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991.
992.
Marcelo P. Pereira Paulo H. S. Pelicioni Lilian T. B. Gobbi 《Somatosensory & motor research》2016,33(2):86-92
We tested local vibration effects during upright standing considering: (i) the orientation of vibratory devices in relation to muscle fibres; (ii) the muscle region stimulated; and (iii) the number of stimulation spots. Results showed a higher balance disturbance with vibration devices oriented parallel to triceps surae muscle fibres. The single stimulation of the proximal region of the tibialis anterior muscle belly induces the same proprioceptive disturbance as stimulating multiple regions simultaneously. 相似文献
993.
994.
Abiotic and Biotic Stresses and Changes in the Lignin Content and Composition in Plants 总被引:4,自引:0,他引:4
Jullyana Cristina Magalhães Silva Moura Cesar Augusto Valencise Bonine Juliana De Oliveira Fernandes Viana Marcelo Carnier Dornelas Paulo Mazzafera 《植物学报(英文版)》2010,52(4):360-376
Lignin is a polymer of phenylpropanoid compounds formed through a complex biosynthesis route, represented by a metabolic grid for which most of the genes involved have been sequenced in several plants, mainly in the model-plants Arabidopsis thaliana and Populus. Plants are exposed to different stresses, which may change lignin content and composition. In many cases, particularly for plant-microbe interactions, this has been suggested as defence responses of plants to the stress. Thus, understanding how a stressor modulates expression of the genes related with lignin biosynthesis may allow us to develop study-models to increase our knowledge on the metabolic control of lignin deposition in the cell wall. This review focuses on recent literature reporting on the main types of abiotic and biotic stresses that alter the biosynthesis of lignin in plants. 相似文献
995.
Geruza de Oliveira Ceita Laurival Ant?nio Vilas-Boas Marcelo Santos Castilho Marcelo Falsarella Carazzolle Carlos Priminho Pirovani Alessandra Selbach-Schnadelbach Karina Peres Gramacho Pablo Ivan Pereira Ramos Luciana Veiga Barbosa Gon?alo Amarante Guimar?es Pereira Aristóteles Góes-Neto 《Genetics and molecular biology》2014,37(4):683-693
The phytopathogenic fungus Moniliophthora perniciosa (Stahel) Aime & Philips-Mora, causal agent of witches’ broom disease of cocoa, causes countless damage to cocoa production in Brazil. Molecular studies have attempted to identify genes that play important roles in fungal survival and virulence. In this study, sequences deposited in the M. perniciosa Genome Sequencing Project database were analyzed to identify potential biological targets. For the first time, the ergosterol biosynthetic pathway in M. perniciosa was studied and the lanosterol 14α-demethylase gene (ERG11) that encodes the main enzyme of this pathway and is a target for fungicides was cloned, characterized molecularly and its phylogeny analyzed. ERG11 genomic DNA and cDNA were characterized and sequence analysis of the ERG11 protein identified highly conserved domains typical of this enzyme, such as SRS1, SRS4, EXXR and the heme-binding region (HBR). Comparison of the protein sequences and phylogenetic analysis revealed that the M. perniciosa enzyme was most closely related to that of Coprinopsis cinerea. 相似文献
996.
Ana C. C. Silva Elizabeth P. G. Arêas Marcelo A. Silva José Alfredo G. Arêas 《Food biophysics》2010,5(2):94-102
Defatted rumen protein and soy protein concentrate were extruded in a 15.5:1 L/D single-screw extruder at the optimum conditions
for their expansion (150°C and 35% moisture, and 130°C and 35% moisture, respectively). Emulsions were produced with these
proteins and studied by rheology and time domain low-resolution 1H nuclear magnetic resonance (TD-NMR). Extrusion increased storage modulus of rumen protein emulsions. The opposite was observed
for soy protein. Mechanical relaxation showed the existence of three relaxing components in the emulsions whose relative contributions
were changed by extrusion. Likewise, spin–spin relaxation time constants (T
2) measured by TD-NMR also showed three major distinct populations of protons in respect to their mobility that were also altered
by extrusion. Extrusion increased surface hydrophobicity of both rumen and soy protein. Solubility of rumen protein increased
with extrusion whereas soy protein had its solubility decreased after processing. Extrusion promoted molecular reorganization
of protein, increasing its superficial hydrophobicity, affecting its interfacial properties and improving its emulsifying
behavior. The results show that extrusion can promote the use of rumen, a by-product waste from the meat industry, in human
nutrition by replacing soy protein in food emulsions. 相似文献
997.
