Funding for this research was provided by:
Department of Science and Technology of Sichuan Province (2015JQ0026)
Text and Data Mining valid from 2019-04-05
Received: 11 November 2018
Accepted: 27 March 2019
First Online: 5 April 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This study was approved by the Institutional Ethics Committee of West China Second University Hospital. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: As this was a retrospective study, formal consent was not required. However, informed consent was obtained from each patient for specimen collection.