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An official website of the United States government
The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.
The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
structure in first source
Date introduced: May 11, 2010
MeSH Unique ID: C549278
Heading Mapped to: