Many studies of the human vascular tree have shown that atherosclerosis develops at an early age, with areas of the posterior aorta and branch sites showing the earliest fatty streaks. Closer analysis of the branch points showed that the flow dividers, regions of high shear stress with laminar flow, were relatively protected from fatty streak formation. In contrast, there was a predilection for...

OBJECTIVES We compared the accuracy of quantified myocardial flow reserve and absolute stress myocardial blood flow (MBF) alone in the detection of coronary artery disease (CAD). BACKGROUND Myocardial flow reserve, i.e. ratio of stress and rest flow, has been commonly used to detect CAD with many imaging modalities. However, it is not known whether absolute stress flow alone is sufficient for...

Dinoflagellate bioluminescence provides a near-instantaneous reporter of cell response to flow. Although both fluid shear stress and acceleration are thought to be stimulatory, previous studies have used flow fields dominated by shear. In the present study, computational and experimental approaches were used to assess the relative contributions to bioluminescence stimulation of shear stress and...

Gojova, Andrea, and Abdul I. Barakat. Vascular endothelial wound closure under shear stress: role of membrane fluidity and flow-sensitive ion channels. J Appl Physiol 98: 2355–2362, 2005. First published February 10, 2005; doi:10.1152/japplphysiol.01136.2004.— Sufficiently rapid healing of vascular endothelium following injury is essential for preventing further pathological complications. Rece...

In the present investigation, a mathematical model is developed to study the flow of blood in a multiple stenosed artery employing velocity slip condition under the externally applied transverse magnetic field. Blood is modeled as Herschel-Bulkley fluid to represent the non-Newtonian character of blood in small blood vessels. The expressions for wall shear stress, volumetric flow rate, axial ve...

The effects of an overlapping stenosis on blood flow characteristics in a narrow artery have been investigated. To account for the non-Newtonian behavior, blood has been represented by a Casson fluid. The equation describing the flow has been solved and the expressions for the flow characteristics, namely, the impedance, the wall shear stress, the shear stress at the stenosis throats and the sh...

the main objective of an extrusion die is flow balancing as an unbalanced flow causes a distorted product together with residual stress. in this paper a strategy is presented for flow balancing a u-shaped profile with different wall thicknesses. for this purpose, a choker bar is provided at thicker wall to locally restrict excessive flow passing through the thicker section. for optimal design s...

Endothelial cells in vivo are well known to respond to parallel shear stress induced by luminal blood flow. In addition, fluid filtration across endothelium (transendothelial flow) may trigger nitric oxide (NO) production, presumably via shear stress within intercellular clefts. Since NO regulates neutrophil-endothelial interactions, we determined whether transendothelial flow regulates neutrop...

The validity of the flow-mediated dilation test has been questioned due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using Poiseuille's law. However, little attention has been given to the most appropriate blood velocity parameter(s) for calculating shear stress. The pulsatile nature of blood flow exposes the endothelial cells to two distinc...

Microscopic structure in bubbly flows is a topic of interest in the study of fluid flows. In the present paper, the Ultrasonic Doppler Method was applied to the measurement of bubbly flows from which Reynolds stress profiles were obtained. Experiments were carried out for an air-water dispersed bubbly flow in a 20mm x 100 mm vertical rectangular channel having a void fraction smaller than 3%. T...