• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1447-1452
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• 2011

Polyphenol oxidase (PPO) isoforms were partially purified from oyster mushroom (Pleurotus ostreatus) using various chromatography techniques, and their characteristics of heat stability, substrate affinity, optimum pH, and optimum temperature were investigated. Three PPO isoforms named PO-I, PO-II-1, and PO-II-2 were partially purified from oyster mushroom. The molecular weight of PO-II-1 was 70 kDa and PO-I and PO-II-2 were less than 6 kDa each. Characterization was carried out using a PPO isoform partially purified by hydrophobic interaction chromatography. Optimum temperature was $55^{\circ}C$ and optimum pH 5.0. However, the PPO was inactivated at neutral pH or by heating at $80^{\circ}C$ for 30 min, while the 40% PPO still remained active after heating at $60^{\circ}C$ for 45 min. The PPO isoform showed the highest substrate affinity to chlorogenic acid and pyrogallol, in which KM values were 1.01 and 2.06 mM, respectively. Therefore, these results suggested that the mushrooms should be stored at a pH higher than 7.0 and at a low temperature to prevent enzymatic browning.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.116-121
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• 2001

The compositions of essential oils isolated from the leaves and fruits of Chamaecyparis obtusa (Sieb. et Zucc). Endl. and Chamaecyparis pisifera (Sieb. et Zucc.) Endl. were analyzed through GC and GC-MS. The oil yields were 0.83% (as fresh weight) and 1.36% in the leaves and the fruits of C. obtusa, and were 0.92% and 1.28% in those of C. pisifera, respectively. More than 90 components were identified, including high contents of monoterpenoids and sesquiterpenoids. Contents of monoteipenoids in the leaf and fruit oils of C. pisifera were higher than in those of C. obutsa. The major constituents in the leaf oil of C. obtusa were sabinene (11.81% as determined through GC peak area), limonene (7.73%), bornyl acetate (6.92%), $borneol+{\alpha}-teirineol$ (15.67%), and elemol (12.82%), and those in the fruit oil were myrcene (8.12%), ${\gamma}-terpinene$(5.91%), p-cymene(7.62%), $borneol+{\alpha}-terpineol$(6.53%) and ${\beta}-caryophyllene$ (23.74%). The major constituents in the leaf oil of C. pisifera were ${\alpha}-pinene$(32.34%), ${\delta}-3-carene$(25.28%), myrcene(11.72%), and bornyl acetate (8.77%), and those in the fruit oil were ${\alpha}-pinene$ (29.38%), ${\delta}-3-carene$(30.27%), myrcene(15.05%), and limonene(8.10%).

• Membrane Journal
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• v.23 no.5
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• pp.332-342
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• 2013

In the present study, carbon molecular sieve (CMS) hollow fiber membranes were prepared by carbonizing a methyl imide hollow fiber precursor, which was spun by non-solvent induced phase separation process. And effects of carbonization parameters such as pre-oxidation, pyrolysis, and post-oxidation on the gas permeation were systematically investigated. CMS membrane having the highest gas flux was obtained by carbonizing the precursor through a combined process of air pre-oxidation at $250^{\circ}C$ for 2h, nitrogen pyrolysis at $550^{\circ}C$ for 2h, and oxygen post-oxidation at $250^{\circ}C$ for 2h. The optimized membrane showed a considerable gas permeance : the $H_2$, He, $CO_2$ permeances were 69.72, 35.61, 31.01 GPU, respectively, and the $O_2$ and $N_2$ permeances were ignorable. Therefore, it was clear that the prepared CMS hollow fiber membrane was a promising membrane for recovering small gases such as hydrogen and hellium and carbon dioxide.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.22-22
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• 1992

국내의 토양에서 Streptomyces spp.를 분리하였고 이 중 항균활성이 우수한 균주들을 선별하였다. 이들 균주들을 적절한 조건에서 배양하여 얻은 배양액을 이온 교한 수지와 흡착 크로마토그래피를 행하여 항생물질들을 분리하였다. 이들 항생물질들은 Bacillus subtilis, Pyricularia oryzae, Alternaria mail, Candida albicans, Mycobacterium smegmatis, Pseudomonas aeruginosa , 및 Escherichia coli에 강한 항균활성을 나타내었다. 각 항생물질들을 산으로 가수분해하고 흡착관 크로마토그래피로 가수분해 생성물을 분리하였다. 분리한 항생물질과 가수분해 생성물들의 $^1$IH-NMR, $13^{C}$ -NMR, FAB-Mass 스펙트럼을 분석하여 구조를 연구하였다.

• Membrane Journal
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• v.3 no.1
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• pp.12-21
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• 1993

세라믹 분리막은 알루미나($Al_2O_3$), 지르코니아($ZrO_2$), Carbon, 실리콘 카바이드, 스테인레스 등의 무기재료를 이용하여 제조된 분리막이다. 압출성형공정으로 제조된 지지체는 1700$^{\circ}C$ 이상의 소결공정을 거치므로 지지체 상단에 슬러리 코팅공정으로 형성된 얇은 막에게 안정된 분리기능을 수행할 수 있도록 커다란 물리적 강도를 제공한다. 따라서, 세라믹 분리막은 다공성 세라믹 구조를 갖는 특징적인 두 개 또는 세 개의 균일한 층으로 구성된 복합막이라 할 수 있다.

