• Title/Summary/Keyword: Cell permeability

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Ceramic Green Sheet and Sintering Properties on Solvent Mixture Rate of Electrolyte for Solid Oxide Fuel Cells Fabrication (유기 용매 혼합비에 따른 고체산화물 연료전지 전해질 지지체용 세라믹 그린 시트성형 및 소결 특성)

  • Moon, Bong-Hwa;Lee, Kyung-Min;Lim, Kyoung-Tae;Lee, Chung-Hwan;Lee, Heun-Young;Yoon, Jung-Rag
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.6
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    • pp.426-430
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    • 2012
  • The properties of green sheet were investigated in order to understanding an effects of organic solvent mixture ratio for solid oxide fuel cells fabrication. The purpose of this work is to optimize the slurry condition using the design of experiment to improve green sheet properties. The elongation increased with increasing amount of binder and solvent. With increasing amount of solvent, the air permeability increased but the tensile strength decreased. The best properties of the green sheet appeared amount of the binder 17 wt%, solvent 35 wt% and powder 48 wt%. The optimum condition of green and sintered density for solid oxide fuel cells fabrication was obtained in the sample pressured at 800 $kgf/cm^2$.

The Characteristic of Titanium Composites Including of Nano-sized TiNx for Stack Separator

  • Park, Sung-Bum;Ban, Tae-Ho;Woo, Heung-Sik;Kim, Sung-Jin
    • Journal of Powder Materials
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    • v.17 no.2
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    • pp.123-129
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    • 2010
  • The fabrication of interconnect from titanium powders and $TiN_x$ powders is investigated. Corrosion-resistant titanium and $TiN_x$ are used as reinforcement in order to reveal high heat and corrosion resistance at the elevated temperature. We fabricated the plates for interconnect reinforced with $TiN_x$ by mixing titanium powders with 10 wt.% of nano-sized $TiN_x$. Spark Plasma Sintering (SPS) was chosen for the sintering of these composites. The plate made of titanium powders and $TiN_x$ powders demonstrates higher corrosion resistance than that of the plate of titanium powders alone. The physical properties of specimens were analyzed by performing hardness test and biaxial strength test. The electrochemical properties, such as corrosion resistance and hydrogen permeability at high temperature, were also investigated. The microstructures of the specimens were investigated by FESEM and profiles of chemical compositions were analyzed by EDX.

Transdermal Delivery of Porcine Placenta Extracts using Linolenic Acid-based Emulsion Formulations

  • Kim, Dong-Chan;Noh, Sang-Myoung;Park, Ki-Tae;Kim, Young-Bong;Baek, Kwang-Hyun;Oh, Yu-Kyoung
    • Journal of Pharmaceutical Investigation
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    • v.37 no.5
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    • pp.281-286
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    • 2007
  • For transdermal delivery of porcine placenta extract (PPE), various emulsion formulations were prepared and evaluated. Polysorbate surfactants were used as emulsifiers and various C-18 unsaturated fatty acids as enhancers. The skin permeation of PPE was tested using a cellulose nitrate membrane-loaded Franz cell apparatus. Among emulsifiers, Tween 20 provided higher penetration effect than did Tween 80. Meanwhile, of various fatty acids, linolenic acid (18:3) revealed the highest skin permeation of PPE than the other C-18 unsaturated fatty acids. Stability of PPE emulsions was determined by cycles of freezing and thawing processes. The stability of emulsions depended on the percentage of Tween 20. Minimum 20% of Tween 20 was required to stabilize emulsions at room temperature for several days. Taken together, our results suggest that Tween 20 and linolenic acids might be key components to formulate PPE emulsion to provide the desirable skin permeability and stability.

In vitro and Cellular Antioxidant Activity of Arginyl-fructose and Arginyl-fructosyl-glucose

  • Lee, Jung-Sook;Kim, Gyo-Nam;Lee, Sang-Hyun;Kim, Eui-Su;Ha, Kyoung-Soo;Kwon, Young-In;Jeong, Heon-Sang;Jang, Hae-Dong
    • Food Science and Biotechnology
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    • v.18 no.6
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    • pp.1505-1510
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    • 2009
  • Arginyl-fructose (AF) and arginyl-fructosyl-glucose (AFG) were chemically synthesized and purified. Their in vitro and cellular antioxidant activity was investigated using oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity assay, respectively. The peroxyl radical scavenging activity of AF was much higher than that of AFG, which was in good agreement with their reduction capacity to donate electrons or hydrogen atoms. On the other hand, the hydroxyl radical scavenging activity of AF was weaker than that of AFG, which was consistent with their metal chelating activity, suggesting that AFG-$Cu^{2+}$ complex may be less redox-active than AF-$Cu^{2+}$ complex due to 1 glucose molecule attached. The cellular antioxidant activity of AF and AFG appeared to depend on both their permeability into cell membrane and the scavenging activity on peroxyl or hydroxyl radicals. These results indicate that AF and AFG, Maillard reaction products, may have a high potential as a material for the development of nutraceutical food with antioxidant activity.

