• KSBB Journal
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• v.6 no.3
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• pp.249-254
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• 1991

Permeabilization of Zymomonas mobilis with CTAB(Cetyltrimethylammoniumbromide) was investigated in order to obtain stable process for sorbitol production in the immobilized system. The optimum conditions for sorbitol formation were obtained in the case of using cells treated with 0.2% CTAB at$ 4^{\circ}C$ for 10 min. Permeabilized cells were treated with glutaraldehyde to cross-link the internal enzyme for the improvement of the enzyme stability. In this way, no significant loss of enzyme activity was apparent during 30-day operation in a continuous process. The productivity of the continuous process at dilution rate 0.2h-1 was 6.51g/1/h for sorbitol. The CTAB permeabilized cells could be used to produce sorbitol in the long term continuous process.

• Toxicological Research
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• v.14 no.3
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• pp.371-377
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• 1998

We have cloned a soluble type human folate receptor(hFR type${\gamma}$) from human thymus cDNA library using the PCR amplification technique. To examine whether hFR type${\gamma}$ has a folate transport activity, CHO cells were transfected with the pcDNAhFR${\gamma}$ expression plasmid, and the stable cell line CHO/hFR${\gamma}$ expressing a high level of the hFR type${\gamma}$ was identified by northern and western blot analysis. The CHO/hFR${\gamma}$ cells produced a [$H^3$]folic acid binding protein in the culture medium. However, we couldn't detect any cell surface [$H^3$] folic acid binding and transport activities. The growth of the CHO/hFR${\gamma}$ cells was more rapidly inhibited than the wild type CHO cells in the low concentration folic acid media. These observations indicate that although soluble type human folate receptor can bind [$H^3$]folate, it does not involve in folate transport.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.3
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• pp.199-205
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• 2005

Polycrystalline cadmium sulfide(CdS) thin films were deposited on glass substrate by chemical bath deposition(CBD) and vacuum evaporation (VE) techniques. VE-CdS films consisted primarily of hexagonal phase, whereas CBD CdS films containing primarily the cubic form. VE-grown films were shown to have better crystallinity than CBD-grown films. The grain size of the CBD films is smaller than the ones of VE films. VE-CdS films exhibited relatively high transmittance in the above-gap region and band gap compared with CBD films. However, CdTe solar cells with these low quality CBD-CdS layers yield higher and more stable characteristics. Current-voltage-temperature measurements showed that the current transport for both cells was controlled by both tunneling and interface recombination but the cells with CBD-CdS displayed less tunneling.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.75-78
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• 2002

Difference in the structure of AC PDP cells makes the cells have various discharge characteristics. Therefore, a ramp-reset must be adjusted for the stable driving of AC PDP. If any ramp-reset can reduce the difference in discharge characteristics between cells, the conditions of the address discharge could become almost the same. It is very important to understand these to design a good driving waveform. In this paper, we proved the mentioned facts with the change of barrier rib heights.

• Journal of Microbiology
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• v.37 no.2
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• pp.90-96
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• 1999

The core protein of the hepatitis C virus (HCV) is a multifunctional protein. The HCV core protein was reported to regulate cellular gene expression and transform primary rat embryo fibroblast cells. However, the role of the core protein in the pathogenesis of HCV-associated liver diseases is not well understood. To investigate the functional role of the core protein in cytophathogenicity, we have constructed stable expression systems of full length or truncated HCV core protein lacking the C-terminal hyderophobic domains and established HepG2 cell clones constitutively expressing the core protein. The full length core protein was localized in the cytoplasm and the C-terminal truncated core protein was localized in the nucleus. HepG2 cells expressing nuclear, truncated core protein showed elevated cell death during cultivation compared to untransfected cells and full length core-expressing cells. In the treatment with bleomycin, both cell clones expressing full length or truncated core protein appeared to be more sensitive to blemoycin than the parental HepG2 cells. These results suggest that the core protein may play a role in HCV pathogenesis promoting apoptotic cell death of infected cells.

