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      • 배양 사구체 내피세포의 고포도당유발 유전자 분석

        우지수,한동철 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

        Background : Actin disassembly is one of the main pathogenic phenomena in diabetic nephropathy. Small GTPases, related with actin cytoskeleton, may have a pathogenic role in high glucose (HG) induced renal injury. Methods : HG-stimulated gene profiling in cultured human glomerular endothelial cells (GEC) was examined by using oligonucleotide microarray technique. Human GEC were isolated from normal part of nephrectomy specimen and cultured under normal glucose (5.6 mM) or HG (30 mM) for 24 h, 48 h and 72 h. Total RNA was purified from the cell and then applied on 10 K-DNA chip (Macrogen) after amplified with T7 RNA polymerase. Results : About 2,400 genes showed 2-fold difference by HG. Approximately, 300 out of 2,400 genes were down-regulated and about 460 genes were up-regulated continuously by HG. Rho GTPase-related molecules and actin cytoskeleton regulatory gene expressions were highly regulated. Rho7, Rho guanine nucleotide exchange factor 1 and 3, and Rho GDP dissociation inhibitor were significantly up-regulated by HG without alteration of Rho GTPase activation protein 5, suggesting increased activity of Rho GTPase. In addition, myosin light chain 2 and 3, and p21-activated kinase, possibly related with actin-myosin interaction, were also significantly up-regulated by HG. Western blot revealed HG induced increase of CDC42 protein expression, not RhoA and Rac1 in total cell lysates of GEC. Conclusion : Enhanced gene profile encoding Rho GTPase and actin cytoskeleton is one of prominent components of the GEC transcriptomic response under HG.

      • 천수만층의 형성과 진화

        이철우,백창훈,이동우 충남대학교 기초과학연구소 1995 연구논문집 Vol.15 No.-

        천수만층은 백악기의 육성 퇴적물로 구성되어 있다. 퇴적작용은 주로 선상지에서 이루어졌다. 남북방향으로 발달하는 천수만층은 대규모 좌수향 주향이동 단층에 고각으로 발달하는 이차 단층계에 의하여 생성하는 것으로 추정된다. 전체적인 층후는 약 200∼300 m에 달하는 것으로 보인다. 층의 서측 경계는 단층으로 기반암과 접하며 동측은 바트리스(buttress)부정합과 단층으로 기반암과 접한다. 지질시대는 화산쇄설성 퇴적물이 전 지층에 걸쳐 고루 나타나는 것으로 보아 경상누층군의 하양층군에 대비되는 것으로 보인다. 천수만층 형성 초기의 퇴적작용는 넓은 지역에 걸쳐 박층으로 퇴적되었고 후기 침식 작용에 의하여 좁고 긴 형태로 나타나게 되었다. The Chonsuman Formation consists of Cretaceous non-marine sequences which were deposited in proximal to medial alluvial fan environments. The depression was probably by secondary fault of large-scale sinistral strike-slip fault system trending NE-SE. Distributary pattern of the Chonsuman Formation shows N-S trend. The total thickness of the formation reaches ca. 200-300meters. Western margin of the formation contacts with the Taean Formation by fault. Eastern one shows both fault and buttress unconformity. Based on the volcanogenic components broadly distributed on all sequence, it may be correlated largely with that of the Hayang Group. In the initial stage of the basin-formation, sedimentation was shallow an broad, and occupied in a narrow and long after erosion.

      • 퍼지추론을 이용한 비선형성 해석 및 자동동조의 구현

        이은철,이동진,변황우 건국대학교 1994 대학원 학술논문집 Vol.38 No.-

        This paper presents a new identification method which utilizes fuzzy inference in parameter identification. The proposed system has an additional control loop where a real plant is replaced by a plant model. The control system to be designed is to satisfy the following specifications: 1) It has zero steady-state error. 2) It has adequate damping characteristics. 3) 1), 2) satisfied, it has a shortest rise-time, Fuzzy rules describe the relationship between comparison results of the features and magnitude of modification in the model parameter values. This method is effective in auto-tuning because the response of the closed loop is verified. The proposed method is tested in simulation for several plants with high-order lags and dead-times.

