1. Department of Oncology, Yantai Yuhuangding Hospital, Medical College, Qingdao University, Yantai, Shandong 264000, P.R. China
2. Cardiff China Medical Research Collaborative, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
3. Department of Anaesthesiology, Yantai Yuhuangding Hospital, Medical College, Qingdao University, Yantai, Shandong 264000, P.R. China