• 생명과학회지
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• 제12권6호
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• pp.715-720
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• 2002

Arabidopsis thaliana columbia의 종자에 EMS를 처리하여 돌연변이체들을 만들었고 이중 UV-B에 감수성이 높은 돌연변이체를 골랐다. 이 UV-B 감수성 돌연변이체의 원인 유전자를 밝히기 위하여 교배 실험을 한 결과 이는 Mendel 유전법칙을 따르고 단일 유전자의 돌연변이에 의하여 나타나며 열성 유전을 하는 것으로 밝혀져 이 유전자를 uvs라 하였다. 염색체상의 uvs의 위치를 밝히기 위하여 CAPS maker를 이용한 연관분석을 하고자 하였고 이를 위하여 각각 maker의 primer 10종류를 제작하였다. 이를 이용, 각 PCR 산물에 대하여 uvs mutant와는 다른 제한효소 pattern를 갖는 Lansberg와 uvs mutant를 교배시켜서 얻은 것들로부터 DNA를 추출하여 PCR을 수행하였다. 이들과 자외선과의 감수성을 연관시켜 교차율을 계산한 결과 5번 염색체의 LFY3과 가장 가까웁게 연관되어 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.235-238
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• 2005

Sulfonated poly(ether sulfone) copolymers (PESs) were synthesized using hydroquinone 2-potassium sulfonate (HPS) with other monomers (bisphenol A and 4-fluorophenyl sulfone). PESs with different $mole\%$ of hydrophilic group were prepared by changing the mole ratio of HPS in the polymerization reaction. The chemical structure and the thermal stability of these polymers were characterized by using $^1H-NMR$, FT-IR and TGA techniques. The PES 60 membrane, which has $60 mole\%$ of HPS unit in the polymer backbone, has a proton conductivity of 0.091 S/cm and good insolubility in boiling water. The TGA showed that PES 60 was stable up to $272^{\circ}C$ with a char yield of about $29\%\;at\;900^{\circ}C\;under\;N_2$ atmosphere. To investigate the single cell performance, the catalyst coated PES 60 membrane was used and a single cell test was carried out using $H_2/O_2$ gases as fuel and oxidant at various temperatures. We observed that the cell performance was enhanced by increasing the cell temperature. A current density of $1400 mA/cm^2$ at 0.60 V was obtained at $70^{\circ}C$.

• Journal of Microbiology
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• 제37권3호
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• pp.148-153
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• 1999

Laccase produced by Coriolus hirsutus was purified to electrophoretic homogeneity by acetone precipitation, Sephacryl S-2000 HR chromatography, DEAE Sepharose CL-6B chromatography, and Mono Q HR 5/5 chromatography. The purification of laccase was 46.6-fold with an overall yield of 23.7%. Laccase from this fungus was a monomeric glycoprotein with 16% carbohydrate content, and has an isoelectric point of 4.2, and molecular mass of 78 kDa, respectively. The N-terminal amino acid sequence of the enzyme showed significant homology to hoste of laccases from Coriolus versicolor, Pycnoporus cinnabarius, and an unidentified basidiomycete, PM1. The highest rate of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) oxidation by laccase was reached at 45$^{\circ}C$, and te pH optima of the enzyme varied depending on the substrate in the range of 2.0 to 4.5. The enzyme was stable at 60$^{\circ}C$ for 5 h and lost 80% activity at 80$^{\circ}C$ in 30 min. The enzyme oxidized a variety of usual laccase substrates including lignin-related phenol, and had the highest affinity toward ABTS. Under standard assay conditions, the apparent Km value of the enzyme toward ABTS was 8.1 ${\mu}$M. The enzyme was completely inhibited by L-cysteine and sodium azide, but not by potassium cyanide, SDS, ad thiourea.

• 조명전기설비학회논문지
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• 제29권3호
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• pp.88-95
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• 2015

The accelerated thermal aging of CSPE(Chloro Sulfonate Polyethylene) was carried out for 40.41, 121.22, 202.04 days, 16.82, 50.45, 84.09 days and 7.32, 21.96, 36.59 days at 100, 110, and $120^{\circ}C$, respectively, which are equivalent to 20, 60, 100 years of aging at $50^{\circ}C$. The permittivities and the apparent densities of the accelerated thermally aged CSPE samples are increased with accelerated thermal aging year but EAB(Elongation at Break) is decreased with that. The dielectric strength and the electric breakdown of the non-accelerated and accelerated thermally aged CSPE samples do not depend on accelerated thermal aging year and applied voltage rising time. density and EAB measures.

• 펄프종이기술
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• 제41권4호
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• pp.65-72
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• 2009

We investigated the effect of polyelectrolyte types in Layer-by-Layer multilayering and furnish combination on physical properties of paper. Handsheets were made from pulp fibers with different polyelectrolytes composition, and their density, formation, tensile strength, strain, tear strength and burst strength were evaluated. The density of handsheet was slightly decreased by polyelectrolyte multilayering. Formation did not show a significant change, but all mechanical properties were increased by polyelectrolyte multilayering. Remarkable improvement in tensile and tear strengths was obtained when pulp fibers were treated with cationic starch and poly styrene 4-sulfonate. Irrespectively of final ionicity of pulp fiber, tensile index, strain and tear strength of paper could be improved simultaneously by polyelectrolyte multilayering.

