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101.
Valsecchi Elena Coppola Emanuele Pires Rosa Parmegiani Andrea Casiraghi Maurizio Galli Paolo Bruno Antonia 《Biodiversity and Conservation》2022,31(4):1175-1196
Biodiversity and Conservation - The monk seal is the most endangered pinniped worldwide and the only one found in the Mediterranean, where its distribution and abundance have suffered a drastic... 相似文献
102.
Divisome‐dependent subcellular localization of cell–cell joining protein SepJ in the filamentous cyanobacterium Anabaena 下载免费PDF全文
Félix Ramos‐León Vicente Mariscal José E. Frías Enrique Flores Antonia Herrero 《Molecular microbiology》2015,96(3):566-580
Heterocyst‐forming cyanobacteria are multicellular organisms that grow as filaments that can be hundreds of cells long. Septal junction complexes, of which SepJ is a possible component, appear to join the cells in the filament. SepJ is a cytoplasmic membrane protein that contains a long predicted periplasmic section and localizes not only to the cell poles in the intercellular septa but also to a position similar to a Z ring when cell division starts suggesting a relation with the divisome. Here, we created a mutant of Anabaena sp. strain PCC 7120 in which the essential divisome gene ftsZ is expressed from a synthetic NtcA‐dependent promoter, whose activity depends on the nitrogen source. In the presence of ammonium, low levels of FtsZ were produced, and the subcellular localization of SepJ, which was investigated by immunofluorescence, was impaired. Possible interactions of SepJ with itself and with divisome proteins FtsZ, FtsQ and FtsW were investigated using the bacterial two‐hybrid system. We found SepJ self‐interaction and a specific interaction with FtsQ, confirmed by co‐purification and involving parts of the SepJ and FtsQ periplasmic sections. Therefore, SepJ can form multimers, and in Anabaena, the divisome has a role beyond cell division, localizing a septal protein essential for multicellularity. 相似文献
103.
Noelia Inés Burgardt Andreas Schmidt Annika Manns Alexandra Schutkowski Günther Jahreis Yi-Jan Lin Bianca Schulze Antonia Masch Christian Lücke Matthias Weiwad 《The Journal of biological chemistry》2015,290(27):16708-16722
Recently we have shown that the peptidyl-prolyl cis/trans isomerase parvulin 17 (Par17) interacts with tubulin in a GTP-dependent manner, thereby promoting the formation of microtubules. Microtubule assembly is regulated by Ca2+-loaded calmodulin (Ca2+/CaM) both in the intact cell and under in vitro conditions via direct interaction with microtubule-associated proteins. Here we provide the first evidence that Ca2+/CaM interacts also with Par17 in a physiologically relevant way, thus preventing Par17-promoted microtubule assembly. In contrast, parvulin 14 (Par14), which lacks only the first 25 N-terminal residues of the Par17 sequence, does not interact with Ca2+/CaM, indicating that this interaction is exclusive for Par17. Pulldown experiments and chemical shift perturbation analysis with 15N-labeled Par17 furthermore confirmed that calmodulin (CaM) interacts in a Ca2+-dependent manner with the Par17 N terminus. The reverse experiment with 15N-labeled Ca2+/CaM demonstrated that the N-terminal Par17 segment binds to both CaM lobes simultaneously, indicating that Ca2+/CaM undergoes a conformational change to form a binding channel between its two lobes, apparently similar to the structure of the CaM-smMLCK796–815 complex. In vitro tubulin polymerization assays furthermore showed that Ca2+/CaM completely suppresses Par17-promoted microtubule assembly. The results imply that Ca2+/CaM binding to the N-terminal segment of Par17 causes steric hindrance of the Par17 active site, thus interfering with the Par17/tubulin interaction. This Ca2+/CaM-mediated control of Par17-assisted microtubule assembly may provide a mechanism that couples Ca2+ signaling with microtubule function. 相似文献
104.
