The cerebrovasculature dilates or constricts in response to acute blood pressure changes to stabilize cerebral blood flow across a range of blood pressures. It is unclear, however, whether such dynamic cerebral autoregulation (dCA) is equally effective in responding to falling versus rising blood pressure. In this study we applied a pharmacological approach to evaluate dCA gain to transient hyp...

The aim of the present study was to perform a comparative biomechanical analysis of four antidecubitus wheelchair cushions. Thirty wheelchair users were considered divided into three groups: paraplegic subjects (with no cutaneous sensation), neurologic subjects (with intact cutaneous sensation), and elderly subjects. The biomechanical evaluation was performed using a piezoresistive sensor matri...

BACKGROUND Blood pressure is a determinant of the risk of stroke among both hypertensive and non-hypertensive individuals with cerebrovascular disease. However, there is uncertainty about the efficacy and safety of blood-pressure-lowering treatments for many such patients. The perindopril protection against recurrent stroke study (PROGRESS) was designed to determine the effects of a blood-press...

Abstract Despite significant advancements in geomodelling technologies, Accurately estimating hydraulic fracture half-length remains a challenging task. This paper introduces detailed estimation approach using the Gaussian Pressure Transient (GPT) method, which is relatively new. The GPT method iterative, ensuring fast convergence and providing reliable estimations of b’ased on predetermined di...

A high pressure drop happens when heavy oil with high viscosity moves through the oil pipeline. A variety of methods to avoid this pressure drop is available. One of which is injection of chemicals to reduce the viscosity and ultimately reduce pressure drop. Using the pipesim software, the effect of dispersion of nano and micro-particles into the oil has been simulated to study the amount of th...

On the basis of flow characteristics and material balance principle, a one-dimensional theoretical model of heavy-oil migration in porous media was established. The model considered micro-compressible property and nonNewtonian behavior of heavy oil. A new method, the transient method, was introduced to calculate the threshold pressure gradient in porous media. The method was designed to measure...

A high pressure drop happens when heavy oil with high viscosity moves through the oil pipeline. A variety of methods to avoid this pressure drop is available. One of which is injection of chemicals to reduce the viscosity and ultimately reduce pressure drop. Using the pipesim software, the effect of dispersion of nano and micro-particles into the oil has been simulated to study the amount of th...

Bladder smooth muscle shows spontaneous phasic contractions, which undergo a variety of abnormal changes depending on pathological conditions. How abnormal contractions affect the activity of bladder afferent nerves remains to be fully tested. In this study, we examined the relationship between transient increases in bladder pressure, representing transient contraction of bladder smooth muscle,...

BACKGROUND Decreased arterial oxygen pressure obtained at peak exercise is strong evidence of walking-induced hypoxemia, assuming that the lower pressure occurs just before exercise is stopped. Using empirical predefined models and transcutaneous oximetry, we have shown that some patients reporting exercise intolerance show a minimal value at the onset of walking and a post-exercise overshoot. ...

A laboratory-based experimental study was conducted to more completely understand the fundamentals of pressure transients produced by Formation Testing While Drilling (FTWD) equipment. These tools can be run in open hole, positioned at a desired level, and actuated to measure reservoir pressure and flow capacity while in a dynamic drilling environment. Any number of pressure measurements can be...