• 제목/요약/키워드: substrate interaction

검색결과 364건 처리시간 0.03초

Discrimination of JNK3 bound small molecules by saturation transfer difference NMR experiments

  • Lim, Jong-Soo;Ahn, Hee-Chul
    • 한국자기공명학회논문지
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    • 제16권1호
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    • pp.67-77
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    • 2012
  • The small molecule binding to the c-Jun N-terminal kinase 3 (JNK3) was examined by the measurements of saturation transfer difference (STD) NMR experiments. The STD NMR experiment of ATP added to JNK3 clearly showed the binding of the nucleotide to the kinase. The STD NMR spectrum of dNTPs added to JNK3 discriminated the kinase-bound nucleotide from the unbound ones. After the five-fold addition of ATP to the dNTPs and JNK3 mixture, only signals of the cognate substrate of JNK3, ATP, were observed from the STD NMR experiment. These results signify that by the STD NMR the small molecules bound to JNK3 can be discriminated from the pool of the unbound molecules. Furthermore the binding mode of the small molecule to JNK3 can be determined by the competition experiments with ATP.

Functional Layer-by-Layer Assembled Multilayers Based on Nucleophilic Substitution reaction

  • 조진한
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.9.2-9.2
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    • 2011
  • Ultrathin polyelectrolyte (PE) multilayer films prepared by the versatile layer-by layer (LbL) assembly method have been utilized for the preparation of light-emitting diodes, electrochromic, membrane, and drug delivery system, as well as for selective area patterning and particle surface modification because the various materials with specific properties can be inserted into the film with nano-level thickness irrespective of the size or the shape of substrate. Since the introduction of the LbL technique in 1991 by Decher and Hong, various hydrophilic materials can be inserted within LbL films through complementary interactions (i.e., electrostatic, hydrogen-bonding or covalent interaction). In this study, it is demonstrated that LbL SA multilayer films based on nucleophilic substitution reaction can allow the preparation of the highly efficient magnetic and/or optical films and nonvolatile memory devices.

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4단자 GaAs MESFET Model의 SPICE 탑재 (Implementation of the Four-Terminal GaAs MESFET Model on SPICE)

  • 조남홍;곽계달
    • 전자공학회논문지A
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    • 제31A권1호
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    • pp.39-47
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    • 1994
  • The drain current reduction effect due to the side-gating phenomena resulted from interaction between the neighbor gates is lead to degradation of circuit performance. In this paper, these effect were modelized for circuit simulation with the shift of threshold voltage resulting from negative charge formation and the analysis of substrate leakage current resulting trapping effect. To remove dificiencies of the conventional three terminal structure, these model were implemented in SPICE with the four terminal structure, and then the constructed environment enables the simulation of circuit performance degradation resulted from side-gating effect. The validity of implemented model is proved by comparisoin with experiment data.

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Finite Element Analysis of Electrical Double Layers near Triple Contact Lines

  • Kang Kwan Hyoung;Kang In Seok;Lee Choung Mook
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.491-494
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    • 2002
  • To assess the electrostatic interaction of surfaces at the triple contact line, the electrostatic field is analyzed by using the finite element method. The Helmholtz free energy is used as a functional which should be minimized under an equilibrium condition. The numerical results are compared with the nonlinear analytical solution for a two-dimensional charged interface and linear solution for a wedge shaped geometry, which shows fairly good agreement. The method is applied to the analysis of electrostatic influence on the contact angle on a charged substrate. The excess free energy found to increase drastically as the contact angle approaches to zero. This excess free energy Plays an opposite role to the Primary electrocapillary effect, as the contact angle gets smaller. This enables an alternative explanation for the contact-angle saturation phenomenon occurring in electrical control of surface tension and contact angle.

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Beyond the Grating Equation: Light Patterns in the Era of Diffractive Optics

  • O′Shea, D.C.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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    • pp.1-1
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    • 2000
  • The interaction of light with periodic patterns generates beautiful color patterns and interesting applications. The basic equation for understanding this phenomena is the grating equation. It tells us the angles, relative to a perpendicular to a grating with a specific period, into which light of a specific wavelength will be diffracted. But what it does not tell us is how much light will be directed into the various "orders" of the grating. It was found that by controlling the shape of the diamond point used to cut the periodic structure into the substrate, a traditional grating could be made to direct most of the light diffracted from it into a single order. This type of grating is referred to as a "blazed" grating. (omitted); grating. (omitted)

