• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.23-29
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• 1999

An yttria-stabilized zirconia(YSZ) thin film on a porous NiO-YSZ substrate for an anode support type solid oxide fuel cell(SOFC) was prepared by an electrophoretic deposition(EPD). Deposition condition and film properties in order to obtain the homogeneous YSZ thin film from the EPD solution with different polarity were studied. In different case of alcohol solution, hydrogen gas was produced in aqueous solution from the electrolyte reaction under constant current above 0.138 mA /$\textrm{cm}^2$.Its reaction generated the bubble-formed defect in the deposited film and decreased weight of the film. The homogeneous YSZ thin film was formed in alcohol solution at a constant current, 0.035 mA /$\textrm{cm}^2$ for 10 s.

• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.295-300
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• 2016

Flavonoids are widely reported to be beneficial to human health. Among flavonoids, in general, flavonoid aglycons have better biological activities than flavonoid glycosides, in that aglycons can easily penetrate through cell membrane because of their low polarity. Therefore, kaempferol, quercetin and various their glycosides were evaluated for their abilities to inhibit NO and $PGE_2$ productions in LPS-induced RAW 264.7 cells. Of these flavonoids and flavonoid glycosides, kaempferol-7-O-${\beta}$-D-glucoside(kp-7-glu) which possesses a glycoside at C-7 position of the A ring in kaempferol, potently inhibited NO, $PGE_2$ and $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 productions in LPS-induced RAW 264.7 macrophages.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.545-555
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• 2015

Oxyresveratrol (trans-2,3',4,5'-tetrahydroxystilbene) has been receiving increasing attention because of its astonishing biological activities, including antihyperlipidemic, neuroprotection, antidiabetic, anticancer, antiinflammation, immunomodulation, antiaging, and antioxidant activities. Oxyresveratrol is a stilbenoid, a type of natural phenol and a phytoalexin produced in the roots, stems, leaves, and fruits of several plants. It was first isolated from the heartwood of Artocarpus lakoocha, and has also been found in various plants, including Smilax china, Morus alba, Varatrum nigrum, Scirpus maritinus, and Maclura pomifera. Oxyresveratrol, an aglycone of mulberroside A, has been produced by microbial biotransformation or enzymatic hydrolysis of a glycosylated stilbene mulberroside A, which is one of the major compounds of the roots of M. alba. Oxyresveratrol shows less cytotoxicity, better antioxidant activity and polarity, and higher cell permeability and bioavailability than resveratrol (trans-3,5,4'-trihydroxystilbene), a well-known antioxidant, suggesting that oxyresveratrol might be a potential candidate for use in health functional food and medicine. This review focuses on the plant sources, chemical characteristics, analysis, biosynthesis, and biological activities of oxyresveratrol as well as describes the perspectives on further exploration of oxyresveratrol.

• Korean Journal of Pharmacognosy
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• v.37 no.3
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• pp.130-135
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• 2006

The present study describes the preliminary evaluation of the cytotoxic activity of the extracts from Inula japonica. I. japonica was extracted with methanol, ethanol, acetone, and water, and then cytotoxic activity of these extracts were evaluated. The cytotoxic activity of each extract was assessed by the MTT-dye reduction assay. Both ethanol and acetone extracts from I. japonica showed the cytotoxic activity against the HT-29 human colon cancer cells. Furthermore, the ethanol extract was fractionated with n-hexane, diethyl ether, ethyl acetate, and water according to degree of Polarity, The diethyl ether fraction showed the highest cytotoxic activity against HT-29 cells, but the other fractions showed low cytotokic activity. In addition, diethyl ether layer also showed the cytotoxic activity against various tumor cells, such as human colon carcinoma SW620, human cervix adenocarcinoma HeLa, and human breast adenocarcinoma MCF-7 cells as well as HT-29 cells. These studies support that extracts of I. japonica may be a potential candidate as possible chemotherapeutic agent against human cancer.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.66-71
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• 2011

Various single solvents were tested to find the effective solvent for the extraction of algae oil from wet-form Chlorella minutissima. In the case of single solvents, their extractabilities for algae oil were increased with their polarity because the water in wet algae cell is to form a solvent shell around the lipids. Based on these results, the wet-form algae samples were treated with a polar alcohol solvent and then a nonpolar solvent was added in algae residue. In the algae oil extraction by ethanol/n-hexane, total lipid contents were 40-50% and composition of triglyceride in extracted oil was 46.50%. Considering solvent toxicity of conventional solvent mixture such as chloroform and methanol for algae oil extraction, the ethanol/n-hexane system was identified as the effective one for the oil extraction from wet-form Chlorella minutissima.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.26 no.2
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• pp.45-63
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• 1996

