Samples were allowed to undergo rigor in a neutral pH buffer containing a protease inhibitor. Myofibrils were isolated and incubated at room temperature with excess exogenous mu-calpain at a ratio of 1: 800 (wt/wt; enzyme: myofibrillar protein) at pH 6.8 for 0, 2, 60, 1,440, or 2,880 min. Purified troponin was AZD4547 ic50 subjected to the same digestion conditions. Proteolysis of troponin T (TnT) was monitored using SDS-PAGE and Western blotting. Sarcomere length was greater (P < 0.0001) in stretched versus shortened samples (2.99 mu m +/- 0.03 vs. 2.12 +/- 0.03 mu m, respectively, means +/- SE). Western blots for both stretched and

shortened samples exhibited bands corresponding to intact TnT and TnT fragments. The abundance of intact TnT decreased (P < 0.0001) with incubation time across both treatments. At 1,440 and 2,880 min, less (P < 0.05) intact TnT was detected in samples with long sarcomeres. These data indicate

proteolysis of TnT occurs to a greater extent in samples with longer sarcomeres, possibly due to easier access of proteases AZD6094 to their targeted substrates. Degradation patterns of TnT were qualitatively similar between myofibrils and purified troponin after incubation with mu-calpain. Therefore, it is unlikely that the mechanism by which proteolysis is limited in short sarcomeres involves an actomyosin-mediated interference of TnT.”
“The diffusivity and solubility of cyclohexane in a high density polyethylene, HDPE, were studied using a gravimetric, quartz-spring, sorption balance. Solvent concentrations up to a weight fraction of 0.15 over a temperature range of 90 to 160 degrees C were measured. Diffusion coefficients in the range of 10-6 to 10-7 were determined. Two types of polymer samples were used:

a commercial bead form and flat sheets prepared by melting the polymer. Within the experimental error no differences were observed between the two forms indicating selleck chemicals llc that there were no significant effects caused by the melting and compression. The solubility of cyclohexane in the HDPE as a function of the activity of the cyclohexane was linear. Above the melt temperature the solubility data were predicted better by the group-contribution, lattice-fluid equation of state (GCLF-EoS) than by the van der Waals free-volume (UNIFAC-vdw-FV) model. Below the melt temperature a correction factor for the elasticity significantly improved the predictions for both models. Although the HDPE has a crystallinity of 77.6%, the experimental data and the Vrentas-Duda free-volume theory indicated no significant tortuosity effects. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012″
“We report on the resistive switching effect in metal/organic semiconductor/metal structures and present a general explanation of the switching mechanism in these devices.