32,768 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
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
Método potenciodinâmico aplicado ao estudo da difusão iônica limitada por camada porosa em substratos de ITO
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2013.Esta dissertação tem como objetivo estudar o comportamento do substrato transparente condutor composto por óxido de índio dopado com estanho (ITO) durante tratamento catódico em eletrólitos inertes de NaCl, KCl, KI e AlCl3, em diferentes concentrações possuindo a mesma força iônica e em seu pH natural. Após o tratamento é observada a formação de partículas esféricas metálicas de In-Sn, decorrentes da redução do ITO. A morfologia dos depósitos varia com o eletrólito usado e com a velocidade do processo de redução. Os resultados obtidos através dos estudos potenciodinâmicos dos eletrodos indicam um processo controlado por resistência ôhmica. O comportamento resistivo observado durante a formação da camada porosa metálica sugere a aplicação do modelo de resistência de camada porosa LPRM (do inglês Layer-Pore Resistance Model) para análise do processo. No entanto, o modelo LPRM, na forma como foi originalmente desenvolvido, não descreve bem o processo. Uma modificação ao modelo é proposta, a partir da qual, logra-se obter bons ajustes do modelo às curvas potenciodinâmicas. O conjunto de parâmetros extraído do ajuste de curvas obtidas com diferentes taxas de varredura mostra boa correlação com o crescimento da camada porosa e pode ser interpretado como uma medida do caminho difusivo que os íons do eletrólito necessitam percorrer para atingir a camada de ITO subjacente. A modificação da morfologia do substrato durante o processo de redução catódica foi caracterizada por microscopia eletrônica de varredura (MEV) e microscopia de força atômica (AFM). Da análise da rugosidade superficial, obtida das micrografias de AFM, extraiu-se o comprimento de correlação, que mede a granularidade da camada porosa. Usando conceitos simples de passeio aleatório, foi possível estabelecer uma relação entre o caminho difusivo iônico determinado eletroquimicamente, e a morfologia da camada porosa, para os diferentes eletrólitos utilizados.Abstract : This work investigates the behavior of transparent conducting substrates composed of indium tin oxide (ITO) during cathodic treatment in inert aqueous electrolytes (NaCl, KCl, KI e AlCl3), using different concentrations with same ionic force. The treatment causes the formation of spherical metallic particles of In-Sn, resulting from ITO reduction. It is possible to observe that the morphology of deposits is affected by the electrolyte composition and sweep rate. Potentiodynamic studies indicate a process controlled by Ohmic resistance. The resistive behavior observed during growth of the porous metallic layer suggests the application of the Layer-Pore Resistance Model (LPRM) to analyze the results. However, the LPRM model, in its original form, does not give a good description of the process. A modified version of the LPRM is proposed, which yields very good fits to the potentiodynamic curves. The set of fit parameters extracted from the curves, obtained at different scan rates, shows a good correlation with the growth of the porous layer, and could be interpreted as a measure of diffusion paths that ions must travel to reach the underlying ITO layer. The changes on morphology of the substrates during the cathodic reduction was characterized by scanning electron microscope (SEM) and atomic force microscope (AFM). From the roughness analysis obtained from the AFM micrographs, a correlation length was determined that describes the granularity of the porous layer. Using simple concepts of random walk, it was possible to establish a relationship between the ionic diffusion path determined electrochemically, and the morphology of porous layer, for the different electrolytes used
Martingales on manifolds and geometric Ito calculus
No full textThis work studies properties of stochastic processes taking
values in a differential manifold M with a linear connection Γ, or
in a Riemannian manifold with a metric connection.
Part A develops aspects of Ito calculus for semimartingales
on M, using stochastic moving frames instead of local co-ordinates.
New results include:
-a formula for the Ito integral of a differential form along a
semimartingale, in terms of stochastic moving frames and the
stochastic development (with many useful corollaries);
- an expression for such an integral as the limit in probability
and in L2 of Riemann sums, constructed using the exponential map;
- an intrinsic stochastic integral expression for the 'geodesic
deviation', which measures the difference between the stochastic
development and the inverse of the exponential map;
-a new formulation of 'mean forward derivative' for a wide class
of processes on M.
