Funding for this research was provided by:
National Natural Sciences Foundation of People’s Republic of China (11561070)
Natural Scientific Research Fund Project of Yunnan Province (2014FD049)
Article History
Received: 21 February 2019
Accepted: 22 April 2019
First Online: 9 May 2019
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have no competing interests.
: Not applicable.