• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.513-516
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• 2001

Water stress measurements of rice that use spectral reflection characteristics have been conducted to detect a water stress of rice during growing stage. Water stress reaction was measured using a spectroradiometer in the wavelength range from 300nm to 1100nm. In order to maintain all the experimental conditions, the measurement time have been settled at a fixed solar radiation times. Spectral reflectance were measured as a function of the moisture content. The results indicate that the spectral reflectance of rice was dependent on moisture content. As the moisture content is lowered the spectral reflectance of rice formed in NIR wavelength range increased. This effect can be best explained in terms of water stress.

• Food Science and Biotechnology
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• 제18권2호
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• pp.475-480
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• 2009

Ultraviolet B (UVB) radiation provokes the generation of reactive oxygen species (ROS) in the cells and skin, which induce oxidative stress in the exposed cells, leading to photoaging and cancer. Using the human keratinocytes HaCaT cell line, we investigated the photoprotective effects of aucubin isolated from Eucommia ulmoides. Pretreatment with aucubin markedly suppressed UVB-induced oxidative stress, which manifests as a decrease in intracellular lipid peroxidation, elevation of catalase activity, and reduced glutathione content. In addition, aucubin significantly reduced expression of matrix metalloproteinase-1 (MMP-1) protein (54%) and mRNA. Taken together, these results suggest that aucubin may offer protection against UVB-induced oxidative stress and may be used as a potential agent in prevention of UVB-induced photoaging.

• 한국환경과학회지
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• 제21권12호
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• pp.1435-1447
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• 2012

The present study was conducted to determine the effect of hexaconazole (HEX), a triazole fungicide, on the growth, yield, photosynthetic response and antioxidant potential in cucumber (Cucumis sativus L.) plants subjected to UV-B stress. UV-B radiation and HEX were applied separately or in combination to cucumber seedlings. The growth parameters were significantly reduced under UV-B treatment, however, this growth inhibition was less in HEX treated plants. HEX caused noticeable changes in plant morphology such as reduced shoot length and leaf area, and increased leaf thickness. HEX was quite persistent in inhibiting shoot growth by causing a reduction in shoot fresh and dry weight. HEX noticeably recovered the UV-B induced inhibition of biomass production. Significant accumutation in anthocyanin and flavonoid pigments in the leaves occurred as a result of HEX or UV-B treatments. HEX permitted the survival of more green leaf tissue preventing chlorophyll content reduction and higher quantum yield for photosystemII under UV-B exposure. HEX treatment induced a transient rise in ABA levels in the leaves, and combined application of HEX and UV-B showed a significant enhancement of ABA content which activates $H_2O_2$ generation. UV-B exposure induced accumulation of $H_2O_2$ in the leaves, while HEX prevented UV-B induced increase in $H_2O_2$, indicating that HEX serves as an antioxidant agent able to scavenge $H_2O$ to protect cells from oxidative damage. An increase in the ascorbic acid was observed in the HEX treated cucumber leaves affecting many enzyme activities by removing $H_2O_2$ during photosynthetic processes. The activities of antioxidant enzymes including catalase(CAT), ascorbate peroxidase(APX), superoxide dismutase(SOD) and peroxidase(POD) in the leaves in the presence of HEX under UV-B stress were higher than those under UV-B stress alone. These findings suggest that HEX may participate in the enhanced tolerance to oxidative stress. From these results it can be concluded that HEX moderately ameliolate the effect of UV-B stress in cucumber by improving the components of antioxidant defense system.

• Journal of Radiation Protection and Research
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• 제34권2호
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• pp.49-54
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• 2009

Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging and also contributes to their unfavorable effects in cultured cells and animal tissues. This study was conducted to investigate the effect of ionizing radiation (IR) on mtDNA deletion and the involvement of reactive oxygen species (ROS) in this process in human lung fibroblast (IMR-90) cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated with $^{137}Cs$ $\gamma$-rays and the intracellular ROS level was determined by 2',7'-dichlorofluorescein diacetate (DCFH-DA) and mtDNA common deletion (4977bp) was detected by nested PCR. Old cells at PD 55 and $H_2O_2$-treated young cells were compared as the positive control. IR increased the intracellular ROS level and mtDNA 4977 bp deletion in IMR-90 cells dose-dependently. The increases of ROS level and mtDNA deletion were also observed in old cells and $H_2O_2$-treated young cells. To confirm the increased ROS level is essential for mtDNA deletion in irradiated cells, the effects of N-acetylcysteine (NAC) on IRinduced ROS and mtDNA deletion were examined. 5 mM NAC significantly attenuated the IR-induced ROS increase and mtDNA deletion. These results suggest that IR induces the mtDNA deletion and this process is mediated by ROS in IMR-90 cells.

