• Biomedical Science Letters
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• v.11 no.4
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• pp.533-538
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• 2005

This investigation was performed to study the antioxidant activities of Hovenia dulcis THUNBER var. koreana Nakai fruits extracts and the effect of Hovenia dulcis fruits extracts on glucose, lipid metabolism in diabetic rats. DPPH free radical scavanging activitiy and superoxide anion radical Scavenging of Hovenia dulcis fruits $80\%$ methanol extracts were $0.06\pm0.002mg$ polyphrnol/ml and $0.l2\pm0.00lmg$ polyphmol/ml, respectively. Hovenia dulcis fruits $80\%$ methanol extracts were partitioned into hexan, dichloro methane, ethyl acetate and butanol, successively. Ethyl acetate fraction were good antioxidant activity. Streptozotocin (45 mg/kg body weight, i.p.) induced diabetic rats showed a significant increases of plasma glucose, triglyceride and total cholesterol. Concomitantly significant decrease of plasma high density lipoprotein. Glutathione level were decrease in cytosol of liver. Lipid peroxide were increase in microsome of liver. Group 1 and 2 were treated with Hovenia dulcis fruits ethyl acetate extracts 50 mg/kg body weight and 20mg/kg body weight for 24 days, individually. Group land 2 rats showed decreased plasma glucose, triglyceride, total cholesterol and lipide peroxide in microsome of liver tissue of rats, and increased plasma high density lipoprotein and glutathione in cytosol of liver tissue rats. The result suggest that Hovenia dulcis THUNBER var. koreana Nakai fruits extracts may effectively normalize the impaired antioxiants status in streptozotocin induced diabetic rats. Hovenia dulcis fruits ethyl acetate extracts were used to improve the imbalance between free radicals and antioxidant system due to the diabetes.

• Journal of environmental and Sanitary engineering
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• v.11 no.1
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• pp.45-55
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• 1996

An experimental research was conducted in order to study the combined treatment o of municipal landfill leachate and municipal sewage. The landfill leachate was that of Nanjido landfill site, and the municipal sewage was that of Chungnang municipal sewage treatment plant in Seoul. Several sets of bench~scale sequencing batch reactor(SBR) were used as e experimental apparatus. Specially investigated items in this experiment were the removal efficiency of substrate and the influence of treatment time. The experiment lasted for about 2 years. The result are as follows ; 1. The characteristics of leachate were pH 7.5~8.2, BOD 80~336mg/L, COD 908~1,460mg/L, NH3-N 1,409~2,330mg/L, T~P 2.7~7.lmg/L, Cl~3,540~4,085mg/L, a and heavy metals are a very small amount. And the characteristics of sewage were pH 6.9~7.3, BOD 78.4~129.3mg/L, COD 121.2~305.0mg/L, T~N 14.9~36.4mg/L, T-P 2.3~8.9mg/L. 2. The treatability of leachate alone was not treat well. So for the good treatment of leachate, it was necessary to deal with the pretreatment before bi이ogical treatment and a combined treatment of municipal sewage. 3. The various contents of the leachate were 5%, 10%, 30%, and 50%, and the removal efficiency of COD was 86.0%, 82.8%, 60.6%, and 31.7%. The maximum content of the leachate which could be sucessfully treated by SBR in the combined treatment was 10% of that of sewage. And the removal efficiency of COD increased n notably, as its treatment time increased. 4. The various contents of the electrolytic treated leachate were 5%, 10%, 30%, and 50%, and the removal efficiency of COD was 89.9%, 86.1%, 79.2%, and 69.8%. The maximum content of the leachate which could be sucessfully treated by SBR in the combined treatment was 30 % of that of sewage. And the removal efficiency of C COD increased notably, as its treatment time increased.

