Olanzapine for the prevention of postoperative nausea and vomiting after gynecologic laparoscopic surgery: a randomized controlled trial oleh Nanjin Chen, Shuman Ji, Junfei Liu, Liping Wang, Fenglin Chen, Yanwu Zhu, Jiao Li, Minjuan Chen, Lingyang Chen, Mingcang Wang, Ruyi He, Xiaopeng Mei, Zhanqin Zhang, Shengwei Jin, Jingming Zheng, Yongpo Jiang