• Membrane and Water Treatment
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• 제1권1호
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• pp.1-12
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• 2010

Membrane distillation process was used for purification of pre-treated natural water (tap water). The rejection of inorganic and organic compounds in this process was investigated. The obtained rejection of inorganic solutes was closed to 100%, but the volatile organic compounds (VOCs) diffused through the membrane together with water vapour. The content of trihalomethanes (THMs) in the obtained distillate was two-three fold higher than that in the feed, therefore, the rejection of the total organic compounds present in the tap water was reduced to a level of 98%. The intensive membranes scaling was observed during the water separation. The morphology and composition of the fouling layer was studied using scanning electron microscopy coupled with energy dispersion spectrometry. The influence of thermal water pre-treatment performed in a heat exchanger followed by filtration on the MD process effectiveness was evaluated. This procedure caused that significantly smaller amounts of $CaCO_3$ crystallites were deposited on the membrane surface, and a high permeate flux was maintained over a period of 160 h.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.500-507
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• 1998

The measures for water quality improvement have been planned to introduce for several reservoirs which were badly polluted among the sites included in the Network of Agricultural Water Quality Survey (NAWQS). Considering conditions of circumstances around reservoirs, self-purification systems such as natural ecosystem, oxidation ponds with plants, grassed waterways, weirs, and manmade plant-islands are taking into account enhancing to trap nutrients in waters running off from agricultural lands. The Pollutant Run off Ratios were analysed to predict the effects of water quality improvement for self-purification systems. The cost of water quality improvement was evaluated. The correlation equation between cost and irrigation area showing high correlation coefficient was derived.

• Fisheries and Aquatic Sciences
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• 제15권3호
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• pp.191-195
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• 2012

We report here the use of high-speed countercurrent chromatography (HSCCC) in the preparative isolation and purification of the bioactive component, fucosterol, from Pelvetia siliquosa. A crude extract was obtained by ultrasonic extraction of powdered P. siliquosa using methylene chloride and was then subjected to separation and purification by HSCCC, coupled with evaporative light-scattering detection. Preparative HSCCC was performed successfully using a two-phase solvent system, n-heptane:methanol (3:2, v/v), to obtain 10.96 mg fucosterol with 96.8% purity from 50 mg of crude extract; the recovery rate was approximately 90.5%.

• 한국식품영양과학회지
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• 제28권4호
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• pp.816-821
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• 1999

Cholesterol esterase(pCEH, pancreas cholesterol ester hydrolase, E.C.3.1.1.13) which is secreted from pancreas has been known as an important lipase for cholesterol uptake. cholesteryl acyl esters from a diet must be hydrolyzed to free cholesterol and fatty acid by cholesterol esterase before the absorption in small intestine. For the development of inhibitory substances from natural source, we screened many extracts of oriental herbs for the inhibition of cholesterol esterase in vitro. The ethanol extract of Ephedra herba showed strong inhibitory activity. Solvent fractionation and silica gel column chromatography with the extract lead to the purification of the inhibitory principle in Ephedra herba. Crystallized inhibitor was identified as ( ) ephedrine by using UV, FT IR, 1H NMR, 13C NMR and GC/Mass. These results suggest that ( ) ephedrine can be used as a potential lead compound for the development of inhibitor for cholesterol uptake by cholesterol esterase inhibition.

• 미생물학회지
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• 제30권6호
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• pp.519-523
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• 1992

The glucoamylase of Candida tsuubaensis was purified to homogeneity form culture filtrate by means of ultrafiltration, Sephacryl S-200 gel filtration and Sp-Sephadex C-50 chromatography. The purified enzyme was a glycoprotein with a molecular mass of approximately 50 kDa, which was a monomeric protein. Km values were 5.8 mg/ml for soluble starch and 0.04 mM for maltose. Glucoamylase also released only glucose from both pullulan and isomaltose. The analysis of amino acid composition revealed that the enzyme contained a high content of acidic and polar amino acids. In addition, Western blotting analysis indicates that C. tsukubaensis glucoamylase is resistant to glucose repression.

• KSBB Journal
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• 제30권6호
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• pp.291-295
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• 2015

The limited productivity of natural shell matrix proteins has hampered the investigation of their biochemical properties and practical applications, although biominerals in nature obtained by organic-inorganic assemblies have attractive mechanical and biological properties. Here, we prepared a vector for the expression of a fusion protein of a shell matrix protein from Pinctada fucata (named as GRP_BA) with the GRGDSP residue. The fusion protein of BA-RGD was simply produced in E. coli and purified through sequential steps including the treatment with $CaCl_2$ and EDTA solution for cell membrane washing, mechanical cell disruption and the application of non-ionic surfactant of Triton X-100 for BA-RGD inclusion body washing. The production yield was approximately 60 mg/L, any other protein band was not observed in SDS-PAGE and it was estimated that above 97% endotoxin was removed compared to the endotoxin level of whole cell. This study showed this simple and easy purification approach could be applied to the purification of BA-RGD fusion protein. It is expected that the protein could be utilized for the preparation of biominerals in practical aspects.

