PURPOSE Examine the effects of incremental and submaximal exercise on structural and hemodynamic changes in the brachial artery flow parameters using Doppler ultrasonography. MATERIALS AND METHODS Twenty four healthy sedentary males (aged 19.54+/-0.59) performed submaximal (15 minutes heart rate to 75% maximal) and incremental (workload was increased 20W every 3 minutes until exhaustion) exer...

Mixing-transport of solute entering at sinkholes or from within the limestone matrix in cavernous conduits is an important process for contaminant migration in karst aquifers. This process may be described with a one-dimensional advection-dispersion equation incorporating the fluxes of solute and water across the conduit wall. For the dilution-dispersion equation, which does not include solute ...

Objectives: To investigate the effect of short-term statin treatment on impaired endothelium-dependent vasodilatation and haemodynamic abnormalities typically occurring in chronic heart failure (CHF). Methods: In a double-blind, crossover study endothelium-dependent vasodilatation was measured in conduit and resistance vessels of 23 patients with non-ischaemic CHF after 6 weeks of placebo and 4...

BACKGROUND Aortic valve bypass (AVB; apicoaortic conduit) surgery relieves aortic stenosis (AS) by shunting blood from the apex of the left ventricle to the descending thoracic aorta through a valved conduit. We have performed AVB surgery as an alternative to conventional aortic valve replacement for high-risk AS patients. METHODS AND RESULTS Between 2003 and 2007, 31 high-risk AS patients we...

OBJECTIVES To investigate the effect of short-term statin treatment on impaired endothelium-dependent vasodilatation and haemodynamic abnormalities typically occurring in chronic heart failure (CHF). METHODS In a double-blind, crossover study endothelium-dependent vasodilatation was measured in conduit and resistance vessels of 23 patients with non-ischaemic CHF after 6 weeks of placebo and 4...

Diffusers and nozzles within a flow system are optimized with respect to their wall shapes for a given change in cross sections. The optimization target is a low value of the head loss coefficientK, which can be linked to the overall entropy generation due to the conduit component. First, a polynomial shape of the wall with two degrees of freedom is assumed. As a second approach six equally spa...

Constriction of the fetal ductus arteriosus (DA) has disparate effects on mean and phasic hemodynamics, as mean DA blood flow is preserved until constriction is severe, but DA systolic and diastolic blood velocities change with only mild constriction. To determine the basis of this disparity and its physiological significance, seven anesthetized late-gestation fetal sheep were instrumented with...

To test models of the hydraulics and geometry of englacial conduits, 48 holes (3900m of ice) were drilled into Storglaciaren, Sweden, in search of conduits. About 79% of the holes intersected a hydraulically connected englacial feature. A video camera was used to examine the features and measure local water-flow rates. Because of the extremely clear ice that surrounded most features, their geom...

Aortic root and valve clots are rare but well described in patients on maximal left ventricular assist device (LVAD) support. We performed a theoretical analysis using computational fluid dynamic analyses in two dimensions to try and ascertain if inflow cannula design/orientation/placement affect aortic root flow dynamics. Two-dimensional computational fluid dynamics using easy CFD-G was perfor...

Magnetohydrodynamics may potentially provide a convenient means for controlling fluid flow and stirring fluids in minute fluidic networks. The branches of such fluidic networks consist of conduits with rectangular cross sections. Each conduit has two individually controlled electrodes positioned along opposing walls and additional disk-shaped electrodes deposited in the conduit's interior away ...