• Journal of Preventive Medicine and Public Health
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• 제57권1호
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• pp.55-64
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• 2024

Objectives: This study investigated the prevalence and characteristics of comorbid conditions in patients exposed to ionizing radiation and those who were involved in the Soviet-Afghan war. Methods: This study analyzed the frequency and spectrum of morbidity and comorbidity in patients over a long-term period (30-35 years) following exposure to ionizing radiation at the Semipalatinsk nuclear test site or the Chornobyl nuclear power plant, and among participants of the Soviet-Afghan war. A cohort study, both prospective and retrospective, was conducted on 675 patients who underwent comprehensive examinations. Results: Numerical data were analyzed using the Statistica 6 program. The results are presented as the mean±standard deviation, median, and interquartile range (25-75th percentiles). The statistical significance of between-group differences was assessed using the Student t-test and Pearson chi-square test. A p-value of less than 0.05 was considered statistically significant. We found a high prevalence of cardiovascular diseases, including hypertension (55.0%) and cardiac ischemia (32.9%); these rates exceeded the average for this age group in the general population. Conclusions: The cumulative impact of causal occupational, environmental, and ultra-high stress factors in the combat zone in participants of the Soviet-Afghan war, along with common conventional factors, contributed to the formation of a specific comorbidity structure. This necessitates a rational approach to identifying early predictors of cardiovascular events and central nervous system disorders, as well as pathognomonic clinical symptoms in this patient cohort. It also underscores the importance of selecting suitable methods and strategies for implementing treatment and prevention measures.

• 대한방사선기술학회지:방사선기술과학
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• 제22권1호
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• pp.73-78
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• 1999

The purposes of this study are to analyze the realities after enforcements of safety control regulations for diagnostic X-ray equipments and to suggest means for an improvement of low radiation safety control. A questionnaire survey for medical radiologic technologists was carried out to determine enforcement effects of the safety control regulations. The results of analysis from the survey are as follows. That is, most of the respondents realized the importance of the radiation safety control system, but about a half of them revealed that the regulations were not well observed in accordance with their purposes. Only 43.9% of the respondents took an active part in quality control and safety control of radiation. And respondents responsibility, sex, age, and knowledge for safety control were important indicators for observations of the regulations. Trainings for the safety control regulations are needed to ensure safety control and proper usage of diagnostic X-ray equipments. And management of organizations using diagnostic X-ray equipments have to understand and stress the importance of radiation safety control system.

• 식물조직배양학회지
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• 제26권4호
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• pp.265-269
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• 1999

고구마 산성 peroxidase (POD) (swpal) 또는 중성 POD(swpnl)을 도입한 형질전환 담배에 다양한 선량의 감마선을 조사한 후 30일에 항산화효소 활성과 식물생장에 미치는 영향을 조사하였다. 감마선은 조사선량에 비례하여 형질전환 식물체와 정상식물에 관계없이 모든 식물체의 생장을 크게 억제시켰다. 50-70 Gy 처리에서 식물체의 신장이 크게 억제되었고 새로운 잎이 발생되지 못하였다. 10-50 Gy의 조사선량에서는 POD, superoxide dismutase, catalase 활성에 큰 변화를 주지 않았다. 이러한 결과는 고구마 POD는 감마선 조사에 의해 유도되는 산화적인 스트레스에 대한 보호효과에 관여하지 않음이 시사된다.

• 한국자원식물학회지
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• 제22권5호
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• pp.461-466
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• 2009

식물세포에 마(Dioscorea batatas Dence) 추출액의 전처리가 방사선 스트레스에 노출된 배양세포의 활력, 생장 및 핵 DNA 손상에 미치는 영향을 조사하였다. 마의 분획추출물 중 EtOAc 분획추출물을 식물세포에 전처리하고 20 Gy의 방사선에 노출시키면, 마 추출물을 전처리하지 않고 방사선 20 Gy만 처리한 세포보다 세포의 활력과 생체중이 20%이상 증가하였다. Comet 분석에서 꼬리부분의 길이 (T)와 머리부분의 길이 (H)를 측정하여 T/H 비율을 조사하였다. 무처리 세포와 방사선 20 Gy를 처리한 세포의 T/H 비율은 각각 1.05 및 1.68로 나타났고, head DNA 량은 각각 86.7% 및 71.3%로 무처리 세포와 방사선을 처리한 세포간에는 큰 차이를 보여, 방사선에 의한 심각한 핵 DNA 손상을 관찰할 수 있었다. 그러나 마 추출물 중 MeOH, EtOAc 및 n-BuOH 분획추출물을 식물세포에 전처리하고 20 Gy 방사선을 처리하면, T/H 비율은 각각 1.37, 1.01 및 1.10이었고, head DNA량은 81.5%, 87.6% 및 88.7%로 방사선을 처리 하지 않은 무처리 세포 수준으로 회복되었다.

• 한국환경과학회지
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• 제5권5호
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• pp.635-642
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• 1996

UV-B증가가 지질과산화에 미치는 영향과 UV-B조사에 대한 carotenoid 및 polyamine의 지질과산화 방어반응을 조사하기 위해 자연광 이용의 인공기상실내에서 12일간 벼 (Oryza sativa L., cv. Koshihikari) 유식물에 2단계의 UV-B조사 실험을 수행했다. UV-B처리에 의한 건물량의 감소는 조사시간의 경과와 함께 증가하였다. 지질과산화산물인 malondialdehyde (MDA)의 함량은 6일간의 UV-B처리에 의해 약 30 %의 증가를 보였다. Carotenoid의 함량은 UV-B처리에 의해 약 10% 감소하는 경향을 보였으나 통계학적 유의성은 없었다. 한편, 벼에는 크게 3종류의 polyamines (putrescine, spermidine, spermine)이 존재하였으며, 이들 모두 UV-B처리에 의해 상당히 증가되었다. 이상의 결과로 볼 때, UV-B조사에 의해 생성된 활성산소가 생체막지질의 산화에 관여하는 것으로 사료되며, polyamine의 증가는 UV-B조사에 의한 세포막 파괴를 막기 위한 생화학적 방어반응으로 사료된다.

• Journal of Radiation Protection and Research
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• 제40권3호
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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.