Rifampicin에 의한 것으로 추정되는 위막성 대장염1예

김수현,이은우,정종혁,문승현,김동한,양혁승,오영상,김호동,김도현,박혁,박정환,박경옥,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Pseudomembranous colitis, caused by altering the normal colonic flora and allowing the multiplication of Clostridium difficile, is an deleterious adverse effect of antibiotics. But it is rarely reported by rifampicin. Rifampicin is one of the first line drug in the treatment of tuberculosis and many patients are exposed to its potential adverse effects. We experienced a patient that had abdominal discomfort and hematochezia due to pseudomembranous colitis after receiving antituberculous medication, and which was probably caused by rifampicin. A 82 years old man was admitted with abdominal discomfort and hematochezia for one week. On the past history he had been diagnosed as endobronchial tuberculosis about 4 months ago. Colonoscopy revealed multiple discrete whitish mucosal lesion on rectosigmoid colon, and histologic findings were consistent with pseudomembranous colitis. The antituberculous agents were discontinued and vancomycin was administered. The patient's symptoms were resolved within several days. There was no recurrence after reinstitution of the antituberculous agents excluding rifampicin. We report here on a case of pseudomembranous colitis probably due to rifampicin.

인체 대장암 및 자궁경부암에서 PCR-SSCP법을 이용한 Ki-ras 암유전자의 점돌연변이에 관한 연구

박영홍,백낙환,김현찬,김상효,홍관희,김기태,이기영 인제대학교 1994 仁濟醫學 Vol.15 No.2

인체 대장암 20례와 자궁경부암 10례의 암조직을 대상으로 c-Ki-ras 유전자 codon 12와 13에서의 점돌연변이를 알아보고자 polymerase chain reaction(PCR)과 single-strand conformation polymorphism(SSCP) 검사법을 시행하였다. 대장암의 경우 20례중 9례(45%)에서, 자궁경부암의 경우 10례중 1례(10%)에서 양성으로 나왔다. 대장암에서는 codon 12에서 GGT가 TGT로의 치환이 4례로서 가장 많았으며, AGT, CGT로의 치환이 각 1례였고 codon 13에서는 GGC가 GAC로의 치환이 2례, TGC로의 치환이 1례인 것으로 나타났다. 자궁경부암의 경우 codon 12에서 GGT가 AGT로의 치환이 1례인 것으로 나타났다. In an attempt to clarify the role of genetic alteration in the genesis of human colorectal and cervical cancers, tissue specimens from 20 patients with colorectal cancer and 10 patients with cervical cancer were examined for the presence of point mutation in K-ras2 exon 1 by single strand conformation polymorphism analysis of PCR product. Exon I of c-Ki-ras2 was amplified by polymerase chain reaction(PCR) and comparison was made between the normal and mutated genes by nondenaturing polyacrylamide gel electrophoresis(PAGE) of PCR product and nucleotide sequence analysis using asymmetric PCR with direct sequencing. Genomic DNA from white blood cells were used as normal control and those from A427 cell line were used as mutated control. 1.PCR product from A427 cell line showed a distinct migration shift pattern compared to the normal control in PAGE and the direct sequencing indicated that nucleotide sequence of codon 12 was mutated from GGT to GAT. In addition, there was a loss of normal allele in A427 cell line. 2.PCR product from 9 cases(45%) out of a 20 colon cancer patients showed migration shifts in PAGE, and all of these 9 patients invariably demonstrated mutation of ras gene, either in codon 12(6 cases:30%) or 13(3 cases:15%). The base substitutions in codon 12 were: from GGT to AGT(1), CGT(1), or TGT(4). Base changes in codon 13 were from GGC to TGC(1) or GAC(2). 3.PCR product from 1 cases(10%) out of a 10 cervical cancer patients showed migration shrifts in PAGE, Invariably demonstrated mutation of ras gene in codon 12. The base substitutions was from GGT to AGT(1) TQE incidence of point mutation of c-Ki-ras in colon cancer was high, however, it was low in cervical cancer, which showed the relation of ruts gene mutation with colon cancer. PCR -SSCP analysis is a simple, rapid and efficient method of detection of point mutation, especially when dealing with multiple samples.

