课程文献中心 更多>>

关键词： Atangana-Baleanu Caputo derivative   Fractional integro-differential equation   Linear scheme   Quadratic scheme   Quadratic-linear scheme  

摘要： This study contains numerical schemes namely Linear scheme, Quadratic scheme, and Quadratic-linear scheme to solve a fractional integro-differential equation using the Atangana-Baleanu derivative defined in Caputo sense. The error bounds of the schemes are obtained. We discuss four test examples to perform the numerical simulations, and the obtained numerical results ensure that the presented schemes work well and the obtained approximate solution agrees with the analytical solution. The convergence order and maximum absolute errors of the schemes are calculated and their comparative performances are discussed.

关键词： Nonlinear fractional differential equation   Caputo derivative   Generalized Mittag-Leffler function   Exponential integrator  

摘要： The fractional differential equation has been used to describe many phenomenons in almost all applied sciences, such as fluid flow in porous materials, anomalous diffusion transport, acoustic wave propagation in viscoelastic materials, and others. In some cases, it is complicated to find the analytical solution of a fractional differential equation, so there are some special techniques to approximate the solution. In this paper, a new collocation method for a class of semilinear fractional differential equations has been constructed. The convergence properties of the proposed methods and the computational complexity are treated. Some numerical experiments are presented to validate the theoretical results. The proposed numerical method provides an alternative way to study some physical phenomena by fractional differential equations.

关键词： analysis of rate data   differential method   fractional calculus   integral method  

摘要： The kinetic study of chemical reactions is usually carried out by means of analysis of experimental rate data obtained during the evolution of a reaction in a batch reactor. The methods for analysis of rate data obtained in a batch reactor include the classical integral methods (CIM) and classical differential methods (CDM), which use temporal derivatives of the unit-order concentration, dC(A)/dt, in the mass balance equation. The present study proposes these two methods of analysis in a generalized formulation that makes use of non-integer order temporal derivatives, d(alpha)C(A)/dt(alpha), 0

关键词： conceptus elongation   porcine   RNA-Seq   transcriptome   uterine environment  

摘要： This study aimed to identify transcriptome differences between distinct or transitional stage spherical, ovoid, and tubular porcine blastocysts throughout the initiation of elongation. We performed a global transcriptome analysis of differential gene expression using RNA-Seq with high temporal resolution between spherical, ovoid, and tubular stage blastocysts at specific sequential stages of development from litters containing conceptus populations of distinct or transitional blastocysts. After RNA-Seq analysis, significant differentially expressed genes (DEGs) and pathways were identified between distinct morphologies or sequential development stages. Overall, 1898 significant DEGs were identified between distinct spherical and ovoid morphologies, with 311 total DEGs between developmental stages throughout this first morphological transition, while 15 were identified between distinct ovoid and tubular, with eight total throughout these second morphological transition developmental stages. The high quantity of DEGs and pathways between conceptus stages throughout the spherical to ovoid transition suggests the importance of gene regulation during this first morphological transition for initiating elongation. Further, extensive DEG coverage of known elongation signaling pathways was illustrated from spherical to ovoid, and regulation of lipid signaling and membrane/ECM remodeling across these early conceptus stages were implicated as essential to this process, providing novel insights into potential mechanisms governing this rapid morphological change.

关键词： gene regulatory network   local network entropy   lung adenocarcinoma   multi-omics data   small-word characteristic   tumor progression  

摘要： A systematic method was proposed to infer differential gene regulatory networks (GRNs) among lung adenocarcinoma (LUAD) samples at different stages by integrating multi-omics data to uncover significant network features and to identify tumor progression (TP) biomarker genes. The mRNA expressions, copy number variations, and DNA methylations of two independent LUAD cohorts (TCGA and SPORE) at stages I, II, and III were used, respectively. As results, the transition from normal to early onset was showed to be critical to reveal the pathogenesis of LUAD;61 genes were identified as TP-related biomarkers, including two types of microRNAs of ABLIM2 and ZFAS1. These identified biomarkers may set light on the underlying mechanism of LUAD TP and may serve as potential drug targets for new treatments. Moreover, our study provides a general framework for TP biomarker identification for other types of cancer, which may improve the mechanism research for cancer development.

关键词： magnetoencephalography   MEG   oscillations   occipital cortex   peak frequency  

摘要： Visual processing is widely understood to be served by a decrease in alpha activity in occipital cortices, largely concurrent with an increase in gamma activity. Although the characteristics of these oscillations are well documented in response to a range of complex visual stimuli, little is known about how these dynamics are impacted by concurrent motor responses, which is problematic as many common visual tasks involve such responses. Thus, in the current study, we used magnetoencephalography (MEG) and modified a well-established visual paradigm to explore the impact of motor responses on visual oscillatory activity. Thirty-four healthy adults viewed a moving gabor (grating) stimulus that was known to elicit robust alpha and gamma oscillations in occipital cortices. Frequency and power characteristics were assessed statistically for differences as a function of movement condition. Our results indicated that occipital alpha significantly increased in power during movement relative to no movement trials. No differences in peak frequency or power were found for gamma responses between the two movement conditions. These results provide valuable evidence of visuomotor integration and underscore the importance of careful task design and interpretation, especially in the context of complex visual processing, and suggest that even basic motor responses alter occipital visual oscillations in healthy adults. NEW & NOTEWORTHY Processing of visual stimuli is served by occipital alpha and gamma activity. Many studies have investigated the impact of visual stimuli on motor cortical responses, but few studies have systematically investigated the impact of motor responses on visual oscillations. We found that when participants are asked to move in response to a visual stimulus, occipital alpha power was modulated whereas gamma responses were unaffected. This suggests that these responses have dissociable roles in visuomotor integration.

