Li, Wenfu
Wang, Xianfu
Li, Shibo
Article History
Received: 6 March 2018
Accepted: 19 July 2018
First Online: 10 August 2018
Ethics approval and consent to participate
: This study (#5938) was approved by University of Oklahoma Institutional Review Board for the Protection of Human Subjects.
: Not applicable.
: The authors declare that they have no competing interests.
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