http://europepmc.org/abstract/MED/24675358
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http://europepmc.org/abstract/MED/11464291
http://europepmc.org/abstract/MED/15223963
http://europepmc.org/abstract/MED/17350138
http://europepmc.org/abstract/MED/22705117
http://europepmc.org/abstract/MED/12754743
http://europepmc.org/abstract/MED/29874541
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