Status of Post Irradiation Examination of FCAB and FCAT Irradiation Capsules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Yamamoto, Yukinori; Howard, Richard H.

A series of irradiation programs are ongoing to address the need for determining the radiation tolerance of FeCrAl alloys. These irradiation programs, deemed the FCAT and FCAB irradiation programs, use the High Flux Isotope Reactor (HFIR) to irradiate second generation wrought FeCrAl alloys and early-generation powder-metallurgy (PM) oxide dispersion-strengthened (ODS) FeCrAl alloys. Irradiations have been or are being performed at temperatures of 200°C, 330°C, and 550°C from doses of 1.8 dpa up to 16 dpa. Preliminary post-irradiation examination (PIE) on low dose (<2 dpa) irradiation capsules of tensile specimens has been performed. Analysis of co-irradiated SiC thermometry have shown reasonablemore » matching between the nominal irradiation temperatures and the target irradiation temperatures. Room temperature tensile tests have shown typical radiation-induced hardening and embrittlement at irradiations of 200°C and 330°C, but a propensity for softening when irradiated to 550°C for the wrought alloys. The PM-ODS FeCrAl specimens showed less hardening compared to the wrought alloys. Future PIE includes high temperature tensile tests on the low dose irradiation capsules as well as the determination of reference fracture toughness transition temperature, T o, in alloys irradiated to 7 dpa and higher.« less

Post-irradiation examinations of Li 4SiO 4 pebbles irradiated in the EXOTIC-7 experiment

NASA Astrophysics Data System (ADS)

Piazza, G.; Scaffidi-Argentina, F.; Werle, H.

2000-12-01

Extraction of tritium in ceramics-7 (EXOTIC-7) was the first in-pile test with 6Li-enriched (50%) lithium orthosilicate (Li 4SiO 4) pebbles and with DEMO representative Li-burnup. Post-irradiation examinations (PIEs) of the Li 4SiO 4 have been performed at the Forschungszentrum Karlsruhe (FZK) to investigate the tritium release kinetics, the effects of Li-burnup, of the contact with beryllium during irradiation and the changes in the mechanical stability of the pebbles due to irradiation. Based on these data one can conclude that neither the contact with beryllium nor a burnup up to 13% have a detrimental effect on the tritium release of Li 4SiO 4 pebbles, but at 18% Li-burnup the residence time is increased by about a factor of 3. The mechanical strength of both irradiated and unirradiated pebbles has been examined by means of crush tests. According to the PIE no significant changes in the mechanical stability of the pebbles have been observed.

Effect of post-irradiation annealing on the irradiated microstructure of neutron-irradiated 304L stainless steel

NASA Astrophysics Data System (ADS)

Jiao, Z.; Hesterberg, J.; Was, G. S.

2018-03-01

Post-irradiation annealing was performed on a 304L SS that was irradiated to 5.9 dpa in the Barsebäck 1 BWR reactor. Evolution of dislocation loops, radiation-induced solute clusters and radiation-induced segregation at the grain boundary was investigated following thermal annealing at 500 °C and 550 °C up to 20 h. Dislocation loops, Ni-Si and Al-Cu clusters, and enrichment of Ni, Si and depletion of Cr at the grain boundary were observed in the as-irradiated condition. Dislocation loop size did not change significantly after annealing at 550 °C for 5 h but the loop number density decreased considerably and loops mostly disappeared after annealing at 550 °C for 20 h. The average size of Ni-Si and Al-Cu clusters increased while the number density decreased with annealing. The increase in cluster size was due to diffusion of solutes rather than cluster coarsening. Significant volume fractions of Ni-Si and Al-Cu clusters still remained after annealing at 550 °C for 20 h. Substantial recovery of Cr and Ni at the grain boundary was observed after annealing at 550 °C for 5 h but neither Cr nor Ni was fully recovered after 20 h. Annihilation of dislocation loops, driven by the thermal vacancy concentration gradient caused by the strain field and stacking fault associated with the loops appeared to be faster than annihilation of solute clusters and recovery of Ni and Si at the grain boundary, both of which are driven by the solute concentration gradients.

Role of isolated and clustered DNA damage and the post-irradiating repair process in the effects of heavy ion beam irradiation.

PubMed

Tokuyama, Yuka; Furusawa, Yoshiya; Ide, Hiroshi; Yasui, Akira; Terato, Hiroaki

2015-05-01

Clustered DNA damage is a specific type of DNA damage induced by ionizing radiation. Any type of ionizing radiation traverses the target DNA molecule as a beam, inducing damage along its track. Our previous study showed that clustered DNA damage yields decreased with increased linear energy transfer (LET), leading us to investigate the importance of clustered DNA damage in the biological effects of heavy ion beam radiation. In this study, we analyzed the yield of clustered base damage (comprising multiple base lesions) in cultured cells irradiated with various heavy ion beams, and investigated isolated base damage and the repair process in post-irradiation cultured cells. Chinese hamster ovary (CHO) cells were irradiated by carbon, silicon, argon and iron ion beams with LETs of 13, 55, 90 and 200 keV µm(-1), respectively. Agarose gel electrophoresis of the cells with enzymatic treatments indicated that clustered base damage yields decreased as the LET increased. The aldehyde reactive probe procedure showed that isolated base damage yields in the irradiated cells followed the same pattern. To analyze the cellular base damage process, clustered DNA damage repair was investigated using DNA repair mutant cells. DNA double-strand breaks accumulated in CHO mutant cells lacking Xrcc1 after irradiation, and the cell viability decreased. On the other hand, mouse embryonic fibroblast (Mef) cells lacking both Nth1 and Ogg1 became more resistant than the wild type Mef. Thus, clustered base damage seems to be involved in the expression of heavy ion beam biological effects via the repair process. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Final Report on MEGAPIE Target Irradiation and Post-Irradiation Examination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yong, Dai

2015-06-30

Megawatt pilot experiment (MEGAPIE) was successfully performed in 2006. One of the important goals of MEGAPIE is to understand the behaviour of structural materials of the target components exposed to high fluxes of high-energy protons and spallation neutrons in flowing LBE (liquid lead-bismuth eutectic) environment by conducting post-irradiation examination (PIE). The PIE includes four major parts: non-destructive test, radiochemical analysis of production and distribution of radionuclides produced by spallation reaction in LBE, analysis of LBE corrosion effects on structural materials, T91 and SS 316L steels, and mechanical testing of the T91 and SS 316L steels irradiated in the lower partmore » of the target. The non-destructive test (NDT) including visual inspection and ultrasonic measurement was performed in the proton beam window area of the T91 calotte of the LBE container, the most intensively irradiated part of the MEGAPIE target. The visual inspection showed no visible failure and the ultrasonic measurement demonstrated no detectable change in thickness in the beam window area. Gamma mapping was also performed in the proton beam window area of the AlMg 3 safety-container. The gamma mapping results were used to evaluate the accumulated proton fluence distribution profile, the input data for determining irradiation parameters. Radiochemical analysis of radionuclides produced by spallation reaction in LBE is to improve the understanding of the production and distribution of radionuclides in the target. The results demonstrate that the radionuclides of noble metals, 207Bi, 194Hg/Au are rather homogeneously distributed within the target, while radionuclides of electropositive elements are found to be deposited on the steel-LBE interface. The corrosion effect of LBE on the structural components under intensive irradiation was investigated by metallography. The results show that no evident corrosion damages. However, unexpected deep cracks were found in the

High post-irradiation ductility thermomechanical treatment for precipitation strengthened austenitic alloys

DOEpatents

Laidler, James J.; Borisch, Ronald R.; Korenko, Michael K.

1982-01-01

A method for improving the post-irradiation ductility is described which prises a solution heat treatment following which the materials are cold worked. They are included to demonstrate the beneficial effect of this treatment on the swelling resistance and the ductility of these austenitic precipitation hardenable alloys.

Advanced Post-Irradiation Examination Capabilities Alternatives Analysis Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeff Bryan; Bill Landman; Porter Hill

2012-12-01

An alternatives analysis was performed for the Advanced Post-Irradiation Capabilities (APIEC) project in accordance with the U.S. Department of Energy (DOE) Order DOE O 413.3B, “Program and Project Management for the Acquisition of Capital Assets”. The Alternatives Analysis considered six major alternatives: ? No Action ? Modify Existing DOE Facilities – capabilities distributed among multiple locations ? Modify Existing DOE Facilities – capabilities consolidated at a few locations ? Construct New Facility ? Commercial Partnership ? International Partnerships Based on the alternatives analysis documented herein, it is recommended to DOE that the advanced post-irradiation examination capabilities be provided by amore » new facility constructed at the Materials and Fuels Complex at the Idaho National Laboratory.« less

US RERTR FUEL DEVELOPMENT POST IRRADIATION EXAMINATION RESULTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

A. B. Robinson; D. M. Wachs; D. E. Burkes

2008-10-01

Post irradiation examinations of irradiated RERTR plate type fuel at the Idaho National Laboratory have led to in depth characterization of fuel behavior and performance. Both destructive and non-destructive examination capabilities at the Hot Fuels Examination Facility (HFEF) as well as recent results obtained are discussed herein. New equipment as well as more advanced techniques are also being developed to further advance the investigation into the performance of the high density U-Mo fuel.

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

NASA Technical Reports Server (NTRS)

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

1991-01-01

The effects of neutron and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 10(exp 13) n/sq cm and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are presented. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed.

Enhanced cued fear memory following post-training whole body irradiation of 3-month-old mice.

PubMed

Olsen, Reid H J; Weber, Sydney J; Akinyeke, Tunde; Raber, Jacob

2017-02-15

Typically, in studies designed to assess effects of irradiation on cognitive performance the animals are trained and tested for cognitive function following irradiation. Little is known about post-training effects of irradiation on cognitive performance. In the current study, 3-month-old male mice were irradiated with X-rays 24h following training in a fear conditioning paradigm and cognitively tested starting two weeks later. Average motion during the extinction trials, measures of anxiety in the elevated zero maze, and body weight changes over the course of the study were assessed as well. Exposure to whole body irradiation 24h following training in a fear conditioning resulted in greater freezing levels 2 weeks after training. In addition, motion during both contextual and cued extinction trials was lower in irradiated than sham-irradiated mice. In mice trained for cued fear conditioning, activity levels in the elevated zero maze 12days after sham-irradiation or irradiation were also lower in irradiated than sham-irradiated mice. Finally, the trajectory of body weight changes was affected by irradiation, with lower body weights in irradiated than sham-irradiated mice, with the most profound effect 7days after training. These effects were associated with reduced c-Myc protein levels in the amygdala of the irradiated mice. These data indicate that whole body X ray irradiation of mice at 3 months of age causes persistent alterations in the fear response and activity levels in a novel environment, while the effects on body weight seem more transient. Copyright © 2016 Elsevier B.V. All rights reserved.

Irradiated Chinese Rugao ham: Changes in volatile N-nitrosamine, biogenic amine and residual nitrite during ripening and post-ripening.

PubMed

Wei, Fashan; Xu, Xinglian; Zhou, Guanghong; Zhao, Gaiming; Li, Chunbao; Zhang, Yingjun; Chen, Lingzhen; Qi, Jun

2009-03-01

N-nitrosamines, biogenic amines and residual nitrite are harmful substances and often present in cured meat. The effects of gamma-irradiation (γ-irradiation) on these chemicals in dry-cured Chinese Rugao ham during ripening and post-ripening were investigated. Rugao hams were irradiated at a dose of 5kGy before ripening and were then ripened in an aging loft. Although γ-irradiation degraded tyramine, putrescine and spermine, on the other hand, it promoted the formation of spermidine, phenylethylamine, cadaverine and tryptamine. Residual nitrite was significantly reduced by γ-irradiation. N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA) and N-nitrosopyrrolidine (NPYR) were found in Chinese Rugao ham during ripening and post-ripening but could be degraded with γ-irradiation. The results suggest that γ-irradiation may be a potential decontamination measure for certain chemical compounds found in dry-cured meat.

On the determination of the post-irradiation time from the glow curve of TLD-100.

PubMed

Weinstein, M; German, U; Dubinsky, S; Alfassi, Z B

2003-01-01

The ratio of peak 3 to the sum of peaks 4 + 5 in TLD-100 was measured for various pre-irradiation and post-irradiation time periods, under conditions characteristic of routine personal dosimetry. It was confirmed that the value of this ratio depends only on the elapsed time between the prior readout and the present one, independent of the moment when the irradiation took place during the total time interval (storage time). This effect indicates that fading of peak 3 seems to be due mainly to changes in the unoccupied traps, and not to decay of trapped charges, being almost independent of the presence of electrons or holes in the traps. This observation leads to the conclusion that the suggestions in the past to use the decay of peak 3 in TLD-100 for the measurement of the elapsed time between irradiation and readout may have been wrong. On the other hand, the decay of peak 2 can be used to measure the elapsed time from irradiation, since the rate of decay is different when related to pre-irradiation and post-irradiation times, indicating a much higher decay rate of the trapped charges (Randall-Wilkins decay). However, because of the fast decay rate of peak 2, its use for determination of the elapsed time since irradiation is of little practical significance.

AGR-1 Compact 1-3-1 Post-Irradiation Examination Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demkowicz, Paul Andrew

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance modeling, and fission product transport (INL 2015). A seriesmore » of fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously (Grover, Petti, and Maki 2010, Maki 2009).« less

AGR-1 Compact 5-3-1 Post-Irradiation Examination Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demkowicz, Paul; Harp, Jason; Winston, Phil

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance, and fission product transport (INL 2015). A series ofmore » fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously.« less

Proton irradiation effects on beryllium - A macroscopic assessment

NASA Astrophysics Data System (ADS)

Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; Camino, Fernando

2016-10-01

Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting its lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This paper focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.

Shear Wave Elastography--A New Quantitative Assessment of Post-Irradiation Neck Fibrosis.

PubMed

Liu, K H; Bhatia, K; Chu, W; He, L T; Leung, S F; Ahuja, A T

2015-08-01

Shear wave elastography (SWE) is a new technique which provides quantitative assessment of soft tissue stiffness. The aim of this study was to assess the reliability of SWE stiffness measurements and its usefulness in evaluating post-irradiation neck fibrosis. 50 subjects (25 patients with previous radiotherapy to the neck and 25 sex and age-matched controls) were recruited for comparison of SWE stiffness measurements (Aixplorer, Supersonic Imagine). 30 subjects (16 healthy individuals and 14 post-irradiated patients) were recruited for a reliability study of SWE stiffness measurements. SWE stiffness measurements of the sternocleidomastoid muscle and the overlying subcutaneous tissues of the neck were made. The cross-sectional area and thickness of the sternocleidomastoid muscle and the overlying subcutaneous tissue thickness of the neck were also measured. The post-irradiation duration of the patients was recorded. The intraclass correlation coefficients for the intraoperator and interoperator reliability of deep and subcutaneous tissue SWE stiffness ranged from 0.90-0.99 and 0.77-0.94, respectively. The SWE stiffness measurements (mean +/- SD) of deep and subcutaneous tissues were significantly higher in the post-irradiated patients (64.6 ± 46.8 kPa and 63.9 ± 53.1 kPa, respectively) than the sex and age-matched controls (19.9 ± 7.8 kPa and 15.3 ± 8.37 respectively) (p < 0.001). The SWE stiffness increased with increasing post-irradiation therapy duration in the Kruskal Wallis test (p < 0.001) and correlated with muscle atrophy and subcutaneous tissue thinning (p < 0.01). SWE is a reliable technique and may potentially be an objective and specific tool in quantifying deep and subcutaneous tissue stiffness, which in turn reflects the severity of neck fibrosis. © Georg Thieme Verlag KG Stuttgart · New York.

Post-irradiation examinations of THERMHET composite fuels for transmutation

NASA Astrophysics Data System (ADS)

Noirot, J.; Desgranges, L.; Chauvin, N.; Georgenthum, V.

2003-07-01

The thermal behaviour of composite targets dedicated to minor actinide transmutation was studied using THERMHET (thermal behaviour of heterogeneous fuel) irradiation in the SILOE reactor. Three inert matrix fuel designs were tested (macro-mass, jingle and microdispersion) all with a MgAl 2O 4 spinel inert matrix and around 40% weight of UO 2 to simulate minor actinide inclusions. The post-irradiation examinations led to a new interpretation of the temperature measurement by thermocouples located in the central hole of the pellets. A major change in the micro-dispersed structure was detected. The examinations enabled us to understand the behaviour of the spinel during the different stages of irradiation. They revealed an amorphisation at low temperature and then a nano re-crystallisation at high temperature of the spinel in the micro-dispersed case. These results, together with those obtained in the MATINA irradiation of an equivalent structure, show the importance of the irradiation temperature on spinel behaviour.

Irradiation and post-irradiation examination of uranium-free nitride fuel

NASA Astrophysics Data System (ADS)

Hania, P. R.; Klaassen, F. C.; Wernli, B.; Streit, M.; Restani, R.; Ingold, F.; Fedorov, A. V.; Wallenius, J.

2015-11-01

Two identical Phénix-type 15-15Ti steel pinlets each containing a 70 mm Pu0.3Zr0.7N fuel stack in a 1-bar helium atmosphere have been irradiated in the HFR Petten at medium high linear power (46-47 kW/m at BOL) and an average cladding temperature of 505 °C. The pins were irradiated to a plutonium burn-up of 9.7% (88 MWd/kgHM) in 170 full power days. Both pins remained fully intact. Post-irradiation examination performed at NRG and PSI showed that the overall swelling rate of the fuel was 0.92 vol-%/%FIHMA. Fission gas release was 5-6%, while helium release was larger than 50%. No fuel restructuring was observed, and only mild cracking. EPMA measurements show a burn-up increase toward the pellet edge of up to 4 times. All investigated fission products except to some extent the noble metals were found to be evenly distributed over the matrix, indicating good solubility. Local formation of a secondary phase with high Pu content and hardly any Zr was observed. A general conclusion of this investigation is that ZrN is a suitable inert matrix for burning plutonium at high destruction rates.

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

NASA Astrophysics Data System (ADS)

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

2014-09-01

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

Proton irradiation effects on beryllium – A macroscopic assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong

Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting itsmore » lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This study focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.« less

Proton irradiation effects on beryllium – A macroscopic assessment

DOE PAGES

Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; ...

2016-07-01

Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting itsmore » lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This study focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.« less

Microstructural evolution of nanochannel CrN films under ion irradiation at elevated temperature and post-irradiation annealing

NASA Astrophysics Data System (ADS)

Tang, Jun; Hong, Mengqing; Wang, Yongqiang; Qin, Wenjing; Ren, Feng; Dong, Lan; Wang, Hui; Hu, Lulu; Cai, Guangxu; Jiang, Changzhong

2018-03-01

High-performance radiation tolerance materials are crucial for the success of future advanced nuclear reactors. In this paper, we present a further investigation that the "vein-like" nanochannel films can enhance radiation tolerance under ion irradiation at high temperature and post-irradiation annealing. The chromium nitride (CrN) nanochannel films with different nanochannel densities and the compact CrN film are chosen as a model system for these studies. Microstructural evolution of these films were investigated using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Elastic Recoil Detection (ERD) and Grazing Incidence X-ray Diffraction (GIXRD). Under the high fluence He+ ion irradiation at 500 °C, small He bubbles with low bubble densities are observed in the irradiated nanochannel CrN films, while the aligned large He bubbles, blistering and texture reconstruction are found in the irradiated compact CrN film. For the heavy Ar2+ ion irradiation at 500 °C, the microstructure of the nanochannel CrN RT film is more stable than that of the compact CrN film due to the effective releasing of defects via the nanochannel structure. Under the He+ ion irradiation and subsequent annealing, compared with the compact film, the nanochannel films have excellent performance for the suppression of He bubble growth and possess the strong microstructural stability. Basing on the analysis on the sizes and number densities of bubbles as well as the concentrations of He retained in the nanochannel CrN films and the compact CrN film under different experimental conditions, potential mechanism for the enhanced radiation tolerance are discussed. Nanochannels play a crucial role on the release of He/defects under ion irradiation. We conclude that the tailored "vein-like" nanochannel structure may be used as advanced radiation tolerance materials for future nuclear reactors.

Post-irradiation time effects on the graft of poly(ethylene-alt-tetrafluoroethylene) (ETFE) films for ion exchange membrane application

NASA Astrophysics Data System (ADS)

Geraldes, Adriana N.; Zen, Heloísa A.; Ribeiro, Geise; Ferreira, Henrique P.; Souza, Camila P.; Parra, Duclerc F.; Santiago, Elisabete I.; Lugão, Ademar B.

2010-03-01

Grafting of styrene followed by sulfonation onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) was studied for synthesis of ion exchange membranes. Radiation-induced grafting of styrene onto ETFE films was investigated after simultaneous irradiation (in post-irradiation condition) using a 60Co source. The ETFE films were irradiated at 20 kGy dose at room temperature and chemical changes were monitored after contact with styrene for grafting. The post-irradiation time was established at 14 days when the films were remained in styrene/toluene 1:1 v/v. After this period the grafting degree was evaluated in the samples. The grafted films were sulfonated using chlorosulfonic acid and 1, 2-dichloroethane 20:80 (v/v) at room temperature for 5 h. The membranes were analyzed by infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), thermogravimetric measurements (TG) and degree of grafting (DOG). The ion exchange capacity (IEC) of membranes was determined by acid-base titration and the values for ETFE membranes were achieved higher than Nafion ® films. Preliminary single cell performance was made using pure H 2 and O 2 as reactants at a cell temperature of 80 °C and atmospheric gas pressure. The fuel cell performance of ETFE films was satisfactory when compared to state-of-art Nafion ® membranes.

Post-irradiation hardening of dual-cured and light-cured resin cements through machinable ceramics.

PubMed

Yoshida, Keiichi; Atsuta, Mitsuru

2006-10-01

To evaluate the surface hardness (Knoop Hardness Number) of the thin layer in three light-cured and dual-cured resin cements irradiated through or not through 2.0 mm thick machinable ceramics. A piece of adhesive polyethylene tape with a circular hole was positioned on the surface of the ceramic plate to control the cement layer (approximately 50 microm). The cement paste was placed on the ceramic surface within the circle. The ceramic plate with resin cement paste was placed on a clear micro cover glass over a zirconia ceramic block to obtain a flat surface, and the material was polymerized using a visible-light-curing unit. The surface hardness was recorded at a series of time intervals up to 5 days, starting from the end of a light-irradiation period. The hardness steadily increased with post-irradiation time and tended towards a maximum, usually reached after 1 or 2 days. In all cases, the increase in hardness was relatively rapid over the first 30 minutes and continued at a lower rate thereafter. The dual-cured resin cement for each material showed a significantly higher hardness value than the light-cured resin cement irradiated either through or not through ceramics at all post-irradiation times. The resin cements cured through ceramic for each material were significantly less hard compared with those cured not through ceramics at all post-irradiation times.

The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

NASA Astrophysics Data System (ADS)

Lee, Ju-Woon; Oh, Sang-Hee; Kim, Jae-Hun; Byun, Eui-Hong; Ree Kim, Mee; Baek, Min; Byun, Myung-Woo

2007-05-01

The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring.

Modeling plastic deformation of post-irradiated copper micro-pillars

NASA Astrophysics Data System (ADS)

Crosby, Tamer; Po, Giacomo; Ghoniem, Nasr M.

2014-12-01

We present here an application of a fundamentally new theoretical framework for description of the simultaneous evolution of radiation damage and plasticity that can describe both in situ and ex situ deformation of structural materials [1]. The theory is based on the variational principle of maximum entropy production rate; with constraints on dislocation climb motion that are imposed by point defect fluxes as a result of irradiation. The developed theory is implemented in a new computational code that facilitates the simulation of irradiated and unirradiated materials alike in a consistent fashion [2]. Discrete Dislocation Dynamics (DDD) computer simulations are presented here for irradiated fcc metals that address the phenomenon of dislocation channel formation in post-irradiated copper. The focus of the simulations is on the role of micro-pillar boundaries and the statistics of dislocation pinning by stacking-fault tetrahedra (SFTs) on the onset of dislocation channel and incipient surface crack formation. The simulations show that the spatial heterogeneity in the distribution of SFTs naturally leads to localized plastic deformation and incipient surface fracture of micro-pillars.

Pre- and post-irradiation characterization and properties measurements of ZrC coated surrogate TRISO particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vasudevamurthy, Gokul; Katoh, Yutai; Hunn, John D

2010-09-01

Zirconium carbide is a candidate to either replace or supplement silicon carbide as a coating material in TRISO fuel particles for high temperature gas-cooled reactor fuels. Six sets of ZrC coated surrogate microsphere samples, fabricated by the Japan Atomic Energy Agency using the fluidized bed chemical vapor deposition method, were irradiated in the High Flux Isotope Reactor at the Oak Ridge National Laboratory. These developmental samples available for the irradiation experiment were in conditions of either as-fabricated coated particles or particles that had been heat-treated to simulate the fuel compacting process. Five sets of samples were composed of nominally stoichiometricmore » compositions, with the sixth being richer in carbon (C/Zr = 1.4). The samples were irradiated at 800 and 1250 C with fast neutron fluences of 2 and 6 dpa. Post-irradiation, the samples were retrieved from the irradiation capsules followed by microstructural examination performed at the Oak Ridge National Laboratory's Low Activation Materials Development and Analysis Laboratory. This work was supported by the US Department of Energy Office of Nuclear Energy's Advanced Gas Reactor program as part of International Nuclear Energy Research Initiative collaboration with Japan. This report includes progress from that INERI collaboration, as well as results of some follow-up examination of the irradiated specimens. Post-irradiation examination items included microstructural characterization, and nanoindentation hardness/modulus measurements. The examinations revealed grain size enhancement and softening as the primary effects of both heat-treatment and irradiation in stoichiometric ZrC with a non-layered, homogeneous grain structure, raising serious concerns on the mechanical suitability of these particular developmental coatings as a replacement for SiC in TRISO fuel. Samples with either free carbon or carbon-rich layers dispersed in the ZrC coatings experienced negligible grain size

Post-Irradiation Non-Destructive Analyses of the AFIP-7 Experiment

NASA Astrophysics Data System (ADS)

Williams, W. J.; Robinson, A. B.; Rabin, B. H.

2017-12-01

This article reports the results and interpretation of post-irradiation non-destructive examinations performed on four curved full-size fuel plates that comprise the AFIP-7 experiment. These fuel plates, having a U-10 wt.%Mo monolithic design, were irradiated under moderate operating conditions in the Advanced Test Reactor to assess fuel performance for geometries that are prototypic of research reactor fuel assemblies. Non-destructive examinations include visual examination, neutron radiography, profilometry, and precision gamma scanning. This article evaluates the qualitative and quantitative data taken for each plate, compares corresponding data sets, and presents the results of swelling analyses. These characterization results demonstrate that the fuel meets established irradiation performance requirements for mechanical integrity, geometric stability, and stable and predictable behavior.

SU-E-T-222: Investigation of Pre and Post Irradiation Fading of the TLD100 Thermoluminescence Dosimetry for Photon Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sina, S; Sadeghi, M; Faghihi, R

2014-06-01

Purpose: The pre-irradiation and post-irradiation fading of the Thermoluminescense dosimeter signals were investigated in this study. Methods: Two groups of TLD chips with pre-determined ECC values were used in this study. The two groups were divided into 6 series, each composing of 5 TLD chips.The first group was used for pre-irradiation fading. 5 TLDs were exposed to a known amount of radiation from Cs-137 source, and were read out the next day. After seven days, the other 5 TLDs were exposed to the same amount of radiation and were read out after a day. The other series of 5 TLDsmore » were also exposed after 7,19,28, 59, and 90 days, and were read out a day after irradiation. The loss in TLD signal were obtained for all the above cases. The second group, was used for postirradiation fading. All the TLDs of this group were exposed to a known amount of radiation from Cs-137 source. The 6 series composed of 5 TLDs were read out after 1,7,19,28,59, and 90 days. The above-mentioned procedures for obtaining pre-irradiation, and post-irradiation fading were performed for three storage temperatures (25°C, 4°C, and −18°C). Results: According to the results obtained in this study, in case of pre-irradiation fading study, the signal losses after 90 days are 12%, 24%, and 17% for 25°C, 4°C, and −18°C respectively. In case of post-irradiation fading study, the sensitivity losses after 90 days are 25%, 216%, and 20% for 25°C, 4°C, and −18°C respectively. Conclusion: The results indicate that the optimized time between exposing and reading out, and also the optimized time between annealing and exposing is 1 day.The reduction of Storage temperature will reduce the post-irradiation fading, While temperature reduction does not have any effect on pre-irradiation fading.« less

The combined effects of irradiation and herpes simplex virus type 1 infection on an immortal gingival cell line.

PubMed

Turunen, Aaro; Hukkanen, Veijo; Nygårdas, Michaela; Kulmala, Jarmo; Syrjänen, Stina

2014-07-08

Oral mucosa is frequently exposed to Herpes simplex virus type 1 (HSV-1) infection and irradiation due to dental radiography. During radiotherapy for oral cancer, the surrounding clinically normal tissues are also irradiated. This prompted us to study the effects of HSV-1 infection and irradiation on viability and apoptosis of oral epithelial cells. Immortal gingival keratinocyte (HMK) cells were infected with HSV-1 at a low multiplicity of infection (MOI) and irradiated with 2 Gy 24 hours post infection. The cells were then harvested at 24, 72 and 144 hours post irradiation for viability assays and qRT-PCR analyses for the apoptosis-related genes caspases 3, 8, and 9, bcl-2, NFκB1, and viral gene VP16. Mann-Whitney U-test was used for statistical calculations. Irradiation improved the cell viability at 144 hours post irradiation (P = 0.05), which was further improved by HSV-1 infection at MOI of 0.00001 (P = 0.05). Simultaneously, the combined effects of infection at MOI of 0.0001 and irradiation resulted in upregulation in NFκB1 (P = 0.05). The combined effects of irradiation and HSV infection also significantly downregulated the expression of caspases 3, 8, and 9 at 144 hours (P = 0.05) whereas caspase 3 and 8 significantly upregulated in non-irradiated, HSV-infected cells as compared to uninfected controls (P = 0.05). Infection with 0.0001 MOI downregulated bcl-2 in non-irradiated cells but was upregulated by 27% after irradiation when compared to non-irradiated infected cells (P = 0.05). Irradiation had no effect on HSV-1 shedding or HSV gene expression at 144 hours. HSV-1 infection may improve the viability of immortal cells after irradiation. The effect might be related to inhibition of apoptosis.

The combined effects of irradiation and herpes simplex virus type 1 infection on an immortal gingival cell line

PubMed Central

2014-01-01

Background Oral mucosa is frequently exposed to Herpes simplex virus type 1 (HSV-1) infection and irradiation due to dental radiography. During radiotherapy for oral cancer, the surrounding clinically normal tissues are also irradiated. This prompted us to study the effects of HSV-1 infection and irradiation on viability and apoptosis of oral epithelial cells. Methods Immortal gingival keratinocyte (HMK) cells were infected with HSV-1 at a low multiplicity of infection (MOI) and irradiated with 2 Gy 24 hours post infection. The cells were then harvested at 24, 72 and 144 hours post irradiation for viability assays and qRT-PCR analyses for the apoptosis-related genes caspases 3, 8, and 9, bcl-2, NFκB1, and viral gene VP16. Mann–Whitney U-test was used for statistical calculations. Results Irradiation improved the cell viability at 144 hours post irradiation (P = 0.05), which was further improved by HSV-1 infection at MOI of 0.00001 (P = 0.05). Simultaneously, the combined effects of infection at MOI of 0.0001 and irradiation resulted in upregulation in NFκB1 (P = 0.05). The combined effects of irradiation and HSV infection also significantly downregulated the expression of caspases 3, 8, and 9 at 144 hours (P = 0.05) whereas caspase 3 and 8 significantly upregulated in non-irradiated, HSV-infected cells as compared to uninfected controls (P = 0.05). Infection with 0.0001 MOI downregulated bcl-2 in non-irradiated cells but was upregulated by 27% after irradiation when compared to non-irradiated infected cells (P = 0.05). Irradiation had no effect on HSV-1 shedding or HSV gene expression at 144 hours. Conclusions HSV-1 infection may improve the viability of immortal cells after irradiation. The effect might be related to inhibition of apoptosis. PMID:25005804

The effect of a 980 nm diode laser with different parameters of irradiation on the bond strength of fiberglass posts.

PubMed

Garcia, Lucas da Fonseca Roberti; Naves, Lucas Zago; Farina, Ana Paula; Walker, Cristiane Mezzena; Consani, Simonides; Pires-de-Souza, Fernanda de Carvalho Panzeri

2011-01-01

The aim of this study was to assess bond strength of fiberglass posts to root canal dentin irradiated with a 980 nm diode laser at different parameters of power and frequency. Fifty human maxillary canines were separated into five groups (n = 10) according to the following parameters of laser power and frequency: Group 1 (1.5 W/100 Hz), Group 2 (1.5 W/continuous wave [CW]), Group 3 (3.0 W/100 Hz), Group 4 (3.0 W/CW), and Group 5 (no irradiation). Following post cementation, samples underwent a push-out test (0.5 mm/min); next, fracture analysis was performed with a light microscope at 50x and 100x magnification. All of the irradiated groups had increased bond strength values compared to the nonirradiated group. Groups 1 and 2 demonstrated the highest bond strength values; however, statistically significant differences were observed for only the cervical third of Group 4 and the cervical/apical thirds of Group 5. Fracture analysis showed a predominance of mixed failures for Groups 1 and 2 and adhesive failures between dentin and cement for the other groups.

Ductility recovery in structural materials for spallation targets by post-irradiation annealing

NASA Astrophysics Data System (ADS)

Chen, J.; Jung, P.; Rödig, M.; Ullmaier, H.; Bauer, G. S.

2005-08-01

Low temperature irradiation embrittlement is one of the major criteria to determine the lifetime of spallation targets. Embrittlement is especially high at low service temperatures, e.g. 250 °C in liquid-mercury sources. It was the aim of the present study to investigate the effect of post-irradiation annealing on the mechanical properties of irradiated structural materials. The specimens used were obtained from spent target components of operating spallation facilities (Los Alamos Neutron Science Center, LANSCE, and the Spallation Neutron Source at Rutherford-Appleton Laboratory, ISIS). The investigated materials include a nickel-based alloy (IN718), an austenitic stainless steel (AISI 304L), a martensitic stainless steel (DIN 1.4926) and a refractory metal (Ta) which experienced 800 MeV proton irradiation to fluences of several 10 25 p/m 2. The specimens were annealed from 300 °C to 700 °C for 1 to 10 h, respectively, and their mechanical property changes were subsequently investigated at room temperature and 250 °C by tensile testing and fracture surface analysis conducted by scanning electron microscopy (SEM). The results showed that the ductility recovered to a large degree in 304L and DIN 1.4926 materials while their strength remained almost unchanged. Especially for DIN 1.4926, the ductility recovery is remarkable already at 400 °C. Together with its favorable thermo-mechanical properties, this makes martensitic steel a candidate for structural materials of spallation targets.

RERTR-12 Post-irradiation Examination Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rice, Francine; Williams, Walter; Robinson, Adam

2015-02-01

The following report contains the results and conclusions for the post irradiation examinations performed on RERTR-12 Insertion 2 experiment plates. These exams include eddy-current testing to measure oxide growth; neutron radiography for evaluating the condition of the fuel prior to sectioning and determination of fuel relocation and geometry changes; gamma scanning to provide relative measurements for burnup and indication of fuel- and fission-product relocation; profilometry to measure dimensional changes of the fuel plate; analytical chemistry to benchmark the physics burnup calculations; metallography to examine the microstructural changes in the fuel, interlayer and cladding; and microhardness testing to determine the material-propertymore » changes of the fuel and cladding.« less

A stochastic post-processing method for solar irradiance forecasts derived from NWPs models

NASA Astrophysics Data System (ADS)

Lara-Fanego, V.; Pozo-Vazquez, D.; Ruiz-Arias, J. A.; Santos-Alamillos, F. J.; Tovar-Pescador, J.

2010-09-01

Solar irradiance forecast is an important area of research for the future of the solar-based renewable energy systems. Numerical Weather Prediction models (NWPs) have proved to be a valuable tool for solar irradiance forecasting with lead time up to a few days. Nevertheless, these models show low skill in forecasting the solar irradiance under cloudy conditions. Additionally, climatic (averaged over seasons) aerosol loading are usually considered in these models, leading to considerable errors for the Direct Normal Irradiance (DNI) forecasts during high aerosols load conditions. In this work we propose a post-processing method for the Global Irradiance (GHI) and DNI forecasts derived from NWPs. Particularly, the methods is based on the use of Autoregressive Moving Average with External Explanatory Variables (ARMAX) stochastic models. These models are applied to the residuals of the NWPs forecasts and uses as external variables the measured cloud fraction and aerosol loading of the day previous to the forecast. The method is evaluated for a set one-moth length three-days-ahead forecast of the GHI and DNI, obtained based on the WRF mesoscale atmospheric model, for several locations in Andalusia (Southern Spain). The Cloud fraction is derived from MSG satellite estimates and the aerosol loading from the MODIS platform estimates. Both sources of information are readily available at the time of the forecast. Results showed a considerable improvement of the forecasting skill of the WRF model using the proposed post-processing method. Particularly, relative improvement (in terms of the RMSE) for the DNI during summer is about 20%. A similar value is obtained for the GHI during the winter.

The molecular cues for the biological effects of ionizing radiation dose and post-irradiation time on human breast cancer SKBR3 cell line: A Raman spectroscopy study.

PubMed

Jafarzadeh, Naser; Mani-Varnosfaderani, Ahmad; Gilany, Kambiz; Eynali, Samira; Ghaznavi, Habib; Shakeri-Zadeh, Ali

2018-03-01

Radiotherapy is one of the main modalities of cancer treatment. The utility of Raman spectroscopy (RS) for detecting the distinct radiobiological responses in human cancer cells is currently under investigation. RS holds great promises to provide good opportunities for personalizing radiotherapy treatments. Here, we report the effects of the radiation dose and post-irradiation time on the molecular changes in the human breast cancer SKBR3 cells, using RS. The SKBR3 cells were irradiated by gamma radiation with different doses of 0, 1, 2, 4, and 6 Gy. The Raman signals were acquired 24 and 48 h after the gamma radiation. The collected Raman spectra were analyzed by different statistical methods such as principal component analysis, linear discriminant analysis, and genetic algorithm. A thorough analysis of the obtained Raman signals revealed that 2 Gy of gamma radiation induces remarkable molecular and structural changes in the SKBR3 cells. We found that the wavenumbers in the range of 1000-1400 cm -1 in Raman spectra are selective for discriminating between the effects of the different doses of irradiation. The results also revealed that longer post-irradiation time leads to the relaxation of the cells to their initial state. The molecular changes that occurred in the 2Gy samples were mostly reversible. On the other hand, the exposure to doses higher than 4Gy induced serious irreversible changes, mainly seen in 2700-2800 cm -1 in Raman spectra. The classification models developed in this study would help to predict the radiation-based molecular changes induced in the cancer cells by only using RS. Also, this designed framework may facilitate the process of biodosimetry. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of Processing, Post-Harvest Irradiation, and Production System on the Cytotoxicity and Mutagenicity of Vitis labrusca L. Juices in HTC Cells

PubMed Central

Düsman, Elisângela; de Almeida, Igor Vivian; Lucchetta, Luciano; Vicentini, Veronica Elisa Pimenta

2014-01-01

The juices of grapes (Vitis labrusca L.) are similar to the fruit itself because the main constituents of the fruit are present in the juice. However, their quality characteristics may be modified by the harsh technological processes used for the production of integral food, such as production systems of raw materials and post-harvest treatment of grapes with ultraviolet (UV) irradiation. Therefore, the present study analyzed juices produced naturally (by liquefying the fruit) or by the technological process of extraction by steam distillation (90°C) of grapes from organic and conventional production systems that were untreated or treated with UV type C (65.6 J/m2 for 10 minutes). Using cultures of Rattus norvegicus hepatoma cells (HTC) in vitro, cytotoxic effects were assayed by the MTT test and by calculating the cytokinesis blocked proliferation index (CBPI), and mutagenic effects were measured by the cytokinesis block micronucleus assay. The results of the MTT assay and the CBPIs indicated that none of the juices were cytotoxic, including those that induced cell proliferation. The results of the micronucleus assay showed that none of the juices were mutagenic. However, the average number of micronuclei was lower in the juices produced from organic grapes, and cell proliferation, soluble acids and phenolic compounds were significantly higher. Compared with the natural juices, the integral juices of conventional grapes showed a higher average number of micronuclei as well as lower stimulation of cell proliferation and lower levels of bioactive compounds. The results demonstrate a beneficial effect of UV-C irradiation of post-harvest grapes in stimulating the synthesis of nutraceutical compounds without generating cytotoxic or mutagenic substances. Taken together, our findings support the consumption of grape juice and the application of food production techniques that enhance its nutritional value and promote its production, marketing and consumption. PMID

Effect of processing, post-harvest irradiation, and production system on the cytotoxicity and mutagenicity of Vitis labrusca L. juices in HTC cells.

PubMed

Düsman, Elisângela; de Almeida, Igor Vivian; Lucchetta, Luciano; Vicentini, Veronica Elisa Pimenta

2014-01-01

The juices of grapes (Vitis labrusca L.) are similar to the fruit itself because the main constituents of the fruit are present in the juice. However, their quality characteristics may be modified by the harsh technological processes used for the production of integral food, such as production systems of raw materials and post-harvest treatment of grapes with ultraviolet (UV) irradiation. Therefore, the present study analyzed juices produced naturally (by liquefying the fruit) or by the technological process of extraction by steam distillation (90°C) of grapes from organic and conventional production systems that were untreated or treated with UV type C (65.6 J/m² for 10 minutes). Using cultures of Rattus norvegicus hepatoma cells (HTC) in vitro, cytotoxic effects were assayed by the MTT test and by calculating the cytokinesis blocked proliferation index (CBPI), and mutagenic effects were measured by the cytokinesis block micronucleus assay. The results of the MTT assay and the CBPIs indicated that none of the juices were cytotoxic, including those that induced cell proliferation. The results of the micronucleus assay showed that none of the juices were mutagenic. However, the average number of micronuclei was lower in the juices produced from organic grapes, and cell proliferation, soluble acids and phenolic compounds were significantly higher. Compared with the natural juices, the integral juices of conventional grapes showed a higher average number of micronuclei as well as lower stimulation of cell proliferation and lower levels of bioactive compounds. The results demonstrate a beneficial effect of UV-C irradiation of post-harvest grapes in stimulating the synthesis of nutraceutical compounds without generating cytotoxic or mutagenic substances. Taken together, our findings support the consumption of grape juice and the application of food production techniques that enhance its nutritional value and promote its production, marketing and consumption.

Towards evaluating post-irradiation tissue alterations

NASA Astrophysics Data System (ADS)

Daar, Eman; Bradley, D. A.; Alkhorayef, M.; Al-Mugren, K. S.; Abdallat, R. G.; Al-Dousari, H.

2017-08-01

There is apaucity of data concerning irradiation effects on the extracellular matrix and on organised tissues. Examples of such research are cited as are some of the limiting factors towards obtaining meaningful results. This would engender a range of research towards further improving the quality of life, most pointedly of those receiving radiotherapy. As cancer survivor rates increase, survivors are more likely to experience side effects of radiotherapy. This study examines the effects of radiotherapy doses on the extracellular matrix as hyaluronic acid (HA) and pericardium.

Post Irradiation Examination for Advanced Materials at Burnups Exceeding the Current Limit

DOE Office of Scientific and Technical Information (OSTI.GOV)

John H. Strumpell

2004-12-31

Permitting fuel to be irradiated to higher burnups limits can reduce the amount of spent nuclear fuel (SNF) requiring storage and/or disposal and enable plants to operate with longer more economical cycle lengths and/or at higher power levels. Therefore, Framatome ANP (FANP) and the B&W Owner's Group (BWOG) have introduced a new fuel rod design with an advanced M5 cladding material and have irradiated several test fuel rods through four cycles. The U.S. Department of Energy (DOE) joined FANP and the BWOG in supporting this project during its final phase of collecting and evaluating high burnup data through post irradiationmore » examination (PIE).« less

Calibrated photostimulated luminescence is an effective approach to identify irradiated orange during storage

NASA Astrophysics Data System (ADS)

Jo, Yunhee; Sanyal, Bhaskar; Chung, Namhyeok; Lee, Hyun-Gyu; Park, Yunji; Park, Hae-Jun; Kwon, Joong-Ho

2015-06-01

Photostimulated luminescence (PSL) has been employed as a fast screening method for various irradiated foods. In this study the potential use of PSL was evaluated to identify oranges irradiated with gamma ray, electron beam and X-ray (0-2 kGy) and stored under different conditions for 6 weeks. The effects of light conditions (natural light, artificial light, and dark) and storage temperatures (4 and 20 °C) on PSL photon counts (PCs) during post-irradiation periods were studied. Non-irradiated samples always showed negative values of PCs, while irradiated oranges exhibited intermediate results after first PSL measurements. However, the irradiated samples had much higher PCs. The PCs of all the samples declined as the storage time increased. Calibrated second PSL measurements showed PSL ratio <10 for the irradiated samples after 3 weeks of irradiation confirming their irradiation status in all the storage conditions. Calibrated PSL and sample storage in dark at 4 °C were found out to be most suitable approaches to identify irradiated oranges during storage.

EFFECT OF ABDOMINAL SHIELDING ON THE METABOLISM OF HYDROCORTISONE BY LIVER TISSUE OF X-IRRADIATED RATS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lott, J.R.

Liver slices removed from adult rats at various times following whole body x-irradiations of 850, 1500, and 2000 r were tested for their ability to metabolize hydrocortisone ( free alcohol). The animals were divided into a non- irradiated control group, an irradiated unshielded group, and an abdominal- shielded irradiated group. It was found that the irradiated unshielded liver slices metabo lized the hydrocortisone at a lower rate than control slices. Liver slices removed from animals whose abdominal regions were shielded during irradiation were found to metabolize hydrocortisone at a higher rate than control slices. The effects observed appeared to bemore » dependent on total dosage and time of removal of the liver post-irradiation. (auth)« less

Post-irradiation examination of uranium 7 wt% molybdenum atomized dispersion fuel

NASA Astrophysics Data System (ADS)

Leenaers, A.; Van den Berghe, S.; Koonen, E.; Jarousse, C.; Huet, F.; Trotabas, M.; Boyard, M.; Guillot, S.; Sannen, L.; Verwerft, M.

2004-10-01

Two low-enriched uranium fuel plates consisting of U-7wt%Mo atomized powder dispersed in an aluminum matrix, have been irradiated in the FUTURE irradiation rig of the BR2 reactor at SCK•CEN. The plates were submitted to a heat flux of maximum 353 W/cm 2 while the surface cladding temperature is kept below 130 °C. After 40 full power days, visual examination and profilometry of the fuel plates revealed an increase of the plate thickness. In view of this observation, the irradiation campaign was prematurely stopped and the fuel plates were retrieved from the reactor, having at their end-of-life a maximum burn-up of 32.8% 235U (6.5% FIMA). The microstructure of one of the fuel plates has been characterized in an extensive post-irradiation campaign. The U(Mo) fuel particles have been found to interact with the Al matrix, resulting in an interaction layer which can be identified as (U,Mo)Al 3 and (U,Mo)Al 4. Based on the composition of the interaction layer it is shown that the observed physical parameters like thickness of the interaction layer between the Al matrix and the U(Mo) fuel particles compare well to the values calculated by the MAIA code, an U(Mo) behavior modeling code developed by the Commissariat à l'énergie atomique (CEA).

Dose-time relationships for post-irradiation cutaneous telangiectasia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, L.; Ubaldi, S.E.

1977-01-01

Seventy-five patients who had received electron beam radiation a year or more previously were studied. The irradiated skin portals were photographed and late reactions graded in terms of the number and severity of telangiectatic lesions observed. The skin dose, number of fractions, overall treatment time and irradiated volume were recorded in each case. A Strandqvist-type iso-effect line was derived for this response. A multi-probit search program also was used to derive best-fitting cell population kinetic parameters for the same data. From these parameters a comprehensive iso-effect table could be computed for a wide range of treatment schedules including daily treatmentmore » as well as fractionation at shorter and longer intervals; this provided a useful set of normal tissue tolerance limits for late effects.« less

Acute and long-term effects of irradiation on pine (Pinus silvestris) strands post-Chernobyl.

PubMed

Arkhipov, N P; Kuchma, N D; Askbrant, S; Pasternak, P S; Musica, V V

1994-12-11

The effect of ionizing irradiation on the viability of pine stands after the fallout from the damaged nuclear energy plant at Chernobyl (ChNPP) was shown within the territory of the 10-km zone. During the period 1986-1991, irradiated and damaged forest stands, so-called 'red forest', located in this area were systematically classified by observation. Mortality rate, re-establishment, development of tree canopies, reproduction anomalies and stand viability were shown to be dependent on absorbed irradiation dose, on the age of the stand and on forest composition. For pine stands in the acutely affected zone, doses of more than 60 Gy resulted in a massive mortality and no regeneration of pine trees since 1987. The injured trees had burned or had dried-up. The drying process was accelerated by a massive production of pathogenic insects invading the dying trees. Specifically, irradiation doses of 10-60 Gy, 1-10 Gy and 0.1-1 Gy caused high, medium and low injury to the forest stands, respectively. Doses of less than 0.1 Gy did not cause any visible damage to the trees. In 1987, repair processes were displayed by the tree canopies and practically the entire viability of the forest stands had recovered except for trees in the acute and highly affected zones. The young forest was reestablished in the same place as the perished trees and new pine saplings were planted on the reclaimed areas.

The post-thaw irradiation of avian spermatozoa with He-Ne laser differently affects chicken, pheasant and turkey sperm quality.

PubMed

Iaffaldano, N; Paventi, G; Pizzuto, R; Passarella, S; Cerolini, S; Zaniboni, L; Marzoni, M; Castillo, A; Rosato, M P

2013-11-30

The effects of post-thaw Helium-Neon (He-Ne) laser irradiation on mobility and functional integrity of frozen/thawed chicken, pheasant and turkey spermatozoa were investigated. Cytochrome C oxidase (COX) activity was also determined as a measure of the effect of irradiation on mitochondrial bioenergetics. Semen samples from each species were collected, processed and frozen according to the pellet procedure. After thawing, each semen sample was divided into two subsamples: the first one was the control; the second one was irradiated with a single mode continuous He-Ne laser wave (wavelength 632.8 nm; 6 mW; 3.96 J/cm(2)). Then the samples were assessed for sperm mobility (Accudenz(®) swim-down test), viability (SYBR-14/PI staining), osmotic-resistance (HOS test) and COX activity. The irradiation was effective P<0.05 increasing sperm motility in the turkey semen (0.228 ± 0.01 compared with 0.294 ± 0.02). The irradiation also caused an increase (P<0.05) of the COX activity in pheasant (+135 ± 4%) and turkey (+116 ± 4%) sperm, without affecting viability and osmotic-resistance. The COX was positively correlated (P<0.05) with the viability of chicken sperm, however no significant interactions were found between mobility and COX activity in the three avian species. Due to the difference in energetic metabolism among avian species used in this study, the He-Ne laser irradiation has a differential action on bio-stimulation of turkey, chicken and pheasant spermatozoa. The present results are the first to elucidate the possibility for restoration of motility of cryopreserved avian spermatozoa by bio-stimulation provided via He-Ne laser irradiation. Copyright © 2013 Elsevier B.V. All rights reserved.

