全文获取类型
收费全文 | 728篇 |
免费 | 86篇 |
出版年
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 11篇 |
2017年 | 16篇 |
2016年 | 15篇 |
2015年 | 19篇 |
2014年 | 29篇 |
2013年 | 25篇 |
2012年 | 36篇 |
2011年 | 31篇 |
2010年 | 26篇 |
2009年 | 32篇 |
2008年 | 44篇 |
2007年 | 42篇 |
2006年 | 33篇 |
2005年 | 32篇 |
2004年 | 28篇 |
2003年 | 30篇 |
2002年 | 29篇 |
2001年 | 27篇 |
2000年 | 22篇 |
1999年 | 22篇 |
1998年 | 6篇 |
1997年 | 9篇 |
1996年 | 18篇 |
1995年 | 10篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1978年 | 6篇 |
1976年 | 7篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1969年 | 3篇 |
1967年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有814条查询结果,搜索用时 15 毫秒
811.
Thierry Langin Pierre Capy Marie-Josée Daboussi 《Molecular genetics and genomics : MGG》1995,246(1):19-28
A new transposable element has been isolated from an unstable niaD mutant of the fungus Fusarium oxysporum. This element, called impala, is 1280 nucleotides long and has inverted repeats of 27 bp. Impala inserts into a TA site and leaves behind a “footprint” when it excises. The inserted element, impala-160, is cis-active, but is probably trans-defective owing to several stop codons and frameshifts. Similarities exist between the inverted repeats of impala and those of transposons belonging to the widely dispersed mariner and Tc1 families. Moreover, translation of the open reading frame revealed three regions showing high similarities with Tc1 from Caenorhabditis elegans and with the mariner element of Drosophila mauritiana. The overall comparison shows that impala occupies an intermediate position between the mariner and Tcl-like elements, suggesting that all these elements belong to the same superfamily. The degree of relatedness observed between these elements, described in different kingdoms, raises the question of their origin and evolution. 相似文献
812.
System analysis and nucleic acid sequence banks 总被引:2,自引:0,他引:2
The mass of published nucleic acid sequence data has required the design of several computerized data bases. We show that this activity is related to the methodology of System Analysis and that data bases are a means of modeling biological knowledge. As an example, the ACNUC data base we have created is presented. 相似文献
813.
M Belbekouche C Gautier R Vaillant 《Biochemical and biophysical research communications》1985,129(3):780-788
Ornithine transcarbamylase activity and immunoreactive enzyme level are compared during perinatal period and in adult rat. Ornithine transcarbamylase activity regularly rises during late fetal period and presents a marked increase 24 hours after birth. Immunoreactive enzyme level does not correlate with this developmental pattern. Ornithine transcarbamylase level increases from 0.06 mg on day 19.5 of pregnancy to 0.417 mg/g liver on day 21.5 and remains constant after birth (0.418 mg/g liver). These results suggest that inactive mitochondrial ornithine transcarbamylase accumulates before birth and that the postnatal increase in enzyme activity is mainly associated with an activation. Furthermore, the paradoxical effect of actinomycin D on ornithine transcarbamylase activity is associated with an increase in enzyme level (about 25%). 相似文献
814.