Su, Hao
Liu, Hongzhi
Liu, Juan
Wang, Xin
Article History
First Online: 19 March 2018
Compliance with ethical guidelines
:
: H. Su, H. Liu, J. Liu and X. Wang declare that they have no competing interests.
: All procedures performed in studies involving human participants were in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki (and its current revised form). This study was approved by the medical ethics committee of the affiliated Yantai Yuhuangding hospital of Qingdao university. Informed consent was obtained from all patients.