http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Expression Patterns of HIF-1α Under Hypoxia in Vascular Smooth Muscle Cells of Venous Malformations
Chung, Ho Yun,Lee, Seok Jong,Lee, Jong Min,Huh, Seung,Kim, Hyung Kee,Kwon, O Hyun,Lim, Hyun Ju,Oh, Eun Jung,Kim, Tae Jung,O, Teresa M.,Waner, Milton Wolters Kluwer Health, Inc. All rights reserved. 2015 Annals of plastic surgery Vol.75 No.3
PURPOSE: The molecular pathophysiology of venous malformations (VMs), which are a type of vascular malformation, is poorly understood. Until now, it is known that VM lesions are related to the process of angiogenesis. Because angiogenesis is induced under hypoxic conditions, hypoxia is thought to be important in VM lesion formation. Therefore, we examined the implications of hypoxia on the biological behavior of VM vascular smooth muscle cells (VSMCs). In doing so, we investigated the expression patterns of hypoxia-inducible factor-1α (HIF-1α), which plays a key role in hypoxia-induced angiogenesis, to provide a further understanding of the molecular mechanisms involved in VM. METHODS: Vascular smooth muscle cells from 5 normal veins and 5 VM lesions were cultured under moderate hypoxic conditions (3% O2, 5% CO2). The effects of hypoxia on HIF-1α expression were measured by immunocytochemical staining, reverse transcription-polymerase chain reaction, and real-time reverse transcription-polymerase chain reaction. RESULTS: Overall, the expression of HIF-1α in cells was high after exposure to hypoxia for 6 or 12 hours, but decreased after 24 hours of hypoxia. HIF-1α expression in VM VSMCs was 2 times higher than that in normal VSMCs. Immunocytochemically, HIF-1α was mainly located in the nucleus and the intensity in VM VSMCs was stronger after 6 and 12 hours of hypoxia when compared to the expression pattern of HIF-1α in VSMCs from normal tissue. This suggested that VM tissue is more susceptible to the effects of hypoxia than normal tissue. CONCLUSIONS: These results indicate that the high expression of HIF-1α in VM VSMCs under hypoxic conditions could be an important factor for stimulating downstream angiogenesis in VM. Furthermore, the results of this investigation could provide the basis for future studies of VM pathophysiology, and ultimately lead to the development of new therapeutic approaches.
Ramos, Kristine Rose M.,Valdehuesa, Kris Niñ,o G.,Nisola, Grace M.,Lee, Won-Keun,Chung, Wook-Jin Elsevier 2018 New biotechnology Vol.40 No.2
<P><B>Abstract</B></P> <P>Research on the enzymatic breakdown of seaweed-derived agar has recently gained attention due to the progress in green technologies for marine biomass utilization. The enzymes known as agarases catalyze the cleavage of glycosidic bonds within the polysaccharide. In this study, a new β-agarase, Aga2, was identified from <I>Cellulophaga omnivescoria</I> W5C. Aga2 is one of four putative agarases from the W5C genome, and it belongs to the glycoside hydrolase 16 family. It was shown to be exclusive to the <I>Cellulophaga</I> genus. Agarase activity assays showed that Aga2 is an endolytic-type β-agarase that produces tetrameric and hexameric neoagaro-oligosaccharides, with optimum activity at 45°C and pH 8.0. Zinc ions slightly enhanced its activity while manganese ions had inhibitory effects even at very low concentrations. Aga2 has a K<SUB>m</SUB> of 2.59mgmL<SUP>−1</SUP> and V<SUB>max</SUB> of 275.48Umg<SUP>−1</SUP>. The K<SUB>cat</SUB> is 1.73×10<SUP>2</SUP> s<SUP>−1</SUP>, while the K<SUB>cat</SUB>/K<SUB>m</SUB> is 8.04×10<SUP>6</SUP> s<SUP>−1</SUP> M<SUP>−1</SUP>. Aga2 also showed good thermostability at 45°C and above, and retained >90% of its activity after repeated freeze-thaw cycles. Bioinformatic analysis of its amino acid sequence revealed that intrinsic properties of the protein (e.g. presence of certain dipeptides and the relative volume occupied by aliphatic amino acids) and tertiary structural elements (e.g. presence of salt bridges, hydrophobic interactions and H-bonding) contributed to its thermostability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endolytic β-agarase Aga2 was identified from <I>Cellulophaga omnivescoria</I> W5C. </LI> <LI> Aga2 optimum activity was at 45°C, pH 8.0, with NA4 and NA6 as major products. </LI> <LI> Aga2 was thermostable at high temperatures as well as after many freeze-thaw cycles. </LI> <LI> Intrinsic properties and tertiary structural elements confer the thermostability. </LI> </UL> </P>
장기 저장연료의 열안정성 및 연료접촉 고무오링의 수명예측 연구
정근우(K. W. Chung),홍진숙(J. S. Hong),김영운(Y. W. Kim),한정식(J. S. Han),정병훈(B. H. Jeong),권태수(T. S. Kwon),서동욱(D. O. Suh),성민준(M. J. Sung),권영일(Y. I. Kwon) 한국트라이볼로지학회 2018 한국윤활학회지(윤활학회지) Vol.34 No.5
Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.
