Funding for this research was provided by:
Lanzhou science and technology plan program (2016-2-71)
Article History
Received: 15 May 2019
Accepted: 19 July 2019
First Online: 6 September 2019
Compliance with ethical standards
:
: Lan Bu, Dan Yang, Fang Nie, Qi Li, and Yan-fang Wang declare that they have no conflicts of interest.
: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. Informed consent was obtained from all patients for being included in the study.