An outbreak of highly pathogenic H5N1 avian influenza in Korea, 2008

Kim, H.R.,Park, C.K.,Lee, Y.J.,Woo, G.H.,Lee, K.K.,Oem, J.K.,Kim, S.H.,Jean, Y.H.,Bae, Y.C.,Yoon, S.S.,Roh, I.S.,Jeong, O.M.,Kim, H.Y.,Choi, J.S.,Byun, J.W.,Song, Y.K.,Kwon, J.H.,Joo, Y.S. Elsevier Scientific Pub. Co 2010 Veterinary microbiology Vol.141 No.3

In spite of intensive surveillance programs for the control of HPAI, an outbreak of highly pathogenic avian influenza (HPAI) H5N1 in Korea in April 2008 caused serious damage to poultry farms, as did previous outbreaks in 2003/2004 and 2006/2007. Six viruses were selected from the Korean 2008 isolates for genetic analysis, and all eight gene segments from each of the influenza viruses were sequenced. A phylogenetic analysis showed that all of the viruses were of the same virus type and that the hemagglutinin (HA) gene was clustered with that of clade 2.3.2 viruses. However, the internal and neuraminidase (NA) genes were closely related to those of the clade 2.3.4 viruses (recent human and bird isolates from Southeast Asia).

Differentiation Between Hepatocellular Carcinoma and Colorectal Cancer Liver Metastases on High-Resolution Magic Angle Spinning Spectroscopy: Preliminary Study

Kim, S. Y.,Kim, S.,Woo, C. W.,Byun, J. H.,Lee, S. S.,Lee, M. G.,Kim, H.,Lee, K. H.,Kim, Y. H.,Cho, J. Y. SPRINGER-VERLAG 2014 Applied magnetic resonance Vol.45 No.1

To explore the potential of high-resolution magic angle spinning (HRMAS) H-1 nuclear magnetic resonance (NMR) spectroscopy for differentiation and metabolite characterization of hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM), we prospectively included 21 pathologically confirmed malignant hepatic tumors (8 HCC and 13 CRLM) and 26 non-tumorous hepatic parenchyma from 26 patients who underwent hepatic tumor resection. Using intact tissue samples obtained during surgery, HRMAS H-1 NMR spectroscopy was performed at 11.7 T. All observable metabolite signals were acquired using a water-presaturated standard one-dimensional Carr-Purcell-Meiboom-Gill sequence. Metabolomic profiles contributing to the differentiation of HCC and CRLM and of each tumor and non-tumorous hepatic parenchyma were represented by orthogonal partial least squares discriminant analysis (OPLS-DA) and loading plots. Metabolite intensity normalized by total spectral intensities in both tumors was compared using student's t tests. OPLS-DA and loading plots demonstrated good separation between tumors and non-tumorous hepatic parenchyma. The metabolomic characteristics of HCC showed separation from those of CRLMs according to OPLS-DA. Compared with CRLM, HCC showed significantly elevated levels of glucose (P < 0.01) and sn-Glycero-3-phosphocholine (P < 0.01), and decreased levels of hypoxanthine (P = 0.04). HCC and CRLM could be differentiated by the metabolic profile using HRMAS H-1 NMR spectroscopy.

Overestimation of on-road air quality surveying data measured with a mobile laboratory caused by exhaust plumes of a vehicle ahead in dense traffic areas

Woo, S.H.,Kwak, K.H.,Bae, G.N.,Kim, K.H.,Kim, C.H.,Yook, S.J.,Jeon, S.,Kwon, S.,Kim, J.,Lee, S.B. Elsevier Applied Science Publishers 2016 Environmental pollution Vol.218 No.-