• Journal of the Korean Institute of Gas
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• v.4 no.2 s.10
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• pp.7-14
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• 2000

LNG (Liquified Natural Gas) carried by LNG ship is unloaded into the LNG storage tanks at the very low temperature (a little lower than the boiling point of LNG). Because LNG is unloaded through the pipeline, two phase flow appears in the pipeline. In this study, we have studied the pressure-drop mechanisms of the two-phase flow in the pipeline, and the calculation method of BOG (Boil-off Gas) amount based on the heat transfer mechanism through the insulation and the surface of the pipeline. We have developed a computer program for thermal-hydraulic analysis on the LNG pipeline system. We have also developed the optimal design program to find the optimal thickness of insulation and the pipeline size. The program searches the optimal design with the minimum capital cost of pipelines and insulation on the operating conditions of maximum allowance pressure-drop and BOG amount, etc.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.602-609
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• 2012

Burkholderia anthina R-4183, Burkholderia diffusa R-15930 and Burkholderia stabilis LMG 14294 isolated from green house soils (Gongju-Gun area, South Korea) were characterized and their phosphate solubilizing ability was assessed. Under in vitro culture conditions, all three species were proved to be effective in solubilizing phosphates in varying degrees. Strain Burkholderia anthina exhibited the highest phosphate solubilization in NBRIP medium ($665{\mu}g\;ml^{-1}$) followed by Burkholderia diffusa ($630{\mu}g\;ml^{-1}$) and Burkholderia stabilis ($578{\mu}g\;ml^{-1}$). However, solubilization of $FePO_4$ and $AlPO_4$ was found to be poor in all the strains. Acidification by means of gluconic and oxalic acids accumulation in the culture medium could be the possible mechanism responsible for phosphate solubilization. Glucose at the rate of 3% was found be the best carbon source for Burkholderia anthina while other two Burkholderia species showed maximum phosphate solubilization at 2% of glucose. In the case of nitrogen sources, ammonium and nitrate were equally effective in solubilizing phosphates by Burkholderia species. Despite a slight decrease in phosphate solubilization observed at increasing temperature, all three Burkholderia species could withstand a temperature of $30-35^{\circ}C$, pH at the range of 7-9 and the presence of NaCl (up to 2.5%) without much compromising the phosphate solubilization. As shown with potted mung bean seedlings, all the three isolates could enhance soil fertility and plant growth indicating their great potential to be used as bio-inoculants.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1011-1015
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• 2008

A Gram-negative, strictly aerobic, motile bacterial strain, designated Gsoil $124^T$, was isolated from a soil sample taken from a ginseng field in Pocheon Province (South Korea). The isolate contained Q-10 as the predominant lipoquinone, plus $C_{18:1}\;{\omega}7c$ and summed feature 4 ($C_{16:1}\;{\omega}6c$ and/or iso-$C_{15:0}$ 2-OH) as the major fatty acids. The G+C content of the genomic DNA was 68.1 mol%, and the major polar lipids consisted of sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, and phosphatidylethanolamine. A comparative 16S rRNA gene sequence analysis showed that strain Gsoil $124^T$ was most closely related to Sphingopyxis chilensis (98.7%), Sphingopyxis alaskensis (98.2%), Sphingopyxis witflariensis (98.2%), Sphingopyxis taejonensis (98.0%), and Sphingopyxis macrogoltabida (97.6%). However, the DNA-DNA relatedness between strain Gsoil $124^T$ and its phylogenetically closest neighbors was less than 22%. Thus, on the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $124^T$ should be classified as representing a novel species in the genus Sphingopyxis, for which the name Sphingopyxis panaciterrae sp. nov. is proposed. The type strain is Gsoil $124^T$ (=KCTC $12580^T$=LMG $24003^T$).

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1728-1733
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• 2006

A Gram-negative, strictly aerobic, nonmotile, and nonspore-forming bacterial strain, designated $T5-12^T$, was isolated from compost and characterized using a polyphasic taxonomical approach. The isolate was positive for catalase and oxidase tests. It could degrade DNA, but was negative for degradation of macromolecules such as casein, collagen, starch, chitin, cellulose, and xylan. The DNA G+C content was 36.0 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major fatty acids were $iso-C_{15:0}$ (45.6%), $iso-C_{17:0}$ 3OH (17.2%), and summed feature 4 ($C_{16:0}\;{\omega}7c$ and/or $iso-C_{15:0}$ 2OH, 14.9%). Comparative 16S rRNA gene sequence analysis showed that strain $T5-12^T$ fell within the radiation of the cluster comprising members of the genus Sphingobacterium. Strain $T5-12^T$ exhibited lower than 94% of 16S rRNA gene sequence similarity with respect to the type strains of recognized Sphingobacterium species. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain $T5-12^T$ ($=KCTC\;12578^T=LMG\;23401^T=CCUG\;52467^T$) should be classified in the genus Sphingobacterium as the type strain of a novel species, for which the name Sphingobacterium composti sp. novo is proposed.

• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.43-52
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• 1996

This study was carried out to establish the in vitro short-term culture system of developing male germ cells by purifing germ cells of various stages. The decapulated testicular cells were incubated with collagenase (lmg/ml) and try psin (2.5mg/ml) in HBSS. After separating male germ cell, the separated germ cells were stained with heamatoxylin/eosin and determined developing stages under light microscopy. The purity of pachtene spermatocytes a and round spermatid were 85%, respectively. Yield of total male germ cells was highly variable between individuals, with a mean value of 3.5 to 4.5 ${\times}$ 10$^7$ cells/testis. Viability of the cell was over 97% after separation. In DMEM medium, the optimal cell number for culture is approximately 1 x 10$^5$ cells/dish, but low cell den-sities than 1 ${\times}$ 10$^5$ cell/dish showed a decreased cell viability. Furthermore, about :36.8% of pac-hytene cells was successfully cultured for 6 days and some of cells were developed to secondary spermatids and round spermatids. Therefore, our data suggested that this culture conditions will be utilize as a feasible tools to produce tran-sgenic livestock using techniques such as intrac-ytoplasmic injection and cell fusion.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.259-262
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• 2002

The efficiency of regeneration of callus and explants from leaf and stem disks of Epimedium koreanum was examined on the MS media containing 2,4-D, NAA, Kinetin, BA and TDZ. Calli were formed on the 2mg/l 2,4-D media at the rate of 32% from leaf discs and 52% from stems. No callus was produced on the media which are containing BA or TDZ alone. The combination of 2,4-D and BA showed the effect on the formation of callus. The combination of 2mg/l 2,4-D and 0.lmg/l BA in the MS media had produced the highest percentage of callus formation, 50% from leaf discs and 40% from stems, respectively. The combination of 2mg/l 2,4-D and 1mg/1 BA in the MS media had affected the formation of callus in the rate of 40% from leaf discs and 25% from stems. The combined plant growth regulators of 2,4-D and BA increased the formation of calli from leaf discs, but single treatment of 2,4-D showed the highest callus formation from stems. Multiple shoots from leaf discs were formed on the media containing NAA, BA, kinetin, and TDZ. The highest number of multiple shoots were obtained 0.1mg/l NAA combined with 1mg/l kinetin. As a result, leaf discs or stems can be used for the mass propagation of Epimedium koreanum, but stem elongation of shoots from calli was not easy.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.44-50
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• 1986

Tissue distribution and blood chemistry of uranium in serum levels of BUN, Creatinine, SGPT and SGOT were determined in rats after the administration of uranylnitrate. Determination of uranium in organ was done by radio activation analysis. Radioactivity of $^{239}Np$ in lung was higher than in other tissues (e.g. liver, kidneys, spleen, tibia, testes, stomach and brain). Correlations between BUN and Creatinine were positively increased after the administration of 25 mg/kg uranylnitrate. The SGPT and SGOT activities showed weak correlation with the control group. However, activities of SGPT and SGOT after the administration of lmg/kg uranylnitrate showed high peak at 90 min interval. Uranium uptake by liver and kidneys increased at early period and decreased immediately to the control level. Lung who confirmed to be the critical organ on toxic effect by uranylnitrate.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.143-148
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• 1995

The competence of callus formation and plant regeneration from root derived callus was higher in japonica cultivars than those of Tongil-type cultivars of rice. A japonica type cultivars Yeongdeogbyeo, showed the highest capacity (13%) for plant regeneration from root calli of 6 cultivars tested. The callus induced from seed and root tissues maintained higher capacity for plant regeneration during 7 passages of subculture on N$_{6}$ solid media at 2-week intervals. The maximum frequency (2 x 10$^{5}$ mL) of round cells and their cell colonies showed about 24 days after suspension culture of root-derived callus in N$_{6}$ medium with lmg/L 2,4-D, 300mg/L casein hydrolysate, 10mM L-proline, 20g/L sucrose and 30g/L sorbitol. The frequency of somatic embryo formation in suspension cultures of root-derived callus increased with prolonged advance of subculture time from 30 to 90 days, but their regenerative capacities decreased.