Progress In Developing Laser Based Post Irradiation Examination Infrastructure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, James A.; Scott, Clark L.; Benefiel, Brad C.

To be able to understand the performance of reactor fuels and materials, irradiated materials must be characterized effectively and efficiently in a high rad environment. The characterization work must be performed remotely and in an environment hostile to instrumentation. Laser based characterization techniques provide the ability to be remote and robust in a hot-cell environment. Laser based instrumentation also can provide high spatial resolution suitable for scanning and imaging large areas. The INL is currently developing three laser based Post Irradiation Examination (PIE) stations for the Hot Fuel Examination Facility at the INL. These laser based systems will characterize irradiatedmore » materials and fuels. The characterization systems are the following: Laser Shock Laser based ultrasonic C-scan system Gas Assay, Sample, and Recharge system (GASR, up-grade to an existing system). The laser shock technique will characterize material properties and failure loads/mechanisms in various materials such as LWR fuel, plate fuel, and next generation fuel forms, for PIE in high radiation areas. The laser shock-technique induces large amplitude shock waves to mechanically characterize interfaces such as the fuel-clad bond. The shock wave travels as a compression wave through the material to the free (unconfined) back surface and reflects back through the material under test as a rarefaction (tensile) wave. This rarefaction wave is the physical mechanism that produces internal de-lamination failure. As part of the laser shock system, a laser-based ultrasonic C-scan system will be used to detect and characterize debonding caused by the laser shock technique. The laser ultrasonic system will be fully capable of performing classical non-destructive evaluation testing and imaging functions such as microstructure characterization, flaw detection and dimensional metrology in complex components. The purpose of the GASR is to measure the pressure/volume of the plenum of an

Dyeing of γ-irradiated cotton with natural flavonoid dye extracted from irradiated onion shells (Allium cepa) powder

NASA Astrophysics Data System (ADS)

Rehman, Fazal-ur; Adeel, Shahid; Shahid, Muhammad; Bhatti, Ijaz Ahmad; Nasir, Faiza; Akhtar, Nasim; Ahmad, Zulfiqar

2013-11-01

Powder of Onion shells as a source of natural flavonoid dye (Quercetin) and cotton fabrics were exposed to absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. Irradiated and un-irradiated dye powder was used for extraction of quercetin as well as antibacterial, hemolytic and antioxidant activities were also determined to observe the effect of radiation. Furthermore, color strength and colourfastness of irradiated fabrics were improved by using pre and post-mordants such as alum and iron. It is found that 4 kGy is the optimal absorbed dose for extraction of natural quercetin extracted from onion shells while maximum color strength and acceptable fastness properties are obtained on dyeing of irradiated fabric at 60 °C keeping M:L of 1:30 using 10% alum as pre-mordant and 6% alum as post-mordant. Gamma irradiation has not only improved the color strength of the dye using irradiated cotton but also that of colourfastness properties.

Post-irradiation examinations of a Zr2.5Nb pressure tube of the Karachi nuclear power plant (KANUPP)

NASA Astrophysics Data System (ADS)

Zaheer, Mohammed Sajjad; Akhtar, Javed Iqbal; Ahmad, Ejaz; Saleem, Muhammad; Hussain, Syed Mukarrum; Qureshi, Masroor Ahmad; Khan, Azmatullah; Ali, Rafaqat; Zafarullah, Muhammad

1996-09-01

The results of post-irradiation examinations of a pressure tube of fuel channel No. G-12 of KANUPP have been described. A detailed study was made in Canada by AECL. A parallel investigation on its seven rings of about 50 mm length each was also carried out at PINSTECH. Visual inspection showed normal oxidation effects. Gamma spectrometry showed the presence of 95Zr and 95Nb. Microstructural study revealed the characteristic alpha plus a transformed beta phase structure.

[Effects of damage and post-radiation reparation of cornea epithelium cells chromosomal apparatus in mice following irradiation by protons with the energy of 25 MeV].

PubMed

2012-01-01

Damage and post-radiation reparation processes were studied in cornea epithelium cells of mice irradiated by protons with the energy of 25 MeV and 60Co gamma-rays singly and in 2 fractions. Protons linear energy transfer (LET) was equal to 2.1 keV/microm, dose rate - 0.5 cGy/s. Animals were irradiated singly by 25 and 750 cGy and doubly (25 + 25; 50 + 50; 125 + 125; 250 + 250 cGy) with a 24-hr interval. Investigations were performed in 24, 72 and 120 hrs. after single and in 24 hrs. after double irradiation. Preparations were analyzed with the anaphase technique. 25 MeV protons were shown to cause more severe damages to the chromosomal apparatus in mammal cells including dramatic suppression of cell division and profuse formation of cells with aberrant mitoses as compared with gamma-induced damages. Exchange-type aberrations were more frequent. There was a reliable decrease of the aberrant mitosis rate in consequence of fractionated irradiation by 25 MeV protons and gamma-rays. On passing 24, 72 and 120 hours, coefficients of relative biological effectiveness (RBE) of 25 MeV protons were equal to 1.4 +/- 0.2; 1.3 +/- 0.1; 1.2 +/- 0.1 for the mitotic index and 1.5 +/- 0.1; 1.3 +/- 0.2; 1.1 +/- 0.1 for aberrant mitosis, respectively.

Cumulative dose 60Co gamma irradiation effects on AlGaN/GaN Schottky diodes and its area dependence

NASA Astrophysics Data System (ADS)

Sharma, Chandan; Laishram, Robert; Rawal, Dipendra Singh; Vinayak, Seema; Singh, Rajendra

2018-04-01

Cumulative dose gamma radiation effects on current-voltage characteristics of GaN Schottky diodes have been investigated. The different area diodes have been fabricated on AlGaN/GaN high electron mobility transistor (HEMT) epi-layer structure grown over SiC substrate and irradiated with a dose up to the order of 104 Gray (Gy). Post irradiation characterization shows a shift in the turn-on voltage and improvement in reverse leakage current. Other calculated parameters include Schottky barrier height, ideality factor and reverse saturation current. Schottky barrier height has been decreased whereas reverse saturation current shows an increase in the value post irradiation with improvement in the ideality factor. Transfer length measurement (TLM) characterization shows an improvement in the contact resistance. Finally, diodes with larger area have more variation in the calculated parameters due to the induced local heating effect.

Effect of gamma irradiation and cooking on cowpea bean grains ( Vigna unguiculata L. Walp)

NASA Astrophysics Data System (ADS)

Lima, Keila dos Santos Cople; Souza, Luciana Boher e.; Godoy, Ronoel Luiz de Oliveira; França, Tanos Celmar Costa; Lima, Antônio Luís dos Santos

2011-09-01

Leguminous plants are important sources of proteins, vitamins, carbohydrates, fibers and minerals. However, some of their non-nutritive elements can present undesirable side effects like flatulence provoked by the anaerobic fermentation of oligosaccharides, such as raffinose and stachyose, in the gut. A way to avoid this inconvenience, without any change in the nutritional value and post-harvesting losses, is an irradiation process. Here, we evaluated the effects of gamma irradiation on the amino acids, thiamine and oligosaccharide contents and on the fungi and their toxin percentages in cowpea bean ( Vigna unguiculata L. Walp) samples. For irradiation doses of 0.0, 0.5, 1.0, 2.5, 5.0 and 10.0 kGy the results showed no significant differences in content for the uncooked samples. However, the combination of irradiation and cooking processes reduced the non-nutritive factors responsible for flatulence. Irradiation also significantly reduced the presence of Aspergillus, Penicilium, Rhizopus and Fusarium fungi and was shown to be efficient in grain conservation for a storage time of 6 months.

A Multi-stage Carcinogenesis Model to Investigate Caloric Restriction as a Potential Tool for Post-irradiation Mitigation of Cancer Risk

PubMed Central

Tani, Shusuke; Blyth, Benjamin John; Shang, Yi; Morioka, Takamitsu; Kakinuma, Shizuko; Shimada, Yoshiya

2016-01-01

The risk of radiation-induced cancer adds to anxiety in low-dose exposed populations. Safe and effective lifestyle changes which can help mitigate excess cancer risk might provide exposed individuals the opportunity to pro-actively reduce their cancer risk, and improve mental health and well-being. Here, we applied a mathematical multi-stage carcinogenesis model to the mouse lifespan data using adult-onset caloric restriction following irradiation in early life. We re-evaluated autopsy records with a veterinary pathologist to determine which tumors were the probable causes of death in order to calculate age-specific mortality. The model revealed that in both irradiated and unirradiated mice, caloric restriction reduced the age-specific mortality of all solid tumors and hepatocellular carcinomas across most of the lifespan, with the mortality rate dependent more on age owing to an increase in the number of predicted rate-limiting steps. Conversely, irradiation did not significantly alter the number of steps, but did increase the overall transition rate between the steps. We show that the extent of the protective effect of caloric restriction is independent of the induction of cancer from radiation exposure, and discuss future avenues of research to explore the utility of caloric restriction as an example of a potential post-irradiation mitigation strategy. PMID:27390741

Current understanding of the effects of enviromental and irradiation variables on RPV embrittlement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odette, G.R.; Lucas, G.E.; Wirth, B.

1997-02-01

Radiation enhanced diffusion at RPV operating temperatures around 290{degrees}C leads to the formation of various ultrafine scale hardening phases, including copper-rich and copper-catalyzed manganese-nickel rich precipitates. In addition, defect cluster or cluster-solute complexes, manifesting a range of thermal stability, develop under irradiation. These features contribute directly to hardening which in turn is related to embrittlement, manifested as shifts in Charpy V-notch transition temperature. Models based on the thermodynamics, kinetics and micromechanics of the embrittlement processes have been developed; these are broadly consistent with experiment and rationalize the highly synergistic effects of most important irradiation (temperature, flux, fluence) and metallurgical (copper,more » nickel, manganese, phosphorous and heat treatment) variables on both irradiation hardening and recovery during post-irradiation annealing. A number of open questions remain which can be addressed with a hierarchy of new theoretical and experimental tools.« less

Biomodulatory effects of laser irradiation on dental pulp cells in vitro

NASA Astrophysics Data System (ADS)

Milward, Michael R.; Hadis, Mohammed A.; Cooper, Paul R.; Gorecki, Patricia; Carroll, James D.; Palin, William M.

2015-03-01

Low level laser/light therapy (LLLT) or photobiomodulation is a biophysical approach that can be used to reduce pain, inflammation and modulate tissue healing and repair. However, its application has yet to be fully realized for dental disease treatment. The aim of this study was to assess the modulation of dental pulp cell (DPC) responses using two LLLT lasers with wavelengths of 660nm and 810nm. Human DPCs were isolated and cultured in phenol-red-free α- MEM/10%-FCS at 37°C in 5% CO2. Central wells of transparent-based black walled 96-microplates were seeded with DPCs (passages 2-4; 150μL; 25,000 cell/ml). At 24h post-seeding, cultures were irradiated using a Thor Photomedicine LLLT device (THOR Photomedicine, UK) at 660nm (3, 6 or 13s to give 2, 5 and 10J/cm2) or 810nm (for 1, 2 or 5s to deliver 5, 10 and 20J/cm2). Metabolic activity was assessed via a modified MTT assay 24h post-irradiation. Statistical differences were identified using analysis of variance and post-hoc Tukey tests (P=0.05) and compared with nonirradiated controls. Significantly higher MTT activity was obtained for both lasers (P<0.05) using the high and intermediate radiant exposure (5-20J/cm2). The MTT response significantly decreased (P<0.05) at lower radiant exposures with no statistical significance from control (P>0.05). Consequently, enhanced irradiation parameters was apparent for both lasers. These parameters should be further optimised to identify the most effective for therapeutic application.

Meso-scale modeling of irradiated concrete in test reactor

DOE PAGES

Giorla, Alain B.; Vaitová, M.; Le Pape, Yann; ...

2015-10-18

In this paper, we detail a numerical model accounting for the effects of neutron irradiation on concrete at the mesoscale. Irradiation experiments in test reactor (Elleuch et al.,1972), i.e., in accelerated conditions, are simulated. Concrete is considered as a two-phase material made of elastic inclusions (aggregate) subjected to thermal and irradiation-induced swelling and embedded in a cementitious matrix subjected to shrinkage and thermal expansion. The role of the hardened cement paste in the post-peak regime (brittle-ductile transition with decreasing loading rate), and creep effects are investigated. Radiation-induced volumetric expansion (RIVE) of the aggregate cause the development and propagation of damagemore » around the aggregate which further develops in bridging cracks across the hardened cement paste between the individual aggregate particles. The development of damage is aggravated when shrinkage occurs simultaneously with RIVE during the irradiation experiment. The post-irradiation expansion derived from the simulation is well correlated with the experimental data and, the obtained damage levels are fully consistent with previous estimations based on a micromechanical interpretation of the experimental post-irradiation elastic properties (Le Pape et al.,2015). In conclusion, the proposed modeling opens new perspectives for the interpretation of test reactor experiments in regards to the actual operation of light water reactors.« less

The effects of tungsten's pre-irradiation surface condition on helium-irradiated morphology

DOE PAGES

Garrison, Lauren M.; Kulcinski, Gerald L.

2015-07-17

Erosion is a concern associated with the use of tungsten as a plasma-facing component in fusion reactors. To compare the damage progression, polycrystalline tungsten (PCW) and (110) single crystal tungsten (SCW) samples were prepared with (1) a mechanical polish (MP) with roughness values in the range of 0.018–0.020 μm and (2) an MP and electropolish (MPEP) resulting in roughness values of 0.010–0.020 μm for PCW and 0.003–0.005 μm for SCW samples. Samples were irradiated with 30 keV He + at 1173 K to fluences between 3 × 10 21 and 6 × 10 22 He/m 2. The morphologies that developedmore » after low-fluence bombardment were different for each type of sample—MP SCW, MPEP SCW, MP PCW, and MPEP PCW. At the highest fluence, the SCW MPEP sample lost significantly more mass and developed a different morphology than the MP SCW sample. The PCW samples developed a similar morphology and had similar mass loss at the highest fluence. Surface preparation can have a significant effect on post-irradiation morphology that should be considered for the design of future fusion reactors such as ITER and DEMO.« less

Detrimental effects of electron beam irradiation on the cowpea bruchid Callosobruchus maculatus.

PubMed

Sang, Wen; Speakmon, Mickey; Zhou, Lan; Wang, Yu; Lei, Chaoliang; Pillai, Suresh D; Zhu-Salzman, Keyan

2016-04-01

Electron beam (eBeam) irradiation technology is an environmentally friendly, chemical-free alternative for disinfesting insect pests of stored grains. The underlying hypothesis is that specific doses of eBeam will have defined detrimental effects on the different life stages. We evaluated the effects of eBeam exposure in a range of doses (0.03-0.12 kGy) on the development of the cowpea bruchid (Callosobruchus maculatus) at various stages of its life cycle. Differential radiosensitivity was detected during egg development. Early and intermediate stages of eggs never hatched after exposure to a dose of 0.03 kGy, whereas a substantial portion of black-headed (i.e. late) eggs survived irradiation even at 0.12 kGy. However, further development of the hatched larvae was inhibited. Although midgut protein digestion remained intact, irradiated larvae (0.06 kGy or higher) failed to develop into normal living adults; rather, they died as pupae or abnormally eclosed adults, suggesting a detrimental effect of eBeam on metamorphosis. Emerged irradiated pupae had shorter longevity and were unable to produce any eggs at 0.06 kGy or higher. At this dose range, eggs laid by irradiated adults were not viable. eBeam treatment shortened adult longevity in a dose-dependent manner. Reciprocal crosses indicated that females were more sensitive to eBeam exposure than their male counterparts. Dissection of the female reproductive system revealed that eBeam treatment prevented formation of oocytes. eBeam irradiation has very defined effects on cowpea bruchid development and reproduction. A dose of 0.06 kGy could successfully impede cowpea burchid population expansion. This information can be exploited for post-harvest insect control of stored grains. © 2015 Society of Chemical Industry.

[Ultrahigh dose-rate, "flash" irradiation minimizes the side-effects of radiotherapy].

PubMed

Favaudon, V; Fouillade, C; Vozenin, M-C

2015-10-01

Pencil beam scanning and filter free techniques may involve dose-rates considerably higher than those used in conventional external-beam radiotherapy. Our purpose was to investigate normal tissue and tumour responses in vivo to short pulses of radiation. C57BL/6J mice were exposed to bilateral thorax irradiation using pulsed (at least 40 Gy/s, flash) or conventional dose-rate irradiation (0.03 Gy/s or less) in single dose. Immunohistochemical and histological methods were used to compare early radio-induced apoptosis and the development of lung fibrosis in the two situations. The response of two human (HBCx-12A, HEp-2) tumour xenografts in nude mice and one syngeneic, orthotopic lung carcinoma in C57BL/6J mice (TC-1 Luc+), was monitored in both radiation modes. A 17 Gy conventional irradiation induced pulmonary fibrosis and activation of the TGF-beta cascade in 100% of the animals 24-36 weeks post-treatment, as expected, whereas no animal developed complications below 23 Gy flash irradiation, and a 30 Gy flash irradiation was required to induce the same extent of fibrosis as 17 Gy conventional irradiation. Cutaneous lesions were also reduced in severity. Flash irradiation protected vascular and bronchial smooth muscle cells as well as epithelial cells of bronchi against acute apoptosis as shown by analysis of caspase-3 activation and TUNEL staining. In contrast, the antitumour effectiveness of flash irradiation was maintained and not different from that of conventional irradiation. Flash irradiation shifted by a large factor the threshold dose required to initiate lung fibrosis without loss of the antitumour efficiency, suggesting that the method might be used to advantage to minimize the complications of radiotherapy. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Performance of AGR-1 high-temperature reactor fuel during post-irradiation heating tests

DOE PAGES

Morris, Robert N.; Baldwin, Charles A.; Demkowicz, Paul A.; ...

2016-05-18

The fission product retention of irradiated low-enriched uranium oxide/uranium carbide tri-structural isotropic (TRISO) fuel compacts from the Advanced Gas-Cooled Reactor 1 (AGR-1) experiment has been evaluated at temperatures of 1600–1800 °C during post-irradiation safety tests. Fourteen compacts (a total of ~58,000 particles) with a burnup ranging from 13.4% to 19.1% fissions per initial metal atom (FIMA) have been tested using dedicated furnace systems at Idaho National Laboratory and Oak Ridge National Laboratory. The release of fission products 110mAg, 134Cs, 137Cs, 154Eu, 155Eu, 90Sr, and 85Kr was monitored while heating the fuel specimens in flowing helium. The behavior of silver, europium,more » and strontium appears to be dominated by inventory that was originally released through intact SiC coating layers during irradiation, but was retained in the compact at the end of irradiation and subsequently released during the safety tests. However, at a test temperature of 1800 °C, the data suggest that release of these elements through intact coatings may become significant after ~100 h. Cesium was very well retained by intact SiC layers, with a fractional release <5 × 10–6 after 300 h at 1600 °C or 100 h at 1800 °C. However, it was rapidly released from individual particles if the SiC layer failed, and therefore the overall cesium release fraction was dominated by the SiC defect and failure fractions in the fuel compacts. No complete TRISO coating layer failures were observed after 300 h at 1600 or 1700 °C, and 85Kr release was very low during the tests (particles with failed SiC, but intact outer pyrocarbon, retained most of their krypton). Krypton release from TRISO failures was only observed after ~210 h at 1800 °C in one compact. As a result, post-safety-test examination of fuel compacts and particles has focused on identifying specific particles from each compact with notable fission product release and detailed analysis of the coating layers

Performance of AGR-1 high-temperature reactor fuel during post-irradiation heating tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morris, Robert N.; Baldwin, Charles A.; Demkowicz, Paul A.

The fission product retention of irradiated low-enriched uranium oxide/uranium carbide tri-structural isotropic (TRISO) fuel compacts from the Advanced Gas-Cooled Reactor 1 (AGR-1) experiment has been evaluated at temperatures of 1600–1800 °C during post-irradiation safety tests. Fourteen compacts (a total of ~58,000 particles) with a burnup ranging from 13.4% to 19.1% fissions per initial metal atom (FIMA) have been tested using dedicated furnace systems at Idaho National Laboratory and Oak Ridge National Laboratory. The release of fission products 110mAg, 134Cs, 137Cs, 154Eu, 155Eu, 90Sr, and 85Kr was monitored while heating the fuel specimens in flowing helium. The behavior of silver, europium,more » and strontium appears to be dominated by inventory that was originally released through intact SiC coating layers during irradiation, but was retained in the compact at the end of irradiation and subsequently released during the safety tests. However, at a test temperature of 1800 °C, the data suggest that release of these elements through intact coatings may become significant after ~100 h. Cesium was very well retained by intact SiC layers, with a fractional release <5 × 10–6 after 300 h at 1600 °C or 100 h at 1800 °C. However, it was rapidly released from individual particles if the SiC layer failed, and therefore the overall cesium release fraction was dominated by the SiC defect and failure fractions in the fuel compacts. No complete TRISO coating layer failures were observed after 300 h at 1600 or 1700 °C, and 85Kr release was very low during the tests (particles with failed SiC, but intact outer pyrocarbon, retained most of their krypton). Krypton release from TRISO failures was only observed after ~210 h at 1800 °C in one compact. As a result, post-safety-test examination of fuel compacts and particles has focused on identifying specific particles from each compact with notable fission product release and detailed analysis of the coating layers

Effect of gamma irradiation on the color, structure and morphology of nickel-doped polyvinyl alcohol films: Alternative use as dosimeter or irradiation indicator

NASA Astrophysics Data System (ADS)

Raouafi, A.; Daoudi, M.; Jouini, K.; Charradi, K.; Hamzaoui, A. H.; Blaise, P.; Farah, K.; Hosni, F.

2018-06-01

Nickel-doped poly vinyl alcohol (PVA) films were developed for potential application in industrial sectors like radiation processing. We report in this paper the results of an experimental investigation of 60Co source γ-radiation effect on colorimetric, structural and morphological properties of PVA films doped with 0.5% Ni2+ ions (PVA/Ni2+). The PVA/Ni2+ films were irradiated by different gamma-radiation doses varying from 5 to 100 kGy. Color modification of films were studied using L∗, a∗ and b∗ color space measurements as function of the γ-dose and post-irradiation time. The visual change in all samples was verified by microstructure analysis, Fourier transforms infrared (FTIR) spectroscopy, X-Rays diffraction (XRD) and scanning electron microscopy (SEM). The color space exhibited a linear dose response at a dose ranging from 5 to 50 kGy, and then it reached saturation for higher γ-doses. The calculated color changes (ΔE) show a linear dose response relationship from 9.90 to 115.02 in the dose range from 0 to 50 kGy. It showed also the activation of stable color centers. The variability of the color change did not exceed 3% during 80 h (h) post-irradiation. Furthermore, the microstructure analysis evidenced that the color modification due to the optical activation of nickel-oxide (NiO) color center were obtained by complexing Ni2+ ions in irradiated PVA films. The obtained results inspire the possibility to use PVA films for the control process in industrial radiation facilities in dose range 5-50 kGy.

Post-irradiation-examination of irradiated fuel outside the hot cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawn E. Janney; Adam B. Robinson; Thomas P. O'Holleran

Because of their high radioactivity, irradiated fuels are commonly examined in a hot cell. However, the Idaho National Laboratory (INL) has recently investigated irradiated U-Mo-Al metallic fuel from the Reduced Enrichment for Research and Test Reactors (RERTR) project using a conventional unshielded scanning electron microscope outside a hot cell. This examination was possible because of a two-step sample-preparation approach in which a small volume of fuel was isolated in a hot cell and shielding was introduced during later stages of sample preparation. The resulting sample contained numerous sample-preparation artifacts but allowed analysis of microstructures from selected areas.

Potential Protective Effects of Ursolic Acid against Gamma Irradiation-Induced Damage Are Mediated through the Modulation of Diverse Inflammatory Mediators

PubMed Central

Wang, Hong; Sim, Meng-Kwoon; Loke, Weng Keong; Chinnathambi, Arunachalam; Alharbi, Sulaiman Ali; Tang, Feng Ru; Sethi, Gautam

2017-01-01

This study was aimed to evaluate the possible protective effects of ursolic acid (UA) against gamma radiation induced damage both in vitro as well as in vivo. It was observed that the exposure to gamma radiation dose- and time-dependently caused a significant decrease in the cell viability, while the treatment of UA attenuated this cytotoxicity. The production of free radicals including reactive oxygen species (ROS) and NO increased significantly post-irradiation and further induced lipid peroxidation and oxidative DNA damage in cells. These deleterious effects could also be effectively blocked by UA treatment. In addition, UA also reversed gamma irradiation induced inflammatory responses, as indicated by the decreased production of TNF-α, IL-6, and IL-1β. NF-κB signaling pathway has been reported to be a key mediator involved in gamma radiation-induced cellular damage. Our results further demonstrated that gamma radiation dose- and time-dependently enhanced NF-κB DNA binding activity, which was significantly attenuated upon UA treatment. The post-irradiation increase in the expression of both phospho-p65, and phospho-IκBα was also blocked by UA. Moreover, the treatment of UA was found to significantly prolong overall survival in mice exposed to whole body gamma irradiation, and reduce the excessive inflammatory responses. Given its radioprotective efficacy as described here, UA as an antioxidant and NF-κB pathway blocker, may function as an important pharmacological agent in protecting against gamma irradiation-induced injury. PMID:28670276

Post-focus expansion of ion beams for low fluence and large area MeV ion irradiation: Application to human brain tissue and electronics devices

NASA Astrophysics Data System (ADS)

Whitlow, Harry J.; Guibert, Edouard; Jeanneret, Patrick; Homsy, Alexandra; Roth, Joy; Krause, Sven; Roux, Adrien; Eggermann, Emmanuel; Stoppini, Luc

2017-08-01

Irradiation with ∼3 MeV proton fluences of 106-109 protons cm-2 have been applied to study the effects on human brain tissue corresponding to single-cell irradiation doses and doses received by electronic components in low-Earth orbit. The low fluence irradiations were carried out using a proton microbeam with the post-focus expansion of the beam; a method developed by the group of Breese [1]. It was found from electrophysiological measurements that the mean neuronal frequency of human brain tissue decreased to zero as the dose increased to 0-1050 Gy. Enhancement-mode MOSFET transistors exhibited a 10% reduction in threshold voltage for 2.7 MeV proton doses of 10 Gy while a NPN bipolar transistor required ∼800 Gy to reduce the hfe by 10%, which is consistent the expected values.

Post Irradiation Evaluation of Thermal Control Coatings and Solid Lubricants to Support Fission Surface Power Systems

NASA Astrophysics Data System (ADS)

Bowman, Cheryl L.; Jaworske, Donald A.; Stanford, Malcolm K.; Persinger, Justin A.; Khorsandi, Behrooz; Blue, Thomas E.

2007-01-01

The development of a nuclear power system for space missions, such as the Jupiter Icy Moons Orbiter or a lunar outpost, requires substantially more compact reactor design than conventional terrestrial systems. In order to minimize shielding requirements and hence system weight, the radiation tolerance of component materials within the power conversion and heat rejection systems must be defined. Two classes of coatings, thermal control paints and solid lubricants, were identified as material systems for which limited radiation hardness information was available. Screening studies were designed to explore candidate coatings under a predominately fast neutron spectrum. The Ohio State Research Reactor Facility staff performed irradiation in a well characterized, mixed energy spectrum and performed post irradiation analysis of representative coatings for thermal control and solid lubricant applications. Thermal control paints were evaluated for 1 MeV equivalent fluences from 1013 to 1015 n/cm2. No optical degradation was noted although some adhesive degradation was found at higher fluence levels. Solid lubricant coatings were evaluated for 1 MeV equivalent fluences from 1015 to 1016 n/cm2 with coating adhesion and flexibility used for post irradiation evaluation screening. The exposures studied did not lead to obvious property degradation indicating the coatings would have survived the radiation environment for the previously proposed Jupiter mission. The results are also applicable to space power development programs such as fission surface power for future lunar and Mars missions.

Post Irradiation Evaluation of Thermal Control Coatings and Solid Lubricants to Support Fission Surface Power Systems

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.; Jaworske, Donald A.; Stanford, Malcolm K.; Persinger, Justin A.; Khorsandi, Behrooz; Blue, Thomas E.

2007-01-01

The development of a nuclear power system for space missions, such as the Jupiter Icy Moons Orbiter or a lunar outpost, requires substantially more compact reactor design than conventional terrestrial systems. In order to minimize shielding requirements and hence system weight, the radiation tolerance of component materials within the power conversion and heat rejection systems must be defined. Two classes of coatings, thermal control paints and solid lubricants, were identified as material systems for which limited radiation hardness information was available. Screening studies were designed to explore candidate coatings under a predominately fast neutron spectrum. The Ohio State Research Reactor Facility staff performed irradiation in a well characterized, mixed energy spectrum and performed post irradiation analysis of representative coatings for thermal control and solid lubricant applications. Thermal control paints were evaluated for 1 MeV equivalent fluences from 10(exp 13) to 10(exp 15) n per square centimeters. No optical degradation was noted although some adhesive degradation was found at higher fluence levels. Solid lubricant coatings were evaluated for 1 MeV equivalent fluences from 10(exp 15) to 10(exp 16) n per square centimeters with coating adhesion and flexibility used for post irradiation evaluation screening. The exposures studied did not lead to obvious property degradation indicating the coatings would have survived the radiation environment for the previously proposed Jupiter mission. The results are also applicable to space power development programs such as fission surface power for future lunar and Mars missions.

Post-irradiation examination of prototype Al-64 wt% U{sub 3}Si{sub 2} fuel rods from NRU

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sears, D.F.; Primeau, M.F.; Buchanan, C.

1997-08-01

Three prototype fuel rods containing Al-64 wt% U{sub 3}Si{sub 2} (3.15 gU/cm{sup 3}) have been irradiated to their design burnup in the NRU reactor without incident. The fuel was fabricated using production-scale equipment and processes previously developed for Al-U{sub 3}Si fuel fabrication at Chalk River Laboratories, and special equipment developed for U{sub 3}Si{sub 2} powder production and handling. The rods were irradiated in NRU up to 87 at% U-235 burnup under typical driver fuel conditions; i.e., nominal coolant inlet temperature 37{degrees}C, inlet pressure 654 kPa, mass flow 12.4 L/s, and element linear power ratings up to 73 kW/m. Post-irradiation examinationsmore » showed that the fuel elements survived the irradiation without defects. Fuel core diametral increases and volumetric swelling were significantly lower than that of Al-61 wt% U{sub 3}Si fuel irradiated under similar conditions. This irradiation demonstrated that the fabrication techniques are adequate for full-scale fuel manufacture, and qualified the fuel for use in AECL`s research reactors.« less

Risk factors for recurrent pneumonia in post-irradiated patients with nasopharyngeal carcinoma.

PubMed

Wang, Jing-Jie; Jiang, Rong-San; Yen, Ting-Ting; Liang, Kai-Li

2017-09-01

Nasopharyngeal carcinoma (NPC) is a common cancer in eastern Asia. Chemoradiotherapy is the main treatment modality for NPC. Dysphagia and aspiration is not uncommon in post-irradiated NPC patients. The purpose of this study was to investigate the risk factors for recurrent pneumonia and the prognosis. A retrospective chart review was conducted from January 2004 to December 2014. NPC patients who had been hospitalized for pneumonia in the study hospital were enrolled. The diagnosis of pneumonia was based on radiological evidence of chest inflammation and clinical symptoms. Patients' characteristics including demographic data, the hospital course, and the outcome of pneumonia were collected and analyzed. A total of 113 NPC patients were enrolled in this study. Among them, 96 NPC patients had pneumonia after radiotherapy: 43 had pneumonia twice, and 18 had multiple episodes of pneumonia. Forty-nine patients had tube feeding. The 30-day mortality rate was 51%. The mortality rate was significantly associated with metastatic nasopharyngeal carcinoma (r = 0.328, p < 0.001). Older age, smoking, body weight loss, and lower cranial nerve (vagus or hypoglossal nerve palsy) were significant predictors of multiple episodes of pneumonia (r 2  = 0.687, p = 0.033, 0.034, 0.036, and 0.027, respectively). We concluded that old age, smoking, body weight loss, and lower cranial nerve palsies are predisposing factors for multiple episodes of pneumonia in post-irradiated NPC patients. Metastatic cancer status usually leads to a lethal outcome. Early interventions to manage dysphagia in high-risk patients are necessary. Copyright © 2017. Published by Elsevier Taiwan LLC.

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

PubMed Central

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

2014-01-01

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

Physiological responses of spring rapeseed (Brassica napus) to red/far-red ratios and irradiance during pre- and post-flowering stages.

PubMed

Rondanini, Deborah P; del Pilar Vilariño, Maria; Roberts, Marcos E; Polosa, Marina A; Botto, Javier F

2014-12-01

Early shade signals promote the shade avoidance syndrome (SAS) which causes, among others, petiole and shoot elongation and upward leaf position. In spite of its relevance, these photomorphogenic responses have not been deeply studied in rapeseed (Brassica napus). In contrast to other crops like maize and wheat, rapeseed has a complex developmental phenotypic pattern as it evolves from an initial rosette to the main stem elongation and an indeterminate growth of floral raceme. In this work, we analyzed (1) morphological and physiological responses at individual level due to low red/far-red (R/FR) ratio during plant development, and (2) changes in biomass allocation, grain yield and composition at crop level in response to high R/FR ratio and low irradiance in two modern spring rapeseed genotypes. We carried out pot and field experiments modifying R/FR ratios and irradiance at vegetative or reproductive stages. In pot experiments, low R/FR ratio increased the petiole and lamina length, upward leaf position and also accelerated leaf senescence. Furthermore, low R/FR ratio reduced main floral raceme and increased floral branching with higher remobilization of soluble carbohydrates from the stems. In field experiments, low irradiance during post-flowering reduced grain yield, harvest index and grain oil content, and high R/FR ratio reaching the crop partially alleviated such effects. We conclude that photomorphogenic signals are integrated early during the vegetative growth, and irradiance has stronger effects than R/FR signals at rapeseed crop level. © 2014 Scandinavian Plant Physiology Society.

Radioprotective effect of Ganoderma lucidum (Leyss. ex. Fr. ) Karst after X-ray irradiation in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, H.Y.; Lian, S.L.; Lin, C.C.

1990-01-01

Six to seven week old male mice of ICR strain were exposed to 500 or 650 cGy of X-ray during experiments to determine if Ganoderma lucidum could be a factor in modification of radiation damage. Continuous intraperitoneal injection of the extract from Ganoderma lucidum before or after irradiation of 500 and 650 cGy of X-ray was found to improve the 30-day survival fractions of ICR mice, but wasn't significant by statistical analysis. The administration also enhanced the recoveries of the body weights and increased the recovery of hemograms of irradiated mice from radiation damage by injecting before or after radiationmore » exposure, especially for the treatment of 500 cGy irradiation. The 10-day CFUs was significantly higher for Ganoderma lucidum treated groups than for untreated groups. However, the differences of radioprotective effect between the X-ray irradiated groups with Ganoderma lucidum pretreated and post-treated were not significant (p greater than 0.05).« less

Post Irradiation Examination Results of the NT-02 Graphite Fins NUMI Target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ammigan, K.; Hurh, P.; Sidorov, V.

2017-02-10

The NT-02 neutrino target in the NuMI beamline at Fermilab is a 95 cm long target made up of segmented graphite fins. It is the longest running NuMI target, which operated with a 120 GeV proton beam with maximum power of 340 kW, and saw an integrated total proton on target of 6.1 1020. Over the last half of its life, gradual degradation of neutrino yield was observed until the target was replaced. The probable causes for the target performance degradation are attributed to radiation damage, possibly including cracking caused by reduction in thermal shock resistance, as well as potentialmore » localized oxidation in the heated region of the target. Understanding the long-termstructural response of target materials exposed to proton irradiation is critical as future proton accelerator sources are becoming increasingly more powerful. As a result, an autopsy of the target was carried out to facilitate post-irradiation examination of selected graphite fins. Advanced microstructural imaging and surface elemental analysis techniques were used to characterize the condition of the fins in an effort to identify degradation mechanisms, and the relevant findings are presented in this paper.« less

Effects of Aminoguanidine on Pre- and Post-Irradiation Regional Cerebral Blood Flow, Systemic Blood Pressure and Plasma Histamine Levels in the Primate,

DTIC Science & Technology

1991-01-01

released HA may not be the sole mediator of these effects. Because elevations in plasma HA are probably due to HA derived from degranulation of mast cells ...release of other bioactive substances from mast cells may also influence these cardiovascular effects. Surprisingly, in sham-irradiated monkeys. AG...histaminergic nificantly altered by the administration ofAG. Al- mechanisms may be misguided. Mast cells , the though the two irradiated groups were

Beta1-integrin and IL-1alpha expression as bystander effect of medium from irradiated cells: the pilot study.

PubMed

Osterreicher, Jan; Skopek, Jirí; Jahns, Juta; Hildebrandt, Guido; Psutka, Jan; Vilasová, Zdenka; Tanner, Judith Maria; Vogt, Jürgen; Butz, Tilman

2003-01-01

Bystander effects have been proposed as a third action pathway of ionising radiation besides direct and indirect effects. The purpose of the study was to investigate whether expression of interleukin-1alpha (IL-1alpha) and beta1-integrin is elevated in bystander cells as a marker for bystander effects in comparison with classical markers such as the clonogenic assay, apoptosis and the presence of micronuclei. The hybrid cell line E.A. hy.926 obtained by fusion of HUVEC cells with the epithelial cell line A 459 was irradiated with 0-5 Gy. Bystander effects were established via medium transfer at 45 min and 4 h after irradiation from irradiated to nonirradiated cell populations. In order to exclude effects of the irradiated medium itself, irradiated medium only was also used for transfer to nonirradiated cells. Then, cells were fixed at 1, 2, 6, and 24 h after irradiation or medium transport and IL-1alpha and beta1-integrin were detected and evaluated. A higher number of beta1-integrin-positive cells was observed in both irradiated and bystander cell populations than in the control group at 1 and 24 h after irradiation with 1 Gy or medium transfer. Significantly higher numbers of IL-1alpha-positive cells were found at 1, 2, and 6 h after irradiation with 1 Gy or medium transfer as well as at 2 and 6 h after irradiation with 5 Gy or medium transfer. Clonogenic survival decreased dependently on the dose in irradiated cells but did not show any significant difference between the bystander cell populations and sham-irradiated cells. The irradiated medium itself did not have any effect. It is concluded that beta1-integrin and IL-1alpha expression may serve as more sensitive markers of post-irradiation responses in bystander cell populations than the classical radiobiological markers. Moreover, overexpression of beta1-integrin and IL-1alpha may induce increased susceptibility to inflammation of bystander cells.

The Possible Pre- and Post-UVA Radiation Protective Effect of Amaranth Oil on Human Skin Fibroblast Cells.

PubMed

Wolosik, Katarzyna; Zareba, Ilona; Surazynski, Arkadiusz; Markowska, Agnieszka

2017-07-01

The health effects of Amaranth Oil (AO) are attributed to its specific chemical composition. That makes it an outstanding natural product for the prevention and treatment of ultraviolet (UV) irradiation-related pathologies such as sunburn, photoaging, photoimmunosuppression, and photocarcinogenesis. Most of the studies are taken on animal model, and there is a lack of research on the endogenous effect of AO on fibroblast level, where UVA takes it harmful place. The aim of this study was evaluation if AO can protect or abolish UVA exposure effect on human skin fibroblast. The 0.1% AO, 0.25% AO, and 0.5% AO concentration and irradiation for 15 min under UVA-emitting lamp were studied in various condition. In all experiments, the mean values for six assays ± standard deviations were calculated. Pretreatment with various concentrations of AO was tested. The highest concentration of AO where cell survival was observed was 0.5%. Cytotoxicity assays provided evidence for pre- and post-UVA protective effect of 0.1% AO among three tested concentrations. The results also provide evidence that UVA has inhibitory effect on collagen biosynthesis in confluent skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effect comparing to other used AO concentration. The assessment results on DNA biosynthesis show the significant abolished post-UVA effect when 0.1% and 0.5% of AO were added. AO gives pre- and post-UVA protection in low concentration. This provides the evidence for using it not as a main protective factor against UV but as one of the combined components in cosmetic formulation. The recommended Amaranth Oil (AO) concentration in cosmetic formulation is between 0.1 and 5%Pretreatment with various concentrations of AO suggests to use the highest 0.5% concentration of AO in human skin fibroblast culturesThe 0.1% of AO in fibroblast cultures, protects and abolishes effect of ultraviolet A (UVA) exposureUVA has inhibitory effect on collagen biosynthesis in

Effects of a granulocyte colony stimulating factor, Neulasta, in mini pigs exposed to total body proton irradiation

PubMed Central

Sanzari, Jenine K.; Krigsfeld, Gabriel S.; Shuman, Anne L.; Diener, Antonia K.; Lin, Liyong; Mai, Wilfried; Kennedy, Ann R.

2015-01-01

Astronauts could be exposed to solar particle event (SPE) radiation, which is comprised mostly of proton radiation. Proton radiation is also a treatment option for certain cancers. Both astronauts and clinical patients exposed to ionizing radiation are at risk for white blood cell (WBC) loss, which are the body’s main defense against infection. In this report, the effect of Neulasta treatment, a granulocyte colony stimulating factor, after proton radiation exposure is discussed. Mini pigs exposed to total body proton irradiation at a dose of 2 Gy received 4 treatments of either Neulasta or saline injections. Peripheral blood cell counts and thromboelastography parameters were recorded up to 30 days post-irradiation. Neulasta significantly improved white blood cell (WBC), specifically neutrophil, loss in irradiated animals by approximately 60% three days after the first injection, compared to the saline treated irradiated animals. Blood cell counts quickly decreased after the last Neulasta injection, suggesting a transient effect on WBC stimulation. Statistically significant changes in hemostasis parameters were observed after proton radiation exposure in both the saline and Neulasta treated irradiated groups, as well internal organ complications such as pulmonary changes. In conclusion, Neulasta treatment temporarily alleviates proton radiation-induced WBC loss, but has no effect on altered hemostatic responses. PMID:25909052

Effects of a granulocyte colony stimulating factor, Neulasta, in mini pigs exposed to total body proton irradiation

NASA Astrophysics Data System (ADS)

Sanzari, Jenine K.; Krigsfeld, Gabriel S.; Shuman, Anne L.; Diener, Antonia K.; Lin, Liyong; Mai, Wilfried; Kennedy, Ann R.

2015-04-01

Astronauts could be exposed to solar particle event (SPE) radiation, which is comprised mostly of proton radiation. Proton radiation is also a treatment option for certain cancers. Both astronauts and clinical patients exposed to ionizing radiation are at risk for loss of white blood cells (WBCs), which are the body's main defense against infection. In this report, the effect of Neulasta treatment, a granulocyte colony stimulating factor, after proton radiation exposure is discussed. Mini pigs exposed to total body proton irradiation at a dose of 2 Gy received 4 treatments of either Neulasta or saline injections. Peripheral blood cell counts and thromboelastography parameters were recorded up to 30 days post-irradiation. Neulasta significantly improved WBC loss, specifically neutrophils, in irradiated animals by approximately 60% three days after the first injection, compared to the saline treated, irradiated animals. Blood cell counts quickly decreased after the last Neulasta injection, suggesting a transient effect on WBC stimulation. Statistically significant changes in hemostasis parameters were observed after proton radiation exposure in both the saline and Neulasta treated irradiated groups, as well as internal organ complications such as pulmonary changes. In conclusion, Neulasta treatment temporarily alleviates proton radiation-induced WBC loss, but has no effect on altered hemostatic responses.

Mechanism of hypocoagulability in proton-irradiated ferrets

PubMed Central

Krigsfeld, Gabriel S.; Savage, Alexandria R.; Sanzari, Jenine K.; Wroe, Andrew J.; Gridley, Daila S.; Kennedy, Ann R.

2014-01-01

Purpose To determine the mechanism of proton radiation-induced coagulopathy. Material and methods Ferrets were exposed to either solar particle event (SPE)-like proton radiation at a predetermined dose rate of 0.5 Gray (Gy) per hour (h) for a total dose of 0 or 1 Gy. Blood was collected pre- and post-irradiation for a complete blood cell count or a soluble fibrin concentration analysis, to determine whether coagulation activation had occurred. Tissue was stained with an anti-fibrinogen antibody to confirm the presence of fibrin in blood vessels. Results SPE-like proton radiation exposure resulted in coagulation cascade activation, as determined by increased soluble fibrin concentration in blood from 0.7 – 2.4 at 3 h, and 9.9 soluble fibrin units (p < 0.05) at 24 h post-irradiation and fibrin clots in blood vessels of livers, lungs and kidneys from irradiated ferrets. In combination with this increase in fibrin clots, ferrets had increased prothrombin time and partial thromboplastin time values post-irradiation, which are representative of the extrinsic/intrinsic coagulation pathways. Platelet counts remained at pre-irradiation values over the course of 7 days, indicating that the observed effects were not platelet-related, but instead likely to be due to radiation-induced effects on secondary hemostasis. White blood cell (WBC) counts were reduced in a statistically significant manner from 24 h through the course of the seven-day experiment. Conclusions SPE-like proton radiation results in significant decreases in all WBC counts as well as activates secondary hemostasis; together, these data suggest severe risks to astronaut health from exposure to SPE radiation. PMID:23651328

Effects of HZE irradiation on chemical neurotransmission in rodent hippocampus

NASA Astrophysics Data System (ADS)

Machida, Mayumi

Space radiation represents a significant risk to the CNS (central nervous system) during space missions. Most harmful are the HZE (high mass, highly charged (Z), high energy) particles, e.g. 56Fe, which possess high ionizing ability, dense energy deposition pattern, and high penetrance. Accumulating evidence suggests that radiation has significant impact on cognitive functions. In ground-base experiments, HZE radiation induces pronounced deficits in hippocampus dependent learning and memory in rodents. However, the mechanisms underlying these impairments are mostly unknown. Exposure to HZE radiation elevates the level of oxidation, resulting in cell loss, tissue damage and functional deficits through direct ionization and generation of reactive oxygen species (ROS). When hippocampal slices were exposed to ROS, neuronal excitability was reduced. My preliminary results showed enhanced radio-vulnerability of the hippocampus and reduction in basal and depolarization-evoked [3H]-norepinephrine release after HZE exposure. These results raised the possibility that HZE radiation deteriorates cognitive function through radiation-induced impairments in hippocampal chemical neurotransmission, the hypothesis of this dissertation. In Aim 1 I have focused on the effects of HZE radiation on release of major neurotransmitter systems in the hippocampus. I have further extended my research on the levels of receptors of these systems in Aim 2. In Aim 3, I have studied the level of oxidation in membranes of my samples. My research reveals that HZE radiation significantly reduces hyperosmotic sucrose evoked [3H]-glutamate and [14C]-GABA release both three and six months post irradiation. The same radiation regimen also significantly enhances oxidative stress as indicated by increased levels of lipid peroxidation in the hippocampus, suggesting that increased levels of lipid peroxidation may play a role in reduction of neurotransmitter release. HZE radiation also significantly reduces

Effect of irradiation of frozen meat/fat trimmings on microbiological and physicochemical quality attributes of dry fermented sausages.

PubMed

Chouliara, I; Samelis, J; Kakouri, A; Badeka, A; Savvaidis, I N; Riganakos, K; Kontominas, M G

2006-10-01

Changes in microbiological and physicochemical quality attributes resulting from the use of irradiation in the production of Greek dry fermented sausage were investigated as a function of fermentation/ripening time. Results showed that irradiating meat/fat trimmings at 2 or 4kGy prior to sausage production eliminated natural contamination with Listeria spp., and reduced pseudomonads, enterococci and pathogenic staphylococci, and enterobacteria, to less than 2 and 1logcfug(-1), respectively. Pseudomonads were very sensitive (>3.4 log reduction) to either radiation dose. Yeasts were the most resistant followed by inherent lactic acid bacteria; their reductions on the trimmings were radiation dose-dependent. Residual effects of irradiation were noted against enterococci, but not against gram-negatives which died off fast during fermentation even in non-irradiated samples. Growth of the starter bacteria, Lactobacillus pentosus and Staphylococcus carnosus, inoculated in the sausage batters post-irradiation was unaffected by the 2 or 4kGy pre-treatment of the trimmings. Irradiation had little or no effect at the end of ripening period (28 days) on pH, moisture content and color (parameters L(∗), a(∗), and b(∗)). Changes in TBA values were small but statistically significant with irradiated samples having higher TBA values than control samples.

ATF Neutron Irradiation Program Irradiation Vehicle Design Concepts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geringer, J. W.; Katoh, Yutai; Howard, Richard H.

The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post irradiation examination and characterizationmore » of irradiated materials and the shipment of irradiated materials to Japan. This report discusses the conceptual design, the development and irradiation of the test vehicles.« less

The effect of low-level laser irradiation (In-Ga-Al-AsP - 660 nm) on melanoma in vitro and in vivo

PubMed Central

2009-01-01

Background It has been speculated that the biostimulatory effect of Low Level Laser Therapy could cause undesirable enhancement of tumor growth in neoplastic diseases. The aim of the present study is to analyze the behavior of melanoma cells (B16F10) in vitro and the in vivo development of melanoma in mice after laser irradiation. Methods We performed a controlled in vitro study on B16F10 melanoma cells to investigate cell viability and cell cycle changes by the Tripan Blue, MTT and cell quest histogram tests at 24, 48 and 72 h post irradiation. The in vivo mouse model (male Balb C, n = 21) of melanoma was used to analyze tumor volume and histological characteristics. Laser irradiation was performed three times (once a day for three consecutive days) with a 660 nm 50 mW CW laser, beam spot size 2 mm2, irradiance 2.5 W/cm2 and irradiation times of 60s (dose 150 J/cm2) and 420s (dose 1050 J/cm2) respectively. Results There were no statistically significant differences between the in vitro groups, except for an increase in the hypodiploid melanoma cells (8.48 ± 1.40% and 4.26 ± 0.60%) at 72 h post-irradiation. This cancer-protective effect was not reproduced in the in vivo experiment where outcome measures for the 150 J/cm2 dose group were not significantly different from controls. For the 1050 J/cm2 dose group, there were significant increases in tumor volume, blood vessels and cell abnormalities compared to the other groups. Conclusion LLLT Irradiation should be avoided over melanomas as the combination of high irradiance (2.5 W/cm2) and high dose (1050 J/cm2) significantly increases melanoma tumor growth in vivo. PMID:19930543

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Richard W., E-mail: rich.wilson.smith@gmail.com; Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario; Seymour, Colin B.

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48 h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyedmore » eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. - Highlights: • We evaluated the transgenerational effect of early life irradiation in rainbow trout. • Trout irradiated as eggs, yolk sac larvae or first feeders were crossed. • A transgenerational effect was evident in two generations after irradiation. • F1 and F2 generation fish induced a bystander effect in non-irradiated fish. • The precise effects were tissue specific and dependent

Potential Beneficial Effects of Si-Wu-Tang on White Blood Cell Numbers and the Gastrointestinal Tract of γ-Ray Irradiated Mice

PubMed Central

Ni, Jin; Romero-Weaver, Ana L.; Kennedy, Ann R.

