Multiple heterologous M2 extracellular domains presented on virus-like particles confer broader and stronger M2 immunity than live influenza A virus infection

Kim, M.C.,Lee, J.S.,Kwon, Y.M.,O, E.,Lee, Y.J.,Choi, J.G.,Wang, B.Z.,Compans, R.W.,Kang, S.M. Elsevier/North-Holland 2013 Antiviral research Vol.99 No.3

The influenza M2 ectodomain (M2e) is poorly immunogenic and has some amino acid changes among isolates from different host species. We expressed a tandem repeat construct of heterologous M2e sequences (M2e5x) derived from human, swine, and avian origin influenza A viruses on virus-like particles (M2e5x VLPs) in a membrane-anchored form. Immunization of mice with M2e5x VLPs induced protective antibodies cross-reactive to antigenically different influenza A viruses and conferred cross protection. Anti-M2e antibodies induced by heterologous M2e5x VLPs showed a wider range of cross reactivity to influenza A viruses at higher levels than those by live virus infection, homologous M2e VLPs, or M2e monoclonal antibody 14C2. Fc receptors were found to be important for mediating protection by immune sera from M2e5x VLP vaccination. The present study provides evidence that heterologous recombinant M2e5x VLPs can be more effective in inducing protective M2e immunity than natural virus infection and further supports an approach for developing an effective universal influenza vaccine.

The effect of non-equilibrium condensation on the coefficients of force with the angle of attack in the transonic airfoil flow of NACA0012

S. M. Choi,J. S. Kim,권영두,S. B. Kwon 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6

A transonic flow with a non-equilibrium condensation past NACA0012 profile whose aspect ratio AR is 1.0 with the angle of attack was analyzed by numerical analysis using a TVD scheme, and investigated using an intermittent indraft type supersonic wind tunnel. Transonic flows of 0.70-0.90 in free stream Mach number with variations of Φ0 and α were tested. For the same M∞ and α, the increase in stagnation relative humidity Φ0 caused a decrease in the drag coefficient of profile (that is total) which is composed of the components of form, viscous, wave and condensation; however, the lift coefficient up to Φ0 = 50% increased in the opposite direction. As an example, in the case of M∞ = 0.83, Φ0 = 50%, α = 3o and T0 = 298K, the decreasing rate of the coefficient of profile drag and the increasing rate of the lift coefficient compared to the case of Φ0 = 0% caused by non-equilibrium condensation amounted to 65% and 52%, respectively. In addition, for the same Φ0 and α, as the free stream Mach number M∞ increased, at first, the lift coefficient increased slightly, and then suddenly severely dropped, and finally remained nearly constant. The suddenly dropped free stream Mach number in CL became larger with an increase of Φ0. It turned out that the drag coefficients of form and viscous were almost independent of Φ0. The contribution of wave drag to the coefficient of profile drag for M∞ = 0.83, Φ0 = 30%, α = 3o and T0 = 298K amounted to approximately 79%, and in the case of Φ0 = 60%, the contribution of the non-equilibrium condensation to the reduction in the coefficient of the profile drag compared to the case without condensation amounted to 75%. Especially, for the case of Φ0 = 0% and α = 0o, there was an oscillatory flow region around M∞ = 0.87.

Modeling of thermodynamic properties of an oxygenate+aromatic hydrocarbon: Excess molar enthalpy

Gahlyan, S.,Rani, M.,Maken, S.,Kwon, H.,Tak, K.,Moon, I. Korean Society of Industrial and Engineering Chemi 2015 Journal of industrial and engineering chemistry Vol.23 No.-

