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排序方式: 共有514条查询结果,搜索用时 15 毫秒
331.
Luisa Zupin Giulia Ottaviani Katia Rupel Matteo Biasotto Serena Zacchigna Sergio Crovella Fulvio Celsi 《Journal of biophotonics》2019,12(10)
Laser therapy, also known as Photobiomodulation (PBM) is indicated to reduce pain associated with different pathologies and applied using protocols that vary in wavelength, irradiance and fluence. Its mechanisms of action are still unclear and possibly able to directly impact on pain transmission, reducing nociceptor response. In our study, we examined the effect of two specific laser wavelengths, 800 and 970 nm, extensively applied in the clinical context and known to exert important analgesic effects. Our results point to mitochondria as the primary target of laser light in isolated dorsal root ganglion (DRG) neurons, reducing adenosine triphosphate content and increasing reactive oxygen species levels. Specifically, the 800 nm laser wavelength induced mitochondrial dysregulation, that is, increased superoxide generation and mitochondrial membrane potential. When DRG neurons were firstly illuminated by the different laser protocols and then stimulated with the natural transient receptor potential cation channel subfamily V member 1 (TRPV1) ligand capsaicin, only the 970 nm wavelength reduced the calcium response, in both amplitude and frequency. Consistent results were obtained in vivo in mice, by subcutaneous injection of capsaicin. Our findings demonstrate that the effect of PBM depends on the wavelength used, with 800 nm light mainly acting on mitochondrial metabolism and 970 nm light on nociceptive signal transmission. 相似文献
332.
Lipid droplets and their component triglycerides and steryl esters regulate autophagosome biogenesis
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Tomer Shpilka Evelyn Welter Noam Borovsky Nira Amar Muriel Mari Fulvio Reggiori Zvulun Elazar 《The EMBO journal》2015,34(16):2117-2131
Autophagy is a major catabolic process responsible for the delivery of proteins and organelles to the lysosome/vacuole for degradation. Malfunction of this pathway has been implicated in numerous pathological conditions. Different organelles have been found to contribute to the formation of autophagosomes, but the exact mechanism mediating this process remains obscure. Here, we show that lipid droplets (LDs) are important for the regulation of starvation-induced autophagy. Deletion of Dga1 and Lro1 enzymes responsible for triacylglycerol (TAG) synthesis, or of Are1 and Are2 enzymes responsible for the synthesis of steryl esters (STE), results in the inhibition of autophagy. Moreover, we identified the STE hydrolase Yeh1 and the TAG lipase Ayr1 as well as the lipase/hydrolase Ldh1 as essential for autophagy. Finally, we provide evidence that the ER-LD contact-site proteins Ice2 and Ldb16 regulate autophagy. Our study thus highlights the importance of lipid droplet dynamics for the autophagic process under nitrogen starvation. 相似文献
333.
Annemarie Kralt Marco Carretta Muriel Mari Fulvio Reggiori Anton Steen Bert Poolman Liesbeth M. Veenhoff 《Traffic (Copenhagen, Denmark)》2015,16(2):135-147
Membrane junctions or contact sites are close associations of lipid bilayers of heterologous organelles. Ist2 is an endoplasmic reticulum (ER)‐resident transmembrane protein that mediates associations between the plasma membrane (PM) and the cortical ER (cER) in baker's yeast. We asked the question what structure in Ist2 bridges the up to 30 nm distance between the PM and the cER and we noted that the region spacing the transmembrane domain from the cortical sorting signal interacting with the PM is predicted to be intrinsically disordered (ID). In Ssy1, a protein that was not previously described to reside at membrane junctions, we recognized a domain organization similar to that in Ist2. We found that the localization of both Ist2 and Ssy1 at the cell periphery depends on the presence of a PM‐binding domain, an ID linker region of sufficient length and a transmembrane domain that most probably resides in the ER. We show for the first time that an ID amino acid domain bridges adjacent heterologous membranes. The length and flexibility of ID domains make them uniquely eligible for spanning large distances, and we suggest that this domain structure occurs more frequently in proteins that mediate the formation of membrane contact sites. 相似文献
334.
