5,841 research outputs found
Regulation of the subcellular distribution and gene expression of GABAA receptor by microtubules and microfilaments in cultured brain neurons.
No full textUnusual magnetic properties of Ho(Fe0.6Mn0.4)(12)
No full textThe magnetic properties of Ho(Fe0.6Mn0.4)(12) were studied by X-ray diffraction and magnetic measurements. The X-ray diffraction pattern shows that the compound is of single phase and has the TnMn(12) tetragonal structure. Magnetic measurements show that the Curie temperature is 204 K. The magnetization curve crosses zero at 98 K and exhibits a negative value below the compensation point. The hystersis loops at different temperatures have been measured: the magnetization curves show complicated magnetic properties in a strong external field. (C) 1999 Elsevier Science Ltd. All rights reserved.Physics, Condensed MatterSCI(E)EI8ARTICLE10655-65910
Full-dimensional quantum calculations of the rate constant for the HO+H2 -> H2O+H reaction
No full textManthe U, Seideman T, Miller WH. Full-dimensional quantum calculations of the rate constant for the HO+H2 -> H2O+H reaction. JOURNAL OF CHEMICAL PHYSICS. 1993;99(12):10078-10081
Wh-Islands: A View from Correspondence Theory
No full textThis paper discusses a family of restrictions on syntactic extraction, so-called wh-islands. The analysis will be based on the OT syntax model developed in Vogel (2004a,b) which focuses on the correspondence between semantic, syntactic and phonological representations, in the spirit of work by Jackendoff (1997), Williams (2003) and Culicover & Jackendoff (2005). I will argue that the wh-island restriction results from the impossibility to establish a perfect semantics-syntax mapping in the relevant structures. The resulting constraint violations add up to yield the wh-island effect. Exceptions to the wh-island restrictions in English are argued to be prosodically licensed.
Section 2 introduces the model I am using, and presents examples of some accounts of ineffability which I developed elsewhere. That section also introduces the basics of my treatment of wh-movement. Section 3 develops the account of wh-islands. Section 4 discusses the exceptions to the wh-island restriction that we see in English, and extends my account to handle these cases. The OT implementation of this account is presented in Section 5.The definitive version of this paper is published in Modeling Ungrammaticality in Optimality Theory. It is available at https://www.equinoxpub.com/equinox/books/showbook.asp?bkid=212Vogel, R. (2009). Wh-Islands: A View from Correspondence Theory. In C. Rice (Ed.), Ungrammaticality in Optimality Theory. Oakville, CT:Equinox Pub. Ltd, 2009ISBN-13 9781845532154 (published book
Differential effects of amphetamine on the expression of metabotropic glutamate receptor 5 and GluR2 subunit of AMPA receptor in cultured cortical and hippocampal neurons.
No full textMicrostructure and mechanical properties of mechanically alloyed and solid-state sintered tungsten heavy alloys
No full textThe mechanical properties of solid-state sintered 93W-5.6Ni-1.4Fe tungsten heavy alloys fabricated by mechanical alloying were investigated. Blended W, Ni and Fe powders were mechanically alloyed in a tumbler ball mill at a milling speed of 75 rpm employing a ball-to-powder ratio of 20:1 and a ball filling ratio of 15%. A nanocrystalline size of 16 nm and fine lamellar spacings of 0.2 mu m were obtained in mechanically alloyed powders at a steady state milling stage. Mechanically alloyed powders were consolidated into green compacts and solid-state sintered at 1300 degrees C for 1 h in a hydrogen atmosphere. The alloys sintered from mechanically alloyed powders showed fine tungsten particles (about 3 mu m in diameter) and a relative density above 99%. The volume fraction of the matrix phase was 11% and the tungsten/tungsten contiguity was determined to be 0.74. The alloys exhibited high yield strengths (about 1100 MPa) due to their fine microstructures, but exhibited reduced elongation and impact energy due to a large area fraction of tungsten/tungsten boundaries and the low volume fraction of matrix phase. (C) 2000 Elsevier Science S.A. All rights reserved.Korea Research Foundation
HMOX1 gene promoter alleles and high HO-1 levels are associated with severe malaria in Gambian children.
Full text linkHeme oxygenase 1 (HO-1) is an essential enzyme induced by heme and multiple stimuli associated with critical illness. In humans, polymorphisms in the HMOX1 gene promoter may influence the magnitude of HO-1 expression. In many diseases including murine malaria, HO-1 induction produces protective anti-inflammatory effects, but observations from patients suggest these may be limited to a narrow range of HO-1 induction, prompting us to investigate the role of HO-1 in malaria infection. In 307 Gambian children with either severe or uncomplicated P. falciparum malaria, we characterized the associations of HMOX1 promoter polymorphisms, HMOX1 mRNA inducibility, HO-1 protein levels in leucocytes (flow cytometry), and plasma (ELISA) with disease severity. The (GT)(n) repeat polymorphism in the HMOX1 promoter was associated with HMOX1 mRNA expression in white blood cells in vitro, and with severe disease and death, while high HO-1 levels were associated with severe disease. Neutrophils were the main HO-1-expressing cells in peripheral blood, and HMOX1 mRNA expression was upregulated by heme-moieties of lysed erythrocytes. We provide mechanistic evidence that induction of HMOX1 expression in neutrophils potentiates the respiratory burst, and propose this may be part of the causal pathway explaining the association between short (GT)(n) repeats and increased disease severity in malaria and other critical illnesses. Our findings suggest a genetic predisposition to higher levels of HO-1 is associated with severe illness, and enhances the neutrophil burst leading to oxidative damage of endothelial cells. These add important information to the discussion about possible therapeutic manipulation of HO-1 in critically ill patients
Matrix pools in a partially mechanically alloyed tungsten heavy alloy for localized shear deformation
No full textA fabrication process for a tungsten heavy alloy with matrix pools was suggested in order to increase the susceptibility to localized shear deformation. A partial mechanical alloying process was introduced to form matrix pools intentionally within a tungsten heavy alloy. The partially mechanically alloyed powders were sintered by solid-state sintering, followed by liquid-phase sintering. The volume fraction of matrix pools was decreased with an increase in the secondary liquid-phase sintering time. Penetration test showed that the matrix pools were effective in enhancing the triggering of localized shear deformation. (C) 2002 Elsevier Science B.V. All rights reserved.
Effect of SiC volume fraction on creep behavior of SiCp/2124Al metal matrix composite
No full textThe high temperature creep behavior of SiCp/2124Al metal matrix composites containing 10similar to30 vol.% of SiC particulate reinforcement was investigated to clarify the effect of the volume fraction of SiC particles on creep deformation. The SiCp/2124Al composites were fabricated by mixing 8mum SiC particles and 20mum 2124 Al powders and were followed by hot pressing at 570degreesC and hot extrusion at 500degreesC with an extrusion ratio of 25:1. The high temperature creep behavior of SiCp/2124Al composites was investigated by constant stress creep tests at 300degreesC. The load transfer phenomena of a spherical particle in metal matrix composite were analyzed based on the shear-lag model. The minimum creep rate of SiCp/2124Al composite decreased with increasing the volume fraction of SiC particles. The increase in the volume fraction of SiC particles reduces the effective stress for creep deformation of the Al matrix by the load transfer from the matrix to SiC particles. The minimum creep rates of SiCp/2124Al composites with different volume fractions of SiC particles were found to be similar under an identical effective stress on the matrix, which is calculated by the modified shear-lag model. It is suggested that the role of SiC particles is to increase the creep resistance by reducing the effective stress acting on the matrix in metal matrix composites
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