Funding for this research was provided by:
Beijing Chao-Yang Hospital middle-aged and young cultivation Funds (No. YQ2014-30)
Received: 18 October 2019
Accepted: 19 April 2020
First Online: 29 April 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Beijing Chao-Yang Hospital (No.2014-KE-124). All written informed consents were obtained from all participants and/or their legal guardians. Firstly, patients who conformed to the inclusion and exclusion criteria were screened in this study. Secondly, we notified patients and/or their legal guardians by telephone and asked for consent, and for those who did not, we waived the use of their data. Thirdly, we sent written informed consents to patients and/or their legal guardians who agreed to participate in the study for signature. Finally, they returned the signed informed consents to us.
: Not applicable.
: The author reports no conflicts of interest in this work.