Author Correction: Comparative metabolomics study on therapeutic mechanism of electro-acupuncture and moxibustion on rats with chronic atrophic gastritis (CAG) oleh Cai-chun Liu, Jiao-long Chen, Xiao-rong Chang, Qi-da He, Jia-cheng Shen, Lin-yu Lian, Ya-dong Wang, Yuan Zhang, Fu-qiang Ma, Hui-ying Huang, Zong-bao Yang