• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.2
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• pp.103-118
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• 2012

In this study, the cellular protective effect of isoquercitrin against $H_2O_2$ and rose bengal-indued HaCaT cell damage was investigated. The ethosome and elastic liposome for enhanced transdermal delivery were prepared. Particle size, loading efficiency and cumulative permeated amounts of them were evaluated. Isoquercitrin didn't show any characteristic cytotoxicity at 50 ${\mu}M$. When HaCaT cells were treated with 5 mM $H_2O_2$ and 25 ${\mu}M$ rose bengal, isoquercitrin protected the cells against the oxidative damage in a concentration dependent manner (6.25 ~ 50 ${\mu}M$). The size of 0.03 % isoquercitrin loaded ethosome was 222.85 nm and the loading efficiency was 82.26 %. The ethosome loaded with 0.03 % isoquercitrin was stable and maintained the constant particle size for 2 weeks after being prepared. The ethosome exhibited more enhanced skin permeability than general liposome and ethanol solution. The optimal ratio of lipid to surfactant of 0.1 % isoquercitrin loaded elastic liposomes was observed to be 89 : 5 through evaluating particle size (341.2 nm), deformability index (59.89), loading efficiency (54.3 %), and skin permeability (54.4 %).

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.407-415
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• 2013

In this study, we investigated the antioxidant activities on HaCaT and the whitening effects on B16F1 melanoma cells of Dendropanax morbifera leaf extract. In an antioxidative activity assay using HaCaT cells, the ethyl acetate ($50{\mu}g/ml$) and aglycone fractions ($25{\mu}g/ml$) of the D. morbifera leaf extract didn't exhibit any characteristics of cytotoxicity. When HaCaT cells were exposed to a single large dose ($800mJ/cm^2$) of UVB, the extracts protected the cells against UVB radiation. When HaCaT cells were treated with 10 mM $H_2O_2$ and $4{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/ml$) and aglycone ($6.25{\sim}25{\mu}g/ml$) fractions protected the cells against oxidative damage in a concentration dependent manner. When the whitening effects of D. morbifera leaf extract were tested in melanoma B16/F1 cells treated with the a-melanocyte stimulating hormone (${\alpha}$-MSH), the extracts inhibited ${\alpha}$-MSH-stimulated intra/extracellular melanogenesis in a concentration dependent manner. The inhibitory effects of the ethyl acetate and aglycone fractions of D. morbifera leaf extract were 21% and 44% at $25{\mu}g/ml$, respectively. Both are more effective than arbutin (15% at $25{\mu}g/ml$) which is known as a whitening agent. These results indicate that fractions of the D. morbifera leaf can function as cell protectants and natural antioxidants in biological systems, particularly skins exposed to UV radiation by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cells against ROS. In addition, fractions of the D. morbifera leaf can be applied to new whitening cosmetics because of their inhibitory effects on ${\alpha}$-MSH stimulated melanogenesis in B16F1 melanoma cells.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.681-685
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• 2008

Chiral separation of racemic mandelic acid was achieved on a Kromasil KR100-5CHI-TBB column. Some chromatographic parameters (resolution, number of theoretical plates, capacity factor) are calculated under different separation conditions such as changes of mobile phase compositions (hexane/t-BME = 85/15 - 10/90) as well as formic acid concentrations for adjusting pH (0.1, 0.5, 1.0 v/v%). Flow rate versus number of theoretical plates was compared to evaluate column efficiency. To determine the adsorption isotherms, PIM (Pulse Input Method) was carried out. At the concentrations of racemic mandelic acid between 0.1 and 0.3 mg/ml, L- and D-mandelic acids have the same retention times of 8.8 and 9.4 min respectively. Mandelic acid isotherms show a linear form under the concentrations of 0.3 mg/ml with eluent (hexane/t-BME = 75/25). As the concentrations of mandelic acids increase, nonlinear Langmuir isotherms were observed as $C_{S,L}=3.358C_{M,L}/(1+0.0897C_{M,L})$ for L-mandelic acid and, $C_{S,D}=3.692C_{M,D}/(1+0.1457C_{M,D})$ for D-mandelic acid.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.81-90
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• 2008

This study was carried out to investigate the effects of the organic feed on weight gain, feed conversion rate, and carcass characteristics of Hanwoo steers. Three feeding treatments(T1 : rice straw and commercial concentrates, T2 : organic hay and concentrates, T3 : organic corn silage and concentrates) for 22 months (from 6 to 28 months) were used. As a result, weight gain was not significantly different among treatments throughout this study. Also T1 tended to improve weight gain and daily weight gain without significance. The percentage of meat quality grade over the first grads ($1,\;1^+,\;1^{++}$) were 50% in the carcass of Hanwoo steers fed T1 and T2, and 70% fed T3, respectively. T2 and T3 tended to improve marbling score and oleic acid content.

