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101.
102.
John J. Malinowski Bruce L. Grasberger Gary Trakshel Edward E. Huston Tracey M. Banks Patricia G. Brake Richard B. Ciccarelli Barry N. Jones James A. Koehn Diane Kratz Nicole Lundberg Panayiotis E. Stevis Carla T. Helaszek Mark A. Ator Angela M. Small Wood Travis Stams Byron Rubin Richard S. Alexander 《Protein science : a publication of the Protein Society》1995,4(10):2149-2155
103.
Timothy A. McCaffrey Domenick J. Falcone Diane Vicente Baoheng Du Seth Consigli Wolfgang Borth 《Journal of cellular physiology》1994,159(1):51-59
The transforming growth factor-β (TGF-β) family of proteins exert diverse and potent effects on proliferation, differentiation, and extracellular matrix synthesis. However, relatively little is known about the stability or processing of endogenous TGF-β activity in vitro or in vivo. Our previous work indicated that (1) TGF-β1 has strong heparin-binding properties that were not previously recognized because of neutralization by iodination, and (2) heparin, and certain other polyanions, could block the binding of TGF-β1 to α2-macroglobulin (α2-M). The present studies investigated the influence of heparin-like molecules on the stability of the TGF-β1 signal in the pericellular environment. The results indicate that heparin and fucoidan, a naturally occurring sulfated L-fucose polymer, suppress the formation of an initial non-covalent interaction between 125I-TGF-β1 and activated α2-M. Electrophoresis of 125I-TGF-β1 showed that fucoidan protects TGF-β1 from proteolytic degradation by plasmin and trypsin. While plasmin caused little, if any, activation of latent TGF-β derived from vascular smooth muscle cells (SMC), plasmin degraded acid-activated TGF-β, and purified TGF-β1, and this degradation was inhibited by fucoidan. In vitro, heparin and fucoidan tripled the half-life of 125I-TGF-β1 and doubled the amount of cell-associated 125I-TGF-β1. Consistent with this protective effect, heparin- and fucoidan-treated SMC demonstrated elevated levels of active, but not latent, TGF-β activity. © 1994 wiley-Liss, Inc. 相似文献
104.
105.
Vines CM Revankar CM Maestas DC LaRusch LL Cimino DF Kohout TA Lefkowitz RJ Prossnitz ER 《The Journal of biological chemistry》2003,278(43):41581-41584
Arrestins mediate phosphorylation-dependent desensitization, internalization, and initiation of signaling cascades for the majority of G protein-coupled receptors (GPCRs). Many GPCRs undergo agonist-mediated internalization through arrestin-dependent mechanisms, wherein arrestin serves as an adapter between the receptor and endocytic proteins. To understand the role of arrestins in N-formyl peptide receptor (FPR) trafficking, we stably expressed the FPR in a mouse embryonic fibroblast cell line (MEF) that lacked endogenous arrestin 2 and arrestin 3 (arrestin-deficient). We compared FPR internalization and recycling kinetics in these cells to congenic wild type MEF cell lines. Internalization of the FPR was not altered in the absence of arrestins. Since the FPR remains associated with arrestins following internalization, we investigated whether the rate of FPR recycling was altered in arrestin-deficient cells. While the FPR was able to recycle in the wild type cells, receptor recycling was largely absent in the arrestin double knockout cells. Reconstitution of the arrestin-deficient line with either arrestin 2 or arrestin 3 restored receptor recycling. Confocal fluorescence microscopy studies demonstrated that in arrestin-deficient cells the FPR may become trapped in the perinuclear recycling compartment. These observations indicate that, although the FPR can internalize in the absence of arrestins, recycling of internalized receptors to the cell surface is prevented. Our results suggest a novel role for arrestins in the post-endocytic trafficking of GPCRs. 相似文献
106.
Diane Y Kim Peter D Countway Adriane C Jones Astrid Schnetzer Warren Yamashita Christine Tung David A Caron 《The ISME journal》2014,8(3):515-530
The monthly, seasonal and interannual variability of microbial eukaryote assemblages were
examined at 5 m, the deep chlorophyll maximum, 150 m and 500 m at the
San Pedro Ocean Time-series station (eastern North Pacific). The depths spanned
transitions in temperature, light, nutrients and oxygen, and included a persistently
hypoxic environment at 500 m. Terminal restriction fragment length polymorphism was
used for the analysis of 237 samples that were collected between September 2000 and
December 2010. Spatiotemporal variability patterns of microeukaryote assemblages indicated
the presence of distinct shallow and deep communities at the SPOT station, presumably
reflecting taxa that were specifically adapted for the conditions in those environments.
