OBJECTIVE Arterial-venous specification in the embryo has been assumed to depend on the influence of fluid mechanical forces, but its cellular and molecular mechanisms are still poorly understood. Our previous in vitro study revealed that fluid shear stress induces endothelial cell (EC) differentiation by murine embryonic stem (ES) cells. In the present study we investigated whether shear stres...

Fluid shear stress is an important regulator of vascular and endothelial cell (EC) functions. Its effect is dependent not only on magnitude but also on flow type. Although laminar flow predominates in the vasculature, transitional flow can occur and is thought to play a role in vascular diseases. While a great deal is known about the mechanisms and signaling cascades through which laminar shear...

foundations behavior is affected by soil behavior which can vary from dilative to contractive depending on the stress level, particularly in dense frictional soils. the zero extension lines (zel) method has been generally developed to predict the foundations behavior. knowledge of soil behavior enables the zel method to predict the general and local shear failure modes. in this paper, a relativ...

this study deals with the applications of a trigonometric shear deformation theory considering the effect of the transverse shear deformation on the static flexural analysis of the soft core sandwich beams. the theory gives realistic variation of the transverse shear stress through the thickness, and satisfies the transverse shear stress free conditions at the top and bottom surfaces of the bea...

Interstitial fluid flow (IFF) within the extracellular matrix (ECM) produces low magnitude shear stresses on cells. Fluid flow-induced stress (FSS) plays an important role during tissue morphogenesis. To investigate the effect of low FSS generated by IFF on cells, we developed a microfluidic-based cell culture device that can generate multiple low shear stresses. By changing the length and widt...

BACKGROUND Regions in the vasculature exposed to steady laminar flow have a lower likelihood for atherosclerosis than regions exposed to disturbed flow with low shear stress. We previously found that laminar flow of short duration inhibited tumor necrosis factor (TNF)-alpha-mediated proinflammatory signaling in cultured endothelial cells (ECs). However, mechanisms responsible for the atheroprot...

In startup of steady shearing flow of two viscous unentangled liquids, namely low-molecular-weight polystyrene and -Dglucose, the shear stress catastrophically collapses if the shear rate is raised above a value coresponding to a critical initial shear stress of around 0.1-0.3 Mpa. The time-dependence of the shear stress during

Selectins are cell adhesion molecules that mediate capture and rolling adhesion of white blood cells to vascular walls, an essential component of the inflammatory response. Adhesion through L-selectin requires a hydrodynamic shear stress above a threshold level, a phenomenon known as the shear threshold effect. We have reported that the shear threshold effect can he re-created in cell-free syst...

We tested the hypothesis that under physiological conditions, arterioles match their diameter to the level of shear stress. Haemodynamic and anatomical data were obtained in segments of the first-order arteriole of the rat cremaster muscle. Along this segment of ~10 mm in length, local blood pressure decreased from 68 +/- 4 mmHg upstream to 54 +/- 3 mmHg downstream (n = 5). Pulse pressure decre...

BACKGROUND The complement system is implicated in the pathogenesis of atherosclerosis. Complement has been shown to activate endothelial cells (ECs) by inducing a proinflammatory response. Physiological levels of shear stress exert potent antiatherosclerotic effects. Therefore, we investigated whether shear stress antagonizes the effects of complement on ECs. METHODS AND RESULTS Incubation of...