새로운 Acetylcholinesterase inhibitors의 합성

최순규,김형민,조승환,최학기,박유미,이용균,정대일,김인식,한정태 동아대학교 부설 기초과학연구소 2004 基礎科學硏究論文集 Vol.21 No.1

노인성 치매의 일종인 alzheimer's disease의 효과적인 억제제를 합성하기 위해 우리는 분자 모델링에 의한 가장 적합한 물질인 m-[(N,N,N-trimethylammonio)phenyl]boronic acid를 합성하였다. 출발물질인 3-aminophenylboronic acid monohydrate의 경우 boronic acid의 작용기인 hydroxyl group을 protecting시킴으로써 반응의 안정성을 기하였다. Quarternary ammonium salt는 과량의 methyliodide와 염기 촉매인 potassium hydrogen carbonate를 사용하여 용매인 methanol에서 반응시켜 상당히 높은 수율을 얻을 수 있었다. 또한 과량의 methyliodide와 염기촉매인 potassium hydrogen carbonate를 사용하여 용매인 methanol에서 반응시킨 결과 boronic acid의 protection없이도 안정하게 반응이 진행되어짐을 확인할 수 있었다. In order to syntheisize a effective inhibotor for alzheimer's disease, we synthesized m-[(N,N,N-trimethylammonio)phenyl]boronic acid 4 which is designed by molecular modeling form. We protected the hydroxyl group of 3-aminophenylboronic acid monohydrate 1 with ethlyne glycol to remove the reactivity if hydroxyl group. To synthesize m-[(N,N,N-trimethylammonio)phenyl]boronic acid 4, we reacted 3-aminophenylboronic acid monohydrate 1 with ezcess methyl iodide and potassium hydrogen carbonate as a base-catalyst in methanol. but On executed reaction without protection on hydroxyl group, we found out the result that the hydroxyl group of boronic acid group at 3-aminophenylboronic acid monohydrate 1 didn't react with excess methyliodide. Synthesized m-[(N,N,N-trimethylammonio)phenyl]boronic acid 4 is in progress about biological tests as a plausible acetylcholinesterase inhibitor.

우리나라 일부 석면사업장의 석면폐 유병률

백도명,백남원,최정근,손미아,임정기,이원진,문영한,박정선,최병순 大韓産業醫學會 1995 대한직업환경의학회지 Vol.7 No.1

Asbestos industry has been in operation over 60 years in Korea. However, the prevalence of asbestosis has not been yet reported. With rapid turn-over of workers, previous cross-sectional studies of current workers on the job could not find cases with exposures long enough for the development of asbestosis. This study was done to evaluate asbestosis prevalence of those worksites with operation history of more than 20 years. In total, 139 workers from 5 worksites were examined. Asbestos industries covered in the study include 2 asbestos textile, 1 brake lining, and 2 ship repairing worksites. Chest x-ray was taken from all workers and read by two experts familiar with pneumoconiosis classification according to 1980 ILO guidelines. Those with findings compatible with asbestosis were further ckecked with high resolution computerized tomography (HRCT). Pulmonary function tests were done according to ATS guidelines, and occupational and previous medical history was taken through a standardized interview. Air-borne asbestos was measured according to NIOSH method 7400. The air-borne asbestos concentrations ranged from 0.2-1.3 f/cc for asbestos textile, from 0.7-1.0 f/cc for brake lining, and from 6.3-7.8 f/cc during asbestos removal at ship repairing worksite. Of the 139 workers 25 had abnormal chest radiographic findings, and 10 of them had findings compatible with pneumoconiosis. When work history and current asbestos measurements were accounted, 9 workers who had more than 10 years of asbestos exposure history showed chest radiographic findings of pneumoconiosis with Finally, 4 workers showed finding of pulmonary fibrosis and/or pleural thickening at HRCT, and 2 of them had restrictive lung function changes. The study results showed that, among 139 subjects, there were 4(3%) definite asbestosis cases confirmed with HRCT. The prevalence of probable asbestosis was 7% for 10-14 years of exposure, 13% for 15-19 years of exposure, and 23% for 20 or more years of exposure. The prevalence of compensable asbestosis with abnormal lung function was 4-6% for those with 15 or more years of exposure.

OFDM에서 Bitloading 알고리즘의 성능평가

최정식,이성신,김기표,변건식 東亞大學校附設 情報技術硏究所 2005 情報技術硏究所論文誌 Vol.13 No.1

OFDM technique which the available bandwidth is split into several narrowband subchannels at different frequencies is particularly suited for transmission over frequency selective channels. But if the states of some subchannel are bad, the performance of system become to decrease. The principle of bitloading is to adjust the date rate on the individual subchannels based on the current SNR. A subchannel with high SNR is then assigned more bits than a subchannels with lower SNR. As a results, we confirmed the superior performance if we used bitloading algorithm in OFDM system.

