• 한국환경과학회지
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• 제23권3호
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• pp.483-492
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• 2014

DNA damage such as genotoxicity was identified with comet assay, which blood cell of a marine parrot fish (Oplegnathus fasciatus) was exposed to an acidified seawater, lowered pH gradient making of $CO_2$ gas. The gradient of pH were 8.22, 8.03, 7.81, 7.55 with control as HBSS solution with pH 7.4. DNA tail moment of fish blood cell was $0.548{\pm}0.071$ exposed seawater of pH 8.22 condition, on the other hand, DNA tail moment $1.601{\pm}0.197$ exposed acidified seawater of pH 7.55 lowest condition. The approximate difference with level of DNA damage was 2.9 times between highest and lowest of pH. DNA damage with decreasing pH was significantly increased with DNA tail moment on blood cell of marine fish (ANOVA, p < 0.001). Ocean acidification, especially inducing the leakage of sequestered $CO_2$ in geological structure is a consequence from the burning of fossil fuels, and long term effects on marine habitats and organisms are not fully investigated. The physiological effects on adult fish species are even less known. This result shown that the potential of dissolved $CO_2$ in seawater was revealed to induce the toxic effect on genotoxicity such as DNA breakage.

• Journal of Nutrition and Health
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• 제40권8호
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• pp.708-718
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• 2007

본 연구는 비타민 E의 보충섭취가 폐경기 여성의 항산화 영양상태 및 임파구 DNA 손상을 개선할 수 있는지를 알아보고자 수행되었으며, 이중맹검법으로 실시되었고 플라시보를 위약군으로 하였다. 폐경기 여성 35명을 대상으로 6주 동안 비타민 E 보충섭취군에게는 비타민 E 캡슐($\alpha$-tocopherol 성분 400 IU/capsule)을, 위약군에게는 대두유로 만든 위약 캡슐(400 mg/capsule)을 하루 2회 섭취하도록 하였으며, 이 때 두 군의 분류는 무작위로 하였다. 항산화 영양상태를 알아보기 위해 혈장 vitamin C, $\alpha$-tocopherol, $\gamma$-tocopherol, $\alpha$-carotenoid, $\beta$-carotenoid, lycopene 농도를 측정하였고, 임파구 DNA 손상정도를 알아보기 위해서는 Comet assay를 이용하여 tail length, %DNA in tail, tail moment를 측정하였다. 비타민 E 보충섭취군에서는 혈장 vitamin C(p<0.05)와 $\alpha$-tocopherol(p<0.000)농도가 유의적으로 증가하였고, $\gamma$-tocopherol(p<0.000) 농도와 tail length(p<0.05)는 유의적으로 감소하였다. 반면, 위약군에서는 혈장 vitamin C(p<0.05)의 농도만이 유의적으로 증가하였다. 결론적으로, 본 연구는 비타민 E의 보충섭취가 혈장 항산화 상태 및 DNA 손상에 대해 부분적인 개선 효과가 있음을 보여주었다.

• Nutrition Research and Practice
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• 제3권2호
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• pp.114-121
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• 2009

The effect of diet supplemented with red beet (Beta vulgaris L.) leaf on antioxidant status of plasma and tissue was investigated in C57BL/6J mice. The mice were randomly divided into two groups after one-week acclimation, and fed a high fat (20%) and high cholesterol (1%) diet without (control group) or with 8% freeze-dried red beet leaf (RBL group) for 4 weeks. In RBL mice, lipid peroxidation determined as 2-thiobarbituric acid-reactive substances (TBARS value) was significantly reduced in the plasma and selected organs (liver, heart, and kidney). Levels of antioxidants (glutathione and $\beta$-carotene) and the activities of antioxidant enzyme (glutathione peroxidase) in plasma and liver were considerably increased, suggesting that antioxidant defenses were improved by RBL diet. Comet parameters such as tail DNA (%), tail extent moment, olive tail moment and tail length were significantly reduced by 25.1%, 49.4%, 35.4%, and 23.7%, respectively, in plasma lymphocyte DNA of RBL mice compared with control mice, and indicated the increased resistance of lymphocyte DNA to oxidative damage. In addition, the RBL diet controlled body weight together with a significant reduction of fat pad (retroperitoneal, epididymal, inguinal fat, and total fat). Therefore, the present study suggested that the supplementation of 8% red beet leaf in high fat high cholesterol diet could prevent lipid peroxidation and improve antioxidant defense system in the plasma and tissue of C57BL/6J mice.

