It is assumed that critical hemodynamic factors play an important role in the onset, localization and degree of post-operative complications, for example, thrombosis and restenosis. Of special interest are sudden expansion flows, which may occur in straight artery segments such as the common carotid after endarterectomy or end-to-end anastomoses. Sudden expansion geometries are possible origins...

The magnitude of shear stimulus has been shown to determine the level of growth factor expression in cell culture. However, little is known regarding what effect shear level has on specific arterial wall remodeling events in vivo. We have hypothesized that the rate of luminal diameter change and specific remodeling events within the arterial wall layers are dependent on shear level. Selective l...

An experimental investigation of the wall shear stress distribution downstream of a backward-facing step is carried out. The wall shear stress distribution was determined by measuring the deformation of a gel layer, attached to the wall downstream of the step. Speckle pattern interferometry was applied to measure the deformation of the gel layer. The measured deformation, combined with the prop...

Running Title: Transmural mechanics at a LV epicardial pacing site ABSTRACT (250 words) Left ventricular (LV) epicardial pacing acutely reduces wall thickening at the pacing site. Because LV epicardial pacing also reduces transverse shear deformation, which is related to myocardial sheet shear, we hypothesized that impaired end-systolic wall thickening at the pacing site is due to reduction in ...

Wall shear stress in postcapillary venules varies widely within and between tissues and in response to inflammation and exercise. However, the speed at which leukocytes roll in vivo has been shown to be almost constant within a wide range of wall shear stress, i.e., force on the cell. Similarly, rolling velocities on purified selectins and their ligands in vitro tend to plateau. This may be imp...

The effect of (a huge number of) pumping holes on beam dynamics and stability, described in terms of coupling impedances, is a fundamental issue and has been carefully investigated, both theoretically [1] and experimentally [2]. With the exception of a few very simple pipe geometris, for which the modal expansion of the electromagnetic field is available, beam coupling impedances can be only co...

Background Gene transfer can potentially alter vessel wall biology and intervene in the pathogenesis of human disease. Although several methods for vector delivery have been described, systematic comparisons of these methods are unavailable. Therefore, this study compared three catheter-based strategies and a surgical technique to assess efficient and selective gene transfer to the vascular wal...

BACKGROUND AND PURPOSE Systemic and local coronary heart disease (CHD) risk factors participate in atherogenesis. The role of wall shear stress, a major local risk factor, remains to be elucidated. METHODS Two hundred thirty-four subjects were carefully characterized for the presence of hypertension, hyperlipidemia, diabetes mellitus, obesity, and cigarette smoking and were divided into low- ...