Funding for this research was provided by:
the National Natural Science Foundation of China (41501059)
the Fundamental Research Funds for the Central Non-profit Research Institution of CAF (CAFYBB2016QB004, CAFYBB2017ZA004-7)
the National Science and Technology Program for Public Wellbeing (2012GS610203)
Article History
Received: 1 February 2018
Accepted: 30 March 2018
First Online: 9 April 2018
Compliance with ethical standards
:
: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.