Victor Túlio Ribeiro-Resende Tiago Araújo Gomes Silmara de Lima Maiara Nascimento-Lima Michele Bargas-Rega Marcelo Felipe Santiago Ricardo Augusto de Melo Reis Fernando Garcia de Mello 《PloS one》2014,9(10)
The ganglioside 9-O-acetyl GD3 is overexpressed in peripheral nerves after lesioning, and its expression is correlated with axonal degeneration and regeneration in adult rodents. However, the biological roles of this ganglioside during the regenerative process are unclear. We used mice lacking GD3 synthase (Siat3a KO), an enzyme that converts GM3 to GD3, which can be further converted to 9-O-acetyl GD3. Morphological analyses of longitudinal and transverse sections of the sciatic nerve revealed significant differences in the transverse area and nerve thickness. The number of axons and the levels of myelin basic protein were significantly reduced in adult KO mice compared to wild-type (WT) mice. The G-ratio was increased in KO mice compared to WT mice based on quantification of thin transverse sections stained with toluidine blue. We found that neurite outgrowth was significantly reduced in the absence of GD3. However, addition of exogenous GD3 led to neurite growth after 3 days, similar to that in WT mice. To evaluate fiber regeneration after nerve lesioning, we compared the regenerated distance from the lesion site and found that this distance was one-fourth the length in KO mice compared to WT mice. KO mice in which GD3 was administered showed markedly improved regeneration compared to the control KO mice. In summary, we suggest that 9-O-acetyl GD3 plays biological roles in neuron-glia interactions, facilitating axonal growth and myelination induced by Schwann cells. Moreover, exogenous GD3 can be converted to 9-O-acetyl GD3 in mice lacking GD3 synthase, improving regeneration. 相似文献
998.
Marcos Amaku Marcelo Nascimento Burattini Francisco Antonio Bezerra Coutinho Eduardo Massad 《Bulletin of mathematical biology》2010,72(5):1294-1314
We consider two viral strains competing against each other within individual hosts (at cellular level) and at population level
(for infecting hosts) by studying two cases. In the first case, the strains do not mutate into each other. In this case, we
found that each individual in the population can be infected by only one strain and that co-existence in the population is
possible only when the strain that has the greater basic intracellular reproduction number, R
0c
, has the smaller population number R
0p
. Treatment against the one strain shifts the population equilibrium toward the other strain in a complicated way (see Appendix B).
In the second case, we assume that the strain that has the greater intracellular number R
0c
can mutate into the other strain. In this case, individual hosts can be simultaneously infected by both strains (co-existence
within the host). Treatment shifts the prevalence of the two strains within the hosts, depending on the mortality induced
by the treatment, which is, in turn, dependent upon the doses given to each individual. The relative proportions of the strains
at the population level, under treatment, depend both on the relative proportions within the hosts (which is determined by
the dosage of treatment) and on the number of individuals treated per unit time, that is, the rate of treatment. Implications
for cases of real diseases are briefly discussed. 相似文献
999.
1000.
Fiona R. Straehl Torsten M. Scheyer Analía M. Forasiepi Ross D. MacPhee Marcelo R. Sánchez-Villagra 《PloS one》2013,8(7)
Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xenarthran long bones is composed of a mixture of woven, parallel-fibered and lamellar bone. The vascular canals have a longitudinal, reticular or radial orientation and are mostly arranged in an irregular manner. Concentric rows of vascular canals and laminar organization of the tissue are only found in anteater bones. The long bones of adult specimens are marked by dense Haversian bone, a feature that has been noted for most groups of mammals. In the long bones of armadillos, secondary osteons have an oblique orientation within the three-dimensional bone tissue, thus resulting in their irregular shape when the bones are sectioned transversely. Secondary remodeling is generally more extensive in large taxa than in small taxa, and this could be caused by increased loading. Lines of arrested growth are assumed to be present in all specimens, but they are restricted to the outermost layer in bones of armadillos and are often masked by secondary remodeling in large taxa. Parameters of bone compactness show a pattern in the femur that separates Cingulata and Pilosa (Folivora and Vermilingua), with cingulates having a lower compactness than pilosans. In addition, cingulates show an allometric relationship between humeral and femoral bone compactness. 相似文献