Funding for this research was provided by:
National Natural Science Foundation of China (21605032)
Undergraduate Innovation and Entrepreneurship Training Program (2017CXCYS083)
Text and Data Mining valid from 2018-02-17
Received: 13 December 2017
Revised: 29 January 2018
Accepted: 2 February 2018
First Online: 17 February 2018
Compliance with ethical standards
: The experimental protocol was approved by the Research Ethics Committee of Hefei University of Technology, China. All participants provided written informed consent.
: The authors declare that they have no conflict of interest.