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991.
Laurent Mottron Michelle Dawson Isabelle Soulières 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2009,364(1522):1385-1391
According to the enhanced perceptual functioning (EPF) model, autistic perception is characterized by: enhanced low-level operations; locally oriented processing as a default setting; greater activation of perceptual areas during a range of visuospatial, language, working memory or reasoning tasks; autonomy towards higher processes; and superior involvement in intelligence. EPF has been useful in accounting for autistic relative peaks of ability in the visual and auditory modalities. However, the role played by atypical perceptual mechanisms in the emergence and character of savant abilities remains underdeveloped. We now propose that enhanced detection of patterns, including similarity within and among patterns, is one of the mechanisms responsible for operations on human codes, a type of material with which savants show particular facility. This mechanism would favour an orientation towards material possessing the highest level of internal structure, through the implicit detection of within- and between-code isomorphisms. A second mechanism, related to but exceeding the existing concept of redintegration, involves completion, or filling-in, of missing information in memorized or perceived units or structures. In the context of autistics'' enhanced perception, the nature and extent of these two mechanisms, and their possible contribution to the creativity evident in savant performance, are explored. 相似文献
992.
This article first proposes a reduction strategy of the activated sludge process model with alternated aeration. Initiated with the standard activated sludge model (ASM1), the reduction is based on some biochemical considerations followed by linear approximations of nonlinear terms. Two submodels are then obtained, one for the aerobic phase and one for the anoxic phase, using four state variables related to the organic substrate concentration, the ammonium and nitrate‐nitrite nitrogen, and the oxygen concentration. Then, a two‐step robust estimation strategy is used to estimate both the unmeasured state variables and the unknown inflow ammonium nitrogen concentration. Parameter uncertainty is considered in the dynamics and input matrices of the system. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献
993.
An outcome of the photochemistry during oxygenic photosynthesis is the rapid turn over of the D1 protein in the light compared
to the other proteins of the photosystem II (PS II) reaction center. D1 is a major factor of PS II instability and its replacement
a primary event of the PS II repair cycle. D1 also undergoes redox-dependent phosphorylation prior to its degradation. Although
it has been suggested that phosphorylation modulates D1 metabolism, reversible D1 phosphorylation was reported not to be essential
for PS II repair in Arabidopsis. Thus, the involvement of phosphorylation in D1 degradation is controversial. We show here that nitric oxide donors inhibit
in vivo phosphorylation of the D1 protein in Spirodela without inhibiting degradation of the protein. Thus, D1 phosphorylation is not tightly linked to D1 degradation in the intact
plant. 相似文献
994.
Estelle Dumont Véronique Fontaine Christophe Vuylsteker Hélène Sellier Sylvie Bodèle Najia Voedts Rosemonde Devaux Marlène Frise Komlan Avia Jean-Louis Hilbert Nasser Bahrman Eric Hanocq Isabelle Lejeune-Hénaut Bruno Delbreil 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(8):1561-1571
To increase yield in pea (Pisum sativum L.), autumn sowing would be preferable. Hence, frost tolerance of pea became a major trait of interest for breeders. In order
to better understand the cold acclimation in pea, Champagne a frost tolerant line and Terese, a frost sensitive line, and
their recombinant inbred lines (RIL) were studied. RIL frost tolerance was evaluated by a frost damage scale under field as
well as controlled conditions. A quantitative trait loci (QTL) approach was used to identify chromosomal regions linked to
frost tolerance. The detected QTL explained from 6.5 to 46.5% of the phenotypic variance. Amongst them, those located on linkage
groups 5 and 6 were consistent with over all experiments, in field as well as in controlled environments. In order to improve
the understanding of the frost tolerance mechanisms, several cold acclimation key characters such as concentration of sugars,
electrolyte leakage, osmotic pressure, and activity of RuBisCO were assessed. Some of these physiological QTL colocalised
with QTL for frost damage, in particular two raffinose QTL on LG5 and LG6 and one RuBisCO activity QTL on LG6, explaining
8.8 to 27.0% of the phenotypic variance. In addition, protein quantitative loci were mapped; some of them colocalised with
frost damage and physiological QTL on LG5 and LG6, explaining 16.0–43.6% of the phenotypic variance. Raffinose metabolism
and RuBisCO activity and its effect on photosynthesis might play a major role in cold acclimation of pea.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
995.
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997.