The unintended influence of exhaust plumes emitted from a vehicle ahead to on-road air quality surveying data measured with a mobile laboratory (ML) at 20-40 km h<SUP>-1</SUP> in dense traffic areas was investigated by experiment and life-sized computational fluidic dynamics (CFD) simulation. The ML equipped with variable sampling inlets of five columns by four rows was used to measure the spatial distribution of CO<SUB>2</SUB> and NO<SUB>x</SUB> concentrations when following 5-20 m behind a sport utility vehicle (SUV) as an emitter vehicle equipped with a portable emission monitoring system (PEMS). The PEMS measured exhaust gases at the tailpipe for input data of the CFD simulations. After the CFD method was verified with experimental results of the SUV, dispersion of exhaust plumes emitted from a bus and a sedan was numerically analyzed. More dilution of the exhaust plume was observed at higher vehicle speeds, probably because of eddy diffusion that was proportional to turbulent kinetic energy and vehicle speed. The CO<SUB>2</SUB> and NO<SUB>x</SUB> concentrations behind the emitter vehicle showed less overestimation as both the distance between the two vehicles and their background concentrations increased. If the height of the ML inlet is lower than 2 m and the ML travels within 20 m behind a SUV and a sedan ahead at 20 km h<SUP>-1</SUP>, the overestimation should be considered by as much as 200 ppb in NO<SUB>x</SUB> and 80 ppm in CO<SUB>2</SUB>. Following a bus should be avoided if possible, because effect of exhaust plumes from a bus ahead could not be negligible even when the distance between the bus and the ML with the inlet height of 2 m, was more than 40 m. Recommendations are provided to avoid the unintended influence of exhaust plumes from vehicles ahead of the ML during on-road measurement in urban dense traffic conditions.

Reoxygenation following hypoxia activates DNA-damage checkpoint signaling pathways that suppress cell-cycle progression in cultured human lymphocytes

Kim, B.M.,Choi, J.Y.,Kim, Y.J.,Woo, H.D.,Chung, H.W. North-Holland Pub ; Elsevier Science Ltd 2007 FEBS letters Vol.581 No.16

Cellular responses to DNA damage after hypoxia and reoxygenation (H/R) were examined in human lymphocytes. Cultured lymphocytes exposed to H/R showed a lower cytokinesis block proliferation index and a higher frequency of micronuclei in comparison to control cells. Western blots showed that H/R exposure induced p53 expression; however, p21 and Bax expression did not increase, indicating that H/R did not affect p53 transactivational activity. Phosphorylation of p53 (Ser15), Chk1 (Ser345), and Chk2 (Thr68) was also observed, suggesting that H/R activates p53 through checkpoint signals. In addition, H/R exposure caused the phosphorylation and negative regulation of Cdc2 and Cdc25C, proteins that are involved in cell-cycle arrest at the G2/M checkpoint. The S-phase checkpoint, regulated by the ATM-p95/NBS1-SMC1 pathway, was also triggered in H/R-exposed lymphocytes. These results demonstrate that H/R exposure triggers checkpoint signaling and induces cell-cycle arrest in cultured human lymphocytes.

위식도 역류성질환 관련 인후두역류(Laryngopharyngeal Refulx : LPR)증상을 호소하는 환자에서의 라니티딘의 치료효과 연구

장혁순,고윤우,김광현,김민식,김상윤,김영모,도남용,백정환,안순현,엄재욱,양훈식,우훈영,이형석,Chang, H.S.,Ko, Y.W.,Kim, K.H.,Kim, Y.M.,Kim, S.Y.,Kim, Y.M.,Do, M.Y.,Beak, C.H.,Ahn, S.H.,Eom, J.W.,Yang, H.S.,Woo, H.Y.,Lee, H.S. 대한기관식도과학회 2004 大韓氣管食道科學會誌 Vol.10 No.2

Background : LPRD(Laryngopharyngeal reflux disease) gives rise to inflammatory change in the pharyngolaryngeal tissue with various otolaryngologic symptoms. Ranitidine, histamine H2receptor antagonists, are currently used as therapeutic medications. However, the efficacy of Ranitidine on LPRD has not been proven yet. Objectives : We intended to analyze the efficacy of the Ranitidine on LPRD. Materials :md Methods : In 20 multicenter, 607 patients with LPR(laryngopharyngeal reflux) symptom were observed to evaluate their symptoms and laryngoscopic findings after 4 weeks, 8 weeks, and 12 weeks of treatment of Ranitidine. Results : The symptom of LPR including globus sensation, sore throat hoarseness, regurgitatioin are improved after 4 weeks $86.2\%,\;8 weeks\;91.5\%,\;12 weeks\;92.9\%$ of Ranitidine treatment and improved after 4 weeks $91.5\%,\;8 weeks\;94.5\%,\;12 weeks\; 97.2\%$ of Ranitidine combined with prokinetics. The rates of sore throat, chronic cough, globus sensation improvement at 8 weeks after treatment are $26.7\%,\;16.7\%,\;16\%$. Conclusion : In patient with LPR, Ranitidine treatment reduces LPR symptoms very effectively.

