The vascular endothelium is exposed to a spectrum of fluid mechanical forces generated by blood flow; some of these, such as fluid shear stress, can directly modulate endothelial gene expression. Previous work by others and in our laboratory, using an in vitro uniform laminar shear stress model, has identified various shear stress response elements (SSREs) within the promoters of certain endoth...

Dyslipidemia is a primary risk factor for cardiovascular disease, but the specific mechanisms that determine the localization of atherosclerotic plaques in arteries are not well defined. Triglyceride-rich lipoproteins (TGRL) isolated from human plasma after a high-fat meal modulate TNF-α-induced VCAM-1 expression in cultured human aortic endothelial cells (HAECs) via an interferon regulatory fa...

An electro-rheological fluid is a material in which a particulate solid is suspended in an electrically non-conducting fluid such as oil. On the application of an electric field, the viscosity and other material properties undergo dramatic and significant changes. In this paper, the particulate imbedded fluid is considered as a homogeneous continuum. I t is assumed that the Cauchy stress depend...

The problem of blood flow through an overlapping constriction in arteries is investigated in this work. To account for the non-Newtonian behavior and the peripheral layer, blood has been represented by a two-fluid model, consisting of a core region of suspension of all the erythrocytes assumed to be a Casson fluid and a peripheral layer of plasma (Newtonian fluid). The expression for the flow c...

BACKGROUND AND PURPOSE Attempts have been made to associate intracranial aneurysmal hemodynamics with aneurysm growth and rupture status. Hemodynamics in aneurysms is traditionally determined with computational fluid dynamics by using generalized inflow boundary conditions in a parent artery. Recently, patient-specific inflow boundary conditions are being implemented more frequently. Our purpos...

Fluid shear stress enhances NO production in endothelial cells by a mechanism involving the activation of the phosphatidylinositol 3-kinase and the phosphorylation of the endothelial NO synthase (eNOS). We investigated the role of the scaffolding protein Gab1 and the tyrosine phosphatase SHP2 in this signal transduction cascade in cultured and native endothelial cells. Fluid shear stress elicit...

Objective. This in vitro study compared the flow pattern and shear stress of an irrigant induced by ultrasonic and polymer rotary finishing file activation in an acrylic root canal model. Flow visualization analysis was performed using an acrylic canal filled with a mixture of distilled water and rheoscopic fluid. The ultrasonic and polymer rotary finishing file were separately tested in the ca...

Fluid shear stress greatly influences the biology of vascular endothelial cells and the pathogenesis of atherosclerosis. Endothelial cells undergo profound shape change and reorientation in response to physiological levels of fluid shear stress. These morphological changes influence cell function; however, the processes that produce them are poorly understood. We have examined how actin assembl...

New analytic solutions for unsteady magnetohydrodynamic (MHD) flows of a generalized second-grade fluid have been derived. The generalized second-grade fluid saturates the porous space. Fractional derivative is used in the governing equation. The analytical expressions for velocity and shear stress fields have been obtained by using Laplace transform technique for the fractional calculus. The o...