• Title/Summary/Keyword: $Na^+$ pump

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Implementation of Charge-Pump Active-Matrix OLED Panel with $64\;{\times}\;64$ Pixels Using $ITO/SiO_2/ITO$ Capacitors and a-Si:H Schottky Diodes

  • Na, Se-Hwan;Seo, Jong-Wook;Kwak, Mi-Young;Shim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1267-1270
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    • 2006
  • Organic light-emitting diode (OLED) display panel with $64\;{\times}\;64$ pixels utilizing the charge-pump (CP) pixel addressing method was fabricated using conventional thin-film processes. Each pixel consists of a-Si:H Schottky diode and $ITO/SiO_2/ITO$ capacitor. It is shown that CP-OLED is technically feasible for information display and a driving voltage below $4V_{pp}$ is enough for nominal operation.

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Preparation and Characterization of Porous Polycaprolactone Membrane for Tissue Engineering (조직공학용 다공성 Polycaprolactone 멤브레인의 제조 및 특성)

  • Kim, Jin-Tae;Kim, Tae-Hyung;Choi, Jae Ha
    • Membrane Journal
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    • v.26 no.1
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    • pp.26-31
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    • 2016
  • Polycaprolactone (PCL) has been fabricated into the membrane type scaffolds of 3 dimensional pore network for the tissue engineering applications by the blade method of salt (NaCl) leaching and solution casting. In this study, the experimental designs have each conditions of drying temperature, salt particle size, salt content. The modified dispensing pump connected up to homogenizing mixer system is used for mixing the $PCL/CHCl_3$ solution and NaCl particles. The membrane fabricated use by the film applicator to poured mixed solution on the glass plate. The great pore by NaCl particles and the small pore by the evaporated $CHCl_3$ in the frame wall of great pores are multiply formed in membrane scaffolds.

A Safety Improvement for the Design Change of Westinghouse 2 Loop Auxiliary Feedwater System (웨스팅하우스형 원전의 보조급수계통 설계변경 영향 평가)

  • Na, Jang Hwan;Bae, Yeon Kyoung;Lee, Eun Chan
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.9 no.1
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    • pp.15-19
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    • 2013
  • The auxiliary feedwater is an important to remove the heat from the reactor core when the main feedwater system is unavailable. In most initiating events in Probabilistic Safety Assessment(PSA), the operaton of this system is required to mitigate the accidents. For one of domestic nuclear power plants, a design change of a turbine-driven auxiliary feedwater pump(TD-AFWP), pipe, and valves in the auxiliary system is implemented due to the aging related deterioration by long time operation. This change includes the replacement of the TD-AFWP, the relocation of some valves for improving the system availability, a new cross-tie line, and the installation of manual valves for maintenance. The design modification affects the PSA because the system is critical to mitigate the accidents. In this paper, the safety effect of the change of the auxiliary feedwater system is assessed with regard to the PSA view point. The results demonstrate that this change can supply the auxiliary feedwater from the TD-AFWP in the accident with the motor-driven auxiliary feedwater pump(MD-AFWP) unavailable due to test or maintenance. In addition, the change of MOV's normal position from "close" to "open" can deliver the water to steam generator in the loss of offsite power(LOOP) event. Therefore, it is confirmed that the design change of the auxiliary feedwater system reduces the total core damage frequency(CDF).

A Study on the Effects of Heat Pump Using Standing Column Well on Soil and Groundwater Microorganisms (스탠딩컬럼웰을 적용한 지열히트펌프의 토양 및 지하수 미생물에 대한 영향 연구)

  • Jun, Jungeui;Park, Sisam;Na, Sangmin;Rhee, Keonjoong;Park, Jaewoo
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.7
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    • pp.93-101
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    • 2009
  • Standing column well (SCW) heat pump system produces geothermal energy by the heat exchange of the groundwater. If SCW system changed the temperature of soil and groundwater, it could also change species or population of microorganisms. Therefore it is needed to research about the effect of temperature change on microorganisms to use eco-friendly geothermal energy. We produced the simulative heat pump system (SHPS) and observed the change of the soil temperature in SHPS. Characteristic analysis of microorganisms isolated from soil was performed and groundwater temperature variation was evaluated. Also the bleeding effect in SHPS was investigated and the results are included. As the results, the population of microorganisms was increased about 90%, as the groundwater temperature increased 2-3 celsius degree. However the species of microorganism was little influenced by the temperature change of the soil.

