• 한국식품위생안전성학회지
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• 제16권1호
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• pp.41-47
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• 2001

녹차카테킨(GTC)의 항산화 작용을 알아보고자 in vitro와 in vivo에서 지질과산화와 superoxide dismutase(SOD), catalase 활성에 미치는 영향에 대한 실험을 행하였다. In vitro 시험계에서의 항산화활성 실험결과, GTC는 peroxide value와 과산화지질 생성을 유의성 있게 억제시켰고, SOD 활성이 매우 높았다. 또한 GTC를 rat에 경구투여 한 후 항산화활성실험 결과, GTC는 $CCl_4$로 유도된 rat의 간 microsome의 지질과산화를 유의성 있게 억제시켰으며, SOD와 catalase 활성을 유의성 있게 증가시켰다. 따라서 GTC는 암과 노화의 예방과 관련이 되는 항산화 활성이 있는 것을 알 수 있었다.

• 한국식품위생안전성학회지
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• 제11권2호
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• pp.83-87
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• 1996

The objective of this study is to investigate the direct effects of green tea catechins(GTC) on vascular smooth muscle tension and 45Ca2+ Uptake in rat aorta. The methods used in this study are isometric tension measurements using physiograph, Lanthanum method for 45Ca2+(2 uCi/ml) uptake measurement in rat aorta. GTC modified tension induced by 40 mM KCl or 1 uM norepinephrine in rat aorta. Low concentrations of GTC(<0.5mg/ml) increased tension by 40 mM KCl or 1 uM norepinephrine, individually. However, high conecentration of GTC(>0.5 mg/ml) inhibiited tension by 40 mM KCl or 1 uM norepinephrine, individually. GTC increased 45Ca uptake induced by 40 mM KCl in a dose-dependent manner. From these results, GTC has the dual actions in vascular smooth muscle in vitro. Low concentrations of GTC augments tension by K or norepinephrine. However, high concentrations of GTC inhibits tension by K or norepinephrine GTC may have Ca2+ channel activation, action, which may result in unphysiological vasodilation by Ca2+ overload in vascular smooth muscle.

• 한국식품위생안전성학회지
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• 제11권2호
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• pp.77-82
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• 1996

Green tea catechins(GTC) were studied for its inhibitory effect on human platelet aggregation in vitro, for its antithrombotic effect in mice in viro, and bleeding and clotting time in rats. The catechins were isolated and purified from green tea, which were composed of (-)-epigallocatechin gallate, (-)-epigallocatechin, (-)epicatechin gallate and (-)-epicatechin, GTC produced a potent inhibition of human platelet aggregation in a dose-dependent manner against the stimulants such as ADP, collagen, epinephrine and ristocetin n vitro. GTC also prevented death due to the formation of pulmonary thrombosis by platelet aggregates in mice in a dose-de-pendent manner in viro. GTC increased the bleeding time, whole blood clotting time and plasma clotting time in rats, too. These results suggest that GTC is a promising antithrombotic agent.

• 대한임상검사과학회지
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• 제46권2호
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• pp.75-78
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• 2014

Green tea and tea polyphenols have been studied extensively as cancer chemopreventive agents in recent years. Epigallocatechin-3-gallate (EGCG) is widely recognized as a powerful antioxidant and a free radical scavenger. The purpose of this study was to evaluate the protective effects of green tea catechins (GTC) on the Bleomycin- and Cyclophosphamide-induced cytotoxicity. Cell viability was measured by MTT assay. In the protective effect of GTC, the cell viability was significantly increased by the treatment of GTC. Furthermore, GTC showed the higher protective effect than EGCG and vitamin E. These results suggest that GTC has the protective effect which is related to the prevention of cancer. Our studies show that the continuous presence of EGCG can reduce radical-induced DNA damage in Chinese hamster lung fibroblast cells (CHL cells).

• 대한임상검사과학회지
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• 제46권4호
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• pp.131-135
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• 2014

Over-consumption of alcohol leads to many side-effects such as malnutrition, liver disease, and neuronal disorders and many investigators have tried to identify methods for preventing the side-effects of drinking. This study was carried out to investigate the effect of the beverage contained green tea catechins (GTC) on the alcohol administered rats. We observed that blood alcohol concentration level decreased significantly in plasma. GTC (200 mg/kg) also reduced the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) level of the intoxicated rats. These results suggest that GTC may be useful for the prevention and therapy of hepatotoxic pathogenesis.

• Biomolecules & Therapeutics
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• 제14권2호
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• pp.96-101
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• 2006

Amyloid$\beta(A{\beta})$ has been reported have an effect on the induction of oxidative stress that involves the functional and structural abnormalities in Alzheimer's disease. As a role of a radical scavenger, a green tea treatment was found have some inhibitory effect on the neurodegenerative process. The aim of this study was to determine if green tea catechin (GTC) reduces in transgenic model. To test this, transgenic mice carrying neuronspecific enolase (NSE) controlled C-terminus (105) of APP (APP-C105) were created and treated them with a low ana high dose of GTC for 6 months. Herein, we conclude that transgenic mice expressing NSE/APP-C105 were successfully created and the GTC-treated group exhibited significant reduction in body weight. Thus, GTC might be a good prevention of obesity or good treatment for AD patient.

