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21.
The convergence of complementary and alternative medicine (CAM) and evidence-based medicine (EBM) is a prominent feature of healthcare in western countries, but it is currently undertheorised, and its implications have been insufficiently considered. Two models of convergence are described – the totally integrated evidence-based model (TI) and the multicultural-pluralistic model (MP). Both models are being incorporated into general medical practice. Against the background of the reasons for the increasing utilisation of CAM by the public and by general practitioners, TI-convergence is supported and MP-convergence is rejected. MP-convergence is epistemologically and clinically incoherent, and it cannot be regulated. It is also inconsistent with developments in the legal determination of the standard of care for both diagnosis/treatment and disclosure. These claims concerning MP-convergence are justified by the fact that science is not a member of the group of perspectives or world-views which postmodernism treats as equally valid, and this is especially important for healthcare.  相似文献   
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In order to elucidate the functional role of TRPC genes, in vivo, the targeted inactivation of these genes in mice is an invaluable technique. In this review, we summarize the currently available results on the phenotype of TRPC-deficient mouse lines. The analysis of mice with targeted deletion in three TRPC genes demonstrates that these proteins represent essential constituents of agonist-activated and phospholipase C-dependent Ca2+ entry channels in primary cells. Furthermore, from the deficits observed in these TRPC-deficient mouse lines a striking number of biological functions could already be ascribed to TRPC2, TRPC4, and TRPC6, not only on the cellular level but also for complex organ functions and integrative physiology. Accordingly, TRPC2 proteins are critically involved in pheromone sensing by neurones of the vomeronasal organ and, thereby, in the regulation of sexual and social behavior of mice, TRPC4 proteins are essential determinants of endothelial-dependent regulation of vascular tone, endothelial permeability, and neurotransmitter release from thalamic interneurones, and TRPC6 proteins are supposed to have a fundamental role in the regulation of smooth muscle tone in blood vessels and lung.  相似文献   
24.
Potential community effects of nutrient enhancement are a topic of theoretical interest and increasing management concern in coastal marine systems. While increased nutrient levels may lead to increased microalgal production and biomass, studies have provided variable evidence regarding the existence of upward cascade effects on macrofauna. In benthic marine communities, limitation by predation or factors preventing recruitment response may contribute to weak coupling between resource availability and macrobenthos abundances. We conducted blocked nutrient addition and predator exclusion experiments in the intertidal of two estuaries that varied in background nutrient concentrations (Cape Fear and White Oak, southeastern North Carolina). Benthic community comparisons were also made among these and two other North Carolina estuaries to examine correlations in distribution patterns. Cape Fear, which had the highest background nitrogen and phosphorus concentrations, also had highest ambient benthic microalgal biomass. There was no significant response of microalgal biomass to local nutrient additions in Cape Fear and only one macrofaunal taxon during one season exhibited abundance responses to nutrient additions. White Oak, with lower background nutrient levels, was characterized by significant microalgal responses to nutrient additions and significant macrofauna abundance responses for 50% of the species examined during summer experiments. However, all of these macrofauna declined in abundance with nutrient enhancement while biomass remained constant or significantly increased with nutrient additions. This suggests a complex response of macrofauna to nutrient additions in this estuary with greater biomass per individual but a corresponding decline in abundances. Top-down/bottom-up interactive effects were observed for haustoriid amphipods, which were uncommon or absent when predators had access, but exhibited strong biomass responses to nutrient enhancement when predators were excluded. These results support a growing body of literature that indicates the importance of background conditions in regulating benthic community responses to nutrient enhancement. However, responses may be complex with biomass per individual rather than densities being the primary response variable for some taxa and predator moderation of responses occurring for some taxa but not others.  相似文献   
25.
Amyloid imaging with positron emission tomography (PET) is presently used in Alzheimer's disease (AD) research. In this study we investigated the possibility to use early frames (ePIB) of the PIB scans as a rough index of CBF by comparing normalised early PIB values with cerebral glucose metabolism (rCMRglc). PIB-PET and FDG-PET were performed in 37 AD patients, 21 subjects with mild cognitive impairment (MCI) and 6 healthy controls (HC). The patients were divided based on their PIB retention (amyloid load) as either PIB positive (PIB+) or PIB negative (PIB−). Data of the unidirectional influx K1 from a subset of the subjects including 7 AD patients and 3 HC was used for correlative analysis. Data was analysed using regions of interest (ROI) analysis. A strong, positive correlation was observed across brain regions between K1 and ePIB (r = 0.70; p ≤ 0.001). The ePIB values were significantly lower in the posterior cingulate (p ≤ 0.001) and the parietal cortices (p = 0.002) in PIB+ subjects compared to PIB−, although the group difference were stronger for rCMRglc in cortical areas (p ≤ 0.001). Strong positive correlations between ePIB and rCMRglc were observed in all cortical regions analysed, especially in the posterior cingulate and parietal cortices (p ≤ 0.001). A single dynamic PIB-PET scan may provide information about pathological and functional changes (amyloidosis and impaired blood flow). This might be important for diagnosis of AD, enrichment of patients in clinical trials and evaluation of treatment effects. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.  相似文献   
26.