자동차 변속기용 기어설계 프로그램 개발

김영환,박태조,문영재 慶尙大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.13 No.-

A new interactive computer program for design and examination of the automobile transmission gear is developed. The design data of a shifted helical gear sets are calculated and the contact ratio and the strength condition are examined. The involute curve and a root fillet of the designed tooth profile are graphically presented, and the informations for tooth profile such as root point, weakest section point, etc. are obtained. The whole engaging gear shape and contact state are certificated in Autocad. To check the lubrication conditions, the minimum film thickness is calculated and compared with the surface roughness data. Therefore the computer program made in this paper gives more improved practical tool in designing a automobile gear set.

네트워크를 근간으로하는 분산 시스템을 위한 CNU File Server의 구현

김봉환,황영원,이광일,김상하 충남대학교 자연과학연구소 1993 忠南科學硏究誌 Vol.20 No.1

A file server provides remote centralized storage of data to computers connected to it via a communication network: it facilitates data sharing among autonomous computers and support of inexpensive computers that have limited or no secondary storage. The prototype of CNU File Server(CNUFS) is designed, and the implementation aspacts and initial experiences with applications are discussed in this paper.

황 첨착 활성탄에 의한 구리제거

김영환,박정훈,김정섭,유현철,이봉섭,곽명화,우성훈,박승조 東亞大學校 環境問題硏究所 2005 硏究報告 Vol.27 No.1

This study was carried out to remove copper ion in case of activated carbon impregnated sulphur(ACS) dose and different pH using activated carbon impregnated sulphur that prepared from activated carbon at sulphur dioxide atmosphere. Removal copper ion concentration was increased as increasing the ACS dose when copper ion concentration was 10 mg/L. Optimum dose of ACS 13.3 g ACS/L and maximum removal efficiency was 93%. The results obtained from adsorption experiment in the condition of ACS optimum dose when the pH was 3, 4, 5 respectively was pH 5 was excellent.

유압 피스톤 펌프의 피스톤과 실린더 사이의 압력분포

김영환,박태조 경상대학교 생산기술연구소 2002 工學硏究院論文集 Vol.2 No.-

Under the tendency of higher speed and pressure requirements in hydraulic machinery, the clearance between piston and cylinder became gradually smaller. This results in many new tribological problems. Therefore exact understanding of oil pressure distribution in the clearance is vital for designers in reducing the energy losses due to friction and improving its reliability. This paper aimed at measuring oil pressure distribution in the clearance considering the effect of piston speed. We designed a piston-cylinder type test apparatus and measured oil pressure distributions accurately. The results showed that the pressure distributions are highly affected by the piston speed, and present experimental method can be used to enhance the performance of hydraulic piston pumps.

자동차 드라이브 샤프트의 정적강도 및 피로특성에 관한 연구

金永煥 진주여자전문대학 1998 論文集 Vol.21 No.-

Practically, induction surface hardening is used widely to enhance mechanical strength of vehicle's drive shaft. In this study, the static torsional strength and it's S-N characteristic for various effective case depth specimen of XCD43N is studied experimentally In addition, this is intended to suggest optimal limits of effective case depth for induction hardened drive shafts of XCD43N in a point of view both static strength and fatigue life.

알루미늄기 비정질 와이어의 제조와 그 특성연구

김영환 釜山大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.56 No.-

높은 반응성을 가지는 Al-Ni-Y(또는 Ce)합금을 60°각도의 날카로운 edge를 가지는 구리휠을 사용하여 용탕추출법(melt extration)에 의해 연속적인 비정질 와이어를 제조할 수 있었다. 와이어는 원형 단면을 가지고 지름이 35∼50㎛범위였다. 와이어의 열적 성질은 멜트스피닝법으로 제조딘 두께 15㎛인 리본재와 거의 같앗다. 그리고 연성도 우수하고 1020MPa의 커다란 인장강도가 비정질 Al86Nil0Y4합금와이어에서 얻어졌다. 리본재에 비해서 본 제조기술이 높으 응고속도를 가지는 것이 밝혀졌는데, 이것은 체적에 비해서 훨씬 큰 표면적을 가짐으로써 아르곤 가스 분위기하에서 쉽게 과냉이 되기 때문이라고 생각된다. The application of a melt extraction method using a copper wheel with a steep edge to Al-Ni-Y(or Ce) alloys with highly reactive molten states was found to cause the formation of continuous amorphous wire. The wires have circular cross section and the diameters are in the range of 35 to 50㎛. The thermal property of the wire is nearly the same as that of the melt-spun ribbon with the 15㎛ thick. and same composition. The wires have good bending ductility and a tensile strength of 1020 MPa. The high cooling rate for the present pocess is accomplished presumably because the supercooled liquid with a small volume and a large outer area to volume ratio is solidified homogeneously without contact of other substances. The combination of the solidification process with high cooling rate and the good bending ductility into the wire shape allows us to expect that the present process develops as an alternative method to produce amorphous ally wires in various kinds of alloy systems including reactive elements as main components.

