3 RESULTS
During the initial literature search, 942 articles were found. After removing duplicates, 550 articles remained. Next, 201 articles were selected for full-text review after reviewing the titles and abstracts. Finally, 19 articles were included in the analysis after a thorough reading of the full text (Y. Deng et al., 2016; Fu et al., 2018; J. Guo et al., 2010; Y. Hu et al., 2016; H. Li et al., 2018; L. Li et al., 2014; P. Ma, Zhang, Su, Qiu, & Wu, 2015; Shao et al., 2015; Su et al., 2018; Tao et al., 2013; Wei et al., 2015; Wu et al., 2011; Xie et al., 2018; Xiong et al., 2016; C. Q. Xu et al., 2010; F. Zhang et al., 2015; L. Zhang, Wang, Li, Zhang, & Hao, 2017; X. Zhang et al., 2018; J. Zhou et al., 2011)(Figure 2 ).