1. Department of Cardiothoracic Surgery, The Affiliated Lihuili Hospital, Ningbo University, Ningbo, Zhejiang 315041, P.R. China
2. Department of Respiratory Medicine, Ningbo Yinzhou No. 2 Hospital, Ningbo, Zhejiang 315192, P.R. China
3. Department of Cardiothoracic Surgery, Li Huili Hospital Affiliated to Ningbo University, Ningbo, Zhejiang 315041, P.R. China