http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Yoo Hyun-Joong (검색결과 343 건)
- 무료
- 기관 내 무료
- 유료
-
조현덕,김유종,용부중,동유게 한국공작기계학회 2005 한국생산제조학회지 Vol.14 No.2
A mirror cam mechanism, a kind of conjugate cam mechanism, consists of two cams, two rollers, and two links. Since profiles of two mirror cams are identical, a simultaneous machining of two cams is achievable. Some machining errors on cam profiles do not result in the internal acting force, which often causes problems in high speed cam mechanism, between two links. Also, since angular accelerations of two links are same, the internal acting force by the difference of the angular accelerations does not occur in the mechanism. Thus the mirror cam mechanism is very useful in high speed machinery. This paper studies a design method as well as a machining method, and develops an exclusive CAD/CAM software for mirror cam profiles. The developed CAD/CAM software is applied to a typical mirror cam mechanism, and a mock-up equipment is built in order to test the machined mirror cam. Experimental investigations show that the contact between cam surface and roller surface according to cam rotation agrees well with the simulation on the developed CAD/CAM software.
-
제 2형 당뇨병 환자에서 혈중 Metalliproteinase-9의 농도
김상용,김희중,주유철,최동현,배학연 조선대학교 2000 The Medical Journal of Chosun University Vol.25 No.2
Purpose : Diabetic nephropathy is a serious complication of diabetes and accounts for much of its morbidity and mortality. It is well known that the overt clinical phase of diabetic nephropathy is preceded for many years by the presence of microalbuminuria. Microalbuminuria is thought to be a marker of widespread vascular damage and may underlie the propensity toward severe extrarenal vascular disease in microalbuminuric patients. Metalloproteinase-9 has a broad substrate specificity for native collagens as well as proteoglycan and elastin. One study reported that an increased plasma metalloproteinase-9 concentration precedes the development of microalbuminuria in type 2 diabetic patients. Another study reported that a high glucose concentration cause a abnormality on the activity of metalloproteinase by the mesangeal cell. The purpose of the present study was to examine whether palsma metalloproteinase-9 concentrations are altered at various complications in type 2 diabetic patients. Methods : Sixty patients with type 2 diabetes and thirty healthy control were recruited for the present study. No patient had any malignancy or history of heart disease, liver disease, collagen disease. We recorded age, duration of diabetes, and blood pressure. After an overnight fast, blood was drawn from an antecubita1 vein of measurement of glucose, metalloproteinase-9, HbA1C, and serum creatinine. To measure plasma concentration of metalloproteinase-9, a one step sandwich enzyme immunoassay using two monoclonal antibodies was used. Patients were divided into two group according to the presence or abscence of microalbuminuria. The groups were then compared with regard to clinical and laboratory characteristics and serum concentration of metalloproteinase-9. Results : The mean serum levels of metalloproteinase-9 in diabetic patients (62.32±25.83ng/㎖) were significantly higher than in healthy controls(12.92±4.97ng/㎖) (p<01). The mean serum levels of metalloproteinase-9 in diabetic patients with microalbuminuria(81.16±41.43ng/㎖) were significantly higher than in those with normoalbuminuria(31.48±7.34ng/㎖) (p<01) and much more than in healthy control(12.92±4.97ng/㎖) (p<05). Furthermore, the severity of nephropathy were closely associated with the serum metalloproteinase-9 level and the serum metalloproteinase-9 level was significantly correlated with microalbuminuria. The mean serum level of metalloproteinase-9 in diabetic patients with retinopathy(61.74±39.07ng/㎖) was significantly higher than in those with no retinopathy(34.98±9.02ng/㎖) (p<05). But, in diabetic patients with normoalbuminuria, there is no difference between the groups with retinopathy versus no retinopathy. Conclusion : In summary, a sustained increase in serum metalloproteinase-9 in patients with type 2 diabetes is associated with a high risk for the development of microalbuminuria. The results of this study suggest that the serum rnetalloproteinase-9 was a useful and noninvasive marker for the development of diabetic nephropathy. It could be also used to predict the development of diabetic complications and to assess therapeutics or the prognosis of diabetes. The usefulness of this model will be clarified by a larger scale and serial study.
