4,476 research outputs found

    Weight quantification of deposits on hydrogel lenses: A clinical trial

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    A new method for quantifying of soft contact lens deposits that causes minimal damage to the lens was investigated. Fourteen subjects were fit with Hydrocurve II 55% and Hydrocurve Elite contact lenses. Subjects wore one of each type of lens for three months and lenses were weighed three times (t= 0, 1, 3 months). Lenses were assessed for fitting charicteristics and comfort after each weighing. Six subjects completed the study for three months. Eight of the subjects were dropped from -the study because of decreased lens comfort, torn lenses and contact lens optical problems. Weight data from the six subjects who completed the study were analyzed with one factor repeated measure ANOVA p \u3c 0.05. Hydrocurve II 55% lenses gained a significant amount of weight over the three months while the Hydrocurve Elite did not. We feel that a fifty-seven percent drop-out rate is acceptable for this quantification method. The method (with refinement) has value for future use in contact lens material and solution research

    O crescimento de plântulas de tomateiro é afetado por extratos de vermicomposto.

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    O objetivo desse trabalho foi avaliar o efeito de extratos de vermicomposto sobre a morfologia da parte aérea e radicular de plantulas de tomateiro. Observou-se um aumento linear significativo da área foliar (AF) e massa foliar fresca (MFF)

    Spatial Current Patterns, Dephasing and Current Imaging in Graphene Nanoribbons

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    Using the non-equilibrium Keldysh Green's function formalism, we investigate the local, non-equilibrium charge transport in graphene nanoribbons (GNRs). In particular, we demonstrate that the spatial current patterns associated with discrete transmission resonances sensitively depend on the GNRs' geometry, size, and aspect ratio, the location and number of leads, and the presence of dephasing. We identify a relation between the spatial form of the current patterns, and the number of degenerate energy states participating in the charge transport. Furthermore, we demonstrate a principle of superposition for the conductance and spatial current patterns in multiple-lead configurations. We demonstrate that scanning tunneling microscopy (STM) can be employed to image spatial current paths in GNR with atomic resolution, providing important insight into the form of local charge transport. Finally, we investigate the effects of dephasing on the spatial current patterns, and show that with decreasing dephasing time, the current patterns evolve smoothly from those of a ballistic quantum network to those of classical resistor network.Comment: 25 pages, 12 figure

    π\piNN coupling and two-pion photoproduction on the nucleon

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    Effects of non-resonant photoproductions arising from two different πNN\pi NN couplings are investigated in the γNππN\gamma N\to\pi\pi N reaction. We find that the pseudoscalar (PS) πNN\pi NN coupling is generally preferable to the pseudovector (PV) πNN\pi NN coupling and particularly the total cross sections are successfully described by the model with the PS πNN\pi NN coupling. In order to see the difference between the two couplings, we also show the results of invariant mass spectra and helicity-dependent cross sections in various isospin channels calculated with the PS and PV couplings.Comment: 35 pages, 11 figures, minor changes and version to be published in Phys.Rev.

    Intensity of singular stress field for three-dimensional butt joint to evaluate the adhesive strength

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    Adhesive joints are extensively used in various manufacturing processes in different industrial sectors because of its high fatigue resistance. Different materials properties cause the singular stress field, whose intensity is depending on the adhesive joint geometry. Our previous studies show that debonding strength can be expressed as a constant value of the critical intensity of singular stress field (ISSF) by using two-dimensional butt joint models. By considering real specimen geometry, in this paper, the ISSFs on the interface outer edges of three-dimensional butt joints are analysed by varying the adhesive thicknesses. A mesh-independent technique combined with three-dimensional finite element method (FEM) is shown to evaluate the ISSF. The ISSF distributions on the interface outer edges are analysed in comparison with the previous two-dimensional results. It is found that the critical ISSF considered 3D geometry is almost constant independent of the adhesive thickness.2018 5th Global Conference on Polymer and Composite Materials (PCM 2018), April 10th - 13th, 2018, in Kitakyushu City, Kokura region, Japan

