Funding for this research was provided by:
National Natural Science Foundation of China (91132703, 31230031, 31471067)
National Basic Research Program of China (973 Program) (2014CB846101)
Text and Data Mining valid from 2017-07-07
First Online: 7 July 2017
Compliance with Ethical Standards
: We declare that we have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.