Ruan, Zhengmin
Wu, Mei
Shao, Chunchun
Zhang, Yuan
Zhang, Caikun
Zhang, Feixue
Zhao, Bin
Article History
Received: 20 July 2019
Accepted: 4 November 2019
First Online: 3 January 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Second Hospital of Shandong University. Informed consent was obtained from each participant or guardian.
: Consent to publication has been signed by each participant or guardian.
: The authors declare that they have no competing interests.