Part A also includes an exposition of the construction of non-degenerate
diffusions on manifolds from the viewpoint of geometric Ito
calculus, and of a Girsanov-type theorem due to Elworthy.
Part B applies the methods of Part A to the study of 'Γ-martingales'
on M. It begins with six characterizations of Γ-martingales,
of which three are new; the simplest is: a process whose image under
every local Γ-convex function is (in a certain sense) a submartingale,
However to obtain the other characterizations from this one requires
a difficult proof. The behaviour of Γ-martingales under harmonic
maps, harmonic morphisms and affine maps is also studied.
On a Riemannian manifold with a metric connection Γ, a Γ-martingale
is said to be L2 if its stochastic development is an L2
Γ-martingale. We prove that if M is complete, then every such process
has an almost sure limit, taking values in the one-point compactification
of M. No curvature conditions are required. (After this
result was announced, a simpler proof was obtained by P. A. Meyer,
and a partial converse by Zheng Wei-an.)
The final chapter consists of a collection of examples of
Γ-martingales, e.g. on parallelizable manifolds such as Lie groups,
and on surfaces embedded in R3. The final example is of a Γ-martingale
on the torus T (Γ is the Levi-Civita connection for the
embedded metric) which is also a martingale in R3
Microptila orienthula Kjaerandsen & Ito 2009
No full text<i>Microptila orienthula</i> Kjaerandsen & Ito 2009 <p>(Figs 1–3)</p> <p> <i>Microptila orienthula</i> Kjaerandsen & Ito 2009, 177–180, male, female, Japan (Hokkaido, Honshu); Ito 2017a, 105–107, male, female, Japan (Hokkaido, Honshu, Shikoku, Kyushu, Yakushima); Ito in press, adult flight period, Japan (Honshu).</p> <p> <b>Final instar larva</b> (Figs 1, 2, 3D, 3E).</p> <p>Body length up to about 2.2 mm in alcohol.</p> <p> <i>Head</i> (Figs 1A–1G). Elongate, sides subparallel, ecdysial sutures indistinct.Width about 0.22 mm; width: length: depth about 1.0: 1.25: 0.85; uniformly brown; longest seta (seta 9 of Wiggins 1996) situated mesal side of eye spot, about 1.5 times head width. Labrum symmetrical with four pairs of setae at anterior half and numerous fine setae on anterior margin. Mandibles robust, asymmetrical, left one with acute apex and long mesal blade distinguished by basal notch, right one with blunt apex and sinuous mesal blade lacking distinguishing notch. Antennae situated mid-way between eye spots and anterolateral corners, each with seta at mid-length and sensillum apically. Dorsal surface densely covered with short hair-like spines (<i>sensu</i> Graf <i>et al</i>. 2004; “minute spinules” of Wells 1985).</p> <p> <i>Thoracic segments</i> (Figs 2A–2F). Pronotum completely covered with pair of brown plates, round at anterolateral corners, concave at posterolateral corners. Each of meso- and metanota covered with a pair of rectangular brown plates. Dorsal surfaces of plates covered with short hair-like spines. Number of setae about 30 on each plate of pronotum, about 20 on each plate of meso- and metanota. Sternites absent.</p> <p>Foretrochantins and pleura of meso- and metathoraces subquadrate. Thoracic legs similar in structure except foretibiae each with apicoventral lobe with subapicolateral seta, subapicodistal plate with brush of fine hairs, and stout apical spur; femora successively longer from foreleg to hind leg.