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51.
Hominin-cercopithecid comparisons have been used in palaeoanthropology for over forty years. Fossil cercopithecids can be used as a 'control group' to contextualize the adaptations and evolutionary trends of hominins. Observations made on modern cercopithecids can also be applied to questions about human evolution. This article reviews the history of hominin-cercopithecid comparisons, assesses the strengths and weaknesses of cercopithecids as comparators in studies of human evolution, and uses cercopithecid models to explore hominin inter-specific dynamics. Cercopithecids appear to be excellent ecological referents, but may be less good when considering the cognitive abilities and cultural adaptations of hominins. Comparison of cercopithecid and hominin adaptations at Koobi Fora in East Africa indicates that, whereas the cercopithecids were largely grass- or leaf-eating, the hominins occupied a generalist niche, apparently excluding other primate generalist-frugivores. If any of the hominin species at Koobi Fora were sympatric, analogies with modern cercopithecids suggest that inter-specific contact cannot be discounted and may even have been beneficial. 相似文献
52.
A method to immobilize fungal hyphae onto the wells of 96-well microplates for use in an in-direct ELISA to screen for antifungal antibodies in sera and cell culture supernatants is described. The hyphae from three genera (Penicillium, Eurotium andFusarium) were successfully attached by overnight drying onto wells precoated with poly-L-lysine and glutaraldehyde. Microscopy revealed that the hyphae remained attached to the wells throughout the ELISA and antiserum titrations showed that the attached hyphae were uniformly coated and remained reactive. Background absorbances were low and the plates could be stored at –20 °C without loss of reactivity. 相似文献
53.
HGF/SF Induces Mesothelial Cell Migration and Proliferation by Autocrine and Paracrine Pathways 总被引:7,自引:0,他引:7
Richard Warn Pascale Harvey Alba Warn Adam Foley-Comer Paraskevi Heldin Marjan Versnel Naokatu Arakaki Yasushi Daikuhara Geoffrey J. Laurent Sarah E. Herrick Steven E. Mutsaers 《Experimental cell research》2001,267(2):258-266
Mesothelial repair differs from that of other epithelial-like surfaces as healing does not occur solely by centripetal in-growth of cells as a sheet from the wound margins. Mesothelial cells lose their cell-cell junctions, divide, and adopt a fibroblast-like morphology while scattering across and covering the wound surface. These features are consistent with a cellular response to hepatocyte growth factor/scatter factor (HGF/SF). In this study, we examined the ability of mesothelial cells to secrete HGF/SF and investigated its possible role as an autocrine regulator of mesothelial cell motility and proliferation. We found that human primary mesothelial cells expressed HGF/SF mRNA and secreted active HGF/SF into conditioned medium as determined by ELISA and in a scattering bioassay. These cells also expressed the HGF/SF receptor, Met, as shown by RT-PCR and by Western blot analysis and immunofluorescence. Incubation of mesothelial cells with neutralizing antibodies to HGF/SF decreased cell migration to 25% of controls, whereas addition of HGF/SF disrupted cell-cell junctions and induced scattering and enhanced mesothelial cell migration. Furthermore, HGF/SF showed a small but significant mitogenic effect on all mesothelial cell lines examined. In conclusion, HGF/SF is produced by mesothelial cells and induces both motility and proliferation of these cells. These data are consistent with HGF/SF playing an autocrine role in mesothelial healing. 相似文献
54.
Sillitoe I Dibley M Bray J Addou S Orengo C 《Protein science : a publication of the Protein Society》2005,14(7):1800-1810
There are more than 200 completed genomes and over 1 million nonredundant sequences in public repositories. Although the structural data are more sparse (approximately 13,000 nonredundant structures solved to date), several powerful sequence-based methodologies now allow these structures to be mapped onto related regions in a significant proportion of genome sequences. We review a number of publicly available strategies for providing structural annotations for genome sequences, and we describe the protocol adopted to provide CATH structural annotations for completed genomes. In particular, we assess the performance of several sequence-based protocols employing Hidden Markov model (HMM) technologies for superfamily recognition, including a new approach (SAMOSA [sequence augmented models of structure alignments]) that exploits multiple structural alignments from the CATH domain structure database when building the models. Using a data set of remote homologs detected by structure comparison and manually validated in CATH, a single-seed HMM library was able to recognize 76% of the data set. Including the SAMOSA models in the HMM library showed little gain in homolog recognition, although a slight improvement in alignment quality was observed for very remote homologs. However, using an expanded 1D-HMM library, CATH-ISL increased the coverage to 86%. The single-seed HMM library has been used to annotate the protein sequences of 120 genomes from all three major kingdoms, allowing up to 70% of the genes or partial genes to be assigned to CATH superfamilies. It has also been used to recruit sequences from Swiss-Prot and TrEMBL into CATH domain superfamilies, expanding the CATH database eightfold. 相似文献
55.