• Journal of Forest and Environmental Science
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• 제34권2호
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• pp.165-168
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• 2018

Mt. Bongeui is a neighborhood park of 66.4 ha as a major natural landscape resource located in the center of Chuncheon City. This study quantified the reduction of carbon, $SO_2$, $NO_2$, $O_3$, and $PM_{2.5}$, and the production of $O_2$ to explore the role for Mt. Bongeui to contribute to annual atmospheric purification. The main forest types and age classes of the study site included age-class III broadleaved forest at 35.8%, age-class VI coniferous forest at 17.2%, and age-class IV broadleaved forest at 15.7%. The annual atmospheric purification effect per unit area was as follows: 7.6 t carbon/ha/yr, 16.6 kg $SO_2/ha/yr$, 40.4 kg $NO_2/ha/yr$, 41.5 kg $O_3/ha/yr$, 53.7 kg $PM_{2.5}/ha/yr$, and 20.2 t $O_2/ha/yr$. The economic value of these effects was equivalent to about 12.9 million KRW/ha/yr. The study site annually offset carbon emissions of about 300 citizens, $SO_2$ emissions of 220 citizens, and $NO_2$ emissions of 92 citizens in Chuncheon. It also played an important role in annually producing 1.5% of the amount of $O_2$ necessary for the respiration of Chuncheon's total population. This study pioneers in comprehensively quantifying the atmospheric purification effect and could be useful in guiding the planning and management to improve the effect.

• 생명과학회지
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• 제20권12호
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• pp.1801-1806
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• 2010

Klebsiella sp. Sc로부터 birchwood xylan을 분해하는 $\beta$-xylosidase를 분리하였다. 이 $\beta$-xylosidase는 63 kDa의 분자량을 가지는 559개의 아미노산을 암호화하며 1,680개의 뉴클레오타이드로 구성 되는 것으로 밝혀졌다. 기존에 밝혀진 세균성 $\beta$-xylosidase와 상동성을 비교해 보았을 때, Klebsiella oxytoca (KOX)와 90% identities와 95% positives를 나타내었으며 Lactobacillus lactis (LAC, 82%, 90%), Bacillus longum (BLON, 69%, 81%) 그리고 Escherichia coli (ECOLI, 47%, 63%)를 나타내었다. 분리된 $\beta$-xylosidase는 GST-fusion 정제 시스템을 이용하여 순수 정제하였다. 이 효소 활성의 최적 pH는 6.6이었으면 최적 온도는 $55^{\circ}C$였다. TLC를 통해 효소 분해 산물을 관찰한 결과, xylobiose를 분해하여 xylose를 생산하는 것을 관찰 할 수 있었다.

• Journal of Microbiology
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• 제35권2호
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• pp.109-116
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• 1997

An extracellular proteinase of Candida albicans was purified by a combination of 0~75% ammonium sulfate precipitation, DEAE Sepharose Fast Flow ion exchange chromatography, and Sephacryl S-200 HR molecular sieve chromatography. Its mlecular weight was approximately 41 kDa on SDS-PAGE and isoelectric point was 4.4. The enzyme was inhibited by pepstain A. Optimum enzyme activity ranged from pH 2.0 to 3.5 with its maximum at pH 2.5 and a temperature of 45$^{\circ}C$. The addition of divalent cations, $Ca^{2+}$, Zn$^{2+}$ and $Mg^{2+}$, resulted in no significant inhibition of enzymatic activity. However, some inhibitory effects were observed by Fe$^{2+}$, Ag$^{2+}$ and Cu$^{2+}$. With BSA as substrate, an apparent $K_m$ was determined to be 7$\times$10$^{-7}$ M and $K_i$, using pepstatin A as an inhibitor, was 8.05$\times$10$^{-8}$ M. N-terminal amino acid sequence was QAVPVTLXNEQ. Degradation of BSA and fibronectin was shown but not collagen, hemoglobin, immunoglobulin G, or lysozyme. The enzyme preferred peptides with Glu and Leu at the P$_1$ position, but the enzyme activity was highly reduced when the P$_2$ position was phe or pro. This enzyme showed antigenicity against sera of patients with candidiasis.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2001년도 제44회 춘계 학술연구 발표자료
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• pp.63-63
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• 2001

No Abstract. See Full-text