Kai Zhang1, Yan Li2, Qilin Tang3. 1. Department of Acupuncture and Moxibustion, Tianjin Gong An Hospital, Tianjin, China. Electronic address: coolzhangkai@163.com. 2. Department of Acupuncture and Moxibustion, Tianjin Gong An Hospital, Tianjin, China. 3. School of Basic Medical Sciences, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China.