• Journal of Microbiology
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• 제39권4호
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• pp.279-285
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• 2001

Vibrio parahaemolyticus is a halophilic bacterium associated with seafood gastroenteritis. An unusual strain of Kanagawa-positive urease producing Vibrio parahaemolyticus O1:K1 was isolated from the environment and identified . A polymerase chain reaction assay revealed that this strain harbored both the tdh and the genes. The urease from this strain was studied. Maximum urease production was induced in LB medium containing 0.2% urea, 0.5% glucose, 2% NaCl and pH 5.5 with 6h of culti-vation at 37$\^{C}$ under aeration. Purification of urease was achieved by the process of whole cell lysate, 65% ammonium sulphate precipitation, DEAE-cellulose ion exchange column chromatography, Sepharose CL-6B gel filtration and oxirane activated Sepharose 6B-urea affinity chromatography with 203 fold purification and 2.2% yield. Analysis of the purified enzyme by SDS-PAGE demonstrated the presence of the subunits with a molecular weight of 85kDa, 59kDa, 41kDa and the molecular weight for the native enzyme by nondenaturing PAGE and gel filtration chromatography was 255kDa. The purified urease was stable at pH 7.5 and the opeimal pH in HEPES buffer was 8.0 The enzyme was stable at 60$\^{C}$ for 2 h with a residual activity of 32% . The addition of 10$\mu$M if NiCl$_2$maintained stability for 30 min. The Km value of the purified enzyme was 35.6 mM in urea substrate. The TD$\_$50/(median toxic dose) of the purified urease was 2.5$\mu\textrm{g}$/ml on human leukemia cells.

• 자원환경지질
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• 제41권2호
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• pp.253-265
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• 2008

지속가능한 자원관리모형(SRM)구축은 탈물질화 및 환경과 경제의 디커플링을 이루기 위한 핵심적 요소로 여겨지고 있다. 본 연구에서는 세계 각국의 지속가능한 자원관리 정책 및 연구방향을 살펴보고, decoupling factor를 이용하여 국내제조업의 경제활동과 에너지소비간의 디커플링현상을 살펴보았다. 마지막으로 이를 바탕으로 국내 실정에 맞는 SRM모형구축과 전략을 제시하였다. 자원관리 시스템은 수요전망, 물질흐름분석과 가치사슬분석, 시장구조분석 등의 분석과 조사 등을 바탕으로 구축된다. 이러한 분석들을 통해 환경적 문제 해결, 재활용시장관리방안 및 시장의 구조적 문제점 도출, 필요 재활용기술 도출, 1차자원과 2차자원의 최적 공급비율 등의 Hot-spot 도출 및 해결방안모색이 가능하다. 또한 지속가능한 자원 관리시스템과 국가단위, 권역단위의 물질흐름분석을 유기적으로 연계하고, 효과적인 이의 운영을 위해서는 국가차원의 법제화와 뒷받침이 이뤄져야 할 것이다.

• Genomics & Informatics
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• 제13권3호
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• pp.70-75
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• 2015

MicroRNAs (miRNAs) have been demonstrated to play an important role in carcinogenesis. Previous studies revealed that miRNAs are present in human plasma in a remarkably stable form that is protected from endogenous RNase activity. In this study, we measured the plasma expression levels of three miRNAs (miR-21, miR-27a, and miR-155) to investigate the usefulness of miRNAs for gastric cancer detection. We initially examined plasma miRNA expression levels in a screening cohort consisting of 15 patients with gastric cancer and 15 healthy controls from Korean population, using TaqMan quantitative real-time polymerase chain reaction. We observed that the expression level of miR-27a was significantly higher in patients with gastric cancer than in healthy controls, whereas the miR-21 and miR-155a expression levels were not significantly higher in the patients with gastric cancer. Therefore, we further validated the miR-27a expression level in 73 paired gastric cancer tissues and in a validation plasma cohort from 35 patients with gastric cancer and 35 healthy controls. In both the gastric cancer tissues and the validation plasma cohort, the miR-27a expression levels were significantly higher in patients with gastric cancer. Receiver-operator characteristic (ROC) analysis of the validation cohort, revealed an area under the ROC curve value of 0.70 with 75% sensitivity and 56% specificity in discriminating gastric cancer. Thus, the miR-27a expression level in plasma could be a useful biomarker for the diagnosis and/or prognosis of gastric cancer.

