1 Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital, Shandong University, No.324, Jingwu Road, Jinan, Shandong, 250021, China.
2 Department of Pathology, Shandong Provincial Hospital, Shandong University, No.324, Jingwu Road, Jinan, Shandong, 250021, China.
3 Department of Pulmonary and Critical Care Medicine, The Third Affiliated Hospital of Shandong First Medical University (Affiliated Hospital of Shandong Academy of Medical Sciences), No.38, Wuyingshan Road, Jinan, Shandong, 250021, China. Electronic address: longfei@sdfmu.edu.cn.