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.
Liu X, Li N, Liu C, Ren X, Liu D, Gao B, Liu Y.Liu X, et al. Among authors: liu y, liu c, liu d.Medicine (Baltimore). 2016 Sep;95(37):e4783. doi: 10.1097/MD.0000000000004783.Medicine (Baltimore). 2016.PMID: 27631229Free PMC article.
Ying GY, Li NX, Ren XH, Liu CJ.Ying GY, et al.Zhonghua Yu Fang Yi Xue Za Zhi. 2003 May;37(3):161-6.Zhonghua Yu Fang Yi Xue Za Zhi. 2003.PMID: 12880560Chinese.
Liu C, Li N, Ren X, Liu D.Liu C, et al. Among authors: liu d.Qual Life Res. 2010 Feb;19(1):31-6. doi: 10.1007/s11136-009-9567-y. Epub 2009 Dec 15.Qual Life Res. 2010.PMID: 20013158
Xia P, Li NX, Liu CJ, Lü YB, Zhang Q, Ou AH.Xia P, et al.Sichuan Da Xue Xue Bao Yi Xue Ban. 2010 Jul;41(4):678-83.Sichuan Da Xue Xue Bao Yi Xue Ban. 2010.PMID: 20848795Chinese.
Ke X, Liu C, Li N.Ke X, et al. Among authors: liu c.BMC Public Health. 2010 Sep 24;10:573. doi: 10.1186/1471-2458-10-573.BMC Public Health. 2010.PMID: 20863410Free PMC article.
Li NX, Liu DP, Liu CJ, Ren XH, Gao B.Li NX, et al.Sichuan Da Xue Xue Bao Yi Xue Ban. 2010 Nov;41(6):1044-6.Sichuan Da Xue Xue Bao Yi Xue Ban. 2010.PMID: 21265112Chinese.
Xia P, Li N, Hau KT, Liu C, Lu Y.Xia P, et al. Among authors: liu c.BMC Med Res Methodol. 2012 Mar 27;12:37. doi: 10.1186/1471-2288-12-37.BMC Med Res Methodol. 2012.PMID: 22452994Free PMC article.
Li Y, Wu Q, Liu C, Kang Z, Xie X, Yin H, Jiao M, Liu G, Hao Y, Ning N.Li Y, et al. Among authors: liu c, liu g.PLoS One. 2014 Apr 8;9(4):e93253. doi: 10.1371/journal.pone.0093253. eCollection 2014.PLoS One. 2014.PMID: 24714605Free PMC article.