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A novel coronavirus first discovered in late December 2019 has spread to many countries around the world. An increasing number of asymptomatic patients have been reported and their ability to spread the virus has been proven. This brings major challenges to the control of the transmission. The discovery and control of asymptomatic patients with COVID-19 are the key issues in future epidemic prevention and recovery. In this narrative review, we summarise the existing knowledge about asymptomatic patients and put forward detection methods that are suitable for finding such patients. Besides, we compared the characteristics and transmissibility of asymptomatic patients in different populations in order to find the best screening, diagnosis and control measures for different populations. Comprehensive preventive advice is also provided to prevent the spread of infection from asymptomatic patients.

The energy conversion efficiency of conventional binary dielectric triboelectric nanogenerators is not satisfactory due to the limitations of material selection and triboelectrification, which motivates the design of more efficient multicomponent structures to reveal the charge accumulation mechanism for improving the energy conversion efficiency. Herein, a rotating quaternary dielectric triboelectric nanogenerator (Q-TENG) is designed to construct a self-powered system integrating illumination, sensing, and electrochemical decolorization. Through the equivalent capacitance model, the mechanisms for charge generation, transfer, and accumulation in a Q-TENG are elucidated to achieve efficient matching of quaternary dielectric materials and high output performance. At a wind speed of 3.5 m s–1, the peak power density of the Q-TENG reaches 44.94 W m–2, setting a new record for a wind-driven TENG. A 5 ppm solution of methyl orange is completely degraded by the wind-driven Q-TENG in <6 h. This work not only guides the direction for constructing more efficient TENG systems but also promotes the practical development of self-powered electrochemical systems.

Embedding metal clusters in surface-supported metal-organic frameworks gives rise to multinuclear metal-organic coordination structures (MMOCs). The controllable configurations, exposed clusters, and multilevel interactions of MMOCs imply numerous potential applications, such as in catalysis, light-energy conversion, spintronics, and molecular electronics. Thus, the fabrication of MMOCs has been investigated extensively. According to the formation mechanism of metal clusters, we summarize five types of MMOCs. Attractive properties, e.g., magnetism, charge transfer and chirality, emerge in these systems. The surface-supported feature enables researchers to detect these properties via surface-sensitive techniques, such as scanning tunneling microscopy/spectroscopy, X-ray photoelectron spectroscopy, noncontact atomic force microscopy and local contact potential difference measurement. In addition, the results obtained from density functional theory calculations can be mutually verified with experiments. These studies pave the way for further applications of MMOCs.