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991.
Antonio Christian de A. Moura Hermano G. Nunes Alfredo Langguth 《International journal of primatology》2010,31(5):848-862
Food sharing with immatures is an important and relatively well studied aspect of infant care in many cooperative species.
A key point that has not yet been fully addressed, however, is how increasing the difficulty of obtaining food influences
the willingness of breeders and helpers to provision immature offspring. We used captive golden headed lion tamarins (Leontopithecus chrysomelas) to examine how breeders and helpers differ in provisioning juvenile individuals according to the level of difficulty of
obtaining food. The level of difficulty in obtaining food was varied by placing the food inside tubes that allowed access
only by adults. When food acquisition became more difficult, food sharing with juveniles and breeding females increased significantly.
Begging calls by breeding females and juveniles increased during the experimental condition, which probably led to increases
in food sharing. Breeders and helpers did not differ in their contribution to provisioning when food was easily available,
nor did they differ in their contribution when food was difficult to obtain. Breeding males in callitrichids have a prominent
role in transferring food to offspring, but contrary to our expectations, they did not increase food transfer in the experimental
condition. An unexpected result was the increased investment of the breeding female into her current offspring when the level
of difficulty of obtaining food was higher. We suggest that breeding lion tamarin females are not as constrained by reproductive
costs as breeding females of other callitrichids. Degree of reproductive skew is hypothesized as a factor affecting the contribution
of breeders and helpers to offspring care in cooperative breeding mammals, though we suggest that more studies are needed
to validate such a generalization. 相似文献
992.
Raf Brouns Robert Verkerk Tony Aerts Didier De Surgeloose Annick Wauters Simon Scharpé Peter P. De Deyn 《Neurochemical research》2010,35(9):1315-1322
Post-stroke inflammation may induce upregulation of the kynurenine (KYN) pathway for tryptophan (TRP) oxidation, resulting
in neuroprotective (kynurenic acid, KA) and neurotoxic metabolites (3-hydroxyanthranillic acid, 3-HAA). We investigated whether
activity of the kynurenine pathway in acute ischemic stroke is related to initial stroke severity, long-term stroke outcome
and the ischemia-induced inflammatory response. Plasma concentrations of TRP and its metabolites were measured in 149 stroke
patients at admission, at 24 h, at 72 h and at day 7 after stroke onset. We evaluated the relation between the KYN/TRP ratio,
the KA/3-HAA ratio and stroke severity, outcome and inflammatory parameters (C-reactive protein (CRP), erythrocyte sedimentation
rate (ESR) and neutrophil/lymphocyte ratio (NLR)). KYN/TRP but not KA/3-HAA correlated with the NIHSS score and with the infarct
volume. Patients with poor outcome had higher mean KYN/TRP ratios than patients with more favourable outcome. The KYN/TRP
ratio at admission correlated with CRP levels, ESR and NLR. The activity of the kynurenine pathway for tryptophan degradation
in acute ischemic stroke correlates with stroke severity and long-term stroke outcome. Tryptophan oxidation is related to
the stroke-induced inflammatory response. 相似文献
993.
Yan Li Yunshan Ning Yundan Wang Dandan Peng Yaodong Jiang Lili Zhang Min Long Jun Luo Ming Li 《BMC biotechnology》2010,10(1):84
Background
Urease B is an important virulence factor that is required for Helicobacter pylori to colonise the gastric mucosa. Mouse monoclonal antibodies (mAbs) that inhibit urease B enzymatic activity will be useful as vaccines for the prevention and treatment of H. pylori infection. Here, we produced murine mAbs against urease B that neutralize the enzyme's activity. We mapped their epitopes by phage display libraries and investigated the immunogenicity of the selected mimotopes in vivo. 相似文献994.
995.
