Prediction of Re-positivity for Coronavirus Nucleic Acid Among COVID-19 Patients in the Recovery Phase oleh Shu-fen Zhu, Bo Sun, Jin-kuang Li, Yue Cai, Peng-fei Li, Ji-chang Hong, Jin-hai Li, Shi-wen Xu, Xiao-yang Li, Chen-wei Xue, Bin-bin Gu, Jian-fen Wu, Xian-bin Zhou, Hong Suo, Pei-lin Duan, Xin-xin Wu, Shao-wei Li, Shao-wei Li