1 Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region; Peter Hung Pain Research Centre and State Key Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: wukakei@cuhk.edu.hk.
2 City University of Hong Kong Shenzhen Research Institute, Shenzhen, China; Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, Hong Kong Special Administrative Region. Electronic address: jianbyue@cityu.edu.hk.