Funding for this research was provided by:
National Natural Science Foundation of China (81470704, 81670932, 81670942)
Key Technology Research and Development Program of Shandong (2019GSF108248)
Received: 18 December 2019
Accepted: 2 July 2020
First Online: 25 July 2020
Ethics approval and consent to participate
: The study protocol was permitted by the Ethics Committee of Shandong Provincial ENT Hospital, Shandong University (XYK20140101), and adhered to the Declaration of Helsinki principles. Informed written consent was obtained from each subject or, in the case of minors, from their parents.
: Written consent was obtained from all the participants or their guardians for the publication of this study.
: The authors declare no conflicts of interest.