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991.
Glen John Mcintyre Jennifer Lynne Groneman Yi-Hsin Yu Angel Jaramillo Sylvie Shen Tanya Lynn Applegate 《Retrovirology》2009,6(1):1-15
Background
Extensive studies of primary infection are crucial to our understanding of the course of HIV disease. In SIV-infected macaques, a model closely mimicking HIV pathogenesis, we used a combination of three markers -- viral RNA, 2LTR circles and viral DNA -- to evaluate viral replication and dissemination simultaneously in blood, secondary lymphoid tissues, and the gut during primary and chronic infections. Subsequent viral compartmentalization in the main target cells of the virus in peripheral blood during the chronic phase of infection was evaluated by cell sorting and viral quantification with the three markers studied.Results
The evolutions of viral RNA, 2LTR circles and DNA levels were correlated in a given tissue during primary and early chronic infection. The decrease in plasma viral load principally reflects a large decrease in viral replication in gut-associated lymphoid tissue (GALT), with viral RNA and DNA levels remaining stable in the spleen and peripheral lymph nodes. Later, during chronic infection, a progressive depletion of central memory CD4+ T cells from the peripheral blood was observed, accompanied by high levels of viral replication in the cells of this subtype. The virus was also found to replicate at this point in the infection in naive CD4+ T cells. Viral RNA was frequently detected in monocytes, but no SIV replication appeared to occur in these cells, as no viral DNA or 2LTR circles were detected.Conclusion
We demonstrated the persistence of viral replication and dissemination, mostly in secondary lymphoid tissues, during primary and early chronic infection. During chronic infection, the central memory CD4+ T cells were the major site of viral replication in peripheral blood, but viral replication also occurred in naive CD4+ T cells. The role of monocytes seemed to be limited to carrying the virus as a cargo because there was an observed lack of replication in these cells. These data may have important implications for the targeting of HIV treatment to these diverse compartments. 相似文献992.
993.
Vanessa Deveaux Thomas Cadoudal Yasukatsu Ichigotani Fatima Teixeira-Clerc Alexandre Louvet Sylvie Manin Jeanne Tran-Van Nhieu Marie Pierre Belot Andreas Zimmer Patrick Even Patrice D. Cani Claude Knauf Remy Burcelin Adeline Bertola Yannick Le Marchand-Brustel Philippe Gual Ariane Mallat Sophie Lotersztajn 《PloS one》2009,4(6)
Background
Obesity-associated inflammation is of critical importance in the development of insulin resistance and non-alcoholic fatty liver disease. Since the cannabinoid receptor CB2 regulates innate immunity, the aim of the present study was to investigate its role in obesity-induced inflammation, insulin resistance and fatty liver.Methodology
Murine obesity models included genetically leptin-deficient ob/ob mice and wild type (WT) mice fed a high fat diet (HFD), that were compared to their lean counterparts. Animals were treated with pharmacological modulators of CB2 receptors. Experiments were also performed in mice knock-out for CB2 receptors (Cnr2 −/−).Principal Findings
In both HFD-fed WT mice and ob/ob mice, Cnr2 expression underwent a marked induction in the stromal vascular fraction of epididymal adipose tissue that correlated with increased fat inflammation. Treatment with the CB2 agonist JWH-133 potentiated adipose tissue inflammation in HFD-fed WT mice. Moreover, cultured fat pads isolated from ob/ob mice displayed increased Tnf and Ccl2 expression upon exposure to JWH-133. In keeping, genetic or pharmacological inactivation of CB2 receptors decreased adipose tissue macrophage infiltration associated with obesity, and reduced inductions of Tnf and Ccl2 expressions. In the liver of obese mice, Cnr2 mRNA was only weakly induced, and CB2 receptors moderately contributed to liver inflammation. HFD-induced insulin resistance increased in response to JWH-133 and reduced in Cnr2 −/− mice. Finally, HFD-induced hepatic steatosis was enhanced in WT mice treated with JWH-133 and blunted in Cnr2 −/− mice.Conclusion/Significance
These data unravel a previously unrecognized contribution of CB2 receptors to obesity-associated inflammation, insulin resistance and non-alcoholic fatty liver disease, and suggest that CB2 receptor antagonists may open a new therapeutic approach for the management of obesity-associated metabolic disorders. 相似文献994.
