1 Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Gansu University of Chinese Medicine, Lanzhou, China.
2 School of Life Sciences, Lanzhou University, Lanzhou, China.
3 Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Gansu University of Chinese Medicine, Lanzhou, China. Electronic address: chenyanwen0129@126.com.