In attempt to determine radiation effect on the mandibular condyle of the growing rat, 27 white female rats (Sprague-Dawley) were divided into 3 groups and irradiated respectively 5Gy, 10Gy, 20Gy using MK Cell Irradiator. Mandibular condyles from rats on the day of 1, 7, 14 after the irradiation day were obtained, sectioned sagittally and examined by light microscopy, and thereafter middle portion through anteroposterior direction on the sagittal plane was selected to examine the ultrastructural change by transmission electron microscopy. The obtained results are followings. 1. In the proliferative zone some cells showed little organelles in case of 5Gy irradiation, in addition the number of degenerative cells increased and in case of 10Gy irradiation, and in case of 20 Gy irradiation total number of cells decreased. 2. In the hypertrophic zone, narrowing of width and partial disorder in hypertrophic process were noted in case of 5 Gy irradiation, and more prominent narrowing of width and more irregular disorder in hypertrophic process in case of both 10Gy and 20Gy irradiation. 3. In the upper hypertrophic zone some chondrocytes seemed to be dying and the polarity of nuclei could not be seen, if any. 4. The periodic observation showed the severest change at day 7 and the signs of recovery at day 14 after irradiation.

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.275-281
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• 2004

We have studied the effect of polarity, current density, current duration, crosslinking density, swelling ratio, and permeation enhancers on the transdermal flux of ketoprofen from acrylamide hydrogel. Hydrogel was prepared by free radical crosslinking polymerization of acrylamide. Drug loading was made just before transport experiment by soaking the hydrogel in solution containing drug. In vitro flux study using hairless mouse skin was performed at $36.5^{\circ}C$ using side-by-side diffusion cell, and the drug was analysed using HPLC/UV system. The result showed that, compared to passive flux, the total amount of drug transported increased about 18 folds by the application of $0.4\;mA/cm^2$ cathodal current. Anodal delivery with same current density also increased the total amount of drug transported about 13 folds. It seemed that the increase in flux was due to the electrorepulsion and the increase in passive permeability of the skin by the current application. Flux increased as current density, the duration of current application and loading amount (swelling duration) increased. As the cross linking density of the hydrogel increased, flux clearly decreased. The effect of hydrophilic enhancers (urea, N-methyl pyrrolidone, Tween 20) and some hydrophobic enhancers (propylene glycol monolaurate and isopropyl myristate) was minimal. However, about 3 folds increase in flux was observed when 5% oleic acid was used. Overall, these results provide some useful information on the design of an optimized iontophoretic delivery system of ketoprofen.

• Macromolecular Research
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• v.9 no.6
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• pp.303-312
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• 2001

The fabrication of liquid crystal display (LCD) panels involves several thermal processes such as imidization of the alignment layer (AL) and annealing of the rubbed polyimide AL. The nature of these processes on the LC alignment, especially on the pretilt angle (Θ$\_$p/) has been systematically studied, employing various types of polyimide structures. The imidization effect depends on the nature of polyimid precursors; Θ$\^$p/ increases with the degree of the imidization for the main-chain type of ALs, due to the decrease in the surface polarity, but this relation is not applicable to the alkylated ones in which the steric effect at the AL surface by the aliphatic side chains is dominant. Annealing of the rubbed polyimide AL deteriorates its rubbing-induced molecular orientation and subsequently the overlying LC alignment, resulting in the decrease in Θ$\_$p/. Especially, annealing of the LC cell affects the LC-AL interaction as well as the AL orientation and thus its effect on LC alignment depends sensitively on the nature of LC-polyimide interface; aromatic moiety in the polyimide structure gives better thermal stability of LC alignment while fluorinated polyimide ALs induce the less stable alignment.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.6
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• pp.44-51
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• 1999

The electrical conduction mechanism of high dielectric $(Ba,Sr)TiO_3$ (BST) thin film capacitor, which is the promising cell capacitor for high density DRAM, was investigated in low field region (<0.2MV/cm). It is known that the current in the low field region consists of dielectric relaxation current and leakage current. The current-time (I-t) measurement technique under the constant voltage was used for extracting successfully each current component. The conduction mechanism of the BST capacitor was deduced from the dependency of the current on the measurement temperature, strength of electric field, the polarity of applied electric field and post annealing process. From these results, it was suggested that the dielectric relaxation current and the leakage current are originated from the redistribution of internally trapped electron by hopping process and Pool-Frenkel conduction mechanism, respectively. It was also concluded that traps causing these two current components are due to oxygen vacancies within the BST film.

• Clean Technology
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• v.14 no.4
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• pp.248-255
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• 2008

The volume expansion of three ionic liquids (ILs) in the presence of supercritical carbon dioxide has been measured at pressures up to 32 MPa and at temperatures from 313.15 to 333.15 K in a high-pressure view cell. The imidazolium-derivative ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$]), and 1-octyl-3-methylimidazolium tetrafluoroborate ([omim][$BF_4$]) were employed in this research. The effects of pressure, temperature, nature of anion and cation as well as the water content on the volume expansion of ILs by absorbing $CO_2$ were investigated experimentally. The volume expansion was higher for the ILs with longer cationic alkyl group and for the ILs with lower anion polarity. The lower the water content, the lower the temperature, or the higher the pressure, the higher was the expansion of IL phase.