• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.197-197
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• 2011

In this study, in contrast with cases in which Scanning Tunneling Microscopy (STM) tip-induced reactions were instigated by the tunneling electrons, the local electric field, or the mechanical force between a tip and a surface, we found that the tungsten oxide (WO3) covered tungsten (W) tip of a STM acted as a chemical catalyst for the S-H dissociative adsorption of phenylthiol and 1-octanethiol onto a Ge(100) surface. By varying the distance between the tip and the surface, the degree of the tip-catalyzed adsorption could be controlled. We have found that the thiol head-group is the critical functional group for this catalysis and the catalytic material is the WO3 layer of the tip. After removing the WO3 layer by field emission treatment, the catalytic activity of the tip has been lost. 3-mercapto isobutyric acid is a chiral bi-functional molecule which has two functional groups, carboxylic acid group and thiol group, at each end. 3-Mercapto Isobutyric Acid adsorbs at Ge(100) surface only through carboxylic acid group at room temperature and this adsorption was enhanced by the tunneling electrons between a STM tip and the surface. Using this enhancement, it is possible to make thiol group-terminated surface where we desire. On the other hand, surprisingly, the WO3 covered W tip of STM was found to act as a chemical catalyst to catalyze the adsorption of 3-mercapto isobutyric acid through thiol group at Ge(100) surface. Using this catalysis, it is possible to make carboxylic acid group-terminated surface where we want. This functional group-selective adsorption of bi-functional molecule using the catalysis may be used in positive lithographic methods to produce semiconductor substrate which is terminated by desired functional groups.

• Archives of Pharmacal Research
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• 제11권4호
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• pp.285-291
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• 1988

2-mercaptoethanol, thioglycolic acid, glutathione, 3-mercapto-1, 2-propanediol and 3-mercapto-2-butanol showed catalytic activities on the hydrolysis of $\alpha$-amino-phenylacetonitrile to phenylglycineamide at the rate of 12.19 $\times$ $10^{-2}$, 8.03 $\times$ $10^[-2}$, 6.83 $\times$ $10^{-2}$, 8.60 $\times$ $10^{-2}$ and 6.04 $\times$ $10^{-2}$ mM $min^{-1}$, respectively. hte hydrolysis rate was faster in buffer than in water. The hydrolysis of the nitrile compound to phenylglycine was limited.

• Current Research on Agriculture and Life Sciences
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• 제5권
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• pp.168-172
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• 1987

광학성체인 isopropylidene glycerols로 부터 mercaptogiycerol을 합성하였다. 1,2-Isopropylideneglycerol을 tosyl화 하고 다시 tosyl group을 thiolacetate로 치환하였다. 염기성 가수분해와 산화에 의해 1,1'-dithiobis-2,3-isopropylidene-2,3-propanediol이 생성되었다. 이 화합물을 mercaptogiycerol 합성을 위해 사용함으로써 1-decenyl lithium으로 cis-S-dec-1'-enyl-2,3-isopropylidene-1-mercapto-2,3-propanediol을 생성하였다. 본 생성물은 plasmalogenase용 thioplasmaloger 기질 조제에 사용된다.

• 폴리머
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• 제29권4호
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• pp.331-337
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• 2005

일반적으로 꼬리부분에 카복실산을 갖는 알칸티올레이트는 바이오 물질의 고정화 활성물질로 사용되고 있다. 본 연구에서는 알칸티올레이트의 전기적 성질과 물리적 안정성을 향상시키기 위해 공액구조를 갖는 방향족계 티올레이트를 사용하여 cytochrome c와 같은 단백질을 고정화시켰다. 방향족계 자기조립 단분자막의 패턴 형성은 다음과 같은 공정으로 행하였다. 4'-Mercapto-biphenyl-4-carboxylic acid와 4-mercapto-[1,1';4',1']terphenyl-4'-carboxylic acid와 같은 방향족 티올레이트 분자를 금 기판에 흡착시킨 다음 네거티브 마스크를 가지고 원자외선 조사에 의해 산화반응을 시킨 후 deioniz water로 현상하였다. 공액계 자기조립 단분자막의 패턴형성과 전기적 성질은 STM과 AFM 측정을 통해 조사하였다. 또한 cytochrome c 또는 ferrocene amide를 패턴이 형성된 금 기판에 고정화시킨 다음 cyclic voltammeoy 측정을 통해 공액계 방향족 티올레이트의 전기적 활성을 검토하였다.

