1. Department of Pulmonary Medicine, Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, China
2. Internal Medicine, Qingdao Municipal Hospital, Qingdao, Shandong, China
3. Department of Intensive Care Unit, The 903rd Hospital of People’s Liberation Army, Hangzhou, Zhejiang, China
4. Department of Respiratory & Critical Care Medicine, Affiliated Hospital of Qingdao University, Qingdao, Shandong, China