• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.199-207
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• 1993

In order to obtain a good microorganism capable of degrading microcrystaline cellulose (avicel), the screening test was carried out from soil and brown-rot wood. 8 strains which had good avicel-hydrolyzing activity were isolated. Among them, HK 47 which exhibited the highest avicel hydrolyzing activity was identified as Trichoderma sp. HK 47. Maximum avicel-hydrolyzing enzyme production from Trichoderma sp. HK 47 was obtained with the optimum medium contained carboxymethylcellulose 1.5% as carbon source, NaN030.75% as nitrogen source, KH2P040.5%, MgSO4.7H2O 0.1%, Tween 800.005% (V/V) during stationary cultivation at pH 6.0, 3$0^{\circ}C$ In this case, the production of avicel-hydrolyzing enzyme was 0.028 U/ml.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.230-237
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• 2004

In this study nitroreductase from Pseudomonas sp. HK-6 capable of degrading 2,4,6-trinitrotoluene (TNT) was characterized. Through a series of purification process including ammonium sulfate precipitation, DEAE-sepharose, and Q-sepharose, three different fractions I, II, and III having the enzyme activity of NTRs whose molecular weights were approximately 27 kDa were detected in fractions from HK-6 cells. Specific activity of the three fractions were approximately 4.85 unit/mg, 5.47 unit/mg, and 5.01 unit/mg, and concentrated to 9.0-, 10.1-, and 9.3-fold compared to crude extract, respectively. The optimal pH and temperature for the three NTR fractions were approximately 7.5 and $30^{\circ}C$, respectively. Metal ions, $Ag^{＋}$ , $Cu^{ 2+}$, $Hg^{2＋}$ inhibited approximately 70% of enzymes activities of all NTR, while $Fe^{2＋}$ did not stimulate or inhibit the activities. Monitoring the effect of chemicals on the enzyme activity revealed that those NTR fractions lost enzyme activity in presence of $\beta$-mercaptoethanol, but were a little influenced by dithiothreitol, EDTA and NaCl. The three NTR fractions demonstrated enzyme activities for nitrobenzene and RDX as well as TNT.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.227-234
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• 2020

To produce the miraculin protein in suspension cultures, rice (Oryza sativa L.) was transformed with Agrobacterium tumefacience EHA105 containing the miraculin AB512278 gene. The cell suspension cultures were established using cell lines selected from transgenic rice callus. The integration of the miraculin gene into the rice chromosome was confirmed using genomic PCR analysis. In addition, RT-PCR analysis indicated that the miraculin gene is expressed in the selected suspension cell lines. Thus, the recombinant miraculin was expressed in the transgenic suspension cell line, HK-2. Therefore, we have successfully developed a HK-2 line that produces miraculin. These results demonstrate that transformed cell suspension cultures can be used to produce a taste-modifying protein such as miraculin.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.658-666
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• 2015

The aim of this study was to investigate the effects of rice contatining Aspergillus terreus (Hwangkuk, HK) on lipid metabolism in male Sprague-Dawley (SD) rats fed a high-cholesterol diet (HCD) for 8 weeks. SD rats were divided into five groups: Normal, [Negative Control (HCD), Positive Control (lovastatin)], [HK 0.5 g/kg and HK 2 g/kg]. Hepatic total lipids significantly decreased following treatment with rice contatining Asp. terreus. Furthermore, this treatment led to higher expression levels of HMG-CoA reductase, LDL receptor and SREBP2 mRNA in the liver compared with the HCD group. In addition, histopathologic evaluation showed that feeding rats with rice containing Asp. terreus suppressed hepatic steatosis. These results suggest that rice containing Asp. terreus may be able to regulate of cholesterol synthesis and prevent hyperlipidemia.

• Journal of the Korean Society for Heat Treatment
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• v.20 no.2
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• pp.78-83
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• 2007

CrN coatings were deposited by cathodic arc ion plating method on the SKD11 steel substrates. Atmosphere temperature of $350^{\circ}C$, arc current of 90 A, nitrogen partial pressure of 1.0-5.3 Pa, and negative bias voltage of 30-135 V were selected. The characteristics of microstructure were investigated with XRD. Hardness, adhesion and friction coefficient measured by microhardness tester, scratch tester, and ball on disk tribometer. Microstructures depended on nitrogen partial pressure and bias voltage. The preferred orientation of the films was changed from (200) to (111) with decreasing pressure and increasing bias voltage. Adhesion properties related with microstructure, but microstructure changes slightly influenced on hardness and friction properties. The critical load.($Lc_1$) and hardness of CrN films deposited at 5.3 Pa, -30 V condition were 55 N(HF1), $2157{\pm}47\;Hk_{0.025}$. The friction coefficient were about 0.5 under dry condition.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.133-146
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• 2014

There are many studies for the economic impact assessment of natural disasters, but there are few for volcanic disasters. Domestic academic research is not under active discussion because of the lack of national and social interest for volcanic eruption. This study investigated the research methodology for the economic impact assessment of natural disasters and discussed whether these can be applied to the economic impact analysis for the Baekdu Mountain volcanic disaster. The main findings are as follows: Firstly, Asia-Pacific region is the most affected by natural disasters and has the largest scale of damage. Asian and American Continent have the most economic damage. Secondly, Considering the types of damage caused by natural disasters and its complex structure, several methodologies that could be possible to estimate economic consequential damages have been compared. When applying each methodology to the Baekdu Mountain volcanic disaster, the scale of damage is likely to be over-estimated or under-estimated because of model-specific features. Thus, estimated values should be compared to each other after calculating the damage results. Thirdly, Japanese academic research on the volcanic disaster will be used as the starting point of the economic impact assessment studies for Baekdu Mountain. Using computer SW such as Hazus which is used in United States and RiskScape from New Zealand is also a good method to predict economic impact of the Baekdu Mountain volcanic disaster.