    Studies of efficiency in a perforated rotating disc contactor using a polymer-polymer aqueous two-phase systems

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    The mass transfer process in a perforated rotating disc contactor (PRDC) using a polymer-polymer aqueous two-phase system was investigated. The results show that the efficiency did not show a regular trend with the increase of the dispersed phase velocity and increased with the rotation velocity. The separation efficiency was higher for three rotating discs than for four discs. The increase in tie-line length decreased the efficiency. The separation efficiency reached high values, about 96% under conditions studied in this work.489493Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Downregulation of functional Reelin receptors in projection neurons implies that primary Reelin action occurs at early/premigratory stages

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    Reelin signaling is essential for correct development of the mammalian brain. Reelin binds to apolipoprotein E receptor 2 and very low-density lipoprotein receptor and induces phosphorylation of Dab1. However, when and where these reactions occur is essentially unknown, and the primary function(s) of Reelin remain unclear. Here, we used alkaline phosphatase fusion of the receptor-binding region of Reelin to quantitatively investigate the localization of functional Reelin receptors (i.e., those on the plasma membrane as mature forms) in the developing brain. In the wild-type cerebral cortex, they are mainly present in the intermediate and subventricular zones, as well as in radial fibers, but much less in the cell bodies of the cortical plate. Functional Reelin receptors are much more abundant in the Reelin-deficient cortical plate, indicating that Reelin induces their downregulation and that it begins before the neurons migrate out of the intermediate zone. In the wild-type cerebellum, functional Reelin receptors are mainly present in the cerebellar ventricular zone but scarcely expressed by Purkinje cells that have migrated out of it. It is thus strongly suggested that Reelin exerts critical actions on migrating projection neurons at their early/premigratory stages en route to their final destinations, in the developing cerebral cortex and cerebellum. Copyright © 2009 Society for Neuroscience.This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Science, Sports, and Culture (M.H., A.B.), Ono Medical Research Foundation, and Kanae Foundation for the Promotion of Medical Science (M.H.). T.H. is a Research Fellow of Japan Society for the Promotion of Science. J.M.L. is a Ramón y Cajal Research Fellow funded by Grant SAF2004-07685 and Fundación Mutua Madrileña.Peer Reviewe

    Anomalous Flux Flow Resistivity in Two Gap Superconductor MgB_2

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    The flux flow resistivity associated with purely viscous motion of vortices in high-quality MgB_2 was measured by microwave surface impedance. Flux flow resistivity exhibits unusual field dependence with strong enhancement at low field, which is markedly different to conventional s-wave superconductors. A crossover field which separates two distinct flux flow regimes having different flux flow resistivity slopes was clearly observed in H//ab-plane. The unusual H-dependence indicates that two very differently sized superconducting gaps in MgB_2 manifest in the vortex dynamics and almost equally contribute to energy dissipation. The carrier scattering rate in two different bands is also discussed with the present results, compared to heat capacity and thermal conductivity results.Comment: 4 pages, 3figure

    Confinement and Low Adhesion Induce Fast Amoeboid Migration of Slow Mesenchymal Cells

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    The mesenchymal-amoeboid transition (MAT) was proposed as a mechanism for cancer cells to adapt their migration mode to their environment. While the molecular pathways involved in this transition are well documented, the role of the microenvironment in the MAT is still poorly understood. Here, we investigated how confinement and adhesion affect this transition. We report that, in the absence of focal adhesions and under conditions of confinement, mesenchymal cells can spontaneously switch to a fast amoeboid migration phenotype. We identified two main types of fast migration-one involving a local protrusion and a second involving a myosin-II-dependent mechanical instability of the cell cortex that leads to a global cortical flow. Interestingly, transformed cells are more prone to adopt this fast migration mode. Finally, we propose a generic model that explains migration transitions and predicts a phase diagram of migration phenotypes based on three main control parameters: confinement, adhesion, and contractility
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