Funding for this research was provided by:
National Natural Science Foundation of China (No.81400549)
Article History
Received: 5 February 2019
Accepted: 16 May 2019
First Online: 24 May 2019
Compliance with ethical standards
:
: The authors declare that they 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.
: Informed consent was obtained from all individual participants included in the study.