• Title/Summary/Keyword: Ionizing irradiation

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Co60 Gamma-Ray Effects on the DAC-7512E 12-Bit Serial Digital to Analog Converter for Space Power Applications

  • Shin, Goo-Hwan
    • Journal of Electrical Engineering and Technology
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    • v.9 no.6
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    • pp.2065-2069
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    • 2014
  • The DAC-7512E is a 12-bit digital to analog converter that is low power and a single package with internal buffers. The DAC-7512E takes up minimal PCB area for applications of space power electronics design. The spacecraft mass is a crucial point considering spacecraft launch into space. Therefore, we have performed a TID test for the DAC-7512E 12-bit serial input digital to analog converter to reduce the spacecraft mass by using a low-level Gamma-ray irradiator with $Co^{60}$ gamma-ray sources. The irradiation with $Co^{60}$ gamma-rays was carried out at doses from 0 krad to 100 krad to check the error status of the device in terms of current, voltage and bit error status during conversion. The DAC-7512E 12-bit serial digital to analog converter should work properly from 0 krad to 30 krad without any error.

Identification of Irradiated Foods by Using DNA, Immunochemical, and Biological Methods

  • Kim, Kyeung-Eun;Yang, Jae-Seung
    • Preventive Nutrition and Food Science
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    • v.4 no.4
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    • pp.276-282
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    • 1999
  • Ionizing radiation is considered to be an efficient technology to improve food safety and to extend food shelf-life in the food industry, and it has been used in food processing with a number of attributes. Food labeling should be established to enable the consumer to choose food freely, based on label information. A variety of methodologies to determine the physical, chemical, microbiological, and biological changes due to irradiation has been investigated in order to discriminate the irradiated and unirradiated food products for the consumer's free choice in food selection. However, no satisfactory method has been developed so far. In this review, various approaches based on DNA, immunochemical, and biological methods are addressed.

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Development of an open-source GUI computer program for modelling irradiation of multi-segmented phantoms using grid-based system for PHITS

  • Hiroshi Watabe;Kwan Ngok Yu;Nursel Safakatti;Mehrdad Shahmohammadi Beni
    • Nuclear Engineering and Technology
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    • v.55 no.1
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    • pp.373-377
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    • 2023
  • The Monte Carlo (MC) method has become an indispensable part of the nuclear radiation research field. Several widely used and well-known MC packages were developed for simulation of radiation transport and interaction with matter. All these MC packages require users to prepare an input script. The input script can become lengthy for complex models. The process of preparing these input scripts is time-consuming and error-prone. In the present work, we have developed an open-source GUI computer program for modelling radiation transport and interaction in multi-segmented slab phantoms using grid-based system for the widely used PHITS MC package. The developed tools would be useful for future users of PHITS MC package and particularly inexperienced users. The present program is distributed under GPL license and all users can freely download, modify and redistribute the program without any restrictions.

Radioprotective effect of fucoidan against hematopoietic and small intestinal stem cells of γ-ray irradiated mice (감마선을 조사한 마우스의 조혈 및 소장줄기세포에 대한 fucoidan의 방호효과)

  • Park, Eunjin;Jeon, Seong Mo;Joo, Hong-Gu;Hwang, Kyu-Kye;Jee, Youngheun
    • Korean Journal of Veterinary Research
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    • v.48 no.4
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    • pp.393-399
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    • 2008
  • We investigated the potential of fucoidan for its ability to provide protection from gamma rayinduced damage. In our results, the fucoidan significantly improved the counts of endogenous colony forming unit to $9.5 {\pm} 1.5$, from $5.5 {\pm} 2.5$ compared with un-treated irradiated control group at 10 day after 7 Gy whole body irradiation. After 2 Gy irradiation, fucoidan treatment attenuated the percent of tail DNA of splenocytes, parameters of DNA damage, from $30.17 {\pm} 1.7%$ to $13.67 {\pm} 2.81%$ 2.81% by comet assay and also accelerated the proliferation of splenocytes, compared with un-treated irradiated control group by 3Hthymidine incorporation assay. Furthermore, fucoidan decreased the number of apoptotic fragments per intestinal crypt by 31.8% at 1 days after 2 Gy irradiation. These results indicated that the fucoidan significantly improved the hematopoietic recovery, prevented the DNA damage in immune cells and enhanced their proliferation, which had been suppressed by ionizing radiation. in addition, fucoidan rescued intestinal cells from radiation-induced apoptosis. Thus, this study raises the possibility of using fucoidan as adjuvant therapeutic agent after radiotherapy.

