the cell still has good set-reset operation ability (above 10{sup 5} cycles). Furthermore, the resistance ratio remains at 1000 even after 10{sup 5} cycles of the set-reset operation. The results show the PCM cell with Ge{sub 2}Sb{sub 2}Te{sub 5} alloy has a strong ion-irradiation tolerance. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  16. Chronic meralgia paresthetica and neurectomy: a clinical pathologic study.

    Science.gov (United States)

    Berini, Sarah E; Spinner, Robert J; Jentoft, Mark E; Engelstad, Janean K; Staff, Nathan P; Suanprasert, Narupat; Dyck, P James B; Klein, Christopher J

    2014-04-29

    To understand the pathologic and clinical correlates of patients with chronic meralgia paresthetica (MP) undergoing lateral femoral cutaneous nerve (LFCN) neurectomy. A retrospective cohort approach was utilized to identify 7 patients undergoing LFCN neurectomy for intractable pain. Control autopsied LFCN was obtained. Clinical, radiologic, and electrophysiologic features were reviewed. In identified cases, preoperative symptoms included severe lateral thigh pain and numbness. The duration of symptoms prior to surgery ranged from 2 to 15 years. Body mass index (BMI) varied from 20 kg/m(2) to 44.8 kg/m(2) (normal-morbidly obese), with 6 out of 7 patients being obese. No patients were diabetic. Focal nerve indentation at the inguinal ligament was seen intraoperatively and on gross pathology in 4 of 7 cases. Multifocal fiber loss, selective loss of large myelinated fibers, thinly myelinated profiles, regenerating nerve clusters, perineurial thickening, and subperineurial edema were seen. None of these features were observed in control nerve. Morphometric analysis confirmed loss of large myelinated fibers with small and intermediate size fiber predominance. Five patients had varying degrees of intraneural and epineurial inflammation. Six of 7 reported improved pain after neurectomy, sometimes dramatic. Patients with chronic MP and intractable pain have an LFCN mononeuropathy with loss of nerve fibers. Pathologic and clinical study supports a compressive pathogenesis as the primary mechanism. Abnormal nerve inflammation coexists and may play a role in pathogenesis. These selected patients typically benefited from neurectomy at a site of inguinal ligament compression. This study provides Class IV evidence that patients with chronic MP LFCN neurectomy experience improvement in MP-related pain.

  17. EPR study of the formation of radicals in PP with antioxidants irradiated with gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Silva, P. [Instituto Venezolano de Investigaciones Cientificas, Centro de Fisica, Carretera Panamericana Km. 11, Caracas 1020-A (Venezuela)], E-mail: silva@ivic.ve; Albano, C. [Instituto Venezolano de Investigaciones Cientificas, Centro de Quimica, Universidad Central de Venezuela, Facultad de Ingenieria (Venezuela); Perera, R. [Departamento de Mecanica, Universidad Simon Bolivar (Venezuela)

    2007-12-15

    The behavior of different compounds of polypropylene (PP) with stabilizers such as buthyl-hydroxy-toluene (BHT), Chimassorb 944 (Hals) (CHIM), and a copolymer of styrene-butadiene-styrene (SBS) was studied using electron paramagnetic resonance (EPR). A characteristic spectra for pure PP irradiated in air was obtained for all the samples just after being irradiated [M. Dole, The Radiation Chemistry of Macromolecules, Vol. 2, Academic Press, 1973]. A change in the lineshape of the spectra from a pure PP's EPR signal to that of nitroxyl radical as a function of time was observed. The total free radical concentration (TFRC) decayed until approximately 800 h in the PP-HALS and until around 2000 h in all other cases, when the TFRC began to increase in all the cases, except in that of PP-BHT. In this last case, the EPR signal was not detectable after 4000 h. The BHT and the SBS diluted the free radical concentrations, being them smaller when they are present. The behavior observed in all the samples is consistent with the formation of nitroxyl radicals by gamma rays.

  18. Feasibility study of on-line digital X-ray imaging for irradiated fuel rods

    Energy Technology Data Exchange (ETDEWEB)

    Parthoens, Y.; Gys, A. [Reactor Material Research Department, SCK-CEN, Mol (Belgium); Smolders, V. [Industrial Engineer Department, Katholieke Hogeschool Kempen, Geel (Belgium)

    2003-07-01

    At the Reactor Material Research Department of the Belgian Nuclear Research Centre SCK-CEN Xray imaging of the internal parts of irradiated fuel rods is done on silver-halide films using a 420 kV X-ray source. The replacement of the films by an on-line digital X-ray imaging system implies several advantages. Images can be evaluated instantly and source parameters can be optimized more easily. Time consuming film development is superfluous. The images can digitally be enhanced, processed, reported and archived. Within this work the feasibility of four commercial on-line digital X-ray imaging systems were studied for post-irradiation examination on fuel rods in a hot cell environment. The criteria to evaluate the systems were image quality, integration in the existing hot cell infrastructure, durability and cost price. For the evaluation and comparison of the image quality a simulation fuel rod was fabricated. Three systems suffered from lack of sensitivity, contrast and/or resolution. Only the CsI-scintillator coupled to a CCD-camera with image intensifier gave a sufficient image quality. On the other hand the image intensifiers' dimensions are difficult to integrate in the existing hot cell infrastructure. Also the durability of intensifier screens is questionable as they are susceptible to image burn. Smaller image intensifiers easier to integrate are commercial available nowadays.

  19. Ultrastructural study of seminiferous tubules in the rat after prenatal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hatier, R.; Grignon, G.; Touati, F.

    1982-01-01

    Is the presence of germinal cells necessary for the Sertoli cells to acquire normal features. To respond to this question we have studied the development of the Sertoli cells in rats irradiated at the end of the foetal life. In the prenatal irradiated rats, the lumen of the seminiferous tubules appears later than in the control rats. The Sertoli cells show numerous flexuous apical processes, with central microtubule bundles. These processes regress progressively after the 40th day of life when the tubular lumen appears; numerous junctional complexes differentiate with the same structure as those of control animals. There are important dilatations of the intercellular spaces. The cytoplasmic organelles show a normal development up to the 40th day of life. After this period, the rough endoplasmic reticulum and the Golgi apparatus clearly regress while important dilatations appear in the smooth endoplasmic reticulum and persist in the adult animal. From the 35th day on, the basal lamina of the seminiferous tubules is irregular and multilayered. The differentiation of the Sertoli cells seems to be independent of the presence of germinal cells until the 40th day of life and presents several particularities; thereafter the Sertoli cells show signs of regression.

  20. Radiation damage to the normal monkey brain: experimental study induced by interstitial irradiation.

    Directory of Open Access Journals (Sweden)

    Mishima N

    2003-06-01

    Full Text Available Radiation damage to normal brain tissue induced by interstitial irradiation with iridium-192 seeds was sequentially evaluated by computed tomography (CT, magnetic resonance imaging (MRI, and histological examination. This study was carried out in 14 mature Japanese monkeys. The experimental area received more than 200-260 Gy of irradiation developed coagulative necrosis. Infiltration of macrophages to the periphery of the necrotic area was seen. In addition, neovascularization, hyalinization of vascular walls, and gliosis were found in the periphery of the area invaded by the macrophages. All sites at which the vascular walls were found to have acute stage fibrinoid necrosis eventually developed coagulative necrosis. The focus of necrosis was detected by MRI starting 1 week after the end of radiation treatment, and the size of the necrotic area did not change for 6 months. The peripheral areas showed clear ring enhancement with contrast material. Edema surrounding the lesions was the most significant 1 week after radiation and was reduced to a minimum level 1 month later. However, the edema then expanded once again and was sustained for as long as 6 months. CT did not provide as clear of a presentation as MRI, but it did reveal similar findings for the most part, and depicted calcification in the necrotic area. This experimental model is considered useful for conducting basic research on brachytherapy, as well as for achieving a better understanding of delayed radiation necrosis.

  1. Fracture behaviors of neutron-irradiated ferritic steels studied by the instrumented charpy impact test

    Science.gov (United States)

    Yoshida, H.; Miyata, K.; Narui, M.; Kayano, H.

    1989-12-01

    The instrumented Charpy impact test for quarter-size specimens was developed and applied to study fracture behavior of ferritic steels and a ferritic-martensitic steel (JFMS) before and after neutron irradiation. The load-deflection curves obtained for U- and V-notched specimens showed typical characteristics of fracture properties of these steels. The temperature dependence of the fracture energy ( Ef) and the failure deflection ( Df) clearly indicates ductile-brittle transition and the DBTT can be determined from the Ef and Df versus temperature curves. The V-notched specimens showed sharper transition at higher temperatures for the JFMS than the U-notched ones, where the former were sensitive to brittle fracture and the latter well demonstrated the behavior of crack propagation. For the ferritic steels the DBTTs showed low values at compositions containing approximate 8-10% Cr and the increase of the DBTT (Δ DBTT) due to irradiation also showed a similar tendency. The Δ DBTT appeared to be relatively larger for the JFMS than the ferritic steels.

  2. In-situ studies on phase transformations under electron irradiation in a high voltage electron microscope

    Indian Academy of Sciences (India)

    S Banerjee

    2003-06-01

    High voltage electron microscopy (HVEM), using electron energies adequate for causing displacements of atoms from lattice sites, is a very effective technique for studying mechanisms of solid state phase transformations and for charting the path of phase evolution in real time. This has been demonstrated in studies on chemical ordering in nickel–molybdenum alloys and on the $\\beta \\to \\omega$ displacement ordering in zirconium-niobium alloys. The enhanced diffusivity due to electron irradiation makes it possible to explore a sequence of phase evolution at low enough temperatures where even some first-order transformations are driven by free energy (G) instabilities with respect to the relevant order parameter $(\\eta)$. Specific issues addressed in these studies are reviewed in this paper.

  3. Muon Beam Studies in the H4 beam line and the Gamma Irradiation Facility (GIF++)

    CERN Document Server

    Margraf, Rachel; CERN. Geneva. EN Department

    2017-01-01

    In this report, I summarize my work of detailed study and optimization of the muon beam configuration of H4 beam line in SPS North Area. Using Monte-Carlo simulations, I studied the properties and behavior of the muon beam in combination with the field of the large, spectrometer “ GOLIATH” magnet at -1.5, -1.0, 0, 1.0 and 1.5 Tesla, which is shown to affect the central x position of the muon beam that is delivered to the Gamma Irradiation Facility (GIF++). I also studied the muon beam for different configurations of the two XTDV beam dumps upstream of GIF++ in the H4 beam line. I will also discuss my role in mapping the magnetic field of the GOLIATH magnet in the H4 beam line.

  4. DLTS study of deep level defects in Li-ion irradiated bipolar junction transistor

    Science.gov (United States)

    Madhu, K. V.; Kulkarni, S. R.; Ravindra, M.; Damle, R.

    2007-01-01

    Commercial npn transistor (2N 2219A) irradiated with 50 MeV Li 3+-ions with fluences ranging from 3.1 × 10 13 ions cm -2 to 12.5 × 10 13 ions cm -2, is studied for radiation induced gain degradation and minority carrier trap levels or recombination centers. The properties such as activation energy, trap concentration and capture cross section of induced deep levels are studied by deep level transient spectroscopy (DLTS) technique. Minority carrier trap levels with energies ranging from 0.237 eV to 0.591 eV were observed in the base-collector junction of the transistor. In situ I- V measurements were made to study the gain degradation as a function of ion fluence. Ion induced energy levels result in increase in the base current through Shockley Read Hall (SRH) or multi-phonon recombination and subsequent transistor gain degradation.

  5. PSEUDOMONAS AERUGINOSA IN CHRONIC SUPPURATIVE OTITIS MEDIA- A DRUGSENSITIVITY STUDY

    Directory of Open Access Journals (Sweden)

    Anoop M

    2017-05-01

    Full Text Available BACKGROUND Chronic suppurative otitis media is one among the commonest ENT disease seen in day-to-day practice. It is seen mainly among low socioeconomic class. MATERIALS AND METHODS The present study was conducted in the Department of ENT, Shadan Institute of Medical Sciences. Fifty patients with CSOM of all age groups and both sexes attending the Outpatient Department of ENT were selected randomly for the study. RESULTS From our study, we found mainly children of age group 10-11 years commonly affected. They belong to poor socioeconomic background. Pseudomonas aeruginosa is the most common organism isolated in the present study. Ciprofloxacin was found to be the most sensitive antibiotic to Pseudomonas aeruginosa. CONCLUSION We noticed that drug resistance is on the rise due to misuse of antibiotics, over-the-counter treatment, inadequate period of therapy and less awareness among public regarding drug resistance. Constant monitoring of antibiotic sensitivity is needed to prevent drug resistance in CSOM.

  6. Study on changes of sperm count and testis tissue in black mouse after neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Ki Jung; Seo, Won Sook [KAERI, Daejeon (Korea, Republic of); Son, Hwa Young [Chungnam National Univ., Daejeon (Korea, Republic of)

    2006-03-15

    For the purpose of the biological effect in black mouse by neutron irradiation, mice were irradiated with 16 or 32 Gy neutron (flux: 1.036739E+09) by lying flat pose at BNCT facility on HANARO Reactors. And 90 days later of irradiation, physical changes of testis and testis tissue were examined. There were no weight changes but a little bit volume changes and sperm counts in the tests. Atrophy of seminiferous tubules irradiated with 32 Gy neutron is increased in number and severity and those in stage VI showed depletion of spermatogonia and pachytene spermatocytes compared to the non-irradiated control group. Testis damage of black mouse was not recovered after long time by 32 Gy neutron irradiation.

  7. Xenon migration in UO2 under irradiation studied by SIMS profilometry

    Science.gov (United States)

    Marchand, B.; Moncoffre, N.; Pipon, Y.; Bérerd, N.; Garnier, C.; Raimbault, L.; Sainsot, P.; Epicier, T.; Delafoy, C.; Fraczkiewicz, M.; Gaillard, C.; Toulhoat, N.; Perrat-Mabilon, A.; Peaucelle, C.

    2013-09-01

    During Pressurized Water Reactor operation, around 25% of the created Fission Products (FP) are Xenon and Krypton. They have a low solubility in the nuclear fuel and can either (i) agglomerate into bubbles which induce mechanical stress in the fuel pellets or (ii) be released from the pellets, increasing the pressure within the cladding and decreasing the thermal conductivity of the gap between pellets and cladding. After fifty years of studies on the nuclear fuel, all mechanisms of Fission Gas Release (FGR) are still not fully understood. This paper aims at studying the FGR mechanisms by decoupling thermal and irradiation effects and by assessing the Xenon behavior for the first time by profilometry. Samples are first implanted with 136Xe at 800 keV corresponding to a projected range of 140 nm. They are then either annealed in the temperature range 1400-1600 °C, or irradiated with heavy energy ions (182 MeV Iodine) at Room Temperature (RT), 600 °C or 1000 °C. Depth profiles of implanted Xenon in UO2 are determined by Secondary Ion Mass Spectrometry (SIMS). It is shown that Xenon is mobile during irradiation at 1000 °C. In contrast, thermal treatments do not induce any Xenon migration process: these results are correlated to the formation of Xenon bubbles observed by Transmission Electron Microscopy. At depths lower than about 40 nm (zone 1), no bubbles are observed, At depths in between 40 nm and 110 nm (zone 2), a large number of small bubbles (around 2 nm in diameter) can be observed. By comparing with the SRIM profile, it appears that this area corresponds to the maximum of the defect profile, The third zone displays two bubble populations. The first population has the same size than the bubbles present in zone 2. The bubble size of the second population is significantly larger (up to around 10 nm). A STEM micrograph is presented in Fig. 4. It highlights the Xenon bubbles more clearly. It appears that the largest bubbles are located mainly near dislocations

  8. Evaluation of radioprotectors by the Na/sup +/ influx study in RBC of lethally irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, M.N.; Basu, S.K.; Ghose, A.