-
H9c2 심근 세포주에서 외인성 nitric oxide가 허혈에 의한 세포 독성에 미치는 영향
정성구,장현용,김명천,고영관,정주호,배영미,박원서,김대중,유영민,김성수,임성빈 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4
Background: Nitric oxide(NO) is known to have protective effects on an ischemic heart and to exert triggering effects on ischemic preconditioning. However, the effects of NO during the ischemic period have not been investigated. To investigate the role of exogenous nitric oxide in a model of ischemic heart cell death, we studied the effects of ischemic preconditioning and ischemia in a normal and an ischemic buffer. Methods: Rat cardiac myoblast cells(H9c2) were cultured in a normal and an ischemic buffered medium. For the ischemic culture of heart cells, the cells were cultured in a dessicator with GasPak for 5 hrs. In ischemic preconditioning, the cells were pretreated with ischemic buffer for 5 min and then perfused with normal medium for 30 min. For the measurement of the cytotoxicity, a MTT(3-4-Sdimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide) assay was performed. A DAPI(4',6-diamidino-2-phenylindole dihydrochloride) staining procedure and a flow cytometry analysis were performed to confirm apoptotic cell death by ischemia. Results: Cell viability, as determined by using a MTT assay, showed that the preconditioned group treated with NO showed more cell death than with the not-preconditioned groups in both normal and ischemic buffers. But, In normal medium and not-preconditioned groups, NO showed protective effect according to the concentrations(100,1000μM) . No treatment with NO produced the different results. In normal medium, the protective effect of ischemic preconditioning was demonstrated, but no protective effect of ischemic preconditioning could be seen in the case of the ischemic buffer. The DAPI staining and flow cytometry analysis of heart cells showed characteristic apoptotic features. Conclusion: NO added in the ischemic phase had deterious effects on heart cells. Ischemic preconditioning was more harmful than ischemia alone. The toxicity of the cells was characteristic apoptosis.
-
-
-
김문기,국정한,유중학,성호현 韓國技術敎育大學校 1996 論文集 Vol.3 No.1
In this study, fracture aspects for dissimilar materials welded by right and left or up and down in symmetry are examined by using Finite Element Method(FEM) in case that holes exist at up and down in symmetry for the center of crack, and the results of this study are as follows ; 1. When the strength(E₁) of a material with a center crack is lower than that (E₂) of the dissimilar material which is welded by right and left in symmetry, the crack propagation rate decreases by about 25%, while it increases by about 20% when the E₁ is higher than E₂. 2. When the E₁ is lower than the E₂ which is welded by up and down in symmetry, the crack propagation rate decreases by about 25% while it increases by about 75% when the E₁ is higher than the E₂. 3. The value of K₁/K?? is constant up to 2.0 in which is the ratio (a/R) between crack length and hole radius, and the value is decreased or increased a little above 2.0. It is regarded that a phenomenon of crack closure is applied according to the welded type of dissimilar material. In addition, It is noticed that retardation effect of crack propagation is changed greatly according to the distributed position of dissimilar material.
-
-
김한중,유대현,김성윤,이창우 ( Han Joong Kim,Dae Hyun Yoo,Seong Yoon Kim,Chang Woo Lee ) 대한피부과학회 1991 대한피부과학회지 Vol.29 No.3
A Case of Polyarteritis Nodosa Associated with Systemic Lupus Erythematiosus Han Joong Kim, M.D., Dae Hyun Yoo, M.D.*, Seong Yoon Kim, M.D.*, Chang Woo Lee, M.D. Departments of Dermatology & Rheumatology*, College of Medicine, Hanyang University, Seoul, Korea A 24-year-old female with systemic lupus erythematosus(SLE) diagnosed 3 year prior, presented with star-burst patches on her lower legs, which resembled livedo reticularis. In addition, she complained of intermittent lower abdominal pain. Histopathologic findings of the lesional skin showed necrotizing vasculitis of the medium sized dermal arteries. Direct immunofluorescent studies revealed deposits of IgG, IgM, and C_3 in the depp dermal arteries. Angiographic findings showed several foci of aneurysms in the superior mesenteric artery. Among those patients with SLE, the co-existences with polyarteritis nodosa have rarely been reported in the literature. We believe that circulating immune complexes of pahtological quantity and quality, which are thought to be related to the clinical activity of SLE, maybe relevant to the development of immune-complex mediated necrotizing arteritis in this patient.
-
박동준,최영미,이옥재,조중현,양중일,김휘종,조중현,유진종 대한내과학회 2000 대한내과학회지 Vol.59 No.1
Intraabdominal abscess, resulting from primary intraperitoneal disease such as appendicitis, diverticulitis or as a complication of surgery, remains a serious problem with high mortality if not treated early and adequately. In the case of acute bowel perforation, surgery is the treatment of choice, but radiologically guided percutaneous drainage is very effective for the subacute and localized abscess within the peritoneal cavity. However, perirectal abscesses located deep within the pelvis are unapproachable percutaneously because of interposed structures such as the urinary bladder, loops of bowel. Transrectal drainage overcomes these limitations. We present here a case of perirectal abscess treated successfully and safe with transrectal catheter drainge.(Korean J Med 59:59-63, 2000)
-
RISS
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