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Studies on Active Center of $(Na^{+}+K^{+})-ATPase$ in Rabbit Red Cell Membranes (토끼 적혈구막의 $(Na^{+}+K^{+})-ATPase$의 active center에 관한 연구)

  • Lim, Bo-Sang
    • The Korean Journal of Physiology
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    • v.9 no.1
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    • pp.1-11
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    • 1975
  • The present experiments were carried out to investigate the active center of sodium and potassium ion activated adenosine triphosphatase. An ATPase, activated by sodium ion Plus potassium ion in the presence of magnesium ion, and inhibited by ouabain, has been obtained from rabbit red cell ghosts. The ATPase activity was measured by inorganie phosphate released from ATP. From this values of the measured inorganic phosphate, the activity of ATPase was calculated. The following results were observed. 1. The activity of $(Na^++K^+)-ATPase$ is inhibited by ouabain. This effect may not be due to an effect on sulfhydryl groups, amino groups, carboxyl groups, imidazole groups and hydroxyl groups. 2. The $(Na^++K^+)$-activated enzyme system is inhibited by p-chloromercuribenzoate and by d nitroflurobenzene, and this effect may be due to an effect on sulfhydryl groups. These results indicate that the sulfhydryl groups is attached to sodium-potassium dependent adenosine triphosphate, an aspect of the pump. 3. The $(Na^++K^+)-activated$ enzyme system is inhibited by maleic anhydride and this inhibition is reversed by lysine. This Seems to indicate that the active center of this enzyme is the amino groups. 4. The $(Na^++K^+)$-activated enzyme system is inhibited by iodoacetamide and this inhibition is reversed by the simultaneous present of cysteine and aspartic acid in the suspension medium. This result indicates that this enzyme contains sulfhydryl groups and carboxyl groups. 5. The $(Na^++K^+)-ATPase$ activity is accelerated by adrenaline and this effect is abolished by aspartic acid. This effect of aspartic acid indicate that carboxyl group might be involved in the hydrolysis of ATP by the enzyme system. On the hydrolysis of ATP by the enzyme system. On the basis of these experiments it f·as suggested that the active center of $(Na^++K^+)-activated$ ATPase contains sulfhydryl groups, amino groups and carboxyl groups.

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Alterations in Membrane Transport Function and Cell Viability Induced by ATP Depletion in Primary Cultured Rabbit Renal Proximal Tubular Cells

  • Lee, Sung-Ju;Kwon, Chae-Hwa;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.1
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    • pp.15-22
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    • 2009
  • This study was undertaken to elucidate the underlying mechanisms of ATP depletion-induced membrane transport dysfunction and cell death in renal proximal tubular cells. ATP depletion was induced by incubating cells with 2.5 mM potassium cyanide(KCN)/0.1 mM iodoacetic acid(IAA), and membrane transport function and cell viability were evaluated by measuring $Na^+$-dependent phosphate uptake and trypan blue exclusion, respectively. ATP depletion resulted in a decrease in $Na^+$-dependent phosphate uptake and cell viability in a time-dependent manner. ATP depletion inhibited $Na^+$-dependent phosphate uptake in cells, when treated with 2 mM ouabain, a $Na^+$ pump-specific inhibitor, suggesting that ATP depletion impairs membrane transport functional integrity. Alterations in $Na^+$-dependent phosphate uptake and cell viability induced by ATP depletion were prevented by the hydrogen peroxide scavenger such as catalase and the hydroxyl radical scavengers(dimethylthiourea and thiourea), and amino acids(glycine and alanine). ATP depletion caused arachidonic acid release and increased mRNA levels of cytosolic phospholipase $A_2(cPLA_2)$. The ATP depletion-dependent arachidonic acid release was inhibited by $cPLA_2$ specific inhibitor $AACOCF_3$. ATP depletion-induced alterations in $Na^+$-dependent phosphate uptake and cell viability were prevented by $AACOCF_3$. Inhibition of $Na^+$-dependent phosphate uptake by ATP depletion was prevented by antipain and leupetin, serine/cysteine protease inhibitors, whereas ATP depletion-induced cell death was not altered by these agents. These results indicate that ATP depletion-induced alterations in membrane transport function and cell viability are due to reactive oxygen species generation and $cPLA_2$ activation in renal proximal tubular cells. In addition, the present data suggest that serine/cysteine proteases play an important role in membrane transport dysfunction, but not cell death, induced by ATP depletion.