    1984-09-01

    Sodium homeostasis in adult male albino Sprague Dawley rats has been examined 24 hours after exposure to 11 Gy whole-body gamma irradiation. Rate of influx of /sup 22/Na in red blood corpuscles (in vitro) of irradiated rats significantly increased and was modified by the administration of some radioprotective drugs prior to irradiation. Solcoseryl and AET (200 mg/kg) gave excellent protection and the combinations of 5-HTP with AET or MPG rendered better protection than when used alone.

  9. Parental behaviour in paediatric chronic pain: a qualitative observational study.

    Science.gov (United States)

    Dunford, Emma; Thompson, Miles; Gauntlett-Gilbert, Jeremy

    2014-10-01

    Parental behaviour appears to influence the adjustment of children with chronic pain. However, research in this area has failed to produce consistent evidence. Studies have tended to rely on self-report measures derived from adult pain populations. This qualitative, observational research provides descriptive data of parental behaviour in a clinical environment. A qualitative observational study was made of parents and adolescents in a physically stressful setting. Modified grounded theory was used to analyse verbal and non-verbal behaviours. Eight parent-adolescent dyads seeking treatment for chronic pain were videoed during physical exercise sessions. Verbal and non-verbal behaviours were recorded and transcribed. Four overarching categories emerged: 'monitoring', 'protecting', 'encouraging' and 'instructing'. These often had both verbal and non-verbal aspects. Within these categories, more precise behavioural groups were also identified. This research identifies categories of parental behaviour that were derived directly from observation, rather than imposed on the basis of results from different populations. Four categories of behaviour were derived, which clarify and extend dimensions used in existing self-report instruments. Careful description of parental behaviours showed features that past research has neglected, and highlighted potential drawbacks of apparently positive parental actions. © The Author(s) 2013.

  10. Cytogenetic studies on bone marrow cells in rats irradiated with helium nuclei and protected with adeturone

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, B.; Bulanova, M.; Mileva, M. (Meditsinska Akademiya, Sofia (Bulgaria). Nauchen Inst. po Rentgenologiya i Radiobiologiya); Govorun, R.; Rizhov, N.; Fedorenko, B. (Institut Mediko-Biologicheskikh Problem, Moscow (USSR))

    1981-01-01

    Rats of the ''Wistar'' breed have been irradiated with helium nuclei-energy 3.3 Gev/nucleon with doses of 0.5 to 4 Gy. 15 minutes prior to irradiation part of the patients were injected intraperitoneally with 300 mg/kg Adeturone. The structural chromosome aberrations in medullar cells of non-protected and protected animals have been established microscopically. An increase has been found of the different kinds of aberrations depending on the applied irradiation dose. Adeturone decreases the irradiation effect, especially in higher doses. After 1 Gy the aberrations decrease from 1.5 to 3 times.

  11. Cell kinetic study on the relation between irradiation hypogeusia and taste buds in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Hideharu; Furumoto, Keiichi [Nippon Dental Univ., Tokyo (Japan)

    1998-12-01

    The present study was designed to elucidate the mechanism of hypogeusia caused by irradiation. X-ray treatment at 10 Gy or 20 Gy was given to the maxillofacial region including the tongue in rats, and the involvement of taste bud for hypogeusia was investigated. In addition, cytological kinetics were immunohistologically studied using bromodeoxyuridine in the taste bud and in the lingual mucosal epithelium. The following results were obtained: In the 10 Gy group, the number of taste bud become less after the exposure, but no hypogeusia was observed during the experimental period. In the 20 Gy group, any labeled taste bud was not observed on the 7th day, and all taste buds disappeared by the 10th day. In the lingual mucosal epithelium, the number of basal cells decreased to the minimum, and the body weight and total water intake decreased coincidently in the 20 Gy group, which were few in the 10 Gy group. (author)

  12. STUDY OF EXTRA CRANIAL COMPLICATIONS OF CHRONIC SUPPURATIVE OTITIS MEDIA

    Directory of Open Access Journals (Sweden)

    Sanal Mohan

    2016-10-01

    Full Text Available BACKGROUND Chronic Suppurative Otitis Media (CSOM refers to a chronic inflammatory condition of the middle ear and mastoid cavity. There is acute inflammation of middle ear leading to irritation and then inflammation of the mucosa producing oedema. Breakdown of the epithelium causes ulceration subsequent infection and formation of granuloma/granulation tissue. Granuloma formation leads to the development of polyps in middle ear. Factors influencing development of complications are, age, low socio-economic status, virulence of organism, immune compromised host, previous surgeries, fractures, fistulas, cholesteatoma. The complications developed spread through various modes like direct bone erosion, thrombophlebitis, preformed pathways, congenital bony defects, sutures of skull that remains patent, old fractures-heal by fibrosis, defects caused by surgery, oval and round windows, infection from labyrinth. The extracranial complications which can be encountered in chronic suppurative otitis media are, acute mastoiditis, petrositis, facial nerve palsy, labyrinthitis and discharging sinuses. MATERIALS AND METHODS Sample size for the present study was fifty four. This study was done in the Department of ENT, Travancore Medical College, Kollam. This study was done from January 2015 To January 2016. Detailed clinical history was taken and the clinical examination was conducted. The extracranial complications were noted and reported. RESULTS In the present study, maximum number of cases belonged male sex which was thirty eight cases. Sixteen cases belonged to female sex. Maximum number of cases which amounted to forty one in number belonged to age group zero to twenty years, followed by age group twenty to forty years which amounted to eleven cases, followed by age group forty to sixty which amounted to two cases. No cases were reported in age group more than sixty years in our study. Based on socioeconomic data, maximum number of cases belonged to low

  13. Kinetic and mechanistic study of microcystin-LR degradation by nitrous acid under ultraviolet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qingwei; Ren, Jing [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Huang, Honghui [Key Laboratory of Fisheries Ecology Environment, Ministry of Agriculture, Guangzhou 510300 (China); Wang, Shoubing [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Wang, Xiangrong, E-mail: xrxrwang@vip.sina.com [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Fan, Zhengqiu, E-mail: zhqfan@fudan.edu.cn [Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer For the first time, degradation of MC-LR by nitrous acid under UV 365 nm was discovered. Black-Right-Pointing-Pointer The effects of factors on MC-LR degradation were analyzed based on kinetic study. Black-Right-Pointing-Pointer Mass spectrometry was applied for identification of intermediates and products. Black-Right-Pointing-Pointer Special intermediates involved in this study were identified. Black-Right-Pointing-Pointer Degradation mechanisms were proposed according to the results of LC-MS analysis. - Abstract: Degradation of microcystin-LR (MC-LR) in the presence of nitrous acid (HNO{sub 2}) under irradiation of 365 nm ultraviolet (UV) was studied for the first time. The influence of initial conditions including pH value, NaNO{sub 2} concentration, MC-LR concentration and UV intensity were studied. MC-LR was degraded in the presence of HNO{sub 2}; enhanced degradation of MC-LR was observed with 365 nm UV irradiation, caused by the generation of hydroxyl radicals through the photolysis of HNO{sub 2}. The degradation processes of MC-LR could well fit the pseudo-first-order kinetics. Mass spectrometry was applied for identification of the byproducts and the analysis of degradation mechanisms. Major degradation pathways were proposed according to the results of LC-MS analysis. The degradation of MC-LR was initiated via three major pathways: attack of hydroxyl radicals on the conjugated carbon double bonds of Adda, attack of hydroxyl radicals on the benzene ring of Adda, and attack of nitrosonium ion on the benzene ring of Adda.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-15

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

  15. Longitudinal study of leptin levels in chronic hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Averbukh Zhan

    2011-06-01

    Full Text Available Abstract Background The influence of serum leptin levels on nutritional status and survival in chronic hemodialysis patients remained to be elucidated. We conducted a prospective longitudinal study of leptin levels and nutritional parameters to determine whether changes of serum leptin levels modify nutritional status and survival in a cohort of prevalent hemodialysis patients. Methods Leptin, dietary energy and protein intake, biochemical markers of nutrition and body composition (anthropometry and bioimpedance analysis were measured at baseline and at 6, 12, 18 and 24 months following enrollment, in 101 prevalent hemodialysis patients (37% women with a mean age of 64.6 ± 11.5 years. Observation of this cohort was continued over 2 additional years. Changes in repeated measures were evaluated, with adjustment for baseline differences in demographic and clinical parameters. Results Significant reduction of leptin levels with time were observed (linear estimate: -2.5010 ± 0.57 ng/ml/2y; p Conclusions Thus leptin levels reflect fat mass depots, rather than independently contributing to uremic anorexia or modifying nutritional status and/or survival in chronic hemodialysis patients. The importance of such information is high if leptin is contemplated as a potential therapeutic target in hemodialysis patients.

  16. Chinese cohort study of chronic kidney disease: design and methods

    Institute of Scientific and Technical Information of China (English)

    Gao Bixia; Zhang Luxia; Wang Haiyan; Zhao Minghui

    2014-01-01

    Background Chronic kidney disease (CKD) is a common disorder associated with multiple adverse clinical consequences,especially cardiovascular risk and end-stage renal disease.A recent national survey demonstrated that CKD has become a leading health problem in China.There is an urgent need to implement an in-depth investigation of the CKD burden and also to explore underlying mechanisms of CKD progression and it association with adverse consequences.Methods The Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE) is the first national CKD cohort in China.It will enroll approximately 3 000 pre-dialysis CKD patients aged between 18 and 74 years and follow-up for at least 5 years.Questionnaires,anthropometric measures,laboratory tests,and biomaterials will be collected at baseline and annually.The principal clinical outcomes of the C-STRIDE consist of renal disease events,cardiovascular events,and death.Based on the longitudinal clinical data and biomaterials,the risk factors with CKD progression and other outcomes will be analyzed,and candidate markers and predicted models will be established.Conclusion The C-STRIDE would provide important evidence for underlying mechanisms of CKD progression,valuable information for clinical guidelines,and healthcare policies in China.

  17. Symptomatic Acute-on-Chronic Subdural Hematoma: A Clinicopathological Study.

    Science.gov (United States)

    Castellani, Rudy J; Mojica-Sanchez, Gruschenka; Schwartzbauer, Gary; Hersh, David S

    2017-06-01

    The pathophysiology of acute-on-chronic subdural hematoma (ACSDH) is complex and incompletely understood. Evidence to date indicates that the overall process is initiated by rotational force with movement of the brain inside the skull, which exerts tensile strain and rupture of bridging veins, leading in turn to acute hemorrhage in the subdural potential space. This is followed by the proliferation of mesenchymal elements with angiogenesis and inflammation, which in turn becomes a substrate for repeated hemorrhage and expansion of the lesion. Given the prevalence of traumatic subdural processes in the forensic setting and the importance of proper assessment of timing, etiology, risk factors, and clinicopathological correlation, we studied 47 patients presenting to the University of Maryland Shock Trauma Center, all of whom underwent craniotomy with resection of the outer membrane due to symptomatic ACSDH. The surgically resected tissue was examined for histopathologic features in all cases. Our findings highlight that ACSDH is a condition precipitated by trauma that affects middle-aged and older adults, is relatively indolent, is unilateral or asymmetric, and has a low in-hospital mortality rate. Pathological analysis demonstrates a substantial outer membrane in all cases with varying degrees of inflammation and organization that cannot be precisely dated as a function of clinical presentation. The extrapolation of adult ACSDH to mixed acute and chronic subdural hemorrhage in the pediatric setting is problematic due to substantial differences in clinical presentation, severity of underlying brain injury, gross and microscopic findings, and outcome.

  18. Squamous cell carcinoma in situ after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi [Yokohama City Univ. (Japan). School of Medicine; Sugiyama, Asami

    1997-12-31

    We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

  19. On the evolution of irradiated turbulent clouds: a comparative study between modes of triggered star formation

    Science.gov (United States)

    Anathpindika, S.; Bhatt, H. C.

    2012-12-01

    Gas within molecular clouds (MCs) is turbulent and unevenly distributed. Interstellar shocks such as those driven by strong fluxes of ionizing radiation (IR) profoundly affect MCs. While small dense MCs exposed to a strong flux of IR have been shown to implode due to radiation-driven shocks, a phenomenon called radiation-driven implosion, larger MCs, however, are likely to survive this flux, which, in fact, may produce new star-forming sites within these clouds. Here we examine this hypothesis using the smoothed particle hydrodynamics algorithm coupled with a ray-tracing scheme that calculates the position of the ionization front at each time-step. We present results from simulations performed for three choices of IR flux spanning the range of fluxes emitted by a typical B-type star to a cluster of OB-type stars. The extent of photoablation, of course, depends on the strength of the incident flux and a strong flux of IR severely ablates an MC. Consequently, the first star formation sites appear in the dense shocked layer along the edges of the irradiated cloud. Radiation-induced turbulence readily generates dense filamentary structure within the photoablated cloud although several new star-forming sites also appear in some of the densest regions at the junctions of these filaments. Prevalent physical conditions within an MC play a crucial role in determining the mode, i.e. filamentary as compared to isolated pockets, of star formation, the time-scale on which stars form and the distribution of stellar masses. The probability distribution functions derived for irradiated clouds in this study are intriguing due to their resemblance with those presented in a recent census of irradiated MCs. Furthermore, irrespective of the nature of turbulence, the protostellar mass functions(MFs) derived in this study follow a power-law distribution. When turbulence within the cloud is driven by a relatively strong flux of IR such as that emitted by a massive O-type star or a cluster

  20. Chronic disease and independence in old age: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, Pauline J. [Radiology Department, Arrowe Park Hospital, Upton, Wirral CH49 5EP (United Kingdom)]. E-mail: pauline.reeves@whnt.nhs.uk

    2006-08-15

    This report uses case study methodology to examine the issue of long-term care of the elderly in the United Kingdom, including where that care should take place. The report will examine the difficulties inherent in maintaining independent living for the elderly (in particular the danger and cost of falls). The case study presented is that of an elderly female patient who had suffered from chronic rheumatoid arthritis for over 10 years. She was admitted to hospital several times from December 2003 to January 2004. The discussion of her case is set in the context of the sociology of ageing; long-term care of the elderly and the UK National Service Frameworks, of which standard six relates to falls in the elderly. The report will also consider the problems in deciding whether it is necessary to terminate independent living for an individual.

  1. Electron thermalization and attachment in pulse-irradiated oxygen studied by time-resolved microwave conductivity

    Science.gov (United States)

    Warman, John M.; Cooper, Ronald

    The microwave conductivity of oxygen gas following nanosecond pulsed irradiation has been studied for pressures from 5 to 50 torr. The conductivity is found to decrease by a factor of approx. 20 in the early stages ( tN < 2 x 10 11 s cm -3) following the pulse. This is attributed to a decrease in the electron collision frequency as the initial excess energy of the electrons becomes degraded. A further decrease found at longer times is due to the three-body attachment of electrons to O 2 with a rate constant of 2.4 x 10 -30 cm 6s -1. Above a pressure of approx. 30 torr significant attachment begins to occur while electrons are still superthermal. The time at which the microwave signal is within 10% of the value corresponding to thermal energies is given by τ thP ≈ 15 μs.torr.

  2. Systematic study of pre-irradiation effects in high efficiency CVD diamond nuclear particle detectors

    CERN Document Server

    Marinelli, M; Milani, E; Paoletti, A; Pillon, M; Tucciarone, A; Verona-Rinati, G

    2002-01-01

    Many outstanding properties of diamond can, in principle, lead to the development of radiation detectors with interesting capabilities. In particular, diamond-based nuclear particle detectors are good candidates to replace silicon-based detectors in several fields, e.g. in high-flux applications such as next generation particle-accelerator experiments or beam monitoring. However, the high concentration of defects (grain boundaries, impurities) in synthetic diamond films can strongly limit the detector's performance. A significant increase in the efficiency of CVD diamond detectors is achieved by means of pre-irradiation (pumping) with beta particles. We report here on a systematic study of the effects of pumping in high-quality microwave CVD diamond films. The efficiency (eta) and charge collection distance (CCD) of nuclear particle detectors based on these films depend on the methane content in the growth gas mixture and on the film thickness. Both efficiency and CCD behave in a markedly different way in the...