Proton Implantation Mechanism in GaN Layer Transfer by Using the Ion-Cut Process

H. J Woo,C. H Eum,G. D Kim,H. W Choi,J. K Kim,W. Hong,Y. H Bae 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.I

The proton implantation condition for the ion-cut process in wurtzite-phase GaN and the associated mechanisms of surface blistering of GaN films were investigated. Etch-pit density (EPD) measurements, photoluminescence (PL) spectroscopy, and high resolution X-ray diffraction (HRXRD) were used to investigate the crystalline quality of the as-grown GaN epi-wafers. The proton beam was implanted at 60 keV with fluences in the range of 3 $\sim$ 5 $\times$ 10$^{17}$ H$^+$/cm$^2$ at room temperature. The influences of the crystallinity of the GaN wafers, the ion fluence and the post-implantation annealing conditions (200 $\sim$ 450 $^\circ$C) on the blistering process were studied. Optical microscopy, field emission scanning electron microscopy (FE-SEM), HRXRD, Rutherford backscattering Spectrometry (RBS)/channeling (RBS/C), and cross-sectional transmission electron microscopy (XTEM) were used to investigate splitting kinetics, and the optimum conditions for achieving exfoliation only after post-implantation annealing were determined for the GaN ion-cut process. Our results suggest that the ion-cut process is sensitive to both the implant fluence and the annealing conditions, however, so far as the measured crystal quality is concerned, against our expectations, there was no notable influence on the blistering property. The optimum post-implantation annealing temperature was less than 350 $^\circ$C, and low temperature splitting is of importance for layer transfer between dissimilar materials with very different thermal expansion coefficients.

발사체 공력해석 프로그램 RocketAeroMaster2005 개발

김재수,김종록,우철훈,김태훈,임오택,박정주,오범석,옥호남 朝鮮大學校 機械技術硏究所 2005 機械技術硏究 Vol.8 No.1

예비설계 단계에서 외형설계, 구조설계를 위한 하중분포 계산, 발사체의 안정성 및 성능분석을 위하여 데이터베이스형 발사체 공력코드를 개발하였다. 분석방법으로는 동체, 스트랩온 부스터의 공력계수와 동체와 스트랩온 부스터의 간섭 동의 분석을 거쳐 전체 발사체에 대한 분석이 이루어졌다. 발사체 공력코드의 데이터베이스구성은 기존의 DATCOM의 데이터베이스를 기반으로 발사체 형상에 대한 실험데이터(MD)를 추가 구성함으로서 발사체 공력코드의 신뢰성을 증대시켰다. 또한, 기존의 발사체 공력설계코드와 비교 분석을 수행하여 발사체 공력코드를 검증하였다. For the development of launch vehicle, the aerodynamic characteristics have to be performed for the configuration design in the preliminary design, the load distribution in the detail design, and the performance analysis. The static and dynamic coefficients are analyzed for strap on booster, body and strap on booster-body interface characteristics. A detail analysis is required during the detail design phase, but a rapid analysis is better in the preliminary design. Therefore, the database code, based on the theory and experimental datum, is useful to analyze the variety of models during the preliminary design phase, and the computational aerodynamic code is required to calculate the detail load distribution during the detail design phase. In this computational aerodynamic code, based on the database of theoretical and experimental datum, have been developed.

