Pseudomonas sp. DJ-12의 pcbCD 유전자의 클로닝과 Escherichia coli에서의 발현

김치경,성태경,남정현,김영창,이재구,Kim, Chi-Kyung,Sung, Tae-Kyung,Nam, Jung-Hyun,Kim, Chang-Young,Lee, Jae-Koo 한국미생물학회 1994 미생물학회지 Vol.32 No.1

Polychlorinaed biphenyls(PCBs) 와 biphenyl을 분해하는 Pseudomonas sp. DJ-12에서는 그 초기 분해과정에 pcb ABCD 유전자들이 관여하고 있음이 밝혀졌다. 그 중 pcbCD와 pcdD 유전자를 E. coli XL1-Blue에 클로닝하여 E. coli CU103 과 CU105 균주를 각각 제조하였다. E. coli CU103은 2,3-dehydroxybuphenyl dioxygenase(2,3-DHBP)와 meta-cleavage compound(MCP) hydrolase를 생성하여 2,3-dihydroxybiphenyl을 benzoate로 변환시켜 주었다. E. coli CU1 과 CU103 에서 pcbC 유전자의 산물인 2,3-DHBP dioxygense의 활성도는 Pseudomonas sp. DJ-12에서 보다 약 17배 높았으며, E. coli CU105에서 pcbD의 산물인 MCP hydrolase는 약 3배 더 높게 나타났다. The pcb genes of Pseudomonas sp. DJ-12 coded for the catabolism of polychlorinated biphenyl (PCBs) and biphenyl. The products of the pcbCD genes were 2,3-dihydroxy-4'-chlorobiphenyl dioxygenase and meta-cleavage product (MCP) hydrolase, which acted on degradation of 2,3-dihydroxy-4'-chlorobiphenyl to 4-chlorobenzoate. The pcbCD genes were cloned in E. coli XLl-Blue, and then the pcbD gene was further subcloned. As a metabolite transformed from 2,3-dihydroxybiphenyl by the cloned cell of E coli CU103, benzoate was detected by the resting cell assay. The enzyme activities of 2,3-dihydroxybiphenyl dioxygease and MCP hydrolase produced in the cloned cells E. coli CU103 and CU105 were about 17 and 3 times higher than those of Pseudomonas sp. DJ-12, respectively.

Application of the Unstructured Finite Element to Longitudinal Vibration Analysis

김치경,Kim Chi-Kyung Computational Structural Engineering Institute of 2006 한국전산구조공학회논문집 Vol.19 No.1

본 연구는 파 해석에 있어서 공간-시간 분할 개념을 도입하여 켈러킨 방법으로 해석하였다. 공간-시간 유한요소법은 오직 공간에 대해서만 분할하는 일반적인 유한요소법보다 간편하다. 비교적 큰 시간간격에 대해서 공간과 시간을 동시에 분할하는 방법을 제시하며 가중잔차법이 공간-시간 영역에서 유한요소 정식화에 이용되었다. 큰 시간 간격으로 인하여 문제의 해가 발산하는 경우가 동적인 문제에서 흔히 발생한다. 이러한 결점을 보완한 사각형 공간-시간 요소를 취하여 문제를 해석하고 해의 안정에 대해 기술하였다. 다수의 수치해석을 통하여 이 방법이 효과적 임을 알 수 있었다. This paper analyzes the continuous Galerkin method for the space-time discretization of wave equation. The method of space-time finite elements enables the simple solution than the usual finite element analysis with discretization in space only. We present a discretization technique in which finite element approximations are used in time and space simultaneously for a relatively large time period called a time slab. The weighted residual process is used to formulate a finite element method for a space-time domain. Instability is caused by a too large time step in successive time steps. A stability problem is described and some investigations for chosen types of rectangular space-time finite elements are carried out. Some numerical examples prove the efficiency of the described method under determined limitations.

