Funding for this research was provided by:
Natural Science Foundation of Shandong Province (ZR2015HM029)
Qingdao Municipal Science and Technology Bureau (186179nsh)
Article History
Received: 22 May 2019
Accepted: 14 July 2019
First Online: 23 July 2019
Compliance with ethical standards
: This article does not contain any studies with human participants or animals performed by any of the authors. Informed consent was obtained from all individual participants included in the study.
: None.