Liu, Haina
Li, Xia
Song, Yanpeng
Wang, Zhibin
Article History
Received: 5 June 2018
Accepted: 11 July 2018
First Online: 24 July 2018
Ethics approval and consent to participate
: All procedures performed in studies were in accordance with the ethical standards of the research committee of The Affiliated Qingdao Municiple Hospital of Qingdao University and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: All participants have given consent for publication.
: The authors have declared that no conflicts of interest exist.
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