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In this study, the tensile and high-cycle fatigue properties of as-cast, solid solution treated and as-extruded Mg-8Li-3Al-2Zn-0.5Y alloy are investigated. The results show that the yield strength and ultimate tensile strength of as-cast alloy is 198.1 MPa and 222.5 MPa, which are improved to 274.7 MPa and 321.7 MPa, 282.4 MPa and 319.3 MPa after solid solution and extrusion treatment, respectively. The high-cycle fatigue strength (at 107 cycles, R = -1) of as-cast studied alloy is 65 MPa, which is improved to 90 MPa and 105 MPa after solid solution and extrusion treatment, respectively. The improvement of fatigue property of the solid solution treated alloy is mainly due to the lattice distortion caused by solid solution hindering the crack propagation. However, the improvement of fatigue property of the as-extruded alloy is mainly due to that the refined grains, stacked dislocations and dispersed secondary particles impede the crack propagation. [ABSTRACT FROM AUTHOR]

Fritillaria thunbergii Miq. has been widely used in traditional Chinese medicine for its expectorant, antitussive, antiinflammatory and analgesic properties. Moreover, modern pharmacological studies have demonstrated that F. thunbergii Miq. has efficacy in the treatment of leukemia and cancers of the liver and cervix. Although the alkaloid, peimine, is largely responsible for these pharmacological effects, it has very low oral bioavailability. The aim of this study was to investigate the intestinal absorption of peimine in Caco-2 cell monolayers. Having demonstrated that peimine is non-toxic to Caco-2 cells at concentrations <200 μmol/L, the effect of peimine concentration, pH, temperature, efflux transport protein inhibitors and EDTA-Na 2 on peimine transport were studied. The results show that peimine transport is concentration-dependent; that at pH 6.0 and 7.4, the P app(AP-BL) of peimine is not significantly different but the P app(BL-AP) ) is; that both P app(AP-BL) and P app(BL-AP) at 4 °C are significantly higher than their corresponding values at 37 °C; that the P-glycoprotein (P-gp) inhibitors, verapamil and cyclosporin A, increase absorption of peimine; and that EDTA-Na 2 has no discernible effect. In summary, the results demonstrate that the intestinal absorption of peimine across Caco-2 cell monolayers involves active transport and that peimine is a substrate of P-gp. [ABSTRACT FROM AUTHOR]