http://europepmc.org/abstract/MED/23856246
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http://europepmc.org/abstract/MED/28413162
http://europepmc.org/abstract/MED/9230279
http://europepmc.org/abstract/MED/26928463
http://europepmc.org/abstract/MED/7603913
http://europepmc.org/abstract/MED/7573356
http://europepmc.org/abstract/MED/22722839
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