  3. Study of the temperature evolution of defect agglomerates in neutron irradiated molybdenum single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Lambri, O.A. [Instituto de Fisica Rosario. Member of the CONICET' s Research Staff, Avda. Pellegrini 250, (2000) Rosario, Santa Fe (Argentina); Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Laboratorio de Materiales, Escuela de Ingenieria Electrica, Avda. Pellegrini 250, (2000) Rosario, Santa Fe (Argentina)], E-mail: olambri@fceia.unr.edu.ar; Zelada-Lambri, G.I. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Laboratorio de Materiales, Escuela de Ingenieria Electrica, Avda. Pellegrini 250, (2000) Rosario, Santa Fe (Argentina); Cuello, G.J. [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble (France); Departamento de Fisica Aplicada II, Facultad de Ciencias y Tecnologia, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao, Pais Vasco (Spain); Bozzano, P.B. [Laboratorio de Microscopia Electronica. Unidad de Actividad Materiales, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Avda. Gral. Paz 1499, (1650) San Martin (Argentina); Garcia, J.A. [Departamento de Fisica Aplicada II, Facultad de Ciencias y Tecnologia, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao, Pais Vasco (Spain)

    2009-04-15

    Small angle neutron scattering as a function of temperature, differential thermal analysis, electrical resistivity and transmission electron microscopy studies have been performed in low rate neutron irradiated single crystalline molybdenum, at room temperature, for checking the evolution of the defects agglomerates in the temperature interval between room temperature and 1200 K. The onset of vacancies mobility was found to happen in temperatures within the stage III of recovery. At around 550 K, the agglomerates of vacancies achieve the largest size, as determined from the Guinier approximation for spherical particles. In addition, the decrease of the vacancy concentration together with the dissolution of the agglomerates at temperatures higher than around 920 K was observed, which produce the release of internal stresses in the structure.

  4. FLUKA studies of hadron-irradiated scintillating crystals for calorimetry at the High-Luminosity LHC

    Science.gov (United States)

    Quittnat, Milena; CMS Collaboration

    2015-02-01

    Calorimetry at the High-Luminosity LHC (HL-LHC) will be performed in a harsh radiation environment with high hadron fluences. The upgraded CMS electromagnetic calorimeter design and suitable scintillating materials are a focus of current research. In this paper, first results using the Monte Carlo simulation program FLUKA are compared to measurements performed with proton-irradiated LYSO, YSO and cerium fluoride crystals. Based on these results, an extrapolation to the behavior of an electromagnetic sampling calorimeter, using one of the inorganic scintillators above as an active medium, is performed for the upgraded CMS experiment at the HL-LHC. Characteristic parameters such as the induced ambient dose, fluence spectra for different particle types and the residual nuclei are studied, and the suitability of these materials for a future calorimeter is surveyed. Particular attention is given to the creation of isotopes in an LYSO-tungsten calorimeter that might contribute a prohibitive background to the measured signal.

  5. FLUKA studies of hadron-irradiated scintillating crystals for calorimetry at the High-Luminosity LHC

    CERN Document Server

    Quittnat, Milena Eleonore

    2015-01-01

    Calorimetry at the High-Luminosity LHC (HL-LHC) will be performed in a harsh radiation environment with high hadron fluences. The upgraded CMS electromagnetic calorimeter design and suitable scintillating materials are a focus of current research. In this paper, first results using the Monte Carlo simulation program FLUKA are compared to measurements performed with proton-irradiated LYSO, YSO and cerium fluoride crystals. Based on these results, an extrapolation to the behavior of an electromagnetic sampling calorimeter, using one of the inorganic scintillators above as an active medium, is performed for the upgraded CMS experiment at the HL-LHC. Characteristic parameters such as the induced ambient dose, fluence spectra for different particle types and the residual nuclei are studied, and the suitability of these materials for a future calorimeter is surveyed. Particular attention is given to the creation of isotopes in an LYSO-tungsten calorimeter that might contribute a prohibitive background to the measu...

  6. Deep level transient spectroscopy (DLTS) study of defects introduced in antimony doped Ge by 2 MeV proton irradiation

    Science.gov (United States)

    Nyamhere, C.; Das, A. G. M.; Auret, F. D.; Chawanda, A.; Pineda-Vargas, C. A.; Venter, A.

    2011-08-01

    Deep level transient spectroscopy (DLTS) and Laplace-DLTS have been used to investigate the defects created in Sb doped Ge after irradiation with 2 MeV protons having a fluence of 1×10 13 protons/cm 2. The results show that proton irradiation resulted in primary hole traps at E V +0.15 and E V +0.30 eV and electron traps at E C -0.38, E C -0.32, E C -0.31, E C -0.22, E C -0.20, E C -0.17, E C -0.15 and E C -0.04 eV. Defects observed in this study are compared with those introduced in similar samples after MeV electron irradiation reported earlier. E C -0.31, E C -0.17 and E C -0.04, and E V +0.15 eV were not observed previously in similar samples after high energy irradiation. Results from this study suggest that although similar defects are introduced by electron and proton irradiation, traps introduced by the latter are dose dependent.

  7. The Effects of Storage on Irradiated Red Blood Cells: An In Vitro and In Vivo Study

    Science.gov (United States)

    1991-08-01

    L, Rosi A, Bmiincontro A, Cametti C. Effect of gam, irradiation on membranes of normal and pathological erythrocytes ( beta - thalassemia ). Radiation...Center and National Naval Medical Center. Major Ciment and the Clinical Chemistry Department, the staff of the Department of Clinical Investigations and...16 Prevention ................................................ 17 Mechanics of Irradiation

  8. Mechanical properties of neutron-irradiated nickel-containing martensitic steels: I. Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L. [Oak Ridge National Laboratory, P.O. Box 2008, MS 6151, Oak Ridge, Tennessee 37831-6151 (United States)]. E-mail: kluehrl@ornl.gov; Hashimoto, N. [Oak Ridge National Laboratory, P.O. Box 2008, MS 6151, Oak Ridge, Tennessee 37831-6151 (United States); Sokolov, M.A. [Oak Ridge National Laboratory, P.O. Box 2008, MS 6151, Oak Ridge, Tennessee 37831-6151 (United States); Shiba, K. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Tokai, Ibaraki 319-1195 (Japan); Jitsukawa, S. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Tokai, Ibaraki 319-1195 (Japan)

    2006-10-15

    Tensile and Charpy specimens of 9Cr-1MoVNb (modified 9Cr-1Mo) and 12Cr-1MoVW (Sandvik HT9) steels and these steels doped with 2% Ni were irradiated at 300 and 400 deg. C in the High Flux Isotope Reactor (HFIR) up to {approx}12 dpa and at 393 deg. C in the Fast Flux Test Facility (FFTF) to {approx}15 dpa. In HFIR, a mixed-spectrum reactor (n, {alpha}) reactions of thermal neutrons with {sup 58}Ni produce helium in the steels. Little helium is produced during irradiation in FFTF. After HFIR irradiation, the yield stress of all steels increased, with the largest increases occurring for nickel-doped steels. The ductile-brittle transition temperature (DBTT) increased up to two times and 1.7 times more in steels with 2% Ni than in those without the nickel addition after HFIR irradiation at 300 and 400 deg. C, respectively. Much smaller differences occurred between these steels after irradiation in FFTF. The DBTT increases for steels with 2% Ni after HFIR irradiation were 2-4 times greater than after FFTF irradiation. Results indicated there was hardening due to helium in addition to hardening by displacement damage and irradiation-induced precipitation.

  9. Simulated carbon irradiation of carbon nanotubes – A comparative study of interatomic potentials

    Energy Technology Data Exchange (ETDEWEB)

    Heredia-Avalos, Santiago, E-mail: sheredia@ua.es [Departament de Física, Enginyeria de Sistemes i Teoria de la Senyal, Universitat d’Alacant, Apartat 99, E-03080 Alacant (Spain); Moreno-Marín, Juan Carlos [Departament de Física, Enginyeria de Sistemes i Teoria de la Senyal, Universitat d’Alacant, Apartat 99, E-03080 Alacant (Spain); Denton, Cristian D. [Departament de Física Aplicada, Universitat d’Alacant, Apartat 99, E-03080 Alacant (Spain)

    2014-05-01

    We simulate the irradiation of carbon nanotubes (CNT) with carbon ions using a molecular dynamics code. In order to describe the interaction between carbon ions we use the Tersoff or Brenner potential, both joined smoothly to the Universal ZBL potential at short distances. We have analyzed the defects produced after irradiation, the subsequent modification of the CNT structure, and their dependence on the used interatomic potential, the projectile energy (from 10 eV to 5 keV) and the dose. For single projectile irradiation, we have obtained that the coordination defect number increases with the projectile energy, although a saturation value is achieved at high projectile energies (∼3 keV). For continuous projectile irradiation, we have observed that for low energies (∼10 eV) the accumulation of adatoms produces a bump in the irradiated region. However, at intermediate energies (∼100 eV) the irradiation produces vacancies which are healed through non-hexagonal rings. This gives rise to a shrinking of the CNT diameter in the irradiated region. Finally, if the projectile energy is high enough (∼1 keV) the continuous irradiation produces the breaking of the CNT.

  10. Thermoluminescence Study of Gamma Irradiated Cr-Doped LiF Phosphors

    Science.gov (United States)

    Kumar, Satinder; Gathania, A. K.; Vij, Ankush; Kumar, Ravi

    2016-06-01

    We have synthesized Cr-doped LiF phosphors by using modified co-precipitation. X-ray diffraction study confirms the single-phase cubic structure up to 0.05 mol.% of Cr in LiF; afterwards, a secondary phase of formation was observed. The field emission scanning electron microscope (FESEM) images revealed micro-cubic surface morphology of samples. The thermoluminescent (TL) behavior of the samples studied after irradiating them with gamma rays in the dose range 0.1-30 kGy. The TL glow curve of Cr-doped LiF comprises a prominent peak observed at 407 K and a broad band ranging from 448 K to 512 K at a fixed gamma dose of 10 kGy. The shape of the TL glow curve remained similar at all concentrations of Cr in LiF; however, TL intensity was found to vary with Cr concentration, and Cr (0.02 mol.%)-doped LiF sample exhibit highest TL response. The glow curve of the optimized sample as a function of gamma irradiation dose within the range 0.1-30 kGy shows an almost linear increase in TL intensity of the main glow peak up to 10 kGy, and afterwards it decreases. Further, at the high dose of 30 kGy, the intensity of the prominent TL glow peak at 407 K decreases and another broad peak starts growing at 468 K signifying the formation of new trapping sites. The kinetic parameters, namely activation energy, order of kinetics, and frequency factor of the optimized sample were evaluated by using Chen's peak shape method and glow curve deconvolution (GCD) functions based on Kitti's equations.

  11. Oxidative degradation of alternative gasoline oxygenates in aqueous solution by ultrasonic irradiation: Mechanistic study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Duk Kyung, E-mail: dkim@aum.edu [Department of Physical Science, Auburn University Montgomery, Montgomery, AL 36117 (United States); O' Shea, Kevin E., E-mail: osheak@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, University Park, Miami, FL 33199 (United States); Cooper, William J. [Department of Civil and Environmental Engineering, Urban Water Research Center, University of California Irvine, Irvine, CA 92697-2175 (United States)

    2012-07-15

    Widespread pollution has been associated with gasoline oxygenates of branched ethers methyl tert-butyl ether (MTBE), di-isopropyl ether (DIPE), ethyl tert-butyl ether (ETBE), and tert-amyl ether (TAME) which enter groundwater. The contaminated plume develops rapidly and treatment for the removal/destruction of these ethers is difficult when using conventional methods. Degradation of MTBE, with biological methods and advanced oxidation processes, are rather well known; however, fewer studies have been reported for degradation of alternative oxygenates. Degradation of alternative gasoline oxygenates (DIPE, ETBE, and TAME) by ultrasonic irradiation in aqueous oxygen saturation was investigated to elucidate degradation pathways. Detailed degradation mechanisms are proposed for each gasoline oxygenate. The common major degradation pathways are proposed to involve abstraction of {alpha}-hydrogen atoms by hydroxyl radicals generated during ultrasound cavitation and low temperature pyrolytic degradation of ETBE and TAME. Even some of the products from {beta}-H abstraction overlap with those from high temperature pyrolysis, the effect of {beta}-H abstraction was not shown clearly from product study because of possible 1,5 H-transfer inside cavitating bubbles. Formation of hydrogen peroxide and organic peroxides was also determined during sonolysis. These data provide a better understanding of the degradation pathways of gasoline oxygenates by sonolysis in aqueous solutions. The approach may also serve as a model for others interested in the details of sonolysis. - Highlights: Black-Right-Pointing-Pointer Gasoline oxygenates (ETBE, TAME, DIPE) were completely degraded after 6 hours under ultrasonic irradiation in O{sub 2} saturation. Black-Right-Pointing-Pointer The major degradation pathways were proposed to involve abstraction of {alpha}-hydrogen atoms by hydroxyl radicals and low temperature pyrolytic degradation. Black-Right-Pointing-Pointer The effect of {beta

  12. Chronic pain, perceived stress, and cellular aging: an exploratory study

    Directory of Open Access Journals (Sweden)

    Sibille Kimberly T

    2012-02-01

    Full Text Available Abstract Background Chronic pain conditions are characterized by significant individual variability complicating the identification of pathophysiological markers. Leukocyte telomere length (TL, a measure of cellular aging, is associated with age-related disease onset, psychosocial stress, and health-related functional decline. Psychosocial stress has been associated with the onset of chronic pain and chronic pain is experienced as a physical and psychosocial stressor. However, the utility of TL as a biological marker reflecting the burden of chronic pain and psychosocial stress has not yet been explored. Findings The relationship between chronic pain, stress, and TL was analyzed in 36 ethnically diverse, older adults, half of whom reported no chronic pain and the other half had chronic knee osteoarthritis (OA pain. Subjects completed a physical exam, radiographs, health history, and psychosocial questionnaires. Blood samples were collected and TL was measured by quantitative polymerase chain reaction (qPCR. Four groups were identified characterized by pain status and the Perceived Stress Scale scores: 1 no pain/low stress, 2 no pain/high stress, chronic pain/low stress, and 4 chronic pain/high stress. TL differed between the pain/stress groups (p = 0.01, controlling for relevant covariates. Specifically, the chronic pain/high stress group had significantly shorter TL compared to the no pain/low stress group. Age was negatively correlated with TL, particularly in the chronic pain/high stress group (p = 0.03. Conclusions Although preliminary in nature and based on a modest sample size, these findings indicate that cellular aging may be more pronounced in older adults experiencing high levels of perceived stress and chronic pain.

  13. Moessbauer study of FINEMET type nanocrystalline ribbons irradiated with swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, Erno, E-mail: kuzmann@ludens.elte.hu; Stichleutner, Sandor; Sapi, Andras [Institute of Chemistry, Eoetvoes University (Hungary); Varga, Lajos Karoly [Research Institute for Solid State Physics and Optics, HAS (Hungary); Havancsak, Karoly [Eoetvoes University, Department of Materials Physics (Hungary); Skuratov, Vlamidir [Joint Institute for Nuclear Research (Russian Federation); Homonnay, Zoltan; Vertes, Attila [Institute of Chemistry, Eoetvoes University (Hungary)

    2012-03-15

    As-quenched and stress field annealed FINEMET ribbons were irradiated with 246 MeV energy Kr, 470 MeV energy Xe and 720 MeV energy Bi ions and investigated by {sup 57}Fe Moessbauer spectroscopy and XRD methods. The change in relative areas of the 2nd and 5th lines in the Moessbauer spectra indicated significant changes in the magnetic anisotropy of both as-quenched and stress annealed FINEMET due to irradiation with swift heavy ions. Differences were observed between the effect of irradiations with various ions having different energy and fluence. The effect of irradiation on the magnetic orientation in FINEMET was explained in terms of radiation induced defects. The swift heavy ion irradiation can be applied to produce FINEMET ribbons with more favorable soft magnetic properties for technological applications.

