RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 음성지원유무
        • 원문제공처
          펼치기
        • 등재정보
          펼치기
        • 학술지명
          펼치기
        • 주제분류
          펼치기
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • SCIESCOPUSKCI등재
      • KCI등재후보

        Stem cell과 Myeloperoxidase가 스티렌, 하이드로퀴논 및 트리클로로에틸렌에 의한 림프구의 자매염색분체 교환과 소핵체 유도에 미치는 영향

        이경재,김형아,신민정,성재혁,박정일,한훈,이세훈 대한산업의학회 2001 대한직업환경의학회지 Vol.13 No.3

        목적 : 스티렌, 하이드필퀴논 및 트리클로로에틸렌 (TCE)이 사람의 stem cell과 human myeloperoxidase (MPO)에 의해 대사성 활성화되는 지를 규명하고자 스티렌, 하이드로퀴논 및 TCE에 사람의 stem cell 또는 MPO 효소의 첨가가 이들 화학물질에 의한 자매염색분체교환(SCE)과 소핵체 (MN) 빈도에 미치는 영향을 관찰하였다. 방법 : 건강한 남자의 전혈에서 림프루를 분리하여 72시간동안 이중배양하되 배양개시 24시간만에 0.05mM 하이드로퀴논, 1.50 mM 스티렌, 혹은 1.50mM TCE를 전체용량이 30 ㎕가 되도록 아세톤에 희석하여 배양액에 주입하였고 대조군은 아세톤으로 처리하였다. 화학물질 처리 후 즉시 1.3×106 및 2.6×106 cells/ml 농도의 제대혈액으로부터 나온 stem cell 세포액의 상층액이나 1.0 및 2.0 unit의 human myeloperoxidase를 H2O2와 함께 첨가하였다. SCE분석을 위한 배양액에는 배양종료 2.5시간 전에 colchicine을 가한 후 수확하여 Giemsa염색을 하여 metaphase 세포에서 SCE빈도를 분석하였다. MN분석을 위한 배양액에는 배양개시 44시간만에 cytochalasin-B를 가하였고 acridine orange 염색 후 이핵체에서 MN수를 분석하였다. 결과 : 1. stem cell이나 MPO 자체는 SCE나 MN의 빈도에 영향을 미치지 않았다. 2. stem cell이나 MPO는 스티렌에 의해 유도되는 SCE의 빈도를 용량-반응관계로 유의하게 증가시켰고, MN빈도의 경우 step cell이나 MPO에 의해 증가되는 경향이 있었으나 2.0 unit MPO를 첨가한 경우에만 첨가하지 않은 경우에 비하여 유의하게 증가하였다. 3. 하이드로퀴논은 stem cell이나 MPO가 없는 상태에서도 대조군에 비하여 SCE빈도가 대조군에 비하여 높았다. stem cell이나 MPO는 하이드로퀴논에 의한 SCE 빈도를 용량 반응관계로 유의하게 증가시켰지만, MN의 경우에는 증가시키는 경향만 있을 뿐 유의한 차이는 아니었다. 4. TCE자체는 SCE나 MN빈도를 증가시키지 않았다. stem cell은 1.3 ×106 및 2.6 × 106 cells/ml 농도 모두에서 SCE빈도를 유의하게 증가시켰고 MPO는 2.0 unit농도에서만 유의하게 증가시켰다. stem cell이나 MPO모두 TCE에 의한 MN빈도를 증가시키는 경향이 있었으나 유의한 차이는 아니었다. 결론 : 저자들은 스티렌, 하이드로퀴논, 및 트리클로로에틸렌에 의해 유도되는 자매염색분체교환과 소핵체의 빈도가 사람의 stem cell이나 myeloperoxidase에 의해 증가됨을 발견하였으며, 이러한 결과는 myeloperoxidase가 이들 물질의 대사성활성화에 관여함을 암시하고, 또한 아마도 이 물질들의 골수독성과 관련이 있는 것이라고 제시된다. Objectives : The objective of this study was to identify the possible role of stem cell and myeloperoxidase (MPO) in the metabolic activation of styrene, hydroquinone and trichloroethylene, by investigating the effects of stem cell from umbilical cord blood and MPO on the frequency of sister chromatid exchange (SCE) and micronuclei (MN) induction in cultured human peripheral lymphocytes exposed to hese chemicals. Methods : Islated lymphocytes from whole blood were cultured for 72 hours. The cells were treated with 1.50 mM styrene, 50 μM hydroquinone and 1.50 mM trichloroethylene dissolved with acetone (30㎕ in total volume) at 24 hours after the beginning of culture. Control group was treated with acetone only. Immediately after adding these chemicals, 1.3×106 cells/ml and 2.6×106 cells/ml stem cell/ml stained with Giemsa's solution, and acridine orange for sister chromatid exchange, and for micronucleus analysis, respectively. Results : The results were as follows: 1) Myeloperoxidase and stem cell did not significantly affect the frequencies of SCE or MN in the control group. 2) The frequency of SCE or MN with exposure to styrene did not different from control in the absence of stem cell or MPO. Sister chromatid exchange induced by styrene was significantly increased by adding stem cell or MPO in dose-dependent relationship. The frequency of MN induced by styrene significantly increased in the presence of 2.0 unit MPO. 3) The frequency of SCE was significantly increased with exposure to hydroquinone than acetone treated control in the absence of stem cell or MPO. Sister chromatid exchange induction by hydroquinone significantly increased dose-dependently in the presence of stem cell or MPO. There was a tnendency of increase of the MN frequency induced by hydroquinone in the presence of stem cell or MPO, but not significant. 4) It was found that trichloroethylene itself did not increase SCE or MN frequency. Frequency of SCE induced by trichloroethylene was significantly increased with adding stem cell (low and high) and 2.0 unit MPO. Even though them cell or MPO increased the frequency of MN of lymphocyte exposed to trichloroethylene, the difference was not significant. Conclusions : Authors found that the frequencies of both sister chromatid exchange and micronucleus induced by styrene, hydroquinone, and trichloroethylene were increased significantly with the treatment of stem cell or myeloperoxidase. It was suggested that myeloperoxidase may therefore play an important role in the metabolic activation of styrene, hydroquinone, and trichloroethylene and myeloperoxidase probably be involved in the myelotoxicity of these chemicals.

