Switches in cardiac muscle gene expression as a result of pressure and volume overload

In the mammalian heart, the expression of genes encoding proteins responsible for contraction, relaxation, and endocrine function changes in hypertrophy resulting from hemodynamic overload. Different mechanisms are involved in this mechanogenic transduction, including 1) differential expression of myosin and actin multigene families, which may account for the decreased velocity of contractile element shortening in hypertrophied heart, 2) nonactivation of the sarcoplasmic reticulum Ca2+-ATPase gene, which may explain the increased duration of isometric relaxation, and finally 3) activation in the ventricle of the atrial natriuretic factor gene that is responsible in part for the high plasma levels of this peptide. It is increasingly apparent that these changes are independently regulated, but little is known about the mechanisms underlying this regulation. Preliminary results indicate that it is now possible to analyze the early time course or transcription for each gene after the imposition of hemodynamic overload. This should significantly enhance our understanding of the regulatory mechanisms involved in the phenoconversions of the hemodynamically overloaded heart.link_to_subscribed_fulltex

Study on super-capacitor with Polypyrrole/Polyaniline composite

Conducting composite polymers consisting of Polypyrrole (PPy) and Polyaniline (Pani) were synthesized successfully using galvanostatic technique in the corresponding monomer solution. The properties of electrochemical super-capacitor assembled with conducting polymers were investigated by cyclic voltammetry, charging-discharging cycles and electrochemical impedance spectroscopy. The result has shown that the capacitor properties depend heavily on the deposit order: the composite polymers with PPy as the primer have better capacitive than that with Pani as the primer. The specific capacitance of stainless steel/PPy/Pani and stainless steel/PPy/Pani/PPy electrodes is far higher (up to 196.08 F/g and 212.53 F/g) than that of pure conducting polymers or other composite polymers.link_to_subscribed_fulltex