Excess molar enthalpy (H<SUB>m</SUB><SUP>E</SUP>) have been measured at 303.15K for 1-propanol+benzene or toluene or o- or m- or p-xylene mixtures using flow micro calorimeter. The H<SUB>m</SUB><SUP>E</SUP>versusx<SUB>1</SUB> plots are skewed toward y-axis showing maxima at x<SUB>1</SUB>~0.3. At (x<SUB>1</SUB>=0.5)H<SUB>m</SUB><SUP>E</SUP> vary in the order: toluene<benzene<m-xylene<p-xylene~o-xylene. The excess volume data have also been interpreted in terms of Graph-theoretical approach and Prigogine-Flory-Patterson theory. It has been observed that while PFP theory fails to predict the H<SUB>m</SUB><SUP>E</SUP> values for these systems in the composition range x<SUB>1</SUB><0.5, agreement with experimental values is reasonably good thereafter. The H<SUB>m</SUB><SUP>E</SUP> values calculated by Graph theory compared well with the corresponding experimental values.

Tribology Characteristics in 200 μm of Hexagonal Array Dimple Pattern

W. S. Choi,Angga S. H.,S. H. Kwon,S. G. Kwon,J. M. Park,J. S. Kim,S. W. Chung,Y. H. Chae 한국트라이볼로지학회 2015 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.31 No.2

This study investigates the effects of a pattern of 200 μm dimples in a hexagonal array on tribological characteristics. A textured surface might reduce the friction coefficient and wear caused by third-body abrasion and thus improve the tribological performance. There are three friction conditions based on the Stribeck curve: boundary friction, mixed friction, and fluid friction conditions. In this experiment, we investigate the friction characteristics by carrying out the friction tests at sliding speeds ranging from 0.06 to 0.34 m/s and normal load ranging from 10 to 100 N. We create dimple surfaces for texturing by using the photolithography method. There are three kinds of specimens with different dimple densities ranging from 10% to 30%. The dimple density on the surface area is the one of the important factors affecting friction characteristics. Friction coefficient generally decreases with an increase in the velocity and load, indicating that the lubrication regime changes depending on the load and velocity. The fluid friction regime is fully developed, as indicated by the duty number graph. Fluid friction occurs at a velocity of 0.14-0.26 m/s. The best performance is seen at 10% dimple density and 200 μm dimple circle in the hexagonal array.

Improvement in the Electrochemical Properties of ZrMn2 Hydrides by Substitution of Elements

Song, M . Y .,Kwon, I . H .,Ahn, D . S .,Sohn, M . S . 대한금속재료학회(대한금속학회) 2001 METALS AND MATERIALS International Vol.7 No.3

The hydrogen-storage properties and the electrochemical properties are investigated for the alloys ZrMn₂Nix, ZrMnNi_(1+x), Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(1-x)Fe_x and Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15). The C14 Laves phase forms in all the alloys ZrMn₂Ni_x (x=0.0, 0.3, 0.6, 0.9 and 1.2). Among the alloys ZrMn₂Ni_x, ZrMn₂Ni_(0.6) has the largest discharge capacity (29 mAh/g) and a relatively good cycling performance, and shows a relatively easy activation. The C14 Laves phase also forms in all the alloys ZrMnNi_(1+x) (x=0.0, 0.1, 0.2, 0.3 and 0.4). Among the alloys ZrMnNi_(1+x), ZrMnNi_(1.0) has the largest discharge capacity (42 mAh/g) and a relatively good cycling performance, and shows the easiest activation. Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(1+x)Fe_x (x=0.00, 0.15, 0.30, 0.45 and 0.60) has the C14 Laves phase hexagonal structure. Their hydrogen storage capacities do not show significant differences. The discharge capacity just after activation decreases with an increase in the amount of the substituted Fe but the cycling performance is improved. The discharge capacity after activation of the alloy with x=0.00 is about 240 mAh/g at the current density 60 mA/g. Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) is the best composition with a relatively large discharge capacity and a good cycling performance. The increase in the discharge capacity of Zro.sTio.sMno.qVo.bNio,asFeo.,s with the increase in the current density (from 60 mA/g to 125 mA/g) is considered to result from the self-discharge property of the electrode. Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) (M=Fe, Co, Cu, Mo and Al) alloys also have the C14 Laves phase hexagonal structure. The alloys with M=Co and Fe have relatively larger hydrogen storage capacities. The discharge capacities just after activation are relatively large in the case of the alloys with M=Co and Fe. The Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) alloy is best with a relatively large discharge capacity (257 mAh/g at the current density 250 mA/g for the 12^(th) cycle) and a good cycling performance. During activation form Ni-rich and Fe-rich regions on the surface of the Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) alloy. They may act as the active sites for the electrochemical reaction. With the increase in the number of charge-discharge cycles for the Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) alloy, the quantities of the Zr and Fe dissolved in the electrolyte solution increase.

