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정석찬,한태창,서범수,조장혁,주경준 한국경영과학회 1998 한국경영과학회 학술대회논문집 Vol.- No.1
CITIS(Contractor Integrated Technical Information Service) is a contractor's developed service to provide electronic access and/or delivery of contractually required information. CITIS satisfies one of the major CALS objectives to furnish a single-entry point for authorized access to contractor-generated Contract Data Requirement List(CDRL) data. A critical requirement for the practical implementation of the CITIS concept is the ability to access multiple existing heterogeneous databases in a fashion transparent to the CITIS user. In this paper, we will propose a prototype system model for CITIS, and discuss the system architecture of proposed CITIS system as a global information management system for distributed and heterogeneous local information systems. Furthermore, we will discuss about the required server module and using-scenario of proposed CITIS system.
전주원,이병찬,한두석,서부일 대한본초학회 2004 大韓本草學會誌 Vol.19 No.1
Objective : This study was done to examine the cytotoxicity of styrax benzoin (SB) on human oral epithelioid carcinoma cell line (KI3). Methods : The cytotoxic effect of SB was measured by MTT assay or XTT assay. The microscopic study was performed to observe the mophorlogical changes of KI3 cells. Results : The cytotoxic effect of SB on KI3 cells showed a significant increase at 50 uM or 100 uM SB by MTT assay or XTT assay compared with control after cells were treated with various concentrations of SB for 48 hours. MTT_(50) and XTTg were 419.9 uM and 375.5 uM, respectively. In microscopic study, KB cells exposed to SB showed both the decreased cell number and the morphological changes. Conclusion : From these results, SB has a midcytotoxicity by the showing the decrease of cell number and the morphological changes in KJ3 by MTT and XTT assays.
전주원,손영우,서부일,한두석 대한본초학회 2004 大韓本草學會誌 Vol.19 No.1
Objective : The aim of this study was to evaluate cytotoxic effect of benzoic acid on normal human skin fibroblast cell line , Detroit 551. Methods : The cytotoxicity was determined by colorimetric assays such as MTT assay or XTT assay. The microscopy was carried out to observe Detroit 551 cell line. Cells were incubated with various concentrations of benzoic acid in CQ incubator controlled with 37 c for 48 hours. Results : The cytotoxic effect of benzoic acid on Detroit 551 did not show a positive significance at 50 uM and 100 uM benzoic acid by MTT assay or X T T assay compared with control. MTTB and XTTg were 900.6 uM and 974.6 uM, respectively. In microscopic study, Detroit 551 treated with benzoic acid showed a slightly decreased cell number, while the morphological changes of cell was not showed. Conclusion : Above the results, the cytotoxicity of benzoic acid was midtoxicity on normal human skin fibroblasts cell line. Detrit 551
흰쥐 악하선 세포에서 gap junction 봉쇄제인 octanol이 타액분비 및 세포내 Ca²+ 농도 조절에 미치는 영향
이승일,서정택,이종갑,이주석,손흥규 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.2
세포내 유리칼슘(free calcium. Ca²+)은 세균에서 고등동물에 이르기까지 거의 모든 세포에서 세포 고유작용을 조절하는 중요한 세포내 신호전달체계(signal transduction system)의 매개체이다. 타액선 세포에서 부교감 신경 자극으로 타액분비가 증가될 때에도 세포내 Ca²+ 농도 증가가 가장 중요한 역할을 한다. 그러나 췌장(pancreas)의 경우 세포내 Ca²+ 이외에도 인접세포를 전기적, 화학적으로 연결해주는 gap junction이 외분비 기능을 직접적으로 조절할 가능설이 제시되었다. 타액선 세포에서도 세포막에 고농도의 gap junction이 존재하고 있으며, gap junction을 통해 인접세포들이 전기적, 화학적으로 연계되어 있어 gap junction이 타액선 세포의 기능을 직접적으로 조절할 가능성을 내포하고 있다. 따라서 gap junction이 타액선의 타액분비 작용에도 중요한 역할을 하며 이러한 작용이 세포내Ca²+ 농도를 조절하여 이루어질 것이라는 가정하에 이를 확인하는 실험을 시행하였다. 흰쥐 악하선에서 유리되는 타액양을 측정하기 위해서 악하선으로 혈액을 공급하는 동맥에 가는 관을 삽입하여 생리 식염수를 관류하면서 타액선관을 통해 타액을 채취하였다. 세포내Ca²+ 농도는 분리한 악하선 acini 내에Ca²+ 농도 변화에 민감하게 반응하는 형광물질인 fura-2를 축적시키고 형광 분석기를 사용하여 형광강도를 측정하여 다음과 같은 결과를 얻었다. 1. CCh 투여로 타액 분비가 증가하였을 때 gap junction을 봉쇄하는 약물인 octanol(1 mM)을 투여하면 타액분비가 봉쇄되었으며 이는 가역적 반응이었다. 2. CCh 투여로 세포내 Ca²+ 농도가 증가하였을 때 1mM octanol을 투여하면 세포내 Ca²+농 도가 CCh 투여전의 상태로 감소되었다. 3. Octanol은 CCh에 의하여 유발된 초기Ca²+ 증가를 억제하지는 못한 반면에 후기 vvvvv 농도를 감소시켰다. 4. 