가토 외고정 모델을 이용한 치밀체형 세라믹스의 골결합능 평가

이재협,이동호,이재학,공현식,안영준,류현승,서준혁,홍국선,김환,장봉순,이춘기 대한정형외과연구학회 2003 대한정형외과연구학회지 Vol.6 No.2

한국인 심부전증 환자 심근에서의 인형 거대 세포 바이러스 감염

이명용,이무용,김영권,한성식,최성준,김효수,이영우,서정돈 단국대학교 1998 論文集 Vol.33 No.-

Objectives: In order to evaluated the prevalence and the site of infection of cytomegalovirus in terminally failing heart, cytomegaloviral DNA was detected in the explanted hearts of transplantation recipients. Methods: DNA extractions were performed from explanted failing hearts(N=22) and normal hearts(N=5) and polymerase cain reactions(PCRs) were done for detection of late gene sequence coding pp150 glycoprotein. The products were confirmed by electrophoresis on the 1% agarose gel. n order to improve the detectability of cytomegaloviral genome, nested PCRs were executed with the primers designed for the original 607 bp products. In situ PCRs also were done with the samples which were confirmed as positive for CMV viral genome by nested PCRs. Results: All patients had IgG anti-cytomegalovirus antibody and did not have IgM anti-cytomegalovirus antibody. Cytomegaloviral genomes in myocardium were detected by polymerase chain reaction. The 607bp products by PCRs were found in both explanted failing heart(3 cases/22. 13.5%) and normal hearts( 1 case/5, 20.0%). In nested PCRs, 186bp products were found in both failing hearts(LV 4/22, LA 3/2, RV 4/22, RA 0/17) and normal hearts(LV 2/5, LA 1/4, RV 2/5, RA 2/5). These was no significant change in positivity of cytomegaloviral DNA genome between failing and normal hearts. Total positivity of cytomegaloviral genome in explanted hearts was 44.4% according to the nested PCR results. The positivity of cytomegaloviral DNA by n situ PCR was 33.3%(4/12), and the site of positive reaction was the nuclei of the myocardial cells. Conclusion: Cytomegalovirus was rarely observed in explanted hearts of terminal heart failure and nested PCR could enhance the sensitivity of cytomegaloviral genome detection. The result of the in situ PCR showed the site of the cytomegaloviral infection was nuclei of the myocardial cells. Cytomegalovirus, however, might have no direct causal relationship in the development of terminal heart failure.

소수성 물질을 포함한 커들란 겔의 특성 및 식품으로의 활용 연구

최춘순,이기영,이창문,정제명,이인영 전남대학교 촉매연구소 2001 觸媒硏究 論文集 Vol.22 No.-

The thermal stability of curdlan suspension was investigated. Also curdlan gel containing hydrophobic materials (DHA(Docosa hexaenoic acid), olive oil and Dong-chunghacho (Militaris)) were prepared. Curdlan suspension prepared under 40℃ and 15000rpm was stable for 1 hour. Curdlan gel, including hydrophobic material were dried at 30℃ and swollen in the water. Curdlan gel including Dongchunghacho absorbed water of 980%.

영구형 항서맥 심박조율기 환자의 장기추적관찰

최현석,이무용,최영진,최성준,김효수,손대원,오병희,이명묵,박영배,최윤식,이영우,이명용 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.5

노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

위장관을 침범한 Henoch-Sch o¨nlein purpura 1예

이승곤,김채규,서종옥,이호영,이호준,정회상,박유환,정춘해 朝鮮大學校 附設 醫學硏究所 1996 The Medical Journal of Chosun University Vol.21 No.2

Henoch-Scho¨nlein purpura(H-S purpura) is a systemic necrotizing vasculitis of small vessels that is characterized by nonthrombocytopenic palpable purpura on the buttocks and extremities, arthritis of knees and ankles, glomerulonephritis, and colicky abdominal pain, histologically characterized by leukocytoclastic vasculitis. Gastrointestinal involvement with colicky abdominal pain and GI bleeding, most frequently in jejunum and ileum, occurs in above a half of all patients, but common in children. We performed GI endoscopy in a case of H-S Purpura. Gastroduodenoscopic findings showed erythemas and erosions in gastric antrum, and mucosal edema and petechiae in duodenal 2nd portion. Colonoscopic findings showed 5-10㎜ sized multiple shallow hemorrhagic ulcers in transverse and descending colons We report a case of H-S purpura involving colon with literatural review.

