Photoredox-Catalyzed Plastic Waste Conversion: Nonselective Degradation versus Selective Synthesis

Plastic waste pollution is becoming one of the most pressing environmental crises due to the large-scale production without satisfactory recycling schemes, especially with the outbreak of the COVID-19 pandemic in recent years. Upcycling of plastic waste into valuable chemicals powered by solar energy presents a substantially untapped opportunity to turn waste into treasure. In this review, the fundamental principles from plastic nonselective degradation to selective synthesis are first clarified. Then, we aim to outline the representative recent advances in photoredox-based catalytic plastic waste conversion. Particular emphasis is placed on the valorization of plastic waste regarding nonselective degradation versus selective synthesis. Finally, we present challenges and individual insights for further exploration of the plastic waste conversion domain. It is anticipated that this timely and critical review would provide an instructive direction and foresight on the selective conversion of plastics to value-added chemical feedstocks, thus stimulating the development of a circular and sustainable plastic economy in the coming decades. © 2023 American Chemical Society.

[Epidemiological investigation of a family clustering of COVID-19].

Objective: To investigate the epidemiological characteristics of a family clustering of COVID-19. Methods: Field epidemiological survey was conducted. Results: Case 1 of the long-term residents from Hubei province was the source of infection of this family clustering. There were 6 cases (from case 2 to case 7) infected in the whole incubation period. The incubation period was more than 14 days for 3 of the second-generation cases. Routes of transmission included respiratory droplets (from case 1 transmitted to case 6, from case 1 to her family members) and close contact (from case 1 to other cases in her family). All the age groups were generally susceptible, while elderly were easier to progress to critically ill. Besides respiratory symptoms, there were also gastrointestinal symptoms, of which diarrhea was the most common one. Conclusions: Family clustering had been an important part for COVID-19 cases.