Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

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.

Https

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.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation

Search Page

Filters

My Custom Filters

Results by year

Table representation of search results timeline featuring number of search results per year.

Year Number of Results
1946 1
1961 2
1964 2
1965 4
1966 26
1967 41
1968 41
1969 69
1970 57
1971 61
1972 58
1973 58
1974 77
1975 83
1976 55
1977 59
1978 35
1979 52
1980 42
1981 25
1982 30
1983 18
1984 34
1985 39
1986 46
1987 31
1988 45
1989 40
1990 70
1991 91
1992 143
1993 179
1994 225
1995 281
1996 278
1997 332
1998 386
1999 381
2000 420
2001 444
2002 471
2003 520
2004 551
2005 578
2006 630
2007 624
2008 596
2009 632
2010 646
2011 655
2012 636
2013 642
2014 612
2015 580
2016 565
2017 516
2018 559
2019 575
2020 560
2021 483
2022 400
2023 326
2024 449
2025 10

Publication date

Text availability

Article attribute

Article type

Additional filters

Article Language

Species

Sex

Age

Other

Search Results

15,561 results

Results by year

Filters applied: . Clear all
Page 1
15,561 results
You have reached the last available page of results. Please see the User Guide for more information.