1,894 research outputs found

    Transient outward K+ current (ITO) reduction prolongs action potentials and promotes afterdepolarisations: a dynamic-clamp study in human and rabbit cardiac atrial myocytes

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    Background and aim: Human atrial transient outward K+ current (ITO) is decreased in a variety of cardiac pathologies, but how ITO reduction alters action potentials (AP) and arrhythmia mechanisms is poorly understood, owing to non-selectivity of ITO blockers.<p></p> Aim: to investigate effects of selective ITO changes on AP shape and duration (APD), and on afterdepolarisations or abnormal automaticity with beta-adrenergic-stimulation, using the dynamic-clamp technique in atrial cells.<p></p> Methods and Results: Human and rabbit atrial cells were isolated by enzymatic dissociation, and electrical activity recorded by whole-cell-patch clamp (35-37oC). Dynamic-clamp-simulated ITO reduction or block slowed AP phase 1 and elevated the plateau, significantly prolonging APD, in both species. In human atrial cells, ITO block (100% ITO subtraction) increased APD50 by 31%, APD90 by 17%, and APD-61mV (reflecting cellular effective refractory period) by 22% (P<0.05 for each). Interrupting ITO block at various time points during repolarisation revealed that the APD90 increase resulted mainly from plateau-elevation, rather than from phase 1-slowing or any residual ITO. In rabbit atrial cells, partial ITO block (~40% ITO subtraction) reversibly increased the incidence of cellular arrhythmic depolarisations (CADs; afterdepolarisations and/or abnormal automaticity) in the presence of the beta-agonist isoproterenol (0.1 μM; ISO), from 0% to 64% (P<0.05). ISO-induced CADs were significantly suppressed by dynamic-clamp increase in ITO (~40% ITO addition). ISO+ITO decrease-induced CADs were abolished by beta1-antagonism with atenolol at therapeutic concentration (1 μM).<p></p> Conclusion. Atrial cell action potential changes from selective ITO modulation, shown for the first time using dynamic-clamp, have the potential to influence reentrant and non-reentrant arrhythmia mechanisms, with implications for both the development and treatment of atrial fibrillation

    Bonding InGaAsP/ITO/Si Hybrid Laser With ITO as Cathode and Light-Coupling Material

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    A 1.5-mu m InGaAsP/ITO/Si hybrid laser with indium tin oxide (ITO) as both a cathode and a light-coupling material is presented. The InGaAsP gain structure with a transparent ITO cathode is flip-chip bonded onto a patterned silicon-on-insulator wafer. The light generated in the InGaAsP multiquantum wells is coupled through the ITO cathode into the Si waveguide to form an InGaAsP/ITO/Si hybrid laser. The threshold current density of this hybrid laser is 20 kA/cm(2) at 210 K. Due to the advantages of post-bonding and simplicity of the fabrication process, such a hybrid laser may be a promising Si light source.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000302534300023&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Engineering, Electrical & ElectronicOpticsPhysics, AppliedSCI(E)EI14ARTICLE8712-7142

    Letter from Kazuo Ito to Lea Perry, July 15, 1942

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    Transcript of a letter from Kazuo Ito to Lea Perry. The original letters are housed with the Sonoma County Japanese American Citizens League (JACL), and were borrowed for digitization courtesy of the JACL, December 2014. Digital reproduction of the original item is found in item: ssu_nbea_0010.The North Bay Ethnic Archive features material related to the forced relocation of northern San Francisco Bay Area residents to the Granada (Amache) incarceration camp, Colorado. It includes correspondence, photographs, and reports. Some of the original items are housed with the Sonoma County Japanese American Citizens League (JACL), and were borrowed for digitization courtesy of the JACL. The remainder are housed in Special Collections

    Letter from Kazuo Ito to Lea Perry, August 13 1942

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    Transcript of a letter from Kazuo Ito to Lea Perry. The original letters are housed with the Sonoma County Japanese American Citizens League (JACL), and were borrowed for digitization courtesy of the JACL, December 2014. Digital reproduction of the original item is found in item: ssu_nbea_0012.The North Bay Ethnic Archive features material related to the forced relocation of northern San Francisco Bay Area residents to the Granada (Amache) incarceration camp, Colorado. It includes correspondence, photographs, and reports. Some of the original items are housed with the Sonoma County Japanese American Citizens League (JACL), and were borrowed for digitization courtesy of the JACL. The remainder are housed in Special Collections

    Magnetoresistance in triphenyl-diamine derivative blue organic light emitting devices

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    Copyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics 103, 043706 (2008) and may be found at

