4,485 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
No full textBackground 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
Stock ownership and corporate performance in Japan: Corporate governance by institutional investors
No full textFaced with an aging population and a low fertility rate, Japan finds it increasingly essential to shift diminishing national savings into productive investment in order to preserve the dynamism of its economy. Stock investment by institutional investors is important for corporate financing, and shareholder involvement in governance influences corporate growth. Using panel data for Japan's listed companies and foreign investors' votes on shareholder proposals, this paper demonstrates: (1) an increase in stock ownership by foreign investors' had a positive effect on productivity growth, but it has not recently improved other corporate performance indices, and (2) foreign investors' strong attitudes towards voting had a positive effect on productivity growth. This paper concludes that external stakeholders' active, qualitative involvement in corporate governance and their quantitative involvement by increasing stock ownership are key to improving corporate growth.
Bonding InGaAsP/ITO/Si Hybrid Laser With ITO as Cathode and Light-Coupling Material
No full textA 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
No full textTranscript 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
No full textTranscript 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
No full textCopyright 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
No full textTranscript 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
Millimetre Wave Power Measurement
No full textThere is currently no traceable power sensor for millimetre wave frequencies above 110 GHz. This thesis investigates a novel approach to remove this limitation by combining the placement of a uniquely designed microchip directly in waveguide. The design of the chip is novel in that it does not rely on a supporting structure or an external antenna when placed in the waveguide.
The performance of the design was primarily analysed by computer simulation and verified with the measurement of a scale model. The results show
that it is feasible to measure high frequency power by placing a chip directly in waveguide. It is predicted that the chip is able to absorb approximately 60% of incident power. Any further efficiency would require modification of the chip substrate. However, this proposed design should allow the standards institutes a reference that will enable the calibration of equipment to beyond
110 GHz
Radioactive iodine-refractory differentiated thyroid cancer: unmet needs and future directions
No full textApproximately 90% of thyroid cancers are differentiated (DTCs) and have papillary, follicular or Hürthle cell morphology. Although treatment with surgery and radioactive iodine (I-131; RAI), as appropriate, is associated with significant cure rates and survival benefits, clonal disease progression with development of refractoriness to RAI poses a major therapeutic challenge in about 15% of patients. Traditional chemotherapeutic agents are relatively ineffective and are associated with significant toxicities. Molecular studies have demonstrated that the development and progression of DTC are associated with a series of consistent abnormalities in pathways such as MAPK/ERK and PI3/Akt, which govern cellular growth, proliferation, apoptosis and angiogenesis. Small molecular inhibitors that target these pathogenic pathways, without many of the impairments associated with cytotoxic chemotherapy, have demonstrated efficacy in a variety of malignancies, including renal cell carcinoma, hepatocellular carcinoma, non-small-cell lung cancer and chronic myelogenous leukemia. Several targeted therapeutic agents are in development for the treatment of RAI-refractory DTC. Sorafenib and lenvatinib are being studied in placebo-controlled Phase III trials based on encouraging efficacy results observed in single-arm Phase II studies. © 2012 Expert Reviews Ltd
Influence of ITO deposition and post annealing on HIT solar cell structures
No full textHeterojunction 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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