• The Korean Journal of Physiology and Pharmacology
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• 제6권5호
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• pp.255-260
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• 2002

The effects of intracellular and extracellular pH on the inwardly rectifying $K^+$ (IRK) channel of the bovine aortic endothelial cells (BAECs) were examined using whole-cell patch-clamp technique. The IRK current, efficiently blocked by $Ba^{2+}\;(200{\mu}M),$ is the most prominent membrane current in BAECs, which mainly determines the resting membrane potential. The expression of Kir2.1 was observed in BAECs using reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Intracellular alkalinization, elicited by the extracellular substitution of NaCl with $NH_4Cl$ (30 mM), significantly augmented the amplitude of IRK current. On the contrary, the amplitude of IRK current was attenuated by the Na-acetate (30 mM)-induced intracellular acidification. The changes in extracellular pH also closely modulated the amplitude of IRK current, which was decreased to $40.2{\pm}1.3%$ of control upon switching the extracellular pH to 4.0 from 7.4. The extracellular pH value for half-maximal inhibition (pK) of IRK current was 5.11. These results demonstrate that the activity of IRK channel in BAECs, probably Kir2.1, was suppressed by proton at both sides of plasma membrane.

• 한국유기농업학회지
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• 제23권3호
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• pp.423-453
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• 2015

This study started with two questions. The first question is 'Why does organic agriculture want to be linked with cooperative?' The second is 'What is the characteristics of the mutual relationship between organic agriculture and cooperative?', especially in Wonju. Up to now, there have been various kinds of discussion about cooperation between organic agricultural campaign and cooperative in Wonju. But there are few concrete data showing what role cooperative plays in the cyclical process of production-distribution-consumption of organic agriculture. Thus, we conducted a survey applying the Delphi technique to the 35 organic agricultural specialists active in Wonju. First, small-scale family farm producers established a social economic cooperative network in around 2003 to perform 'the activities of innovators' through forming an organization. Producers moved from the stage in which they were supported one-sidedly by consumers to the stage where they could 'lead' cooperation. Each farm organization built a vertical integration, and horizontal cooperative systems with other farm organizations. But, practical cooperative activities have remained in the doldrums. They tend to show trends deviating from the principles of organic agriculture and cooperative. Second, the relationship between producers and consumers in Wonju can be described as 'producer-consumer cooperative type'. In Wonju, the producers' organization is not a sub-contractor which simply deliver organic agricultural products to producers' cooperative, but is an equal subject which creates its own value chain. The cooperative (cooperative organization) leads distribution and consumption of organic agricultural products and mutual communication. But, the closeness between producers and consumers has got loosened. And, it is problematic that the proportion of local food consumption in Wonju is very low. There is a very strong tendency to ride the central distribution system of producers' cooperative coalition. Consequently, it is necessary for producers' cooperatives in Wonju to run a local food distribution system based on the 'cooperative system among cooperatives'.

• 한국축산식품학회지
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• 제42권5호
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• pp.800-815
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• 2022

