• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.471-478
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• 2018

Oogenesis process of ovary produces a lot of undifferentiated cells. Especially, the radiation exposure of early immature cells in the process of growth to oocyte causes serious disabilities. This study examined the radiation damage mechanism of undifferentiated cells and organelles in oogenesis process, and the radioprotection after injection of alliin. The ultrastructure after 7Gy X-ray irradiation on the white rat was observed in the experiment. The results is as follows. It was observed that the nucleus membrane of an oogonium was damaged and vacuolated in the several parts after 15 days of irradiation. The damage of mitochondria membrane and flow in cytoplasm after 20 and 30 days was found in the oogonium. After 40 days observation, peroxidation of fat droplets was found and organelles were tangled each other in ovary tissue. The partial damage of nuclear membrane in oogonium past 15 days after injection of alliin was found, but decreased remarkably. Mitochondria, Golgi body, and rough endoplasmic reticulum were also clearly observed, therefore, radioprotection effects in alliin was confirmed partially.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제21권3호
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• pp.141-146
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• 2010

This summary of literature during the past year reviews published studies relating to risk factors for depressive disorders in children and adolescents. Risk factors include environmental toxins, socio-environmental, and genetic factors. As depression has a complex, multifactorial causal mechanism, it is likely that the accumulation and/ or interaction among multiple risk factors lead to depression. Findings related to the result of toxin exposure have been difficult to interpret given that risk factors tend to interact and that higher mental functions are not easily measurable. However, some findings have been consistent. Clinical research data has also shown that the risk for negative outcomes may be modified both by genetic and environmental factors through a gene environment interplay mechanism.

• ALGAE
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• 제31권4호
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• pp.403-414
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• 2016

The use of ionizing radiation and radioactive elements is becoming increasingly popular with the rapid developments in nuclear technology, radiotherapy, and radio diagnostic methods. However, ionizing radiation can directly or indirectly cause life-threatening complications such as cancer, radiation burns, and impaired immunity. Environmental contamination with radioactive elements and the depletion of ozone layer also contribute to the increased levels of radiation exposure. Radioprotective natural products have particularly received attention for their potential usefulness in counteracting radiation-induced damage because of their reduced toxicity compared with most drugs currently in use. Moreover, radioprotective substances are used as ingredients in cosmetic formulations in order to provide protection against ultraviolet radiation. Over the past few decades, the exploration of marine algae has revealed the presence of radioprotective phytochemicals, such as phlorotannins, polysaccharides, carotenoids and other compounds. With their promising radioprotective effects, marine algae could be a future source for discovering potential radioprotective substances for development as useful in therapeutics.

• The Journal of the Acoustical Society of Korea
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• 제16권1E호
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• pp.9-14
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• 1997

Check valves used in industrial and Nuclear Power Plant safety systems are susceptible to failure modes generally associated with wear of internal parts. Specifically, hinge pins, disc studs, pistons, and other mechanical parts may degrade over time, and in some cases, may which might produce a disabling event leading to plant or process shutdown. The primary diagnostic technique in the past has been to disassemble the valves. This procedure is costly, time consuming, and in the nuclear industry, it can lead to radiation exposure in some situations. Additionally repair and reassembly of a valve does not ensure proper operation. Non-intrusive diagnostic technologies including acoustics and magnetics with a digital signal analysis allow to evaluate check valve performance without a disassembly and is able to help the user detect degraded valve conditions.

• Asian Journal of Atmospheric Environment
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• 제9권2호
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• pp.101-113
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• 2015

Air quality index (AQI) or air pollution index (API) is commonly used to report the level of severity of air pollution to public. A number of methods were developed in the past by various researchers/environmental agencies for determination of AQI or API but there is no universally accepted method exists, which is appropriate for all situations. Different method uses different aggregation function in calculating AQI or API and also considers different types and numbers of pollutants. The intended uses of AQI or API are to identify the poor air quality zones and public reporting for severity of exposure of poor air quality. Most of the AQI or API indices can be broadly classify as single pollutant index or multi-pollutant index with different aggregation method. Every indexing method has its own characteristic strengths and weaknesses that affect its suitability for particular applications. This paper attempt to present a review of all the major air quality indices developed worldwide.

• Safety and Health at Work
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• 제4권2호
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• pp.84-86
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• 2013

Despite the fact that asbestos is a known carcinogen to humans, it is still used in industrialized countries, especially Asian countries. The global incidence of asbestos-related diseases (ARDs) due to the past use of asbestos, continues to increase, although many countries have adopted a total ban on asbestos use. The implementation of effective strategies to eliminate ARDs is therefore an important challenge in Asia, where asbestos is still mined and consumed. Collaborative efforts and strategies at the local and international levels are vital, in the pursuit toward the elimination of ARDs in this region.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.321-329
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• 2009

Following their applications in cardiology, ophthalmology and dentistry among others, the advent of lasers in dermatology and urology had become the success story of the past decade. Laser-assisted treatments in dermatology and urology are mainly based on the laser-induced tissue injury/coagulation and/or ablation, depending upon the desirable clinical endpoint. In this review, we discussed the underlying mechanisms of the laser induced tissue ablation. In any medical laser application, the controlled thermal injury and coagulation, and the extent of ablation, if required, are critical. The laser thermal mechanism of injury is intricately related to the selective absorption of light and its exposure duration, similarly to the laser induced ablation. The laser ablation mechanisms were categorized into four different categories (the photo-thermally induced ablation, the photo-mechanically induced ablation, the plasma induced ablation and the photoablation) and their fundamentals are herein described. The brief history of laser treatment modality in dermatology and urology are summarized.