2014-01-01

Si-Wu-Tang (SWT) is a decoction consisting of a mixture of ingredients of Rehmanniae Radix, Angelica Radix, Chuanxiong Rhizoma and Paeoniae Radix. As a traditional Chinese herbal decoction, SWT has been widely used for the treatment of diseases characterized as blood and/or energy deficit. The present study was performed to evaluate the effects of SWT on the different populations of circulating white blood cells (WBCs) and gastrointestinal changes in γ-ray irradiated mice. Female mice were treated daily with orally administered SWT seven days before irradiation, until one day before irradiation or until one day before sample collection. WBC counts were determined from peripheral blood samples taken from the mice at different times post-irradiation. Hematoxylin and eosin (H&E) staining, as well as immunohistochemical analysis of fibrinogen, were utilized to evaluate the effects of SWT in the intestines of mice after radiation exposure. The results of the present studies demonstrate that SWT has protective effects against radiation damage to circulating WBCs, specifically to lymphocytes, and to the gastrointestinal tract of the irradiated animals. PMID:25324699

Evidence relevant to untargeted and transgenerational effects in the offspring of irradiated parents

PubMed Central

Little, Mark P.; Goodhead, Dudley T.; Bridges, Bryn A.; Bouffler, Simon D.

2013-01-01

In this article we review health effects in offspring of human populations exposed as a result of radiotherapy and some groups exposed to chemotherapy. We also assess risks in offspring of other radiation-exposed groups, in particular those of the Japanese atomic bomb survivors and occupationally and environmentally exposed groups. Experimental findings are also briefly surveyed. Animal and cellular studies tend to suggest that the irradiation of males, at least at high doses (mostly 1 Gy and above), can lead to observable effects (including both genetic and epigenetic) in the somatic cells of their offspring over several generations that are not attributable to the inheritance of a simple mutation through the parental germ line. However, studies of disease in the offspring of irradiated humans have not identified any effects on health. The available evidence therefore suggests that human health has not been significantly affected by transgenerational effects of radiation. It is possible that transgenerational effects are restricted to relatively short times post-exposure and in humans conception at short times after exposure is likely to be rare. Further research that may help resolve the apparent discrepancies between cellular/animal studies and studies of human health are outlined. PMID:23648355

Neutron irradiation effects on plasma facing materials

NASA Astrophysics Data System (ADS)

Barabash, V.; Federici, G.; Rödig, M.; Snead, L. L.; Wu, C. H.

2000-12-01

This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.

Effect of X-ray irradiation on the optical absorption of СdSe1-xTex nanocrystals embedded in borosilicate glass

NASA Astrophysics Data System (ADS)

Prymak, M. V.; Azhniuk, Yu. M.; Solomon, A. M.; Krasilinets, V. M.; Lopushansky, V. V.; Bodnar, I. V.; Gomonnai, A. V.; Zahn, D. R. T.

2012-07-01

The effect of X-ray irradiation on the optical absorption spectra of CdSe1-xTex nanocrystals embedded in a borosilicate matrix is studied. The observed blue shift of the absorption edge and bleaching of the confinement-related features in the spectra are related to X-ray induced negative ionization of the nanocrystals with charge transfer across the nanocrystal/matrix interface. The radiation-induced changes are observed to recover after longer post-irradiation storage at room temperature.

Activation of adenosine A(3) receptors supports hematopoiesis-stimulating effects of granulocyte colony-stimulating factor in sublethally irradiated mice.

PubMed

Hofer, Michal; Pospísil, Milan; Sefc, Ludek; Dusek, Ladislav; Vacek, Antonín; Holá, Jirina; Hoferová, Zuzana; Streitová, Denisa

2010-08-01

Research areas of 'post-exposure treatment' and 'cytokines and growth factors' have top priority among studies aimed at radiological nuclear threat countermeasures. The experiments were aimed at testing the ability of N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA), an adenosine A(3) receptor agonist, to modulate hematopoiesis in sublethally irradiated mice, when administered alone or in a combination with granulocyte colony-stimulating factor (G-CSF) in a two-day post-irradiation treatment regimen. A complete analysis of hematopoiesis including determination of numbers of bone marrow hematopoietic progenitor and precursor cells, as well as of numbers of peripheral blood cells, was performed. The outcomes of the treatment were assessed at days 3 to 22 after irradiation. IB-MECA alone has been found to induce a significant elevation of numbers of bone marrow granulocyte-macrophage progenitor cells (GM-CFC) and peripheral blood neutrophils. IB-MECA given concomitantly with G-CSF increased significantly bone marrow GM-CFC and erythroid progenitor cells (BFU-E) in comparison with the controls and with animals administered each of the drugs alone. The findings suggest the ability of IB-MECA to stimulate hematopoiesis and to support the hematopoiesis-stimulating effects of G-CSF in sublethally irradiated mice.

Anti-inflammatory effect of 635 nm irradiations on in vitro direct/indirect irradiation model.

PubMed

Lim, WonBong; Choi, Hongran; Kim, Jisun; Kim, Sangwoo; Jeon, SangMi; Zheng, Hui; Kim, DoMan; Ko, Youngjong; Kim, Donghwi; Sohn, HongMoon; Kim, OkJoon

2015-02-01

Low-level laser therapy (LLLT) has been promoted for its beneficial effects on tissue healing and pain relief. As during laser treatment it is possible to irradiate only a small area of the surface body or wound and, correspondingly, of a very small volume of the circulating blood, it is necessary to explain how its photomodification can lead to a wide spectrum of therapeutic effects. To establish the experimental model for indirect irradiation, irradiation with 635 nm was performed on immortalized human gingival fibroblasts (IGFs) in the presence of Porphyromonas gingivalis lipopolysaccharides (LPS). The irradiated medium was transferred to non-irradiated IGFs which were compared with direct irradiated IGFs. The protein expressions were assessed by Western blot, and prostaglandin E2 (PGE2 ) was measured using an enzyme-linked immunoassay. Reactive oxygen species (ROS) were measured by DCF-DA; cytokine profiles were assessed using a human inflammation antibody array. Cyclooxygenase-2 (COX-2) protein expression and PGE2 production were significantly increased in the LPS-treated group and decreased in both direct and indirect irradiated IGFs. Unlike direct irradiated IGFs, ROS level in indirect irradiated IGFs was decreased by time-dependent manners. There were significant differences of released granulocyte colony-stimulating factor (G-CSF), regulated on activated normal T-cell expressed and secreted (RANTES), and I-TAC level observed compared with direct and indirect irradiated IGFs. In addition, in the indirect irradiation group, phosphorylations of C-Raf and Erk1/2 increased significantly compared with the direct irradiation group. Thus, we suggest that not only direct exposure with 635 nm light, but also indirect exposure with 635 nm light can inhibit activation of pro-inflammatory mediators and may be clinically useful as an anti-inflammatory tool. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of Microwave Irradiation on Embryonic Brain Tissue.

DTIC Science & Technology

1979-03-01

less than 1 hour) post partum in the experiment described in Section III, page 13. Table 2 The significance of the difference in weight of the irradiated...appeared normal. Two of the control and two of the exposed rats showed small depressions of the external surface of the hemisphere unilaterally with...some thinning of the underlying cortex. The depressions occurred, one just dorsal to the rhinal fissure and the other lateral to the longitudinal sulcus

Positron irradiation effect on positronium formation in gamma-irradiated LDPE and unplasticized PVC

NASA Astrophysics Data System (ADS)

Yang, J.; Zang, P.; Cao, X. Z.; Yu, R. S.; Wang, B. Y.

2017-06-01

Positron irradiation effects on positronium formation in low-density polyethylene (LDPE), gamma-irradiated LDPE and unplasticized PVC (UPVC) are studied. At least in one of the three different measurements, i.e., prolonged positron annihilation measurement at room temperature, low temperature in darkness and subsequent measurement under light, changes in o-Ps intensity are observed in non-irradiated LDPE and gamma-irradiated LDPE. While in UPVC, change in o-Ps intensity is hardly observable in all the above-mentioned three measurements. Reduction of o-Ps intensity by light indicates that positronium formation via the recombination of a positron and a trapped electron exists in LDPE and gamma-irradiated LDPE. The absence of light bleaching effect, together with the fact that the value of o-Ps intensity in heating and cooling process of a thermal circle is nearly the same, indicates that in UPVC, positronium can not be formed through trapped electron mechanism. This study highlights the speciality of positronium formation in UPVC, positronium is formed exclusively by the recombination of electron-positron pairs with short separations.

TECHNOLOGICAL EFFECTS OF GAMMA IRRADIATION OF WHEAT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milner, M.

Extensive literature appearing in the past six years suggests that few if any useful modifications of wheat and flour are produced by gamma irradiation. Deinfestation by treatments of 25,000 to 50,000 rep was proposed, but more information is needed about possible deleterious effects. Fungi, the cause of deterioration of damp grain, can be eliminated by irradiation levels around 250,000 rep, but damage to germination, starch, and protein, as well as darkening due to non-enzymatic browning, question the practicality of such treatment for improving storage properties. A decrease in power consumption in milling occurs, probably related to radiation-splitting of starch, whichmore » also involves decrease in dextrin chain length and gelatinization viscosity, as well as increases in maltose value. An increase in the soluble pentosans and loss of their gelling characteristic when treated with oxidizing agents is also observed, paralleling the appearance of major deterioration in breadmaking quality and loss of bromate response. Reduction of grain viability with irradiation is not paralleled by a corresponding drop in formazan production from TTC, due apparently to the formation of browning products, reducing in character (reductones), at high radiation levels. Evidence concerning the effects of irradiation on dough and breadmaking properties is conflicting but the improvement claimed in weak wheats can be explained on the basis of a stimulation in gas production during dough fermentation due to increase in starch degradation products; probably it does not involve beneficial modification of the gluten. Thus, when irradiated flours are baked with optimum quantities of sugar, amylase supplements and oxidizing agents, no improving effect due to irradiation is observed and the damage to bread properties is progressive; it is reversible in terms of loaf volume but not crumb grain by treatment with potassium bromate, but only at moderate irradiation levels. Reduction of dough

Evolution of Helium Bubbles and Discs in Irradiated 6H-SiC during Post-Implantation Annealing.

PubMed

Shen, Qiang; Zhou, Wei; Ran, Guang; Li, Ruixiang; Feng, Qijie; Li, Ning

2017-01-24

The single crystal 6H-SiC with [0001] crystal direction irradiated by 400 keV He⁺ ions with 1 × 10 17 ions/cm² fluence at 400 °C were annealed at 600, 900, 1200 and 1400 °C for different durations. The evolution of helium bubbles and discs was investigated by transmission electron microscopy. An irradiated layer distributed with fine helium bubbles was formed with a width of ~170 nm after helium ion irradiation. The size of gas bubbles increased with increasing annealing time and temperature and finally reached stable values at a given annealing temperature. According to the relationship between the bubble radii and annealing time, an empirical formula for calculating the bubble radii at the annealing temperature ranged from 600 to 1400 °C was given by fitting the experiment data. Planar bubble clusters (discs) were found to form on (0001) crystal plane at both sides of the bubble layer when the annealing temperature was at the range of 800-1200 °C. The mechanism of bubble growth during post-implantation annealing and the formation of bubble discs were also analyzed and discussed.

Development of a short-term irradiance prediction system using post-processing tools on WRF-ARW meteorological forecasts in Spain

NASA Astrophysics Data System (ADS)

Rincón, A.; Jorba, O.; Baldasano, J. M.

2010-09-01

The increased contribution of solar energy in power generation sources requires an accurate estimation of surface solar irradiance conditioned by geographical, temporal and meteorological conditions. The knowledge of the variability of these factors is essential to estimate the expected energy production and therefore help stabilizing the electricity grid and increase the reliability of available solar energy. The use of numerical meteorological models in combination with statistical post-processing tools may have the potential to satisfy the requirements for short-term forecasting of solar irradiance for up to several days ahead and its application in solar devices. In this contribution, we present an assessment of a short-term irradiance prediction system based on the WRF-ARW mesoscale meteorological model (Skamarock et al., 2005) and several post-processing tools in order to improve the overall skills of the system in an annual simulation of the year 2004 in Spain. The WRF-ARW model is applied with 4 km x 4 km horizontal resolution and 38 vertical layers over the Iberian Peninsula. The hourly model irradiance is evaluated against more than 90 surface stations. The stations are used to assess the temporal and spatial fluctuations and trends of the system evaluating three different post-processes: Model Output Statistics technique (MOS; Glahn and Lowry, 1972), Recursive statistical method (REC; Boi, 2004) and Kalman Filter Predictor (KFP, Bozic, 1994; Roeger et al., 2003). A first evaluation of the system without post-processing tools shows an overestimation of the surface irradiance, due to the lack of atmospheric absorbers attenuation different than clouds not included in the meteorological model. This produces an annual BIAS of 16 W m-2 h-1, annual RMSE of 106 W m-2 h-1 and annual NMAE of 42%. The largest errors are observed in spring and summer, reaching RMSE of 350 W m-2 h-1. Results using Kalman Filter Predictor show a reduction of 8% of RMSE, 83% of BIAS

Protective effects of sodium selenite supplementation against irradiation-induced damage in non-cancerous human esophageal cells.

PubMed

Puspitasari, Irma M; Yamazaki, Chiho; Abdulah, Rizky; Putri, Mirasari; Kameo, Satomi; Nakano, Takashi; Koyama, Hiroshi

2017-01-01

The administration of radioprotective compounds is one approach to preventing radiation damage in non-cancerous tissues. Therefore, radioprotective compounds are crucial in clinical radiotherapy. Selenium is a radioprotective compound that has been used in previous clinical studies of radiotherapy. However, evidence regarding the effectiveness of selenium in radiotherapy and the mechanisms underlying the selenium-induced reduction of the side effects of radiotherapy remains insufficient. To further investigate the effectiveness of selenium in radiotherapy, the present study examined the protective effects of sodium selenite supplementation administered prior to X-ray radiation treatment in CHEK-1 non-cancerous human esophageal cells. Sodium selenite supplementation increased glutathione peroxidase 1 (GPx-1) activity in a dose- and time-dependent manner. The sodium selenite dose that induced the highest GPx-1 activity was determined to be 50 nM for 72 h prior to radiotherapy. The half-maximal inhibitory concentration of sodium selenite in CHEK-1 cells was 3.6 µM. Sodium selenite supplementation increased the survival rate of the cells in a dose-dependent manner and enhanced the degree of cell viability at 72 h post-irradiation (P<0.05). Combined treatment with 50 nM sodium selenite and 2 gray (Gy) X-ray irradiation decreased the number of sub-G 1 cells from 5.9 to 4.2% (P<0.05) and increased the proportion of G 1 cells from 58.8 to 62.1%, compared with 2 Gy X-ray irradiation alone; however, this difference was not statistically significant (P=1.00). Western blot analysis revealed that treatment with 2 Gy X-ray irradiation significantly increased the expression levels of cleaved poly (ADP-ribose) polymerase (PARP; P<0.05). In addition, combined treatment with 50 nM sodium selenite and 2 Gy X-ray irradiation reduced the expression levels of cleaved PARP protein, compared with 2 Gy X-ray irradiation alone; however, this reduction was not statistically significant (P=0

Disruption of the blood-brain barrier as the primary effect of CNS irradiation.

PubMed

Rubin, P; Gash, D M; Hansen, J T; Nelson, D F; Williams, J P

1994-04-01

The blood-brain barrier (BBB) is believed to be unique in organ microcirculation due to the 'tight junctions' which exist between endothelial cells and, some argue, the additional functional components represented by the perivascular boundary of neuroglial cells; these selectively exclude proteins and drugs from the brain parenchyma. This study was designed to examine the effects of irradiation on the BBB and determine the impact of the altered pathophysiology on the production of central nervous system (CNS) late effects such as demyelination, gliosis and necrosis. Rats, irradiated at 60 Gy, were serially sacrificed at 2, 6, 12 and 24 weeks. Magnetic resonance image analysis (MRI) was obtained prior to sacrifice with selected animals from each group. The remaining animals underwent horse-radish peroxidase (HRP) perfusion at the time of sacrifice. The serial studies showed a detectable disruption of the BBB at 2 weeks post-irradiation and this was manifested as discrete leakage; late injury seen at 24 weeks indicated diffuse vasculature leakage, severe loss of the capillary network, cortical atrophy and white matter necrosis. Reversal or repair of radiation injury was seen between 6 and 12 weeks, indicating a bimodal peak in events. Blood-brain barrier disruption is an early, readily recognizable pathophysiological event occurring after radiation injury, is detectable in vivo/in vitro by MRI and HRP studies, and appears to precede white matter necrosis. Dose response studies over a wide range of doses, utilizing both external and interstitial irradiation, are in progress along with correlative histopathologic and ultrastructural studies.

Functional modifications of macrophage activity after sublethal irradiation. [Toxoplasma gondii

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swartz, R.P.

1982-01-01

The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytesmore » exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin.« less

UVA Irradiation of Dysplastic Keratinocytes: Oxidative Damage versus Antioxidant Defense

PubMed Central

Nechifor, Marina T.; Niculiţe, Cristina M.; Urs, Andreea O.; Regalia, Teodor; Mocanu, Mihaela; Popescu, Alexandra; Manda, Gina; Dinu, Diana; Leabu, Mircea

2012-01-01

UVA affects epidermal cell physiology in a complex manner, but the harmful effects have been studied mainly in terms of DNA damage, mutagenesis and carcinogenesis. We investigated UVA effects on membrane integrity and antioxidant defense of dysplastic keratinocytes after one and two hours of irradiation, both immediately after exposure, and 24 h post-irradiation. To determine the UVA oxidative stress on cell membrane, lipid peroxidation was correlated with changes in fatty acid levels. Membrane permeability and integrity were assessed by propidium iodide staining and lactate dehydrogenase release. The effects on keratinocyte antioxidant protection were investigated in terms of catalase activity and expression. Lipid peroxidation increased in an exposure time-dependent manner. UVA exposure decreased the level of polyunsaturated fatty acids, which gradually returned to its initial value. Lactate dehydrogenase release showed a dramatic loss in membrane integrity after 2 h minimum of exposure. The cell ability to restore membrane permeability was noted at 24 h post-irradiation (for one hour exposure). Catalase activity decreased in an exposure time-dependent manner. UVA-irradiated dysplastic keratinocytes developed mechanisms leading to cell protection and survival, following a non-lethal exposure. The surviving cells gained an increased resistance to apoptosis, suggesting that their pre-malignant status harbors an abnormal ability to control their fate. PMID:23222638

5 MeV Proton irradiation effects on 200 GHz silicon-germanium heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Gnana Prakash, A. P.; Hegde, Vinayakprasanna N.; Pradeep, T. M.; Pushpa, N.; Bajpai, P. K.; Patel, S. P.; Trivedi, Tarkeshwar; Cressler, J. D.

2017-12-01

The total dose effects of 5 MeV proton and Co-60 gamma irradiation in the dose range from 1 to 100 Mrad on advanced 200 GHz Silicon-Germanium heterojunction bipolar transistors (SiGe HBTs) are investigated. The SRIM simulation study was conducted to understand the energy loss of 5 MeV proton ions in SiGe HBT structure. Pre- and post-radiation DC figure of merits such as forward- and inverse-mode Gummel characteristics, excess base current, DC current gain and output characteristics were used to quantify the radiation tolerance of the devices. The results show that the proton creates a significant amount of damages in the surface and bulk of the transistor when compared with gamma irradiation. The SiGe HBTs shows robust ionizing radiation tolerance even up to a total dose of 100 Mrad for both radiations.

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish.

PubMed

Smith, Richard W; Seymour, Colin B; Moccia, Richard D; Mothersill, Carmel E

2016-02-01

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyed eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. Copyright © 2015 Elsevier Inc. All rights reserved.

Dose and dose rate effects of whole-body proton irradiation on leukocyte populations and lymphoid organs: part I

NASA Technical Reports Server (NTRS)

Gridley, Daila S.; Pecaut, Michael J.; Dutta-Roy, Radha; Nelson, Gregory A.

2002-01-01

The goal of part I of this study was to evaluate the effects of whole-body proton irradiation on lymphoid organs and specific leukocyte populations. C57BL/6 mice were exposed to the entry region of the proton Bragg curve to total doses of 0.5 gray (Gy), 1.5 Gy, and 3.0 Gy, each delivered at a low dose rate (LDR) of 1 cGy/min and high dose rate (HDR) of 80 cGy/min. Non-irradiated and 3 Gy HDR gamma-irradiated groups were included as controls. At 4 days post-irradiation, highly significant radiation dose-dependent reductions were observed in the mass of both lymphoid organs and the numbers of leukocytes and T (CD3(+)), T helper (CD3(+)/CD4(+)), T cytotoxic (CD3(+)/CD8(+)), and B (CD19(+)) cells in both blood and spleen. A less pronounced dose effect was noted for natural killer (NK1.1(+) NK) cells in spleen. Monocyte, but not granulocyte, counts in blood were highly dose-dependent. The numbers for each population generally tended to be lower with HDR than with LDR radiation; a significant dose rate effect was found in the percentages of T and B cells, monocytes, and granulocytes and in CD4(+):CD8(+) ratios. These data indicate that mononuclear cell response to the entry region of the proton Bragg curve is highly dependent upon the total dose and that dose rate effects are evident with some cell types. Results from gamma- and proton-irradiated groups (both at 3 Gy HDR) were similar, although proton-irradiation gave consistently lower values in some measurements.

Effect of gamma-irradiation on degradation of alginate.

PubMed

Lee, Dong Wook; Choi, Won Seok; Byun, Myung Woo; Park, Hyun Jin; Yu, Yong-Man; Lee, Chong M

2003-07-30

The aqueous solution of alginate was irradiated by 60Co gamma-rays in the dose range of 10-500 kGy. To assess the effect of irradiation on the degradation of alginate, the irradiation-induced changes in the viscosity, molecular weight, color, monomer composition, and sequence were measured. The molecular weight of raw alginate was reduced from 300000 to 25000 when irradiated at 100 kGy. The degradation rate decreased and the chain breaks per molecule increased with increasing irradiation dose. The viscosity of irradiated alginate solution reached a near minimum as low as at 10 kGy. No appreciable color changes were observed in the samples irradiated at up to 100 kGy, but intense browning occurred beyond 200 kGy. The 13C NMR spectra showed that homopolymeric blocks, MM and GG, increased and the M/G ratio decreased with irradiation. Considering both the level of degradation and the color change of alginate, the optimum irradiation dose was found to be 100 kGy.

Evaluating the irradiation effects on the elastic properties of miniature monolithic SiC tubular specimens

NASA Astrophysics Data System (ADS)

Singh, G.; Koyanagi, T.; Petrie, C.; Terrani, K.; Katoh, Y.

2018-02-01

The initial results of a post-irradiation examination study conducted on CVD SiC tubular specimens irradiated under a high radial heat flux are presented herein. The elastic moduli were found to decrease more than that estimated based on previous studies. The significant decreases in modulus are attributed to the cracks present in the specimens. The stresses in the specimens, calculated through finite element analyses, were found to be greater than the expected strength of irradiated specimens, indicating that the irradiation-induced stresses caused these cracks. The optical microscopy images and predicted stress distributions indicate that the cracks initiated at the inner surface and propagated outward.

Irradiation response of commercial, high-Tc superconducting tapes: Electromagnetic transport properties

DOE PAGES

Gapud, A. A.; Greenwood, N. T.; Alexander, J. A.; ...

2015-07-01

Effects of low dose irradiation on the electrical transport current properties of commercially available high-temperature superconducting, coated-conductor tapes were investigated, in view of potential applications in the irradiative environment of fusion reactors. Three different tapes, each with unique as-grown flux-pinning structures, were irradiated with Au and Ni ions at energies that provide a range of damage effects, with accumulated damage levels near that expected for conductors in a fusion reactor environment. Measurements using transport current determined the pre- and post-irradiation resistivity, critical current density, and pinning force density, yielding critical temperatures, irreversibility lines, and inferred vortex creep rates. Results showmore » that at the irradiation damage levels tested, any detriment to as-grown pre-irradiation properties is modest; indeed in one case already-superior pinning forces are enhanced, leading to higher critical currents.« less

[Effect of electromagnetic pulse irradiation on mice reproduction].

PubMed

Wang, Shui-ming; Wang, De-wen; Peng, Rui-yun; Chen, Hao-yu; Gao, Ya-bing; Cao, Xiao-zhe; Cui, Xue-mei; Zhao, Mei-lan

2003-10-01

To evaluate the effect of electromagnetic pulse (EMP) irradiation on mice reproduction. Female/male Kunming mice, 6 - 8 weeks old, prior to mating, or female after pregnancy were treated with whole body irradiation by 6 x 10(4) V/m electromagnetic pulse (EMP) for five times. The pregnant mice were killed on the 18th days, and teratological markers were analysed. EMP irradiation caused no significant changes in most of female organ weight and organ/body weight ratio. But it caused significant shortening in tail length of live foetus in the female mice before conception (prior to mating) or after pregnancy (P < 0.05), and obvious decrease in male offspring ratio (0.85 +/- 0.09 vs 1.09 +/- 0.17, P < 0.05). The male offspring ratio also significantly decreased (0.76 +/- 0.18 vs 1.09 +/- 0.17, P < 0.01) after male mice irradiated by EMP. The tail length of live foetus was shortened and male offspring sex ratio was increased after both male and female mice were irradiated by EMP. EMP irradiation also caused a significantly higher fetal death rate than normal control (P < 0.05). The embryo absorption rate was increased after irradiation except that was decreased in male mice. EMP irradiation has effect on pregnancy and offspring development in both male and female mice before mating and in female mice after pregnancy.

Horizontal and sun-normal spectral biologically effective ultraviolet irradiances.

PubMed

Parisi, A V; Kimlin, M G

1999-01-01

The dependence of the spectral biologically effective solar UV irradiance on the orientation of the receiver with respect to the sun has been determined for relatively cloud-free days at a sub-tropical Southern Hemisphere latitude for the solar zenith angle range 35-64 degrees. For the UV and biologically effective irradiances, the sun-normal to horizontal ratio for the total UV ranges from 1.18 +/- 0.05 to 1.27 +/- 0.06. The sun-normal to horizontal ratio for biologically effective irradiance is dependent on the relative effectiveness of the relevant action spectrum in the UV-A waveband. In contrast to the total UV, the diffuse UV and diffuse biologically effective irradiances are reduced in a sun-normal compared with a horizontal orientation by a factor ranging from 0.70 +/- 0.05 to 0.76 +/- 0.03.

Effect of tocopherol-monoglucoside (TMG), a water-soluble glycosylated derivate of vitamin E, on hematopoietic recovery in irradiated mice.

PubMed

Cherdyntseva, Nadezda; Shishkina, Anna; Butorin, Ivan; Murase, Hironobu; Gervas, Polina; Kagiya, Tsutomu V

2005-03-01

A preparation of alpha-tocopherol monoglucoside (TMG) administered i.p. at a dose of 600 mg/kg immediately after whole body gamma irradiation was examined for its radioprotective efficacy towards bone marrow and peripheral blood nucleated cells. When mice received X-rays at a dose of 5,6 Gy, a marked decrease in bone marrow karyocytes and a reduction of peripheral leukocytes within the early post-irradiated period were observed. However these changes were attenuated in TMG-treated mice. Significant protection of blood lymphocytes was found for the TMG group of mice. The return to normal value of the reduced blood leukocyte count starting from the 8th day was more rapid in TMG-treated mice than in untreated irradiated mice. TMG administration was found to enhance hematopoietic recovery, as measured by the exceeded nucleated bone marrow cell count due to elevated amount of both lymphoid and granulocytic elements in the TMG-group, in comparison with that of both control irradiated and non-irradiated animals. These findings indicate that the radioprotective effect of TMG is apparently realized through its influence on hematopoietic system.

Effects of gamma irradiation on the radiation-resistant bacteria and polyphenol oxidase activity in fresh kale juice

NASA Astrophysics Data System (ADS)

Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Yun, Hyejeong; Chung, Jinwoo

2007-07-01

Gamma radiation was performed to prolong the shelf life of natural kale juice. The total aerobic bacteria in fresh kale juice, prepared by a general kitchen process, was detected in the range of 10 6 cfu/ml, and about 10 2 cfu/ml of the bacteria survived in the juice in spite of gamma irradiation treatment with a dose of 5 kGy. Two typical radiation-resistant bacteria, Bacillus megaterium and Exiguobacterium acetylicum were isolated and identified from the 5 kGy-irradiated kale juices. The D10 values of the vegetative cell and endospore of the B. megaterium in peptone water were 0.63±0.05 and 1.52±0.05 kGy, respectively. The D10 value of the E. acetylicum was calculated as 0.65±0.06 kGy. In the inoculation test, the growth of the surviving B. megaterium and E. acetylicum in the 3-5 kGy-irradiated kale juice retarded and/or decreased significantly during a 3 d post-irradiation storage period. However, there were no significant differences in the residual polyphenol oxidase activity and browning index between the nonirradiated control and the gamma irradiated kale juice during a post-irradiation period.

Radiographic findings after treatment with balloon brachytherapy accelerated partial breast irradiation.

PubMed

Ibrahim, Nafisa B; Anandan, Srividya; Hartman, Audrey L; McSweeney, Michelle; Chun, Jeanette; McKee, Andrea; Yang, Rebecca; Kim, Cathleen

2015-01-01

The use of accelerated partial breast irradiation (APBI) following breast-conserving surgery is rapidly gaining popularity as an alternative to whole-breast irradiation (WBI) in selected patients with early-stage breast cancer. Although data on the long-term effectiveness and safety of APBI accelerated partial breast irradiation are still being gathered, the shorter treatment course and narrowed radiation target of APBI accelerated partial breast irradiation provide an attractive alternative for carefully selected patients. These patients include those with relatively small tumors (≤3 cm), negative or close margins, and negative sentinel lymph nodes. Possible long-term complications include telangiectasia and the development of a palpable mass at the lumpectomy site. Mammographic findings in patients who have undergone APBI accelerated partial breast irradiation are distinct from those in patients who have undergone conventional WBI whole-breast irradiation . The most common post-APBI accelerated partial breast irradiation radiographic findings include formation of seromas at the lumpectomy site, focal parenchymal changes such as increased trabeculation and parenchymal distortion, fat necrosis, and skin changes such as thickening or retraction. Given the continued evolution of breast cancer treatment, it is important that radiologists have a comprehensive understanding of APBI accelerated partial breast irradiation in terms of rationale, patient selection criteria, common postprocedural radiographic findings (and how they differ from post-WBI whole-breast irradiation findings), and advantages and potential complications. RSNA, 2015

The effect of 648 nm diode laser irradiation on second messengers in senescent human keratinocytes

NASA Astrophysics Data System (ADS)

Hawkins Evans, D.; Abrahamse, H.

2009-02-01

Background/purpose: Stress induced premature senescence (SIPS) is defined as the long-term effect of subcytotoxic stress on proliferative cell types. Cells in SIPS display differences at the level of protein expression which affect energy metabolism, defense systems, redox potential, cell morphology and transduction pathways. This study aimed to determine the effect of laser irradiation on second messengers in senescent cells and to establish if that effect can be directly linked to changes in cellular function such as cell viability or proliferation. Materials and Methods: Human keratinocyte cell cultures were modified to induce premature senescence using repeated sub-lethal stresses of 200 uM H2O2 or 5% OH every day for four days with two days recovery. SIPS was confirmed by senescence-associated β-galactosidase staining. Control conditions included normal, repeated stress of 500 uM H2O2 to induce apoptosis and 200 uM PBN as an anti-oxidant or free radical scavenger. Cells were irradiated with 1.5 J/cm2 on day 1 and 4 using a 648 nm diode laser (3.3 mW/cm2) and cellular responses were measured 1 h post irradiation. The affect on second messengers was assessed by measuring cAMP, cGMP, nitric oxide and intracellular calcium (Ca2+) while functional changes were assessed using cell morphology, ATP cell viability, LDH membrane integrity and WST-1 cell proliferation. Results: Results indicate an increase in NO and a decrease in cGMP and Ca2+ in 200 uM H2O2 irradiated cells while PBN irradiated cells showed a decrease in cAMP and an increase in ATP viability and cell proliferation. Conclusion: Laser irradiation influences cell signaling which ultimately changes the biological function of senescent cells. If laser therapy can stimulate the biological function of senescent cells it may be beneficial to conditions such as immune senescence, skin ageing, muscle atrophy, premature ageing of arteries in patients with advanced heart disease, neurodegenerative disorders and

Research of epidermal cellular vegetal cycle of intravascular low level laser irradiation in treatment of psoriasis

NASA Astrophysics Data System (ADS)

Zhu, Jing; Bao, Xiaoqing; Zhang, Mei-Jue

2005-07-01

Objective: To research epidermal cellular vegetal cycle and the difference of DNA content between pre and post Intravascular Low Level Laser Irradiation treatment of psoriasis. Method: 15 patients suffered from psoriasis were treated by intravascular low level laser irradiation (output power: 4-5mw, 1 hour per day, a course of treatment is 10 days). We checked the different DNA content of epidermal cell between pre and post treatment of psoriasis and 8 natural human. Then the percentage of each phase among the whole cellular cycle was calculated and the statistical analysis was made. Results: The mean value of G1/S phase is obviously down while G2+M phase increased obviously. T test P<0.05.The related statistical analysis showed significant difference between pre and post treatments. Conclusions: The Intravascular Low Level Laser Irradiation (ILLLI) in treatment of psoriasis is effective according to the research of epidermal cellular vegetal cycle and the difference DNA content of Intravascular Low Level Laser Irradiation between pre and post treatment of psoriasis

Effect of gamma irradiation on Korean traditional multicolored paintwork

NASA Astrophysics Data System (ADS)

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

2015-10-01

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

The Effects of Stellar Irradiation on Gravitational Instabilities in Protoplanetary Disks

NASA Astrophysics Data System (ADS)

Cai, Kai; Durisen, R. H.; Zhu, Z.

2009-01-01

It has been suggested that giant protoplanets form in protoplanetary disks when the disks undergo rapid cooling and fragment into dense Jupiter-mass clumps under the disks' own self-gravity. Previous three-dimensional simulations of protoplanetary disks investigated the effects of envelope irradiation on the development of gravitational instabilities (GIs) in such disks. We found that the irradiation tends to suppress the nonlinear amplitude of GIs and no dense clumps form, arguing against direct formation of giant planets by disk instability in irradiated disks (Cai et al. 2008). In this work, by utilizing an improved radiative cooling scheme in the optically thin regions, we present some preliminary results from simulations with a variable irradiation temperature that mimics the effects of stellar irradiation. Comparisons with results from an envelope-irradiated disk suggest that stellar irradiation may be more effective in suppressing GIs than envelope irradiation.

Radio-Protective Effects of Melatonin on Subventricular Zone in Irradiated Rat: Decrease in Apoptosis and Upregulation of Nestin.

PubMed

Naseri, Shafigheh; Moghahi, Seyed Mohammad Hossein Noori; Mokhtari, Tahmineh; Roghani, Mehrdad; Shirazi, Ali Reza; Malek, Fatemeh; Rastegar, Tayebeh

2017-10-01

Neural stem cells are self-renewing, multipotent cells that can be found in subventricular (SVZ) and subgranular (SGZ) zones of the brain. These zones are susceptible to irradiation-induced apoptosis and oxidative stress. Melatonin (MLT) is a natural protector of neural cells against toxicity. The aim of this study was to evaluate the effects of MLT as a radio-protective material effective in reducing tissue lesions in the SVZ of the brain and changing local apoptotic potential in rats. Twenty-five Gray irradiation was applied on adult rat brain for this study. One hour before irradiation, 100 mg/kg/IP MLT was injected, and 6 h later, the animals were sacrificed. The antioxidant enzymes and MDA activity levels were measured post-sacrifice. Also, the expression level of Nestin and caspase 3 were studied by immunohistochemistry. Spectrophotometric analysis showed significant increases in the amount of malondialdehyde (MDA) levels in the irradiation-exposed (RAD) group compared to that of the control (Co) group (P < 0.05). Pre-treatment with MLT (100 mg/kg) ameliorates the harmful effects of the aforementioned 25 Gy irradiation by increasing antioxidant enzyme activity and decreasing MDA levels. A significant reduction in apoptotic cells was observed in rats treated with MLT 1 h before exposure (P < 0.001). Nestin-positive cells were also reduced in the RAD group (P < 0.001). Our results confirm the anti-apoptotic and antioxidant role of MLT. The MLT concentration used may serve as a threshold for significant protection against 25 Gy gamma irradiations on neural stem cells in SVZ.

New insight into mitochondrial changes in vascular endothelial cells irradiated by gamma ray.

PubMed

Hu, Shunying; Gao, Yajing; Zhou, Hao; Kong, Fanxuan; Xiao, Fengjun; Zhou, Pingkun; Chen, Yundai

2017-05-01

To investigate alterations of mitochondria in irradiated endothelial cells to further elucidate the mechanism underlying radiation-induced heart disease. Experiments were performed using human umbilical vein endothelial cells (HUVECs). HUVECs were irradiated with single gamma ray dose of 0, 5, 10 and 20 Gy, respectively. Apoptosis was assessed by flow cytometry at 24, 48 and 72 h post-irradiation, respectively. The intracellular reactive oxygen species (ROS) was measured with 2',7'-dichlorofluorescein-diacetate (DCFH-DA) at 24 h post-irradiation. Mitochondrial membrane potential (ΔΨm) by JC-1 and the opening of mitochondrial permeability transition pore (mPTP) by a calcein-cobalt quenching method were detected at 24 h post-irradiation in order to measure changes of mitochondria induced by gamma ray irradiation. Gamma ray irradiation increased HUVECs apoptosis in a dose-dependent and time-dependent manner. Irradiation also promoted ROS production in HUVECs in a dose-dependent manner. At 24 h post-irradiation, the results showed that irradiation decreases ΔΨm, however, paradoxically, flow cytometry showed green fluorescence instensity higher in irradiated HUVECs than in control HUVECs in an irradiation dose-dependent manner which indicated gamma ray irradiation inhibited mPTP opening in HUVECs. Gamma ray irradiation induces apoptosis and ROS production of endothelial cells, and decreases ΔΨm meanwhile contradictorily inhibiting the opening of mPTP.

Radioprotective effects of Silymarin on the sperm parameters of NMRI mice irradiated with γ-rays.

PubMed

Fatehi, Daryoush; Mohammadi, Mohsen; Shekarchi, Babak; Shabani, Arash; Seify, Mohammad; Rostamzadeh, Ayoob

2018-01-01

Free radicals and reactive oxygen species (ROS) are generated using various endogenous systems or from external sources such as exposure to different physiochemicals. Ionizing radiation damage to the cell can be caused by the direct or indirect effects of radiotherapy processes. Silymarin (SM), a flavanolignan compound, has been identified as a natural potent antioxidant with cytoprotection activities due to scavenging free radicals. The aim of the present study was to evaluate the radioprotective effect of SM on sperm parameters of mice induced by γ-rays. A total number of 40 adult, male NMRI mice were randomly divided into four equal groups. The control group was neither treated with SM nor irradiated by γ-rays. The second group was only irradiated with 2Gy of γ-rays. The third group was firstly treated with 50mg/kg of SM for 7 consecutive days, and one day later, last injections were irradiated by 2Gy of γ-rays. The fourth groups received only 50mg/kg of SM for 7 consecutive days. All the animals were treated intraperitoneally. Histopathological and morphometrical examinations were performed. The data were analyzed using ANOVA and Tukey post hoc test. A value of p<0.05 was considered significant. The results showed that in the radiation-only group when compared with those treated with SM and irradiated, a significant different was observed in testicular parameters and DNA damage (p<0.05). In conclusion, SM can be considered as a promising herbal radioprotective agent in complementary medicine which may play an important role to protect normal spermatocytes against possible effects of γ-radiation-induced cellular damage. Copyright © 2017 Elsevier B.V. All rights reserved.

Paracrine Effects of Bone Marrow Soup Restore Organ Function, Regeneration, and Repair in Salivary Glands Damaged by Irradiation

PubMed Central

Tran, Simon D.; Liu, Younan; Xia, Dengsheng; Maria, Ola M.; Khalili, Saeed; Wang, Renee Wan-Jou; Quan, Vu-Hung; Hu, Shen; Seuntjens, Jan

2013-01-01

Background There are reports that bone marrow cell (BM) transplants repaired irradiated salivary glands (SGs) and re-established saliva secretion. However, the mechanisms of action behind these reports have not been elucidated. Methods To test if a paracrine mechanism was the main effect behind this reported improvement in salivary organ function, whole BM cells were lysed and its soluble intracellular contents (termed as “BM Soup”) injected into mice with irradiation-injured SGs. The hypothesis was that BM Soup would protect salivary cells, increase tissue neovascularization, function, and regeneration. Two minor aims were also tested a) comparing two routes of delivering BM Soup, intravenous (I.V.) versus intra-glandular injections, and b) comparing the age of the BM Soup’s donors. The treatment-comparison group consisted of irradiated mice receiving injections of living whole BM cells. Control mice received irradiation and injections of saline or sham-irradiation. All mice were followed for 8 weeks post-irradiation. Results BM Soup restored salivary flow rates to normal levels, protected salivary acinar, ductal, myoepithelial, and progenitor cells, increased cell proliferation and blood vessels, and up-regulated expression of tissue remodeling/repair/regenerative genes (MMP2, CyclinD1, BMP7, EGF, NGF). BM Soup was as an efficient therapeutic agent as injections of live BM cells. Both intra-glandular or I.V. injections of BM Soup, and from both young and older mouse donors were as effective in repairing irradiated SGs. The intra-glandular route reduced injection frequency/dosage by four-fold. Conclusion BM Soup, which contains only the cell by-products, can be advantageously used to repair irradiation-damaged SGs rather than transplanting whole live BM cells which carry the risk of differentiating into unwanted/tumorigenic cell types in SGs. PMID:23637870

Paracrine effects of bone marrow soup restore organ function, regeneration, and repair in salivary glands damaged by irradiation.

PubMed

Tran, Simon D; Liu, Younan; Xia, Dengsheng; Maria, Ola M; Khalili, Saeed; Wang, Renee Wan-Jou; Quan, Vu-Hung; Hu, Shen; Seuntjens, Jan

2013-01-01

There are reports that bone marrow cell (BM) transplants repaired irradiated salivary glands (SGs) and re-established saliva secretion. However, the mechanisms of action behind these reports have not been elucidated. To test if a paracrine mechanism was the main effect behind this reported improvement in salivary organ function, whole BM cells were lysed and its soluble intracellular contents (termed as "BM Soup") injected into mice with irradiation-injured SGs. The hypothesis was that BM Soup would protect salivary cells, increase tissue neovascularization, function, and regeneration. Two minor aims were also tested a) comparing two routes of delivering BM Soup, intravenous (I.V.) versus intra-glandular injections, and b) comparing the age of the BM Soup's donors. The treatment-comparison group consisted of irradiated mice receiving injections of living whole BM cells. Control mice received irradiation and injections of saline or sham-irradiation. All mice were followed for 8 weeks post-irradiation. BM Soup restored salivary flow rates to normal levels, protected salivary acinar, ductal, myoepithelial, and progenitor cells, increased cell proliferation and blood vessels, and up-regulated expression of tissue remodeling/repair/regenerative genes (MMP2, CyclinD1, BMP7, EGF, NGF). BM Soup was as an efficient therapeutic agent as injections of live BM cells. Both intra-glandular or I.V. injections of BM Soup, and from both young and older mouse donors were as effective in repairing irradiated SGs. The intra-glandular route reduced injection frequency/dosage by four-fold. BM Soup, which contains only the cell by-products, can be advantageously used to repair irradiation-damaged SGs rather than transplanting whole live BM cells which carry the risk of differentiating into unwanted/tumorigenic cell types in SGs.

Effects of gamma irradiation on deteriorated paper

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

EFFECTS OF CHRONIC IRRADIATION ON EINKORN WHEAT (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsumura, S.; Fujii, T.

1963-01-01

An experiment was carried out with seedlings of einkorn wheat ( Triticum monococcum flavescens), planted at the stage of 3 to 4 foilage leaves on Feb 23rd at several distances from the source and irradiated with varying dose rates and dosages. The plants wer irradiated during their growth and harvested on June 21st. Regular irradiation followed the routine of the gamma field; that is it was applied 20 hr per day starting from April 1st, but before that time, irradiation was occasionally given for mearsurement of dosage or dose rates and checks of the apparatus. Therefore, total irradiation time frommore » planting to harvest amounted to 1843 hours. Total dosages were calculated as 369 r minimum and 4608 r maximum, intensity being 4 to 50 r/20 hr. Survival rate clearly decreased at the highest dosage, while there was no marked difference between the other five irradiated lots and the nonirradiated one. On the other hand, seed fertility was nonlinearly (gradually at higher dosages) decreased with increasing dosage and reached to about one-half of that of the control lot at the highest dosage. For comparison, seedlings of the same kind were irradiated by 0.5 and 1 kr acute gamma rays (1 kr/hr) 16 days after sowing. Survival rate and fertility markedly decreased at 1-kr irradiation. The results were not easily comparable with those of chronic irradiation because acute irradiation was done only in the early seedling stage. Acute 1-kr irradiation showed severe effects and a similar effect was seen at the highest dosage of chronic irradiation (4607 r). Thus, the plants must be more tolerant to higher dosage when radiation intensity is low. (P.C.H.)« less

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

PubMed

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

2017-01-01

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

Electron beam irradiation effects on ethylene-tetrafluoroethylene copolymer films

NASA Astrophysics Data System (ADS)

Nasef, Mohamed Mahmoud; Saidi, Hamdani; Dahlan, Khairul Zaman M.

2003-12-01

The effects of electron beam irradiation on ethylene-tetrafluoroethylene copolymer (ETFE) films were studied. Samples were irradiated in air at room temperature by a universal electron beam accelerator for doses ranging from 100 to 1200 kGy. Irradiated samples were investigated with respect to their chemical structure, thermal characteristics, crystallinity and mechanical properties using FTIR, differential scanning calorimeter (DSC) and universal mechanical tester. The interaction of electron irradiation with ETFE films was found to induce dose-dependent changes in all the investigated properties. A mechanism for electron-induced reactions is proposed to explain the structure-property behaviour of irradiated ETFE films.

Effect of gamma-ray irradiation on the unloaded animal model

NASA Astrophysics Data System (ADS)

Choi, Jong-Il; Yoon, Min-Chul; Sung, Nak-Yoon; Kim, Jae-Hun; Jong Lee, Yun; Lee, Ki-Soo; Choi, In-Ho; Nam, Gung Uk; Lee, Ju-Woon

During the space flight, human beings encountered the extreme conditions such as the cosmic ray irradiation and microgravity. There have been developed the animal models to simulate the microgravity condition in laboratory, but no study was carried out to investigate the combined effect of microgravity and exposure to irradiation. In this study, it was examined the effect of gamma irradiation on the suspension model. Rats were divided into four groups, Group I was loaded and not exposed to gamma irradiation, Group 2 was unloaded and not exposed, Group 3 was loaded and exposed to gamma irradiation at the dose of 50 mSV, and Group 4 was unloaded and exposed to gamma irradiation at the same dose. It was measured body, muscles and tissues weights and the biological analysis and the hematological response in blood samples were conducted. Anti-gravity tissue weight was only changed between loading and un-loading condition. However, there was no difference between irradiation exposed and not exposed unloaded groups. To know the difference of protein expression in anti-gravity tissues, 2 dimensional electrophoresis was performed. It has been found that the expression levels of several proteins were different by unloading condition and by irradiation exposed condition, respectively. These results provided the information on the combined effect of irradiation and microgravity to simulate space flight, and could be useful to search the candidate material for the countermeasure against space environment.

Irradiation-induced effects of proton irradiation on zirconium carbides with different stoichiometries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Y. Huang; B.R. Maier; T.R. Allen

2014-10-01

Zirconium carbide (ZrC) is being considered for utilization in deep burn TRISO fuel particles for hightemperature, gas-cooled reactors. Zirconium carbide has a cubic B1 type crystal structure along with a very high melting point (3420 ?C), exceptional hardness and good thermal and electrical conductivities. Understanding the ZrC irradiation response is crucial for establishing ZrC as an alternative component in TRISO fuel. Until now, very few studies on irradiation effects on ZrC have been released and fundamental aspects of defect evolution and kinetics are not well understood although some atomistic simulations and phenomenological studies have been performed. This work was carriedmore » out to understand the damage evolution in float-zone refined ZrC with different stoichiometries. Proton irradiations at 800 ?C up to doses of 3 dpa were performed on ZrCx (where x ranges from 0.9 to 1.2) to investigate the damage evolution. The irradiation-induced defects, such as density of dislocation loops, at different stoichiometries and doses which were characterized by transmission electron microscopy (TEM) is presented and discussed.« less

DNA microarray analyses reveal a post-irradiation differential time-dependent gene expression profile in yeast cells exposed to X-rays and gamma-rays.

PubMed

Kimura, Shinzo; Ishidou, Emi; Kurita, Sakiko; Suzuki, Yoshiteru; Shibato, Junko; Rakwal, Randeep; Iwahashi, Hitoshi

2006-07-21

Ionizing radiation (IR) is the most enigmatic of genotoxic stress inducers in our environment that has been around from the eons of time. IR is generally considered harmful, and has been the subject of numerous studies, mostly looking at the DNA damaging effects in cells and the repair mechanisms therein. Moreover, few studies have focused on large-scale identification of cellular responses to IR, and to this end, we describe here an initial study on the transcriptional responses of the unicellular genome model, yeast (Saccharomyces cerevisiae strain S288C), by cDNA microarray. The effect of two different IR, X-rays, and gamma (gamma)-rays, was investigated by irradiating the yeast cells cultured in YPD medium with 50 Gy doses of X- and gamma-rays, followed by resuspension of the cells in YPD for time-course experiments. The samples were collected for microarray analysis at 20, 40, and 80 min after irradiation. Microarray analysis revealed a time-course transcriptional profile of changed gene expressions. Up-regulated genes belonged to the functional categories mainly related to cell cycle and DNA processing, cell rescue defense and virulence, protein and cell fate, and metabolism (X- and gamma-rays). Similarly, for X- and gamma-rays, the down-regulated genes belonged to mostly transcription and protein synthesis, cell cycle and DNA processing, control of cellular organization, cell fate, and C-compound and carbohydrate metabolism categories, respectively. This study provides for the first time a snapshot of the genome-wide mRNA expression profiles in X- and gamma-ray post-irradiated yeast cells and comparatively interprets/discusses the changed gene functional categories as effects of these two radiations vis-à-vis their energy levels.

Effects of temperature during the irradiation of calcium carbonate.

PubMed

Negrón-Mendoza, Alicia; Camargo-Raya, Claudia; Gómez-Vidales, Virginia; Uribe, Roberto M; Ramos-Bernal, Sergio

2016-05-01

Calcium carbonate received gamma irradiation at different doses (0-309kGy) and temperature regimes (77-298K) to study the effects of irradiation temperature. The changes were followed by EPR spectroscopy. We observed the formation of a composite EPR spectrum, even at low radiation doses and temperature. There was a strong effect on the evaluation of the radicals formed as a function of irradiation temperature, probably due to the diffusion in the frozen powder and the recombination of some radicals at room temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Technique for Murine Irradiation in a Controlled Gas Environment

PubMed Central

Walb, M. C.; Moore, J. E.; Attia, A.; Wheeler, K. T.; Miller, M. S.; Munley, M. T.

