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In order to obtain the mechanical behavior and failure mode of interface, the uniaxial tension experiments are conducted on HTPB propellant/liner adhesive specimen. The deformation images of various stages are achieved, and the debonding process is observed macroscopically. A cohesive element model is adopted to simulate propellant/liner interface. The results show that the failure mode experiences damage initiation, damage evolution and debonding, and the stress-strain response of adhesive specimen has a distinct nonlinear characteristic. The simulated results of stress-strain response and deformation are consistent with the data obtained from experiment. [ABSTRACT FROM AUTHOR]

In order to study the failure behavior of HTPB propellant/liner interface, a kind of small specimen was designed and its fracture behavior under axial tensile was observed by using a CCD microscope. The relations of the average crack width and dewet length with the clamping fixture displacement were determined by using image measurement method, and the bonding quality of the interface was analyzed from the macroscopic and microscopic views. The experiment results show that the dewet of interface between the granulated AP close to liner and the liner is the main cause of the performance degradation, and the interface energy between AP and propellant binder is greater than that between AP and liner. It can be a supplement to the traditional way to assess the bonding quality of solid propellant and liner. [ABSTRACT FROM AUTHOR]

Aim: To investigate the biological role and underlying mechanism of miR-132 in colorectal cancer (CRC) progression and invasion., Methods: Quantitative RT-PCR analysis was used to examine the expression levels of miR-132 in five CRC cell lines (SW480, SW620, HCT116, HT29 and LoVo) and a normal colonic cell line NCM460, as well as in tumor tissues with or without metastases. The Kaplan-Meier method was used to analyze the prognostic significance of miR-132 in CRC patients. The biological effects of miR-132 were assessed in CRC cell lines using the transwell assay. Quantitative RT-PCR and western blot analyses were employed to evaluate the expression of miR-132 targets. The regulation of ZEB2 by miR-132 was confirmed using the luciferase activity assay., Results: miR-132 was significantly down-regulated in the CRC cell lines compared with the normal colonic cell line (P < 0.05), as well as in the CRC tissues with distant metastases compared with the tissues without metastases (10.52 ± 4.69 vs 23.11 ± 7.84) (P < 0.001). Down-regulation of miR-132 was associated with tumor size (P = 0.016), distant metastasis (P = 0.002), and TNM stage (P = 0.020) in CRC patients. Kaplan-Meier survival curve analysis indicated that patients with low expression of miR-132 tended to have worse disease-free survival than patients with high expression of miR-132 (P < 0.001). Moreover, ectopic expression of miR-132 markedly inhibited cell invasion (P < 0.05) and the epithelial-mesenchymal transition (EMT) in CRC cell lines. Further investigation revealed ZEB2, an EMT regulator, was a downstream target of miR-132., Conclusion: Our study indicated that miR-132 plays an important role in the invasion and metastasis of CRC.