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931.
Regardless of the importance of bacterial assemblages as essential components of ecosystems, little is known about how their populations are structured. We analyzed the composition and turnover rates, based on 16S rDNA sequences, of surface water oceanic bacterial assemblages of the fraction between 0.1 and 0.8 μm along a latitudinal gradient (45°6′42′′N in the North Atlantic to 15°8′37′′S in the South Pacific) including geographic distance, temperature, chlorophyll a and salinity. Here we show that oceanic bacterial assemblages between 0.1 and 0.8 μm, can be structured by a variety of environmental interactions that include separation by distance and chlorophyll a concentration in temperate North Atlantic coastal samples and temperature in tropical Atlantic and Pacific coastal and open ocean samples. Bacterial phyla composition diverged between temperate and tropical regions. This study suggests that some bacterial assemblages could be structured both by environmental and spatial factors, while others by environmental factors alone. 相似文献
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934.
Rosa A. Cardone Giovanni Busco Maria R. Greco Antonia Bellizzi Rosita Accardi Antonella Cafarelli Stefania Monterisi Pierluigi Carratù Valeria Casavola Angelo Paradiso Massimo Tommasino Stephan J. Reshkin 《PloS one》2008,3(10)
Background
Neoplastic transformation originates from a large number of different genetic alterations. Despite this genetic variability, a common phenotype to transformed cells is cellular alkalinization. We have previously shown in human keratinocytes and a cell line in which transformation can be turned on and followed by the inducible expression of the E7 oncogene of human papillomavirus type 16 (HPV16), that intracellular alkalinization is an early and essential physiological event driven by the up-regulation of the Na/+H+ exchanger isoform 1 (NHE1) and is necessary for the development of other transformed phenotypes and the in vivo tumor formation in nude mice.Methodology
Here, we utilize these model systems to elucidate the dynamic sequence of alterations of the upstream signal transduction systems leading to the transformation-dependent activation of NHE1.Principal Findings
We observe that a down-regulation of p38 MAPK activity is a fundamental step in the ability of the oncogene to transform the cell. Further, using pharmacological agents and transient transfections with dominant interfering, constitutively active, phosphorylation negative mutants and siRNA strategy to modify specific upstream signal transduction components that link HPV16 E7 oncogenic signals to up-regulation of the NHE1, we demonstrate that the stimulation of NHE1 activity is driven by an early rise in cellular cAMP resulting in the down-stream inhibition of p38 MAPK via the PKA-dependent phosphorylation of the small G-protein, RhoA, and its subsequent inhibition.Conclusions
All together these data significantly improve our knowledge concerning the basic cellular alterations involved in oncogene-driven neoplastic transformation. 相似文献935.
M. A. Sherif L. Paranskaya S. Yuecel S. Kische O. Thiele G. D’Ancona A. Neuhausen-Abramkina J. Ortak H. Ince A. Öner 《Netherlands heart journal》2017,25(2):125-130
The MitraClip system is a device for percutaneous edge-to-edge reconstruction of the mitral valve in patients with severe mitral regurgitation who are deemed at high risk for surgery. Studies have underlined the therapeutic benefit of the MitraClip system for patients at extreme and high risk for mitral valve surgery, suffering from either degenerative or functional mitral regurgitation. The MitraClip procedure shows low peri-procedural complication rates, and a significant reduction in mitral regurgitation, as well as an improvement in functional capacity and most importantly quality of life. It hereby widens the spectrum of mitral valve repair for the Heart Team. The current review underscores the efficacy of the procedure and describes the technique to simplify the procedure. 相似文献
936.
Perfusion of isolated rat kidney with Mesenchymal Stromal Cells/Extracellular Vesicles prevents ischaemic injury
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Marilena Gregorini Valeria Corradetti Eleonora Francesca Pattonieri Chiara Rocca Samantha Milanesi Andrea Peloso Silvana Canevari Loris De Cecco Matteo Dugo Maria Antonietta Avanzini Melissa Mantelli Marcello Maestri Pasquale Esposito Stefania Bruno Carmelo Libetta Antonio Dal Canton Teresa Rampino 《Journal of cellular and molecular medicine》2017,21(12):3381-3393
Kidney donation after circulatory death (DCD) is a less than ideal option to meet organ shortages. Hypothermic machine perfusion (HMP) with Belzer solution (BS) improves the viability of DCD kidneys, although the graft clinical course remains critical. Mesenchymal stromal cells (MSC) promote tissue repair by releasing extracellular vesicles (EV). We evaluated whether delivering MSC‐/MSC‐derived EV during HMP protects rat DCD kidneys from ischaemic injury and investigated the underlying pathogenic mechanisms. Warm ischaemic isolated kidneys were cold‐perfused (4 hrs) with BS, BS supplemented with MSC or EV. Renal damage was evaluated by histology and renal gene expression by microarray analysis, RT‐PCR. Malondialdehyde, lactate, LDH, glucose and pyruvate were measured in the effluent fluid. MSC‐/EV‐treated kidneys showed significantly less global ischaemic damage. In the MSC/EV groups, there was up‐regulation of three genes encoding enzymes known to improve cell energy metabolism and three genes encoding proteins involved in ion membrane transport. In the effluent fluid, lactate, LDH, MDA and glucose were significantly lower and pyruvate higher in MSC/EV kidneys as compared with BS, suggesting the larger use of energy substrates by MSC/EV kidneys. The addition of MSC/EV to BS during HMP protects the kidney from ischaemic injury by preserving the enzymatic machinery essential for cell viability and protects the kidney from reperfusion damage. 相似文献
937.