  14. Study of swift (100 MeV) Fe{sup 9+} ion irradiated gallium antimonide

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, Vidya [Department of Physics, University of Mumbai, Santacruz (E), Mumbai 400 098 (India); Dubey, S.K. [Department of Physics, University of Mumbai, Santacruz (E), Mumbai 400 098 (India)], E-mail: skdubey@physics.mu.ac.in; Dubey, R.L.; Tripathi, S.; Yadav, A.D.; Gupta, S.J. [Department of Physics, University of Mumbai, Santacruz (E), Mumbai 400 098 (India); Gundu Rao, T.K. [SAIF, Indian Institute of Technology, Powai, Mumbai 400 076 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2008-04-15

    The effect of 100 MeV irradiation of iron ions in p-type gallium antimonide for ion fluences varying from 1 x 10{sup 11} to 5 x 10{sup 13} cm{sup -2} was investigated using Raman scattering, Fourier transform infrared and X-ray diffraction measurements. Raman spectra showed a strong peak at 232.82 cm{sup -1} (LO) and a weak peak at 223.79 cm{sup -1} (TO). The peaks were shifted towards higher wave number compared to non-irradiated sample indicating the presence of stress in the irradiated samples. The increase of optical absorbance of samples irradiated with different fluences indicates the increase in the amount of disorder and defect concentrations with fluence. The intensity of the XRD peak (2{theta} = 61.07 degree) of the irradiated samples for (4 0 0) reflections was found to decrease with ion fluence.

  15. Chronic pain following total hip arthroplasty: a nationwide questionnaire study

    DEFF Research Database (Denmark)

    Nikolajsen, Lone; Brandsborg, Birgitte; Lucht, Ulf;

    2006-01-01

    BACKGROUND: Chronic post-operative pain is a well-recognized problem after various types of surgery, but little is known about chronic pain after orthopedic surgery. Severe pre-operative pain is the primary indication for total hip arthroplasty (THA). Therefore, we examined the prevalence...... was 93.6%. Two hundred and ninety-four patients (28.1%) had chronic ipsilateral hip pain at the time of completion of the questionnaire, and pain limited daily activities to a moderate, severe or very severe degree in 12.1%. The chronic pain state was related to the recalled intensity of early post...

  16. Antibiotic protocol for the prevention of osteoradionecrosis following dental extractions in irradiated head and neck cancer patients: A 10 years prospective study

    Directory of Open Access Journals (Sweden)

    Saleh A Al-Bazie

    2016-01-01

    Conclusion: Based on the results of this study, perioperative oral antibiotics in combination with antibacterial mouthwashes are effective in preventing ORN following dental extractions in irradiated patients.

  17. Effects of CO2 laser irradiation on matrix-rich biofilm development formation–an in vitro study

    Directory of Open Access Journals (Sweden)

    Bruna Raquel Zancopé

    2016-11-01

    Full Text Available Background A carbon dioxide (CO2 laser has been used to morphologically and chemically modify the dental enamel surface as well as to make it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of a CO2 laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2 laser (λ = 10.6 µM. Methods For this in vitro study, 96 specimens of bovine enamel were employed, which were divided into two groups (n = 48: 1 Control-non-irradiated surface and 2 Irradiated enamel surface. Biofilms were grown on the enamel specimens by one, three and five days under intermittent cariogenic condition in the irradiated and non-irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and, in fifth day, were evaluated by polysaccharides analysis, quantitative real time Polymerase Chain Reaction (PCR as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM. Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test. Results The mean of log CFU/mL obtained for the one-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to the CO2 laser, CFU/mL and CFU/dry weight in three day was reduced significantly compared with control group. The difference in the genes expression (Glucosyltransferases (gtfB and Glucan-binding protein (gbpB and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with the CO2 laser. Similar

  18. Liver fibrosis in chronic viral hepatitis: An ultrasonographic study

    Institute of Scientific and Technical Information of China (English)

    Rong-Qin Zheng; Qing-Hui Wang; Ming-De Lu; Shi-Bin Xie; Jie Ren; Zhong-Zhen Su; Yin-Ke Cai; Ji-Lu Yao

    2003-01-01

    AIM: To select valuable ultrasonographic predictors for the evaluation of hepatic inflammation and fibrosis degree in chronic hepatitis, and to study the value of ultrasonography in the evaluation of liver fibrosis and compensated liver cirrhosis in comparison with serology and histology.METHODS: Forty-four ultrasonographic variables were analyzed and screened using color Doppler ultrasound system in 225 patients with chronic viral hepatitis and compensated liver cirrhosis. The valuable ultrasonographic predictors were selected on the basis of a comparison with histopathological findings. The value of ultrasonography and serology in the evaluation of liver fibrosis degree and the diagnosis of compensated liver cirrhosis was also studied and compared. Meanwhile, the influencing factors on ultrasonographic diagnosis of compensated liver cirrhosis were also analyzed.RESULTS: By statistical analysis, the maximum velocity of portal vein and the degree of gall-bladder wall smoothness were selected as the valuable predictors for the inflammation grade (G), while liver surface, hepatic parenchymal echo pattern, and the wall thickness of gall-bladder were selected as the valuable predictors for the fibrosis stage (S). Three S-related independent ultrasonographyic predictors and three routine serum fibrosis markers (HA, HPCIII and CIV) were used to discriminate variables for the comparison of ultrasonography with serology. The diagnostic accuracy of ultrasonography in moderate fibrosis was higher than that of serology (P<0.01), while there were no significant differences in the general diagnostic accuracy of fibrosis as well as between mild and severe fibrosis (P<0.05). There were no significant differences between ultrasonography and serology in the diagnosis of compensated liver cirrhosis.However, the diagnostic accuracy of ultrasonography was higher in inactive liver cirrhosis and lower in active cirrhosis than that of serology (both P<0.05). False positive and false

  19. Genome-wide association studies in pediatric chronic kidney disease.

    Science.gov (United States)

    Gupta, Jayanta; Kanetsky, Peter A; Wuttke, Matthias; Köttgen, Anna; Schaefer, Franz; Wong, Craig S

    2016-08-01

    The genome-wide association study (GWAS) has become an established scientific method that provides an unbiased screen for genetic loci potentially associated with phenotypes of clinical interest, such as chronic kidney disease (CKD). Thus, GWAS provides opportunities to gain new perspectives regarding the genetic architecture of CKD progression by identifying new candidate genes and targets for intervention. As such, it has become an important arm of translational science providing a complementary line of investigation to identify novel therapeutics to treat CKD. In this review, we describe the method and the challenges of performing GWAS in the pediatric CKD population. We also provide an overview of successful GWAS for kidney disease, and we discuss the established pediatric CKD cohorts in North America and Europe that are poised to identify genetic risk variants associated with CKD progression.

  20. Nursing diagnoses in patients with chronic venous ulcer: observational study

    Directory of Open Access Journals (Sweden)

    Glycia de Almeida Nogueira

    2015-06-01

    Full Text Available This study aimed to analyze nursing diagnoses in people with chronic venous ulcer. An observational, descriptive, quantitative research conducted in an ambulatory specialized in wound treatment, with a non-probabilistic sample of 20 patients.  Data collection was performed in an institutional form denominated Assessment Protocol for Clients with Tissue Lesions. Diagnoses were established by consensus among four researchers with experience in nursing diagnoses and wound treatments. From data analysis, 16 diagnoses were identified, with 100% of participants presenting: Impaired tissue integrity, Ineffective peripheral tissue perfusion, Risk of infection, Impaired physical mobility and Ineffective health self-control. These diagnoses are found in Safety/Protection, Activity/Rest and Health promotion domains, which from the clinical practice stand point should be priority focuses in nursing intervention and assessment.

  1. Chronic toxicity study of Hyptis suaveolens (L. Poit in rats

    Directory of Open Access Journals (Sweden)

    Bunjong Chaorai

    2005-09-01

    Full Text Available The effect of water extract of Hyptis suaveolens (H. suaveolens was evaluated for 6-month chronic toxicity in Wistar rats. Control group received distilled water orally 10 ml/kg/day. The extract was orally given to five treatment groups at the doses of 5, 50, 250, 500 and 500 mg/kg/day for 6 months. The last group was served as the recovery group. Changes in the body weights, actual and relative organ weights were not significantly demonstrated in all groups throughout the study. The results of hematological, biochemical parameters and histopathological lesions showed that the extract did not produce any significant doserelated changes. Therefore, it may be concluded that the extract of H. suaveolens at the given doses did not produce any significant toxic effect in rats during 6-month period of the treatment.

  2. HANARO instrumented capsule development for supporting a study on the irradiation damage of stainless steels for nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Y. H.; Cho, M. S.; Sohn, J. M.; Kim, H. R.; Lee, B. C.; Kim, K. H

    2000-10-01

    As a part of the program for the maximum utilization of HANARO by MOST, Korea, an instrumented capsule (00M-01U) was designed and fabricated for supporting a study on the irradiation damage of stainless steels for nuclear applications. The basic structure of the capsule for the irradiation of Stainless steels was based on that of the 99M-01K capsule irradiated successfully in HANARO. To satisfy the user requirements such as irradiation temperature and neutron fluence, the optimal arrangement of test specimens was done in the axial and circumferential direction. The temperature distribution and thermal stress of a capsule with multi-holes were obtained by a finite element analysis code, ANSYS. From these analyzed data, this capsule was found to be compatible with HANARO design requirement. Various types of specimens such as small tensile, Charpy, TEM and EPMA specimens were inserted in the capsule. The specimens will be irradiated in the IR2 test hole of HANARO at 288, 300 and 350 deg C up to a fast neutron fluence of 1.0x10{sup 20}(n/cm{sup 2})(E>1.0MeV)

  3. Parametric study of irradiation effects on the ductile damage and flow stress behavior in ferritic-martensitic steels

    Science.gov (United States)

    Chakraborty, Pritam; Biner, S. Bulent

    2015-10-01

    Ferritic-martensitic steels are currently being considered as structural materials in fusion and Gen-IV nuclear reactors. These materials are expected to experience high dose radiation, which can increase their ductile to brittle transition temperature and susceptibility to failure during operation. Hence, to estimate the safe operational life of the reactors, precise evaluation of the ductile to brittle transition temperatures of ferritic-martensitic steels is necessary. Owing to the scarcity of irradiated samples, particularly at high dose levels, micro-mechanistic models are being employed to predict the shifts in the ductile to brittle transition temperatures. These models consider the ductile damage evolution, in the form of nucleation, growth and coalescence of voids; and the brittle fracture, in the form of probabilistic cleavage initiation, to estimate the influence of irradiation on the ductile to brittle transition temperature. However, the assessment of irradiation dependent material parameters is challenging and influences the accuracy of these models. In the present study, the effects of irradiation on the overall flow stress and ductile damage behavior of two ferritic-martensitic steels is parametrically investigated. The results indicate that the ductile damage model parameters are mostly insensitive to irradiation levels at higher dose levels though the resulting flow stress behavior varies significantly.

  4. Effects of total body irradiation-based conditioning allogenic sem cell transplantation for pediatric acute leukemia: A single-institution study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Moo; Choi, Eun Kyung; Kim, Jong Hoon [Dept.of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); and others

    2014-09-15

    To evaluate the effects of total body irradiation (TBI), as a conditioning regimen prior to allogeneic stem cell transplantation (allo-SCT), in pediatric acute leukemia patients. From January 2001 to December 2011, 28 patients, aged less than 18 years, were treated with TBI-based conditioning for allo-SCT in our institution. Of the 28 patients, 21 patients were diagnosed with acute lymphoblastic leukemia (ALL, 75%) and 7 were diagnosed with acute myeloid leukemia (AML, 25%). TBI was completed 4 days or 1 day before stem cell infusion. Patients underwent radiation therapy with bilateral parallel opposing fields and 6-MV X-rays. The Kaplan-Meier method was used to calculate survival outcomes. The 2-year event-free survival and overall survival rates were 66% and 56%, respectively (71.4% and 60.0% in AML patients vs. 64.3% and 52.4% in ALL patients, respectively). Treatment related mortality rate were 25%. Acute and chronic graft-versus-host disease was a major complication; other complications included endocrine dysfunction and pulmonary complications. Common complications from TBI were nausea (89%) and cataracts (7.1%). The efficacy and toxicity data in this study of TBI-based conditioning to pediatric acute leukemia patients were comparable with previous studies. However, clinicians need to focus on the acute and chronic complications related to allo-SCT.

  5. Proteinuria, but Not eGFR, Predicts Stroke Risk in Chronic Kidney Disease: Chronic Renal Insufficiency Cohort Study.

    Science.gov (United States)

    Sandsmark, Danielle K; Messé, Steven R; Zhang, Xiaoming; Roy, Jason; Nessel, Lisa; Lee Hamm, Lotuce; He, Jiang; Horwitz, Edward J; Jaar, Bernard G; Kallem, Radhakrishna R; Kusek, John W; Mohler, Emile R; Porter, Anna; Seliger, Stephen L; Sozio, Stephen M; Townsend, Raymond R; Feldman, Harold I; Kasner, Scott E

    2015-08-01

    Chronic kidney disease is associated with an increased risk of cardiovascular events. However, the impact of chronic kidney disease on cerebrovascular disease is less well understood. We hypothesized that renal function severity would be predictive of stroke risk, independent of other vascular risk factors. The study population included 3939 subjects enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study, a prospective observational cohort. Stroke events were reported by participants and adjudicated by 2 vascular neurologists. Cox proportional hazard models were used to compare measures of baseline renal function with stroke events. Multivariable analysis was performed to adjust for key covariates. In 3939 subjects, 143 new stroke events (0.62 events per 100 person-years) occurred over a mean follow-up of 6.4 years. Stroke risk was increased in subjects who had worse baseline measurements of renal function (estimated glomerular filtration rate and total proteinuria or albuminuria). When adjusted for variables known to influence stroke risk, total proteinuria or albuminuria, but not estimated glomerular filtration rate, were associated with an increased risk of stroke. Treatment with blockers of the renin-angiotensin system did not decrease stroke risk in individuals with albuminuria. Proteinuria and albuminuria are better predictors of stroke risk in patients with chronic kidney disease than estimated glomerular filtration rate. The impact of therapies targeting proteinuria/albuminuria in individuals with chronic kidney disease on stroke prevention warrants further investigation. © 2015 American Heart Association, Inc.

  6. Electron paramagnetic resonance study on n-type electron-irradiated 3C-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, P; Rabia, K; Son, N T; Janzen, E [Department of Physics, Chemistry and Biology, Linkoeping University, SE-581 83 Linkoeping (Sweden); Ohshima, T; Morishita, N; Itoh, H [Japan Atomic Energy Research Institute, Takasaki 370-1292 (Japan); Isoya, J [University of Tsukuba, Tsukuba 305-8550 (Japan)], E-mail: paca@ifm.liu.se

    2008-03-15

    Electron Paramagnetic Resonance (EPR) was used to study defects in n-type 3C-SiC films irradiated by 3-MeV electrons at room temperature with a dose of 2x10{sup 18} cm{sup -2}. After electron irradiation, two new EPR spectra with an effective spin S = 1, labeled L5 and L6, were observed. The L5 center has C{sub 3v} symmetry with g = 2.004 and a fine-structure parameter D = 436.5x10{sup -4} cm{sup -1}. The L5 spectrum was only detected under light illumination and it could not be detected after annealing at {approx}550{sup 0}C. The principal z-axis of the D tensor is parallel to the <111>-directions, indicating the location of spins along the Si-C bonds. Judging from the symmetry and the fact that the signal was detected under illumination in n-type material, the L5 center may be related to the divacancy in the neutral charge state. The L6 center has a C{sub 2v}-symmetry with an isotropic g-value of g = 2.003 and the fine structure parameters D = 547.7x10{sup -4} cm{sup -1} and E = 56.2x10{sup -4} cm{sup -1}. The L6 center disappeared after annealing at a rather low temperature ({approx}200 deg. C), which is substantially lower than the known annealing temperatures for vacancy-related defects in 3C-SiC. This highly mobile defect may be related to carbon interstitials.