• Ocean and Polar Research
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• 제23권3호
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• pp.285-290
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• 2001

The strength of juvenile black rockfish, Sebastes schlegeli, raised in different hatcheries for wild stock enhancement was evaluated in terms of resistance to an anesthetizing agent, tricaine methane-sulfonate (MS-222), and exposure to drying. The working dosage of MS-222 varied significantly with fish size and hatchery population. Smaller fish were less resistant to the chemical than larger ones. MS-222 effects also differed with fish growth history. The fish cultured in embanked populations showed stronger resistance, earlier recovery, and lower mortality, compared to those cultured in land-based tanks or collected from wild stocks. Similar results were seen in juveniles challenged to dry exposure. These results suggest that an embanked population of black rockfish is more resistant to anesthetic stress, expressed as anesthesia recovery and mortality, and that this population is healthier than others.

• Journal of Pharmaceutical Investigation
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• 제17권2호
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• pp.55-60
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• 1987

WR 2721 (S-2-(3-aminopropylaminoethylphosphorothioate) is a radioprotective drug that is now undergoing clinical trials in the United States and Japan. a liquid chromatographic electrochemical method for the determination of WR 2721 an WR 3689 [S-2-(3-methylaminopropylamino)ethylphorothioate] in human plasma was developed in this study. This method includes the use of a Hg/Au electrochemical detector and a cyano column for the direct measurement of WR 2721 and WR 3689 in plasma. An analog of WR 2721, WR 149846 was used as an internal standard. WR 2721 and WR 3689 could be well separated from the solvent front, with a mobile phase of acetonitrile-water (20:80), 0.1M acetic acid and 1.2 mM sodium octane sulfonate. This method was shown to be precise. Both intra-day and inter-day results were within 10% CV. Also, sample preparation was fairly simple. Since WR 2721 and WR 3689 were unstable at room temperature, it was essential to use an automatic sample processor with a refrigerator, especially for carrying out routine analyses.

• Journal of Microbiology and Biotechnology
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• 제1권3호
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• pp.151-156
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• 1991

In order to construct a yeast strain having high ethanol tolerance together with good lactose fermentation ability, the protoplast fusion using Saccharomyces cerevisiae STV 89 and Kluyveromyces fragilis CBS 397 was carried out. Auxotrophic mutants of K. fragilis were obtained as a selection marker by treatment of ethylmethane sulfonate. The best mutant for protoplast fusion was selected based on the capabilities of ${\beta}-galactosidase$ production and lactose fermentation. The protoplast fusion using polyethylene glycol and calcium chloride solution led to the fusion frequence of $3{\times}10^{-6}$ and a number of fusants were obtained. Among these fusants, a fusant F-3-19 showed the best results in terms of ethanol tolerance, ${\beta}-galactosidase$ activity and lactose fermentation. The performance of lactose fermentation and ethanol tolerance by this fusant were better than those of K. fragilis. Study on the ethanol tolerance having relation to fatty acid composition and intracellular ethanol concentration revealed that the fusant F-3-19 had a higher unsaturated fatty acids content and accumulated less amount of intracellular ethanol compared with a parent of K. fragilis.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.383-389
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• 1991

저온에서 높은 활성을 나타내는 알칼리성 protease를 생산하기 위하여 여러가지 시료로부터 집적배양에 의해 저온성 세균을 분리하였다. 분리된 세균은 저온.알칼리성 Pseudomonas sp.인 것으로 판명되었으며, 효소생산을 위한 균생육의 최적 pH는 10.0, 온도 $20^{\circ}C$에서 4일간 배양하였을 때였다. 이 효소 활성의 최적 pH 및 온도는 각각 pH 10.5 및 $40^{\circ}C$였으며, pH 및 열안정성은 각각 pH 7.0~13.0, 온도 $50^{\circ}C$이하의 범위에서 비교적 안정하였다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 KSAM Annual Meeting
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• pp.14-16
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• 2001

The outer membrane (OM) of gram-negative bacteria acts as an effective permeability barrier against noxious agents including several antibiotics and organic solvents, and lipopolysaccharide (LPS) is the key molecule for this function. Outer membrane modified mutants (Ml-166, M2-42, M3-21) of E. coli DH5$\alpha$/pBSl were selected through a mutation using EMS (ethyl-methane-sulfonate). Among the selected mutants, M3-21 was twice as sensitive as LumisTo $x^{ }$ to benzene and M2-41 was 8 times as sensitive as LumisTo $x^{ }$ to toluene. To identify the structural change in the membrane by mutation, the relative cell surface hydrophobicities and the absorption of the crystal violet to the organisms were measured. All the mutants absorbed more crystal violet than their parent and the absorption of crystal violet increased in cell walls as carbohydrate of lipopolysaccharide decreased. When the cell surface hydrophobicities of DH5/pBSl and its mutants were measured by the BATH, the hydrophobicities of mutants increased compared to their parent in several organic solvents. The difference of lipopolysaccharide between DH5/pBSl and its mutants was identified by various ways such as the SDS-PAGE gel, the screening of LPS molecular weights, the mass spectrometry, and MALDI-TOF.F.