1. Department of Thoracic Surgery, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou 563000, P.R. China
2. Department of Infectious Disease, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
3. Department of Nursing, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou 563000, P.R. China