• Proceedings of the Botanical Society of Korea Conference
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• 1994.09a
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• pp.29-39
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• 1994

Serious issues about the changes in the environmental conditions on earth associated with human activities have arisen, and the interest in these problems has increased. It is urgent to determine how the expansion of terrestrial UV-B radiation due to the stratospheric ozone depletion influences living matters. In this connection, we have been investigating the effects of UV-B radiation on the growth of rice cultivars (Oryza sativa L.). We report here some physiological and genetic aspects of resistance to inhibitory effects of UV-B radiation on growth of rice cultivars as described below. Elevated UV radiation containing large amount of UV-B and a small amount of UV-C inhibited the development of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Similar results were obtained in experiments, in which elevated UV-V radiation. Similar results were obtained in experiments, in which elevated UV-B radiation (transmission down to 290 nm) was applied instead of UV-B radiation containing a small amount of UV-C. The inhibitory effects of UV radiation was alleviated by the elevated CO2 atmospheric environment or by the exposure to the high irradiance visible radiation. The latter suggested the possibility that the resistance to the effects of UV radiation was either due to a lower sensitivity to UV radiation or to a greater ability to recover from the injury caused by UV radiation through the exposure to visible radiation. The examination of cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes (aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups showed the following: Various cultivars having different sensitivities to the effects of UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to UV rakiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultuvars are cultivated. Form the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F2 plants generated by reciprocally crossing Sasanishiki and Norin 1 and F3 lines generated by self-fertilizing F2 plants, it was evident that the resistance to the inhibitory of elebated UV radiation in these rice plants was controlled by recessive polygenes.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.135-142
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• 2017

Selenium (Se), which is natural materials existing was known as an important component of selenoprotein, one of the important proteins responsible for the redox pump of a living body. Selenium was orally administered to Rat and irradiated with 10 Gy of radiation. Then, the thyroid gland was used as a target organ for 1 day, 7 days and 21 days to investigate the radiation protection effect of selenium (Se) through changes of blood components, thyroid hormones (T3, T4), antioxidant enzyme (GPx) activity and thyroid tissue changes. As a result, there was a significant protective effect of hematopoietic immune system(hemoglobin concentration, neutrophil, platelet)(p<0.05). The activity of Glutathione Peroxidase (GPx), the antioxidant enzyme, and the activity of the target organ, thyroid hormone (T3, T4), also showed significant activity changes (p<0.05). In the observation of tissue changes, it was confirmed that there was a protective effect of thyroid cell damage which caused the cell necrosis by radiation treatment. Therefore, it is considered that selenium(Se) can be utilized as a radiation defense agent by inducing immunogenic activity effect of a living body.

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.402-408
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• 2016

Background: Ascertainment bias are common in epidemiologic studies to assess the association between thyroid cancer risk and living near nuclear power plants because many thyroid cancers are diagnosed by chance through health examination. We surveyed the ultra sonography (USG) examination history and conducted thyroid and breast USG in residents living near nuclear power plants. Materials and Methods: The study population comprised 2,421 residents living near nuclear power plants in Korea. Information on demographic characteristics, including diagnostic examination history, was collected by interview using questionnaires. USG examination was conducted to evaluate the presence of thyroid nodules and breast lesion. Study participants were divided into 3 groups according to the distance of their respective villages from a nuclear power plant. The proportions of USG examination history and prevalence of thyroid nodules and breast lesions were compared between groups. Results and Discussion: Examination histories of thyroid USG were 23.1%, 13.7%, and 10.5% in men and 31.3%, 26.7%, 18.3% in women in the short, intermediate, and long distance groups, respectively. There were significant inverse associations between thyroid USG history and the distance from nuclear power plants (P for trend = 0.001 for men and 0.017 for women). However, there was no association between the distance of villages from nuclear power plants and prevalence of thyroid nodules. Conclusion: Our results suggest that there may be an ascertainment bias in population-based studies examining the harmful effects of NPPs examination and researchers should pay attention to ascertainment bias resulted from differential health examination. Correction for ascertainment bias, active follow-up and examination for all study population to remove differential health examination is needed.