알팔파 캘러스로부터 삼투압 스트레스 처리에 의한 효율적인 식물체 재분화

김진수,이동기,이상훈,우현숙,이병현 Plant molecular biology and biotechnology research 2004 Plant molecular biology and biotechnology research Vol.2004 No.-

Effects of culture medium supplements and osmotic stress treatment on embryogenic callus induction and somatic embryogenesis were investigated in order to optimize tissue culture conditions of alfalfa(Medicago sativa L.). SH medium containing 5 ㎎/L 2,4-D and 0.2 ㎎/L kinetin was optimal for embryogenic callus induction from cotyledon tissue of alfalfa. Somatic embryos were formed when the embryogenic callus was cultured on SH medium supplemented with 1 ㎎/L 2,4-D and 2 ㎎/L BA. Supplementation of 5 mM L-pro-line and 1g/L casein hydrolysate into the regeneration medium further increased plant regeneration frequency. Osmotic stress treatment of callus appeared to improve the frequency of somatic embryo formation, but the frequency of somatic embryo formation differed by the osmotic stress treatment using different osmotic stressors. The highest plant regeneration frequency of 30.7% was observed when embryogenic callus was treated with 0.7M sucrose for 18h. Efficient regeneration system established in this study will be useful for molecular breeding of alfalfa through genetic transformation.

Laminar shear stress suppresses vascular smooth muscle cell proliferation through nitric oxide-AMPK pathway

Kim, S.A.,Sung, J.Y.,Woo, C.H.,Choi, H.C. Academic Press 2017 Biochemical and biophysical research communication Vol. No.

In healthy condition, vascular smooth muscle cells (VSMCs) are not directly exposed to shear stresses, because they are shielded by endothelial cell (EC) layer that lines blood vessels. After injury to EC layer caused by rupture of atherosclerotic lesions or invasive techniques such as angioplasty, VSMCs are directly exposed to blood flow which modulate molecular signaling and function. In endothelium, exposure to fluid shear stress has been reported to induce AMP-activated protein kinase (AMPK) phosphorylation and nitric oxide (NO) production. However, the influence of laminar shear stress on exposed VSMC is not defined. In this study, we investigated whether laminar shear stress regulates AMPK phosphorylation in VSMC and tried to identify underlying signaling pathway. NO production was increased by shear stress. The expression of NOS isoforms was increased 1 h after exposure to shear stress, and AMPK phosphorylation started to increase after 2 h. AMPK and LKB1, the upstream kinases of AMPK, phosphorylation were decreased by the non-selective NOS inhibitor l-NAME and the selective iNOS inhibitor aminoguanidine despite exposure to shear stress. On the other hand, compound C, a specific AMPK inhibitor, did not affect the expression of NOS isoforms. In addition, PDGF-induced VSMC proliferation was decreased by shear stress and restored by l-NAME. These findings suggest that shear stress upregulated AMPK phosphorylation in VSMC via NOS expression may be a beneficial route to prevent pathogenesis in the vascular system.

우주발사체 예비설계 단계의 공력설계 연구

김재수,박남은,김종록,김양수,우철훈,박정주,오범석,옥호남 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.1

예비설계 단계에서 외형설계,구조설계를 위한 하중분포 계산,발사체의 안정성 및 성능분석을 위하여 데이터베이스형 발사체 공력코드를 개발하였다. 분석방법으로는 동체, 핀의 공력계수와 동체와 핀의 간섭, 핀과 핀사이의 간섭 등의 분석을 거쳐 전체 발사체에 대한 분석이 이루어졌다. 발사체 공력코드의 데이터베이스구성은 기존의 DATCOM의 데이터베이스를 기반으로 발사체 형상에 대한 실험데이터를 추가 구성함으로서 발사체 공력코드의 신뢰성을 증대시켰다. 또한, 기존의 발사체 공력셜계코드와 비교 분석을 수행하여 발사체 공력코드를 검증하였다. For the development of launch vehicle, the aerodynamic characteristics have to be performed for the configuration design in the preliminary design, the load distribution in the detail design, and the performance analysis. The static and dynamic coefficients are analyzed for fins, body and fin-body interface characteristics. A detail analysis is required during the detail design phase, but a rapid analysis is better in the preliminary design. Therefore, the database code, based on the theory and experimental datum, is useful to analyze the variety of models during the preliminary design phase, and the computational aerodynamic code is required to calculate the detail load distribution during the detail design phase. In this computational aerodynamic code, based on the database of theoretical and experimental datum, have been developed.