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91.
Alexandra Bruel Jean-Christophe Rozé Cyril Flamant Umberto Simeoni Gwena?lle Roussey-Kesler Emma Allain-Launay 《PloS one》2013,8(12)
Background
Renal failure in neonates is associated with an increased risk of mortality and morbidity. But critical values are not known.Objective
To define critical values for serum creatinine levels by gestational age in preterm infants, as a predictive factor for mortality and morbidity.Study Design
This was a retrospective study of all preterm infants born before 33 weeks of gestational age, hospitalized in Nantes University Hospital NICU between 2003 and 2009, with serum creatinine levels measured between postnatal days 3 to 30. Children were retrospectively randomized into either training or validation set. Critical creatinine values were defined within the training set as the 90th percentile values of highest serum creatinine (HSCr) in infants with optimal neurodevelopmental at two years of age. The relationship between these critical creatinine values and neonatal mortality, and non-optimal neural development at two years, was then assessed in the validation set.Results and Conclusion
The analysis involved a total of 1,461 infants (gestational ages of 24-27 weeks (n=322), 28-29 weeks (n=336), and 30-32 weeks (803)), and 14,721 creatinine assessments. The critical values determined in the training set (n=485) were 1.6, 1.1 and 1.0 mg/dL for each gestational age group, respectively. In the validation set (n=976), a serum creatinine level above the critical value was significantly associated with neonatal mortality (Odds ratio: 8.55 (95% confidence interval: 4.23-17.28); p<0.01) after adjusting for known renal failure risk factors, and with non-optimal neurodevelopmental outcome at two years (odds ratio: 2.06 (95% confidence interval: 1.26-3.36); p=0.004) before adjustment. Creatinine values greater than 1.6, 1.1 and 1.0 mg/dL respectively at 24-27, 28-29, 30-32 weeks of gestation were associated with mortality before and after adjustment for risk factors, and with non-optimal neurodevelopmental outcome, before adjustment. 相似文献92.
93.
TIMP-3 inhibition of ADAMTS-4 (Aggrecanase-1) is modulated by interactions between aggrecan and the C-terminal domain of ADAMTS-4 总被引:1,自引:0,他引:1
Wayne GJ Deng SJ Amour A Borman S Matico R Carter HL Murphy G 《The Journal of biological chemistry》2007,282(29):20991-20998
ADAMTS-4 (aggrecanase-1) is a glutamyl endopeptidase capable of generating catabolic fragments of aggrecan analogous to those released from articular cartilage during degenerative joint diseases such as osteoarthritis. Efficient aggrecanase activity requires the presence of sulfated glycosaminoglycans attached to the aggrecan core protein, implying the contribution of substrate recognition/binding site(s) to ADAMTS-4 activity. In this study, we developed a sensitive fluorescence resonance energy transfer peptide assay with a K(m) in the 10 microm range and utilized this assay to demonstrate that inhibition of full-length ADAMTS-4 by full-length TIMP-3 (a physiological inhibitor of metalloproteinases) is enhanced in the presence of aggrecan. Our data indicate that this interaction is mediated largely through the binding of glycosaminoglycans (specifically chondroitin 6-sulfate) of aggrecan to binding sites in the thrombospondin type 1 motif and spacer domains of ADAMTS-4 to form a complex with an improved binding affinity for TIMP-3 over free ADAMTS-4. The results of this study therefore indicate that the cartilage environment can modulate the function of enzyme-inhibitor systems and could have relevance for therapeutic approaches to aggrecanase modulation. 相似文献
94.
Light detection by vertebrate rod photoreceptor outer segments results in the destruction of the visual pigment, rhodopsin, as its retinyl moiety is photoisomerized from 11-cis to all-trans. The regeneration of rhodopsin is necessary for vision and begins with the release of the all-trans retinal and its reduction to all-trans retinol. Retinol is then transported out of the rod outer segment for further processing. We used fluorescence imaging to monitor retinol fluorescence and quantify the kinetics of its formation and clearance after rhodopsin bleaching in the outer segments of living isolated frog (Rana pipiens) rod photoreceptors. We independently measured the release of all-trans retinal from bleached rhodopsin in frog rod outer segment membranes and the rate of all-trans retinol removal by the lipophilic carriers interphotoreceptor retinoid binding protein (IRBP) and serum albumin. We find that the kinetics of all-trans retinol formation in frog rod outer segments after rhodopsin bleaching are to a good first approximation determined by the kinetics of all-trans retinal release from the bleached pigment. For the physiological concentrations of carriers, the rate of retinol removal from the outer segment is determined by IRBP concentration, whereas the effect of serum albumin is negligible. The results indicate the presence of a specific interaction between IRBP and the rod outer segment, probably mediated by a receptor. The effect of different concentrations of IRBP on the rate of retinol removal shows no cooperativity and has an EC50 of 40 micromol/L. 相似文献
95.
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97.
Olivier Jolliet Rolf Frischknecht Jane Bare Anne-Marie Boulay Cecile Bulle Peter Fantke Shabbir Gheewala Michael Hauschild Norihiro Itsubo Manuele Margni Thomas E. McKone Llorenç Mila y Canals Leo Postuma Valentina Prado-Lopez Brad Ridoutt Guido Sonnemann Ralph K. Rosenbaum Tom Seager Jaap Struijs Rosalie van Zelm Bruce Vigon Annie Weisbrod 《The International Journal of Life Cycle Assessment》2014,19(4):962-967
98.
Olivier Jolliet Rolf Frischknecht Jane Bare Anne-Marie Boulay Cecile Bulle Peter Fantke Shabbir Gheewala Michael Hauschild Norihiro Itsubo Manuele Margni Thomas E. McKone Llorenç Mila y Canals Leo Posthuma Valentina Prado-Lopez Brad Ridoutt Guido Sonnemann Ralph K. Rosenbaum Tom Seager Jaap Struijs Rosalie van Zelm Bruce Vigon Annie Weisbrod 《The International Journal of Life Cycle Assessment》2014,19(8):1566-1566
99.
Jan Kern Johan Hattne Rosalie Tran Roberto Alonso-Mori Hartawan Laksmono Sheraz Gul Raymond G. Sierra Jens Rehanek Alexei Erko Rolf Mitzner Phillip Wernet Uwe Bergmann Nicholas K. Sauter Vittal Yachandra Junko Yano 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2014,369(1647)
X-ray free-electron lasers (XFELs) open up new possibilities for X-ray crystallographic and spectroscopic studies of radiation-sensitive biological samples under close to physiological conditions. To facilitate these new X-ray sources, tailored experimental methods and data-processing protocols have to be developed. The highly radiation-sensitive photosystem II (PSII) protein complex is a prime target for XFEL experiments aiming to study the mechanism of light-induced water oxidation taking place at a Mn cluster in this complex. We developed a set of tools for the study of PSII at XFELs, including a new liquid jet based on electrofocusing, an energy dispersive von Hamos X-ray emission spectrometer for the hard X-ray range and a high-throughput soft X-ray spectrometer based on a reflection zone plate. While our immediate focus is on PSII, the methods we describe here are applicable to a wide range of metalloenzymes. These experimental developments were complemented by a new software suite, cctbx.xfel. This software suite allows for near-real-time monitoring of the experimental parameters and detector signals and the detailed analysis of the diffraction and spectroscopy data collected by us at the Linac Coherent Light Source, taking into account the specific characteristics of data measured at an XFEL. 相似文献
100.