• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.105-111
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• 2005

An experimental study is performed for extinguishing of n-heptane pool fire by water mist containing potassium acetate as a fire suppression additive. Water mist was generated by a single pressure nozzle in a small-scale chamber. The drop size distribution of water mist was measured using laser diffraction(Malvern particle sizer). The flame temperature, oxygen concentration and carbon monoxide concentration were measured. In case of using additives, the fire extinguishing time was shorter than that of pure water at a given discharge pressure and it was because the momentum of a water droplet containing additives was increased. And also dissociated metal atoms, potassium, were reacted as a scavenger of the major radical species OH, H which were generated for combustion process. Moreover, at a high pressure of 4MPa, the fire was extinguished through blowing effect as well as primary extinguishing mechanisms.

• Natural Product Sciences
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• v.16 no.2
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• pp.111-115
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• 2010

Anti-inflammatory and anti-oxidant effect of Spirodela polyrrhiza (Lemnaceae), a widely used traditional medicinal plant were investigated. In macrophages nitric oxide (NO) is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions including inflammation. 85% MeOH extracts of S. polyrrhiza (0.01, 0.1, 1 mg/mL) suppressed nitric oxide production in interferone-$\gamma$ (IFN-$\gamma$) and lipopoloysaccharide(LPS)-stimulated macrophages. It also attenuated the expression of inflammatory enzymes like inducible NOS (iNOS) and cyclooxygenase-2(COX-2) as assessed by immunoblotting with specific antibodies. Moreover, the values obtained with DPPH radical, superoxide anion and NO radical scavenging assay showed that S. polyrrhiza has potent antioxidant properties as a natural ROS scavenger. The results of the present study suggest the potential use of S. polyrrhiza in the treatment of ROS-mediated chronic inflammatory diseases such as atherosclerosis and rheumatoid arthritis.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.211-217
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• 2002

Hepatoprotective activity of methanol extract of Angelica tenuissima Nakai on the $CCl_4$-induced hepatotoxicity was investigated. To elucidate the hepatoprotective activity and free radical scavenging effect, we examined alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, total protein, cholesterol, malondialdehyde (MDA) levels in serum and activities of superoxide dismutase (SOD), catalase (CAT) in hepatic tissue as compared with those of carbon tetrachloride-induced rats. The action mechanism also has been estimated by quantative analysis of cytochrome P450 (CYP), NADPH-CYP reductase for phase I metabolism and glutathion (GSH), glutathion S-transferase (GST) level for phase II metabolsim. Treatment of Angelica tenuissima methanol extract significantly lowered the levels of alanine aminotransferase and aspartate aminotransferase. In addition, the levels of cholesterol, triglyceride, MDA, CAT were decreased, and SOD was activated. This result indicates that the hepatoprotective effect of Angelica tenuissima methanol extract on the CCl4-induced hepatotoxicity would be originated from reduction of the NADPH-CYP reductase, GSH and the enhancement of the activities of GST, CYP.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.2
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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).

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.107-107
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• 2000

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.103-103
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• 2000

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.100-100
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• 2000

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.98-98
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• 2000

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.105-105
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• 2000

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.107-109
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• 1993

Non-enzymatic glycosylation and fragmentation of collagen molecule were investigated by irradiating Ultraviolet A(UV-A) with or without scavengers of reactive oxygen species (ROS) in the presence of glucose. Non-enzymatic glycosylation was increased by UV-A at high concentration of glucose. It was reduced in the presence of the scavengers of superoxide radical and singlet oxygen, but not reduced in the presence of hydroxy radical scavenger. Fragmentation of collagen was increased by UV-A, but it was decreased in the presence of all ROS scavengers tested. Superoxide radical and singlet oxygen produced by autoxidation of glucose without UV-A may encounter the initial phase of glycosylation. Data presented here suggest that UV-A affects only on the fragmentation process, but all ROS except hydroxy radical act on both processes. It appears that hydroxy radical does not act on the glycosylation process.