1. Department of Respiratory and Critical Care Medicine, Ningbo First Hospital, Ningbo, Zhejiang, P. R. China
2. Ningbo University School of Medicine, Ningbo, Zhejiang, P. R. China
3. Department of Traditional Medicine, Ningbo First Hospital, Ningbo, Zhejiang, P. R. China
4. Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, P. R. China