全文获取类型
收费全文 | 720篇 |
免费 | 55篇 |
专业分类
775篇 |
出版年
2023年 | 4篇 |
2022年 | 18篇 |
2021年 | 21篇 |
2020年 | 19篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 17篇 |
2015年 | 26篇 |
2014年 | 38篇 |
2013年 | 38篇 |
2012年 | 55篇 |
2011年 | 59篇 |
2010年 | 30篇 |
2009年 | 29篇 |
2008年 | 31篇 |
2007年 | 36篇 |
2006年 | 40篇 |
2005年 | 41篇 |
2004年 | 27篇 |
2003年 | 33篇 |
2002年 | 29篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 8篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1981年 | 4篇 |
1978年 | 4篇 |
1974年 | 3篇 |
1968年 | 3篇 |
1967年 | 2篇 |
1965年 | 3篇 |
1956年 | 1篇 |
1955年 | 2篇 |
1941年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有775条查询结果,搜索用时 15 毫秒
131.
132.
133.
134.
Effect of vanadate on bean leaf movement, stomatal conductance, barley leaf unrolling, respiration, and phosphatase activity 总被引:1,自引:2,他引:1 下载免费PDF全文
Vanadate (Na3 VO4) inhibits leaf movement and stomatal conductance of Phaseolus vulgaris L. cv. Carlos Favorit in light-dark cycles as well as photomorphogenetic leaf unrolling of Hordeum vulgare L. cv. Rupal. Inhibition was 50% by 10 to 100 micromolar vanadate and 100% by millimolar vanadate. Leaf unrolling was also inhibited by oligomycin and diethylstilbestrol. 相似文献
135.
Microbes are known for their unique ability to adapt to varying lifestyle and environment, even to the extreme or adverse ones. The genomic architecture of a microbe may bear the signatures not only of its phylogenetic position, but also of the kind of lifestyle to which it is adapted. The present review aims to provide an account of the specific genome signatures observed in microbes acclimatized to distinct lifestyles or ecological niches. Niche-specific signatures identified at different levels of microbial genome organization like base composition, GC-skew, purine-pyrimidine ratio, dinucleotide abundance, codon bias, oligonucleotide composition etc. have been discussed. Among the specific cases highlighted in the review are the phenomena of genome shrinkage in obligatory host-restricted microbes, genome expansion in strictly intra-amoebal pathogens, strand-specific codon usage in intracellular species, acquisition of genome islands in pathogenic or symbiotic organisms, discriminatory genomic traits of marine microbes with distinct trophic strategies, and conspicuous sequence features of certain extremophiles like those adapted to high temperature or high salinity. 相似文献
136.
137.
Selvaraj Jayaraman Vishnupriya Veeraraghavan Radhika Nalinakumari Sreekandan Surapaneni Krishna Mohan Sumetha Suga Deiva Suga Devakumar Kamaraj Sonaimuthu Mohandoss Ponnulakshmi Rajagopal 《Bioinformation》2020,16(11):893
Type 2 diabetes mellitus (T2DM) is linked with Glycogen synthase kinase-3 β.Therefore, it is ofinterest to document molecular docking analysis data of compounds from Justica adhatoda L with glycogen synthase kinase-3 β. We report the binding features of ethambutol, pyrazinamide, stigmasterol and vasicoline with GSK-3 β. 相似文献
138.