Heparin-Protamin Sulfate 상호작용의 실험적 연구

김치경,이홍균,Kim, Chi-Kyung,Lee, Hong-Kyun 대한흉부심장혈관외과학회 1980 Journal of Chest Surgery (J Chest Surg) Vol.13 No.1

Heparin would have been used for preventing clotting of blood during extracorporeal circulation and subsequent use of protamine sulfate and made possible the neutralization of heparin. This procedure has been adopted for eliminating one of the great causes of bleeding, especially in cardiac surgery. In this experiment, the hypocoagulability of blood induced by heparin followed by neutralization with treatment of protamine sulfate were estimated by the Lee-White clotting time [CT], partial thromboplastin time [PTT] and protamine titration test. The results were as follows: 1] Comparison of clotting time between the heparinized [2.0 mg/kg] and non-heparinized dogs was done using CT and PT`I` of the blood. In heparinized group [Group I], the CT lasted infinitively and prolongation of PTT [4 times than normal] until 60 minutes. The CT [2 times] and PTT [3 times] has been shortened after 90 minutes, however they returned to normal limit level within 180 minutes. 2] The determination of appropriate ratio of heparin and protamine In vivo were performed. The group II [heparin 2.0 mg/kg, protamine 1.0 mg/kg] revealed rapid decrease of CT and PTT, but returned to normal after 120 minutes. The group III [heparin 2.0 mg/kg, protamine 2.0 mg/kg] returned rapidly to normal within 15 minutes. The group IV [heparin 2.0 mg/kg, protamine 3.0 mg/kg] recovered its normal level after 60 minutes. The group V [heparin 2.0 mg/kg, protamine 4.0 mg/kg] recovered its normal level after 90 minutes. 3] In the combined experimental study In vivo and vitro, the protamine titration test was done using the dog which were given 2.0 mg/kg and 3.0 mg/kg of heparin, respectively and coagulation time were checked after 15, 30, 60 and 120 minutes. The complete neutralization was showed to be heparin-protamine ratio of 1:1 to 1.5. 4] In vitro study, fresh blood was drawn into known amount of heparin content [20, 40, 60 and 100/ug per 1 ml of blood] syringe, thereafter protamine titration test was done. In all cases, the complete neutralization was found in heparin-protamine ratio of 1:0.85 to 1.5. 5] It was found by the present experiment that the ideal heparin-protamine ratio was 1:1 within 60 minutes and 1:0.5 after 60 minutes for avoiding the serious side effect due to overadministration of protamine sulfate.

하천수의 오염도와 Escherichia coli 의 생존율과의 상관성에 관한 원위치 실험연구

김치경,정만희,김근식 ( Chi Kyung Kim,Man Hee Chung,Keun Sik Kim ) 한국하천호수학회 1984 생태와 환경 Vol.17 No.1·2

The survival of enteric bacteria in river water has been extensively studied under laboratory conditions or by jug method in river, but the correlations between the survival rate and the level of water pollution have not been reported. In this study, the survival of two strains of Escherichia coli (ATCC #25922 and a fresh isolate from polluted water) was comparatively studied in gradually polluted river waters by in situ method using dialysis sac. In all cases which the dialysis sacs containing sterile or non-sterile river water inoculated with E. coli were examined in the river waters, the survival rates were proportionally increased by the level of water pollution. The higher survival rate of E. coli in the more polluted rivers seems to be attributed to the higher growth rate of the organism on the organic pollutants in spite of the higher number of predators. Therefore, the high number of E. coli found in the more polluted river is thought to be due to the growth of the existing bacteria, not due to the influx of the bacteria including in domestic sewage. This means that the organic pollutants in river could be not only the primary problem as itself, but also the secondary problems promoting growth of the enteric bacteria in river waters, maintaining them in high number, and increasing the chances for the enteric pathogens to spread to outbreak waterborne diseases.

하천수에서 Campylobacter jejuni 의 오염도와 그 생존율에 관한 연구

김치경,오학식,염곤,조민기 ( Chi Kyung Kim,Hak Shik Oh,Kon Ryeom,Min Ki Cho ) 한국하천호수학회 1986 생태와 환경 Vol.19 No.3·4

Campylobacter jejuni isolated from river and lake waters and chicken samples were examined for their contamination and survival in surface waters and for inactivation by chlorination. The isolation rates of C. jejuni from chicken samples were 50 to 100%, while only one out of 48 studies was positive from the surface water. When the organisms suspended in sterile river water were incubated at 4℃, they survived upto 20 days, but they died off after 1 day incubation at 30℃ or above. The in situ survival studies of C. jejuni in the waters of Dsecheong Dam and Han-river (1st bridge) revealed that they survived upto 14 days in winter, but for shorter period of time in spring and summer. The survival rates of the organism in the deeper water were a little longer than in the surface water, but the rates were not different between the both water environments. When the organisms were treated with 0. 5, 1. 0 and 2. 0 ㎎/ℓ chlorine solution at pH 7. 0 and 15℃ for 60 minutes, they were inactivated by about 1, 4, and 6 logs, respectively, The inactivation rate was increasingly affected by lowering the reaction pH and by increasing the reaction temperature.