Alfano C Viola L Heng JI Pirozzi M Clarkson M Flore G De Maio A Schedl A Guillemot F Studer M 《Development (Cambridge, England)》2011,138(21):4685-4697
During corticogenesis, late-born callosal projection neurons (CPNs) acquire their laminar position through glia-guided radial migration and then undergo final differentiation. However, the mechanisms controlling radial migration and final morphology of CPNs are poorly defined. Here, we show that in COUP-TFI mutant mice CPNs are correctly specified, but are delayed in reaching the cortical plate and have morphological defects during migration. Interestingly, we observed that the rate of neuronal migration to the cortical plate normally follows a low-rostral to high-caudal gradient, similar to that described for COUP-TFI. This gradient is strongly impaired in COUP-TFI(-/-) brains. Moreover, the expression of the Rho-GTPase Rnd2, a modulator of radial migration, is complementary to both these gradients and strongly increases in the absence of COUP-TFI function. We show that COUP-TFI directly represses Rnd2 expression at the post-mitotic level along the rostrocaudal axis of the neocortex. Restoring correct Rnd2 levels in COUP-TFI(-/-) brains cell-autonomously rescues neuron radial migration and morphological transitions. We also observed impairments in axonal elongation and dendritic arborization of COUP-TFI-deficient CPNs, which were rescued by lowering Rnd2 expression levels. Thus, our data demonstrate that COUP-TFI modulates late-born neuron migration and favours proper differentiation of CPNs by finely regulating Rnd2 expression levels. 相似文献
105.
Merino-Puerto V Schwarz H Maldener I Mariscal V Mullineaux CW Herrero A Flores E 《Molecular microbiology》2011,82(1):87-98
The filamentous, heterocyst‐forming cyanobacteria are multicellular organisms in which two different cell types, the CO2‐fixing vegetative cells and the N2‐fixing heterocysts, exchange nutrients and regulators. In Anabaena sp. strain PCC 7120, inactivation of sepJ or genes in the fraC operon (fraC, fraD and fraE) produce filament fragmentation. SepJ, FraC and FraD are cytoplasmic membrane proteins located in the filament's intercellular septa that are needed for intercellular exchange of the fluorescent tracer calcein (622 Da). Transmission electron microscopy showed an alteration in the heterocyst cytoplasmic membrane at the vegetative cell‐heterocyst septa in ΔfraC and ΔfraD mutants. Immunogold labelling of FraD confirmed its localization in the intercellular septa and clearly showed the presence of part of the protein between the cytoplasmic membranes of the adjacent cells. This localization seemed to be affected in the ΔfraC mutant but was not impaired in a ΔsepJ mutant. Intercellular transfer of a smaller fluorescent tracer, 5‐carboxyfluorescein (374 Da), was largely impaired in ΔfraC, ΔfraD and double ΔfraC‐ΔfraD mutants, but much less in the ΔsepJ mutant. These results show the existence in the Anabaena filaments of a FraC/FraD‐dependent intercellular molecular exchange that does not require SepJ. 相似文献
106.
Zapf CW Bloom JD Li Z Dushin RG Nittoli T Otteng M Nikitenko A Golas JM Liu H Lucas J Boschelli F Vogan E Olland A Johnson M Levin JI 《Bioorganic & medicinal chemistry letters》2011,21(15):4602-4607
An extension of our previously reported series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. Addition of a second methyl group to the tether provided analogs that show increased potency in binding as well as cell-proliferation assays and, more importantly, are stable toward microsomes. We wish to disclose the discovery of a macrocycle which showed impressive biomarker activity 24-h post dosing and which demonstrated prolonged exposure in tumors. When studied in a lung cancer xenograft model, the compound demonstrated significant tumor size reduction. 相似文献
107.
Microautophagy of cytosolic proteins by late endosomes 总被引:2,自引:0,他引:2
Sahu R Kaushik S Clement CC Cannizzo ES Scharf B Follenzi A Potolicchio I Nieves E Cuervo AM Santambrogio L 《Developmental cell》2011,20(1):131-139
Highlights? Late endosomes take up cytosolic proteins through membrane invaginations ? Endosomal microautophagy (eMI) requires multivesicular body formation ? hsc70 mediates selective targeting of cytosolic proteins during eMI ? hsc70 binds to the endosomal membrane through its polybasic cluster 相似文献
108.
