• 대한수의학회지
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• 제41권1호
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• pp.99-104
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• 2001

불의의 방사선 피폭 환자의 체내 방사선 피폭선량의 예측을 위한 방사선 생물학적 선량측정 개발의 일환으로 저선량 피폭환자의 체내 피폭선량 측정 지표로서의 미소핵 분석법 이용 가능성을 평가하기 위하여 코발트-60 감마선을 0.25 Gy에서 1 G의 선량을 인체 말초 혈액에 조사한 후 임파구내에 미소핵의 수적 변화를 형태학적으로 관찰하였다. 저선량에 피폭된 임파구에서 미소핵이 관찰되었으며, 선량에 따른 수적인 변화도 나타났다. 저선량 피폭에 대한 미소핵의 수적 변화에 대한 선량-반응 곡선은 $Y=(0.02{\pm}0.0009)+(0.033{\pm}0.010)D+(0.012{\pm}0.012)D^2$의 식을 얻었으며, linear quadratic model 이였다. 이상의 결과에서 미소핵의 발생 빈도와 피폭 선량간에 유의한 효과가 있는 것으로 확인되었다. 그리고 정상대조군에서는 세포당 $0.02{\pm}0.0009$개가 관찰되었다. 따라서 말초 임파구를 이용한 미소핵 분석법은 저선량 피폭환자의 체내 피폭선량 측정은 물론 방사선 방호제의 검색 및 방사선 민감도 검사를 위한 방사선 생물학적 지표로 이용 가능하며, 특히 이 방법은 간편하고 정확하며 재현성이 있는 방법으로 불의의 방사선 피폭 사고시 체내 피폭선량을 예측하는 좋은 지표로 사용되어질 수 있을 것으로 사료됨.

• 방사선산업학회지
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• 제5권3호
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• pp.253-258
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• 2011

Acetylsalicylic acid (ASA) has been issued recently in contaminated water environments because of potential impacts on ecosystem and public health. This study was aimed at investigating the possibility of ASA degradation using gamma ray irradiation. In addition, the use of sodium persulfate, hydrogen peroxide, ferrous sulfate were tested in order to examine a synergistic effect with gamma ray. The absorbed dose was ranged from 0.2 to 10 kGy and the concentration of oxidants were from 0.1 to 10 mM in this study. The concentration of ASA was gradually decreased corresponding to the increase of the absorbed dose. When soudium persulfate was simultaneously applied, most of the parent compound was completely degraded even at a low dose of 0.8 kGy. The removal efficiency of total organic carbon was 90% even at the highest dose of 10 kGy without sodium persulfate. However, the efficiency was dramatically enhanced up to 98% at the same dose by adding 10 mM of oxidants. It was suggested that hydroxyl radical ($OH{\cdot}$) and sulfate radical ($SO{_4}^-{\cdot}$) were formed in the system and made roles in degrading ASA at the same time.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3335-3343
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• 2021

The impact of gamma radiation on a commercial off the shelf microcontroller board has been investigated. Three different tests have been performed to ascertain the radiation tolerance of the device from a nuclear decommissioning deployment perspective. The first test analyses the effect of radiation on the output voltage of the on-board voltage regulator during irradiation. The second test evaluated the effect of gamma radiation on the voltage characteristics of analogue and digital inputs and outputs. The final test analyses the functionality of the microcontroller when using an external, shielded voltage regulator instead of the on-board voltage regulator. The results suggest that a series of latch-ups occurs in the microcontroller during irradiation, causing increased current drain which can damage the voltage regulator if it does not have short-circuit protection. The analogue to digital conversion functionality appears to be more sensitive to gamma radiation than digital and analogue output functionality. Using an external, shielded voltage regulator can prove beneficial when used for certain applications. The collected data suggests that detaching the voltage regulator can extend the lifespan of the platform up to approximately 350 Gy.

