흰쥐에서 니켈 및 카드뮴의 동시노출이 간에 미치는 영향

차봉석,왕승준,장세진 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.1

목적 : 이 연구는 적출간 관류법을 이용하여 영화니켈과 염화카드뮴의 동시 노출로 인하여 간에 나타나는 효과를 확인하는 데에 있다. 방법 : 간독성의 지표로서 AST, ALT, LDH의 농도 및 관류속도를 이용하였고 생존력에 대한 지표로서 산소소모율을 측정하였다. 300(±50) g의 흰쥐를 노출군(비노출군 및 50 μM/ 200 μM의 각 농도별 염화니켈과 염화카드뮴의 개별 투여군 및 동시 투여군)별로 5마리씩 총 35마리를 할당하였다. 간을 통과한 관류액을 채취하여 생화학적 간독성 지표를 측정했고 집단간의 시간의 경과에 따른 측정치의 비교를 위해 반복 측정된 2요인 분산분석을 실시하였다. 개별 투여군과 동시 투여군의 생화학적 지표간의 평균을 비교함으로써 상승효과에 대한 가능성을 확인했다. 결과 : 개별 투여군 및 동시 투여군 모두에서 AST, ALT, LDH가 증가했다. 관류속도 및 산소 소모율은 시간의 경과에 따라 감소했으나 통계적으로 유의한 차이를 보이지는 못했다. AST, ALT, LDH, 산소소모율이 일정 시간대 이후로 개별 노출군의 합보다 동시 노출군에서의 측정치가 더욱 크게 증가하였다. 결론 : 간독성에 대한 생화학적 지표의 변화를 확인함으로써 두 물질의 동시노출로 인한 복합적 효과는 상승효과일 가능성이 높은 것으로 보인다. Objectives : This research was intended to verify hepatic effect of simutaneously com-bined exposure of nickel chloride and cadmium chloride with IPRL (Isolated Perfumed Rat Liver) method. Methods : AST(aspartate aminotransferase), ALT(alanine aminotransferase), LDH (lac-tate dehydrogenase) and perfusion flow rate were used as the indicator of hepatotoxicity and oxygen consumption rate were used as the indicator of viability. 300(±50) g - weighted rats were allocated randomly to each group (control group, 50 μM·200 μM sera-rately exposure group of NiCl₂and CdCl₂, simultaneously combined exposure group of NiCl₂and CdCl₂by 5, totally 35. Buffer which got out of liver was sampled and then biochemical indicator of hepatotoxlcity was measured. In order to verify difference among groups, two way - repeated ANOVA was used. With comparing mean summation of sepa-rate exposure group with mean of simultaneous exposure group, possibility that combined effect could be synergistic effect was verified. Results : AST, ALT, LDH increased in both of separate exposure group and simultaneous exposure group. Perfusion flow rate and oxygen consumption rate decreased but statlstically significant difference among groups was not found. In each exposure group, AST, ALT, 7DH, oxygen consumption rate of simultaneous exposure group increased more than sum of separate exposure group after any sampling time. Conclusions : It was found that simultaneous combined effect could be synergistic effect through the biochemical indicator of hepatotoxicity.

사무직 근로자들의 직무 스트레스와 피로

차경태,김일희,고상백,현숙정,박준호,박종구,차봉석,장세진 大韓産業醫學會 2008 대한직업환경의학회지 Vol.20 No.3

목적: 이 연구는 전국 규모의 조사 연구에서 수집된 자료 중 사무직 근로자들을 대상으로,사회인구학적 특성,직업 특성,건강행태,직무 스트레스와 피로수준 간의 관련성을 분석하는 데 있다. 방법:‘한국인 직무스트레스 측정도구의 표준화 전국 조사연구National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002∼2004)’를 위해 2002년 5월 1일부터 2003년 5윌 30일 까지 수행되었으며,전국의 사업장에 근무하는 근로자 30,146명(남자: 84%,여자: 16%) 중 사무직 근로자 4,457명(남자: 68.9%,여자 31.1%)을 연구 대상으로 하였다. 자료수집방법은 사업장을 방문하여 보건 및 안전관리자 등에게 연구의 취지를 알린 후 설문조사에 대한 협조를 구하고 응답자 직접 기입법을 이용 하였으며,사회인구학적 특성,직업적 특성,건강관련 요인,KOSS-SF를 이용한 7개의 직무 스트레스 요인,그리고 MFS를 이용하여 피로 수준에 영향을 주는 요인에 대해 분석하였다. 결과: 일반적 특성,작업관련 특성,건강행태관련 특성 및 직무 스트레스 요인이 근로자들의 피로와 강한 관련성이 있음이 입증되었으며,특히 직무 스트레스의 하부 요인 중에서도 피로와 관련성을 보이는 요인이 남녀별로 다소 상이 하게 관련된다는 것을 발견할 수 있었다. 남자의 경우는 직무 스트레스의 하부 영역 중 직무 요구도,직무 불안정성,보상부적절 등이 영향력이 높은 주요 직무 스트레스 요인이었던 반면,여자는 직무 요구도,보상부적절,직장문화가 주요한 직무 스트레스 요인이었다. 결론: 직장인 피로가 갖는 보건학적 의학적 경제학적 중요성을 감안할 때,조직의 생산성 향상과 근로자 개개인의 삶의 질 향상 및 건강증진을 위해선 직무 스트레스 관리 프로그램이 절실히 요청된다고 볼 수 있다. Background & Objectives: A growing body of research has documented that occupational stress is closely associated with increased risk of fatigue. This study was conducted in an effort to assess the relationship of occupational stress to self-perceived fatigue among Korean white collar employees. Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project, 2002-2004). Among them, a total of 4,502 white collar employees were recruited. A structured questionnaire was employed to evaluate the participants' sociodemographics, job-related factors, health-related behaviors, occupational stress, and self-perceived fatigue. Occupational stress and self-perceived fatigue were assessed using the Korean Occupational Stress ScaleShort form (KOSS-SF) and the Multidimensional Fatigue Scale (MFS), respectively. Results: In logistic regression analyses, occupational stress was associated with an increased risk of fatigue, and some domains of occupational stress had different effects on fatigue by gender (job demand, job insecurity, and lack of reward for men, job demand, lack of reward, and discomfort in occupational climate for women), which indicates that occupational stress may perform a slightly different role in increasing the risk of fatigue by gender. Conclusion: The results of this study suggest that occupational stress is a determinant predictor of self-perceived fatigue. Thus, a stress management program for the reduction of occupational stress, and the promotion of white collar worker's health and quality of life is strongly recommended. Some limitations of this study and considerations for future studies were also discussed.