Two amphipods, the hypogean Niphargus stygius and epigean Gammarus fossarum, were analyzed for fatty acid (FA) composition, electron transport system (ETS) activity and respiration (R) during a laboratory
fasting experiment. In agreement with ETS and R measurements (and the ETS/R ratio), the hypogean N. stygius utilized FA more slowly than the epigean G. fossarum. Inter-specific differences in the utilization of certain FA during fasting were also revealed. While N. stygius tended to preserve all of its FA during the experimental fasting period, G. fossarum showed a tendency to utilize MUFA (monounsaturated FA) and SAFA (saturated FA) and preferentially retain PUFA (polyunsaturated
FA). The significant correlations between ETS activity and composition of specific FA during fasting can be linked to R. During
the fasting, both ETS activity and respiration rate of G. fossarum decreased, however, ETS/R ratio increased. In contrast, N. stygius did not show significant changes in these parameters. This is the first report, which connects ETS activity with changes
in concentrations of specific FA during fasting. Such evolutionary adaptations of hypogean species enables them to better
survive chronically low and/or discontinuous food supplies compared to epigean species, which live in environments where food
shortages are much less frequent. 相似文献
996.
Danilo E Xavier Renata C Picão Raquel Girardello Lorena CC Fehlberg Ana C Gales 《BMC microbiology》2010,10(1):217
Background
Multi-drug efflux pumps have been increasingly recognized as a major component of resistance in P. aeruginosa. We have investigated the expression level of efflux systems among clinical isolates of P. aeruginosa, regardless of their antimicrobial susceptibility profile. 相似文献997.
998.
999.
Bihao Cao Yaqing Lu Guoju Chen Jianjun Lei 《Plant Cell, Tissue and Organ Culture》2010,103(2):217-226
The translationally controlled tumor protein (TCTP) is an important component of the target of rapamycin (TOR) signaling pathway,
the major regulator of cell growth in animals and fungi. Despite its relevance, knowledge on plant TCTP homologs is still
limited. In the present study, the full-length BoTCTP cDNA was isolated from a cabbage (Brassica oleracea L.) cDNA library. The BoTCTP cDNA encodes a polypeptide of 168 amino acids and shared the highly conserved GTPase binding surface in all of the species
analyzed. Northern blotting analysis showed that BoTCTP was specifically expressed in the root and stem. Furthermore, the expression of BoTCTP could be obviously enhanced by stress stimuli, including high temperature and salt stresses, while no significant changes
in the BoTCTP expression were observed under ABA stress. Functional analysis of BoTCTP was performed by the silencing of BoTCTP using RNA interference (RNAi) and the BoTCTP RNAi plants exhibited reduced vegetative growth rate and decreased tolerance of the cold, high temperature, and salt stresses.
The reported results clearly suggest that the BoTCTP gene is involved in the regulation of both growth and stress response in cabbage. 相似文献
1000.
Robert S. Donofrio Lorelle L. Bestervelt Ratul Saha Susan T. Bagley 《Journal of industrial microbiology & biotechnology》2010,37(9):909-918
Brevundimonas diminuta is a small Gram-negative bacterium used for validation of membranes and filters used in the pharmaceutical and drinking water
treatment industries. Current assays are time consuming, nonselective, and may be subject to interference by competing indigenous
microorganisms. The focus of this study is to develop rapid and specific enumeration methodologies for B. diminuta. Quantitative real-time polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FISH) assays were developed
based on the gyrB (1,166 bp) and rpoD (829 bp) gene sequences of B. diminuta ATCC 19146. Species-specific primers and probes were designed, and a 100–200 bp segment of each gene was targeted in the
qPCR studies. For both the qPCR and FISH assays, an internal 25 bp sequence was selected for use as a TaqMan probe (labeled
with 6-FAM and a Black Hole Quencher). Probe specificity studies, conducted against Gram-negative and Gram-positive reference
strains as well as environmental strains, revealed high specificity of the primer/probe pairs to B. diminuta. Sensitivities of the qPCR reactions using purified genomic DNA from B. diminuta were determined to be 0.89 pg for rpoD and 8.9 pg for gyrB. The feasibility of using whole-cell B. diminuta suspensions directly with the rpoD qPCR protocol was also evaluated. The greatest sensitivity observed for B. diminuta was 1 × 103 colony forming units (CFU) per mL when tryptic soy broth was used as the growth medium. When compared with direct microscopic
enumeration using a 5′ 6-FAM FISH probe, traditional plating methods showed significant underestimation of B. diminuta concentration (P = 0.01) when this organism was cultivated in saline lactose broth. The results of this investigation demonstrate that qPCR
and FISH are effective methods for rapid (<4 h) enumeration of B. diminuta and may be viable alternatives to plating when validating drinking water filtration systems. 相似文献