1. School of pharmacy, Ningxia Medical University, Yinchuan 750004, China
2. School of Public Health & Management, Ningxia Medical University, Yinchuan 750004, China
3. Key Laboratory of Modernization of Traditional Chinese Medicine, Ministry of Education, Yinchuan 750004, China
4. School of Basic Medical Science, Ningxia Medical University, Yinchuan 750004, China