Effects of Ixeris dentata Extracts on the Genotoxicity Induced by Gamma Irradiation in Rats

  • Kim, Jin Kyu;Woo, Hyun Jung;Kim, Ji Hyang;Yoon, Yang Dal
    • Korean Journal of Environmental Biology
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    • v.22 no.4
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    • pp.543-549
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    • 2004
  • Ixeris dentata is a typical oriental herb. It is a widely distributed perennial in Korea, Japan and China, which belongs to the Compositae Family. The whole plant of I. dentata has been used for the treatment of pneumonia, contusion, tumor and hepatitis. It has also been used for the treatment of allergic diseases as a folk therapy in Korea. I. dentata is known to have aliphatics, triterpenoids and sesquiterpene glycosides in its composition. The present study was designed to explore the protective effects of water- and ethanol- extracts from I. dentata on irradiated rodents. For oral administration (twice per day), the extractive powder of I. dentata and the positive control (ascorbic acid) were dissolved at a concentration of 0.5 and 250mg $ml^{-1}$ in saline, respectively. Thirty days after irradiation, the ratio of the weight of the testis to the body weight was lower than 50% in the radiation groups than the control group. The ALP concentrations in the group treated with the water-extracts of the leaf were $79.68\pm{1.39%}$ (p<0.05) of those of the radiation control. Both of the SGOT and SGPT in the group treated with the ethanol-extract of the root were $72.68\pm{0.95}\;and\;77.87\pm{5.74}$ (p<0.05) of those of the radiation control, respectively. The levels of DNA damage induced by gamma radiation decreased in the experimental group to which the extracts of I. dentata were administered before irradiation. In conclusion, these results indicate that the extracts of I. dentata have an excellent ability to reduce the radicals and they have a protective effect on DNA breakage caused by radiation.

Utilization of Ionizing Radiation on the Preservation of Sprouting Foods (발아식품의 품질보존을 위한 전리방사선의 이용)

  • Yoon, Hyung Sik;Kwon, Joong Ho
    • Current Research on Agriculture and Life Sciences
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    • v.3
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    • pp.79-84
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    • 1985
  • This research was attempted in order to develop a long-term storage method for sprouting foods such as potatoes, onions, garlic and chestnuts using Co-60 gamma irradiation combined with a natural low temperature. The sprouting of the irradiated groups, 150 Gy in potatoes, 50 Gy in onions and garlic, and 250 Gy in chestnuts was almost completely inhibited until 8 to 10 months of storage. The rotting rate of loss of weight influenced a little by irradiation with a sprout inhibiting dose, and the weight of loss of the optimum dose irradiated groups was reduced by about 6 to 24% as against that of the nonirradiated in the four stored foods. The chemical components relating to the quality of sprouting foods were better retained in the irradiated groups than in the nonirradiated until the latter period of storage. Therefore, it was shown that the long term storage of sprouting foods is possible using gamma irradiation of 50 to 150 Gy for potatoes, onions, and garlic and 250Gy for chestnuts followed by storage at a natural low temperature($10{\pm}5^{\circ}C$, R.H. 75-85%).

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CHANGING OF RGS TRANSCRIPTS LEVELS BY LOW-DOSE-RATE IONIZING RADIATION IN MOUSE TESTIS

  • Kim, Tae-Hwan;Baik, Ji Sue;Heo, Kyu;Kim, Joong Sun;Lee, Ki Ja;Rhee, Man Hee;Kim, Sung Dae
    • Journal of Radiation Protection and Research
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    • v.40 no.3
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    • pp.187-193
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    • 2015
  • Deleterious effects of high dose radiation exposure with high-dose-rate are unarguable, but they are still controversial in low-dose-rate. The regulator of G-protein signaling (RGS) is a negative regulator of G protein-coupled receptor (GPCR) signaling. In addition, it is reported that irradiation stress led to GPCR-mediated mitogen-activated protein kinase (MAPK) and phosphotidylinositol 3-kinase (PI3-k) signaling. The RGS mRNA expression profiles by whole body radiation with low-dose-rate has not yet been explored. In the present study, we, therefore, examined which RGS was modulated by the whole body radiation with low-dose-rate ($3.49mGy{\cdot}h^{-1}$). Among 16 RGS expression tested, RGS6, RGS13 and RGS16 mRNA were down-regulated by low-dose-rate irradiation. This is the first report that whole body radiation with low-dose-rate can modulate the different RGS expression levels. These results are expected to reveal the potential target and/or the biomarker proteins associated with male testis toxicity induced by low-dose-rate irradiation, which might contribute to understanding the mechanism beyond the testis toxicity.

