The effects of isoproterenol were examined in 10 conscious, chronically instrumented adult dogs with left ventricular (LV) failure after pressure overload hypertrophy induced by aortic banding at 8-10 weeks of age (LV free wall plus septum-to-body weight ratio, 8.6 +/- 0.5 g/kg) and also in eight control dogs (LV free wall plus septum-to-body weight ratio, 5.1 +/- 0.3 g/kg). Baseline values of ...

We examine the influence of the Reynolds stress as the main contribution of turbulence on the oscillation frequencies of the solar p-modes. We regard the radial oscillations as well as the nonradial ones in order to study the influence depending on the degree l of the modes. For the radial modes we find that the influence of the turbulence gives corrections that reduce significantly the differe...

Angular momentum in protostellar discs can be transported either radially, through turbulence induced by the magnetorotational instability (MRI), or vertically, through the torque exerted by a large-scale magnetic field. We present a model of steady-state discs where these two mechanisms operate at the same radius and derive approximate criteria for their occurrence in an ambipolar diffusion do...

OBJECTIVE The aim of this study was to analyse the arterial wall mechanics and the vasoreactive properties of the radial artery in comparison with those of the internal mammary artery and to discuss their implications for coronary bypass grafts. METHODS Measurements of pressure and diameter were obtained from cylindrical segments, whereas measurements of reactivity were obtained from ring seg...

The pathomechanics, ligamentous damage, and degree of carpal instability in perilunate and lunate dislocations were analyzed by experimentally loading 32 cadaver wrists to failure. Thirteen perilunate and two lunate dislocations were produced. The mechanism of injury was extension, ulnar deviation, and intercarpal supination. These dislocations occurred in a sequential fashion due to progressiv...

The mechanical properties of fully demineralized, fully deproteinized and untreated cortical bovine femur bone were investigated by compression testing in three anatomical directions (longitudinal, radial and transverse). The weighted sum of the stress-strain curves of the treated bones was far lower than that of the untreated bone, indicating a strong molecular and/or mechanical interaction be...

In this paper, an analytical study is made for the dynamic behavior of human brain tissue under transient loading. In this analytical model the Mooney-Rivlin constitutive law is coupled with visco-elastic constitutive equations to take into account both the nonlinear and time-dependent mechanical behavior of brain tissue. Five ordinary differential equations representing the relationships of fi...

Current methodologies used for the inference of thin film stress through curvature measurements are strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate system. By considering a circular thin film/substrate system subject to non-uniform, but axisymmetric misfit strain distributions in the thin film, we derived relations between th...

This study aims to explore the effects of heat and cold stress on the radial pressure pulse (RPP) and heart rate variability (HRV). The subjects immersed their left hand into 45°C and 7°C water for 2 minutes. Sixty healthy subjects (age 25 ± 4 yr; 29 men and 31 women) were enrolled in this study. All subjects underwent the supine temperature measurements of the bilateral forearms, brachial arte...

Radial tears during continuous curvilinear capsulorrhexis (CCC) are one of the most unwanted events that a surgeon may experience during cataract surgery. There are many factors that may play a role in inducing radial tears during CCC, such as a shallow anterior chamber, weak zonules as seen in pseudoexfoliative syndrome (PEX), high positive vitreous pressure, intumescent and hypermature catara...