1. Department of Infectious Diseases, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
2. Department of Thoracic Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
3. Department of Internal Medicine, Hebei Yi County Hospital, Baoding, Hebei 074200, P.R. China