$[^3H]$ Ouabain Binding and Effect of Ouabain on $^{45}Ca^{2+}$-Uptake in Rat Cardiac Myocytes (쥐 심근 세포의 $[^3H]$ Ouabain 결합과 $^{45}Ca^{2+}}$섭취에 미치는 Ouabain의 영향)

  • 이신웅;김영희;진갑덕
    • YAKHAK HOEJI
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    • v.28 no.3
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    • pp.129-138
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    • 1984
  • Specific [$^{3}H$] ouabain binding and $Ca^{2+}$ -uptake were measured to elucidate the role of high affinity [$^{3}H$] ouabain binding site in rat cardiac myocytes which contain 65% of rod cells. High affinity [$^{3}$H] ouabain binding site, which is about 3% of total pump sites, with apparent dissociation constant ($K_{D}$) of $1.1{\times}10^{-7}M$ and maximum binding site concentration (Bmax) of 1.2 pmol/mg protein ($1.754{\times}10^{5}cells$) were identified. At the concentration of $10^{-7}M$ to $10^{-4}M$, ouabain produced concentration dependent increase in $Ca^{2+}$-uptake of myocytes. The effect of ouabain on $Ca^{2+}$-uptake was not effected by membrane depolarization (elevated K+ in incubation medium) or verapamil. These results suggest that in rat ventricular myocytes the ouabain receptor complex to high affinity site may increase Na+ - $Ca^{2+}$ exchange across the sarcolemmal membrane by inhibition of Na+, K+ - ATPase.

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Optical Properties of Sulfur and NaI by Microwave Discharge (마이크로파 방전에 의한 Sulfur와 NaI의 광학적 특성)

  • Lee, Jong-Chan;Hwang, Myung-Keun;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.109-111
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    • 2002
  • The fundamental principles of the operation of microwave discharges that are used to convert microwave energy to broad spectrum visual light are known. In this paper, emission dependance of microwave discharges in mixture content of sulfur with noble gases was studied. It is shown that the excitation of this gaseous mixture is carried out in two phases; (1) ionization of noble gas atoms by a microwave field and (2) the consequent maintenance of slightly ionized nonequilibrium plasma by the field. These two processes have essentially various thresholds for the microwave pump. The purpose of this work is to investigate spectral properties of the high frequency discharges in a mixture sulfur vapors with noble gases.

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Effects of SITS on Sodium Transport, Oxygen Consumption and Na-K-ATPase of the Frog Skin (개구리 피부의 Sodium 이동, 산소 소모량 및 Na-K-ATPase에 대한 SITS의 영향)

  • Lee, Seung-Mook;An, Mi-Ra;Lee, Syng-Ill;Park, Yang-Saeng
    • The Korean Journal of Physiology
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    • v.17 no.1
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    • pp.55-61
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    • 1983
  • Effects of SITS (4-acetamido-4'-isothiocyano-2, 2'-disulfonic stilbene) on a $Na^+$ transport, tissue oxygen consumption and Na-K-ATPase activity were studied in isolated frog skin preparations. $Na^+$ transport was estimated by measuring the short-circuit current(SC) across the skin; oxygen consumption was measured in separated epidermis as well as in intact skin; and Na-K-ATPase was assayed in $24,000{\times}g$ fraction of epidermal homogenates. The SCC across the skin Was rapidly and substantially reduced in the presence of 10 mM SITS in the medium bathing the outside(mucosal) surface of the skin. When the drug was added to the inside(serosal) bathing medium, there was about 20 min delay for inhibition of SCC and the effect was less pronounced. The above effect of SITS was independent of the presence of $Cl^-$ in the bathing medium. The oxygen consumption of the skin tissue was not affected by SITS, but the Na-K-ATPase activity of a subcellular fraction of the skin was significantly inhibited. These results suggest that SITS retards $Na^+$ transport across the frog skin primarily by interfering $Na^+$ entry across the mucosal membrance of the epithelial cell, although an effect on $Na^+$ pump can not be ruled out completely.

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