• 대한의생명과학회지
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• 제17권2호
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• pp.167-171
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• 2011

[ ${\alpha}$ ]synuclein (${\alpha}$-syn) is implicated in the pathogenesis of Parkinson's disease (PD) and other related diseases. We have previously reported that ${\alpha}$-syn binds to the cell membranes in a transient and reversible manner. However, little is known about the physiologic function and/or consequence of this association. Here, we examined whether chemically induced perturbations to the cellular membranes enhance the binding of ${\alpha}$-syn, based on hypothesis that ${\alpha}$-syn may play a role in maintenance of membrane integrity or repair. We induced membrane perturbations or alterations in ${\alpha}$-syn-overexpressing human neuroblastoma cells (SH-SY5Y) by treating the cells with hydrogen peroxide ($H_2O_2$) or oleic acid. In addition, membranes fractionated from these cells were perturbed by treating them with proteinase K or chloroform. Dynamic interaction of ${\alpha}$-syn to the membranes was analyzed by the chemical cross-linking assay that we developed in the previous study. We found that membrane interaction of ${\alpha}$-syn was increased upon treatment with membrane-perturbing reagents in a dose and time dependent manner. These results suggest that perturbations in the cellular membranes cause increased binding of ${\alpha}$-syn, and this may have significant implication in the physiological function of ${\alpha}$-syn in cells.

• 대한의생명과학회지
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• 제18권4호
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• pp.329-337
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• 2012

${\alpha}$-synuclein (${\alpha}$-syn) is known to be implicated in the pathogenesis of Parkinson's disease and transiently bind to biological vesicles. In this study, we examined the effect of molecular crowding on the interaction of ${\alpha}$-syn with biological vesicles by using inert polymers since the environment of proteins in cells are crowded with other macromolecules. The addition of different polymers including polyethylene glycol, dextran, and ficoll enhanced the binding of ${\alpha}$-syn to vesicles in a concentration-dependent manner and the association of ${\alpha}$-syn with vesicle was proportionally augmented by increased expression of ${\alpha}$-syn. However, molecular crowding had a neglectable effect on the vesicle binding of ${\alpha}$-syn mutants (A30P, TG6), which has been reported to show impaired vesicle binding capacity. These results suggest that transient interaction of ${\alpha}$-syn with vesicles occurs more commonly in cells than expected implying interaction with vesicles may be one of the physiological processes in which ${\alpha}$-syn is involved.

• Bulletin of the Korean Chemical Society
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• 제16권1호
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• pp.12-16
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• 1995

The diastereoselectivity of addition reaction of crotylmetal reagents to cobalt-complexed acetylenic aldehydes and metal-free aldehydes was examined. The anti-diastereomer was the predominant product when the crotyl metallics were Cr, Sn, and Zr. In THF, the uncomplexed aldehydes normally gave higher anti-diastereoselectivity. However, the cobalt-complex of silicon-substituted propynals with three bulky substituents produced increased proportions of syn-diastereomer. In DMF, the selectivity shifted towards syn-isomer except in the case of dimethylphenylsilyl substituent. When tributylstannane was used in the presence of BF3 etherate, moderate syn- selectivity was observed with uncomplexed aldehydes, but only decomposed products from complexed aldehydes.

• 한국안전학회지
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• 제17권2호
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• pp.32-38
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• 2002

In this paper, a new approach for the SynRM(Synchronous Reluctance Motor) control which ensures producing MTPA(Maximum Torque per Ampere) over the entire field weakening region is presented. In addition, this paper presents a speed sensorless control scheme of SynRM using flux observer. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The validity of the proposed scheme is verified through simulation.

• 전기학회논문지P
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• 제54권4호
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• pp.185-191
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• 2005

In this paper, a new approach for the Synchronous Reluctance Motor control which ensures producing Maximum Torque per Ampere(MTPA) over the entire field weakening region is presented. In addition, This paper presents a speed sensorless control scheme of SynRM using artificial neural network. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The proposed scheme is verified validity through simulation.

• Journal of Photoscience
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• 제12권3호
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• pp.185-186
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• 2005

The electronic structure of photoskinsensitizing psoralens has been investigated by the ab initio calculations. The photocycloaddition reaction of 8-methoxypsoralen with thymine is studied as a model for the photosensitizing reaction of psoralen with DNA bases. The photocycloadduct was inferred to be a C4-cycloaddition product with the stereochemistry of Syn, H-H, Syn, H-T formed through [2+2] addition reaction between the 3,4-double bonds of 8-methoxypsoralen and 5,6-double bond of thymine base.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.311-315
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• 2007

In this paper, a new approach for the Synchronous Reluctance Motor control which ensures producing Maximum Torque per Ampere(MTPA) over the entire field weakening region is presented. In addition, This paper presents a speed sensorless control scheme of SynRM using artificial neural network. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved The proposed scheme is verified validity through simulation.

• 한국세라믹학회지
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• 제38권2호
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• pp.238-238
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• 2001

본 연구에서는 kaolin을 이용하여 반기상법, gel coating법, seed 첨가법으로 mullite를 합성하였으며 mullite 15 wt%를 고 알루미나질 내화물 원료에 첨가하여 내화물 시편을 제조하였다. 제조된 시편의 물성을 분석한 결과 seed 첨가법으로 제조된 mullite를 첨가한 시편의 물성이 338.60 MPa의 꺾임강도와 9,427 kgf/㎠의 압축강도값을 나타내었다. 제조된 시편의 내화도 및 잔존선팽창수축률을 측정한 결과 나머지 두가지 방법으로 합성한 mullite나 일반적인 고 알루미나질 내화물에 비하여 좋은 특성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1325-1327
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• 2002

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1456-1458
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• 2005

In this paper, a new approach for the synchronous reluctance motor control which ensures producing maximum torque per ampere(MIPA) over the entire field weakening region is presented. In addition, This paper presents a speed sensorless control scheme of SynRM using artificial neural network. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The proposed scheme is verified validity through simulation.