1. Department of Cardiovascular Medicine, The First People's Hospital of Changde, Changde, Hunan 415000, P.R. China
2. Department of Infectious Disease, The First People's Hospital of Changde, Changde, Hunan 415000, P.R. China
3. Department of Science and Education, The First People's Hospital of Changde, Changde, Hunan 415000, P.R. China