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In this article, a streamline diffusion finite element method is proposed and analyzed for stationary incompressible magnetohydrodynamics (MHD) equations. This method is stable for any combinations of velocity, pressure, and magnet finite element spaces, without requiring Ladyzenskaja-Babuska-Brezzi (LBB) condition. The well-posedness and convergence (at optimal error rate) of this scheme are proved in terms of some conditions. Two numerical experiments are illustrated to validate our theoretical analysis and show the streamline diffusion finite element approach is effective for solving the MHD problems. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1877–1901, 2014

The epithelial-mesenchymal transition (EMT) of tumor cells is deemed to be closely associated with tumor metastasis. CXCR4 has been proved to play an important role in the process of tumor metastasis. This study illustrates the function and expression of CXCR4 silencing and the EMT related genes in the human glioma cell line U87. The results showed that CXCR4 silencing could inhibit the cell invasive and adhesion potentials, expression of N-cadherin, vimentin, β-catenin, TGF-β1, p-Smad2, and p-Akt, and the activity of transcription factors NF-κB, AP-1, Snail, and twist. Meanwhile, CXCR4 silencing could also up-regulate the expression of E-cadherin, indicating that silencing of CXCR4 expression can inhibit the expression of EMT related genes in U87 cells. The study would provide a potential theoretical basis for the further exploration of the role of CXCR4 in human glioma.

A vibrating system with some kind of internal damping represents a distributed or passive control. In this article, a wave equation with clamped boundary conditions and internal Kelvin-Voigt damping is considered. It is shown that the spectrum of the system operator is composed of two parts: point spectrum and continuous spectrum. The point spectrum consists of isolated eigenvalues of finite algebraic multiplicity, and the continuous spectrum that is identical to the essential spectrum is an interval on the left real axis. The asymptotic behavior of eigenvalues is presented.

The synthesis of hydroxyl-terminated poly(trifluoropropylmethyl)siloxane (PTFPMS-OH) by anionic ring-opening polymerization of 1,3,5-tris(trifluoropropylmethyl)cyclotrisiloxane (D3F) was studied in bulk using potassium hydroxide as an initiator in the presence of several reaction stabilizers. The promoting effect of the reaction stabilizers for the polymerization of D3F was investigated by GPC and NMR analyses. Results showed that the selected reaction stabilizers exhibited a significant promoting effect. This new process of polymerization produced well-defined α,ω-dihydroxylated polysiloxane in very high yields. The addition of reaction stabilizers could almost completely suppress back-biting reactions during the polymerization. It was found that there lies an exponential decay relationship between the molecular weight of PTFPMS-OH and amount of end-capping agent. Thus, by adjusting the reaction conditions strictly, the molecular weight of the fluorosilicone could be controlled accurately, and meanwhile a broad “terminate window” could be implemented. Thermogravimetic (TG) analysis indicated that PTFPMS-OH could be used in a wide range of operational temperatures. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43220.

ABSRACT: The structure and viscoelastic properties of fumed silica gels in low molecular weight hydroxyl silicone oil were investigated by means of steady and dynamic rheology. It is found that the fumed silica/hydroxyl silicone oil suspension exhibits shear-thickening under steady shear and “strain-thickening” under oscillatory shear condition. Effects of hydroxy groups on the rheological behavior of silicone oil suspension with highly dispersed hydrophilic amorphous silica were investigated by infrared, 1 H-NMR, and rheological test. The results show that the hydroxy groups on this system play an important role on the formation of shear thickening behavior of the suspension solution. At the same particle diameter and mass fraction, the amount of hydroxy groups on this system has a strong effect on increasing the viscosity of the suspension, which is likely due to multiassociation hydrogen bonding between liquid molecules and silanol groups on fumed silica surfaces (SiAOH). V C 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40722.