• 약학회지
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• 제45권1호
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• pp.101-107
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• 2001

Green tea catechins (GTC) and its major component, (-)-epigallocatechin gallate (EGCG) were studied for their protective effects against reactive oxygen species (ROS)-induced oxidative stress. GTC and EGCG skewed the strong antioxidative effects on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. They also protected $H_2O$$_2$- or KO$_2$-induced cytotoxicity in CHL cells or mouse splenocytes. These results indicate that GTC and EGCG are capable of protecting the lipid peroxidation, flee radical generation and cytotoxicity induced by ROS. The mechanism of inhibition in ROS-induced cytotoxicity may be due to their antiofidative and free radical scavenging properties. Therefore, GTC and EGCG may be useful chemopreventive agents by protecting the free radical generation which are involved in cancer and aging.

• 무역상무연구
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• 제62권
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• pp.55-86
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• 2014

Korea has become a member of the United Nations Convention on Contract of the International Sales of Goods (the 'CISG') effective since March 1, 2005. As, therefore, the governing law of the general terms and conditions (the 'GTC') in the Government Foreign Procurement Contract (the 'Contract') is mandatorily fixed to the Korean Law, the CISG, as an International Convention, now having an equivalent or even higher status to the Korean Law, unless expressly excluded, will be priorly applied to the Contract where a transaction occurs between its members. In this regard, this study focuses on how to find the way for the CISG to be a governing law of the GTC in order to eliminate legal uncertainties and lacks of foreseeability prevailed in the international trade. For that purpose, the legal aspects of GTC, and the Buyer's remedy for the Seller's breach of the Contract are analyzed in accordance with the comparative study between the CISG and the GTC including the relevant case studies. As a result of this study, the application of the CISG into the GTC is highly recommended in order to reflect into the Contract such features as fairly harmonized for the interest of both parties. Taking this opportunity, a GTC, amended from the existing one, or newly formed, within the perimeter of not conflicting with the provisions of the CISG, including but not limited to the Civil Law and Commercial Law, is required in order to evenly share each party's responsibilities and obligations where the breach or remedy of the Contract is, and, thus, which will ultimately contribute to an efficient conduct of the Contract.

• 한국식품위생안전성학회지
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• 제19권3호
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• pp.105-111
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• 2004

녹차카테킨은 다양한 생리활성을 지닌 것으로 알려지고 있다. 본 실험에서는 사염화탄소와 갈락토사민으로 유발된 간독성에 대한 녹차카테킨의 간기증보호효과가 연구되었다. 녹차 카테킨(50 mg/kg와 100 mg/kg)은 사염화탄소 (0.5 ml/kg)와 갈락토사민(400 mg/kg)이 투여되기 전 그리고 투여후 3일동안 흰쥐에 경구투여되었고, 간기능지표로 AST와 ALT를 측정하였다. 녹차카테킨(50 mg/kg)은 사염화탄소 처리된 랫드에서 상승된 혈중 AST와 ALT 확성을 전투여군(262${\pm}$11, 80${\pm}$19에서 153${\pm}$22, 55${\pm}$25로)과 후투여군(156${\pm}$40, 105${\pm}$3 에서 106${\pm}$22, 55${\pm}$9로) 모두 감소시켰다. 또한 갈락토사민으로 유도한 경우에도 AST와 ALT 수치는 전투여군(576${\pm}$24, 276${\pm}$68 에서 236${\pm}$13, 115${\pm}$13로)과 후투여군(233${\pm}$54, 137${\pm}$11 에서 119${\pm}$23, 44${\pm}$17로)에서 모두 유의성있게 감소된 결과를 나타내었다. 또한 간 조직학적 검사에서도 사염화탄소와 갈락토사민으로 유도된 간경변을 유의성있게 억제하였다. 이상의 결과로 볼 때 녹차카테킨은 간독성에 의한 병변을 예방 및 치료할 수 있는 신약후보물질로서의 가능성을 시사한다.

• 인터넷정보학회논문지
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• 제18권5호
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• pp.31-38
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• 2017

최근 LBS(Location-based Services)기술의 발달로 사용자의 위치를 보호하는 연구가 활발히 진행 되고 있다. LBS를 사용하기 위해서는 사용자의 정확한 위치 데이터를 LBS 서버에게 공개해야 한다. 그러나 사용자의 위치를 서버에게 공개하면 서버는 사용자의 위치를 파악할 수 있다. 또한 사용자의 위치 데이터가 지속적으로 서버에게 공개 된다면 질의자의 이동 궤적 또한 노출 될 수 있다. 이를 해결하기 위해 본 논문에서는 GTC (Grid-based Trajectory Cloaking) 기법을 제안한다. GTC 기법은 사용자가 목적지 까지 경로와 사용자가 원하는 프라이버시 레벨 수준 (UPL : User's desired Privacy Level)의 그리드로 분할 한 뒤 클로킹 영역을 설정해 랜덤으로 질의한다. GTC 기법은 순차적인 궤적 k-익명화기법 보다 질의 처리 비용을 줄였고 출발지와 도착지를 알 수 없는 궤적을 생성해 궤적 노출 확률을 줄였다. 실험 결과를 통하여 제안 기법의 우수성을 증명하였다.