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. 2017 Jan 31;7:41695. doi: 10.1038/srep41695

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(A) The localized stage group: χ2 = 88.888, P < 0.001; (B) The regional stage group: χ2 = 12.846, P = 0.005; (C) The distant stage group: χ2 = 18.761, P < 0.001.