• Textile Coloration and Finishing
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• v.18 no.4
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• pp.37-42
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• 2006

Two kinds of sea-island type polyester ultramicro fibers (fiber fineness : 0.01 and 0.05 denier) were treated with NaOH varying time and concentration. Surface morphology of the treated fibers with alkaline weight loss was observed by SEM. The treated effects were investigated by measuring density, melting temperature, and X-ray diffraction patterns. The surface morphology of the polyester ultramicro fiber was changed by NaOH concentration. Weight loss of 0.01d fiber was much larger than that of 0.05d fiber. Density and crystallinity were increased with weight loss of fiber. After the weight loss had finished, the density and crystallinity were decreased because of attack of island partition of the fiber. A melting temperature$(T_m)$ is $250^{circ}$ at untreated fiber on the whole and in 0.05d fiber the $(T_m)$ is $252^{circ}$ at untreated. In 0.01d fiber the $(T_m)$ was increased with weight loss of fiber.

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.1
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• pp.44-54
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• 2015

Breakwaters are the coastal structures constructed either perpendicular (shore connected) or parallel (detached) to the coast. The main function of breakwater is to create a tranquil medium on its leeside by reflecting the waves and also dissipating the wave energy arriving from seaside, resulting in ease of manoeuvrability to boats or ships to their berthing places. Different types of breakwaters are being used at present, such as rubble mound breakwater, vertical wall type breakwater and composite breakwater. The objective of this paper is to investigate reflection coefficients (Kr) and dissipation (loss) coefficients (Kl) for physical models of Quarter circle caisson breakwater of three different radii of 0.550 m, 0.575 m and 0.600 m with S/D ratio of 2.5 (S=spacing between perforations, D=diameter of perforations). The models were tested in the monochromatic wave flume of the department, for different incident wave heights (Hi), Wave periods (T) and water depths (d). It was observed that reflection coefficient increased with increase in the wave steepness (Hi/gT2) and decreased with increase in depth parameter (d/gT2) and hs/d (Height of structure including rubble base/depth of water). The loss coefficient decreased with increase in the wave steepness and increased with increase in depth parameter and hs/d.

• Journal of Life Science
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• v.19 no.12
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• pp.1802-1807
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• 2009

Platycodin D, a major component of Platycodi radix, is known to have various activities including anti-inflammatory, anti-hyperlipidemic, anti-tumor activities and others. Recently, it was reported that platycodin D inhibits fat accumulation and adipogenesis. The aim of this study was to investigate whether various adipogenic regulators are modulated by platycodin D treatment during the adipogenesis of 3T3-L1 cells. mRNA levels of terminal markers of adipogenesis such as ADIPOQ (adiponectin) and GLUT (glucose transporter) 4, which were quantified by real time PCR, were decreased by platycodin D treatment. mRNA expression of PPAR (peroxisome proliferator-activated receptor) $\gamma$ and C/EBP (CCAAT/enhaner binding protein) $\alpha$, which are central transcription factors of adipogenesis, were also decreased by platycodin D treatment. To elucidate the detailed molecular mechanism of platycodin D-induced inhibition of adipogenesis, we analyzed mRNA expression of upstream regulators of PPAR$\gamma$ and C/EPB$\alpha$. mRNA levels of the pro-adipogenic regulators, KROX20 and KLF (Kruppel-like factor) 15 were markedly down-regulated by platycodin D treatment. On the other hand, mRNA expression of CHOP (C/EBP homologous protein), an anti-adipogenic regulator, was significantly up-regulated by platycodin D treatment. mRNA levels of other pro-adipogenic regulators, C/EBP$\beta$ and C/EPB$\delta$, were not affected by platycodin D treatment, and another anti-adipogenic regulator, C/EBP$\gamma$ was also not affected by platycodin D treatment. Taken together, these results suggest that platycodin D-induced inhibition of adipogenesis is mediated by gene interactions including the down-regulation of pro-adipogenic regulators, KROX20 and KLF15, and the up-regulation of an anti-adipogenic regulator, CHOP.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.223-231
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• 1983

