PubMed options for focusing your search::
Filters: Use filters to narrow your search results by date, language, article type, etc.
Building Blocks: Use Boolean logic (AND, OR, and NOT), search history, phrase searching, and truncation.
MeSH: An acronym for Medical Subject Headings; PubMed/MEDLINE uses MESH terms for indexing articles.
Clinical Queries: Prefrabricated searches that limit to specific clinical studies (i.e., etiology, diagnosis, therapy, prognosis, or clinical prediction).
Display/Sort: Use the Display Settings menu to change the display format, the number of citations per page and the sort order of your results.
Send to: An menu option to send or copy PubMed records to a file, to the Clipboard, to Collections, to E-Mail, to order, to My Bibliography, or to a Citation manager program.
MyNCBI: A feature that allows you to save records and searches, and customize your results display with filters and other options.