Endothelial Nitric Oxide Synthase Oxygenase on Lipid Nanodiscs: A Nano-Assembly Reflecting Native-Like Function of eNOS

© 2017 Elsevier Inc. Endothelial nitric oxide synthase (eNOS) is a membrane-anchored enzyme. To highlight the potential role and effect of membrane phospholipids on the structure and activity of eNOS, we have incorporated the recombinant oxygenase subunit of eNOS into lipid nanodiscs. Two different size distribution modes were detected by multi-angle dynamic light scattering both for empty nanodiscs, and nanodiscs-bound eNOSoxy. The calculated hydrodynamic diameter for mode 1 species was 9.0 nm for empty nanodiscs and 9.8 nm for nanodisc bound eNOSoxy. Spectroscopic Griess assay was used to measure the enzymatic activity. Remarkably, the specific activity of nanodisc-bound eNOSoxy is ∼65% lower than the activity of free enzyme. The data shows that the nano-membrane environment affects the catalytic properties of eNOS heme domain

Simulation of three dimensional double-diffusive throughflow in internally heated anisotropic porous media

A model for double-diffusive convection in an anisotropic porous layer with a constant throughflow is explored, with penetrative convection being simulated via an internal heat source. The validity of both the linear instability and global nonlinear energy stability thresholds are tested using three dimensional simulation. Our results show that the linear threshold accurately predicts on the onset of instability in the steady state throughflow. However, the required time to arrive at the steady state increases significantly as the Rayleigh number tends to the linear threshold. © 2014 Elsevier Ltd. All rights reserved

Cyclic compression increases F508 DEL CFTR expression in ciliated human airway epithelium

The mechanisms by which transepithelial pressure changes observed during exercise and airway clearance can benefit lung health are challenging to study. Here, we have studied 117 mature, fully ciliated airway epithelial cell filters grown at air-liquid interface grown from 10 cystic fibrosis (CF) and 19 control subjects. These were exposed to cyclic increases in apical air pressure of 15 cmH2O for varying times. We measured the effect on proteins relevant to lung health, with a focus on the CF transmembrane regulator (CFTR). Immunofloures-cence and immunoblot data were concordant in demonstrating that air pressure increased F508Del CFTR expression and maturation. This effect was in part dependent on the presence of cilia, on Ca2+ influx, and on formation of nitrogen oxides. These data provide a mechanosensory mechanism by which changes in luminal air pressure, like those observed during exercise and airway clearance, can affect epithelial protein expression and benefit patients with diseases of the airways

A Switching-Gain Controller for Grid-Connected MMC Complying with Voltage Ride-Through Requirements

Connecting high-power Renewable Energy Sources (RESs) to the utility grid has to be secured considering international standards to guarantee the efficiency, reliability, and stability of the power system. Redundancy, modularity, and scalability of the Modular Multilevel Converter (MMC) make it a proper option for high-power RESs such as offshore wind energy and PV systems. In this paper, the control of grid-connected MMC is investigated in order to comply with low voltage ride-through requirements. The modeling of MMC is achieved in this study using the Average Value Model (AVM). Grid integration through LCL-filter is explored since an LCL-filter may be required for Quasi two-level (Q2L) PWM operation of MMC and/or MMC with a relatively low-level order. A switching-gain integral state feedback with full-order observer controller is designed, evaluated, and verified for LCL-filter connecting MMC to the utility grid. Low Voltage Ride Through (LRVT) capability using Reactive Power Compensation (RPC) technique for grid voltage sag based on international codes such as German code is considered with the designed controller.Qatar Foundation; Qatar National Research FundScopu

On the optimized energy transport rate of magnetized micropolar fluid via ternary hybrid ferro-nanosolids: A numerical report

In the current era, a chemical, industrial, or production process may not be devoid of heat transfer processes through fluids. This is seen in evaporators, distillation units, dryers, reactors, refrigeration and air conditioning systems, and others. On the other hand, the micropolar model effectively simulates microstructured fluids like animal blood, polymeric suspensions, and crystal fluid, paving the way for new potential applications based mainly on complex fluids. This investigation attempts to figure out and predict the thermal behavior of a polar fluid in motion across a solid sphere while considering the Lorentz force and mixed convection. To support the original fluid's thermophysical characteristics, two types of ternary hybrid ferro-nanomaterials are used. The problem is modelled using a single-phase model. Then, using the Keller box approximation, a numerical finding is obtained. The study reveals that Increasing the volume fraction of the ternary hybrid nonsolid results in optimized values of Nusselt number, velocity, and temperature. The presence of Lorentz forces effectively mitigates flow strength, skin friction, and energy transfer rate. The mixed convection factor contributes significantly to enhanced energy transfer and improved flow scenarios. For maximum heat transfer efficiency, employing Fe3O4–Cu–SiO2 is recommended over Fe3O4–Al2O3–TiO2