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XPS Characterization and Morphology of MgO Thin Films grown on Single-Crystalline Diamond (100)

  • Lee, S.M.;Ito, T.;Murakami, H.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.19-27
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    • 2003
  • Morphology and composition of MgO films grown on single-crystalline diamond (100) have been studied. MgO thin films were deposited in the substrate temperature range from room temperature (RT) to 723K by means of electron beam evaporation using MgO powder source. Atomic force microscopy images indicated that the film grown at RT without $O_2$ supply was relatively uniform and flat whereas that deposited in oxygen ambient yielded higher growth rates and rough surface morphologies. X-ray photoelectron spectroscopy analyses demonstrate that the MgO film deposited at RT without $O_2$ has the closest composition to the stoichiometric MgO, and that a thin contaminant layer composed mainly of magnesium peroxide (before etching) or hydroxide (after etching) was unintentionally formed on the film surface, respectively. These results will be discussed in relation to the interaction among the evaporated species and intentionally supplied oxygen molecules at the growth front as well as the interfacial energy between diamond and MgO.

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공정변수에 따른 레이저표면합금층의 형상 및 성분변화에 관한 연구 (Shape and Chemical Composition of Laser Surface Alloyed Layer under Moving Laser Source)

  • 최정영;이창희
    • 한국레이저가공학회지
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    • 제2권2호
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    • pp.8-17
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    • 1999
  • This study includes a basic feature of laser surface alloying for enhancing the surface properties of materials. Effects of laser processing parameters such as beam power, beam size, scanning speed on the shape and composition of alloyed layer was simulated in case of moving beam conditions (2-dimensional numerical methods). Simulated results were compared with experiments, in which the plasma coating of 80% Ni + 20% Cr deposited on the SS41 substrate was remelted with CO2 laser with Gaussian energy distribution. Simulation and experiments revealed that the shape (dimension)and composition of laser alloyed layer were strongly dependent upon the process parameters, especially interaction time (travel speed) as compared to beam diameter, beam power and absorptivity. The shape and composition of alloyed layervaried more or less exponentially with parameters.

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IN VITRO INHIBITION BY TRICYCLIC ANTIDEPRESSANTS OF PHENYTOIN p-HYDROXYLATION: MECHANISTIC APPROACH

  • Park, Ji-Young;Kim, Min-Jung;Shon, Ji-Hong;Shin, Jae-Gook
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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    • pp.195-195
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    • 2001
  • The inhibitory potentials of TCAs (imipramine, desipramine, amitriptyline, and nortriptyline) on phenytoin p-hydroxylation and probe metabolic pathways of each CYP isoforms were evaluated from incubation studies of human liver microsomes and cDNA-expressed cytochrome P450s in vitro in order to understand the mechanism of drug interaction between TCAs and phenytoin, a substrate of CYP2C9 and CYP2C19. (omitted)

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Mixed-Island Formation and Electronic Structure of Metallo-Porphyrin Molecules on Au(111)

  • 김호원;정경훈;강세종
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.303-303
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    • 2011
  • Orderings and electronic structures of organic molecules on metal substrates have been studied due to possible applications in electronic devices. In molecular systems, delocalized pi-electrons play important roles in the adsorption behaviors and electronic structures. We studied the adsorption and electronic structures of Co-Porphyrin molecules on Au(111) using scanning tunneling microscopy (STM) and spectroscopy (STS) at low temperature. Molecules form closely packed two-dimensional islands on Au(111) surface with two different types, having different shape evolutions in our energy-dependent STM observations. The Kondo resonance state, occurred by spin exchange interaction between the Co center atom and conduction electrons in the metal substrate, was observed in one type, while it was absent in the other type in scanning tunneling spectroscopy measurements. Possible origins of two molecular shapes will be discussed.

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Near-Field Imaging of Graphene

  • 권혁상;김덕수;김지환
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.127-127
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    • 2012
  • We carried out the high-resolution dielectric mapping of graphenes on $SiO_2$/Si substrate, using the scattering Apertureless Near-Field Scanning Optical Microscopy (s-ANSOM) in both visible (633 nm) and infrared (3.6 um) wavelengths. In the visible wavelength, the dielectric contrasts are almost proportional to the number of the graphene layers, which indicates that the near-field interaction between the tip and individual graphene layers leads to an image charge oscillation in two-dimension. In the infrared region, on the other hand, we observe unique layer-specific contrasts that do not linearly increase with number of layers. It is attributed to the layer-dependent band- structure of graphenes.

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