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 NCBI Filters

Results by year

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

Year Number of Results
1947 3
1949 1
1951 11
1952 45
1953 74
1954 67
1955 59
1956 56
1957 52
1958 50
1959 62
1960 67
1961 65
1962 51
1963 3
1964 31
1965 86
1966 176
1967 142
1968 168
1969 158
1970 180
1971 137
1972 168
1973 125
1974 139
1975 126
1976 132
1977 150
1978 169
1979 133
1980 137
1981 149
1982 173
1983 147
1984 162
1985 147
1986 126
1987 143
1988 153
1989 147
1990 167
1991 137
1992 154
1993 148
1994 140
1995 183
1996 165
1997 147
1998 168
1999 192
2000 209
2001 208
2002 218
2003 293
2004 270
2005 274
2006 304
2007 308
2008 295
2009 311
2010 360
2011 389
2012 381
2013 474
2014 472
2015 541
2016 513
2017 492
2018 506
2019 562
2020 478
2021 406
2022 144
2023 133
2024 226
2025 1

Search Results

13,611 results

Results by year

Filters applied: . Clear all
Page 1
13,611 results
You have reached the last available page of results. Please see the User Guide for more information.