• 대한수의학회지
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• 제43권4호
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• pp.633-639
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• 2003

We investigated the effect of green tea and its fractions of alcohol and polysaccharide on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gamma-irradiation. Jejunal crypts were protected by pretreatment of green tea (i.p.: 50 mg/kg of body weight, at 12 and 36 hours before irradiation., p.o.: 1.25% water extract, for 7days before irradiation, p<0.01) and alcohol and polysaccharide fractions showed no significant modifying effects. Green tea and its fractions administration before irradiation (i.p. at 12 and 36hours before irradiation) resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment of green tea (i.p. at 12 and 36 hours before irradiation, p<0.05., p.o. for 7days before irradiation, p<0.001) and its fractions (p<0.001). These results indicated that green tea might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of green tea and its components.

• 상하수도학회지
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• 제26권3호
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• pp.373-381
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• 2012

Antibiotics have been issued recently in water environments because of potential impacts on ecosystem and public health. This study was aimed to investigating the degradation of antibiotics such as tetracycline, lincomycin, sulfamethazine and cephradine using gamma ray irradiation. And the toxicity before and after irradiation on antibiotics was tested in order to examine the aquatic eco-risk assessment by aquatic organisms. In addition, comparing tests on toxicity for gamma ray and UV irradiated antibiotics was conducted. Four different antibiotics were prepared by concentration of 30 mg/L with demi-water respectively. The absorption dose of gamma ray was ranged from 0.2 to 2 kGy. The concentration of four antibiotics was gradually decreased corresponding to the increase of the absorption dose. A method for toxicity assessment using Pseudokirchneriella subcapitata was evaluated to the most acceptable compared with methods by Daphnia magna and Microtox$^{(R)}$ in terms of sensibility. It showed that the reduction of toxicity on antibiotics treated by gamma ray was superior comparing to the test results obtained from UV treatment. By-products from antibiotics treated by gamma ray were easily decomposed by microorganism and their toxicity was also evaluated to low.

• Journal of Radiation Protection and Research
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• 제24권3호
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• pp.171-184
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• 1999

본 논문에서는 저준위 환경방사능 측정시 이용되는 검출한계에 대한 기본개념 및 수식을 통계학적 이론을 기초로 서술하였다. 방사능을 정확하게 검출할 신뢰도를 95%로 설정하여 알파 베타 및 감마선 측정기에 대한 검출한계치값을 계산하였다. 또한 환경 방사능 계측에 많이 사용되는 방사능 핵종에 대해 최소 검출 방사능 농도값을 검출한계치 개념을 근거로 계산하여 저준위 환경 방사능 분석시 환경방사능 측정결과에 대한 신뢰도 평가에 활용 가능 하도록 하였다.

• 한국물환경학회지
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• 제20권5호
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• pp.452-456
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• 2004

Gamma-rays effectively decomposed TPA and EG, thus removal of $1.0{\times}10^{-3}$ M pollutants was near 65 and 95%, respectively, at an absorbed dose of 10 kGy. However, TOC removal in the radiation treatment was less than 5% due to a low transformation of both TPA and EG to $CO_2$. For TPA, gamma-ray treatment largely reduced biodegradability($BOD_5/COD$) by degrading TPA to non-biodegradable organic acids. This implies that the change of biodegradability should be considered when the radiation treatment is combined with conventional biological techniques. A weight-loss wastewater containing TPA and EG was also purified by gamma-ray treatment. Extraordinarily, biodegradability of the wastewater was increased at a low dose of 1 kGy. Though underlying mechanism was not clearly identified, this result stresses the effect of wastewater composition and absorbed dose on the biodegradability change.

• Journal of Radiation Protection and Research
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• 제30권3호
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• pp.107-112
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• 2005

단일 핵종의 붕괴시 방출된 두 감마선이 함께 검출기에 흡수될 때 cascade summing이 일어난다. 이 효과는 일부 핵종에서 10% 이상의 계통적 오차를 야기한다. 이들 동시합성 효과를 추산하기 위해 검출기 주위에서 측정한 피크-토탈 비를 사용하여 그 효과를 직접 계산하였다. 검출기 주번에서 주어진 에너지에 대한 피크-토탈 비는 일정하지 않을 수 있으며, 따라서 측정된 값의 평균을 사용하여야 한다 산란 물체에 의한 피크-토달 비의 영향에 대한 결과도 함께 포함되어 있다.