2013-01-01

NASA’s extra-vehicular activities (EVAs) involve exposure to high energy photons while breathing 100% oxygen. Using previously verified mouse models, our laboratory is studying whether low dose irradiation under these hyperoxic conditions could lead to an increase in carcinogenic potential. To simulate the environment astronauts encounter during an EVA, enclosed chambers were constructed that allowed for mouse movement, controlled gas conditions, and uniform radiation dose delivery. Custom-built gas chambers with input/output gas valves and dividers that allowed for uniform gas flow were used to keep 6 unanesthetized mice separated while they were irradiated. The chambers were supplied with 100% oxygen or air using ball valves linked together with T-splitters. A calibrated ion chamber was used to verify the radiation dose distribution across an entire chamber. Mice were placed in the gas environments for 0.5 h, irradiated with a 10 or 18 MV photon beam from a medical linear accelerator, and left in their gas environment for 2 h post-irradiation. We irradiated 200 mice (5 different doses between 0–1000 mGy) under normoxic or 100% oxygen conditions. For the next step of this research, these mice will be euthanized 9 months post-irradiation, and lung tumors will be counted and sized to determine if hyperoxia increases the carcinogenic effect for this model. PMID:22846321

Effect of gamma irradiation in presence of ascorbic acid on microbial composition and TBARS concentration of ground beef coated with an edible active coating

NASA Astrophysics Data System (ADS)

Lacroix, M.; Ouattara, B.; Saucier, L.; Giroux, M.; Smoragiewicz, W.

2004-09-01

The present study was conducted to evaluate the combined effect of gamma irradiation in presence of ascorbic acid on the microbiological characteristics and thiobarbituric acid-reactive substances (TBARS) concentration of ground beef coated with an edible coating, crosslinked by gamma irradiation. The medium fat ground beef patties (23% fat ) were divided into two separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid. Meat samples were irradiated at doses of 0, 1, 2, and 3 kGy and stored at 4±2°C. The content of TBARS was evaluated. After 7 days of storage, Enterobacteriaceae, presumptive Staphylococcus aureus, presumptive Pseudomonas spp., Brochothrix thermosphacta and lactic acid bacteria were enumerated. Results showed that lactic acid bacteria and Br. thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. The content in TBARS was stabilized during post-irradiation storage for samples containing ascorbic acid. Shelf life extension periods estimated on the basis of a limit level of 6 log CFU/g for APCs were 4, 7, and 10 days for samples irradiated at 1, 2, and 3 kGy, respectively. However, the incorporation of ascorbic acid in ground beef did not improve significantly ( p>0.05) the inhibitory effect of gamma irradiation.

Glass transition temperature of hard chairside reline materials after post-polymerisation treatments.

PubMed

Urban, Vanessa M; Machado, Ana L; Alves, Marinês O; Maciel, Adeilton P; Vergani, Carlos E; Leite, Edson R

2010-09-01

This study evaluated the effect of post-polymerisation treatments on the glass transition temperature (T(g)) of five hard chairside reline materials (Duraliner II-D, Kooliner-K, New Truliner-N, Ufi Gel hard-U and Tokuso Rebase Fast-T). Specimens (10 x 10 x 1 mm) were made following the manufacturers' instructions and divided into three groups (n = 5). Control group specimens were left untreated. Specimens from the microwave group were irradiated with pre-determined power/time combinations, and specimens from the water-bath group were immersed in hot water at 55 degrees C for 10 min. Glass transition ( degrees C) was performed by differential scanning calorimetry. Data were analysed using anova, followed by post hoc Tukey's test (alpha = 0.05). Both post-polymerisation treatments promoted a significant (p < 0.05) increase in the T(g) of reline material K. Materials K, D and N showed the lowest T(g) (p < 0.05). No significant difference between T and U specimens was observed. Post-polymerisation treatments improved the glass transition of material Kooliner, with the effect being more pronounced for microwave irradiation.

Effects of gamma irradiation on the performance of Jatropha (Jatropha curcas L.) accessions

NASA Astrophysics Data System (ADS)

Surahman, M.; Santosa, E.; Agusta, H.; Aisyah, S. I.; Nisya, F. N.

2018-03-01

This study aimed to assess the effects of mutation by using gamma ray on the performance of jatropha plants. The study was conducted at PAIR BATAN. Jatropha seeds obtained from the collection farm of SBRC LPPM IPB and PT Indocement Tunggal Prakarsa Tbk in Gunung Putri, Bogor, were irradiated. The irradiated seeds were grown in Jonggol Trial Farm of IPB. Gamma irradiation was conducted by using a GCM 4000A device. Treatments consisted of irradiation doses, irradiation methods, and accessions. Irradiation doses given were 175, 200, 225 Gy, and no irradiation (control). Irradiation methods consisted of acute, intermittent, and split-dose. Accessions used in this study were Dompu, Medan, Bima, Lombok, ITP II, IP2P, and Thailand. Results of the study were analysed until 5 months after planting showed that gamma ray mutation gave stimulating and inhibiting effects on similar traits. Irradiation dose of 225 Gy was good to be given in acute, intermittent, and split-dose methods. Irradiation effects were found to be significant in jatropha accessions. Effects of irradiation on production will be published soon.

The pre- and post-accretion irradiation history of cometary ices

NASA Technical Reports Server (NTRS)

Chyba, Christopher; Sagan, Carl

1989-01-01

Comets Halley and Wilson exhibited similar 3.4 micron emission features at approx. 1 AU from the Sun. A simple model of thermal emission from organic grains fits the feature, provides optical depths in good agreement with spacecraft measurements, and explains the absence of longer-wavelength organic features as due to spectral heliocentric evolution (Chyba and Sagan, 1987). The model utilizes transmission spectra of organics synthesized in the laboratory by irradiation of candidate cometary ices; the authors have long noted that related gas-phase syntheses yield polycyclic aromatic hydrocarbons, among other organic residues (Sagan et al., 1967). The authors previously concluded (Chyba and Sagan, 1987) that Halley's loss of several meters' depth with each perihelion passage, combined with the good fit of the Halley 3.4 micron feature to that of comet Wilson (Allen and Wickramasinghe, 1987), argues for the primordial - but not necessarily interstellar - origin of cometary organics. The authors examine the relative importance to the formation of organics of the variety of radiation environments experienced by comets. They conclude that there is at present no compelling reason to choose any of three contributing mechanisms (pre-accretion UV, pre-accretion cosmic ray, and post-accretion radionuclide processing) as the most important.

THE ABSCOPAL EFFECT OF X IRRADIATION ON BONE GROWTH IN RATS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pappas, A.M.; Cohen, J.

1963-06-01

The abscopal effect of irradiation (that which is evident at a distance from the irradiated volume but within the same organism) was investigated in rats. It was possible to demonstrate the effects on growth locally and abscopally when x-ray doses of 400 and 800 r were delivered to the lower extremity and when 800 r was delivered to the knee alone. A distinction between abscopal effects after local irradiation and systemic effects after whole-body irradiation is discussed. The weights of control and irradiated animals were similar for the first 21 days, during which period they did not exhibit any untowardmore » effects of irradiation. However, after 21 days there was a decrease in weight gain, which persisted until the 72nd day. Group A (controls) was the heaviest group, with a mean weight of 412 g. Group B (800 r to the left hind extremity) had a mean weight of 378. Group C (400 r to the left hind extremity) and Group D (800 r to the left knee) exhibited mean weights of 391 and 394 g, respectively. Roentgenographic measurements revealed that all animals receiving irradiation had retardation in the growth of the irradiated tibiae, which were shorter than both the control and the contralateral (unirradiated) tibiae. Only the animals that had received 800 r to their leff hind extremity showed significant differences in the lengths of their unirradiated bones compared with the bones of the control animals of Group A, that is, a significant abscopal growth retardation. Although the abscopal effect appeared to be associated with the volume of tissue irradiated, the way this effect is mediated is not known. The weight gains of the animals demonstrated a strong association between decrease in weight gain, the volume of tissue irradiated, and the dose administered. The impaired weight gsin roughly paralleled the abscopal retardation of bone growth. The animals which received the highest dose of irradiation, 800 r, to the largest volume of tissue, 10% of the body volume

Radioprotective Effect of Aminothiol PrC-210 on Irradiated Inner Ear of Guinea Pig

PubMed Central

Choo, Daniel I.; Riazuddin, Saima; Ahmed, Zubair M.

2015-01-01

Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino)-2-((methylamino)methyl)propane-1-thiol) on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiation (3000 cGy) to each ear. Auditory Brainstem Responses (ABRs) were recorded one week and two weeks after the radiation and compared with the sham animal group. ABR thresholds of guinea pigs that received an intra-peritoneal dose of PrC-210 were significantly better compared to the non-treated, control animals at one week post-radiation. Morphologic analysis of the inner ear revealed significant inflammation and degeneration of the spiral ganglion in the irradiated animals not treated with PrC-210. In contrast, when treated with PrC-210 the radiation effect and injury to the spiral ganglion was significantly alleviated. PrC-210 had no apparent cytotoxic effect in vivo and did not affect the morphology or count of cochlear hair cells. These findings suggest that aminothiol PrC-210 attenuated radiation-induced cochlea damage for at least one week and protected hearing. PMID:26599238

X-Ray Irradiation Effects in Top Contact, Pentacene Based Field Effect Transistors for Space Related Applications

DTIC Science & Technology

2006-01-01

Journal Article POSTPRINT 3. DATES COVERED (From - To) 2006 4. TITLE AND SUBTITLE X-ray irradiation effects in top contact, pentacene based field 5a...Preliminary studies of the effect of x-ray irradiation, typically used to simulate radiation effects in space, on top contract, pentacene based field effect...irradiation, radiation, radiation effects, pentacene 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF

Comparison of the effects of photon versus carbon ion irradiation when combined with chemotherapy in vitro.

PubMed

Schlaich, Fabian; Brons, Stephan; Haberer, Thomas; Debus, Jürgen; Combs, Stephanie E; Weber, Klaus-Josef

2013-11-06

Characterization of combination effects of chemotherapy drugs with carbon ions in comparison to photons in vitro. The human colon adenocarcinoma cell line WiDr was tested for combinations with camptothecin, cisplatin, gemcitabine and paclitaxel. In addition three other human tumour cell lines (A549: lung, LN-229: glioblastoma, PANC-1: pancreas) were tested for the combination with camptothecin. Cells were irradiated with photon doses of 2, 4, 6 and 8 Gy or carbon ion doses of 0.5, 1, 2 and 3 Gy. Cell survival was assessed using the clonogenic growth assay. Treatment dependent changes in cell cycle distribution (up to 12 hours post-treatment) were measured by FACS analysis after propidium-iodide staining. Apoptosis was monitored for up to 36 hours post-treatment by Nicoletti-assay (with qualitative verification using DAPI staining). All cell lines exhibited the well-known increase of killing efficacy per unit dose of carbon ion exposure, with relative biological efficiencies at 10% survival (RBE10) ranging from 2.3 to 3.7 for the different cell lines. In combination with chemotherapy additive toxicity was the prevailing effect. Only in combination with gemcitabine or cisplatin (WiDr) or camptothecin (all cell lines) the photon sensitivity was slightly enhanced, whereas purely independent toxicities were found with the carbon ion irradiation, in all cases. Radiation-induced cell cycle changes displayed the generally observed dose-dependent G2-arrest with little effect on S-phase fraction for all cell lines for photons and for carbon ions. Only paclitaxel showed a significant induction of apoptosis in WiDr cell line but independent of the used radiation quality. Combined effects of different chemotherapeutics with photons or with carbon ions do neither display qualitative nor substantial quantitative differences. Small radiosensitizing effects, when observed with photons are decreased with carbon ions. The data support the idea that a radiochemotherapy with common

Phytosanitary irradiation and fresh fruit quality: Cultivar and maturity effects

USDA-ARS?s Scientific Manuscript database

Irradiation is an effective quarantine treatment for global trade of fresh produce. Variation in cultivars and maturity stages can impact the tolerance of fresh fruits to irradiation for the purposes of quarantine security. Tolerance thresholds for irradiated fruit are lacking for a large number of ...

N-Acetyl-L-cysteine protects thyroid cells against DNA damage induced by external and internal irradiation.

PubMed

Kurashige, Tomomi; Shimamura, Mika; Nagayama, Yuji

2017-11-01

We evaluated the effect of the antioxidant N-acetyl-L-cysteine (NAC) on the levels of reactive oxygen species (ROS), DNA double strand breaks (DSB) and micronuclei (MN) induced by internal and external irradiation using a rat thyroid cell line PCCL3. In internal irradiation experiments, ROS and DSB levels increased immediately after 131 I addition and then gradually declined, resulting in very high levels of MN at 24 and 48 h. NAC administration both pre- and also post- 131 I addition suppressed ROS, DSB and MN. In external irradiation experiments with a low dose (0.5 Gy), ROS and DSB increased shortly and could be prevented by NAC administration pre-, but not post-irradiation. In contrast, external irradiation with a high dose (5 Gy) increased ROS and DSB in a bimodal way: ROS and DSB levels increased immediately after irradiation, quickly returned to the basal levels and gradually rose again after >24 h. The second phase was in parallel with an increase in 4-hydroxy-2-nonenal. The number of MN induced by the second wave of ROS/DSB elevations was much higher than that by the first peak. In this situation, NAC administered pre- and post-irradiation comparably suppressed MN induced by a delayed ROS elevation. In conclusion, a prolonged ROS increase during internal irradiation and a delayed ROS increase after external irradiation with a high dose caused serious DNA damage, which were efficiently prevented by NAC. Thus, NAC administration even both after internal or external irradiation prevents ROS increase and eventual DNA damage.

Tracking ion irradiation effects using buried interface devices

NASA Astrophysics Data System (ADS)

Cutshall, D. B.; Kulkarni, D. D.; Miller, A. J.; Harriss, J. E.; Harrell, W. R.; Sosolik, C. E.

2018-05-01

We discuss how a buried interface device, specifically a metal-oxide-semiconductor (MOS) capacitor, can be utilized to track effects of ion irradiation on insulators. We show that the exposure of oxides within unfinished capacitor devices to ions can lead to significant changes in the capacitance of the finished devices. For multicharged ions, these capacitive effects can be traced to defect production within the oxide and ultimately point to a role for charge-dependent energy loss. In particular, we attribute the stretchout of the capacitance-voltage curves of MOS devices that include an irradiated oxide to the ion irradiation. The stretchout shows a power law dependence on the multicharged ion charge state (Q) that is similar to that observed for multicharged ion energy loss in other systems.

Recovery behavior of high purity cubic SiC polycrystals by post-irradiation annealing up to 1673 K after low temperature neutron irradiation

NASA Astrophysics Data System (ADS)

Idris, Mohd Idzat; Yamazaki, Saishun; Yoshida, Katsumi; Yano, Toyohiko

2015-10-01

Two kinds of high purity cubic (β) SiC polycrystals, PureBeta-SiC and CVD-SiC, were irradiated in the BR2 reactor (Belgium) up to a fluence of 2.0-2.5 × 1024 (E > 0.1 MeV) at 333-363 K. Changes in macroscopic lengths were examined by post-irradiation thermal annealing using a precision dilatometer up to 1673 K with a step-heating method. The specimen was held at each temperature step for 6 h and the change in length of the specimen was recorded during each isothermal annealing step from 373 K to 1673 K with 50 K increments. The recovery curves were analyzed with the first order model, and rate constants at each annealing step were obtained. Recovery of defects, induced by neutron irradiation in high purity β-SiC, has four stages of different activation energies. At 373-573 K, the activation energy of PureBeta-SiC and CVD-SiC was in the range of 0.17-0.24 eV and 0.12-0.14 eV; 0.002-0.04 eV and 0.006-0.04 eV at 723-923 K; 0.20-0.27 eV and 0.26-0.31 eV at 923-1223 K; and 1.37-1.38 eV and 1.26-1.29 eV at 1323-1523 K, respectively. Below ∼1223 K the recombination occurred possibly for closely positioned C and Si Frenkel pairs, and no long range migration is deemed essential. Nearly three-fourths of recovery, induced by neutron irradiation, occur by this mechanism. In addition, at 1323-1523 K, recombination of slightly separated C Frenkel pairs and more long-range migration of Si interstitials may have occurred for PureBeta-SiC and CVD-SiC specimens. Migration of both vacancies may be restricted up to ∼1523 K. Comparing to hexagonal α-SiC, high purity β-SiC recovered more quickly in the lower annealing temperature range of less than 873 K, in particular less than 573 K.

IMMEDIATE EFFECTS OF X-IRRADIATION ON THE HEART OF THE FROG

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onkelinx, Cl.

1962-07-21

The effects of whole-body irradiations on the heartbeat of pithed frogs were studied. A strong bradycardia was observed after 1 to 5 min of irradiation and is reversible within 1 min after irradiation. A sino-auricular block was observed in some cases. No response was found in any of the frogs during the cold months. The effects of atropine, physostigmine, and eserine on the response were studied. The results suggest a vagal excitation or acetylcholine liberation from the irradiation. (D.L.C.)

Delayed Effects of Acute Radiation Exposure in a Murine Model of the H-ARS: Multiple-Organ Injury Consequent to <10 Gy Total Body Irradiation.

PubMed

Unthank, Joseph L; Miller, Steven J; Quickery, Ariel K; Ferguson, Ethan L; Wang, Meijing; Sampson, Carol H; Chua, Hui Lin; DiStasi, Matthew R; Feng, Hailin; Fisher, Alexa; Katz, Barry P; Plett, P Artur; Sandusky, George E; Sellamuthu, Rajendran; Vemula, Sasidhar; Cohen, Eric P; MacVittie, Thomas J; Orschell, Christie M

2015-11-01

The threat of radiation exposure from warfare or radiation accidents raises the need for appropriate animal models to study the acute and chronic effects of high dose rate radiation exposure. The goal of this study was to assess the late development of fibrosis in multiple organs (kidney, heart, and lung) in survivors of the C57BL/6 mouse model of the hematopoietic-acute radiation syndrome (H-ARS). Separate groups of mice for histological and functional studies were exposed to a single uniform total body dose between 8.53 and 8.72 Gy of gamma radiation from a Cs radiation source and studied 1-21 mo later. Blood urea nitrogen levels were elevated significantly in the irradiated mice at 9 and 21 mo (from ∼22 to 34 ± 3.8 and 69 ± 6.0 mg dL, p < 0.01 vs. non-irradiated controls) and correlated with glomerosclerosis (29 ± 1.8% vs. 64 ± 9.7% of total glomeruli, p < 0.01 vs. non-irradiated controls). Glomerular tubularization and hypertrophy and tubular atrophy were also observed at 21 mo post-total body irradiation (TBI). An increase in interstitial, perivascular, pericardial and peribronchial fibrosis/collagen deposition was observed from ∼9-21 mo post-TBI in kidney, heart, and lung of irradiated mice relative to age-matched controls. Echocardiography suggested decreased ventricular volumes with a compensatory increase in the left ventricular ejection fraction. The results indicate that significant delayed effects of acute radiation exposure occur in kidney, heart, and lung in survivors of the murine H-ARS TBI model, which mirrors pathology detected in larger species and humans at higher radiation doses focused on specific organs.

Ion Beam Irradiation Studies Of Ultrananocrystalline Diamond (UNCD)

NASA Astrophysics Data System (ADS)

Kayani, A.; Garratt, E.; AlFaify, S.; Dissanayake, A.; Tecos, G.; Mancini, D. C.; Syed, M.

2011-06-01

Investigations into the effects of high-energy ion bombardment of ultrananocrystalline diamond (UNCD) thin films was performed using 3 and 6 MeV protons and 24 MeV F4+, with the fluence of 2.1×1017 ions/cm2, 2.9×1017 ions/cm2, and 6.7×1015 ions/cm2 respectively. Objective of the research is to investigate the effect of structural damage on the physical properties of the material and compare it with the structure of unirradiated and N doped UNCD. Pre- and post-irradiated samples were analyzed by ion beam analysis (IBA) measurements, Raman spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). IBA measurements including Rutherford backscattering spectrometry (RBS), non-Rutherford backscattering spectrometry (NRBS) and elastic recoil detection analysis (ERDA) were used to determine elemental concentration of pre- and post-irradiated samples. Visible Raman spectra corresponding to samples irradiated at 3 and 6 MeV protons did not show much variation. For 24 MeV F4+ irradiated sample, significant changes were observed, particularly the loss of a shoulder at 1179 cm-1 and sharpening of the G peak at around 1532 cm-1, indicating possible significant changes at the grain boundary and increase in sp2 phase. AFM measurements show a reduction in RMS roughness after bombardment possibly due to the graphitization of the UNCD surface. The results of IBA measurements did not show any change in the elemental concentration or interface region between film and substrate.

Effects of laser-magnetic blood irradiation in vivo

NASA Astrophysics Data System (ADS)

Zalesskaya, Galina; Ulaschik, Vladimir; Kuchinsky, Andrej; Galay, Olga

2007-06-01

Laser-magnetic field action on blood in vivo was studied within a range 440-650 nm. The primary mechanisms of laser-magnetic blood irradiation in vivo were studied at (1) laser and non-laser irradiation with light of various wavelengths, (2) autohemo-magnetic-therapy, (3) multicolored over-vein irradiation of the blood, (4) the laser-magnetic field actions. Hemoglobin is considered as primary photoacceptor of radiation. The dependence of effectiveness of laser action on light wavelength was compared with known action spectra for blood photostimulation. Magnetic field enhancement of the laser- induced reactions was discussed as result of magnetic field influence on ferromagnetic hem inclusions and on a structure of hemoglobin peptide chains. Hemoglobin oxygenation or deoxygenation processes were analyzed as a first stage of the therapeutic effects depending on a preceding hemoglobin oxygenation degree at pathological state. The laser- magnetic irradiation causes tendency to the normalization of these process. It is proposed that the secondary reactions are initiated by reversible structural changes of erythrocytes membrane caused the strong hemoglobin absorption.

Characterization of irradiated blends of alpha-tocopherol and UHMWPE.

PubMed

Oral, Ebru; Greenbaum, Evan S; Malhi, Arnaz S; Harris, William H; Muratoglu, Orhun K

2005-11-01

Adhesive/abrasive wear in ultra-high molecular weight polyethylene (UHMWPE) has been minimized by radiation cross-linking. Irradiation is followed by melting to eliminate residual free radicals and avoid long-term oxidative embrittlement. However, post-irradiation melting reduces the crystallinity of the polymer and hence its strength and fatigue resistance. We proposed an alternative to post-irradiation melting to be the incorporation of the antioxidant alpha-tocopherol into UHMWPE prior to consolidation. alpha-Tocopherol is known to react with oxygen and oxidized lipids, stabilizing them against further oxidative degradation reactions. We blended GUR 1050 UHMWPE resin powder with alpha-tocopherol at 0.1 and 0.3 wt% and consolidated these blends. Then we gamma-irradiated these blends to 100-kGy. We characterized the effect of alpha-tocopherol on the cross-linking efficiency, oxidative stability, wear behavior and mechanical properties of the blends. (I) The cross-link density of virgin, 0.1 and 0.3 wt% alpha-tocopherol blended, 100-kGy irradiated UHMWPEs were 175+/-19, 146+/-4 and 93+/-4 mol/m3, respectively. (II) Maximum oxidation indices for 100-kGy irradiated UHMWPE previously blended with 0, 0.1 and 0.3 wt% alpha-tocopherol that were subjected to accelerated aging at 80 degrees C in air for 5 weeks were 3.32, 0.09, and 0.05, respectively. (III) The pin-on-disc wear rates of 100-kGy irradiated UHMWPE previously blended with 0.1 and 0.3 wt% alpha-tocopherol that were subjected to accelerated aging at 80 degrees C in air for 5 weeks were 2.10+/-0.17 and 5.01+/-0.76 mg/million cycles, respectively. (IV) Both accelerated aged, alpha-tocopherol-blended 100-kGy irradiated UHMWPEs showed higher ultimate tensile strength, higher yield strength, and lower elastic modulus when compared to 100-kGy irradiated, virgin UHMWPE. These results showed that alpha-tocopherol-blended 100-kGy irradiated UHMWPEs were not cross-linked to the same extent as the 100-kGy irradiated

Renal effects of renal x irradiation and induced autoallergic glomerulonephritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1979-09-01

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

The effects of gamma-ray irradiation on organic materials of different conjugation lengths

NASA Astrophysics Data System (ADS)

Zhang, Cheng; Taylor, Edward W.

2009-08-01

The radiation resistance of organic electro-optic and optoelectronic materials of different conjugation lengths for space applications is receiving increased attention. Earlier investigation reported that guest-host (G-H) poled polymer EO modulator devices composed of a phenyltetraene bridge-type chromophore in amorphous polycarbonate (CLD/APC) did not exhibit a decrease in EO response (i.e., an increase in modulation-switching voltage- Vπ) following irradiation by low dose [10-160 krad(Si)] 60Co gamma-rays. In this work, the post-irradiation responses of 60Co gamma-rays on CLD1/APC thin films are examined by various chemical and spectroscopic methods including: a solubility test, thin-layer chromatography, proton nuclear magnetic resonance spectroscopy, UV-vis absorption, and infra-red absorption. The results indicate that CLD1 and APC did not decompose under gamma-ray irradiation at dose levels ranging from 66-274 krad(Si) and from 61-154 krad(Si), respectively which support the previously reported data. A comparison with an in situ proton irradiated DRI/PMMA material is also presented.

The nature of compensatory and restorative processes in the livers of animals irradiated during hypokinesia

NASA Technical Reports Server (NTRS)

Chernov, I. P.; Trusova, L. V.

1981-01-01

The nature of postirradiation repair in the livers of rats irradiated during hypokinesia is investigated. Hepatocyte population counts, mitotic activity, binuclear cell content, and karyometric studies were done to ascertain the effects of combined hypokinesia and radiation. Hypokinesia is shown to change the nature and rate of post-irradiation changes in the liver, the effect varying with the timing of irradiation relative to the length of hypokinesia. It is concluded that the changes in the compensatory and restorative processes are caused by stress developed in response to isolation and restricted mobility. By changing neuroendocrine system activity, the stress stimulates cell and tissue repair mechanisms at a certain stage essential to the body's reaction of subsequent irradiation.

Silicon/HfO{sub 2} interface: Effects of gamma irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maurya, Savita

2016-05-23

Quality of MOS devices is a strong function of substrate and oxide interface. In this work we have studied how gamma photon irradiation affects the interface of a 13 nm thick, atomic layer deposited hafnium dioxide deposited on silicon wafer. CV and GV measurements have been done for pristine and irradiated samples to quantify the effect of gamma photon irradiation. Gamma photon irradiation not only introduces positive charge in the oxide and at the interface of Si/HfO{sub 2} interface but also induce phase change of oxide layer. Maximum oxide capacitances are affected by gamma photon irradiation.

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

NASA Technical Reports Server (NTRS)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p < 0.05). Basal proliferation of leukocytes in the blood and spleen increased significantly with increasing dose (p < 0.05). Significant dose rate effects were observed only in thrombocyte counts. Plasma levels of transforming growth factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Preparation-induced errors in EPR dosimetry of enamel: pre- and post-crushing sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haskell, E.H.; Hayes, R.B.; Kenner, G.H.

1996-01-01

Errors in dose estimation as a function of grain size for tooth enamel has been previously shown for beta irradiation after crushing. We tested the effect of gamma radiation applied to specimens before and after crushing. We extend the previous work in that we found that post-crushing irradiation altered the slope of the dose-response curve of the hydroxyapatite signal and produced a grain-size dependent offset. No changes in the slope of the dose-response curve were seen in enamel caps irradiated before crushing.

Dose and dose rate effects of whole-body proton-irradiation on lymphocyte blastogenesis and hematological variables: part II

NASA Technical Reports Server (NTRS)

Pecaut, Michael J.; Gridley, Daila S.; Smith, Anna L.; Nelson, Gregory A.

2002-01-01

The goal of part II of this study was to evaluate functional characteristics of leukocytes and circulating blood cell parameters after whole-body proton irradiation at varying doses and at low- and high-dose-rates (LDR and HDR, respectively). C57BL/6 mice (n=51) were irradiated and euthanized at 4 days post-exposure for assay. Significant radiation dose- (but not dose-rate-) dependent decreases were observed in splenocyte responses to T and B cell mitogens when compared to sham-irradiated controls (P<0.001). Spontaneous blastogenesis, also significantly dose-dependent, was increased in both blood and spleen (P<0.001). Red blood cell counts, hemoglobin concentration, and hematocrit were decreased in a dose-dependent manner (P<0.05), whereas thrombocyte numbers were only slightly affected. Comparison of proton- and gamma-irradiated groups (both receiving 3 Gy at HDR) showed a higher level of spontaneous blastogenesis in blood leukocytes and a lower splenocyte response to concanavalin A following proton irradiation (P<0.05). There were no dose rate effects. Collectively, the data demonstrate that the measurements in blood and spleen were largely dependent upon the total dose of proton radiation and that an 80-fold difference in the dose rate was not a significant factor. A difference, however, was found between protons and gamma-rays in the degree of change induced in some of the measurements.

Breast Cancer Patients' Preferences for Adjuvant Radiotherapy Post Lumpectomy: Whole Breast Irradiation vs. Partial Breast Irradiation-Single Institutional Study.

PubMed

Bonin, Katija; McGuffin, Merrylee; Presutti, Roseanna; Harth, Tamara; Mesci, Aruz; Feldman-Stewart, Deb; Chow, Edward; Di Prospero, Lisa; Vesprini, Danny; Rakovitch, Eileen; Lee, Justin; Paszat, Lawrence; Doherty, Mary; Soliman, Hany; Ackerman, Ida; Cao, Xingshan; Kiss, Alex; Szumacher, Ewa

2018-02-01

This study was conducted to elucidate patients with early breast cancer preference for standard whole breast irradiation (WBI) or partial breast irradiation (PBI) following lumpectomy, as well as identify important factors for patients when making their treatment decisions. Based on relevant literature and ASTRO consensus statement guidelines, an educational tool and questionnaire were developed. Consenting, eligible women reviewed the educational tool and completed the trade-off questionnaire. Descriptive statistics were calculated, as well as chi-squares and a logistic regression model. Of the 90 patients who completed the study, 62 % preferred WBI, 30 % preferred PBI, 4 % required more information, and 3 % had no preferences. Of the patients who chose WBI, 58 % preferred hypofractionated RT, whereas 25 % preferred the conventional RT regimen. The majority of patients rated recurrence rate [WBI = 55/55 (100 %), PBI = 26/26 (100 %)] and survival [WBI = 54/55 (98 %), PBI = 26/26 (100 %)] as important factors contributing to their choice of treatment preference. Financial factors [WBI = 21/55 (38 %), PBI = 14/26 (53 %)] and convenience [WBI = 36/54 (67 %), PBI = 18/26 (69 %)] were rated as important less frequently. Significantly, more patients who preferred WBI also rated standard method of treatment as important when compared to patients who preferred PBI [WBI = 52/54 (96 %), PBI = 16/26 (61 %), χ 2  = 16.63, p = 0.001]. The majority of patients with early breast cancer who were surveyed for this study preferred WBI as an adjuvant treatment post lumpectomy, yet there was a sizeable minority who preferred PBI. This was associated with the importance patients place on standard treatment. These results will help medical professionals treat patients according to patient values.

Irradiation effects in monazite-(Ce) and zircon: Raman and photoluminescence study of Au-irradiated FIB foils

NASA Astrophysics Data System (ADS)

Nasdala, Lutz; Akhmadaliev, Shavkat; Artac, Andreas; Chanmuang N., Chutimun; Habler, Gerlinde; Lenz, Christoph

2018-05-01

Lamellae of 1.5 µm thickness, prepared from well-crystallised monazite-(Ce) and zircon samples using the focused-ion-beam technique, were subjected to triple irradiation with 1 MeV Au+ ions (15.6% of the respective total fluence), 4 MeV Au2+ ions (21.9%) and 10 MeV Au3+ ions (62.5%). Total irradiation fluences were varied in the range 4.5 × 1012 - 1.2 × 1014 ions/cm2. The highest fluence resulted in amorphisation of both minerals; all other irradiations (i.e. up to 4.5 × 1013 ions/cm2) resulted in moderate to severe damage. Lamellae were subjected to Raman and laser-induced photoluminescence analysis, in order to provide a means of quantifying irradiation effects using these two micro-spectroscopy techniques. Based on extensive Monte Carlo calculations and subsequent defect-density estimates, irradiation-induced spectroscopic changes are compared with those of naturally self-irradiated samples. The finding that ion irradiation of monazite-(Ce) may cause severe damage or even amorphisation, is in apparent contrast to the general observation that naturally self-irradiated monazite-(Ce) does not become metamict (i.e. irradiation-amorphised), in spite of high self-irradiation doses. This is predominantly assigned to the continuous low-temperature damage annealing undergone by this mineral; other possible causes are discussed. According to cautious estimates, monazite-(Ce) samples of Mesoproterozoic to Cretaceous ages have stored only about 1% of the total damage experienced. In contrast, damage in ion-irradiated and naturally self-irradiated zircon is on the same order; reasons for the observed slight differences are discussed. We may assess that in zircon, alpha decays create significantly less than 103 Frenkel-type defect pairs per event, which is much lower than previous estimates. Amorphisation occurs at defect densities of about 0.10 dpa (displacements per lattice atom).

THE EFFECT OF IRRADIATION ON REPRODUCTION BY THE HETEROGENETIC GENERATION OF STRONGYLOIDES PAPILLOSUS. I. IRRADIATION OF MALES AND FEMALES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katz, F.F.

1960-06-01

Fourth and fifth stage male and third and fourth stage female S. papillosus were subjected to various doses of Co/sup 60/ gamma irradiation and cultured in vitro with controls of the opposite sex. Fewer offspring were produced in cultures containing irradiated males than in cultures of irradiated females. A single experiment involving several doses and one control gave a more linear picture of the effects of irradiation than individual experiments carried out at various times for different dose levels. In the former, larvae were obtained in cultures of nematodes exposed to 20 kr but not to 40, 60, 80 ormore » 100 kr; in the latter, larvae occurred in cultures of males irradiated at 42 kr and in cultures of females exposed to 50 kr but not at the higher levels employed. With increased doses of irradiation, there was a decrease in the percentage of eggs hatching. The dominant lethal effect was observed in cultures with males exposed to 20 kr and higher doses. In cultures with irradiated females, this phenomenon was observed at 40 kr and higher levels. (auth)« less

Effect of gamma irradiation on the photoluminescence of porous silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elistratova, M. A., E-mail: Marina.Elistratova@mail.ioffe.ru; Romanov, N. M.; Goryachev, D. N.

The effect of gamma irradiation on the luminescence properties of porous silicon produced by the electrochemical technique is studied. Changes in the photoluminescence intensity between irradiation doses and over a period of several days after the last irradiation are recorded. The quenching of photoluminescence at low irradiation doses and recovery after further irradiation are registered. It is found that porous silicon is strongly oxidized after gamma irradiation and the oxidation process continues for several days after irradiation. It is conceived that the change in the photoluminescence spectra and intensity of porous silicon after gamma irradiation is caused by a changemore » in the passivation type of the porous surface: instead of hydrogen passivation, more stable oxygen passivation is observed. To stabilize the photoluminescence spectra of porous silicon, the use of fullerenes is proposed. No considerable changes in the photoluminescence spectra during irradiation and up to 18 days after irradiation are detected in a porous silicon sample with a thermally deposited fullerene layer. It is shown that porous silicon samples with a deposited C{sub 60} layer are stable to gamma irradiation and oxidation.« less

Irradiation and Thermal Annealing Effects in Amorphous Magnetic Alloys.

NASA Astrophysics Data System (ADS)

Fisher, David G.

Irradiation with protons, electrons, and alpha particles produces effects in amorphous magnetic alloys (Fe(,x)Ni(,80)P(,20-y)B(,y), where x was 20, 27, 34, or 40 and y was either 6 or 20) that appear analogous to effects produced by thermal annealing. The work presented in this dissertation represents an extension of work performed by Franz('(1)) and/or Donnelly.('(2)) The work of Franz, Donnelly, and this author has been a coordinated investigation into various aspects of radiation damage and thermal annealing effects in the above-mentioned amorphous alloys' magnetic properties. Upon either irradiation or thermal annealing, the Curie temperature, T(,c), is enhanced in these alloys. Also the relative permeability, (mu)(,r), is raised as much as seven-fold. Electrolytic layer removal experiments on proton-irradiated (0.25-MeV) samples conclusively demonstrate that the particle irradiation does not merely heat the sample bulk. Annealing studies performed on both irradiated and as-quenched samples suggested, via T(,c) measurement, that a structural relaxation process had taken place. The structural relaxation takes place as a result of a macroscopic heating in the case of the annealed samples and it is postulated that the structural relaxation takes place as a result of a miroscopic heating about the particle track (thermal spike mechanism) in the case of the irradiated samples. This work also presents preliminary results concerning the influence of irradiation and thermal annealing on the crystallization process in these alloys. The results of DSC and electrical resistivity (above room temperature) are presented. Using electrical resistivity as an indicator, a series of isothermal recrystallization measurements were performed using samples of 2.25-MeV proton-irradiated, 200(DEGREES)C-annealed, and as-quenched Fe(,20)Ni(,60)P(,14)B(,6). The activation energy for the onset of recrystallization is 2.0 eV for as-quenched samples and is 5.3 eV for the irradiated and

Modulation of in vitro transformation and the early and late modes of DNA replication of uv-irradiation Syrian hamster cells by caffeine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doniger, J.; DiPaolo, J.A.

1981-09-01

The effect of caffeine on post-uv DNA replication was studied to determine its relevance to carcinogenesis. The level of uv-induced transformed colonies of Syrian hamster embryo cells (HEC) was increased up to fivefold when caffeine was added to cells between 0 and 6 h post-uv. The greatest increase was observed when the interval between uv irradiation and caffeine addition was 4 h. Two modes of DNA replication occurred after uv irradiation. During the early mode (0 to 3 h post-uv) the size of nascent strands, as measured by alkaline sucrose sedimentation, was smaller than those in nonirradiated cells, whereas duringmore » the late mode they recovered to normal size. Caffeine inhibited the rate of elongation of nascent strands during the early mode. When caffeine was added immediately after uv irradiation, the conversion of the early mode to the late mode was inhibited. Studies on the effects of caffeine have now been extended to the late mode. While caffeine has little effect with the fd elements beginning from the 10th day after irradiation is connected with their proliferation but not with the migration out from lymphoid organs.« less

Long-term cognitive effects of human stem cell transplantation in the irradiated brain.

PubMed

Acharya, Munjal M; Martirosian, Vahan; Christie, Lori-Ann; Limoli, Charles L

2014-09-01

Radiotherapy remains a primary treatment modality for the majority of central nervous system tumors, but frequently leads to debilitating cognitive dysfunction. Given the absence of satisfactory solutions to this serious problem, we have used human stem cell therapies to ameliorate radiation-induced cognitive impairment. Here, past studies have been extended to determine whether engrafted cells provide even longer-term benefits to cognition. Athymic nude rats were cranially irradiated (10 Gy) and subjected to intrahippocampal transplantation surgery 2 days later. Human embryonic stem cells (hESC) or human neural stem cells (hNSC) were transplanted, and animals were subjected to cognitive testing on a novel place recognition task 8 months later. Grafting of hNSC was found to provide long lasting cognitive benefits over an 8-month post-irradiation interval. At this protracted time, hNSC grafting improved behavioral performance on a novel place recognition task compared to irradiated animals not receiving stem cells. Engrafted hESC previously shown to be beneficial following a similar task, 1 and 4 months after irradiation, were not found to provide cognitive benefits at 8 months. Our findings suggest that hNSC transplantation promotes the long-term recovery of the irradiated brain, where intrahippocampal stem cell grafting helps to preserve cognitive function.

Survival after total body irradiation: Effects of irradiation of exteriorized small intestine. (Reannouncement with new availability information)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vriesendorp, H.M.; Vigneulle, R.M.; Kitto, G.

1993-12-31

Rats receiving lethal irradiation to their exteriorized small intestine with pulsed 18 MVp bremsstrahlung radiation live about 4 days longer than rats receiving a dose of total-body irradiation (TBI) causing intestinal death. The LD50 for intestinal irradiation is approximately 6 Gy higher than the LD50 for intestinal death after TBI. Survival time after exteriorized intestinal irradiation can be decreased, by adding abdominal irradiation. Adding thoracic or pelvic irradiation does not alter survival time. Shielding of large intestine improves survival after irradiation of the rest of the abdomen while the small intestine is also shielded. The kinetics of histological changes inmore » small intestinal tissues implicate the release of humoral factors after irradiation of the abdomen. Radiation injury develops faster in the first (proximal) 40 cm of the small intestine and is expressed predominantly as shortening in villus height. In the last (distal) 40 cm of the small intestine, the most pronounced radiation effect is a decrease in the number of crypts per millimeter. Irradiation (20 Gy) of the proximal small intestine causes 92 % mortality (median survival 10 days). Irradiation (20 Gy) of the distal small intestine causes 27% mortality (median survival > 30 days). In addition to depletion of crypt stem cells in the small intestine, other issues (humoral factors, irradiated subsection of the small intestine and shielding of the large intestine) appear to influence radiation-induced intestinal mortality.« less

Late effects of 1H irradiation on hippocampal physiology

NASA Astrophysics Data System (ADS)

Kiffer, Frederico; Howe, Alexis K.; Carr, Hannah; Wang, Jing; Alexander, Tyler; Anderson, Julie E.; Groves, Thomas; Seawright, John W.; Sridharan, Vijayalakshmi; Carter, Gwendolyn; Boerma, Marjan; Allen, Antiño R.

2018-05-01

NASA's Missions to Mars and beyond will expose flight crews to potentially dangerous levels of charged-particle radiation. Of all charged nuclei, 1H is the most abundant charged particle in both the galactic cosmic ray (GCR) and solar particle event (SPE) spectra. There are currently no functional spacecraft shielding materials that are able to mitigate the charged-particle radiation encountered in space. Recent studies have demonstrated cognitive injuries due to high-dose 1H exposures in rodents. Our study investigated the effects of 1H irradiation on neuronal morphology in the hippocampus of adult male mice. 6-month-old mice received whole-body exposure to 1H at 0.5 and 1 Gy (150 MeV/n; 0.35-0.55 Gy/min) at NASA's Space Radiation Laboratory in Upton, NY. At 9-months post-irradiation, we tested each animal's open-field exploratory performance. After sacrifice, we dissected the brains along the midsagittal plane, and then either fixed or dissected further and snap-froze them. Our data showed that exposure to 0.5 Gy or 1 Gy 1H significantly increased animals' anxiety behavior in open-field testing. Our micromorphometric analyses revealed significant decreases in mushroom spine density and dendrite morphology in the Dentate Gyrus, Cornu Ammonis 3 and 1 of the hippocampus, and lowered expression of synaptic markers. Our data suggest 1H radiation significantly increased exploration anxiety and modulated the dendritic spine and dendrite morphology of hippocampal neurons at a dose of 0.5 or 1 Gy.

Transgenerational effects of proton beam irradiation on Caenorhabditis elegans germline apoptosis.

PubMed

Min, Hyemin; Sung, Minhee; Son, Miseol; Kawasaki, Ichiro; Shim, Yhong-Hee

2017-08-26

When treating cancer using radiation therapy, it is critical to increase patient survival rates and to reduce side effects. In this respect, proton beam radiation treatment performs better than other radiation treatments because of its high target specificity. However, complications still remain after proton beam radiation treatment. Among them, the risk to progeny after irradiation of their parents is a major concern. In this study, we analyzed the transgenerational effects of proton beam irradiation using the model organism Caenorhabditis. elegans. We found that germline apoptosis increased after proton beam irradiation and its effects were sustained transgenerationally. Moreover, we identified that a germline-specific histone methyltransferase component, SET-2, has a critical role in transmitting the transgenerational effect on germline apoptosis to the next generation after proton beam irradiation. Copyright © 2017 Elsevier Inc. All rights reserved.

Skeletal effects of megavoltage irradiation in survivors of Wilms' tumor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heaston, D.K.; Libshitz, H.I.; Chan, R.C.

1979-09-01

The skeletal effects of megavoltage irradiation (/sup 60/Co) in 25 long term survivors of Wilms' tumor are described. In general, the changes seen with megavoltage irradiation are as frequent but not as severe as those previously reported after orthovoltage irradiation. Vertebral body changes generally occur within 5 years after irradiation. Scoliosis and/or kyphosis do not usually develop until after five years postirradiation. Kyphotic curves tend to progress after the adolescent growth spurt while scoliotic curves do not. Other bony and nonosseous changes are detailed.

Royal jelly modulates oxidative stress and tissue injury in gamma irradiated male Wister Albino rats.

PubMed

Azab, Khaled Shaaban; Bashandy, Mohamed; Salem, Mahmoud; Ahmed, Osama; Tawfik, Zaki; Helal, Hamed

2011-06-01

Royal jelly is a nutritive secretion produced by the worker bees, rich in proteins, carbohydrates, vitamins and minerals. The present study was designed to determine the possible protective effects of royal jelly against radiation induced oxidative stress, hematological, biochemical and histological alterations in male Wister albino rats. Male Wister albino rats were exposed to a fractionated dose of gamma radiation (2 Gy every 3 days up to 8 Gy total doses). Royal jelly was administrated (g/Kg/day) by gavages 14 days before exposure to the 1(st) radiation fraction and the treatment was continued for 15 days after the 1(st) irradiation fraction till the end of the experiment. The rats were sacrificed 3(rd), equivalent to 3rd post 2nd irradiation fraction, and equivalent to 3rd day post last irradiation fraction. In the present study, gamma- irradiation induced hematological, biochemical and histological effects in male Wister albino rats. In royal jelly treated irradiated group, there was a noticeable decrease recorded in thiobarbituric reactive substances concentration when compared to γ-irradiated group. Also, the serum nitric oxide concentration was significantly improved. The administration of royal jelly to irradiated rats according to the current experimental design significantly ameliorates the changes induced in serum lipid profile. Moreover, in royal jelly treated irradiated group, there was a noticeable amelioration recorded in all hematological parameters along the three experimental intervals. The microscopic examination of cardiac muscle of royal jelly treated irradiated rats demonstrated structural amelioration, improved nuclei and normal features of capillaries and veins in endomysium when compared to gamma-irradiated rats. It was suggested that the biochemical, hematological and histological amelioration observed in royal jelly (g/Kg/day) treated irradiated rats might be due to the antioxidant capacity of royal jelly active constituents.

Hematological and TGF-beta variations after whole-body proton irradiation

NASA Technical Reports Server (NTRS)

Kajioka, E. H.; Andres, M. L.; Mao, X. W.; Moyers, M. F.; Nelson, G. A.; Gridley, D. S.

2000-01-01

The acute effects of proton whole-body irradiation on five bone-marrow-derived cell types and transforming growth factor-beta 1 (TGF-beta 1) were examined and compared to the effects of photons (60Co). C57BL/6 mice were exposed to 3 Gy (0.4 Gy/min) protons at spread-out Bragg peak (SOBP), protons at entry (E), or 60Co and euthanized on days 0.5-17 thereafter. 60Co-irradiated animals had decreased erythrocytes, hemoglobin and hematocrit at 12 hours post-exposure; depression was not noted in proton (SOBP or E)-irradiated groups until day 4. Significantly decreased leukocyte counts were observed at this same time in all irradiated groups, with lymphocyte loss being greater than that of monocytes, and the depression was generally maintained. In contrast, the levels of neutrophils and thrombocytes fluctuated, especially during the first week; significant differences were noted among irradiated groups in neutrophil levels. Plasma TGF-beta 1 was elevated on day 7 in the 60Co, but not proton, irradiated mice. Collectively, the data show that dramatic and persistent changes occurred in all irradiated groups. However, few differences in assay results were seen between animals exposed to protons (SOBP or E) or photons, as well as between the groups irradiated with either of the two regions of the proton Bragg curve.

Effect of soy sauce on lipid oxidation of irradiated pork patties

NASA Astrophysics Data System (ADS)

Kim, Hyun-Wook; Hwang, Ko-Eun; Choi, Yun-Sang; Choi, Ji-Hun; Lee, Mi-Ai; Song, Dong-Heon; Kim, Hack-Youn; Lee, Ju-Woon; Kim, Cheon-Jei

2013-09-01

This study was conducted to find out the antioxidant effect of the soy sauce on lipid oxidation of electron beam irradiated pork patties. The pork patties prepared with sodium chloride or soy sauce solution at identical salt concentrations were irradiated at 0 or 5 kGy, and peroxide value, conjugated diene, 2-thiobarbituric acid, and free fatty acid values were evaluated for 10 days (4 °C). The irradiated pork patties treated with soy sauce showed the lowest peroxide value and 2-thiobarbituric acid value at the end of storage compared to those prepared with sodium chloride. The irradiated pork patties formulated with soy sauce and 0.5% ascorbic acid had similar 2-thiobarbituric acid and free fatty acid values compared to those of the non-irradiated pork patties treated with sodium chloride. Our results suggested that the soy sauce can retard the lipid oxidation of irradiated pork patty, and a synergistic effect between soy sauce and ascorbic acid was observed.

EFFECTS OF X IRRADIATION ON ENZYME SYNTHESIS DURING LIVER REGENERATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, D.K.

1962-05-01

Twenty-four different enzymes or enzyme systems were assayed in regenerating rat liver from control and irradiated animals at various times after partial hepatectomy. X irradiation, either of the whole liver region or of an exteriorized liver lobule, interfered with the accumulation of only three of these enzymes: deoxycytidylate deaminase, thymidine phosphorylase, and NAD pyrophosphorylase. Irradiation did not affect the synthesis of related enzymes such as adenosine and guanine deaminases, and inosine and uridine phosphorylases. The effects of irradiation on enzyme synthesis in regenerating liver would appear to be highly selective. (auth)

The Effects of Local Supralethal Irradiation on Renal Function

DTIC Science & Technology

1974-05-01

304), 1957. 18. Kay, R, E. and Entenman, C. Polydipsia and polyuria by the X-irradiated rat. Am. J, Physiol. 197:169-172, 1959. 19. Klapproth...postirradiation polydipsia and polyuria in the rat. Radiation Res. 10:410-417, 1959. 36. Zaruba, K. Effect of local irradiation of the kidneys on the

Identification of irradiated spices by the use of thermoluminescence method (TL)

NASA Astrophysics Data System (ADS)

Sharifzadeh, M.; Sohrabpour, M.

1993-07-01

In this paper the results of the investigations of identification of irradiated spices by the use of thermoluminescence method is reported. The materials used were black and red peppers, turmeric, cinnamon, and garlic powder. Gamma Cell 220 was used for irradiating samples at dose values of 2.5, 5, 7.5 and 10 kGy respectively. The TL intensity of the unirradiated spices as well as the fading characteristics of the irradiated samples having received a dose of 10 kGy have been measured. Post-irradiation temperature treatment of the irradiated (10 kGy) and unirradiated samples at 60°C and 100°C for 24 hours have been also performed. The results show that the TL intensities of unirradiated and irradiated samples from different batches of each spice are fairly distributed. A reasonable TL intensity versus dose has been observed in nearly all cases. Based on the observations made it is possible to distinguish irradiated spices after (4-9) months post-irradiation.

PIE on Safety-Tested Loose Particles from Irradiated Compact 4-4-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunn, John D.; Gerczak, Tyler J.; Morris, Robert Noel

2016-04-01

Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High Temperature Gas-cooled Reactors (HTGRs). This work is sponsored by the Department of Energy Office of Nuclear Energy (DOE-NE) through the Advanced Reactor Technologies (ART) Office under the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program. The AGR-1 experiment was the first in a series of TRISO fuel irradiation tests initiated in 2006. The AGR-1 TRISO particles and fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 using laboratory-scale equipment and irradiated for 3 years in themore » Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. Post-irradiation examination was performed at INL and ORNL to study how the fuel behaved during irradiation, and to test fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing and post-safety testing PIE conducted at ORNL on loose particles extracted from irradiated AGR-1 Compact 4-4-2.« less

Radiation testing of composite materials, in situ versus ex situ effects

NASA Technical Reports Server (NTRS)

Kurland, R. M.; Thomasson, J. F.; Beggs, W. C.

