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Variations in genomic DNA methylation during the long-term in vitro proliferation of oil palm embryogenic suspension cultures 总被引:1,自引:0,他引:1
Alain Rival Pascal Ilbert Axel Labeyrie Esperanza Torres Sylvie Doulbeau Aline Personne Stéphane Dussert Thierry Beulé Tristan Durand-Gasselin James W. Tregear Estelle Jaligot 《Plant cell reports》2013,32(3):359-368
Key message
The long-term proliferation of embryogenic cell suspensions of oil palm is associated with changes in both genomic methylation rates and embryogenic capacities.Abstract
In the aim of exploring the relationship between epigenetic stability and the long-term in vitro proliferation of plant tissues, we have studied changes in genomic DNA methylation levels in embryogenic suspensions of oil palm (Elaeis guineensis Jacq.). Five embryogenic callus lines were obtained from selected hybrid seeds and then proliferated as suspension cultures. Each clonal line obtained from a single genotype was subdivided into three independent subclonal lines. Once established, cultures proliferated for 12 months and genomic DNA was sampled at 4 months intervals for the estimation of global DNA methylation rates through high performance liquid chromatography (HPLC) quantitation of deoxynucleosides. Our results show that in vitro proliferation induces DNA hypermethylation in a time-dependent fashion. Moreover, this trend is statistically significant in several clonal lines and shared between subclonal lines originating from the same genotype. Interestingly, the only clonal line undergoing loss of genomic methylation in the course of proliferation has been found unable to generate somatic embryos. We discuss the possible implications of genome-wide DNA methylation changes in proliferating cells with a view to the maintenance of genomic and epigenomic stability. 相似文献44.
Axel Kammerer Álvaro Tejero-Cantero Christian Leibold 《Journal of computational neuroscience》2013,34(1):125-136
Recurring sequences of neuronal activation in the hippocampus are a candidate for a neurophysiological correlate of episodic memory. Here, we discuss a mean-field theory for such spike sequences in phase space and show how they become unstable when the neuronal network operates at maximum memory capacity. We find that inhibitory feedback rescues replay of the sequences, giving rise to oscillations and thereby enhancing the network’s capacity. We further argue that transient sequences in an overloaded network with feedback inhibition may provide a mechanistic picture of memory-related neuronal activity during hippocampal sharp-wave ripple complexes. 相似文献
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Carmen Methner Guido Buonincontri Chou-Hui Hu Ana Vujic Axel Kretschmer Stephen Sawiak Adrian Carpenter Johannes-Peter Stasch Thomas Krieg 《PloS one》2013,8(12)
Aim
Stimulation of the nitric oxide (NO) – soluble guanylate (sGC) - protein kinase G (PKG) pathway confers protection against acute ischaemia/reperfusion injury, but more chronic effects in reducing post-myocardial infarction (MI) heart failure are less defined. The aim of this study was to not only determine whether the sGC stimulator riociguat reduces infarct size but also whether it protects against the development of post-MI heart failure.Methods and Results
Mice were subjected to 30 min ischaemia via ligation of the left main coronary artery to induce MI and either placebo or riociguat (1.2 µmol/l) were given as a bolus 5 min before and 5 min after onset of reperfusion. After 24 hours, both, late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) and 18F-FDG-positron emission tomography (PET) were performed to determine infarct size. In the riociguat-treated mice, the resulting infarct size was smaller (8.5±2.5% of total LV mass vs. 21.8%±1.7%. in controls, p = 0.005) and LV systolic function analysed by MRI was better preserved (60.1%±3.4% of preischaemic vs. 44.2%±3.1% in controls, p = 0.005). After 28 days, LV systolic function by echocardiography treated group was still better preserved (63.5%±3.2% vs. 48.2%±2.2% in control, p = 0.004).Conclusion
Taken together, mice treated acutely at the onset of reperfusion with the sGC stimulator riociguat have smaller infarct size and better long-term preservation of LV systolic function. These findings suggest that sGC stimulation during reperfusion therapy may be a powerful therapeutic treatment strategy for preventing post-MI heart failure. 相似文献46.