    Letter from Frank Ito to Joe and Lea Perry, November 2, 1943

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    Transcript of a letter from Frank Ito to Joe and Lea Perry. The original letters are housed with the Sonoma County Japanese American Citizens League (JACL), and were borrowed for digitization courtesy of the JACL, December 2014. Digital reproduction of the original item is found in item: ssu_nbea_0130.The North Bay Ethnic Archive features material related to the forced relocation of northern San Francisco Bay Area residents to the Granada (Amache) incarceration camp, Colorado. It includes correspondence, photographs, and reports. Some of the original items are housed with the Sonoma County Japanese American Citizens League (JACL), and were borrowed for digitization courtesy of the JACL. The remainder are housed in Special Collections

    Influence of ITO deposition and post annealing on HIT solar cell structures

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    Heterojunction silicon with intrinsic thin layer (HIT) solar cells that combine advanced thin-film hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si) technologies are promising because of the high performance at low cost. Due to the low conductivity of a-Si:H, indium tin oxide (ITO) needs to be used as a front contact layer on top of a-Si:H in order to collect photogenerated currents. The thin a-Si:H layer requires the ITO deposition to be soft so that the passivation is maintained after deposition. Otherwise, the passivation degradation resulting from ITO deposition should be recovered by some post processing. In this contribution, we investigate how the power density and the temperature during ITO deposition as well as post annealing influence the passivation quality of HIT solar cells as characterised by the open-circuit voltage (Voc) and minority carrier lifetime. Firstly, ITO sputtering with lower power density can reduce the degradation of the passivation quality after ITO deposition. Secondly, we have investigated the simultaneous annealing during ITO deposition at elevated temperature. On one hand, simultaneous annealing can recover some of the degradation resulting from sputtering. On the other hand, there is a temperature threshold above which degradation of the passivation is observed, probably by hydrogen effusion. Thirdly, we observe that post annealing can fully recover the degradation resulting from ITO sputtering at room temperature (RT).Electrical Sustainable EnergyElectrical Engineering, Mathematics and Computer Scienc

    Antecedents of the ITO Charter and their Relevance for the Uruguay Round

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    The author discusses the origins of the International Trade Organization ( ITO ) and the International Monetary Fund ( IMF ). Next, the author addresses the issue of legalism versus pragmatism in the administration of the ITO and IMF. The author closes with a warning that the Uruguay Round did little to satisfy criticism that the General Agreement on Tariffs and Trade was too legalistic

    Optimization of ITO TCO for thin-film silicon and HIT solar cells

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    Within thin-film silicon solar cells, the so-called Transparent Conductive Oxide (TCO) plays an important role. The optimization of TCOs is a very meticulous process since these thin layers not only need to be both highly transparent and conductive, but are also used for light management; that is manipulating the path of the light through the active layer by means of a textured TCO surface which scatters the light. Besides, the TCOs are also used as back reflector in combination with metallic films. By using these methods both the short circuit current and the overall conversion efficiency of the thin-film silicon solar cells is improved. This report focuses on the actual optimization of the RF magnetron sputtering deposition process of tin-doped indium (ITO) TCO’s for application in thin-film silicon and HIT solar cells. By varying deposition parameters such as power, pressure and temperature an optimal recipe for each specific type of thin-film solar cell could be established. The optimized ITO TCO recipes are utilized as both front and back TCO in a-Si:H, ?c-Si:H and HIT thin-film solar cells. Thanks to these optimizations we were able to achieve efficiencies which were comparable, and in some cases even better, to similar devices made with the already optimized aluminum-doped zinc oxide (AZO) TCO’s. A highest initial efficiency of 10.7% was achieved for a p-i-n solar cell with front Asahi U-type TCO and back ITO TCO. Besides the actual optimization process the consistency and repeatability of the ITO depositions with time was investigated. Since the optimization process is so elaborate, repeatability of depositions is very important. Regularly scheduled depositions were made to check the variations of thin-film quality with time. The results show that the quality of the ITO thin-films is quite variable. The ITO quality is known to drop significantly after a deposition chamber ventilation. The number of hours of sputtering needed to return to original and acceptable quality was investigated by means of a post-ventilation recovery series.Sustainable Energy TechnologyElectrical Sustainable EnergyElectrical Engineering, Mathematics and Computer Scienc

    Beikoku korekushon ni okeru Nihon kosho oyobi kikosho

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    Based on a survey questionnaire and personal visits, this illustrated article discusses the various patterns of organization of rare and old Japanese books in 15 U.S. academic, research and museum libraries. A lack of standardization of criteria for rarity and special status is noted but an even more critical problem is the dearth of the bibliographic control over these rich resources. Brief histories and content of these collections is provided. This is a translation of the original article that appeared in College and Research Libraries, 39 (May 1978), 197-206.Translated from the English by Naotake Ito
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