• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.173-176
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• 1999

Bioassay-guided fractionation of a $H_2O$ extract of the roots of Gentiana scabra has furnished 5-(hydroxymethyl)-2-furfural (1) as an inhibitory compound for nitric oxide (NO) production in murine macrophage RAW 264.7 cells stimulated with $interferon-{\gamma}$ plus lipopolysaccharide. Compound 1 showed the moderate inhibition of NO production with $IC_{50}$ value of $803\;{\mu}M$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.207-210
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• 2002

This paper is concerned with the experiments on the active vibration control of a plate with piezoceramic sensors and actuators. The natural frequencies of the composite plate featured by a piezo-film sensor and piezo-ceramic actuator are calculated by using the modal analysis method. Modal coordinates are introduced to obtain the state equations of the structural system. Six natural frequencies were considered in the modelling, because robust control theory which has inherent robustness to structured uncertainty is adopted to suppress the transients vibrations of a glass fiber reinforced(GFR) composite beam. A robust controller satisfying the nominal performance and robust performance is designed using robust theory based on the structured singular value. Simulations were carried out with the designed controller and effectiveness of the robust control strategy was verified by results.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.388-394
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• 2011

Mume fructus is the roasted fruits of Prunus mume and has been used as traditional chinese medicine. In this study, mume fructus extracts were prepared by three different methods including hot water extract (sample1), fermentation extract using Lactobacillus (Sample2-LP and sample-LA) and ethanol extract (sample3). Total polyphenol and flavonoid contents were improved by fermentation process, compared to water extract. Sample 3 showed the highest activity in DPPH radical scavenging. The cytotoxicity of the sample 2-LP was in the range of 83.3% cell viability at $300{\mu}g/m{\ell}$ concentration. Mume fructus extracts in a concentration-dependent manner inhibited melanogenesis and NO synthesis was inhibited. Specifically, the extracts fermented by L. plantarum (sample2-LP) showed higher anti-oxidant activity, anti-inflammatory and skin whitening activity than other extracts. It suggests that sample 2-LP could be potentially used as a resource of materials for functional cosmetics.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.137-144
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• 1994

Spherical multicellular aggregates of adult rat hepatocytes (spheroid) which have tissue like structure, were formed and immobilized in the pores of polyurethane foam (PUF) which was used as a culture substratum. These hepatocyte/spheroids, about 100 $\mu\textrm{m}$ in diameter, have maintained higher differentiated functions than those of hepatocyte/monolayer for about 3 weeks in serum-free medium. Then, we designed a prototype module of an artificial liver support system using a PUF/spheroid packed-bed, in which hepatocyte/spheroids were immobilized at high density. The urea synthesis activity of the artificial liver was maintained at least 10 days in 100% rat blood plasma. We start examining the performance of hybrid artificial liver in an ex vivo extracorporeal experiment with an acute hepatic failure rat.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.19-24
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• 1996

Carbamates are generally used as insecticide, thus 5.7-dichloro-8~hydroxyquinolinyl- N-ethylcarbamate was newly synthesized. Its physical properties were determined and chemical structure was identified by means of I.R., nmr in addition to elemental analysis. The yield of addition, using triethylamine as catalyst, 5.7-dichloro-8-hydroxyquinoline and isocyanate was better than that of condensation of 5.7-dichloro-8-hydroxyquinoline with carbamoylchloride. The effct of the compound on rabbit's ileum, and antibacterial activity against Staphylococcus aureus, Salmonella typhi, Echerichia coli, and Pseudomonas aeruginosa were examined. The present organic synthesized compound showed the bacteriostatic action on salmonella typhi, escherichia coli, and pseudomonas aeruginosa, but no otherwise effect of contraction of rabbit's ileum in the concentration of $250 \mu g/ml$.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.251-254
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• 2009

A new type of dye-sensitized solar cells(DSCs) based on Ti-mesh electrode without using TCO layer is fabricated for high-efficient and low-cost solar cell application. The TCO-Iess DSCs sample is composed of a [glass/ dye sensitized $TiO_2$ layer/ Ti-mesh electrode/ electrolyte/ metal counter electrode]. The Ti-mesh electrode with high conductivity can collect electrons from the $TiO_2$ layer and allows the ionic diffusion of $I^-/I_3{^-}$ through the mesh hole. Thin Ti-mesh (${\sim}40{\mu}m$ in thickness) electrode material is processed using rapid prototype method. Electrical performance of as-fabricated DSCs is presented and discussed in detail.

• MALSORI
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• no.49
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• pp.63-75
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• 2004

Most existing telephone speech transmitted in current public networks is band-limited to 0.3-3.4 kHz. Compared with wideband speech(0-8 kHz), the narrowband speech lacks low-band (0-0.3 kHz) and high-band(3.4-8 kHz) components of sound. As a result, the speech is characterized by the reduced intelligibility and a muffled quality, and degraded speaker identification. Bandwidth extension is a technique to provide wideband speech quality, which means reconstruction of low-band and high-band components without any additional transmitted information. Our new approach considers to exploit harmonic synthesis method for reconstruction of low-band speech over the CELP coded speech. A spectral distortion measurement and listening test are introduced to assess the proposed method, and the improvement of synthesized speech quality was verified.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1074_1075
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• 2009

A new type of dye-sensitized solar cells(DSCs) based on Ti-mesh electrode without using TCO layer is fabricated for high-efficient low-cost solar cell application. The TCO-less DSCs sample is composed of a [glass/ dye sensitized $TiO_2$ layer/ Ti-mesh electrode/ electrolyte/ metal counter electrode]. The Ti-mesh electrode with high conductivity can collect electrons from the $TiO_2$ layer and allows the ionic diffusion of $I^-/I_3^-$ through the mesh hole. Thin Ti-mesh ($\sim40{\mu}m$ in thickness) electrode material is processed using rapid prototype method. Electrical performance of as-fabricated DSCs is presented and discussed in detail.

• Journal of Powder Materials
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• v.10 no.6
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• pp.436-442
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• 2003

The magnetic Nd-Fe-B powders were prepared by a thermochemical method, consisting of the processes of spray-drying, debinding, milling, H$_2$-reduction, Ca-reduction, and washing. The optimum process conditions were studied by microstructural and thermal analysis. The resultant Nd-Fe-B powder was spherical with the size of 1 ${\mu}{\textrm}{m}$. Effects of the process parameters of each step on the microstructure of the powders were investigated, and their magnetic properties were evaluated.

• Journal of Biomedical Engineering Research
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• v.13 no.1
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• pp.55-64
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• 1992

AB -type block copolymers of poly($\tau$-benzyl L-glutamate) (PBLG, a segment) and polyoxypropylene (POP, Bsegment) were synthesized and they were reacted with polyoxypropylene his(6-aminohexyl) (POE) to enhance the hydrophilicity of the poly- mers. The degree of swelling of the POE -crosslinked block copolymers (CPB -2) was higher than that of the block dopolymers (PB). The amount of 5-fluorouracil re- leased from CPB-2 block copolymers was greater than that from the PB block copol- ymers when they were incubated in the same period. These results indicate that the amount of 5-fluorouracil released from the matrices is proportional to the hydrophilicity of the polymers. Observing polymer surfaces by scanning electron mi- croscope, pores (diameter ; $0.5-1.5{\mu}$m) were appeared on the surface of CPB-2