치과병원에서 사용되는 진단영상에 대한 JPEG 2000 압축률에 대한 평가

정기훈,한원정,유동수,최순철,김은경 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.3

Purpose : To find out the proper compression ratios without degrading image quality and affecting lesion detectability on diagnostic images used in dentistry compressed with JPEG 2000 algorithm. Materials and Methods : Sixty Digora periapical images, sixty panoramic computed radiographic (CR) images, sixty computed tomographic (CT) images, and sixty magnetic resonance (MR) images were compressed into JPEG 2000 with ratios of 10 levels from 5 : 1 to 50 : 1. To evaluate the lesion detectability, the images were graded with 5 levels (1: definitely absent; 2: probably absent; 3: equivocal; 4: probably present; 5: definitely present), and then receiver operating characteristic analysis was performed using the original image as a gold standard. Also to evaluate subjectively the image quality, the images were graded with 5 levels (1: definitely unacceptable; 2: probably unacceptable; 3: equivocal; 4: probably acceptable; 5: definitely acceptable), and then paired t-test was performed. Results : In Digora, CR panoramic and CT images, compressed images up to ratios of 15 : 1 showed nearly the same lesion detectability as original images, and in MR images, compressed images did up to ratios of 25 : 1. In Digora and CR panoramic images, compressed images up to ratios of 5 : 1 showed little difference between the original and reconstructed images in subjective assessment of image quality. In CT images, compressed images did up to ratios of 10 : 1 and in MR images up to ratios of 15 : 1. Conclusion : We considered compression ratios up to 5 : 1 in Digora and CR panoramic images, up to 10 : 1 in CT images, up to 15 : 1 in MR images as clinically applicable compression ratios.

지각된 스트레스와 스트레스 대처방식이 직장인의 우울과 불안에 미치는 영향

최영민,이정호,이기철 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.6

Objectives : We attempted to clarify the relationship of perceived stress and the ways of coping to depression and anxiety in the white-collar workers. Methods : Fine Humded forty-five white-collar workers in a large enterprise were studied using a questionnaire package composed of demographic data, job stress questionnaire, global assessment of recent stress, the ways of coping checklist, Beck depression inventory, and state-trait anxiety inventory. And self reports of the subjects were statistically analyzed with the method of path analysis. Results & Conclusions : Perceived stress(job stress plus life stress) and the coping(problem-focused plus emotion-focused) determined 28.2% of the depression, 39.1% of the state-anxiety, and 35.4% of the trait-anxiety. These findings suggest that perceived stress and the coping have significant effects on the depression and state-trait anxiety of the white-collar workers. Although seemingly similar, problem-focused and emotion-focused copings, were contrary to each other in effects. Problem-focused coping reduced depression, anxiety and perceived life stress. However, emotion-focused coping didn't reduce the depression and anxiety. Furthermore, emotion-focused coping tended to increase perceived life stress. From these findings the authors inferred that emotion-focused coping interpreted the perceived stress as threatening and consequently became ineffectively defensive. On the other hand, problem-focused coping appeared to interpret the perceived stress as challenge and this challenge-appraisal mobilized effective coping resources. Applying path analysis, the aurhors could make the interactional stress model in the white-collar workers comprised of perceived job stress, perceived life stress, problem-focused coping, emotion-focused coping, depression, and state-trait anxiety.