Morten Frederiksen Tycho Anker‐Nilssen Grégory Beaugrand Sarah Wanless 《Global Change Biology》2013,19(2):364-372
The boreal Northeast Atlantic is strongly affected by current climate change, and large shifts in abundance and distribution of many organisms have been observed, including the dominant copepod Calanus finmarchicus, which supports the grazing food web and thus many fish populations. At the same time, large‐scale declines have been observed in many piscivorous seabirds, which depend on abundant small pelagic fish. Here, we combine predictions from a niche model of C. finmarchicus with long‐term data on seabird breeding success to link trophic levels. The niche model shows that environmental suitability for C. finmarchicus has declined in southern areas with large breeding seabird populations (e.g. the North Sea), and predicts that this decline is likely to spread northwards during the 21st century to affect populations in Iceland and the Faroes. In a North Sea colony, breeding success of three common piscivorous seabird species [black‐legged kittiwake (Rissa tridactyla), common guillemot (Uria aalge) and Atlantic puffin (Fratercula arctica)] was strongly positively correlated with local environmental suitability for C. finmarchicus, whereas this was not the case at a more northerly colony in west Norway. Large seabird populations seem only to occur where C. finmarchicus is abundant, and northward distributional shifts of common boreal seabirds are therefore expected over the coming decades. Whether or not population size can be maintained depends on the dispersal ability and inclination of these colonial breeders, and on the carrying capacity of more northerly areas in a warmer climate. 相似文献
56.
Haberer G Young S Bharti AK Gundlach H Raymond C Fuks G Butler E Wing RA Rounsley S Birren B Nusbaum C Mayer KF Messing J 《Plant physiology》2005,139(4):1612-1624
Maize (Zea mays or corn) plays many varied and important roles in society. It is not only an important experimental model plant, but also a major livestock feed crop and a significant source of industrial products such as sweeteners and ethanol. In this study we report the systematic analysis of contiguous sequences of the maize genome. We selected 100 random regions averaging 144 kb in size, representing about 0.6% of the genome, and generated a high-quality dataset for sequence analysis. This sampling contains 330 annotated genes, 91% of which are supported by expressed sequence tag data from maize and other cereal species. Genes averaged 4 kb in size with five exons, although the largest was over 59 kb with 31 exons. Gene density varied over a wide range from 0.5 to 10.7 genes per 100 kb and genes did not appear to cluster significantly. The total repetitive element content we observed (66%) was slightly higher than previous whole-genome estimates (58%-63%) and consisted almost exclusively of retroelements. The vast majority of genes can be aligned to at least one sequence read derived from gene-enrichment procedures, but only about 30% are fully covered. Our results indicate that much of the increase in genome size of maize relative to rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) is attributable to an increase in number of both repetitive elements and genes. 相似文献
57.
Horton R Gibson R Coggill P Miretti M Allcock RJ Almeida J Forbes S Gilbert JG Halls K Harrow JL Hart E Howe K Jackson DK Palmer S Roberts AN Sims S Stewart CA Traherne JA Trevanion S Wilming L Rogers J de Jong PJ Elliott JF Sawcer S Todd JA Trowsdale J Beck S 《Immunogenetics》2008,60(1):1-18
The human major histocompatibility complex (MHC) is contained within about 4 Mb on the short arm of chromosome 6 and is recognised
as the most variable region in the human genome. The primary aim of the MHC Haplotype Project was to provide a comprehensively
annotated reference sequence of a single, human leukocyte antigen-homozygous MHC haplotype and to use it as a basis against
which variations could be assessed from seven other similarly homozygous cell lines, representative of the most common MHC
haplotypes in the European population. Comparison of the haplotype sequences, including four haplotypes not previously analysed,
resulted in the identification of >44,000 variations, both substitutions and indels (insertions and deletions), which have
been submitted to the dbSNP database. The gene annotation uncovered haplotype-specific differences and confirmed the presence
of more than 300 loci, including over 160 protein-coding genes. Combined analysis of the variation and annotation datasets
revealed 122 gene loci with coding substitutions of which 97 were non-synonymous. The haplotype (A3-B7-DR15; PGF cell line)
designated as the new MHC reference sequence, has been incorporated into the human genome assembly (NCBI35 and subsequent
builds), and constitutes the largest single-haplotype sequence of the human genome to date. The extensive variation and annotation
data derived from the analysis of seven further haplotypes have been made publicly available and provide a framework and resource
for future association studies of all MHC-associated diseases and transplant medicine.