Scale of human mobility in the southern Andes (Argentina and Chile): A new framework based on strontium isotopes
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938.
Vincenza Rita Lo Vasco Martina Leopizzi Valeria Di Maio Tania Di Raimo Stefania Cesa Alessandra Masci Carlo Della Rocca 《Journal of cell communication and signaling》2017,11(4):317-327
Endothelial cells (EC) act as leading actors in angiogenesis. Understanding the complex network of signal transduction pathways which regulate angiogenesis might offer insights in the regulation of normal and pathological events, including tumours, vascular, inflammatory and immune diseases. The effects of olive oil and of Blueberry extracts upon the phosphoinositide (PI)-specific phospholipase C (PLC) enzymes were evaluated both in quiescent and inflammatory stimulated human umbilical vein EC (HUVEC) using molecular biology (multiliquid bioanalysis) and immunofluorescence techniques. Oleuropein significantly increased the number of surviving HUVEC compared to untreated controls, suggesting that it favours the survival and proliferation of EC. Our results suggest that Oleuropein might be useful to induce EC proliferation, an important event during angiogenesis, with special regard to wound healing. Blueberry extracts increased the number of surviving HUVEC, although the comparison to untreated controls did not result statistically significant. Lipopolysaccharide (LPS) administration significantly reduced the number of live HUVEC. LPS can also modify the expression of selected PLC genes. Adding Blueberry extracts to LPS treated HUVEC cultures did not significantly modify the variations of PLC expression induced by LPS. Oleuropein increased or reduced the expression of PLC genes, and statistically significant results were identified for selected PLC isoforms. Oleuropein also modified the effects of LPS upon PLC genes’ expression. Thus, our results corroborate the hypothesis that Oleuropein owns anti-inflammatory activity. The intracellular localization of PLC enzymes was modified by the different treatments we used. Podosome-like structures were observed in differently LPS treated HUVEC. 相似文献
939.
ecospat: an R package to support spatial analyses and modeling of species niches and distributions
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Valeria Di Cola Olivier Broennimann Blaise Petitpierre Frank T. Breiner Manuela D'Amen Christophe Randin Robin Engler Julien Pottier Dorothea Pio Anne Dubuis Loic Pellissier Rubén G. Mateo Wim Hordijk Nicolas Salamin Antoine Guisan 《Ecography》2017,40(6):774-787
The aim of the ecospat package is to make available novel tools and methods to support spatial analyses and modeling of species niches and distributions in a coherent workflow. The package is written in the R language (R Development Core Team) and contains several features, unique in their implementation, that are complementary to other existing R packages. Pre‐modeling analyses include species niche quantifications and comparisons between distinct ranges or time periods, measures of phylogenetic diversity, and other data exploration functionalities (e.g. extrapolation detection, ExDet). Core modeling brings together the new approach of ensemble of small models (ESM) and various implementations of the spatially‐explicit modeling of species assemblages (SESAM) framework. Post‐modeling analyses include evaluation of species predictions based on presence‐only data (Boyce index) and of community predictions, phylogenetic diversity and environmentally‐constrained species co‐occurrences analyses. The ecospat package also provides some functions to supplement the ‘biomod2’ package (e.g. data preparation, permutation tests and cross‐validation of model predictive power). With this novel package, we intend to stimulate the use of comprehensive approaches in spatial modelling of species and community distributions. 相似文献
940.
Ca2+ binding to F‐ATP synthase β subunit triggers the mitochondrial permeability transition
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Valentina Giorgio Marco Schiavone Claudio Bassot Giovanni Minervini Valeria Petronilli Francesco Argenton Michael Forte Silvio Tosatto Giovanna Lippe Paolo Bernardi 《EMBO reports》2017,18(7):1065-1076
F‐ATP synthases convert the electrochemical energy of the H+ gradient into the chemical energy of ATP with remarkable efficiency. Mitochondrial F‐ATP synthases can also undergo a Ca2+‐dependent transformation to form channels with properties matching those of the permeability transition pore (PTP), a key player in cell death. The Ca2+ binding site and the mechanism(s) through which Ca2+ can transform the energy‐conserving enzyme into a dissipative structure promoting cell death remain unknown. Through in vitro, in vivo and in silico studies we (i) pinpoint the “Ca2+‐trigger site” of the PTP to the catalytic site of the F‐ATP synthase β subunit and (ii) define a conformational change that propagates from the catalytic site through OSCP and the lateral stalk to the inner membrane. T163S mutants of the β subunit, which show a selective decrease in Ca2+‐ATP hydrolysis, confer resistance to Ca2+‐induced, PTP‐dependent death in cells and developing zebrafish embryos. These findings are a major advance in the molecular definition of the transition of F‐ATP synthase to a channel and of its role in cell death. 相似文献