http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
산화적 스트레스에 대한 Bacillus subtilis의 thiol peroxidase 유전자의 생리적인 기능
김하근,김성진,Kim, Ha-Kun,Kim, Sung-Jin 배재대학교 자연과학연구소 2005 自然科學論文集 Vol.15 No.1
산화적 스트레스에 대한 Bacillus subtilis의 thiol peroxidase 유전자의 생리적인 기능을 연구하기 위해 thiol peroxidase 유전자의 기능이 손상된 녹아웃 돌연변이주를 상동성 재조합에 의해 제조하였다. 호기적 조건에서 배양할 때 야생형과 녹아웃 돌연변이주 사이에는 성장속도에서 차이를 관찰할 수 없었다. 그러나 paraquat 처리할 때와는 달리 $H_2O_2$와 cumene hydroperoxide (CHP)에 의한 산화적 스트레스에 대해 역할을 하고 있음을 시사하는 결과이다. In Order to investigate the physiological role of thiol peroxidase in Bacillus subtilis, a thiol peroxidase (btpx) knock-out mutant was generated by homologous recombination. The growth of btpx knock-out mutant in aerobic condition showed a similar pattern with that of wild type of Bacillus subtilis 168/ But btpx knock-out mutant showed a retarded growht in response to oxidative stress such as $H_2O_2$, cumene hydroperoxide (CHP) treatments.
대장균에서 발현되는 Cellulomonas fimi $\beta$-glucosidase의 효소학적 특징
김하근,Kim, Ha-Kun 배재대학교 자연과학연구소 1996 自然科學論文集 Vol.8 No.2
Cellulomonas fimi에서 유래한 $\beta$-glucosidase 유전자를 갖고 있는 대장균으로부터 $\beta$-glucosidase 효소를 정제하였다. 전기 영동과 크로마토그라피 실험을 수행함으로써 정제된 효소의 분자량은 56,000 달톤이며 단일 폴리펩티드로 구성되어 있음을 알 수 있었다. 정제된 $\beta$-glucosidase 효소는 당이 $\beta$-결합을 하고 있는 cellobiose, PNPG, PNPC 등의 기질에 대하여 작용하여 분해시킬 수 있었으나, $\alpha$-결합을 갖고있는 maltose는 분해할 수 없었으므로, $\beta$-결합에 대한 기질 특이성을 갖고 있음을 알았다. 철, 수은, 구리 등의 중금속 이온들에 의해 효소 활성이 저해되었고 DTT에 의해 효소의 활성이 활성화됨을 보임으로써 $\beta$-glucosidase 효소의 활성화 부위는 -SH 기가 중요하게 작용하고 있음을 시사하였다. The $\beta$-glucosidase enzyme was purified from E. coli carrying Cellulomonas fimi $\beta$-glucosidase gene. SDS-PAGE and analytical gel filtration revealed that molecular weight of this enzyme was 56,000 dalton and consisted of a single polypeptide.Inhibition caused by heavy metals and activation by dithiothreitol suggest the existence of essential thiol group in the enzyme. The enzyme was not active on maltose (glucose $\alpha$-1,4-glucose) which has a $\alpha$-linkage, whereas it was active on lactose (glucose $\beta$-1,4-glucose), PNPG (p-nitrophenyl $\beta$-D-glucopyranoside) and PNPC (p-nitrophenyl $\beta$-D-cellobioside), although its reaction rates were different.
김하근,신상범,김경규,Kim, Ha-Geun,Shin, Sang-Beom,Kim, Kyung-Gyu 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.5
The purpose of this study is to develop the control technology of global distortion in the deck of superstructures during manufacturing processes. The behavior of global distortion in the deck was evaluated by FEA and verified through comparing with the measured results by 3D measuring instrument. It was seen from the results that the principal factor inducing the global distortion is to be the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding of stiffeners and flame heating to correct the excessive local out-of-plane distortion. Based on the results, the amount of reverse distortion in the thin deck plate was determined to control the global distortion in the deck plate. The proposed distortion control technology was verified by applying it to the actual structure.
