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991.
Pierre Delattre Nicolas Morellet Peggy Codreanu Sandrine Miot Jean -Pierre Quéré Florent Sennedot Jacques Baudry 《Acta theriologica》2009,54(1):51-60
Vole demographics are often modified close to wooded environments. Population monitoring in such settings reveals substantial
edge effects, although these have seldom been quantified. This study compares the abundance of common voleMicrotus arvalis (Pallas, 1778) populations at various distances from three types of wooded environment (hedgerow, copse and forest) and in
two types of habitat (temporary and permanent grassland). In temporary grassland, substantial edge effects were detected along
the boundaries of forests and hedgerows. At 100 m from the forest edge, voles were twice more abundant than at 50 m, four
times more than at 25 m and eight times more than at 5 m. In permanent grassland, the edge effect was such that voles were
practically absent up to 100 m from the forest edge. For both types of grassland, the edge effect was more pronounced for
forest habitat than for hedgerows, that is, for elements with a large surface area of wooded environment. Our results suggest
that landscape context may greatly affect the local abundance of voles. Given the considerable damage done byM. arvalis, the presence of wooded patches in grassland areas leads to lower vole densities in adjacent areas and this might be an alternative
method to controlM. arvalis as a pest species. 相似文献
992.
Xenie Johnson Guillaume Vandystadt Sandrine Bujaldon Francis-André Wollman Rémi Dubois Pierre Roussel Jean Alric Daniel Béal 《Photosynthesis research》2009,102(1):85-93
Here, we describe a new imaging setup able to assess in vivo photosynthetic activity. The system specifically measures time-resolved
chlorophyll fluorescence in response to light. It is composed of a fast digital camera equipped with a wide-angle lens for
the analysis of samples up to 10 × 10 cm, i.e. entire plants or petri dishes. In the choice of CCD, we have opted for a 12-bits
high frame rate [150 fps (frames per second)] at the expense of definition (640 × 480 pixels). Although the choice of digital
camera is always a compromise between these two related features, we have designed a flexible system allowing the fast sampling
of images (down to 100 μs) with a maximum spatial resolution. This image readout system, synchronized with actinic light and
saturating pulses, allows a precise determination of F
0 and F
M, which is required to monitor PSII activity. This new imaging system, together with image processing techniques, is useful
to investigate the heterogeneity of photosynthetic activity within leaves or to screen large numbers of unicellular algal
mutant colonies to identify those with subtle changes in photosynthetic electron flow. 相似文献
993.
Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant 总被引:1,自引:0,他引:1
994.
995.
Filippo Molica Merlijn J.P. Meens Sandrine Morel Brenda R. Kwak 《Biology of the cell / under the auspices of the European Cell Biology Organization》2014,106(9):269-293
Connexins (Cxs) form a family of transmembrane proteins comprising 21 members in humans. Cxs differ in their expression patterns, biophysical properties and ability to combine into homomeric or heteromeric gap junction channels between neighbouring cells. The permeation of ions and small metabolites through gap junction channels or hemichannels confers a crucial role to these proteins in intercellular communication and in maintaining tissue homeostasis. Among others, Cx37, Cx40, Cx43, Cx45 and Cx47 are found in heart, blood and lymphatic vessels. Mutations or polymorphisms in the genes coding for these Cxs have not only been implicated in cardiovascular pathologies but also in a variety of other disorders. While mutations in Cx43 are mostly linked to oculodentodigital dysplasia, Cx47 mutations are associated with Pelizaeus–Merzbacher‐like disease and lymphoedema. Cx40 mutations are principally linked to atrial fibrillation. Mutations in Cx37 have not yet been described, but polymorphisms in the Cx37 gene have been implicated in the development of arterial disease. This review addresses current knowledge on gene mutations in cardiovascular Cxs systematically and links them to alterations in channel properties and disease. 相似文献
996.
997.
