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Poulsen JA, Nyman G, Rossky PJ.Poulsen JA, et al.Proc Natl Acad Sci U S A. 2005 May 10;102(19):6709-14. doi: 10.1073/pnas.0408647102. Epub 2005 Apr 28.Proc Natl Acad Sci U S A. 2005.PMID: 15860585Free PMC article.