오존에 의한 bacteriophage f2의 살균작용(殺菌作用)

김치경,Kim, Chi-Kyung 한국현미경학회 1981 Applied microscopy Vol.11 No.1

Bacteriophage f2 were treated with ozone at various concentrations for 20 minutes. The inactivation kinetics of f2 phage were examined during ozonation. In order to study the mode of action of ozone on the phage f2, absorption of the phage to the host pili was meassured by utilyzing radioactivity of tritium incorporated into the phage RNA. Sucrose density gradient analysis and electron microscopy were also used to prove the mechanism of ozone inactivation of the phage. Strucural proteins of the phage were broken by ozonation into many protein subunits. The extent of phage breakage was proportional to ozone concentration and reaction time. Percent decrease of the phage absorption to the host pili was coincident with the rate of ozone inactivation of the phage. Ozone inactivation of bacteriophage f2 was shown to be caused by the breakage of the structural protein and blockage of the phage absorption to the host pili.

Analysis for Torsion of Hollow Beam by Least Squares and Boundary Elements Method

김치경,배준태,Kim, Chi-Kyung,Bae, Joon-Tai Computational Structural Engineering Institute of 2012 한국전산구조공학회논문집 Vol.25 No.2

본 연구에서는 뒤틀림을 받고 있는 정사각형 단면의 중공단면 보를 최소자승법과 경계요소법을 이용하여 수치 해석하고 구조물을 해석하였다. 임계하중은 하중을 점차적으로 증가하여 구조물이 파괴가 발생하여 안정성을 상실하는 상태에서 가장 작은 하중을 의미한다. 뒤틀림을 받고 있는 beam은 일반 구조물에서 많이 발생하는 현상이며, 구조물의 안정성에 크게 영향을 미치고 있다. 최소자승법과 경계요소법은 복잡한 구조물에서도 물론, 다양한 경계조건을 포함하는 문제에 이르기까지 구조물의 안정성을 검사하는데 효과적인 수치해석 방법이다. 특히 뒤틀림의 문제에서는 단순성 및 일반성에 기인하여 매우 적합한 해석방법이다. 본 연구에서는 뒤틀림을 받고 있는 중공단면 보의 해석해를 유도하여 최소자승법으로 수치 해석하고 또한 경계요소법을 적용하여 빔의 안정성을 비교 검토하였다. 개발한 컴퓨터 프로그램의 타당성을 증명하기 위하여 삼각형, 사각형 그리고 타원형 단면에 대하여 각각 해석하여 해석해와 비교 검토하였다. In this paper we are concerned with the performance of structural stability of torsion in square cross section of a beam with holes. The critical load is defined as the smallest load at which the equilibrium of the structure fails to be stable as the load is slowly increased from zero. The beams subjected to torsion are frequently encountered in general structures and these forces influence to the stability of structure. The boundary element method is found to be very efficient and accurate for the analysis of torsion problems including complex boundary conditions with respect to its simplicity and generality. In this paper, it is required to derive the boundary element formulation for torsion problem and integrate directly on the discrete boundary. To investigate the validity of the developed computer program, three distinctly solid cross-sections which are elliptical, rectangular and triangular one are analyzed, and comparisons are made with analytical approaches where these can also be used.