  7. Thermoluminescence studies of γ-irradiated ZnO:Mg{sup 2+} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pushpa, N. [Department of Physics, Bangalore University, Bangalore 560 056 (India); Kokila, M.K., E-mail: drmkkokila@gmail.com [Department of Physics, Bangalore University, Bangalore 560 056 (India); Nagabhushana, K.R. [Department of Physics - S & H, PES University, Bangalore 560 085 (India)

    2016-07-15

    Pure and Mg{sup 2+} doped ZnO nanoparticles are synthesized by solution combustion method. X-ray diffraction studies of the samples confirm hexagonal phase. Crystallite size is calculated using Scherer formula and found to be ∼30 nm for undoped ZnO and 34–38 nm for Mg{sup 2+} doped ZnO. A broad PL emission in the range 400–600 nm with peaks at 400, 450, 468, 483, 492, 517, 553 nm are observed in both pure and Mg{sup 2+} doped nanoparticles. Near band edge emission of ZnO is observed at 400 nm. The broad band emissions are due to surface defects. PL emission intensity is found to increase with Mg{sup 2+} concentration up to 1.5 mol% and then decreases due to concentration quenching. Samples are irradiated with γ-rays in a dose range 0.05–8 kGy. Gamma irradiation doesn’t affect PL properties. Undoped samples exhibit unstructured low intense TL glow with peak at 720 K. Whereas Mg{sup 2+} doped samples exhibit well structured TL glow curves with peak at ∼618 K. TL glow peak intensity of Mg{sup 2+} doped samples increases with Mg{sup 2+} concentration up to 2 mol%, thereafter decreases. TL curves of Mg{sup 2+} (2 mol%) doped ZnO exhibit two glows, a high intense peak at 618 K and a weak one with peak at ∼485 K. TL intensity of Mg{sup 2+} (2 mol%) doped ZnO samples increases with gamma dose up to 1 kGy and then decreases. Kinetic parameters of TL glows are calculated by deconvolution technique. Activation energy and frequency factor are found to be 1.5 eV and 3.38 × 10{sup 11} s{sup −1} respectively.

  8. Study of human blood and hemocomponents irradiated by low angle x ray scattering (LAXS)

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Nivia G. Villela; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica], e-mail: nitatag@gmail.com; Mota, Carla L.S.; Almeida, Andre P.; Azeredo, Soraia R.; Braz, Delson [Coordenacao dos Programas de Pos-graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear], e-mail: delson@lin.ufrj.br

    2009-07-01

    Irradiation of blood and blood components is currently practiced in developed and in a few developing countries. The main purpose of this process is the prevention of graft versus host disease in immunodeficient patients. The Food and Drug Administration recommends a dose range of 15 Gy to 25 Gy for these blood components. When x-ray photons are scattered from biological samples, their angular distribution shows one or more peaks in the forward direction of scattering. These peaks are characteristic for the investigated samples. Due to its wide range of biological and medical applications, low-angle x-ray scattering has attracted the attention of many authors. Thus in this present work was studied the possible variations in scattering profiles due to the irradiation when the gender of patients was considered. Fresh blood specimens were obtained from volunteers using vacutainer tubes containing EDTA, at the Dr. Eliel Figueiredo Laboratory, Rio de Janeiro. All the samples were lyophilized for 48 hours in a freeze drier in order to remove the water. The scattering measurements were carried out in e-2e reflection geometry using a powder diffractometer Shimadzu XRD- 6000. The measured characterization parameters for LAXS were associated with epidemiological data (gender). The mean values of the different parameters were compared using the Students's t-test for each characterization parameters. The scattering profiles from plasma and formed elements are characterized by the presence of two peaks in the forward direction of scattering. For epidemiological data (gender) analyzed was not found significant changes in the mostly of characterization parameters (p>0.05). (author)

  9. Patients with chronic pain after abdominal surgery show less preoperative endogenous pain inhibition and more postoperative hyperalgesia: a pilot study.

    NARCIS (Netherlands)

    Wilder-Smith, O.H.G.; Schreyer, T.; Scheffer, G.J.; Arendt-Nielsen, L.

    2010-01-01

    Chronic pain is common and undesirable after surgery. Progression from acute to chronic pain involves altered pain processing. The authors studied relationships between presence of chronic pain versus preoperative descending pain control (diffuse noxious inhibitory controls; DNICs) and postoperative

  10. Online in situ x-ray diffraction setup for structural modification studies during swift heavy ion irradiation

    Science.gov (United States)

    Grygiel, C.; Lebius, H.; Bouffard, S.; Quentin, A.; Ramillon, J. M.; Madi, T.; Guillous, S.; Been, T.; Guinement, P.; Lelièvre, D.; Monnet, I.

    2012-01-01

    The high energy density of electronic excitations due to the impact of swift heavy ions can induce structural modifications in materials. We present an x-ray diffractometer called ALIX ("Analyse en Ligne sur IRRSUD par diffraction de rayons X"), which has been set up at the low-energy beamline (IRRadiation SUD - IRRSUD) of the Grand Accélérateur National d'Ions Lourds facility, to allow the study of structural modification kinetics as a function of the ion fluence. The x-ray setup has been modified and optimized to enable irradiation by swift heavy ions simultaneously to x-ray pattern recording. We present the capability of ALIX to perform simultaneous irradiation-diffraction by using energy discrimination between x-rays from diffraction and from ion-target interaction. To illustrate its potential, results of sequential or simultaneous irradiation-diffraction are presented in this article to show radiation effects on the structural properties of ceramics. Phase transition kinetics have been studied during xenon ion irradiation of polycrystalline MgO and SrTiO3. We have observed that MgO oxide is radiation-resistant to high electronic excitations, contrary to the high sensitivity of SrTiO3, which exhibits transition from the crystalline to the amorphous state during irradiation. By interpreting the amorphization kinetics of SrTiO3, defect overlapping models are discussed as well as latent track characteristics. Together with a transmission electron microscopy study, we conclude that a single impact model describes the phase transition mechanism.

  11. 8 MeV electron irradiation studies on electrical characteristics of Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Asha [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore 574 227 (India); Krishnan, Sheeja; Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri 574 199 (India); Siddappa, K. [JSS Foundation for Science and Society, Bangalore 560 085 (India); Ullal, Harin S.; Wu, Xuanzhi [National Center for Photovoltaics, National Renewable Energy Laboratory, 1617, Cole Boulevard, Golden, CO 80401 (United States)

    2009-09-15

    Cu(In,Ga)Se{sub 2} (CIGS) solar cells are gaining considerable interest due to their high optical absorption coefficient and adjustable band gap, which enables them to achieve high conversion efficiency and also present many promising applications in space power systems. In this paper we report the results of the effect of temperature and 8 MeV electron irradiation on the electrical characteristics of ZnO/CdS/Cu(In,Ga)Se{sub 2}/Mo polycrystalline thin-film solar cells under forward and reverse bias studied in the temperature range 270-315 K. The solar cells were subjected to 8 MeV electron irradiation from the Microtron accelerator and were exposed to graded doses of electrons up to 75 kGy. I-V characteristics of the cells under dark and AM 1.5 illumination condition were studied before and after the irradiation. Capacitance measurements were also carried out at various frequencies before and after irradiation. In the measured temperature range, the dark current contribution is due to the generation-recombination of the minority carriers in the depletion region. The ideality factor is found to decrease with increase in temperature. It seems that electron irradiation has not altered the dark current conduction mechanism significantly. The effect of electron irradiation on the solar cell parameters such as fill factor (FF), conversion efficiency ({eta}), saturation current (I{sub o}), short circuit current (I{sub sc}), open circuit voltage (V{sub oc}), and ideality factor (n) was studied. They were found to be stable up to 75 kGy of electron dose as only small changes were observed in the solar cell parameters. (author)

  12. Online in situ x-ray diffraction setup for structural modification studies during swift heavy ion irradiation.

    Science.gov (United States)

    Grygiel, C; Lebius, H; Bouffard, S; Quentin, A; Ramillon, J M; Madi, T; Guillous, S; Been, T; Guinement, P; Lelièvre, D; Monnet, I

    2012-01-01

    The high energy density of electronic excitations due to the impact of swift heavy ions can induce structural modifications in materials. We present an x-ray diffractometer called ALIX ("Analyse en Ligne sur IRRSUD par diffraction de rayons X"), which has been set up at the low-energy beamline (IRRadiation SUD - IRRSUD) of the Grand Accélérateur National d'Ions Lourds facility, to allow the study of structural modification kinetics as a function of the ion fluence. The x-ray setup has been modified and optimized to enable irradiation by swift heavy ions simultaneously to x-ray pattern recording. We present the capability of ALIX to perform simultaneous irradiation-diffraction by using energy discrimination between x-rays from diffraction and from ion-target interaction. To illustrate its potential, results of sequential or simultaneous irradiation-diffraction are presented in this article to show radiation effects on the structural properties of ceramics. Phase transition kinetics have been studied during xenon ion irradiation of polycrystalline MgO and SrTiO(3). We have observed that MgO oxide is radiation-resistant to high electronic excitations, contrary to the high sensitivity of SrTiO(3), which exhibits transition from the crystalline to the amorphous state during irradiation. By interpreting the amorphization kinetics of SrTiO(3), defect overlapping models are discussed as well as latent track characteristics. Together with a transmission electron microscopy study, we conclude that a single impact model describes the phase transition mechanism.

  13. X-ray diffraction study of the Y2Ti2O7 pyrochlore disordering sequence under irradiation

    Science.gov (United States)

    Soulié, Aurélien; Menut, Denis; Crocombette, Jean-Paul; Chartier, Alain; Sellami, Neila; Sattonnay, Gaël; Monnet, Isabelle; Béchade, Jean-Luc

    2016-11-01

    The disordering sequence of Y2Ti2O7 pyrochlore, a nano-oxide phase that strengthens ODS steels under irradiation is studied in the experimental and modeling framework. XRD analysis has been performed considering both swift heavy ion and low energy/low mass ion irradiations. The simulation within molecular dynamics of Frenkel pair accumulation proves able to reproduce the variation of the amorphization fluence with temperature. XRD patterns calculated from the simulations reproduce well the patterns observed experimentally in the literature. Both experiments and calculations point to a first transition from pyrochlore to fluorite before an eventual amorphization. For swift heavy ion irradiations with 93 MeV Xe ions, tracks of direct impact amorphization are visible by HRTEM. Advanced refinement shows that one third of the pyrochlore impacted by an ion transforms into fluorite, while two third are directly amorphized.

  14. Magnetization studies of YBa/sub 2/Cu/sub 3/Osub(7-x) irradiated by fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Wisniewski, A.; Baran, M.; Przyslupski, P.; Szymczak, H.; Pajaczkowska, A.; Pytel, B.; Pytel, K.

    1988-02-01

    Studies of the effect of fast neutron damage on the magnetic hysteresis of YBa/sub 2/Cu/sub 3/Osub(7-x) ceramic samples subjected to fluence of neutrons of 2x10/sup 16/ n/cm/sup 2/ up to 6x10/sup 17/ n/cm/sup 2/ have been performed. Irradiation up to dose of 1x10/sup 17/ did not cause any change in the critical temperature. However it causes a strong increase of the magnetic hysteresis which is presumably connected with the creation of defects. The critical current density at 77 K in H = 10 KOe for the sample irradiated with the dose 1x10/sup 17/ n/cm/sup 2/ was estimated to be 520 A/cm/sup 2/ as compared to 29 A/cm/sup 2/ for the reference non-irradiated sample.

  15. EPR study of gamma and neutron irradiation effects on KU1, KS-4V and Infrasil 301 silica glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lagomacini, Juan C., E-mail: jc.lagomacini@uam.es [Dept. Fisica de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Bravo, David [Dept. Fisica de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Leon, Monica; Martin, Piedad; Ibarra, Angel [Materiales para Fusion, CIEMAT, Avda. Complutense 22, E-28040 Madrid (Spain); Martin, Agustin [Dept. Fisica e Instalaciones, ETS Arquitectura UPM, E-28040 Madrid (Spain); Lopez, Fernando J. [Dept. Fisica de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain)

    2011-10-01

    Electron paramagnetic resonance (EPR) studies have been carried out on KU1 and KS-4V high purity quartz glasses and commercial silica Infrasil 301, irradiated with gamma rays up to a dose of 11.6 MGy and neutron fluences of 10{sup 21} and 10{sup 22} n/m{sup 2}. Gamma irradiations produce a much higher concentration of defect centres (mainly E', POR and NBOHC) for KU1 and I301 than for KS-4V silica. In contrast, neutron irradiation at the highest fluence produces similar concentrations in all silica types. These results agree to a good extent with those obtained in previous optical absorption measurements. Moreover, oxygen-related centres (POR and NBOHC) have been well characterized by means of electron paramagnetic resonance.

  16. Chronic pain in children and adolescents: observational studies

    NARCIS (Netherlands)

    C.W. Perquin (Christel)

    2002-01-01

    textabstractIn adults, chronic pain is by most people involved considered to be a serious disorder. Although chronic pain in adults is in general not life-threatening, a considerable amount of literature elucidates the large number of sufferers, the high cost to the person in question and to the soc

  17. Chronic pain after lung transplantation: a nationwide study

    DEFF Research Database (Denmark)

    Wildgaard, Kim; Iversen, Martin; Kehlet, Henrik

    2010-01-01

    Little is known about persistent postsurgical pain after lung transplantation with the associated intensive and continuous immunosuppressive treatment. Therefore, we investigated the nationwide incidence of chronic pain after lung transplantations.......Little is known about persistent postsurgical pain after lung transplantation with the associated intensive and continuous immunosuppressive treatment. Therefore, we investigated the nationwide incidence of chronic pain after lung transplantations....

  18. Experimental study of different histologic types of lung cancers after irradiation. Etude experimentale des differents types histologiques de cancers pulmonaires induits par l'irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Morin, M.; Masse, R.; Lafuma, J. (CEA Centre d' Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Pathologie et de Toxicologie Experimentales)

    1994-01-01

    Recent epidemiologic studies suggested that some histologic types of carcinomas were preferentially induced in the lung by irradiation, whatever the mode of exposure and the radiation quality. Since smoking and other environmental airborne pollutants may be strong confounding factors in humans, we have investigated whether histological subtypes were dependent or not on the mode of exposure, in a large series of 9000 rats exposed to external and internal sources at high and low Linear Energy Transfer. Despite comparable overall risk coefficients in rats and humans, our results show that histological types are influenced not only by dose but also by radiation quality and heterogeneity of dose delivering. We suggest that extrapolation from one group to an other take this information in consideration. (authors). 10 refs., 1 tab.

