• Applied Biological Chemistry
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• 제39권3호
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• pp.177-182
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• 1996

액체배양 실험으로 14가지 탄수화물을 사용하여 B. thuringiensis의 생장, 포자형성 및 살충성 결정단백질 생성에 대한 탄소원의 영향을 조사하였다. 최대 세포밀도는 B. thuringiensis 균주에 따라 접종 $16.7{\sim}22$시간 후에 모든 탄소원배지에서 $10^7{\sim}10^8\;cells/ml$ 수준으로 나타났고, 접종 $16.7{\sim}24.7$시간 후에 포자가 나타나기 시작하여 포자형성율이 80%에 이르는 시간은 균주에 따라 $28{\sim}51.3$ 시간이 소요되었다. 배양에 따른 배지의 pH변화는 없었고, 단백질 총량은 sucrose를 사용한 배지에서 가장 높았고, 전분을 첨가했을때 가장 낮았다. Glucose, lactose, maltose 또는 sucorse를 탄소원으로 사용한 배지에서 살충성 결정단백질 생성량이 많았고, 단백질 총량과 살충성 결정단백질량은 비례관계에 있었다. B.t. kurstaki와 B.t. israelensis에서 생성되는 서로 다른 종류의 살충성 결정 단백질의 양은 사용한 모든 탄소원의 경우 그 개별적 증감의 경향이 같았다.

• 한국전기전자재료학회논문지
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• 제25권12호
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• pp.996-999
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• 2012

From UV irradiation, we achieved homeotropic liquid crystal alignment on blended photo-polymer layer which is composed of polyvinyl-cinnamate (PVCi) and homeotropic polyimide (PI). From vertical alignment (VA) mode, we measured threshold voltages by various PVCi doping concentration. Also, the rise time and fall time of VA cells were measured to verify the best doping concentration. Transmittance curves showed about 70% value between 380 nm and 780 nm wavelength which mean visible region.

• Interaction and multiscale mechanics
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• 제1권4호
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• pp.467-476
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• 2008

In this work, a nano-size rocksalt crystal (magnesium oxide) is considered as a continuous collection of unit cells, while each unit cell consists of discrete atoms; and modeled by a multiscale concurrent atomic/continuum field theory. The response of the crystal to an electromagnetic (EM) wave is studied. Finite element analysis is performed by solving the governing equations of the multiscale theory. Due to the applied EM field, the inhomogeneous motions of discrete atoms in the polarizable crystal give rise to the change of microstructure and the polarization wave. The relation between the natural frequency of this system and the driving frequency of the applied EM field is found and discussed.

• 한국광학회지
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• 제14권5호
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• pp.498-503
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• 2003

뽀앙카레 공에서 액정셀의 전기광학적 편광투과특성을 분석하고, 이를 바탕으로 여러 파장에 대해 액정표시소자의 밝기와 명암대비를 최적화하는 위상판의 규격을 정하는 기본조건을 찾았다. 이 조건에 따르면 두 파장에 대해서는 분산특성이 적절하게 조절된 위상판 2매, 세 파장의 경우에는 두 파장으로 근사하거나 위상판 3매가 필요하다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.180-182
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• 1996

In this study, we have investigated the characteristics of the response time and the viewing angle on twisted nematic (TN)-liquid crystal display (LCD) and amorphous (a) TN-LCD without rubbing. To measure the transmission-voltage, response time, and viewing angle characteristics, we prepared three kinds of LC cells and then studied the surface liquid crystal alignment effect. We studied that the response time on a-TN-LCD is fast compared to the TN-LCD. We suggest that the weak anchoring strength is attributed to the fast response time on a-TN-LCD. Also, we obtained the uniform viewing angle characteristics on a-TN-LCD. From these results, we consider that the liquid crystal alignment on LCD device are very important factor for electro-optical characteristics.

• 한국결정성장학회지
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• 제15권6호
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• pp.252-259
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• 2005

[ $CuGaSe_2$ ] 단결정 박막은 수평 전기로에서 합성한 $CuGaSe_2$ 다결정을 증발원으로하여, hot wall epitaxy(HWE) 방법으로 증발원과 기판(반절연성 GaAs(100))의 온도를 각각 $610^{\circ}C,\;450^{\circ}C$로 고정하여 단결정 박막을 성장하였다. 이때 단결정 박막의 결정성은 광발광 스펙트럼(PL)과 이중결정 X-선 요동곡선 (DCRC)으로부터 구하였다. Hall 효과는 Van der Pauw 방법에 의해 측정되었으며, 293 K에서 운반자 농도와 이동도는 각각 $4.87{\times}10^{17}/cm^3,\;129cm^2/V{\cdot}s$였다. $n-Cds/p-CuGaSe_2$ 합 태양전지에 $80mW/cm^2$의 광을 조사시켜 최대 출력점에서 전압은 0.41 V, 전류밀도는 $21.8mA/cm^2$였고, fill factor는 0.75 그리고 태양전지 전력변환 효율은 11.17% 였다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.772-776
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• 2004

