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Johannsen NM, Swift DL, Johnson WD, Dixit VD, Earnest CP, Blair SN, Church TS.Johannsen NM, et al. Among authors: swift dl.PLoS One. 2012;7(2):e31319. doi: 10.1371/journal.pone.0031319. Epub 2012 Feb 17.PLoS One. 2012.PMID: 22363616Free PMC article.Clinical Trial.