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
      • Para형 다단맥동 추출탑의 유동특성과 물질전달

        윤장효,염경호,김우식,김원규 연세대학교 대학원 1986 延世論叢 Vol.22 No.1

        The dynamic characteristics and mass transfer effects in Para-type plate pulsed column was investigated. The axial dispersion coefficient of continuous phase was constant in the range above that continuous phase flow rate was 200ml/min, and was more influnced by amplitude than by frequency. The hold-up of continuous phase was more influnced by amplitude and saunter mean diameter was more influnced by frequency. As the experimental results of acetone extraction, the column efficiency was slightly decreased with the pulse velocity increased, but was stabilized in the range of 80~90%. The acetone concentration profiles with the change of column height at steady state more approached to the backflow model than the diffusion model.

      • Para형 다단맥동 추출탑에서의 액-액 물질전달 효과

        김우식,이호원,이성,염경호 연세대학교 산업기술연구소 1988 논문집 Vol.20 No.1

        The mass transfer characteristics of para-type plate pulse column were studied in Toluene-Acetone-Water system. The mass transfer effects in this column were investigated by the changes of the amplitude, frequency and each phase velocity, and the overall volumetric mass transfer coefficient was correlated as follow: Koc·a = 0.02595 A¹????f¹??³????³U??????⁴?????? This result coincided with the Higbie's penetration theory. The efficiency of this column was decreased with the increase of pulse velocity, and was 70-95% in the range of 30-90 cm/min of the pulse velocity. The acetone concentration profile at the steady state was coincident with the diffusion model and the back flow model within the relative error range of 0.15.

      • KCI등재후보

        삼일열 말라리아에 합병된 비장 파열 1예

        홍경욱,이정아,김원진,박철민,권혜리,박혜원,엄중식 대한감염학회 2007 감염과 화학요법 Vol.39 No.5

        국내의 토착형 말라리아는 삼일열 말라리아로, 1993년부터 재유행이 시작되었다. 말라리아의 중요한 합병증으로 드물지만 비장 파열이 있는데, 이는 주로 삼일열 말라리아에 의해서 발생되며, 국내에서는 1999년 말라리아에 의한 비장 파열로 비장 절제술을 시행한 예가 보고된 바 있다. 현재까지는 비장 파열이 있을 때 비장 절제술이 일차적인 치료로 되어 있으나, 비장 절제술 후의 감염 위험성이 크므로, 활력 징후가 불안정하거나, 출혈이 지속되는 소견이 보이지 않으면 가급적 보존적 치료를 하는 것이 추천된다. 저자들은 비장 파열이 동반된 말라리아 환자에서 비장 절제술을 시행하지 않고 보존적 치료로 호전된 예를 경험하여 보고하는 바이다. Plasmodium vivax has been the predominant Plasmodium species in the Republic of Korea and reemerged in 1993. Spontaneous rupture of malarial spleen is a rare but important complication associated with P. vivax infection. Only one case of spontaneous rupture of malarial spleen was reported in Korea in 1999. Splenectomy is still accepted as the treatment of choice in cases of spontaneous rupture of the spleen. But, considering increased risk of postsplenectomy infecion, splenectomy should be reserved for those patients with severe rupture or those with continued or recurrent bleeding. And conservative treatment should be considered in selected, closely monitored patients. We report a patient with P. vivax malaria who developed a spontaneous splenic rupture and was improved by conservative treatment.

      • 연령에 따른 흰쥐 망막 속얼기층의 미세구조 변화

        오원영,고정식,양남길,안의태,박경호 순천향의학연구소 1995 Journal of Soonchunhyang Medical Science Vol.1 No.2