Horton and Gibson contributed equally to this work. 相似文献
58.
Dependence of pathogen molecule-induced Toll-like receptor activation and cell function on Neu1 sialidase 总被引:1,自引:0,他引:1
Schammim Ray Amith Preethi Jayanth Susan Franchuk Sarah Siddiqui Volkan Seyrantepe Katrina Gee Sameh Basta Rudi Beyaert Alexey V. Pshezhetsky Myron R. Szewczuk 《Glycoconjugate journal》2009,26(9):1197-1212
The signaling pathways of mammalian Toll-like receptors (TLR) are well characterized, but the initial molecular mechanisms activated following ligand interactions with the receptors remain poorly defined. Here, we show a membrane controlling mechanism that is initiated by ligand binding to TLR-2, -3 and-4 to induce Neu1 sialidase activity within minutes in live primary bone marrow (BM) macrophage cells and macrophage and dendritic cell lines. Central to this process is that Neu1 and not Neu2,-3 and-4 forms a complex with TLR-2,-3 and-4 on the cell surface of naïve macrophage cells. Neuraminidase inhibitors BCX1827, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (DANA), zanamivir and oseltamivir carboxylate have a limited significant inhibition of the LPS-induced sialidase activity in live BMC-2 macrophage cells but Tamiflu (oseltamivir phosphate) completely blocks this activity. Tamiflu inhibits LPS-induced sialidase activity in live BMC-2 cells with an IC50 of 1.2?μM compared to an IC50 of 1015?μM for its hydrolytic metabolite oseltamivir carboxylate. Tamiflu blockage of LPS-induced Neu1 sialidase activity is not affected in BMC-2 cells pretreated with anticarboxylesterase agent clopidogrel. Endotoxin LPS binding to TLR4 induces Neu1 with subsequent activation of NFκB and the production of nitric oxide and pro-inflammatory IL-6 and TNFα cytokines in primary and macrophage cell lines. Hypomorphic cathepsin A mice with a secondary Neu1 deficiency respond poorly to LPS-induced pro-inflammatory cytokines compared to the wild-type or hypomorphic cathepsin A with normal Neu1 mice. Our findings establish an unprecedented mechanism for pathogen molecule-induced TLR activation and cell function, which is critically dependent on Neu1 sialidase activity associated with TLR ligand treated live primary macrophage cells and macrophage and dendritic cell lines. 相似文献
59.
60.
Tom Bongiorno Jacob Kazlow Roman Mezencev Sarah Griffiths Rene Olivares-Navarrete John F. McDonald Zvi Schwartz Barbara D. Boyan Todd C. McDevitt Todd Sulchek 《Journal of biomechanics》2014
Although it has been established that cellular stiffness can change as a stem cell differentiates, the precise relationship between cell mechanics and other phenotypic properties remains unclear. Inherent cell heterogeneity and asynchronous differentiation complicate population analysis; therefore, single-cell analysis was employed to determine how changes in cell stiffness correlate with changes in molecular biomarkers during differentiation. Design of a custom gridded tissue culture dish facilitated single-cell comparisons between cell mechanics and other differentiation biomarkers by enabling sequential measurement of cell mechanics and protein biomarker expression at the single cell level. The Young’s modulus of mesenchymal stem cells was shown not only to decrease during chemically-induced osteoblast differentiation, but also to correlate more closely with the day of differentiation than did the relative expression of the traditional osteoblast differentiation markers, bone sialoprotein and osteocalcin. Therefore, cell stiffness, a measurable property of individual cells, may serve as an improved indicator of single-cell osteoblast differentiation compared to traditional biological markers. Revelation of additional osteoblast differentiation indicators, such as cell stiffness, can improve identification and collection of starting cell populations, with applications to mesenchymal stem cell therapies and stem cell-based tissue engineering. 相似文献