Atherosclerotic lesions are found opposite vascular flow dividers at sites of low shear stress and oscillatory flow. Since endothelial proinflammatory genes prominent in lesions are regulated by oxidation-sensitive transcriptional control mechanisms, we examined the redox state of cultured human umbilical vein endothelial cells after either oscillatory or steady laminar fluid shear stress. Endo...

The dynamics and rheological behavior of colloidal gels under oscillatory shear flow have been studied by using the Brownian dynamics simulations. The dynamics is studied under the oscillatory shear of small, medium, and large amplitudes. In the small amplitude oscillatory shear (SAOS) regime, the colloidal gel retains a rigid-chain network structure. The colloidal gel oscillates with small str...

BACKGROUND Exposure to disturbed flow, including oscillatory shear stress, stimulates endothelial cells (ECs) to produce bone morphogenic protein (BMP) 4, which in turn activates inflammation, a critical atherogenic step. BMP activity is regulated by the level of BMP antagonists. Until now it was not known whether shear also regulates the expression of BMP antagonists and whether they play a ro...

Organic nanoparticles of poly(styrene-co-maleimide) or SMI were synthesized in aqueous dispersion with a maximum concentration of 35 wt.% and are favorably applied in industrial coating processes. In order to evaluate the further processability and flow behavior of these nanoparticle dispersions, general rheological characterization under creep, oscillatory and rotational testing was done by ap...

Low and oscillatory shear stresses are major features of the hemodynamic environment of sites opposite arterial flow dividers that are predisposed to atherosclerosis. Atherosclerosis is a focal inflammatory disease characterized initially by the recruitment of mononuclear cells into the arterial wall. The specific characteristics of the hemodynamic environment that facilitate the generation of ...

Nitric oxide (NO) has been demonstrated to play a central role in vascular biology and pathobiology. The expression of endothelial NO synthase (eNOS) is regulated in part by blood flow-induced mechanical factors. The purpose of this study was to evaluate how the expression of eNOS mRNA correlates with the activation of its promoter in both arterial and venous endothelial cells (ECs) exposed to ...

In this study, we characterize the shear and extensional rheology of dilute to semidilute solutions of cellulose in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIAc). In steady shear flow, the semidilute solutions exhibit shear thinning, and the high-frequency complex modulus measured in small amplitude oscillatory shear flow exhibits the characteristic scaling expected for solutions...

We investigate spinodal decomposition and structuring effects in binary immiscible and ternary amphiphilic fluid mixtures under shear by means of three-dimensional lattice Boltzmann simulations. We show that the growth of individual fluid domains can be arrested by adding surfactant to the system, thus forming a bicontinuous microemulsion. We demonstrate that the maximum domain size and the tim...

Endothelial cells (ECs) play a significant role in modulating arterial functions [1,2]. ECs are the interface between vessel wall and blood flow, and perform tasks such as the regulation of permeability and the sensing of fluid forces acting on the vessels’ walls. ECs have shown contrasting effects between laminar shear flow with a definite direction the “disturbed” shear seen at arterial branc...

Variable-amplitude oscillatory shear tests are emerging as powerful tools to investigate and quantify the nonlinear rheology of amorphous solids, complex fluids, and biological materials. Quite a few recent experimental and atomistic simulation studies demonstrated that at low shear amplitudes, an amorphous solid settles into an amplitude- and initial-conditions-dependent dissipative limit cycl...