• Journal of Life Science
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• v.18 no.2
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• pp.175-179
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• 2008

Cornus controversa is a long-lived woody species mostly distributed in East Asia. Random amplified polymorphic DNA (RAPD) markers were used to investigate the genetic diversity and population structure of Korean populations of this species. A high level of genetic variation was found in seven populations of C. controversa. The mean genetic diversity (H) was 0.222 across populations, varying from 0.200 to 0.238. Eighty of the 93 loci (86.0%) showed detectable polymorphism in at least one population. Total genetic diversity values ($H_T$) varied between 0.192 and 0.231, giving an average overall polymorphic loci of 0.212. The interlocus variation of genetic diversity within populations ($H_S$) was high (0.167). Mean of genetic diversity in C. controversa was higher than average values for species with similar life history traits. The sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. On a per locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.169 to 0.278 with a mean of 0.216, indicating that about 21.6% of the total genetic variation was among populations. An indirect estimate of the number of migrants per generation (Nm=1.893) indicated that gene flow was extensive among Korean populations of C. controversa.

• IMMUNE NETWORK
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• v.13 no.5
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• pp.199-204
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• 2013

Syntenin is an adaptor molecule containing 2 PDZ domains which mediate molecular interactions with diverse integral or cytoplasmic proteins. Most of the results on the biological function of syntenin were obtained from studies with malignant cells, necessitating exploration into the role of syntenin in normal cells. To understand its role in normal cells, we investigated expression and function of syntenin in human lymphoid tissue and cells in situ and in vitro. Syntenin expression was denser in the germinal center than in the extrafollicular area. Inside the germinal center, syntenin expression was obvious in follicular dendritic cells (FDCs). Flow cytometric analysis with isolated cells confirmed a weak expression of syntenin in T and B cells and a strong expression in FDCs. In FDC-like cells, HK cells, most syntenin proteins were found in the cytoplasm compared to weak expression in the nucleus. To study the function of syntenin in FDC, we examined its role in the focal adhesion of HK cells by depleting syntenin by siRNA technology. Knockdown of syntenin markedly impaired focal adhesion kinase phosphorylation in HK cells. These results suggest that syntenin may play an important role in normal physiology as well as in cancer pathology.

• Fibers and Polymers
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• v.3 no.1
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• pp.38-42
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• 2002

Polypropylene filaments were spun from a mixture of PP chips of two different Melt Flow Index (MFI) (3 MFI and 35 MFI). A significant difference was observed in the melting characteristics of the resultant filaments from either of the individual components as observed from the DSC. The main difference being in the degree of melting achieved at any temperature in the initial stages of the melting range, which was found to be higher in case of the filaments spun from the b]end. These filaments were then thermally bonded using silicon oil bath and heated roller method. Subsequently the bond strength of the filaments was measured on the Instron Tensile Tester using the loop technique. The values of the world strengths obtained from the blend were compared with those made from the individual component. It was found that the bond strength of the bonds obtained from the blended filament at a given temperature was higher than that of the bonds made from the filaments of either of the individual components, which is also suggested by the DSC curves. The difference in the bond strength was found to be as high as 25% in case of the blend with 60:40 composition ratios of the 3 MFI and 35 MFI components respectively.

• BMB Reports
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• v.32 no.3
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• pp.273-278
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• 1999

Cytolysin produced by Vibrio vulnificus has been known to be lethal to mice by increasing vascular permeability and neutrophil sequestration in the lung. In the present study, a cytotoxic mechanism of V. vulnificus cytolysin on the neutrophil was investigated. Cytolysin rapidly bound to neutrophils and induced cell death, as determined by the trypan blue exclusion test. V. vulnificus cytolysin caused the depletion of cellular ATP without the release of ATP or lactate dehydrogenase. Formation of transmembrane pores was evidenced by the rapid efflux of potassium and 2-deoxy-D-[$^3H$]glucose from cytolysin-treated neutrophils. It was further confirmed by the rapid flow of monovalent ions in the patch clamp of cytolysin-treated neutrophil membrane. The pore formation was accompanied by the oligomerization of cytolysin monomers on the neutrophil membrane as demonstrated by immunoblot, which exhibited a 210 kDa band corresponding to a tetramer of the native cytolysin of $M_r$ 51,000. These findings indicate that V. vulnificus cytolysin rapidly binds to the neutrophil membrane and oligomerizes to form small transmembrane pores, which induce the efflux of potassium and the depletion of cellular ATP leading to cell death without cytolysis.

• BMB Reports
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• v.48 no.3
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• pp.184-189
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• 2015

Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) is known to protect neurons from neurodegeneration during ischemia/reperfusion injury. We recently reported that ROS-mediated oxidative stress promotes phosphorylation of endogenous SHP-2 in astrocytes and complex formation between caveolin-1 and SHP-2 in response to oxidative stress. To examine the region of SHP-2 participating in complex formation with caveolin-1, we generated three deletion mutant constructs and six point mutation constructs of SHP-2. Compared with wild-type SHP-2, binding of the N-SH2 domain deletion mutant of SHP-2 to p-caveolin-1 was reduced greatly, using flow cytometric competitive binding assays and surface plasmon resonance (SPR). Moreover, deletion of the N-SH2 domain of SHP-2 affected $H_2O_2$-mediated ERK phosphorylation and Src phosphorylation at Tyr 419 in primary astrocytes, suggesting that N-SH2 domain of SHP-2 is responsible for the binding of caveolin-1 and contributes to the regulation of Src phosphorylation and activation following ROS-induced oxidative stress in brain astrocytes.