Physiological and molecular characteristics of Bacillus thuringiensis SR6 and SR8 were investigated, and phase contrast and electron microscopies revealed that a large rhomboidal crystal protein was present in the sporulating cells. SDS-PAGE and Western blot analyses showed that B. thuringiensis SR8 produced 70 kDa protein much more than other proteins, and that the 70 kDa protein could bind to the antibody of B. thuringiensis subsp. tenebrionis-crystal toxin protein, indicating that the crystal 70 kDa protein has an immunological homology with B. thuringiensis subsp. tenebrionis-crystal toxin protein. The DNA fragment of B. thuringiensis subsp. tenebrionis-toxin gene was detected in B. thuringiensis SR6 and SR8 by using PCR amplification analysis. Furthermore, the insect bioassay showed the insecticidal activity against Colorado potato beetle larvae. Based on the physiological and molecular similarities to B. thuringiensis subsp. tenebrionis, it is suggested that the B. thuringiensis SR6 and SR8 may be mutants of the B. thuringiensis subsp. tenebrionis strain overexpressing the crystal of 70 kDa toxin protein.

• Molecules and Cells
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• 제45권7호
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• pp.495-501
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• 2022

Leucine dehydrogenase (LDH, EC 1.4.1.9) catalyzes the reversible deamination of branched-chain L-amino acids to their corresponding keto acids using NAD⁺ as a cofactor. LDH generally adopts an octameric structure with D4 symmetry, generating a molecular mass of approximately 400 kDa. Here, the crystal structure of the LDH from Pseudomonas aeruginosa (Pa-LDH) was determined at 2.5 Å resolution. Interestingly, the crystal structure shows that the enzyme exists as a dimer with C2 symmetry in a crystal lattice. The dimeric structure was also observed in solution using multiangle light scattering coupled with size-exclusion chromatography. The enzyme assay revealed that the specific activity was maximal at 60℃ and pH 8.5. The kinetic parameters for three different amino acid and the cofactor (NAD⁺) were determined. The crystal structure represents that the subunit has more compact structure than homologs' structure. In addition, the crystal structure along with sequence alignments indicates a set of non-conserved arginine residues which are important in stability. Subsequent mutation analysis for those residues revealed that the enzyme activity reduced to one third of the wild type. These results provide structural and biochemical insights for its future studies on its application for industrial purposes.

• 대한본초학회지
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• 제20권4호
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• pp.77-82
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• 2005

Objectives : In order to distinguish Akebiae Caulis and Aristoiochiae Manshuriensis Caulis, their external and internal states were examined by microscope. Methods : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Results : 1. Akebiae Caulis has stone cells and fiber bundles in its pericycle part, which include square crystal of calcium oxalate. Outside of neogenesis has a lot of cells with square crystal of calcium oxalate. 2. Aristoiochiae Manshuriensis Caulis has a little lignified fiber bundles in its pericycle part, and parenchymatous cell has delicate starch grains and druse of calcium oxalate. Conclusions : In conclusion, internal forms of Akebiae Caulis and of Aristoiochiae Manshuriensis Caulis are different in that each includes square crystal of calcium oxalate and druse of calcium oxalate respectively, so that it may be possible to distinguish them with optical microscope.

• Molecules and Cells
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• 제27권6호
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• pp.667-671
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• 2009

Visfatin (Nampt/PBEF) plays a pivotal role in the salvage pathway for $NAD^+$ biosynthesis. Its potent inhibitor, FK866, causes cellular $NAD^+$ levels to decline, thereby inducing apoptosis in tumor cells. In an effort to improve the solubility and binding interactions of FK866, we designed and synthesized IS001, in which a ribose group is attached to the FK866 pyridyl ring. Here, we report the crystal structure of rat visfatin in complex with IS001. Like FK866, IS001 is positioned at the dimer interface, and all of the residues that interact with IS001 are involved in hydrophobic or ${\pi}-{\pi}$-stacking interactions. However, we were unable to detect any strong interactions between the added ribose ring of IS001 and visfatin, which implies that a bulkier modifying group is necessary for a tight interaction. This study provides additional structure-based information needed to optimize the design of visfatin inhibitors.