  19. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

  20. An aetiopathological study of chronic bronchopneumonia in lambs in Ireland.

    Science.gov (United States)

    Sheehan, Maresa; Cassidy, Joseph P; Brady, Joseph; Ball, Hywel; Doherty, Michael L; Quinn, Patrick J; Nicholas, Robin A J; Markey, Bryan K

    2007-05-01

    Chronic bronchopneumonia in lambs, also known as 'atypical' or 'chronic, non-progressive' pneumonia is a common, frequently sub-clinical disease affecting animals under 12-months-old in intensive production systems. Infection with both Mycoplasma ovipneumoniae and Mannheimia haemolytica have been implicated in the aetiology of this condition and a variety of pulmonary lesions can result. In this study, detailed laboratory examination of 30 abattoir-derived lungs with the characteristic gross features of atypical pneumonia (AP) was carried out with a view to refining and correlating the histopathological and microbiological criteria required for the diagnosis of this disease. For the first time a broad range of laboratory detection techniques including bacterial and virus isolation, fluorescent antibody tests and immunohistochemistry were used in parallel to identify potential causative pathogens such as M. ovipneumoniae, M. haemolytica, parainfluenza type-3 (PI3) virus and respiratory syncytial virus (RSV) in AP lesions. The most consistent finding was the association of gross AP lesions with M. ovipneumoniae, identified by either culture or immunohistochemistry in 27 (90%) of the 30 cases. However the presence M. ovipneumoniae organisms or antigen did not consistently correlate with particular histopathological changes. Furthermore, peri-airway lymphoid hyperplasia, intra-alveolar exudation and nodular 'hyaline scars', which are all previously reported microscopic lesions of AP, were not identified in 12 (40%) of the cases and isolation of M. haemolytica was over-represented in lungs exhibiting suppurative lesions. These findings illustrate the complex aetiopathogenesis of this disease and highlight the requirement to use a combination of diagnostic criteria in its laboratory diagnosis.

  1. Positron annihilation study of defects in GaAs irradiated by fission neutron

    Institute of Scientific and Technical Information of China (English)

    ZhuSheng-Yun; QianJia-Yu; 等

    1997-01-01

    The defects in Si-doped,N-type HB GaAs single crystal irradiated by En≥1 MeV fission neutrons(6.5×1015cm-2 and 1.4×1014cm-2)have been investigated using positron annihilation lifetime technique.The mono-and di-vacancies were created by irradiation and the tri-vacancies were formed during annealing.The concentration of defects is proportional to the irradiating neutron fluence.Three annealing stages were obsered at 250,450 and 650℃ for the mono-,di-and tri-vacancies,respectively.

  2. Barium swallow study in routine clinical practice: a prospective study in patients with chronic cough

    Directory of Open Access Journals (Sweden)

    Carlos Shuler Nin

    2013-12-01

    Full Text Available OBJECTIVE: To assess the routine use of barium swallow study in patients with chronic cough.METHODS: Between October of 2011 and March of 2012, 95 consecutive patients submitted to chest X-ray due to chronic cough (duration > 8 weeks were included in the study. For study purposes, additional images were obtained immediately after the oral administration of 5 mL of a 5% barium sulfate suspension. Two radiologists systematically evaluated all of the images in order to identify any pathological changes. Fisher's exact test and the chi-square test for categorical data were used in the comparisons.RESULTS: The images taken immediately after barium swallow revealed significant pathological conditions that were potentially related to chronic cough in 12 (12.6% of the 95 patients. These conditions, which included diaphragmatic hiatal hernia, esophageal neoplasm, achalasia, esophageal diverticulum, and abnormal esophageal dilatation, were not detected on the images taken without contrast. After appropriate treatment, the symptoms disappeared in 11 (91.6% of the patients, whereas the treatment was ineffective in 1 (8.4%. We observed no complications related to barium swallow, such as contrast aspiration.CONCLUSIONS: Barium swallow improved the detection of significant radiographic findings related to chronic cough in 11.5% of patients. These initial findings suggest that the routine use of barium swallow can significantly increase the sensitivity of chest X-rays in the detection of chronic cough-related etiologies.

  3. WE-D-BRE-01: A Sr-90 Irradiation Device for the Study of Cutaneous Radiation Injury

    Energy Technology Data Exchange (ETDEWEB)

    Dorand, JE; Bourland, JD [Department of Radiation Oncology and Department of Physics, Wake Forest University, Winston-Salem, NC (United States); Burnett, LR [KeraNetics, LLC, Winston-Salem, NC (United States); Tytell, M [Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, NC (United States)

    2014-06-15

    Purpose: To determine dosimetric character for a custom-built Sr-90 beta irradiator designed for the study of Cutaneous Radiation Injury (CRI) in a porcine animal model. In the event of a radiological accident or terrorist event, Sr-90, a fission by-product, will likely be produced. CRI is a main concern due to the low energy and superficial penetration in tissue of beta particles from Sr-90. Seven 100 mCi plaque Sr-90 radiation sources within a custom-built irradiation device create a 40 mm diameter region of radiation-induced skin injury as part of a larger project to study the efficacy of a topical keratin-based product in CRI healing. Methods: A custom-built mobile irradiation device was designed and implemented for in vivo irradiations. Gafchromic™ EBT3 radiochromic film and a PTW Markus chamber type 23343 were utilized for dosimetric characterization of the beta fluence at the surface produced by this device. Films were used to assess 2-dimensional dose distribution and percent depth dose characteristics of the radiation field. Ion chamber measurements provided dose rate data within the field. Results: The radiation field produced by the irradiation device is homogeneous with high uniformity (∼5%) and symmetry (∼3%) with a steep dose fall-off with depth from the surface. Dose rates were determined to be 3.8 Gy/min and 3.3 Gy/min for film and ion chamber measurements, respectively. A dose rate of 3.4 Gy/min was used to calculate irradiation times for in vivo irradiations. Conclusion: The custom-built irradiation device enables the use of seven Sr-90 beta sources in an array to deliver a 40 mm diameter area of homogeneous skin dose with a dose rate that is useful for research purposes and clinically relevant for the induction of CRI. Doses of 36 and 42 Gy successfully produce Grade III CRI and are used in the study of the efficacy of KeraStat™. This project has been funded in whole or in part with Federal funds from the Biomedical Advanced Research and

  4. Detection of sexually transmitted pathogens in patients with chronic prostatitis/chronic pelvic pain: a prospective clinical study.

    Science.gov (United States)

    Papeš, Dino; Pasini, Miram; Jerončić, Ana; Vargović, Martina; Kotarski, Viktor; Markotić, Alemka; Škerk, Višnja

    2017-01-01

    In <10% of patients with prostatitis syndrome, a causative uropathogenic organism can be detected. It has been shown that certain organisms that cause sexually transmitted infections can also cause chronic bacterial prostatitis, which can be hard to diagnose and treat appropriately because prostatic samples obtained by prostatic massage are not routinely tested to detect them. We conducted a clinical study to determine the prevalence of Chlamydia, mycoplasma, and trichomonas infection in 254 patients that were previously diagnosed and treated for chronic prostatitis/chronic pelvic pain syndrome due to negative urethral swab, urine, and prostate samples. Urethral swabs and standard Meares-Stamey four-glass tests were done. Detailed microbiological analysis was conducted to detect the above organisms. Thirty-five (13.8%) patients had positive expressed prostatic secretions/VB3 samples, of which 22 (10.1%) were sexually transmitted organisms that were not detected on previous tests.

  5. Hereditary radiation effects in offspring of the second and third generations after irradiation of both grandparents. Experimental studies and Hereditary radiation effects in offspring of the first generation after irradiation of one and both parents. Experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Nefyodova, I.; Nefyodov, I [Medical Radiological Research Centre RAMS, Obninsk (Russian Federation)

    2000-05-01

    The parent study has investigated hereditary radiation effects in progeny of the second and third generations of Wistar rats after irradiation of both grandparents with doses of 2-4 Gy. Attention was focused on the relationship between stages of gametogenesis in grandparents at the moment of radiation exposure and death of progeny in embryogenesis and early postnatal ontogenesis. Totals of 4207 mature males and females Wistar rats, 13539 offspring of the second generation (F2) and 746 offspring of the third generation (F3) were the subjects of investigation. Male and female rat grandparents (P) of 220-250 g were exposed to an external single irradiation by gamma rays to doses of 2,3 and 4 Gy at a dose rate of 0.003 Gy.s{sup -1} ({sup 60}Co source). The animals were mated at different times after irradiation so that different stages in gametogenesis were studied. When F1 sexual maturity was achieved, F1 males of each experimental group were mated with intact females to produce F2 descendants from the father's line and conversely F1 females use mated with intact males to produce F2 descendants from the mother's line. Embryogenesis F2 was studied after euthanasia of some females by ether on the 20th day of pregnancy. The fetuses were scored for size and mass, pathology of viscera and skeleton and the total, pre- and postimplantation death of embryos was calculated. In addition development of young rats was observed for 30 days after the birth. The numbers surviving on the 1st and 30th days after the birth were calculated, giving the death rate for this period of time. It was stated: for F2; radiation effects depend upon a dose stage of gametogenesis of both P at the time of radiation exposure; F2 death in embryogenesis occurred only after irradiation of P with a dose of 4 Gy; ossification disorder of the skeleton in F2 embryogenesis was found in all experimental groups; high F2 death is observed after birth which depends much more on the stage of

  6. Carcinoma of the prostate treated by pelvic node dissection, iodine-125 seed implant and external irradiation; a study of rectal complications

    Energy Technology Data Exchange (ETDEWEB)

    Abadir, R.; Ross, G. Jr.; Weinstein, S.H. (Missouri Univ., Columbia (USA). Hospital and Clinics)

    1984-09-01

    The University of Missouri-Columbia protocol for localised cancer of the prostate calls for pelvic node dissection, 10 000 cGy at the periphery of the prostate from /sup 125/I and 4000 cGy in 20 fractions to the whole pelvis using supervoltage X-ray therapy. Rectal complications were studied in 104 patients; acute and chronic reactions were defined. During external irradiation 54% did not develop diarrhoea, 43% had mild diarrhoea and 3% had severe diarrhoea. In the chronic stage 77% did not have diarrhoea, 12% had delayed, non-distressing rectal bleeding which did not need specific treatment or needed only simple treatment, 7% had prolonged distressing proctitis and 4% had rectal ulceration or recto-urethral fistula necessitating colostomy. Each of the four patients who had colostomy had an additional aetiological factor (arterial disease, pelvic inflammation, additional radiation, pelvic malignancy or second operation). None of the patients entered in the combined brachytherapy and teletherapy programme, and in whom 0.5 cm space was maintained between the closest seed and the rectal mucosa, developed prolonged proctitis.

  7. A NEXAFS and mass spectrometry study of cysteine, cystine and insulin irradiated with intermediate energy (0.8 keV) electrons

    Energy Technology Data Exchange (ETDEWEB)

    Simões, G., E-mail: simoes.grazieli@gmail.com [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil); Rodrigues, F.N. [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil); Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Maracanã, 20270-021 Rio de Janeiro (Brazil); Bernini, R.B. [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil); Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Duque de Caxias, 25050-100 Rio de Janeiro (Brazil); Castro, C.S.C. [Instituto Nacional de Metrologia, Qualidade e Tecnologia – Inmetro, 25250-020 Rio de Janeiro (Brazil); Souza, G.G.B. de, E-mail: gerson@iq.ufrj.br [Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-909 Rio de Janeiro (Brazil)

    2014-03-01

    Highlights: • Structural modifications in sulfur containing biomolecules were investigated. • Significant modifications were observed in insulin irradiated NEXAFS spectra. • Degradation of insulin can be observed even at low temperature. • Alterations in insulin spectrum were characterized according to the state of sulfur. - Abstract: We have performed a NEXAFS (S 1s) and mass spectrometry study of solid samples of cysteine, cystine and insulin irradiated with 0.8 keV electrons. The measured mass spectra point out to processes of desulfurization, deamination, decarbonylation and decarboxylation in the irradiated biomolecules. Electron beam irradiation was also conducted at low temperatures in order to evaluate the possible contribution from thermal degradation processes. The NEXAFS spectra of irradiated cysteine and cystine did not show substantial changes when compared to the same spectra obtained using non-irradiated samples. The sulfur K-edge photoabsorption spectrum of irradiated insulin, however, showed clear modifications when compared to the spectrum of the non-irradiated protein, even when the irradiation was conducted at low temperature. Using an empirical combination of the photoabsorption spectra of cysteine and cystine (which are associated respectively with reduced and oxidized forms of sulfur) we have been able to reproduce the absorption spectrum of irradiated insulin.

  8. Longitudinal trajectory of sexual functioning after hematopoietic cell transplantation: impact of chronic graft-versus-host disease and total body irradiation

    Science.gov (United States)

    Wong, F. Lennie; Francisco, Liton; Togawa, Kayo; Kim, Heeyoung; Bosworth, Alysia; Atencio, Liezl; Hanby, Cara; Grant, Marcia; Kandeel, Fouad; Forman, Stephen J.

    2013-01-01

    This prospective study described the trajectory of sexual well-being from before hematopoietic cell transplantation (HCT) to 3 years after in 131 allogeneic and 146 autologous HCT recipients using Derogatis Interview for Sexual Function and Derogatis Global Sexual Satisfaction Index. Sixty-one percent of men and 37% of women were sexually active pre-HCT; the prevalence declined to 51% (P = .01) in men and increased to 48% (P = .02) in women at 3 years post-HCT. After HCT, sexual satisfaction declined in both sexes (P sexual function domains were worse in women compared with men (P ≤ .001). Orgasm (P = .002) and drive/relationship (P sexual cognition/fantasy (P = .01) and sexual behavior/experience (P = .01) improved in women. Older age negatively impacted sexual function post-HCT in both sexes (P sexual cognition/fantasy (P = .003) and orgasm (P = .006) in men and sexual arousal (P = .05) and sexual satisfaction (P = .005) in women. All male sexual function domains declined after total body irradiation (P sexual well-being. PMID:24159171

  9. Alteration of T cell function in healthy persons with a history of thymic x irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

    1975-10-01

    The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis.

  10. Charge deep-level transient spectroscopy study of high-energy-electron-beam-irradiated hydrogenated amorphous silicon

    NARCIS (Netherlands)

    Klaver, A.; Nádaždy, V.; Zeman, M.; Swaaiij, R.A.C.M.M.

    2006-01-01

    We present a study of changes in the defect density of states in hydrogenated amorphous silicon (a-Si:H) due to high-energy electron irradiation using charged deep-level transient spectroscopy. It was found that defect states near the conduction band were removed, while in other band gap regions the

  11. Effects of Low-Level Laser Irradiation on the Pathogenicity of Candida albicans: In Vitro and in Vivo Study

    NARCIS (Netherlands)

    Seyedmousavi Tasieh, S.; Hashemi, S.J.; Rezaie, S.; Fateh, M.; Djavid, G.E.; Zibafar, E.; Morsali, F.; Zand, N.; Alinaghizadeh, M.; Ataie-Fashtami, L.

    2014-01-01

    Abstract Objective: The purpose of this study was to evaluate the effects of low-level laser irradiation (LLLI) on the in vitro growth characteristics and in vivo pathogenicity of Candida albicans in a murine model in the absence of a photosensitizer. Background data: C. albicans is an opportunistic

  12. EPR studies of free radicals decay and survival in gamma irradiated aminoglycoside antibiotics: sisomicin, tobramycin and paromomycin.

    Science.gov (United States)

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

    2012-02-14

    Radiation sterilization technology is more actively used now that any time because of its many advantages. Gamma radiation has high penetrating power, relatively low chemical reactivity and causes small temperature rise. But on the other hand radiosterilization can lead to radiolytic products appearing, in example free radicals. Free radicals in radiative sterilized sisomicin, tobramycin and paromomycin were studied by electron paramagnetic resonance (EPR) spectroscopy. Dose of gamma irradiation of 25kGy was used. Concentrations and properties of free radicals in irradiated antibiotics were studied. EPR spectra were recorded for samples stored in air and argon. For gamma irradiated antibiotics strong EPR lines were recorded. One- and two-exponential functions were fitted to experimental points during testing and researching of time influence of the antibiotics storage to studied parameters of EPR lines. Our study of free radicals in radiosterilized antibiotics indicates the need for characterization of medicinal substances prior to sterilization process using EPR values. We propose the concentration of free radicals and other spectroscopic parameters as useful factors to select the optimal type of sterilization for the individual drug. The important parameters are i.a. the τ time constants and K constants of exponential functions. Time constants τ give us information about the speed of free radicals concentration decrease in radiated medicinal substances. The constant K(0) shows the free radicals concentration in irradiated medicament after long time of storage.

