1. Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, the Second Military Medical University, Shanghai, China
2. Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
3. Department of Anesthesiology, The University of Hong Kong, Pokfulam, Hong Kong
4. Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong