The present article concerns the problem of blood flow through an artery with an axially asymmetric stenosis (constriction). The two-layered macroscopic model consisting of a cell-rich core of suspension of all the erythrocytes described as a particle-fluid suspension (Jeffrey fluid) and a peripheral zone of cell-free plasma (Newtonian fluid). The analytical expressions for flow characteristics...

This article describes molecular dynamics simulations of an ionic liquid (IL) confined between iron oxide surfaces under relatively high pressure and severe shearing, representative of a typical steel-steel lubricated contact. The simulations reveal the presence of hydrodynamic and thermal slip at the walls, despite the wetting nature of the fluid/wall interface. A crucial consequence of the te...

Mechanical loading is crucial for maintenance of bone integrity and architecture, and prostaglandins are an important mediator of mechanosensing. Cyclooxygenase-2 (COX-2), an inducible isoform of prostaglandin G/H synthase, is induced by mechanical loading-derived fluid shear stress in bone-forming cells such as osteoblasts and osteocytes. In this study, we investigated transcription factor and...

Our goal was to develop a method to identify the optimal elastic modulus, Poisson's ratio, porosity, and permeability values for a mechanically stressed bone substitute. We hypothesized that a porous bone substitute that favors the transport of nutriments, wastes, biochemical signals, and cells, while keeping the fluid-induced shear stress within a range that stimulates osteoblasts, would likel...

Interstitial flow is an important regulator of various cell behaviors both in vitro and in vivo, yet the forces that fluid flow imposes on cells embedded in a 3D extracellular matrix (ECM), and the effects of matrix architecture on those forces, are not well understood. Here, we demonstrate how fiber alignment can affect the shear and pressure forces on the cell and ECM. Using computational flu...

Endothelial cells (ECs) line the mammalian vascular system and respond to the hemodynamic stimulus of fluid shear stress, the frictional force produced by blood flow. When ECs are exposed to shear stress, one of the fastest responses is an increase of K(+) conductance, which suggests that ion channels are involved in the early shear stress response. Here we show that an applied shear stress ind...

The binding of plasma von Willebrand factor (VWF) to platelet receptor GpIb under high hydrodynamic shear leads to platelet activation and subsequent shear-induced platelet aggregation (SIPA). We quantitatively examined the aspects of fluid flow that regulate platelet activation by subjecting human blood and isolated platelets to well-defined shear conditions in a cone-plate viscometer. We made...

Success of a drilling, workover or completion fluid can be directly attributed to its viscosity at the shear rate of interest. In practice, fluids are subjected to a wide range of shear rates; therefore, a thorough understanding of fluid rheology and the impact of shear is necessary to optimize fluid design. Ideally, high viscosity is desirable only under low shear rate conditions, and should d...

Soluble inhibitors find widespread applications as therapeutic drugs to reduce the ability of eukaryotic cells, bacteria, or viruses to adhere to surfaces and host tissues. Mechanical forces resulting from fluid flow are often present under in vivo conditions, and it is commonly presumed that fluid flow will further add to the inhibitive effect seen under static conditions. In striking contrast...

A theoretical connection between nonlinear shear viscosity and the long time tail of the equilibrium stress-stress correlation function is pointed out. The connection is a consequence of the Goddard-Miller rheological equation of state which takes into account the angular rotation of a fluid in steady uniform shear.