난소절제후 Estrogen을 투여한 흰쥐 대동맥에서 Protein Kinase C-α와 Fas 발현의 변화

이왕수,이상엽,안지현,송영빈,김학진,이광재,유재격,김상욱,김태호,김치정,류왕성 중앙대학교 의과대학 의과학연구소 2001 中央醫大誌 Vol.26 No.3

Estrogen is believed to decrease coronary artery disease. Protein kinase C-α(PKCα)appear to be important in signal conduction pathways. Estrogen treatment increases catalytic activity of PKCα,and activation of PKCαcan modulate estrogen receptor levels and responsiveness. And it was reported that activation of PKC can protect cells from apoptosis induced by Fas ligation. But the beneficial effect of estrogen on PKCαwas not clearly demonstrated. The objective of this study was to evaluate the role of PKCαafter ovariectomy and estrogen therapy in rat aorta. The results were summarized as below: 1. The significant pathological changes were not observed in the rat aorta irrelevant to ovariectomy and estrogen therapy. 2. The expression of Fas was decreased in the aorta of estrogen-treated rats than that of ovariectomized rats without estrogen therapy. 3. Increased expression of PKCαwas more marked in the aprta of estrogen-treated rats than that of ovariectomized rat without estrogen therapy. In conclusion,PKCαmay be important in signal conduation pathway on the effect of estrogen. Activation of PKCαby estrogen reduced Fas expression, suggesting that PKCαactivation may play a role in protection against atherasclerosis. Further studies are needed to elucidate the role of PKCαafter estrogen therapy.

열싸이펀을 이용한 간접 열교환기에 관한 실험

이승홍,이승엽 釜山大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.53 No.-

2상 밀폐형 열싸이펀이 냉,온수 사이의 열전달 매개체가 되는 간접 열교환기에 관한 실험을 수행하였다. 에탄올, 물, 아세톤 중에서 열싸이펀의 작동 유체로 물을 사용했을 때 열싸이펀 및 열교환기의 열전달 성능이 최대가 되었다. 냉, 온수 Re수의 비 Re*(=??/??)의 값에 따라 열교환기가 우수한 열전달 성능을 낼 수 있는 범위를 조사했다. 열싸이펀의 작동 유체로 물을 사용한 경우, 본 연구의 실험 범위중 Re*가 0.5∼3.0정도일 때 열교환기의 전체 열저항이 최소가 되었으며 열전달 성능이 우수한 범위였다. An indirect type heat exchanger using a two phase-closed thermosyphon as a heat transfer device operating between hot and cold water has been experimentally investigated. The best working fluid of thermosyphon is water among ethanol, water, acetone. The range of the best heat transfer capability has been investigated depending on the ratio of heating and cooling fluids' Reynolds number, Re*(=??/??). For water, as a working fluid of thermosyphon, in the range of Re* between 0.5∼3.0, total thermal resistance of heat exchanger is found to be minimum and to show maximum heat transfer performance.

헤게모니에 의한 유행전파 이론의 통합

이승엽 기전여자대학 1999 論文集 Vol.19 No.-

We have heard many things about fashion theory, and we know that there exist too different viewpoints and conclusions among them. But, I think they imply main points from the viewpoint of macro. If we take out something general among them, we can approach the truth of fashion theory. For that purpose we will cite the concept of Gramci's hegemony, and through the hegemony concept we can gain an insight into fashion theory.

