BACKGROUND Cerebral blood flow (CBF) may decrease during intermittent hemodialysis (IHD). Patients with acute kidney injury (AKI) may be more vulnerable to cerebral hypoperfusion than patients with end-stage renal disease (ESRD), due to concomitant critical illness and hemodynamic instability. METHODS In this observational, prospective study, we measured mean flow velocity at the level of the...

We study the necessary condition under which a resonantly driven exciton polariton superfluid flowing against an obstacle can generate turbulence. The value of critical velocity is well estimated by transition from elliptic to hyperbolic operator following ideas developed Frisch, Pomeau, Rica for flow around obstacle, though nature equations governing quite different. find analytical estimates ...

____________ _ To minimize hemolysis rate and damage to blood due to characteristics of aortic cannulae, critical blood velocity, blood cannula interactions and shear stress ranges for extracorporeal circulation (ECC) must be determined. At blood flow rates and viscosity levels typically experienced during ECC mean blood velocity, critical blood velocity, shear stress, and kinetic energy are de...

The traditional range/velocity limitation for blood velocity estimation systems using ultrasound is elucidated. It is stated that the equation is a property of the estimator used, not the actual physical measurement situation, as higher velocities can be estimated by the time domain cross-correlation approach. It is demonstrated that the time domain technique under certain measurement condition...