1. College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
2. School of Pharmacy, Tsinghua University, Beijing 100084, P.R. China
3. Department of Critical Care Medicine, The Fifth Hospital of the Chinese People's Liberation Army, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China