Melittin-Hybrid 합성 폡타이드가 Fusarium oxysporum의 성장에 미치는 저해효과

이동건,신송엽,이성구,이명규,함경수 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

꿀벌의 독액으로부터 분리된 ME은 강항 항균활성을 가지나, 진핵세포에 대하여 세포독성 활성을 포함하고 있다. 본 연구에서는 구조와 항진균활성과 상관관계를 검토하며, 세포독성을 가지지 않으며 보다 강한 항진균활성을 가진 펩타이드의 디자인하기 위하여, ME와 CA 또는 MA으로 이루어진 hybid 펩타이드인 MA(10-17)ME(1-12) 및 CA(1-8)ME(1-12)을 고상합성법의 의하여 합성 하였다. CA(1-8)ME(1-12) 및 MA(10-17)ME(1-12)는 인간의 적혈구에 대하여 용혈현상을 나타내지 않으며, Fusarium oxysporum에 대하여 ME 만큼의 강한 항진균활성을 나타내었다. 또한 이들 hybrid 펩타이드는 (1,3)-β-D-glucan synthase의 활성을 강하게 억제하였다. 이 결과는 Fusarium oxysporum에 대한 hybrid 펩타이드의 활성은 균의 세포벽의 합성의 억제에 의한 것과 관련성이 있는 것을 시사한다. 또한 본 연구의 결과는 세포독성을 가지며 강한 항진균활성을 가지는 펩타이드의 설계에 기초를 제공하였다고 생각된다. Melittin (ME) from honeybee venom has a broad range of strong antimicrobial activity, but it has hemolytic activity against eukaryotic cells. In order to design peptides with powerful antifungal activity without cytotoxic property of ME and understand structure-antifungal activity relationships, the hybrid peptides derived from the sequences of ME and cecropin A (CA) or magainin 2 (MA), MA(10-17) ME(1-12) and CA(1-8)ME(1-12), were synthesized by solid phase method. MA(10-17)ME(1-12) showed potent antifungal activity comparable to ME against Fusarium oxysporum with no hemolytic activity against human red blood cells. The hybrid peptides showed strong inhibition of (1,3)-β-D-glucan synthase. This result indicates that the antifungal activity of the hybrid peptides against Fusarium oxysporum is attributed to the inhibition of cell wall synthesis. The results therefore showed a successful design of a peptide having antifungal activity without hemolytic property.

Pentoxifylline과 고압산소요법이 백서 무축 피판 생존율에 미치는 영향

김사엽,이상한 慶北大學校 齒科大學 1991 慶北齒大論文集 Vol.8 No.2

The effects of pentoxifylline, hyperbaric oxygen and combination of the two on the survival rate of random pattern skin flaps were evaluated in an experimental study in rats. Thirty-five rate were divided into five groups. Cephalic based random pattern flaps were designed on the back of the rats and control group animals received twice-daily an intraperitoneal injection of 1cc normal saline solution for seven days before surgery and every 12 hours after the operation for seven days and to control for the stress of injection. Group I rats were treated with pentoxifylline received 20 ㎎/kg intraperitoneally at 24, 12, and 1 hour(s) before flap elevation and every 12 hours after the operation for seven days. Group Ⅱ rats were treated with twicedaily pentoxifylline injections for seven days before surgery and were then managed as Group I. Group Ⅲ rats were treated with hyperbaric oxygen within four hours after flap operation. Group Ⅳ rats were given exactly as Group Ⅱ and Group Ⅲ. The survival rate to the total flap was calculated. The results were as follows: 1. The mean survival rate of the flaps was 54.60±16.78% in control, 61.34±10.62% in group I, 64.96±3.08% in group Ⅱ, 71.93±9.26% in group Ⅲ, 86.67±8.17% in group Ⅳ. 2. The survival rate of the flaps were increased in group Ⅰ,Ⅱ, Ⅲ, Ⅳ when compared with the control group. 3. The combination of pentoxifylline and hyperbaric oxygen showed synergistic effect on the survival rate of the flap. 4. In the histopathologic study at postoperative 7th day, abundant proliferation of fibroblast and capillary blood vessels were observed in the experimental Ⅲ group, while severe infiltration of inflammatory cells were observed in the control group.

실험적 동소성 전 간이식후 이식간의 초기 간 기능 예측 지표에 관한 연구 : 조직검사를 통한 보존 손상정도와 혈청 젖산, 혈중 암모니아 및 동맥혈 pH의 변화 Analysis of preservation injury seen in protocol biopsy, change of plasma lactate, ammonia and arterial pH

