Toluene, Xylene, Trichloroethylene 투여가 흰쥐의 시상하부와 뇌하수체의 GnRH, GnRH Receptor, Pit-1 유전자 발현에 미치는 영향

기노석,이종태,강대성,김대환,이채관,이헌,전진호,김정호,이채언 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.2

The workplace exposure of chemicals has steadily increased, therefore the concern for subsequent effect on reproductive outcome has been an important issue in occupational medicine. In previous studies, higher rates of spontaneous abortion, reduced fertility and menstrual disorder among women, and an impairement of sperm quantity and quality among men have been associated with a wide variety of chemical agents. This study was conducted to evaluate the effects of toluene, xylene and trichloroethylene(TCE) injection on the mRNA levels of GnRH, GnRH receptor and Pit-1 genes in male rats hypothalamus and pituitary and the effects on the plasma levels of FSH, LH, prolactin and testosterone. Sprague-Dawley male rats were divided into five groups of five each according to concentration of toluene, xylene and TCE. The rats were injected subcutaneously to 0, 50, 100, 200, 400 mg/kg body weight/day of toluene, xylene and TCE, respectively for 6 days. Rat brains were excised and hypothalamus and pituitary were separated. Reverse transcription-polymerase chain reaction (RT-PCR) and RNase protection assay(RPA) were used to evaluate the GnRH, GnRH receptor and Pit-1 mRNA levels. Plasma concentrations of FSH, LH, prolactin and testosterone were assayed by radioimmunoassay(RIA). The results were as follows; 1. GnRH, GnRH receptor and Pit-1 mRNA levels in toluene and xylene injected groups, and GnRH receptor mRNA levels in TCE injected group were lowered dose-dependently. Especially, GnRH receptor and Pit-1 mRNA levels in 200mg/kg of toluene injected group, and GnRH, GnRH receptor and Pit-1 mRNA levels in 400mg/kg of toluene injected group were significantly lower than control group (p<0.05). GnRH receptor and Pit-1 mRNA levels in 400mg/kg of xylene injected group, and GnRH receptor mRNA levels in 400mg/kg of TCE injected group were significantly lower than control group(p<0.05). 2. The plasma levels of prolactin and testosterone in 400mg/kg of toluene injected group, and LH in 100, 200 and 400mg/kg of xylene injected group, and testosterone in 400 mg/kg of TCE injected group were significantly lower than control group(p<0.05). In conclusion, we speculated that toluene and xylene affected reproductive system secondarily through hypothalamus-pituitary axis, and TCE affected directly through steroidogenesis. And we recommended that further study for assessment of the reproductive toxicity of mixed organic solvent exposures should be conducted.

원통 연삭에서 가공 능률 향상을 위한 연삭 저항의 측정에 관한 연구

김원일,이진,이윤경,왕덕현,이상복,이관철,문원길 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

본 연구에서는 원통 연삭 가공에서 가공 능률 향상을 위한 연삭 저항을 측정하고자 연삭 가공 중에 발생하는 연삭 저항의 추이를 확인하였고 다음과 같은 결과를 얻었다. 숫돌과 공작물간의 연삭 강성은 공작 속도의 증가에 따라 지지계의 강성이 높은 경우 증가하였고 절삭 깊이와 연삭 숫돌의 속도에는 연삭 강성이 감소하는 경향을 보였다. 또한 총합 강성은 공작 속도, 절삭 깊이 및 연삭 숫돌의 속도 증가에 따라 지지계의 강성이 높을 수록 증가하였다. 연삭기의 강성 변형과 가공 능률에 영향을 주는 값으로 연삭 강성비는 지지계의 강성이 높을 수록 감소하였다. In this study, the measurement of grinding resistance to improve grinding efficiency in cylindrical grinding was studied and the following conclusions could be obtained. Relation grinding wheel and workpiece, grinding stiffness increases according to increase of work speed for high machine stiffness and decreases depth of cut and grinding wheel speed. Also, resultant stiffness increases high machine stiffness according to increase work speed, depth of cut and grinding wheel speed. The values of the effect stiffness deflection in grinding machine, grinding stiffness ratio decrease according to high machine stiffness.