• Journal of Preventive Medicine and Public Health
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• 제37권4호
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• pp.373-380
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• 2004

Objectives : There has been gradually increasing concern about the adverse health effects of electromagnetic radiation originating from cell phones which are widely used in modern life. Cell phone radiation may affect human health by increasing free radicals of human blood cells. This study has been designed to identify DNA damage of blood cells by electromagnetic radiation caused by cell phone use. Methods : This study investigated the health effect of acute exposure to commercially available cell phones on certain parameters such as an indicator of DNA damage for 14 healthy adult volunteers. Each volunteer during the experiment talked over the cell phone with the keypad facing the right side of the face for 4 hours. The single cell gel electrophoresis assay (Comet assay), which is very sensitive in detecting the presence of DNA strand-breaks and alkali-labile damage in individual cells, was used to assess peripheral blood cells (T-cells, B-cells, granulocytes) from volunteers before and after exposure to cell phone radiation. The parameters of Comet assay measured were Olive Tail Moment and Tail DNA %. Results : The Olive Tail Moment of B-cells and granulocytes and Tail DNA % of B-cells and granulocytes were increased by a statistically significant extent after 4-hour use of a cell phone compared with controls. Conclusion : It is concluded that cell phone radiation caused the DNA damage during the 4 hours of experimental condition. Nonetheless, this study suggested that cell phone use may increase DNA damage by electromagnetic radiation and other contributing factors.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.543-552
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• 2007

We consider estimation of the right-tail probability in a half-triangle distribution, and also consider inference on reliability, and derive the k-th moment of ratio of two independent half-triangle distributions with different supports. As we define a skew-symmetric random variable from a symmetric triangle distribution about origin, we derive its k-th moment.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.15-20
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• 2015

Unlike a typical metal spring, a gas spring uses compressed gas contained in a cylinder and compressed by a piston to exert a force. A common application includes automobiles where gas spring are incorporated into the design of open struts that support the weight of tail gate. They are also used in furniture such as office chairs, and in medical and aerospace applications. The gas spring works by the application of pressurized gas (nitrogen) contained in a cylinder. The internal pressure of the gas spring greatly exceeds atmospheric pressure. This differential in pressure exists at any rod position and generates an outward force on the rod, making the gas spring extend. In this paper, we investigated the dynamic characteristics of a gas spring on an automotive tail gate system.

• Communications for Statistical Applications and Methods
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• 제26권3호
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• pp.239-259
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• 2019

The transmuted generalized extreme value (TGEV) distribution was first introduced by Aryal and Tsokos (Nonlinear Analysis: Theory, Methods & Applications, 71, 401-407, 2009) and applied by Nascimento et al. (Hacettepe Journal of Mathematics and Statistics, 45, 1847-1864, 2016). However, they did not give explicit expressions for all the moments, tail behaviour, quantiles, survival and risk functions and order statistics. The TGEV distribution is a more flexible model than the simple GEV distribution to model extreme or rare events because the right tail of the TGEV is heavier than the GEV. In addition the TGEV distribution can adjusted various forms of asymmetry. In this article, explicit expressions for these measures of the TGEV are obtained. The tail behavior and the survival and risk functions were determined for positive gamma, the moments for nonzero gamma and the moment generating function for zero gamma. The performance of the maximum likelihood estimators (MLEs) of the TGEV parameters were tested through a series of Monte Carlo simulation experiments. In addition, the model was used to fit three real data sets related to financial returns.