Accurate species delimitation is fundamental for many fields of biology. Although a wide range of evolutionary-biological patterns are known to promote failure in species delimitation when any single information source is considered, the majority of species characterisations are still based on single disciplines. Using Alpine jumping bristletails we here showcase the establishment of morphological and molecular tools for multi-source species delimitation in a taxonomically problematic arthropod group and stress its advantages over single-discipline approaches. Once sound species delimitations have been achieved, Alpine jumping bristletails will be available as a prime model system for addressing questions related to the emergence of endemism and parthenogenesis.  相似文献   
27.
Bond JE  Hamilton CA  Garrison NL  Ray CH 《ZooKeys》2012,(190):95-109
The trapdoor spider genus Myrmekiaphila currently comprises 11 nominal species. A recent molecular phylogenetic evaluation of the group identified a number of problems with respect to how species and species groups were delineated by Bond and Platnick in their 2007 taxonomic revision of the genus. We report herein the discovery of a new species, Myrmekiaphila tigrissp. n. The phylogenetic position of the species is evaluated using a molecular phylogenetic approach based on a set of mtDNA markers. Our preferred phylogenetic hypothesis supports the recognition of a new species and further highlights the need to more carefully investigate species boundaries within the genus. These results further indicate that palpal bulb morphology is rapidly evolving and has likely been a contributing factor in rendering a number of species paraphyletic with respect to the molecular data.  相似文献   
28.
A major challenge in structural biology is to determine the configuration of domains and proteins in multidomain proteins and assemblies, respectively. All available data should be considered to maximize the accuracy and precision of these models. Small-angle X-ray scattering (SAXS) efficiently provides low-resolution experimental data about the shapes of proteins and their assemblies. Thus, we integrated SAXS profiles into our software for modeling proteins and their assemblies by satisfaction of spatial restraints. Specifically, we modeled the quaternary structures of multidomain proteins with structurally defined rigid domains as well as quaternary structures of binary complexes of structurally defined rigid proteins. In addition to SAXS profiles and the component structures, we used stereochemical restraints and an atomic distance-dependent statistical potential. The scoring function is optimized by a biased Monte Carlo protocol, including quasi-Newton and simulated annealing schemes. The final prediction corresponds to the best scoring solution in the largest cluster of many independently calculated solutions. To quantify how well the quaternary structures are determined based on their SAXS profiles, we used a benchmark of 12 simulated examples as well as an experimental SAXS profile of the homotetramer d-xylose isomerase. Optimization of the SAXS-dependent scoring function generally results in accurate models if sufficiently precise approximations for the constituent rigid bodies are available; otherwise, the best scoring models can have significant errors. Thus, SAXS profiles can play a useful role in the structural characterization of proteins and assemblies if they are combined with additional data and used judiciously. Our integration of a SAXS profile into modeling by satisfaction of spatial restraints will facilitate further integration of different kinds of data for structure determination of proteins and their assemblies.  相似文献   
29.
Zhang H  Georgescu P  Chen L 《Bio Systems》2008,93(3):151-171
From a practical point of view, the most efficient strategy for pest control is to combine an array of techniques to control the wide variety of potential pests that may threaten crops in an approach known as integrated pest management (IPM). In this paper, we propose a predator-prey (pest) model of IPM in which pests are impulsively controlled by means of spraying pesticides (the chemical control) and releasing natural predators (the biological control). It is assumed that the biological and chemical control are used with the same periodicity, but not simultaneously. The functional response of the predator is allowed to be predator-dependent, in the form of a Beddington-DeAngelis functional response, rather than to have a perhaps more classical prey-only dependence. The local and global stability of the pest-eradication periodic solution, as well as the permanence of the system, are obtained under integral conditions which are shown to have biological significance. In a certain limiting case, it is shown that a nontrivial periodic solution emerges via a supercritical bifurcation. Finally, our findings are confirmed by means of numerical simulations.  相似文献   
30.
The interactive effects of light, nutrients, and simulated herbivory on the structure and functioning of a subtropical turtlegrass bed were analyzed monthly from May to October 2001 in Perdido Bay, FL. For each of the three factors, two levels were evaluated in a factorial design with four replicates per treatment. The variables included: light, at ambient and 40% reduction; nutrients, at ambient and 2× ambient concentrations; and herbivory, with no herbivory and simulated effects of a density of 15 sea urchins/m2. In practice, light levels turned out to be 40% of surface PAR for ambient conditions, and 16% for shaded plots. Biomass removed as herbivory represented, on average, slightly less than 20% of the above-ground biomass. Separate three-way ANOVAs found no significant three-way interactions for any of the response variables, and few two-way interactions. There were no significant nutrient effects on turtlegrass above-ground biomass, although nutrient additions produced significant decreases in epibiont biomass, and net above-ground primary production (NAPP); significant increases in below-ground biomass during the peak of the growing season. Shoot density and average number of leaves per shoot increased significantly, while the C/N ratio of the oldest leaf in the enriched plots decreased significantly. Light reduction significantly negatively affected all response variables, except below-ground biomass, shoot density and leaf length. Herbivory had isolated and inconsistent significant effects on below-ground biomass, shoot density, average number of leaves per shoot, and leaf length and width. Overall, our results indicate that nutrients are not limiting in Perdido Bay, and that nutrient additions had mostly detrimental effects. Light appeared to be the most important variable limiting seagrasses growth and abundance, and as with terrestrial plants, seagrasses seemed to respond more to light and nutrients than to herbivory. However, it is essential that additional tests of the single and interactive effects of the three key factors of light, nutrients and herbivory be done to evaluate the generality of our work, since our study is the first of its kind in seagrass meadows.  相似文献   
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