• Journal of Korean Dental Science
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• v.8 no.2
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• pp.57-64
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• 2015

Purpose: This study was conducted to determine cell viability and differentiation capability of human periodontal ligament (PDL) cells and to elucidate the effects of cryopreservation on the activity of human third molar PDL cells by comparing PDL cells with and without cryopreservation. Materials and Methods: Human PDL fibroblasts obtained from immature third molars were cultured and divided into two groups. The experimental group was cryopreserved with a slow freezing rate of $0.5^{\circ}C/min$ from $4^{\circ}C$ to $-35^{\circ}C$ followed by plunging in liquid nitrogen at $-196^{\circ}C$ and cultured after fast thawing. The control group was cultured without cryopreservation. Cell viability, growth capacity and morphology were evaluated in both groups. Bivariate statistics were used to compare 2 groups and linear mixed model analysis was used to investigate the growth trends difference over time. Result: Cell viability and growth capacity were not significantly different between the 2 groups (P>0.05). Cultured cell of both groups showed fibroblast-like in appearance, and there were no significant differences in morphology between 2 groups. The mixed model analysis revealed no significant difference of growth capacity between 2 groups over time (${\beta}=-0.0009$; P=0.138). Conclusion: This study demonstrates that cryopreservation under control does not affect the biological properties of PDL cells, supporting the feasibility of autotransplantation of cryopreserved impacted third molars.

• Molecular & Cellular Toxicology
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• v.1 no.4
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• pp.237-247
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• 2005

Several features of the implant surface, such as roughness, topography, and composition play a relevant role in implant integration with bone. This study was conducted in order to determine the effects of various thin layer hydroxyapatite (HA) coatings on anodized Ti surfaces on the biological responses of a human osteoblast-like cell line (MG63). MG63 cells were cultured on A (100 nm HA coating on anodized surface), B (500-700 nm HA coating on anodized surface), C ($1{\mu}m$ HA coating on anodized surface), and control (non HA coating on anodized surface) Ti. The morphology of these cells was assessed by SEM. The cDNAs prepared from the total RNAs of the MG63 were hybridized into a human cDNA microarray (1,152 elements). The appearances of the surfaces observed by SEM were different on each of the four dental substrate types. MG63 cells cultured on A, C and control exhibited cell-matrix interactions. It was B surface showing cell-cell interaction. In the expression of several genes were up-, and down-regulated on the different surfaces. The attachment and expression of key osteogenic regulatory genes were enhanced by the surface morphology of the dental materials used.

• Journal of Electrochemical Science and Technology
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• v.7 no.3
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• pp.190-198
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• 2016

Application of fuel cell to produce renewable energy for commercial purpose is limited by the high cost of Pt based electrode materials. Development of inexpensive, high energetic electrode is the need of the hour to produce pollution free energy using bio-fuel through a fuel cell. Ni-Cu and Ni-CeO₂-Cu electrode materials, electro synthesized by pulse current have been developed. The surface morphology of the electrode materials is controlled by different deposition parameters in order to produce a high current from the electro-oxidation of the fuel, the ethanol. The developed materials are electrochemically characterized by Cyclic Voltammetry (CV), Chronoamperometry (CA) and Potentiodynamic polarization tests. The results confirm that the high current is due to their enhanced catalytic properties viz. high exchange current density (i₀), low polarization resistance (R_p) and low impedance. It is worthwhile to mention here that the addition of CeO₂ to Ni-Cu has outperformed Pt as far as the high electro catalytic properties are concerned; the exchange current density is about eight times higher than the same on Pt surface. The morphology of the electrode surface examined by SEM and FESEM exhibits that the grains are narrow and sub spherical with 3D surface, containing vacancies in between the elongated grains. The fact has enhanced more surface area for electro oxidation of the fuel, giving rise to an increase in current. Presence of Ni, CeO₂, and Cu is confirmed by the XRD and EDXS. Fuel cell fabricated with Ni-CeO₂-Cu material electrode is expected to produce clean electrical energy at cheaper rates than conventional one, using bio fuel the derived from biomass.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.399-402
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• 1998

Electroluminescent(EL) devices based on organic thin films have attracted lots of interests in large-area light-emitting display. One of the problems of such device is a lifetime, where a degradation of the cell is possibly due to an organic layers thickness, morphology and interface with electrode. In this study, light-omitting organic electroluminescent devices were fabricated using Alq$_3$(8-hydroxyquinolinate aluminum) and TPD(N,N'-diphenyl-N,N'-bis(3-methylphenyl(1-1\`-biphenyl]-4,4'-diamine). Where Alq$_3$ is an electron-transport and emissive layer, TPD is a hole-transport layer. The cell structure is ITO/TPD/Alq$_3$/Al and the cell is fabricated by vacuum evaporation method. In a measurement of current-voltage characteristics, we obtained a turn-on voltage at about 9 V. We also investigated stability of the devices using buffer layer with blend of PEI (Poly ether imide) and TPD by varying mot ratios between ITO and Alq$_3$. In current-voltage characteristics measurement, we obtained the turn-on voltage at about 6 V and observed an anomalous behavior at 3∼4 V. And we used other buffer layer of PEDT(3,4-pyrazino-3',4'-ethylenedithio-2,2',5,5'-tetrathiafulvalenium) with ITO/PEDT/TPD/Alq$_3$Al structure. We observed a surface morphology by AFM(Atomic Force Microscopy), UV/visible absorption spectrum, and PL(Photoluminescence) spectrum. We obtained the UV/visible absorption peak at 358nm in TPD and at 359nm in Alq$_3$, and the PL peaks at 410nm in TPD and at 510nm in Alq$_3$. We also studied EL spectrum in the cell structure of ITO/(TPD+PEI)/Alq$_3$/Al.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.73-80
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• 2016