진위천 유역 수질 특성 분석

박병기 ( Byeong Ky Park ),김진혁 ( Jin Yuk Kim ),이동준 ( Dong Jun Lee ),신경용 ( Kyung Yong Shin ),박민지 ( Min Ji Park ),문정숙 ( Jeong Suk Moon ),이영준 ( Young Joon Lee ),이재관 ( Jae Kwan Lee ) 한국물환경학회(구 한국수질보전학회) 2014 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2014 No.-

야뇨증 환아들의 심리사회적 특성에 대한 다기관 연구 : 행동 및 정서 문제를 중심으로

조수철,김재원,신민섭,황준원,한상원,박관현,이상돈,김경도,김건석,서홍진,이유식,정재용,김영균,문두건,남궁미경,한창희,조원열,김영식,배기수,이종국,정우영,신의진 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.6

Objectives : The aim of this study was to examine the behavioral and emotional problems associated with nocturnal enuresis in Korean children. Methods : Three hundred eighteen children with nocturnal enuresis, together with their parents, completed the Child Behavior Checklist (CBCL), Disruptive Behavior Disorder Scale according to DSM-IV (DBDS), Children's Depression Inventory (CDI), State-Trait Anxiety Inventory for Children (STAIC), and Piers-Harris Children's Self-Concept Scale (PHCSC). Ninety-three normal students were selected as the control group. Results : Compared to the normal control group, the mean scores with regard to the withdrawn, social problems, attention problems, delinquent behavior, aggressive behavior, externalizing problems and total problems profiles were significantly higher in the nocturnal enuresis group according to the CBCL results. The nocturnal enuresis group also scored significantly higher in the ADHD and ODD profiles of the DBDS. The nocturnal enuresis group was more depressed and anxious than the control group according to the results of the CDI and STAI. The mean score of the PHCSC was significantly lower in the nocturnal enuresis group when compared to the normal control group. Conclusion : The results of this study suggest that children with nocturnal enuresis in Korea have clinically relevant behavioral and emotional problems. The findings support the link between nocturnal enuresis and psychopathology in Korean children.

직접추정법에서 작업평가에 대한 기준작업 변화의 영향 연구

양진석,이관석 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.2

Among various method in determining the maximum acceptable weights of lift(MAWL), the psychophysical method has been popularly used for the infrequent but repetitive lifting. This method still takes substantial amount of time in case there are many different combinations of tasks. To further shorten the time taken to determine MAWL's for different tasks, the direct estimation method which employs the ratio scale between the person's feeling of stress in lifting has been used. However, no study was conducted about the standard lifting task which is used as a basis for the scale in the direct estimation method. Therefore, the effect of different standard lifting tasks to the MAWL in certain lifting situations was studied in this research. Four lifting frequencies(1,2,4, and 6 lift/min) were tested in two different lifting situations(Floor to knuckle, Knuckle to shoulder) in a laboratory. It was found that the MAWL determined in the task of 1 lift/min showed the closest value to the MAWL determined by the psychopysical method in the floor to knukle lifting situation. The MAWL in the task of 4 lift/min also showed the closest value to the MAWL obtained by the psychophysical method in the knuckle tl shoulder lifting situation.

특별활동 부서 배정업무 자동화 시스템 구축

이진관,김귀복,박기홍 군산대학교 정보통신기술연구소 2000 情報通信技術硏究論文集 Vol.4 No.-

This thesis tries to rule out the problems of the existing method in which teachers assigns students the club activity department respectively in manual manner. The proposed system assigns club activity department automatically on the web according to the students' application. And thus it reduces both time and cost spent in organizing, arranging and managing which characteristic provides teachers with a turning point in teaching- learning fields.

체육교사의 자기수업장학이 교수행동에 미치는 영향

이병익,김관현,김진표,김기환,김윤태 龍仁大學校 2001 용인대학교 논문집 Vol.19 No.-

This study was to analyze the effect of psical teacher's self-directed super- vision on teaching behavior. The prpose of this study is to identify the effect of pysical teacher's self director supervision of their teaching trough other teacher's teaching and all of physical education methods. Therefore research models and hypothesis were established on previous research and theories. Background variable was physical teacher's personal factor and Independent variable was physical teacher's sect-directed supervision. Dependent variable was teaching behavior of physical teacher. The data were collected by using simple random sampling of 360 physical teacher's in Seoul , Kyung-gi-Do, and In-chun. To survey the data question paper was used. T-test and one-way ANOVA were used to test hypothesis. Multiple-Regression Analysis was used to know effect of physical teacher's self-directed supervision on teaching behavior. Each hypothesis was tested at the significance level of 0.5 The conclusions were drawn as the followings First. influence of self- directed supervision by physical teacher's personal factor was following. According to sender there was no difference in teaching behavior. There was a significant influence in understanding students according to school's situation(girls, boys, and co-ed). There was a significant influence in class managing, understanding students, class preparing, teaching method according to class reflection. Second. influence of teaching behavior by physical teacher's personal factor was following influence. The gender had influence on dynamism and creativity. School situation(boys, girls, co-ed) had influence on individuality and creativity. Class reflection had influence on dynamism, creativity, obviousness and individuality. Third. effect of physical teacher's self-directed supervision on teaching behavior was followings. In dynamism, it had influence on teaching method, class managing, understanding students, sequentially. But not on preparation. In Individuality, it had influence on preparation, understanding students. Class managing sequentially. But not on teaching method. In obviousness. It had influence on class managing and Preparation. sequentially. but not on understanding students. and teaching method. In creativity, it had influence on understanding students, preparation, class manacling sequentially, but not on teaching method.

