Article History
Received: 1 September 2017
Revised: 29 November 2017
Accepted: 19 December 2017
First Online: 15 January 2018
Ethics approval and consent to participate
: All experiments involving animals were performed in accordance with guidelines approved by the Committee for Animal Care at Nankai University and coincided with the National Institutes of Health’s Guide for the Care and Use of Laboratory Animals. Human umbilical cords were obtained from full-term births after either cesarean section or normal vaginal delivery with the consent of parents in Tianjin First Center Hospital, Tianjin, China. This study was performed in accordance with the principles of human subject protection in the Declaration of Helsinki and with Nankai University’s Institutional Review Board approval.
: All authors consent for the publication of this study.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.