全文获取类型
收费全文 | 2689篇 |
免费 | 248篇 |
出版年
2023年 | 7篇 |
2022年 | 16篇 |
2021年 | 36篇 |
2020年 | 23篇 |
2019年 | 36篇 |
2018年 | 58篇 |
2017年 | 43篇 |
2016年 | 86篇 |
2015年 | 117篇 |
2014年 | 135篇 |
2013年 | 147篇 |
2012年 | 198篇 |
2011年 | 197篇 |
2010年 | 150篇 |
2009年 | 138篇 |
2008年 | 176篇 |
2007年 | 165篇 |
2006年 | 133篇 |
2005年 | 129篇 |
2004年 | 133篇 |
2003年 | 138篇 |
2002年 | 129篇 |
2001年 | 26篇 |
2000年 | 19篇 |
1999年 | 26篇 |
1998年 | 36篇 |
1997年 | 32篇 |
1996年 | 27篇 |
1995年 | 39篇 |
1994年 | 26篇 |
1993年 | 36篇 |
1992年 | 34篇 |
1991年 | 21篇 |
1990年 | 22篇 |
1989年 | 25篇 |
1988年 | 20篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 6篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1975年 | 6篇 |
1972年 | 6篇 |
1970年 | 7篇 |
排序方式: 共有2937条查询结果,搜索用时 15 毫秒
11.
Hans-Jürgen Peter Christiane Krüger-Alef Wolfgang Knogge Klaus Brinkmann Gottfried Weissenböck 《Planta》1991,183(3):409-415
Chalcone-synthase (CHS) activity was followed during the development of primary leaves of oat (Avena sativa L.) seedlings grown under different illumination conditions. Continuous darkness and continuous light resulted in similar time courses of enzyme activity. The maximum of CHS activity in etiolated leaves was delayed by 1 d and reached about half the level of that of light-grown leaves. In seedlings grown under defined light-dark cycles a diurnal rhythm of CHS activity and its protein level was observed which followed the rhythm of CHS-mRNA translational activity (Knogge et al. 1986). This rhythm persisted in continuous light after a short-term pre-exposure to the light-dark cycle but not in continuous darkness.Abbreviations CHS
chalcone synthase
- PAL
phenylalanine ammonio lyase
Financial support by the Deutsche Forschungsgemeinschaft is gratefully acknowledged (G.W., We 630/9-7; We 630/10-1). Thanks are given to Dr. St. Kellam (Department of Plant Microbiological Sciences, University of Canterbury, New Zealand) for correcting the English. 相似文献
12.
Christiane M.-R. Fauron Mark Casper Raymond Gesteland Marc Albertsen 《The Plant journal : for cell and molecular biology》1992,2(6):949-958
Regeneration of plants from maize cytoplasmic male sterile type T (cmsT) callus tissue culture promotes, in some instances, genetic variability in their mitochondrial genomes. These mutations have been analyzed in various cmsT regenerated plants that have or have not regained the male fertile phenotype. A unique multi-recombination model explains the various mitochondrial genome rearrangements. First, recombination involving two different sets of direct repeats gives rise to subgenomic recombinant circles. Second, intermolecular recombination between some selected subgenomes gives rise to a new rearranged master chromosome. The consequence of these events is the formation of a new master chromosome containing sequence deletions and duplications when compared to the progenitor. This new mitochondrial genome seems stable, although it does not contain the entire genetic complexity of the progenitor. 相似文献
13.
The chromosomal region 36C on 2L contains two maternal-effect loci, dorsal (dl) and Bicaudal-D (Bic-D), which are involved in establishing polarity of the Drosophila embryo along the dorsal-ventral and anterior-posterior axes, respectively. To analyze the region genetically, we isolated X-ray-induced dorsal alleles, which we recognized by virtue of the haplo-insufficient temperature-sensitive dorsal-dominant phenotype in progeny of single females heterozygous for a mutagenized chromosome. From the 20,000 chromosomes tested, we isolated three deficiencies, two inversions with breakpoint in dl and one apparent dl point mutant. One of the deficiencies, Df(2L)H20 (36A6,7; 36F1,2) was used to screen for EMS-induced lethal- and maternal-effect mutants mapping in the vicinity of dl and Bic-D. We isolated 44 lethal mutations defining 11 complementation groups. We also recovered as maternal-effect mutations four dl alleles, as well as six alleles of quail and one allele of kelch, two previously identified maternal-effect genes. Through complementation tests with various viable mutants and deficiencies in the region, a total of 18 loci were identified in an interval of about 30 cytologically visible bands. The region was subdivided into seven subregions by deficiency breakpoints. One lethal complementation group as well as the two maternal loci, Bic-D and quail, are located in the same deficiency interval as is dl. 相似文献
14.
15.
Edmond A. Goidl Christiane Samarut Ansbert Schneider-Gadicke Neal L. Hochwald G.Jeanette Thorbecke Gregory W. Siskind 《Cellular immunology》1984,85(1):25-33
Using hapten-reversible inhibition of plaque formation as an assay for auto-anti-idiotype antibody (anti-Id) and as a means for following idiotype (Id) expression, we have obtained evidence that following immunization with trinitrophenyl (TNP) conjugates (a) there are differences in Id expression in the anti-TNP antibody response to different TNP conjugates although there is some overlap; (b) different strains, although showing some differences in Id expression, tend to produce cross-reactive Ids, thus no obvious allotype linked inheritance of Id expression is observed in this heterogeneous immune response; (c) the auto-anti-Id produced following immunization with TNP-Brucella abortus or TNP-Ficoll tends to be of the IgG2a and IgG2b isotypes. 相似文献
16.
17.
Cathepsin B, H, L and D activities in liver lysosomes were compared between species. Although cathepsin B and D were detected in bovine, pig, chicken and rat liver, striking species differences were evident for cathepsin H and L. Cathepsin L activity was particularly high in chicken lysosomal extracts, but could not be detected in bovine and pig extracts. Whereas there was no significant cathepsin H activity in bovine extracts, rat liver lysosomal extracts contained large amounts of cathepsin H activity. 相似文献
18.
A cDNA clone containing the entire coding sequence of a mouse H-2Kd histocompatibility antigen 总被引:14,自引:4,他引:10
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jean-Louis Lalanne Christiane Delarbre Gabriel Gachelin Philippe Kourilsky 《Nucleic acids research》1983,11(5):1567-1577
We have isolated a cDNA clone carrying a 1560 bp long insert which contains the entire coding and 3' untranslated regions of an H-2K(d) mouse histocompatibility antigen. Its sequence and overal features are described. They point to the existence of unique properties of DNA sequences associated with the H-2K(d) antigen. 相似文献
19.
The composition of 3 species of genus Cistus L. has been analysed and compared: C. labdaniferus L. contains essentially compounds of labdane type, namely labdane-8, 15, 19-triol whose structure has been confirmed; C. monspeliensis L. contains almost exclusively compounds having a new squeleton, the cistane, with a cis-junction of A and B; no cyclic diterpenes have been isolated from C. salvifolius L. which has been found rich in unsaturated aliphatic acids one of which is a mono conjugated triethylenic acid. 相似文献
20.