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921.
922.
Gary Kusdian Christian Woehle William F. Martin Sven B. Gould 《Cellular microbiology》2013,15(10):1707-1721
Trichomonas vaginalis is the most widespread non‐viral pathogen of the human urogenital tract, infecting ~ 3% of the world's population annually. At the onset of infection the protist changes morphology within minutes: the flagellated free‐swimming cell converts into the amoeboid‐adherent stage. The molecular machinery of this process is not well studied, but is thought to involve actin reorganization. We have characterized amoeboid transition, focusing in particular on TvFim1, the only expressed protein of the fimbrin family in Trichomonas. Addition of TvFim1 to actin polymerization assays increases the speed of actin filament assembly and results in bundling of F‐actin in a parallel and anti‐parallel manner. Upon contact with vaginal epithelial cells, the otherwise diffuse localization of actin and TvFim1 changes dramatically. In the amoeboid TvFim1 associates with fibrous actin bundles and concentrates at protrusive structures opposing the trailing ends of the gliding amoeboid form and rapidly redistributes together with actin to form distinct clusters. Live cell imaging demonstrates that Trichomonas amoeboid stages do not just adhere to host tissue, rather they actively migrate across human epithelial cells. They do so in a concerted manner, with an average speed of 20 μm min?1 and often using their flagella and apical tip as the leading edge. 相似文献
923.
B V Geisbrecht K Schulz K Nau M T Geraghty H Schulz R Erdmann S J Gould 《Biochemical and biophysical research communications》1999,260(1):28-34
Here we report the preliminary characterization of Yor180Cp, a novel peroxisomal protein involved in fatty acid metabolism in the yeast Saccharomyces cerevisiae. A computer-based screen identified Yor180Cp as a putative peroxisomal protein, and Yor180Cp targeted GFP to peroxisomes in a PEX8-dependent manner. Yor180Cp was also detected by mass spectrometric analysis of an HPLC-separated extract of yeast peroxisomal matrix proteins. YOR180C is upregulated during growth on oleic acid, and deletion of YOR180C from the yeast genome resulted in a mild but significant growth defect on oleic acid, indicating a role for Yor180Cp in fatty acid metabolism. In addition, we observed that yor180cDelta cells fail to efficiently import the enzyme Delta3,Delta2-enoyl-CoA isomerase (Eci1p) to peroxisomes. This result suggested that Yor180Cp might associate with Eci1p in vivo, and a Yor180Cp-Eci1p interaction was detected using the yeast two-hybrid system. Potential roles for Yor180Cp in peroxisomal fatty acid metabolism are discussed. 相似文献
924.
Zoltán Imrei Zsófia Lohonyai József Muskovits Eszter Matula József Vuts József Fail Philip J. L. Gould Michael A. Birkett Miklós Tóth Michael J. Domingue 《Journal of Applied Entomology》2020,144(3):224-231
There is an urgent need in Europe to prepare resources for the arrival of the emerald ash borer, Agrilus planipennis (Buprestidae, Coleoptera) from European Russia, and possibly other invasive jewel beetles. A lightweight, easy to handle, non-sticky trap could facilitate monitoring and detection to derive information about emerald ash borer and other jewel beetle populations. In two experiments carried out over two consecutive years in an oak forest, a new non-sticky multi-funnel trap design with a light-green (sometimes described as fluorescent yellow) visual cue was developed. Altogether, there were 238 (2018) and 194 (2019) specimens captured often (2018) and eight (2019) Agrilus species, eight of which are oak-related and one (A. convexicollis) was linked to ash. The new light-green multi-funnel trap performed similarly to the sticky design with a similar coloured surface. Our results suggest that the new trap design may be suitable for catching a wide range of buprestid species. It may also have the potential to be further optimized with respect to visual and olfactory cues, which would provide an even more useful tool for monitoring both invasive and indigenous buprestids. 相似文献
925.