Background
Perception of the cardinal directions of the body, right-left, up-down, ahead-behind, which appears so absolute and fundamental to the organisation of behaviour can in fact, be modified. Perhaps unsurprisingly, it has been shown that prolonged distorted perception of the orientation of body axes can be a consequence of disordered sensori-motor signals, including long-term prismatic adaptation and lesions of the central nervous system. We report the novel and surprising finding that a long-lasting distortion of perception of personal space can also be induced by an ecological pointing task without the artifice of distorting normal sensori-motor relationships.Methodology/Principal Findings
Twelve right-handed healthy adults performed the task of pointing with their arms, without vision, to indicate their subjective ‘straight ahead’, a task often used to assess the Egocentric Reference. This was performed before, immediately, and one day after a second task intended to ‘modulate’ perception of spatial direction. The ‘modulating’ task lasted 5 minutes and consisted of asking participants to point with the right finger to targets that appeared only in one (right or left) half of a computer screen. Estimates of the ‘straight-ahead’ during pre-test were accurate (inferior to 0.3 degrees deviation). Significantly, up to one day after performing the modulating task, the subjective ‘straight-ahead’ was deviated (by approximately 3.2 degrees) to the same side to which subjects had pointed to targets.Conclusion/Significance
These results reveal that the perception of directional axes for behaviour is readily influenced by interactions with the environment that involve no artificial distortion of normal sensori-motor-spatial relationships and does not necessarily conform to the cardinal directions as defined by the anatomy of orthostatic posture. We thus suggest that perceived space is a dynamic construction directly dependent upon our past experience about the direction and/or the localisation of our sensori-motor spatial interaction with environment. 相似文献995.
Xanthomonas T3S Effector XopN Suppresses PAMP-Triggered Immunity and Interacts with a Tomato Atypical Receptor-Like Kinase and TFT1 总被引:1,自引:0,他引:1
Jung-Gun Kim Xinyan Li Julie Anne Roden Kyle W. Taylor Chris D. Aakre Bessie Su Sylvie Lalonde Angela Kirik Yanhui Chen Gayathri Baranage Heather McLane Gregory B. Martin Mary Beth Mudgett 《The Plant cell》2009,21(4):1305-1323
XopN is a virulence factor from Xanthomonas campestris pathovar vesicatoria (Xcv) that is translocated into tomato (Solanum lycopersicum) leaf cells by the pathogen''s type III secretion system. Xcv ΔxopN mutants are impaired in growth and have reduced ability to elicit disease symptoms in susceptible tomato leaves. We show that XopN action in planta reduced pathogen-associated molecular pattern (PAMP)-induced gene expression and callose deposition in host tissue, indicating that XopN suppresses PAMP-triggered immune responses during Xcv infection. XopN is predicted to have irregular, α-helical repeats, suggesting multiple protein–protein interactions in planta. Consistent with this prediction, XopN interacted with the cytosolic domain of a Tomato Atypical Receptor-Like Kinase1 (TARK1) and four Tomato Fourteen-Three-Three isoforms (TFT1, TFT3, TFT5, and TFT6) in yeast. XopN/TARK1 and XopN/TFT1 interactions were confirmed in planta by bimolecular fluorescence complementation and pull-down analysis. Xcv ΔxopN virulence defects were partially suppressed in transgenic tomato leaves with reduced TARK1 mRNA levels, indicating that TARK1 plays an important role in the outcome of Xcv–tomato interactions. These data provide the basis for a model in which XopN binds to TARK1 to interfere with TARK1-dependent signaling events triggered in response to Xcv infection. 相似文献
996.