      • Mossbauer 分光法과 選擇的 抽出方法에 의한 濟州島 土壤에서의 酸化鐵의 特性 究明

        宋寬哲,姜東佑,金斗哲,高正大,洪性樂 濟州大學校 基礎科學硏究所 1997 基礎科學硏究 Vol.10 No.1

        濟州島의 8개 代表土壤을 對象으로 하여 X-線 螢光分析, X-線 回折 分析, oxalate와 dithionite-citrate를 사용한 選擇的 抽出方法 및 Mossbauer 分光法으로 一次鑛物, ferrihydrite, 結晶質 酸化鐵의 種類, 含量 및 非磁性 Al이온의 置煥程度에 대하여 考察하였다. 1. X-線 螢光 分析에 의한 濟州島 8개 土壤統의 酸化鐵(Fe₂O₃) 含量은 噴石口 토양인 松岳統에서 18.21%로 가장 높았고 논토양인 大靜統에서 8.03%로 가장 낮았다. 2. X-線 回折 分析 結果 8개 土壤統 모두에서 ferrihydrite와 結晶質 goethite의 回折 피크는 나타나지 않았지만, 結晶質 hematite는 松岳統, 舊巖統 및 黑岳統에서 檢出할 수 있었다. 3. 선택적 침출방법으로 측정한 ferrihydrite 含量은 흑색토인 松堂과 吐坪統, 농암갈색의 분석구 토양인 柑山統 및 갈색삼림토인 黑岳統에서 20.9-35.2g/㎏으로 높았고, 논토양인 大靜統에서 0.85g/㎏으로 가장 낮았다. 結晶質 酸化鐵 含量인 Fed-Feo 含量 松岳統에서 28.7g/㎏으로 가장 높았고 黑岳統에서 7.6g/㎏으로 가장 낮았다. 4. 濟州島 8개 土壤統에 함유되어 있는 常磁性 Fe³+ 鑛物들은 化學造成이 거의 같은 ferrihydrite, 超常磁性 goethite, 층형 硅酸鑒粘土鑛物로서 柑山統에서 그 含量이 가장 높았고 松岳統에서 가장 낮은 것으로 분석되었다. 常磁性 Fe²+ 一次鑛物은 柑山統과 黑岳統에서 olivine, illite의 含量이 優勢하였으나 그 외 土壤에서는 小量의 chlorite, augite, biotite, hornblende 등이 含有되어 있는 것으로 분석되었다. 5. 18K에서 측정된 超微細磁氣場값으로 부터 大靜統에서는 미세한 goethite 만이 含有되어 있는 것으로 確認되었고, 그외 7개 土壤에서는 입자 크기가 작은(∼180Å) 結晶質 hematite와 goethite이 것으로 分析되었다. 6. 濟州島 8개 土壤統에 함유되어 있는 酸化鐵의 구조에서 Fe³+와 非磁性 Al³+이 相堂量 部分 置煥되었음을 確認할 수 있었다. Iron oxide compounds in 8 selected Cheju Island soil samples have been analized by X-ray fluorescence spectrometer(XRF), X-ray diffractometry(XRD), selected chemical techniques, and Mossbauer spectroscopy. The result of this analysis by XRF shows that the rate of quantity of Fe₂O₃ in 8 soil samples was from 8.03wt.%(Daejeong paddy soil ) to 18.21wt.%(Songag soils). Songag, Heugag and Gueom soils were detected to have lower peaks of intensity of hematite by XRD. In addition, these soils were not detected to have hematite and goethite peaks. Ferrihydrite, which is a short-range-order mineral commonly present in volcanic ash soil, was not detected by XRD due to low concentration and/or poor cristallinity. Ferrihydrite contents estimated from Feo values were 8.8∼35.2g/㎏ for volcanic ash soils and 0.85g/㎏ for the Daejeong soil. Most of the soil samples represented by the paramagnetic Fe³+ doublet obtained from Mossbauer spectra at room temperature and 18K were considered to arise from the presence of ferrihydrite, superparamagnetic goethite, and silicate minerals. Also the paramagnetic Fe²+ doublets are attributable to primary minerals such as olivine, illite, chlorite, augite, biotite, and hornblende. Goethite and hematite were identified as the dominant crystalline iron oxides in these soils from Mossbauer spectra obtained at room temperature and 18K. All the soil samples exhibited strong superparamagnetic relaxation. Collapse of the Mossbauer magnetic hyperfine splitting at room temperature was due to the small size(∼180Å) of the oxide particles and/or Al-subsituted goethite.