시기능 향상을 위한 시각장애인용 전자시력보조장치의 개발

이용천,유영기,오춘석 선문대학교 ·중소기업기술지원연구소 2002 선문공대 연구/기술 논문집 Vol.7 No.1

최근 의료기술이 발달함에 따라 평균연령이 증가하면서 노인성변화나 변성에 의한 시력장애가 많아지고 사고에 의한 시력장애가 발생함에 따라 시각재활을 필요로 하는 시각장애인의 수는 현저히 늘어가고 있다. 질환에 대한 치료 못지 않게 중요한 것이 장애에 대한 재활이다. 시각장애인이 시기능을 향상시킬 수 있는 대표적인 것이 시력보조기구를 사용하는 것이다. 하지만, 각자 시각 장애에 대한 원인이 다른 환자들은 이미 상용화된 저시력 기구나 장비로 일상생활에 필요한 충분한 시기능 향상을 얻지 못하고 있다. 더구나 우리나라에서는 저시력에 대한 연구가 미비한 상태로 대개의 보조기구들은 전적으로 수입에 의존하고 있는 실정이다. 최근 국내의 한 기업이 시각장애인용 전자시력보조장비를 개발하였지만 고가이면서 부피가 크고, 머리에 착용하는 HMD형이기 때문에 시각장애인들이 활동을 하는데 있어서 불편하고 사용자가 국한된다는 단점을 가지고 있다. 본 연구에서는 앞에서 언급한 단점들을 보완하여 많은 시각장애인들이 사용할 수 있는 소형이면서 저가의 목걸이형 전자 시력보조장치를 개발한다. The number of persons with defective vision by senile change or degenerative illness has been increased remarkably as the life expectancy of a person has enhanced a lot with the advent of advanced medical technology. The number becomes still higher with the number of accidents. Now rehabilitation has become more important than cure. The normal method of improving visual ability of a person is to use the visual enhancement system. However, commercially available systems are not sufficient for the proper enhancement of differently caused visual obstacles. Furthermore, our country is unprepared for the research in this field and most of the enhancement equipment are imported. Recently, a Domestic Corporation has developed sightvisual enhancement equipment for low vision, but it is bulk in size and expensive as well. A person feels uncomfortable while using it dueto its size and has to be mounted on the head. In this research, we have developed a low cost, compact, neckwear type visual enhancement system that could be accessible and user friendly to all the visually impaired persons.

임펄스성 잡음이 존재하는 실내 무선 환경에서 Multi-Carrier CDMA 시스템의 성능 분석

이영춘,박기식,조성준 한국항행학회 2003 韓國航行學會論文誌 Vol.7 No.1

본 논문에서는 Middleton 이 제안한 A급 임펄스성 잡음이 존재하는 실내 무선 환경에서 MC (Multi-Carrier) CDMA 시스템의 BER (Bit Error Rate) 성능을 분석하였고, 임펄스성이 약한 환경에서부터 강한 환경까지 성능을 평가하였다. 그리고 임펄스성 잡음에 대한 보상 방법으로 Turbo 부호기를 사용하여 성능 개선 정도를 평가하였다. 성능 해석 결과, 임펄스성 잡음 환경에서는 강력한 성능 개선 기법이 시스템에 반드시 필요함을 알 수 있었다. 그리고 임펄스성 잡음 환경에서 터보 부호를 적용하면BER 면에서 약 10?₂정도 개선됨을 알 수 있었고, AWGN 환경에 근접할수록 터보 부호에 의한 성능 개선 효과가 뚜렷이 나타남을 알 수 있었다. In this paper, we have analyzed the BER (Bit Error Rate) performance of MC-CDMA systems under indoor wireless environment with class A impulsive noise suggested by Middleton. For the performance evaluation, we considered from strong to weak impulsive noise characteristics. And we have evaluated the degree of performance improvement by using turbo code as a compensation technique to impulsive noise. From the result of analysis, it is found powerful performance improvement scheme must be adopted in the system under impulsive noise environment, and when turbo code scheme is adopted, system BER performance is improved by the 10^2. As the impulsive noise characteristics approaches AWGN characteristics, the degree of performance improvement by adopting turbo code become large.

MQL 선삭가공시 가공조건의 표면거칠기 영향 분석

이춘만,황영국,정종윤 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

At present, industry and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. This paper presents an investigation into MQL(Minimum Quantity Lubrication) machining with the objective of deriving the optimum cutting conditions for the turning process of SM45C. To reach these goals several finish turning experiments were carried out, varying cutting speed, feed rate and oil quantity, with MQL. The surface roughness results of tests were measured and the effects of cutting conditions were analyzed by the method of Analysis of Variance(ANOVA). From the experimental results and ANOVA, it is found that a better surface roughness can be obtained by decreasing oil quantity and feed rate.

障碍領域別 特殊學敎 敎師의 스트레스 比較

李相春,吳永愛 大邱大學校再活科學硏究所 1986 再活科學硏究 Vol.7 No.1

The purpose of this survey is to grasp the Korean special school teachers' stress degrees in the real educational fields, and to compare the different stress degrees by the teaching responsibilities, by sex, by age, by the careers of special teaching profession, by his or her assiduity, by the academic careers and teacher-qualification, and by the reasons of stress. To perform this survey, the writer analysed the answer sheets of the questionnairs returned by 766 special school teachers throughout the country. The results of the analysis are as follows: First, the mean value of stress by the whole teachers was shown as endurable, and there was no difference among stress levels by the teaching responsibilities. As for the ratio of teachers confronted with the dangerous level of stress, the teachers taking charge of mentally retarded students occupied the highest ratio, and those charging of visually handicapped students, the lowest. Second, the comparison by age didn't result in any difference, but in the relation of age to the teaching responsibilities there appeared meaningful differences. That is in the case of the teachers charging of mentally retarded students, it revealed that the older they were, the more stress they suffered. In the case of the teachers charging of visually handicapped students, the tendency was opposite. The comparison by the special teaching profession careers, there showed no difference in the- stress degree. The comparision by theachers' assiduity showed that the stress by the teachers having the intention to stay in the job for the time being was much higher than that by the teachers who had made up their minds to think of their job as a permanent one. The high or low academic careers didn't make any influence on the teachers' stress degree, but the teacher-qualifications made a meaningful difference on their stress degree. That is, the teachers having the special teacher-qualification turned out being suffered much more stress than those having the general teacher-qualification. Third, the comparison of stress degree by the reasons revealed that the most severe degree of stress came from the relations with the parents as well as students' behaviors. The teachers in charge of mentally retarded and physically handicapped students had highest degree of stress because of students' behaviors, while the teachers taking care of visually and auditory handicapped students had the highist degree of stress because of the relation with the students' parents.