Biomimetic microspheres containing alginate/carboxymethylcellulose/gelatin and coated with 0%, 1%, 3%, and 6% berberine (BACG, BACG-1B, BACG-3B, BACG-6B) were prepared by the oil-in-water emulsion method combined with spray drying. Through a series of physicochemical parameters and determination of hemostatic properties in vitro and in vivo, the results indicated that BACG and BACG-Bs were effective in inducing platelet adhesion/aggregation and promoting the hemostatic potential due to their biomimetic structure and rough surface. In addition, BACG-6B with high berberine proportion presented better hemostatic performance compared with the commercial hemostatic agent compound microporous polysaccharide hemostatic powder (CMPHP). BACG-6B also showed strong antibacterial activity in the in vitro test. The hemolysis test and cytotoxicity evaluation further revealed that the novel composite biomaterials have good hemocompatibility and biocompatibility. Thus, BACG-6B provides a new strategy for developing a due-functional (hemostat/antibacterial) biomedical material, which may have broad and promising applications in the future.
The quasi-zero stiffness (QZS) isolator shows excellent characteristics of low-frequency vibration isolation. However, the jump behavior caused by the strong nonlinearity is a primary reason for the failure of QZS isolators. In order to grasp the effective frequency range and failure mechanism of a horizontal QZS isolator comprehensively, the dynamics of the isolator were studied in the following two cases. In the first case, the isolator is subject to a base displacement excitation; in the second case, the isolator is installed on a linear structure that is subject to a harmonic force. The nonlinear algebraic equations describing the steady-state response of the two systems were derived via the complexification-averaging method, and the results obtained using the derived expressions were verified by comparing the results of the complexification-averaging method and the Runge–Kutta method. The effective frequency ranges of the isolator were then obtained, and the jump phenomena in the response amplitude induced by the strong nonlinearity of the isolator were analyzed. The results show that when the excitation amplitude is small, the vibration isolation system does not exhibit jumping behavior and the effective frequency range is relatively wide. With increases in the excitation amplitude, the system can exhibit jumping behavior when an additional impact load is considered, and this phenomenon leads to a narrowing of the effective frequency range. The characteristics of the jump phenomena produced in the two cases were analyzed, and the differences in the jump behaviors were elucidated. Furthermore, the effect of the isolator parameters on the effective frequency range was investigated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.