Text and Data Mining valid from 2018-04-26
Received: 6 August 2017
Accepted: 19 March 2018
First Online: 26 April 2018
Ethics approval and consent to participate
: The study was reviewed and approved by the institutional review boards and ethics committees of Beijing Tiantan Hospital affiliated to Capital Medical University. (KY2014-033-01).
: Not applicable.
: The authors declare that they have no competing interests.