Li, Shilun
Yin, Yingchao
Zhang, Ruipeng
Chen, Wei
Zhang, Yingze http://orcid.org/0000-0001-8042-6105
Funding for this research was provided by:
Youth science and technology project of hebei provincial health and family planning commission (20180429)
Article History
Received: 6 June 2018
Accepted: 23 July 2018
First Online: 30 July 2018
Compliance with ethical standards
: The Institutional Review Board of the local hospital approved this study after a thorough examination. The study was performed in accordance with the ethical standards of the Declaration of Helsinki from 1964.
: The authors declare that they have no conflict of interest.
: Signed informed consent was obtained from all patients.