• 제목/요약/키워드: Thiol

검색결과 426건 처리시간 0.032초

Novel Patterning of Gold Using Spin-Coatable Gold Electron-Beam Resist

  • Kim, Ki-Chul;Lee, Im-Bok;Kang, Dae-Joon;Maeng, Sung-Lyul
    • ETRI Journal
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    • 제29권6호
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    • pp.814-816
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    • 2007
  • Conventional lithography methods of gold patterning are based on deposition and lift-off or deposition and etching. In this letter, we demonstrate a novel method of gold patterning using spin-coatable gold electron-beam resist which is functionalized gold nanocrystals with amine ligands. Amine-stabilized gold electron beam resist exhibits good sensitivity, 3.0 mC/$cm^2$, compared to that of thiol-stabilized gold electron beam resists. The proposed method reduces the number of processing steps and provides greater freedom in the patterning of complex nanostructures.

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메주 유래의 Syncephalastrum racemosum PDA 132-2가 생산하는 Protease의 정제 및 특성 (Purification and Characteristics of Protease Produced by Syncephalastrum racemosum PDA 132-2 from Korean Traditional Meju)

  • 유진영;임성일
    • 한국식품영양과학회지
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    • 제28권5호
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    • pp.1010-1016
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    • 1999
  • Protease related mold was isolated and selected as a starter culture for commercial production of meju. Isolated microorganism was identified as Syncephalastrum racemosum PDA 132 2. To obtain basic data about protease for production of soybean peptides and application of the strain in meju fermentation, we extrated and purified protease and charateristics of the enzyme were investigated. The optimum condition for the production of enzyme was pH 4.0, 30oC, 5 days. The protease was purified 19.7 folds by gel filtration and ion exchange chromatography and specific activity was 12.4unit/mg. The purified enzyme was 34kDa in size, thiol protease(100% inhibited by PCMB), and was acidic protease(stable between pH 2.0~5.0). Vmax of the enzyme was 2.14 g/min which was lower(1/50) than that of by Asp. wentti and B. subtilis.

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Synthesis and characterization of new liquid crystalline polymer for in-cell retardation film

  • Wang, Lei;Lim, Yeong-Jin;Kang, Hoon;Choi, Min-Oh;Lee, Seung-Hee;Lee, Myong-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1409-1411
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    • 2006
  • A new rod-like liquid crystalline monomer having divinyl terminal groups was synthesized and polymerized by using thiol-ene UV polymerization technique. High quality thin film with good retardation value was prepared on a rubbed alignment layer without the inert gas purging. The retardation value of the resulting film was controlled by experimental conditions such as spin speed, concentration, and spin time. From the retardation value and thickness measurement, ${\bigtriangleup}n$ was calculated to be 0.169 for the resulting film having thickness of 815.1 nm.

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STM을 이용한 Dipyridinium 유기 단분자막의 모폴로지 관찰 및 전기적 특성 연구 (Study on the Mophology Observation and Electrical Properties of Dipyridinium Organic Monolayer Using STM)

  • 이남석;신훈규;권영수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권2호
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    • pp.51-54
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    • 2005
  • In this work, the attempt has been made to investigate the morphology of self-assembled dipyridinium dithioacetate on Au(111) substrate by Scanning Tunneling Microscopy(STM). Also, we measured electrical properties(I-V) using Scanning Tunneling Spectroscopy(STS). Sample used in this experiment is dipyridinium dithioacetate, which contains thiol functional group, this structure that can be self-assembled easily to Au(111) substrate. The self-assembly procedure was used for two different concentrations, 0.5 mM/ml and 1 mM/ml. Dilute density of sample by 0.5 mM/ml, 1 mM/ml and observed dipyridinium dithioacetate's image by STM after self-assembled on Au(111) substrate. The structure of STM tip-SAMs-Au(111) substrate has been used measurement for electrical properties(I-V) using STS. The current-voltage(I-V) measurement result, observed negative differential resistance(NDR) properties.

이온성 액체를 이용한 수계 양자 점 합성 (Aqueous synthesis of quantum dots using functionalized ionic liquid)

  • 최숙영;김태영;서광석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.254-254
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    • 2010
  • We report aqueous synthesis of cadmium telluride (CdTe) quantum dots(QDs) using imidazolium-based ionic liquids with various functional groups. The functinalized ionic liquids were designed to have thiol groups, and then phase transfer with aqueous or organic solvents can be adjusted by changing side chain lengths of the cation and the choice of anion. The quantum yield was obtained IL-functionalized CdTe QDs reached up to 40% by post-treatment method.

