Endothelial cells (ECs) subjected to shear stress constantly release nitric oxide (NO). The effect of NO on shear stress-induced endothelial responses was examined. ECs subjected to shear stress induced a transient and shear force-dependent increase in early growth response-1 (Egr-1) mRNA levels. Treatment of ECs with an NO donor, S-nitroso-N-acetylpenicillamine (SNAP) or 3-morpholinosydnonimin...

This paper presents the results of a series of hollow cylinder tests carried out to investigate the role of drainage conditions on the response of railway track foundation materials during cyclic loading. Three sand–clay mixes were tested. It was found that, below a certain cyclic shear stress threshold, and depending on the drainage conditions, changes in principal stress direction should not ...

We find that unjammed packings of frictionless particles with rather weak attraction can always be driven into solidlike states by shear. The structure of shear-driven solids evolves continuously with packing fraction from gel-like to jamminglike, but is almost independent of the shear stress. In contrast, both the density of vibrational states (DOVS) and force network evolve progressively with...

OBJECTIVES It has been postulated that in the arterial system mean wall shear stress is maintained at a constant value. The present study was performed to investigate the level of wall shear stress in the common carotid artery (CCA) as function of age and possible interactions between diameter and storage capacity, defined as the absolute area change per heart beat, with mean wall shear stress....

The vascular vessel wall is constantly exposed to biomechanical forces, such as shear and tensile stress. Biomechanical forces are important for several physiological and pathological processes and have been shown to regulate a number of fundamental vascular functions, such as vascular tone and remodeling processes. The aim of the present thesis was to study the effects of biomechanical forces ...

The average bed and sidewall shear stresses in smooth rectangular open-channel flows are determined after solving the continuity and momentum equations. The analysis shows that the shear stresses are function of three components: (1) gravitational; (2) secondary flows; and (3) interfacial shear stress. An analytical solution in terms of series expansion is obtained for the case of constant eddy...

High levels of fluid shear stress at the blood vessel wall directly stimulate von Willebrand factor (vWF)-mediated platelet adhesion and aggregation and thereby contribute to the pathogenesis of arterial thrombosis. We have found that a pathological level of arterial wall shear stress (90 dynes/cm2) induces platelet aggregation that is associated with the phosphorylation of pleckstrin, a M(r) 4...

The glycocalyx layer on the surface of an endothelial cell is an interface barrier for uptake of macromolecules, such as low-density lipoprotein and albumin, in the cell. The shear-dependent uptake of macromolecules thus might govern the function of the glycocalyx layer. We therefore studied the effect of glycocalyx on the shear-dependent uptake of macromolecules into endothelial cells. Bovine ...

Fluid shear stress has profound effects on cell physiology. Here we present a versatile microfluidic method capable of generating variable magnitudes, gradients, and different modes of shear flow, to study sensory and force transduction mechanisms in cells. The chip allows cell culture under spatially resolved shear flow conditions as well as study of cell response to shear flow in real-time. U...

The wall shear stress pattern was measured in a rigid plastic cast of a canine artery during steady flow by means of an electrochemical technique. The topographic distribution of shear stress is very nonuniform, with regions of high and low shear in close proximity. The steady shear stresses are highest at the leading edge of flow dividers and at the entrance regions to branch vessels. The shap...