Dietary emodin alleviates lipopolysaccharide-induced intestinal mucosal barrier injury by regulating gut microbiota in piglets

This study was to determine the effects of dietary emodin(ED)on the intestinal mucosal barrier,nuclear factor kappa-B(NF-κB)pathways,and gut microbial flora in lipopolysaccharide(LPS)-induced piglets.Twenty-four weaned piglets were chosen and 4 treatments were created by randomly distributing piglets into CON,ED,LPS,and ED_LPS groups.Experiments were done in a 2×2 factorial arrangement and maintained for 21 d.Dietary treatment(a basal diet or 300 mg/kg ED)and immunological challenge(LPS or sterile saline)were 2 major factors.Intraperitoneal injections of LPS or sterilized saline were given to piglets on d 21.Six hours after the LPS challenge,all piglets were euthanized for sample collection and analysis.The results showed that piglets of the ED_LPS group had higher(P<0.05)villus height to crypt depth ratio(VCR),and lower(P<0.05)plasma D-lactate and diamine oxidase(DAO)than the LPS group.Furthermore,ED inhibited(P<0.05)the decrease of glutathione peroxidase(GSH-Px)and catalase(CAT)activities and increase of malonaldehyde level(P<0.05)in jejunal mucosa induced by LPS.The mRNA levels of pro-inflammatory cytokine genes(IL-6,IL-1β,and TNF-a)were significantly reduced(P<0.05),and the mRNA levels of antioxidant enzyme genes(GPX-1,SOD2 and CAT),as well as protein and mRNA levels of tight junction proteins(occludin,claudin-1,and ZO-1),were also significantly increased(P<0.05)by ED addition in LPS-induced piglets.Meanwhile,ED supplementation significantly decreased the LPS-induced protein levels of cyclooxygenase-2 and phosphorylation levels of NF-κB p65and IκBa in jejunal mucosa.Emodin had a significant effect on the composition of gut microbial flora at various taxonomic positions as indicated by 16S RNA sequencing.The acetic acid,isobutyric acid,valeric acid,and isovaleric acid concentrations in the cecum were also increased by ED addition in pigs(P<0.05).Furthermore,the correlation analysis revealed that some intestinal microbiota had a potential relationship with jejunal VCR,plasma D-lactate and DAO,jejunal mucosa GSH-Px and CAT activity,and cecal short-chain fatty acid concentration.These data suggest that ED is effective in alleviating LPSinduced intestinal mucosal barrier injury by modulating gut microbiota in piglets.

Reliability and global sensitivity analysis for an airplane slat mechanism considering wear degradation

This paper focuses on the issue of reliability and global sensitivity analysis for an airplane slat mechanism considering the uncertainties in the wear process of mechanical components.First,the multi-body kinematic model of the slat mechanism is built in the ADAMS software.The geometrical sizes of the roller wheels after wear degradation are considered as input variables and the angle the slat should turn is considered as the output response.To accurately identify the influential roller wheels to the reliability and robustness of the slat mechanism,the failure probability based sensitivity and variance-based sensitivity indices are introduced.Comprehensive analysis of the results have shown that the reliability analysis and global sensitivity theory can help engineers find significant parts by their contributions,thus provide guidance for mechanical design and maintenance.