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To investigate the difference of the components and antioxidant activity between the Se-enriched and the common chlorella extract, as well as the correlation between the components and antioxidant activity. This study determined the content of total nitrogen, total sugar, polyphenols, flavonoids, saponins, total selenium, polysaccharide and polysaccharide selenium in selenium-enriched and common chlorella extract and their ability to reduce Fe3+, scavenge DPPH·, ABTS+·, · OH and O2-·, as well as the correlation between the content and antioxidant capacity. The results showed that compared with common chlorella extract, selenium-enriched chlorella extract contained more content of total sugar, polyphenol, flavonoid, total selenium, polysaccharide and polysaccharide selenium (P<0.05), but less total nitrogen and saponins (P<0.05). The Se-enriched chlorella extract had higher activity in reducing Fe3+ and scavenging DPPH· and ABTS+·, but lower activity in scavenging ·OH and O2-· than that of common chlorella extract. Correlation analysis showed that higher content of nitrogen, total sugar, polyphenols, flavonoids, saponins, total selenium, polysaccharide and polysaccharide selenium could strengthen the antioxidant activity (P<0.05). The ·OH scavenging capacity was negatively correlated with total selenium and polysaccharide selenium (P<0.05). In general, Se-enriched chlorella extract had more physiological active substances (except total nitrogen and saponins) and stronger antioxidant activity, which would provide the potential application for Se-enriched chlorella extract in health food products. [ABSTRACT FROM AUTHOR]

While advances in technology have led to the widespread use of artificial intelligence (AI) in frontline services, the AI empathic effect is often overlooked. Based on emotional contagion theory, this research explores the impacts of AI emotional mimicry and empathic concern in service success and failure via experimental designs, respectively. Results indicate that AI with high emotional mimicry and empathic concern resulted in higher arousal and pleasure, increasing tourists' continuous usage intention. Arousal and pleasure played significant mediating roles in service success. However, while empathic concern significantly affected continuous usage intention through pleasure, arousal did not have a similar effect. The joint effects of extrinsic and intrinsic anthropomorphism (emotional mimicry) were significant in a successful service context, but not in service failure. These results have important implications for the development and promotion of AI and enriches theoretical applications of emotional contagion theory and empathy. [ABSTRACT FROM AUTHOR]

This paper investigates the secure optimal tracking control problem for cyber-physical systems, in which the controller-actuator channel is jammed by denial-of-service attacks. Without leveraging model knowledge, learning-based tracking control algorithms are proposed by utilizing the measured input-output data. The impact of malicious attacks on tracking performance is discussed. More specifically, an augmented system consisted of the system model and the reference model is derived. Then the states of the augmented system are rewritten by utilizing the input, output, and reference trajectory, following which both the Bellman equation and algebraic Riccati equation are given. The conditions of existence and uniqueness of the solution to the algebraic Riccati equation are derived. Furthermore, both policy iteration and value iteration learning-based tracking control algorithms are provided for cyber-physical systems against denial-of-service attacks, and the convergence of the algorithms is also proved. Finally, a DC motor system and a numerical example are given to illustrate the effectiveness of the proposed control algorithms. [ABSTRACT FROM AUTHOR]

Metabolic diseases such as obesity and diabetes are often thought to be caused by reduced energy expenditure, which poses a serious threat to human health. Cold exposure, exercise and caloric restriction have been shown to promote adipose tissue browning and thermogenesis. These physiological interventions increase energy expenditure and thus have emerged as promising strategies for mitigating metabolic disorders. However, that increased adipose tissue browning and thermogenesis elevate thermogenic consumption is not a reasonable explanation when humans and animals confront energetic challenges imposed by these interventions. In this review, we collected numerous results on adipose tissue browning and whitening and evaluated this bi‐directional conversion of adipocytes from the perspective of energy homeostasis. Here, we propose a new interpretation of the role of adipose tissue browning under energetic challenges: increased adipose tissue browning and thermogenesis under energy challenge is not to enhance energy expenditure, but to reestablish a more economical thermogenic pattern to maintain the core body temperature. This can be achieved by enhancing the contribution of non‐shivering thermogenesis (adipose tissue browning and thermogenesis) and lowering shivering thermogenesis and high intensity shivering. Consequently, the proportion of heat production in fat increases and that in skeletal muscle decreases, enabling skeletal muscle to devote more energy reserves to overcoming environmental stress. [ABSTRACT FROM AUTHOR]

The 3R (reuse, recycling, and recovery) waste management of wind turbine blades (WTBs) is becoming a popular subject, since it has a great practical significance in the disposal of the large numbers of upcoming end-of-life WTBs. Repurposing or reuse is a priority option, but the disposal of end-of-life WTBs on a large scale is a great challenge. Recycling or recovery is considered a priority for effectively dealing with end-of-life WTBs. This review focuses on the progress and challenges in the recycling and recovery of end-of-life WTBs, which are mainly composed of fiber-reinforced polymer composites. Among the commonly-used recycling methods, one advantage of thermal recycling processes is their tolerance of contaminated material. Thermal recycling processes can also effectively treat various polymer composites on a large scale. In particular, pyrolysis and cement kiln co-processing currently show the highest potential in treating end-of-life WTBs in commercial applications. In addition, chemical recycling processes such as solvolysis are promising methods that can achieve the closed-loop recovery of monomers and high-quality fibers, if green and recyclable solvents as well as mild reaction processes can be developed. Importantly, the life cycle management (LCM) of WTBs ending with solvolysis recycling is identified as the most circular and low-carbon solution. The recycling and recovery of end-of-life WTBs have been developed at an initial stage. Although a number of commercial applications have been achieved, most of these projects are built on extensive methods, focusing on mechanical recycling and cement kiln co-processing. This review will guide researchers to make more effort in the recycling of end-of-life WTBs, covering the reuse of gas and oil products as fuels for sustaining thermal processes and the development of green closed-loop recycling processes. [ABSTRACT FROM AUTHOR]