The former chairman of a state-owned real estate company who publicly criticized President Xi Jinping's handling of the coronavirus pandemic was sentenced to 18 years in prison on Tuesday on corruption charges, a court announced.Ren Zhiqiang, who became known for speaking up about censorship and other sensitive topics, disappeared from public view in March after publishing an essay online that accused Xi of mishandling the outbreak that began in December in the central city of Wuhan.