        이 실험은 연령에 따른 흰쥐 망막 속얼기층의 미세구조적 변화를 관찰하기 위하여 시행하였다. 실험동물로는 생후 3개월(어린 흰쥐), 12개월(젊은 흰쥐) 및 30개월(늙은 흰쥐)된 Fisher계통 344흰쥐를 사용하였다. 각 동물은 4% chloral hydrate로 마취한 후 2.5% glutaradehyde-1.5% paraformaldehyde로 관류 고정한 다음, 안구를 적출하여 톱니둘레를 다라 절단한 후 시신경원반외측의 일정부위에서 망막조직을 떼어내었다. 떼어낸 조직은 2.5% glutaradehyde- 1.5% paraformaldehyde 고정액에 다시 고정한 후, 1% osmium tetroxide액에 또 다시 고정하였다. 고정된 조직은 ethyl alcohol과 acetone으로 탈수한 후 araldite혼합액에 포매하였다. 포매된 조직은 LKB-V ultratome으로 얇은 절편을 작성하여 uranyl acetate와 lead citrate로 염색한 후 JEM 100CX-Ⅱ 전자현미경으로 관찰하여 다음과 같은 결론을 얻었다. 1. 무축삭신경원의 세포질돌기는 세포질의 전자밀도, 연접소포의 종류 및 양에 따라 4종류 구분되었다. 2. 속얼기층에서 관찰되는 신경연접의 형태는 연접리본복합체외에 4종류의 일반신경연접을 관찰할 수 있었으나, 연령증가에 따른 연접형태의 미세구조적 변화는 관찰할 수 없었다. 3. 연령이 증가함에 따라 부챗살아교세포의 상대적 영역이 넓어졌다. 4. 연령이 증가함에 따라 무착삭신경원과 신경절세포의 가지돌기안에 수초구조, 용해소체, 잔여소체가 자주 관찰되었다. 이상의 결과를 종합해 보면 흰쥐의 망막속얼기층은 연령이 증가하면 무축삭신경원과 신경절세포는 기능이 점점 약해지므로 부챗살아교세포의 영역이 상대적으로 더 넓어진다고 생각된다. Morphological differences among the inner plexiform layers at different age groups have been studied in young(three months old), adult(twelve months old) and old(thirty months old) Fisher stain 344 rats. Under anethesia, 2.5% glutaraldehyde- 1.5% paraformaldehyde solution was perfused through the heart. Pieces of the tissue taken from the posterior region of the retina were fixed in 2.5% glutaraldehyde- 1.5% paraformaldehyde, and in 1% osmium tetroxide followed by fixation embedded in aralditse mixture. Ultrathin seciton were statined with uranyl acetate and lead citrate solution and were observed with JEM 100CX-II electron microscope. The results were as follows: 1. Four types of amacrine cells were found according to their electron densities, and kind and amount of the synaptic vesicles, were found, i.e., dark amacrine cell with clear vesicles(Al cell), light amacrine cell with clear vesicles(A2 cell), dark amacrine cell with clear and granular vesicles(A3 cell) and light amacrine cell with clear and granular vesicles(A4 cell) 2. In the inner plexiform layer, there appear two types of synapses : 1) synaptic ribbon complex and 2) conventional synapses. Conventional ones exhibited four different types, showing, i.e., prominent presynaptic density(type 1), prominent postsnaptic density(type 2), prominent pre-and postsynaptic densities(type 3), and lesser prominent pre-and postsynaptic densites. 3. Territories of the Muller cells were expanded during aging. 4. Myelin figures, lysosomes, lipofuscin granules and lipid droplets were frequently observed in the amacrine and ganglion cells of the adult and old rats. From the above results, it was suggested that functions of the bipolar, amacrine and ganglion cells were diminished gradually, whereas territories of the Muller cells were expanded during aging.

      • 새로운 의약품의 합성에 관한 연구(IV):새로운 세파로스포린 항생물질의 합성과 그의 생물활성에 관한 연구

        최원식,최소영,윤경하 순천향대학교 1994 논문집 Vol.17 No.3

        New cephalosporin antibiotics, 7-[(3, 4-dihydro-6-alkoxycarbonyl-2, 2-dimethyl-2H-l, 4-thiazin-3-yl) acetamido]-3-[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-l, 2, 4-triazin-3-yl) thiomethyl]-3-cephem-4-carboxylic acid derivatives (2a-2d) were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and their avtivities were examined. Among them, 7-[(3,4-dihydro-6-methoxycarbonyl-2, 2-dimethyl-2H-l, 4-thiazin-3-yl) -acetamido] -3- [ (2, 5-dihydro-6-hydroxy-2-methyl-5-oxo-l, 2,4-triazin-3-yl) thiomethyl] -3-cep-hem-4-carboxylic acid exhibited the broad antibacterial activities against Gram(+) and Gram (-) bacteria.

