Funding for this research was provided by:
National Nature Science Foundation of China (U1611461, 61672241, 61602184, 61528204)
Cultivation Project of Major Basic Research of NSF-Guangdong Province (2016A030308013)
Science and Technology Program of Guangzhou (201707010147)
Article History
Received: 25 August 2016
Accepted: 5 January 2018
First Online: 19 January 2018
Compliance with ethical standards
:
: Tangquan Qi, Yong Xu and Haibin Ling state that there are no conflicts of interest.