Cu and Cu-SWCNT Nanoparticles' Suspension in Pulsatile Casson Fluid Flow via Darcy-Forchheimer Porous Channel with Compliant Walls: A Prospective Model for Blood Flow in Stenosed Arteries.

The use of experimental relations to approximate the efficient thermophysical properties of a nanofluid (NF) with Cu nanoparticles (NPs) and hybrid nanofluid (HNF) with Cu-SWCNT NPs and subsequently model the two-dimensional pulsatile Casson fluid flow under the impact of the magnetic field and thermal radiation is a novelty of the current study. Heat and mass transfer analysis of the pulsatile flow of non-Newtonian Casson HNF via a Darcy-Forchheimer porous channel with compliant walls is presented. Such a problem offers a prospective model to study the blood flow via stenosed arteries. A finite-difference flow solver is used to numerically solve the system obtained using the vorticity stream function formulation on the time-dependent governing equations. The behavior of Cu-based NF and Cu-SWCNT-based HNF on the wall shear stress (WSS), velocity, temperature, and concentration profiles are analyzed graphically. The influence of the Casson parameter, radiation parameter, Hartmann number, Darcy number, Soret number, Reynolds number, Strouhal number, and Peclet number on the flow profiles are analyzed. Furthermore, the influence of the flow parameters on the non-dimensional numbers such as the skin friction coefficient, Nusselt number, and Sherwood number is also discussed. These quantities escalate as the Reynolds number is enhanced and reduce by escalating the porosity parameter. The Peclet number shows a high impact on the microorganism's density in a blood NF. The HNF has been shown to have superior thermal properties to the traditional one. These results could help in devising hydraulic treatments for blood flow in highly stenosed arteries, biomechanical system design, and industrial plants in which flow pulsation is essential.

Frequency of QTc prolongation in patients with hemorrhagic stroke.

BACKGROUND: Acute cerebral events play an important role in generating autonomic imbalance especially cardiac rhythm disturbances. This forms the basis of significant lethal abnormalities of heart rate and rhythm like QTc prolongation, ventricular fibrillation, asystole, and ultimately death. This study was conducted to determine the frequency of QTc prolongation in patients presenting with acute haemorrhagic stroke at a tertiary care hospital. METHODS: This descriptive case series was conducted at Medical Unit-I, ward-5, Jinnah Postgraduate Medical Centre (JPMC), Karachi, from 13 October, 2009 to 12 April, 2010. Patients of either gender and age > 18 years who presented within 48 hours of onset of acute hemorrhagic stroke for the first time, confirmed by computerized tomography (CT) scan of brain were included. A 12 lead electrocardiogram (ECG) was performed. Lead III and VI were used for this due to their importance in this aspect. QTc was then calculated by using Bazetts formula. Data was analysed using SPSS-12. RESULTS: Among 95 patients of acute haemorrhagic stroke, 48 (50.5%) had prolonged QTc in lead III, 47 (49.5%) had prolonged QTc in lead VI. The average QTc interval in lead III was 440.4 +/- 45.2 (Range = 364-571). Proportion of prolonged QTc in lead III was higher in males than females. Frequency of QTc III prolongation was higher in comparatively younger age groups than older age groups. CONCLUSION: The frequency of prolonged QTc interval among patients of acute hemorrhagic stroke is alarmingly higher in our setup. Prolonged QTc is a useful predictor of impending clinical deterioration and provide an opportunity for early intervention to reduce severe loss like mortality.