Wei, Zhongcao
Yang, Xing
Xing, Xin
Dong, Lei
Wang, Jinhai
Qin, Bin
Funding for this research was provided by:
Shaanxi key research and development projects (16KTZDSF02-02)
Article History
Received: 11 January 2021
Accepted: 3 May 2021
First Online: 12 May 2021
Declarations
:
: The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Xi’an Jiaotong University (2015163). Written informed consent was obtained from school administrators and the participating children prior to the survey.
: Not applicable.
: The authors declare that they have no competing interests.