근관치료시 flare-up 발생빈도와 관련요소에 관한 연구

정혜영,박상혁,최기운 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.2

본 연구는 근관치료시의 flare-up발생률과 환자의 술 전 상태 및 술식 등에 따른 flare-up의 발생 빈도를 알아보고자 한 것이다. 자료는 근관치료 받은 840개 치아로부터 얻었다. 심한 동통이나 종창으로 응급 내원하여 보다 적극적인 치료를 필요로 하는 경우만을 flare-up으로 분류하였다. 1. 전체 840개 치아 중 13개에서 발생, 1.55%의 발생률을보였다. 2. 성별 및 치아에 따른 유의차는 없었다. 3. 술 전 증상이 존재하는 경우 및 치근단 병소가 존재하는 경우가 높은 발생률을 보였다. 4. 무수치의 경우가 생활치나 비가역성 치수염 보다 높은 발생률을 보였다. 5. 다내원 근관치료의 경우 높은 발생률을 보였다. 6. 재근관치료시 높은 발생률을 보였다. 이상의 결론을 통해 flare-up은 환자의 술 전 증상, 치아의 술 전 상태 및 재근관치료 여부에 따라 높은 발생률을 보이고 있음을 알 수 있었다. The purpose of this study was to assess the incidence of flare-ups among patients who received endodontic treatment and to examine the correlation with pre-operative and operative variables. Analysis was in two aspects (a) overall incidence of flare-ups as expressed by a percentage of all patients visits and (b) percentage of flare-ups that occurred as related to various factors suck as patient demo-graphics, diagnosis, and treatment procedures. 1. From the 840 teeth which were examined in this study, the total number of flare-ups was 13. 2. As to gender of patients, there was no significant difference in flare-ups. 3. As to tooth groups, there was no significant difference in flare-ups. 4. In the teeth with pre-operative symptom, there was a statistically significant higher incidence of flare-ups than the teeth without it. 5. In the teeth with apical periodontitis, there was a statistically significant higher incidence of flare-ups. 6. As to pulp and periapical status. non-vital teeth had a higher incidence as compared with vital teeth, irreversible pulpitis. 7. Multi-visit treatment resulted in the higher incidence of flare-ups than one visit treatment. 8. Re-treatment procedures had a statistically significant higher incidence of flare-ups than root canal treatment. In this study, overall percentages of flare-ups was 1.55%. It showed a statistically significant higher incidence related to pre-operative symptom, apical periodontitis, and re-treatment. There was no significant difference in flare-ups related to gender, tooth groups, and fistula.

DLTS에 의한 열처리시킨 HB-GaAs에서의 깊은준위

崔玄泰,金仁洙,孫貞植,裵仁鎬,金相基 嶺南大學校 基礎科學硏究所 1993 基礎科學硏究 Vol.13 No.-

Deep levels in horizontal Bridgman(HB) undoped GaAs were investigated by DLTS system personally manufactured. In as grown sample, three electron traps of which activation energies are T1(E?-0.32eV), T2(E?-0.54eV) and T3(E?-0.82eV) were observed. As sample was annealed at 650℃, T3 level was separated into T3?(E?-0.74eV) and T3 level. When sample was annealed at 800℃, only T3* level was observed. For sample annealed at 900℃, T3* and T3 level were observed. From these results, EL2's origin is very complicated complex and explanation is very difficult, but the model of As??-V??-A??-V?? is enough to explain the EL2's behavior of annealing temperature.

중학교 가정과 '인간발달과 가족관계' 영역에서 Gordon의 창의적 문제 해결법의 적용

최기옥,채정현 한국 가정과 교육 학회 2000 한국가정과교육학회지 Vol.12 No.3

The purpose of this research was to apply and conduct a class with Cordon's Creative Problem Solving Method(Synectics) to the area of 'human development and family relations'among male students in a jr. high school. Subject matters which were appropriate for applying Cordon's Creative Problem Solving method were selected from 'human development and family relations 'area. With problem circumstances set to reflect to the highest degree the interests of individuals and families. An 8 hour teaching instructional guide was constructed with 「strategyl」 of Gordon's Creative Problem Solving method in order to solve creatively the established problem. This was practically implied to 70 students (each class had 34 and 36 students respectively) in K middle school located in Seoul. The period of this application was for 3 months during March through May of 1999. The perception of this method was examined by the teachers and students through open-ended questions. The record of perception showed that 56 students out of 70(with no response from 5 students) thought that the class done by the creativity problem solving method was good. The majority of reasons mentioned for the Positive answers were 'being able to express thoughts freely in a familiar environment which improves thought process', 'enhancement of Presentational skills and concentration', 'being exposed to various ideas was interesting'and'rewarding to be able to receive different thoughts which were unusual of daily life'. In addition the students who participated in the class were able to fester a joint experience which improved their understanding of relationships and sense of community. Moreover students who did not do well in the class, or were diffident were encouraged to participate, which in result showed that there was even an internal effect.

