• 한국산학기술학회논문지
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• 제6권2호
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• pp.129-133
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• 2005

분자 에너지 준위, 분자구조, 흡수, 방출, 상호분자 반응, 또는 약하게 결합된 분자에너지, 광화학, 형광, PDT치료에 관한 연구를 수행하는데 분광계에서 CCD는 매우 중요하다. CCD는 현대 물리화학 분야에서 레이저 분광학에 의한 의공학 및 분자 구조의 연구에 필수적이다. 그리하여 CCD를 이용한 전자기 분광계의 설계 및 제작을 연구하였으며 프린트된 전자회로 및 포르폴린을 분석하였다. 예전에 CCD는 방송장비에만 사용한다고 생각했지만 현대에는 산업발전에 의한 응용으로 로봇공학, 기기분석 및 관측에 대한 산업적 요구에 더욱 많이 활용된다.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2487-2493
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• 2014

Dimeric ${\beta}$-cyclodextrin linked by a thioether bridge was synthesized from a reaction of mono-6-iodo-6-deoxy-${\beta}$-cyclodextrin with sodium sulfide, and the structure was analyzed using nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The effects of thioether-bridged dimeric ${\beta}$-CD on the aqueous solubility of flavonols (myricetin, quercetin, and kaempferol) were investigated by ultraviolet-visible spectroscopy. The aqueous solubility of myricetin, quercetin, and kaempferol were enhanced 33.6-, 12.4-, and 10.5-fold following the addition of 9 mM of thioether-bridged dimeric ${\beta}$-CD. In comparison, the aqueous solubility of myricetin, quercetin, and kaempferol were enhanced 5.4-, 3.3-, and 2.7-fold using the same concentration of monomeric ${\beta}$-cyclodextrin. Furthermore, the formation of flavonol/thioether-bridged dimeric ${\beta}$-CD inclusion complexes was confirmed with nuclear magnetic resonance, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The results showed that the nature of the complexes significantly differed from that of free flavonols. Herein, we suggest that the thioether-bridged dimeric ${\beta}$-CD can act as an effective complexing agent for flavonols.

• Molecules and Cells
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• 제27권6호
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• pp.651-656
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• 2009

The formation of ${\beta}$-amyloid peptide ($A{\beta}$) is initiated from cleavage of amyloid precursor protein (APP) by a family of protease, ${\alpha}$-, ${\beta}$-, and ${\gamma}$-secretase. Sub W, a substrate peptide, consists of 10 amino acids, which are adjacent to the ${\beta}$-cleavage site of wild-type APP, and Sub M is Swedish mutant with double mutations on the left side of the ${\beta}$-cleavage site of APP. Sub W is a normal product of the metabolism of APP in the secretary pathway. Sub M is known to increase the efficiency of ${\beta}$-secretase activity, resulting in a more specific binding model compared to Sub W. Three-dimensional structures of Sub W and Sub M were studied by CD and NMR spectroscopy in water solution. On the basis of these structures, interaction models of ${\beta}$-secretase and substrate peptides were determined by molecular dynamics simulation. Four hydrogen bonds and one water-mediated interaction were formed in the docking models. In particular, the hydrogen bonding network of Sub M-BACE formed spread over the broad region of the active site of ${\beta}$-secretase (P5-P3'), and the side chain of P2- Asn formed a hydrogen bond specifically with the side chain of Arg235. These are more favorable to the cleavage of Sub M by ${\beta}$-secretase than Sub W. The two substrate peptides showed different tendency to bind to ${\beta}$-secretase and this information may useful for drug development to treat and prevent Alzheimer's disease.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.23.1-23.1
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• 2007

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.364-366
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• 1994

Molecular properties of streptococcal nuclease purified from Streptococcus sp. were examined. The purified enzyme was stable in the range of pH 7 to 10 and easily inactivated above $60^{\circ}C$. Atomic spectroscopy analysis indicated that the enzyme contains Ca, Mg, Zn. Circular dichroism study showed 25% $\alpha$ -helix, 15% $\beta$-sheet and 30% $\beta$-tums.