The purpose of this study was to investigate cortical mechanisms upstream to the corticospinal motor neuron that may be associated with central fatigue and sense of effort during and after a fatigue task. We used two different isometric finger abduction protocols to examine the effects of muscle activation and fatigue the right first dorsal interosseous (FDI) of 12 participants. One protocol was intended to assess the effects of muscle activation with minimal fatigue (control) and the other was intended to elicit central fatigue (fatigue). We hypothesized that high frequency repetitive transcranial magnetic stimulation (rTMS) of the supplementary motor area (SMA) would hasten recovery from central fatigue and offset a fatigue-induced increase in sense of effort by facilitating the primary motor cortex (M1). Constant force-sensation contractions were used to assess sense of effort associated with muscle contraction. Paired-pulse TMS was used to assess intracortical inhibition (ICI) and facilitation (ICF) in the active M1 and interhemispheric inhibitory (IHI) was assessed to determine if compensation occurs via the resting M1. These measures were made during and after the muscle contraction protocols. Corticospinal excitability progressively declined with fatigue in the active hemisphere. ICF increased at task failure and ICI was also reduced at task failure with no changes in IHI found. Although fatigue is associated with progressive reductions in corticospinal excitability, compensatory changes in inhibition and facilitation may act within, but not between hemispheres of the M1. rTMS of the SMA following fatigue enhanced recovery of maximal voluntary force and higher levels of ICF were associated with lower sense of effort following stimulation. rTMS of the SMA may have reduced the amount of upstream drive required to maintain motor output, thus contributing to a lower sense of effort and increased rate of recovery of maximal force. 相似文献
926.
Many vector-borne diseases lack effective vaccines and medications, and the limitations of traditional vector control have inspired novel approaches based on using genetic engineering to manipulate vector populations and thereby reduce transmission. Yet both the short- and long-term epidemiological effects of these transgenic strategies are highly uncertain. If neither vaccines, medications, nor transgenic strategies can by themselves suffice for managing vector-borne diseases, integrating these approaches becomes key. Here we develop a framework to evaluate how clinical interventions (i.e., vaccination and medication) can be integrated with transgenic vector manipulation strategies to prevent disease invasion and reduce disease incidence. We show that the ability of clinical interventions to accelerate disease suppression can depend on the nature of the transgenic manipulation deployed (e.g., whether vector population reduction or replacement is attempted). We find that making a specific, individual strategy highly effective may not be necessary for attaining public-health objectives, provided suitable combinations can be adopted. However, we show how combining only partially effective antimicrobial drugs or vaccination with transgenic vector manipulations that merely temporarily lower vector competence can amplify disease resurgence following transient suppression. Thus, transgenic vector manipulation that cannot be sustained can have adverse consequences—consequences which ineffective clinical interventions can at best only mitigate, and at worst temporarily exacerbate. This result, which arises from differences between the time scale on which the interventions affect disease dynamics and the time scale of host population dynamics, highlights the importance of accounting for the potential delay in the effects of deploying public health strategies on long-term disease incidence. We find that for systems at the disease-endemic equilibrium, even modest perturbations induced by weak interventions can exhibit strong, albeit transient, epidemiological effects. This, together with our finding that under some conditions combining strategies could have transient adverse epidemiological effects suggests that a relatively long time horizon may be necessary to discern the efficacy of alternative intervention strategies. 相似文献
927.
Mathieu Legros Chonggang Xu Kenichi Okamoto Thomas W. Scott Amy C. Morrison Alun L. Lloyd Fred Gould 《PloS one》2012,7(12)
Suppression of dengue and malaria through releases of genetically engineered mosquitoes might soon become feasible. Aedes aegypti mosquitoes carrying a conditionally lethal transgene have recently been used to suppress local vector populations in small-scale field releases. Prior to releases of transgenic insects on a wider scale, however, most regulatory authorities will require additional evidence that suppression will be effective in natural heterogeneous habitats. We use a spatially explicit stochastic model of an Ae. aegypti population in Iquitos, Peru, along with an uncertainty analysis of its predictions, to quantitatively assess the outcome of varied operational approaches for releases of transgenic strains with conditional death of females. We show that population elimination might be an unrealistic objective in heterogeneous populations. We demonstrate that substantial suppression can nonetheless be achieved if releases are deployed in a uniform spatial pattern using strains combining multiple lethal elements, illustrating the importance of detailed spatial models for guiding genetic mosquito control strategies. 相似文献
928.
929.
David J Gould 《BMJ (Clinical research ed.)》1983,287(6396):913-914
930.