• Radiation Oncology Journal
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• v.2 no.1
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• pp.11-20
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• 1984

The renewed interest in the use of hyperthermia in cancer therapy is bases on radiobiological and clinical evidence indicated that there may be a significant therapeutic advantage with the use of heat alone or combined with radiation or chemotherapy, There are many methods for generating heat for localized tumor as like radiofrequency, microwave, electromagnetic induction and ultrasound. But it is very difficult to be even thermal dose distribution and stable output of power and then the detection of temperature in tumor is difficult to be precise with thermocouples and semiconductor sensors. We designed the microwave heating generator, dipole antenna applicators and autometic temperature controlled thermocouples for localized hyperthermia on skin and in cavities. 1. The microwave generator with 120 W, 2,450MHz magnetron could be heating up to $40^{\circ}C\~50^{\circ}C\;for\;1\~2$ hours in living tissues. 2. The thermal dose distribution in tissue with microwave was described $42^{\circ}C\~44^{\circ}C$ with in 3 cm depth and $2\~6cm$ diameter area. 3. Skin surface heating applicator with spiral 3 times wave length antenna radiated high Power of microwave. 4, Intracavitary heating applicator with dipole antenna with autometic control temperature sensor kept up continuously constant temperature in tissue. 5. For constant thermal distribution, applied two steps power with 10W microwave after $17\~20W$ during first 10 minutes. 6. The cooling rate by blood flew in living tissue was rised as $10\%$ then meats.

• Journal of the Korean Solar Energy Society
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• v.40 no.2
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• pp.25-36
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• 2020

The Korean government has a plan to mandate zero-energy buildings in 2020 for public and 2025 for private buildings. In order to design a zero-energy building, insulation and airtightness, which are the most basic elements of passive house technology, are required, and the government has been accomplished this through step-by-step strengthening of related standards. In passive house with high thermal insulation and airtightness performance, the heat introduced into the building through solar radiation can be stored for a long time to keep the inside warm during winter. On the other hand, during summer, heat introduced into the building cannot be easily released to outside, so it is necessary to actively block solar radiation and high temperature outdoor air to prevent an increase of indoor temperature. Therefore, this study aims to derive an appropriate operation condition of passive house to maintain the indoor temperature at an suitable level according to the ventilation methods and solar shading conditions. As a result, under the conditions that the outdoor temperature was 28℃ or less, the ventilation using a heat recovery ventilation system at daytime and natural ventilation at nighttime were selected for the most appropriate operation method. In addition, in the case of solar shading, it was found that blocking solar radiation at daytime using the blind and open the blind at nighttime to ensure natural ventilation were selected for the most appropriate solar shading condition.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1772-1777
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• 2017

Korean nuclear power plants (NPPs) periodically evaluate the radioactive gaseous and liquid effluents released from power reactors to protect the public from radiation exposure. This paper provides a comprehensive overview of the release of radioactive effluents from Korean NPPs and the effects on the annual radiation doses to the public. The amounts of radioactive effluents released to the environment and the resulting radiation doses to members of the public living around NPPs were analyzed for the years 2011-2015 using the Korea Hydro & Nuclear Power Co., Ltd's annual summary reports of the assessment of radiological impact on the environment. The results show that tritium was the primary contributor to the activity in both gaseous and liquid effluents. The averages of effective doses to the public were approximately on the order of $10^{-3}mSv$ or $10^{-2}mSv$. Therefore, even though Korean NPPs discharged some radioactive materials into the environment, all effluents were within the regulatory safety limits and the resulting doses were much less than the dose limits.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.4 no.2
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• pp.90-94
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• 2018