George S. Mahuku María Antonia Henríquez Carmenza Montoya Carlos Jara Henry Teran Stephen Beebe 《Molecular breeding : new strategies in plant improvement》2011,28(1):57-71
Angular leaf spot (ALS) is one of the major diseases of the common bean (Phaseolus vulgaris L.). Different sources of resistance have been identified but few have been characterized. Studies were conducted to elucidate
the inheritance of ALS resistance in the bean accession G10909 and to identify molecular markers linked to these genes. Evaluation
of parental genotypes, F1, F2 and backcross to susceptible parent (Sprite) populations revealed that two dominant and complementary genes conditioned ALS
resistance. Allelism tests showed that the ALS resistance genes in G10909 were different from those in the Mesoamerican cultivars
Mexico 54, MAR 2, G10474 and Cornell 49-242. Three sequence-characterized amplified region (SCAR) markers, PF13310, PF9260 and OPE04709, and a microsatellite, Pv-gaat001, segregated in coupling with the resistance genes in G10909. Pairwise segregation analysis
revealed that markers PF13310, PF9260 and OPE04709 were linked, while Pv-gaat001 segregated in a 9:3:3:1 ratio from all markers. Markers PF13310, PF9260 and OPE04709 were mapped to linkage group B08, and segregated with resistance gene Phg
G10909B
at 4.9, 7.4 and 9.9 cM, respectively. Pv-gaat001, previously mapped to linkage group B04, segregated with resistance gene
Phg
G10909A
at 13 cM. The potential utility of these markers to aid breeding for ALS resistance is discussed. 相似文献
109.
Rama AR Prados J Melguizo C Alvarez PJ Ortiz R Madeddu R Aranega A 《Bioengineered bugs》2011,2(3):163-167
The limited ability of conventional therapies to achieve the long-term survival of metastatic lung and colon cancer patients suggests the need for new treatment options. In this respect, genes encoding cytotoxic proteins have been proposed as a new strategy to enhance the activity of drugs, and combined therapies involving such genes and classical antitumoral drugs have been studied intensively. The E gene from phiX174 encodes a membrane protein with a toxic domain that leads to a decrease in tumour cell growth rates. Therefore, in order to improve the anti-tumour effects of currently used chemotherapeutic drugs on cancer cells, we investigated the association of the E suicide gene with these antineoplastic drugs. The E gene has antitumoral effects in both lung and colon cancer cells. In addition, expression of this gene induces ultrastructural changes in lung cancer transfected cells (A-549), although the significance of these changes remains unknown. The effect of combined therapy (gene and cytotoxic therapy) enhances the inhibition of tumour cell proliferation in comparison to single treatments. Indeed, our in vitro results indicate that an experimental therapeutic strategy based on this combination of E gene therapy and cytotoxic drugs may result in a new treatment strategy for patients with advanced lung and colon cancer. 相似文献
110.
Noll GA Müller B Ernst AM Rüping B Groscurth S Twyman RM Kawchuk LM Prüfer D 《Bioengineered bugs》2011,2(2):111-114
Forisomes are protein bodies found exclusively in the phloem of the Fabaceae (legumes). In response to wounding, the influx of Ca ( 2+) induces a conformational change from a condensed to a dispersed state which plugs the sieve tubes and prevents the loss of photoassimilates. This reversible, ATP-independent reaction can be replicated with purified forisomes in vitro by adding divalent cations or electrically inducing changes in pH, making forisomes ideal components of technical devices. Although native forisomes comprise several subunits, we recently showed that functional homomeric forisomes with distinct properties can be expressed in plants and yeast, providing an abundant supply of forisomes with tailored properties. Forisome subunits MtSEO-F1 and MtSEO-F4 can each assemble into homomeric artificial forisomes, which indicates functional redundancy. However, we provide further evidence that both proteins are subunits of the native heteromeric forisome body in planta. We also show that the properties of artificial forisomes can be modified by immobilization, which is a prerequisite for their incorporation into technical devices. 相似文献