Development of Postharvest Technologies to Preserve High Quality of Greenhouse Horticultural Commodities and their Processed Products -Development of Natural Antimicrobial Agents for preserving Greenhouse Fresh Produce(II) (남부지역 시설원예산물의 저장성 향상 및 가공품 개발에 관한 연구-시설원예산물의 선도유지를 위한 항균소재의 개발을 중심으로(II)-)

  • 조성환;정순경;김영록
    • Food Science and Preservation
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    • v.7 no.1
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    • pp.1-7
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    • 2000
  • To develop natural antimicrobial agents for keeping qualities of postharvested greenhouse produce the antimiocrobial actions of Polygonum cuspidatum Sieb. et Zucc. extract , which showed remarkable antimicrobial effects against microorganism causing the postharvest decay of greenhouse produce, were investigate. In the inhibitory experiment of enzymes related to energy production metabolism hexokinase activities decreased to 73% and 68% by treating with Polygonum cuspidatum Sieb. et.Zucc. extract and Eugenia caryophyllata Thumnberg extract in comparison with control, respectively. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed that microbial cell membrane was destroyed by treating with the dilute extract solution. this change of celluloar membrane permeability could be identified in the experiment that 0-nitrophenyl-${\beta}$-D-galactopyrano-side(ONPG), the artificial substrate of ${\beta}$-galactosidase, was hydrolyzed in the presence of the extract, indicating that the membrane was perturbed. The separation and identification of the most antimicrobialo substances isolated from Polygonum cuspidatum Sieb et. Zucc. extract and Eugenia caryophyllata Thunberg extract were carried out by using gas chromatography and mass spectrometry 9GC/MSD), which were identified as eugenol. As a result, the functionality of Polygonum cuspidatum Sieb. et Zucc. extract and Eugenia caryophyllata Thunberg extract as antimicrobial agents for keeping qualities of postharvested greenhouse produce may be recommended.

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Effect of Ginseng Alcohol Extract on Short-Circuit Current Across the Frog Skin (인삼 알콜 추출물이 개구리 피부를 통한 short circuit current에 미치는 영향)

  • Lee, Joong-Woo;Kim, Hee-Joong;Kang, Doo-Hee
    • The Korean Journal of Physiology
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    • v.10 no.1
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    • pp.35-40
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    • 1976
  • In an attempt to examine the effect of ginseng on sodium transport across the biological membrane, we have studied effects of ginseng alcohol extract on the short-circuit current(SCC) and the $Na^+-K^+$-activated ATPase activity in isolated frog skin preparations. 1. Ginseng alcohol extract applied to the mucosal surface of the frog skin significantly increased SCC at low concentration($1{\sim}10mg%$) but decreased SCC at higher concentration($50{\sim}250mg%$). 2. Similarly, when the drug was added to the serosal bathing medium, the SCC was stimulated at low doses($5{\sim}25mg%$) and inhibibited at high doses($50{\sim}250mg%$). 3. $Na^+-K^+$-activated ATPase activity of the frog skin epidermal homogenate was significantly inhibited by ginseng alcohol extract, the effect being proportional to the concentration of the drug in the incubation mixture. These results may suggest that a low dose of ginseng alcohol extrat enhances the transepithelial sodium transport probably by increasing the permeability of outer membrane of the transporting cell to sodium ion, whereas a high dose of drug reduces the sodium transport primarly by inhibiting $Na^+-K^+$ ATPase mediated active transport step.

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Action of Dammarane-Type Triterpenoidal Glycosides and Their Aglycones on Lipid Membranes (지질막에 대한 Dammarane-Type Triterpenoidal Glycosides와 그 Aglycones의 작용)

  • Kim, Yu.A.;Park, Kyeong-Mee;Hyun, Hack-Chul;Song, Yong-Bum;Shin, Han-Jae;Park, Hwa-Jin
    • Journal of Ginseng Research
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    • v.20 no.3
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    • pp.269-273
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    • 1996
  • We investigated the effects of ginseng glycosides and their aglycones on processes of single ion channel formation and channel properties. The glycosides, Rg, and Rb, , and their aglycones, 20-(S)-protopanaxatriol (PT) and 20-(S)-protopanaxadiol (PD) increased the membrane permeability for ions. PT, PD, Rg1, and Rb1; at concentrations of 0.5, 3.0, 10.0 and 30.0 $\mu\textrm{g}$/ml respectively; Induced single ion channel fluctuations with the life times in the range of 0.1~1005 in open states and conductances from 5 to 30 pS in 1 M KCI. At high concentrations of these substances, rapid fluctuations of transmembrane ion current with amplitude from hundred pS to dozen nS were observed. Against other substances, ginsenoside Rbl began to increase the membrane conductance at concentration of about 60 $\mu\textrm{g}$/ml without fluctuation of single ion channel. Membranes treated with PT, PD, Rg1 and Rb1 are more permeable to K+, than to Cl while zero current membrane potentials with 10 gradients of KCI were 12, 16, 8, 25 mV respectively. Key words : Membrane conductance, single ion channel, ginsenosides.