주정폐수의 혐기성 소화처리시와 포기처리시 처리특성에 관한 연구

金煥起,李城白,黃譚勇 全北大學校 附設 都市및環境硏究所 1996 都市 및 環境硏究 Vol.11 No.1

The wastewater of alcohol manufactory plant has very high suspended soild and BOD concentration, acidity, and high temperture. Thus most of the plants drive on anaerobic digestion method of biological treatment because of using a lot of generated methane gas and possible to disinfect pathogenic bacteria in sluge and wastewater. But because of the problem in the concentration of anaerobic treatment water, second treatment is necessary 2-step activated treatment for increasing treatment efficiency. The purpose of this study was performed to know a difference between last 1-step digestion 1-step aeration treatment and 2-step digestion 2-step aeration treatment with retention time in digestion and aerator. The obtained results can be summarized as follows; 1. The concentration characteristic of alchohol production wastewater was analyzed COD 50,000∼80,000㎎/ℓ, BOD 22,000∼41,000㎎/ℓ, SS 20,000∼45,000㎎/ℓ, pH 4.1∼4.2, and 75∼80℃ according to the raw material of alchohol. 2. In case of the anaerobic digestion method of rice-barley wastewater, average COD removal rate of 2-step digestion appeared to 91.9% compared to average COD removal rate 59.3% on 1-step digestion. It is necessary to drive above 20 day of retention time in metane degestor because of increasing organic load causing the decrease of pH and the increase of VFA/COD within aerator. 3. Alcohol wastewater of tapioka is generally much treatment efficiency of 2-step digestion than that of 1-step digestion, but below 2.7㎏-COD/㎥·d of COD bulk load showed the possibility of treatment at 1-step and 2-step digestion method. 4. Amount of gas generation in anaerobic digestion was almost similar at 1-step and 2-step digestion. 5. In the result of aerobic treatment, treatment efficiency of 2-step consecutive aeration was highly about 3% compared to 1-step combined aeration and in the condition of COD 4,000㎎/ℓ, COD load 800㎏ -COD/d, COD volume-load 0.8㎏-COD/㎥·d were difficult two treatment methods both. 6. pH and VFA concentrations are considered as important factors to determine VFA restriction and the harmfulness of fatty acid was seemed to be related to pH. VFA in 1-step digestion appeared strong change with the increase of input wastewater quantity, but 2-step digestion was treated to stable change in output COD 1,230∼2,246㎎/ℓ.

低炭素 Dual-Phase鋼의 引張性質과 베이크 硬化性에 關한 硏究

김영환 釜山工業大學校 1984 論文集 Vol.26 No.-

The present investigation was conducted to study the bake-hardenability behavior of iced-water quenched low carbon dual-phase steel with emphasis on the effect of prior tempering treatment on the subsequent bake-hardenability response. The results obtained are as follows; 1) The steels quenched from intercritically annealed range were softened during paint-bake treatment. 2) The quench-tempered steels did not show softening but was hardened during paint-bake treatment. However, in steels tempered from insufficient temperature (e.g., 150℃ for 1 minute) prior to paint-bake treatment, further softening takes place during paint-bake treatment. 3) All the steels showed discontinuous yielding. This phenomenon was explained by the diffusion of solute carbon to mobile dislocation and removal of residual stress. But the steel that has 45 percentage of martensite volume showed continuous yielding. 4) The product of tensile strength and elongation(TS.EL value) was slightly decreased with increasing the volume fraction of martensite but rapidly decreased above 35 percentage of martensite volume. 5) The presense of martensite phase suppressed the change of yield point elongation at room temperature and decreased the increase of yield stress, that is, bake-hardenability above 35 percentage of martensite volume.