• 한국식품과학회지
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• 제9권1호
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• pp.36-40
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• 1977

밤 품종(品種)에 따른 적정선량(適正線量)을 구하고 조사(照射)밤의 저장말기(貯藏末期)에 발생(發生)하는 과육흑반점(果肉黑斑點) 억제(抑制)에 대한 실험(實驗)을 하여 다음과 같은 결과(結果)를 얻었다. 1. 대기하(大氣下)에서 방사선(放射線)을 조사(照射)할 경우 밤의 발근(發根), 발아율(發芽率), 부패율(腐敗率) 및 과육흑반점(果肉黑斑點) 발생율(發生率)을 고려(考慮)할 때, 품종(品種)에 따라 약간의 차이는 있으나 적정선량(適正線量)은 25~35Krad였다. 2. 저산소상태(低酸素狀態)에서의 방사선조사(放射線照射)는 부패(腐敗), 과육흑반점(果肉黑斑點) 발생을 현저하게 억제(抑制)할 뿐 아니라 15Krad로서도 발아억제효과(發芽抑制效果)가 현저하였다. 3. 저장중(貯藏中)인 밤의 품종(品種)별 화학성분(化學成分)의 큰 변화는 없고 저장기간(貯藏期間)에 따라 감소하는 경향이었으며, 방사선조사(放射線照射)로 인한 영양소(營養素)의 변화가 뚜렷하지 않았다. 4. 호흡(呼吸)은 방사선조사(放射線照射) 직후(直後)에 급격(急激)히 상승(上昇)하였으나 시일이 경과함에 따라 점차 정상화(政常化)되었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1123-1124
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• 2004

• 한국식품영양과학회지
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• 제28권3호
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• pp.646-653
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• 1999

This study was done to investigate the effect of ${\gamma}$ irradiated beef feeding on antioxidant vitamin levels and defense enzyme activities in diethylnitrosamine(DEN) initiated rats. Weaning Sprague Dawley male rats were fed the diet containing ${\gamma}$ irradiated ground beef at the dose 0, 3, 5 kGy 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, serum level of vitamin C, serum and hepatic levels of retinol and tocopherol were determined. In addition, activities of cytosolic glutathione peroxidase, glutathione reductase, glutathione S transferase, catalase and hepatic superoxide dismutase(SOD) were measured. By ${\gamma}$ irradiation, there was no significant effect on serum and hepatic levels of vitamin C and tocopherol except a significant decreasing effect on hepatic retinol level. There was also no significant effect on the activities of enzymes involved in antioxidative defense system, However, DEN treatment led to a significant increase in activities of glutathione reductase and glutathione S transferase while the activity of glutathione peroxidase was decreased. The activities of hepatic SOD and catalase were not changed by DEN treatment. Overall results indicate that the consumption of low dose of ${\gamma}$ irradiated beef does not affect antioxidative defense system.

• BMB Reports
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• 제34권2호
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• pp.123-129
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• 2001

Cellular response to ionizing radiation is affected by cell types, radiation doses, and post-irradiation time. Based on the trypan blue dye exclusion assay in normal oral mucosal cells (OM cells), a 48 h post-irradiation was sufffcient and an adequate time point for the evaluation of radiation sensitivity Its $LD_{50}$ was approximately 1.83 Gy To investigate possible biomarkers useful for the biological radiodosimetry of normal epithelial cells (p53, c-fos, cyclin D1, cdc-2, pRb) EGF receptor phosphorylation and Erk activation were evaluated at different radiation doses and different post-irradiation times. From 0.5 Gy, p53 was accumulated in the nucleus of basal cells of the OM raft culture at 4 h post-irradiation and sustained up to 24 h post-irradiation, which suggests that radiation-induced apoptosis or damage repair was not yet completed. The number of p53 positive cells and biosynthesis of p53 were correlated with radiation doses. Both cyclin D1 and c-fos were only transiently induced within 1 h post-irradiation. Cyclin D1 was induced at all radiation doses. However, cfos induction was highest at 0.1 Gy, approximately 7.3 fold more induction than the control, whose induction was reduced in a reverse correlation with radiation dose. The phosphorylation pattern of cdc-2 and pRb were unaffected by radiation. In contrast to A431 tails overexpressing the EGF receptor approximately 8.5 fold higher than normal epithelial, the OM cells reduced the basal level of the EGF receptor phosphorylation in a radiation dose dependent fashion. In conclusion, among radiation-induced biomolecules, the p53 nuclear accumulation may be considered for the future development of a useful marker far biological radiodosimetry in normal epithelial tissue since it was sustained for a longer period and showed a dose response relationship. Specific c-fos induction at a low dose may also be an important finding in this study It needs to be studied further for the elucidation of its possible connection with the low dose radio-adaptive response.