      • KCI등재

        인터넷 벤처비즈니스 평가체계에 관한 연구

        이명호,이우형,손성혁 한국경영과학회 2001 韓國經營科學會誌 Vol.26 No.3

        Riding on the wave of the information technology revolution, a slew of internet venture businesses(IVB) came into being. Hence, one of the recent deveopments in Korean capital market has been the proliferation of IVB, which is in accordance with the worldwide trend of 'new economy'. Although the fair valuation is crucial for the nourishment of IVB. It is difficult to apply traditional valuation methods to these firms without reservation. It is due to the facts that most venture firms have little records of performance, grow unprecedently fast, and have highly uncertain future. The main purpose of this study is to suggest performance evaluation system of IVB and to develop KPI(Key Performance Indicators). Our empirical study is based upon Kaplan & Norton's Balance Scorecard (BSC) approach. Specifically, our research has been conducted by the following two subsequent procedures: Firstly, seven internet venture firms have been selected and their executives have been interviewed by FGI(Focus Group Interview) method. Based upon these results, performance indicators been developed. Secondly, by using the above mentioned BSC items(i.e., financial perspective, customer perspective, internal perspective and innovation & learning perspective), questionnaires have been costructed and sent to IVB through e-mail as well as over the Fax. Among the collected 110 samples, reliable 106 samples have been used to build BSC model and to draw our conclusion. In the future study. It would be much better to consider the role of strategy in IVB and the causal relationships among Key Performance Indicators of BSC.

