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β-SiaIon ceramics were prepared by reactive hot pressing sintering method with α-Si3N4 , α-AI203, and sintering additive MgO as raw materials. Effect of sintering additive MgO and the sintering temperature on mechanical property and morphology were systematically studied. The results indicate thai the sintering additives MgO grealh improve β-Sialon ceramics density and reduce the sintering temperature. Along with the sintering temperature increasing, the bending strength and the fracture toughness of β-Sialon ceramics increased before they are lower. At the sintering temperature of 1 600 °C , the preparation of β-Sialon ceramics obtained the highest bending strength and fracture toughness, the value(423 MPa, 2.73 MPa ∙ m½ ) , combined closely. The principal fracture mode of composites is inlergranular fracture. [ABSTRACT FROM AUTHOR]

Al2O3-TiC composites were prepared by hot-pressing with α- Al2O3 and TiC as raw materials. Effects of sintering temperature and TiC content on microstructure and mechanical properties have been systematically studied. The results indicate that there is no chemical reaction between α- Al2O3 and TiC, which suggests that they have fine chemical compatibility. The introducing TiC is benefitial to improve mechanical properties of Al2O3-TiC composites. The Al2O3-20% TiC composite sintered at 1, 600 °C obtained the highest bending strength and fracture toughness (509MPa and 5. 27 MPa ⋅ m1/2) . The principal fracture mode of composites is intergranular fracture, with transgranular frature. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of E 4031, a sodium calcium exchanger (NCX) agonist, on the isolated cardiac function and resting Ca2+ level in myocardial cells from rats with chronic heart failure., Methods: Rats chronic heart failure model was established by abdominal aorta coarctation with; Isolated heart perfusion by Langendorff apparatus was used to detect heart function and the effects of E 4031 on haemodynamic indexes; Myocardial cells of rats in the model group were extracted quickly and co-incubated with calcium fluorescent indicator fluo3/AM and the impact of E 4031 on the fluorescence intensity in myocardial cells were evaluated by confocal microscopy., Results: Heart function of rats in the model group detected by Langendorff perfusion was significantly reduced after 12 weeks, E 4031 at 10 micromol/L could improve their left ventricular developed pressure(LVDP) and systolic / diastolic maximum rate (+/- dp/dtmax). Compared with the control and sham operation groups, the resting Ca2+ fluorescence intensity of the myocardial cells of rats in model group was at a higher level and went through a process of transient rise and drop, then stably remaining at a low level after co-incubated with 10 micromol/L E 4031., Conclusion: E 4031 can improve the isolated heart function of rats with chronic heart failure, which may be associated with its enhancing the activity of NCX in the myocardial cell membrane and stabilizing intracellular Ca2+ level.