• BMB Reports
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• 제28권6호
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• pp.546-551
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• 1995

The conformation studies of myelin P2 protein and two of its major peptides were carried out using circular dichroism and fluorescence spectroscopy in water and in lipid environments. Significant conformational changes occur when the protein or peptides were bound to gangliosides. Similar effects were also found in trifluoroethanol solutions. The conformational features of P2 protein and its major peptides were discussed in relation to the environmental changes and the disease-inducing effects.

• Journal of the Optical Society of Korea
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• 제18권4호
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• pp.365-369
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• 2014

We present accurate analytical solutions of the lineshapes of birefringence (rotation) and dichroism (absorption) spectroscopy for a circular anisotropic medium composed of atoms of the transition $J_g=0{\rightarrow}J_e=1$. The susceptibility of a weak probe beam was analytically calculated and was averaged over a Maxwell-Boltzmann velocity distribution. The lineshapes of the two spectroscopies were then presented in analytical forms at arbitrary values of the linewidths of the inhomogeneous (Doppler) broadening and the homogeneous (natural) broadening of the atoms.

• Journal of Magnetics
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• 제13권3호
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• pp.85-87
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• 2008

I report a simple method to correct the saturation effect in absorption spectra measured in total electron yield (TEY) mode. It does not require additional measurements of the X-ray penetration depth. In order to check the reliability of the method, X-ray magnetic circular dichroism (XMCD) spectra for polycrystalline Fe were measured at two different incident angles, and then processed with the method. The two resultant XMCD spectra were identical, and their sum rule analysis produced the ratios of orbital magnetic moment to spin magnetic moment, which were very close to the well-known value.

• 한국자기학회지
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• 제20권5호
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• pp.201-205
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• 2010

X-선 자기 원형 이색성 측정은 자성물질을 구성하는 원소별 자기적 성질의 측정 및 궤도 자기 모멘트와 스핀 자기 모멘트를 구별하여 측정할 수 있다는 장점으로 인해 여러 가지 자성 신물질 및 다양한 기능성 자성 다층 박막의 연구에 많이 이용되어 왔다. 이 글에서는 이러한 X-선 자기 원형 이색성 현상의 원리 및 실험 방법 등을 설명하겠다. 또한 몇 가지 X-선 자기 원형 이색성을 이용한 최근 몇 가지 연구도 소개하려 한다.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.415-418
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• 2009

Concerned with ambiguous stereochemistry assignment of natural (+)-glabridin, absolute configurations of (${\pm}$)-glabridin enantiomers were studied with synthetic glabridin. Synthetic glabridin enantiomers were separated by semi-preparative Sumi-chiral column chromatography, and characterized by UV-Vis and NMR spectroscopy. Three-dimensional molecular structure of glabridin was obtained as equatorial Ph-3 half chair chroman ring from semi-empirical PM3 calculation, and refined by coupling constants in $^1H$ NMR spectrum. Finally, absolute configurations of two enantiomers were determined by circular dichroism spectroscopy based on the empirical helicity rules. Absolute configuration of natural (+)-glabridin was confirmed as (R)-glabridin, as known.

• Journal of Photoscience
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• 제12권1호
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• pp.11-15
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• 2005

The mechanism of interaction of two drugs viz., amoxicillin and cloxacillin with bovine serum albumin has been investigated using fluorescence absorption and circular dichroism spectroscopy. The quenching mechanism of fluorescence of bovine serum albumin by amoxicillin and cloxacillin was discussed. The binding sites number n and apparent binding constant Kwere measured by fluorescence quenching method. The thermodynamic parameters obtained from data at different temperatures were calculated. The distance r between donor (bovine serum albumin) and acceptor (amoxicillin and cloxacillin) was obtained according to Forster theory of non-radiative energy transfer. The effect of common ions on binding constant was also investigated. The results of synchronous fluorescence spectra, UV-vis absorption spectra and circular dichroism of BSA in presence of amoxicillin and cloxacillin show that the conformation of bovine serum albumin changed

• 공업화학
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• 제23권6호
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• pp.577-582
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• 2012

진동 원편광 이색성(VCD; Vibrational Circular Dichroism) 분석기기를 사용한 키랄 유도체의 광학순도 분석을 수행하였다. 이 분석법을 통하여 광학이성체의 절대배위와 2% 이내의 오차 범위 내에서 %EE 값을 용이하게 측정할 수 있었다. 또한 VCD분석을 연속순환방식으로 시간 변화와 함께 수행하여 키랄화합물의 %EE 값을 측정하였다. ECH와 글리시돌 두 키랄 성분이 섞인 2성분 계에서 특별한 분리조작 없이 각 성분에 대한 농도 및 %EE 변화를 동시에 모니터링하는 것이 가능하였다. 본 연구에서 응용한 VCD 분석법은 반응 중의 반응 속도 등을 연속적으로 측정하는데 유용한 기법이며, 서로 다른 키랄 화합물이 혼합되어 있는 경우에 각각의 광학순도를 시간 변화와 함께 비파괴법으로 측정하기에 편리한 방법임을 확인하였다.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2000년도 동계총회 및 제16회 자기공명 학술발표회
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• pp.28-28
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• 2000

• Journal of Applied Biological Chemistry
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• 제51권1호
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• pp.17-19
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• 2008

Isoflavanone has been synthesized from the reduction of isoflavone in nearly quantitative yield. Isoflavone with seven equivalents of ammonium formate in the presence of Pd/C in ethanol under $N_2$ atmosphere exclusively produced the two-electron reduced product in two hours. It was characterized by various spectroscopic methods, including UV-VIS, EI-MS, $^1H$-NMR, $^{13}C$-NMR and $^1H$, $^1H$-COSY. The racemic mixture was separated by Sumi-Chiral column chromatography and the absolute configurations of the enantiomers were characterized by circular dichroism spectroscopy.

• 한국자기공명학회논문지
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• 제13권1호
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• pp.56-63
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• 2009

SWIRM domain, a core domain of SRG3 is well conserved in SW13, RSC8, and MOIRA family proteins. To understand structural basis for cellular functions of the SWIRM domain, we have initiated biochemical and structural studies on SWIRM domain and mutants using gelfiltration chromatography, circular dichroism and NMR spectroscopy. The structural properties of the mutant SWIRM domains (K34A and M75A) have been characterized, showing that the structures of both wild-type and mutant proteins are a-helical conformation. The data conclude that mutations at interaction sites of its binding partner protein do not affect its secondary and tertiary structure.