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91.
The process of cytokinesis can be divided into two stages: the assembly and constriction of an actomyosin ring giving rise to a narrow intracellular canal and the final breaking and resealing of this canal. Mutations in several genes of Caenorhabditis elegans disrupt the spindle midzone (anti-parallel microtubules and associated proteins that form between the spindle poles) and give rise to failures in the completion of cytokinesis. We show that loss of function of spd-1 causes midzone disruptions, although cytokinesis generally completes. SPD-1 is a conserved microtubule-bundling protein that localizes to the midzone and also to microtubule bundles in the cytoplasm. The midzone localization of SPD-1 is perturbed in embryos depleted of other midzone components, yet the cytoplasmic bundles are not affected. We found that two other midzone components also localize to the ingressing furrow in wild-type embryos; when SPD-1 is depleted, there is no visible midzone, and only this furrow localization remains. SPD-1 differs from other midzone components in that it is essential for the integrity of the midzone, yet not for cytokinesis. Also, it can localize to the midzone when other midzone components are depleted, suggesting that SPD-1 may play an early role in the pathway of midzone assembly. 相似文献
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Van Aerschot A Meldgaard M Volders F Schepers G Rozenski J Herdewijn P 《Nucleosides, nucleotides & nucleic acids》2001,20(4-7):781-784
1,5-Anhydrohexitol nucleoside congeners with alkoxy substituents, were prepared, resulting in a further improvement of their RNA affinity and antisense potential. 相似文献
94.
We report a female with Prader-Willi syndrome and hemihypertrophy. We discuss the possibility of an undetected mosaicism for trisomy 15 explaining this unusual feature. 相似文献
95.
Assessing metabolic activity in aging Caenorhabditis elegans: concepts and controversies 总被引:1,自引:1,他引:0
It is widely believed that normal by-products of oxidative metabolism and the subsequent molecular damage inflicted by them couple the aging process to metabolic rate. Accordingly, high metabolic rates would be expected to accelerate aging, and life-extending interventions are often assumed to act by attenuating metabolic rate. Notorious examples in Caenorhabditis elegans are food restriction, mutation in the Clock genes and several genes of the insulin-like signalling pathway. Here we discuss how metabolic rate can be accurately measured and normalized, and how to deal with differences in body size. These issues are illustrated using experimental data of the long-lived mutant strains clk-1(e2519) and daf-2(e1370). Appropriate analysis shows that metabolic rates in wildtype and in the clk-1 mutant are very similar. In contrast, the metabolic rate profiles point to a metabolic shift toward enhanced efficiency of oxidative phosphorylation in the daf-2 worms. 相似文献
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Mikhailov SN Efimtseva EV Ermolinsky BS Bobkov GV Andreeva OI Golubeva AS Kochetkov SN Van Aerschot A Schepers G Herdewijn P 《Nucleosides, nucleotides & nucleic acids》2003,22(5-8):1117-1118
The efficient synthesis of oligonucleotides containing 2'-O-beta-D-ribofuranosyl (and beta-D-ribopyranosyl)nucleosides, 2'-O-alpha-D-arabinofuranosyl (and alpha-L-arabinofuranosyl)nucleosides. 2'-O-beta-D-erythrofuranosylnucleosides, and 2'-O-(5'-amino-5-deoxy-beta-D-ribofuranosyl)nucleosides have been developed. 相似文献
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Nadine Veith Margrete Solheim Koen W. A. van Grinsven Brett G. Olivier Jennifer Levering Ruth Grosseholz Jeroen Hugenholtz Helge Holo Ingolf Nes Bas Teusink Ursula Kummer 《Applied and environmental microbiology》2015,81(5):1622-1633
Increasing antibiotic resistance in pathogenic bacteria necessitates the development of new medication strategies. Interfering with the metabolic network of the pathogen can provide novel drug targets but simultaneously requires a deeper and more detailed organism-specific understanding of the metabolism, which is often surprisingly sparse. In light of this, we reconstructed a genome-scale metabolic model of the pathogen Enterococcus faecalis V583. The manually curated metabolic network comprises 642 metabolites and 706 reactions. We experimentally determined metabolic profiles of E. faecalis grown in chemically defined medium in an anaerobic chemostat setup at different dilution rates and calculated the net uptake and product fluxes to constrain the model. We computed growth-associated energy and maintenance parameters and studied flux distributions through the metabolic network. Amino acid auxotrophies were identified experimentally for model validation and revealed seven essential amino acids. In addition, the important metabolic hub of glutamine/glutamate was altered by constructing a glutamine synthetase knockout mutant. The metabolic profile showed a slight shift in the fermentation pattern toward ethanol production and increased uptake rates of multiple amino acids, especially l-glutamine and l-glutamate. The model was used to understand the altered flux distributions in the mutant and provided an explanation for the experimentally observed redirection of the metabolic flux. We further highlighted the importance of gene-regulatory effects on the redirection of the metabolic fluxes upon perturbation. The genome-scale metabolic model presented here includes gene-protein-reaction associations, allowing a further use for biotechnological applications, for studying essential genes, proteins, or reactions, and the search for novel drug targets. 相似文献
100.
Michael Dumbacher Tom Van Dooren Katrien Princen Koen De Witte Mélissa Farinelli Sam Lievens Jan Tavernier Wim Dehaen Stefaan Wera Joris Winderickx Sara Allasia Amuri Kilonda Stéphane Spieser Arnaud Marchand Patrick Chaltin Casper C. Hoogenraad Gerard Griffioen 《Molecular neurodegeneration》2018,13(1):50