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91.
Leblond CS Heinrich J Delorme R Proepper C Betancur C Huguet G Konyukh M Chaste P Ey E Rastam M Anckarsäter H Nygren G Gillberg IC Melke J Toro R Regnault B Fauchereau F Mercati O Lemière N Skuse D Poot M Holt R Monaco AP Järvelä I Kantojärvi K Vanhala R Curran S Collier DA Bolton P Chiocchetti A Klauck SM Poustka F Freitag CM Waltes R Kopp M Duketis E Bacchelli E Minopoli F Ruta L Battaglia A Mazzone L Maestrini E Sequeira AF Oliveira B Vicente A Oliveira G Pinto D Scherer SW Zelenika D 《PLoS genetics》2012,8(2):e1002521
Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23–4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11–q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the “multiple hit model” for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD. 相似文献
92.
E Lohou J Sopkova-de Oliveira Santos P Schumann-Bard M Boulouard S Stiebing S Rault V Collot 《Bioorganic & medicinal chemistry》2012,20(17):5296-5304
Taking into account the potency of 4- and 7-nitro and haloindazoles as nNOS inhibitors previously reported in the literature by our team, a multidisciplinary study, described in this article, has recently been carried out to elucidate their binding mode in the enzyme active site. Firstly, nitrogenous fastening points on the indazole building block have been investigated referring to molecular modeling hypotheses and thanks to the in vitro biological evaluation of N(1)- and N(2)-methyl and ethyl-4-substituted indazoles on nNOS. Secondly, we attempted to confirm the importance of the substitution in position 4 or 7 by a hydrogen bond acceptor group thanks to the synthesis and the in vitro biological evaluation of a new analogous 4-substituted derivative, the 4-cyanoindazole. Finally, by opposition to previous hypotheses describing NH function in position 1 of the indazole as a key fastening point, the present work speaks in favour of a crucial role of nitrogen in position 2. 相似文献
93.
Arash Rafii Pejman Mirshahi Mary Poupot Anne-Marie Faussat Anne Simon Elodie Ducros Eliane Mery Bettina Couderc Raphael Lis Jerome Capdet Julie Bergalet Denis Querleu Francoise Dagonnet Jean-Jacques Fournié Jean-Pierre Marie Eric Pujade-Lauraine Gilles Favre Jeanine Soria Massoud Mirshahi 《PloS one》2008,3(12)
Background
The microenvironment plays a major role in the onset and progression of metastasis. Epithelial ovarian cancer (EOC) tends to metastasize to the peritoneal cavity where interactions within the microenvironment might lead to chemoresistance. Mesothelial cells are important actors of the peritoneal homeostasis; we determined their role in the acquisition of chemoresistance of ovarian tumours.Methodology/Principal Findings
We isolated an original type of stromal cells, referred to as “Hospicells” from ascitis of patients with ovarian carcinosis using limiting dilution. We studied their ability to confer chemoresistance through heterocellular interactions. These stromal cells displayed a new phenotype with positive immunostaining for CD9, CD10, CD29, CD146, CD166 and Multi drug resistance protein. They preferentially interacted with epithelial ovarian cancer cells. This interaction induced chemoresistance to platin and taxans with the implication of multi-drug resistance proteins. This contact enabled EOC cells to capture patches of the Hospicells membrane through oncologic trogocytosis, therefore acquiring their functional P-gp proteins and thus developing chemoresistance. Presence of Hospicells on ovarian cancer tissue micro-array from patients with neo-adjuvant chemotherapy was also significantly associated to chemoresistance.Conclusions/Significance
This is the first report of trogocytosis occurring between a cancer cell and an original type of stromal cell. This interaction induced autonomous acquisition of chemoresistance. The presence of stromal cells within patient''s tumour might be predictive of chemoresistance. The specific interaction between cancer cells and stromal cells might be targeted during chemotherapy. 相似文献94.
The HIV-1 envelope glycoprotein gp120 features four heparan sulfate binding domains, including the co-receptor binding site 总被引:1,自引:0,他引:1
Crublet E Andrieu JP Vivès RR Lortat-Jacob H 《The Journal of biological chemistry》2008,283(22):15193-15200
It is well established that the human immunodeficiency virus-1 envelope glycoprotein surface unit, gp120, binds to cell-associated heparan sulfate (HS). Virus infectivity is increased by such interaction, and a variety of soluble polyanions efficiently neutralize immunodeficiency virus-1 in vitro. This interaction has been mainly attributed to the gp120 V3 loop. However, although evidence suggested that this particular domain does not fully recapitulate the binding activity of the protein, the ability of HS to bind to other regions of gp120 has not been completely addressed, and the exact localizations of the polysaccharide binding sites are not known. To investigate in more detail the structural basis of the HS-gp120 interaction, we used a mapping strategy and compared the heparin binding activity of wild type and mutant gp120 using surface plasmon resonance-based binding assays. Four heparin binding domains (1-4) were identified in the V2 and V3 loops, in the C-terminal domain, and within the CD4-induced bridging sheet. Interestingly, three of them were found in domains of the protein that undergo structural changes upon binding to CD4 and are involved in co-receptor recognition. In particular, Arg(419), Lys(421), and Lys(432), which directly interact with the co-receptor, are targeted by heparin. This study provides a complete account of the gp120 residues involved in heparin binding and identified several binding surfaces that constitute potential target for viral entry inhibition. 相似文献
95.
