High-cycle fatigue behavior of Mg-8Li-3Al-2Zn-0.5Y alloy under different states

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 10^(7)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.

Effects of Injection of Oregano Oil Submicron Emulsion on Lipopolysaccharide-induced Pneumonia in Rats

[Objectives]To explore the effects of injection of oregano oil submicron emulsion on lipopolysaccharide-induced pneumonia in rats.[Methods]Rats induced by lipopolysaccharide were used as animal models of acute pneumonia.The experiment was divided into blank group,model group,administration group and positive drug control group.The morphology of lung tissue and the changes of cells and inflammatory factors in each group were observed,and the anti-inflammatory effects of injection of oregano oil submicron emulsion.[Results]The injection of oregano oil submicron emulsion can improve the pathological injury of rat lung tissue,inhibit the release of IL-6,IL-10,TNF-αcytokines induced by lipopolysaccharide,and significantly reduce the value of CRP.[Conclusions]Oregano oil submicron emulsion has a certain therapeutic effect on lipopolysaccharide-induced pneumonia in rats,and its mechanism may be related to reducing the release of cytoinflammatory factor IL-6,IL-10,and TNF-αand alleviating the injury to tissues and organs.

Prescription Design and Preparation Process of Paeonol Bead Popping Gum with Hypoglycemic Effect

[Objectives]To develop a paeonol bead popping gum with hypoglycemic effect.[Methods]The paeonol bead popping gum was prepared by the"two-step method",that is,the pill core was prepared by the guttate pill method,and then the coating was cured by sodium alginate solution and CaCl_(2) solution.The single factor method was used to determine the effects of PEG-4000:paeonol dosage ratio,dropper diameter,condensation time,dropping distance,melting temperature on the comprehensive score of paeonol guttate pill,and the effects of sodium alginate solution concentration,CaCl_(2) solution concentration,number of coating layers,drying time on the comprehensive score of popping gum.Finally,the optimal process was determined and verified by orthogonal experiment method.[Results]When the dosage ratio of PEG-4000:paeonol was 4∶1,the dropper diameter was 4 mm,the condensation time was 5 min,the dropping distance was 6 cm,and the melting temperature was 90℃,the quality of the prepared guttate pill was the optimal.When the concentration of sodium alginate solution was 0.02 g/mL,the concentration of CaCl_(2) solution was 0.25 g/mL,the number of coating layers was 3,and the drying time was 25 min,the appearance and comprehensive score of the obtained popping beads were the optimal.[Conclusions]This study is expected to provide some reference and basis for the development and utilization of hypoglycemic products of traditional Chinese medicine.

Mechanistic studies of the transport of peimine in the Caco-2 cell model

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 o200 μmol/L, the effect of peimine concentration, p H, 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 p H 6.0 and 7.4, the P_(app(AP-BL))of peimine is not significantly different but the Papp(BL-AP)) is; that both Papp(AP-BL)and P_(app(BL-AP))at 4 1C are significantly higher than their corresponding values at 37 1C; that the P-glycoprotein(P-gp) inhibitors, verapamil and cyclosporin A, increase absorption of peimine; and that EDTA-Na2 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.

Effect and molecular mechanism research of Astragalus membranaceus on inhibiting intestinal absorption of six alkaloids of Aconitum carmichaelii in spleen deficiency rats

Objective:To investigate the effect and the mechanism of Astragalus membranaceus(Huangqi in Chinese,HQ)extract on the intestinal absorption of six alkaloids of Aconitum carmichaelii(Fuzi in Chinese,FZ)in rats with spleen deficiency and provide novel insights into the application of HQ on modulating intestinal barrier.Methods:Four-week-old male Sprague-Dawley rats were fed with Xiaochengqi Decoction to induce the spleen deficiency model for 40 d.Single-pass intestinal perfusion model were used to study the effects of HQ extract on the absorption of alkaloids.Protein expression and mRNA levels of MRP2 and BCRP and tight junction proteins(TJ,including Claudin-1,Occludin and ZO-1)were measured using Western blot and real-time PCR,respectively.The location and expression of TJ protein was also investigated by the immunofluorescence method.Results:Compared with the normal group,the protein expression of MRP2,BCRP and TJ proteins in the model group were significantly down-regulated.After oral administration of HQ,the alkaloid absorption in intestinal villi was inhibited,MRP2,BCRP and TJ proteins were up-regulated,the green fluorescence staining of Claudin-1,Occludin,and ZO-1 was enhanced,and a thick layer of mucus was deposited on the surface of the epithelium of the intestinal cavity.Conclusion:HQ as an intestinal barrier modulator improves the physiological changes of the intestinal environment of spleen deficiency to reduce the absorption of toxic components,leading to a decrease in the absorption of drug-like molecules.