• Journal of the Korean Society of Visualization
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• v.12 no.1
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• pp.49-53
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• 2014

In this study, a novel FDR-SPC is first synthesized in this study. The drag reducing functional radical such as PEGMA (Poly(ethylene) glycol methacrylate) has been utilized to participate in the synthesis process of the SPC. The types of the baseline SPC monomers, the molecular weight and the mole fraction of PEGMA were varied in the synthesis process. The resulting SPCs were coated to the substrate plates for the subsequent hydrodynamic test for skin friction measurement. In a low-Reynolds number flow measurement using PIV (Particle Image Velocimeter), a significant reduction in Reynolds stress was observed in a range of specimen, with the maximum drag reduction being 15.9% relative to the smooth surface.

• Korean Journal of Materials Research
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• v.21 no.3
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• pp.149-155
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• 2011

We investigated tribological characteristics of diamond-like carbon (DLC) in a condition with carbon nanotube (CNT) content of 1wt% in aqueous solution. Si-DLC films were deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process on Al6061 aluminum alloy. In this study, the deposition of DLC films was carried out in vacuum with a chamber pressure of 10-5 to 10-3 Torr achieved by mechanical pump followed by turbo molecular pump. The surface adsorbed oxygen on the Aluminum substrates was removed by passing Ar gas for 10 minutes. The RF power was maintained at 500W throughout the experiment. A buffer layer of HMDSO was deposited on the substrate to improve the adhesion of DLC coating. At this point CH4 gas was introduced in the chamber using gas flow controller and DLC coating was deposited on the buffer layer along with HMDSO for 50 min. The thickness of 1 ${\mu}m$ was obtained for DLC films on aluminum substrates The tribological properties of as synthesized DLC films were analyzed by wear test in the presence of dry air, water and lubricant such as CNT ink.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.88-97
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• 1999

To characterize the effects of Gilgyung-Tang(GGT) on cellular proliferation and viability of normal lung fibroblast cells, we examined the cell cycle progression and cell cycle-related gene expression in T3891 using a flow cytometry and a quantitative RT-PCR analysis. 1. The significant surpression effect of cellular proliferations of GGT was observed in proportion to a certain concentration and time. 2. GGT was identified to induce apoptotic death of damaged cells by treatment with a DNA-damage agent and etoposide, while it stimulated the recovery of cellular viability of normal cells. 3 The significant reductions of mRNA expression of PCAN, c-Fos treated by GGT were observed. 4. The significant inductions of mRNA expression of p53, CDKN1. Gadd45 treated by GGT were observed. 5. The apoptosis caused by the reduction of Bcl-2 genes was significant and the Bax genes were increased. but the amount of Fas genes were not changed. These results strongly suggest that GGT triggers arrest of the cell cycle at G1 phase, and thus causes an inhibition of cellular proliferation of human normal lung cells through the transcriptional up-regulation of cell cycle inhibitory genes and down-regulation of induction of cell cycle stimulating genes respectably.

• BMB Reports
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• v.32 no.6
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• pp.567-572
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• 1999

We have previously shown that a DNA fragment is responsible for the anticoagulatory effect of an earthworm, Lumbricus rubellus. The anticoagluant increased the activated partial thromboplastin time (APTT) and also inhibited the thrombin activity observed with either N-${\alpha}$-p-tosyl-L-arginine methyl ester (TAME) or H-D-phenyl-alanyl-L-pipecoil-L-arginine-p-nitroanilide (S-2238). Since trypsin digestion of the anticoagulant further increased the APTT, the possible presence of a regulatory protein for the anticoagulatory DNA was investigated by digesting the anticoagulant with trypsin and isolating the DNA fragment with C4-reversed phase HPLC. The DNA fragment lacking a regulatory protein was eluted in the flow-through fraction, and analyzed with thrombin and activated factor X. Activated factor X activity was more strongly inhibited than thrombin activity. For DNA digestion, we treated the anticoagulant with DNase and purified the DNA-binding protein with a FPLC Resource-S cation exchange column. The regulatory protein, with an $M_r$ of 55.0 kDa, reduced the anticoagulatory effect of the DNA fragment.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.11-19
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• 2005

First, methods of numerical analysis of gas-particle flows is classified into micro, meso and macro scale approaches based on the concept of multi-scale mechanics. Next, the explanation moves on to discrete particle simulation where motion of individual particles is calculated numerically using the Newtonian equations of motion. The author focuses on the cases where particle-to-particle interaction has significant effects on the phenomena. Concerning the particle-to-particle interaction, two cases are considered: the one is collision-dominated flows and the other is the contact-dominated flows. To treat this interaction mathematically, techniques named DEM(Distinct Element Method) or DSMC (Direct Simulation Monte Carlo) have been developed DEM, which has been developed in the field of soil mechanics, is useful for the contact -dominated flows and DSMC method, developed in molecular gas flows, is for the collision-dominated flows. Combining DEM or DSMC with CFD (computer fluid dynamics), the discrete particle simulation becomes a more practical tool for industrial flows because not only the particle-particle interaction but particle-fluid interaction can be handled. As examples of simulations, various results are shown, such as hopper flows, particle segregation phenomena, particle mixing in a rotating drum, dense phase pneumatic conveying, spouted bed, dense phase fluidized bed, fast circulating fluidized bed and so on.