Situs inversus totalis (SIT) is characterized by complete mirroring of gross cardiac anatomy and position combined with an incompletely mirrored myofiber arrangement, being normal at the apex but inverted at the base of the left ventricle (LV). This study relates myocardial structure to mechanical function by analyzing and comparing myocardial deformation patterns of normal and SIT subjects, fo...

UNLABELLED Hypertension is the leading cause of heart failure and cardiovascular comorbidities in developed countries. Left ventricular structural/functional alterations such as concentric remodeling or hypertrophy have been extensively studied in hypertensive heart diseases. Furthermore, it is also well-recognized that diastolic function actually deteriorates in hypertensive subjects prior to ...

The coupling between electronic and nuclear degrees of freedom in low-dimensional, nanoscale systems plays a fundamental role in shaping many of their properties. Here, we report the disentanglement of axial and radial expansions of carbon nanotubes, and the direct role of electronic and vibrational excitations in determining such expansions. With subpicosecond and subpicometer resolutions, str...

Previous studies of transmural left ventricular (LV) strains suggested that the myocardium overlying the papillary muscle displays decreased deformation relative to the anterior LV free wall or significant regional heterogeneity. These comparisons, however, were made using different hearts. We sought to extend these studies by examining three equatorial LV regions in the same heart during the s...

Microtubules (MTs) are the largest type of cellular filament, essential in processes ranging from mitosis and meiosis to flagellar motility. Many of the processes depend critically on the mechanical properties of the MT, but the elastic moduli, notably the Young's modulus, are not directly revealed in experiment, which instead measures either flexural rigidity or response to radial deformation....

The stability of supercritical Couette flow has been studied extensively, but few measurements of the velocity field of flow have been made. Particle image velocimetry (PIV) was used to measure the axial and radial velocities in a meridional plane for non-wavy and wavy Taylor–Couette flow in the annulus between a rotating inner cylinder and a fixed outer cylinder with fixed end conditions. The ...

PURPOSE The purpose of the present study was to evaluate the stability of a high-porosity expanded polytetrafluoroethylene (ePTFE) graft, which has been shown to possess excellent biocompatibility and tissue integration. METHODS The graft used in the present study was a high-porosity ePTFE graft , which had an average internodal distance of approximately 60 microm and a random node architectu...

Chondrogenesis in cartilage development and repair and cartilage degeneration in arthritis can be regulated by mechanical-load-induced physical factors such as tissue deformation, interstitial fluid flow and pressure, and electrical fields or streaming potentials. Previous animal and tissue explant studies have shown that time-varying dynamic tissue loading can increase the synthesis and deposi...

INTRODUCTION Wall shear stress (WSS) is critically important in both vascular remodeling and atherosclerosis. Carotid intima-media thickness (IMT) and deformation parameters have been used as relevant indicators of carotid atherosclerosis. This study aimed to investigate the relationships between hemodynamic parameters in the common carotid artery (CCA) and the severity of carotid atheroscleros...

To date, there are no constitutive models for either the natural or bioprosthetic aortic valve (AV), in part due to experimental complications related to the AV's small size and heterogeneous fibrous structure. In this study, we developed specialized biaxial testing techniques for the AV cusp, including a method to determine the local structure-strain relationship to assess the effects of bound...