In Situ‐Forming Cross‐linking Hydrogel Systems: Chemistry and Biomedical Applications

With the development of chemical synthetic strategies and available building blocks, in situ‐forming hydrogels have attracted significant attention in the biomedical fields over the past decade. Due to their distinct properties of easy management and minimal invasiveness via simple aqueous injections at target sites, in situ‐forming hydrogels have found a broad spectrum of biomedical applications including tissue engineering, drug delivery, gene delivery, 3D bioprinting, wound healing, antimicrobial research, and cancer research. The objective of this chapter is to provide a comprehensive review of updated research methods in chemical synthesis of in situ‐forming cross‐linking hydrogel systems and their diverse applications in the biomedical fields. This chapter concludes with perspectives on the future development of in situ‐forming hydrogels to facilitate this multidisciplinary field

Dynamic Behaviors of a Discrete Lotka-Volterra Competition System with Infinite Delays and Single Feedback Control

A nonautonomous discrete two-species Lotka-Volterra competition system with infinite delays and single feedback control is considered in this paper. By applying the discrete comparison theorem, a set of sufficient conditions which guarantee the permanence of the system is obtained. Also, by constructing some suitable discrete Lyapunov functionals, some sufficient conditions for the global attractivity and extinction of the system are obtained. It is shown that if the the discrete Lotka-Volterra competitive system with infinite delays and without feedback control is permanent, then, by choosing some suitable feedback control variable, the permanent species will be driven to extinction. That is, the feedback control variable, which represents the biological control or some harvesting procedure, is the unstable factor of the system. Such a finding overturns the previous scholars’ recognition on feedback control variables

A Unified Picture for Single Transverse-Spin Asymmetries in Hard Processes

Using Drell-Yan pair production as an example, we explore the relation between two well-known mechanisms for single transverse-spin asymmetries in hard processes: twist-three quark-gluon correlations when the pair's transverse momentum is large, $q_\perp \gg \Lambda_{\rm QCD}$, and time-reversal-odd and transverse-momentum-dependent parton distributions when $q_\perp$ is much less than the pair's mass. We find that although the two mechanisms have their own domain of validity, they describe the same physics in the kinematic region where they overlap. This unifies the two mechanisms and imposes an important constraint on phenomenological studies of single spin asymmetries.Comment: 4 pages, 3 figure

The Outbreak Evaluation of COVID-19 in Wuhan District of China

There were 27 novel coronavirus pneumonia cases found in Wuhan, China in December 2019, named as 2019-nCoV temporarily and COVID-19 formally by WHO on 11 February, 2020. In December 2019 and January 2020, COVID-19 has spread in large scale among the population, which brought terrible disaster to the life and property of the Chinese people. In this paper, we will first analyze the feature and pattern of the virus transmission, and discuss the key impact factors and uncontrollable factors of epidemic transmission based on public data. Then the virus transmission can be modelled and used for the inflexion and extinction period of epidemic development so as to provide theoretical support for the Chinese government in the decision-making of epidemic prevention and recovery of economic production. Further, this paper demonstrates the effectiveness of the prevention methods taken by the Chinese government such as multi-level administrative region isolation. It is of great importance and practical significance for the world to deal with public health emergencies.Comment: 7 pages, 18 figure

Unipolar resistance switching and abnormal reset behaviors in Pt/CuO/Pt and Cu/CuO/Pt structures

The effects of Pt and Cu top electrodes on resistance switching properties were investigated for CuO thin films with Pt/CuO/Pt and Cu/CuO/Pt sandwich structures. Typical unipolar resistance switching (URS) behaviors and two different kinds of resistance changes in the reset process were observed in both structures. When voltages were applied to the film, the low-resistance state (LRS) with relatively low resistance value (50 Ω), the resistance first decreased then increased to HRS, showing abnormal reset behavior. The former variation of LRS could be ascribed to the decrease in filament size induced by Joule heating, while the latter one could be ascribed to the growth of disconnected filaments induced by high electric fields. This study indicates that the switching modes and the abnormal reset behaviors in CuO thin films are not due to Pt and Cu top electrodes, but the intrinsic properties of CuO film

