Duration of Acute Kidney Injury and In-Hospital Mortality in Elder Patients with Severe COVID-19: A Retrospective Cohort Study. - Cai, Yue; Tang, Chong; Song, Yun; Li, Qinglin; Guo, Shanshan; Chen, Yanyan; Wang, Fang; Li, Yangping; Lei, Yan; Li, Fei; Tao, Ling (BioMed Research International, 2022)