• Food Science and Biotechnology
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• 제14권3호
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• pp.355-357
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• 2005

This study evaluated the binding abilities of rabbit anti-ovalbumin (OVA) immunoglobulin G (IgG) and egg-allergic patient IgE on gamma-irradiated OVA during proteolysis using pepsin and trypsin. The concentrations of both the intact and the irradiated OVAs decreased during proteolysis when detected with IgG However, when detected by patient IgE the concentration of the intact OVA decreased up to 30 min after the trypsin treatment and increased thereafter. Irradiated OVA detected by patient IgE showed a lower initial concentration (0.16%) than that of the intact OVA, and this reduced concentration was maintained stably. The results indicate that irradiation, rather than enzymatic treatment, could reduce the binding of the irradiated and enzyme-treated OVA. Therefore, gamma irradiation has potential as an effective method to reduce OVA-induced allergy and may enhance the safety of egg-allergic individuals.

• Journal of Radiation Protection and Research
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• 제34권1호
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• pp.9-14
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• 2009

High density polyethylene (HDPE) is degraded due to a radiation-induced oxidation when it is used as a neutron moderator in a neutron counter for a nuclear material accounting of spent fuels. The HDPE exposed to the gamma-ray emitted from the fission products in a spent nuclear fuel results in a radiation-induced degradation which changes its original molecular structure to others. So a neutron moderating power variation of HDPE, irradiated by a gamma radiation, was investigated in this work. Five HDPE moderator structures were exposed to the gamma radiation emitted from a $^{60}Co$ source to a level of $10^5-10^9$ rad to compare their post-irradiation properties. As a result of the neutron measurement test with 5 irradiated HDPE structures and a neutron measuring system, it was confirmed that the neutron moderating power for the $10^5$ rad irradiated HDPE moderator revealed the largest decrease when the un-irradiated pure one was used as a reference. It implies that a neutron moderating power variation of HDPE is not directly proportional to the integrated gamma dose rate. To clarify the cause of these changes, some techniques such as a FTIR, an element analysis and a densitometry were employed. As a result of these analyses, it was confirmed that the molecular structure of the gamma irradiated HDPEs had partially changed to others, and the contents of hydrogen and oxygen had varied during the process of a radiation-induced degradation. The mechanism of these changes cannot be explained in detail at present, and thus need further study.

• 한국식품영양과학회지
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• 제28권3호
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• pp.638-645
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• 1999

This study was done to investigate effects of ${\gamma}$ irradiated beef feeding on the formation of gluta thione S transferase placental form positive(GST P+) foci, lipid peroxidation, cytochrome P450 system and microsomal glucose 6 phosphate activity in diethylnitrosamine(DEN) initiated rat hepatocarci nogenesis. Weaning Sprague Dawley male rats were fed the diet containing ${\gamma}$ irradiatied ground beef at the dose of 0, 3, 5kGy as a 20% of protein source for 8 weeks. One week after feeding, rats were intraperitoneally injected twice with a dose of DEN(50mg/kg BW). As a promoter, 0.05% phenobarbital was fed in drinking water from one week after DEN treatment until the end of experiment. At the end of 8th week, rats were sacrificed and hepatic GST P+ foci, microsomal malondialdehyde(MDA) and conjugated diene contents were determined. In addition, cytochrome P450 content and the activities of NADPH cytochrome P450 reductase and glucose 6 phosphatase were also measured. There was no significant effect by gamma irradiation on microsomal MDA content, conjugated diene, cytochrome P450 content and activities of NADPH cytochrome P450 reductase and glucose 6 phosphatase. However with DEN treatment, microsomal MDA content and conjugated diene contents were significantly changed. Cytochrome P450 content was also significantly increased while microsomal glucose 6 phophatase activity was significantly decreased with DEN treatment. However activity of NADPH cytochrome P450 reductase was not affected. An interesting finding in this study was that the number and area of hepatic GST P+ foci of the rats fed gamma irradiated beef were significantly(p<0.05) lower than those of the control. Such a lowering effect on GST P+ foci formation was highest at the dose of 3kGy than others. Overall results suggest that the consumption of low dose of gamma irradiated beef does not affect the formation of lipid peroxide, cytochrome P450 system and membrane stability.

• 방사선산업학회지
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• 제5권2호
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• pp.169-173
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• 2011

This study investigated the effect of gamma irradiation on immune enhancing activity of Chaga mushroom extract (CME). CME was prepared by hot water extraction at $70^{\circ}C$ for 4 hours and lyophilized. Lyophilized CME powder was dissolved with deionized water at $10mg\;ml^{-1}$ and then irradiated at the doses of 10, 30 and 50 kGy by cobalt 60 gamma irradiator. The gamma-irradiated and non-irradiated CME were treated into the splenocyte separated from mouse. Cell proliferation and cytokine production of the immune cells were increased by gamma-irradiated CME and these increases were more prominent when CME was irradiated at higher doses. Therefore, it is considered that gamma irradiation can be an effective method for improvement of the immunomodulating activity Chaga mushroom extract.