Control of electrical properties and gate bias stress stability in solution-processed a-IZO TFTs by Zr doping

Choi, W.S.,Jo, H.,Kwon, M.S.,Jung, B.J. Elsevier 2014 CURRENT APPLIED PHYSICS Vol.14 No.12

Zr-doped indium zinc oxide (IZO) thin film transistors (TFTs) are fabricated via a solution process with different Zr doping ratios. The addition of Zr suppressed the carrier concentration in the IZO films, which was confirmed by Hall Effect measurements. As the amount of Zr was increased in the oxide active layer of TFTs, the subthreshold swing (S.S) reduced, the ON/OFF ratio improved, and the threshold voltage (V<SUB>th</SUB>) shifted positively. Moreover, the starting points of the ON state for TFTs near the point zero gate voltage could be controlled by the addition of Zr. The 0.3% Zr-doped IZO TFT exhibited a high saturation mobility of 7.0 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP>, ON/OFF ratio of 2.6 x 10<SUP>6</SUP> and S.S of 0.57 V/decade compared the IZO TFT with 10.1 cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP>, 1.7 x 10<SUP>6</SUP> and 0.75 V/decade. The Zr effect of the gate bias stability was examined. Zr-doped IZO TFTs were relatively unstable under a positive bias stress (PBS), whereas they showed good stability at a negative bias stress (NBS). The gate bias stability of the oxide TFTs were compared with the extracted parameters through a stretched-exponential equation. The characteristic trapping time under NBS of 0.3% Zr-doped IZO TFTs was improved from 8.3 x 10<SUP>4</SUP> s for the IZO TFT to 3.1 x 10<SUP>5</SUP> s.

Tribology Characteristics in 200 μm of Hexagonal Array Dimple Pattern

Choi, W. S.,Angga, S.H.,Kwon, S. H.,Kwon, S. G.,Park, J. M.,Kim, J. S.,Chung, S. W.,Chae, Y. H. Korean Tribology Society 2015 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.31 No.2

This study investigates the effects of a pattern of 200 μm dimples in a hexagonal array on tribological characteristics. A textured surface might reduce the friction coefficient and wear caused by third-body abrasion and thus improve the tribological performance. There are three friction conditions based on the Stribeck curve: boundary friction, mixed friction, and fluid friction conditions. In this experiment, we investigate the friction characteristics by carrying out the friction tests at sliding speeds ranging from 0.06 to 0.34 m/s and normal load ranging from 10 to 100 N. We create dimple surfaces for texturing by using the photolithography method. There are three kinds of specimens with different dimple densities ranging from 10% to 30%. The dimple density on the surface area is the one of the important factors affecting friction characteristics. Friction coefficient generally decreases with an increase in the velocity and load, indicating that the lubrication regime changes depending on the load and velocity. The fluid friction regime is fully developed, as indicated by the duty number graph. Fluid friction occurs at a velocity of 0.14-0.26 m/s. The best performance is seen at 10% dimple density and 200 μm dimple circle in the hexagonal array.

