Funding for this research was provided by:
National Natural Science Foundation of China (81770356)
Text and Data Mining valid from 2019-04-04
Received: 28 January 2019
Accepted: 20 March 2019
First Online: 4 April 2019
Conflict of interest
: There were no potential conflicts of interest in this study, including related consultancies, shareholdings and grant funding.
: Our study has been approved by the institutional research ethics committee of our hospital (2014PHB125-01) and has been performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki.
: Informed consent was obtained from each patient.