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1.
The biogeographic history of the Chihuahuan Desert is known to be complex, and there is evidence of the effects of physiographic and climatic events in species diversification and demographic population changes in many taxa. Here, using DNA sequence data, we studied the influence of the physiographic and climatic events that occurred in the Chihuahuan Desert during the Pliocene–Pleistocene transition on the speciation and evolutionary history of the sister lizard species Sceloporus cyanostictus and S. gadsdeni. First, based on mtDNA and nDNA sequences, we estimated the divergence times of the sister species. Then, based on mtDNA sequences, we investigated the demographic history of both species within a phylogeographic framework. The divergence time was inferred to be 1.48 Mya, date that corresponds to the existence of a large lake in the Mapimian subprovince, between the current geographic locations of S. cyanostictus and S. gadsdeni. This lake could have acted as a barrier, leading to the speciation of both species. For the demographic history of the two species, we identified two distinct patterns: the population expansion of S. gadsdeni within the Last Glacial Maximum and the potential population decline of S. cyanostictus. Our results can be used as a guide for the study of other aspects that could be critical to developing conservation actions that ensure the survival of not only S. gadsdeni and S. cyanostictus, but also other co‐occurring lizard species.  相似文献   
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Cell protection against different noxious stimuli like oxidative stress or chemical toxins plays a central role in the treatment of many diseases. The inducible heme oxygenase isoform, heme oxygenase-1 (HO-1), is known to protect cells against a variety of harmful conditions including apoptosis. Because a number of medium strong electrophiles from a series of α-X-substituted 2’,3,4,4’-tetramethoxychalcones (α-X-TMCs, X = H, F, Cl, Br, I, CN, Me, p-NO2-C6H4, Ph, p-OMe-C6H4, NO2, CF3, COOEt, COOH) had proven to activate Nrf2 resulting in HO-1 induction and inhibit NF-κB downstream target genes, their protective effect against staurosporine induced apoptosis and reactive oxygen species (ROS) production was investigated. RAW264.7 macrophages treated with 19 different chalcones (15 α-X-TMCs, chalcone, 2’-hydroxychalcone, calythropsin and 2’-hydroxy-3,4,4’-trimethoxychalcone) prior to staurosporine treatment were analyzed for apoptosis and ROS production, as well as HO-1 protein expression and enzyme activity. Additionally, Nrf2 and NF-κB activity was assessed. We found that amongst all tested chalcones only E-α-(4-methoxyphenyl)-2’,3,4,4''-tetramethoxychalcone (E-α-p-OMe-C6H4-TMC) demonstrated a distinct, statistically significant antiapoptotic effect in a dose dependent manner, showing no toxic effects, while its double bond isomer Z-α-p-OMe-C6H4-TMC displayed no significant activity. Also, E-α-p-OMe-C6H4-TMC induced HO-1 protein expression and increased HO-1 activity, whilst inhibition of HO-1 by SnPP-IX abolished its antiapoptotic effect. The only weakly electrophilic chalcone E-α-p-OMe-C6H4-TMC reduced the staurosporine triggered formation of ROS, while inducing the translocation of Nrf2 into the nucleus. Furthermore, staurosporine induced NF-κB activity was attenuated following E-α-p-OMe-C6H4-TMC treatment. Overall, E-α-p-OMe-C6H4-TMC demonstrated its effective cytoprotective potential via a non-toxic induction of HO-1 in RAW264.7 macrophages. The observed cytoprotective effect may partly be related to both, the activation of the Nrf2- and inhibition of the NF-κB pathway.  相似文献   
3.