• 한국전자현미경학회:학술대회논문집
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• 1998.05a
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• pp.48-52
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• 1998

본 연구에서는 저온에서 InP 기판 위에 성장한 InAlAs 에피층에 존재하는 상분리와 규칙 현상을 투과전자현미경 관찰을 통해 관찰하였다. 저온에서 성장한 에피층에서 상분리의 거동이 크게 나타났으나 규칙 현상은 특정한 온도에서 최대를 나타낸다. $800^{\circ}C$ 이상에서 3분간의 열처리로 규칙 현상이 사라졌으나 상분리 현상은 변화를 보이지 않는다. 그러나 Zn가 포함된 장시간, 저온에서 열처리로 상분리 현상이 완전히 사라졌다.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.57-66
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• 2007

Natural gases generally consist of mainly $^{12}C$ and about 1.1% of $^{13}C$. It is well known that a stable carbon isotope, $^{13}C$, has been widely used for the applications of medical, pharmaceutical, and agricultural tracers. As a result, the development of the separation and concentrating technology of $^{13}C$ can cause of high value-added products and the possibility of the generation of new carbon materials, In general, there are two kinds of approaches to obtain a stable $^{13}C$ isotope by the separation of cryogenic distillation. One is to obtain a concentrated $^{13}CH_4$ isotope from natural gas. Another approach is to get concentrated $^{13}CO$ by distillation followed by a chemical reaction of $CH_4$ and $H_2O$. In this study, rigorous process simulations of the cryogenic distillation have been performed and analyzed for the concentrated separation of $^{13}C$ isotopes from LNG and NG by using commercial process simulator. Due to the very small differences of relative volatilities and separabilities of $^{12}C$ and $^{13}C$, the process design and operation of effective separation and concentration of $^{13}C$ need special strategies and feasibility studies. Utilization of vapor pressure data to acentric factor in SRK equation of state and optimized process conditions have been able to predict for the effective of the separation yield and concentration of $^{13}C$ for the cryogenic distillation. The various operation strategies for both batch and continuous cryogenic distillation are also studied and suggested for the basic design of the process. Development of this study can provide a tool for the effective design and operation of the cryogenic separation of $^{13}C$.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.1023-1027
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• 2004

The RAD3 gene of Saccharomyces cerevisiae is essential for the incision step of UV-induced excision repair. An yeast RAD3 gene has been previously isolated by functional complementation. In order to identify the RAD3 homologous gene from fungus Coprinus cinereus, we have constructed cosmid libraries from electrophoretically separated chromosomes of the C. cinereus. The 13 C. cinereus chromosomes were resolved by pulse-field gel electrophoresis, hybridized with S. cerevisiae RAD3 DNA, and then isolated RAD3 homologous DNA from C. cinereus chromosome. The RAD3 homolog DNA was contained in 3.2 kb DNA fragment. Here, we report the results of characterization of a fungus C. cinereus homolog to the yeast RAD3 gene. Southern blot analysis confirmed that the C. cinereus chromosome contains the RAD3 homolog gene and this gene exists as a single copy in C. cinereus genome. When total RNA isolated from the C. cinereus cells were hybridized with the 3.4 kb PvuII DNA fragment of the S. cerevisiae RAD3 gene, transcripts size of 2.8 kb were detected. In order to investigate whether the increase of the amount of transcripts by DNA damaging agent, transcript levels were examined after treating agents to the cells. The level of transcripts were not increased by untraviolet light (UV). This result indicated that the RAD3 homologous gene is not UV inducible gene. Gene deletion experiments indicate that the HRD3 gene is essential for viability of the cells and DNA repair function. These observations suggest an evolutionary conservation of other protein components with which HRD3 interacts in mediating its DNA repair and viability functions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.73-79
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• 1968

The resolving capacities of xanthophyll pigments on thin-layers of Silica Gel, Hyflo super-Cel, and Micro-Cel C with varying concentrations of acetone in petroleum ether as the developing solvent were compared. The results showed that the resolving capacity of Micro-Cel C thin-layer was superior to others and satisfactory for the separation of leaf carotenoids in clearly separated six bands; carotenes, lutein-zeaxanthin, antheraxanthin, violaxanthin, an unidentified band, and neoxanthin, when it was developed with $13\%$ acetone-petroleum ether solution for 15 to 20minutes in an unsaturated chamber. Adhension of Micro-Cel C to glass was adequate without binder. Calcium sulfate used as a binder appeared to inactivate the resolving capacity of Micro-Cel C. Removing an about 0.2cm-wide layer on bo side of thin-layer slide helped to prevent 'edge effect' which gave tailing and faster solvent ascending along the side than the center. An adequate thickness of thin-layer was obtained when a 3 ml aliquot of the suspension in which l0g powdered Micro-Cel C was suspended in 75 ml distilled water was coated on a $2\times20cm$ glass slide.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.20-25
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• 2000

One of endoglucanases(F-II-II) was purified from the culture filtrate of Trichoderma sp. C-4 through two step procedures including chromatography on Sephacryl S-200 and Sephacryl S-100. The molecular weight of the enzyme was determined to be about 26,000 by SDS-PAGE and the isoelectric point as 8.0 by analytical isoelectric focusing. The optimum temperature of the enzyme was $50^{\circ}C$ and the optimum pH was 5.0. No loss of activity was observed when the enzyme was preincubated at $50^{\circ}C$ for 24 hours. The specific activity of the enzyme toward carboxymethylcellulose (CMC) was estimated to be 776.2 U/mg. The internal amino acid sequence was analysed.