Searching for "stem cells" or "stem cell" on Scirus returns 995,702 results, of which 152,648 are journal publications with the term in the title, abstract or contents, and 62,220 patents. According to Wikipedia, Stem cells were postulated in the early 1960s and shown to exist in 1963, giving us a 40-year window to chart the progress of human knowledge. However, looking at Scirus, I find articles as early as 1916 that seem relevant, and a patent in 1947 that also looks relevant to a layman.
Starting in 1960 excludes 74 journal articles and 2 patents, so we will make that our base year. That gives us a Compound Annual Growth Rate (CAGR) of 16.63%, or enough to double human knowledge about stem cells every five years. Hooray! We have another winner. That actually would double every 4.5 years. For patents, the CAGR is higher, 26.47%, which would double every 2.95 years. (Just for fun, if I used a base year of 1947, when the first patent was filed, the CAGR is still enough to double human knowledge every five years, although it drops to 20.2%).
Perhaps the most important finding is that President Bush's restrictions on stem-cell work in the U.S.A. has not dragged progress down, with over 100,000 journal publications and over 56,000 patents filed since he took office. Of course, I'm not counting how many of each are American, but that's for domestic policy wonks to debate... or even research, if they have the time.
As in some (not all) other sectors, we see that the quickest growth for academic publications is early, while patents explode just about the time that growth slows in academia. I'm not sure that's a coincidence...
Again, we see that when the incentives are properly allocated, we can double human knowledge in a sector every five years.
Click to see the figures below.
Please remember that undated results on Scirus are automatically classed in their decade results for 1920-1930.
Here are the five year aggregated totals for a search for "stem cell" or "stem cells" on Scirus.
Year Journals Patents
2002-2006 65,509 43,215
1997-2001 35,512 13,558
1992-1996 18,980 2,693
1987-1991 10,887 710
1982-1986 8,412 167
1977-1981 4,144 76
1972-1976 2,060 10
1967-1971 608 7
1962-1966 179 7
Here are the annual results:
Year Journals Patents
Totals: 152,608 62,220
2007 6,269 1,783
2006 16,563 8,694
2005 14,647 8,194
2004 13,013 8,486
2003 11,454 10,683
2002 9,832 7,158
2001 9,299 4,484
2000 7,757 2,942
1999 6,482 2,565
1998 5,897 2,258
1997 6,077 1,309
1996 5,325 986
1995 4,729 658
1994 3,724 442
1993 2,836 360
1992 2,366 247
1991 2,232 210
1990 2,081 172
1989 2,460 152
1988 2,094 91
1987 2,020 85
1986 1,986 51
1985 2,019 40
1984 1,746 33
1983 1,389 18
1982 1,272 25
1981 1,027 27
1980 979 23
1979 860 8
1978 717 10
1977 561 8
1976 522 4
1975 476 0
1974 391 2
1973 341 1
1972 330 2
1971 239 1
1970 135 1
1969 80 2
1968 95 1
1967 59 2
1966 41 0
1965 50 1
1964 35 0
1963 32 0
1962 21 0
1961 15 0
1960 12 0
1950-1960 50 0
1940-1950 10 1
1930-1940 10 1
1920-1930 4* 0
*only counts valid results--undated articles not included
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