1981-01-01

The effect of post irradiation test environments on tensile properties of representative advanced composite materials (T300/5208, T300/934, C6000/P1700) was investigated. Four ply (+ or - 45 deg/+ or - 45 deg) laminate tensile specimens were exposed in vacuum up to a bulk dose of 1 x 10 to the 10th power rads using a mono-energetic fluence of 700 keV electrons from a Van de Graaff accelerator. Post irradiation testing was performed while specimens were being irradiated (in situ data), in vacuum after cessation of irradiation (in vacuo data), and after exposure to air (ex situ data). Room temperature and elevated temperature effects were evaluated. The radiation induced changes to the tensile properties were small. Since the absolute changes in tensile properties were small, the existance of a post irradiation test environment effect was indeterminate.

95 MeV oxygen ion irradiation effects on N-channel MOSFETs

NASA Astrophysics Data System (ADS)

Prakash, A. P. G.; Ke, S. C.; Siddappa, K.

2003-09-01

The N-channel metal oxide semiconductor field effect transistors (MOSFETs) were exposed to 95 MeV oxygen ions, in the fluence range of 5 x 10(10) to 5 x 10(13) ions/cm(2). The influence of ion irradiation on threshold voltage (V-TH), linear drain current (I-DLin), leakage current (I-L), drain conductance (g(D)), transconductance (g(m)), mobility (mu) and drain saturation current (I-DSat) of MOSFETs was studied systematically for various fluence. The V-TH of the irradiated MOSFET was found to decrease significantly after irradiation. The interface (N-it) and oxide trapped charge (N-ot) were estimated from the subthreshold measurements and were found to increase after irradiation. The densities of oxide-trapped (DeltaN(it)) charge in irradiated MOSFETs were found to he higher than those of the interface trapped charge (DeltaN(ot)). The I-DLin and I-Dsat of MOSFETs were also found to decrease significantly after irradiation. Studies on effects of 95 MeV oxygen ion irradiation on g(m), g(D) and mu show a degradation varying front 70 to 75% after irradiation. The mobility degradation coefficients for N-it(alpha(it)) and N-ot(alpha(it)) were estimated. The results of these studies are presented and discussed.

The Effect of Lycopene Preexposure on UV-B-Irradiated Human Keratinocytes

PubMed Central

Ascenso, Andreia; Pedrosa, Tiago; Pinho, Sónia; Pinho, Francisco; de Oliveira, José Miguel P. Ferreira; Cabral Marques, Helena; Oliveira, Helena; Simões, Sandra; Santos, Conceição

2016-01-01

Lycopene has been reported as the antioxidant most quickly depleted in skin upon UV irradiation, and thus it might play a protective role. Our goal was to investigate the effects of preexposure to lycopene on UV-B-irradiated skin cells. Cells were exposed for 24 h to 10 M lycopene, and subsequently irradiated and left to recover for another 24 h period. Thereafter, several parameters were analyzed by FCM and RT-PCR: genotoxicity/clastogenicity by assessing the cell cycle distribution; apoptosis by performing the Annexin-V assay and analyzing gene expression of apoptosis biomarkers; and oxidative stress by ROS quantification. Lycopene did not significantly affect the profile of apoptotic, necrotic and viable cells in nonirradiated cells neither showed cytostatic effects. However, irradiated cells previously treated with lycopene showed an increase in both dead and viable subpopulations compared to nonexposed irradiated cells. In irradiated cells, lycopene preexposure resulted in overexpression of BAX gene compared to nonexposed irradiated cells. This was accompanied by a cell cycle delay at S-phase transition and consequent decrease of cells in G0/G1 phase. Thus, lycopene seems to play a corrective role in irradiated cells depending on the level of photodamage. Thus, our findings may have implications for the management of skin cancer. PMID:26664697

CNS effects of heavy particle irradiation in space: behavioral implications.

PubMed

Joseph, J A; Erat, S; Rabin, B M

1998-01-01

Research from several sources indicates that young (3 mo) rats exposed to heavy particle irradiation (56Fe irradiation) produces changes in motor behavior as well as alterations in neuronal transmission similar to those seen in aged (22-24 mo) rats. These changes are specific to neuronal systems that are affected by aging. Since 56Fe particles make up approximately 1-2% of cosmic rays, these findings suggest that the neuronal effects of heavy particle irradiation on long-term space flights may be significant, and may even supercede subsequent mutagenic effects in their mission capabilities. It is suggested that among other methods, it may be possible to utilize nutritional modification procedures to offset the putative deleterious effects of these particles in space.

Effect of gamma irradiation on quality of dried potato

NASA Astrophysics Data System (ADS)

Wang, J.; Chao, Y.

2003-03-01

The objectives of this study were to obtain the effect of gamma irradiation on the quality of dried potato. Experiments were conducted to study the influence of different doses, air temperatures, slice thickness of potatoes on the dehydration rate, appearance quality ( L-values), vitamin C content, and the rehydration ratio of dried potatoes. The greater the dose, the higher the dehydration rate, the lesser the vitamin C content, and the lower the rehydration ratio. The L-values for low-dose irradiation was greater than that for non-irradiated potatoes.

Effects of erbium,chromium:YSGG laser irradiation on canine mandibular bone.

PubMed

Kimura, Y; Yu, D G; Fujita, A; Yamashita, A; Murakami, Y; Matsumoto, K

2001-09-01

Only relatively few reports have described the morphological effects on bone produced by erbium,chromium: yttrium,scandium,gallium,garnet (Er,Cr:YSGG) laser irradiation, and none has investigated the atomic changes or estimated the temperature increases involved. The objectives of this study were to investigate the morphological, atomic, and temperature changes in irradiated areas during and after laser irradiation, and to evaluate the cutting effect on canine mandibular bone in vitro. Two canine mandibular bones were cut into 3 to 5 cm pieces and irradiated by an Er,Cr:YSGG laser utilizing a water-air spray at 5 W and 8 Hz for 10 or 30 seconds. During and after laser irradiation, temperature increases in the irradiated areas were measured by thermography. The samples were then observed by stereoscopy and scanning electron microscopy to determine morphological changes and by energy dispersive x-ray spectroscopy to evaluate atomic alterations. Regular holes or grooves having sharp edges and smooth walls were produced, but no melting or carbonization was observed. The maximum temperature increase was an average 12.6 degrees C for 30-second irradiation. The continuous time of a temperature increase of more than 10 degrees C was consistently less than 10 seconds. An atomic analytical examination revealed that the calcium:phosphorus ratio was not significantly changed between the lased and unlased areas (P>0.0 1). These results showed that the Er,Cr:YSGG laser cuts canine mandibular bone effectively without burning, melting, or altering the calcium:phosphorus ratio of the irradiated bone.

14 MeV Neutron Irradiation Effect on Superconducting Magnet Materials for Fusion Device

NASA Astrophysics Data System (ADS)

Nishimura, A.; Hishinuma, Y.; Seo, K.; Tanaka, T.; Muroga, T.; Nishijima, S.; Katagiri, K.; Takeuchi, T.; Shindo, Y.; Ochiai, K.; Nishitani, T.; Okuno, K.

2006-03-01

As a large-scale plasma experimental device is planned and designed, the importance of investigations on irradiation effect of 14 MeV neutron increases and an experimental database is desired to be piled up. Recently, intense streaming of fast neutron from ports are reported and degradation of superconducting magnet performance is anticipated. To investigate the pure neutron effect on superconducting magnet materials, a cryogenic target system was newly developed and installed at Fusion Neutronics Source in Japan Atomic Energy Research Institute. Although production rate of 14 MeV neutron is not large, only 14 MeV neutron can be supplied to irradiation test without gamma ray. Copper wires, superconducting wires, glass fiber reinforced composites are irradiated and the irradiation effects are characterized. At the same time, sensors for measuring temperature and magnetic field are irradiated and their performance was investigated after irradiation. This paper presents outline of the cryogenic target system and some irradiation test results.

Depuration of shellfish by irradiation: Final technical report, October 1, 1987--March 31, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beghian, L.E.; Mallett, J.C.

1989-01-01

Studies by the University of Lowell Radiation Laboratory and the US National Marine Fisheries Service N.E. Laboratory in Gloucester, MA on softshelled clams (Mya arenaria) demonstrated the effectiveness of low to medium doses of Cobalt 60 source gamma irradiation in the inactivation of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Streptococcus faecalis. Post-irradiation survival and organoleptic studies when extended to hardshelled clams (Mercinaria mercenaria) and American oysters (Crassostrea virginica) showed no significant decline in consumer qualities or 6 day post irradiation survival in oysters at doses of up to 3.0 kGy. The capacities of the American oyster to sustain relativelymore » high doses of gamma irradiation were demonstrated by 6 day post-exposure survivorship values of greater than 90% for samples receiving 3.0, 5.0 and 7.0 kGy. Initial studies of inactivation of Polio I virus and a simian rotavirus (SA-11) was conducted in both hardshelled clams and oysters. Of greatest interest was the behavior of Hepatitis A virus (HAV), in live, irradiated shellfish. The average log decrement value for HAV in oysters was calculated at 2.0 kGy. From these data it appears that doses of up to 2 kGy can be applied to: reduce or eliminate bacterial pathogens, reduce the infectivity of human viral pathogens by one or more orders of magnitude, and preserve market qualities of longevity, appearance, odor, taste and texture. 23 refs., 11 figs., 3 tabs.« less

Effects of ion irradiation on the mechanical properties of several polymers

NASA Astrophysics Data System (ADS)

Sasuga, Tsuneo; Kawanishi, Shunichi; Nishii, Masanobu; Seguchi, Tadao; Kohno, Isao

The effects of high-energy ion irradiation (8 MeV protons, 30 MeV He 2+, 80 MeV C 4+, and N 4+) on the tensile properties of polymers were studied under conditions in which ions should pass completely through the specimen and the results were compared with 2 MeV electron irradiation effects. Experiments were carried out on polymers having various constituents and molecular structures, i.e. eight aliphatic polymers and four aromatic polymers. In the aliphatic polymers studied (PE, PP, PVdF, ETFE, EVA, nylon-6, EPDM, and PE-TPE), there was scarcely any difference in the dose dependence of the tensile strength and ultimate elongation between proton and electron irradiation. In aromatic polymers (PET, PES, U-PS, and U-polymer), however, the decrements in the tensile strength and ultimate elongation vs proton dose were less than those for electron irradiation. In heavy-ion irradiation, the radiation damage of PE (an aliphatic polymer) decreased with increase of LET, but no obvious LET effects were observed in PES (an aromatic polymer).

Effects of gamma irradiation on physicochemical properties of native and acetylated wheat starches.

PubMed

Kong, Xiangli; Zhou, Xin; Sui, Zhongquan; Bao, Jinsong

2016-10-01

Effects of gamma irradiation on the physicochemical and crystalline properties of the native and acetylated wheat starches were investigated. Peak, hot paste, cool paste and setback viscosities of both native and acetylated wheat starches decreased continuously and significantly with the increase of the irradiation dose, whereas breakdown viscosity increased after irradiation. However, gamma irradiation only exerted slight effects on thermal and retrogradation properties of both native and acetylated wheat starches. X-ray diffraction and fourier transform infrared spectroscopy revealed that acetylation modification had considerable effects on the molecular structure of wheat starch, and the crystallinity of both untreated and acetylated starches increased slightly with the increase of irradiation dose. However, the V-type crystallinity of amylose-lipid complex was not affected by gamma irradiation treatments with doses up to 9kGy. Copyright © 2016 Elsevier B.V. All rights reserved.

Retention of storage quality and post-refrigeration shelf-life extension of plum (Prunus domestica L.) cv. Santa Rosa using combination of carboxymethyl cellulose (CMC) coating and gamma irradiation

NASA Astrophysics Data System (ADS)

Hussain, Peerzada R.; Suradkar, Prashant P.; Wani, Ali M.; Dar, Mohd A.

2015-02-01

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation was tested for maintaining the storage quality and extending shelf-life of plum. Matured green plums were CMC coated at levels 0.5-1.0% w/v and gamma irradiated at 1.5 kGy. The treated fruit including control was stored under ambient (temperature 25±2 °C, RH 70%) and refrigerated (temperature 3±1 °C, RH 80%) conditions. In fruits treated with individual treatments of 1.0% w/v CMC; 1.5 kGy irradiation and combination of 1.0% w/v CMC and 1.5 kGy irradiation, no decay was recorded up to 11, 17 and 21 days of ambient storage. Irradiation alone at 1.5 kGy gave 8 days extension in shelf-life of plum compared to 5 days by 1.0% w/v CMC coating following 45 days of refrigeration. All combinatory treatments of CMC coating and irradiation proved beneficial in maintaining the storage quality as well as delaying the decaying of plum during post-refrigerated storage at 25±2 °C, RH 70% but, combination of CMC at 1.0% w/v and 1.5 kGy irradiation was found significantly (p≤0.05) superior to all other treatments in maintaining the storage quality and delaying the decaying of plum. CMC coating of plums at 1.0% w/v followed by irradiation at 1.5 kGy resulted in chlorophyll retention of 19.4% after 16 days compared to 10% in control after 8 days of ambient storage. Under refrigerated conditions, same treatment gave retention of 67.6% in chlorophyll compared to 10.6% in control after 35 days of storage. The above combinatory treatment resulted in extension of 11 days in shelf-life of plum during post-refrigerated storage at 25±2 °C, RH 70% following 45 days of refrigeration. Based on microbial analysis, irradiation alone at 1.5 kGy and in combination with 1.0% w/v CMC resulted in 2.0 and 1.8 log reduction in yeast and mold count of plum fruit after 20 and 35 days of ambient and refrigerated storage, thereby ensuring consumer safety.

Evaluation of the Effect of a Gamma Irradiated DBM-Pluronic F127 Composite on Bone Regeneration in Wistar Rat

PubMed Central

Canciani, Barbara; Losi, Paola; Tripodi, Maria; Burchielli, Silvia; Ottoni, Priscilla; Salvadori, Piero Antonio; Soldani, Giorgio

2015-01-01

Demineralized bone matrix (DBM) is widely used for bone regeneration. Since DBM is prepared in powder form its handling properties are not optimal and limit the clinical use of this material. Various synthetic and biological carriers have been used to enhance the DBM handling. In this study we evaluated the effect of gamma irradiation on the physical-chemical properties of Pluronic and on bone morphogenetic proteins (BMPs) amount in DBM samples. In vivo studies were carried out to investigate the effect on bone regeneration of a gamma irradiated DBM-Pluronic F127 (DBM-PF127) composite implanted in the femur of rats. Gamma irradiation effects (25 kGy) on physical-chemical properties of Pluronic F127 were investigated by rheological and infrared analysis. The BMP-2/BMP-7 amount after DBM irradiation was evaluated by ELISA. Bone regeneration capacity of DBM-PF127 containing 40% (w/w) of DBM was investigated in transcortical holes created in the femoral diaphysis of Wistar rat. Bone porosity, repaired bone volume and tissue organization were evaluated at 15, 30 and 90 days by Micro-CT and histological analysis. The results showed that gamma irradiation did not induce significant modification on physical-chemical properties of Pluronic, while a decrease in BMP-2/BMP-7 amount was evidenced in sterilized DBM. Micro-CT and histological evaluation at day 15 post-implantation revealed an interconnected trabeculae network in medullar cavity and cellular infiltration and vascularization of DBM-PF127 residue. In contrast a large rate of not connected trabeculae was observed in Pluronic filled and unfilled defects. At 30 and 90 days the DBM-PF127 samples shown comparable results in term of density and thickness of the new formed tissue respect to unfilled defect. In conclusion a gamma irradiated DBM-PF127 composite, although it may have undergone a significant decrease in the concentration of BMPs, was able to maintains bone regeneration capability. PMID:25897753

Anaplastic carcinoma of the thyroid in a population irradiated for Hodgkin Disease, 1910-1960

DOE Office of Scientific and Technical Information (OSTI.GOV)

Getaz, E.P.; Shimaoka, K.

Post-irradiation carcinoma of the thyroid is usually histologically well-differentiated. In general, those subjects who developed carcinoma had been exposed to low-to-moderate doses of irradiation for benign conditions. We reviewed the charts of 520 patients with Hodgkin's disease seen at Roswell Park Memorial Institute, and found 2 cases of anaplastic carcinoma amongst other thyroidal abnormalities. The existing reports of post-irradiation carcinoma are reviewed and suggestions are made for the management of heavily irradiated, potentially cured patients with Hodgkin's disease.

X-ray versus gamma irradiation effects on polymers

NASA Astrophysics Data System (ADS)

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

2007-11-01

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

Proton Irradiation Induced Effects in Titanium Carbide and Titanium Nitride: An Evaluation of Microstructures and Mechanical Properties

NASA Astrophysics Data System (ADS)

Dickerson, Clayton A.

The materials TiC and TiN have been identified as potential candidate materials for advanced coated nuclear fuel components for the gas-cooled fast reactor (GFR). While a number of their thermal and mechanical properties have been studied, little is known about how these ceramics respond to particle irradiation. The goal of this study was to investigate the radiation effects in TiC and TiN by analyzing the irradiated microstructures and mechanical properties. Irradiations of TiC and TiN were conducted with 2.6 MeV protons at the University of Wisconsin -- Madison to simulate proposed conditions expected in a reactor. Each material was subjected to three incident proton fluences resulting in doses of ˜0.2 dpa to ˜1 dpa at three temperatures, 600°C, 800°C, and 900°C. Post irradiation examination included microstructural analysis via TEM, lattice parameter determinations with XRD, and mechanical property measurements with micro indentation hardness and fracture toughness tests. The predominant irradiation induced aggregate defects found by high resolution TEM and diffraction contrast TEM in both irradiated TiC and TiN were interstitial faulted dislocation loops. Only circular loops were identified in TiC while both circular and triangular loops were present in TiN. The influences on the microstructural evolution from a high inherent density of dislocations and high porosity were also determined. The strains resulting from the development of the defective microstructures were measured with XRD and shown to be highly dependent on the density of dislocation loops. Maximum strains for the irradiated samples were on the order of 0.5%. Measurements of the fracture toughness of Tic samples were made by ion milling the surface of the samples to create micro cantilever beams which were subsequently fractured by nano indentation. The formation of high densities of dislocation loops in the irradiated samples was found to significantly decrease the material's fracture

Some effects of irradiation on the tick Rhipicephalus appendiculatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purnell, R.E.; Dargie, J.D.; Gilliver, B.

1972-06-01

A series of experiments to study the effects of gamma irradiation on the tick, Rhipicephalus appendiculatus, is described. It was intended to define the tolerance limits to irradiation of different stages of the tick so that a subsequent series of experiments could be carried out to study the effects on developmental stages of Theileria parva in the tick and also to explore the possibility of producing sterile male ticks in spite of the obvious difficulties of attempting to use this technique for tick eradication. (auth)

One-shot LC-MS/MS analysis of post-translational modifications including oxidation and deamidation of rat lens α- and β-crystallins induced by γ-irradiation.

PubMed

Kim, Ingu; Saito, Takeshi; Fujii, Norihiko; Kanamoto, Takashi; Fujii, Noriko

2016-12-01

The eye lens is a transparent organ that functions to focus light and images on the retina. The transparency and high refraction of the lens are maintained by the function of α-, β-, and γ-crystallins. These long-lived proteins are subject to various post-translational modifications, such as oxidation, deamidation, truncation and isomerization, which occur gradually during the aging process. Such modifications, which are generated by UV light and oxidative stress, decrease crystallin solubility and lens transparency, and ultimately lead to the development of age-related cataracts. Here, we irradiated young rat lenses with γ-rays (5-500 Gy) and extracted the water-soluble (WS) and water-insoluble (WI) protein fractions. The WS and WI lens proteins were digested with trypsin, and the resulting peptides were analyzed by one-shot LC-MS/MS to determine the specific sites of oxidation of methionine and tryptophan, deamidation sites of asparagine and glutamine, and isomerization of aspartyl in rat α- and β-crystallins in the WS and WI fractions. Oxidation and deamidation occurred in several crystallins after irradiation at more than, respectively, 50 and 5 Gy; however, isomerization did not occur in any crystallin even after exposure to 500 Gy of irradiation. The number of oxidation and deamidation sites was much higher in the WI than in the WS fraction. Furthermore, the oxidation and deamidation sites in rat crystallins resemble those reported in crystallins from human age-related cataracts. Thus, this study on post-translational modifications of crystallins induced by ionizing irradiation may provide useful information relevant to the formation of human age-related cataracts.

An SEM Approach for the Evaluation of Intervention Effects Using Pre-Post-Post Designs

ERIC Educational Resources Information Center

Mun, Eun Young; von Eye, Alexander; White, Helene R.

2009-01-01

This study analyzes latent change scores using latent curve models (LCMs) for evaluation research with pre-post-post designs. The article extends a recent article by Willoughby, Vandergrift, Blair, and Granger (2007) on the use of LCMs for studies with pre-post-post designs, and demonstrates that intervention effects can be better tested using…

Effect of amino acid starvation on UV sensitivity of Lactobacillus acidophilus cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soška, J.; Nečasová, J.

1973-11-01

In Lactobacillus acidophilus cultures uv irradiated in the exponential phase of growth, the dose-survival curve was of the simple exponential type, without any shoulder. If the bacteria were subjected to amino acid starvation prior to irradiation, a shoulder corresponding to a quasi-threshold dose (D) of about 780 ergs/mm/sup 2/ appeared in the curve. The administration of protein- or RNA-synthesis inhibitors prior to irradiation had the same effect. The effect of pre-irradiation amino acid starvation was abolished by simuitaneous thymidine starvation. It was likewise abolished if amino acid starvation was followed by incubation in the presence of amino acids (without thymidine)more » and then by irradiation of the cells. Post-irradiation amino acid starvation did not lead to the formation of a shoulder but if combined with thymidine starvation it did. It can be concluded from the results that post-irradiation repair processes are facilitated or promoted if, during the post-irradiation interval DNA synthesis is delayed. This delay represents a compensation of the pre-irradiation increase of cellular DNA-content, taking place during inhibition of proteosynthesis. The post-irradiation administration of caffeine did not abolish the formation of the shoulder induced by pre-irradiation amino acid starvation; on the contrary, it induced its formation even in exponentially growing, irradiated control bacteria. (auth)« less

Using laser irradiation for the surgical treatment of periodontal disease

NASA Astrophysics Data System (ADS)

Vieru, Rozana D.; Lefter, Agafita; Herman, Sonia

2002-10-01

In the marginal pr ogressive profound periodontities, we associated low level laser therapy (LLLT) to the classical surgical treatment with implant of biovitroceramics. From a total of 50 patients, 37 where irradiated with the laser. We used a diode laser, =830 nm, energy density up to 2 J cm2, in Nogier pulsed mode. The laser treatment is used in a complex of therapeutic procedures: odontal, local anti-inflammatory -- as well as in the cabinet and at home --, prosthetic, and for the morphologic and functional rebalancing. The immediate effects where: an evolution without bleeding and without post-surgical complications, as can appear at the patients who didn't benefit of laser irradiation (hematom, pain, functional alteration in the first post-surgical week). Operated tissue is recovering faster. The percentage of recurrences decreases and the success depends less on the biological potential and the immunity of each individual.

EFFECT OF GAMMA IRRADIATION AND AET ON RAT BLOOD CHOLINESTERASE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, M.W.; Baker, R.D.; Covill, R.W.

1961-03-01

Whole-body gamma irradiation in the rat produced significant whole-blood cholinesterase depression on the tenth day at a dosage level of 75 r. The levels tested when plotted and extrapolared indicated threshold changes in cholinesterase activity would be in the vicinity of 20 to 30 r. AET alone, while producing some mild cholinesterase depression, failed to protect whole-blood cholinesterase activity from the effects of gamma irradiation at the levels of agent and irradiation tested. (auth)

Effects of the shape of the foil corners on the irradiation performance of U10Mo alloy based monolithic mini-plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozaltun, Hakan; Medvedev, Pavel G

2015-06-01

Monolithic plate-type fuel is a fuel form being developed for high performance research and test reactors to minimize the use of enriched material. These fuel elements are comprised of a high density, low enrichment, U-Mo alloy based fuel foil, sandwiched between Zirconium liners and encapsulated in Aluminum cladding. The use of a high density fuel in a foil form presents a number of fabrication and operational concerns, such as: foil centering, flatness of the foil, fuel thickness variation, geometrical tilting, foil corner shape etc. To benchmark this new design, effects of various geometrical and operational variables on irradiation performance havemore » been evaluated. As a part of these series of sensitivity studies, the shape of the foil corners were studied. To understand the effects of the corner shapes of the foil on thermo-mechanical performance of the plates, a behavioral model was developed for a selected plate from RERTR-12 experiments (Plate L1P785). Both fabrication and irradiation processes were simulated. Once the thermo-mechanical behavior the plate is understood for the nominal case, the simulations were repeated for two additional corner shapes to observe the changes in temperature, displacement and stress-strain fields. The results from the fabrication simulations indicated that the foil corners do not alter the post-fabrication stress-strain magnitudes. Furthermore, the irradiation simulations revealed that post-fabrication stresses of the foil would be relieved very quickly in operation. While, foils with chamfered and filleted corners yielded stresses with comparable magnitudes, they are slightly lower in magnitudes, and provided a more favorable mechanical response compared with the foil with sharp corners.« less

Irradiation at 636 nm positively affects diabetic wounded and hypoxic cells in vitro.

PubMed

Sekhejane, Palesa R; Houreld, Nicolette N; Abrahamse, Heidi

2011-08-01

This study investigated the effect of low-intensity laser irradiation (LILI) on pro-inflammatory cytokines involved in wound healing processes in diabetes and hypoxia. Diabetes is associated with impaired wound healing and a prolonged inflammatory phase. Pro-inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6 are elevated in diabetes. LILI has been reported to accelerate wound healing and decrease inflammatory cytokines. A human skin fibroblast cell line (WS1) was used in vitro. Cells were exposed to various insults, namely, wounding, and a diabetic or hypoxic environment. Experimental cells were exposed to an energy density of 5  J/cm(2) using a continuous wave 636-nm diode laser at an average power of 95  mW, an illuminated area of 9.05  cm(2), and an irradiance of 11 mW/cm(2) (irradiation time, 476  sec). The effect of laser irradiation on cytokine expression was examined at 1 or 24  h post-irradiation. Cellular morphology, viability, proliferation, and cytokine expression (IL-1β, IL-6, and TNF-α) were investigated. Translocation of nuclear factor-kappa B (NF-κB) was also determined. There was a higher rate of migration in irradiated wounded cultures, and irradiated hypoxic cells showed an improvement in cellular morphology. All cell models showed an increase in proliferation. Normal wounded cells showed a decrease in apoptosis, TNF-α, and IL-1β. Diabetic wounded cells showed an increase in viability and a decrease in apoptosis and IL-1β, whereas hypoxic cells showed an increase in viability and IL-6, and a decrease in apoptosis and TNF-α. NF-κB was translocated into the nucleus post-irradiation. Phototherapy resulted in hastened wound closure, increased proliferation, and normalization of cellular function. The decrease in the different pro-inflammatory cytokines and NF-κB translocation was model and time dependent. Overall, laser irradiation resulted in a reduction in inflammatory cytokines and

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

PubMed

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.

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

PubMed Central

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. PMID:22593697

Phytosanitary irradiation - Development and application

NASA Astrophysics Data System (ADS)

Hallman, Guy J.; Loaharanu, Paisan

2016-12-01

Phytosanitary irradiation, the use of ionizing radiation to disinfest traded agricultural commodities of regulated pests, is a growing use of food irradiation that has great continued potential for increase in commercial application. In 2015 approximately 25,000 t of fresh fruits and vegetables were irradiated globally for phytosanitary purposes. Phytosanitary irradiation has resulted in a paradigm shift in phytosanitation in that the final burden of proof of efficacy of the treatment has shifted from no live pests upon inspection at a port of entry (as for all previous phytosanitary treatments) to total dependence on certification that the treatment for target pests is based on adequate science and is commercially conducted and protected from post-treatment infestation. In this regard phytosanitary irradiation is managed more like a hazard analysis and critical control point (HACCP) approach more consistent with food safety than phytosanitation. Thus, phytosanitary irradiation offers a more complete and rigorous methodology for safeguarding than other phytosanitary measures. The role of different organizations in achieving commercial application of phytosanitary irradiation is discussed as well as future issues and applications, including new generic doses.

Effects of electron beam irradiation on polyamide 12 with fiberglass reinforcement

NASA Astrophysics Data System (ADS)

Jeun, Joon-Pyo; Shin, Bum-Sik; Kim, Hyun-Bin; Nho, Young-Chang; Kang, Phil-Hyun

2010-06-01

In the present study, the effects of electron beam irradiation of polyamide 12 (PA12) with fiberglass reinforcement on the thermal and wear properties were investigated. Electron beam irradiation of PA 12 was carried out over a range of irradiation doses (100-600 kGy) in air. The gel formation in the presence of a curing agent was dependent on the radiation doses. The thermal properties of irradiated PA 12 were studied in the temperature region 50-250° C to observe the changes in the melting point with radiation dose. The dimensional stability was significantly increased by electron beam irradiation and the related crosslinking of the PA 12.

Heavy ion irradiation effects of brannerite-type ceramics

NASA Astrophysics Data System (ADS)

Lian, J.; Wang, L. M.; Lumpkin, G. R.; Ewing, R. C.

2002-05-01

Brannerite, UTi 2O 6, occurs in polyphase Ti-based, crystalline ceramics that are under development for plutonium immobilization. In order to investigate radiation effects caused by α-decay events of Pu, a 1 MeV Kr + irradiation on UTi 2O 6, ThTi 2O 6, CeTi 2O 6 and a more complex material, composed of Ca-containing brannerite and pyrochlore, was performed over a temperature range of 25-1020 K. The ion irradiation-induced crystalline-to-amorphous transformation was observed in all brannerite samples. The critical amorphization temperatures of the different brannerite compositions are: 970 K, UTi 2O 6; 990 K, ThTi 2O 6; 1020 K, CeTi 2O 6. The systematic increase in radiation resistance from Ce-, Th- to U-brannerite is related to the difference of mean atomic mass of A-site cation in the structure. As compared with the pyrochlore structure-type, brannerite phases are more susceptible to ion irradiation-induced amorphization. The effects of structure and chemical compositions on radiation resistance of brannerite-type and pyrochlore-type ceramics are discussed.

Dietary flaxseed administered post thoracic radiation treatment improves survival and mitigates radiation-induced pneumonopathy in mice

PubMed Central

2011-01-01

Background Flaxseed (FS) is a dietary supplement known for its antioxidant and anti-inflammatory properties. Radiation exposure of lung tissues occurs either when given therapeutically to treat intrathoracic malignancies or incidentally, such as in the case of exposure from inhaled radioisotopes released after the detonation of a radiological dispersion devise (RDD). Such exposure is associated with pulmonary inflammation, oxidative tissue damage and irreversible lung fibrosis. We previously reported that dietary FS prevents pneumonopathy in a rodent model of thoracic X-ray radiation therapy (XRT). However, flaxseed's therapeutic usefulness in mitigating radiation effects post-exposure has never been evaluated. Methods We evaluated the effects of a 10%FS or isocaloric control diet given to mice (C57/BL6) in 2 separate experiments (n = 15-25 mice/group) on 0, 2, 4, 6 weeks post a single dose 13.5 Gy thoracic XRT and compared it to an established radiation-protective diet given preventively, starting at 3 weeks prior to XRT. Lungs were evaluated four months post-XRT for blood oxygenation levels, inflammation and fibrosis. Results Irradiated mice fed a 0%FS diet had a 4-month survival rate of 40% as compared to 70-88% survival in irradiated FS-fed mouse groups. Additionally, all irradiated FS-fed mice had decreased fibrosis compared to those fed 0%FS. Lung OH-Proline content ranged from 96.5 ± 7.1 to 110.2 ± 7.7 μg/ml (Mean ± SEM) in all irradiated FS-fed mouse groups, as compared to 138 ± 10.8 μg/ml for mice on 0%FS. Concomitantly, bronchoalveolar lavage (BAL) protein and weight loss associated with radiation cachexia was significantly decreased in all FS-fed groups. Inflammatory cell influx to lungs also decreased significantly except when FS diet was delayed by 4 and 6 weeks post XRT. All FS-fed mice (irradiated or not), maintained a higher blood oxygenation level as compared to mice on 0%FS. Similarly, multiplex cytokine analysis in the BAL fluid revealed a

Delayed effects of proton irradiation in Macaca Mulatta (22-year summary)

NASA Astrophysics Data System (ADS)

Woods, D. H.; Hardy, K. A.; Cox, A. B.; Salmon, Y. L.; Yochmowitz, M. G.; Cordts, R. E.

1989-05-01

Lifetime observations on a group of rhesus monkeys indicate that life expectancy loss from exposure to protons in the energy range encountered in the Van Allen belts and solar proton events can be correlated with the dose and energy of radiation. The primary cause of life shortening is nonleukemic cancers. Radiation also increased the rise of endometriosis (an abnormal proliferation of the lining of the uterus in females). Other effects associated with radiation exposures are lowered glucose tolerance and increased incidence of cataracts. Calculations of the relative risk of fatal cancers in the irradiated subjects reveal that the total body surface dose required to double the risk of death from cancer over a 20-year post exposure period varies with the linear energy transfer (LET) of the radiation. The ability to determine the integrated dose and LET spectrum in space radiation exposures of humans is, therefore, critical to the assessment of lifetime cancer risk.

Delayed effects of proton irradiation in Macaca Mulatta (22-year summary)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woods, D.H.; Hardy, K.A.; Cox, A.B.

1989-05-15

Lifetime observations on a group of rhesus monkeys indicate that life expectancy loss from exposure to protons in the energy range encountered in the Van Allen belts and solar proton events can be correlated with the dose and energy of radiation. The primary cause of life shortening is nonleukemic cancers. Radiation also increased the rise of endometriosis (an abnormal proliferation of the lining of the uterus in females). Other effects associated with radiation exposures are lowered glucose tolerance and increased incidence of cataracts. Calculations of the relative risk of fatal cancers in the irradiated subjects reveal that the total bodymore » surface dose required to double the risk of death from cancer over a 20-year post exposure period varies with the linear energy transfer (LET) of the radiation. The ability to determine the integrated dose and LET spectrum in space radiation exposures of humans is, therefore, critical to the assessment of lifetime cancer risk.« less

The Effect of Methysergide and X-irradiation on the Barbiturate Sleeping-time in Rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varagić, V.; Stepanović, S.; Hajduković, S.

1962-10-01

Methysergide (1-methyl-D-lysergic acid butanolamide bimaleate), a highly potent and specific 5-hydroxytryptamine antagonist, if injected after irradiation, significantly depresses the proionging effect of x irradiation on the barbiturate sleeping-time in rats. Lysergic acid diethylamide did not show tius type of activity. 5-Hydroxytryptamine, when injected before irradiation, did not depress the typical response of the irradiated animals to barbiturates. When used after irradiation, 5-hydroxytryptamine caused a further prolongation of the barbiturate sleeping-time. Cysteamine, when injected before irradiation, depressed or blocked the prolonging effect of x irradiation on the barbiturate sleeping-time. When injected after irradiation, cysteamine was found to cause a further prolongationmore » of the barbiturate sleeping-time. The mechanisms of action of methysergide, 5-hydroxytryptamine, and cysteamine are briefly discussed. (auth)« less

Effect of low power laser irradiation on macrophage phagocytic capacity

NASA Astrophysics Data System (ADS)

Lu, Cuixia; Song, Sheng; Tang, Yu; Zhou, Feifan

2011-03-01

Phagocytosis and subsequent degradation of pathogens by macrophages play a pivotal role in host innate immunity in mammals. Laser irradiation has been found to produce photobiological effects with evidence of interference with immunological functions. However, the effects of laser on the immune response have not been extensively characterized. In this study, we focused our attention on the effects of He-Ne laser on the phagocytic activity of macrophages by using flow cytometry (FCM). After irradiating at fluence of 0, 1, 2 J/cm2 with He-Ne laser (632.8 nm, 3mw), the cells were incubated with microsphere and then subjected to FACS analysis. The results showed that Low-power laser irradiation (LPLI) leads to an increase in phagocytosis on both mouse peritoneal macrophages and the murine macrophage-like cell line RAW264.7. In addition, we demonstrated that LPLI increased phagocytosis of microsphere in a dose-dependent manner, reaching a maximum at fluence of 2 J/cm2. Taken together, our results indicated that Low-power laser irradiation with appropriate dosage can enhance the phagocytosis of macrophage, and provided a theoretical base for the clinical use of the He-Ne laser.

Effect of Ultrasonic Frequency on Lactic Acid Fermentation Promotion by Ultrasonic Irradiation

NASA Astrophysics Data System (ADS)

Shimada, Tadayuki; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi

2004-05-01

The authors have been researching the promotion of lactic acid fermentation by ultrasonic irradiation. In the past research, it was proven that ultrasonic irradiation is effective in the process of fermentation, and the production of yoghurt and kefir was promoted. In this study, the effect of the ultrasonic frequency in this fermentation process was examined. In the frequency range of this study, it was found that the action of fermentation promotion was exponentially proportionate to the irradiated ultrasonic frequency.

THE EFFECT OF X IRRADIATION AND CYSTEAMINE ON THE BARBITURATE SLEEPING TIME IN RATS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varagic, V.; Stepanovic, S.; Hajdukovic, S.

Whole-body x irradiation with 600 and 800 r prolongs barbiturate sleeping time in the rat. In the head-irradiated animals (with the same doses) no prolongation of barbiturate sleeping time was observed. Irradintion of the animal with the head shielded produced the same effect as irradiation of the whole body. Cysteamine depressed or even blocked the prolonging action of x irradiation on barbiturate sleeping time. This action of cysteamine was evident 24 hr after irradiation and was still present 30 days after irradiation. The prolonging effect of x irradiation was significant as early as 24 hr after exposure but was moremore » pronounced 14, 21, and 30 days after irradiation. This suggests that even the primary event which takes place immediately after absorption of radiation energy produces a change in reactivity to barbiturates. The results obtained with headirradiated animals indicate that the reactivity of the central nervous system to barbiturates is not significantly changed. Therefore, x irradiation may produce some change in the detoxication process of barbiturates in the liver. Or, some biologically active substance might be released which contributes to the prolongation of the effect of barbiturates. Possibly 5-hydroxytryptamine liberated by x irradiation from intestine might contribute to the prolongation of the barbiturate hypnosis. (H.H.D.)« less

Effects of self-irradiation in plutonium alloys

DOE PAGES

Chung, B. W.; Lema, K. E.; Allen, P. G.

2015-09-16

In this paper, we present updated results of self-irradiation effects on 238Pu-enriched 239Pu alloys measured by immersion density, dilatometry, and tensile tests. We obtained the self-irradiation equivalent time of nearly 200 years, nearly 100 years longer than in our previous papers. At this extended aging, we find the rate of decrease in density has slowed significantly, stabilizing around 15.73 g/cc, without signs of void swelling. The volume expansion measured at 35°C also shows apparent saturation at less than 0.25%. Quasi-static tensile measurement still show gradual increase in the strength of plutonium alloys with age.

ATF Neutron Irradiation Program Technical Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geringer, J. W.; Katoh, Yutai

The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post-irradiation examination and characterization ofmore » irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.« less

THE SIGNIFICANCE OF SCOLIOSIS IN POST-IRRADIATED WILMS'S TUMOR AND NEUROBLASTOMA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rubin, P.; Duthie, R.B.; Young, L.W.

1962-10-01

Radiographic changes in the vertebrae are described that were observed following orthovoltage therapeutic irradiation in the treatment of Wilms's tumor, neuroblastoma, and medulloblastoma. Historical data and treatment faetors are tabulated for 17 cases. Observations on the incidence and severity of scoliosis and accompanying bony changes in l3 cases are presented. A review of the findings showed that the degree of scoliosis that developed was not related to the the fields of irradiation, whether they were unilateral or bilateral, and that the osseous changes in the vertebrae, pelvis, or ribs. The use of irradiation with surgery in the treatment of Wilms'smore » tumor is discussed. Radiological techniques are described to deliver maximum doses to the tumor and minimum doses to the surrounding normal structures in the treatment of these tumors. (C.H.)« less

Effects of electron beam irradiation on polyamide 12 with fiberglass reinforcement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeun, Joon-Pyo; Shin, Bum-Sik; Kim, Hyun-Bin

2010-06-02

In the present study, the effects of electron beam irradiation of polyamide 12 (PA12) with fiberglass reinforcement on the thermal and wear properties were investigated. Electron beam irradiation of PA 12 was carried out over a range of irradiation doses (100-600 kGy) in air. The gel formation in the presence of a curing agent was dependent on the radiation doses. The thermal properties of irradiated PA 12 were studied in the temperature region 50-250 deg. C to observe the changes in the melting point with radiation dose. The dimensional stability was significantly increased by electron beam irradiation and the relatedmore » crosslinking of the PA 12.« less

The effect of low dose rate irradiation on the tensile properties and microstructure of austenitic stainless steel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, T. R.; Tsai, H.; Cole, J. I.

2002-09-17

To assess the effects of long-term, low-dose-rate neutron exposure on mechanical strength and ductility, tensile properties were measured on 12% and 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-56 dpa at temperatures from 371-440 C and dose rates from 0.5-5.8 x10{sup -7} dpa/s. These dose rates are approximately an order of magnitude lower than those of typical EBR-II test sample locations. The tensile tests for the 12% CW material were performed at 380 C and 430more » C while those for the 20% CW samples were performed at 370 C. In each case, the tensile test temperature approximately matched the irradiation temperature. To help understand the tensile properties, microstructural samples with similar irradiation history were also examined. The strength and loss of work hardening increase the fastest as a function of irradiation dose for the 12% CW material irradiated at lower temperature. The decrease in ductility with increasing dose occurs more rapidly for the 12% CW material irradiated at lower temperature and the 20% cold-worked material. Post-tensile test fractography indicates that at higher dose, the 20% CW samples begin a shift in fracture mode from purely ductile to mainly small facets and slip bands, suggesting a transition toward channel fracture. The fracture for all of the 12% cold-worked samples was ductile. For both the 12% and 20% CW materials, the yield strength increases correlate with changes in void and loop density and size.« less

Effect of laser irradiation on the functional activity of enzymes with different structural complexity

NASA Astrophysics Data System (ADS)

Ostrovtsova, Svetlana A.; Volodenkov, Alexander P.; Maskevich, Alexander A.; Artsukevich, Irina M.; Anufrik, Slavomir S.; Makarchikov, Alexander F.; Chernikevich, Ivan P.; Stepuro, Vitali I.

1998-05-01

Three enzymes differing in their structural composition were irradiated by UV lasers to study the effect of temperature, protein concentration and addition of small molecules on their sensitivity to radiation exposure. The laser-induced effects were due to the structural complexity of the protein molecules and depended on the dose applied, the wavelength and the density of irradiation. The multi-enzyme 2- oxoglutarate dehydrogenase complex was subjected to pronounced irradiation-induced changes whereas the response of the two other enzymes was less significant. Reduction of the protein levels in irradiated samples was important under the XeCl laser coercion and the effects depended on the doses applied. The laser irradiation effects are suggested to be realized by means of conformational changes in the protein molecules and intermolecular association- dissociation processes.

Sub ablative Er: YAG laser irradiation on surface roughness of eroded dental enamel.

PubMed

Curylofo-Zotti, Fabiana Almeida; Lepri, Taísa Penazzo; Colucci, Vivian; Turssi, Cecília Pedroso; Corona, Silmara Aparecida Milori

2015-11-01

This study evaluated the effects of Er:YAG laser irradiation applied at varying pulse repetition rate on the surface roughness of eroded enamel. Bovine enamel slabs (n = 10) were embedded in polyester resin, ground, and polished. To erosive challenges, specimens were immersed two times per day in 20mL of concentrated orange juice (pH = 3.84) under agitation, during a two-day period. Specimens were randomly assigned to irradiation with the Er:YAG laser (focused mode, pulse energy of 60 mJ and energy density of 3.79 J/cm(2) ) operating at 1, 2, 3, or 4 Hz. The control group was left nonirradiated. Surface roughness measurements were recorded post erosion-like formation and further erosive episodes by a profilometer and observed through atomic force microscopy (AFM). Analysis of variance revealed that the control group showed the lowest surface roughness, while laser-irradiated substrates did not differ from each other following post erosion-like lesion formation. According to analysis of covariance, at further erosive episodes, the control group demonstrated lower surface roughness (P > 0.05), than any of the irradiated groups (P < 0.05). The pulse repetition rate of the Er:YAG laser did not affect roughness of dental enamel eroded. The AFM images showed that the specimens irradiated by the Er:YAG laser at 1 Hz presented a less rough surface than those irradiated at 2, 3, and 4 Hz. © 2015 Wiley Periodicals, Inc.

The effect of gamma irradiation on curcumin component of Curcuma domestica

NASA Astrophysics Data System (ADS)

Chosdu, R.; Erizal; Iriawan, T.; Hilmy, N.

1995-02-01

The effect of gamma irradiation on curcumin component of Curcuma domestica rhizome were investigated. Pure curcumin, sliced and powdered rhizome with 10% of moisture content were irradiated at 0, 10, 30 and 50 kGy (dose rate of 6 kGy/h). Curcumin content was analysed using HPLC method and ESR spectra. Results show that free radicals are already present in unirradiated rhizome. Gamma irradiation at the doses of 10, 30 and 50 kGy induced the free radicals formation of pure curcumin and Curcuma domestica rhizome. The ESR spectra of irradiated rhizome gave a very similar spectra to the signal of irradiated pure curcumin. The percentage of free radicals intensity from pure curcumin was very stable at room temperature up to 670 hours of storage. However, the percentage intensity of free radicals in the irradiated rhizome were decay during storage. Irradiation treatment and storage time did not give a significant change on curcumin content, water activity, pH and moisture content of rhizome investigated.

Effect of antioxidants on the quality of irradiated sausages prepared with turkey thigh meat.

PubMed

Du, M; Ahn, D U

2002-08-01

The effects of antioxidants on the flavor and color of electron-beam-irradiated turkey sausages were studied. Sausages were prepared from turkey thigh meat, NaCl (2.0%), phosphate (0.5%), water (10%), and one of five antioxidant treatments (none, vitamin E, sesamol, rosemary extract, or gallic acid at 0.02%). Sausages were stuffed and cooked in an 85 C smokehouse to an internal temperature of 74 C, then chilled and sliced to 1.5-cm thickness, and vacuum-packaged. Packaged sausages were randomly divided into three groups and irradiated at 0, 1.5 or 3.0 kGy, using an electron beam. Volatiles, color, 2-TBA-reactive substances values, and sensory characteristics were analyzed. The antioxidant effect of sesamol was the highest, followed by vitamin E and gallic acid; rosemary extract had the weakest antioxidant effect. Irradiation induced red color in sausages, but addition of gallic acid, rosemary extract, or sesamol reduced it. Gallic acid was very effective in lowering the redness of irradiated and nonirradiated sausages. The redness (a*) values of sausages with added gallic acid that were irradiated at 0, 1.5, and 3.0 kGy were 1.49,2.03, and 2.29, respectively, whereas those of control sausages under the same irradiation conditions were 2.58, 2.81, and 3.25, respectively. The reduction of redness in irradiated sausages by antioxidants was not related to CO, because antioxidants had no effect on CO production by irradiation. The amount of total volatiles was decreased significantly by antioxidants, but antioxidants had minimal effect on the off-flavor of turkey sausages induced by irradiation.

Swift heavy ion irradiation effects in Pt/C and Ni/C multilayers

NASA Astrophysics Data System (ADS)

Gupta, Ajay; Pandita, Suneel; Avasthi, D. K.; Lodha, G. S.; Nandedkar, R. V.

1998-12-01

Irradiation effects of 100 MeV Ag ion irradiation on Ni/C and Pt/C multilayers have been studied using X-ray reflectivity measurements. Modifications are observed in both the multilayers at (dE/dx)e values much below the threshold values for Ni and Pt. This effect is attributed to the discontinuous nature of the metal layers. In both the multilayers interfacial roughness increases with irradiation dose. While Ni/C multilayers exhibit large ion-beam induced intermixing, no observable intermixing is observed in the case of Pt/C multilayer. This difference in the behavior of the two systems suggests a significant role for chemically guided defect motion in the mixing process associated with swift heavy ion irradiation.

Anti-inflammatory effect of selenium nanoparticles on the inflammation induced in irradiated rats.

PubMed

El-Ghazaly, M A; Fadel, N; Rashed, E; El-Batal, A; Kenawy, S A

2017-02-01

Selenium (Se) has been reported to possess anti-inflammatory properties, but its bioavailability and toxicity are considerable limiting factors. The present study aimed to investigate the possible anti-inflammatory and analgesic effects of selenium nanoparticles (Nano-Se) on inflammation induced in irradiated rats. Paw volume and nociceptive threshold were measured in carrageenan-induced paw edema and hyperalgesia model. Leukocytic count, tumor necrosis factor-α (TNF-α), prostaglandin E 2 (PGE 2 ), thiobarbituric acid reactive substances (TBAR), and total nitrate/nitrite (NOx) were estimated in the exudate collected from 6 day old air pouch model. Irradiated rats were exposed to 6 Gy gamma (γ)-irradiation. Nano-Se were administered orally in a dose of 2.55 mg/kg once before carrageenan injection in the first model and twice in the second model. The paw volume but not the nociceptive response produced by carrageenan in irradiated rats was higher than that induced in non-irradiated rats. Nano-Se were effective in reducing the paw volume in non-irradiated and irradiated rats but it did not alter the nociceptive threshold. The inflammation induced in irradiated rats increased all the estimated parameters in the exudate whereas; Nano-Se decreased their elevation in non-irradiated and irradiated rats. Nano-Se possess a potential anti-inflammatory activity on inflammation induced in irradiated rats.

The fate of mitochondrial loci in rho minus mutants induced by ultraviolet irradiation of Saccharomyces cerevisiae: effects of different post-irradiation treatments.

PubMed

Heude, M; Moustacchi, E

1979-09-01

Three main features regarding the loss of mitochondrial genetic markers among rho- mutants induced by ultraviolet irradiation are reported: (a) the frequency of loss of six loci examined increases with UV dose; (b) preferential loss of one region of the mitochondrial genome observed in spontaneous rho- mutants is enhanced by UV; and (c) the loss of each marker results from large deletions. Marker loss in rho- mutants was also investigated under conditions that modulate rho- induction. Liquid holding of irradiated exponential or stationary phase cells, as well as a split-dose regime applied to stationary phase cells, results in rho- mutants in which the loss of markers is correlated with rho- induction: the more sensitive the cells are to rho- induction, the more frequent are the marker losses among rho- clones derived from these cells. This correlation is not found in exponential-phase cells submitted to a split-dose treatment, suggesting that a different mechanism is involved in the latter case. It is known that UV-induced pyrimidine dimers are not excised in a controlled manner in mitochondrial DNA. However, our studies indicate that an accurate repair mechanism (of the recombinational type ?) can lead to the restoration of mitochondrial genetic information in growing cells.

Temperature Effects of Ultraviolet Irradiation on Material Degradation

NASA Astrophysics Data System (ADS)

Mori, Kazuyuki; Ishizawa, Junichiro

Ultraviolet rays (UV) cause organic materials to deteriorate. UV irradiation ground testing is therefore important to understand the “adequate lifetime assessment” and the “end-of-life (EOL) characteristic” of materials used in space. In previous experiments, high temperatures were found to accelerate the UV degradation of cross-linked ethylene tetrafluoroethylene (X-ETFE). This causes concern of potentially similar effects in other materials. In this study, we evaluated UV degradation at high temperatures and subsequently determined materials usable in space that had shown accelerated degradation due to UV irradiation at high temperatures.

