Modeling and analysis of magnetic hybrid nanoparticle (Au-Al2O3/blood) based drug delivery through a bell-shaped occluded artery with Joule heating, viscous dissipation and variable viscosity effects

The present work deals with the impact of hybrid nanoparticles (Au-Al2O3/Blood) on the blood flow pattern through a porous cylindrical artery with bell-shaped stenosis in the presence of an external magnetic field, Joule heating, and viscous dissipation by considering twodimensional pulsatile blood flow. The temperature-dependent viscosity model is utilized in this model. The blood flow is assumed to be unsteady, laminar, viscous, and incompressible. The mild stenotic presumption normalizes and reduces the bi-directional flow to uni-directional. The Crank-Nicolson scheme is applied to solve the continuity, momentum, and energy equations with appropriate initial and boundary conditions. The acquired results of the work are presented graphically. They have been examined for several values of the dimensionless parameters such as Magnetic number (M2 ), Darcy number (Da), Grashof number (Gr), viscosity parameter (β0), Reynolds number (Re), Eckert Number (Ec), Prandtl number (Pr), different concentration of both the nanoparticles (φ1, φ2), and pressure gradient parameter (B1). The velocity contours for different emerging parameters have been drawn to analyze the overall behavior of blood flow patterns. The non-dimensional velocity profile enhances with increment in values of Da, implying that the medium’s permeability provides less barrier to flow. The cumulative impact of Joule Heating and viscous dissipation are discussed. It demonstrates that increasing viscous dissipation (Ec) and Joule heating (M2 ) parameter simultaneously raise the nanofluid temperature since the mechanical energy is transformed to thermal energy within molecules, which causes a hike in temperature. The findings reveal that hybrid nanoparticles (Au-Al2O3/blood) effectively reduce hemodynamic variables such as wall shear stress and resistance impedance. Results indicate that nanoparticles may be helpful to keep the blood velocity under control and allow the surgeons to adjust it as and when required. The present work aims to get insight into the treatment of atherosclerosis without surgery, lower medical costs, and reduce post-surgical complications. Also, it has broad implications in treating various conditions, including cancers, infections, and the removal of blood clots. The current findings are consistent with recent findings in earlier blood flow research studies

A Common Carcinogen Benzo[a]pyrene Causes Neuronal Death in Mouse via Microglial Activation

BACKGROUND: Benzo[a]pyrene (B[a]P) belongs to a class of polycyclic aromatic hydrocarbons that serve as micropollutants in the environment. B[a]P has been reported as a probable carcinogen in humans. Exposure to B[a]P can take place by ingestion of contaminated (especially grilled, roasted or smoked) food or water, or inhalation of polluted air. There are reports available that also suggests neurotoxicity as a result of B[a]P exposure, but the exact mechanism of action is unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using neuroblastoma cell line and primary cortical neuron culture, we demonstrated that B[a]P has no direct neurotoxic effect. We utilized both in vivo and in vitro systems to demonstrate that B[a]P causes microglial activation. Using microglial cell line and primary microglial culture, we showed for the first time that B[a]P administration results in elevation of reactive oxygen species within the microglia thereby causing depression of antioxidant protein levels; enhanced expression of inducible nitric oxide synthase, that results in increased production of NO from the cells. Synthesis and secretion of proinflammatory cytokines were also elevated within the microglia, possibly via the p38MAP kinase pathway. All these factors contributed to bystander death of neurons, in vitro. When administered to animals, B[a]P was found to cause microglial activation and astrogliosis in the brain with subsequent increase in proinflammatory cytokine levels. CONCLUSIONS/SIGNIFICANCE: Contrary to earlier published reports we found that B[a]P has no direct neurotoxic activity. However, it kills neurons in a bystander mechanism by activating the immune cells of the brain viz the microglia. For the first time, we have provided conclusive evidence regarding the mechanism by which the micropollutant B[a]P may actually cause damage to the central nervous system. In today's perspective, where rising pollution levels globally are a matter of grave concern, our study throws light on other health hazards that such pollutants may exert

Influence of hydride orientation on fracture toughness of CWSR Zr-2.5%Nb pressure tube material between RT and 300 degrees C

An experimental setup was designed, fabricated and used to form radial hydrides in Zr-2.5%Nb alloy pressure tube spool. The design of setup was based on ensuring a hoop stress in the spool greater than threshold stress for reorientation of hydrides in this alloy, which was achieved by manipulating the thermal expansion coefficient of the plunger and pressure tube material and diametral interference between them. The experimental setup was loaded on a universal testing machine (UTM) fitted with an environmental chamber and subjected to a temperature cycle for the stress reorientation treatment. The metallographic examination of the hydrogen charged spools subjected to stress re-orientation treatment using this set up revealed formation of predominantly radial hydrides. The variation of fracture toughness of material containing radial hydride with test temperature showed typical 'S' curve behavior with transition temperatures more than that of the material containing circumferential hydride. (C) 2017 Elsevier B.V. All rights reserved

Book title: Trends in Arid Zone research in India

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