1. Laboratory of Ethnopharmacology, West China School of Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P. R. China
2. Department of Ophthalmology, West China School of Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P. R. China
3. Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
4. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, P. R. China
5. Metrology Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
6. College of Mathematics, Sichuan University, Chengdu, Sichuan 610065, P. R. China
7. Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China