• Toxicological Research
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• v.11 no.1
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• pp.23-29
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• 1995

Microsomes from human liver sample HL 110 oxidized aflatoxin $B_1$ $(AFB_1)$ to $AFB_1$ exo-8, 9-epoxide which was detected as a glutathione (GSH) conjugate with excess GSH S-transferase and to aflatoxin $Q_1$ ($AFB_1$; 3$\alpha$-hydroxyafiatoxin $B_1$), and testosterone to 6$\beta$-hydroxytestosterone. Anti-P450 3A4 nearly completely inhibited all of the reactions. Some fiavonoids inhibited all of the reactions. While other fiayonolds stimulated 8, 9-epoxidation and inhibited 3$\alpha$-hydroxylation. Gestodene inhibited all of the reactions when gestodene was metabolized by human liver microsomal P450 3A4 prior to adding substrate. But, ges-todene was added in the enzyme mixtures in the presence of $AFB_1$, it could not inhibit 8, 9-epoxidation of $AFB_1$. Nifedipine and troleandomycin inhibited both of the reactions of $AFB_1$ but only 3$\alpha$-hydroxylation was inhibited by the oxidation product of nifedipine. Although, troleandomycin was known as a mechanism-based inhibitor, the chemical did not show any detectable inhibitory effect on 6$\beta$-hydroxylation of testosterone. The results suggest that there are several different substrate-binding sites on P450 3A4.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.1
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• pp.159-171
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• 2009

Objectives This study was evaluated the effects of CSE the regulatory mechanism of NO and cytokines in the LPS-stimulated Raw 264.7 cells. Methods The Coicis Semen MeOH extract dissolved in EMEM for 1 hour prior to the addition of LPS(1${mu}g/ml$). The cell viability was measured by MTT assay, and Nitric Oxide production was monitored by measuring the nitrite content in culture medium. The levels of cytokine and PGE2 were analyzed by sandwich immunoassays. Results CSE inhibited the production of NO (0.03 and 0.1 mg/ml), $TNF-{\alpha}$ (0.03 and 0.1 mg/ml), $IL-1{\beta}$ (0.03 and 0.1 mg/ml), IL-6 (0.03, 0.1 mg/ml) and PGE2(0.03 and 0.1 mg/ml) in Raw 264.7 cells activated with LPS(lipopolysaccharide). Conclusion According to the results above, Coicis Semen can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

• Journal of Korean Academy of Nursing
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• v.34 no.3
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• pp.534-540
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• 2004

Purpose: The purposes of this study were to describe the relationship between depression and resilience and to identify variables associated with depression among children with nephrotic syndrome. Method: Data was collected from 45 children who were registered at one hospital in Seoul. The criteria for sample selection were 10 to 15 year-old children who were diagnosed at least 6 month prior. The instruments included a self-reported questionnaire on resilience by Kim, CDI by Beck, and MBRI by Kwak. Descriptive, Pearson correlation and multiple regression analyses were done. Result: The mean score of depression was 11.44 (range:0-54) and resilience was 97.47 (range:32-128). There were significant positive relationships between depression and age (r=0.302, p<.005) and academic achievement (r=-0.318, p<.005). In addition, negative relationships between depression and maternal attitude (r=-0.412, p<.001) and resilience (r=-0.649, p<.001) occurred. The results of multiple regression analysis showed that maternal behavior (${\beta}$=-0.421, p<.005) and resilience (${\beta}$=-0.639, p<.001) were related to depression. Conclusion: Children with higher resilience and with an affectionate mother were less depressed. Thus, it is important to identify strengths of children and help them to increase resilience and implement parenting and counseling programs for parents' of these children. Similar studies with children with other chronic illnesses are needed.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.3
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• pp.165-176
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• 2009

