Digital refraction distortion correction with an astigmatic coherence sensor

We demonstrate the sensing and correction of an isoplanatic refractive distortion (not lens aberrations), using the complete measurement of the partially coherent field in an aperture that the previously described astigmatic coherence sensor provides. Isoplanatic distortions, and in general distortions that do not cause energy loss, maintain the orthogonality of the coherent modes. We use the fact that a common distortion will occur to all coherent modes to separate the distortion from the source behind it, rather than requiring a reference source at a different wavelength. Digital deconvolution was performed on the full four-dimensional partially coherent field for simultaneously computing the distortion and the source intensity distribution.     

Tribocorrosion behaviour of TiCxOy thin films in bio-fluids

Decorative coatings require not only an attractive appearance for market applications, but also an ability to protect the surface underneath. Because of this, corrosion, wear and their combined effects (termed tribocorrosion) are particularly important for lifetime prediction. In this paper, the tribocorrosion behaviour of a range of single layered titanium oxycarbide, TiC_xO_y, coatings, produced by DC reactive magnetron sputtering, has been studied and reported as a function of electrode potential and applied load. The study was conducted in a reciprocating sliding tribo-system (Plint TE 67/E) in a bio-fluid (an artificial perspiration solution) at room temperature. During the wear tests, both the open-circuit potential and the corrosion current were monitored. The results showed that electrode potential and load have a significant influence on the total material loss. The variations in R_p (polarization resistance) and C_f (capacitance) before and after sliding, obtained by Electrochemical Impedance Spectroscopy (EIS) were evaluated in order to provide an understanding of the resistance of the film in such conditions. Tribocorrosion maps were generated, based on the results, indicating the change in mechanisms of the tribological and corrosion parameters for such coatings, as a function of load and applied potential.     

The effects of high hematocrit on arterial flow—A phenomenological study of the health risk implications

Though red blood cells are essential to deliver oxygen to tissue, abnormally high levels can have deadly consequences. High hematocrit (Hct)—the percentage of total blood volume occupied by red blood cells (RBCs)—can occur in arterial flow due to a variety of causes. Examples include: dehydration, polycythemia vera, and exogenous use of recombinant human erythropoietin. In this phenomenological study, we present a simplified quantitative analysis of the physiological effects of increased hematocrit, especially for small arteries. In particular, we are primarily interested in the potential relation between the exogenous use of recombinant human erythropoietin by athletes (blood ‘doping’) and the not insignificant numbers of sudden heart attacks suffered by these otherwise superbly conditioned contestants. We proceed as follows: An expression for the variation of the viscosity of blood with both shear rate and hematocrit is obtained using the low and high shear experimental measurements of Chien and Çinar, respectively. This is done in a two-step process: (i) curve fits of shear rate dependent viscosity for hematocrits ranging from 40% to 80% are derived with resulting R-squared values greater than 0.99; (ii) viscosity is shown to be well-represented as an exponential function of shear rate for various hematocrit levels. The resulting relationship is used, in a simplified analysis, to calculate velocity profiles in a generic coronary artery as a non-linear function of viscosity for various hematocrit levels. Using these relationships, increasing hematocrit is shown to dramatically decrease and flatten velocity profiles in a small artery. The resulting velocity profiles of slower flow with greater area of low shear rate due to increased hematocrit makes likely a corresponding increased risk of thrombus formation.     

Converting excess low-price electricity into high-temperature stored heat for industry and high-value electricity production

The large-scale deployment of wind or solar energy results in electricity prices below the price of fossil fuels at times of high wind or solar output. Price collapse can be limited by using low-price electricity to heat firebrick to high temperatures, store the heat in firebrick, and provide hot air as needed to industrial furnaces, kilns, power plants and gas turbines. This sets a minimum price on electricity near that of fossil fuels.     

Heterotrimeric G proteins physically associated with the lipopolysaccharide receptor CD14 modulate both in vivo and in vitro responses to lipopolysaccharide

Septic shock induced by lipopolysaccharide (LPS) triggering of cytokine production from monocytes/macrophages is a major cause of morbidity and mortality. The major monocyte/macrophage LPS receptor is the glycosylphosphatidylinositol (GPI)-anchored glycoprotein CD14. Here we demonstrate that CD14 coimmunoprecipitates with Gi/Go heterotrimeric G proteins. Furthermore, we demonstrate that heterotrimeric G proteins specifically regulate CD14-mediated, LPS-induced mitogen-activated protein kinase (MAPK) activation and cytokine production in normal human monocytes and cultured cells. We report here that a G protein binding peptide protects rats from LPS-induced mortality, suggesting a functional linkage between a GPI-anchored receptor and the intracellular signaling molecules with which it is physically associated.