201 research outputs found

    A Prediction of Young\u27s Modulus for Tin Containing Phosphate Glasses using Quantitative Structural Information

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    A Rigid Unit Packing Fraction (RUPF) Model Was Used to Better Understand the Influence of Local Structural Units on the Young\u27s Elastic Modulus (E) of Binary and Ternary Tin Phosphate Glasses. Quantitative Analyses of the Units that Constitute the Glass Structure, Obtained from X-Ray/neutron Diffraction and 31P MAS-NMR Spectroscopy, Were Used to Calculate Polyhedral Packing Fractions that, with Tabulated Bond Dissociation Energies, Were Used to Predict E based on a Modification of the Makashima-Mackenzie Relationship, Which Uses Ion Sizes to Calculate Packing Fractions. Predictions based on the RUPF Model Are Better Than Those based on Ion Sizes, and Extending the RUPF Model to All Cation-Polyhedra Accounts for the Compositional Dependence of the Sn-Coordination Number

    Asymptotic expansions of the solutions of the Cauchy problem for nonlinear parabolic equations

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    Let uu be a solution of the Cauchy problem for the nonlinear parabolic equation ∂tu=Δu+F(x,t,u,∇u)inRN×(0,∞),u(x,0)=φ(x)inRN, \partial_t u=\Delta u+F(x,t,u,\nabla u) \quad in \quad{\bf R}^N\times(0,\infty), \quad u(x,0)=\varphi(x)\quad in \quad{\bf R}^N, and assume that the solution uu behaves like the Gauss kernel as t→∞t\to\infty. In this paper, under suitable assumptions of the reaction term FF and the initial function φ\varphi, we establish the method of obtaining higher order asymptotic expansions of the solution uu as t→∞t\to\infty. This paper is a generalization of our previous paper, and our arguments are applicable to the large class of nonlinear parabolic equations

    Characterization of BNL and HPK AC-LGAD sensors with a 120 GeV proton beam

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    We present measurements of AC-LGADs performed at the Fermilab's test beam facility using 120 GeV protons. We studied the performance of various strip and pad AC-LGAD sensors that were produced by BNL and HPK. The measurements are performed with our upgraded test beam setup that utilizes a high precision telescope tracker, and a simultaneous readout of up to 7 channels per sensor, which allows detailed studies of signal sharing characteristics. These measurements allow us to assess the differences in designs between different manufacturers, and optimize them based on experimental performance. We then study several reconstruction algorithms to optimize position and time resolutions that utilize the signal sharing properties of each sensor. We present a world's first demonstration of silicon sensors in a test beam that simultaneously achieve better than 6-10 micron position and 30 ps time resolution. This represents a substantial improvement to the spatial resolution than would be obtained with binary readout of sensors with similar pitch

    Plasma MicroRNA Profiles in Rat Models of Hepatocellular Injury, Cholestasis, and Steatosis

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    MicroRNAs (miRNAs) are small RNA molecules that function to modulate the expression of target genes, playing important roles in a wide range of physiological and pathological processes. The miRNAs in body fluids have received considerable attention as potential biomarkers of various diseases. In this study, we compared the changes of the plasma miRNA expressions by acute liver injury (hepatocellular injury or cholestasis) and chronic liver injury (steatosis, steatohepatitis and fibrosis) using rat models made by the administration of chemicals or special diets. Using miRNA array analysis, we found that the levels of a large number of miRNAs (121–317 miRNAs) were increased over 2-fold and the levels of a small number of miRNAs (6–35 miRNAs) were decreased below 0.5-fold in all models except in a model of cholestasis caused by bile duct ligation. Interestingly, the expression profiles were different between the models, and the hierarchical clustering analysis discriminated between the acute and chronic liver injuries. In addition, miRNAs whose expressions were typically changed in each type of liver injury could be specified. It is notable that, in acute liver injury models, the plasma level of miR-122, the most abundant miRNA in the liver, was more quickly and dramatically increased than the plasma aminotransferase level, reflecting the extent of hepatocellular injury. This study demonstrated that the plasma miRNA profiles could reflect the types of liver injury (e.g. acute/chronic liver injury or hepatocellular injury/cholestasis/steatosis/steatohepatitis/fibrosis) and identified the miRNAs that could be specific and sensitive biomarkers of liver injury

    A Novel PAN/Apple Domain-Containing Protein from Toxoplasma gondii: Characterization and Receptor Identification

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    Toxoplasma gondii is an intracellular parasite that invades nucleated cells, causing toxoplasmosis in humans and animals worldwide. The extremely wide range of hosts susceptible to T. gondii is thought to be the result of interactions between T. gondii ligands and receptors on its target cells. In this study, a host cell-binding protein from T. gondii was characterized, and one of its receptors was identified. P104 (GenBank Access. No. CAJ20677) is 991 amino acids in length, containing a putative 26 amino acid signal peptide and 10 PAN/apple domains, and shows low homology to other identified PAN/apple domain-containing molecules. A 104-kDa host cell-binding protein was detected in the T. gondii lysate. Immunofluorescence assays detected P104 at the apical end of extracellular T. gondii. An Fc-fusion protein of the P104 N-terminus, which contains two PAN/apple domains, showed strong affinity for the mammalian and insect cells evaluated. This binding was not related to protein-protein or protein-lipid interactions, but to a protein-glycosaminoglycan (GAG) interaction. Chondroitin sulfate (CS), a kind of GAG, was shown to be involved in adhesion of the Fc-P104 N-terminus fusion protein to host cells. These results suggest that P104, expressed at the apical end of the extracellular parasite, may function as a ligand in the attachment of T. gondii to CS or other receptors on the host cell, facilitating invasion by the parasite
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