• 한국식품영양과학회지
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• 제26권5호
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• pp.814-821
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• 1997

Kimchi is composed of many ingredients such as Chinese cabbage, garlic, ginger, and red pepper and fermented fish extract. Some of them were known to have antioxidative activities due to their scavenging effect against reactive oxygen species(ROS). To study the health effects of kimchi on human skin cells, keratinocyte(A431, epidermoid carcinoma, human) and fibroblast(CCD-986SK, normal control, human) were cultured in oxidative stress condition provoked by paraquat, a superoxide anion generator, and hydrogen peroxide in the absence and presence of kimchi extract. The survival rate of keratinocyte was greatly reduced when exposed over 1mM concentration of hydrogen peroxide($H_{2}O_{2}$), but cytotoxicity of $H_{2}O_{2}$ was significantly reduced by kimchi extracts on cells. Especially 2 week-fermented kimchi decreased remarkably the cytotoxicity by $H_{2}O_{2}$ to keratinocyte cells. Over 1mM of paraquat concentration showed strong cell toxicity on keratinocyte, but the extracts from kimchi fermented for 1, 2 and 3 weeks showed protective effects in order. Fibroblast cells were significantly affected by $H_{2}O_{2}$ as were keratinocyte cells. Although almost all extacts of kimchi of different fermentation periods showed protective effect against cell killing at 0.5mM concentration of $H_{2}O_{2}$ week-fermented kimchi extract showed the strongest protective effect on fibroblast cells treated with 1mM $H_{2}O_{2}$ for either 1 day or 4 days. However most of kimchi extracts showed weak preventive effect or no effect on oxidative stress produced by paraquat. In conclusion, 2 week-fermented kimchi extract seems to have the best potential in preventing skin cells against oxidative damage which might be related to their scavenging effects of kimchi components produced during their fermentation process.

• BMB Reports
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• 제30권1호
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• pp.13-17
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• 1997

The inhibitory effect of herbicides such as sulfonylurea derivatives, imidazolinones and pyrimidylsalicylate has been examined on the purified valine sensitive acetolactate synthase (ALS) from Serratia marcescens. The concentration of sulfometuron methyl which inhibits 50% of the ALS activity was 2.5 mM. The required concentrations of triasulfuron, primisulfuron methyl and imazaquin for the 50% inhibition of the ALS activity were 1 mM. The resistance of Serratia ALS to sulfometuron methyl, imazapyr and imazaquin is similar to that of E. coli ALS 1. However, pyrimidylsalicylate showed a potent inhibitory effect on the Serratia ALS almost 13 times more potent than on E. coli ALS II, which is known as herbicide-sensitive isozyme. The inhibitory mode was competitive against pyruvate. 150 value was determined to be $17{\mu}M$ in an assay mixture containing 20 mM pyruvate, and the $K_1$, value was calculated to be $0.4{\mu}m$ from the modified double reciprocal plot of 1/V versus $1/S^2$.

• Animal cells and systems
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• 제4권3호
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• pp.293-297
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• 2000

The present investigation was performed to elucidate the effect of pretreatment with low dose ultraviolet radiation (UV) and ethyl methanesulfonate (EMS) on cell survival by trypan blue dye exclusion method and plasma membrane glycoconjugates by lectin-cytochemistry in sarcoma 180 (S180) cells. Pretreatment with 2 J/$m^2$ UV or 2 mM EMS increased the percentage of survival of cells subsequently treated with high dose UV (10 or 20 J/$m^2$) or EMS (10 or 20 mM), respectively. Staining intensity of concanavalin A (Con A) of the cells pretreated with 2J/$m^2$ UV or 2 mM EMS and subsequently treated with 10 or 20 mM EMS was stronger than that of the cellstreated with 10 or 20 mM EMS. These results suggest that there is an adaptive response on cell survival to EMS or UV in S180 cells. And the results show a change in mannose-containing glycoconjugates of plasma membrane in S180 cells pretreated with EMS or UV and subsequently treated with EMS.

