Measuring the simultaneous effects of hypoxia and deformation on ATP release from erythrocytes

It is known that adenosine triphosphate (ATP) is released from red blood cells (RBCs) due to various forms of stimulation such as deformation, pharmacological stimuli, and hypoxia. To date, these various stimuli have been investigated individually. Here, we have combined a microflow system capable of initiating deformation-induced release of ATP from the RBCs at various levels of hypoxia as measured by percent oxygen saturation in the RBC sample. When values of ATP released from deformation and hypoxia are compared to values of ATP release due to hypoxia alone, the relationship between the two stimuli can be deduced. Measurement of RBC-derived ATP with the well-known chemiluminescence assay employing luciferin/luciferase indicates that RBCs deoxygenated for 4 min released 1.84 +/- 0.075 microM ATP. The largest decrease in oxygen saturation was found to be between 0 s (66.3% O(2) saturation) and 15 s (22.3% O(2) saturation). RBCs deoxygenated to a 22.3% O(2) saturation released 0.374 +/- 0.011 microM ATP when pumped through the microflow system. This value is an increase from 0.281 +/- 0.007 microM ATP in the presence of flow alone. The ATP release after exposure to hypoxia at 22.3% O(2) saturation was 0.381 +/- 0.014 microM ATP, a value statistically equivalent to that of hypoxia and flow combined. These data suggest that, at an oxygen saturation point of around 25.0% or above, deformation contributes to ATP release from the RBC; however, beyond this saturation point, the ATP release is largely due to hypoxia.     

Al2O3-47 nm and Al2O3-36 nm characterizations of nonlinear differential equations for biomedical applications: Magnetized peristaltic transport

Current research models the Al₂O₃ 47nm and Al₂O₃ 36nm nanoparticles transportation through peristalsis with entropy optimization. Conservation laws for mass, momentum and energy are used to model the present flow situation. These equations elaborates the magnetohydrodynamics, Hall, thermal radiation, Joule heating, heat generation and absorption. Convective heat transfer impacts are studied at channel walls. Entropy is modeled in view of thermodynamics second law. Two different expressions for effective viscosity are accounted. Simplification of the modeled equations is done through lubrication assumptions. Solution for momentum equation is obtained analytically and for numerically for temperature equation. Built-in shooting procedure is utilized to obtain the desired numerical results. Later on these obtained results are used to sketch and discussed the flow quantities of interest for the influential parameters accounted in the problem.