Testing an intervention codesigned with stakeholders for altering wildlife consumption: Health messaging matters

Consumer behavior change is a key priority to address the illegal wildlife trade, but evaluation of these interventions is lacking. We used surveys and randomized controlled trials to assess the effectiveness of three types of messages, which were codesigned with key stakeholders, with 2496 potential consumers and nontarget consumers in China. We found a 23% decrease in intention among potential consumers to use wild animal medicinal products by health‐related messages, and a 14% decrease by legality‐related messages, compared with the control group, though the effect size was small. Furthermore, we revealed that the effect of health‐related messages occurred indirectly by increasing health risk perceptions associated with improper utilization of wild animals. Yet, we did not find a clear effect pathway of the legality‐related messages. Regarding the nontarget consumers, information of whistleblowing platforms and incentives improved willingness to report illegal wildlife use directly, as well as indirectly through adding messages to increase perceived legality risk of using wild products and improve self‐efficacy in identifying legal products. Our findings can inform future larger scale efforts to influence wildlife consumption

Applying a co-design approach with key stakeholders to design interventions to reduce illegal wildlife consumption

1. Co-design, an approach that seeks to incorporate the experiences and perspectives of different stakeholders, is increasingly being used to develop audience-oriented behaviour change interventions. 2. The complexity of wildlife consumption behaviour makes the co-design approach an important potential tool for the design of conservation interventions that aim to reduce illegal wildlife trade. Yet, little is known about how to adapt and apply the co-design approach to the wildlife trade sector. 3. Here, we applied a co-design approach to develop interventions aimed at reducing illegal animal-based medicine consumption in China. We conducted three workshops with key stakeholders: consumers of animal-based medicines, pharmacy workers who sell them and traditional Chinese medicine (TCM) doctors who prescribe them. We then developed a theory of change to ensure the relevance of the co-designed intervention prototypes. 4. Our co-design process identified five main pathways of interventions, including two inclusive solutions that may have been previously overlooked in behaviour change work in this context. These were an intervention to promote the appropriate use of TCM and one to increase consumers' capacity to identify the legality of products. Our prototype interventions also enhanced existing views related to the role of medical practitioners in health-risk communication. 5. We used our co-design process and reflections on its application to this specific market to provide guidelines for future conservation program planning in the broader wildlife trade context. Some intervention prototypes produced during co-design may need wider stakeholder involvement to increase their feasibility for implementation. 6. We show that the co-design process can integrate multiple stakeholders' perspectives in the ideation stage, and has the potential to produce inclusive intervention designs that could drive innovation in conservation efforts to reduce illegal consumption of a range of wild species

Early warning technique research of surface subsidence for safe mining in underground goaf in Karst Plateau zone

Underground mining in Karst Plateau landform area may cause the loss of support for the upper rock stratum, resulting in rock collapse and large-scale subsidence of the ground surface. Also, the formation of a large-scale goafs may further lead to geo-hazards such as collapse, water gushing, slope instability and so on in the area. To reduce the impact of goaf settlement on local strata stability, this paper established a standardized safe mining detection model for goafs based on the geological safety characteristics of mining goafs. With reference to the statistical analysis of the geological conditions in the mining area, a numerical model with 358 goafs and the proposed mining area was established using FLAC3D numerical software. The surface subsidence and variations of plastic zone in the mining area were comprehensively analyzed. The results indicated that there was a correlation between the stability of the mining area and the geological occurrence conditions of the goafs. By quantitatively taking the values from standardized safety mining detection models, the standardized safety mining detection and warning technique was finally established. The findings can provide technical guidance for safety detection and early warning in the whole process of underground goaf mining in Karst Plateau karst development zone