      • 三種 黃連類의 血管弛緩 作用에 關한 比較實驗 硏究 : The Experimental relative study on the Vasodilating action of Three kinds of Coptis Rhizoma

        이경애,박성식,이원철 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

        This study was carried out to investigate the vasodilating action of water extracts of three kinds of Coptis rhizorna and also compare their effects with berberine and palmatine, which are the important alkaloid components of Coptis rhizoma, in isolated rat aorta. As a result, Coptis chinensis showed significant vasodilatlng activities on KCl­induced contraction and more markedly em phenylephrine-induced contraction in dose-dependent manner. Coptis japonica exhibited also vasodilating actions on both contractions with slightly weaker activities than those of Coptis chinensis. The activities of the root hair of Coptis chinensis were the most weakest in three rhizomas. Berberine and palmatine had strong vasodilating actions. especially, on phenylephrine-induced contraction, however, their activities on KCI-induced contraction were weaker than that of Coptis chinensis. The inhibitory effects of three kinds of Coptis rhizoma on the contraction by phenylephrine and Ca2+ were investigated to explain the process of their vasodilating action. All rhizomas inhibited the contraction by both agents, among them, Coptis chinensis showed the most significant effect, so indicating that the vasodilating action of Coptis rhizoma may be concerned with the blocking of α-adrenalin receptor and also Ca2+ channel.

      • 사람 말초혈액 림프구에서 Bromodeoxyuridine에 의해 유도되는 Fraglie Sites

        박경란,김원식 충남대학교 의과대학 지역사회의학연구소 1995 충남의대잡지 Vol.22 No.2

        Chromosomal abnormalities including fragile sites induced by 50㎍/ml and 100㎍/ml bromodeoxyuridine (BrdU) was studied in lymphocytes cultures of six healthy individuals. A significant decrease in mitotic indexes in respect to control cultures was observed with both BrdU concentrations used. The cells showing chromosome aberrations and the total number of cytogenic alterations were significantly increased both BrdU treated cultures with respect to control cultures. Damaged cells showing chromosome aberrations and total number of chromosomal aberrations were increased in BrdU, 100㎍/ml treated groups compared to BrdU 50㎍/ml treated groups. The most frequent type of chromosomal aberration is a gap. A site showing a gap or break was defind as fragile if it appeared in 1% of cells analyzed and in at least three of six individuals studied with the same culture treatment. Using these criteria, fragile sites 4q31, 5q31, 6p22, 6q13, 9q21, and 15q24 were induced in different proportions by different concentration of BrdU.

      • ZVS를 이용한 풀 브릿지 단일 전력단 고주파 공진 AC-DC 컨버터의 특성해석

        남승식,황계호,오경섭,원재선,조규판,김동희 嶺南大學校 工業技術硏究所 2003 工業技術硏究所論文集 Vol.31 No.2

        This paper proposes a single-stage high frequency resonant AC-DC converter using zero voltage switching with high input power factor. The proposed high frequency resonant converter ingegrates a half bridge boost rectifier as power factor corrector(PFC) and half resonant converter into a single stage. The input stage of the half bridge boost converter is working in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. Therefore, high power factor is achieved naturally. The results of simulation using the Pspice have demonstrated the feasibility of the proposed AC-DC converter. The proposed converter will be able to be practically used as power supply.

