Text and Data Mining valid from 2020-04-22
Received: 30 January 2020
Accepted: 15 April 2020
First Online: 22 April 2020
Ethics approval and consent to participate
: Informed consent was obtained and had been written from all patients and the parents/legally authorized representatives of participants. The study protocol was approved by the Ethics Committee of Chongqing Public Health Medical Center of China. All methods were performed in accordance with the relevant guidelines and regulations.
: Not applicable.
: The authors declare that they have no competing interests.