Vappou J Breton E Choquet P Willinger R Constantinesco A 《Journal of biomechanics》2008,41(14):2954-2959
The knowledge of in vivo brain tissue mechanical properties is essential in several biomedical engineering fields, such as injury biomechanics and neurosurgery simulation. Almost all existing available data have been obtained in vitro by invasive experimental protocols. However, the difference between in vivo and post-mortem mechanical properties remains poorly known, essentially due to the lack of a common method that could measure them both in vivo and ex vivo. In this study, we report the use of magnetic resonance elastography (MRE) for the non-invasive assessment of in vivo brain tissue viscoelastic properties and for the investigation of their evolution after the death. Experiments were performed on seven adult male rats. Shear storage and loss moduli were measured in vivo, just after death and at post-mortem time of approximately 24h. A significant increase in shear storage modulus G(') of approximately 100% was found to occur just after death (p=0.002), whereas no significant difference was found between in vivoG(') and G(') at 24h post-mortem time. No significant difference was found between shear loss modulus G(')in vivo and just after death, whereas a decrease of about 50% was found to occur after 24h (p=0.02). These results illustrate the ability of MRE to investigate some of the critical soft tissue biomechanics-related issues, as it can be used as a non-invasive tool for measuring soft tissue viscoelastic properties. 相似文献
96.
Insights into the binding and activation sites of the receptors for cholecystokinin and gastrin 总被引:1,自引:0,他引:1
Foucaud M Archer-Lahlou E Marco E Tikhonova IG Maigret B Escrieut C Langer I Fourmy D 《Regulatory peptides》2008,145(1-3):17-23
CCK receptors represent potential targets in a number of diseases. Knowledge of CCK receptor binding sites is a prerequisite for the understanding of the molecular basis for their ligand recognition, partial agonism, ligand-induced trafficking of signalling. In the current paper, we report studies from our laboratory and others which have provided new data on the molecular basis of the pharmacology and functioning of CCK1 and CCK2 receptors. It has been shown that: 1) homologous regions of the two receptors are involved in the binding site of CCK, however, positioning of CCK slightly differs in agreement with distinct pharmacophores of CCK toward the two receptors and receptor sequence variations; 2) Binding sites of most of non-peptide agonists/ antagonist are buried in the pocket formed by transmembrane helices and overlap that of CCK; Aromatic amino acids within and near the binding site, especially in helix VI, are involved in receptor activation; 4) Like for other members of family A of G-protein coupled receptors, residues of the binding sites as well as of conserved motifs such as E/DRY, NPXXY are crucial for receptor activation. 相似文献
97.
Microchemical imaging of iodine distribution in the brown alga Laminaria digitata suggests a new mechanism for its accumulation 总被引:2,自引:0,他引:2
Elodie Françoise Verhaeghe Aurélien Fraysse Jean-Luc Guerquin-Kern Ting-Di Wu Guillaume Devès Charles Mioskowski Catherine Leblanc Richard Ortega Yves Ambroise Philippe Potin 《Journal of biological inorganic chemistry》2008,13(2):257-269
Brown algal kelp species are the most efficient iodine accumulators among all living systems, with an average content of 1.0%
of dry weight in Laminaria digitata. The iodine distributions in stipe and blade sections from L. digitata were investigated at tissue and subcellular levels. The quantitative tissue mapping of iodine and other trace elements (Cl,
K, Ca, Fe, Zn, As and Br) was provided by the proton microprobe with spatial resolutions down to 2 μm. Chemical imaging at
a subcellular resolution (below 100 nm) was performed using the secondary ion mass spectrometry microprobe. Sets of samples
were prepared by both chemical fixation and cryofixation procedures. The latter prevented the diffusion and the leaching of
labile inorganic iodine species, which were estimated at around 95% of the total content by neutron activation analysis. The
distribution of iodine clearly shows a huge, decreasing gradient from the meristoderm to the medulla. The contents of iodine
reach very high levels in the more external cell layers, up to 191 ± 5 mg g−1 of dry weight in stipe sections. The peripheral tissue is consequently the main storage compartment of iodine. At the subcellular
level, iodine is mainly stored in the apoplasm and not in an intracellular compartment as previously proposed. This unexpected
distribution may provide an abundant and accessible source of labile iodine species which can be easily remobilized for potential
chemical defense and antioxidative activities. According to these imaging data, we proposed new hypotheses for the mechanism
of iodine storage in L. digitata tissues.
In memory of Dr. Charles Mioskowski, “Miko,” who died on 2 June 2007. 相似文献
98.
99.
Contribution of the β‐glucosidase BglC to the onset of the pathogenic lifestyle of Streptomyces scabies 下载免费PDF全文