• 대한한의학회지
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• 제22권3호
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• pp.31-41
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• 2001

Objectives : This study was performed to investigate the effects of Cordyceps Sinensis (CS) and Cordyceps Militaris (CM) on anti oxidation in the livers of ${CCl_4}-treated$ rats. Methods : Hepatotoxicity in rats was induced by carbon tetracWoride. $CCl_4-induced$ rats were administered with the extract of CS and CM. Results : In vitro, CS and CM didn't affect levels of lipid peroxide and the activities and type conversion ratio of xanthine oxidase. However, hydroxyl radicals and DPPHL radicals were decreased. In vivo, in the ${CCl_4}-treated$ rats, lipid peroxide, the activities and type conversion ratio of xanthine oxidase and superoxide radicals were increased but superoxide dismutase was decreased. After CS and CM were administered to ${CCl_4}-treated$ rats, levels of lipid peroxide, the activities and type conversion ratio of xanthine oxidase and superoxide radicals were decreased but superoxide dismutase was increased. Conclusions : These results suggest that CS and CM decrease the activities of free-radical-generating enzymes which form lipid peroxide and increase the activities of oxygen free radical scavenging enzymes.

• 대한화학회지
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• 제15권5호
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• pp.256-265
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• 1971

An ESR study has been made on free radicals produced in frozen aqueous solutions (ices) of glycine, DL-${\alpha}$-alanine, DL-serine, L-cysteine, DL-leucine and DL-isoleucine by gamma-irradiation at dry ice temperature. All free radicals induced were decayed concomitant to the successive annealing but the radical species which is believed to be dominant seems to be stable even near the melting point of the ice. These dominant species were found to be identical to those resulted from direct action of radiation in the solid at room temperature. Small but significant changes in the spectra of glycine and DL-${\alpha}$-alanine were observed by varying the microwave power. These results seem to support the view that the spectra obtained were composite consisting of more than two different resonances having different power saturation characteristics. The relative contribution of unidentified resonances to the composite spectra was greater for solutions of low concentration. These resonances are assumed to be induced by indirect effects, mainly hydrogen abstraction by radiation produced hydroxyl radicals and also C-N bond cleavage by hydrated electrons.

• 대한의생명과학회지
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• 제7권3호
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• pp.99-102
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• 2001

Toluene is mainly metabolized in liver by oxidative pathway. Oxigen free radicals occur through the process of toluene metabolism Therefore it causes tissue and cell min by the oxygen free radicals from the metabolism of toluene. Melatonin acts as a highly efficient free radical scavenger that protects cells from damage by oxygen free radicals. To test this hypothesis, toluene hepatotoxicity was induced by an abdominal injection of toluene. To see if the melatonin protects the rat's liver, melatonin was administrated orally, at the time of each toluene injection. Aspartate aminotransferase(AST), alanin aminotransferase(ALT), latic dehydrogenase(LDH) and alkaline phosphatase(ALP) levels in serum were measured to estimate hepatic function. Malondialdehyde(MDA), which gives an indirect index of oxidative injury was also measured. Hippuric acid is the last metabolic Production of toluene was measured by HPLC. There were significantly higher in AST, ALT, LDH, MDA and hippuric acid in toluene group, but there were no significant difference in melatonin group except ALT and hippuric acid. There was significantly lower in ALP level in toluene group, but there was no significant difference melatonin group, suggesting a significant hepatotoxicity due to oxygen free radicals through the process of toluene metabolism Melatonin treatment significantly protected hepatic function and free radical-mediated injury in the liver against toluene-induced changes. Accordingly, this study shows that melatonin is helpful in protecting liver injury by acute toluene intoxication.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권9호
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• pp.449-454
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• 2016

한글의 자소들은 몇 가지의 획으로 구성되어 있고, 완전한 글자들은 자소들의 조합으로 구성되어 있다. 획과 자소들을 조합하는 과정에서 그 구성들의 크기나 위치가 변화할 수 있으므로 폰트를 제작하는데 많은 노력이 필요하다. 이와 달리 METAFONT는 매개변수 값을 변경하면서 획과 자소의 크기와 위치를 쉽게 변환할 수 있는 시스템을 제공하여 폰트 제작 과정에 효율성을 높일 수 있다. 본 논문은 METAFONT를 기반으로 사용자가 매개변수를 수정하여 다양한 폰트를 자동으로 생성할 수 있는 구조적 한글 폰트 생성기를 제안한다. 본 논문에서 제안한 한글 폰트 생성기는 폰트 임베딩 분야와 폰트 편집기 분야에 적용할 수 있다.

• 대한한의학방제학회지
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• 제10권2호
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• pp.243-249
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• 2002

This study was performed to investigate the effects of fermented extract of Pinus densiflora (FPD) on oxygen radicals and $H_2O_2$-induced damage. The results are as follows: 1. The 1.1-diphenyl-2-picrylhydrazyl (DPPH) free radicals were considerably reduced by FPD and $IC_{50}$ value was showed the concentration of 20 ㎍／㎖. 2. The cytotoxicity did not observe by FPD treatment in A548 cells. 3. The $H_2O_2$-induced cell damage was recovered by FPD pretreatment in A549 cells. These results suggest that FPD, as a natural antioxidant, has scavenging effect of free radicals and protection effect from $H_2O_2$-induced cytotoxicity.