Invariant Natural Killer T (iNKT) cells are a T cell subset expressing an invariant T Cell Receptor (TCR) that recognizes glycolipid antigens rather than peptides. The cells have both innate-like rapid cytokine release, and adaptive-like thymic positive selection. iNKT cell activation has been implicated in the pathogenesis of allergic asthma and inflammatory diseases, while reduced iNKT cell activation promotes infectious disease, cancer and certain autoimmune diseases such as Type 1 diabetes (T1D). Therapeutic means to reduce or deplete iNKT cells could treat inflammatory diseases, while approaches to promote their activation may have potential in certain infectious diseases, cancer or autoimmunity. Thus, we developed invariant TCR-specific monoclonal antibodies to better understand the role of iNKT cells in disease. We report here the first monoclonal antibodies specific for the mouse invariant TCR that by modifying the Fc construct can specifically deplete or activate iNKT cells in vivo in otherwise fully immuno-competent animals. We have used both the depleting and activating version of the antibody in the NOD model of T1D. As demonstrated previously using genetically iNKT cell deficient NOD mice, and in studies of glycolipid antigen activated iNKT cells in standard NOD mice, we found that antibody mediated depletion or activation of iNKT cells respectively accelerated and retarded T1D onset. In BALB/c mice, ovalbumin (OVA) mediated airway hyper-reactivity (AHR) was abrogated with iNKT cell depletion prior to OVA sensitization, confirming studies in knockout mice. Depletion of iNKT cells after sensitization had no effect on AHR in the conducting airways but did reduce AHR in the lung periphery. This result raises caution in the interpretation of studies that use animals that are genetically iNKT cell deficient from birth. These activating and depleting antibodies provide a novel tool to assess the therapeutic potential of iNKT cell manipulation.  相似文献   
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In order to test whether rooks (Corvus frugilegus) represent good indicators for the potential circulation of antibiotics in their native habitat, two populations with different migratory behavior were tested for the presence of beta-lactamase producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA). In all, 54 and 102 samples of fresh feces of a migratory and a resident population were investigated. A total of 24 and 3 cefotaxime-resistant enterobacterial isolates were obtained from the migratory and resident population, respectively. In these isolates CTX-M-1 (n = 15), CTX-M-3 (n = 3), and CTX-M-15 (n = 3) genes were detected. TEM-1 and OXA-1 were associated with CTX-M in 3 and 2 isolates, respectively. In two E. coli isolates CMY-2 could be detected, where from one isolate displayed an overexpression of chromosomal AmpC as well. Among E. coli isolates the most common phylogenetic group was A (n = 11) and ST1683 (n = 5). In one E. coli of B2-ST131 the rfbO25b locus was detected. Three Enterobacter isolates were stably derepressed AmpC-producers. In five samples of the migratory population, PVL positive MRSA could be isolated. Two isolates were typed SCCmec IVa, spa type t127, and ST1. Three isolates carried a SCCmec type IVc, with spa type t852 and ST22. The highly significant difference of the occurrence of antibiotic resistance between the migratory population from eastern Europe compared to resident population in our study indicates that rooks may be good indicator species for the evaluation of environmental contamination with antibiotic resistant bacteria, especially due to their ecology, foraging behavior and differing migratory behavior.  相似文献   
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Widely known for pest species that include major modulators of temperate forests, the genus Choristoneura is part of the species‐rich tribe Archipini of leafroller moths (Tortricidae). Delimitation of the genus has remained unresolved because no phylogeny has included species endemic to Africa and studies have often omitted the type species of the genus. Further taxonomic confusion has been generated by the transfer of Archips occidentalis (Walsingham) to Choristoneura, creating a homonym with Choristoneura occidentalis Freeman, an important defoliator of North American forests. To define the limits of the genus, we reconstructed a phylogeny using DNA sequences for mitochondrial cytochrome oxidase subunit I and nuclear ribosomal 28S genes. Our ingroup included 23 Choristoneura species‐level taxa, complemented by a large sample of outgroups comprising 82 species of Archipini and other Tortricidae. We generated a time‐calibrated tree using fossil and secondary calibrations and we inferred biogeographic and diversification processes in Choristoneura. Our analysis recovered the genus as polyphyletic, with Archips occidentalis, Choristoneura simonyi and Choristoneura evanidana excluded from the main clade. Based on the recovered phylogenies and a redefinition, we restrict Choristoneura primarily to species with a northern hemisphere distribution. Our analysis supports A. occidentalis as the sister group of Cacoecimorpha pronubana, C. simonyi as the sister of ‘Xenotemnapallorana, and C. evanidana as the sister of Archips purpurana. A new combination is proposed: Archips evanidana comb.n. ; the availability of ‘Xenotemna’ as a valid name is discussed and A. occidentalis is considered as an orphaned name within the Archipini. We found support for a Holarctic origin of Choristoneura about 23 Ma, followed by early divergence in the Palearctic region. The main divergence occurred at 16 Ma, with one clade in the Nearctic and another in the Palearctic. Subsequent cladogenetic events were synchronous and related to herbivorous specialization, with each clade divided into coniferophagous and polyphagous lineages. Their specialization as conifer feeders temporally matched the expansion of boreal forest during the Miocene.  相似文献   
9.