• 대한화학회지
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• 제30권5호
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• pp.475-482
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• 1986

$Ni^{2+}$와 D-penicillamine사이의 착물형성반응에 대한 반응속도 및 평형에 관한 수용액중에서 실시하였다. 속도론적 실험은 압력-급변법을 사용하여 pH8~9범위에서 실시하였다. D-Penicillamine은 질소와 유황원자를 주게로 하여 pH＞9.2조건에서 $Ni^{2+}$이온에 배위하나 pH값 8.25∼9.07범위에서 총괄 안정도 상수값이 급격히 감소하며 비해리된 mercapto기가 결합에 참여하지 않는 것으로 밝혀졌다. 또한 이 착물 형성반응에 있어 율속단계는 $Ni^{2+}$이온의 내부 배위권으로 부터 물분자가 유리되는 과정임이 밝혀졌다.

• 대한화학회지
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• 제47권5호
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• pp.439-446
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• 2003

Au와 Ag 콜로이드 단일막 표면위에 흡착된 4-biphenylcarboxylic acid(BPCA)의 유도체인 4''-cyano-BPCA(c-BPCA), 4''-mercapto-BPCA(m-BPCA), 그리고 4''-amino-BPCA(a-BPCA)가 어떠한 배향을 하는지 알아보기 위해 표면증강라만(SER)분광법을 이용하여 연구하였다. 체계적인 분석을 위해 benzoic acid, biphenyl, 그리고 BPCA의 분자 배향에 대한 정보를 기본으로 위 분자들에 대한 흡착정보를 유추해내었다. 배향에 대한 정보를 위해 벤젠고리 모드, C-H 신축진동모드, carboxylate 음이온의 신축진동모드, 그리고 각각의 주요 작용기에 해당되는 모드들의 거동변화를 살펴보았으며 이로부터 m-BPCA는 thiol 그룹이 금속에 흡착되고 biphenyl 그룹이 기울어 서 있는 형태를 취하고 있고 나머지 분자들은 금속표면에 편평한 형태로 흡착됨을 알아내었다.

• 폴리머
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• 제26권4호
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• pp.445-451
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• 2002

본 연구에서는 실리카의 표면처리를 위해 실란 커플링제인, ${\gamma}$-methacryloxy propyl trimethoxy silane (MPS), ${\gamma}$-glycidoxy propyl trimethoxy silane (GPS), and ${\gamma}$-mercapto propyl trimethoxy silane (MCPS) 등을 사용하여 실리카 흡착특성과 기계적 계면물성에 대하여 고착하였다. 실란처리에 따른 실리카의 평형 확산압력, 표면 자유에너지, 비표면적을 BET법을 이용한 $N_2$/77 K 기체 흡착을 통하여 알아보았다. 본 실험결과 신란처리에 의해 실리카 표면에 도입된 비극성 관능기로 인해 실리카의 비표면적, 평형 확산압력, 표면 자유에너지의 비극성 요소가 증가하였으며 결과적으로 실리카/고무 복합재료의 기계적 계면 물성인 tearing energy ($G_{mc}$)가 향상되었음을 확인할 수 있었다. 그리고 MPS로 표면처리한 경우가 GPS, MCPS에 비해서 우수한 기계적 계면물성을 나타남을 관찰할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.2979-2984
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• 2014

Silver nanoparticles have been synthesized by liquid-phase and alcohol reduction methods. Silver-doped silica-complex nanoparticles were prepared using a sol-gel process. The formation, structure, morphology, and particle size of the nanoparticles have been studied using several techniques. Silver nanoparticles of size of 30-40 nm were formed successfully by alcohol reduction. TEM images show that both the concentration and the molecular weight of polyvinyl pyrrolidone (PVP) considerably affect the size of the emerging silver nanoparticles. The number of silver-doped silica-complex particles increased by a mercapto-group treatment that showed a narrower size distribution than that of silica treated with amino groups. The silver/polyester and silver-doped silica/polyester masterbatch chips showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli.