      • 실시간 응용프로그램을 위한 최악 실행 시간 분석

        元裕憲,徐鎭哲,李俊東 弘益大學校 科學技術硏究所 1999 科學技術硏究論文集 Vol.10 No.1

        Worst-case execution time(WCET) is part of the timing analysis of real-time systems. The goal of timing analysis is to validate that a real-time computer system fulfills the specified temporal requirements of a given application in all predicated situation. In this paper, We illustrate a new language, Timing-C, and design a timing tool for predicting WCET in it. Timing-C is added time constraint and a few restriction in the subset of C. Using Timing-C, programmer need not learn a new language and can demonstrate program's timing activity.

      • 유도형 변위 센서의 전기 노이즈 분석과 센서 성능에 미치는 영향 고찰

        신우철,홍준희,이동주 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

        Noise is a problem in many electronic circuits and active control system. Arising from spuriously coupled noise from other circuits, it corrupts the signal of interest and introduces an uncertainty into information it contains. In this paper, we have researched noise characteristics of the inductive displacement sensor which has been designed. we first present basic concept and characteristics of magnetic field-coupled noise in the sensor output signal. Then, we are present relation noise and sensor performances. Finally, we concentrate low noise design of a sensor driver and a signal detection circuit.

      • 반응소결에 의한 근사기본형 Al₂O₃/ZrO₂복합체의 제조 및 치밀화

        김철진,박홍래,신동우 慶尙大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.13 No.-

        Al₂O₃/ZrO₂ composites were fabricated by the reaction bonding process. Starting materials of 20-70 vol% Al, 10-65 vol% Al₂O₃, and 15-20 vol% ZrO₂ were milled for 8 h using attritor with ZrO₂ball media and isostatically pressed into the rectangular shape. The compacts were heat treated with two steps at the temperatures of 1000-1200℃ and 1400-1650℃ for 3-12 h with the heating rates of 1℃ /min and 1-5℃ /min, respectively. The sintered specimens showed the relative density of 95% to the theoretical value with the linear shrinkage of 10.5%. The large pores and cracks were not observed in the sintered body.

      • KCI등재후보

        표면근전도와 전자각도기를 이용한 자동차 부품 조립작업 위험요인 평가

        강동묵,이철호,,신용철,김은아,우지훈,조병만,이수일 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

        Objectives: As automobile part manufacturing is characterized by high speed and high repetition, observation methods which are usually utilized for static posture are inappropriate to evaluate musculoskeleatal risk factors. This study quantified the risk factors of musculoskeletal disorders on the forearm and suggested exposure limits by estimating the risk factors using surface electromyography (EMG) and electrogoniometer. Methods: Ten percent of the total workers at 3 automobile part manufacturing factories were randomly selected, and 99 male workers were recruited as study subjects. The study was conducted during May 2003 to September 2004. The workers were equipped with electrogoniometers on the wrist and the elbow, surface EMGs on the skin of the flexor digitorum superficialis (FDS) and extensor carpi radialis (ECR) muscles, and the heart beat recorder during work as indicators of joint movement, local muscle tension and physical work load, respectively. Results: After controlling for age, body mass index and job stress, wrist flexion maximum angle, FDS relative activity (RA) and ECR RA were significantly associated with forearm musculoskeletal symptoms. The odds ratios of the forearm were 5.0(95% CI: 1.1-22.7), 14.0(95% CI: 1.5-128.8) and 7.3(95% CI: 1.1-49.4) for wrist flexion maximum angle more than 76˚, FDS RA more than 2.8%, and ECR RA more than 3.5%, respectively. Conclusions: Joint angle and focal muscle activity were associated with forearm musculoskeletal symptoms. To reduce forearm musculoskeletal symptoms among automobile part manufacturers, the wrist flexion angle, and FDS and ECR activity need to be reduced below the guidelines recommended in this study.

