Advances in modelling of biomimetic fluid flow at different scales

The biomimetic flow at different scales has been discussed at length. The need of looking into the biological surfaces and morphologies and both geometrical and physical similarities to imitate the technological products and processes has been emphasized. The complex fluid flow and heat transfer problems, the fluid-interface and the physics involved at multiscale and macro-, meso-, micro- and nano-scales have been discussed. The flow and heat transfer simulation is done by various CFD solvers including Navier-Stokes and energy equations, lattice Boltzmann method and molecular dynamics method. Combined continuum-molecular dynamics method is also reviewed

Voltage clamping single cells in intact Malpighian tubules of mosquitoes

Principal cells of the Malpighian tubule of the yellow fever mosquito were studied with the methods of two-electrode voltage clamp (TEVC). Intracellular voltage ( Vpc) was −86.7 mV, and input resistance ( Rpc) was 388.5 kΩ ( n = 49 cells). In six cells, Ba2+(15 mM) had negligible effects on Vpc, but it increased Rpcfrom 325.3 to 684.5 kΩ ( P&lt; 0.001). In the presence of Ba2+, leucokinin-VIII (1 μM) increased Vpcto −101.8 mV ( P &lt; 0.001) and reduced Rpcto 340.2 kΩ ( P &lt; 0.002). Circuit analysis yields the following: basolateral membrane resistance, 652.0 kΩ; apical membrane resistance, 340.2 kΩ; shunt resistance ( Rsh), 344.3 kΩ; transcellular resistance, 992.2 kΩ. The fractional resistance of the apical membrane (0.35) and the ratio of transcellular resistance and Rsh(3.53) agree closely with values obtained by cable analysis in isolated perfused tubules and confirm the usefulness of TEVC methods in single principal cells of the intact Malpighian tubule. Dinitrophenol (0.1 mM) reversibly depolarized Vpcfrom −94.3 to −10.7 mV ( P&lt; 0.001) and reversibly increased Rpcfrom 412 to 2,879 kΩ ( P &lt; 0.001), effects that were duplicated by cyanide (0.3 mM). Significant effects of metabolic inhibition on voltage and resistance suggest a role of ATP in electrogenesis and the maintenance of conductive transport pathways.</jats:p