권태원,이승규,공경엽 울산대학교 의과대학 1996 울산의대학술지 Vol.5 No.1

One of the most dramatic advances in the field of liver diseases in the twentieth century is the successful transplantation of the human liver, now on a worldwide scale. With the developments of new surgical techniques, transplantation immunology, and the capability to prevent and to control infections, it has been developed and become an acceptable therapy for patients with irreversible fiver diseases. After transplantation, it is of paramount importance to predict the function of allograft, which affects the result of transplantation and patient's survival. After transplantation, the first two or three days are always characterized by a marked elevation of transaminase levels and hepatocellular failure. Poor early graft function(PEGF) has a clinical spectrum characterized by varying degrees of coma and renal failure associated with lactic acidosis, persistent coagulopathy, poor bile production and marked elevations of ALT and AST. The occurrence of PEGF is unpredictable : its most severe form, requiring retransplantation and termed primary nonfunction(PNF), is seen following approximately 10 % of transplant procedures. Possible etiologic factors include liver disease in the donor, technical errors, ischemic injury, and immunologic damage. Ischemic injury is inherent in the process of organ retrieval, storage, and implantation and is considered as the main factor to contribute to PEGF. Protocol biopsies of liver allografts obtained during backtable preparation and 1 to 2 hours after revascularization in the recipients have detailed the sequential histologic events that occur after reperfusion. Once the liver is revascularized, quick assessment of its quality from metabolic studies is far more practical than a postperfusion biopsy. The purpose of this experiment is to observe whether protocol biopsy of allografts(during backtable procedure and 2 hours after revascularization), serum 1actate, serum ammonia and arterial pH would be used as the indicators of initial graft function after canine orthotopic whole liver transplantation. The experiment consisted of ten cases of orthotopic whole liver transplantation in mongrel dogs using venovenous bypass. The arterial blood were taken as just after anesthesia, anhepatic period, 15 minutes, 2 hours, and 6 hours after reperfusion in recipients. Protocol biopsies of allograft were taken at backtable preparation and 2 hours after reperfusion. We grouped the recipients according to the result of survival time(group A ;short survival time group, B ; long survival time group) and according to the degree of preservation injury(group C ; histologically no preservation injury group, D ; histologically preservation injury group). And we analysed the change of parameters (serum lactate, ammonia, ALT, AST, arterial pH, histologic finding) between group A and B and between group C and D. To evaluate the statistical significance, we used the SAS program and IBM - PC. In conclusion, we found out that preservation injury seen in protocol biopsy would be one of the indicators to predict the initial function of allograft and the pattern of change of serum lactate and blood ammonia are another possible indicators. And we also found out that immediate correction of metabolic acidosis which usually happens just after reperfusion would be related to the result of transplantation.

GC/NPD를 이용한 다성분 잔류농약의 동시분석

김우성,이선화,김상엽,정동윤,김재이,이영자,이홍재,정성욱,박흥재 한국환경과학회 2003 한국환경과학회지 Vol.12 No.10

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with fiorisil, and finally analyzed simultaneously the organophosphorus pesticides using GC/NPD, Ultra-2 and Ultra-1 fused silica capillary columns were used to separate and identify the products. Recovery of most analytes from soybean sample, taken from pesticide residues well, was greater than(80%) for all except(6) analytes. This method can simultaneously determine multiple pesticides with a high degree of accuracy and precision.

光電 方法에 의한 MOS구조의 산화층내의 電荷分布 연구

심성엽,金末文,이동건,문영희 嶺南大學校 基礎科學硏究所 1993 基礎科學硏究 Vol.13 No.-

Charge trapping in the insulator of a metal-oxide-semiconductor (MOS) structure strongly influences photocurrents resulting from electron photoinjection from gate into this insulator. These electric characteristics are investigated by Przewlocki method for determination of trapped charge distribution in the dielectric of a MOS structure. Silicon dioxide films were grown thermally in a dry oxygen ambient at 1000℃ to a thickness of 2000Å on (100) 6-9Ωcm p-type Si Wafers. As a result, it is found that the negative charge distribution is an exponential profile of decay lengthλ=9.907×10??cm and trapped charge density N。=3.912×10??cm-₃in the dielectric of this MOS structure.

How do you set up and educate surgical endoscopy in medium-sized hospital

Sang Yub Lee 대한외과학회 2015 대한외과학회 학술대회 초록집 Vol.2015 No.11

Performance of the Kronecker Barker Sequences for UWB systems

Sang-Yub Lee,Wan-Cheol Yang 한국통신학회 2005 한국통신학회 학술대회논문집 Vol.2005 No.11