• Preventive Nutrition and Food Science
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• 제9권3호
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• pp.227-231
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• 2004

Green, black and oolong teas were irradiated by $^{60}$ Co-gamma rays (0～10 kGy) and were investigated for detection of irradiation treatment using pulsed photostimulated luminescence (PPSL) and thermoluminescence (TL) during storage. Teas irradiated at 2.5 kGy or more showed a photon count of greater than 5000 counts/60 sec while the non-irradiated yielded only 650～1000 count/60 sec. Correlation coefficients between irradiation dose and photon counts/60 sec were 0.8951, 0.7934 and 0.9007 for green, black and oolong teas, respectively. The TL glow curves for minerals isolated from the non-irradiated teas were situated at about 30$0^{\circ}C$ with a low intensity, but for irradiated samples were approximately 15$0^{\circ}C$ with a high intensity. The TL ratios (TL$_1$/TL$_2$), calculated from values after initial radiation and then after re-irradiation of the teas, were below 0.1 for the non-irradiated samples and higher than 1.44 for all irradiated samples, enhanced the reliability of the identification results for TL. The signal intensity of PPSL and TL for irradiated teas decreased with the lapse of post-irradiation storage time at room temperature but was still distinguishable from that of the non-irradiated samples even after one year.

• 한국식품과학회지
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• 제32권5호
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• pp.1051-1057
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• 2000

관능적 품질이 우수하고 저장성을 향상시킨 저염 새우젓 개발을 위해 감마선 조사기술을 이용하였다. 식염농도를 15% 및 20%로 조절한 새우젓을 제조하여 $15^{\circ}C$에서 발효시키면서, 최적 숙성기에 도달하기 직전 아미노태 질소의 함량이 400mg% 수준에서 5 kGy 및 10 kGy 선량의 감마선을 조사하였으며, 대조구로는 30% 식염농도의 새우젓을 제조하여 저장기간 동안 화학적 품질을 평가하였다. 최적 숙성직전 감마선을 조사한 결과, 감마선 조사직후 아미노태 질소, 휘발성 염기태 질소, trimethylamine 및 효소활성은 감마선 조사에 의한 영향은 나타나지 않았다. 저장기간에 따른 성분의 변화는 식염함량 및 감마선 조사선량이 증가할수록 낮았으며, 효소활성은 발효 4∼5주까지 계속 증가하다가 감소하는 경향으로 대조구와 유사한 활성을 나타내었다. 특히 15% 식염과 10 kGy의 감마선 조사 및 20% 식염과 5 kGy 이상의 감마선을 최적 숙성직전 조사한 새우젓의 경우 젓갈의 화학적 품질지표인 아미노태 질소, 휘발성 염기태 질소, trimethylamine 함량 및 단백질분해 효소활성이 30% 고염농도인 대조구와 비슷한 수준으로, 발효기간 동안 적정수준의 함량 및 활성을 나타내어 양호한 품질특성을 보였다.

• 동아시아식생활학회지
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• 제18권6호
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• pp.989-996
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• 2008

매실의 저장 유통 과정에서 저장성을 증가시키고 식품산업에 적용할 수 있는 자료 제공을 위한 연구의 일환으로 매실에 $0.5{\sim}3\;kGy$로 감마선 조사를 실시하여 $20^{\circ}C$에서 9일간 저장하면서 매실의 미생물학적 및 이화학적 품질 특성을 조사하였다. 매실의 호기성 세균과 효모 및 곰팡이 변화는 조사선량이 증가할수록 감소하였고, 매실의 색도 변화에서는 감마선 조사에 의해 녹색도가 감소하였으며, 경도 변화에서는 조사선량이 증가함에 따라 유의적으로 감소하였다. 총 당, 수소공여능 및 유기산은 감마선 조사에 의한 뚜렷한 차이를 보이지 않았고, 환원당 함량은 비조사구에 비해 조사구에서 높은 값을 나타내었으며, vitamin C 함량은 저장 기간 및 감마선 조사에 의해 감소하였다. 따라서 매실에 대한 감마선 조사는 매실의 총 당, 수소공여능, 유기산 등에 대한 영향이 적고 0.5 kGy의 감마선 조사만으로도 미생물을 효과적으로 제어할 수 있으나, 매실의 색도, 경도, vitamin C 함량 등에 좋지 않은 영향을 미치므로 감마선 조사 단독 처리만으로는 매실의 저장성 증진에 효과적이지 않을 것으로 판단되므로 저온 처리, CA 저장 처리, 포장 방법 등과 함께 병용하여 처리하였을 때의 매실의 저장성 증진 및 이화학적 성분 변화에 대한 연구가 필요할 것으로 사료된다.