상실성빈맥의 수술치험 -1예 보고-

김치경,정진용,곽문섭,김세화,이홍균,홍순조,Kim, Chi-Kyung,Jeong, Jin-Yong,Kwack, Moon-Sup,Kim, Se-Wha,Lee, Hong-Kyun,Hong, Sun-Jo 대한흉부심장혈관외과학회 1988 Journal of Chest Surgery (J Chest Surg) Vol.21 No.6

Supraventricular tachyarrhythmias are readily characterized and understood, but the surgical procedures for their correction are complex and not easily mastered. Conversely, ventricular tachyarrhythmias are frequently difficult to characterize and localize electrophysiologically and their basic mechanisms are poorly understood. The role of the surgeon in the treatment of cardiac arrhythmia has changed dramatically during the past decade. This report is a case of 26 years old male with supraventricular tachyarrhythmia. The result of endocardial electrophysiologic study demonstrated accessory pathway connecting left atrium to left ventricle which located at left atrial free wall about 4 cm apart from the coronary sinus orifice. The accessory bundle interruption has been successfully accomplished utilizing the internal open heart technique. The operation consisted of dissection of the atrioventricular fat pad and division of all the superficial fibers going from the ventricle to the annulus. Following this, cryoablation made with cryoprobe at - 60$^\circ{C}$ for 90 seconds. The accessory pathway was successfully ablated without specific problems.

유독성 4-Chlorobiphenyl의 생분해를 위한 탈염소화 유전자의 클로닝

김치경,채종찬,한재진,Kim, Chi-Kyung,Chae, Jong-Chan,Han, Jae-Jin 한국미생물학회 1994 미생물학회지 Vol.32 No.2

4-Chlorobiphebyl(4CB)를 분해한 Pseudomonas sp. DJ-12가 가지고 있는 pcbABCD 유전자를 Escherichia coli에 클로닝한 결과, 재조합 균주인 E. coli CU1과 CU101은 모두 Pseudomonas sp. DJ-12에서와 같이 4CB를 분해하여 2,3-dihydrozybiphenyl(2,3-DHBP)을 생성하는 탈염소화 기능을 보여주었다. 특히 pcbAB를 포함하는 재조합 플라스미드인 pCU101을 가지고 있는 E. coli CU101은 Pserudomonas sp. DJ-12에서와 같이 4CB로부터 4-chlorobenzoic acid를 생성하지 않고 2, 3-DHBP만을 생성하는 탈염소화 기능을 보여주었다. 그러므로 Pseudomonas sp. DJ-12의 염색체 DNA로부터 클로닝한 약 2.2kb의 pcbAB 유전자는 4CB로부터 2,3-DHBP만을 생성하는 탈염소화기능을 가지고 있음이 밝혀졌다. The pchABCD genes in Pseudomonas sp. DJ-12 speciyin degradation o 4-chlorobiphenyl(4CB) were cloned in Eschericia coli. The cloned cells of E. coli CU1 and CU101 showed to produce 2,3-dihydroxybiphenyl (2,3-DHBP) from 4-chlorobiphenyl by dechlorination, as Pseudomonas so. DJ-12 produced 2,3-DHBP from both biphenyl and 4CB. In particular, E. coli CU101 transformed with the recombinant plasmid of pCU101 revealed dechlorination activity to produce 2,3-DHBP from 4CB without production of 4-chlorobenzoic acid. Therefore, the pcbAB genes (2.2 kb in size) cloned from the chromosome of Pseudomonas sp. DJ-12 were found to have dechlorination activity on 4CB to produce 2,3-DHNP.

Pseudomonas spp . 에 의한 4 - chlorobiphenyl 의 분해 및 Plasmid 와의 연관성

김치경,이익근 ( Chi Kyung Kim,Ik Keun Lee ) 생화학분자생물학회 1990 BMB Reports Vol.23 No.3

Including the Pseudomonas strains reported in the previous works, two bacterial strains which are able to degrade 4-chlorobiphenyl(4CB) were isolated from natural environments. They were investigated for their ability to degrade 4CB and for growth on 4CB as a sole source of carbon and energy. It was found by UV-scanning spectrophotometry that both strains of DJ-12 and DJ-26 degraded 4CB to produce the meta-cleavage compound and then to 4-chlorobenzoic acid (4CBA) through the meta-cleavage pathway without dechlorination step. The DJ-12 strain was also turned out to degrade 4CB to produce 4CBA as assayed by HPLC. Through conjugation with Pseudomonas putida KT2440, the genes responsible for degradation of 4CB in the strain DJ-12 were found to be associated with a plasmid of about 65kb in size.