Received: 26 August 2018
Accepted: 18 February 2019
First Online: 22 February 2019
Ethics approval and consent to participate
: All the procedures performed were in full accordance with the ethical standards of the appropriate national and institutional committees on human experimentation and with the Helsinki Declaration. This study was approved by the institution Ethics Commission of Tianjin Medical University General Hospital and the Second Hospital of Tianjin Medical University. The need for consent to participate was waived by Ethics Commission of Tianjin Medical University General Hospital and the Second Hospital of Tianjin Medical University.
: Not applicable.
: All authors declare that they have no competing interests.
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