• 한국환경농학회지
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• 제21권3호
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• pp.202-207
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• 2002

참박과 호박 채종종자의 발아율을 증진시킬 수 있는 종자처리 방법을 확립하고자 저선량 감마선을 1$\sim$20 Gy 까지 조사하여 발아와 초기생육 및 생리활성을 관찰하였다. 저선량 조사한 참박과 호박종자의 발아율은 대조구보다 증가하는 경향을 보였는데 그 효과는 종자상태에 따라 다르게 나타났다. 참박 70$\sim$80% 발아율종자의 발아는 4$\sim$20 Gy에서 증가하였는데 특히 4 Gy조사에서 가장 높았고, 80$\sim$90% 발아율종자도 4 Gy 조사에서 효과를 보였다. 파종 4일 후의 발아율은 참박 70$\sim$80%와 80$\sim$90% 발아율 종자의 경우는 4 Gy조사에서 대조구보다 각각 66%와 26% 증가하였고, 호박의 70$\sim$80% 발아율종자는 2 Gy 조사에서, 80$\sim$90% 발아율종자는 8 Gy 조사에서 향상되었다. 저선량 조사한 유묘생육은 발아율이 증가한 선량에서 증가하였는데 특히 호박 70$\sim$80% 종자의 2 Gy 조사에서 가장 높았다. 파종 6일 후에 조사한 참박의 효소활성은 4 Gy 조사시에 단백질과 catalase 활성이, 호박의 경우는 catalase와 peroxidase 활성이 2 Gy와 8 Gy 조사에서 증가하였다. 참박과 호박종자의 발아와 유묘생육 및 생리활성은 저선량 감마선 조사에 의해 촉진됨을 확인할 수 있었다.

• 방사선산업학회지
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• 제5권4호
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• pp.347-352
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• 2011

In order to identify the genetic relationship analysis by acute and chronic gamma irradiation, Arabidopsis (Arabidopsis thaliana L.) were irradiated with 200 Gy of gamma-rays using gamma-irradiator (3,000 Ci; Nordion, Canada) and gamma-phytotron (400 Ci; Nordion, Canada) for acute and chronic irradiation, respectively. Genetic relationship among two acute gamma-irradiated plants (A1 and A24) and three chronic gamma-irradiated plants (C1W, C2W, C3W) were analyzed using the amplified fragment length polymorphism (AFLP) technique compared with each non-irradiated plant. A total of 28 EcoRI and MseI primer combinations were used to screen 8 treatments by the ABI3130 capillary electrophoresis system. Amplified products by 28 primer sets showed 1,679 bands with an average of 51 bands per primer combination. Out of the total bands scored, 1,164 fragments were polymorphic bands, with different alleles existing among the treatments. The cluster analysis was performed using the UPGMA (Unweighted Pair Group Method using Arithmetic) in the computer program NTSYS-pc. In clustery analysis, acute gamma-irradiation showed higher genetic variation compared with chronic gamma-irradiation.

• Journal of Ginseng Research
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• 제37권4호
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• pp.483-490
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• 2013

Gamma-irradiation (0-7 kGy) of ginseng is permitted in Korea for the purpose of microbial decontamination; with strict labeling, traceability and monitoring requirements. An identification study was conducted to determine the photostimulated-luminescence (PSL) and thermoluminescence (TL) properties of gamma-irradiated fresh and white ginsengs cultivated in different areas. Dose- dependent PSL-based screening was possible for white ginseng samples; however, inappropriate results from non-irradiated fresh ginseng samples were obtained, showing intermediate (700 to 5,000) or positive ($T_2$ >5,000, irradiated) PSL counts due to the abundance of minerals on the surfaces of the samples. TL analysis of separated minerals from all non-irradiated samples gave TL glow curves of low intensity with a maximum peak after $300^{\circ}C$. However, well-defined irradiation-specific (high intensity with a maximum peak at about $200^{\circ}C$) glow curves were observed for all the irradiated samples, regardless of their type and origins. TL ratios (first glow curve /second glow curve) were also determined to confirm the irradiated (>0.1) and non-irradiated (<0.1) results. SEM-EDX (scanning electron microscope-energy dispersive X-ray) and XRD (X-ray diffraction) spectroscopic analyses showed that feldspar and quartz minerals were the main source for the typical radiation-specific luminescence properties.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1521-1527
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• 2019