• The Korea Journal of Herbology
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• v.22 no.3
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• pp.47-55
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• 2007

Objectives : This study was carried out to know the effect of Cordyceps sinensis(CS) on the immune inflammatory responses of spleen cells and function or immunocytes of the normal mouse. Methodes: We investigated effects of Cordyceps sinensis(CS) on normal immunocytes, gene expression of IL-12, IFN-$\gamma$ and surface-receptor expression of $CD3_{\epsilon}+$, CD4+, CD8+ and CD19+ cells were measured by PCR and FACS. Results : CS activated adhisive splenic cells morphologically as compared with the control group in the normal spleen cells of BALB/C mice. CS enhanced gene expression of interleukin-12 and interferon-gamma in a dose-dependent manner in the normal spleen cells of BALB/C mice. CS reduced the number of activating cells and surface-receptor expression of CD4+, CD8+ and CD19+. Conclusion : Cordyceps sinensis will be used as a stable remedium in the auto-immune diseases.

• The Korea Journal of Herbology
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• v.22 no.3
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• pp.67-76
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• 2007

Objectives : This study was carried out to know the effect of Cordyceps sinensis(CS) on the immune inflammatory responses of athritis and function. Methodes : To analyse immunomodulatory effects of CS, cytotoxicity and inhibition of proliferation against of synovial cells, gene expression of inflammatory mediators such as TNF-$\alpha$, IL-1$\beta$ and IL-6, DNA-binding activity of $NF-_{k}B$ and AP-1 were measured in vitro. Results : CS didn't show cytotoxicity against human synovial cells and inhibited proliferation of human synovial cells in a dose-dependent manner in combination with rIL-6. CS reduced the gene expression of IL-6 and IL-1$\beta$ in a dose- dependent manner but didn't reduced that of TNF-$\alpha$ in human synovial cells. CS reduced the binding-activity of $NF-_{k}B$ and also reduced that of AP-1 remarkably. Conclusion: We found out that Cordyceps sinensis has immunomodulatory effect of suppressing synovial cells. And Cordyceps sinensis will be used as a stable remedium in the auto-immune disease in the future.

• BMB Reports
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• v.48 no.12
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• pp.668-676
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• 2015

Pluripotent stem cells only exist in a narrow window during early embryonic development, whereas multipotent stem cells are abundant throughout embryonic development and are retainedin various adult tissues and organs. While pluripotent stem cell lines have been established from several species, including mouse, rat, and human, it is still challenging to establish stable multipotent stem cell lines from embryonic or adult tissues. Based on current knowledge, we anticipate that by manipulating extrinsic and intrinsic signaling pathways, most if not all types of stem cells can be maintained in a long-term culture. In this article, we summarize current culture conditions established for the long-term maintenance of authentic pluripotent and multipotent stem cells and the signaling pathways involved. We also discuss the general principles of stem cell maintenance and propose several strategies on the establishment of novel stem cell lines through manipulation of signaling pathways.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.59-63
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• 1994

Chromosome variation in callus cells initiated from different cytogenetic type plane of Scilla scilloides Complex was analysed Considerable variation in both chromosome number and struchure was found in type AA, while no autosomal variation was detected in type BB callus cells. In allotetraploid AABB, two hypoploid cells were fount while a hypoploid cell and three hyperploid cells were found in eutetraploid cells of BBBB. Autosomes in callus cells derived from the plant with B-chromosomes were more stable than those from the plant without B-chromosome. We doubt that B-chromosomes have a selective function for the autosomes in culture of S. scilloides Complex.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1100-1105
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• 2006

During involution of the mammary gland after the lactation period, the gland undergoes an extensive epithelial cell death. In our previous study, overexpression of an extracellular proteinase inhibitor (Expi) gene accelerated apoptosis of mammary epithelial cells. Here we found that expression of the cathepsin D gene was induced in the Expi-overexpressed apoptotic cells. To understand the role of cathepsin D in apoptosis, we transfected cathepsin D gene into mammary epithelial HC11 cells and established the stable cell lines overexpressing the cathepsin D gene. We found that overexpression of the cathepsin D gene partially induced apoptosis of mammary epithelial cells. Expression patterns of the cathepsin D gene were examined in mouse mammary gland at various reproductive stages. Expression of the cathepsin D gene was increased during involution stages compared to lactation stages, and highest expression levels were shown at involution on day 4. We also examined expression of the cathepsin D gene in various mouse tissues. Mammary gland at involution on day 2 showed highest levels of cathepsin D mRNA of the mouse tissues that we examined. Liver tissues showed high levels of cathepsin D expression. These results demonstrate that cathepsin D may contribute to the apoptotic process of mammary epithelial cells.