Neutron and gamma irradiation effects on power semiconductor switches

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

Neutron and gamma irradiation effects on power semiconductor switches

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

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

PubMed Central

Hazekamp, Arno

2016-01-01

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

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

PubMed

Hazekamp, Arno

2016-01-01

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

Antimicrobials in the Management of Post-Irradiation Infection

DTIC Science & Technology

2005-01-01

infection due to Gram-negative bacteria in the immunocompromised host generally in- volves the use of an aminoglycoside in combination with a beta ...neutropenic cancer patient: Clinical efficacy and impact of monotherapy. Antimicrob Agents Chemother, 31, 971–7, 1987. [Kaplan 1958] Kaplan HW, Speck RS...pefloxacin in irradiated C3H/HeN mice: Correction with glucan therapy. Antimicrob Agents Chemother; 37:1882–9, 1993. [Rozenberg-Arska 1985] Rozenberg

Effect of gamma irradiation on the properties of tyre cords

NASA Astrophysics Data System (ADS)

Aytaç, Ayşe; Şen, Murat; Deniz, Veli; Güven, Olgun

2007-12-01

Gamma irradiation of high tenacity Nylon 6.6 (Ny 66) and polyester (PET) tyre cords was investigated. The untreated and treated tyre cords with different twist levels were irradiated at different dose rates in air. The effects of irradiation on both Ny 66 and PET cords were not found to be depending on the twist levels of the cords. The changes in the mechanical and thermal properties with absorbed dose at two different dose rates were measured. The mechanical properties were observed to deteriorate with increasing dose for Ny 66 cords, whereas remained almost unchanged for PET cords both in greige and dipped forms. Hot shrinkage value for the greige Ny 66 cords was found to be improved, i.e. decreased. This decrease was much lower for greige PET than Ny 66 cords. It is concluded that PET cord has higher radiation resistance than Ny 66 cord and the effects of high energy irradiation on tyre cords have to be taken into consideration during tyre design if pre-vulcanization with high energy radiation is to be applied.

Effect of gamma irradiation on high temperature hardness of low-density polyethylene

NASA Astrophysics Data System (ADS)

Chen, Pei-Yun; Yang, Fuqian; Lee, Sanboh

2015-11-01

Gamma irradiation can cause the change of microstructure and molecular structure of polymer, resulting in the change of mechanical properties of polymers. Using the hardness measurement, the effect of gamma irradiation on the high temperature hardness of low-density polyethylene (LDPE) was investigated. The gamma irradiation caused the increase in the melting point, the enthalpy of fusion, and the portion of crystallinity of LDPE. The Vickers hardness of the irradiated LDPE increases with increasing the irradiation dose, annealing temperature, and annealing time. The activation energy for the rate process controlling the reaction between defects linearly decreases with the irradiation dose. The process controlling the hardness evolution in LDPE is endothermic because LDPE is semi-crystalline.

Irradiation behavior of U 6Mn-Al dispersion fuel elements

NASA Astrophysics Data System (ADS)

Meyer, M. K.; Wiencek, T. C.; Hayes, S. L.; Hofman, G. L.

2000-02-01

Irradiation testing of U 6Mn-Al dispersion fuel miniplates was conducted in the Oak Ridge Research Reactor (ORR). Post-irradiation examination showed that U 6Mn in an unrestrained plate configuration performs similarly to U 6Fe under irradiation, forming extensive and interlinked fission gas bubbles at a fission density of approximately 3×10 27 m-3. Fuel plate failure occurs by fission gas pressure driven `pillowing' on continued irradiation.

Recent results on the neutron irradiation of ITER candidate copper alloys irradiated in DR-3 at 250{degrees}C to 0.3 dpa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, D.J.; Singh, B.N.; Toft, P.

1997-04-01

Tensile specimens of CuCrZr and CuNiBe alloys were given various heat treatments corresponding to solution anneal, prime-ageing and bonding thermal treatment with additional specimens re-aged and given a reactor bakeout treatment at 350{degrees}C for 100 h. CuAl-25 was also heat treated to simulate the effects of a bonding thermal cycle on the material. A number of heat treated specimens were neutron irradiated at 250{degrees}C to a dose level of {approximately}0.3 dpa in the DR-3 reactor as Riso. The main effect of the bonding thermal cycle heat treatment was a slight decrease in strength of CuCrZr and CuNiBe alloys. The strengthmore » of CuAl-25, on the other hand, remained almost unaltered. The post irradiation tests at 250{degrees}C showed a severe loss of ductility in the case of the CuNiBe alloy. The irradiated CuAl-25 and CuCrZr specimens exhibited a reasonable amount of uniform elongation, with CuCrZr possessing a lower strength.« less

Effect of electron beam irradiation on the viscosity of carboxymethylcellulose solution

NASA Astrophysics Data System (ADS)

Choi, Jong-il; Lee, Hee-Sub; Kim, Jae-Hun; Lee, Kwang-Won; Chung, Young-Jin; Byun, Myung-Woo; Lee, Ju-Woon

2008-12-01

In this study, the effects of an electron beam irradiation on the viscosity of a carboxymethylcellulose (CMC) solution were investigated. The viscosity of the CMC solution was decreased with an increase in the irradiation dose. Interestingly, the extent of the degradation of the CMC was found to decrease with an increase of the CMC concentration in the solution. The change of the average molar mass confirmed the decrease in the viscosity due to the degradation of the polymer. The energy of the electron beam also affected the degradation of the CMC. Lower degradation of the CMC was obtained with a decreasing electron beam energy due to its lower penetration. Addition of vitamin C as a radical scavenger to the solution and an irradiation at -70 °C were shown to be moderately effective in preventing a decrease in the viscosity of the solution by irradiation.

Postharvest changes in the phenolic profile of watercress induced by post-packaging irradiation and modified atmosphere packaging.

PubMed

Pinela, José; Barros, Lillian; Barreira, João C M; Carvalho, Ana Maria; Oliveira, M Beatriz P P; Santos-Buelga, Celestino; Ferreira, Isabel C F R

2018-07-15

The effects of γ-ray irradiation and modified atmosphere packaging (MAP) on watercress (Nasturtium officinale R. Br.) phenolic compounds were evaluated after 7-day storage at 4 °C. Irradiation doses of 1, 2 and 5 kGy were tested, as well as vacuum-packaging and MAP enriched with 100% N 2 and Ar. A non-irradiated, air-packaged control was included in all experiments. p-Coumaric acid was the most abundant compound in fresh watercress, followed by quercetin-3-O-sophoroside and isorhamnetin-O-hydroxyferuloylhexoside-O-hexoside. Four kaempferol glycoside derivatives were identified for the first time in this species. In general, flavonoids predominated over phenolic acids. Samples stored under vacuum and irradiated at 2 kGy revealed lower phenolic levels. Ar-enriched MAP and control conditions preserved the initial phenolic content. The 5 kGy dose also maintained concentrations of flavonoids and total phenolic compounds, but increased the phenolic acids content. Additionally, flavonoids were found strongly correlated to DPPH scavenging activity and β-carotene bleaching inhibition capacity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of gamma-ray irradiation on isothermal crystallization of biodegradable poly(ethylene succinate)

NASA Astrophysics Data System (ADS)

Chuang, Yu-Fan; Chou, Yu-Cheng; Yang, Fuqian; Lee, Sanboh

2016-09-01

The effects of gamma-ray irradiation on the isothermal crystallization of biodegradable poly(ethylene succinate) (PESu) and the growth behavior of PESu spherulites have been studied by differential scanning calorimetry and polarized optical microscopy. The irradiation doses used in the study are 0, 200, 400, and 600 kGy. The kinetic parameters for the isothermal crystallization have been determined, using the Avrami relationship. The nucleation constants and activation energy for the growth of the PESu spherulites have been analyzed, using the Lauritzen-Hoffman growth theory. Triple melting points have been observed for all the irradiated PESu. The gamma irradiation has no observable effect on the Avrami exponent, and the composite rate constant increases first with the increase of the crystallization temperature, reaches maximum at the crystallization temperature of 35 °C, and then decreases with the increase of the crystallization temperature for both the non-irradiated and irradiated PESu. There exists a transition of the growth of the PESu spherulites from regime II to regime III. Both the nucleation constants and activation energy increase with increasing the irradiation dose. The gamma irradiation increases the energy barrier for the migration of polymer chains.

Bactericidal effect of Nd:YAG laser irradiation in endodontics

NASA Astrophysics Data System (ADS)

Aun, Carlos E.; Barberini, Alexandre F.; Camargo, Selma C. C.; Silva Kfouri, Luciana; Lorenzetti Simionato, Maria R.

1999-05-01

The success of endodontic therapy is based on the elimination of bacterial colonization from the endodontic system and periapical tissues. Recent studies have been showing the bactericidal effect of laser in root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canals from upper central incisor. For the experiment 12 teeth were selected, respect at the apical third, sterilized, and 10 μm Streptococcus sanguis liquid culture were inoculated in the root canals. The laser test groups were irradiated with Nd:YAG laser at standard setting of 15Hz, 100mj and 1,5 W for 10, 20 and 30 seconds each in slow helicoidal movements from the apex to the top using a 300 micrometers fiber. After the procedure the specimens were placed in Tryptic Soy Agar, the number of colony forming units was evaluated. The experiment showed a significant reduction on viability of Streptococcus sanguis at the respective time of 20 and 30 seconds.

Effect of gamma irradiation on the wear behaviour of human tooth enamel

NASA Astrophysics Data System (ADS)

Qing, Ping; Huang, Shengbin; Gao, Shanshan; Qian, Linmao; Yu, Haiyang

2015-06-01

Radiotherapy is a frequently used treatment for oral cancer. Extensive research has been conducted to detect the mechanical properties of dental hard tissues after irradiation at the macroscale. However, little is known about the influence of irradiation on the tribological properties of enamel at the micro- or nanoscale. Therefore, this study aimed to investigate the effect of gamma irradiation on the wear behaviour of human tooth enamel in relation to prism orientation. Nanoscratch tests, surface profilometer and scanning electron microscope (SEM) analysis were used to evaluate the friction behaviour of enamel slabs before and after treatment with identical irradiation procedures. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were performed to analyse the changes in crystallography and chemical composition induced by irradiation. Surface microhardness (SMH) alteration was also evaluated. The results showed that irradiation resulted in different scratch morphologies, friction coefficients and remnant depth and width at different loads. An inferior nanoscratch resistance was observed independent of prism orientation. Moreover, the variation of wear behaviours was closely related to changes in the crystallography, chemical composition and SMH of the enamel. Together, these measures indicated that irradiation had a direct deleterious effect on the wear behaviour of human tooth enamel.

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

NASA Astrophysics Data System (ADS)

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

1995-02-01

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

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

NASA Astrophysics Data System (ADS)

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

2012-08-01

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

Effects of telmisartan and losartan on irradiated testes.

PubMed

da Silva Mansano, Naira; Jorge, Isabela Fernandes; Chies, Agnaldo Bruno; Viani, Gustavo Arruda; Spadella, Maria Angélica

2018-02-01

To analyze the effects of radiation on the reproductive tissue of male Wistar rats and to evaluate whether treatment with the Ang II AT1 receptor antagonists telmisartan and losartan mitigate the dysfunctions resulting from this exposure. Rats were randomly divided into groups: Control, Irradiated, Telmisartan, Losartan, Irradiated+Telmisartan, and Irradiated+Losartan. Single dose of 5Gy was administered directly into the scrotum, followed by treatment with telmisartan (12mg/kg/day) or losartan (34mg/kg/two times/day) for 60days. Testicular function parameters were evaluated from spermatozoa of the vas deferens. Testes were processed for histopathological and morphometric-stereological analysis. Proliferating cell nuclear antigen (PCNA) immunohistochemistry was evaluated. Radiation significantly reduced sperm motility, concentration, vitality, and increased the number of abnormal spermatozoa. Telmisartan and losartan did not significantly prevent these radiation-induced disorders. Seminiferous tubules were atrophied in both untreated and treated irradiated testes, and exhibited vacuoles, increased interstitial tissue and high number of blood vessels. However, several seminiferous tubules in recuperation were founded among damaged tubules in the testes of treated animals. The PCNA immunohistochemistry confirmed these outcomes. PCNA-positive cells were detected in dividing spermatogonia and spermatocytes from irradiated telmisartan and losartan treated rats whereas in the only-irradiated group, PCNA staining was observed in the nuclei of only the surviving spermatogonia. Under these experimental conditions, the testicular function parameters showed that radiation produced marked damage that was not reversed by treatments. However, gonadal restructuring and recovery of spermatogenesis in treated animals may to reflect attenuation of radiation-induced damages and potential start of recovery. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of irradiation upon the bacterial flora in patients with head and neck cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rice, D.H.; Gill, G.

1979-11-01

Twenty-two consecutive patients with cancer of the head and neck, who were to receive a full tumoricidal dose of irradiation to a field that included the oral cavity and pharynx, were studied to determine the effect of the irradiation on their local bacterial flora. Aerobic cultures were taken prior to, at the completion of, and one month after the completion of their irradiation. The percentage of patients with potentially pathogenic organisms increased dramatically as the effect of the irradiation increased. This change in the local flora has obvious implications concerning the increased incidence of postoperative wound infections in patients whomore » have received prior irradiation.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teysseyre, Sebastien Paul

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.

The effect of friction in the hold down post spherical bearings on hold down post loads

NASA Technical Reports Server (NTRS)

Richardson, James A.

1990-01-01

The effect of friction at the connection of the Solid Rocket Booster (SRB) aft skirt and the mobile launch platform (MLP) hold down posts was analyzed. A simplified model of the shuttle response during the Space Shuttle Main Engine (SSME) buildup was constructed. The model included the effect of stick-slip friction for the rotation of the skirt about the spherical bearing. Current finite element models assume the joint is completely frictionless in rotation and therefore no moment is transferred between the skirt and the hold down posts. The model was partially verified against test data and preliminary parameter studies were performed. The parameter studies indicated that the coefficient of friction strongly influenced the moment on the hold down posts. The coefficient of friction had little effect on hold down post vertical loads, however. Further calibration of the model is necessary before the effect of friction on the hold down post horizontal loads can be analyzed.

Effects of alpha-lipoic acid on associative and spatial memory of sham-irradiated and 56Fe-irradiated C57BL/6J male mice.

PubMed

Villasana, Laura E; Rosenthal, Rosalind A; Doctrow, Susan R; Pfankuch, Timothy; Zuloaga, Damian G; Garfinkel, Alexandra Maccoll; Raber, Jacob

2013-01-01

Cranial irradiation with (56)Fe, a form of space radiation, causes hippocampus-dependent cognitive changes. (56)Fe irradiation also increases reactive oxygen species (ROS) levels, which may contribute to these changes. Therefore, we investigated the effects of the antioxidant alpha lipoic acid (ALA) on cognition following sham-irradiation and irradiation. Male mice were irradiated (brain only) with (56)Fe (3 Gy) or sham-irradiated at 6-9 months of age. Half of the mice remained fed a regular chow and the other half of the mice were fed a caloric-matched diet containing ALA starting two-weeks prior to irradiation and throughout cognitive testing. Following cognitive testing, levels of 3-nitrotyrosine (3NT), a marker of oxidative protein stress, and levels of microtubule-associated protein (MAP-2), a dendritic protein important for cognition, were assessed using immunohistochemistry and confocal microscopy. ALA prevented radiation-induced impairments in spatial memory retention in the hippocampal and cortical dependent water maze probe trials following reversal learning. However, in sham-irradiated mice, ALA treatment impaired cortical-dependent novel object recognition and amygdala-dependent cued fear conditioning. There was a trend towards lower 3NT levels in irradiated mice receiving a diet containing ALA than irradiated mice receiving a regular diet. In the hippocampal dentate gyrus of mice on regular diet, irradiated mice had higher levels of MAP-2 immunoreactivity than sham-irradiated mice. Thus, ALA might have differential effects on the brain under normal physiological conditions and those involving environmental challenges such as cranial irradiation. Copyright © 2012 Elsevier Inc. All rights reserved.

Study on Effects of Gamma-Ray Irradiation on TlBr Semiconductor Detectors

NASA Astrophysics Data System (ADS)

Matsumura, Motohiro; Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira; Kimura, Norihisa; Nagano, Nobumichi; Hitomi, Keitaro

Radiation hardness of thallium bromide (TlBr) semiconductor detectors to 60Co gamma-ray irradiation was evaluated. The energy spectra and μτ products of electrons were measured to evaluate the irradiation effects. No significant degradation of spectroscopic performance of the TlBr detector for 137Cs gamma-rays was observed up to 45 kGy irradiation. Although the μτ products of electrons in the TlBr detector slightly decreased, position of the photo-peak was stable without significant degradation after the gamma-ray irradiation. We confirmed that the TlBr semiconductor detector has a high tolerance for gamma-ray irradiation at least up to 45 kGy.

Magnetic resonance thermometry for monitoring photothermal effects of interstitial laser irradiation

NASA Astrophysics Data System (ADS)

Goddard, Jessica; Jose, Jessnie; Figueroa, Daniel; Le, Kelvin; Liu, Hong; Nordquist, Robert E.; Hode, Tomas; Chen, Wei R.

2012-03-01

Selective photothermal interaction using dye-assisted non-invasive laser irradiation has limitations when treating deeper tumors or when the overlying skin is heavily pigmented. We developed an interstitial laser irradiation method to induce the desired photothermal effects. An 805-nm near-infrared laser with a cylindrical diffuser was used to treat rat mammary tumors by placing the active tip of the fiber inside the target tumors. Three different power settings (1.0 to 1.5 watts) were applied to treat animal tumors with an irradiation duration of 10 minutes. The temperature distributions of the treated tumors were measured by a 7.1-Tesla magnetic resonance imager using proton resonance frequency (PRF) method. Three-dimensional temperature profiles were reconstructed and assessed using PRF. This is the first time a 7.1-Tesla magnetic resonance imager has been used to monitor interstitial laser irradiation via PRF. This study provides a basic understanding of the photothermal interaction needed to control the thermal damage inside tumor using interstitial laser irradiation. It also shows that PRF can be used effectively in monitoring photothermal interaction. Our long-term goal is to develop a PRF-guided laser therapy for cancer treatment.

Effects of electromagnetic pulse irradiation on the mouse blood-testicle barrier.

PubMed

Hou, Wu-Gang; Zhao, Jie; Li, Zhen; Li, Wei; Li, Teng; Xiong, Li-Ze; Zhang, Yuan-Qiang

2012-07-01

To investigate the effects of electromagnetic pulse irradiation on the mouse blood-testicle barrier (BTB) and spermatogenesis. After whole body irradiation with 400 kV/m electromagnetic pulse irradiation, the mouse testicles and BTB permeability were observed using hematoxylin-eosin, Evans blue, and lanthanum nitrate as tracers. The expression of the BTB tight junction protein occludin was examined using real-time polymerase chain reaction and Western blotting. At 1, 7, and 14 days after irradiation, the BTB structure was damaged, the BTB permeability was significantly increased, numerous apoptotic or necrotic spermatogenic cells were found in the lumen, and the mRNA and protein expression levels of occludin were markedly decreased. The BTB structure and occludin expression levels had gradually recovered by 21 and 28 days after irradiation. Electromagnetic pulse irradiation damaged the structure and function of mouse BTB, resulting in apoptosis or necrosis of the spermatogenic cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Post retention: the effect of sequence of post-space preparation, cementation time, and different sealers.

PubMed

Boone, K J; Murchison, D F; Schindler, W G; Walker, W A

2001-12-01

Many endodontic sealers contain constituents that have been shown to inhibit the polymerization of resin cements. This may be important when prefabricated posts are cemented at the same appointment as root canal obturation. This study evaluated the effects of cementing posts with a resin cement immediately or at a delayed time period after obturation using Roth's 801 Elite Grade or AH26 sealer cements. The contribution of mechanical post-space preparation was also assessed as a critical variable. One hundred twenty extracted canines were randomly divided into eight experimental groups. The variables evaluated were the order of post preparation (either before or after obturation), the type of sealer used, and the time of post cementation. All teeth received a stainless steel #6 Parapost XP cemented with a resin cement, Panavia 21. Each experimental group underwent tensile testing for retention using an Instron universal testing machine. For both sealers posts cemented in teeth in which the canal was obturated before post-space preparation and thus had sealer-contaminated dentin removed by the space preparation procedure had significantly higher retentive values than those obturated after post-space preparation in which contaminated dentin might remain. Sealer used and time of cementation had no specific effect on retention. Achieving a clean, "freshened" dentinal surface during mechanical post-space preparation seems to be a critical variable for post retention when a resin cement is used.

Effect of abdominal irradiation on growth in boys treated for a Wilms' tumor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, W.H.; Shalet, S.M.; Morris-Jones, P.H.

1990-01-01

To study the effect of abdominal irradiation on spinal growth in childhood we have measured final height, sitting height, and leg length in 30 male survivors of a Wilms' tumor. Twenty-one patients received whole abdominal irradiation by either megavoltage therapy (MV: n = 11) or orthovoltage therapy (OV: n = 10); the remainder received flank irradiation. To examine the effect of the adolescent growth spurt on the irradiated spine we have followed prospectively seven patients who received whole abdominal irradiation and nine patients who received flank irradiation through puberty. Compared to a normal population there is a modest reduction inmore » median final standing height SDS (H.SDS: -1.15) accompanied by a marked reduction in median final sitting height SDS (S.HT SDS: -2.41) with no apparent effect on median subischial leg length SDS (SILL.SDS: 0.04). This reduction in spinal growth is reflected by a strongly positive disproportion score (DPS; (SILL SDS-S.HT SDS) + 2.81). The incidence of scoliosis after abdominal irradiation has been low (10%). During puberty there is a significant fall in median sitting height SDS after both whole abdominal (median fall: -0.9, P = 0.02) and flank irradiation (median fall: -1.85, P = 0.01), and this is reflected in a significant increase in disproportion (DPS: whole abdominal; median rise +1.4, P = 0.02: flank, median rise +1.34, P = 0.01). After MV irradiation there is a significant correlation between the degree of disproportion and the age at treatment (P less than 0.0005). The younger the patient is at treatment the more severe is the restriction on spinal growth and the shorter and more disproportionate they become as an adult. The estimated eventual loss in potential height from abdominal irradiation at the age of one is 10 cm and at five years is 7 cm.« less

Spherical nanoindentation of proton irradiated 304 stainless steel: A comparison of small scale mechanical test techniques for measuring irradiation hardening

NASA Astrophysics Data System (ADS)

Weaver, Jordan S.; Pathak, Siddhartha; Reichardt, Ashley; Vo, Hi T.; Maloy, Stuart A.; Hosemann, Peter; Mara, Nathan A.

2017-09-01

Experimentally quantifying the mechanical effects of radiation damage in reactor materials is necessary for the development and qualification of new materials for improved performance and safety. This can be achieved in a high-throughput fashion through a combination of ion beam irradiation and small scale mechanical testing in contrast to the high cost and laborious nature of bulk testing of reactor irradiated samples. The current work focuses on using spherical nanoindentation stress-strain curves on unirradiated and proton irradiated (10 dpa at 360 °C) 304 stainless steel to quantify the mechanical effects of radiation damage. Spherical nanoindentation stress-strain measurements show a radiation-induced increase in indentation yield strength from 1.36 GPa to 2.72 GPa and a radiation-induced increase in indentation work hardening rate of 10 GPa-30 GPa. These measurements are critically compared against Berkovich nanohardness, micropillar compression, and micro-tension measurements on the same material and similar grain orientations. The ratio of irradiated to unirradiated yield strength increases by a similar factor of 2 when measured via spherical nanoindentation or Berkovich nanohardness testing. A comparison of spherical indentation stress-strain curves to uniaxial (micropillar and micro-tension) stress-strain curves was achieved using a simple scaling relationship which shows good agreement for the unirradiated condition and poor agreement in post-yield behavior for the irradiated condition. The disagreement between spherical nanoindentation and uniaxial stress-strain curves is likely due to the plastic instability that occurs during uniaxial tests but is absent during spherical nanoindentation tests.

Spherical nanoindentation of proton irradiated 304 stainless steel: A comparison of small scale mechanical test techniques for measuring irradiation hardening

DOE PAGES

Weaver, Jordan S.; Pathak, Siddhartha; Reichardt, Ashley; ...

2017-06-27

Experimentally quantifying the mechanical effects of radiation damage in reactor materials is necessary for the development and qualification of new materials for improved performance and safety. This can be achieved in a high-throughput fashion through a combination of ion beam irradiation and small scale mechanical testing in contrast to the high cost and laborious nature of bulk testing of reactor irradiated samples. The current paper focuses on using spherical nanoindentation stress-strain curves on unirradiated and proton irradiated (10 dpa at 360 °C) 304 stainless steel to quantify the mechanical effects of radiation damage. Spherical nanoindentation stress-strain measurements show a radiation-inducedmore » increase in indentation yield strength from 1.36 GPa to 2.72 GPa and a radiation-induced increase in indentation work hardening rate of 10 GPa–30 GPa. These measurements are critically compared against Berkovich nanohardness, micropillar compression, and micro-tension measurements on the same material and similar grain orientations. The ratio of irradiated to unirradiated yield strength increases by a similar factor of 2 when measured via spherical nanoindentation or Berkovich nanohardness testing. A comparison of spherical indentation stress-strain curves to uniaxial (micropillar and micro-tension) stress-strain curves was achieved using a simple scaling relationship which shows good agreement for the unirradiated condition and poor agreement in post-yield behavior for the irradiated condition. Finally, the disagreement between spherical nanoindentation and uniaxial stress-strain curves is likely due to the plastic instability that occurs during uniaxial tests but is absent during spherical nanoindentation tests.« less

Spherical nanoindentation of proton irradiated 304 stainless steel: A comparison of small scale mechanical test techniques for measuring irradiation hardening

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weaver, Jordan S.; Pathak, Siddhartha; Reichardt, Ashley

Experimentally quantifying the mechanical effects of radiation damage in reactor materials is necessary for the development and qualification of new materials for improved performance and safety. This can be achieved in a high-throughput fashion through a combination of ion beam irradiation and small scale mechanical testing in contrast to the high cost and laborious nature of bulk testing of reactor irradiated samples. The current paper focuses on using spherical nanoindentation stress-strain curves on unirradiated and proton irradiated (10 dpa at 360 °C) 304 stainless steel to quantify the mechanical effects of radiation damage. Spherical nanoindentation stress-strain measurements show a radiation-inducedmore » increase in indentation yield strength from 1.36 GPa to 2.72 GPa and a radiation-induced increase in indentation work hardening rate of 10 GPa–30 GPa. These measurements are critically compared against Berkovich nanohardness, micropillar compression, and micro-tension measurements on the same material and similar grain orientations. The ratio of irradiated to unirradiated yield strength increases by a similar factor of 2 when measured via spherical nanoindentation or Berkovich nanohardness testing. A comparison of spherical indentation stress-strain curves to uniaxial (micropillar and micro-tension) stress-strain curves was achieved using a simple scaling relationship which shows good agreement for the unirradiated condition and poor agreement in post-yield behavior for the irradiated condition. Finally, the disagreement between spherical nanoindentation and uniaxial stress-strain curves is likely due to the plastic instability that occurs during uniaxial tests but is absent during spherical nanoindentation tests.« less

Ultraviolet Irradiation Effect on Apple Juice Bioactive Compounds during Shelf Storage

PubMed Central

Juarez-Enriquez, Edmundo; Salmerón, Ivan; Gutierrez-Mendez, Nestor; Ortega-Rivas, Enrique

2016-01-01

Clarified and standardized apple juice was ultraviolet-irradiated to inactivate polyphenol oxidase enzyme and microbiota, and its effect on bioactive compounds and stability during storage was also evaluated. Apple juice was irradiated with 345.6 J/cm2 and treatment effect was evaluated in terms of color, antioxidant capacity, polyphenol content, pH, titratable acidity and total soluble solids. Using a linear regression design, inactivation kinetic of polyphenol oxidase enzyme was also described. In addition, a repeated measures design was carried out to evaluate apple juice during 24 days of storage at 4 °C and 20 °C. After irradiation, reduction of antioxidant capacity was observed while during storage, ascorbic acid content decreased up to 40% and total polyphenol content remain stable. Ultraviolet irradiation achieved a complete inactivation of polyphenol oxidase enzyme and microbiota, keeping apple juice antioxidants during ultraviolet treatment and storage available until juice consumption. UV-treated apple juice can be used as a regular beverage, ensuring antioxidant intake. PMID:28231106

Effect of annealing high-dose heavy-ion irradiated high-temperature superconductor wires

NASA Astrophysics Data System (ADS)

Strickland, N. M.; Wimbush, S. C.; Kluth, P.; Mota-Santiago, P.; Ridgway, M. C.; Kennedy, J. V.; Long, N. J.

2017-10-01

Heavy-ion irradiation of high-temperature superconducting thin films has long been known to generate damage tracks of amorphized material that are of close-to-ideal dimension to effectively contribute to pinning of magnetic flux lines and thereby enhance the in-field critical current. At the same time, though, the presence of these tracks reduces the superconducting volume fraction available to transport current while the irradiation process itself generates oxygen depletion and disorder in the remaining superconducting material. We have irradiated commercially available superconducting coated conductors consisting of a thick film of (Y,Dy)Ba2Cu3O7 deposited on a buffered metal tape substrate in a continuous reel-to-reel process. Irradiation was by 185 MeV 197Au ions. A high fluence of 3 × 1011 ions/cm2 was chosen to emphasize the detrimental effects. The critical current was reduced following this irradiation, but annealing at relatively low temperatures of 200 °C and 400 °C substantially restore the critical current of the irradiated material. At high fields and high temperatures there is a net benefit of critical current compared to the untreated material.

Effect of gamma-ray irradiation on the dewaterability of waste activated sludge

NASA Astrophysics Data System (ADS)

Wu, Yuqi; Jiang, Yinghe; Ke, Guojun; Liu, Yingjiu

2017-01-01

The effect of gamma-ray irradiation on waste activated sludge (WAS) dewaterability was investigated with irradiation doses of 0-15 kGy. Time to filter (TTF50), specific resistance of filtration (SRF) and water content of sludge cake were measured to evaluate sludge dewaterability. Soluble chemical oxygen demand (SCOD), soluble extracellular polymeric substances (EPS) concentration and sludge particle size were determined to explain changes in sludge dewaterability. The optimal irradiation dose to obtain the maximum dewaterability characteristics was 1-4 kGy, which generated sludge with optimal disintegration (1.5-4.0%), soluble EPS concentration (590-750 mg/L) and particle size distribution (100-115 μm diameter). The combination of irradiation and cationic polyacrylamide (CPAM) addition exhibited minimal synergistic effect on increasing sludge dewatering rate compared with CPAM conditioning alone.

Effect of UV irradiation on the evaporation rate of alcohols droplets

NASA Astrophysics Data System (ADS)

Korobko, O. V.; Britan, A. V.; Verbinskaya, G. H.; Gavryushenko, D. A.

2015-06-01

The effect of ultraviolet irradiation with a wavelength of 390 nm on the evaporation of droplets of the homologous series of alcohols ( n-propanol, n-butanol, n-pentanol, n-heptanol, n-octanol, and n-decanol) at 10, 30, 50, 100, and 200 mm Hg in an atmosphere of dry nitrogen is studied. The values of the evaporation rate of alcohols are calculated with and without irradiation. Starting from n-pentanol, the rate of evaporation grows strongly for droplets of higher alcohols under the effect of low-power irradiation not associated with the heating of the evaporating droplets of alcohols. The obtained results are analyzed by comparing them to experimental data on neutron scattering by alcohols. It is shown that free convection must be considered in order to describe the evaporation process. Expressions of different authors for describing this effect are analyzed.

Performance evaluation and post-irradiation examination of a novel LWR fuel composed of U0.17ZrH1.6 fuel pellets bonded to Zircaloy-2 cladding by lead bismuth eutectic

NASA Astrophysics Data System (ADS)

Balooch, Mehdi; Olander, Donald R.; Terrani, Kurt A.; Hosemann, Peter; Casella, Andrew M.; Senor, David J.; Buck, Edgar C.

2017-04-01

A novel light water reactor fuel has been designed and fabricated at the University of California, Berkeley; irradiated at the Massachusetts Institute of Technology Reactor; and examined within the Radiochemical Processing Laboratory at the Pacific Northwest National Laboratory. This fuel consists of U0.17ZrH1.6 fuel pellets core-drilled from TRIGA reactor fuel elements that are clad in Zircaloy-2 and bonded with lead-bismuth eutectic. The performance evaluation and post irradiation examination of this fuel are presented here.

Effects of irradiation source and dose level on quality characteristics of processed meat products

NASA Astrophysics Data System (ADS)

Ham, Youn-Kyung; Kim, Hyun-Wook; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Choi, Yun-Sang; Song, Beom-Seok; Park, Jong-Heum; Kim, Cheon-Jei

2017-01-01

The effect of irradiation source (gamma-ray, electron-beam, and X-ray) and dose levels on the physicochemical, organoleptic and microbial properties of cooked beef patties and pork sausages was studied, during 10 days of storage at 30±1 °C. The processed meat products were irradiated at 0, 2.5, 5, 7.5, and 10 kGy by three different irradiation sources. The pH of cooked beef patties and pork sausages was unaffected by irradiation sources or their doses. The redness of beef patties linearly decreased with increasing dose level (P<0.05), obviously by e-beam irradiation compared to gamma-ray and X-ray (P<0.05). The redness of pork sausages was increased by gamma-ray irradiation, whereas it decreased by e-beam irradiation depending on absorbed dose level. No significant changes in overall acceptability were observed for pork sausages regardless of irradiation source (P>0.05), while gamma-ray irradiated beef patties showed significantly decreased overall acceptability in a dose-dependent manner (P<0.05). Lipid oxidation of samples was accelerated by irradiation depending on irradiation sources and dose levels during storage at 30 °C. E-beam reduced total aerobic bacteria of beef patties more effectively, while gamma-ray considerably decreased microbes in pork sausages as irradiation dose increased. The results of this study indicate that quality attributes of meat products, in particular color, lipid oxidation, and microbial properties are significantly influenced by the irradiation sources.

Irradiation effects on hydrases for biomedical applications

NASA Astrophysics Data System (ADS)

Furuta, Masakazu; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio

2000-03-01

To apply an irradiation technique to sterilize "Hybrid" biomedical materials including enzymes, we selected papain, a well-characterized plant endopeptidase as a model to examine durability of enzyme activity under the practical irradiation condition in which limited data were available for irradiation inactivation of enzymes. Dry powder and frozen aqueous solution of papain showed significant durability against 60Co-gamma irradiation suggesting that, the commercial irradiation sterilizing method is applicable without modification. Although irradiation of unfrozen aqueous papain solution showed an unusual change of the enzymatic activity with the increasing doses, and was totally inactivated at 15 kGy, we managed to keep the residual activity more than 50% of initial activity after 30-kGy irradiation, taking such optimum conditions as increasing enzyme concentration from 10 to 100 mg/ml and purging with N 2 gas to suppress the formation of free radicals.

Gamma irradiation inactivates honey bee fungal, microsporidian, and viral pathogens and parasites.

PubMed

Simone-Finstrom, Michael; Aronstein, Kate; Goblirsch, Michael; Rinkevich, Frank; de Guzman, Lilia

2018-03-01

Managed honey bee (Apis mellifera) populations are currently facing unsustainable losses due to a variety of factors. Colonies are challenged with brood pathogens, such as the fungal agent of chalkbrood disease, the microsporidian gut parasite Nosema spp., and several viruses. These pathogens may be transmitted horizontally from worker to worker, vertically from queen to egg and via vectors like the parasitic mite, Varroa destructor. Despite the fact that these pathogens are widespread and often harbored in wax comb that is reused from year to year and transferred across beekeeping operations, few, if any, universal treatments exist for their control. In order to mitigate some of these biological threats to honey bees and to allow for more sustainable reuse of equipment, investigations into techniques for the sterilization of hive equipment and comb are of particular significance. Here, we investigated the potential of gamma irradiation for inactivation of the fungal pathogen Ascosphaera apis, the microsporidian Nosema ceranae and three honey bee viruses (Deformed wing virus [DWV], Black queen cell virus [BQCV], and Chronic bee paralysis virus [CBPV]), focusing on the infectivity of these pathogens post-irradiation. Results indicate that gamma irradiation can effectively inactivate A. apis, N. ceranae, and DWV. Partial inactivation was noted for BQCV and CBPV, but this did not reduce effects on mortality at the tested, relatively high doses. These findings highlight the importance of studying infection rate and symptom development post-treatment and not simply rate or quantity detected. These findings suggest that gamma irradiation may function as a broad treatment to help mitigate colony losses and the spread of pathogens through the exchange of comb across colonies, but raises the question why some viruses appear to be unaffected. These results provide the basis for subsequent studies on benefits of irradiation of used comb for colony health and productivity

Effects of gamma and electron beam irradiation on the microbial quality of steamed tofu rolls

NASA Astrophysics Data System (ADS)

Jia, Qian; Gao, Meixu; Li, Shurong; Wang, Zhidong

2013-01-01

The effectiveness of two kinds of radiation processing, gamma and electron beam (ebeam) irradiation, for the inactivation of Staphylococcus aureus, Salmonella enteritidis and Listeria innocua which were inoculated in pre-sterilised steamed tofu rolls was studied. The corresponding effects of both irradiation types on total bacterial counts (TBCs) in commercial steamed tofu rolls available in the market were also examined. The microbiological results demonstrated that gamma irradiation yielded D10 values of 0.20, 0.24 and 0.22 kGy for S. aureus, S. enteritidis and L. innocua, respectively. The respective D10 values for ebeam irradiation were 0.31, 0.35 and 0.27 kGy. Gamma and ebeam irradiation yielded D10 values of 0.48 and 0.43 kGy for total bacterial counts in commercial steamed tofu rolls, respectively. The results suggest that ebeam irradiation has similar effect on decreasing TBCs in steamed tofu rolls, and gamma irradiation is slightly more effective than ebeam irradiation in reducing the populations of pathogenic bacteria. The observed differences in D10-values between them might be due to the significant differences in dose rate applied, and radiation processing of soybean products to improve their microbial quality could be available for other sources of protein.

Effect of gamma irradiation on mistletoe (Viscum album) lectin-mediated toxicity and immunomodulatory activity☆

PubMed Central

Sung, Nak-Yun; Byun, Eui-Baek; Song, Du-Sup; Jin, Yeung-Bae; Kim, Jae-Kyung; Park, Jong-Heum; Song, Beom-Seok; Jung, Pil-Mun; Byun, Myung-Woo; Lee, Ju-Woon; Park, Sang-Hyun; Kim, Jae-Hun

2013-01-01

This study evaluated the effect of gamma irradiation on the reduction of the toxicity of mistletoe lectin using both in vitro and in vivo models. To extract the lectin from mistletoe, an (NH4)2SO4 precipitation method was employed and the precipitant purified using a Sepharose 4B column to obtain the pure lectin fraction. Purified lectin was then gamma-irradiated at doses of 0, 5, 10, 15, and 20 kGy, or heated at 100 °C for 30 min. Toxic effects of non-irradiated, irradiated, and heat-treated lectins were tested using hemagglutination assays, cytotoxicity assays, hepatotoxicity, and a mouse survival test and immunological response was tested using cytokine production activity. Hemagglutination of lectin was remarkably decreased (P < 0.05) by irradiation at doses exceeding 10 kGy and with heat treatment. However, lectin irradiated with 5 kGy maintained its hemagglutination activity. The cytotoxicity of lectin was decreased by irradiation at doses over 5 kGy and with heat treatment. In experiments using mouse model, glutamate oxaloacetate transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels were decreased in the group treated with the 5 kGy irradiated and heat-treated lectins as compared to the intact lectin, and it was also shown that 5 kGy irradiated and heat-treated lectins did not cause damage in liver tissue or mortality. In the result of immunological response, tumor necrosis factor (TNF-α) and interleukin (IL-6) levels were significantly (P < 0.05) increased in the 5 kGy gamma-irradiated lectin treated group. These results indicate that 5 kGy irradiated lectin still maintained the immunological response with reduction of toxicity. Therefore, gamma-irradiation may be an effective method for reducing the toxicity of lectin maintaining the immune response. PMID:23847758

Neurocognitive sparing of desktop microbeam irradiation.

PubMed

Bazyar, Soha; Inscoe, Christina R; Benefield, Thad; Zhang, Lei; Lu, Jianping; Zhou, Otto; Lee, Yueh Z

2017-08-11

Normal tissue toxicity is the dose-limiting side effect of radiotherapy. Spatial fractionation irradiation techniques, like microbeam radiotherapy (MRT), have shown promising results in sparing the normal brain tissue. Most MRT studies have been conducted at synchrotron facilities. With the aim to make this promising treatment more available, we have built the first desktop image-guided MRT device based on carbon nanotube x-ray technology. In the current study, our purpose was to evaluate the effects of MRT on the rodent normal brain tissue using our device and compare it with the effect of the integrated equivalent homogenous dose. Twenty-four, 8-week-old male C57BL/6 J mice were randomly assigned to three groups: MRT, broad-beam (BB) and sham. The hippocampal region was irradiated with two parallel microbeams in the MRT group (beam width = 300 μm, center-to-center = 900 μm, 160 kVp). The BB group received the equivalent integral dose in the same area of their brain. Rotarod, marble burying and open-field activity tests were done pre- and every month post-irradiation up until 8 months to evaluate the cognitive changes and potential irradiation side effects on normal brain tissue. The open-field activity test was substituted by Barnes maze test at 8th month. A multilevel model, random coefficients approach was used to evaluate the longitudinal and temporal differences among treatment groups. We found significant differences between BB group as compared to the microbeam-treated and sham mice in the number of buried marble and duration of the locomotion around the open-field arena than shams. Barnes maze revealed that BB mice had a lower capacity for spatial learning than MRT and shams. Mice in the BB group tend to gain weight at the slower pace than shams. No meaningful differences were found between MRT and sham up until 8-month follow-up using our measurements. Applying MRT with our newly developed prototype compact CNT-based image-guided MRT system

Effects of antioxidant combinations on shelf stability of irradiated chicken sausage during storage

NASA Astrophysics Data System (ADS)

Hwang, Ko-Eun; Kim, Hyun-Wook; Song, Dong-Heon; Kim, Yong-Jae; Ham, Yun-Kyung; Lee, Ju-Woon; Choi, Yun-Sang; Kim, Cheon-Jei

2015-01-01

This study was conducted in order to investigate the combined effects of gamma irradiation (0, 2.5, and 5 kGy) and antioxidant combination, mugwort extract (ME) and ascorbic acid (Aa), on the pH, total color difference (ΔE), hue angle (H°), 2-thiobarbituricacid-reactive substances (TBARS) values, residual nitrite contents, and sensory evaluation in chicken sausage during storage. The pH values and sensory properties, except for color, of chicken sausage were not significantly affected by adding ME or treating irradiation during storage. However, ΔE, and H° values of samples containing ME (either alone or with Aa) were higher than that of control, whereas irradiation had no significant effect during storage. A combination of ME+Aa (0.2% ME+0.05% Aa) was effective at delaying lipid oxidation in irradiated chicken sausage. In addition, nitrite contents were reduced by gamma ray as a dose dependent manner and, particularly in ME+Aa was most effective in decreasing the residual nitrite. Our results suggested that gamma irradiation combined with an antioxidant mixture is a useful technology for reducing the residual nitrite and retarding the lipid oxidation in chicken sausage.

Effect of laser soldering irradiation on covalent bonds of pure collagen.

PubMed

Constantinescu, Mihai A; Alfieri, Alex; Mihalache, George; Stuker, Florian; Ducray, Angélique; Seiler, Rolf W; Frenz, Martin; Reinert, Michael

2007-03-01

Laser tissue welding and soldering is being increasingly used in the clinical setting for defined surgical procedures. The exact induced changes responsible for tensile strength are not yet fully investigated. To further improve the strength of the bonding, a better understanding of the laser impact at the subcellular level is necessary. The goal of this study was to analyze whether the effect of laser irradiation on covalent bonding in pure collagen using irradiances typically applied for tissue soldering. Pure rabbit and equine type I collagen were subjected to laser irradiation. In the first part of the study, rabbit and equine collagen were compared using identical laser and irradiation settings. In the second part of the study, equine collagen was irradiated at increasing laser powers. Changes in covalent bonding were studied indirectly using the sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) technique. Tensile strengths of soldered membranes were measured with a calibrated tensile force gauge. In the first experiment, no differences between the species-specific collagen bands were noted, and no changes in banding were found on SDS-PAGE after laser irradiation. In the second experiment, increasing laser irradiation power showed no effect on collagen banding in SDS-PAGE. Finally, the laser tissue soldering of pure collagen membranes showed virtually no determinable tensile strength. Laser irradiation of pure collagen at typical power settings and exposure times generally used in laser tissue soldering does not induce covalent bonding between collagen molecules. This is true for both rabbit and equine collagen proveniences. Furthermore, soldering of pure collagen membranes without additional cellular components does not achieve the typical tensile strength reported in native, cell-rich tissues. This study is a first step in a better understanding of laser impact at the molecular level and might prove useful in engineering of combined

In-Pile Tests for IASCC Growth Behavior of Irradiated 316L Stainless Steel under Simulated BWR Condition in JMTR

NASA Astrophysics Data System (ADS)

Chimi, Yasuhiro; Kasahara, Shigeki; Ise, Hideo; Kawaguchi, Yoshihiko; Nakano, Junichi; Nishiyama, Yutaka

The Japan Atomic Energy Agency (JAEA) has an in-pile irradiation test plan to evaluate in-situ effects of neutron/γ-ray irradiation on stress corrosion crack (SCC) growth of irradiated stainless steels using the Japan Materials Testing Reactor (JMTR). SCC growth rate and its dependence on electrochemical corrosion potential (ECP) are different between in-pile test and post irradiation examination (PIE). These differences are not fully understood because of a lack of in-pile data. This paper presents a systematic review on SCC growth data of irradiated stainless steels, an in-pile test plan for crack growth of irradiated SUS316L stainless steel under simulated BWR conditions in the JMTR, and the development of the in-pile test techniques.

Proton irradiation effects on gallium nitride-based devices

NASA Astrophysics Data System (ADS)

Karmarkar, Aditya P.

Proton radiation effects on state-of-the-art gallium nitride-based devices were studied using Schottky diodes and high electron-mobility transistors. The device degradation was studied over a wide range of proton fluences. This study allowed for a correlation between proton irradiation effects between different types of devices and enhanced the understanding of the mechanisms responsible for radiation damage in GaN-based devices. Proton irradiation causes reduced carrier concentration and increased series resistance and ideality factor in Schottky diodes. 1.0-MeV protons cause greater degradation than 1.8-MeV protons because of their higher non-ionizing energy loss. The displacement damage in Schottky diodes recovers during annealing. High electron-mobility transistors exhibit extremely high radiation tolerance, continuing to perform up to a fluence of ˜1014 cm-2 of 1.8-MeV protons. Proton irradiation creates defect complexes in the thin-film structure. Decreased sheet carrier mobility due to increased carrier scattering and decreased sheet carrier density due to carrier removal by the defect centers are the primary damage mechanisms. Interface disorder at either the Schottky or the Ohmic contact plays a relatively unimportant part in overall device degradation in both Schottky diodes and high electron-mobility transistors.

Low- and high-dose laser irradiation effects on cell migration and destruction

NASA Astrophysics Data System (ADS)

Layton, Elivia; Gallagher, Kyra A.; Zukerman, Sara; Stevens, Brianna; Zhou, Feifan; Liu, Hong; Chen, Wei R.

2018-02-01

Metastases are the cause of more than 90 percent of cancer-related deaths. Current treatment methods, including chemotherapy, radiation, and surgery, fail to target the metastases effectively. One potential treatment for metastatic cancer is laser immunotherapy (LIT). LIT combines the use of a photothermal laser with an immunoadjuvant, Glycated Chitosan (GC). GC combined with single-walled carbon nanotubes (SWNTs) has proven to be a viable alternative to traditional cancer treatment methods, when under irradiation of laser with appropriate wavelength. In this study, the effects of low dose and high dose laser irradiation on metastatic pancreatic cancer cell migration were observed. It was found that low dose irradiation increased the migration rate, but the high dose irradiation significantly decreased the migration rate of the cancer cells. When using LIT, the goal is to kill tumor cells and to prompt the correct immune response. If the tumor were irradiated with a low dose, it would promote metastasis. If the dose of irradiation were too high, it would destroy the entire tumor and the immune response would not recognize the tumor. Therefore, the laser dose plays an important role in LIT, particularly when using SWNT as light absorbing agent. Our results from this study will delineate the optimal laser irradiation dose for destroying tumor cells and at the same time preserve and release tumor antigens as a precursor of antitumor immune response.

Detection of gamma-irradiation effect on DNA and protein using magnetic sensor and cyclic voltammetry.

PubMed

Park, Duck-Gun; Song, Hoon; Kishore, M B; Vértesy, G; Lee, Duk-Hyun

2013-11-01

In this study, a magnetic sensor utilizing Planar Hall Resistance (PHR) and cyclic Voltammetry (CV) for detecting the radiation effect was fabricated. Specifically, we applied in parallel a PHR sensor and CV device to monitor the irradiation effect on DNA and protein respectively. Through parallel measurements, we demonstrated that the PHR sensor and CV are sensitive enough to measure irradiation effect. The PHR voltage decreased by magnetic nanobead labeled DNA was slightly recovered after gamma ray irradiation. The behavior of cdk inhibitor protein p21 having a sandwich structure of Au/protein G/Ab/Ag/Ab was checked by monitoring the cyclic Voltammetry signal in analyzing the gamma ray irradiation effect.

Effect of pelvic irradiation on the absorption of bile acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stryker, J.A.; Demers, L.M.

1979-07-01

The pathophysiology of radiation-induced diarrhea was evaluated in 17 patients undergoing pelvic irradiation for gynecological malignancies. The glycine conjugates of cholic acid (GC) and chenodeoxycholic acid (GCDC) were measured in serum by radioimmunoassay. Fasting and 2 hour post prandial (pp) determinations were performed prior to and in the fifth week of radiotherapy. The pre-treatment fasting and 2 hour pp GC levels were 0.20 +- 0.29 (mean +- SD) and 0.48 +- 0.47 ..mu..M. In the fifth week the fasting and 2 hour pp GC levels were 0.16 +- 0.23 and 0.25 +- 0.27 ..mu..M. The first week fasting and 2more » hour pp GCDC levels were 0.32 +- 0.47 and 0.80 +- 0.83 ..mu..M: in the fifth week they were 0.10 +- 0.06 and 0.33 +- 0.27 ..mu..M. The differences between the first and the fifth week post prandial increases in serum GC and GCDC levels were significant (P<0.02). The reduced post prandial increases in serum GC and GCDC in the fifth week of radiotherapy occurred at a time when the patients' daily stool frequencies were significantly increased (P<0.01). The data suggest that a cholerrheic enteropathy is the major determinant in the pathophysiology of radiation-induced diarrhea.« less

Gastroprotective effect of kefir on ulcer induced in irradiated rats.

PubMed

Fahmy, Hanan A; Ismail, Amel F M

2015-03-01

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

Studies of physiology and the morphology of the cat LGN following proton irradiation.