关键词： Uric acid   Atherosclerosis   Arterial stiffness   Febuxostat   Xanthine oxidase  

摘要： Atherosclerosis and arterial stiffness are phenotypes of atherosclerotic vascular damage. Atherosclerosis originates from endothelial vascular damage and forms focal morphological lesions;arterial stiffness originates from diffuse medial-layer damage in the arterial tree. Thus, the two phenomena reflect different facets of atherosclerotic vascular damage, and they both gradually progress. We conducted a subanalysis to compare the long-term effects of febuxostat on atherosclerosis and arterial stiffness in the PRIZE study (a multicenter, prospective, randomized, open-label, blinded-endpoint clinical trial to examine the effect of febuxostat on carotid atherosclerosis). Among 514 study participants, arterial stiffness parameters (brachial-ankle pulse wave velocity or cardio-ankle vascular index) were obtained at baseline, 12 months, and 24 months in 100 subjects. Among them, 48 subjects were allocated to the control group (i.e., nonpharmacological lifestyle modification for hyperuricemia), and 52 subjects were allocated to the febuxostat treatment group. While the decrease in serum uric acid was greater in the febuxostat group than in the control group, the adjusted percentage decrease in arterial stiffness parameters at month 24 was greater in the febuxostat group than in the control group, with a mean between-group difference (febuxostat - control) of -5.099% (95% confidence interval (CI) -10.009% to -0.188%, p = 0.042). Thus, long-term treatment with febuxostat may exert beneficial effects on arterial stiffness without improving carotid atherosclerosis. A long-term study to examine the effect of febuxostat on cardiovascular outcomes related to increased arterial stiffness is warranted.

关键词： Hammerstein integral equation   Fractional differential equation   Fixed point   b-metric like space  

摘要： Nonlinear integral equations (particularly Hammerstein integral equations) and fractional differential equations have been the center of extensive research for various scientists because of their practical and physical significance. In this article, our focus is to find the sufficient conditions for the existence of solutions of some class of Hammerstein integral equations and fractional differential equations. For this purpose, we extend the notion of Kannan mappings in view of F-contraction in the setting of b-metric like spaces. Moreover, to address conceptual depth within this approach, we supply series of innovative and nontrivial examples to illustrate the established results along with computer simulation, thereby propounding the concept in a quite novel way. At the other end, some open problems are proposed for enthusiastic readers.

关键词： Singular perturbation problems   Boundary layers   System of nonlinear differential equations   Finite difference scheme   Shishkin mesh   Parameter-uniform convergence  

摘要： In this article, a boundary value problem for a nonlinear system of singularly perturbed two second order differential equations in which only the first equation is multiplied by a small positive parameter is considered. The first component of the solution exhibits boundary layers whereas the second component exhibits less-severe layers. A numerical method composed of a classical finite difference scheme applied on a piecewise uniform Shishkin mesh is suggested to solve the system. The method is proved to be essentially second order convergent in the maximum norm uniformly with respect to the perturbation parameter. Numerical illustration presented supports the proved theoretical results.

关键词： GPI-anchored proteins   p24 complex   subunit composition   transport   Wnt1  

摘要： Complexes of p24 proteins act as cargo receptors for the transport of COPII vesicles from the endoplasmic reticulum (ER). The major cargos of p24 complexes are hydrophilic proteins tethered to the ER membrane via a covalently attached glycosylphosphatidylinositol (GPI) or fatty acid. Each p24 complex is known to contain members from all four p24 subfamilies (p24α, p24β, p24γ and p24δ). However, it remains unclear how the cargo specificities of p24 complexes are influenced by member stoichiometry. Here, we report the subunit compositions of mammalian p24 complexes involved in the transport of GPI-anchored proteins and Wnt1. We show that at least one p24α is required for the formation of p24 complexes and that a p24 complex consisting of p24α2, p24β1, p24γ2 and p24δ1 is required for the efficient transport of GPI-anchored proteins. On the other hand, a p24 complex containing p24α2, p24α3, p24β1, p24γ and p24δ1 is involved in the transport of Wnt1. Further, interactions between p24α2 and p24α3 are critical for Wnt1 transport. Thus, p24α and p24γ subfamily members are important for cargo selectivity. Lastly, our data fit with an octamer, rather than a tetramer, model of p24 complexes, where each complex consists of two proteins from each p24 subfamily.