NLM is involved in MEDLINE year-end processing activities which include changing MeSH, Substance Names and other global changes. This always causes a temporary suspension in indexing citations.
So here are some important dates to note:
- November 16, 2011: NLM expects to temporarily suspend the addition of fully-indexed MEDLINE citations to PubMed. Publisher-supplied and in process citations will continue to be added.
- Mid-December 2011: PubMed MEDLINE citations, translation tables, and the MeSH database will have been updated to reflect 2012 MeSH.
For details about the impact on searching from November 16 to mid-December, see: Annual MEDLINE/PubMed Year-End Processing (YEP): Impact on Searching During Fall 2011.
For background information on the general kinds of changes made annually, see: Annual MEDLINE/PubMed Year-End Processing (YEP): Background Information.