  13. Effects of Low-Level Laser Irradiation on the Pathogenicity of Candida albicans: In Vitro and in Vivo Study

    NARCIS (Netherlands)

    Seyedmousavi Tasieh, S.; Hashemi, S.J.; Rezaie, S.; Fateh, M.; Djavid, G.E.; Zibafar, E.; Morsali, F.; Zand, N.; Alinaghizadeh, M.; Ataie-Fashtami, L.

    2014-01-01

    Abstract Objective: The purpose of this study was to evaluate the effects of low-level laser irradiation (LLLI) on the in vitro growth characteristics and in vivo pathogenicity of Candida albicans in a murine model in the absence of a photosensitizer. Background data: C. albicans is an opportunistic

  14. Transgenerational developmental effects and genomic instability after X-irradiation of preimplantation embryos: Studies on two mouse strains

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, P., E-mail: pjacquet@sckcen.be [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium); Buset, J.; Neefs, M. [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium); Vankerkom, J. [Division of Environmental Research, VITO, Boeretang 200, B-2400 Mol (Belgium); Benotmane, M.A.; Derradji, H. [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium); Hildebrandt, G. [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 9a, D-04103 Leipzig (Germany); Department of Radiotherapy, University of Rostock, Suedring 75, D-18059 Rostock (Germany); Baatout, S. [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium)

    2010-05-01

    Recent results have shown that irradiation of a single cell, the zygote or 1-cell embryo of various mouse strains, could lead to congenital anomalies in the fetuses. In the Heiligenberger strain, a link between the radiation-induced congenital anomalies and the development of a genomic instability was also suggested. Moreover, further studies showed that in that strain, both congenital anomalies and genomic instability could be transmitted to the next generation. The aim of the experiments described in this paper was to investigate whether such non-targeted transgenerational effects could also be observed in two other radiosensitive mouse strains (CF1 and ICR), using lower radiation doses. Irradiation of the CF1 and ICR female zygotes with 0.2 or 0.4 Gy did not result in a decrease of their fertility after birth, when they had reached sexual maturity. Moreover, females of both strains that had been X-irradiated with 0.2 Gy exhibited higher rates of pregnancy, less resorptions and more living fetuses. Additionally, the mean weight of living fetuses in these groups had significantly increased. Exencephaly and dwarfism were observed in CF1 fetuses issued from control and X-irradiated females. In the control group of that strain, polydactyly and limb deformity were also found. The yields of abnormal fetuses did not differ significantly between the control and X-irradiated groups. Polydactyly, exencephaly and dwarfism were observed in fetuses issued from ICR control females. In addition to these anomalies, gastroschisis, curly tail and open eye were observed at low frequencies in ICR fetuses issued from X-irradiated females. Again, the frequencies of abnormal fetuses found in the different groups did not differ significantly. In both CF1 and ICR mouse strains, irradiation of female zygotes did not result in the development of a genomic instability in the next generation embryos. Overall, our results suggest that, at the moderate doses used, developmental defects

  15. Effect of irradiation on gene expression of rat liver adhesion molecules. In vivo and in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    Moriconi, Federico; Malik, Ihtzaz; Ahmad, Ghayyor; Dudas, Joszef; Ramadori, Giuliano [Dept. of Gastroenterology and Endocrinology, Goettingen Univ. (Germany); Rave-Fraenk, Margret; Vorwerk, Hilke; Hille, Andrea; Hess, Clemens Friedrich; Christiansen, Hans [Dept. of Radiotherapy, Goettingen Univ. (Germany)

    2009-07-15

    Background and purpose: Migration of leukocytes into tissue is a key element of innate and adaptive immunity. An animal study showed that liver irradiation, in spite of induction of chemokine gene expression, does not lead to recruitment of leukocytes into the parenchyma. The aim of this study was to analyze gene expression of adhesion molecules, which mediate leukocyte recruitment into organs, in irradiated rat liver in vivo and rat hepatocytes in vitro. Material and methods: Rat livers in vivo were irradiated selectively at 25 Gy. Isolated hepatocytes in vitro were irradiated at 8 Gy. RNA extracted within 48 h after irradiation in vivo and in vitro was analyzed by real-time PCR (polymerase chain reaction) and Northern blot. Adhesion molecule concentration in serum was measured by ELISA (enzyme-linked immunosorbent assay). Cryostat sections of livers were used for immunohistology. Results: Significant radiation-induced increase of ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1), JAM-1 (junctional adhesion molecule-1), {beta}{sub 1}-integrin, {beta}{sub 2}-integrin, E-cadherin, and P-selectin gene expression could be detected in vivo, while PECAM-1 (platelet-endothelial cell adhesion molecule-1) gene expression remained unchanged. In vitro, {beta}{sub 1}-integrin, JAM-1, and ICAM-2 showed a radiation-induced increased expression, whereas the levels of P-selectin, ICAM-1, PECAM-1, VCAM-1, Madcam-1 (mucosal addressin cell adhesion molecule-1), {beta}{sub 2}-integrin, and E-cadherin were downregulated. However, incubation of irradiated hepatocytes with either tumor necrosis factor-(TNF-){alpha}, interleukin-(IL-)1{beta}, or IL-6 plus TNF-{alpha} led to an upregulation of P-selectin, ICAM-1 and VCAM-1. Conclusion: The findings suggest that liver irradiation modulates gene expression of the main adhesion molecules in vivo and in cytokine-activated hepatocytes, with the exception of PECAM-1. This may be one reason for the lack of

  16. An electron microscopic study on the cobalt-60 irradiation effects on the salivary gland of the white rat

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Seo; Yoon, Jung Ho [Department of Dental Science, Graduate School, Yonsei University, Seoul (Korea, Republic of)

    1985-11-15

    This study was undertaken to observe the histopathologic changes in salivary gland of the white rats when exposed to megavoltage fractionated dose of cobalt-60 irradiation and 78 female white rats, weighing approximately 180 gm, were divided into control and 3 experimental groups. Irradiation on experimental groups was delivered by using 6000 curies MeV ALCYON cobalt-60 teletherapy unit with exposure rate 183 rads per minute, in source skin distance 80 cm, 600 rads every 3 days. In experimental groups, Group I was irradiated of total dose 1200 rads for a period of 6 days, Group II was irradiated of total dose 2400 rads for a period of 12 days and Group III was irradiated of total dose of 4800 rads for a period of 24 days. The animals were sacrificed serially at 3 hours, 6 hours, 10 hours, 1st day, 4th day, 7th day after each completion of irradiation exposure. At sacrifice, salivary glands were excised and examined microscopically and electromicroscopically. The results were as follows: 1. The acinar cells of parotid and submaxillary gland showed damage varied with dose, 1200 rads resulted in very mild injury while 4800 rads caused most extensive injury. 2. The acinar cells of parotid and submandibular gland showed similar ultrastructural alterations, appeared as pleomorphic nucleus, decreased numbers and pleomorphism of secretory granules, distension of rough endoplasmic reticulum, expansion and pallor appearance of mitochodria, and hypertrophy of Golgi complex. 3. Parotid serous cells were the most sensitive components, displaying morphological alterations of radiation damage as early as 3 hours, followed by submandibular seromucinous cells and secretory tubular cells. 4. The mucous cells of sublingual gland, as well as the whole ductal lining cells of each salivary gland, displayed no significant alterations. 5. No evidence of microvascular injury through whole experimental groups indicated that microvascular impairment does not contribute to early salivary

  17. Cathodoluminescence study of e-irradiated and plastically deformed ZnO crystals

    Energy Technology Data Exchange (ETDEWEB)

    Avella, M.; Hortelano, V.; Martinez, O.; Jimenez, J. [GdS Optronlab., Univ. de Valladolid, Paseo de Belen 1, 47011 Valladolid (Spain); Mass, J. [Grupo de Fisica Aplicada, Universidad del Norte, km 5, Via Pto. Colombia, Barranquilla (Colombia); Wang, B. [Solid State Scientific Corp., 27-2 Wright Rd., Hollis, NH 03049 (United States); Drevinsky, P.; Bliss, D. [Air Force Research Laboratory, Sensors Directorate, Hanscom AFB, MA 01731 (United States)

    2012-07-15

    Intrinsic defects are generated by e-irrradiation, and plastic deformation in ZnO crystals. Spectrally resolved cathodoluminescence (CL) experiments permit the analysis of the optical signature of those defects. We present herein a CL analysis of ZnO crystals irradiated with high energy electrons, and plastically deformed by Vickers indentation. Spectral changes around 3.3 eV and in the deep level emission are observed in the irradiated samples. These changes are compared to those observed around the extended defects introduced by Vickers indentation, which present a similar signature to the e-irradiated samples, suggesting relation between the defects generated by plastic deformation and e-irradiation. Zn vacancies seem to be the dominant defects generated in both processes (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Comprehensive study of the effect of the irradiation temperature on the behavior of cubic zirconia

    Science.gov (United States)

    Debelle, A.; Channagiri, J.; Thomé, L.; Décamps, B.; Boulle, A.; Moll, S.; Garrido, F.; Behar, M.; Jagielski, J.

    2014-05-01

    Cubic zirconia single-crystals (yttria-stabilized zirconia (YSZ)) have been irradiated with 4 MeV Au2+ ions in a broad fluence range (namely from 5 × 1012 to 2 × 1016 cm-2) and at five temperatures: 80, 300, 573, 773, and 1073 K. Irradiated samples have been characterized by Rutherford backscattering spectroscopy in channeling mode, X-ray diffraction and transmission electron microscopy techniques in order to determine the disordering kinetics. All experimental results show that, whatever is the irradiation temperature, the damage build-up follows a multi-step process. In addition, the disorder level at high fluence is very similar for all temperatures. Thus, no enhanced dynamic annealing process is observed. On the other hand, transitions in the damage accumulation process occur earlier in fluence with increasing temperature. It is shown that temperature as low as 573 K is sufficient to accelerate the disordering process in ion-irradiated YSZ.

  19. Cerebral malformation induced by prenatal X-irradiation: an autoradiographic and Golgi study

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer, I.; Xumetra, A.; Santamaria, J. (Neuropatologia, Depto. Anatomia Patologica, C.S. ' Principes de Espana' , Hospitalet de Llobregat, Barcelona (Spain))

    1984-01-01

    Brain malformations are produced after X-irradiation at different post-conceptional ages in the rat. Malformed cortical patterns result from abnormal organisation and capricious orientation of the neurons, while a radical migratory pattern of neuroblasts outwards to the cerebral cortex is preserved in animals irradiated on the fourteenth, sixteenth or eighteenth days of gestation. Migratory disturbances are restricted to the large subcortical ectopic masses found in rats irradiated on the fourteenth gestational day and to pyramidal ectopic nodules in the hippocampus in rats irradiated on the sixteenth gestational day. Subcortical ectopic masses develop from ectopic germinal rosettes and are formed by several types of cortical neuron distributed in a stereotyped pattern. The presence of large numbers of intrinsic, afferent and efferent connections are indicative of integrative functions of the subcortical masses.

  20. Experimental and Computer Simulation Study of Radioactivity of Materials Irradiated by Intermediate Energy Protons

    CERN Document Server

    Titarenko, Y E; Batyaev, V F; Karpikhin, E I; Zhivun, V M; Mulambetov, R D; Mashnik, S G; Prael, R E; Wilson, W B; Titarenko, Yu. E.

    1999-01-01

    The results of measurements and computer simulations of radioactivities and dose rates as functions of decay time are presented for Pb-nat and Bi-209 irradiated by 1.5-GeV protons, Co-59, Cu-63, and Cu-65 irradiated by 0.13- and 1.2-GeV protons, and Th-232 and U-nat irradiated by 0.1- and 0.8-GeV protons. The activities and dose rates are measured by direct high-precision gamma spectrometry. The irradiations were made using external beams extracted from the ITEP U-10 proton synchrotron. Simulations made using the LCS and CINDER'90 code systems are compared with measurements.

  1. TEM and EELS studies of microwave-irradiation synthesis of bimetallic platinum nanocatalysts

    CSIR Research Space (South Africa)

    Mathe, NR

    2014-01-01

    Full Text Available Microwave-irradiation (MW) synthesis of nanostructured materials provides for the synthesis of metal nanoparticles, using fast and uniform heating rates. This procedure affords better control of the shape and size of the nanoparticles when compared...

  2. SURGICAL TREATMENT OF PAIN IN CHRONIC PANCREATITIS:STUDIES OF 111 PATIENTS

    Institute of Scientific and Technical Information of China (English)

    D. Guinier; P. Mathieu; B. Heyd; G. Mantion

    2004-01-01

    Objective Evaluation of the efficacy of pancreatic resections for the treatment of chronic pains during chronic pancreatitis. Methods Retrospective study of inpatients for chronic pancreatitis between 1982 to 2000. Purpose of admission, morphological changes, treatments and results were evaluated. Results 142 patients were admitted for chronic pancreatitis. 111 patients suffered from chronic pains, due to morphological changes such as pseudocysts, inflammatory masses in the head, dilated pancreatic ducts, biliary or duodenal compressions. Denervations were never efficient, pancreatic resections achieved relief of pain in up to 75% of cases and drainages were efficient in 52% of cases. Conclusions Pancreatic resections during chronic pancreatitis seem to be the most efficient treatment of chronic pains. New techniques such as duodenum-preserving head resection or total pancreatectomy with islet autotransplantation should improve these results.

  3. New Predictive Hematologic Parameters in Chronic Rhinosinusitis: A Multicenter Study

    Directory of Open Access Journals (Sweden)

    Beyhan Yilmaz

    2016-12-01

    Full Text Available INTRODUCTION: Our aim was to investigate whether Neutrophil-Lymphocyte Ratio (NLR, Platelet-Lymphocyte Ratio (PLR and Mean Platelet Volume parameters (MPV may be utilized as inflammatory markers of chronic rhinosinusitis with nasal polyps (CRSwNP and without nasal polyps (CRSsNP. METHODS: This retrospective multicenter study was performed on 647 patients who were underwent endoscopic sinus surgery. Clinical and preoperative laboratory data of patients were screened retrospectively. The study and control groups were compared for the parameters NLR, PLR, MPV, neutrophils, lymphocytes, and platelets. RESULTS: Of the 647 patients, 313 were in the CRSwNP group, 334 were in the CRSsNP group. There were 93 individuals in the control group. NLR and PLR levels were significantly higher in study groups compared to control group (p < 0.001. But no statistically significant differences were identified between CRSwNP group and CRSsNP group in terms of NLR, PLR, MPV levels. DISCUSSION AND CONCLUSION: We speculate that high NLR and PLR values may be useful inflammatory indicator for CRSwNP and CRSsNP groups. We believe these parameters will have increasing clinical use in the future on treatment options and prognosis.

  4. Humanized Chronic Graft-versus-Host Disease in NOD-SCID il2rγ-/- (NSG Mice with G-CSF-Mobilized Peripheral Blood Mononuclear Cells following Cyclophosphamide and Total Body Irradiation.