Sarah T. Wagner Linnea Hesse Sandrine Isnard Marie-Stéphanie Samain Jay Bolin Erika Maass Christoph Neinhuis Nick P. Rowe Stefan Wanke 《Annals of botany》2014,113(7):1139-1154
Background and Aims
The order Piperales has the highest diversity of growth forms among the earliest angiosperm lineages, including trees, shrubs, climbers and herbs. However, within the perianth-bearing Piperales (Asarum, Saruma, Lactoris, Hydnora, Prosopanche, Thottea and Aristolochia), climbing species only occur in the most species-rich genus Aristolochia. This study traces anatomical and morphological traits among these lineages, to detect trends in growth form evolution and developmental processes.Methods
Transverse stem sections of different developmental stages of representatives of Asarum, Saruma, Lactoris, Hydnora, Thottea and Aristolochia were compared and anatomical traits were linked to growth form evolution. Biomechanical properties of representative climbers were determined in three-point bending tests and are discussed based on the anatomical observations. Growth form evolution of the perianth-bearing Piperales was reconstructed by ancestral character state reconstruction using Mesquite.Key Results
While species of Asarum and Saruma are exclusively herbaceous, species of the remaining genera show a higher diversity of growth habit and anatomy. This growth form diversity is accompanied by a more complex stem anatomy and appropriate biomechanical properties. The ancestral growth form of the perianth-bearing Piperales is reconstructed with either a shrub-like or herbaceous character state, while the following three backbone nodes in the reconstruction show a shrub-like character state. Accordingly, the climbing habit most probably evolved in the ancestor of Aristolochia.Conclusions
Since the ancestor of the perianth-bearing Piperales has been reconstructed with a herb- or shrub-like habit, it is proposed that the climbing habit is a derived growth form, which evolved with the diversification of Aristolochia, and might have been a key feature for its diversification. Observed anatomical synapomorphies, such as the perivascular fibres in Lactoris, Thottea and Aristolochia, support the phylogenetic relationship of several lineages within the perianth-bearing Piperales. In addition, the hypothesis that the vegetative organs of the holoparasitic Hydnoraceae are most probably rhizomes is confirmed. 相似文献998.
Maeva J. Orliac Sandrine Ladevèze Philip D. Gingerich Renaud Lebrun Thierry Smith 《Proceedings. Biological sciences / The Royal Society》2014,281(1781)
Expansion of the brain is a key feature of primate evolution. The fossil record, although incomplete, allows a partial reconstruction of changes in primate brain size and morphology through time. Palaeogene plesiadapoids, closest relatives of Euprimates (or crown-group primates), are crucial for understanding early evolution of the primate brain. However, brain morphology of this group remains poorly documented, and major questions remain regarding the initial phase of euprimate brain evolution. Micro-CT investigation of the endocranial morphology of Plesiadapis tricuspidens from the Late Palaeocene of Europe—the most complete plesiadapoid cranium known—shows that plesiadapoids retained a very small and simple brain. Plesiadapis has midbrain exposure, and minimal encephalization and neocorticalization, making it comparable with that of stem rodents and lagomorphs. However, Plesiadapis shares a domed neocortex and downwardly shifted olfactory-bulb axis with Euprimates. If accepted phylogenetic relationships are correct, then this implies that the euprimate brain underwent drastic reorganization during the Palaeocene, and some changes in brain structure preceded brain size increase and neocortex expansion during evolution of the primate brain. 相似文献
999.
Karine Guitot Silvia Scarabelli Thierry Drujon Gérard Bolbach Mehdi Amoura Fabienne Burlina Albert Jeltsch Sandrine Sagan Dominique Guianvarc’h 《Analytical biochemistry》2014
Histone lysine methyltransferases (HKMTs) are enzymes that play an essential role in epigenetic regulation. Thus, identification of inhibitors specifically targeting these enzymes represents a challenge for the development of new antitumor therapeutics. Several methods for measuring HKMT activity are already available. Most of them use indirect measurement of the enzymatic reaction through radioactive labeling or antibody-recognized products or coupled enzymatic assays. Mass spectrometry (MS) represents an interesting alternative approach because it allows direct detection and quantification of enzymatic reactions and can be used to determine kinetics and to screen small molecules as potential inhibitors. Application of mass spectrometry to the study of HKMTs has not been fully explored yet. We describe here the development of a simple reliable label-free MALDI-TOF MS-based assay for the detection and quantification of peptide methylation, using SET7/9 as a model enzyme. Importantly, the use of expensive internal standard often required in mass spectrometry quantitative analysis is not necessary in this assay. This MS assay allowed us to determine enzyme kinetic parameters as well as IC50 for a known inhibitor of this enzyme. Furthermore, a comparative study with an antibody-based immunosorbent assay showed that the MS assay is more reliable and suitable for the screening of inhibitors. 相似文献
1000.
Research, conducted under the ANR project “Mammouths”, on “the end of the mammoth steppe: Man/Environment relationship during late Pleniglacial in Eastern Europe”, is the subject of several contributions, a part of them is published in this volume, under the heading “Humans and environments during Upper Paleolithic in mainland Ukraine and Crimea”, in the French journal L’anthropologie. 相似文献