• Biomolecules & Therapeutics
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• v.12 no.2
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• pp.62-67
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• 2004

Trauma remains one of the important sources leading to systemic inflammatory response anti sub-sequent multiple organ failure. Although hepatic microvascular dysfunction occurs during trauma, the mechanism responsible remains unclear. The aim of this study was to investigate the effect of trauma on hepatic vascular stress gene expression. Femur fracture (EFx) was induced by torsion to the femur at midshaft. Liver samples were taken for RT-PCR analysis of mRNA for gtenes of interest: endothelin-1 (ET-1), its receptors $ET_A$ and $ET_B$, nitric oxide synthases (iNOS and eNOS), cyclooxygenase-2 (COX-2), heme oxygenase-1 (HO-1), and tumor necrosis tactor-${\alpha}$ (TNF-${\alpha}$). The expression of ET-1 mRNA was significantly increased by FFx. Expression of mRNA in FFx group showed no change in $ET_A$, $ET_B$, iNOS and HO-1 and showed a slight increase of 2.2-fold and 2.7-fold for eNOS tll1d COX-2, respectively. The level of TNF-${\alpha}$ mRNA significantly increased in FFx group. In conclusion, mild trauma alone causes little change in expression of vasoactive mediators.

• Structural Engineering and Mechanics
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• v.20 no.3
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• pp.279-292
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• 2005

In this study, element loading matrices are defined for static application of classical M$\ddot{u}$ller-Breslau principle to finite element method. The loading matrices are derived from existing element matrices using Betti's law and known governing equations of F.E.M. Thus, the ordinates of influence lines and influence surfaces may be easily obtained from structural analysis for the loading matrices derived from governing equations, instead of through introduced unit force or displacement techniques. An algorithm for a computer program and comparative numerical examples are also presented to illustrate the procedure for determination of influence line and surface ordinates.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.95-108
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• 2001

A system of equations is developed for the theory of bending of thick orthotropic elastic plates which takes into account the transverse shear deformability of the plate. This system of equations is of such nature that three boundary conditions can and must be prescribed along the edge of the plate, i.e. ${\omega}=0,\;M_x=0,\;M_{xy}=0\;({\omega}=0,\;M_x=0,\;M_{xy}=0)$ at simple supported edges. It can be obtained general solution that is added complementary solution ${\omega}^e$ and paticular solution ${\omega}^p$ by an assumption of solution function. In the next paper, this analytical results will be obtained for perforated thick plates.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1716-1723
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• 2017

The rapid dissemination of extended-spectrum ${\beta}$-lactamase (ESBL)-producing Escherichia coli has significantly contributed to public health hazard globally. A total of 281 E. coli strains recovered from pigs and chickens between 2009 and 2015 in South Korea were analyzed for ESBL production. ESBL phenotypes were recognized in 14 E. coli isolates; ten and three ESBL-producing isolates carried only $bla_{CTX-M}$ and $bla_{CMY}$ genes, respectively, and one isolate harbored both genes. The predominant CTX-M and CMY types were CTX-M-15 (n = 8) and CMY-2 (n = 3). We also detected ESBL-producing isolates harboring $bla_{CTX-M-65}$, $bla_{CTX-M-14}$, $bla_{CMY-6}$, $bla_{DHA-1}$, and $bla_{TEM-1}$ genes. All ESBL-producing isolates showed resistance to the extent of the fourth generation cephalosporins, along with multidrug resistance. CTX-M-15-producing isolates showed higher MIC values than CTX-M-14- and CTX-M-65-producing isolates. The $bla_{CTX-M}$ and $bla_{CMY}$ genes have the potential to be transferable. The spreading of $bla_{CMY}$ and $bla_{CTX-M}$ genes was arbitrated mainly via Frep and IncI1 plasmids. Our isolates showed clonal diversity in PFGE analysis. This is the first report of E. coli isolates carrying $bla_{CMY-6}$ in chicken from South Korea. The emergence of CMY-6 ESBLs in a population of poultry suggests that extensive screening with long-term surveillance is necessary to prevent the dissemination of ESBL from chicken to human.

• International Commerce and Information Review
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• v.13 no.4
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• pp.23-49
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• 2011

The of this study was to establish a theoretical basis for relationship marketing exercised in the mB e-Marketplace and to empirically analyze causal relationship among e-CRM factor, together with quality and the performance of the customer relationship. The population sample of this study was the companies who had experience for using the B2B e-Marketplace, and a data analysis was made through y analysis, factor analysis, multiple regression analysis and hierarchical regression analysis, utilizing statistical package of SPSS 18.0. The result of proving the are as follows; First, the e-CRM factors(e-Marketing, e-Service, e-Sales) of B2B e-Marketplace showed the positive influence on the customer relationship quality factor. the e-CRM factors of B2B e-Marketplace showed the positive influence on the customer relationship performance factor. Third, according to the test result on the relationship between quality factor and performance factor, customer relationship quality factor(satisfaction, trust) had positive effect on performance factor. Last, for the moderating effect of switching barrier in the customer relationship quality factor(satisfaction, trust) on the B2B e-Marketplace and its performance factor(reusing intention, long-term orientation) of maintaining the relation, the subordinate variables of switching barrier(alternative attraction, switching cost) showed the positive moderating effects.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.505-510
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• 2002

The Friction Stir Welding (FSW) is a new joining method that was developed at The Welding Institute (TWI) in England in 1991. It applied heating by the rotational friction and material plastic flow. It was developed as a new joining method to solve the problems of epochally in the welding of Al alloys. In the study, 6000series of Alloy composed of AI-Mg-Si, one of the Al alloys that are utilized for shipbuilding and construction, is selected as a specimen and the numerical is executed against the welded zone of FSW. The material used in this study had the unique properties of strength and anti-corrosion, but since the welded joint of this material is easily softened by the welding heat, FSW is executed and the numerical analysis is carried out around the joint. To examine the mechanical behaviors and properties, F.E.M analysis is executed and the developed thermal-elastic-plastic [mite analysis are used.

• Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.140-150
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• 2016

Normally all manufacturing and fabrication processes introduce residual stresses in a component. These stresses exist even after all service or external loads have been removed. Residual stresses have been studied elaborately in the past and even in depth research have been done to determine their magnitude and distribution during different manufacturing processes. But very few works have dealt with the study of residual stresses formation during the casting process. Even though these stresses are less in magnitude, they still result in crack formation and subsequent failure in later phases of the component usage. In this work, the residual stresses developed in a shifter during casting process are first determined by finite element analysis using ANSYS(R) Mechanical APDL, Release 12.0 software. Initially the analysis was done on a simple block to determine the optimum element size and boundary conditions. With these values, the actual shifter component was analyzed. All these simulations are done in an uncoupled thermal and structural environment. The results showed the areas of maximum residual stress. This was followed by the geometrical optimization of the cast part for minimum residual stresses. The resulting shape gave lesser and more evenly distributed residual stresses. Crack compliance method was used to experimentally determine the residual stresses in the modified cast part. The results obtained from the measurements are verified by finite element analysis findings.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.143-150
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• 2018

This work conducted the experimental analysis on ultrasonic acoustic matching in order to measure the accuracy of gaseous fuel level values. The experimental devices were used as 12V-DC supply, control T1 board, oscilloscope (DS01072B), ultrasonic probe and pattern table. The research models were designed by ceramic assay which can determine the transmitting and receiving energies. The result of the ringing area could verify the increased characteristics in the order of D (0.180m) < E (0.184m) < B (0.204m) < A (0.234m) < F (0.244m) < C (0.247m) models based on initial 2.9V of the maximum peak voltage. From the experimental results, the model designed by Ø21*3+2t of the matching layer was notable in that the most outstanding directivity energy could be created.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.1
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• pp.57-65
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• 2012

In the present study, the antioxidative properties, inhibitory activity on tyrosinase, and active components of Eriobotrya japonica (E. japonica) leaf extract were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) of extract/fraction of E. japonica leaf was in the order 50 % ethanol extract ($22.625{\mu}g/mL$) < ethyl acetate fraction (6.75) < deglycosylated aglycone fraction (5.06). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of fraction/extracton ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescenceassay were investigated. $OSC_{50}$ of the ethyl acetate fraction, deglycosylated aglycone fraction, and ethanol extract were 0.75, 0.79, and $1.61{\mu}g/mL$, respectively. The cellular protective effects of E. japonica leaf extract on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The protective effects of extract/fraction of E. japonica leaf were increased in a in a concentration dependent manner ($5{\sim}50{\mu}g/mL$). Especially, ${\tau}50$ of ethyl acetate fraction at concentrations of $10{\mu}g/mL$ and $50{\mu}g/mL$ showed the most protective effects at 390.8 min and 1471.5 min. The inhibitory effect ($IC_50$) on tyrosinase of E. japonica leaf extracts was higher than arbutin, known as a skin-whitening agent. The order of inhibitory effects was acetate fraction ($75.25{\mu}g/mL$) < 50 % extract (74.1) < deglycosylated aglycone fraction (43.35). TLC of the ethyl acetate fraction showed 7 bands (EJL 1 - EJL 7). HPLC of the aglycone fraction exhibited 2 peaks, kaempferol and quercetin. The amounts of kaempferol and quercetin were 53.7 and 46.3 %. respectively. Therefore, The amounts of kaempferol and its glucoside were a little bit higher than quercetin and its glucoside in E. japonica leaf extract. Accordingly, these findings suggest that extracts/fractions of E. japonica leaf can function as antioxidants in biological systems, especially skin exposed to UV radiation, and protect cellular membranes against ROS. Thus, the extract/fraction of E. japonica leaf may be used in novel functional cosmetics as antioxidants against skin photoaging.

• Journal of the Korean Electrochemical Society
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• v.2 no.1
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• pp.23-26
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• 1999

The Langmuir adsorption isotherm at the $(Pt)/0.1M\;H_2SO_4$ electrolyte interface has been qualitatively analyzed using the ac impedance measurement and phase-shift method. The phase shift $(\phi)$ depends on both the cathode potential (E<0) and frequency (f) and is inversely proportional to the factional surface coverage $(\theta)$. At an intermediate frequency band (ca. $1\~100$ Hz), the phase-shift profile $(\phi\;vs.\;E)$ can be related to the fractional surface coverage $(\theta\;vs.\;E)$. The phase-shift profile $(\phi\;vs.\;E)$ can be used as an experimental method to estimate and analyze the Langmuir adsorption isotherm $(\theta\;vs.\;E)$. The equilibrium constant (K) and the standard free energy $({\Delta}G_{ads})$ of the adsorbed hydrogen atom $(H_{ads})\;and\;3\times10^{-4}$ and 20.1 kJ/mol, respectively.