</p> <p> <i>Abdomen</i> (Figs 1A, 2A, 2G, 2H, 3D, 3E). Slightly compressed laterally, distended, segments gradually enlarging from I to IV (or V) then decreasing, curvature of abdomen slight. Segment I with ellipsoidal tergite, very weakly sclerotized especially at middle, with three pairs of setae on tergite and about 5–6 pairs of setae around tergite; dorsal chloride epithelia on terga II–VIII; large dorsal ellipsoidal sclerite on segment IX; two roundish sclerites on segment X dorsolaterally; anal claws each with two accessary hooks.</p> <p> <i>Case</i> (Figs 1I, 1J, 3D). Compressed laterally, composed of two ellipsoidal valves, with slit openings at anterior and posterior edges, made of silk together with few slender plant pieces. Length up to 3.0 mm.</p> <p> <b>Diagnosis from other congeneric species.</b> The larva of <i>M. orienthula</i> is very similar to that of a West Palearctic species, <i>M. minutissima</i> Ris, but can be discriminated from the latter by hair-like spines of thoracic dorsal plates; the hair-like spines are present on each of pro-, meso- and metanota in <i>M. orienthula</i> (Fig. 2B), but on pronotum and anterior half of mesonotum in <i>M. minutissima</i> (Graf <i>et al</i>. 2004).</p> <p> <b>Microhabitat</b> (Figs 3A–3C). The <i>M. orienthula</i> larvae were studied in a hygropetric habitat,Akazawa, Shizuoka, Honshu, Japan (35.0386˚N, 138.2594˚E, 140 m a.s.l.) on 14 April 2023. At this site, 85 males and 25 females of <i>M. orienthula</i>, 985 males of <i>Stactobia japonica</i> Iwata 1930, 246 males of <i>S. distinguenda</i> Botosaneanu & Nozaki 1996 and many unidentified females of <i>Stactobia</i> were collected with net sweeping efforts during 44 visits by Mr. Toshio Hattori during 2009–2013 (Ito in press).</p> <p> <i>Microptila</i> larvae were not found on bare, uncovered rock surfaces (where <i>Stactobia</i> pupae and larvae were abundant; Ito in press, figs 1D, 1E) but rather in plant clusters composed of mosses and liverworts, sometimes accompanied by short grasses (Figs 3B, 3C, indicated by circles). Larvae of many caddisfly taxa, such as <i>Rhyacophila</i> sp. (Rhyacophilidae), <i>Dolophilodes</i> sp. (Philopotamidae), <i>Homoplectra</i> sp. (Hydropsychidae), <i>Micrasema</i> sp. (Brachycentridae), <i>Helicophyche</i> sp. (Helicopsychidae), were also found in the plant clusters. Moreover, water mites, freshwater worms, freshwater crabs, and larvae of various stoneflies and midges were found among these plants.</p> <p> Four hydroptilid genera, <i>Plethus</i> Hagen 1887, <i>Pseudoxyethira</i> Schmid 1958, <i>Stactobia</i> McLachlan 1880, and <i>Microptila</i>, are found in waterfalls and hygropetric habitats in Japan (Ito 2017a, 2017b, 2017c; Ito & Saito 2016). Among them, the larvae and cases of <i>Plethus</i> and <i>Stactobia</i> are depressed dorsoventrally and larvae live on bare rock surfaces (Ito 2017c; Ito & Saito 2016). Their flattened shapes are adapted for life on top of flattened hard substrates in running waters (Huryn <i>et al</i>. 2008; table 9. A). On the other hand, the larva and case of <i>Pseudoxyethira</i> is compressed laterally and larvae live among mosses in hygropetric habitats and waterfalls (Cairns & Wells 2008; Ito 2017a). <i>Microptila</i> is the second genus known to inhabit plant clusters of hygropetric habitats and are similar to <i>Pseudoxyethira</i> in their laterally compressed larvae and cases.