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961.
Mutations conferring resistance to neutralization by a soluble form of the neurotrophin receptor (p75NTR) map outside of the known antigenic sites of the rabies virus glycoprotein 下载免费PDF全文
The neurotrophin receptor (p75NTR) serves as a receptor for rabies virus (RV). We expressed and purified a soluble chimera consisting of the p75NTR ectodomain fused to the human immunoglobulin G1 (IgG1) Fc fragment (p75-Fc). Although p75-Fc interacts with RV, the infectivity of RV did not decrease significantly when it was incubated in the presence of the soluble receptor alone. However, when it was subsequently incubated with an antihuman IgG directed against the Fc fragment of p75-Fc, the infectivity of RV was significantly lowered (>90%), whereas incubation with antihuman IgG alone had no effect. We then selected eight independent RV mutants that were not neutralized by p75-Fc and antihuman IgG (srr [soluble receptor resistant] mutants). Each mutant carried a single mutation in the glycoprotein gene leading to one amino acid substitution in the protein. A total of four different substitutions were found. Two of the mutations were located at position 318 (phenylalanine replaced by a serine or a valine residue), and two were located at position 352 (histidine replaced by a tyrosine or an arginine residue). All of the mutations prevented the interaction with p75NTR as either a soluble or a membrane-anchored form. Two mutants (F318S) and (H352R) resulted in the formation of small plaques on BSR cells, probably due to the slower maturation of the glycoprotein. Immunoprecipitation, immunofluorescence, and neutralization assays showed that the four mutated glycoproteins still interacted with representative anti-RV glycoprotein monoclonal antibodies (MAbs), indicating that p75NTR binds outside of the known RV glycoprotein antigenic sites. 相似文献
962.
Machouart-Dubach M Lacroix C Vaury C Feuilhade de Chauvin M Bellanné C Derouin F Lorenzo F 《FEMS microbiology letters》2002,208(2):187-196
The molds Scytalidium dimidiatum (Nattrassia mangiferae synanamorph) and Scytalidium hyalinum are responsible for dermatomycosis in humans. We sequenced their 18S subunit ribosomal RNA gene to identify these species with molecular biology-based methods. The coding sequences differed by a single polymorphism (A in S. dimidiatum, G in S. hyalinum). Moreover, we found an insert at position 1199 in the 18S rRNA gene sequence of S. dimidiatum. Its potential secondary structure was characteristic of a group IE intron. Bioinformatic and phylogenic group IE intron analyses generated four main homogeneous clusters. The S. dimidiatum intron is original and not related with other known IE group introns. 相似文献
963.
Allaman-Pillet N Størling J Oberson A Roduit R Negri S Sauser C Nicod P Beckmann JS Schorderet DF Mandrup-Poulsen T Bonny C 《The Journal of biological chemistry》2003,278(49):48720-48726
In models of type 1 diabetes, cytokines induce pancreatic beta-cell death by apoptosis. This process seems to be facilitated by a reduction in the amount of the islet-brain 1/JNK interacting protein 1 (IB1/JIP1), a JNK-scaffold with an anti-apoptotic effect. A point mutation S59N at the N terminus of the scaffold, which segregates in diabetic patients, has the functional consequence of sensitizing cells to apoptotic stimuli. Neither the mechanisms leading to IB1/JIP1 down-regulation by cytokines nor the mechanisms leading to the decreased capacity of the S59N mutation to protect cells from apoptosis are understood. Here, we show that IB1/JIP1 stability is modulated by intracellular calcium. The effect of calcium depends upon JNK activation, which primes the scaffold for ubiquitination-mediated degradation via the proteasome machinery. Furthermore, we observe that the S59N mutation decreases IB1/JIP1 stability by sensitizing IB1/JIP1 to calcium- and proteasome-dependent degradation. These data indicate that calcium influx initiated by cytokines mediates ubiquitination and degradation of IB1/JIP1 and may, therefore, provide a link between calcium influx and JNK-mediated apoptosis in pancreatic beta-cells. 相似文献
964.
Characterisation of cellular adhesion reinforcement by multiple bond force spectroscopy in alveolar epithelial cells 下载免费PDF全文
965.