• 약학회지
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• 제47권6호
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• pp.450-455
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• 2003

Synthesis of (lR,5S,6S)-6-[(lR)-1-hydroxyethyl] -2-[(3S,5S)-5-(2-ethoxycarbonyl-1-moxy(hydroxy)iminoethyl)pyrrolidine-3-ylthio]-1-methylcarbapen-2-em-3-carboxylic acids (10a,l0b) were described. Methyl(2S,4S)-4-tritylthio-1-(allyloxycarbonyl)pyrrolidine-2-carboxyla late (I) was prepared from trans-4-hydroxy-L-proline with (2S,4R)-abs olute configuration as starting material. (2S,4S)-1-allyloxycarbonyl-2-(2-ethoxycarbonyl-hydroxy(methoxy )iminoethyl)-4-mercapto- pyrrolidines (6,7) were obtained from the tritylthio compound (I). (lR,5S,6S)-6-[(lR)-1-hydroxyethyl]-2-[(3S,5S)-5-(2-ethoxycarbonyl-1-methoxy(hydroxy)imino-ethyl)pyrrolidine-3-ylthio]-1-methylcarbapem-2-em-3-carboxylic acids (10a,10b) were obtained by the coupling reaction with carbapenem diphenylphosphates (8) and pyrrolidine-thiol moiety (6,7). Their in vitro antibacterial activities against both Gram-positive and Gram-negative were tested. Compounds ( 10a,10b) showed potent antibacterial activity except pseudomonas aerusinosa.

• 약학회지
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• 제40권5호
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• pp.550-557
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• 1996

One of therapeutics in liver disease (morbus wilson) is D-penicillamin (D-pen: D-3-mercapto-valin). Especially the cross-linking of collagen molecules could be inhibited by D-pe n in extracellular space. In this study we investigated the antifibrotic effects of D-pen in rats that were induced the liver fibrosis by bile duct ligation and scission (BDL/S). Rats were treated for 4 weeks with D-pen after BDL/S operation or sham operation. The balance between fibrogenesis-marker (PNIIIP) and the fibrolysis-maker (PNIVP) were observed in sera by RIA (radioimmunoassay), and the parameter of collagen deposition in liver tissue (hydroxyproline: HYP) was measured by colorimetry. The weight of liver in BDL/S operated group was increased significantly in compared with sham operation group (15.2g${\pm}$1.1, vs 11.9g${\pm}$3.9: p<0.005, p<0.05). The rats group treated by D-pen showed the lower level of PNIIIP (6.7ng/ml${\pm}$1.5, vs 9.5ng/ml${\pm}$2.8) and the higher value of PIVCP (14.0ng/ml${\pm}$1.9, vs 7.9ng/ml${\pm}$1.5) in sera that compared to untreated rats. The content of HYP was decreased by 141% in BDL/S with D-pen treated group than that of it in BDL/S group. No correlation was revealed between collagen parameters in sera and HYP in liver tissue of BDL/S operated and D-pen treated rats. The group treated with D-pen showed the lower value of clinical biochemistry parameters (GOT: glutamate oxalacetate transaminase, Total-Bilirubin) in compared with only BDL/S operated rats, but the value of GPT (glutamate pyruvate transaminase) and Alkaline phosphatase in two BDL/S groups was nearly same. In the histological finding, we observed mild bile duct proliferation, weak inflammation and fibrosis in BDL/S with D-pen treated group, but BDL/S operated group showed the formation of septum (island of hepatocytes), massive bile duct proliferation. This result represents that the BDL/S operation induces liver fibrosis (cirrhosis) in 4 weeks, and D-pen inhibits the synthesis of collagen weakly and stimulates the degradation of collagen in the extracellular space. We conclude that the monitoring of PNIIIP, PIVCP in sera is useful parameter for screening of antifibrotic effect, and D-pen delay the liver fibrosis.