Protective effects of Bifi dobacterium breve on imiquimod-induced psoriasis in mice through secondary bile acid production and FXR-TLR4/NF-κB pathway

This study aimed to evaluate the effects of Bifi dobacterium breve CCFM683 on psoriasis and to investigate the underlying mechanisms.B.breve CCFM683 significantly ameliorated psoriasis in mice as well as elevated the deoxycholic acid(DCA)and lithocholic acid(LCA)in the colon compared with those of the imiquimod(IMQ)-treated mice.Meanwhile,B.breve CCFM683 increased the relative abundance of DCA-producing Lachnoclostridium and diminished the harmful Desulfovibrio and Prevotellaceae UCG001.Additionally,the farnesoid X receptor(FXR)in the skin was activated and the expression of the Toll-like receptor 4(TLR4)/nuclear factor kappa-B(NF-κB)pathway was inhibited,and the downstream interleukin(IL)-17 and tumor necrosis factor(TNF)-αwere downregulated whereas IL-10 was up-regulated.Moreover,the subsequent hyperproliferation of keratinocytes and the dysfunction of the epidermal barrier were improved.In conclusion,CCFM683 administration ameliorated IMQ-induced psoriasis via modulating gut microbiota,promoting the DCA production,regulating the FXR-TLR4/NF-κB pathway,diminishing proinflammatory cytokines,and regulating keratinocytes and epidermal barrier.These findings may be conducive to elucidating the mechanism for probiotics to ameliorate psoriasis and to promote its clinical trials in skin disease.

Weak Fault Detection of Rotor Winding Inter-Turn Short Circuit in Excitation System Based on Residual Interval Observer

Aiming at the fact that the rotor winding inter-turn weak faults can hardly be detected due to the strong electromagnetic coupling effect in the excitation system,an interval observer based on current residual is designed.Firstly,the mechanism of the inter-turn short circuit of the rotor winding in the excitation system is modeled under the premise of stable working conditions,and electromagnetic decoupling and system simplification are carried out through Park Transform.An interval observer is designed based on the current residual in the two-phase coordinate system,and the sensitive and stable conditions of the observer is preset.The fault diagnosis process based on the interval observer is formulated,and the observer gain matrix is convexly optimized by linear matrix inequality.The numerical simulation and experimental results show that the inter-turn short circuit weak fault is hardly detected directly through the current signal,but the fault is quickly and accurately diagnosed through the residual internal observer.Compared with the traditional fault diagnosis method based on excitation current,the diagnosis speed and accuracy are greatly improved,and the probability of misdiagnosis also decreases.This method provides a theoretical basis for weak fault identification of excitation systems,and is of great significance for the operation and maintenance of excitation systems.

Vertical nanowires enhanced X-ray radiation damage of cells

Cell behavior is affected by nanostructured surface,but it remains unknown how ionizing radiation af-fects cells on nanostructured surface.This paper reports an experimental investigation of X-ray radiation induced damage of cells placed on an array of vertically aligned silicon nanowires.X-ray photoelectrons and secondary electrons produced from nanowire array are measured and compared to those from flat silicon substrate.The cell functions including morphology,viability,adhesion and proliferation have been examined and found to be drastically affected when cells are exposed to X-ray radiation,compared to those sitting on flat substrate and those only exposed to X-ray.The enhanced cell damage on nanowires upon X-ray exposure is attributed to nanowire enhanced production of photoelectrons including Auger electrons and secondary electrons,which have high escaping probability from sharp tips of nanowires.The escaped photoelectrons ionize water molecules and generate hydroxyl free radicals that can damage DNAs of cells.An inference of this work is that the contrast in scanning electron microscopy is useful in assessing the effects of nanomaterials for enhanced X-ray radiation therapy.