• Korean Journal of Optics and Photonics
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• v.11 no.4
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• pp.255-260
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• 2000

We report that the crack-free organic-inorganic hybrid silica thin films were fabricated by sol-gel process using organometallic compounds as a precursor and that we have established very reproducible fabrication condition with systematic investigation of thickness and refractive index variations for various control parameters, such as, coating type, coating speed, chemical composition, prebake and postbake temperature. Additionally, we measured and compared the change of optical property with the UV exposure dose for three different kinds of photoinitiators. Furthermore, the fabrication of Ix4 MMI optical power splitter using the sol-gel thin film provides the possibility of various applications to the optical waveguide devices. vices.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.639-642
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• 2002

A new PDP barrier rib formation technique was investigated utilizing transparent soft maid made of silicon resin. Transparent soft mold was fabricated by pouring a silicone resin into the base mold made with photosensitive glass. The photosensitive barrier rib paste was coated on the glass substrate and dried in a 90 $^{\circ}C$ convection oven for 20min. The transparent soft mold was pressed on top of the semi-dry barrier rib layer and then irradiated with a UV lamp to a total dose of $900{\sim}1000mJ/cm^2$ The soft maid was then removed from the pressed barrier rib by winding up and fine pattern of barrier rib was obtained. The photosensitive barrier rib paste makes the demolding easy due to reduced interfacial forces and shrinking of paste materials.

• Natural Product Sciences
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• v.5 no.3
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• pp.142-147
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• 1999

Tiliacora racemosa Colebr. belonging to the family Menispermaceae is the biggest store-house of diphenyl bisbenzylisoquinoline (DBBI) alkaloids. Exhaustive chemical processing of the root of T. racemosa by the application of modern separation techniques yielded a DBBI alkaloid which was identified as tiliacorine using sophisticated spectroscopic methods (UV, IR, $1^H-NMR$, Mass). Tiliacorine potentiated the sleeping time induced by standard hypnotics viz. chlorpromazine (CPZ), pentobarbitone (PB) and diazepam (DZ) in a dose dependent manner. Tiliacorine potentiated the analgesic action of standard analgesic agents viz., morphine and meperidine. It was also found to possess anti convulsive activity in the strychnine induced convulsion model.

• Natural Product Sciences
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• v.17 no.3
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• pp.206-211
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• 2011

High-performance liquid chromatography coupled to an online $ABTS^+$-based assay (online HPLC-$ABTS^+$) system was used to determine the principal antioxidants in Cudrania tricuspidata fruits. Six prenylated isoflavonoids (1 - 6) were isolated from C. tricuspidata fruits according to the online HPLC-$ABTS^+$ system. The structures of isolated compounds, alpiniumisoflavone (1), 6,8-diprenylorobol (2), 6,8-diprenylgenistein (3), pomiferin (4), 4'-methylalpiniumisoflavone (5), and osajin (6) were identified by their retention time, UV spectra, ESI-MS, and NMR data. Among these compounds, 6,8-diprenylorobol (2) and pomiferin (4) reduced A2E photooxidation in a dose dependent manner.

• YAKHAK HOEJI
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• v.45 no.6
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• pp.724-729
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• 2001

Melanogenesis is a physiological process resulted in the synthesis of melanin pigments, which has a role in protecting skin front the damaging effect of ultra-violet (UV) radiation. The main aim of the present study was to examine the effect of Ulmus davidiana var. japonica(UL) on Melanogenesis. Cells were cultured in the presence of various concentrations of Ulmus davidiana var. japonica for 48 h, and there were estimated total melanin contents as a final product and activity of tyrosinase, a key enzyme, in Melanogenesis. Among the four solvent extracts tested, EtOAc extract mostly increased tyrosinase activity, And EtOAc extract increased the melanin contents and tyrosinase activity in a dose-dependent manner. Especially It was observed that 100$\mu\textrm{g}$/ml EtOAc extract promotes melanin secretion in B16/F10 melanoma cells by 140% at 48 h treatment and activity of tyrosinase increased by 180% in the presence of same concentration. In conclusion, as for EtOAc extract treatment, there was no effect on the viability of B16/F10 cell, only to stimulate Melanogenesis.