Community similarity values between assemblages collected 1 month apart at each depth
ranged between ∼20% and ∼84% (averages were
∼50–59%). The assemblage at 5 m was temporally more dynamic than
deeper assemblages and also displayed substantial interannual variability during the first
∼3 years of the study. Evidence of seasonality was detected for the microbial
eukaryote assemblage at 5 m between January 2008 and December 2010 and at
150 m between September 2000 and December 2003. Seasonality was not detected for
assemblages at the deep chlorophyll a maximum, which varied in depth seasonally,
or at 500 m. Microbial eukaryote assemblages exhibited cyclical patterns in at
least 1 year at each depth, implying an annual resetting of communities. Substantial
interannual variability was detected for assemblages at all depths and represented the
largest source of temporal variability in this temperate coastal ecosystem. 相似文献
107.
108.
Denis Monneret Jean-Louis Pepin Diane Godin-Ribuot Veronique Ducros Jean-Philippe Baguet Patrick Levy Patrice Faure 《Free radical biology & medicine》2010,48(4):619-625
Obstructive sleep apnea (OSA) is characterized by recurrent apnea during sleep that may unbalance oxidative stress, increasing atherosclerosis. Among oxidative stress markers, 15-F2t-isoprostane is considered one of the most sensitive and specific metabolites of lipid peroxidation. To explore the relationship between urinary 15-F2t-isoprostane with sleep apnea severity and carotid modifications in nonobese OSA patients, 31 nonobese sleep apnea patients were studied, along with 10 lean subjects without OSA. Patients were assessed by polysomnography, blood pressure measurement, and ultrasonography to determine the carotid intima–media thickness (IMT). Urinary 15-F2t-isoprostanes were measured by liquid chromatography–tandem mass spectrometry. Urinary 15-F2t-isoprostane concentrations were increased in severe OSA patients compared to control subjects (20.2 ± 7.3 vs 12.3 ± 2.8 ng/mmol creatinine; P = 0.020). Mean carotid IMT was correlated with 15-F2t-isoprostane (r = 0.532; P < 0.001) and with the apnea–hypopnea index (r = 0.345; P = 0.029). 15-F2t-Isoprostane level was related to the night time spent at SaO2 < 90% (r = 0.478; P = 0.002), the apnea–hypopnea index (r = 0.465; P = 0.003), and the mean nocturnal SaO2 (r = ? 0.424; P = 0.007). These results showed a relationship between lipid peroxidation, carotid intima–media thickness, and intermittent hypoxia in nonobese OSA patients, thus reinforcing the hypothesis that oxidative stress could be involved in the early atherosclerotic process. 相似文献
109.
In some arid regions, rehabilitation of whole system N-fixation may be strongly facilitated by the recovery of populations of the lichen genus Collema . Identification of the limits to recovery of Collema in apparently suitable habitat should inform selection of rehabilitation techniques. We simultaneously tested the relative importance of three hypothetical limits to Collema recovery: active erosion, resource limitation, and propagule scarcity. We found that in our experimental system, active erosion had no effect on short-term establishment of Collema, whereas propagule addition did enhance recovery and microhabitat (a resource availability gradient) also exerted a strong influence. It is possible that attempts to improve N cycling via re-establishment of Collema might be best served by developing economical means of simulating moister, cooler microhabitats, e.g., sloping soil or creating partial shade, which would favor the establishment of naturally dispersed propagules, rather than introducing propagules. 相似文献
110.
Harsh Raman Kerong Zhang Mehmet Cakir Rudi Appels David F Garvin Lyza G Maron Leon V Kochian J Sergio Moroni Rosy Raman Muhammad Imtiaz Fiona Drake-Brockman Irene Waters Peter Martin Takayuki Sasaki Yoko Yamamoto Hideaki Matsumoto Diane M Hebb Emmanuel Delhaize Peter R Ryan 《Génome》2005,48(5):781-791
The major aluminum (Al) tolerance gene in wheat ALMT1 confers. An Al-activated efflux of malate from root apices. We determined the genomic structure of the ALMT1 gene and found it consists of 6 exons interrupted by 5 introns. Sequencing a range of wheat genotypes identified 3 alleles for ALMT1, 1 of which was identical to the ALMT1 gene from an Aegilops tauschii accession. The ALMT1 gene was mapped to chromosome 4DL using 'Chinese Spring' deletion lines, and loss of ALMT1 coincided with the loss of both Al tolerance and Al-activated malate efflux. Aluminium tolerance in each of 5 different doubled-haploid populations was found to be conditioned by a single major gene. When ALMT1 was polymorphic between the parental lines, QTL and linkage analyses indicated that ALMT1 mapped to chromosome 4DL and cosegregated with Al tolerance. In 2 populations examined, Al tolerance also segregated with a greater capacity for Al-activated malate efflux. Aluminium tolerance was not associated with a particular coding allele for ALMT1, but was significantly correlated with the relative level of ALMT1 expression. These findings suggest that the Al tolerance in a diverse range of wheat genotypes is primarily conditioned by ALMT1. 相似文献