Polymer Solar Cells with Efficiency >10% Enabled via a Facile Solution‐Processed Al‐Doped ZnO Electron Transporting Layer
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Lethy Krishnan Jagadamma Mohammed Al‐Senani Abdulrahman El‐Labban Issam Gereige Guy O. Ngongang Ndjawa Jorge C. D. Faria Taesoo Kim Kui Zhao Federico Cruciani Dalaver H. Anjum Martyn A. McLachlan Pierre M. Beaujuge Aram Amassian 《Liver Transplantation》2015,5(12)
A facile and low‐temperature (125 °C) solution‐processed Al‐doped ZnO (AZO) buffer layer functioning very effectively as electron accepting/hole blocking layer for a wide range of polymer:fullerene bulk heterojunction systems, yielding power conversion efficiency in excess of 10% (8%) on glass (plastic) substrates is described. The ammonia‐treatment of the aqueous AZO nanoparticle solution produces compact, crystalline, and smooth thin films, which retain the aluminum doping, and eliminates/reduces the native defects by nitrogen incorporation, making them good electron transporters and energetically matched with the fullerene acceptor. It is demonstrated that highly efficient solar cells can be achieved without the need for additional surface chemical modifications of the buffer layer, which is a common requirement for many metal oxide buffer layers to yield efficient solar cells. Also highly efficient solar cells are achieved with thick AZO films (>50 nm), highlighting the suitability of this material for roll‐to‐roll coating. Preliminary results on the applicability of AZO as electron injection layer in F8BT‐based polymer light emitting diode are also presented. 相似文献
335.
336.
ABSTRACT Capsule: The movements and spatial ecology of non-breeding Eurasian Griffon Vultures Gyps fulvus in northern Italy, Croatia and Austria do not seem to be affected by feeding station use. Aims: The purpose of this study was to assess how the creation of a feeding station at the Riserva Naturale Regionale del Lago di Cornino (Forgaria nel Friuli, northeast Italy) during the 1980s might have affected the spatial and behavioural ecology of the Eurasian Griffon Vulture. Methods: Using global positioning system (GPS) satellite tracking, we studied movements of nine non-breeding Eurasian Griffon Vultures within the Riserva Naturale Regionale del Lago di Cornino in Italy, the Hohe Tauern in Austria and the Kvarner Gulf in Croatia. Results: Both the average foraging range size and the time spent by the birds in Italy were comparable to those recorded in Croatia and Austria, where the vultures depend on unpredictable food resources. A significant difference in terms of foraging range size was recorded among seasons. In winter it seems to be smaller as a consequence of reduced movements performed by the individuals due to harsh climate conditions. Conclusions: Our results suggest that the creation of a feeding station in Forgaria does not seem to have affected the spatial ecology of the Eurasian Griffon Vulture. However, due to the limited sample size and the young age of the individuals monitored, which have a long dispersal period, the findings presented should be considered as preliminary. Further research needs to be implemented to inform decisions regarding the management of supplementary feeding stations to promote the recovery and conservation of scavenger species, particularly in areas in which they have declined massively. 相似文献
337.
Marina Scarpa Adelio Rigo Matilde Maiorino Fulvio Ursini Carlo Gregolin 《Biochimica et Biophysica Acta (BBA)/General Subjects》1984,801(2):215-219
The events accompanying the inhibitory effect of α-tocopherol and/or ascorbate on the peroxidation of soybean L-α-phosphatidylcholine liposomes, which are an accepted model of biological membranes, were investigated by electron paramagnetic resonance, optical and polarograpic methods. The presence of α-tocopherol radical in the concentration range 10?8–10?7 M was detected from its EPR spectrum during the peroxidation of liposomes, catalysed by the Fe3+-triethylnetatramine complex. The α-tocopherol radical, generated in the phosphatidylcholine bilayer, is accessible to ascorbic acid, present in the aqueous phase at physiological concentrations. Ascorbic acid regenerates from it the α-tocopherol itself. A kinetic rate constant of about 2·105 M?·s?1 was estimated from the reaction as it occurs under the adopted experimental conditions. The scavenging effect of α-tocopherol on lipid peroxidation is maintained as long a ascorbic acid is present. 相似文献
338.