Isabelle Bally V��ronique Rossi Thomas Lunardi Nicole M. Thielens Christine Gaboriaud G��rard J. Arlaud 《The Journal of biological chemistry》2009,284(29):19340-19348
The C1 complex of complement is assembled from a recognition protein C1q and C1s-C1r-C1r-C1s, a Ca2+-dependent tetramer of two modular proteases C1r and C1s. Resolution of the x-ray structure of the N-terminal CUB1-epidermal growth factor (EGF) C1s segment has led to a model of the C1q/C1s-C1r-C1r-C1s interaction where the C1q collagen stem binds at the C1r/C1s interface through ionic bonds involving acidic residues contributed by the C1r EGF module (Gregory, L. A., Thielens, N. M., Arlaud, G. J., Fontecilla-Camps, J. C., and Gaboriaud, C. (2003) J. Biol. Chem. 278, 32157–32164). To identify the C1q-binding sites of C1s-C1r-C1r-C1s, a series of C1r and C1s mutants was expressed, and the C1q binding ability of the resulting tetramer variants was assessed by surface plasmon resonance. Mutations targeting the Glu137-Glu-Asp139 stretch in the C1r EGF module had no effect on C1 assembly, ruling out our previous interaction model. Additional mutations targeting residues expected to participate in the Ca2+-binding sites of the C1r and C1s CUB modules provided evidence for high affinity C1q-binding sites contributed by the C1r CUB1 and CUB2 modules and lower affinity sites contributed by C1s CUB1. All of the sites implicate acidic residues also contributing Ca2+ ligands. C1s-C1r-C1r-C1s thus contributes six C1q-binding sites, one per C1q stem. Based on the location of these sites and available structural information, we propose a refined model of C1 assembly where the CUB1-EGF-CUB2 interaction domains of C1r and C1s are entirely clustered inside C1q and interact through six binding sites with reactive lysines of the C1q stems. This mechanism is similar to that demonstrated for mannan-binding lectin (MBL)-MBL-associated serine protease and ficolin-MBL-associated serine protease complexes.The classical pathway of complement, a major component of innate immune defense against pathogens and altered self, is triggered by C1, a 790-kDa Ca2+-dependent complex assembled from a recognition protein C1q and C1s-C1r-C1r-C1s, a tetramer of two modular proteases, C1r and C1s, that respectively mediate activation and proteolytic activity of the complex (1–3). C1q has the overall shape of a bunch of tulips and comprises six heterotrimeric collagen-like triple helices that assemble through their N-terminal moieties to form a “stalk” and then diverge to form individual “stems,” each prolonged by a C-terminal globular recognition domain (4). C1r and C1s are homologous modular proteases each comprising, starting from the N-terminal end, a C1r/C1s, sea urchin EGF2 (uEGF), bone morphogenetic protein (CUB) module (5), an EGF-like module (6), a second CUB module, two complement control protein modules (7), and a serine protease domain. This modular structure is shared by the mannan-binding lectin-associated serine proteases (MASPs), a group of enzymes that associate with mannan-binding lectin (MBL) and the ficolins and thereby trigger activation of the lectin pathway of complement (8).Assembly of the C1s-C1r-C1r-C1s tetramer involves Ca2+-dependent heterodimeric C1r-C1s interactions between the CUB1-EGF segments of each protease (9–12). Similarly, MASP-1, MASP-2, MASP-3, and mannan-binding lectin-associated protein 19 (MAp19), an alternative splicing product of the MASP-2 gene comprising the N-terminal CUB1-EGF segment of MASP-2, all associate as homodimers through their N-terminal CUB1-EGF moieties (13–15). The structures of human C1s CUB1-EGF, human MAp19, human MASP-1/3 CUB1-EGF-CUB2, and rat MASP-2 CUB1-EGF-CUB2 have been solved by x-ray crystallography (16–19), revealing that these domains all associate as head-to-tail homodimers through a highly conserved interface involving interactions between the CUB1 module of one monomer and the EGF module of its counterpart. In addition, all CUB modules contained in these structures were found to contain a hitherto unrecognized Ca2+-binding site involving three conserved acidic residues (Glu45, Asp53, and Asp98 in C1s), defining a novel CUB module subset diverging from the type originally described in the spermadhesins (20).Mutagenesis studies have recently established that assembly of the MBL- and ficolin-MASP complexes involves a major electrostatic interaction between two acidic Ca2+ ligands from the MASP CUB modules and a conserved lysine located in the collagen fibers of MBL and ficolins (16, 18, 21, 22). In the case of C1, a hypothetical model of the C1q/C1r/C1s interface, involving interaction between acidic residues mainly contributed by the C1r EGF module and unmodified lysine residues also located in the collagen-like stems of C1q, was derived from the x-ray structure of the C1s CUB1-EGF interaction domain (16, 23). The aim of this work was to use site-directed mutagenesis to delineate the sites of C1r and C1s involved in the interaction between C1s-C1r-C1r-C1s and C1q. Our data rule out our previous interaction model and provide evidence that C1 assembly involves the same basic Ca2+-dependent mechanism as demonstrated in the case of MBL-MASP and ficolin-MASP complexes. 相似文献
998.
