Shuo Zhao

Friction is an indispensable chapter in mechanics textbooks. It usually covers static friction, kinetic friction, rolling resistance, and so on. Many apparatuse Friction is an indispensable chapter in mechanics textbooks. It usually covers static friction, kinetic friction, rolling resistance, and so on. Many apparatuse

Similar to biological muscles, the actuator materials can function as artificial muscles by directly converting an external stimulus in the form of electrical or chemical energy into a mechanical response through the reversible changes in material dimensions. As a new type of high surface-area actuator materials, nanoporous metals represent a novel class of smart electrodes that undergo reversible dimensional changes when applying an electronic voltage on the surface. The dimensional changes in nanoporous metal/polymer composite still originate from the surface stress of nanoporous metal. Additionally, this surface stress can be modulated by the co-adsorbed sulfate counter-ions that are present in the doped polymer chains coating matrix upon the application of an external potential. Nanoporous metals fabricated by dealloying have received extensive attention in many areas, such as catalysis/electrocatalysis, energy conversion/storage, and sensing/biosensing. In this review, we focus on the recent developments of dealloyed nanoporous metals in the application of actuation. In particular, we summarize the experimental strategies in the studies and highlight the recent advances in the actuator materials. Finally, we conclude with outlook and perspectives with respect to future research on dealloyed nanoporous metals in applications of actuation in electrochemical or chemical environment.

Purpose. Studying the results obtained when applying the perturbation method to the individual contact problems solution. Considering the influence of non-ideal material properties of interaction bodies. Considering the contact area’s complex geometry influence. Methodology. Mathematical models of the interaction of an elastic plate with cylindrical anisotropy in the form of a curvilinear sector problems have been constructed and considered. In the process of interaction between the stamp and the plate, areas of slippage and adhesion occur. The original complex problems of the theory of elasticity in the process of applying the perturbation method are reduced to the sequential solution of the potential theory problems. Findings. An analytical solution to the interaction of an elastic anisotropic plate in the form of a curvilinear sector and a rigid stamp problem was obtained considering the existence of slippage and adhesion areas in the contact area. Laws of stress distribution under the stamp were found, as well as dependence of this distribution on the dimensions of the contact area. Originality. The perturbation method is convenient and expedient to use when solving mining mechanics problems. The study on the stress-strain state of an elastic anisotropic plate for the analogue of Galin’s problem was carried out, and the corresponding analytical solutions were obtained. The dependence of the coupling area size on the dimensions of the stamp and the opening angle of the sector, physical properties of the material is analyzed. Possible boundary transitions have been completed. Practical value. The proposed approach makes it possible to obtain analytical solutions to practically important problems in mining, to evaluate the stress-strain state of thick-walled structures with reinforcing elements, stamps, overlays. The results can be useful when designing mine workings.

Metastasis is a complex process, which depends on the interaction between tumor cells and host organs. Driven by the primary tumor, the host organ will establish an environment suitable for the growth of tumor cells before their arrival, which is called the pre-metastasis niche. The formation of pre-metastasis niche requires the participation of a variety of cells, in which myeloid-derived suppressor cells play a very important role. They reach the host organ before the tumor cells, and promote the establishment of the pre-metastasis niche by influencing immunosuppression, vascular leakage, extracellular matrix remodeling, angiogenesis and so on. In this article, we introduced the formation of the pre-metastasis niche and discussed the important role of myeloid-derived suppressor cells. In addition, this paper also emphasized the targeting of myeloid-derived suppressor cells as a therapeutic strategy to inhibit the formation of pre-metastasis niche, which provided a research idea for curbing tumor metastasis.

Acellular matrix materials have been widely used to repair various tissues and organs. According to the plastic principle, when a part of the body is lost, it should be replaced with a similar material. Therefore, the use of a homologous organ‐specific acellular vaginal tissue in vagina reconstruction repair surgery may show good results. However, the acellular vagina matrix (AVM) form large vertebrates is difficult to isolate. In this study, we described a multistep method to prepare porcine AVM and evaluated the efficacy of acellularization. We also investigated the biomechanical properties, biological activity elements, and biocompatibility of the porcine AVM. We then used this material to reconstruct a rat vagina and performed further morphologic and functional analyses. Small intestinal submucosa (SIS), which is a commonly used acellular matrix material, was used in a control group. Histological examination, DNA content analysis, and agarose gel electrophoresis revealed that the decellularization procedure was effective. The AVM had acceptable biomechanical properties and sufficient growth factor production (VEGF, FGF, TGF‐β1, and PDGF‐BB) compared with that of the SIS. Subcutaneous transplantation in rats showed that the AVM had good biocompatibility. The tissue‐engineered vagina using the AVM more resembled normal‐appearing tissue than did that using SIS following morphologic and functional analyses. The AVM has great potential for application in vaginal reconstructive surgery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1949–1959, 2017.