Cuckoo wasps (Hymenoptera: Chrysididae) are a species‐rich family of obligate brood parasites (i.e. parasitoids and kleptoparasites) whose hosts range from sawflies, wasps and bees, to walking sticks and moths. Their brood parasitic lifestyle has led to the evolution of fascinating adaptations, including chemical mimicry of host odours by some species. Long‐term nomenclatural stability of the higher taxonomic units (e.g. genera, tribes, and subfamilies) in this family and a thorough understanding of the family's evolutionary history critically depend on a robust phylogeny of cuckoo wasps. Here we present the results from phylogenetically analysing ten nuclear‐encoded genes and one mitochondrial gene, all protein‐coding, in a total of 186 different species of cuckoo wasps representing most major cuckoo wasp lineages. The compiled data matrix comprised 4946 coding nucleotide sites and was phylogenetically analysed using classical maximum‐likelihood and Bayesian inference methods. The results of our phylogenetic analyses are mostly consistent with earlier ideas on the phylogenetic relationships of the cuckoo wasps' subfamilies and tribes, but cast doubts on the hitherto hypothesized phylogenetic position of the subfamily Amiseginae. However, the molecular data are not fully conclusive in this respect due to low branch support values at deep nodes. In contrast, our phylogenetic estimates clearly indicate that the current systematics of cuckoo wasps at the genus level is artificial. Several of the currently recognized genera are para‐ or polyphyletic (e.g. Cephaloparnops, Chrysis, Chrysura, Euchroeus, Hedychridium, Praestochrysis, Pseudochrysis, Spintharina, and Spinolia). At the same time, our data support the validity of the genus Colpopyga, previously synonymized with Hedychridium. We discuss possible solutions for how to resolve the current shortcomings in the systematics of cuckoo wasp genera and decided to grant Prospinolia the status of a valid genus (Prospinolia stat.n. ) and transferring Spinolia theresae [du Buysson 1900] from Spinolia to Prospinolia (Prospinolia theresae stat.restit. ). We discuss the implications of our phylogenetic inferences for understanding the evolution of host associations in this group. The results of our study not only shed new light on the evolutionary history of cuckoo wasps, but also set the basis for future phylogenomic investigations on this captivating group of wasps by guiding taxonomic sampling efforts and the design of probes for target DNA enrichment approaches.  相似文献   
10.
The actin cytoskeleton presents the basic force in processes such as cytokinesis, endocytosis, vesicular trafficking and cell migration. Here, we list 30 human singlet CH (calpononin homology/actin binding) containing multidomain molecules, each encoded by one gene. We show the domain distributions as given by the SMART program. These mosaic proteins organize geographically the placement of selected proteins in proximity within the cell. In most instances, their precise location, their actin binding capacity by way of the singlet CH (or by other domains?) and their physiological functions need further elucidation. A dendrogram based solely on the relationship for the human singlet CH domains (in terms of AA sequences) for the various molecules that possess the domain, implies that the singlet descended from a common ancestor which in turn sprouted three main branches of protein products. Each branch bifurcated multiple times thus accounting for a cornucopia of products. Wherever, additional (unassigned), highly homologous regions exist in related proteins (e.g., in LIM and LMO7 or in Tangerin and EH/BP1), these unrecognized domain regions await assignment as specific functional domains. Frequently genes coding multidomain proteins duplicated. The varying modular nature within multidomain proteins should have accelerated evolutionary changes to a degree not feasible to achieve by means of mere post-duplication mutational changes.  相似文献   
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