Feruloyl esterases can liberate ferulic acid (FA) from plant cell wall polymers. They are expressed by plant pathogenic fungi and could play a role in pathogenicity, although this question has not been addressed yet. The fungus Fusarium graminearum is the principal causal agent of fusarium head blight (FHB) and gibberella ear rot (GER), major diseases of wheat, barley, and maize in all temperate regions of the world. The F. graminearum genome contains seven genes with strong homology to feruloyl esterase (FAE) sequences. Phylogenetic analysis showed that these included three type B, three type C, and one type D FAE genes. Expression profiling of the seven FAE genes showed complex regulation patterns unique to each gene. In F. graminearum-infected plant tissues, the FAE genes exhibited host-specific gene expression. On wheat, FAEB1 and FAED1 were strongly expressed while FAEB2, FAEB3, and FAEC1 were expressed at more modest levels. On maize, only FAEB3, FAEC1, and FAED1 were expressed and at low levels. When growing F. graminearum in liquid culture, only FAEB1 and FAEC1 were expressed. Both genes were induced by a small group of related aromatic compounds including FA, caffeic acid, and p-coumaric acid. FAEB1 was induced by xylose, while repressed by glucose and galactose. FAEC1 was constitutively expressed at low levels in the presence of those sugars. Expression of the other five FAE genes was not detected in the culture conditions used. To determine if FAE genes were important for pathogenicity of F. graminearum, mutant strains inactivated for faeB1?, faeD1? or both genes were constructed and tested on wheat plants. No statistically significant change in pathogenicity and no compensatory expression of the other FAE genes were observed in the fae gene mutants. Our results show that FAEB1 and FAED1 are not required for pathogenicity of F. graminearum on wheat. 相似文献
139.
Shinji Kikuchi Raju Bheemanahalli Krishna S.V. Jagadish Etsushi Kumagai Yusuke Masuya Eiki Kuroda Chitra Raghavan Michael Dingkuhn Akira Abe Hiroyuki Shimono 《Plant, cell & environment》2017,40(8):1565-1575
Phenotypic plasticity of plants in response to environmental changes is important for adapting to changing climate. Less attention has been paid to exploring the advantages of phenotypic plasticity in resource‐rich environments to enhance the productivity of agricultural crops. Here, we examined genetic variation for phenotypic plasticity in indica rice (Oryza sativa L.) across two diverse panels: (1) a Phenomics of Rice Adaptation and Yield (PRAY) population comprising 301 accessions; and (2) a Multi‐parent Advanced Generation Inter‐Cross (MAGIC) indica population comprising 151 accessions. Altered planting density was used as a proxy for elevated atmospheric CO2 response. Low planting density significantly increased panicle weight per plant compared with normal density, and the magnitude of the increase ranged from 1.10 to 2.78 times among accessions for the PRAY population and from 1.05 to 2.45 times for the MAGIC population. Genome‐wide‐association studies validate three E nvironmental R esponsiveness (ER) candidate alleles (qER1–3) that were associated with relative response of panicle weight to low density. Two of these alleles were tested in 13 genotypes to clarify their biomass responses during vegetative growth under elevated CO2 in Japan. Our study provides evidence for polymorphisms that control rice phenotypic plasticity in environments that are rich in resources such as light and CO2. 相似文献
140.
Phosphorylation on histidine is accompanied by localized structural changes in the phosphocarrier protein, HPr from Bacillus subtilis. 下载免费PDF全文
B. E. Jones P. Rajagopal R. E. Klevit 《Protein science : a publication of the Protein Society》1997,6(10):2107-2119
The histidine-containing protein (HPr) of bacterial phosphoenolpyruvate:sugar phosphotransferase system (PTS) serves a central role in a series of phosphotransfer reactions used for the translocation of sugars across cell membranes. These studies report the high-definition solution structures of both the unphosphorylated and histidine phosphorylated (P-His) forms of HPr from Bacillus subtilis. Consistent with previous NMR studies, local conformational adjustments occur upon phosphorylation of His 15, which positions the phosphate group to serve as a hydrogen bond acceptor for the amide protons of Ala 16 and Arg 17 and to interact favorably with the alpha-helix macrodipole. However, the positively charged side chain of the highly conserved Arg 17 does not appear to interact directly with phospho-His 15, suggesting that Arg 17 plays a role in the recognition of other PTS enzymes or in phosphotransfer reactions directly. Unlike the results reported for Escherichia coli P-His HPr (Van Nuland NA, Boelens R, Scheek RM, Robillard GT, 1995, J Mol Biol 246:180-193), our data indicate that phosphorylation of His 15 is not accompanied by adoption of unfavorable backbone conformations for active site residues in B. subtilis P-Ser HPr. 相似文献