    Directory of Open Access Journals (Sweden)

    Hisaki Fujii

    Full Text Available Chronic graft-versus-host disease (cGvHD is the major source of late phase morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Humanized acute GvHD (aGvHD in vivo models using NOD-SCID il2rγ-/- (NSG mice are well described and are important tools for investigating pathogenicity of human cells in vivo. However, there have been only few reported humanized cGvHD mouse models. We evaluated if prolonged inflammation driven by low dose G-CSF-mobilized human PBMCs (G-hPBMCs would lead to cGvHD following cyclophosphamide (CTX administration and total body irradiation (TBI in NSG mice. Engraftment was assessed in peripheral blood (PB and in specific target organs by either flow cytometry or immunohistochemistry (IHC. Tissue samples were harvested 56 days post transplantation and were evaluated by a pathologist. Some mice were kept for up to 84 days to evaluate the degree of fibrosis. Mice that received CTX at 20mg/kg did not show aGvHD with stable expansion of human CD45+ CD3+ T-cells in PB (mean; 5.8 to 23.2%. The pathology and fibrosis scores in the lung and the liver were significantly increased with aggregation of T-cells and hCD68+ macrophages. There was a correlation between liver pathology score and the percentage of hCD68+ cells, suggesting the role of macrophage in fibrogenesis in NSG mice. In order to study long-term survival, 6/9 mice who survived more than 56 days showed increased fibrosis in the lung and liver at the endpoint, which suggests the infiltrating hCD68+ macrophages may be pathogenic. It was shown that the combination of CTX and TBI with a low number of G-hPBMCs (1x106 leads to chronic lung and liver inflammation driven by a high infiltration of human macrophage and mature human T cells from the graft, resulting in fibrosis of lung and liver in NSG mice. In conclusion this model may serve as an important pre-clinical model to further current understanding of the roles of human macrophages in cGvHD.

  5. Humanized Chronic Graft-versus-Host Disease in NOD-SCID il2rγ-/- (NSG) Mice with G-CSF-Mobilized Peripheral Blood Mononuclear Cells following Cyclophosphamide and Total Body Irradiation.

    Science.gov (United States)

    Fujii, Hisaki; Luo, Zhi-Juan; Kim, Hye Jin; Newbigging, Susan; Gassas, Adam; Keating, Armand; Egeler, R Maarten

    2015-01-01

    Chronic graft-versus-host disease (cGvHD) is the major source of late phase morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Humanized acute GvHD (aGvHD) in vivo models using NOD-SCID il2rγ-/- (NSG) mice are well described and are important tools for investigating pathogenicity of human cells in vivo. However, there have been only few reported humanized cGvHD mouse models. We evaluated if prolonged inflammation driven by low dose G-CSF-mobilized human PBMCs (G-hPBMCs) would lead to cGvHD following cyclophosphamide (CTX) administration and total body irradiation (TBI) in NSG mice. Engraftment was assessed in peripheral blood (PB) and in specific target organs by either flow cytometry or immunohistochemistry (IHC). Tissue samples were harvested 56 days post transplantation and were evaluated by a pathologist. Some mice were kept for up to 84 days to evaluate the degree of fibrosis. Mice that received CTX at 20mg/kg did not show aGvHD with stable expansion of human CD45+ CD3+ T-cells in PB (mean; 5.8 to 23.2%). The pathology and fibrosis scores in the lung and the liver were significantly increased with aggregation of T-cells and hCD68+ macrophages. There was a correlation between liver pathology score and the percentage of hCD68+ cells, suggesting the role of macrophage in fibrogenesis in NSG mice. In order to study long-term survival, 6/9 mice who survived more than 56 days showed increased fibrosis in the lung and liver at the endpoint, which suggests the infiltrating hCD68+ macrophages may be pathogenic. It was shown that the combination of CTX and TBI with a low number of G-hPBMCs (1x106) leads to chronic lung and liver inflammation driven by a high infiltration of human macrophage and mature human T cells from the graft, resulting in fibrosis of lung and liver in NSG mice. In conclusion this model may serve as an important pre-clinical model to further current understanding of the roles of human macrophages in cGvHD.

  6. DSC studies of gamma irradiation influence on gelatinisation and amylose-lipid complex transition occurring in wheat starch[Wheat starch; Gelatinisation; Amylose-lipid complex transition; Gamma irradiation; Differential scanning calorimetry, DSC

    Energy Technology Data Exchange (ETDEWEB)

    Ciesla, K. E-mail: kciesla@orange.ichtj.waw.pl; Eliasson, A.-C

    2003-12-01

    Differential scanning calorimetry studies are presented dealing with the influence of gamma irradiation (carried out in the solid state) on the structure of amylose-lipid complex in wheat starch. Suspensions of the control and the wheat starch irradiated with a 30 kGy gamma rays (characterised by starch-to-water ratio of 1:1 and ca. 1:4) were examined during several courses of heating and cooling at rates of 2.5 and 10 deg. C min{sup -1}. Differences were observed between enthalpy and temperature of gelatinisation and amylose-lipid complex transition as well as retrogradation taking place in the suspensions and gels of the control and the irradiated starch. The influence of the preceding heating and cooling on further transformations of the amylose-lipid complex differs for the control and the irradiated samples.

  7. Impact of Cirrus Crystal Shape on Solar Spectral Irradiance: A Case Study for Subtropical Cirrus

    Science.gov (United States)

    Wendisch, Manfred; Pilewskie, Peter; Pommier, John; Howard, Steve; Yang, Ping; Heymsfield, Andrew J.; Schmitt, Carl G.; Baumgardner, Darrel; Mayer, Barnhard

    2005-01-01

    Profiles of in situ measurements of ice crystal size distribution of subtropical cirrus were used to calculate solar spectral irradiances above and below the clouds. Spheres and nonspherical ice crystal habits (columns, hollows, plates, bullets, and aggregates) were assumed in the calculations. The simulation results were compared to irradiance measurements from the NASA Solar Spectral Flux Radiometer. The microphysical and radiation data were collected by three aircraft during CRYSTAL-FACE. Two cirrus cases (optical thickness of about 1 and 7) from two mission dates (26 and 23 July 2002) were investigated in detail. The measured downwelling and upwelling irradiance spectra above the cirrus could mostly be reproduced by the radiation model to within +/- 5-10% for most ice crystal habits. Below the cirrus the simulations disagreed with the measured irradiances due to surface albedo variability along the flight track, and nonoptimal colocation between the microphysical and irradiance measurements. The impact of shape characteristics of the crystals was important for the reflected irradiances above the optically thin cirrus, especially for small solar zenith angles, because in this case single-scattering dominated the solar radiation field. For the cirrus of moderate optical thickness the enhanced multiple scattering tended to diminish particular shape features caused by nonspherical single-scattering. Within the ice absorption bands the shape-related differences in the absorption characteristics of the individual nonspherical ice crystals were amplified if multiple scattering prevailed. Furthermore, it was found that below the cloud the shape sensitivity of the downwelling irradiance spectra is larger compared to the nonsphericity effects on reflected irradiances above the cirrus. Finally, it was shown that the calculated cirrus solar radiative forcing could vary by as much as 26% depending on the ice crystal habit.

  8. What level of accuracy is achievable for preclinical dose painting studies on a clinical irradiation platform?

    Science.gov (United States)

    Trani, Daniela; Reniers, Brigitte; Persoon, Lucas; Podesta, Mark; Nalbantov, Georgi; Leijenaar, Ralph T H; Granzier, Marlies; Yaromina, Ala; Dubois, Ludwig; Verhaegen, Frank; Lambin, Philippe

    2015-05-01

    Advancements made over the past decades in both molecular imaging and radiotherapy planning and delivery have enabled studies that explore the efficacy of heterogeneous radiation treatment ("dose painting") of solid cancers based on biological information provided by different imaging modalities. In addition to clinical trials, preclinical studies may help contribute to identifying promising dose painting strategies. The goal of this current study was twofold: to develop a reproducible positioning and set-up verification protocol for a rat tumor model to be imaged and treated on a clinical platform, and to assess the dosimetric accuracy of dose planning and delivery for both uniform and positron emission tomography-computed tomography (PET-CT) based heterogeneous dose distributions. We employed a syngeneic rat rhabdomyosarcoma model, which was irradiated by volumetric modulated arc therapy (VMAT) with uniform or heterogeneous 6 MV photon dose distributions. Mean dose to the gross tumor volume (GTV) as a whole was kept at 12 Gy for all treatment arms. For the nonuniform plans, the dose was redistributed to treat the 30% of the GTV representing the biological target volume (BTV) with a dose 40% higher than the rest of the GTV (GTV - BTV) (~15 Gy was delivered to the BTV vs. ~10.7 Gy was delivered to the GTV - BTV). Cone beam computed tomography (CBCT) images acquired for each rat prior to irradiation were used to correctly reposition the tumor and calculate the delivered 3D dose. Film quality assurance was performed using a water-equivalent rat phantom. A comparison between CT or CBCT doses and film measurements resulted in passing rates >98% with a gamma criterion of 3%/2 mm using 2D dose images. Moreover, between the CT and CBCT calculated doses for both uniform and heterogeneous plans, we observed maximum differences of <2% for mean dose to the tumor and mean dose to the biological target volumes. In conclusion, we have developed a robust method for dose painting

  9. Analytical study of pulsed laser irradiation on some materials used for photovoltaic cells on satellites

    Directory of Open Access Journals (Sweden)

    Afaf M. Abd El-Hameed

    2015-12-01

    Full Text Available The present research concerns on the study of laser-powered solar panels used for space applications. A mathematical model representing the laser effects on semiconductors has been developed. The temperature behavior and heat flow on the surface and through a slab has been studied after exposed to nano-second pulsed laser. The model is applied on two different types of common active semiconductor materials that used for photovoltaic cells fabrication as silicon (Si, and gallium arsenide (GaAs. These materials are used for receivers’ manufacture for laser beamed power in space. Various values of time are estimated to clarify the heat flow through the material sample and generated under the effects of pulsed laser irradiation. These effects are theoretically studied in order to determine the performance limits of the solar cells when they are powered by laser radiation during the satellite eclipse. Moreover, the obtained results are carried out to optimize conversion efficiency of photovoltaic cells and may be helpful to give more explanation for layout of the light-electricity space systems.

  10. A mechanistic study of gold nanoparticle radiosensitisation using targeted microbeam irradiation

    Science.gov (United States)

    Ghita, Mihaela; McMahon, Stephen J.; Taggart, Laura E.; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.

    2017-01-01

    Gold nanoparticles (GNPs) have been demonstrated as effective radiosensitizing agents in a range of preclinical models using broad field sources of various energies. This study aimed to distinguish between these mechanisms by applying subcellular targeting using a soft X-ray microbeam in combination with GNPs. DNA damage and repair kinetics were determined following nuclear and cytoplasmic irradiation using a soft X-ray (carbon K-shell, 278 eV) microbeam in MDA-MB-231 breast cancer and AG01522 fibroblast cells with and without GNPs. To investigate the mechanism of the GNP induced radiosensitization, GNP-induced mitochondrial depolarisation was quantified by TMRE staining, and levels of DNA damage were compared in cells with depolarised and functional mitochondria. Differential effects were observed following radiation exposure between the two cell lines. These findings were validated 24 hours after removal of GNPs by flow cytometry analysis of mitochondrial depolarisation. This study provides further evidence that GNP radiosensitisation is mediated by mitochondrial function and it is the first report applying a soft X-ray microbeam to study the radiobiological effects of GNPs to enable the separation of physical and biological effects. PMID:28300190

  11. Analytical study of pulsed laser irradiation on some materials used for photovoltaic cells on satellites

    Science.gov (United States)

    Abd El-Hameed, Afaf M.

    2015-12-01

    The present research concerns on the study of laser-powered solar panels used for space applications. A mathematical model representing the laser effects on semiconductors has been developed. The temperature behavior and heat flow on the surface and through a slab has been studied after exposed to nano-second pulsed laser. The model is applied on two different types of common active semiconductor materials that used for photovoltaic cells fabrication as silicon (Si), and gallium arsenide (GaAs). These materials are used for receivers' manufacture for laser beamed power in space. Various values of time are estimated to clarify the heat flow through the material sample and generated under the effects of pulsed laser irradiation. These effects are theoretically studied in order to determine the performance limits of the solar cells when they are powered by laser radiation during the satellite eclipse. Moreover, the obtained results are carried out to optimize conversion efficiency of photovoltaic cells and may be helpful to give more explanation for layout of the light-electricity space systems.

  12. DLTS study of deep level defects in Li-ion irradiated bipolar junction transistor

    Energy Technology Data Exchange (ETDEWEB)

    Madhu, K.V. [Department of Physics, Jnanabharati, Bangalore University, Bangalore 560 056, Karnataka (India); Kulkarni, S.R. [Department of Physics, Center for PG Studies, SBMJC, Jayanagar, Bangalore 560 011, Karnataka (India); Ravindra, M. [Components Division, ICG, ISRO Satellite Centre, Airport Road, Bangalore 560 017, Karnataka (India); Damle, R. [Department of Physics, Jnanabharati, Bangalore University, Bangalore 560 056, Karnataka (India)]. E-mail: damleraju@yahoo.com

    2007-01-15

    Commercial npn transistor (2N 2219A) irradiated with 50 MeV Li{sup 3+}-ions with fluences ranging from 3.1 x 10{sup 13} ions cm{sup -2} to 12.5 x 10{sup 13} ions cm{sup -2}, is studied for radiation induced gain degradation and minority carrier trap levels or recombination centers. The properties such as activation energy, trap concentration and capture cross section of induced deep levels are studied by deep level transient spectroscopy (DLTS) technique. Minority carrier trap levels with energies ranging from 0.237 eV to 0.591 eV were observed in the base-collector junction of the transistor. In situ I-V measurements were made to study the gain degradation as a function of ion fluence. Ion induced energy levels result in increase in the base current through Shockley Read Hall (SRH) or multi-phonon recombination and subsequent transistor gain degradation.

  13. Study on the induction of thyroid tumors in rats using x irradiation in conjunction with a goitrogen. [1 methyl--2 mercaptoimidazole (methimazole)

    Energy Technology Data Exchange (ETDEWEB)

    Mahler, P.

    1979-01-01

    The influence of acute localized thyroid x irradiation and chronic goitrogen administration, separately or combined, on thyroid tumor formation in mature female rats was studied. In the first experiment, the radiation doses were 0, 80, 160, 320, or 640 rads, and the dosages of goitrogen were 0, 4, or 40 parts per million (ppM) of 1 methyl - 2 mercaptoimidazole (MMI). The incidence of rats with thyroid tumors in any treated group receiving 0 or 4 ppM MMI was not significantly greater than the incidence in the nontreated control group. However, the incidence in any of the 40 ppM MMI groups was significantly greater than that in the nontreated control group. At all the radiation doses other than 80 rads, the incidence was significantly greater than that in the non-irradiated group. No significant difference was seen in the incidence of rats with thyroid tumors on the basis of radiation dose. The incidence was so high at 80 rads that there was little margin for further increase by increasing the radiation dose. The mean serum thyroxine levels at 40 ppM MMI, 4 ppM MMI, and 0 ppM MMI were 1.9, 3.5, and 3.7 ..mu..g/100 ml, respectively. No markedeffect of thyroid irradiation on mean serum thyroxine levels was seen. In the second experiment, rats receiving 200 ppM MMI and thyroid irradiation were sacrificed at 7-1/2 months after treatment. Nearly all rats in the 0 and 80 rad groups and all in the 160, the 320, and the 640 rad groups had thyroid tumors. In the third experiment, serum T/sub 4/ levels were measured in treated rats. Rats receiving 640 rads + 0 ppM MMI showed a slight decrease in serum T/sub 4/, while no change in serum T/sub 4/ levels was seen in rats receiving 0 rads + 4 ppM MMI or 640 rads + 4 ppM MMI. All rats receiving 40 ppM MMI, regardless of radiation dose, showed decreased serum T/sub 4/ levels.

  14. Radiograaff, a proton irradiation facility for radiobiological studies at a 4 MV Van de Graaff accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Constanzo, J. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Fallavier, M., E-mail: m.fallavier@ipnl.in2p3.fr [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Alphonse, G. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Hospices-Civils-de-Lyon, CHLS, F-69495 Pierre-Bénite (France); Bernard, C. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Battiston-Montagne, P. [Université de