Wang Xiuying

Abstract Microbiologically induced calcite precipitation (MICP) is widely investigated for soil improvement, surface consolidation, and self-healing concrete, yet concrete crack sealing often fails not because calcium carbonate cannot form, but because precipitates are produced at poorly connected locations. In ureolytic systems, Sporosarcina pasteurii and related bacteria raise pH and carbonate alkalinity by hydrolyzing urea, while calcium supplies drive supersaturation.

At​ the end of August, China announced that video game providers could only let minors play online for a single hour, between 8 p.m. and 9 p.m., on Fridays, Saturdays and Sundays. As expected, the children (mostly boys) howled and their parents hoorayed, but to many people’s surprise, the share price of big gaming companies such as Tencent and NetEase shot up. Weren’t they worried about losing customers?

Amassive​ pool party was held recently in Wuhan, ground zero of the pandemic, with thousands of people piling into the water without wearing masks or practising social distancing. This outraged many people on Twitter, who didn’t know that there have been no new cases of Covid-19 in Wuhan for months. For local people, who experienced the chaotic early weeks of the virus in late January and early February, the respite must seem long overdue. Restrictions are diminishing everywhere in China.