Determination of the 50% and 95% effective dose of esketamine combined with propofol for intravenous sedation in pediatric circumcision: study protocol for a randomized controlled, double-blind, dose-finding clinical trial. - Mao, Junqin; Lin, Kang; Liu, Xiang; Liu, Jie; Liang, Gang; Jiang, Chao; Sheng, Zhimin (Trials, 2025)