Effect of adiponectin on bovine granulosa cell steroidogenesis,oocyte maturation and embryo development 总被引:1,自引:0,他引:1
Virginie Maillard Svetlana Uzbekova Florence Guignot Christine Perreau Christelle Ramé Stéphanie Coyral-Castel Joëlle Dupont 《Reproductive biology and endocrinology : RB&E》2010,8(1):23
Background
Adiponectin is an adipokine, mainly produced by adipose tissue. It regulates several reproductive processes. The protein expression of the adiponectin system (adiponectin, its receptors, AdipoR1 and AdipoR2 and the APPL1 adaptor) in bovine ovary and its role on ovarian cells and embryo, remain however to be determined. 相似文献966.
Pierre Sarradin Céline Viglietta Claude Limouzin Olivier Andréoletti Nathalie Daniel-Carlier Céline Barc Mathieu Leroux-Coyau Patricia Berthon Jér?me Chapuis Christelle Rossignol Jean-Luc Gatti Maya Belghazi Valérie Labas Jean-Luc Vilotte Vincent Béringue Frédéric Lantier Hubert Laude Louis-Marie Houdebine 《PLoS pathogens》2015,11(8)
Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases affecting a wide range of mammalian species. They are caused by prions, a proteinaceous pathogen essentially composed of PrPSc, an abnormal isoform of the host encoded cellular prion protein PrPC. Constrained steric interactions between PrPSc and PrPC are thought to provide prions with species specificity, and to control cross-species transmission into other host populations, including humans. Transgenetic expression of foreign PrP genes has been successfully and widely used to overcome the recognized resistance of mouse to foreign TSE sources. Rabbit is one of the species that exhibit a pronounced resistance to TSEs. Most attempts to infect experimentally rabbit have failed, except after inoculation with cell-free generated rabbit prions. To gain insights on the molecular determinants of the relative resistance of rabbits to prions, we generated transgenic rabbits expressing the susceptible V136R154Q171 allele of the ovine PRNP gene on a rabbit wild type PRNP New Zealand background and assessed their experimental susceptibility to scrapie prions. All transgenic animals developed a typical TSE 6–8 months after intracerebral inoculation, whereas wild type rabbits remained healthy more than 700 days after inoculation. Despite the endogenous presence of rabbit PrPC, only ovine PrPSc was detectable in the brains of diseased animals. Collectively these data indicate that the low susceptibility of rabbits to prion infection is not enciphered within their non-PrP genetic background. 相似文献
967.
Audrey Maillet Alexandre Krainik Bettina Deb? Irène Troprès Christelle Lagrange Stéphane Thobois Pierre Pollak Serge Pinto 《PloS one》2012,7(10)
Levodopa (L-dopa) effects on the cardinal and axial symptoms of Parkinson’s disease (PD) differ greatly, leading to therapeutic challenges for managing the disabilities in this patient’s population. In this context, we studied the cerebral networks associated with the production of a unilateral hand movement, speech production, and a task combining both tasks in 12 individuals with PD, both off and on levodopa (L-dopa). Unilateral hand movements in the off medication state elicited brain activations in motor regions (primary motor cortex, supplementary motor area, premotor cortex, cerebellum), as well as additional areas (anterior cingulate, putamen, associative parietal areas); following L-dopa administration, the brain activation profile was globally reduced, highlighting activations in the parietal and posterior cingulate cortices. For the speech production task, brain activation patterns were similar with and without medication, including the orofacial primary motor cortex (M1), the primary somatosensory cortex and the cerebellar hemispheres bilaterally, as well as the left- premotor, anterior cingulate and supramarginal cortices. For the combined task off L-dopa, the cerebral activation profile was restricted to the right cerebellum (hand movement), reflecting the difficulty in performing two movements simultaneously in PD. Under L-dopa, the brain activation profile of the combined task involved a larger pattern, including additional fronto-parietal activations, without reaching the sum of the areas activated during the simple hand and speech tasks separately. Our results question both the role of the basal ganglia system in speech production and the modulation of task-dependent cerebral networks by dopaminergic treatment. 相似文献
968.
Mutations in MDH2, Encoding a Krebs Cycle Enzyme,Cause Early-Onset Severe Encephalopathy 总被引:1,自引:0,他引:1
Samira Ait-El-Mkadem Manal Dayem-Quere Mirjana Gusic Annabelle Chaussenot Sylvie Bannwarth Bérengère François Emmanuelle C. Genin Konstantina Fragaki Catharina L.M. Volker-Touw Christelle Vasnier Valérie Serre Koen L.I. van Gassen Françoise Lespinasse Susan Richter Graeme Eisenhofer Cécile Rouzier Fanny Mochel Anne De Saint-Martin Véronique Paquis-Flucklinger 《American journal of human genetics》2017,100(1):151-159
969.