Chronic inflammation participates in the progression of multiple chronic diseases, including obesity, diabetes mellitus (DM), and DM related complications. Diabetic ulcer, characterized by chronic wounds that are recalcitrant to healing, is a serious complication of DM tremendously affecting the quality of life of patients and imposing a costly medical burden on society. Matrix metalloproteases (MMPs) are a family of zinc endopeptidases with the capacity of degrading all the components of the extracellular matrix, which play a pivotal part in healing process under various conditions including DM. During diabetic wound healing, the dynamic changes of MMPs in the serum, skin tissues, and wound fluid of patients are in connection with the degree of wound recovery, suggesting that MMPs can function as essential biomarkers for the diagnosis of diabetic ulcer. MMPs participate in various biological processes relevant to diabetic ulcer, such as ECM secretion, granulation tissue configuration, angiogenesis, collagen growth, re-epithelization, inflammatory response, as well as oxidative stress, thus, seeking and developing agents targeting MMPs has emerged as a potential way to treat diabetic ulcer. Natural products especially flavonoids, polysaccharides, alkaloids, polypeptides, and estrogens extracted from herbs, vegetables, as well as animals that have been extensively illustrated to treat diabetic ulcer through targeting MMPs-mediated signaling pathways, are discussed in this review and may contribute to the development of functional foods or drug candidates for diabetic ulcer therapy. This review highlights the regulation of MMPs in diabetic wound healing, and the potential therapeutic ability of natural products for diabetic wound healing by targeting MMPs.

The impact of health insurance on residents’ health is one of the focal points of academic research. Due to the fact that China’s medical insurance system is composed of a variety of programs and that the pooling districts are at the lower administrative level, enrollment in different medical insurance programs or at different places may have certain influences on the health of residents. This has mostly been neglected by previous studies. This paper uses data from the 2015 China Migrants Dynamic Survey (CMDS), focusing on the senior floating population and taking the difference in government subsidy proportions as an instrumental variable in order to identify the effects of health insurance programs and regional differences on the health of the senior floating population. Three effects were observed: First, participation in the health insurance system significantly improves floating seniors’ self-rated health. Second, the health status of floating seniors affects their choice of health insurance program: Less healthy persons tend to choose high-paying, wide-coverage basic medical insurance available for urban employees. Using an instrumental variable to control for the problem of endogeneity, it is discovered that compared with the basic medical insurance system for urban residents, the system for urban employees significantly enhances the health of the senior floating population. Third, “adverse selection” could be observed in the choice between enrolling in health insurance at the place of settlement or another place. Senior migrants with worse self-rated health tend to choose place of settlement in order to enjoy higher compensation and less complex reimbursement procedures. With an instrumental variable to control for the problem of endogeneity, it was found that compared with joining the medical insurance system at other places, joining at a place of settlement could improve the health of the floating senior population.

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Multi-pulse soliton molecules are observed in passively mode-locked fiber lasers by using 2D layered metal dichalcogenides (LMDs) as a saturable absorber. LMD has attracted significant attention in photonics and optoelectronics in which tin disulfides (SnS 2 ) are implemented for energy storage, photo-catalysts, and transistor. However, the applications of SnS 2 in optoelectronics fields are quite rare. Soliton supramolecules are the self-assembly of optical solitons into highly-ordered supramolecular structures which have not been experimentally observed due to the absence of techniques for controlling the inter-soliton forces. In this article, SnS 2 LMDs are successfully applied in a passively mode-locked fiber laser. It is confirmed that the proposed fiber laser has a center wavelength of 1561.5 nm, a 3-dB spectral width of 2.45 nm, signal-to-noise ratio of 63 dB, and a radiofrequency of 7.2 MHz. The different interiors of the second-order, third-order, and ninth-order bound state of solitons in the cavity are investigated. Furthermore, it is found that numbers of optical solitons self-assembled into highly ordered supramolecular structures in a passively mode-locked fiber laser for the first time. The bound state between the six supramolecular soliton units is obtained experimentally and theoretically which have potential applications in ultrafast laser-field manipulation and optical information storage because of special interactions between pulses.