Quality Evaluation of Ground Garlic and Onions Treated with Chemical Fumigants and Ionizing Radiation (마늘 및 양파 분말의 품질에 대한 화학 훈증제와 감마선 처리의 비교 연구)

  • Kwon, Joong-Ho;Byun, Myung-Woo;Cho, Han-Ok
    • Korean Journal of Food Science and Technology
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    • v.19 no.2
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    • pp.107-112
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    • 1987
  • Comparative effects of ethylene oxide and gamma radiation treatment of the microbiological and physicochemical qualities of ground garlic and onions were investigated. The standard ethylene oxide cycle employed was substantially less effective in reducing microbial counts than were 7 and 10 kGy of gamma radiation, and was roughly comparable to 5 kGy. Effects of gamma radiation on pungency, nutrient and color were relativey small in comparison with ethylene oxide which adversely affected physicochemical properties. Sensory evaluation indicated that no significant difference was observed between the nontreated control group and 10 kGy irradiated smaples.

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Establishment of micronuclus assay as biological dosimetry in pig lymphocytes after gamma-irradiation (돼지 림프구의 미소핵 형성을 지표로 방사선 생물학적 선량측정법 확립)

  • Kim, Se-ra;Lee, Hae-june;Lee, Jin-hee;Kang, Chang-mo;Kim, Tae-hwan;Jo, Sung-kee;Kim, Jong-choon;Kim, Sung-ho
    • Korean Journal of Veterinary Research
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    • v.44 no.3
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    • pp.323-327
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    • 2004
  • The purpose of the present experiment was to investigate the micronuclei(MN) frequency in cytokinesis-blocked(CB) cells after various doses of gamma-rays in pig (Landrace, male, 3-month-old) and so to contribute to the clarification of the question whether these species are suitable as a target organism in the test system. The frequencies of binucleated cells, and gamma-ray-induced MN in CB cells at several doses were measured in three donors. The peaks of binucleated lymphocyte formation(22%) were found at a concentration of 2% phytohaemagglutinin(PHA) and $4{\mu}g/ml$ Cytochalasin B(Cyt-B) in pig at 72 hours after incubation. Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors studied. When analysed by linear-quadratic model the line of best fit was $y=0.0183D+0.0124D^2+0.0133$(y = number of MN/CB cells and D=irradiation dose in Gy). In conclusion, the results demonstrate that it appears feasible to use pig as target organisms in the micronucleus test to estimate the cytogenetic damage caused by ionizing radiations or, potentially, chemical compounds.

Monitoring of Volatile Flavor Components and Amino Acids in Fresh Mushrooms (Agaricus bisporus) Associated with Shelf-Life Extension (양송이의 숙도지연에 다른 휘발성 향기성분과 아미노산의 변화)

  • Kwon, Joong-Ho;Byun, Myung-Woo;Yoon, Hyung-Sik
    • Korean Journal of Food Science and Technology
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    • v.22 no.5
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    • pp.514-519
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    • 1990
  • Some chemical constituents were monitored to evaluate the biochemical and nutritional aspects of ${\gamma}-irradiated$ mushrooms associated with shelf-life extension. Volatile components identified by GC and GC-MS were composed primarily of 1-octen-3-ol(68%)). benzaldehyde(13%), 3-octanone(8%), benzyl alcohol(5%), 3-octanol(2%)). 1-octen-3one(1%). etc. Treatment with 2kGy-irradiation and subsequent storage for 17 days at $(9{\pm}1^{\circ}C\;and\;80{\pm}7%$ RH resulted in appreciable changes In their contents. even though negligible changes were observed in GC patterns between the nonirradiated and 2 kGy-irradiated samples. Most of the amino acids were resistant to ionizing energy of 2 kGy, while sulfur-containing free amino acids were affected significantly by ${\gamma}-irradiation$.

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