Objectives The purpose of this study is to find out the effect of Taraxaci Herba Extract (THE), LPS, on pro-inflammatory mediatory. Methods After the treatment of Taraxaci Herba MeOH extract dissolved in EMEM for 1 hour prior to the addition of LPS ($1\;{\mu}g/ml$), cell viability was measured by MTT assay, Nitric Oxide production was monitored by measuring the nitrite content in culture medium. And levels of cytokine and PGE2 were analyzed by sandwich immunoassays. Results THE inhibited the production of nitrite and nitrate (0.03 and 0.1 mg/ml), TNF-$\alpha$, (0.03 and 0.1 mg/ml), IL-$1{\beta}$(0.03 and 0.1 mg/ml), IL-6 (0.01, 0.03 and 0.1 mg/ml) and PGE2(0.03 and 0.1 mg/ml) activated with LPS. In Raw 264.7 cells activated with lipopolysaccharide. Conclusions According to the results above, Taraxaci Herba can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

• Journal of Korean Society for Quality Management
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• v.30 no.1
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• pp.74-96
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• 2002

The objectives of this study is to suggest the rectifying sampling inspection plan considering quality cost. Limiting quality level(LQL) plans(also called LTPD plans) and outgoing quality(OQ) plans are considered. The Hald's linear cost model is discussed with and without a beta prior for the distribution of the fraction of nonconforming items in a lot. It is assumed that the sampling inspection is error free. We consider the design of reliability acceptance sampling plan (RASP) for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and K C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level(1-$\beta$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using simple linear cost model considering product cost, capability of environment chamber, environmental test cost, and etc. Especially, we consider a reliability of lots that contain some nonconforming items. In this case we assumed that a nonconforming item fail after environmental life test. Finally, we develope the algorithm of the optimal sampling inspection plan based on minimum costs for rectifying inspection and RASP. And computer application programs are developed So, it is shown how the desired sampling plan can be easily found.

• Journal of the Korean Ceramic Society
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• v.20 no.4
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• pp.305-314
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• 1983

In order to enhance the rate of th nitridation and to give the high density of reaction-bonded silicon nitride MgO powder as nitriding aid were added to silicon powders and the mixture was pressed isostatically into compacts which were nitrided in the furnace of 1, 35$0^{\circ}C$ where 95% $N_2$-5% $H_2$ gases were flowing. As the other nitriding aid $Mg(NO_3)_2 6H_2O$ was selected, A slip made of magnesium nitrate solution and fine silicon particles was spray-dried and then decomposed at 30$0^{\circ}C$. Magnesium oxide-coated silicon powders were formed into compacts prior to the nitridation on the same condition as the former. Magnesium nitrate (MgO, produced from the decomposition of magnesium nitrate) was more effective for the formation of the $\beta$-phase in the initial stage of the nitridation probably due to the easy formation of $MgO-SiO_2$-metal oxide eutectic melt. It has been confirmed that forsterite was formed as a result of the reaction between MgO and $SiO_2$ film of silicon surface. It was considered that MgO produced from magnesium nitrate may be finer more reactive and more uniformly distributed on the surface of silicon particles than original MgO. The higher the forming pressure was the more the $\beta$-phase was formed.

• Journal of the Korean Ceramic Society
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• v.46 no.5
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• pp.452-455
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• 2009

A cost-effective route to synthesize $\beta$-SiAlONs from Si mixtures by reaction bonding followed by post-sintering was investigated. Three different z values, 0.45, 0.92 and 1.87, in $Si_{6-z}Al_zO_zN_{8-z}$ without excess liquid phase were selected to elucidate the mechanism of SiAlON formation and densification. For RBSN (reaction-bonded silicon nitride) specimens prior to post-sintering, nitridation rates of more than 90% were achieved by multistep heating to $1400^{\circ}C$ in flowing 5%$H_2$/95%$N_2$; residual Si was not detected by XRD analysis. An increase in density was acquired with increasing z values in post-sintered specimens, and this tendency was explained by the presence of higher amounts of transient liquid phase at larger z values. Measured z values from the synthesized $\beta$-SiAlONs were similar to the values calculated for the starting compositions. Slight deviations in z values between measurements and calculations were rationalized by a reasonable application of the characteristics of the nitriding and post-sintering processes.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.261-269
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• 2021

