1. Experimental Center of Medical Function, Kunming Medical University, Kunming, Yunnan 650031, P.R. China
2. Department of Anesthesiology, The People's Hospital of Chuxiong Yi Autonomous Prefecture, Chuxiong, Yunnan 675000, P.R. China
3. Department of Anesthesiology, The First People's Hospital of Yunnan Province, Kunming, Yunnan 650032, P.R. China