• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.556-558
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• 2007

We used an elcosanoic acid material and the material was very famous as an thin film bio and insulating material. Eicosanoic acid monolayer was deposited by Langmuir-Blodgett (LB) technique and a subphase was a $CdCl_2$ solution as a $2\times10^{-4}mol/l$. Also, we used a bottom electrode as an $Al/Al_2O_3$ and a top electrode as a Al. When the positive and negative bias applied to the molecular device, the behavior shows that a tunnel switching characteristics. This results were analyzed regarding various mechanisms.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.635-642
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• 1996

Rice plants, cv. Koshihikari, were subjected to the biologically effective ultraviolet-B(UV-BBE) radiation {daily dose : 0.0 (control) and 11.5 (enhanced UV-B) KJ m-2} to investigate the effect of enhanced UV-B radiation on lipid peroxidation and to determine whether carotenoids and polyamines are involved in protection mechanism against enhanced UV-B radiation. Enhanced UV-B radiation significantly depressed plant dW weight. Malondialdehyde (MDA) content in rice leaves was increased by about 30% after 6 days of UV-B irradiation. Total carotenoid contents tended to slightly decrease with the UV-B irradiation, even though there was no significance. In rice leaves, 3 major polyamines, putrescine, spermidine and spermine are observed. All of the polyamine contents were increased with UV-B irradiation. The results suggest that enhanced UV- B radiation caused oxidative stress on lipids and that polyamines may serve as a biochemiral protectant against increased UV-B radiation in rice plants.

• Journal of Life Science
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• v.19 no.2
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• pp.179-184
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• 2009

Zinc is an essential trace element for human and plays an important biological role in antioxidant properties. We have been reported that zinc-enriched S. cerevisiae FF-10 contained 392 mg% in the YM basal and 3,193 mg% in the YM optimal medium. Antioxidative activity of FF-10 was tested in vitro models by DPPH (${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging activity and lipid peroxidation using linoleic acid (LA) and rat liver homogenate. DPPH radical scavenging activity was higher in the cell-free extract of FF-10 cultured in the YM optimal medium (YMOM) than that in the YM basal medium (YMBM). The inhibition activity of lipid peroxidation using rat liver homogenate was shown in the following order: BHT > YMOM > YMBM and these values were dose dependently. The lipid peroxidation of the control mixture by ferric thiocyanate and TBA methods using LA was increased rapidly as typical peroxidation curve of LA from one day and the antioxidation activity of the cell free extracts by cultivating FF-10 in the YMOM were higher than that of the YMBM. Result of this study indicate that the cell-free extracts containing a high intercellular zinc of S. cerevisiae FF-10 cultured in YMOM showed strong antioxidation capacities in DPPH radical scavenging activity and lipid peroxidation using LA and rat liver homogenate.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.177-185
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• 2017

In the present work, the interaction of fatty acid with vesicle membrane of phospholipids was investigated using 3 different kinds of fatty acids such as stearic acid (SA), oleic acid (OA) and linoleic acid (LA). Basically, the same trend has been found in 3 fatty acid systems. The addition of fatty acid produced a close packing of liposome due to the penetration of fatty acid molecules into liposome vesicles, which resulted in a decrease in size and an increase in zeta potential of liposome. However, excessive addition of fatty acid produced a transition from liposomes to aggregates of lipid particles having polymorphic structure. The membrane fluidity, characterized by measuring membrane deformability and fluorescence anisotropy ratio of liposomes, was in good agreement with measurement results of transmission electron microscopy (TEM) and particle size. The minimum size and closest packing of liposome with SA, OA and LA were found when the molar ratios of fatty acid to lecithin were 0.70, 0.50, and 0.25 respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.191-194
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• 1996

Maxwell displacement current clearly shows the onset of a first order phase transition from gaseous to gaseous-fluid phase, and polar ordering of liquid molecules in the solid phase coexisting with fluid. For further monolayer compression in the fluid/solid phase transition, the condensation of domains was suggested.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.291-291
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• 1994

Ibotonic acid와 FeCl$_3$ 투여군은 phosphate buffered saline을 투여한 대조군에 비해 흰쥐의 능동적 회피학습 습득율을 감소시켰고 해마영역의 과산화지질 형성도를 유의하게 증가시켰으며 acetylcholinesterase의 활성을 감소시켰으나 acetylcholine의 농도에는 별영향을 주지 못하였다. 이들 약물은 신경세포 지질막등에 작용하여 노인성 치매에서와 유사한 cholinergic신경계통에 neuronal degeneration을 유발하여 학습능력 감소를 유발한 것으로 보인다. 4,결론 중추 Cholinergic성 신경계활성의 변화와 뇌내 과산화지질의 과다 형성이 학습능력 감소 및 노인성치매의 원인이라고 말할수는 없지만 이러한 뇌내의 변화률이 치매과정과 연관성을 갖는 것으로 보여진다.