Tobias Bidon Christiane Frosch Hans G. Eiken Verena E. Kutschera Snorre B. Hagen Siv G. Aarnes Steven R. Fain Axel Janke Frank Hailer 《Molecular ecology resources》2013,13(3):362-368
We report a new approach for molecular sex identification of extant Ursinae and Tremarctinae bears. Two Y‐specific fragments (SMCY and 318.2) and one X‐specific fragment (ZFX) are amplified in a multiplex PCR, yielding a double test for male‐specific amplification and an internal positive control. The primers were designed and tested to be bear‐specific, thereby minimizing the risk of cross‐amplification in other species including humans. The high sensitivity and small amplicon sizes (100, 124, 160 base pairs) facilitate analysis of non‐invasively obtained DNA material. DNA from tissue and blood as well as from 30 non‐invasively collected hair and faeces yielded clear and easily interpretable results. The fragments were detected both by standard gel electrophoresis and automated capillary electrophoresis. 相似文献
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Ranging from dwarfs to giants, the species of honeybees show remarkable differences in body size that have placed evolutionary constrains on the size of sensory organs and the brain. Colonies comprise three adult phenotypes, drones and two female castes, the reproductive queen and sterile workers. The phenotypes differ with respect to tasks and thus selection pressures which additionally constrain the shape of sensory systems. In a first step to explore the variability and interaction between species size-limitations and sex and caste-specific selection pressures in sensory and neural structures in honeybees, we compared eye size, ommatidia number and distribution of facet lens diameters in drones, queens and workers of five species (Apis andreniformis, A. florea, A. dorsata, A. mellifera, A. cerana). In these species, male and female eyes show a consistent sex-specific organization with respect to eye size and regional specialization of facet diameters. Drones possess distinctly enlarged eyes with large dorsal facets. Aside from these general patterns, we found signs of unique adaptations in eyes of A. florea and A. dorsata drones. In both species, drone eyes are disproportionately enlarged. In A. dorsata the increased eye size results from enlarged facets, a likely adaptation to crepuscular mating flights. In contrast, the relative enlargement of A. florea drone eyes results from an increase in ommatidia number, suggesting strong selection for high spatial resolution. Comparison of eye morphology and published mating flight times indicates a correlation between overall light sensitivity and species-specific mating flight times. The correlation suggests an important role of ambient light intensities in the regulation of species-specific mating flight times and the evolution of the visual system. Our study further deepens insights into visual adaptations within the genus Apis and opens up future perspectives for research to better understand the timing mechanisms and sensory physiology of mating related signals. 相似文献
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Christina R?hr Martin Kerick Axel Fischer Alexander Kühn Karl Kashofer Bernd Timmermann Andriani Daskalaki Thomas Meinel Dmitriy Drichel Stefan T. B?rno Anja Nowka Sylvia Krobitsch Alice C. McHardy Christina Kratsch Tim Becker Andrea Wunderlich Christian Barmeyer Christian Viertler Kurt Zatloukal Christoph Wierling Hans Lehrach Michal R. Schweiger 《PloS one》2013,8(7)
MiRNAs are discussed as diagnostic and therapeutic molecules. However, effective miRNA drug treatments with miRNAs are, so far, hampered by the complexity of the miRNA networks. To identify potential miRNA drugs in colorectal cancer, we profiled miRNA and mRNA expression in matching normal, tumor and metastasis tissues of eight patients by Illumina sequencing. We validated six miRNAs in a large tissue screen containing 16 additional tumor entities and identified miRNA-1, miRNA-129, miRNA-497 and miRNA-215 as constantly de-regulated within the majority of cancers. Of these, we investigated miRNA-1 as representative in a systems-biology simulation of cellular cancer models implemented in PyBioS and assessed the effects of depletion as well as overexpression in terms of miRNA-1 as a potential treatment option. In this system, miRNA-1 treatment reverted the disease phenotype with different effectiveness among the patients. Scoring the gene expression changes obtained through mRNA-Seq from the same patients we show that the combination of deep sequencing and systems biological modeling can help to identify patient-specific responses to miRNA treatments. We present this data as guideline for future pre-clinical assessments of new and personalized therapeutic options. 相似文献