김하근,손장열,김흥식,Kim, Ha-Geun,Sohn, Jang-Yeul,Kim, Heung-Sik 한국음향학회 1995 韓國音響學會誌 Vol.14 No.4
본 연구는 도로교통소음을 보다 정확하게 예측하기 위하여 국립환경연구원과 일본음향학회의 예측방법을 비교, 검토하여 수정 보완된 예측방법을 제시하는 것을 목적으로 한다. 이를 위하여 각각의 예측식 및 계산과정을 컴퓨터 프로그램화하고, 이를 통해 예측된 값을 약 14개의 현장에서 실측된 값과 비교 검토하였다. 그 결과 차량속도가 40km 이상인 고속화도로 주변 및 일반도로에서는 본 연구에서의 예측값이 국립환경연구원 및 일본음향학회에 의한 예측값 보다 더 실측값에 근접하는 것으로 나타났다. This study is aimed to show that revised prediction method in road traffic noise after comparing prediction method of National Institute of Environmental Research with that of the Acoustical Society of Japan. For this purpose, prediction equation and caluation procedure of each case was programmized and data predicted by each method were compared with those measured in the 14 fields. The result show that data predicted by 14 fields. The result show that data predicted by the method proposed in this study were closer to the data measured in the fields than those predicted by National Institute of Environmental Research and the Acoustical Society of Japan in the surroundings of urban express way (include highway) and general traffic road where the vehicle speed is higher than 40km/h.
인장하중법에 따른 STS 304 다층 맞대기 용접부의 변형 제어 특성에 관한 연구
김하근,이동주,신상범,Kim, Ha-Geun,Lee, Dong-Ju,Shin, Sang-Beom 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.3
The purpose of this study is to develop the control technology of the welding distortion caused by Auto NG-GTA(Narrow Gap-GTA) welding process at the STS 304 multi-pass butt weldment. Heat input model for Auto NG-GTA welding process was established and verified by measuring temperature change and molten pool shape at the bead-on-plate weldment. With the heat input model developed, the effect of tension load on the welding distortion at the STS 304 multi-pass butt weldment was evaluated using the thermo-elasto-plastic FE analysis. In accordance with FEA results, the angular distortion and transverse shrinkage sharply decreased with an increase in tension load. This result indicated that tensioning method was an effective countermeasure against the welding distortion of the STS 304 multi-pass butt weldment.
동해안 하조대와 경포대 해수욕장 주변 토양으로부터 분리한 국내 미기록 야생효모들의 균학적 특성과 생리활성
김하근 ( Ha-kun Kim ),김지윤 ( Ji-yoon Kim ),한상민 ( Sang-min Han ),김창무 ( Changmu Kim ),이종수 ( Jong-soo Lee ) 한국균학회 2019 韓國菌學會誌 Vol.47 No.3
The goal of this study was to isolate and characterize the wild yeast strains in the soils of Hajodae and Gyungpodae Beaches, Gyungpo Lake in Kangwon-do, Korea and evaluate their anti-demential and tyrosinase inhibitory activities. Among the 27 yeast strains isolated from 30 soil samples from Hajodae Beach, Cyberlindnera culbertsonii HJ31-1, Dothichiza pithyophila HJ22-4, Metschnikowia bicuspidata HJ16-1, and Sakaguchia cladiensis HJ14-1 were recorded for the first time in Korea. Additionally, six of the 55 wild yeast strains isolated from 45 soil samples from Gyungpodae Beach and Gyungpo Lake had not previously been detected in Korea, such as Aureobasidium melanogenum JR3-1. The microbiological characteristics and anti-demential and tyrosinase inhibitory activities of these previously unrecorded yeasts were investigated. Almost all of them were oval-shaped and had ascospores except for Dothichiza pithyophila HJ22-4, Diutina siamensis JR37-5, and Canadida gelsemii DC 35-1. Furthermore, they were all sugar-tolerant and able to grow in 20% glucose-containing YPD broth, except for Cyberlindnera culbertsonii HJ31-1. Diutina siamensis JR37-5 had the highest tyrosinase inhibitory activity (30.9%).