구간분할 바이너리 제어를 이용한 로봇핸드의 동특성에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

In recent years, as the robot technology is developed the researches on the artificial muscle actuator that enable robot to move dextrously like biological organ become active. The widely used materials for artificial muscle are the shape memory alloy and the electro active polymer. These actuators have the higher energy density than the electromechanical actuator such as motor. However, there are some drawbacks for actuator. SMA has the hysterical dynamic characteristics. In this paper the segmented binary control for reducing the hysteresis of SMA is proposed and the simulation of anthropomorphic robotic hand is performed using ADAMS.

다채널 광정렬 장치에서의 다자유도 회전 스테이지 동작 특성에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

In recent years, as the demands of VBNS(Very high speed Backbone Network Service) and VDSL(Very high-data rate Digital Subscriber Line) increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, WDM elements increase. The alignment and the attachment technology are very important to fabricate the optical elements for communication. In this paper, the mechanism of rotational stage are studied. with the three different method and the results of them are applied to the design of the system. The performance test of resolution and travel is performed.

VDT 취급근로자의 신체적 자각증상과 정신사회적 안녕상태의 관련성

고상백,차봉석,장세진,박창식 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.3

이 연구는 VDT 취급근로자들의 신체적 자각증상의 실태와 신체적 자각증상과 정신사회적 안녕수준간의 관련성을 분석하기 위해 강원도 W시 및 K시에 근무하는 여자 전화 교환원 89명을 대상으로 구조화된 설문지를 이용하여 자료를 수집하여 다음과 같은 결과를 얻었다. 1. 연구대상의 평균연령은 37.7세 (표준편차 3.1세) 였으며 결혼 상태는 기혼자가 81명(91%)으로 대다수를 차지하였다. 2. 연령별, 지역별 VDT자각 증상수준과 정신사회적 안녕수준간에는 모든 항목에서 유의한 차이가 없었다. 3. VDT 자각증상은 어깨, 목, 등, 팔, 손(손가락), 허리 하지 등 7개 부위에 대해 근골격계 증상을 조사하였는데, 조사대상자 중 어깨 98.9%, 목 91.2%, 손 89.9%, 팔 88.9%, 등 87.8%, 하지 85.6%의 증상을 호소하여 대다수의 대상자에게서 높은 자각증상 수준을 보였다. 4. 부위별 자각증상 수준에 따른 정신사회적 안녕수준을 비교한 결과 어깨, 목, 팔, 손, 하지등은 유의한 차이를 보였으나(P<0.05), 등 허리 등은 유의한 차이를 보이지 않았다. 7개 부위의 총 자각증상을 정신사회적 안녕수준과 비교한 결과 VDT자각 증상이 높을수록 낮은 정신사회적 안녕수준을 (P<0.01)보였다. 5. VDT관련 증상 및 일상생활 불편도와 현재의 정신사회적 안녕수준간의 상관분석결과, 불편척도가 가장 유의한 상관관계를 보였고, 등을 제외한 다리, 팔, 목 어깨, 허리, 손 등의 순으로 유의한 상관관계를 보였다. 6. 정신사회적 안녕수준에 미치는 제 변수들의 설명력을 알아보기 위해 불편척도, 각 부위별 자각증상을 독립변수로하여 회귀분석을 시행한 결과 불편척도와 하지의 자각증상이 회귀식에 투입되었고 설명력은 40%였다. This study was undertaken to identify the relationship between the subjective symptoms and the psychosocial well-being status of VDT operators. The study subjects of this study were 89 female telephone operators in Korea Telecom. The mean age of study subjects was 37.7 (s.d; 3.1), and 91% of them were the married and 9% were the single. The mean values of psychosocial well-being status by general characteristics were not statistically significant. Of the 89 operators, 98.9% felt musculoskeletal subjective symptoms in shoulder, 91.2% in neck, 89.9% in hand, 89.9% in lowback, 88.9% in arm, 87.8% in back, and 85.6% in leg, respectively. The mean scores of the psychosocial well-being status by three categories of subjective symptoms were significant in shoulder, neck, arm, hand, and leg, but were not significant in back and lowback. Correlations between the subjective symptoms and the psychosocial well-being status were significant in discomfort scale, leg, arm, neck, shoulder, lowback, and hand, but were not significant in back. Multiple regression analysis were used to determine whether the independent variables (age, discomfort, and subjective symptoms) contributed to explaining the psychosocial well-being status. Discomfort and the subjective symptoms in leg were a correlate of the psychosocial well-being status.