세포막 Ca²+ 통로를 열어주는 약물인 thapsigarain(1μM)을 투여하여 세포내Ca²+ 농도를 증가시킨 후 1mM octanol을 투여하면 세포내 Ca²+ 농도가 thapsigarain 투여 전의 상태로 감소하였다. 5. 2,5-di-tert-butyl-1, 4-benzohydroquinone (TBQ)의 투여로 세포막을 통한 Ca²+농도의 주기적 변동인Ca²+ 의 oscillation이 유발되었는데, 이때 1mM octanol을 투여한 경우에 Ca²+ 농도의 oscillation이 정지하여 역시 gap juncion을 봉쇄하면 TBQ에 의해서 유발된 세포내 Ca²+ 농도의 주기적 변동이 사라지고 Ca²+ 농도의 감소가 나타남을 확인하였다. 6. Gap junction을 봉쇄하는 또 다른 약물인 glycyrrhetinic acid(100μM)도 CCh 자극으로 인한 타액분비를 억제하였다. 이상의 결과로 미루어 gap junction은 흰쥐 악하선 세포로부터의 타액분비 조절에 중요한 역할을 하는 이는 gap junction이 세포막 Ca²+ 통로를 조절함으로써 수용체 자극으로 유발된 세포내 농도 변화에 영향을 미친 결과인 것으로 추측된다. From bacteria to mammalian cells, one of the most important mediators of intracellular signal transduction mechanisms which regulate a variety of intracellular processes is free calcium. In salivary acinar cells, elevation of intracellular calcium concentration ( 〔Ca²+〕 ) is essential for the salivary secretion induced by parasympathetic stimulation. However, in addition to〔Ca²+〕, gap junctions which couple individual cells electrically and chemically have also been reported to regulate enzyme secretion in pancreatic acinar cells. Since the plasma membrane of salivary acinar cells has a high density of gap junctions, and these cells are electrically and chemically coupled with each other, gap junctions may modulate the secretory function of salivary glands. In this reapect, I planned to investigate the role of gap junctions in the modulation of salivary secretion and 〔Ca²+〕 using mandibular salivary glands of rats. In order to measure the salivary flow rate, fluid was collected from the cannulated duct of the isolated perfused rat mandibular glands at 2 min intervals.〔Ca²+〕 was measured form the cells loaded with fura-2 by spectrofluorometry. The results obtained were as follows : 1. CCh-induced salivary secretion was reversibly inhibited by 1 mM octanol, a gap junction blocker. 2. CCh-induced increase in 〔Ca²+ 〕was also reversed by the applocation of 1 mM octanol. 3. Octanol did not block the initial increase in 〔Ca²+〕 caused by CCh, which suggested that the reduction of〔Ca²+〕 caused by gap junction blockade was not resulted from the inhibition of Ca²+ release from intracellular Ca²+ stores. 4. Addition of octanol during stimulation with 1μM thapsigargin, a potent microsomal ATPase inhibitor, reduced 〔Ca²+ 〕to the basal level. This suggested that inhibition of gap junction permeability closed plasma membrane Ca²+ channels. 5. 2,5-di-tert-butyl-1, 4-benzohydroquinone (TBQ) generated 〔Ca²+ 〕oscillations resulting from periodic influx of Ca²+ via plasma membrane. The TBQ-induced〔Ca²+ 〕 oscillations were stopped by the application of 1mM octanol which implicated that gap junctions modulate the permeability of plasma membrane Ca²+ channels. 6. Glycyrrhetinic acid, another well known gap junction blocker, also inhibited CCh-induced salivary secretion from rat mandibular glands. These results suggested that gap junctions play an important role in the modulation of fluid secretion from the fat mandibular glands and this was probably due to the inhibition ofCa²+ influx through the plasma membrane Ca²+ channels.
박형일,신석주,이헌창,장서일,김태옥 한국산업안전학회 2002 한국안전학회지 Vol.17 No.3
The runaway reaction was analyzed experimently and theoretically at the batch styrene suspension polymerization process. In the experiments, the reaction temperature with time was measured at various experimental conditions. According to the experimental results, the risk of the runaway reaction was increased with increasing the ratio of the monomer(styrene, M) to the dispersion medium(water, W), the concentration of the initiator(BPO), and the monomer mass, respectively. And simulation results showed that the runaway reaction was significantly affected by the reaction rate constant of the propagation and that the phenomena of the runaway reaction occurred at about 70% conversion. Also, we found that the runaway reaction did not occur under the operation condition of below 0.5 for M/W, approximate 3 wt% BPO, and below 75℃ for the cooling temperature.