• The Journal of Internal Korean Medicine
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• v.19 no.2
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• pp.381-391
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• 1998

The present study was done to investigate the effects of Bombusae concretio Salicea (BCS) on cultured astrocyte cell system and lipid peroxidation in $A{\beta}25-35$ treatment conditions. Cell killing was significantly enhanced by addition of increasing concentrations of $A{\beta}25-35$. Pretreatment of BCS attenuated in cell killing enhanced by increasing concentrations of $A{\beta}25-35$. MDA level induced by $A{\beta}25-35$ treatment was significantly increased and the level was slightly reduced by pretreatment of BCS. The present study showed that $A{\beta}25-35$ strongly increased MDA level and the level was enhanced by addition of increasing concentrations of In conclusion, it was shown that $A{\beta}25-35$ is not only potent lipid peroxide inducer, but also cause protection of neurodegeneration induced by $A{\beta}25-35$. It can be concluded that the activation of antioxidative enzymes may be related to the inhibition of lipid peroxidative reactions. We cannot fully explain to effects of BCS at present; however, the ability of BCS to reduce cell killing and MDA level induced by $A{\beta}25-35$ suggest that BCS may be a protective agent for free radical generating compounds such as $A{\beta}25-35$.

• Biomedical Science Letters
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• v.6 no.4
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• pp.237-244
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• 2000

It has been reported that plasma membrane activity of the spermatozoa may be susceptible to be influenced by extracellular osmolality and such membranous changes involve infracellular molecular changes, special regard to the structure of membranous lipids, and the accompanying ion-channel of which are closely related with their fluidity of $Ca^{2+}$ and HCO$^{-}_{3}$. It is of common recognition that a certain kind of sterol acceptor player an important to induce lipid fluctuation of the sperm plasma membrane which have been influenced by BSA administration and came in effect to outflow of cholesterol from the spermatozoa and resulted in changes of ionic fluidity to facilitate adenylyl cyclase, and to induce protein tyrosine phosphorylation by increase of cAMP and activation of PKA. Thus it seems likely that an augmentation of the acrosomal reaction is closely related with protein tyrosine phosphorylation. The following experimental results were obtained in the present study; Under the high osmolality conditions, the spermatozoa motility declined significantly and the structural change of the plasma membrane diminished to confirm that the response degrees to the osmolality depended upon the water transfer volume through the plasma membrane and the changes of cellular volume. Those experimental results suggest that a physiological parameter such as low temperature condition played an important role for presentation of spermatozoa and that inducement of spermatozoa activation for reinforcement of protein tyrosine phosphorylation. On the other hand, it seemed likely that the BSA administration as one of sterol accepters might represent a key role also under the high osmolality condition and their result also suggests that osmolality change, special regard to high osmolality condition may play an important role also in the processes of signal transmission.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.341-341
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• 1994

생체막의 주요 구성성분인 인지질의 2번 위치에 결합한 불포화지방산은 각종 전이금속이나 각종 활성산소들의 공격을 쉽게 받아 지질과산화반응이 일어나서 생체에 유독한 화합물을 생성하게 된다. 생체는 이러한 기구의 해독을 위하여 크게 2가지 방어기전을 갖고 있다. 즉 Vitamin- C, $\alpha$-tocopherol, flavonoid, SOD, catalase 등과 같이 생성된 활성산소를 제거시키는 기구와. 활성산소에 의해 생성된 과산화물을 제거시키는 기구로 glutathione peroxidase (GPX)가 알려졌으며 GPX에 의해 독성이 낮은 수산화물까지 환원시키는 기구가 보고되었다. 그러나 인지질의 과산화물 그대로는 GPX의 기질이 쥘수 없으므로, 산화된 지방산을 절단하는 효소에 대한 기구의 해석이 요구되고 있다. 최근 여러질병에 관련되어 있는 인지질 2번위치의 지방산을 분해하는 phospholipase $A_2$ (PLA$_2$)가 과산화지질의 분해에 관여한다는 주장이 제기되었다. 따라서 본 연구에서는 rat liver microsome에 $CCl_4$투여로 일어나는 과산화반응에 있어서 PLA$_2$의 역할을 규명하기 위하여 본 실험을 행하였다.

• Electrical & Electronic Materials
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• v.9 no.5
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• pp.450-454
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• 1996

Maxwell-Displacement-Current(MDC) measuring technique has been applied to the study of monolayers of Dilauroylphosphatidylcholine (L-.alpha.-DLPC) and Dimyristoylphosphatidylcholine (L-.alpha.-DMPC). The displacement current was generated from monolayers on a water surface by monolayer compression. Displacement current was generated when the area per molecule was about 250.angs.$^{2}$, 280.angs.$^{2}$. Displacement current was generated in the gas state, gas/liquid state, and liquid state in the course of monolayer compression. The orientational change of molecules in monolayers was discussed on the basis of the MDCs obtained. Finally, we measured differential thermal analysis of sample.