      • KCI등재

        Induction of Apoptosis by Cordycepin via Reactive Oxygen Species Generation in Human Leukemia Cells

        Jin-Woo Jeong,Cheng-Yun Jin,Gi Young Kim,Cheol Park,Yung Hyun Choi,Jae Dong Lee 한국버섯학회 2009 한국버섯학회지 Vol.7 No.4

        Cordycepin (3’-deoxyadenosin), a polyadenylation specific inhibitor, is the main functional component in Cordyceps militaris which is one of the top three famous traditional Chinese medicine. It has been shown to possess many pharmacological activities including immunologically stimulating, anti-cancer, anti-bacterial, and anti-virus, anti-infection effects. However, its anti-cancer molecular mechanisms are poorly understood. In this study, the apoptotic effects by cordycepin were investigates in human leukemia cells. Treatment of cordycepin significantly inhibited cells growth in a concentrationdependent manner by inducing apoptosis, as evidenced by morphological change and apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of sub-G1. Induction of apoptosis by cordycepin was associated with modulation of Bcl-2 and inhibitor of apoptosis proteins (IAP) family expression. Cordycepin also increased reactive oxygen species (ROS) generation, activation of casepase-3, caspase-8, caspase-9, cleavage of poly(ADP-ribose) polymerase (PARP), β-catenin and phospholipase C (PLC)-γ1 protein. The quenching of ROS generation by N-acetyl-L-cysteine administration, a scavenger of ROS, reversed the cordycepin-induced apoptosis effects. Theresults suggested that cordycepin may be a potential chemotherapeutic agent for the treatment of leukemia patients [This work was supported by Blue-Bio Industry RIC at Dong-Eui University as a RIC (08-06-07) program of ITEP under Ministry of Knowledge Economy].

      • SCOPUSKCI등재

        Killer 효모 Saccharomyces cerevisiae B15-1의 에탄올 발효특성

        이창호,우철주,이종수,정기택,박희동 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.3

        정치배양에 의한 Saccharomyces cerevisiae B15-1의 에탄올 발효에 미치는 영향 인자와 초기 기질농도에 따른 발효 특성을 연구, 검토하여 에탄올 생성 최적 조건하에서 발효액중의 생성된 에탄올 농도, 균체 농도 및 당 농도와의 관계를 규명하고자 하였다. 에탄올 생성의 최적 조건은 배양 온도 30℃, 초기 pH 5.0이었으며, 에탄올 비생성 속도는 초기 기질농도가 150 g/l일 때 1.203 g-EtOH/g-cell·hr로서 가장 높게 나타났다. 에탄올 발효능은 기질농도가 150 g/l 이하에서는 거의 일정하였으나 200 g/l에서는 급격히 감소하였다. 최종 균체량과 최종 에탄올 생성량은 초기 기질의 농도가 증가함에 따라 증가하는 현상을 보였으나 그 증가율은 기질의 농도가 높을 수록 다소 감소하는 경향을 나타내었다. 초기 기질농도가 150 g/l 이하에서는 대부분이 발효에 의해 에탄올로 전환되었으나 200 g/l의 당을 사용한 경우에는 균체의 증식과 발효가 완료된 후에도 약 10.7 g/l의 기질이 에탄올로 전환되지 못하고 배지에 남아 있었다. 초기 기질 농도를 매개변수로 생성된 에탄올과 에탄올 수율을 조사한 결과 에탄올 수율은 초기 당농도가 증가할수록 급격히 감소하였으며, 초기 당농도가 일정한 경우 에탄올 생성량이 소량일 때는 에탄올의 생성량이 증가할수록 에탄올의 수율은 급격히 증가하다가 점차 완만한 증가현상을 보였으며 에탄올 생성량이 60 g/l 이상에서는 거의 일정하였다. Characteristics of ethanol fermentation were investigated during the stationary culture of a killer yeast, Saccharomyces cerevisiae B15-1. Specific ethanol production rate reached the maximum level, 1.203 g-EtOH/g-cell·hr, at 150 g/l of the initial glucose concentration. No big differences were obtained in ethanol fermentability based on the initial sugar concentration below 150 g/l. When 200 g/l of sugar was used, fermentability dropped significantly. Although the final cell mass and the amount of ethanol produced were increased, their increase rates were declined according to the increase of initial sugar concentration. It was found that most of the sugar used below 150 g/l of concentration could be changed to ethanol. However, when 200 g/l of sugar was used, some of them remained in the media even after increase of cell mass and fermentation stopped. The ethanol yield was decreased when initial sugar concentration was high, and were increased when the amount of ethanol produced was increased and finally reached the plateau over 60 g/l of ethanol concentration.

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