      • KCI등재

        석면관련 폐질환의 진단에 있어서 흉부고해상도전산화단층촬영검사(HRCT)의 유용성

        이현재,손지언,,홍영습,,이영일,예병진,유창훈,정갑열,김상훈,임형준,장은철,김정만,김준연 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

        목적: 석면에 노출된 근로자에서 석면관련 폐질환의 양상을 분석하고 진단에 있어 HRCT의 유용성을 연구하여 석면에 대한 의학적 감시프로그램의 개발에 기여하고자 하였다. 방법: 석면에 직접 노출되는 작업자 68명과 간접 노출되는 작업자 94명 등 총 162명에 대해 OSHA 석면 표준, 의학적 감시 프로그램에 따라 단순 흉부방사선검사, 폐활량검사 및 우리나라 실정에 맞게 일부 수정한 의학적 설문지를 통해 면접조사의 방식으로 환자에 관한 정보를 수집하였으며, 자료의 신뢰성을 확보하기 위하여 면접조사는 1달 이상의 기간을 두고 2차례에 걸쳐 실시된 후 확인, 수정하였다. 또한, 석면관련 폐질환을 확진하기 위하여 HRCT를 추가적으로 실시하였다. 결과: HRCT결과 석면관련 폐질환의 유병율은 162명의 근로자중 17명으로 10.5%였는데, 직접 노출군에서 10명 (14.7%), 간접 노출군에서 7명 (7.4%)이었다. HRCT와 비교할 때 단순 흉부방사선검사의 민감도와 특이도는 각각 70.6%와 98.6%이었고, 양성 예측도와 음성 예측도는 각각 85.7%와 96.6%으로, HRCT는 단순흉부방사선검사에 비해 민감도가 높아 초기 석면관련 폐질환을 진단하는데 효과적이었다. 석면관련 폐질환의 진단에 있어 HRCT와 폐활량검사 사이에 유의한 관련성이 관찰되었다. HRCT 결과 석면관련 폐질환의 유무와 의학적 설문조사 결과의 빈도분석을 실시한 결과, 유의한 변수는 작업기간, 흡연량, 호흡기질환의 과거력, 기침, 호흡곤란이었다. 결론: HRCT는 석면관련 폐질환의 진단에 있어 단순 흉부방사선검사와 비교하여 민감도가 높아 초기 진단에 유용하므로 단순 흉부방사선선검사 결과 석면관련 폐질환소견을 보일 때뿐만 아니라, 정상소견을 보이더라도 폐활량 검사결과와 근무력, 흡연력, 호흡기질환의 과거력, 기침, 호흡곤란 등의 호흡기 증상을 참고하여 HRCT검사를 고려해야 한다. 또한, 본 연구에서 관련성이 없었던 요인들에 대해서도 향후 연관성을 규명하는 광범위한 전향적 연구가 필요하다. Objectives: This study was carried out to improve the medical surveillance program of workers exposed to asbestos by examining the usefulness of High Resolution Computed Tomography (HRCT) in the diagnosis of asbestos-related lung disease. Methods: The study subjects comprised 162 workers in a ship-repairing yard, 68 of whom had been directly exposed to asbestos and 94 indirectly exposed. The 'Occupational Safety & Health Administration (OSHA) asbestos standard, medical surveilance program' and HRCT were conducted to analyze the aspects of the asbestos-related lung disease. The OSHA asbestos standard, medical surveilance program consists of simple chest x-ray, spirometry and medical questionnarie. Results: Seventeen (10.5%) of the 162 subjects, 10 (14.7%) directly exposed and 7 (7.4%) indirectly exposed, revealed asbestos-related lung disease on HRCT. The sensitivity and specificity of simple chest x-ray for asbestos-related lung disease were 70.6% and 98.6%, and the positive and negative predictive values were 85.7% and 96.6% respectively, as compared with HRCT, HRCT was an effective diagnostic tool especially to detect early asbestos-related lung disease. The study results indicated a relative significant association between the results of spirometry and HRCT. The variables significantly associated with asbestos-related lung disease on HRCT were work duration, smoking history (pack-years), past history of respiratory disease, cough and dyspnea. Conclusions: In the diagnosis of asbestos-related lung disease, HRCT should be considered not only for workers with positive findings on simple chest x-ray, but also workers with specific findings on spirometry, occupational history, smoking history, and past history of respiratory disease, or with respiratory symptoms such as cough and dyspnea.