cDNA array 방법을 이용한 망간에 노출된 흰쥐 뇌기저핵의 유전자발현 분석

이채관,노성민,문덕환,,김정호,손병철,김대환,이창희,김휘동,김정원,김종은,안진홍,이채언 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Objectives: This study investigated the gene expression profile in basal ganglia of manganese-exposed rats based on cDNA array analysis. Methods: For cDNA array, 25 male Sprague-Dawley rats (250±25 g) were intraperitoneally injected with 25 ㎎/㎏ B. W./day of MnCl2 (0.3 ㎖) for 10 days. For dose-related gene expression analysis, rats were intraperitoneally injected with 0.2, 1.0, and 5.0 ㎎/㎏ B. W/day of MnCl2 for 10 days. Control rats were injected with an equal volume of saline. RNA samples were extracted from brain tissue and reverse-transcribed in the presence of [α^(32)P]-dATP. Membrane sets of the Atlas Rat 1.2 array Ⅱ and Toxicology array 1.2 kit (Clontech, Palo Alto, CA) were hybridized with cDNA probe sets. Northern blot hybridization method was employed to assess the dose-related gene expression. Results: Fifty-two genes showed significant changes in expression of more than two-fold. Twenty-eight were up-regulated and 24 were down-regulated in the manganese-exposed group compared to the control. Among the 52 genes, 28 genes including nuclear factor I-X1 (NF1-X1), neuroligin 2 and 3, mitochondrial stress-70 protein (MTHSP70), neurodegeneration-associated protein 1 (Neurodap 1), multidrug resistance protein (MDR), and endoplasmic reticulum stress protein 72 (ERP72), were reported for the first time related to the manganese-induced neurotoxic-metabolism in the rat basal ganglia. According to the dose-related gene expression analyses, MTHSP70, Neurodap 1 and ERP72 genes were up-regulated compared to the control even in the group exposed to low manganese dose ( 0.2 ㎎/㎏ B.W./day). Conclusions: Twenty-eight genes detected for the first time in this study were closely related to the manganese-induced neurotoxic-metabolism in the rat basal ganglia and further study of these genes can give some more useful information about the manganese metabolism.

HP/3000에서 연속적인 값을 갖는 시스템의 모의 실험 방법에 관한 연구

李萬鎬,劉寬鍾,陳成日 충남대학교 자연과학연구소 1981 忠南科學硏究誌 Vol.8 No.2

There are four methods of solving differential equations appearing in engineering problems. First, analytic method. Second, numerical analytic method using digital computer. Third, method using analog computer. Last, method which simulates analog computer by using digital computer processors. In case where me equations are non-linear, the first and the second method are very difficult and the third method is not used well because of the rareness of the analog computer. So it is economical to simulate the analog computer by using digital computer widely used. But, since mere are no such digital-analog simulation processors in HP/3000 computers currently in KOREA, many computer users have difficulties in solving problems. In this paper, we design and implement a simulation processor which enables the fourth method in HP/3000 computers.

콘서트홀의 音響을 위한 擴散體의 開發

이성찬,류종관,전진용 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

The degree of diffusion, characterized by the "scattering coefficient" of surface materials has been known to be one of the most important factors in determining the acoustical qualities of concert halls. The diffusion phenomenon allows greater musical appreciation by affecting early and reverberant sound in a concert hall. Following the knowledge, gained from many experiments based on the suggested ISO method, a box-type diffuser was planned for walls of the 400-seat Milal Concert Hall. The ceramic tiles ranging from 10 to 20cm in width and length, have a height up to 20cm, which were produced by a ceramic artist, in cooperation with an acoustician and an architect. The scattering coefficient was measured at 1/10 scale using different arrangements. The results were satisfactory: the overall scattering coefficients were 0.61-0.62. During tuning concerts, the acoustics of Milal concert hall was appreciated by several soloists, ensemble players and orchestra conductors. The overall impressions of the audiences from the early performances have been pleasant in terms of its fullness of tones with abundant high pitch.