Funding for this research was provided by:
the Fundamental Research Funds for the Central Universities (sk2018047)
Article History
Received: 13 July 2018
Accepted: 22 February 2019
First Online: 4 March 2019
Compliance with Ethical Standards
:
: Dr. Fangjun Wang has received research grants from Xi’an Jiaotong University. Dr. Luying Xu, Dr. Fei Guo and Dr. Junrui Zhang declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.