• KSBB Journal
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• v.32 no.3
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• pp.193-198
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• 2017

Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. ${\alpha}2,6$-Sialyltransferase (ST), which plays a key role in the attachment of ${\alpha}2,6-sialic$ acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of ${\alpha}2,6-ST$ can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as ${\alpha}2,6-ST$. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and ${\alpha}2,6-sialic$ acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of ${\alpha}2,3-sialic$ acid in wild type cells, 70.9% of total sialylated N-glycans were composed of ${\alpha}2,6-sialic$ acid in transfected cells. In conclusion, overexpression of ${\alpha}2,6-ST$ in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of ${\alpha}2,6-sialic$ acid, which is more resemble to human-like structure of glycosylation.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.29-34
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• 2005

W/O/W (water-in-oil-in-water) type multiple emulsion was applied to improve the storage stability of an antagonistic microorganism, Burkholderia gladioli. Encapsulation of microorganism into a W/O/W emulsion was conducted by using a two-step emulsification method. W/O/W emulsion was prepared by the incorporation of B. gladioli into rapeseed oil and the addition of polyglycerin polyriconolate (PGPR) and castor oil polyoxyethylene (COG 25) as the primary and secondary emulsifier, respectively. Microcrystalline cellulose was used as an emulsion stabilizer. To evaluate the usefulness of W/O/W emulsion formulation as a microbial pesticide for controlling the bacterial wilt pathogen (Ralstonia solanacearum), the storage stability and antagonistic activity of emulsion formulation were tested in vitro. The storage stability test revealed that the viability of formulated cells in emulsion was higher than that of unformulated cells in culture broth. At $4^{\circ}C$, the viabilities of formulated cells and unformulated cells at the end of 20 weeks decreased to about 2 and 5 log cycles, respectively. At $37^{\circ}C$, the viability of formulated cells decreased to only 2 log cycles at the end of storage. On the other hand, the viable cells in culture broth were not detected after 13 weeks. In activity test, formulated cells in emulsion were more effective in inhibiting the growth of pathogen than unformulated cells in culture broth. Unformulated cells completely lost their antagonistic activity during storage under similar conditions. The W/O/W multiple emulsion formulation was shown to be useful as the novel liquid formulation for biological control.

• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.393-398
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• 1999

Somatic cell nuclear transfer is an efficient technique for the multiplication of elite livestock, engineering of transgenic animals, cell therapy and xenotransplantation, and analyzing the interactions between nucleus and cytoplasm, for various agricultural, biomedical and research purposes. Since the first somatic cell clone lamb was born, tremendous progress has been made toward developing technology for animal cloning. Viable farm animals and mice have now been produced by nuclear transfer using various fetal and adult somatic cells as nuclei donors. Transgenic clones were also produced from nuclear transfer of transfected somatic cells. In the future, somatic cell nuclear transfer will provide more numerous opportunities, both in basic and appled research as well as immediate uses in the generations of superior clone and transgenic animals. However, further technology refinement and improved understanding of the process are essential for commercial and basic research applications.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.59.2-59.2
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• 2011

We have demonstrated ink-jet printed indium tin oxide (ITO) and indium tin zinc oxide (IZTO) electrodes for cost-efficient organic solar cells (OSCs). By ink-jetting of crystalline ITO nano-particles and performing a rapid thermal anneal at $450^{\circ}C$, we were able to obtain directly patterned-ITO electrodes with an average transmittance of 84.14% and a sheet resistance of 202.7 Ohm/square without using a conventional photolithography process. The OSCs fabricated on the directly patterned ITO electrodes by ink-jet printing showed an open circuit voltage of 0.57 V, short circuit current of 8.47 mA/cm2, fill factor of 44%, and power conversion efficiency of 2.13%. This indicates that the ITO directly-patterned by ink-jet printing is a viable alternative to sputter-grown ITO electrodes for cost-efficient printing of OSCs due to the absence of a photolithography process for patterning and more efficient ITO material usage.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.251-252
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• 2008

Throughput and quality-of-service (QoS) over multi-cell environments are two of the most challenging issues that must be addressed when developing next generation wireless network standards. Currently, multiple-input/multiple-output (MIMO), inter-cell coordination and multi-hop relay technologies are viable options for improving channel capacity or coverage extension. Nevertheless, severe QoS degradation occurs in the outer region of multi-cells due to significant interference from neighboring cells or relay stations, thereby limiting overall performance. Therefore, we propose a scheme which adapted to hybrid relaying.

