Zhou, Yang
Wang, XiaoLin
Xu, Chen
Zhou, GuoFeng
Zeng, MengSu
Xu, PengJu http://orcid.org/0000-0002-0832-083X
Article History
First Online: 1 February 2018
Compliance with ethical standards
:
: No funding was received for this study.
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study does not contain any studies with animals performed by any of the authors. For this type of study, formal consent is not required.
: The institutional review board approved this study and waived informed consent because of retrospective study.