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Transdermal Delivery System of Triamcinolone Acetonide from a Gel Using Phonophoresis

  • Yang Jae-Heon;Kim Dae-Keun;Yun Mi-Young;Kim Tae-Youl;Shin Sang-Chul
    • Archives of Pharmacal Research
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    • v.29 no.5
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    • pp.412-417
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    • 2006
  • Triamcinolone acetonide (TA) is a corticosteroid that is used in the systemic and topical treatment of many inflammatory diseases. In this study, a phonophoretic drug delivery system was designed to enhance the TA permeability and the influence of ultrasound was examined. In order to establish the transdermal delivery system for TA, a hydrophilic carbopol gel containing TA was prepared after adopting phonophoresis. A permeation study through mouse skin was performed at $37^{\circ}C$ using a Franz diffusion cell, and the ultrasound treatment was carried out for 10 h. The level of TA permeation through the skin was evaluated under various ultrasound conditions including the frequency (1.0, 3.0 MHz), intensity (1.0, $2.5W/cm^2 $), and duty cycle (continuous, pulse mode) using a 0.5% TA gel. The highest permeation was observed under the ultrasound treatment conditions of low frequency, high intensity, and in continuous mode.

A Cellular Physiological Study on the Effects of Korean Ginseng - Part IV. Effects on the Penetration of Glucose - (인삼의 효과에 관한 세포생리학적 연구 - 제 IV 편 포도당의 투과에 미치는 영향 -)

  • Jung, Noh-Pal
    • The Korean Journal of Physiology
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    • v.5 no.1
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    • pp.15-18
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    • 1971
  • The effects of ginseng on the penetration of glucose into Saccharomyces cerevisiae were studied by determining the amount of glucose in the supernatant of the glucose broth medium in which some dose of water extracts of ginseng or saponin were added and the yeast was cultured for 1 hour. 1. In the 1 hour culture with 0.04%, 0.08%, 0.16%, 0.32% and 0.64% dry ginseng glucose broth medium, the penetration rate of glucose into yeast was increased 4.76%, 7.96%, 10.09%, 9.08% and 7.48% respectively. 2. In the 1 hour culture with $10^{-6}%,\;10^{-5}%,\;10^{-4}%,\;10^{-3}%,\;and\; 10^{-2}%$ of saponin glucose broth medium, the penetration rate of glucose into yeast was increased 3.05%, 6.57%, 5.595, 4.44%. and 2.87% respectively. 3. Since the highest increasing percentage of penetration of ginseng and saponin were 10.19% and 5.89% respectively, the increasing rate of the ginseng was about twice that of the saponin. Therefore it could be concluded that the saponin contained in ginseng and other unkown components of ginseng affect the cell permeability.

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Organic-inorganic Nano Composite Membranes of Sulfonated Poly(Ether Sulfone-ketone) Copolymer and $SiO_2$ for Fuel Cell Application

  • Lee, Dong-Hoon;Park, Hye-Suk;Seo, Dong-Wan;Kim, Whan-Gi
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.487-488
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    • 2006
  • Novel bisphenol-based wholly aromatic poly(ether sulfone-ketone) copolymer containing pendant sulfonate groups were prepared by direct aromatic nucleophilic substitution polycondensation of 4,4-difluorobenzophenone, 2,2'-disodiumsulfonyl-4,4'-fluorophenylsulfone (40mole% of bisphenol A) and bisphenol A. Polymerization proceeded quantitatively to high molecular weight in N-methyl-2-pyrrolidinone at $180^{\circ}C$. Organic-inorganic composite membranes were obtained by mixing organic polymers with hydrophilic $SiO_2$ (ca. 20nm) obtained by sol-gel process. The polymer and a series of composite membranes were studied by FT-IR, $^1HNMR$, differential scanning calorimetry (DSC) and thermal stability. The proton conductivity as a function of temperature decreased as $SiO_2$ content increased, but methanol permeability decreased. The nano composite membranes were found to posse all requisite properties; Ion exchange capacity (1.2meq./g), glass transition temperatures $(164-183\;^{\circ}C)$, and low affinity towards methanol $(4.63-1.08{\times}10^{-7}\;cm^2/S)$.

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