      • 기능성 Catechol-O-Methyltransferase 유전자 다형성과 한국인 정신분열병의 관련성

        박태원,홍영준,박임순,김형섭,최인미,배수영,윤경식,강대희 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.4

        연구목적 : Catechol-O-Methyltransferase(COMT)는 카테콜아민 신경전달물질의 불활성화를 담당하는 효소로서, 정신분열병과 관련된 후보 유전자로서 알려져 왔다. 최근, 기능성 COMT유전자 다형성과 정신분열병의 관련성이 제기되었는데, 한국인 정신분열병에서도 이러한 관련성이 있는지를 살피기 위해 본 연구를 시행하였다. 방 법 : 정신분열병으로 진단된 환자군 103명과 성별 및 연령별로 1:1 짝짓기 대조군 사이에 유전자형과 대립유전자의 분포를 비교하였다. 또한, 환자군은 공격적 행동, 가족력, 아동기 발병 여부에 따라 두 군으로 나누어 비교하였다. DNA의 다형성 부의를 중합효소연쇄반응에 의해 증폭한 후 ,NlaⅢ제한효소법과 전기영동을 실시하여 유전자형을 판별하였다. 결 과 : 환자군 전체와 대조군 사이에 유전자형과 대립유전자 빈도의 차이가 없었다. 가족력이 있는 환자군을 대조군과 비교하였을 때는, 대립유전자 L을 포함하는 유전자형과 그렇지 않은 유전자형의 분포에 있어 유의한 차이를 보였다(p=0.02, OR=3.9, 95% Cl=1.1∼14.3). 결 론 : 한국인 정신분열병과 기능성 COMT 유전자 다형성 사이에 유의한 관련성이 없었다. 따라서, 기능성 COMT 유전자 다형성이 한국인 정신분열병의 발병에 영향을 주지 못한다. 그러나, 정신분열병 가족력과 기능성 COMT유전자 다형성의 관련성이 시시돠어, 향후 본 연구에서 나타난 방법론적인 문제점을 보완하고 추가 대상자를 확보한 연구가 필요하다. Objectives : Catechol-O-methyltransferase(COMT) is involved in the degradation of catecholamine meurotransmitters and has been investigated as a candidate gene in schizophrenia. Recently, possible relationship between functional COMT gene polymorphism and schizophrenia has been suggested. To address the possible role of functional COMT gene polymorphism in the predisposition to schizophrenia, we carried out an association study in Korean schizophrenic patients and controls. Methods : One hundred and three Korean inpatients diagnosed as schizophrenia and 103 age and sex matched controls were selected as study subjects. Patients were subgrouped into two groups on the basis of history of aggressive behavior, family history of schizophrenia and related disorders, and age at onset. We determined COMT genotypes using PCR of the relevant region followed by digestion with NlaⅢ and electrophoresis. Results : No significant differences of allele and genotype frequencies were noted between patients and controls. However, when patients were categorized by the presence of family history of schizophrenia and related disorders, patients with family history showed almost 4 fold higher frequency of having COMT L allele containing genotype compared to controls(p=0.02, OR=3.9, 9.5% CI=1.10-14.33). Conclusion : Although our results do not support an association between functional polymorphism of COMT gene and schizophrenia overall, the findings suggest an association between functional COMT gene polymorphism and familial schizophrenia. Further studies with large samples are needed to confirm this association.

      • Methotrexate가 脾臟에 미치는 影響에 관한 硏究

        朴景蘭,李永浩,金源式 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.1

        In order to study the morphological changes of spleen after treatment with methotrexate, ICR mice were used as experimental animal. The experimental mice were divided into control, 50mg/kg and 500mg/kg of methotrexate treated groups. Methotrexate injected intravenously via tail vein once on the 8th day of pregancy. The mice were sacrificed on the 1st, 2nd 3rd and 4th day after treatment, the spleens were removed and fixed in 10% neutral buffered formalin solution for 48hrs. Spleens were cutted 5㎛ thick and stained with H-E, then observed under the light microscope. The results were as follows: 1. The size of spleen were reduced after MTX treatment more on dose day by day. 2. The periarterial lymphatic sheath (PALS) and germinal center were also reduced after MTX treatment. 3. The lymphocytes of white pulp showed nuclear pyknotic changes and many nuclear debris were found after MTX treatment. 4. The brown hemosiderin pigments were increased markedly in the red pulp of MTX treated groups. 5. Marked proliferation of fibrous trabeculae were found in the red pulp of MTX treated mice.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