흰쥐에서 염화비닐 폭로수준에 따른 소변내 thiodiglycolic acid 농도의 변화

왕승준,차봉석,노재훈,신동천,김명수,전근재 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : It is the objective of this research to identify the variation of thiodiglycolic acid(TdGA) in urine with vinyl chloride monamer(VCM) exposure levels through methylation. Methods : After rats were exposed to vinyl chloride monomer of 4 levels, 0㎎/㎥, 50㎎/㎥, 150㎎/㎥, 500㎎/㎥, respectively, of which urine was sampled in each sampling time of 0 hour, 2 hours, 4 hours, 8 hours, 16 hours, 36 hours, 48 hours. After urine had been methylated with diazomethane in the preliminary experiment and the peak of 146 m/z had been verified, the main experiment was done. Results : In the variation of TdGA with sampling times, concentration of TdGA increased rapidly in 4 hours and then decreased after 8 hours. When the variation of urinary TdGA concentration in urine according to exposure level of VGM was verified through Kruskal-Wallis statistical method at each sampling time, the significant increment with the exposure levels at 2 hours, 4 hours, 8 hours after exposure was clarified. Conclusion : TdGA concentration in urine with increment of VCM exposure level increased, especially significantly at 2 hours, 4 hours, 8 hours of sampling time.

극초정밀 다축 스테이지의 광소자 정렬에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

In recent years, as the demands of VBNS and VDSL increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM elements increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the optical alignment characteristics of multi-axis ultra precision stage were studied. The alignment algorithms were studied for applying to the ultra precision multi-axis stage. The alignment algorithm is comprised of field search and peak search algorithms. The contour of optical power signals can be obtained by field search and the precise coordinate can be found out by peak search. Two kinds of alignments, such as 1ch. input vs. 1ch. output optical stack, and 1ch. input vs. 8ch. output PLC stacks were performed for investigating the alignment characteristics.

초정밀 광소자 정렬 스테이지의 구동 특성에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement to the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

스트레스 측정도구의 표준화 방안

장세진,차봉석,박종구,이은경 연세대학교 원주의과대학 1994 원주의대논문집 Vol.7 No.1

무기수은을 투여한 흰쥐에서의 신장독성에 대한 착화제 효과 및 병리조직학적 변화

고상백,홍순원,차봉석 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.2

This study was to determine the effects of Sodium-N-[4-methoxybenzyl]-D-glucamine-N-dithiocarbamate (MeOBGDTC) on the nephrotoxicity of mercury and histopathological change in rats pretreated with mercuric chloride 48h earlier. In a first experiment, 3 groups were given a single injection i.p. of 3.5㎛ol/Kg of Hgcl₂ mixed with 1μCi of 203Hg²+ in a final volume of 0.5ml of physiologic saline. Subsequently the rats also received the chelator, 1mmol/Kg of MeOBGDTC, at 1h in group 2 (Hgcl₂-MeOBGDTC 1h) and 12h in group 3 (Hgcl₂-MeOBGDTC 12h) after injection of mercuric chloride. The results showed that the injection of chelating agent at 1h after mercury injection significantly decreased mercury level in plasma. But not significant in renal cortex. In a second experiment, rats were divided into 4 groups, one group was control group, others were mercury injected group. MeOBGDTC was also administered to mercury-injected, rats as described above. The changes in renal function were determined by measurement of proteinuria, plasma creatinine and urinary osmolality. The results showed that the injection of mercuric chroride incrased the excretion of urinary protein and plasma creatinine, and decreased the urinary osmolarity. However, the injection of chelating agent at 1h after mercury injection significantly decreased the toxic effects of mercury. Finally, histopathological change at the light microscopic level was comparable effect of chelating agent on nephrotoxicity of mercury. Minimal morphological alterations were seen in kindly of rats of Hgcl₂-MeOBGDTC 1h. The Hgcl₂-MeOBGDTC 12h caused necrotic change of the proximal tubule at cortical-medually junction. These changes were more common and more severe at the Hgcl₂alone.