INTRODUCTION Some types of antenatal maternal psychological distress may be associated with reduced fetal growth and birthweight. A stress-mediated reduction in placental blood flow has been suggested as a mechanism. Previous studies have examined this using ultrasound-derived arterial resistance measures in the uterine (UtA) and umbilical (UA) arteries, with mixed conclusions. However, a reduc...

The time courses of vascular resistance and venous blood oxygen (O2) saturation following a brief tetanus of isolated dog calf muscle were studied during free-flow (constant-pressure), high constant-flow (>30 ml/100 g min-), and low constant-flow (<24 ml/100 g mirr) perfusion. A monophasic decrease in resistance followed a 1-second tetanus during either free-flow or high constant-flow perfusion...

Dry powder inhalers (DPIs) are widely and increasingly used in clinical practice because they represent a substantial advancement in inhalation technology. The effectiveness of a powdered drug to inhale depends on the inspiratory flow rate generated by the patient and on the turbulence produced by the intrinsic resistance of the DPI. While the inspiratory flow is variable with the patient's abi...

BACKGROUND The aim of this study was to develop a mathematical model of blood flow in the systemic circulation to emulate the change in hemodynamics by acupuncture therapy to elucidate the mechanism of the therapy. For this purpose, as a first step, a simple model of arterial blood flow was presented to reproduce previously reported change in the blood flow volume by the acupuncture needle stim...

Objective- Obtaining the normal images ofcolor doppler and estimation ofblood flow velocity parametersof femoral and axillary arteries in dog.Design- Descriptive studyAnimals- 7 healthy adult mixed-breed dogs, weighing 14.3 ± 2.8 kg (mean ± SD).Proceudure- Left and right femoral and axillary arteries of hind and forelimbs were evaluated. Colorand spectral doppler images ofthe each artery were o...

Vegetation growing in the water along rivers has been the subject of several studies since it was recognized that it could have a significant impact on the water flow. It may increases resistance to flow and causes higher water levels. Also, it has affects on the turbulent structure such as the mean velocity profiles. For flow of water through emergent vegetation, previous investigations show d...

Flow resistance was measured as bovine and primate aqueous humor was passed through Nuclepore polycarbonate filters having flow dimensions similar to those found within the juxtacanalicular meshwork of the aqueous outflow network. The results indicate that aqueous humor has a greater flow resistance than isotonic saline; this greater resistance is attributable to proteins or glycoproteins in aq...

TVFUMEROUS studies have been published •*• ^ on the effect of heart rate and various drugs on coronary flow. It has not been possible to estimate the relative importance of changes in intravaseular and extravascular resistance in determining the observed alterations in coronary flow. Recently, Sabiston and Gregg suggested that in a heart in which coronary arteries were perfused at constant pres...