Perino A Ghigo A Ferrero E Morello F Santulli G Baillie GS Damilano F Dunlop AJ Pawson C Walser R Levi R Altruda F Silengo L Langeberg LK Neubauer G Heymans S Lembo G Wymann MP Wetzker R Houslay MD Iaccarino G Scott JD Hirsch E 《Molecular cell》2011,42(1):84-95
Adrenergic stimulation of the heart engages cAMP and phosphoinositide second messenger signaling cascades. Cardiac phosphoinositide 3-kinase p110γ participates in these processes by sustaining β-adrenergic receptor internalization through its catalytic function and by controlling phosphodiesterase 3B (PDE3B) activity via an unknown kinase-independent mechanism. We have discovered that p110γ anchors protein kinase A (PKA) through a site in its N-terminal region. Anchored PKA activates PDE3B to enhance cAMP degradation and phosphorylates p110γ to inhibit PIP(3) production. This provides local feedback control of PIP(3) and cAMP signaling events. In congestive heart failure, p110γ is upregulated and escapes PKA-mediated inhibition, contributing to a reduction in β-adrenergic receptor density. Pharmacological inhibition of p110γ normalizes β-adrenergic receptor density and improves contractility in failing hearts. 相似文献
339.
Borriello A Caldarelli I Bencivenga D Criscuolo M Cucciolla V Tramontano A Oliva A Perrotta S Della Ragione F 《Molecular cancer research : MCR》2011,9(10):1269-1284
p57(Kip2) is a cyclin-dependent kinase inhibitor belonging to the Cip/Kip family, which also includes p21(Cip1) and p27(Kip1). So far, p57(Kip2) is the least-studied Cip/Kip protein, and for a long time its relevance has been related mainly to its unique role in embryogenesis. Moreover, genetic and molecular studies on animal models and patients with Beckwith-Wiedemann syndrome have shown that alterations in CDKN1C (the p57(Kip2) encoding gene) have functional relevance in the pathogenesis of this disease. Recently, a number of investigations have identified and characterized heretofore unexpected roles for p57(Kip2). The protein appears to be critically involved in initial steps of cell and tissue differentiation, and particularly in neuronal development and erythropoiesis. Intriguingly, p27(Kip1), the Cip/Kip member that is most homologous to p57(Kip2), is primarily involved in the process of cell cycle exit. p57(Kip2) also plays a critical role in controlling cytoskeletal organization and cell migration through its interaction with LIMK-1. Furthermore, p57(Kip2) appears to modulate genome expression. Finally, accumulating evidence indicates that p57(Kip2) protein is frequently downregulated in different types of human epithelial and nonepithelial cancers as a consequence of genetic and epigenetic events. In summary, the emerging picture is that several aspects of p57(Kip2)'s functions are only poorly clarified. This review represents an appraisal of the data available on the p57(Kip2) gene and protein structure, and its role in human physiology and pathology. We particularly focus our attention on p57(Kip2) changes in cancers and pharmacological approaches for modulating p57(Kip2) levels. 相似文献
340.
Arciello A De Marco N Del Giudice R Guglielmi F Pucci P Relini A Monti DM Piccoli R 《Journal of cellular and molecular medicine》2011,15(12):2652-2663
Apolipoprotein A-I (ApoA-I) is an extracellular lipid acceptor, whose role in cholesterol efflux and high-density lipoprotein formation is mediated by ATP-binding cassette transporter A1 (ABCA1). Nevertheless, some ApoA-I variants are associated to systemic forms of amyloidosis, characterized by extracellular fibril deposition in peripheral organs. Heart amyloid fibrils were found to be mainly constituted by the 93-residue N-terminal fragment of ApoA-I, named [1-93]ApoA-I. In this paper, rat cardiomyoblasts were used as target cells to analyse binding, internalization and intracellular fate of the fibrillogenic polypeptide in comparison to full-length ApoA-I. We provide evidence that the polypeptide: (i) binds to specific sites on cell membrane (K(d) = 5.90 ± 0.70 × 10(-7) M), where it partially co-localizes with ABCA1, as also described for ApoA-I; (ii) is internalized mostly by chlatrin-mediated endocytosis and lipid rafts, whereas ApoA-I is internalized preferentially by chlatrin-coated pits and macropinocytosis and (iii) is rapidly degraded by proteasome and lysosomes, whereas ApoA-I partially co-localizes with recycling endosomes. Vice versa, amyloid fibrils, obtained by in vitro aggregation of [1-93]ApoA-I, were found to be unable to enter the cells. We propose that internalization and intracellular degradation of [1-93]ApoA-I may divert the polypeptide from amyloid fibril formation and contribute to the slow progression and late onset that characterize this pathology. 相似文献