Abstract As an ideal impact energy absorber, the external inversion process of thin-walled metal tubes over circular dies has been studied theoretically since 1960s. However, in the most existing theoretical models, the curvature in the deformation area is a constant and only the steady inversion force is studied. Limited research has been conducted on the whole inversion process. In this study, from experimental and numerical results, the curvature is found to be varying and the whole inversion process can be divided into two stages by three states. Then a modified geometric model is proposed and the force displacement curves is derived. Next, it has been observed that current theoretical results exhibit greater conformity with experimental and numerical results. Finally, the effects of the tube wall thickness, tube average radius and die radius on crashworthiness indicators are studied theoretically by the verified theoretical model. These outcomes offer valuable reference for further research on tube inversion forming and energy absorption characteristics of external inversion mode. absorber thinwalled thin walled 1960s s However models study states derived Next Finally thickness mode

Abstract Purpose: To investigate the specific molecular mechanisms and effects of curcumin derivative J147 on diabetic peripheral neuropathy (DPN). Methods: We constructed streptozotocin (STZ)-induced DPN rat models to detected mechanical withdrawal threshold (MWT) in vivo using Von Frey filaments. In vitro, we measured cell viability and apoptosis, adenosine 5‘-monophosphate-activated protein kinase (AMPK) and transient receptor potential A1 (TRPA1) expression using MTT, flow cytometry, qRT-PCR and western blot. Then, TRPA1 expression level and calcium reaction level were assessed in agonist AICAR treated RSC96cells. Results: The results showed that J147reduced MWT in vivo, increased the mRNA and protein level of AMPK, reduced TRPA1 expression and calcium reaction level in AITCR treated RSC96 cells, and had no obvious effect on cell viability and apoptosis. Besides, AMPK negative regulated TRPA1 expression in RSC96 cells. Conclusions: J147 could ameliorate DPN via negative regulation AMPK on TRPA1 in vivo and in vitro. A curcumin derivative J147might be a new therapeutic potential for the treatment of DPN.