Funding for this research was provided by:
National Key R & D Program of China; National Natuaral Science Foundation of China
Text and Data Mining valid from 2019-03-25
Received: 5 January 2019
Accepted: 13 March 2019
First Online: 25 March 2019
Compliance with ethical standards
: All the authors declare that there is no conflict of interest in this work.
: 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. This study was approved by the hospital ethics committee and conducted in accordance with medical ethics regulations.
: Informed consent was obtained from all individual participants included in the study.