The potential health risk from inhalational exposure of diesel exhaust particulates (DEP) has gained considerable scientific interests. However, the long-term in vivo behavior of DEP have not been clearly understood due to the difficulty of accurate analysis of these substances in a living subject. We herein demonstrate a detail protocol for the preparation of radiolabeled DEP using a radioactive-iodine-tagged pyrene analog. The purified $^{125}I$-labeled pyrene ($[^{125}I]1$) was obtained with a good radiochemical yield ($32{\pm}4%$, n=3) and high radiochemical purity (>99%) from the stannylated precursor 2. Next, the purified $[^{125}I]1$ was successfully assembled into the DEP suspension in an efficient manner. The radiolabeled DEP was highly stable in a mouse serum for 7 days without significant deiodination or dissociation of $[^{125}I]1$. These results clearly indicate that the present radiolabeling method will be useful for biodistribution study of carbonaceous particulates in vivo.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.5.1-5.8
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• 2015

Objectives We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 ($^{137}Cs$) in Seoul. Methods Using information regarding the frequency and duration of passing via the $^{137}Cs$ contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. Results Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. Conclusions An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of $^{137}Cs$ contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.

• Journal of Gynecologic Oncology
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• v.29 no.6
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• pp.97.1-97.12
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• 2018

Objective: Women with cervical cancer (CC) found to have positive surgical margins, positive lymph nodes, and/or parametrial invasion receive a survival benefit from postoperative chemoradiotherapy (CRT) vs. radiation therapy (RT) alone. However, older women may not benefit to the same extent, as they are at increased risk of death from non-oncologic causes as well as toxicities from oncologic treatments. This study sought to evaluate whether there was a survival benefit of CRT over RT in elderly patients with cervical cancer. Methods: The National Cancer Database was queried for patients ${\geq}70$ years old with newly diagnosed IA2, IB, or IIA CC and positive margins, parametrial invasion, and/or positive nodes on surgical resection. Statistics included logistic regression, Kaplan-Meier overall survival (OS), and Cox proportional hazards modeling analyses. Results: Altogether, 166 patients met inclusion criteria; 62 (37%) underwent postoperative RT and 104 (63%) underwent postoperative CRT. Younger patients and those living in areas of higher income were less likely to receive CRT, while parametrial invasion and nodal involvement were associated with an increased likelihood (p<0.05 for all). There were no OS differences by treatment type. Subgroup analysis by number of risk factors, as well as each of the 3 risk factors separately, also did not reveal any OS differences between cohorts. Conclusion: In the largest such study to date, older women with postoperative risk factor(s) receiving RT alone experienced similar survival as those undergoing CRT. Although causation is not implied, careful patient selection is paramount to balance treatment-related toxicity risks with theoretical outcome benefits.

• Journal of radiological science and technology
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• v.34 no.2
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• pp.123-129
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• 2011

This study aimed at 1) investigating the perception, knowledge and behaviors of radiological technologists on radiation defence and 2) preparing plans to reduce the unnecessary radiation dose on practician, patients and their caretakers. For data collection, a structured questionnaire was used to survey 225 radiological technologists living in downtown Busan. To analyze the collected data, SPSS/PC+ Win 13 version was used. For verification of differences between groups, one-way ANOVA was conducted. In addition, multiple regression analysis was conducted to analyze the impact of general variables (knowledge, education, age and length of service) in radiation safety management perspective. No differences were found in terms of the knowledge on radiation/radioactivity according to educational background, age and length of service. In the perspective of radiation safety management, the highest figures were found among those in their 40s and higher and those with the education of college graduation and higher. As for the correlation between radiation safety management and knowledge on radiation/radioactivity, positive correlations were found in all cases. In addition, analysis on the impact of general variables in radiation safety management perspective indicated that the perception on radiation safety management was higher as the level of knowledge on radiation/radioactivity was higher. The correct radiation/radioactivity management through practician training was necessary to reduce radiation dose on radiological technologists and patients.