Pan, Hua
Huo, Yongmin
Sun, Lirong
Article History
Received: 30 March 2018
Accepted: 30 August 2019
First Online: 29 November 2019
Ethics approval and consent to participate
: A copy of the written consent form is available for review by the editor of this journal. The study has been performed with the approval of the Ethics Committee of the Affiliated University of Qingdao University(no: 20161013). The protocol has been designed and the study will be conducted in line with the principles of the Declaration of Helsinki (1964).
: Not applicable.
: The authors declare that they have no competing interests.