• 대한한의학회지
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• 제17권1호
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• pp.21-36
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• 1996

This study was undertaken to examine the effect of Jwagyuyeum and Woogyuycum, being known to reinforce Kidney-yin and yang, on the activities of endogenous antioxidant enzymes and the production of oxygen free radicals in the liver and kidney tissues, Alterations in enzyme activities were observed after in vivo treatment in rats, Jwagyuyeum and Woogyuyeum caused a significant increase in the activities of superoxide dismutase(SOD) and catajase Jwagyuyeum significantly increased the activity of glutathione peroxidase in both liver and kidney, but the enzyme activity was not significantly altered by Woogyuyeum. Treatment in vitro of Jwagyuyeum and Woogyuyeum decreased the production of oxygen free radicals in a dose-dependent fashion. These results suggest that Jwagyuyeum and Woogyuyeum stimulate the activities of antioxidant enzymes and inhibit directly the production of oxygen free radicals. These effects of both herbs may contribute to prevent the oxygen free radical-induced impairment of cell function.

• 대한기계학회논문집B
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• 제21권5호
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• pp.602-614
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• 1997

In order to evaluate the effects of equivalence ratio, initial pressure and temperature on the laminar flame propagation process, and combustion radicals characteristics, experimental approaches are carried out in methane-air premixture using a constant volume chamber. Local and average radical intensities were measured to determine the time and spatial correlations between each radicals; C $H^{*}$(431 nm), $C_{2}$$^{*}$ (517 nm) and O $H^{*}$(309 nm) . The results are showed that two kinds of equation were proposed for the cases of continuous flame and intermittent flame type to evaluate actual equivalence ratio using relative intensities with each radicals. Both equations were agreed with actual equivalence ratio within 10% errors range. And schlieren photo and CCD image were compared with flame sizes at equivalence ratio 1.0.o 1.0.

• Journal of Ginseng Research
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• 제32권2호
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• pp.150-154
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• 2008

Twenty five albino rats were divided into five groups for conducting this experiment. The first group was for positive control (Vitamin C, ascorbic acid), the second group was of Panax ginseng (10 mg/kg body weight) treated group after bio-activity assay, the third group was of mercuric chloride treated group (0.033 mg/kg body weight) based on calculating $LD_{50}$ 9.26 mg/kg body weight by probit analysis, the fourth group was of mercuric chloride (0.033 mg/kg body weight) followed by Panax ginseng (10 mg/kg body weight) and the fifth group was Panax ginseng (10 mg/kg body weight) followed by mercuric chloride (0.033 mg/kg body weight) treated group. The interval between intake of Panax ginseng and mercuric chloride was of 2 hours in groups, fourth and fifth respectively. Comparative free radical scavenging property of Panax ginseng was studied under three in vitro models (role model for calculating scavenging activity) viz. DPPH method (hydroxyl free radicals), Nitric oxide method (nitrile free radicals) and Lipid peroxidation (mercury free radicals).

• 약학회지
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• 제43권5호
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• pp.652-658
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• 1999

To reveal the inhibitory mechanism of NO-dependent vasorelaxation by quinone derivatives (OQ1 and OQ21), we have compared the generation of free radicals by oxidative stress and the formation of cellular adducts by arylation. First, we measured oxygen consumption by quinone derivatives as a marker of oxidative stress in order to investigate whether these quinone compounds could generate reactive oxygen species. Both OQ1 and OQ21 generated free radicals and OQ21 was more potent. These results suggested that free radicals be involved in the inhibition of vasorelaxation by quinones. Next, we measured the binding capacity of quinone derivatives with intracellular GSH and protein thiols (-SH) in order to investigate whether these quinones have arylation capacity. Compared to positive control groups (menadione), both OQ1 and OQ21 depleted intracellular GSH and protein thiols very slightly. These compounds have low toxicities in mammalian tissues. From these results, we concluded that the inhibition of vasorelaxation by quinone derivatives (OQ1, OQ21) may be cuased by generation of free radicals.

• Preventive Nutrition and Food Science
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• 제19권1호
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• pp.34-39
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• 2014

This study evaluated the influence of cooking methods (blanching, pan-frying, and microwaving) on the antioxidant activity of Ligularia fischeri (LF) using myoglobin methods against five different reactive oxygen species (ROS) (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH), hypochlorite ions, hydroxyl radicals, peroxyl radicals, and peroxynitrite ions). With respect to DPPH scavenging activity, the antioxidant activities of blanched LF and pan-fried LF were significantly higher (P<0.05) than that of fresh LF for all cooking times. Pan-fried LF and microwaved LF showed higher antioxidant activities against hydroxyl radicals and peroxyl radicals than uncooked LF, while the protective effect of blanched LF was low, except for the at the 3 min cooking time point. Microwaved LF showed high antioxidant activity against all ROS at the 2 min cooking time point. Interestingly, LF that had been microwaved for 2 min and 3 min had high antioxidant values, whereas blanched LF and pan-fried LF had low antioxidant values. The activities of cooked LF against five different ROS were characterized comprehensively by 5-axe cobweb charts.