Funding for this research was provided by:
National Natural Science Foundation of China (71673169, 71673170)
Article History
Received: 2 September 2019
Accepted: 2 November 2019
First Online: 19 November 2019
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: This study was approved by the Academic Research Ethics Committee of Shandong University. In addition, this study was performed in accordance with the ethical principles of the Declaration of Helsinki.
: Informed consent was obtained from all individual participants included in the study.