Human glioma cell culture: two FCS-free media could be recommended for clinical use in immunotherapy
Anne Clavreul Isabelle Jean Laurence Preisser Agnès Chassevent Anne Sapin Sophie Michalak Philippe Menei 《In vitro cellular & developmental biology. Animal》2009,45(9):500-511
Immunotherapy, particularly active vaccination, may be developed as an effective and safe treatment modality for malignant
gliomas, which continue to have a poor prognosis, despite advances in surgical techniques and adjuvant chemotherapy and radiotherapy.
Since no glioma-specific tumor-associated antigens (TAAs) have been discovered, autologous tumor cells or well-established
glioma cell lines could be used in future vaccination protocols to induce antitumour immunity against unknown TAAs. One obstacle
for clinical use of these tumour cell vaccines is related to foetal calf serum (FCS). Efforts are currently being directed
toward developing FCS-free media and serum-free alternatives to culture these cell vaccines. In this study, a medium containing
human serum and one serum-free medium (UltraCulture), supplemented or not with epidermal growth factor, were tested on morphology,
survival, DNA content and TAA expression of human glioma cell lines and glioma biopsy primary cultures. Their effects were
compared on FCS-containing medium. Results show that, whatever the medium used, no significant variations in morphology and
survival were observed. Furthermore, human serum-containing medium or UltraCulture preserved at early passage cultures the
cell population of interest present in the biopsies before culture. In addition, the expression profile of eight TAAs was
similar between these media. These data indicate that human serum-containing medium and UltraCulture serum-free medium could
be promising candidates to produce tumour-cell vaccines. 相似文献
999.
Peter R. Teske Colin L. McLay Jonathan Sandoval-Castillo Isabelle Papadopoulos Brent K. Newman Charles L. Griffiths Christopher D. McQuaid Nigel P. Barker Gaetan Borgonie Luciano B. Beheregaray 《Molecular phylogenetics and evolution》2009,53(1):23-33
Crabs of the family Hymenosomatidae are common in coastal and shelf regions throughout much of the southern hemisphere. One of the genera in the family, Hymenosoma, is represented in Africa and the South Pacific (Australia and New Zealand). This distribution can be explained either by vicariance (presence of the genus on the Gondwanan supercontinent and divergence following its break-up) or more recent transoceanic dispersal from one region to the other. We tested these hypotheses by reconstructing phylogenetic relationships among the seven presently-accepted species in the genus, as well as examining their placement among other hymenosomatid crabs, using sequence data from two nuclear markers (Adenine Nucleotide Transporter [ANT] exon 2 and 18S rDNA) and three mitochondrial markers (COI, 12S and 16S rDNA). The five southern African representatives of the genus were recovered as a monophyletic lineage, and another southern African species, Neorhynchoplax bovis, was identified as their sister taxon. The two species of Hymenosoma from the South Pacific neither clustered with their African congeners, nor with each other, and should therefore both be placed into different genera. Molecular dating supports a post-Gondwanan origin of the Hymenosomatidae. While long-distance dispersal cannot be ruled out to explain the presence of the family Hymenosomatidae on the former Gondwanan land-masses and beyond, the evolutionary history of the African species of Hymenosoma indicates that a third means of speciation may be important in this group: gradual along-coast dispersal from tropical towards temperate regions, with range expansions into formerly inhospitable habitat during warm climatic phases, followed by adaptation and speciation during subsequent cooler phases. 相似文献
1000.
Isabelle Roszko Atsushi Sawada Lilianna Solnica-Krezel 《Seminars in cell & developmental biology》2009,20(8):986-997
Vertebrate gastrulation entails massive cell movements that establish and shape the germ layers. During gastrulation, the individual cell behaviors are strictly coordinated in time and space by various signaling pathways. These pathways instruct the cells about proliferation, shape, fate and migration into proper location. Convergence and extension (C&E) movements during vertebrate gastrulation play a major role in the shaping of the embryonic body. In vertebrates, the Wnt/Planar Cell Polarity (Wnt/PCP) pathway is a key regulator of C&E movements, essential for several polarized cell behaviors, including directed cell migration, and mediolateral and radial cell intercalation. However, the molecular mechanisms underlying the acquisition of Planar Cell Polarity by highly dynamic mesenchymal cells engaged in C&E are still not well understood. Here we review new evidence implicating the Wnt/PCP pathway in specific cell behaviors required for C&E during zebrafish gastrulation, in comparison to other vertebrates. We also discuss findings on the molecular regulation and the interaction of the Wnt/PCP pathway with other signaling pathways during gastrulation movements. 相似文献