1 Department of Respiratory Medicine, Huizhou Municipal Central Hospital, Huizhou, China.
2 Department of Peripheral Vascular Interventiology, Huizhou Municipal Central Hospital, Huizhou, China.
3 Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, China.
4 Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, China - caishaox@edu.smu.cn.