</p> <p> <b>Distribution.</b> Japan (Hokkaido, Honshu, Shikoku, Kyushu, Yakushima).</p> <p> <b>Specimens examined</b>. <b>Japan, Honshu</b>: 11 larvae, hygropetric habitat, Akazawa, Shizuoka, 14.iv.2023, T. Ito.</p> <p> <b>Japanese name.</b> Mikuro-hime-tobikera.</p>Published as part of <i>Ito, Tomiko, 2023, The larva of Microptila orienthula Kjaerandsen & Ito (Trichoptera, Hydroptilidae), with a description of its microhabitat in Japan, pp. 445-450 in Zootaxa 5357 (3)</i> on pages 445-449, DOI: 10.11646/zootaxa.5357.3.7, <a href="http://zenodo.org/record/10063481">http://zenodo.org/record/10063481</a>
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
Microptila orienthula Kjaerandsen and Ito
No full text<i>Microptila orienthula</i> Kjaerandsen and Ito <p>(Figs 1, 4 A, 5)</p> <p> <i>Microptila orienthula</i> Kjaerandsen and Ito 2009, 177–180, male, female, Japan (Hokkaido, Honshu); Nishimoto and Nishimoto 2014, 63, Japan (Honshu).</p> <p> <b>Male</b>. Length of each forewing and hind wing 1.6–2.2 mm and 1.4–1.8 mm, respectively (n = 4). Antennae each 19-segmented and 0.6–0.9 mm long (n = 4).</p> <p>Genitalia (Figs. 1 B–1G). Segment IX (IX) annular, dorsally with deep and wide triangular excision at anterior margin, posterior margin with shallow and wide concavity, transverse tergal bridge very narrow, dorsal midline about 1/10 as long as segment IX in dorsal view (Fig. 1 C); in ventral view (Fig. 1 D) anteroventral margin with shallow triangular concavity, posteroventral margin with deep wide concavity. Tergite X (t X) quadrate with large median triangular concavity caudally in dorsal view (Fig. 1 C), semimembranous and transparent, lateral margins lightly sclerotized. Subgenital plate (sg plate) semimembranous with slightly sclerotized lateral margins, twice as long as tergite X (Figs. 1 B, 1C), long ovate with tiny U- or V-shaped excavation caudally in dorsal view (Fig. 1 E). Inferior appendages (inf app) well developed, setose, without any branches, each with basal 2/3 stout, tapered in distal 1/3 (Figs. 1 B, 1D), apex in ventral view incurved and acute (Fig. 1 D), in ventromesal view (Fig. 1 F) basal 2/ 3 with longitudinal setose ridge mesally and apical 1/3 triangular with strongly sclerotized dorsomesal edge. Phallus elongate, with slender titillator (ti) arising near apical 1/3, wrapped around phallus 1.5 times (Fig. 1 G).</p> <p> <b>Female</b>. Length of each forewing and hind wing 1.3–1.8 mm and 1.3–1.6 mm, respectively (n = 4). Antennae each 18-segmented and 0.4–0.6 mm long (n = 4).</p> <p>Abdominal segments I–VII densely covered with long thick setae. Segment VII (VII) tergite and sternite fused laterally, conical in ventral view (Fig. 1 H). Segment VIII (VIII) almost as long as segment VII, often withdrawn into segment VII, ventroposterior margin slightly protruded in some specimens (Figs. 1 H–1J).</p> <p> <b>Specimens examined</b>. <b>Type specimens</b>: 3 males, 2 females, <b>Japan</b>, <b>Hokkaido</b>, Shiriuchi-cho, hygropetric zone beside Idesu-gawa, 12.vii.2008, T. Ito (CBM-ZI 135131–135135, on slides).