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페니실린으로부터 유도된 4-Mercaptoazetidin-2-one 의 반응성 연구 (A Study on the Reactivites of a Penicillin-derived 4-Mercaptoazetidin-2-one)

  • 정규현;김형태;허홍일
    • 대한화학회지
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    • 제38권5호
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    • pp.372-376
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    • 1994
  • Penicillin으로부터 유도된 4-mercaptoazetidin-2-one(2a)은 염기조건에서 불안정하지만 Et3N이나 pyridine 염기하에서 acetyl chloride, methyl chloroformate, ethyl iodoacetate, diethyl azodicarboxylate 등의 친전자체와 반응하여 sulfur에 acetyl, methoxycarbonyl, ethoxycarbonylmethyl, diethoxycarbonylhydrazineo원자단이 부착된 화합물이 된다. 반면 thiol의 methylation은 methyl iodide와의 반응으로 얻을 수 없고 diazomethane을 사용해야 한다. 또한 화합물 2a의 이성질체인 화합물 3a의 반응성도 화합물 2a와 거의 비슷하다.

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Nitrofuran계 의약품의 안전성에 관한 착물화학적 연구(I) Mo-thiol착물에 의한 Nitrofurazone의 촉매환원 (Coordination Chemical Approach to the Safety of Nitrofuran Drugs I. Reduction of Nitrofurazone Catalyzed by Molybdothiol Complexes)

  • 김종윤;김보길
    • 약학회지
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    • 제21권4호
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    • pp.184-192
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    • 1977
  • In the presence of dithionite, two kinds of molybdothiol complexes, particularly isolated Mo-cysteine complexes, used as models for xanthine oxidase or aldehyde oxidase exhibited catalytic activity on the reduction of nitrofurazone to its amino derivative. Of the two Mo-cysteine complexes, the activity of oxo-bridged one was apparently greater than that of sulfido-bridged one. The promoting effect was hardly shown by added cofactors or their replacements of the enzymes. The catalyzed reduction is considered to take place by consecutive direct two-electron transfer mechanism from catalytically active reduced form of the molybdothiol complexes to nitrofurazone and the probable intermediates.

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Redox-modulation of NMDA receptor activity by nitric oxide congeners

  • Kim, Won-Ki;Stuart A. Lipton
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 제3회 추계심포지움
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    • pp.125-132
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    • 1995
  • In neurons, nitric oxide(NO) is produced by neuronal nitric oxide synthase following stimulation of N-methyl-D-aspartate(NMDA) receptors and the subsequent influx of Ca$\^$2+/. NO, induced in this manner, reportedly plays critical roles in neuronal plasticity, including neurite outgrowth, synaptic transmission, and long-term potentiation(LTP) (1-7). However, excessive activation of NMDA receptors has also been shown to be associated with various neurological disorders, including focal ischemia, epilepsy, trauma, neuropathic pain and chronic neurodegenerative maladies, such as Parkinson's disease, Hungtington's disease and amyotrophic lateral sclerosis(8). The paradox that nitric oxide(NO) has both neuroprotective and neurodestructive effects may be explained, at least in part, by the finding that NO effects on neurons are dependent on the redox state. This claim may be supported by the recent finding that tissue concentrations of cysteine approach 700 ${\mu}$M in settings of cerebral ischemia (9), levels of thiol that is expected to influence both the redox state of the system and the NO group itself(10).

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Field Emission from Single-Walled Carbon Nanotubes Aligned on a Gold Plate using Self-Assembly Monolayer

  • Lee, Ok-Joo;Jeong, Soo-Hwan;Lee, Kun-Hong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.305-308
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    • 2002
  • Field emission from single-walled carbon nanotubes (SWNTs) aligned on a patterned gold surface is reported. The SWNTs emitters were prepared at room temperature by a self-assembly monolayer technique. SWNTs were cut into sub-micron length by sonication in an acidic solution. Cut SWNTs were attached on the gold surface by the reaction between the thiol groups and the gold surface. The field emission measurement showed that the turn-on field was 4.8 $V/{\mu}m$ at the emission current density of 10 ${\mu}A/cm^2$. The current density was 0.5 $mA/cm^2$ at 6.6 $V/{\mu}m$. This approach provides a novel route for fabricating CNT-based field emission displays.

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수정진동자를 이용한 Viologen Self-Assembly 단분자막의 전기화학적 특성 (Electrochemical Properties of Viologen Self-Assembly Monolayer Using QCM)

  • 옥진영;신훈규;박재철;장정수;권영수
    • 한국전기전자재료학회논문지
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    • 제16권6호
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    • pp.496-500
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    • 2003
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface[1]. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency(ΔF) and resonant resistance(R). The redox process of viologen was observed with resonant frequency(ΔF).