ABSTRACT
In recent years, there is a growing demand for materials that can both improve the mechanical properties of structures and carry out health monitoring and risk warning. In this case, in order to realize distributed deformation monitoring, a new method of making geogrid by 3D printing technology is proposed. The grille rib is made by embedding the conductive polymer (ground carbon fiber as conductive filler) into the insulating shell (PLA material) in the specified path, and then the rib is vertically crossed into each other to form a grille sample. In order to study the distributed deformation monitoring function of this grid, a manual push-pull testing machine was used to conduct a load-unload experiment to analyze the change rule of resistance on the grid plane. The following conclusions were obtained: the closer the ribs are to the load bearing point, the greater the change in resistance, and conversely, the farther the ribs are from the load bearing point, the smaller the change in resistance. Depending on the geogrid network characteristics, the electrical resistance distribution on the geogrid plane can be obtained by superimposing the resistance values of the horizontal and longitudinal ribs, then the location and the magnitude of deformation can be estimated. Additionally, this study carried out numerical simulation of the grid model based on ANSYS 15.0 software and compared with the loading experiment results to verify that the force deformation position can be retrieved through the change of resistance.
ABSTRACT
Administration of inactivated probiotics has been proved to enhance host immunity. Herein, we aim to explore their potential in modulating systemic autoimmune disorders. The bovine type II collagen (CII)-induced arthritis (CIA) and CII antibody-induced arthritis (CAIA) mice models were used in this study. Heat-killed Lactobacillus reuteri (h-L. reuteri) was administered before or after the induction of CIA. The results indicated that the severity of CIA was alleviated and the prevalence of CIA was decreased in the mice pre-treated with h-L. reuteri. Using enzyme-linked immunosorbent assays, we found that decreased serum CII-specific IgG antibody IL-6 and CXCL1 but the increased level of IL-10 was found in h-L. reuteri-treated cohort. Moreover, h-L. reuteri treatment decreased the severity and incidence of arthritis in the CAIA model which was associated with a early decrease of IL-6. Systematic supplement of exogenous IL-6 reversed h-L. reuteri-induced CIA suppression. For regulatory immune responses, the frequency of Tregs and CD4+IL-10+ cells was increased in the draining lymph of joint of h-L. reuteri-treated mice after second immunization. Parallelly, we found that if CIA was induced, CD103+ dendritic cells in mesenteric lymph nodes and α4ß7+ Tregs in the spleen were increased in h-L. reuteri-treated mice, suggesting h-L. reuteri might affect the peripheral migration of Tregs to modulating CIA. Finally, the mice with progressive CIA were treated with h-L. reuteri after the second immunization. No alleviation of CIA severity, as well as an increase of splenic α4ß7+ Tregs, was observed in these mice. This study indicates that pre-administration of h-L. reuteri can alleviate the CIA in mice and may serve as a promising strategy for autoimmune disease prevention.