• 충청수학회지
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• 제25권4호
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• pp.747-752
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• 2012

When the service time distribution has a finite exponential moment, we present a large deviations result for the busy period distribution in the M/G/1 queue without the assumption of Abate and Whitt (1997) and Kyprianou (1971).

• Journal of Nutrition and Health
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• 제43권6호
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• pp.570-577
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• 2010

Water gets magnetically charged when it is contacted with a magnet. Although magnetic water products have been promoted since the 1930's, they have received very little recognition due to questionable effectiveness. Diethylnitrosamine (DEN) is a widely occurring nitrosamine that is one of the most important environmental carcinogens primarily inducing tumors of liver. In this study, the effect of magnetized water supplementation on lymphocyte DNA damage in ICR mice treated with DEN was evaluated using the Comet assay. Mice were divided into 3 groups: control, DEN, and DEN + magnetized water group. Fifteen mice were maintained in each group for the entire experimental period of 6, 12 and 18 weeks. Five mice in each group were sacrificed at 6, 12, and 18th weeks, followed by the Comet assay using the blood obtained from heart puncture of the mice. The level of lymphocyte DNA damage reflected by tail moment and other DNA damage indices of tail DNA (%) or tail length of the magnetized water group were significantly decreased after the 6th, 12th and 18th weeks of supplementation compared with the positive control, the DEN group. The relative DNA damage of the magnetized water groups compared to the DEN control group after 6th, 12th, and 18th weeks of supplementation were 42.2%, 40.8%, and 32.9% for DNA in tail, 31.2%, 32.6%, and 21.3% for tail length, and 33.8%, 33.8%, and 24.6% for tail moment, respectively. This is the first report demonstrating that magnetized water may be involved in the lowering effect of the DNA damage in DEN-treated ICR mice. This result suggests that the magnetized water might have minimized the DNA damage by improving the antioxidant status of the mice. However, further studies are needed to characterize the condition of the magnetization and examine the long-term effect of the water product.

• 환경영향평가
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• 제22권6호
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• pp.591-607
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• 2013

본 연구에서는 생물학적 바이오마커, 물리적 서식지 지표 및 화학적 수질지표를 종합하여 12-메트릭 생태평가 모형을 확립하였고, 도심하천에 적용하여 수생태계 평가를 실시하였다. 생태모형 적용을 위해 도심하천의 상류역의 대조군 지역($C_Z$), 중류의 전이대($T_Z$) 및 하류역의 오염지역(IZ)을 선정한 후, 모델값에 대한 계절별 변이특성을 분석하였다. DNA 손상도 분석은 혈액을 이용한 단세포 전기영동법(Single-cell gel electrophoresis, SCGE)인 Comet assay 지표에 의거한 생지표 메트릭으로 이용되었고, Tail moment, Tail DNA(%) 및 Tail length(${\mu}m$)값이 분석되었다. DNA의 손상은 하류역의 오염지역($I_Z$)에서 분명하게 나타났지만, 대조군($C_Z$) 지역에서는 그렇지 않았다. 개체군 지표로서 비만도 지수인 $C_F$ 값 분석, 체장빈도 분포 지표 및 개체 이상도(Abnormality) 지표가 생물지표로서 이용되었다. 물리적 서식지 지표는 QHEI 모델을 이용하였고, 4개 메트릭이 분석되었다. 화학적 수질지표는 부영양화 지표인 인(P)/질소(N), 화학적 산소요구량 및 전기전도도 지표가 이용되었다. 본 연구를 종합해보면, 12-메트릭 생태모형의 생지표 속성은 대조군($C_Z$)지역에 비해 오염지역($I_Z$)에서 화학적 스트레스 지표(부영양화 지표)에 아주 민감하게 반응 하는 것으로 나타났으며, 또한 이들은 부분적으로 서식지 평가지표에 의해 영향 받는 것으로 분석되었다.