PubMed

Reder, C S; Moyers, M F; Lau, D; Kirby, M A

2000-03-15

We have examined the effects of proton irradiation on the histologic and receptive field properties of thalamic relay cells in the cat visual system. The cat lateral geniculate nucleus (LGN) is a large structure with well-defined anatomical boundaries, and well-described afferent, efferent, and receptive field properties. A 1.0-mm proton microbeam was used on the cat LGN to determine short-term (3 months) and long-term (9 months) receptive field effects of irradiation on LGN relay cells. The doses used were 16-, 40-, and 60-gray (Gy). Following irradiation, abnormalities in receptive field organization were found in 40- and 60-Gy short-term animals, and in all of the long-term animals. The abnormalities included "silent" areas of the LGN where a visual response could not be evoked and other regions that had unusually large or small compound receptive fields. Histologic analysis failed to identify cellular necrosis or vascular damage in the irradiated LGN, but revealed a disruption in retinal afferents to areas of the LGN. These results indicate that microbeam proton irradiation can disrupt cellular function in the absence of obvious cellular necrosis. Moreover, the area and extent of this disruption increased with time, having larger affect with longer post-irradiation periods.

Effects of electron irradiation on LDPE/MWCNT composites

NASA Astrophysics Data System (ADS)

Yang, Jianqun; Li, Xingji; Liu, Chaoming; Rui, Erming; Wang, Liqin

2015-12-01

In this study, mutiwalled carbon nanotubes (MWCNTs) were incorporated into low density polyethylene (LDPE) in different concentrations (2%, 4% and 8%) using a melt blending process. Structural, thermal stability and tensile property of the unirradiated/irradiated LDPE/MWCNT composites by 110 keV electrons were investigated by means of scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), Raman spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, thermogravimetric analysis (TGA) and uniaxial tensile techniques. Experimental results show that the addition of MWCNTs obviously increases the ultimate tensile strength of LDPE and decreases the elongation at break, which is attributed to the homogeneous distribution of the MWCNTs in LDPE and intense interaction between MWCNTs and LDPE matrix. Also, the electron irradiation further increases the ultimate tensile strength of LDPE/MWCNT composites, which can be ascribed to the more intense interaction between MWCNTs and LDPE matrix, and the formation of crosslinking sites in LDPE matrix induced by the electron irradiation. The addition of MWCNTs significantly enhances thermal stability of the LDPE due to the hindering effect and the scavenging free radicals, while the electron irradiation decreases thermal stability of the LDPE/MWCNT composites since the structure of the MWCNTs and LDPE matrix damages.

EFFECTS OF IN VITRO RADIOCOBALT IRRADIATION OF RABBIT OVA ON SUBSEQUENT DEVELOPMENT IN VIVO WITH SPECIAL REFERENCE TO THE IRRADIATION OF MATERNAL ORGANISM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, M.C.; Hunt, D.M.

Fertilized rabbit ova recovered one to six days after mating were irradiated in vitro from a radiocobalt source and then transplanted into recipient animals. When examined 22 to 28 days later 44, 33, 8 and 0% of ova irradiated respectively at 50, 100, 1,000 and 5,000 r developed into apparently normal fetuses without external or internal malformation. No significant differential sensitivity was apparent in ova irradiated at different ages. It was found further that 34, 36, 19 and 10% of two-, 4-, and 6-day ova irradiated respectively in vitro at 200, 400, 600, and 800 r developed into "normal" fetuses.more » Again no malformation of fetuses and no differential radiosensitivity between ova of different ages were observed. Following whole body irradiation at 400 r, it was found that 40% of non-irradiated ova developed into normal fetuses when transplanted into recipient animals that had been irradiated (vs. 36% in the irradiation of ova alone). However, only 17% of estimated ova developed into "normal" fetuses when pregnant rabbits were irradiated 2, 4 or 6 days after insemination (vs. 64% in the control). It appears that irradiation of the maternal organism influences embryonic development and that irradiation of pregnant animals exerts a combination of ill effects, on the ova and on their environment. Cytological study of irradiated blastocysts revealed no chromosomal breakage immediately after irradiation. Chromosomal abnormalities, fragmentation and condensation of chromatin were observed during the culture of irradiated blastocysts in accordance with the dosages applied. From this study it is concluded that (1) although 50 r may affect embryonic development, there seems to be no differential effect up to 400 r, above which greater prenatal death occurs; (2) before implantation, irradiated ova either die or develop into apparently normal fetuses and there is no evidence of differential radiosensitivity at various stages of development; (3) irradiation of the

Combined effect of gamma-irradiation and conventional cooking on Aeromonas hydrophila in meatball.

PubMed

Ozbaş, Z Y; Vural, H; Aytaç, S A

1996-01-01

Irradiation combined with a conventional cooking procedure was applied to meatball and the effects on bacterial load and inoculated Aeromonas hydrophila were determined. Meatball samples were irradiated by using a 60Co source at the dose levels of 0, 0.30, 0.75, 1.50, 2.50 kGy and cold stored at 4 +/- 1 degrees C for 7 days. Bacterial load and the count of A. hydrophila decreased when the irradiation dose level increased. A minimum inhibition effect was found at the dose of 0.30 kGy. Irradiation in combination with a conventional cooking procedure was found to be more effective in reducing A. hydrophila and the bacterial load in meatball. This study indicated that a dose of 0.75 kGy was sufficient to destroy approximately 10(4) cfu/g of A. hydrophila in meatball.

Effect of ND:YAG laser irradiation and root planing on the root surface: structural and thermal effects.

PubMed

Wilder-Smith, P; Arrastia, A M; Schell, M J; Liaw, L H; Grill, G; Berns, M W

1995-12-01

Effects of ND:YAG laser irradiation on untreated and root planed tooth roots were investigated to determine whether a cleaning effect and/or removal of smear layer could be achieved without concomitant microstructural or thermal damage. Sixty (60) healthy extracted teeth were either untreated, irradiated only, root planed only, or irradiated and root planed. Intra-pulpal and surface temperatures were monitored during irradiation, then SEM was performed. Smear layer elimination was achieved without inducing hard tissue microstructural damage at 5W, using pulse durations and intervals of 0.1 s, a fluence of 0.77 J/cm2, and a total energy density of approximately 700 J/cm2. However, these results were not consistent in all samples. At these parameters, intra-pulpal temperature increases of 9 to 22 degrees C and surface temperature increases of 18 to 36 degrees C were recorded. Thus, despite their effectiveness for smear layer removal, these parameters may not be appropriate for clinical use as an adjunct to conventional periodontal therapy.

Effect of different laser irradiation on the dysentery bacilli

NASA Astrophysics Data System (ADS)

Ou, Lin; Chen, Rong; Chen, Yanjiao; Li, Depin; Wen, Caixia

1998-08-01

The S. flexnesi, which have high drug-resistance especially in Cm, Sm, Tc, SD, were irradiated by Ar+ laser at 488 nm and semiconductor laser at 808 nm. The experiment results have shown that both Ar+ laser and semiconductor laser with power density of 1.7 w/cm2 and irradiation dose of 2000 J/cm2 can conduce to the bacterial lethality and increase the mutation rates of the bacterial drug-sensitivity, and 'Colony Count' method have the superiority over the 'Inhibacteria Ring' method. At the mean time it further indicate that the high power semiconductor laser would play an important role in the sciences of laser biological medicine. But the effect of the near infrared semiconductor laser is far lower than that of Ar+ laser of shorter wavelength at the same irradiation dose. It is clear that the output and irradiation dose of near infrared semiconductor laser shall be increased in order to get the same rates of the bacterial lethality and the drug-sensitivity mutation as Ar+ laser's.

Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes.

PubMed

Pongcharoen, Sutatip; Warnnissorn, Prateep; Leŗtkajornsin, Ongart; Limpeanchob, Nanteetip; Sutheerawattananonda, Manote

2013-01-01

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation.

Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo

PubMed Central

Brönnimann, Daniel; Bouchet, Audrey; Schneider, Christoph; Potez, Marine; Serduc, Raphaël; Bräuer-Krisch, Elke; Graber, Werner; von Gunten, Stephan; Laissue, Jean Albert; Djonov, Valentin

2016-01-01

Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25–100 μm wide) and minibeams (200–800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a+ thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool. PMID:27640676

Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo.

PubMed

Brönnimann, Daniel; Bouchet, Audrey; Schneider, Christoph; Potez, Marine; Serduc, Raphaël; Bräuer-Krisch, Elke; Graber, Werner; von Gunten, Stephan; Laissue, Jean Albert; Djonov, Valentin

2016-09-19

Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 μm wide) and minibeams (200-800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a(+) thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool.

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

NASA Astrophysics Data System (ADS)

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

2009-07-01

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

Viability of a human melanoma cell after single and combined treatment with fotemustine, dacarbazine, and proton irradiation.

PubMed

Petrović, Ivan M; Korićanac, Lela B; Todorović, Danijela V; Ristić-Fira, Aleksandra M; Valastro, Lucia M; Privitera, Giuseppe; Cuttone, Giacomo

2007-01-01

Viability of human HTB140 melanoma cells after being exposed to fotemustine (FM) and dacarbazine (DTIC) as well as to proton irradiation was studied. Effects of 100 and 250 microM drugs were assessed after incubation of 6, 24, 48, 72, and 96 h. Irradiations were performed with 62 MeV therapeutic protons, delivering to the cell monolayer single doses of 2, 4, 8, 12, and 16 Gy. Viability was evaluated 7 days after irradiation. Inactivation level was estimated using microtetrasolium (MTT) and sulforhodamine B (SRB) assays. Combined effects of each drug and protons, were carried out using the same drug concentrations. Proton doses applied were those used in therapy, that is, 12 and 16 Gy. With the increase of drug concentration or irradiation dose, level of cell inactivation reached approximately 60%, 48 h after drug treatment or 7 days after irradiation at 16 Gy. Considering the rate of drug concentrations used, as well as the level of doses applied, it appears that HTB140 cells are more resistant to proton irradiation than to alkylating agents tested. The combined treatment with FM or DTIC and protons did not show significant changes of cell viability as compared to the effects of single agents. Since the time point for measuring cumulative effects of drug and irradiation was 48 h post irradiation, it seems that the obtained level of viability could be attributed primarily to the effects of drugs.

Combined effects of gamma irradiation and a modified atmospheric packaging on the physicochemical characteristics of sausage

NASA Astrophysics Data System (ADS)

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

2004-09-01

This study is to investigate the combined effects of irradiation and a modified atmospheric packaging (MAP) on the color, nitrosoheme pigments (NO-Mb), residual nitrite and N-nitrosodimethylamine (NDMA) in sausage during storage. Sausage with air, vacuum, CO 2, N 2, or CO 2/N 2 packaging was irradiated at 5 kGy. Irradiation reduced the red color of sausage, and a vacuum or MAP was effective in minimizing the loss of redness. The reduction of NO-Mb was observed by irradiation, while the MAP was more effective in maintaining the NO-Mb than the aerobic ones. Residual nitrite was reduced by irradiation, and the contents were lower under vacuum or MAP than aerobic ones. NDMA was significantly reduced by irradiation.

Early effects of whole-body (56)Fe irradiation on hippocampal function in C57BL/6J mice.

PubMed

Haley, Gwendolen E; Yeiser, Lauren; Olsen, Reid H J; Davis, Matthew J; Johnson, Lance A; Raber, Jacob

2013-05-01

Relatively little is known about early irradiation effects on hippocampal function in wild-type mice. In this study, the effects of (56)Fe irradiation on hippocampal function were assessed starting 2 weeks after whole-body irradiation. Compared to sham irradiation, radiation impaired novel object recognition in female and male C57BL/6J wild-type mice. There were no effects of irradiation on contextual fear conditioning or spatial memory retention in the water maze. It is possible that oxidative damage might contribute to radiation-induced cognitive changes. Therefore, hippocampal and cortical levels of 3-nitrotyrosine (3NT) and lipid peroxidation, measures of oxidative damage were assessed. There were no effects of irradiation on these measures of oxidative damage. As (56)Fe irradiation can increase reactive oxygen species (ROS) levels, which may contribute to the impairments in novel object recognition, the effects of the antioxidant alpha-lipoic acid (ALA) on cognition following sham irradiation and irradiation were also assessed. ALA did not prevent radiation-induced impairments in novel object recognition and impaired spatial memory retention of sham-irradiated and irradiated mice in the probe trial after the first day of hidden platform training in the water maze. Thus, the novel object recognition test is particularly sensitive to detect early cognitive effects of (56)Fe irradiation through a mechanism unlikely involving ROS or oxidative damage.

Effect of gamma irradiation on rice and its food products

NASA Astrophysics Data System (ADS)

Sung, Wen-Chieh

2005-07-01

Two milled indica rice varieties were exposed to gamma radiation with doses ranging from 0 to 1.0 kGy. The effects of gamma irradiation on rice flour pasting properties and the qualities of its food product, rice curd, were compared to the effects of storage. A dose of 1 kGy can decrease the flour paste viscosity and tenderize the texture of the rice curd to similar levels as those obtained after 12 months of storage. It was thus shown that gamma irradiation could shorten the indica rice aging time and improve the processing stability and quality of rice products.

Effect of irradiation and storage on the antioxidative activity of cashew nuts

NASA Astrophysics Data System (ADS)

Sajilata, M. G.; Singhal, R. S.

2006-02-01

Food irradiation, a cold process employed for preservation of food has been studied extensively for its beneficial and undesirable effects on food constituents. Since nuts have been shown to contain several antioxidants, and ionizing irradiation is known to result in the formation of free radicals, investigation on the antioxidative potential of cashew nuts after irradiation and subsequent storage was undertaken by assessing their ability to inhibit lipid peroxidation using the 1,3-diethyl-2-thiobarbituric acid (DETBA) assay. Irradiation at 0.25-1.00 kGy and subsequent storage was found to considerably reduce antioxidative activity in the cashew nuts.

Factors That Affect Proliferation of Salmonella in Tomatoes Post-Harvest: The Roles of Seasonal Effects, Irrigation Regime, Crop and Pathogen Genotype

PubMed Central

Marvasi, Massimiliano; Hochmuth, George J.; Giurcanu, Mihai C.; George, Andrée S.; Noel, Jason T.; Bartz, Jerry; Teplitski, Max

2013-01-01

Main Objectives Fresh fruits and vegetables become increasingly recognized as vehicles of human salmonellosis. Physiological, ecological, and environmental factors are all thought to contribute to the ability of Salmonella to colonize fruits and vegetables pre- and post-harvest. The goal of this study was to test how irrigation levels, fruit water congestion, crop and pathogen genotypes affect the ability of Salmonella to multiply in tomatoes post-harvest. Experimental Design Fruits from three tomato varieties, grown over three production seasons in two Florida locations, were infected with seven strains of Salmonella and their ability to multiply post-harvest in field-grown tomatoes was tested. The field experiments were set up as a two-factor factorial split plot experiment, with the whole-plot treatments arranged in a randomized complete-block design. The irrigation treatment (at three levels) was the whole-plot factor, and the split-plot factor was tomato variety, with three levels. The significance of the main, two-way, and three-way interaction effects was tested using the (type III) F-tests for fixed effects. Mean separation for each significant fixed effect in the model was performed using Tukey’s multiple comparison testing procedure. Most Important Discoveries and Significance The irrigation regime per se did not affect susceptibility of the crop to post-harvest proliferation of Salmonella. However, Salmonella grew significantly better in water-congested tissues of green tomatoes. Tomato maturity and genotype, Salmonella genotype, and inter-seasonal differences were the strongest factors affecting proliferation. Red ripe tomatoes were significantly and consistently more conducive to proliferation of Salmonella. Tomatoes harvested in the driest, sunniest season were the most conducive to post-harvest proliferation of the pathogen. Statistically significant interactions between production conditions affected post-harvest susceptibility of the crop to the

Factors that affect proliferation of Salmonella in tomatoes post-harvest: the roles of seasonal effects, irrigation regime, crop and pathogen genotype.

PubMed

Marvasi, Massimiliano; Hochmuth, George J; Giurcanu, Mihai C; George, Andrée S; Noel, Jason T; Bartz, Jerry; Teplitski, Max

2013-01-01

Fresh fruits and vegetables become increasingly recognized as vehicles of human salmonellosis. Physiological, ecological, and environmental factors are all thought to contribute to the ability of Salmonella to colonize fruits and vegetables pre- and post-harvest. The goal of this study was to test how irrigation levels, fruit water congestion, crop and pathogen genotypes affect the ability of Salmonella to multiply in tomatoes post-harvest. Fruits from three tomato varieties, grown over three production seasons in two Florida locations, were infected with seven strains of Salmonella and their ability to multiply post-harvest in field-grown tomatoes was tested. The field experiments were set up as a two-factor factorial split plot experiment, with the whole-plot treatments arranged in a randomized complete-block design. The irrigation treatment (at three levels) was the whole-plot factor, and the split-plot factor was tomato variety, with three levels. The significance of the main, two-way, and three-way interaction effects was tested using the (type III) F-tests for fixed effects. Mean separation for each significant fixed effect in the model was performed using Tukey's multiple comparison testing procedure. The irrigation regime per se did not affect susceptibility of the crop to post-harvest proliferation of Salmonella. However, Salmonella grew significantly better in water-congested tissues of green tomatoes. Tomato maturity and genotype, Salmonella genotype, and inter-seasonal differences were the strongest factors affecting proliferation. Red ripe tomatoes were significantly and consistently more conducive to proliferation of Salmonella. Tomatoes harvested in the driest, sunniest season were the most conducive to post-harvest proliferation of the pathogen. Statistically significant interactions between production conditions affected post-harvest susceptibility of the crop to the pathogen. UV irradiation of tomatoes post-harvest promoted Salmonella growth.

Study on elucidation of bactericidal effects induced by laser beam irradiation Measurement of dynamic stress on laser irradiated surface

NASA Astrophysics Data System (ADS)

Furumoto, Tatsuaki; Kasai, Atsushi; Tachiya, Hiroshi; Hosokawa, Akira; Ueda, Takashi

2010-09-01

In dental treatment, many types of laser beams have been used for various surgical treatments, and the influences of laser beam irradiation on bactericidal effect have been investigated. However, most of the work has been performed by irradiating to an agar plate with the colony of bacteria, and very few studies have been reported on the physical mechanism of bactericidal effects induced by laser beam irradiation. This paper deals with the measurement of dynamic stress induced in extracted human enamel by irradiation with Nd:YAG laser beams. Laser beams can be delivered to the enamel surface through a quartz optical fiber. Dynamic stress induced in the specimen using elastic wave propagation in a cylindrical long bar made of aluminum alloy is measured. Laser induced stress intensity is evaluated from dynamic strain measured by small semiconductor strain gauges. Carbon powder and titanium dioxide powder were applied to the human enamel surface as absorbents. Additionally, the phenomenon of laser beam irradiation to the human enamel surface was observed with an ultrahigh speed video camera. Results showed that a plasma was generated on the enamel surface during laser beam irradiation, and the melted tissues were scattered in the vertical direction against the enamel surface with a mushroom-like wave. Averaged scattering velocity of the melted tissues was 25.2 m/s. Induced dynamic stress on the enamel surface increased with increasing laser energy in each absorbent. Induced dynamic stresses with titanium dioxide powder were superior to those with carbon powder. Induced dynamic stress was related to volume of prepared cavity, and induced stress for the removal of unit volume of human enamel was 0.03 Pa/mm 3.

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

NASA Astrophysics Data System (ADS)

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

2015-05-01

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

Effects of Normothermic Conditioned Microwave Irradiation on Cultured Cells Using an Irradiation System with Semiconductor Oscillator and Thermo-regulatory Applicator

PubMed Central

Asano, Mamiko; Sakaguchi, Minoru; Tanaka, Satoshi; Kashimura, Keiichiro; Mitani, Tomohiko; Kawase, Masaya; Matsumura, Hitoshi; Yamaguchi, Takako; Fujita, Yoshikazu; Tabuse, Katsuyoshi

2017-01-01

We investigated the effects of microwave irradiation under normothermic conditions on cultured cells. For this study, we developed an irradiation system constituted with semiconductor microwave oscillator (2.45 GHz) and thermos-regulatory applicator, which could irradiate microwaves at varied output powers to maintain the temperature of cultured cells at 37 °C. Seven out of eight types of cultured cells were killed by microwave irradiation, where four were not affected by thermal treatment at 42.5 °C. Since the dielectric properties such as ε’, ε” and tanδ showed similar values at 2.45 GHz among cell types and media, the degree of microwave energy absorbed by cells might be almost the same among cell types. Thus, the vulnerability of cells to microwave irradiation might be different among cell types. In HL-60 cells, which were the most sensitive to microwave irradiation, the viability decreased as irradiation time and irradiation output increased; accordingly, the decrease in viability was correlated to an increase in total joule. However, when a high or low amount of joules per minute was supplied, the correlation between cellular viability and total joules became relatively weak. It is hypothesized that kinds of cancer cells are efficiently killed by respective specific output of microwave under normothermic cellular conditions. PMID:28145466

Effects of gamma irradiation dose-rate on sterile male Aedesaegypti

NASA Astrophysics Data System (ADS)

Ernawan, Beni; Tambunan, Usman Sumo Friend; Sugoro, Irawan; Sasmita, Hadian Iman

2017-06-01

Aedesaegypti is the most important vector for dengue, yellow fever and Zika viruses. Considering its medical importance, vector population control program utilizing radiation-based sterile insect technique (SIT) is one of the potential methods for preventing and limiting the dispersal of these viruses. The present study was undertaken to evaluate the dose-rates effects of γ-sterilization on quality parameters of sterile males. Males Ae.aegypti at the pupal stage were sterilized by applying 70 Gyγ-rays in varies dose-rates, i.e. 0 (control), 300, 600, 900, 1200 and 1500Gy/h utilizing panoramic irradiator. Adult males that emerged from the pupal stage were assessed for their quality parameters, which are the percentage of emergence, longevity, sterility and mating competitiveness. The results herein indicate that there was no major effect of dose-rate on the percentage of emergence, the data showedthat there were no differences between irradiated males compared with control. Generally, the longevity of irradiated males was lower compared to control. The data also demonstrated that longevity was significantly increased at the dose-rate from 300 to 900Gy/h, then decreased at the dose-rate 900 to 1500 Gy/h. Sterility of irradiated maleswas significantly different compared to control, while there was no significantly different at dose rate 300 to 1500 Gy/h. Mating competitiveness of irradiated males was increased at the dose rate from 300 to 1200 Gy/h, then the value was decreased significantly at the dose rate 1500 Gy/h. The dose-rate effects of γ-sterilization were discussed in the context genetic vector control, in particular, the SIT. The results give information and contribute to better understanding towards γ-sterilization optimization and quality parameters of sterile male Ae. aegypti on SIT methods.

Effect of Electron Beam Irradiation on the Tensile Properties of Carbon Nanotubes Sheets and Yarns

NASA Technical Reports Server (NTRS)

Williams, Tiffany S.; Miller, Sandi G.; Baker, James S.; McCorkle, Linda S.; Meador, Michael A.

2013-01-01

Carbon nanotube sheets and yarns were irradiated using electron beam (e-beam) energy to determine the effect of irradiation dose on the tensile properties. Results showed that a slight change in tensile strength occurred after irradiating as-received CNT sheets for 20 minutes, and a slight decrease in tensile strength as the irradiation time approached 90 minutes. On the other hand, the addition of small molecules to the CNT sheet surface had a greater effect on the tensile properties of e-beam irradiated CNT sheets. Some functionalized CNT sheets displayed up to a 57% increase in tensile strength following 90 minutes of e-beam exposure. In addition, as-received CNT yarns showed a significant increase in tensile strength as the irradiation time increased.

Post-fire treatment effectiveness for hillslope stabilization

Treesearch

Peter R. Robichaud; Louise E. Ashmun; Bruce D. Sims

2010-01-01

This synthesis of post-fire treatment effectiveness reviews the past decade of research, monitoring, and product development related to post-fire hillslope emergency stabilization treatments, including erosion barriers, mulching, chemical soil treatments, and combinations of these treatments. In the past ten years, erosion barrier treatments (contour-felled logs and...

[Effect of irradiation on the degradation of rat thymocyte chromatin].

PubMed

Tsudzevich, B O; Parkhomets', Iu P; Andriĭchuk, T R; Iurkina, V V

1998-01-01

Genome instability of adaptive nature is formed under the experimental influence on a cell. Under critical conditions, strategy of organism is to damage the cells that cannot be restored and controlled by including the program of apoptosis. The ordered internucleosomal DNA degradation is considered to be one of the proof attributes of immunocompetent cell apoptosis. We investigated the effects of various doses of irradiation on the thymocytes chromatine fragmentation in 1,2,3 hours after a single X-ray exposure or after chronic influence in conditions of Chernobyl research base. By the means of electrophoresis in agarose and judging by polydeoxyribonucleotides accumulation we observed the "ladder pattern" of degradation in 3 hr after single 1 Gr irradiation (the smallest dose displaying the effect). We suppose that the influence of both chronic low-intensity irradiation taking place in Chernobyl and single X-ray exposure result in intensifying of DNA fragmentation in the cells of immunocompetent organs.

Irradiation effect on deuterium behaviour in low-dose HFIR neutron-irradiated tungsten

DOE PAGES

Shimada, Masashi; Cao, G.; Otsuka, T.; ...

2014-12-01

Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor, Oak Ridge National Laboratory at reactor coolant temperatures of 50-70°C to low displacement damage of 0.025 and 0.3 dpa under the framework of the US-Japan TITAN program (2007-2013). After cooling down, the HFIR neutron-irradiated tungsten samples were exposed to deuterium plasmas in the Tritium Plasma Experiment, Idaho National Laboratory at 100, 200 and 500 °C twice at the ion fluence of 5×10²⁵ m⁻² to reach a total ion fluence of 1×10²⁶ m⁻² in order to investigate the near surface deuterium retention and saturation via nuclear reaction analysis. Finalmore » thermal desorption spectroscopy was performed to elucidate irradiation effect on total deuterium retention. Nuclear reaction analysis results showed that the maximum near surface (<5 µm depth) deuterium concentration increased from 0.5 at % D/W in 0.025 dpa samples to 0.8 at. % D/W in 0.3 dpa samples. The large discrepancy between the total retention via thermal desorption spectroscopy and the near surface retention via nuclear reaction analysis indicated the deuterium was migrated and trapped in bulk (at least 50 µm depth for 0.025 dpa and 35 µm depth for 0.025 dpa) at 500 °C case even in the relatively low ion fluence of 10²⁶ m⁻².« less

Effect of irradiation on stored vacuum packaged Wiltshire bacon

NASA Astrophysics Data System (ADS)

Dempster, JF; Halls, NA

Wiltshire cured 'middle-cut' bacon (NaCl, 4.87%; 40 mg/kg NO 2; 53 mg/kg NO 3) was boned, sliced and vacuum packaged. It was irradiated (25 kGy: 10 kGy) and stored aerobically (5 0 : 15 0). At weekly intervals the bacon was evaluated bacteriologically and organoleptically (appearance, odour, colour of lean and fat) against unirradiated (control) samples). Results indicated that irradiation (10 kGy) did not permanently inhibit bacterial growth. After initial reductions in count of 0.99 g -1-1(15 0C) and log 3.61 g -1 (5 0C), maximum numbers were reached in 28 days at 15 0C (log 10.32 g -1) and in 35 days at 5 0C (log 8.05 g -1). However viability was significantly affected by 25 kGy irradiation: final numbers reached being log 2.22 g -1 (15 0C) at 35 days and log 3.38 g -1 (5 0C) at 42 days. Appearance and colour (fat and lean) were not significantly impaired by irradiation. However the interaction of storage temperature (5 0 : 15 0C), irradiation (10 kGy: 25 kGy): duration of storage (42 days) and initial count (log 7.24 g -1) had pronounced adverse effects on odour judgements. Evaluation of odour changes in bacon due to irradiation require further investigation. This is especially so since it is often possible to detect odour changes in raw meat after doses as low as 0.5 kGy (Coleby 1959).

Bactericidal Effects of Diode Laser Irradiation on Enterococcus faecalis Using Periapical Lesion Defect Model

PubMed Central

Nagayoshi, Masato; Nishihara, Tatsuji; Nakashima, Keisuke; Iwaki, Shigetsugu; Chen, Ker-Kong; Terashita, Masamichi; Kitamura, Chiaki

2011-01-01

Objective. Photodynamic therapy has been expanded for use in endodontic treatment. The aim of this study was to investigate the antimicrobial effects of diode laser irradiation on endodontic pathogens in periapical lesions using an in vitro apical lesion model. Study Design. Enterococcus faecalis in 0.5% semisolid agar with a photosensitizer was injected into apical lesion area of in vitro apical lesion model. The direct effects of irradiation with a diode laser as well as heat produced by irradiation on the viability of microorganisms in the lesions were analyzed. Results. The viability of E. faecalis was significantly reduced by the combination of a photosensitizer and laser irradiation. The temperature caused by irradiation rose, however, there were no cytotoxic effects of heat on the viability of E. faecalis. Conclusion. Our results suggest that utilization of a diode laser in combination with a photosensitizer may be useful for clinical treatment of periapical lesions. PMID:21991489

Effect of γ-IRRADIATION on the Mechanical Properties of Al-Cu Alloy

NASA Astrophysics Data System (ADS)

Abo-Elsoud, M.; Ismail, H.; Sobhy, Maged S.

SEM observations and Vickers hardness tests were performed to identify the irradiation effects. γ-irradiation effect during the aging hardening process can be explained depending on the composition of the alloy and is used to derive quantitative information on the kinetics of the transformation precipitates. Increasing the Cu content of an Al-Cu alloy can improve the aging hardness. The present results of the hardness behavior, with SEM observations of surveillance specimens at different doses, suggest that the radiation-induced defects are probably complex valence-solute clusters. These clusters act as nuclei for the precipitation of θ-Al2Cu type. This can be effectively utilized to study the systematics of nucleation of precipitates at vacancy-type defects. γ-irradiation probably plays the key role in defects responsible for material strengthening and embrittlement.

Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour

PubMed Central

Bamidele, Oluwaseun P; Akanbi, Charles T

2013-01-01

The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P < 0.05) value of protein and little or no effect on moisture content. There were slight decreases in crude fiber and ash content of the irradiated samples compared with the control sample. The result of functional properties of the irradiated flours showed slight increase in water absorption capacity, swelling capacity and bulk density. The peroxide value of crude oil increased significantly with dose increases for the period of storage. The sensory evaluation of moinmoin samples prepared from irradiated pigeon pea flour showed no significant difference from the moinmoin sample prepared from nonirradiated flour. It can be concluded that gamma irradiation can extend the shelf life of pigeon pea flour. PMID:24804044

Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour.

PubMed

Bamidele, Oluwaseun P; Akanbi, Charles T

2013-09-01

The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P < 0.05) value of protein and little or no effect on moisture content. There were slight decreases in crude fiber and ash content of the irradiated samples compared with the control sample. The result of functional properties of the irradiated flours showed slight increase in water absorption capacity, swelling capacity and bulk density. The peroxide value of crude oil increased significantly with dose increases for the period of storage. The sensory evaluation of moinmoin samples prepared from irradiated pigeon pea flour showed no significant difference from the moinmoin sample prepared from nonirradiated flour. It can be concluded that gamma irradiation can extend the shelf life of pigeon pea flour.

Helium-ion microscopy, helium-ion irradiation and nanoindentation of Eurofer 97 and ODS Eurofer

NASA Astrophysics Data System (ADS)

Bergner, F.; Hlawacek, G.; Heintze, C.

2018-07-01

Understanding of unsolved details of helium embrittlement requires experimental evidence for dedicated sets of materials and over a wide range of irradiation conditions. The study is focussed on the comparison of a reduced-activation ferritic-martensitic 9%Cr steel (Eurofer 97) with its oxide dispersion strengthened counterpart (ODS Eurofer) with respect to irradiation-induced hardening. Imaging and He-ion irradiation in the He-ion microscope at 30 °C in a wide range of appm He (from 0.9 × 102 to 1.8 × 106) and displacements per atom (dpa) (from 3 × 10-3 to 65) were combined with post-irradiation nanoindentation in order to detect blistering and irradiation-induced hardness changes. The applicability of this combination of techniques is demonstrated and pros and cons are discussed. We have found that the indentation hardness increases significantly after in-microscope irradiation to 3 dpa (0.9 × 105 appm He). The irradiation-induced hardness increase is higher and the onset of significant hardening tends to occur at lower fluence for Eurofer 97 than for ODS Eurofer, indicating that the presence of oxide nanoparticles is efficient to reduce the detrimental effect of He under the applied irradiation conditions.

Mechanical and optoelectric properties of post-annealed fluorine-doped tin oxide films by ultraviolet laser irradiation

NASA Astrophysics Data System (ADS)

Tseng, Shih-Feng; Hsiao, Wen-Tse; Chiang, Donyau; Huang, Kuo-Cheng; Chou, Chang-Pin

2011-06-01

The fluorine-doped tin oxide (FTO) thin film deposited on a soda-lime glass substrate was annealed by a defocus ultraviolet (UV) laser irradiation at ambient temperature. The mechanical and optoelectric properties of FTO films annealed by using the various laser processing parameters were reported. After the FTO films were subjected to laser post-annealing, the microhardness were slightly less but the reduced modulus values were larger than that of unannealed FTO films, respectively. The average optical transmittance in the visible waveband slightly increased with increasing the laser annealing energy and scan speed. Moreover, all the sheet resistance of laser annealed films was less than that of the unannealed ones. We found that the sheet resistance decrease was obviously influenced by annealing. The suitable annealing conditions could maintain the film thickness and relief the internal stress generated in the film preparation process to improve the electrical conductivity via decreasing laser energy or increasing scan speed.

Biological effects of ultraviolet irradiation on bees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Es`kov, E.K.

1995-09-01

The influence of natural solar and artificial ultraviolet irradiation on developing bees was studied. Lethal exposures to irradiation at different stages of development were determined. The influence of irradiation on the variability of the morphometric features of bees was revealed. 5 refs., 1 fig.

Liver irradiation causes distal bystander effects in the rat brain and affects animal behaviour.

PubMed

Kovalchuk, Anna; Mychasiuk, Richelle; Muhammad, Arif; Hossain, Shakhawat; Ilnytskyy, Slava; Ghose, Abhijit; Kirkby, Charles; Ghasroddashti, Esmaeel; Kovalchuk, Olga; Kolb, Bryan

2016-01-26

Radiation therapy can not only produce effects on targeted organs, but can also influence shielded bystander organs, such as the brain in targeted liver irradiation. The brain is sensitive to radiation exposure, and irradiation causes significant neuro-cognitive deficits, including deficits in attention, concentration, memory, and executive and visuospatial functions. The mechanisms of their occurrence are not understood, although they may be related to the bystander effects.We analyzed the induction, mechanisms, and behavioural repercussions of bystander effects in the brain upon liver irradiation in a well-established rat model.Here, we show for the first time that bystander effects occur in the prefrontal cortex and hippocampus regions upon liver irradiation, where they manifest as altered gene expression and somewhat increased levels of γH2AX. We also report that bystander effects in the brain are associated with neuroanatomical and behavioural changes, and are more pronounced in females than in males.

Liver irradiation causes distal bystander effects in the rat brain and affects animal behaviour

PubMed Central

Kovalchuk, Anna; Mychasiuk, Richelle; Muhammad, Arif; Hossain, Shakhawat; Ilnytskyy, Slava; Ghose, Abhijit; Kirkby, Charles; Ghasroddashti, Esmaeel; Kovalchuk, Olga; Kolb, Bryan

2016-01-01

Radiation therapy can not only produce effects on targeted organs, but can also influence shielded bystander organs, such as the brain in targeted liver irradiation. The brain is sensitive to radiation exposure, and irradiation causes significant neuro-cognitive deficits, including deficits in attention, concentration, memory, and executive and visuospatial functions. The mechanisms of their occurrence are not understood, although they may be related to the bystander effects. We analyzed the induction, mechanisms, and behavioural repercussions of bystander effects in the brain upon liver irradiation in a well-established rat model. Here, we show for the first time that bystander effects occur in the prefrontal cortex and hippocampus regions upon liver irradiation, where they manifest as altered gene expression and somewhat increased levels of γH2AX. We also report that bystander effects in the brain are associated with neuroanatomical and behavioural changes, and are more pronounced in females than in males. PMID:26678032

Effects Of Continuous Argon Laser Irradiation On Canine And Autopsied Human Cardiac Tissue

NASA Astrophysics Data System (ADS)

Ben-Shachar, Giora; Sivakoff, Mark; Bernard, Steven L.; Dahms, Beverly B.; Riemenschneider, Thomas A.

1984-10-01

In eight human formalin preserved cardiac specimens, various cardiac and vascular obstructions were relieved by argon laser irradiation. Interatrial communication was also produced by a transar'rial approach in a live dog. In-vivo fresh canine cardiac tissues required power density of at feast 80, 90, and 110 watts/cm2 for vaporization of myocardial, vascular and valvular tissues respectively. The fiber tip to tissue distance (effective irradiation distance) for effective vaporization was less than I mm for vascular and valvular tissues and less than 4 mm for myocardium. Light microscopy showed four zones of histological damage common to all tissues - central crater surrounded by layers of charring, vacuolization and coagulation necorsis. Myocardium showed additionally a layer of normal appearing muscle cells (skip area) surrounded by a peripheral coagulation halo. Laser irradiation effects on valvular tissue showed the most lateral extension of coagulation necrosis. It is concluded that palliation and treatment of certain congenital heart defects by laser irradiation is anatomi-cally feasible and may be safe for in vivo application when low power output and short exposure time are used from a very short irradiation distance.

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

PubMed Central

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

2014-01-01

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

Ultraviolet-C irradiation for inactivation of viruses in foetal bovine serum.

PubMed

Vaidya, Vivek; Dhere, Rajeev; Agnihotri, Snehal; Muley, Ravindra; Patil, Sanjay; Pawar, Amit

2018-07-05

Foetal Bovine Serum (FBS) and porcine trypsin are one of the essential raw materials used in the manufacturing of cell culture based viral vaccines. Being from animal origin, these raw materials can potentially contaminate the final product by known or unknown adventitious agents. The issue is more serious in case of live attenuated viral vaccines, where there is no inactivation step which can take care of such adventitious agents. It is essential to design production processes which can offer maximum viral clearance potential for animal origin products. Ultraviolet-C irradiation is known to inactivate various adventitious viral agents; however there are limited studies on ultraviolet inactivation of viruses in liquid media. We obtained a recently developed UVivatec ultraviolet-C (UV-C) irradiation based viral clearance system for evaluating its efficacy to inactivate selected model viruses. This system has a unique design with spiral path of liquid allowing maximum exposure to UV-C light of a short wavelength of 254 nm. Five live attenuated vaccine viruses and four other model viruses were spiked in tissue culture media and exposed to UV-C irradiation. The pre and post UV-C irradiation samples were analyzed for virus content to find out the extent of inactivation of various viruses. These experiments showed substantial log reduction for the majority of the viruses with few exceptions based on the characteristics of these viruses. Having known the effect of UV irradiation on protein structure, we also evaluated the post irradiation samples of culture media for growth promoting properties using one of the most fastidious human diploid cells (MRC-5). UV-C exposure did not show any notable impact on the nutritional properties of culture media. The use of an UV-C irradiation based system is considered to be promising approach to mitigate the risk of adventitious agents in cell culture media arising through animal derived products. Copyright © 2018 Elsevier Ltd. All

Distribution of Facial Exposure to Non-melanoma Biologically Effective UV Irradiance Changes by Rotation Angles.

PubMed

Wang, Fang; Yu, Jia Ming; Yang, De Qi; Gao, Qian; Hua, Hui; Liu, Yang

2017-02-01

To show the distribution of facial exposure to non-melanoma biologically effective UV irradiance changes by rotation angles. This study selected the cheek, nose, and forehead as representative facial sites for UV irradiance measurements, which were performed using a rotating manikin and a spectroradiometer. The measured UV irradiance was weighted using action spectra to calculate the biologically effective UV irradiances that cause non-melanoma (UVBEnon-mel) skin cancer. The biologically effective UV radiant exposure (HBEnon-mel) was calculated by summing the UVBEnon-mel data collected over the exposure period. This study revealed the following: (1) the maximum cheek, nose and forehead exposure UVA and UVB irradiance times and solar elevation angles (SEA) differed from those of the ambient UV irradiance and were influenced by the rotation angles; (2) the UV irradiance exposure increased in the following order: cheek < nose < forehead; (3) the distribution of UVBEnon-mel irradiance differed from that of unweighted UV radiation (UVR) and was influenced by the rotation angles and exposure times; and (4) the maximum percentage decreases in the UVBEnon-mel radiant exposure for the cheek, nose and forehead from 0°to 180°were 48.41%, 69.48% and 71.71%, respectively. Rotation angles relative to the sun influence the face's exposure to non-melanoma biologically effective UV. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Cost effective alternative to low irradiance measurements

NASA Technical Reports Server (NTRS)

Oleary, Scott T.

1988-01-01

Martin Marietta's Space Simulation Laboratory (SSL) has a Thermal Environment Simulator (TES) with 56 individually controlled heater zones. The TES has a temperature range of approximately minus 129 C to plus 149 C. Because of the ability of TES to provide complex irradiance distributions, it is necessary to be able to measure a wide range of irradiance levels. SSL currently uses ambient temperature controlled radiometers with the capacity to measure sink irradiance levels of approximately 42.6 mw/sq cm, sink temperature equals 21 C and up. These radiometers could not be used to accurately measure the lower irradiance levels of the TES. Therefore, it was necessary to obtain a radiometer or develop techniques which could be used to measure lower irradiance levels.

Density Effects on Post-shock Turbulence Structure

NASA Astrophysics Data System (ADS)

Tian, Yifeng; Jaberi, Farhad; Livescu, Daniel; Li, Zhaorui; Michigan State University Collaboration; Los Alamos National Laboratory Collaboration; Texas A&M University-Corpus Christi Collaboration

2017-11-01

The effects of density variations due to mixture composition on post-shock turbulence structure are studied using turbulence-resolving shock-capturing simulations. This work extends the canonical Shock-Turbulence Interaction (STI) problem to involve significant variable density effects. The numerical method has been verified using a series of grid and LIA convergence tests, and is used to generate accurate post-shock turbulence data for a detailed flow study. Density effects on post-shock turbulent statistics are shown to be significant, leading to an increased amplification of turbulent kinetic energy (TKE). Eulerian and Lagrangian analyses show that the increase in the post-shock correlation between rotation and strain is weakened in the case with significant density variations (referred to as the ``multi-fluid'' case). Similar to previous single-fluid results and LIA predictions, the shock wave significantly changes the topology of the turbulent structures, exhibiting a symmetrization of the joint PDF of second and third invariant of the deviatoric part of velocity gradient tensor. In the multi-fluid case, this trend is more significant and mainly manifested in the heavy fluid regions. Lagrangian data are also used to study the evolution of turbulence structure away from the shock wave and assess the accuracy of Lagrangian dynamical models.

Study of the biochemical indicators of chronic irradiation in rats.

PubMed

Szabo, L D; Benko, A B; Gyenge, L; Predmerszky, T

1976-01-01

Daily urinary excretion of pseudouridine, creatinine and creatine of chronically irradiated Wistar rats was estimated. The irradiation conditions were: 60Co gamma source, dose-rate 10 rad/day, total dose 200, 400 and 600 rad. Control groups were kept under similar conditions. Urine samples were taken three times after the end of the irradiation period. It was found that: (1) pseudouridine excretion seems more suitable for indicating radiation injury than the creatine/creatinine ratio in chronic irradiation in rats; (ii) there are significant changes in dose dependence of pseudouridine excretion in the post-irradiation period; (iii) a new method for pseudouridine estimation gives closely similar data to those of earlier investigations.

Temperature effects on the mechanical properties of candidate SNS target container materials after proton and neutron irradiation

NASA Astrophysics Data System (ADS)

Byun, T. S.; Farrell, K.; Lee, E. H.; Mansur, L. K.; Maloy, S. A.; James, M. R.; Johnson, W. R.

2002-05-01

This report presents the tensile properties of EC316LN austenitic stainless steel and 9Cr-2WVTa ferritic/martensitic steel after 800 MeV proton and spallation neutron irradiation to doses in the range 0.54-2.53 dpa at 30-100 °C. Tensile testing was performed at room temperature (20 °C) and 164 °C. The EC316LN stainless steel maintained notable strain-hardening capability after irradiation, while the 9Cr-2WVTa ferritic/martensitic steel posted negative hardening in the engineering stress-strain curves. In the EC316LN stainless steel, increasing the test temperature from 20 to 164 °C decreased the strength by 13-18% and the ductility by 8-36%. The effect of test temperature for the 9Cr-2WVTa ferritic/martensitic steel was less significant than for the EC316LN stainless steel. In addition, strain-hardening behaviors were analyzed for EC316LN and 316L stainless steels. The strain-hardening rate of the 316 stainless steels was largely dependent on test temperature. A calculation using reduction of area measurements and stress-strain data predicted positive strain hardening during plastic instability.

Thermal Regeneration of Sulfuric Acid Hydrates after Irradiation

NASA Technical Reports Server (NTRS)

Loeffler, Mark J.; Hudson, Reggie L.

2012-01-01

In an attempt to more completely understand the surface chemistry of the jovian icy satellites, we have investigated the effect of heating on two irradiated crystalline sulfuric acid hydrates, H2SO4 4H2O and H2SO4 H2O. At temperatures relevant to Europa and the warmer jovian satellites, post-irradiation heating recrystallized the amorphized samples and increased the intensities of the remaining hydrate's infrared absorptions. This thermal regeneration of the original hydrates was nearly 100% efficient, indicating that over geological times, thermally-induced phase transitions enhanced by temperature fluctuations will reform a large fraction of crystalline hydrated sulfuric acid that is destroyed by radiation processing. The work described is the first demonstration of the competition between radiation-induced amorphization and thermally-induced recrystallization in icy ionic solids relevant to the outer Solar System.

No increase in toxicity of pelvic irradiation when intensity modulation is employed: clinical and dosimetric data of 208 patients treated with post-prostatectomy radiotherapy.

PubMed

Jereczek-Fossa, Barbara A; Ciardo, Delia; Ferrario, Silvia; Fossati, Piero; Fanetti, Giuseppe; Zerini, Dario; Zannoni, Davide; Fodor, Cristiana; Gerardi, Marianna A; Surgo, Alessia; Muto, Matteo; Cambria, Raffaella; De Cobelli, Ottavio; Orecchia, Roberto

2016-07-01

To compare the toxicity of image-guided intensity-modulated radiotherapy (IG-IMRT) to the pelvis or prostate bed (PB) only. To test the hypothesis that the potentially injurious effect of pelvic irradiation can be counterbalanced by reduced irradiated normal tissue volume using IG-IMRT. Between February 2010 and February 2012, 208 patients with prostate cancer were treated with adjuvant or salvage IG-IMRT to the PB (102 patients, Group PB) or the pelvis and prostate bed (P) (106 patients, Group P). The Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria were used to evaluate toxicity. Median follow-up was 27 months. Toxicity G ≥ 2 in Group PB: in the bowel acute and late toxicities were 11.8% and 10%, respectively; urinary acute and late toxicities were 10.8% and 15%, respectively. Toxicity G ≥ 2 in Group P: in the bowel acute and late toxicities were both 13.2%; urinary acute and late toxicities were 13.2% and 15.1%, respectively. No statistical difference in acute or late toxicity between the groups was found (bowel: p = 0.23 and p = 0.89 for acute and late toxicity, respectively; urinary: p = 0.39 and p = 0.66 for acute and late toxicity, respectively). Of the clinical variables, only previous abdominal surgery was correlated with acute bowel toxicity. Dosimetric parameters that correlated with bowel toxicity were identified. The toxicity rates were low and similar in both groups, suggesting that IG-IMRT allows for a safe post-operative irradiation of larger volumes. Further investigation is warranted to exclude bias owing to non-randomized character of the study. Our report shows that modern radiotherapy technology and careful planning allow maintaining the toxicity of pelvic lymph node treatment at the acceptable level, as it is in the case of PB radiotherapy.

Heterogeneous dislocation loop formation near grain boundaries in a neutron-irradiated commercial FeCrAl alloy

NASA Astrophysics Data System (ADS)

Field, Kevin G.; Briggs, Samuel A.; Hu, Xunxiang; Yamamoto, Yukinori; Howard, Richard H.; Sridharan, Kumar

2017-01-01

FeCrAl alloys are an attractive class of materials for nuclear power applications because of their increased environmental compatibility compared with more traditional nuclear materials. Preliminary studies into the radiation tolerance of FeCrAl alloys under accelerated neutron testing between 300 and 400 °C have shown post-irradiation microstructures containing dislocation loops and a Cr-rich α‧ phase. Although these initial studies established the post-irradiation microstructures, there was little to no focus on understanding the influence of pre-irradiation microstructures on this response. In this study, a well-annealed commercial FeCrAl alloy, Alkrothal 720, was neutron irradiated to 1.8 displacements per atom (dpa) at 382 °C and then the effect of random high-angle grain boundaries on the spatial distribution and size of a〈100〉 dislocation loops, a/2〈111〉 dislocation loops, and black dot damage was analyzed using on-zone scanning transmission electron microscopy. Results showed a clear heterogeneous dislocation loop formation with a/2〈111〉 dislocation loops showing an increased number density and size, black dot damage showing a significant number density decrease, and a〈100〉 dislocation loops exhibiting an increased size in the vicinity of the grain boundary. These results suggest the importance of the pre-irradiation microstructure and, specifically, defect sink density spacing to the radiation tolerance of FeCrAl alloys.

Effect of gamma irradiation on the wear behavior of human tooth dentin.

PubMed

Qing, Ping; Huang, Shengbin; Gao, ShanShan; Qian, LinMao; Yu, HaiYang

2016-12-01

The objective of this study was to evaluate the effect of gamma irradiation on the wear behavior of human tooth dentin in terms of possible alterations in crystallinity, grain size, and composition. Human premolars (n = 19) were collected to obtain the perpendicular or parallel to the direction of the dentin tubule specimens. Each specimen was subjected to 60 Gy of gamma irradiation, in daily increments of 2 Gy. The nanoscratch tests were conducted. The scratch traces were observed via scanning electron microscope (SEM) and surface profilometer. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to investigate the alteration of crystallography and chemical composition of dentin after irradiation. The change of surface microhardness (SMH) was also evaluated. The nanoscratch results showed that the friction coefficient of dentin after irradiation became higher, and the depths and widths of scratch were greater than that of dentin before irradiation. Additionally, irradiation decreased the crystallinity of dentin and induced the formation of bigger crystals. The carbonate/mineral ratio was increased. Furthermore, a significant reduction in microhardness after irradiation was observed. The main damage mechanisms consisted of the formation of delamination and crack in both the specimens cut perpendicular and parallel to tubule dentin after irradiation. Irradiation affected directly the wear behavior of tooth dentin, accompanied by the alterations in crystallography, chemical composition, and surface microhardness of dentin. This would help extend understanding the influence of irradiation on dentin and provide suggestions for selecting more suitable materials for irradiated tooth.

Modeling of HT and HTO release from irradiated lithium metazirconate

NASA Astrophysics Data System (ADS)

Beloglazov, S.; Nishikawa, M.; Glugla, M.; Kinjyo, T.

2004-08-01

Modeling studies of tritium release from irradiated Li 2ZrO 3 (MAPI) pebbles have been carried out in order to evaluate the effect of purge gas composition on tritium release behavior. The release characteristics were obtained by temperature programmed desorption (TPD) technique in the series of post-irradiation experiments in JRR-4 research reactor of JAERI. Nitrogen with hydrogen at various partial pressures (100 and 1000 Pa) was used as a purge gas. Two sets of ionization chambers and its dedicated electrometers allowed the tritium concentration to be monitored in the chemical form of HT and overall tritium concentration in the mixture HT and HTO simultaneously during desorption runs. The tritium release curves were numerically fitted in order to evaluate the mass transfer coefficients.

