Funding for this research was provided by:
Key Research and Development Program of Shaanxi, China (NO.2019SF-205)
Article History
Received: 28 April 2020
Accepted: 22 July 2020
First Online: 31 July 2020
Ethics approval and consent to participate
: The study protocol was approved by the institutional review board of HongHui Hospital. The trial was registered with the Chinese Clinical Trial Registry (ChiCTR: 1900023408). Informed written consent was obtained from the parents of all children.
: Not applicable.
: The authors have no competing interests to declare.