Ki Hwan Kim Irina Gaisina Franck Gallier Denise Holzle Sylvie Y. Blond Andrew Mesecar Alan P. Kozikowski 《Journal of molecular modeling》2009,15(12):1463-1479
Molecular modeling and docking studies along with three-dimensional quantitative structure relationships (3D-QSAR) studies
have been used to determine the correct binding mode of glycogen synthase kinase 3β (GSK-3β) inhibitors. The approaches of
comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) are used for the
3D-QSAR of 51 substituted benzofuran-3-yl-(indol-3-yl)maleimides as GSK-3β inhibitors. Two binding modes of the inhibitors
to the binding site of GSK-3β are investigated. The binding mode 1 yielded better 3D-QSAR correlations using both CoMFA and
CoMSIA methodologies. The three-component CoMFA model from the steric and electrostatic fields for the experimentally determined
pIC50 values has the following statistics: R2(cv) = 0.386 nd SE(cv) = 0.854 for the cross-validation, and R2 = 0.811 and SE = 0.474 for the fitted correlation. F (3,47) = 67.034, and probability of R2 = 0 (3,47) = 0.000. The binding mode suggested by the results of this study is consistent with the preliminary results of
X-ray crystal structures of inhibitor-bound GSK-3β. The 3D-QSAR models were used for the estimation of the inhibitory potency
of two additional compounds. 相似文献
997.
Ecological effects of invasive alien insects 总被引:1,自引:0,他引:1
Marc Kenis Marie-Anne Auger-Rozenberg Alain Roques Laura Timms Christelle Péré Matthew J. W. Cock Josef Settele Sylvie Augustin Carlos Lopez-Vaamonde 《Biological invasions》2009,11(1):21-45
A literature survey identified 403 primary research publications that investigated the ecological effects of invasive alien
insects and/or the mechanisms underlying these effects. The majority of these studies were published in the last 8 years and
nearly two-thirds were carried out in North America. These publications concerned 72 invasive insect species, of which two
ant species, Solenopsis invicta and Linepithema humile, accounted for 18% and 14% of the studies, respectively. Most publications investigated effects on native biodiversity at
population or community level. Genetic effects and, to a lesser extent, effects on ecosystem services and processes were rarely
explored. We review the effects caused by different insect invaders according to: their ecosystem roles, i.e. herbivores,
predators, parasites, parasitoids and pollinators; the level of biological organisation at which they occur; and the direct
and indirect mechanisms underlying these effects. The best documented effects occur in invasive ants, Eurasian forest herbivores
invasive in North America, and honeybees. Impacts may occur through simple trophic interactions such as herbivory, predation
or parasitism. Alien species may also affect native species and communities through more complex mechanisms such as competition
for resources, disease transmission, apparent competition, or pollination disruption, among others. Finally, some invasive
insects, particularly forest herbivores and ants, are known to affect ecosystem processes through cascading effects. We identify
biases and gaps in our knowledge of ecological effects of invasive insects and suggest further opportunities for research.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
998.
Zoccola D Moya A Béranger GE Tambutté E Allemand D Carle GF Tambutté S 《Marine biotechnology (New York, N.Y.)》2009,11(2):260-269
Bone morphogenetic proteins (BMPs) are members of the transforming growth factor β superfamily, and have been identified by
their ability to induce bone formation in vertebrates. The biomineral-forming process, called biomineralization, is a widespread
process, present in all kingdoms of living organisms and among which stony corals are one of the major groups of calcifying
animals. Here, we report the presence of a BMP2/4 ortholog in eight species of adult corals. The synthesis of such a protein
by the calcifying epithelium of corals suggests that coral BMP2/4 plays a role in skeletogenesis, making BMP the first common
protein involved in biomineralization among Eumetazoans. In addition we show that recombinant coral BMP2/4 is able to inhibit
human BMP2-induced osteoblastic differentiation in mesenchymal C2C12 cells. We suggest that this inhibition results from a
competition between coral BMP2/4 and human BMP2, indicating conservation of binding affinity of BMP and its receptor during
evolution from corals to vertebrates. Further studies are needed to understand interactions between coral BMP2/4 and its receptors,
and, thus, the action of BMP2/4 in adult corals.
Nucleotide sequence of the coral BMP2/4 genes cloned in this study is available in the GenBank under the accession number
EU785981 (Stylophora pistillata) and EU785982 (Acropora sp.). 相似文献
999.
1000.