• Journal of Microbiology
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• v.43 no.2
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• pp.196-203
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• 2005

Here, we attempted to evaluate the activity of artificially transconjugated multiple plasmids in 'designer biocatalysts' for the bioremediation of cocontaminated sites under nonselective conditions. We observed profound losses in the percent survivals of artificially transconjugated plasmid activity ($66 - 78\%$ loss immediately after freeze-drying, $99.45 - 99.88\%$ loss by the end of 6 months storage) in reconstituted Pseudomonas sp. KM12TC. Such unpredictable high losses of this particular plasmid appeared to clearly be a deleterious effect. However, even after 6 months of storage, the cells remained able to degrade $95\%$ of phenol within 9 days, and the full effiux of$^%${73} As, as compared to that of the non-freeze-dried cells, was successfully achieved 4 to 9 days later. These results indicate that 'stable designer biocatalysts' can remain viable, even after freeze-drying and 6 months of storage.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.148-152
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• 2004

Bacillus polyfermenticus SCD and polyfermenticin SCD, named tentatively as the bacteriocin produced by B. polyfermenticus SCD, showed antimicrobial activity against Helicobacter pylori KCTC 2948 growth. When crude polyfermenticin SCD was added to the growing H. pylori cells, viable cell numbers were reduced, indicating antimicrobial action. The antimicrobial effect was increased remarkably at higher concentrations of polyfermenticin SCD and longer exposure. Morphological changes were observed in the bacteriocin-treated cells; in the exponential phase, they appeared as shrunken rods, while in the stationary phase, they showed coccoid forms.

• Natural Product Sciences
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• v.9 no.2
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• pp.60-63
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• 2003

Effect of grape seed extract (GSE) against Candida albicans was examined under in-vitro and in-vivo conditions. The GSE was extracted in ethanol. In-vitro results from an agar diffusion susceptibility assay showed the GSE inhibited C. albicans growth. This anticandidal effect was at dose-dependency. In experiments with animals, mice that received the GSE (0.5 mg per mice), intravenously (i.v.), before i.v.-infection wish viable C. albicans yeast cells survived longer than diluent (buffer)-received control mice. In contrast, when GSE was given to mice after the mice were infected with the yeast cells, these mice showed a similar survival rate as compared to control mice that received no treatment with the GSE. Taken together, these data indicate that GSE has prophylactic effect but not therapeutic effect against disseminated candidiasis.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.221-221
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• 2014

The current energy crisis in many countries has led to the search of an efficient renewable energy source. Among those the solar energy is the most abundant and easily available. However harvesting the solar energy requires a much efficient device. Lot of research has been done in this regard and so far the efficiency of traditional solar cell stands around ~50% and for PET films it is much lesser. The potential application of PET films in the solar cells can be very promising provided the fact that the PET film is lighter and logistically more viable. There is a lot of work that is being done to increase the efficiency of PET based solar cells. The base electrode plays a vital role in increasing the efficiency of the cell.

• Journal of the Korean Solar Energy Society
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• v.28 no.3
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• pp.21-26
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• 2008

Solar cells are renewable energy source which is not only environmentally friendly but also economically viable. For that matter, thin film materials are in observed with great in terest by a number of sources throughout the nations. Among these, CdTe (Cadium telluride) and CIS (copper indium diselenide) are the latest commercial products that are gathering attention in the solar cells markets. However there are some downsides to this newly invention. Since the materials are embedded, in the occasion of damage, certain amount of module residue can be released to water or soil. This paper outlines the results of our outdoor leaching experiments on photovoltaic (PV) samples broken into small fragments and been observed for 1 year.