Funding for this research was provided by:
Anhui Province Returned Overseas Students Innovation Project; China Postdoctoral Science Fund Project (2016M592037)
2016 Anhui Postdoctoral Fund Project (2016B096)
Article History
Received: 14 October 2019
Accepted: 23 December 2019
First Online: 3 January 2020
Change Date: 12 March 2021
Change Type: Correction
Change Details: A Correction to this paper has been published:
Change Details: https://doi.org/10.1186/s12881-020-01178-9
Ethics approval and consent to participate
: The present study was approved by the Ethics Committee of the Maternity and Child Care Center of Liuzhou. The research has been carried out in accordance with the World Medical Association Declaration of Helsinki. All patients and healthy volunteers provided written informed consent prior to their inclusion within the study.
: Not applicable.
: The authors declare that they have no competing interests.