Received: 29 November 2017
Accepted: 22 August 2018
First Online: 4 September 2018
Ethics approval and consent to participate
: “Ethical approval was obtained by Lanzhou University Second Hospital Medical Ethics Committee Review Form. Approval reference if relevant.” We had all necessary consent from any patients involved in the study, including consent to participate in the study where appropriate.
: Not applicable
: The authors declare that they have no competing interests.
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