1. Department of Respiratory Medicine, The Second Xiangya Hospital, Central South University, 139 Renming Middle Road,Changsha, Hunan 410011; Research Unit of Respiratory Disease, Central South University, 139 Renming Middle Road, Changsha, Hunan 410011; Treatment Center of Respiratory Disease, Central South University, 139 Renming Middle Road, Changsha, Hunan 410011, China.
2. Department of Respiratory Medicine, The Second Xiangya Hospital, Central South University, 139 Renming Middle Road,Changsha, Hunan 410011
3. Department of Pathology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China.