• 한국IT서비스학회지
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• 제18권1호
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• pp.173-186
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• 2019

Recently, as the amount of fine dust has risen rapidly, our interest is increasing day by day. It is virtually impossible to remove fine dust. However, it is best to predict the concentration of fine dust and minimize exposure to it. In this study, we developed a mathematical model that can predict the concentration of fine dust using various information related to the weather and air quality, which is provided in real time in 'Air Korea (http://www.airkorea.or.kr/)' and 'Weather Data Open Portal (https://data.kma.go.kr/).' In the mathematical model, various domestic seasonal variables and atmospheric state variables are extracted by multiple regression analysis. The parameters that have significant influence on the fine dust concentration are extracted, and using ANN (Artificial Neural Network) and SVM (Support Vector Machine), which are machine learning techniques, we proposed a prediction model. The proposed model can verify its effectiveness by using past dust and weather big data.

• The Korean Journal of Medicine
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• 제99권3호
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• pp.140-144
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• 2024

Hepatitis B virus (HBV) reactivation associated with various therapeutic interventions is a significant cause of morbidity and mortality among patients with current or resolved HBV infection. Since no curative treatment for HBV infection is currently available, a large number of individuals in the general population are at risk for HBV reactivation. Populations vulnerable to HBV reactivation include those currently infected with HBV or those who have had past exposure to the virus. The potential consequences of HBV reactivation are particularly concerning when these populations undergo anti-cancer chemotherapy, immunosuppressive or immunomodulatory therapies for managing various malignancies, rheumatologic diseases, inflammatory bowel disease, or undergo solid-organ or hematologic stem cell transplantation. This article aims to increase awareness of HBV reactivation and to elucidate the mechanisms and risks associated with HBV reactivation in various clinical settings.

• 농촌의학ㆍ지역보건
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• 제29권2호
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• pp.265-285
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• 2004

이 연구는 농약의 노출에 의해 중추신경 증상이 발생할 수 있으며, 장기간의 농약노출로 인해 중추신경계 영향이 있을 것이라는 가설을 검정하기 위해 농약 누적노출을 추정하였으며, 농약 노출 관련 요인에 따라 신경독성증상 호소의 차이를 보았다. 연구결과는 다음과 같다. 지난 1년 동안 농약살포시간은 과수농민 69.6시간, 밭농민 41.1시간, 축산농업인 25.8시간으로 통계적으로 유의한 차이가 있었으며, 누적노출지수는 과수농민 119.5g, 밭농민 63.9g, 축산농업인 23.7g으로 통계적으로 유의한 차이가 있었다(p<0.01). 누적노출지수에 의해 분류하면, 과수농민은 고노출군, 밭농민은 중간노출군. 축산농민은 저노출군에 해당하였다. 과거 농약중독 경험률은 과수농민 40.7%, 밭농민 35.1%, 축산농민 23.8%로 통계적으로 유의한 차이가 있었으며 (p<0.001), 지난 3개월 동안 농약중독 증상 경험률은 과수농민 67.2%, 밭농민 55.3%, 축산농민 20.5% 순으로 통계 적으로 유의한 차이가 있었다(p<0.001). 신경독성 자각증상의 총점과 6개 이상 증상을 호소하는 경우는 대조군 및 축산농민에 비해 밭농민 및 과수농민에서 유의하게 증가하였다(p<0.001). 연령, 교육수준, 성, 흡연, 음주를 보정한 상태에서도 6개 이상 신경독성 증상 발생의 교차 비는 비노출군에 비해 과수농민이 3.08(95% CI 1.50-6.30)배, 누적노출지수가 75% 이상 높은 군이 2.75(958% CI 1.12-6.78) 배, 과거 농약중독 경험이 있는 경우 1.97(95% CI 1.21-3.20)배, 현재 농약중독증상을 경험한 경우 정상군에 비해 경도 중독군 3.03(95% CI 1.47-6.22)배, 중등도 중독군이 6.34(95% CI 3.03-13.25)배 높게 나타났다. 이상의 결과로 볼 때, 신경독성증상의 발생에 일관되게 농약노출과 관련된 요인이 유의하게 나타나고, 농약노출이 높은 것으로 평가된 과수농민에서 중추신경계 증상 호소가 유의하게 녹게 나타나 만성 농약노출에 의해 중추신경계 영향이 발생할 가능성이 제기된다.