1. Department of Respiratory Medicine, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550001, P.R. China
2. Department of Comprehensive Ward, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550001, P.R. China
3. Department of Clinical Research Centre, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550001, P.R. China
4. Department of Clinical Research State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong 510120, P.R. China