This study aimed to obtain high Fischer's ratio oligopeptides from goat whey (HFO) and investigate antioxidant property of it. Hydrolysis of goat whey was done with the approach of sequential digestion of pepsin and flavourzyme. With the adsorption of aromatic amino acids by activated carbon, HFO with a Fischer's ratio of 27.070 and a molecular weight of 200-1,000 Da were obtained, and the branched-chain amino acids accounted for 22.87%. Then the antioxidant activity of HFO was evaluated. At the concentrations of 2.0 mg/mL and 0.50 mg/mL, HFO scavenged 77.27% and 99.63% of 1,1-diphenyl-2-picrylhydrazyl and 3-ethylbenzthiazoline-6-sulphonate free radicals respectively. The scavenging rate of HFO against hydroxyl radicals reached 92.31% at the concentration of 0.25 mg/mL. Animal experiments demonstrated that HFO could moderate the changes of malondialdehyde, superoxide dismutase and glutathione peroxidase caused by CCl₄-induced oxidative stress in vivo. This study indicated that HFO from goat whey was capable of oxidation resistance both in vivo and in vitro, which provided a scientific basis for the high-value processing and application of goat milk whey.

• 지구물리와물리탐사
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• 제12권1호
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• pp.17-26
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• 2009

향후 발생할 수 있는 자연재해의 기초 자료 확보를 위해 아오가시마섬 지역의 화산 구조를 연구하였다. 아오가시마섬은 일곱개의 섬이 분포하는 이즈열도의 최남단에 위치하고 있는 화산섬으로 효율직인 탐사를 위하여 헬리콥터를 이용한 항공 벡터 자기이상 탐사를 수행하였다. 일반적으로 화산섬의 자기구조를 연구하기 위해서는 총자기이상을 이용하게 되는데 이는 본질적인 오차를 내포하고 있다. 총자기이상은 물리적 특성을 정확히 반영하지 못하기 때문에 맥스웰방정식이나 라플라스 방정식을 만족하지 못하며, 물리적으로 정확한 해석을 수행하기 어려운 단점을 가지고 있다. 또한, 해석을 위하여 한 방향으로 투영된 총자기이상값을 사용하기도 하여 이 과정에서 발생하는 오차 때문에 해석상의 오류가 발생할 수 있다. 이러한 문제점을 보완하기 위하여 이번 연구에서는 벡터 자기이상값을 직접 측정 하였으며, 이를 이용하여 보다 신뢰성 높은 아오가시마섬의 3차원 자기이상 특성을 연구하였다. 이번 연구의 해석결과를 간단히 정리하면, 1A/m 이하의 자화강도를 보이는 지역은 아오가시마섬 남서쪽에 분포하고 있으며, 그 심도는 1-2 km로 해석되었다. 이러한 낮은 자화강도를 보이는 지역은 화산분기 작용의 특성을 고려할 때, 화산분기 작용이 발생했던 지역으로 생각된다.

• Asia Marketing Journal
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• 제11권3호
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• pp.91-124
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• 2009

통신서비스 시장의 경쟁이 날로 심화되고 기술속성이 표준화되면서 접점에서의 차별적 활동과 경험이 고객가치 창출을 위한 중요한 수단으로 인식되고 있지만, 정작 고객접점의 활동이 소비체인에 따라 어떤 식으로 구성되어 있고 어떤 영향력을 행사하는지, 접점의 서비스 품질이 고객성과에 미치는 상대적 영향력을 규명한 연구는 미흡하였다. 특히 현재 가구기반 통신서비스시장은 PLC단계별로 다양한 서비스들이 포진해 있는 바, 서비스가 도입-성장기에 있는지 이미 성숙-쇠퇴기에 들어섰는지에 따라 접점에서 요구되는 소비자들의 서비스 니즈가 달라질 수 있음에도 이를 실증한 연구는 전무한 상황이다. 이에 본 연구에서는 도입-성장기에 있는 가구기반 통신서비스로 VoIP와 IPTV, 성숙쇠퇴기에 있는 가구기반 통신서비스로 유선초고속 인터넷과 유선전화를 선정하여 각 서비스별로 MOT접점에서 고객들이 어떤 경험을 하고 있고 무엇을 중시하고 있는지 영향력을 확인한 후 접점의 서비스 품질이 고객성과에 미치는 효과가 통신서비스의 PLC 단계에 따라 어떻게 달라지는지 그 상대적인 영향력을 살펴보았다. 858명의 응답자를 대상으로 실증한 결과 접점에서 소비자들의 경험과 요구사항은 상이하게 나타났으며 서비스품질과 관련해서는 도입-성장기에 있는 서비스들은 유형성과 확신성이, 성숙-쇠퇴기에 있는 서비스들은 신뢰성과 공감성, 상호관계성이 고객성과(고객만족, 재구매의향, 구전의향)에 긍정적인 역할을 함이 제시되었다. 끝으로 이러한 결과에 대한 시사점과 향후 연구방향을 제시하였다.

