• 대한의생명과학회지
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• 제11권4호
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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.

• 환경위생공학
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• 제11권1호
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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.

• 한국가스학회지
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• 제4권2호
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• pp.7-14
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• 2000

생산지로부터 LNG 선박으로 수송되어 각 생산기지의 저장탱크로 저장되는 액화천연가스 (LNG; Liquified Natural Gas)는 극저은인 Boiling Point보다 약간 낮은 온도 ($-162^{\circ}C$)로 전송된다. LNG 전송은 배관을 통하여 이루어지며, 이로 인하여 배관 내에는 2상 유동 (2-Phase Flow)이 자주 형성된다. 본 연구에서는 일차적으로 이러한 배관내의 2상 유동대한 압력강하량 계산법을 연구하였고, 단열재와 배관 표면을 통한 외부 열유입량과 그에 따른 BOG (Boil-off Gas) 발생량 계산 방법을 연구하여, 이들을 기반으로 LNG 배관시스템의 열유동 해석 프로그램을 개발하였다. 또한 본 연구 및 프로그램 개발을 토대로 최적의 단열재 두께와 배관 Size를 구할 수 있는 최적 설계 프로그램을 구축하였다. 이는 배관설계 시 주어진 최대 허용 압력 강하량과 BOG 발생량 등의 허용 운전 조건과, 단위 길이 당 배관가격과 단위 부피당 단열재가격을 기준으로 허용 범위 내의 최소 설비 비용을 찾는 최적 설계 방법이다.

• 한국토양비료학회지
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• 제45권4호
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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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• 제18권6호
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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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• 제16권11호
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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.

• 한국가축번식학회지
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• 제20권1호
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• pp.43-52
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• 1996

본 연구는 생쥐의 고게정관내에 존재하는 분화단계의 정자세포를 발생단계별로 분리하여, 체외에서 단기간 배양체계를 확립하기 위하여 실시하였다. 8주령 이상된 생쥐의 정소로부터 정소막을 제거시킨 후, collagenase (1mg/ml), trypsin(2.5mg/ml)를 처리하여 곡세정관을 간질세포와 분리하여 배양액에 부유시켰다. 부유세포는 Celcep장치를 이용하여 세포크기와 밀도 차이에 의해 분화 단계별로 분리하였다. 회수된 세포의 균질성은 haematoxylin/eosin 또는 orcein으로 염색한 후, 광학현미경하에서 확인한 결과 약 85% pachytene spermatocyte와 round spermatid을 성공적으로 분리해냈다. 따라서 sedimentation velocity에 의해서 생쥐의 spermatogenic cell의 발달단계별 분리가 가능함을 알 수 있었다. 이러한 방법으로 분리된 pachytene spermatogenic cell들은 DMEM 배양액에서 6일 이상 배양한 결과 약 36%의 생존율을 보였다. 따라서, 분화단계별 정자 세포의 분리 및 배양체계의 확립은 웅성생식세포의 발생과정에 따른 생리 또는 분자생물학적 현상을 규명함은 물론 세포융합기술의 이용에 의한 형질전환동물 생산에의 응용을 통해 가축에 있어서의 형질전환 생산효율의 개선에 기여할 수 있으리라 사료된다.

• 한국약용작물학회지
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• 제10권4호
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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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• 제11권1호
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• pp.44-50
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• 1986

천연우라늄의 생체내 흡수 및 분포의 역학적 정보와 반응을 알기 위하여 질산우라늄을 투여하여 변동되는 조직분포 및 혈중 BUN, Creatinine, SGPT 및 SGOT의 활성도를 측정하였다. 조직중의 우라늄 함량은 방사화분석법을 이용하여 방출되는 ${\gamma}$ 에너지의 강도를 측정함으로써 조사 하였다. 이때 시간이 경과함에 따른 질산우라늄의 조직분포의 양상은 특히 폐가 다른 장기에 비하여 현저하게 축적되는 것을 관찰하였다. 한편 25 mg/kg의 질산우라늄 투여시 비효소계인 질소대사의 임상적 지표인 BUN 및 Creatinine값은 예민한 반응을 나타냈으나 효소계의 SGPT 및 SGOT의 활성도에는 큰 변화가 없었다. 1 mg/kg의 질산우라늄 투여에 의한 SGPT 및 SGOT의 활성도의 변화는 복강투여후 90분에 최고치를 나타내다가 회복되었다. 우라늄 흡수의 조직분포의 실험결과 간장 및 신장의 축적이 흡수초기에 최고치를 나타내다 다시 감소되는 결과로 미루어 보아 우라늄의 독성을 가장 크게 나타나는 결정장기(critical organ)는 신장이나 간장이 아니고 폐장임을 알 수 있었다.

• 식물조직배양학회지
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• 제22권3호
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• pp.143-148
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• 1995

벼의 뿌리조직을 기내배양하여 배발생캘러스의 형성과 식물체 재분화율의 품종간 차이 및 완숙배와 뿌리조직에서 유래된 캘러스의 현탁배양 기간별 부정배 형성정도와 식물체 재분화율 등에 대한 몇가지 실험을 수행하여 얻어진 결과를 요약하면 다음과 같다. 벼 뿌리조직으로부터 캘러스 형성 및 식물체 재분화 능력의 품종간 차이는 뚜렷하게 나타났으며, 자포니카형 품종들이 통일형 품종에 비해 캘러스의 생장량도 많고 식물체 재분화율도 높은 경향이었고, 공시품종 중 "영덕벼"의 식물체 재분화율이 13%로 가장 높았다. 뿌리 및 현미배양에서 형성된 캘러스를 고체배지에서 2 주 간격으로 7회 계대배양한 바, 계대배양 횟수가 증가됨에 따라 식물체 재분화율이 증가되었다가 5회째부터는 점차 감소하였다. 뿌리조직에서 형성된 캘러스의 현탁배양에서 모양이 둥근세포와 그들의 세포괴는 배양 24일 후에 최대치를 나타내었고 그 이후는 감소하였다. 현탁배양 기간별 뿌리조직에서 형성된 캘러스의 체세포배 형성률은 배양 90일까지는 배양기간이 길어질 수록 증가하였으나, 그 이후는 감소하였고, 식물체 재분화율도 배양기간이 길어질수록 감소하는 경향이었다.소하는 경향이었다.