Supercritical accretion flows inevitably produce radiation-pressure driven outflows, which will Compton up-scatter soft photons from the underlying accretion flow, thereby making hard emission. We perform two dimensional radiation hydrodynamic simulations of supercritical accretion flows and outflows, incorporating such Compton scattering effects, and demonstrate that there appears a new hard s...

A randomized, double-blind, crossover trial was designed to compare the acute effects of Combivent and salbutamol on spirometric parameters in patients with moderate to severe asthma. Nineteen patients with a mean baseline forced expiratory volume in 1 sec. (FEV]) less than 65% predicted, were randomized on two separate days to receive two puffs of salbutamol (200 µg) or two puffs of Combiv...

The aim of this study was to assess the effect of sevoflurane and propofol on organ blood flow in a porcine model with a left ventricular assist device (LVAD). Ten healthy minipigs were divided into 2 groups (5 per group) according to the anesthetic received (sevoflurane or propofol). A Biomedicus centrifugal pump was implanted. Organ blood flow (measured using colored microspheres), markers of...

PURPOSE This study aims to investigate quantitative basal blood flow as well as hypercapnia- and hyperoxia-induced blood flow changes in the retinas of the Royal College of Surgeons (RCS) rats with spontaneous retinal degeneration, and to compare with those of normal rat retinas. METHODS Experiments were performed on male RCS rats at post-natal days P90 (n=4) and P220 (n=5), and on age-matche...

Despite the excellent performance of membrane oxygenators, bubble oxygenators continue to dominate routine open heart surgery. Newer versions with reduced gas:blood flow ratios continue to appear for clinical application 1•2. The new models generally provide data on partial pressure of oxygen (p02) of oxygenated blood at given blood and oxygen flow rates from clinical perfusions37. Clinical dat...

BACKGROUND The NO--cGMP system plays a key role in the regulation of sinusoidal tonus and liver blood flow with phosphodiesterase-5 (PDE-5) terminating the dilatory action of cGMP. We, therefore, investigated the effects of PDE-5 inhibitors on hepatic and systemic hemodynamics in rats. METHODS Hemodynamic parameters were monitored for 60 min. after intravenous injection of sildenafil and vard...

OBJECTIVE To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. METHODS One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experimen...

Objective(s): Nucleus Raphe Magnus (NRM) that is involved in the regulation of body temperature contains nitric oxide (NO) synthase. Considering the effect of NO on skin blood flow control, in this study, we assessed its thermoregulatory role within the raphe magnus. Materials and Methods: To this end, tail blood flow of male Wistar rats was measured by laser doppler following the induction of ...

In the venous clip model specific cardiac malformations are induced in the chick embryo by obstructing the right lateral vitelline vein with a microclip. Clipping alters venous return and intracardiac laminar blood flow patterns, with secondary effects on the mechanical load of the embryonic myocardium. We investigated the instantaneous effects of clipping the right lateral vitelline vein on he...

Background To determine hemodynamic parameters from 4D flow MRI, vessel boundaries are typically depicted by calculating a 3D phase contrast MR angiogram (PC-MRA) from 4D flow magnitude and flow images. However, this approach is limited by 1) low blood-tissue contrast of the magnitude images and 2) velocity weighting of PC-MRA may not fully depict areas of slow or swirling (vortex) flow. As a r...