• 한국항공우주학회지
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• 제48권6호
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• pp.479-487
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• 2020

본 논문에서는 라만 분광법과 레이저 유도 플라즈마 분광법(LIPS)을 단일 유닛으로 결합한 새로운 형태의 이중 펄스 레이저 시스템을 제안하였다. 본 연구는 라만 분광법으로부터 분자 신호를 추출하면서, 동시에 레이저 유도 플라즈마 방출 신호를 향상시키고자 하였다. 달의 대기압과 같은 저압 조건에서는 플라즈마 신호 검출은 낮은 전자 밀도와 짧은 지속시간, 빠른 플라즈마 팽창 때문에 어려움을 마주치게 된다. 또한, 우주 탐사를 목표로 하는 검출 시스템의 통합에서, 레이저 시스템의 무게 최소화는 payload의 무게 측면에서 중요하다. 0.07 torr 미만의 저압 조건에서 높은 분해능의 스펙트럼 데이터를 제공하는 본 연구의 동시 분자 및 원자 검출방식은 8개의 암석을 이용하여 증명되었다. 이중 펄스 레이저로부터 생성된 연속된 플라즈마는 종래의 플라즈마 분광과 비교하여 방해석의 산소와 칼슘 신호를 2배 향상시킬 수 있었다.

• 대한전자공학회논문지SD
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• 제39권9호
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• pp.1-10
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• 2002

유기 발광 다이오드를 위한 indium oxide (ITO) 기판을 여러 가지로 방법으로 표면처리를 하고, 이에 따른 atomic force microscopy (AFM)에 의한 morphology의 변화와 표면에서 변화된 원소들의 조성비를 Auger electron spectroscopy (AES)분석에 의하여 조사하였다. 또한 이 기판을 사용하여 초고진공분자선 증착방법에 의하여 유기 발광다이오드를 제작하고 그 특성을 조사하였다. 그 결과 산소플라즈마으로 표면 처리한 ITO 기판 위에 제조된 organic light-emitting diode (OLED)소자의 특성이 향상되었다. 그것은 AES의 분석에 의하면 ITO 표면의 오염된 탄소가 제거되고 ITO의 일함수가 증가되어 정공이 유기물 층으로 용이하게 주입한 결과로 판단된다.

• E2M - 전기 전자와 첨단 소재
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• 제7권6호
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• pp.473-480
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• 1994

The electron tunnel effect in polvimide LB films sandwiched between metal electrodes has been investigated in the present work by a study of both the elastic and inelastic tunneling components. By the results of elastic tunneling experiments in Au/Pl/Au tunneling junction, we can judge the height and thickness of tunnel barrier. The inelastic current in Inelastic Electron Tunneling Spectroscopy(IETS) is due to the interaction of the tunneling electron with the vibrational modes of the molecular species in the barrier. Measurements are done on Au/PI/Pb tunneling junctions. The spectra obtained are the second derivatives of the current-voltage characteristics of these junctions : specifically, d$^{2}$1/dV$^{2}$ as a function of voltage V. Because the energies measured by IETS can be directly compared to those measured by infrared and Raman spectroscopy, IR-RAS spectroscopy also measured for reference.

• 한국자기공명학회논문지
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• 제5권1호
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• pp.37-45
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• 2001

Synthetic pulmonary surfactants consisting of a mixture of phospholipids with synthetic peptides based on human surfactant-associated protein SP-B were prepared. These surfactants were analyzed f3r their secondary structures by circular dichroism (CD) spectroscopy and NMR spectroscopy. Two synthetic peptides (SP-B(3), SP-B(4)) combined with the phospholipid mixture displayed significant surfactant properties. The CD spectra showed that the u-helical propensities of the peptides in DPC micelles. In the NMR spectroscopy, the tertiary structures of SP-B(3) show that it has $\alpha$-helical structure from Gln5 to Arg13 in DPC micelle and SP-B(4) show that they have $\alpha$-helical structure from Gln5 to Leu12 in DPC micelle. Based on these structures, truncated peptides originated from SP-B protein, can be designed as effective synthetic surfactants for clinical use.

• 한국전기전자재료학회논문지
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• 제13권1호
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• pp.21-27
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• 2000

We used the surface photovoltage spectroscopy(SPVS) for characterization of GaAs/Al\ulcornerGa\ulcornerAs multi-quantum well(MQW) structures grown by molecular beam epitaxy(MBE) method. Energy gap related transitions in GaAs and AlGaAs were observed. The Al composition(x=0.3) was determined by Sek's composition formula. Transition energies in MQW were determined using the differential surface photo-volatage spectroscopy)DSPVS) of the measured resonanced. In order to indentify the transitions, the experimentally observed energies were compared with results of the envelope function approximation for a rectangular quantum well. We have observed and interesting behavior of the temperature dependence(80K~300K) of the 11Hand 11L transition for sample.