Funding for this research was provided by:
National Natural Science Foundation of China (Grant numbers: 81271548, 81271560, 81371535, 81428013, and 81471654)
Planned Science and Technology Project of Guangzhou, China (Grant numbers: 20160402007)
Text and Data Mining valid from 2018-08-08
First Online: 8 August 2018
Compliance with ethical standards
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: All of the authors declare no conflicts of interest.
: Informed consent was obtained from all individual participants included in the study.