Notes
Ethical Statement: No ethical approval was required as this is a review article with no original research data.
Data availability statement: The data that support the findings of this study are available on request from the corresponding author.
Acknowledgement: The authors would like to thank all the study participants.
Author contributions: Yu Hu and Shanshan Luo designed the study; Moran Wang and Shengling Ma collected the data, and wrote the paper; Yu Hu and Shanshan Luo analyzed the data and modified the grammatical structure of the article; all authors reviewed the paper and approved the final manuscript.
Potential conflicts of interest:The authors declare no conflicts of interest.
Funding: This work was supported by the National Natural Science Foundation of China (grant number 81601747).