• Macromolecular Research
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• v.11 no.5
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• pp.347-351
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• 2003

The hydrophobic ligand-containing hollow polypropylene (PP) membranes were synthesized by the mutual radiation induced graft copolymerization with glycidylmethacrylate (GMA) onto hollow PP membrane followed by the subsequent functionalization with L-phenylalanine. FT-IR, elemental analysis and UV spectroscopy were utilized to characterize copolymer composition, and degree of grafting, functionalization conversion and ${\gamma}$-globulins adsorption. The degree of grafting on the PP surface increased with the reaction time and total dose of E-beam. In the subsquent functionalization, the amount of L-phenylalanine increased with the increase in the degree of grafting and the degree of conversion was about 30%. The ${\gamma}$-globulins adsorption experiments showed that adsorption capacity had a maximum value at pH 8. The ${\gamma}$-globulins adsorption capacity in the basic pH region was higher than in the acidic pH region.

• Proceedings of the SCSK Conference
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• 1992.09a
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• pp.36-45
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• 1992

The dosal sites of 61 Koreans were exposed to increasing UVB doses in the 10mJ/$\textrm{cm}^2$ interval from 10mJ/$\textrm{cm}^2$ to 100mJ/$\textrm{cm}^2$ by solar-simulator, and at the 24hr after UV-B exposure we determined the first MED (Minimal Erythema Dose). For the precise measurements, we peformed the second exposures arround the first MED with 2.5mJ/$\textrm{cm}^2$ interval. The mean MED of all volunteers was 39.6 $\pm$ 15.7mJ/$\textrm{cm}^2$. As the distinction of sex, the means of male and female were 46.9 $\pm$ 18.1mJ/$\textrm{cm}^2$ and 31.5$\pm$8.5mJ/$\textrm{cm}^2$ respectively. According to the classification of skin type by Greiter. F.(1), the percent of skin type I to Ⅵ were 10.9%, 36.4%, 34.6%, 12.7%, 3.6%, and 1.8% respectively.

• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.154-159
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• 2015

This study was to evaluate the effect of isopropyl alcohol fraction of ultrasonication processed ginseng flower buds(GFB-IF) on the collagen synthesis activity and inhibition of MMP-1 suppression in UV-irradiated human dermal fibroblasts. The higher contents of ginsenoside Rg2(8.234%), Rh1(5.749%), F4(3.881%) in isopropyl alcohol fraction of ginseng flower buds obtained by ultrasonication process at 600W(100℃) for 16 hours. GFB-IF had collagen synthesis effect. GFB-IF induced a significant dose-dependent decrease in the expression for MMP-1 protein. These results suggest that GFB-IF is a potential candidate for the prevention and treatment of wrinkle improving.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.2
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• pp.80-87
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• 1996

Treatment efficiencies of water quality parameters such as $KMnO_4$ Demand, $UV_{254}$, Turbidity, and LAS(Linear Alkyl Sulfonate) were compared between DAF(Dissolved Air Flotation) and CGS(Conventional Gravitational Sedimentation). The experimental results showed that DAF is much more efficient in treatment of water quality parameters than CGS. The optimum pH was about 7, and optimum alum($Al_2(SO_4)_3$) dose was about 30 ppm for DAF treatment. Economic aspects were also analyzed for bath systems. Even though production cost per ton of drinking water is slightly higher in DAF than in CGS, it turned out that construction cost and land value of CGS far surpass the production cost. DAF system is superior in removal efficiency of impurities and in production cost as a whole to CGS system.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.141-147
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• 2013

The simple and facile radiation technique of the preparation of antibacterial biodegradable polymer films containing silver nanoparticles (Ag NPs) was described. The biodegradable poly(butylene adipate-co-terephthalate) (PBAT) films containing silver trifluoroacetate (Ag TFA) were prepared by a solvent casting method, and then the films were irradiated by electron beams at the various doses ranging from 20 to 200 kGy to form Ag NPs in the biodegradable polymers. The results of UV-vis and FE-SEM/EDX analyses revealed that the Ag NPs were successfully formed in the PBAT matrix during the electron beam irradiation, and their amounts were dependant on the absorbed dose and Ag TFA concentrations. Furthermore, on the basis of the results of the antibacterial test through disk diffusion and colony counting test, the irradiated PBAT/Ag TFA films exhibited the antibacterial property due to the formation of Ag NPs.