• Nuclear Engineering and Technology
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• 제7권4호
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• pp.277-284
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• 1975

TRIGA Mark-III 원자로에 설치된 조사시설에서 중성자-감마 혼합 방사선장의 상대적 선량분포 특성을 중성자와 감다 방사선에 대한 감응함수가 다른 한쌍의 열형광선량계를 사용하여 측정한 결과이다. 수평방향 및 수직방향의 거리에 따른 비교적 균일한 선량 분포를 공유한 지역은 조사실 바닥으로부터 약 40cm와 130cm의 높이데 있는 두 수평 평행판사이의 구역증 조사실쪽으로 반원통형으로 돌출된 알미늄 저수조표면에서 수평방향으로 100cm이상의 거리에 있는 지역에 한정됨이 관찰되었다. 그 이외의 지역은 급격한 선량구배 특성을 갖고 있었고 특히 반원통형 알미늄수조 표면근처와 조사실 콩크리트 차폐내벽근처에서 더욱 구배가 컸다.

• Nuclear Engineering and Technology
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• 제7권4호
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• pp.285-293
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• 1975

30cm 직경 포리에티렌 구체내의 길이에 따른 선량분포중 최대흡수선량인 흡수선량지수를 주어진 감마방사선장내에서 열형광선량계를 이용하여 결정하였다. 열형광선량계내의 흡수선량과 주위 눈질내의 흡수선량간의 환산은 Burlin의 general cavity theory에 의거하였다. $^{60}$Co과 $^{137}$Cs에 의한 방사선장에서 구체내 최대흡수선량은 구체표면으로 부터 각각 0.5cm 및 0.3cm에 나타났으며 이 결과는 이론적으로 예상한 분포특성과 아주 근사하였다.

• Journal of Radiation Protection and Research
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• 제15권2호
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• pp.75-85
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• 1990

Kalsruhe원자력 연구소(KfK) 주변의 방사능 측정자료로부터 피폭선량을 계산하였다. 식물성 식품의 섭취가 가장 중요한 피폭 경로였고, 식품중의 자연방사성 동위원소인 K-40 과 Pb-210이 주요 피폭원이었다. 인공방사능에의한 피폭은 대부분 지표에 침척된 Cs-134 와 Cs-137으로부터 방출되는 감마선 때문이었다. KfK주변환경에서의 유효선량당량은 ICRP의 권고제한치보다 훨씬 적은 값이었다.

• Journal of Ginseng Research
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• 제22권1호
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• pp.1-10
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• 1998

In the present study, to determine whether the antioxidative components of Korean red ginseng protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of total saponin (200 mg/kg, ip) and lipophilic fraction (200 mg/kg, oral) preferment of mice on the survival ratio, major antioxidant enzymes (SOD, catalase and glutathione peroxidase) activities, glutathione levels and lipid peroxidation in the liver were exiled for 2 weeks after whole ${\gamma}$-body ${\gamma}$-irradiation (6.5 Gy). The 30-day survival ratio increased from 10% to 57% and 40% for mice treated with total saponin and lipophilic fraction, respectively. On day 14 after ${\gamma}$-irradiation, the ginseng total saponin pretreatment produced a slight increase of antioxidant enzymes activities and significantly Increased reduced glutathione (GSH) contents (p<0.05) in the liver compared with non-treated group. Pretreatment with ginseng total saponin significantly deceased GSSG/total GSH ratio (p<0.05) without change of GSSG in the liver and inhibited the radiation-induced incense in the hepatic malondialdehyde levels. (p<0.05) In these results, GSH plays an important role in the liver in several detoxifications and the reduction of lipid peroxides. Thus, it appears that total saponin of red ginseng exerts its radioprotective effect by accelerating the production of endogenous antioxidants, such as glutathione from radiation induced damages and thereby oxygen free radicals.

• Journal of Radiation Protection and Research
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• 제10권2호
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• pp.130-136
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• 1985

전자포획 핵종인 $^{133}Ba$ 용액의 방사능 측정이 ${\beta}-{\gamma}$ 동시계수 방법에 의하여 수행되었다. $4{\pi}$ 비례계수기와 두개의 NaI(Tl) 섬광검출기를 사용하여 베타, 감마 및 동시계수 채널에서 계수율을 측정하였다. 효율외삽법으로 산출된 용액의 비 방사능은 기준시간(1984년 3월 15일 0시, UT)에 대하여 $(1151.01{\pm})2.99)\;kBq{\cdot}g^{-1}$이었다. 국제도량형국이 주관한 방사능 측정의 국제비교에 의하면, 이 결과는 그 비교에서 얻어진 평균값에 대하여 약 0.84%의 차이를 나타냈다.