Funding for this research was provided by:
National Natural Science Foundation of China (No.81772298)
Natural Science Foundation of Hunan Province (No.2018JJ3848)
Text and Data Mining valid from 2019-07-23
Received: 24 January 2019
Accepted: 15 July 2019
First Online: 23 July 2019
Ethics approval and consent to participate
: This study has been conducted adhering to the principles of the Declaration of Helsinki II and approved by the medical ethics committee of Xiangya Hospital, Central South University (ethical code, 201703358). Written informed consent was obtained from all the study participants or their parents or guardians.
: Not applicable.
: The authors declare that they have no competing interests.