2,738 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

    The Effect of Lighting on Performance of Tasks Requiring Near Vision in Older Adults

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    Abstract Date Presented 4/1/2017 The study examined the impact of lighting on occupational task performance in older adults and the effect of lighting on perceived effort during task performance. Results suggest lighting may affect performance and perceived effort in older adults performing tasks requiring near vision. Primary Author and Speaker: Karen James Contributing Authors: Max Ito, Rachelle Dorne, JoAnne Wright</jats:p

    The Participation of Young Children With Cerebral Palsy: Relationship to Child, Environmental, and Family Factors

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    Abstract Date Presented 3/30/2017 This study examined the degree to which child, family, and environmental factors influence participation in young children with cerebral palsy. Findings suggest that when substantial family and environmental supports are present, participation is largely explained by gross motor impairment and age. Primary Author and Speaker: Claire Morress Contributing Authors: Max Ito, Sandra Winkler, Jilda Vargus Adams</jats:p

    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 &amp; 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

    Max-plus Stochastic Control

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    Max-plus stochastic processes are counterparts of Markov diffusion processes governed by Ito sense stochastic differential equations. In this framework, expectations are linear operations with respect to max-plus arithmetic. Max-plus stochastic control problems are considered, in which a minimizing control enters the state dynamics and running cost. The minimum max-plus expected cost is equal to the upper Elliott-Kalton value of an associated differential game

    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
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