The productions of beta-exotoxin from sixteen Bacillus thuringiensis strains were examined by Micrococus flava primarily, and then measured by spectrophotometer during culturing in Conner and Hansen mineral salts medium at 28$^{\circ}C$. Also the toxic effects of the toxin to mice were checked. The growth of Bacillus thuringiensis K2 and BTK2-T1, -T13, -T33 and -T40 got into stationary phase at 6 hour culture and then maintained it up to 48 hours without severe fluctuation. The production of beta-exotoxin from the strains, BTK2, BTK2-T1, -T13, -T17 and -T33 appeared at 6 hour culture and the amounts of the toxin were about 40 $\mu\textrm{g}$/$m\ell$ at 6 hour culture, approximately 70 $\mu\textrm{g}$/$m\ell$ at 12 hours, approximately 85$\mu\textrm{g}$/$m\ell$ from 24 hours to 48 hours. At 48 hour-culture, BTK2 produced 80 $\mu\textrm{g}$/$m\ell$ of beta-exotoxin (5.5$\times$10$^{8}$ cells/$m\ell$, BTK2-T13 produced 84 $\mu\textrm{g}$/$m\ell$ (4.3$\times$10$^{8}$ cells/$m\ell$), BTK2-T17 produced 87$\mu\textrm{g}$/$m\ell$ (1.4$\times$10$^{8}$ cells/$m\ell$), and BTK2-T33 produced 84 $\mu\textrm{g}$/$m\ell$ (4.9$\times$10$^{8}$ cells/$m\ell$). All other serotypes also produced beta-exotoxin. At 48 hour culture, BTK-37 produced 88$\mu\textrm{g}$/$m\ell$ (6.1$\times$10$^{8}$ cells/$m\ell$), BTK-35 produced 81 $\mu\textrm{g}$/$m\ell$), and the rest of them produced less than 70 $\mu\textrm{g}$/$m\ell$. To check the toxicity of beta-exotoxin and B. thuringiensis, the cultured media with microorganisms were inoculated to mice by per os, intraperiloneal, subcutaneous and intracerebral injection, and nasal cavity inoculation for 30 days. However, the toxin did not kill all of the treated mice.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.5
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• pp.348-357
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• 2005

We have tried to analyze the SEMG interference pattern quantitatively and automatically using T/A variables ZC, TN, mSA, mSD, UCA, AIPEA, ACT and NSS. For the analysis, we have carried out experiments on 14 SEMG interference patterns recorded from the biceps brachii, first dorsal interosseus and abductor policis brevis muscles. Emphasis was placed on the following 3 points in the experiments. 1) Suitable amplitude threshold for the automatic detection of the T/A variables. 2) Variation of the T/A variables to varying $\%$MVC. 3) Variation of the T/A variables to the sustained contraction for 30 seconds. Results of the experiments showed that T/A analysis of the SEMG interference Pattern can be effective tools for diagnostic purposes instead of the conventional NEMG method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.659-664
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• 2006

This paper reports a high power 60 GHz push-push oscillator fabricated using $0.12{\mu}m$ metamorphic high electron-mobility transistors(mHEMTs). The devices with a $0.12{\mu}m$ gate-length exhibited good DC and RF characteristics such as a maximum drain current of 700 mA/mm, a peak gm of 660 mS/mm, an $f_T$ of 170 GHz, and an $f_{MAX}$ of more than 300 GHz. By combining two sub-oscillators having $6{\times}50{\mu}m$ periphery mHEMT, the push-push oscillator achieved a 6.3 dBm of output power at 59.5 GHz with more than - 35 dBc fundamental suppression. The phase noise of - 81.5 dBc/Hz at 1 MHz offset was measured. This is one of the highest output power obtained using mHEMT technology without buffer amplifier, and demonstrates the potential of mHEMT technology for cost effective millimeter-wave commercial applications.