기독교 신앙이 외래 정신분열병 환자의 치료에 미치는 영향

최영민,이정호,이기철,전성일 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.6

연구목적: 정신의학적 치료과정에서 종교적 논점이 무시되거나 지나치게 적용되는 것에 대한 지적들은 있었으나, 구체적으로 종교적 믿음이 정 신분열병환자들의 치료과정에 어떤 영향을 미치는지에 대한 연구는 거의 없는 상태이다. 그래서 기독교 신앙이 통원치료 중인 정 신분열병 환자들의 치료과정에 어떤 영향을 미치는지를 구체적으로 알아보고자 하였다. 방법: GAF 점수가 41 이상으로 부분적인 병식 혹은 병식을 가지고 있으며 1년 6개월 이상 통원치료를 받고 있던 13명의 개신교일,정신분열병 환자들을 대상으로 전향적인 연구를하였다. 결 과: A. 긍정적 영향: 1) 치료자로서 환자들의 .신앙과 관련된 이야기를 편견없이 진지하게 받아준 것이 치료관계 형성에 매우 도움이 되었다. 2) 신앙이 마치 개인의 불안을 잠재워주는 도구와 같은 기능을 하기도 하였다. 3) 기독교인이라고 하는 사회적 자기정체성. 하나님의 자녀라는 신앙적 자기정체성, 하나님 과의 안전한 둘만의 관계체험.나는 하나님에 의해 언제나 받아들여진다는 느낌 교회에서의 안전한 수용체험 등이 정 신분열병 환자들의 자아정체성이나 자기개념의 발달에 도움을 주었다. 4) 신앙적 체험 흑은 영적인 깨달음을 통해서 알게된 신앙의 내용을 자신의 행동의 지침이나 청사진 처럼 사용하면서 도움을 받았다. 5) 정 신분열병 환자들이 하나님과의 관계에서 느끼는 보호받는 느낌. 수용받는 느낌 등의 둘 만의 관계 체험은 일상생활 속에서 다른 사람들과의 관계에서 경험할수 있는 체험과는 다른 종교의 고유한 심리 경험을 환자들에게 제공해 주었다. 마찬가지로 신앙체험이나 신앙의 내용을 자신의 행동의 지침이나 청사진 처럼 사용하면서 생활해 나가는 정신분열 환자들의 심리는 바람직한 일상생활 규범이나 일반적인 사회관습을 따르는 심리와는 전혀 다른 면이 있었다. 이러한 종교의 고유한 신앙체험이 치유적인 힘을 나타내는 것 같았다. B. 부정적 영향: 1) 교회 목회자나 교인들이 기도원과 같은 종교적 방법의 치유를 강요 혹은 권유함으로써 환자들과 가족들을 혼란시키고 치료과정에도 혼란을 가져오는 경우가 있었다. 2) 증상을 종교적으로 해석함으로써 증상에 대한 병식을 얻는 것을 방해하였다. 3) 신앙을 전체적으로 파악하지 못하고 문자적으로만 이해하는 인지적 결함의 위험성이 있었다. 4)지나치게 죄책감을 느끼며 자신을 징계하는 태도를 보이기도 하였다. 결론 : 기독교 신앙은 안정된 상태로 유지치료 중인 외래 정신분열병 환자의 치료과정에 많은 긍정적 영향과 부정적 영향을 미치는 것을 알 수 있었다. 정신과 의사들은 환자들을 치료할 때 신앙이 갖는 이러한 영향들을 신중하게 고려할 필요가 있겠다. . Objectives : Many psychiatrists ignore the behavioral and attitudinal aspects of religious beliefs of patients with schizophrenia. Therefore, how the Christian belief affects the treatment of schizophrenia was investigated. Methods : The subjects of the study were 13 schizophrenic outpatients with protestant belief having partial or full insight. GAf score of each of the patients was above 41. Results A. positive effects ; 1) Taking the patient's belief seriously without prejudice was helpful to therapeutic relation. 2) Faith fulfilled it's function of silencing the anxiety of the patients. 3) The factors which make schizophrenic patients develop serf-identity and self-concept in their religious lives were as follows : social identity as a Christian, religious identity as a child of God, experiences of safe dyadic relationship with God, feelings of being always accepted by God, and experiences of being accepted safely by the church.4) Faith experiences and spiritual enlightenment itself had a therapeutic impact on the patients as a guiding principle of their lives and blueprints for their actions. 5) Experiences of a safe dyadic relationship with God, feelings of being accepted by God, faith experiences, and spiritual enlightenment provided peculiar religious experiences which can not be found in everyday life. And these peculiar religious experiences seemed to have healing power. B. Negative effects; 1) The clergymen and the members of the church put the patients and their families into the confusion by compelling or recommending religious treatment methods like prayer retreats. 2) They interfered with patients getting insights by interpreting their symptoms religiously. 3) There was a risk of cognitive depfect of gasping faith literally.4) There was a tendency to direct punishment and blame inwards, on to the sef with guilty feelings. Conclusions : Christian belief exerted many influences both good and bad, on the treatment of the schizophrenic outpatients. We suggest that psychiatrists should consider the influence of the patient's faith upon the treatment.

특발성 좌심실빈맥(Idiopathic Left Ventricular Tachycardia)의 성공적인 전극도자절제술을 위해 단극전기도(Unipolar Electrogram)가 유용한가?

최기준,남기병,강덕현,홍명기,송재관,김재중,박성욱,박승정,박종훈,김유호 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4