An in vitro assay following culture of endometrial epithelial cells is essential for understanding epithelial cell function in reproduction. Several diverse techniques have been developed for isolating endometrial epithelial cells, although an optimal technique has not been identified. In this study, we describe a sedimentation-adherence (S-A) isolation technique with a high-yield cell-separating ability to isolate endometrial epithelial cells from 8-week-old female C57BL/6 mice. We analyzed total cell number, viability, morphology, and expression of cytokeratin 18 as an endometrial epithelial cell-specific marker in cells isolated using a mechanical method compared to the S-A technique. There were no significant differences in the total number, viability, or morphology of the putative endometrial epithelial cells with either method. In contrast, significantly more endometrial epithelial cells harvested using the S-A method were positively stained for cytokeratin 18 than those isolated using the mechanical method. These results confirm that the S-A method is more efficient for retrieving endometrial epithelial cells than a mechanical method.

• The Journal of Internal Korean Medicine
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• v.33 no.3
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• pp.272-283
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• 2012

Objectives : The purpose of this study was to investigate the mechanism of protective effect of Jinmu-tang (JMT, Zhenwu-tang) extract on $H_2O_2$-induced cell death in C6 glial cells. Methods : Cultured C6 glial cells of white mice were pretreated with JMT extract and exposed to $H_2O_2$ for inducing cell death. We measure the cell viability by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and investigate the cell morphology using a light microscope after crystal violet (CV) staining. Reactive oxygen species (ROS) formation was analyzed using a flow cytometer and a fluorescent microscope after staining with 2'7'-dichlorofluorescein diacetate (DCF-DA). DNA fragmentation was analyzed using a flow cytometer after propidium iodide (PI) staining and nuclei morphology was investigated using a fluorescent microscope after 2-[4-amidinophenyl]-6-indo-lecarbamidine dihydrochloride (DAPI) staining. We analyzed expression of Bax, processing of procaspase-3 and poly (ADP-ribose) polymerase (PARP), and activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) by western blot method. Tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) secretion was analyzed using Quantikine kit. Results : We determined the elevated cell viability by JMT extract on $H_2O_2$-induced C6 glial cell death. ROS formation, DNA fragmentation, $I{\kappa}B{\alpha}$ phosphorylation, NF-${\kappa}B$ activation, and secretion of TNF-${\alpha}$ induced by $H_2O_2$ are inhibited by JMT extract pre-treatment. JMT extract inhibits Bax expression, processing of caspase-3 and PARP that are critical biochemical markers of apoptotic cell death. Conclusions : These results suggest that JMT extract has a protective effect on $H_2O_2$-induced C6 glial cell death in various pathways.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.32-35
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• 2002

In this study, we investigated the mechanism of cell death in rhabdovirus-infected cells, chinook salmon embryonic cell line (CHSE-2l4) infected with hirame rhabdovirus (HIRRV). Studies using light microscopy, fluorescence microscopy, TUNEL method, electron microscopy, and agarose gel electrophoresis revealed changes in the cell morphology and DNA fragmentation indicative of apoptosis in early infection. It was observed that HIRRV induced apoptosis as well as necrosis in infected cells.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.108-113
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• 2016

A miniaturized lab-scale Cu plating cell for the metallization of electronic devices was fabricated and its deposit uniformity and profile were investigated. The plating cell was composed of a polypropylene bath, an electrolyte ejection nozzle which is connected to a circulation pump. In deposit uniformity evaluation, thicker deposit was found on the bottom and sides of substrate, indicating the spatial variation of deposit thickness was governed by the tertiary current distribution which is related to $Cu^{2+}$ transport. The surface morphology of Cu deposit inside photo-resist pattern was controlled by organic additives in the electrolyte as it led to the flatter top surface compared to convex surface which was observed in the deposit grown without organic additives.

• Biomedical Science Letters
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• v.15 no.2
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• pp.147-152
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• 2009

Lycopus lucid us Turcz is well known as traditional Chinese medicine, and it has been shown to exhibit antiinflammatory, -allergic and -oxidative effect. However, its anti-cancer properties have not been examined yet. In this study, we investigated the effect of the methanol extract of Lycopus lucid us Turcz on anti-cancer effect in MCF-7 human breast cancer cells. Treatment of Lycopus lucidus Turcz extract induced apoptosis and inhibition of cell proliferation in dose- and time-dependent manner. Apoptosis in the MCF-7 cells was characterized with the changes in nuclear morphology; decrease of Bcl-2 and caspase-7 expression; and increase of cleaved poly ADP-ribose polymerase(PARP). Furthermore, treatment of Lycopus lucidus Turcz extract caused the down-regulation of cell cycle-related protein including, cdk4, cyclin D1 and E2F-1. These results suggest that Lycopus lucidus Turcz might have the therapeutic value against human breast cancer cells.

• Applied Microscopy
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• v.28 no.3
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• pp.283-297
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• 1998

Hemopoiesis and morphogenesis of the human fetal liver through from 10 to 32 weeks of gestation were investigated by light and electron microscopy. The results obtained were as follows. Hemopoiesis of fetal liver tissue was found from 10 to 32 weeks of gestation, but the hemopoiesis was decreased at 32 weeks of gestation. At the 32 weeks of gestation, matured erythrocytes were observed in the sinusoid, and formation of liver cell cord and portal triad were established. Differentiation of hepatic cell was characterized by the increase of amount of cell organelles within cytoplasm, decrease of hemopoietic cell, morphological change of nuclear envelope from folding form to round form during the developmental period. These results suggest that human fetal liver plays a hematopoietic function until bone marrow and spleen play their function, but morphology of liver at 32 weeks of gestation was differed with structure observed in liver of adult.