Received: 27 August 2018
Accepted: 26 November 2018
First Online: 13 December 2018
Ethics approval and consent to participate
: This study was approved by the ethics committee of Beijing Huairou Hospital. Each patient was informed of the study and signed an informed consent form and had the right to withdraw from the study at any time.
: Not applicable.
: All authors’ declare that they have no competing interests.
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