Multicenter phase II study of docetaxel plus oxaliplatin combination chemotherapy in patients with advanced gastric cancer: Daegu Gyeongbuk Oncology Group

Kim, J G,Sohn, S K,Chae, Y S,Song, H S,Kwon, K-Y,Do, Y R,Kim, M K,Lee, K H,Hyun, M S,Ryoo, H M,Bae, S H,Park, K U,Lee, W S,Baek, J H,Chung, H Y,Yu, W Nature Publishing Group 2008 The British journal of cancer Vol.98 No.3

<P>The present study was conducted to evaluate the efficacy and safety of a combination regimen of docetaxel plus oxaliplatin in patients with advanced gastric cancer. Patients with previously untreated metastatic or recurrent, measurable gastric cancer received intravenous docetaxel 65 mg m<SUP>−2</SUP> plus oxaliplatin 120 mg m<SUP>−2</SUP> on day 1 based on a 3-week cycle. Forty-two patients were enrolled in the current study, among whom 39 were assessable for efficacy and all assessable for toxicity. One complete response and 18 partial responses were confirmed, giving an overall response rate of 45.2% (95% confidence interval (CI); 31.7–59.7%). At a median follow-up of 7.7 months, the median time to progression and median overall survival was 5.7 (95% CI; 4.3–7.2) months and 9.9 (95% CI; 7.8–12.0) months, respectively. Grade 3/4 neutropenia occurred in 11 patients (26.1%) and febrile neutropenia was observed in four patients (9.5%). The common non-haematologic toxicity was fatigue (grade 1/2, 61.9%) and nausea (grade 1/2, 47.7%). The combination of docetaxel and oxaliplatin was found to be well tolerated and effective in patients with advanced gastric cancer.</P>

Supplementation of oil-based inactivated H9N2 vaccine with M2e antigen enhances resistance against heterologous H9N2 avian influenza virus infection

Park, J.K.,Lee, D.H.,Cho, C.H.,Yuk, S.S.,To, E.O.,Kwon, J.H.,Noh, J.Y.,Kim, B.Y.,Choi, S.W.,Shim, B.S.,Song, M.K.,Lee, J.B.,Park, S.Y.,Choi, I.S.,Song, C.S. Elsevier Scientific Pub. Co 2014 Veterinary microbiology Vol.169 No.3

Avian influenza virus (AIV) subtype H9N2 has been evolving rapidly and vaccine escape variants have been reported to cause circulation of infections and economic losses. In the present study, we developed and evaluated ectodomain of the AIV matrix 2 (M2e) protein as a supplementing antigen for oil-based inactivated H9N2 vaccine to increase resistance against vaccine escape variants. AIV H9N2 M2e antigen was expressed in Escherichia coli and supplemented to inactivated H9N2 oil emulsion vaccine. Specific pathogen-free chickens received a single injection of inactivated H9N2 oil emulsion vaccines with or without M2e supplementation. At three weeks post vaccination, hemagglutination inhibition tests and enzyme-linked immunosorbent assays were performed to determine serological immune responses. Challenge study using a vaccine escape H9N2 variant was performed to evaluate the efficacy of M2e supplementation. M2e antigen supplemented in oil emulsion vaccine was highly immunogenic, and a single M2e-supplemented vaccination reduced challenge virus replication and shedding more effectively than non-supplemented vaccination.

수정진동자를 이용한 고분자 감응성막의 유기가스 응답특성

권영수,김정명,유승엽,장상목,김영한 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

It is very useful to use piezoelectric device as transducer of gas sensor. AT-cut quartz crystal with 9 MHz resonant frequency can precisely measure about 1 nanogram as mass sensitivity. There are two different type of Gas sensor. One is the gas sensor coated with functional films which has selectivity to gas. The other is to use pattern recognition and array of quartz crystal with different coating materials, which don't have any selectivity to organic gases. In this paper, we used polymers as coating materials, which has thermal and mechanical stability and investigated the possibility of pattern recognition using new parameter in flow system. Our purpose is to develope gas sensor using pattern recognition and neural network.