This study examines the effect of block diversity on the risk of firms listed on the Korean Stock Exchange between 2010 and 2017. To examine the effect of block diversity on corporate risk, we measure block diversity in terms of a single component, portfolio size, by referring to prior literature. This diversity component accounts for the differences in portfolio size across corporate blocks. In line with existing research on corporate risk, we consider several variables to measure corporate risk: volatility, beta, and idiosyncratic risk. The results show a negative relationship between the size of a block shareholder's portfolio and corporate risk. We also show no difference in the effect of block diversity on the corporate risk between KOSPI and KOSDAQ. This implies that the difference in portfolio size among corporate blocks reduces corporate risk. This may be due to the effect of inter-block monitoring activities in the Korean securities market, which benefits from block diversity. This empirical result supports previous studies that predicted that block diversity would have beneficial influences on firm monitoring in general. This study is significant in that it analyzes the relationship between block diversity and firm risk and provides relevant information to business practitioners and investors.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.1028-1034
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• 2021

The effect of medium composition on enzyme and β-glucan production by Aspergillus oryzae KCCM 12698 was investigated. Brown rice, rice bran, nitrogen, and ascorbic acid are key components of the synthetic medium used in liquid-state fermentation. To determine the optimal concentrations of these components for enzyme and β-glucan production, we conducted one factor at a time experiments, which showed that the optimal concentrations were 30 g/l brown rice, 30 g/l rice bran, 10 g/l soytone, and 3 g/l ascorbic acid. Pretreatment of brown rice for 60 min prior to inoculation enhanced fungal biomass, while increasing the production of enzymes and β-glucan using solid-state fermentation. Maximum fungal biomass of 0.76 mg/g, amylase (26,551.03 U/g), protease (1,340.50 U/g), and β-glucan at 9.34% (w/w) were obtained during fermentation. Therefore, solid-state fermentation of brown rice is a process that could enhance yield and overall production of enzymes and β-glucan for use in various applications.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.1
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• pp.43-50
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• 2015

It has been shown that the extracts including eupatilin and quercetin-3-${\beta}$-D-glucuronopyranoside had mucoprotective effects on the esophagus and stomach through their antioxidant activities. This study was designed to investigate the anti-inflammatory effect of these flavonoid compounds in an animal model of inflammatory bowel disease induced by 2,4,6-trinitrobenzene sulfonic acid. Experimental colitis was induced by intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid. Extracts including eupatilin or quercetin-3-${\beta}$-D-glucuronopyranoside were orally administered to animals 48, 24, and 1 h prior to the induction of colitis and then again 24 h later. The animals were sacrificed 48 h after by 2,4,6-trinitrobenzene sulfonic acid treatment and the macroscopic appearance of the colonic lesions was scored in a blinded manner on a scale of 1 to 10. The inflammatory response to colitis induction was assessed by measuring myeloperoxidase activity, nitric oxide production, tumor necrosis factor-${\alpha}$ expression, total glutathione levels, and malondialdehyde concentrations in the colon. The results indicated that extracts including eupatilin and extracts including quercetin-3-${\beta}$-D-glucuronopyranoside dose-dependently improved the morphology of the lesions induced by 2,4,6-trinitrobenzene sulfonic acid and reduced the ulcer index accordingly. In addition, rats receiving extracts including eupatilin and extracts including quercetin-3-${\beta}$-D-glucuronopyranoside showed significantly decreased levels of mucosal myeloperoxidase activity, nitric oxide production, tumor necrosis factor-${\alpha}$ expression, and malondialdehyde levels, and increased total glutathione levels. Extracts including eupatilin and extracts including quercetin-3-${\beta}$-D-glucuronopyranoside ameliorated the inflammatory response and colonic injury in acute colitis by decreasing oxidative stress and neutrophil activation. Extracts including eupatilin and extracts including quercetin-3-${\beta}$-D-glucuronopyranoside may inhibit acute colitis.