9 research outputs found
PI4,5P2 regulates the polarized trafficking of integrins through EXO70 for directional cell migration
The polarized delivery of integrin adhesion molecules to the leading edge is required
for cell migration and has been linked to cancer cell invasion, cancer aggressiveness, and poor patient
outcome (1,2). Thus, regulators of integrin traffic may represent new molecular targets to inhibit tumor
progression. However, identifying the regulatory networks that control integrin traffic has posed a big
challenge, because, in contrast to the internalization of other cargoes, integrins take diverse routes,
depending on their specific ligand, activation state, type of adhesion structure and cell type assayed
Some Effects of Hydrogen Self-Ignition and Combustion in Supersonic Flow
Results are presented of computational and experimental investigations of the influence of temperature and flow composition on the hydrogen combustion kinetics for a coaxial fuel supersonic flow. Depending on the flow parameters, combustion is shown to occur with an intense heat release governed by the speed of chemical reactions, or a diffusion combustion with heat release governed by mixing. The computational results are in good agreements of with laboratory data and portrays many important features of supersonic combustion. The influence of the gas temperature and composition on the diffusion combustion of a circular hydrogen jet in supersonic coaxial flow at the over expanded exhaust regimes is investigated. It is found that at low flow temperatures (Т2 ~ 900 K) and in the absence of water vapors in the oxidizer gas composition, the speed of chemical reactions is the determining factor for combustion. An increase in the flow temperature (Т2 > 1200 K) causes a reduction of the induction time of the reactive mixture, because the mixing of fuel with oxidizer decreases, and a “sluggish” diffusion combustion of non-mixed gases is observed. The presence of water vapor and active radicals in the gas ensures the self-ignition from the start of the mixing, and the diffusion combustion mode is limited by mixing of the hydrogen jet with the coaxial flow (similar to the case with high initial temperatures of the air stream). In the case of the delay combustion process the maximum pressure level on the wall is 10% more than that in the combustion mode with ignition at the start of mixing. A sluggish combustion regime may lead to an incomplete hydrogen burnout