Protective Effect of 940 nm Laser on Gamma-Irradiated Mice

PubMed Central

Efremova, Yulia; Navratil, Leos

2015-01-01

Abstract Objective: The purpose of this study was to investigate the radioprotective features of 940 nm laser on the life span of mice, and absolute counts of blood cells and their proportions in gamma-irradiated mice. Background data: An important feature of laser light is activation of mitotic division and differentiation of cells, which may be useful in activation of hematopoiesis in gamma-irradiated organisms. Materials and methods: Mice were randomly assigned to 11 groups according to the type(s) of influence. Generally, mice were irradiated in three different ways: with laser at different fluences, with gamma irradiation, or by combination of laser at different fluences and gamma irradiation in a different order. Mice were treated with 940 nm laser at 3, 12, or 18 J/cm2 and/or a lethal dose of gamma irradiation (8.7 Gy). Each group was randomly subdivided into two subgroups, in which the life span of the mice and blood cell counts (on 12th and 45th day after gamma irradiation) were analyzed. Results: Laser (940 nm) at a fluence of 3 J/cm2 significantly prolonged the life span of gamma-irradiated mice (p<0.05). In the same group, counts of white blood cells, lymphocytes, and neutrophils were higher on day 12 than in the gamma group. On day 45 after gamma irradiation, some signs of hematopoiesis repair were found in blood. There were no significant differences in counts of erythrocytes, monocytes, neutrophils, or the proportion of neutrophils between this group and the control group. Conclusions: In summary, 940 nm laser at a fluence of 3 J/cm2 demonstrates radioprotective features in an experiment with lethally irradiated mice. Mechanisms responsible for this effect will be investigated in further studies. PMID:25654740

Effect of irradiation temperature on microstructural changes in self-ion irradiated austenitic stainless steel

NASA Astrophysics Data System (ADS)

Jin, Hyung-Ha; Ko, Eunsol; Lim, Sangyeob; Kwon, Junhyun; Shin, Chansun

2017-09-01

We investigated the microstructural and hardness changes in austenitic stainless steel after Fe ion irradiation at 400, 300, and 200 °C using transmission electron microscopy (TEM) and nanoindentation. The size of the Frank loops increased and the density decreased with increasing irradiation temperature. Radiation-induced segregation (RIS) was detected across high-angle grain boundaries, and the degree of RIS increases with increasing irradiation temperature. Ni-Si clusters were observed using high-resolution TEM in the sample irradiated at 400 °C. The results of this work are compared with the literature data of self-ion and proton irradiation at comparable temperatures and damage levels on stainless steels with a similar material composition with this study. Despite the differences in dose rate, alloy composition and incident ion energy, the irradiation temperature dependence of RIS and the size and density of radiation defects followed the same trends, and were very comparable in magnitude.

The enhanced effects of antibiotics irradiated of extremely high frequency electromagnetic field on Escherichia coli growth properties.

PubMed

Torgomyan, Heghine; Trchounian, Armen

2015-01-01

The effects of extremely high frequency electromagnetic irradiation and antibiotics on Escherichia coli can create new opportunities for applications in different areas—medicine, agriculture, and food industry. Previously was shown that irradiated bacterial sensitivity against antibiotics was changed. In this work, it was presented the results that irradiation of antibiotics and then adding into growth medium was more effective compared with non-irradiated antibiotics bactericidal action. The selected antibiotics (tetracycline, kanamycin, chloramphenicol, and ceftriaxone) were from different groups. Antibiotics irradiation was performed with low intensity 53 GHz frequency during 1 h. The E. coli growth properties—lag-phase duration and specific growth rate—were markedly changed. Enhanced bacterial sensitivity to irradiated antibiotics is similar to the effects of antibiotics of higher concentrations.

Double hemibody irradiation (DHBI) in the management of relapsed and primary chemoresistant multiple myeloma.

PubMed

McSweeney, E N; Tobias, J S; Blackman, G; Goldstone, A H; Richards, J D

1993-01-01

In view of increasing controversy regarding the role of double hemibody irradiation (DHBI) in the treatment of multiple myeloma, we have analysed the use of this technique at our institution over a 6-year period. Fifty-five patients with multiple myeloma were treated with both upper and lower hemibody irradiation between January 1985 and January 1991; 42 had relapsed post-plateau and 13 were chemoresistant to initial therapy. Fifteen patients received alpha IFN-2b maintenance therapy post-DHBI, at a dose of 3 Mu three times per week, as part of a randomized trial. Ninety-five per cent of patients experienced symptomatic improvement in bone pain post-DHBI, 21% of whom discontinued opiate analgesics altogether; 63% had a minor biochemical response and 38% had a partial biochemical response. The overall survival (OS) and progression free survivals (PFS) in all patients were 11 months and 8 months respectively. No significant difference was noted in either OS or PFS, according to whether patients were chemoresistant or had relapsed post-plateau. alpha IFN did not appear to prolong survival (OS or PFS) post-DHBI. Cytopenia was a significant problem, such that only 60% of patients had counts adequate enough to be eligible for alpha IFN. We conclude that DHBI is an effective treatment in patients with relapsed multiple myeloma and in those who are chemoresistant to initial therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

The damaging effect of UV-C irradiation on lens alpha-crystallin.

PubMed

Fujii, Noriko; Uchida, Hiroki; Saito, Takeshi

2004-11-02

To evaluate the effect of UV-C irradiation on the structural properties of alpha-crystallin and its chaperone activity. alpha- and betaL-crystallins were isolated from bovine lenses using gel chromatography. The purified alpha-crystallin was subjected to UV-C irradiation (254 nm; 1, 2, 5, 10, 20, 50 J/cm2). We measured the tryptophan fluorescence, circular dichroism (CD) spectroscopy in the far UV, and the chaperone activity of both irradiated and non-irradiated alpha-crystallin. The tryptophan fluorescence of alpha-crystallin decreased, whereas the N-formylkynurenine fluorescence increased markedly with increasing doses of UV-C irradiation. Both the oxidation of Met1 and the racemization of Asp151 of alphaA-crystallin increased at a dose of 1-2 J/cm2 and then gradually decreased. The CD spectrum showed that the secondary structure of alpha-crystallin altered with increasing radiation dose, and almost all of the beta-sheet structure was lost at doses above 50 J/cm2. The chaperone activity of alpha-crystallin irradiated with doses under 5 J/cm2 remained intact. However, it was reduced to only 40% after irradiation at 10 J/cm2. Our study suggests that photo-oxidation of tryptophan residues in alpha-crystallin may be one of the events that affects the three-dimensional packing array and chaperone activity of this lens protein.

Microstructural Characterization of Irradiated U0.7ZrH1.6 Using Ultrasonic Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramuhalli, Pradeep; Jacob, Richard E.; MacFarlan, Paul J.

In recent years, there has been an increased level of effort to understand the changes in microstructure that occur due to irradiation of nuclear fuel. The primary driver for this increased effort is the potential for designing new fuels that are safer and more reliable, in turn enabling new and improved reactor technologies. Much of the data on microstructural change in irradiated fuels is generated through a host of post irradiation examination techniques such as optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to determine grain structure, porosity, crack geometry, etc. in irradiated fuels. Such “traditional”more » examination techniques were recently used to characterize a novel new fuel consisting of U0.17ZrH1.6 pellets bonded to zircaloy-2 cladded with lead-bismuth eutectic before and after irradiation. However, alternative methods such as ultrasonic inspection can provide an opportunity for nondestructively assessing microstructure in both in-pile and post-irradiation examinations. In this paper, we briefly describe initial results of ultrasonic examination of the U0.17ZrH1.6 pellets (unirradiated and irradiated), in a post-irradiation examination study. Data indicate some correlation with microstructural changes due to irradiation; however, it is not clear what the specific microstructural changes are that are influencing the ultrasonic measurements. Interestingly, specimens with nominally identical burnup show differences in ultrasonic signatures, indicating apparent microstructural differences between these specimens. A summary of the experimental study, preliminary data and findings are presented in this short paper. Additional details of the analysis will be included in the presentation.« less

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

NASA Astrophysics Data System (ADS)

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

2011-01-01

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

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

PubMed

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

2015-01-01

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

Non-thermal cytocidal effect of infrared irradiation on cultured cancer cells using specialized device.

PubMed

Tanaka, Yohei; Matsuo, Kiyoshi; Yuzuriha, Shunsuke; Yan, Huimin; Nakayama, Jun

2010-06-01

As infrared penetrates the skin, thermal effects of infrared irradiation on cancer cells have been investigated in the field of hyperthermia. We evaluated non-thermal effects of infrared irradiation using a specialized device (1100-18000 nm with filtering of wavelengths between 1400 and 1500 nm and contact cooling) on cancer cells. In in vitro study, five kinds of cultured cancer cell lines (MCF7 breast cancer, HeLa uterine cervical cancer, NUGC-4 gastric cancer, B16F0 melanoma, and MDA-MB435 melanoma) were irradiated using the infrared device, and then the cell proliferation activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Proliferation of all the cancer cell lines was significantly suppressed by infrared irradiation. Total infrared output appeared to be correlated with cell survival. Increased temperature during infrared irradiation appeared not to play a role in cell survival. The maximum temperature elevation in the wells after each shot in the 20 and 40 J/cm(2) culture was 3.8 degrees C and 6.9 degrees C, respectively. In addition, we have shown that infrared irradiation significantly inhibited the tumor growth of MCF7 breast cancer transplanted in severe combined immunodeficiency mice and MDA-MB435 melanoma transplanted in nude mice in vivo. Significant differences between control and irradiated groups were observed in tumor volume and frequencies of TUNEL-positive and Ki-67-positive cells. These results indicate that infrared, independent of thermal energy, can induce cell killing of cancer cells. As this infrared irradiation schedule reduces discomfort and side effects, reaches the deep subcutaneous tissues, and facilitates repeated irradiations, it may have potential as an application for treating various forms of cancer.

Investigation of the irradiation history of the Iranian dates and pistachio nuts using thermoluminescence technique

NASA Astrophysics Data System (ADS)

Sharifzadeh, M.; Sohrabpour, M.

1993-07-01

Three different varieties of Iranian fresh dates and five types of raw and salted pistachio nuts have been tested for identification of irradiation histories. Doses of 2.5, 5, 7.5 and 10 kGy from a gamma cell Gc-220 have been administrated to the samples under investigation. TL response versus dose for date and for pistachio nuts have been obtained. The effect of added ingredients such as salt in pistachio nuts, and moisture in date samples on the TL response have been studied. The fading of TL intensity of the irradiated dates and pistachio nuts have also been measured. Based on the latter results, it appears possible to identify the irradiated dates (10 kGy), within (1-2) months post-irradiation. In the salted pistachio nuts, the salt itself gives a very significant and distinguishable response. In the unsalted case, however, the difference between the irradiated and unirradiated samples seem difficult to detect due to partial overlapping of the respective responses.

Performance degradation of ferrofluidic feedthroughs in a mixed irradiation field

NASA Astrophysics Data System (ADS)

Simos, Nikolaos; Fernandes, S.; Mittig, Wolfgang; Pellemoine, Frederique; Avilov, M.; Kostin, M.; Mausner, L.; Ronningen, R.; Schein, M.; Bollen, G.

2017-01-01

Ferrofluidic feedthrough (FF) rotary seals containing either NdFeB or SmCo-type permanent magnets have been considered for use in the target and beam dump systems of the Facility for Rare Isotope Beams (FRIB). To evaluate their performance under irradiation three FF seals were irradiated in a mixed field consisting of fast neutrons, protons and γ-rays to an average absorbed dose of 0.2, 2.0, and 20.0 MGy at the Brookhaven Linac Isotope Producer facility (BLIP). The radiation types and energy profiles mimic those expected at the FRIB facility. Degradation of the operational performance of these devices due to irradiation is expected to be the result of the de-magnetization of the permanent magnets contained within the seal and the changes in the ferrofluid properties. Post-irradiation performance was evaluated by determining the ferrofluidic seal vacuum tightness and torque under static and dynamic conditions. The study revealed that the ferrofluidic feedthrough seal irradiated to a dose of 0.2 MGy maintained its vacuum tightness under both static and rotational condition while the one irradiated to a dose of 2.0 MGy exhibited signs of ferrofluid damage but no overall performance loss. At 20 MGy dose the effects of irradiation on the ferrofluid properties (viscosity and particle agglomeration) were shown to be severe. Furthermore, limited de-magnetization of the annular shaped Nd2Fe14B and Sm2Co17 magnets located within the irradiated FFs was observed for doses of 0.2 MGy and 20 MGy respectively.

Effects of proton irradiation on thin-film materials for optical filters

NASA Astrophysics Data System (ADS)

Scaglione, Salvatore; Piegari, Angela; Sytchkova, Anna; Jakšić, Milko

2017-11-01

The behaviour of interference optical filters for space applications has been investigated under low energy proton irradiation. In order to understand the behaviour of the interference coating subjected to proton irradiation, the interaction of protons with coating and substrate was simulated by the SRIM code. A beam of protons of 60 KeV with an integrated fluence of 1013 p+/cm2 was used. The spectral transmittances of fused silica, TiO2 and HfO2 single layers and interference coatings were measured before and after irradiation and, according to simulations, no significant effects were detected in the visible-near infrared spectrum, while some variations appeared at shorter wavelengths.

Effect of irradiated pork on physicochemical properties of meat emulsions

NASA Astrophysics Data System (ADS)

Choi, Yun-Sang; Sung, Jung-Min; Jeong, Tae-Jun; Hwang, Ko-Eun; Song, Dong-Heon; Ham, Youn-Kyung; Kim, Hyun-Wook; Kim, Young-Boong; Kim, Cheon-Jei

2016-02-01

The effect of pork irradiated with doses up to 10 kGy on meat emulsions formulated with carboxy methyl cellulose (CMC) was investigated. Raw pork was vacuums packaged at a thickness of 2.0 cm and irradiated by X-ray linear accelerator (15 kW, 5 MeV). The emulsion had higher lightness, myofibrillar protein solubility, total protein solubility, and apparent viscosity with increasing doses, whereas cooking loss, total expressible fluid separation, and hardness decreased. There were no significant differences in fat separation, sarcoplasmic protein solubility, springiness, and cohesiveness. Our results indicated that it is treatment by ionizing radiation which causes the effects the physicochemical properties of the final raw meat product.

Tolerance of mango cv. ´Ataulfo' to irradiation with Co-60 vs. hydrothermal phytosanitary treatment

NASA Astrophysics Data System (ADS)

Gómez-Simuta, Y.; Hernández, Emilio; Aceituno-Medina, Marysol; Liedo, Pablo; Escobar-López, Arseny; Montoya, Pablo; Bravo, Bigail; Hallman, Guy J.; Bustos, M. Emilia; Toledo, Jorge

2017-10-01

The use of ionizing irradiation or the use of hot water treatment (HWT) has been demonstrated as a successful commercial phytosanitary treatment during the past two decades. Several countries currently use this technology for commercial treatments to meet plant quarantine requirements. However, hydrothermal treatment has been found to significantly affect the firmness of ;Ataulfo; mango fruit, the susceptibility to damage by cold and it also accelerates their maturation. In this study, we focused on the effect of irradiation doses on the sensorial quality and the physiochemical properties of mango cv ;Ataulfo; compared with the traditional hot water treatment. We found that doses of 150 Gy and 300 Gy of gamma radiation can be applied successfully as well as the hot water treatment. There was no significant difference in between irradiation treatments in terms of weight loss, external and internal color, pH, soluble solids, titratable acidity and firmness, and consumer's acceptance. There was no adverse effect of color appearance, odor and flavor, indicating that consumers will have the willingness to buy and consume irradiated mangoes. Irradiation of mangoes can be a successful post-harvest treatment as an alternative to the hot water treatment.

The Effect of UVC Irradiation on the Mechanical Properties of Chitosan Membrane in Sterilization Process

NASA Astrophysics Data System (ADS)

Rupiasih, N. N.; Sumadiyasa, M.; Putra, I. K.

2018-04-01

The present study, we report about the effect of UVC irradiation on the mechanical properties of chitosan membrane in the sterilization process. The membrane used was chitosan membrane 2% which prepared by a casting method using chitosan as matrix and acetic acid 1% as a solvent. The UVC source used was germicidal ultraviolet (UVG) which widely used for sterilization purposes. Variation doses were done by the varying time of irradiation, e.g. 5 min, 15 min, 30 min, and 60 min. Those samples are named as S1, S2, S3, and S4, respectively. Chitosan membrane before irradiation namely S0 also used for comparative study. The effect of UVC irradiation on the mechanical properties of membranes has been examined by different techniques including FTIR, DMA, and the water uptake capability. The results showed that ultimate tensile strength (UTS) and moduli of elasticity (E) were increased by increasing the irradiation time. From FTIR analysis obtained that no new molecules were formed in irradiated membranes. The water uptakes capability of the membranes after irradiation was smaller compared with before irradiation, and among the irradiated membranes, the water uptake capabilities were increased by increasing the exposure time. These observations suggested that more care should be taken during the sterilization process and outdoor used of the membrane. The other side, the UVC irradiation can improve the mechanical properties of the membranes.

Protective effects of HemoHIM on immune and hematopoietic systems against γ-irradiation.

PubMed

Park, Hae-Ran; Jo, Sung-Kee; Jung, Uhee; Yee, Sung-Tae; Kim, Sung-Ho

2014-02-01

We examined the effect of HemoHIM on the protective efficacy of hematopoietic stem cells and on the recovery of immune cells against sublethal doses of ionizing radiation. Two-month-old mice were exposed to γ-rays at a dose of 8, 6.5, or 5 Gy for a30-day survival study, endogenous spleen colony formation, or other experiments, respectively. HemoHIM was injected intraperitoneally before and after irradiation. Our results showed that HemoHIM significantly decreased the mortality of sublethally irradiated mice. The HemoHIM administration decreased the apoptosis of bone marrow cells in irradiated mice. On the other hand, HemoHIM increased the formation of endogenous spleen colony in irradiated mice. In irradiated mice, the recovery of total leukocytes in the peripheral blood and lymphocytes in the spleen were enhanced significantly by HemoHIM. Moreover, the function of B cells, T cells, and NK cells regenerated in irradiated mice were significantly improved by the administration of HemoHIM. HemoHIM showed an ideal radioprotector for protecting hematopoietic stem cells and for accelerating the recovery of immune cells. We propose HemoHIM as a beneficial supplement drug during radiotherapy to alleviate adverse radiation-induced effects for cancer patients. Copyright © 2013 John Wiley & Sons, Ltd.

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Caitlin; Bufford, Daniel; Muntifering, Brittany

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due tomore » irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2.« less

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

PubMed Central

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana; Senor, David; Steckbeck, Mackenzie; Davis, Justin; Doyle, Barney; Buller, Daniel

2017-01-01

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2. PMID:28961199

17 CFR 230.485 - Effective date of post-effective amendments filed by certain registered investment companies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Effective date of post... Investment Companies; Business Development Companies § 230.485 Effective date of post-effective amendments... provided in this section, a post-effective amendment to a registration statement filed by a registered open...

17 CFR 230.485 - Effective date of post-effective amendments filed by certain registered investment companies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Effective date of post... Investment Companies; Business Development Companies § 230.485 Effective date of post-effective amendments... provided in this section, a post-effective amendment to a registration statement filed by a registered open...

Deuterium desorption from ion-irradiated tantalum and effects on surface morphology

NASA Astrophysics Data System (ADS)

Novakowski, T. J.; Sundaram, A.; Tripathi, J. K.; Gonderman, S.; Hassanein, A.

2018-06-01

Compared to tungsten (W), tantalum (Ta) has shown superior resistance to helium (He)-induced surface morphology changes under fusion-relevant irradiation conditions. However, Ta is also expected to have a stronger interaction with hydrogen isotopes, potentially limiting its use as a plasma-facing material. Despite these concerns, detailed investigations on hydrogen irradiation effects on Ta are scarce. In this study, pristine and fuzzy (He+ ion-irradiated) Ta samples are irradiated with 120 eV deuterium (D) ions at various temperatures and examined with a combination of thermal desorption spectroscopy (TDS), scanning electron microscopy (SEM), and optical reflectivity. TDS reveals discrete D desorption temperatures at 660 and 760 K, corresponding to trapping energies of 1.82 and 2.11 eV, respectively. Although D is retained in Ta both in higher quantities and at higher temperatures compared to W, extreme surface temperatures expected in tokamak divertors may exceed these desorption temperatures and counteract retention. Furthermore, this study indicates that Ta is relatively resistant to adverse surface structuring under D+ ion irradiation. In fact, D+ is shown to prevent and suppress Ta fuzz formation in sequential D+/He+ ion irradiation experiments. While further investigations are needed to elucidate this behavior, these initial investigations show a strong potential for the use of Ta as a PFC material.

Effects of laser irradiation on immature olfactory neuroepithelial explants from the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mester, A.F.; Snow, J.B. Jr.

1988-07-01

The photobiological effect of low-output laser irradiation on the maturation and regeneration of immature olfactory bipolar receptor cells of the rat was studied. The maturation and regeneration of the receptor cells of rat fetuses were quantified in neuroepithelial explants with morphometric analysis. The number of explants with outgrowth and the number and length of neuritic outgrowths were determined on a regular basis for 12 days. Explants in the experimental group were irradiated with a helium-neon laser using different incident energy densities (IED). Explants in the fluorescent light control group were exposed to fluorescent light for the same periods of timemore » as those in the experimental group were exposed to laser irradiation. Explants in another control group were not exposed to laser or fluorescent light irradiation. The IED of 0.5 J/cm2 laser irradiation has been found to increase significantly the number of explants with outgrowth and the number and length of the outgrowths. Other laser IEDs or fluorescent light irradiation did not influence maturation or regeneration.« less

Thermal and microstructural effects of nanosecond pulsed Nd:YAG laser irradiation on tooth root surface

NASA Astrophysics Data System (ADS)

Wilder-Smith, Petra B. B.; Arrastia-Jitosho, Anna-Marie A.; Grill, G.; Liaw, Lih-Huei L.; Berns, Michael W.

1995-05-01

Plaque, calculus and altered cementum removal by scaling and root planing is a fundamental procedure in periodontal treatment. However, the residual smear layer contains cytotoxic and inflammatory mediators which adversely affect healing. Chemical smear layer removal is also problematic. In previous investigations effective smear layer removal was achieved using long pulsed irradiation at 1.06 (mu) . However, laser irradiation was not adequate as an alternative to scaling and root planing procedures and concurrent temperature rises exceeded thermal thresholds for pulpal and periodontal safety. It was the aim of this study to determine whether nanosecond pulsed irradiation at 1.06 (mu) could be used as an alternative or an adjunct to scaling and root planing. Sixty freshly extracted teeth were divided as follows: 5 control, 5 root planed only, 25 irradiated only, 25 root planed and irradiated. Irradiation was performed at fluences of 0.5 - 2.7 J/cm2, total energy densities of 12 - 300 J/cm2, frequencies of 2 - 10 Hz using the Medlite (Continuum) laser. Irradiation-induced thermal events were recorded using a thermocouple within the root canal and a thermal camera to monitor surface temperatures. SEM demonstrated effective smear layer removal with minimal microstructural effects. Surface temperatures increased minimally (< 3 C) at all parameters, intrapulpal temperature rises remained below 4 C at 2 and 5 Hz, F < 0.5 J/cm2. Without prior scaling and root planing, laser effects did not provide an adequately clean root surface.

Effect of electron beam irradiation and storage on the quality attributes of sausages with different fat contents.

PubMed

Kwon, J H; Nam, K C; Lee, E J; Kang, H J; Ahn, D U

2010-02-01

Sausages with different fat contents (16 or 29%) were purchased from local stores, vacuum-packaged in oxygen-impermeable bags, and irradiated at 0 or 5 kGy using a linear accelerator. The changes in quality attributes of irradiated sausages were determined during storage at 4 degrees C. The 2-thiobarbituric acid-reactive substance values of sausages were not affected by fat content but were increased after irradiation (5 kGy). Storage for 60 d increased the 2-thiobarbituric acid-reactive substance values of nonirradiated sausages (P < 0.05) but had no effect on irradiated sausages. The numbers of volatile compounds and the amounts of total volatiles were increased by irradiation in both the high-fat (29% fat) and low-fat (16% fat) sausages. Dimethyl sulfide was detected only in irradiated sausages, regardless of fat content (P < 0.05), but it disappeared after 60 d of storage. Pentane and 1-heptene were detected only in irradiated samples after 60 d of storage. Low-fat sausages had greater L* values, but had lesser a* and b* values than high-fat sausages. Irradiation and storage had little effect on either the exterior or interior color (L*, a*, and b* values) of sausages. Fat content had no effect on the sensory variables of sausages, regardless of irradiation and storage. However, irradiated sausages had significantly stronger off-odors and off-flavors than nonirradiated sausages regardless of fat content (P < 0.05). This indicated that fat content in sausages had a minimal effect on the quality of irradiated sausages during storage.

Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

NASA Astrophysics Data System (ADS)

Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

2007-12-01

Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

Photobiomodulation of breast and cervical cancer stem cells using low-intensity laser irradiation.

PubMed

Kiro, N E; Hamblin, M R; Abrahamse, H

2017-06-01

Breast and cervical cancers are dangerous threats with regard to the health of women. The two malignancies have reached the highest record in terms of cancer-related deaths among women worldwide. Despite the use of novel strategies with the aim to treat and cure advanced stages of cancer, post-therapeutic relapse believed to be caused by cancer stem cells is one of the challenges encountered during tumor therapy. Therefore, further attention should be paid to cancer stem cells when developing novel anti-tumor therapeutic approaches. Low-intensity laser irradiation is a form of phototherapy making use of visible light in the wavelength range of 630-905 nm. Low-intensity laser irradiation has shown remarkable results in a wide range of medical applications due to its biphasic dose and wavelength effect at a cellular level. Overall, this article focuses on the cellular responses of healthy and cancer cells after treatment with low-intensity laser irradiation alone or in combination with a photosensitizer as photodynamic therapy and the influence that various wavelengths and fluencies could have on the therapeutic outcome. Attention will be paid to the biomodulative effect of low-intensity laser irradiation on cancer stem cells.

Chromosome damage evolution after low and high LET irradiation

NASA Astrophysics Data System (ADS)

Andreev, Sergey; Eidelman, Yuri

Ionizing radiation induces DNA and chromatin lesions which are converted to chromosome lesions detected in the first post-irradiation mitosis by classic cytogenetic techniques as chromosomal aberrations (CAs). These techniques allow to monitor also delayed aberrations observed after many cell generations post-irradiation - the manifestation of chromosomal instability phenotype (CIN). The problem discussed is how to predict time evolution from initial to delayed DNA/chromosome damage. To address this question, in the present work a mechanistic model of CIN is elaborated which integrates pathways of (*) DNA damage induction and its conversion to chromosome lesions (aberrations), (**) lesion transmission and generation through cell cycles. Delayed aberrations in subsequent cycles are formed in the model owing to two pathways, DNA damage generation de novo as well as CA transmission from previous cycles. DNA damage generation rate is assumed to consist of bystander and non-bystander components. Bystander signals impact all cells roughly equally, whereas non-bystander DSB generation rate differs for the descendants of unirradiated and irradiated cells. Monte Carlo simulation of processes underlying CIN allows to predict the time evolution of initial radiation-induced damage - kinetics curve for delayed unstable aberrations (dicentrics) together with dose response and RBE as a function of time after high vs low LET irradiation. The experimental data for radiation-induced CIN in TK6 lymphoblastoid cells and human lymphocytes irradiated with low (gamma) and high (Fe, C) LET radiation are analyzed on the basis of the proposed model. One of the conclusions is that without bystander signaling, just taking into account the initial DNA damage and non-bystander DSB generation, it is impossible to describe the available experimental data for high-LET-induced CIN. The exact contribution of bystander effects for high vs low LET remains unknown, but the relative contribution may be

Effect of solar irradiation on extracellular enzymes of Aeromonas proteolytica

NASA Technical Reports Server (NTRS)

Foster, B. G.

1973-01-01

The bacterium Aeromonas proteolytica was selected for studying the effects of solar irradiation on extracellular enzymes because it produces an endopeptidase that is capable of degrading proteins and a hemolysin that is active in lysing human erythrocytes. Possible alterations in the rate of enzyme production in response to the test conditions are currently underway and are not available for this preliminary report. Completed viability studies are indicative that little difference exists among the survival curves derived for cells exposed to various components of ultraviolet irradiation in space.

[Protective Effect of S-isopentenyl-L-cysteine against DNA Damage in Irradiated Mice].

PubMed

Zheng, Qi-sheng; Yu, Guang-yun; He, Xin; Jiang, Ming; Chu, Xiao-fei; Zhao, Shu-yi; Fan, Sai-jun; Liu, Pei-xun

2015-10-01

To evaluate the protective effect of S-isopentenyl-L-cysteine,a new cysteine derivative,on DNA damage induced by radiation by using acute radiation injury animal models. Forty ICR mice were randomly divided into five groups:the control group,1.0Gy gamma irradiation group,1.0Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,7.2Gy gamma irradiation group,and 7.2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,with 8 mice in each group.The comet assay and bone marrow polychromatic micronucleus experiments were performed to evaluate the double-strand DNA breaks in ICR mice exposed to 1.0 and 7.2Gy gamma-ray, respectively. The tail DNA percentage,tail length,tail moment,and olive tail moment of peripheral blood lymphocytes in 7.2Gy gamma irradiation group were significantly higher than that of the control group (P<0.01).And it was also observed that above experimental indexes of 7.2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group was significantly less than that of 7.2Gy gamma irradiation group (P<0.05). In addition,the micronucleus rate of 1.0Gy gamma irradiation group and 7.2Gy gamma irradiation group were both significantly higher than in the control group (P<0.01). In addition,in mice given S-isopentenyl-L-cysteine before irradiation,the micronucleus rate of ICR mice exposed to 1.0 and 7.2Gy gamma-ray decreased from (39.5000 ± 3.3141)‰ to (28.1667±4.1345)‰ (P=0.033) and from (76.5000 ± 4.6242)‰ to (22.8333 ± 3.6553)‰(P=0.000),respectively. The bone marrow polychromatic micronucleus experiment indicated that the value of polychromatic erythrocyte (PCE)/normochromatic erythrocyte(NCE) of ICR mice exposed to 1.0 and 7.2Gy gamma-ray was less than the control group(P<0.05). Meanwhile,after irradiating by certain dose,the value of PCE/NCE in mice given S-isopentenyl-L-cysteine before irradiation was significantly higher than the corresponding groups (P<0.05). S-isopentenyl-L-cysteine has a good protective

Stoichiometry effect on the irradiation response in the microstructure of zirconium carbides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young Yang; Wei-Yang Lo; Clayton Dickerson

2014-11-01

Zone-refined ultra high pure ZrC with five C/Zr ratios ranging from 0.84 to 1.17 was irradiated using a 2 MeV proton beam at 1125 C. The stoichiometry effect on the irradiation response of ZrC microstructure was examined using transmission electron microscopy following the irradiation. The irradiated microstructures generally feature a high density of perfect dislocation loops particularly at away from the graphite precipitates, and the C/Zr ratio shows a notable effect on the size and density of dislocation loops. The dislocation loops are identified as interstitial type perfect loops, and it was indirectly proved that the dislocation loop core likelymore » consists of carbon atoms. Graphite precipitates that form with excess carbon in the super-stoichiometric ZrC are detrimental, and the dramatic increases in the size of and density of dislocation loops in the vicinity of graphite precipitates in ZrC phase were observed. Irradiationinduced faceted voids were only observed in ZrC0.95, which is attributed to the pre-existing dislocation lines as biased sinks for vacancies.« less

Effect of ionizing radiation on human skeletal muscle precursor cells

PubMed Central

Jurdana, Mihaela; Cemazar, Maja; Pegan, Katarina; Mars, Tomaz

2013-01-01

Background Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures. Materials and methods Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin – 6 (IL-6) release and stress response detected by the heat shock protein (HSP) level, while long term effects were followed by proliferation capacity and cell death. Results Compared with non-irradiated control and cells treated with inhibitor of cell proliferation Ara C, myoblast proliferation decreased 72 h post-irradiation, this effect was more pronounced with increasing doses. Post-irradiation myoblast survival determined by measurement of released LDH enzyme activity revealed increased activity after exposure to irradiation. The acute response of myoblasts to lower doses of irradiation (4 and 6 Gy) was decreased secretion of constitutive IL-6. Higher doses of irradiation triggered a stress response in myoblasts, determined by increased levels of stress markers (HSPs 27 and 70). Conclusions Our results show that myoblasts are sensitive to irradiation in terms of their proliferation capacity and capacity to secret IL-6. Since myoblast proliferation and differentiation are a key stage in muscle regeneration, this effect of irradiation needs to be taken in account, particularly in certain clinical conditions. PMID:24294183

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

PubMed

Nakatsukasa, Hiroko; Tsukimoto, Mitsutoshi; Ohshima, Yasuhiro; Tago, Fumitoshi; Masada, Ayako; Kojima, Shuji

2008-07-01

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

Study of antioxidative effects and anti-inflammatory effects in mice due to low-dose X-irradiation or radon inhalation

PubMed Central

Kataoka, Takahiro

2013-01-01

Low-dose irradiation induces various stimulating effects, especially activation of the biological defense system including antioxidative and immune functions. Oxidative stress induced by reactive oxygen species (ROS) can cause cell damage and death and can induce many types of diseases. This paper reviews new insights into inhibition of ROS-related diseases with low-dose irradiation or radon inhalation. X-irradiation (0.5 Gy) before or after carbon tetrachloride (CCl4) treatment inhibits hepatopathy in mice. X-irradiation (0.5 Gy) before ischemia-reperfusion injury or cold-induced brain injury also inhibits edema. These findings suggest that low-dose X-irradiation has antioxidative effects due to blocking the damage induced by free radicals or ROS. Moreover, radon inhalation increases superoxide dismutase activity in many organs and inhibits CCl4-induced hepatic and renal damage and streptozotocin-induced type I diabetes. These findings suggest that radon inhalation also has antioxidative effects. This antioxidative effect against CCl4-induced hepatopathy is comparable to treatment with ascorbic acid (vitamin C) at a dose of 500 mg/kg weight, or α-tocopherol (vitamin E) treatment at a dose of 300 mg/kg weight, and is due to activation of antioxidative functions. In addition, radon inhalation inhibits carrageenan-induced inflammatory paw edema, suggesting that radon inhalation has anti-inflammatory effects. Furthermore, radon inhalation inhibits formalin-induced inflammatory pain and chronic constriction injury-induced neuropathic pain, suggesting that radon inhalation relieves pain. Thus, low-dose irradiation very likely activates the defense systems in the body, and therefore, contributes to preventing or reducing ROS-related injuries, which are thought to involve peroxidation. PMID:23420683

Study of antioxidative effects and anti-inflammatory effects in mice due to low-dose X-irradiation or radon inhalation.

PubMed

Kataoka, Takahiro

2013-07-01

Low-dose irradiation induces various stimulating effects, especially activation of the biological defense system including antioxidative and immune functions. Oxidative stress induced by reactive oxygen species (ROS) can cause cell damage and death and can induce many types of diseases. This paper reviews new insights into inhibition of ROS-related diseases with low-dose irradiation or radon inhalation. X-irradiation (0.5 Gy) before or after carbon tetrachloride (CCl4) treatment inhibits hepatopathy in mice. X-irradiation (0.5 Gy) before ischemia-reperfusion injury or cold-induced brain injury also inhibits edema. These findings suggest that low-dose X-irradiation has antioxidative effects due to blocking the damage induced by free radicals or ROS. Moreover, radon inhalation increases superoxide dismutase activity in many organs and inhibits CCl4-induced hepatic and renal damage and streptozotocin-induced type I diabetes. These findings suggest that radon inhalation also has antioxidative effects. This antioxidative effect against CCl4-induced hepatopathy is comparable to treatment with ascorbic acid (vitamin C) at a dose of 500 mg/kg weight, or α-tocopherol (vitamin E) treatment at a dose of 300 mg/kg weight, and is due to activation of antioxidative functions. In addition, radon inhalation inhibits carrageenan-induced inflammatory paw edema, suggesting that radon inhalation has anti-inflammatory effects. Furthermore, radon inhalation inhibits formalin-induced inflammatory pain and chronic constriction injury-induced neuropathic pain, suggesting that radon inhalation relieves pain. Thus, low-dose irradiation very likely activates the defense systems in the body, and therefore, contributes to preventing or reducing ROS-related injuries, which are thought to involve peroxidation.

A different regional response by mouse oligodendrocyte progenitor cells (OPCs) to high-dose X-irradiation has consequences for repopulating OPC-depleted normal tissue.

PubMed

Irvine, Karen-Amanda; Blakemore, William F

2007-01-01

This study was designed to investigate whether the residual, dysfunctional oligodendrocyte progenitor cells (OPCs) observed following X-irradiation of the mouse spinal cord [D. M. Chari et al. (2003) Exp. Neurol., 198, 145-153], the presence of which prevented the endogenous repopulation of these areas from normal tissue, reflects a general response of OPCs in the mouse central nervous system (CNS) to X-irradiation. The brains of adult mice were exposed to 40 Gy of X-irradiation and the effect of X-irradiation on the OPCs was assessed up to 4 weeks post-irradiation using anti-NG2 antibodies. X-irradiation resulted in almost complete depletion of OPCs within the telencephalon (cortex, corpus callosum and hippocampus) by 7 days post-irradiation, which was followed by progressive repopulation of OPCs from non-irradiated areas of the cortex. By contrast, within the lower brain centres (the diencephalon and mesencephalon) OPC loss occurred much more slowly so that 26% of the OPCs still remained 4 weeks after X-irradiation. The consequence of this heterogeneous response to X-irradiation was that whereas transplanted and endogenous OPCs rapidly established themselves in the OPC-depleted telencephalon this did not occur in the areas where there was incomplete depletion of endogenous OPCs. Our findings confirm not only the requirement for almost complete OPC depletion in order to establish transplanted OPCs in normal tissue but also highlight a heterogeneity of progenitor populations in different areas of the mouse CNS.

Comparison of irradiation behaviour of HTR graphite grades

NASA Astrophysics Data System (ADS)

Heijna, M. C. R.; de Groot, S.; Vreeling, J. A.

2017-08-01

The INNOGRAPH irradiations were executed in the High Flux Reactor (HFR) in Petten by NRG supported by the European Framework programs HTR-M, RAPHAEL, and ARCHER to generate data on the irradiation behaviour of graphite grades for High Temperature Reactor (HTR) application available at that time. Samples of the graphite grades NBG-10, NBG-17, NBG-18, NBG-20, NBG-25, PCEA, PPEA, PCIB, and IG-110 have been irradiated at 750 °C and 950 °C. The inherent scatter induced by the probabilistic material behaviour of graphite requires uncertainty and scatter induced by test conditions and post-irradiation examination to be minimized. The INNOGRAPH irradiations supplied an adequate number of irradiated samples to enable accurate determination of material properties and their evolution under irradiation. This allows comparison of different graphite grades and a qualitative assessment of their appropriateness for HTR applications, as a basis of selection, design and core component lifetime. The results indicate that coarse grained graphite grades exhibit more favourable behaviour for application in HTRs due to their low dimensional anisotropy and fracture propagation resilience.

Effects of γ-Irradiation on the Molecular Structures and Functions of Human Serum Albumin.

PubMed

Hu, Xinxin; Song, Wei; Li, Wei; Guo, Changying; Yu, Zehua; Liu, Rutao

2016-11-01

In this paper, we use spectroscopic methods (fluorescence spectroscopy, UV absorption spectroscopy, and circular dichroism (CD) spectroscopy) to elucidate the effects of reactive oxygen species generated by γ-irradiation on the molecular properties of human serum albumin (HSA). The results of fluorescence spectroscopy indicated that oxidation by γ-irradiation can lead to conformational changes of HSA. Data of CD spectra suggested that with the increase of radiation dose the percentage of α-helix in HSA has decreased. The determination of protein hydrophobicity showed that the effective hydrophobicity of HSA decreased up to 62% compared to the native HSA solution due to the exposure to the γ-irradiation. Furthermore, small changes in the esterase-like activity of HSA were introduced because of oxidation. The content of bityrosine increased markedly, suggesting that the oxidized HSA was aggregated. Moreover, there was no obvious change in the molecular properties of HSA with low γ-irradiation dose. Changes happened when the irradiation dose exceeded 200 Gy. © 2016 Wiley Periodicals, Inc.

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

PubMed

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

2014-07-01

Thyme (Thymus vidgaris L.), rosemary (Rosmarinus officinalis L.), black pepper (Piper nigrum L.) and cumin (Cuminum cyminum L.) in ground form were packaged in either air or 100% N2 and γ-irradiated at 3 different irradiation levels (7kGy, 12kGy, 17kGy). Total viable bacterial count, yeast and mould count, colour, essential oil yield and essential oil composition were determined. Microbial load was not detectable after 12kGy irradiation of all samples. Irradiation resulted in significant changes in colour values of rosemary and black pepper. The discolouration of the irradiated black pepper was lower in modified atmosphere packaging (MAP) compared to air packaging. Essential oil yield of irradiated black pepper and cumin was lower in air packaging compared to MAP. Gamma-irradiation generally decreased monoterpenes and increased oxygenated compounds, but the effect was lower in MAP. Overall, spices should be irradiated under an O2-free atmosphere to minimise quality deterioration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Protective effect of poly (α- L-glutamate) against UV and γ-irradiation

NASA Astrophysics Data System (ADS)

Furuta, Masakazu; Huy, Nguyen Quang; Tsuchiya, Akihito; Nakatsuka, Hiroshige; Hayashi, Toshio

2004-09-01

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

EFFECT OF ULTRA-VIOLET IRRADIATION OF RIBONUCLEIC ACID ON ITS CHROMATOGRAPHIC BEHAVIOUR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubinski, H.

1963-11-01

Experiments were made to illustrate the effects of ultraviolet radiation on RNA isolated from uninfected mammalian cells as well as those from those infected with polio virus. The chromatographic recovery of irradiated RNA, as judged by ultraviolet adsorbance and radioactivity (no plaque formers were found after irradiation), was considerably lower than that of unirradiated RNA. (P.C.H.)

Antibacterial effects of Nd:YAG laser irradiation within root canal dentin.

PubMed

Klinke, T; Klimm, W; Gutknecht, N

1997-02-01

The microbial flora of the root canal dentin can cause failures in the conventional treatment of infected root canals if it cannot be sufficiently removed by preparation and chemical disinfection of the root canal. The aim of this study is to examine the bactericidal effects of neodymium:yttriumaluminum garnet (Nd:YAG) laser irradiation in the depth of the root canal dentin. Following sterilization, longitudinal section dentin slices of different thicknesses (100-1000 microns) were inoculated on one side with 4 microliters of a Streptococcus mutans suspension. The opposite sides of the dentin slices were then irradiated four times for 10-20 sec (according to the sample area) using the Nd:YAG laser at a setting of 1.5 W, 15 pps with a 200 microns glass fiber from an angle of about 5 degrees. The bacteria were then removed from the dentin using vibration and plated out on culture dishes that were selective for Streptococcus mutans. When compared with untreated control slices, counting of the colonies revealed a highly significant elimination of bacteria for all thicknesses following laser irradiation. Although the intensity of the laser irradiation decreased after penetration of a 1000-micron dentin slice, the bactericidal mode of action was still effective.

Understanding the Irradiation Behavior of Zirconium Carbide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Motta, Arthur; Sridharan, Kumar; Morgan, Dane

2013-10-11

-induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.« less

Immunosuppression in irradiated breast cancer patients: In vitro effect of cyclooxygenase inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wasserman, J.; Blomgren, H.; Rotstein, S.

1989-01-01

We have documented in previous studies that local irradiation therapy for breast cancer caused severe lymphopenia with reduction of both T and non-T lymphocytes. Non-T cells were relatively more depressed but recovered within six months. The recovery of T cells, on the other hand, remained incomplete 10-11 years after irradiation. Several lymphocyte functions were also severely impaired. An association was found between prognosis and postirradiation mitogen reactivity of lymphocytes from these patients. Mortality up to eight years after irradiation was significantly higher in patients with low postirradiation phytohemagglutinin and PPD reactivity. The radiation induced decrease in mitogenic response seemed mainlymore » to be caused by immunosuppressive monocytes, which suggests that the underlying mechanism might be mediated by increased production of prostaglandins by monocytes. For this reason we examined the effect of some cyclooxygenase products on different lymphocyte functions and found that prostaglandins A2, D2, and E2 inhibited phytohemagglutinin response in vitro. Natural killer cell activity was also reduced by prostaglandins D2 and E2. The next step was to examine various inhibitors of cyclooxygenase in respect to their capacity to revert irradiation-induced suppression of in vitro mitogen response in lymphocytes from breast cancer patients. It was demonstrated that Diclofenac Na (Voltaren), Meclofenamic acid, Indomethacin, and lysin-mono-acetylsalicylate (Aspisol) could enhance mitogen responses both before and after radiation therapy. This effect was most pronounced at completion of irradiation. On a molar basis, Diclofenac Na was most effective followed by Indomethacin, Meclofenamic acid, and lysin-monoacetylsalicylate.« less

Preliminary study on the effect of x-ray irradiation on Capsicum annum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subhash, K.; Nizam, J.

The present experiment on Capsicum annum was conducted to study various cytological and genetic effects induced by x-ray irradiation. Dry and soaked seeds were exposed to irradiation by deep x rays at the Radium and Cancer Research Institute, Hyderabad at a dose rate of 99 rads/min. The doses administered were as follows: 3000 rads, 4000 rads, 5000 rads, and 10,000 rads. The cytological preparations were made by following Belling's technique. The irradiated seeds along with the controlled were sown in the soil to observe the morphological variations. The root tip squashes from the irradiated seed material revealed various chromosomal aberrationsmore » such as deletions, parallel bridges, and single and paired fragments of acentric chromosomes, showing cytological irregularities. Bridges were quite common at anaphases. The irradiated seeds were germinated in order to record morphological variations. A period of 150 days seems to be necessary from germination to seed formation; this period is not identical for the irradiated and controlled seeds. In some of the irradiated material the duration was reduced to 120 to 130 days. With this observation it may be presumed that mild doses of radiation have accelerated the germination time and also hastened the growth processes. (auth)« less

Effect of alpha-particle irradiation on the electrical properties of n-type Ge

NASA Astrophysics Data System (ADS)

Roro, K. T.; Janse van Rensburg, P. J.; Auret, F. D.; Coelho, S.

2009-12-01

Deep-level transient spectroscopy was used to investigate the effect of alpha particle irradiation on the electrical properties of n-type Ge. The samples were irradiated with alpha particles at room temperature using an americium-241 (Am-241) radionuclide source. The main defects introduced were found to be electron traps with energy levels at EC-0.38, EC-0.21, EC-0.20, EC-0.15, and EC-0.10 eV, respectively. The main defects in alpha particle irradiation are similar to those introduced by MeV electron irradiation, where the main defect is the E-center. A quadratic increase in concentration as a function of dose is observed.

Effect of γ irradiation on the fatty acid composition of soybean and soybean oil.

PubMed

Minami, Ikuko; Nakamura, Yoshimasa; Todoriki, Setsuko; Murata, Yoshiyuki

2012-01-01

Food irradiation is a form of food processing to extend the shelf life and reduce spoilage of food. We examined the effects of γ radiation on the fatty acid composition, lipid peroxidation level, and antioxidative activity of soybean and soybean oil which both contain a large amount of unsaturated fatty acids. Irradiation at 10 to 80 kGy under aerobic conditions did not markedly change the fatty acid composition of soybean. While 10-kGy irradiation did not markedly affect the fatty acid composition of soybean oil under either aerobic or anaerobic conditions, 40-kGy irradiation considerably altered the fatty acid composition of soybean oil under aerobic conditions, but not under anaerobic conditions. Moreover, 40-kGy irradiation produced a significant amount of trans fatty acids under aerobic conditions, but not under anaerobic conditions. Irradiating soybean oil induced lipid peroxidation and reduced the radical scavenging activity under aerobic conditions, but had no effect under anaerobic conditions. These results indicate that the fatty acid composition of soybean was not markedly affected by radiation at 10 kGy, and that anaerobic conditions reduced the degradation of soybean oil that occurred with high doses of γ radiation.

Effects of Ion Irradiation on Seedlings Growth Monitored by Ultraweak Delayed Luminescence

PubMed Central

Abe, Tomoko; Cirrone, Giuseppe A. P.; Cuttone, Giacomo; Gulino, Marisa; Musumeci, Francesco; Romano, Francesco; Ryuto, Hiromichi; Scordino, Agata

2016-01-01

The optical technique based on the measurement of delayed luminescence emitted from the biological samples has demonstrated its ability to provide valid and predictive information on the functional status of various biological systems. We want to extend this technique to study the effect of ionizing radiation on biological systems. In particular we are interested in the action of ion beams, used for therapeutic purposes or to increase the biological diversity. In general, the assessment of the damage that radiation produces both in the target objects and in the surrounding tissues, requires considerable time because is based on biochemical analysis or on the examination of the evolution of the irradiated systems. The delayed luminescence technique could help to simplify this investigation. We have so started our studies performing irradiations of some relatively simple vegetable models. In this paper we report results obtained from mung bean (Vigna radiata) seeds submitted to a 12C ion beam at the energy of 62 MeV/nucleon. The dry seeds were irradiated at doses from 50 to 7000 Gy. The photoinduced delayed luminescence of each seed before and after ion irradiation was measured. The growth of seedlings after irradiation was compared with that of untreated seeds. A growth reduction on increasing the dose was registered. The results show strong correlations between the ion irradiation dose, seeds growth and delayed luminescence intensity. In particular, the delayed luminescence intensity is correlated by a logistic function to the seedlings elongation and, after performing a suitable measurement campaign based on blind tests, it could become a tool able to predict the growth of seeds after ion irradiation. Moreover these results demonstrate that measurements of delayed luminescence could be used as a fast and non-invasive technique to check the effects of ion beams on relatively simple biological systems. PMID:27936220

Ion mobility-enhanced MS(E)-based label-free analysis reveals effects of low-dose radiation post contextual fear conditioning training on the mouse hippocampal proteome.

PubMed

Huang, Lin; Wickramasekara, Samanthi I; Akinyeke, Tunde; Stewart, Blair S; Jiang, Yuan; Raber, Jacob; Maier, Claudia S

2016-05-17

Recent advances in the field of biodosimetry have shown that the response of biological systems to ionizing radiation is complex and depends on the type and dose of radiation, the tissue(s) exposed, and the time lapsed after exposure. The biological effects of low dose radiation on learning and memory are not well understood. An ion mobility-enhanced data-independent acquisition (MS(E)) approach in conjunction with the ISOQuant software tool was utilized for label-free quantification of hippocampal proteins with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-rays, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. Global proteome analysis revealed deregulation of 73 proteins (out of 399 proteins). Deregulated proteins indicated adverse effects of irradiation on myelination and perturbation of energy metabolism pathways involving a shift from the TCA cycle to glutamate oxidation. Our findings also indicate that proteins associated with synaptic activity, including vesicle recycling and neurotransmission, were altered in the irradiated mice. The elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which would be consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation. This study is significant because the biological consequences of low dose radiation on learning and memory are complex and not yet well understood. We conducted a IMS-enhanced MS(E)-based label-free quantitative proteomic analysis of hippocampal tissue with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-ray, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. The IMS-enhanced MS(E) approach in conjunction with ISOQuant software was robust and accurate with low median CV values of

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana