An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Chu Y, Wu Z, Ji J, Sun J, Sun X, Qin G, Qin J, Xiao Z, Ren J, Qin D, Zheng X, Wang XL.Chu Y, et al. Among authors: wu z.BMJ Open. 2017 Mar 6;7(3):e013159. doi: 10.1136/bmjopen-2016-013159.BMJ Open. 2017.PMID: 28264827Free PMC article.
Qian X, Su C, Zhang B, Qin G, Wang H, Wu Z.Qian X, et al. Among authors: wu z.BMC Public Health. 2019 Jun 6;19(1):700. doi: 10.1186/s12889-019-6927-6.BMC Public Health. 2019.PMID: 31170949Free PMC article.