6,807 research outputs found
Wood smoke extract induces oxidative stress-mediated caspase-independent apoptosis in human lung endothelial cells: role of AIF and EndoG
No full textDifferential requirements of NS4A for internal NS3 cleavage and polyprotein processing of hepatitis C virus.
No full textHepatitis C virus NS4A inhibits cap-dependent and the viral IRES-mediated translation through interacting with eukaryotic elongation factor 1A.
No full textHIGH RESOLUTION FOURIER TRANSFORM EMISSION SPECTROSCOPY OF YH AND YD.
No full textAuthor Institution: Department of Chemistry, University of Arizona; Department of Chemistry, University of WaterlooThe electronic emission spectrum of YH and YD has been investigated in the 690 nm to 3 spectral region using a Fourier transform spectrometer. The YH and YD bands were excited in an yttrium hollow cathode lamp operated with neon gas and a trace of of The observed bands have been classified into three different electronic transitions; and . The transition of YD could not be identified due to its very weak intensity. The rotational analysis of several bands of the transition (up to for YH and for YD) provides improved equilibrium vibrational and rotational constants for the ground state of YH and YD. The excited state is involved in several perturbations
Assembly of severe acute respiratory syndrome coronavirus RNA packaging signal into virus-like particles is nucleocapsid dependent.
No full textInvolvement of adrenoceptors, dopamine receptors and AMPA receptors in antidepressant-like action of 7-O-ethylfangchinoline in mice
No full textAim: 7-O-ethylfangchinoline (YH-200) is a bisbenzylisoquinoline derivative. The aim of this study was to investigate the antidepressant-like action and underlying mechanisms of YH-200 in mice. Methods: Mice were treated with YH-200 (15, 30, and 60 mg/kg, ig) or tetrandrine (30 and 60 mg/kg, ig) before conducting forced swimming test (FST), tail suspension test (TST), or open field test (OFT). Results: YH-200 (60 mg/kg) significantly decreased the immobility time in both FST and TST, and prolonged the latency to immobility in FST. YH-200 (60 mg/kg) was more potent than the natural bisbenzylisoquinoline alkaloid tetrandrine (60 mg/kg) in FST. Pretreatment with alpha(1)-adrenoceptor antagonist prazosin (1 mg/kg), beta-adrenoceptor antagonist propranolol (2 mg/kg), dopamine D-1/D-5 receptor antagonist SCH23390 (0.05 mg/kg), dopamine D-2/D-3 receptor antagonist haloperidol (0.2 mg/kg) or AMPA receptor antagonist NBQX (10 mg/kg) prevented the antidepressant-like action of YH-200 (60 mg/kg) in FST. In contrast, pretreatment with alpha(2) adrenoceptor antagonist yohimbine (1 mg/kg) augmented the antidepressant-like action of YH-200 (30 mg/kg) in FST. Chronic administration of YH-200 (30 and 60 mg/kg for 14 d) did not produce drug tolerance; instead its antidepressant-like action was strengthened. Chronic administration of YH-200 did not affect the body weight of mice compared to control mice. Conclusion: YH-200 exerts its antidepressant-like action in mice via acting at multi-targets, including alpha(1), alpha(2) and beta-adrenoceptors, D-1/D-5 and D-2 /D-3 receptors, as well as AMPA receptors.National Natural Science Foundation of China [81173031, 81202511, 81302746]SCI(E)PubMed中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)[email protected]
La doped SrTiO3 thin films on SrLaAlO4 (001) as transparent conductor
No full textTransparent conductors are essential for many optoelectronic applications, and economically viable replacement for the industry standard transparent conductor, indium tin oxide, is in dire need. Electronic structure calculations are performed to confirm that La doping in a band insulator SrTiO3 provides carriers in the conduction band without generating in-gap states and thus La doped SrTiO3 would retain good optical transparency. To realize the computational results, we synthesize La doped SrTiO3 in thin film form and characterize the films. It is demonstrated that 10% La doped SrTiO3 thin films on SrLaAlO4 (001) substrates are indeed transparent conductors with sheet resistance R-S similar to 60 Omega/square and 80% transmission in the visible wavelength range at room temperature. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.open1145sciescopu
Porous structure modeling with computers
No full textPorous structures are a particular type of solids, where a large number of pores exist in the geometric domain of interest. Research on porous structures have received increasingly keen interest in recent years and this is largely because of many unique and superior properties that porous structures possess. They can undertake special tasks which general solid materials are not competent to do.
In recent twenty years numerous representations are put forward for porous structure modeling. But the challenges in practical porous structure design still exist and the structure heterogeneity brings many difficulties. This thesis is motivated to propose new porous structure modeling strategies which are more accurate, flexible and easy for porous structure description.
An approach of porous structure modeling based on quadtree/octree and NURBS is proposed first. Quadtree and octree are tools for modeling domain partition. The pore size and pore distribution are controlled by the flexibility of quadtree and octree enumeration technique. Derived polygon and polyhedron are then introduced to assist the generation of NURBS curves and surfaces. These NURBS curves and surfaces form the boundaries of the porous structures.
However there are limitations of the above method. The accurate control of porosity is not easily achieved in 3D porous structure modeling and seemingly adopting quadtree/octree for the modeling domain partition is also less than satisfactory. Hence a new representation for porous structures based on Centroidal Voronoi tessellation (CVT) and pore-network is put forward. CVT is utilized for modeling domain partition because the CVT cells are approximate hexagons which is widely existent in plants, animals and other cellular structures in nature. The density distribution function used in CVT generation also helps to build functionally graded porous structures. Pore-network, which is a mature and commonly used model in the research of multiphase flow in porous media, is subsequently introduced to build the porous structures. This modeling approach results in porous structures that could mimic the geometry and performance of structures in nature.
To evaluate the object’s properties, finite element analysis (FEA) is conducted on the porous structure models represented by the two methods. The mechanics properties of the two types of models are analyzed. The stress-strain curve of each sample is plotted and the effective Young’s modulus is calculated. Comparison of these two types of models is also done. Besides, the contributions of the thesis and suggestions for future research are also discussed.published_or_final_versionMechanical EngineeringMasterMaster of Philosoph
Labor Migration and Returns to Rural Education in China
No full textThis paper provides an answer to the following question: Why do empirical studies find low returns to schooling in rural China, and yet the schooling rates are high? I find that schooling played a significant role in raising the accessibility of urban formal employment to rural people in the late 1970s and early 1980s in the face of the government's restrictive policy on labor migration from rural to urban areas. The large urban-rural income difference provided a strong incentive for senior high school education. The theory also explains the drop in the senior high school attendance in the mid 1980s. Copyright 1997, Oxford University Press.
The Role of Migrant Networks in Labor Migration: The Case of China
No full textUsing recent household survey data from rural China, this article investigates determinants of labor migration, paying special attention to the role of migrant networks. Migrant networks are measured by the number of early migrants from the village, comprised of experienced migrants who continue their migratory activities and return migrants. Observations of early migrants are excluded from regression analyses to enable identification. Results show that experienced migrants have a positive and significant effect on subsequent migration, but return migrants do not. This implies that migrant networks are important, and their effects materialize through practical assistance in the process of migration. (JEL "J61", "O15", "Z13") Copyright 2003 Western Economic Association International.
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