Koh, W J,Yu, C M,Suh, G Y,Chung, M P,Kim, H,Kwon, O J,Lee, N Y,Chung, M J,Lee, K S The Union 2006 The international journal of tuberculosis and lung Vol.10 No.9
<P>OBJECTIVE: To compare the clinical and radiographic features of pulmonary tuberculosis (PTB) and non-tuberculous mycobacteria (NTM) lung disease in patients with acid-fast bacilli (AFB) positive sputum specimens. DESIGN: The initial clinical and radiographic features of 229 PTB patients were compared with those of 70 patients with NTM lung disease. The most commonly involved organisms in the NTM lung disease cases were Mycobacterium avium complex (n = 38, 54%) and M. abscessus (n = 26, 37%). RESULTS: Clinical and radiographic findings that were more common in patients with NTM lung disease than in PTB patients were: older age (P < 0.001), non-smoker (P < 0.001), history of previous TB treatment (P < 0.001), absence of pleural effusion (P = 0.017), involvement of middle and/or lower lung zones (P = 0.007), and bilateral disease (P = 0.005). Multivariate analysis showed that older age (> or = 40 years), non-smoker, previous TB treatment, absence of pleural effusion and involvement of middle and/or lower lung zones were significant independent predictors for NTM lung disease. CONCLUSIONS: There is considerable overlap in the clinical and radiographic appearances of PTB and NTM lung disease. The isolation and identification of causative organisms are mandatory for a correct diagnosis in patients with AFB-positive sputum specimens.</P>
朴鎭庸,車京玉,李珉湖,鄭廣國 明知大學校 産業技術硏究所 1996 産業技術硏究所論文集 Vol.15 No.-
One of the Characteristics desired of an ideal automotive friction material is a constant coefficient of friction. In practice, it is found that the coefficient frequently varies, for example, frictional force does not increase linearly with increasing normal load. Thus, it appears that the frictional force under sliding conditions is very likely to be dependent upon the normal load speed, and temperature, and the Amontons' law is a very special case rather than a general rule.
김창호,조무식,정재삼,백정선,구영무,송옥평 순천향대학교 1989 논문집 Vol.12 No.3
Chinical observation was made of 202 cases of typhoid fever, whose charts were reviewed at the department of general surgery of Soonchunhyang University, Chunan Hospital from Mar., 1988 to May, 1988. 1) Typhoid fever was occured most frenquetly in those between the age of 0-9 years old. 2) The male-female ratio on admission was 112:90. 3) Symptoms and signs on admission were fever: 87%, abdominal pain: 68%, diarrhea: 52%, headache: 50%, chill: 43%, nausea and vomiting: 38%. 4) In hematologic fidings on admission, the leucocyte count was below 5000/㎣: 33%, between 5000-10000/㎣: 51%, and above 100000/㎣: 16%. 5) The result of Widal test was positive: 69%(above 1:160). 6) Complications of typhoid fever were intestinal bleeding: 29%, hepatitis or decreased liver function and no jaundice: 19%, intestinal perforation: 10%. 7) Intestinal perforation was occured most frequently in those 20-39 years old and the male-female ratio was 7:3. 8) Intestinal hemorrhage(31%) and intestinal perforation(51%) were developed most frequently at 2 to 3 weeks after onset of symptom. 9) Subdiaphragmatic free air in simple X-ray was found in 70% of intestinal perforated cases. 10) The site of intestinal perforation was within 60cm. proximal from ileocecal valve in 65% of the intestinal perforated cases. 11) Intestinal perforation showed multiple perforation(2-5 sites), 55% and single perforation, 45%. 12) In surgical management, primary closure of the perforation site was in 30% of the cases of anastomosis after resection in 70%.