• 한국어병학회지
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• 제36권2호
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• pp.277-286
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• 2023

Korean rockfish, Sebastes schlegelii, is a representative bony fish that belongs to the family Scorpaenidae and the order Scorpaeniformes. It has high ecological and economic value and is widely cultivated in many East Asian countries, including South Korea, Japan and China. One of streptococci, Streptococcus iniae, is Gram-positive cocci with a negative reaction for catalase and oxidase. The Korean rockfish shows clinical signs when infected with S. iniae, such as body darkening, bleeding, enlarged kidneys, blurred eyes, abdominal distension, etc., ultimately leading to death. The Korean rockfish causes significant economic losses every year in South Korea due to streptococcosis. In this study, we identified bacteria from the fish using polymerase chain reaction and conducted analyses of hemolytic activity and biochemical tests using API 20 STREP and API ZYM systems. Results of confirming the hemolytic activity (n=4) observed in alpha-type hemolysis (25%), beta-type hemol- ysis (50%), and gamma-type hemolysis (25%) of isolates. The biochemical test results exhibited sig- nificant variation among S. iniae. Additionally, we performed intraperitoneal injection with S. iniae in the fish and analyzed the phylogenetic tree using housekeeping genes of S. iniae, including cpsD, arcC, glnA, groEL, gyrB, mutS, pheT, prkC, rpoB, and tkt, via multilocus sequence typing (MLST). The lethal dose (LD₅₀) showed strong pathogenicity, such as 3.34 × 10 colony-forming unit (CFU)/ml for 23FBStr0601 strain and 7.16 × 10 CFU/ml for 23FBStr0602 strain. 23FBStr0603 strain showed relatively low pathogenicity at 1.73 × 10⁵ CFU/ml. The strains 23FBStr0601 and 23FBStr0602, which showed strong pathogenicity, clustered into one monophyletic group. The 23FBStr0603 strain showed weak pathogenicity and formed a monophyletic group with KCTC 3657.

• 한국미생물·생명공학회지
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• 제43권3호
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• pp.195-203
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• 2015

전통 발효된장으로부터 α-galactosidase를 분비 생산하는 두 종류 Bacillus licheniformis 균주로 YB-1413과 YB-1414를 분리하여 당 이용능을 비롯한 생화학적 특성 및 16S rRNA 염기서열과 중합효소 연쇄반응에 의한 임의증폭 DNA 다형성의 유전학적 특성을 비교한 결과 두 균주는 매우 유사하였지만 동일 균주는 아닌 것으로 확인되었다. 탄소원으로 wheat bran을 사용하였을 때는 두 균주의 α-galactosidase 생산성이 증가하였으나, melibiose, raffinose 또는 sucrose는 효소 생산성이 급격하게 감소하였다. 질소원으로 yeast extract가 첨가된 배지에서 효소 생산성이 높았으며, YB-1413은 1.87 U/ml, YB-1414는 1.69 U/ml의 효소 생산성을 보였다. 이들 균주가 생산하는 α-galactosidases는 pH 6.0과 45℃에서 모두 최대활성을 보였으며, 낮은 농도의 ribose와 galalctose에 의해서도 효소활성이 급격하게 저해되었다. 한편 이들 효소는 대두와 콩과식품에 존재하는 항영양인자인 raffinose와 starchyose를 완전히 가수분해 하였는데, 이로 보아 분리균 YB-1413과 YB-1414는 콩 발효식품과 대두 사료의 영양가를 개선하는데 활용할 가치가 있다고 여겨진다.