</p> <p> <b>Additional records</b> (other than those of Kjaerandsen and Ito 2009): <b>Japan, Honshu, Niigata</b>: 42 males, 12 females, Itoigawa-shi, Kotaki-gawa, 300–400 m above sea level (a.s.l.), 14.viii.1998, T. Hattori. <b>Toyama</b>: 3 males, Nanto-shi, Taira-mura, Nashidani-gawa, 450 m a.s.l., 30.vii.1995, T. Hattori. <b>Shizuoka</b>: 10 males, 2 females, Shizuoka-shi, Nyujima, 400 m a.s.l., hygropetric zone, 5.vii.1989, T. Hattori; 10 males, same locality, 11.vi.1999, T. Hattori; 2 males, same locality, 18.vi.2001, T. Hattori; 18 males, 2 females, Shizuoka-shi, Yugashima, 400 m a.s.l., hygropetric zone, 30.viii.2005, T. Hattori; 3 males, 1 female, Shizuoka-shi, Akazawa, hygropetric zone, 2.ix.2009, T. Hattori; 1 male, same locality, 19.ix.2013, T. Hattori & T. Ito; 9 males, 4 females, Hamamatsu-shi, Komyo-san, 29.viii.2009, T. Torii. <b>Aichi</b>: 5 males, 2 females, Shinshiro-shi, Horai, 4.viii.1998, H. Nishimoto. <b>Shiga</b>: 2 males, Higashi-omi-shi, Eigenji, Kanzaki-gawa, hygropetric zone near Kazakoshi-bashi, 9.ix.2014, T. Ito; 8 males, 1 female, same locality, 11.vi.2016, T. Ito. <b>Shikoku</b>, Kochi: 2 males, Tosa-shimizu-shi, Akasho, small stream, 21.v.1999, T. Ito & A. Ohkawa. <b>Kyushu</b>, Nagasaki: 1 male, Isahaya-shi, Korai-cho, Todoroki-kyo, 18.ix.2000, A. Ohkawa. <b>Yakushima</b>: 1 male, 2 females, Nagata, Hamanaka, Nakano-bashi, 30.viii.1986, Y. Takemon; 1 female, unnamed tributary of Miyanoura-gawa, 10.v.2006, T. Ito.</p> <p> <b>Remarks</b>. The males of this species are distinguished from other congeneric species by the large, stout inferior appendages and long oval subgenital plate with tiny U- or V-shaped excavation apically.</p> <p> <b>Habitat</b> (Fig. 4 A). Adults of this species were collected from hygropetric zones and fast flowing streams with large rocks.</p> <p> <b>Distribution</b> (Fig. 5). Japan (Hokkaido, Honshu, Shikoku, Kyushu, Yakushima). New to Shikoku, Kyushu and Yakushima.</p> <p> <b>Japanese name</b>. Mikuro-himetobikera.</p>Published as part of <i>Ito, Tomiko, 2017, The genus Microptila Ris (Trichoptera, Hydroptilidae) in Japan, pp. 104-112 in Zootaxa 4232 (1)</i> on pages 105-107, DOI: 10.11646/zootaxa.4232.1.7, <a href="http://zenodo.org/record/292743">http://zenodo.org/record/292743</a>
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
Electrical and optical properties of ITO and ITO/Cr-doped ITO films
No full textIn this paper we report on the effects of the insertion of Cr atoms on the electrical and optical properties of indium tin oxide (ITO) films to be used as electrodes in spinpolarized light-emitting devices. ITO films and ITO(80 nm)/Cr-doped ITO(20 nm) bilayers and Cr-doped ITO films with a thickness of 20 nm were grown by pulsed ArF excimer laser deposition. The optical, structural, morphological wand electrical properties of ITO films and ITO/Cr-doped structures were characterized by UV-Visible transmission and reflection spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Hall-effect analysis. For the different investigations, the samples were deposited on different substrates like silica and carbon coated Cu grids. ITO films with a thickness of 100 nm, a resistivity as low as similar to 4 x 10(-4) Omega cm, an energy gap of similar to 4.3 eV and an atomic scale roughness were deposited at room temperature without any post-deposition process. The insertion of Cr into the ITO matrix in the upper 20 nm of the ITO matrix induced variations in the physical properties of the structure like an increase of average roughness (similar to 0.4-0.5 nm) and resistivity (up to similar to 8x10(-4) Omega cm). These variations were correlated to the microstructure of the Cr-doped ITO films with particular attention to the upper 20 nm
- …