Objective: To study the contribution of plant enzyme and microbial activities on protein degradation in silage, this study evaluated the nitrogen transformation dynamics during ensiling of non- and irradiated alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.). Methods: Alfalfa and red clover silages were prepared and equally divided into two groups. One group was exposed to ${\gamma}$-irradiation at a recommended dosage (25 Gky). Therefore, four types of silages were produced: i) non-irradiated alfalfa silage; ii) irradiated alfalfa silage; iii) non-irradiated red clover silage; and iv) irradiated red clover silage. These silages were opened for fermentation quality and nitrogen components analyses after 1, 4, 8, and 30 days, respectively. Results: The ${\gamma}$-irradiation successfully suppressed microbial activity, indicated by high pH and no apparent increases in fermentation end products in irradiated silages. All nitrogen components, except for peptide-N, increased throughout the ensiling process. Proteolysis less occurred in red clover silages compared with alfalfa silages, indicated by smaller (p<0.05) increment in peptide-N and free amino acid N (FAA-N) during early stage of ensiling. The ${\gamma}$-irradiation treatment increased (p<0.05) peptide-N and FAA-N in alfalfa silage at day 1, whereas not in red clover silage; these two nitrogen components were higher (p<0.05) between day 4 and day 30 in non-irradiated silages than the irradiated silages. The ammonia nitrogen and non-protein nitrogen were highest in non-irradiated alfalfa silage and lowest in irradiated red clover silage after ensiling. Conclusion: The result of this study indicate that red clover and alfalfa are two forages varying in their nitrogen transformation patterns, especially during early stages of ensiling. Microbial activity plays a certain role in the proteolysis and seems little affected by the presence of polyphenol oxidase in red clover compared with alfalfaa.

• 대한수의학회지
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• 제33권4호
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• pp.649-655
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• 1993

E. tenella의 오오시스트에 대한 Cobalt-60 감마선 조사선량과 접종용량을 결정하고 감마선으로 처리한 E tenella와 그 계대원충을 닭에 접종하여 병원성을 조사하고자 일련의 시험을 실시하여 다음과 같은 결과를 얻었다. 증체량, 혈변도 및 병변도 등을 비교할 때 Cobalt-60감마선 조사량은 100 Gy의 수준에서 그리고 계대원충 접종군에서는 10,000개의 오오시스트 수준에서 약간의 병원성이 나타났다. 혈변도, 병변도 및 분변내 오오시스트 배설수는 감마선 조사원충 접종군에서 가장 낮게 나타났고, 1대 및 3대 계대원충 접종군에서는 보통 수준으로 그리고 감마선 조사하지 않은 원충 접종군에서 가장 높았다. 감마선 조사원충 접종군의 증체량이 무감염 대조군을 제외한 다른 시험군보다 높게 나타났다. 1대 및 3대 계대원충 접종군의 증체량이 감마선 조사하지 않은 원충 접종군의 것보다 높게 나타났다. 감마선 조사원충 접종군의 사료요구율이 무감염 대조군을 제외한 다른 시험군보다 낮게 나타났다. 1대 및 3대 계대원충 접종군의 사료요구율이 감마선을 조사하지 않은 원충 접종군보다 낮게 나타났다. 감마선 조사원충 접종군의 항콕시듐지수(190.6)는 1대 및 3대 계대원충 접종군의 항콕시듐지수(142.8과 107.4)보다 높았고, 감마선 조사하지 않은 원충 접종군의 것(87.4)보다는 월등히 높게 나타났다. 그러므로 감마선 조사후 계대수가 증가할수록 병원성이 회복되는 것으로 나타났다. 이는 계대수가 증가할수록 감마선 조사로 인하여 병원성이 약화된 원충의 수는 줄어들고 감마선의 영향을 받지 않은 병원성이 강한 원충의 수가 증가되는 것으로 사료된다.

• 한국식품과학회지
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• 제46권2호
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• pp.256-261
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• 2014

현재 사용되고 있는 물리적 확인시험법인 광자극발광법(PSL), 열발광분석법(TL), 전자스핀공명법(ESR)을 이용하여 4종의 시료에 대해 감마선과 전자선에 의한 확인시험법의 판별 특성을 확인하였다. PSL 측정 결과 고춧가루, 바질, 파슬리 시료는 선원 및 선량에 관계없이 조사된 시료는 photon count 값(PCs)이 5,000 이상인 7,004-70,519의 PCs로 측정되어 조사여부의 판정이 가능하였다. 하지만 조사된 후춧가루에서는 선원에 관계없이 threshold value가 5,000 이하인 442-1,572 PCs로 중간값 및 음성값을 나타냄에 따라 조사여부 확인이 어려웠다. TL 측정 결과에서는 고춧가루, 바질, 파슬리, 후춧가루 4종 모두 선원 및 선량에 관계없이 조사된 시료는 $150-250^{\circ}C$ 사이에서 최대 glow curve peak가 나타났다. 또한 TL ratio값이 0.1 이상인 0.101-0.889을 나타내어 조사여부 판정이 가능하였다. ESR 측정 결과에서는 고춧가루만이 cellulose 유래의 signal을 보이면서 방사선 조사여부를 판정할 수 있었다. 다른 3종 시료에서는 single line signal을 나타내어 ESR 판정이 어렵다는 것이 확인되었다. 따라서 전자선조사 향신료에서도 현행 물리적 판별방법으로 조사 여부 확인이 가능하였으며, false 값에 대한 이유를 밝히는 연구가 추가적으로 수행되어야 할 것으로 사료된다.