Medline This link opens in a new windowMEDLINE provides authoritative medical information on medicine, nursing, dentistry, veterinary medicine, the health care system, pre-clinical sciences, and much more. Created by the National Library of Medicine, MEDLINE uses MeSH (Medical Subject Headings) indexing with tree numbers, tree hierarchy, subheadings and explosion capabilities to search citations fromapproximately 5,400 current biomedical journals.