Funding for this research was provided by:
National Natural Science Foundation of China (81230016)
Shaanxi Health and Family Planning Commission (Sxwsjswzfcght2016-013)
National Key R&D Program of China (2017YFC0907200, 2017YFC0907201)
Chinese National Natural Science Foundation for Young Scientists (81703245)
Shaanxi natural science basic research (2014JM2-8153)
Text and Data Mining valid from 2020-02-18
Received: 26 September 2019
Accepted: 29 January 2020
First Online: 18 February 2020
Ethics approval and consent to participate
: This study was approved by the Human Research Ethics Committee of the Xi’an JiaoTong University Health Science Center (No 2012008), China. Written informed consent was obtained from all study participants after a detailed briefing on the purpose, process and confidentiality of the research.
: Not applicable.
: The authors declare that they have no competing interests.