Funding for this research was provided by:
National Natural Science Foundation of China (31200776)
Text and Data Mining valid from 2019-01-19
Received: 25 October 2018
Accepted: 10 January 2019
First Online: 19 January 2019
Compliance with ethical standards
: All the authors declare that they have no conflict of interest.
: The study was supported by the IRB of Nanjing Normal University. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.