      • KCI등재
      • 적혈구 유무에 따른 벤젠, 스티렌, 트리클로로에틸렌에 의한 림프구 중 자매염색분체 교환 빈도

        성재혁,김형아,신민정,최미정,이세훈 가톨릭대학교 산업의학센터 2001 韓國의 産業醫學 Vol.40 No.4

        This study was performed to investigate the possible role of oxyhemoglobin in the metabolic activation of benzene, styrene and TCE by observing the difference of the SCE frequency between isolated lymphocyte and whole blood lymphocyte cultures exposed to these chemicals. Isolated lymphocyte and fresh heparinized peripheral whole blood samples from a healthy donor(male, smoker) were cultured in the phytohaemagglutinin stimulated culture media for 72 hours. The cells were treated with 100, 300, 1000, 3000 μM benzene, 250, 500, 100, 2000 μM styrene or TCE respectively. Slides were stained with Giemsa's solution for SCE. SCE was analyzed for each subject from coded slides by one researcher. The results were as follows : 1.The frequency of SCE increased dose-dependently with concentration of benzene in isolated lymphocyte and whole blood lymphocyte cultures, however there were no significance. There was no significant difference of SCE frequency between isolated lymphocyte and whole blood lymphocyte cultures. 2.The frequency of SCE in whole blood exposed to sytrene significantly increased in dose-dependant relationship, but not in isolated lymphocyte. The difference of SCE frequency between isolated lymphocyte and whole blood lymphocyte of 2000μM styrene exposure was marginally significant(P=0.0540). 3.In TCE, the frequency of SCE did not increase at any concentration used in this study of isolated lymphocyte and whole blood lymphocyte. Above results suggested that oxyhemoglobin in erythrocytes play an important role in the metabolic activation of styrene but not in benzene or TCE. Key Words : Benzene, Styrene, Trichloroethylene, Sister chromatid exchange, Metabolic activation, Oxyhemoglobin

      • 능동소나에서 다중경로환경을 고려한 표적의 도플러 탐지

        이수형,이철목,박상배,이평기 위덕대학교 산업기술연구소 2000 산업기술연구소 논문집 Vol.4 No.1

        최근 능동 소나에서는 표적의 탐지 성능을 향상시키기 위하여 "높은 시간-대역폭곱"의 파형들을 사용한다. 표적까지의 거리와 표적의 속도를 추정하는 방법으로 FFT-기반 상관관계 기법이 많이 사용되고 있으나, 다중경로 환경에서는 운용자의 요구를 만족하기에 충분한 결과를 나타내지 못하고 있다. 본 논문에서는 다중경로 환경에서 직접경로 신호의 도플러 변이와 도달시간의 탐지 정확도를 높이기 위한 새로운 기법을 제안하였다. In modern active sonar, so-called "high time-bandwidth product" waveforms are used to obtain processing gain for improved detection performance. FFT-based correlation processing is used to detect doppler shift for velocity of target and arrival time, but obtained results are not enough to satisfy the operational needs in multipath environment. In this paper, the new algorithm is proposed in order to improve detection accuracy of doppler shift and arriving time of direct path in multipath environment. It is achieved since the replica is made with considering multipath.

      • 볏짚의 성숙기가 한우 반추위 소화율과 사료가치에 미치는 영향

        이성철,최형송 又石大學校 1994 論文集 Vol.16 No.-

        In order to evaluate the feed value of rice straw as influenced by ripening stage, and in situ studies using a rumen fistulated Korean cow and nylon bag technique were conducted. The results obtained are summarized as follows : 1. The contents of crude fiber and crude ash were increased, while those of crude protein and crude fat were decreased as the ripening of straw progressed. The content of NDF was not affected by the ripening stage. After the yellow stage hemicellulose was remarkably decreased while cellulose and lignin were increased. 2. Degradation of rice straw NDF in the rumen was most rapid when at the heading stage but degradation of straws after the milky stage were similar each other. Degradation of rice straw ADF, on the other hand, did not show any difference with advancing ripening stage. 3. Considering the change of chemical composition and degradation rate of rice straw in the rumen under the different ripening stage, it can be concluded that the lignification of rice straw was accelerated after the heading stage.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