Funding for this research was provided by:
National Natural Science Foundation of China (81500546)
Text and Data Mining valid from 2018-03-20
Received: 10 April 2017
Accepted: 7 March 2018
First Online: 20 March 2018
Ethics approval and consent to participate
: The Ethics Research Committee at Tongji Hospital approved the study and agreed that informed consent was not necessary because of the observational nature (retrospective analysis) of this study. The information of all patients was anonymized and de-identified prior to analysis.
: Not applicable.
: The authors declare that they have no competing interests.
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