1. Department of Neurosurgery, Taihe Hospital, Hubei University of Medicine, Shiyan, China
2. Guangxi Key Laboratory for Transplantation Medicine, Institute of Transplant Medicine, 303 Hospital of People's Liberation Army, Nanning, China
3. The Biomedical Research Center, University of British Columbia, Vancouver, Canada
4. Department of Surgery, University of British Columbia, Vancouver, Canada