• 한국전기전자재료학회논문지
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• 제24권8호
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• pp.669-673
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• 2011

The charged particle type display is a kind of the reflectivity type display and shows an image by absorption and reflection of external light source, which has keep an image without additional electric power because of bistability. In this paper, we made a device whose cell gap is $56\;{\mu}m$ and also analyzed driving and memory characteristics by applied driving voltages. As a result, we found that the driving voltage and memory effect depend on q/m(charge to mass ratio) of charged particle. In this case of breakdown voltage, the devices showed degradation of reflectivity and memory effect due to irregular movement of overcharged particles. In addition, contrast ratio of the device varies with memory effect. Thus, we consider that device needs uniform q/m for improvement of electric and optical properties and memory effect.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 하계학술발표회
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• pp.162-163
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• 2000

We have observed the short-channel effect, narrow-channel effect and small-geometry effect in terms of a variation of the threshold voltage. For a short-channel effect the threshold voltage was largely determined by the DIBL effect which stimulates more carrier injection in the channel by reducing the potential barrier between the source and channel. The effect becomes more significant for a shorter-channel device. However, the potential, field and current density distributions in the channel along the transverse direction showed a better uniformity for shorter-channel devices under the same voltage conditions. The uniformity of the current density distribution near the drain on the potential minimum point becomes worse with increasing the drain voltage due to the enhanced DIBL effect. This means that considerations for channel-width effect should be given due to the variation of the channel distributions for short-channel devices. For CCDs which are always operated at a pinch-off state the channel uniformity thus becomes significant since they often use a device structure with a channel length of > 4 ${\mu}{\textrm}{m}$ and a very high drain (or diffusion) voltage. (omitted)

• 대한소아치과학회지
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• 제47권2호
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• pp.120-127
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• 2020

이 연구의 목적은 치면착색제인 10 - 20 mM erythrosine을 광감각제로 사용한 광역동 치료의 항균 효과를 평가하는 것이다. Streptococcus mutans, Lactobacillus casei, Candida albicans를 포함하는 다종 우식원성 세균막을 hydroxyapatite disc에 형성하였다. 광감각제로 20 μM, 10 mM, 20 mM erythrosine을 3분간 적용 후 24초 동안 광조사를 시행하였다. 각 실험군의 Colony-forming unit (CFU)을 측정하고 세균막을 Confocal laser scanning microscopy (CLSM)을 이용하여 관찰하였다. 10 - 20 mM erythrosine을 광감각제로 사용한 광역동 치료 실험군에서 CFU의 현저한 감소가 관찰되었고, 그 결과는 CLSM 관찰에서도 확인되었다. 이번 연구를 통해 치과 임상에서 사용되는 치면착색제를 광감각제로 이용한 광역동 치료의 높은 항균효과를 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1605-1612
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• 2006

Interleukin (IL)-18, a member of the family of IL-l cytokine, is one of the principal inducers of $interferon-{\gamma}(IFN-{\gamma})$ in T lymphocytes and natural killer cells. The objective of the present study was to evaluate the effect of IL-18 on the expression of chemokine IP-10 (CXCL-10) mRNA in mouse peritoneal macrophages. IL-18 had very weak direct effect or synergistic effect with IL-12 on the expression of IP-10 mRNA in C57BL/6 mouse peritoneal macrophages. However, IL-18 pretreatment was found to playa cooperative role in the expression of lipopolysaccharide (LPS)-induced IP-10 mRNA. For the expression of LPS-induced IP-10 mRNA, the synergistic effect was detected after 16 h of IL-18 pretreatment prior to LPS stimulation. The expression level of CD14 in cells stimulated with LPS was not changed by IL-18 pretreatment, and the level of $IFN-{\gamma}$ production during IL-18 pretreatment plus LPS stimulation was barely discernible ($0.36{\pm}0.31pg/ml$). Namely, the synergistic effect of IL-18 pretreatment was not related to a change of LPS receptor, CD14 expression, and the production of $IFN-{\gamma}$ by the interaction between IL-18 and LPS. The synergistic effect of IL-18 pretreatment on the expression of LPS-induced IP-10 was related to not NF-kB but AP-1 activation, and associated with the extracellular signal-regulated kinase (ERK) pathway, one of the mitogen-activated protein kinase signaling pathways. These results provide useful information that may elucidate the mechanisms underlying the effect of IL-18 on the expression of IP-10 mRNA.

• 열처리공학회지
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• 제22권5호
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• pp.275-281
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• 2009

The microstructure of copper films prepared by a sputtering apparatus, which was fabricated to enhance the shadowing effect, was investigated by scanning electron microscopy. Black copper films were deposited on copper wires at an Ar pressure of 10 Pa. The black films had an extremely porous structure composed of separated columns. This structure is quite similar to that of black titanium films prepared by cylindrical magnetron sputtering. These results suggest that the porous structure composed of separated columns is easily formed for metal films by enhancing the shadowing effect.

• Journal of Acupuncture Research
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• 제21권3호
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• pp.235-248
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• 2004

It has been investigated about aging theory. However, aging mechanism still remains to be unknown. Aging and aging related diseases might be due to oxidative damage and these were modifiable by genetic and environmental factors. For designing an optimal medical treatment and countermeasure against aging and aging related disease, it is necessary to understand the aging mechanism. Acetylcholine(Ach) plays an important role in memory. If someone doesn't have enough Ach, he has a tendency to catch a Alzheimer's disease. Corydalis tuber has been clinically used to treat heart disease, gastrointestinal disease and other diseases including endocrine disease in Oriental medicine. The purpose of this article is to investigate the inhibitory effect on Acetylcholinesterase and scavenging effects on NO, DPPH of Corydalis tuber Acua-acupuncture solution(CTAS). The results are summerised as follows; 1. There is a significant inhibitory effect of $0.01mg/m{\ell}$ CTAS group at 20, 30, 60 minutes and $0.1mg/m{\ell}$ CTAS group at 10, 20, 30, 60 minutes on AchE. 2. There is no significant scavenging effect of CTAS on NO. 3. There is a significant scavenging effect of $0.1mg/m{\ell}$ and $0.01mg/m{\ell}$ CTAS group at 10 minutes but there is no significant scavenging effect at 20, 30, 60 minutes on DPPH. There is a significant scavenging effect of $1mg/m{\ell}$ CTAS group at 10, 20, 30, 60 minutes on DPPH.

• 대한기계학회논문집
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• 제14권2호
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• pp.453-462
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• 1990

The interaction of forced convection-conduction with thermal radiation in laminar boundary layer over a plate fin is studied numerically. The analysis is based on complete solution whereby the heat conduction equation for the fin is solved simultaneously with the conservation equations for mass, momentum and energy in the fluid boundary layer adjacent to the fin. The fluid is a gray medium and diffusion(Rosseland) approximation is used to describe the radiative heat flux in the energy equation. The resulting boundary value problem are convection-conduction parameter N$_{c}$ and radiation-conduction parameter m, Prandtl number Pr. Numerical results are presented for gases with the Prandtl numbers of 0.7 & 5 with values of N$_{c}$ and M ranging from 0 to 10 respectively. The object of this study is to provide the first results on forced convection-radiation interaction in boundary layer flow over a semi-infinite flay plate which can be used for comparisons with future studies that will consider a more accurate expression for the radiative heat flux. The agreement of the results from the complete solution presented by E. M. Sparrow and those from this paper for the special case of M=0 is good. The overall rate of heat transfer from the fin considering radiative effect is higher than that from the fin neglecting radiative effect. The local heat transfer coefficient with radiative effect is higher than that without radiative effect. In the direction from tip to base, those coefficients decrease at first, attain minimum, and then increase. The larger values of N$_{c}$ M, Pr give rise to larger fin temperature variations and the fin temperature without radiative effect is always higher than that with radiative effect.