In this paper, we focus on developing a high efficient algorithm for solving -dimension time-fractional diffusion equation (TFDE). For TFDE, the initial function or source term is usually not smooth, which can lead to the low regularity of exact solution. And such low regularity has a marked impact on the convergence rate of numerical method.
View Article and Find Full Text PDFIn this paper, we derive several a posteriori error estimators for generalized diffusion equation with delay in a convex polygonal domain. The Crank-Nicolson method for time discretization is used and a continuous, piecewise linear finite element space is employed for the space discretization. The a posteriori error estimators corresponding to space discretization are derived by using the interpolation estimates.
View Article and Find Full Text PDFScientificWorldJournal
June 2015
This paper is devoted to investigating the numerical solution for a class of fractional diffusion-wave equations with a variable coefficient where the fractional derivatives are described in the Caputo sense. The approach is based on the collocation technique where the shifted Chebyshev polynomials in time and the sinc functions in space are utilized, respectively. The problem is reduced to the solution of a system of linear algebraic equations.
View Article and Find Full Text PDFScientificWorldJournal
December 2014
In continuum one-dimensional space, a coupled directed continuous time random walk model is proposed, where the random walker jumps toward one direction and the waiting time between jumps affects the subsequent jump. In the proposed model, the Laplace-Laplace transform of the probability density function P(x, t) of finding the walker at position x at time t is completely determined by the Laplace transform of the probability density function φ(t) of the waiting time. In terms of the probability density function of the waiting time in the Laplace domain, the limit distribution of the random process and the corresponding evolving equations are derived.
View Article and Find Full Text PDFInterstitial fibrosis is regarded as the main pathway for the progression of chronic kidney disease (CKD) and is often associated with severe renal dysfunction. Stem cell-based therapies may provide alternative approaches for the treatment of CKD. Human amniotic fluid-derived stem cells (hAFSCs) are a novel stem cell population, which exhibit both embryonic and mesenchymal stem cell characteristics.
View Article and Find Full Text PDFAims: It is well recognized that microvascular injury is a major determinant of renal fibrosis. Mounting evidence shows that nitric oxide (NO) plays an important role in angiogenesis. Therefore, we investigated to the effects of NO on kidney angiogenesis and renal fibrosis.
View Article and Find Full Text PDFBackground/aims: Thrombospondin-1 (TSP-1), a naturally occurring inhibitor of angiogenesis, is an important mediator of renal fibrosis in clinical and experimental kidney disease. Increasing evidence shows that the microvasculature plays a critical role in progressive renal disease. The present study was undertaken to investigate whether interstitial fibrosis could be prevented by abolishing TSP-1 function in unilateral ureteral obstruction (UUO)-induced renal fibrosis.
View Article and Find Full Text PDFQuinocetone (QCT), a new antimicrobial growth promotant of quinoxalines, can effectively improve the growth and feed efficiency of food animals with more safety than is provided by olaquindox and carbadox. To clarify its metabolism and residue levels in animals, a liquid chromatographic method with UV-Vis detection was developed for the determination of QCT and its main metabolites, desoxyquinocetone (DQCT) and 3-methylquinoxaline-2-carboxylic acid (MQCA), in muscle, liver, kidney, and fat of swine and chicken. For sample pretreatment, QCT and DQCT were extracted with ethyl acetate and purified with iso-octane; after alkaline hydrolysis of the tissue, MQCA was extracted with ethyl acetate and citric acid buffer (pH 6.
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