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101.
Regulated relocalization of signaling and trafficking proteins is crucial for the control of many cellular processes and is driven by a series of domains that respond to alterations at membrane surfaces. The first examples of these domains--conditional peripheral membrane proteins--included C1, C2, PH, PX, and FYVE domains, which specifically recognize single tightly regulated membrane components such as diacylglycerol or phosphoinositides. The structural basis for this recognition is now well understood. Efforts to identify additional domains with similar functions that bind other targets (or participate in unexplained cellular processes) have not yielded many more examples of specific phospholipid-binding domains. Instead, most of the recently discovered conditional peripheral membrane proteins bind multiple targets (each with limited specificity), relying on coincidence detection and/or recognizing broader physical properties of the membrane such as charge or curvature. This broader range of recognition modes presents significant methodological challenges for a full structural understanding. 相似文献
102.
Amit Saxena Harry Bj?rkbacka ?sa Str?m Sara Rattik Katarina E. Berg Maria F. Gomez Gunilla Nordin Fredrikson Jan Nilsson Anna Hultg?rdh-Nilsson 《PloS one》2012,7(12)
Aim
T cells have been attributed an important role in modulating repair responses following vascular injury. The aim of this study was to investigate the role of different T cell subsets in this context.Methods and Results
A non-obstructive collar was introduced to inflict carotid artery injury in mice and subsequent activation of immune cells in draining lymph nodes and spleen were studied by flow cytometry. Carotid artery injury of wild type mice was associated with mobilization of both Th1 type CD4+IFNγ+ and regulatory CD4+CD25+FoxP3+ T cells in draining lymph nodes. Studies using FoxP3-green fluorescent protein (GFP) transgenic C57/Bl6 mice demonstrated scattered presence of regulatory T cells in the adventitial tissue of injured arteries as well as a massive emigration of regulatory T cells from the spleen in response to carotid injury. However, deletion of antigen presentation to CD4+ T cells (H20 mice), as well as deletion of regulatory T cells (through treatment with blocking anti-CD25 antibodies), did not affect neointima formation. Also deletion of antigen presentation to CD8+ T cells (Tap10 mice) was without effect on carotid collar-induced neointima formation.Conclusion
The results demonstrate that carotid artery injury is associated with mobilization of regulatory T cells. Depletion of regulatory T cells does not, however, influence the subsequent repair processes leading to the formation of a neointima. The results also demonstrate that lack of CD8+ T cells does not influence neointima formation in presence of functional CD4+ T cells and B cells. 相似文献103.
104.
105.
In a recent study we showed that the surfactant 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine-N-[methoxy(polyethylene glycol)-2000 (DSPE-PEG(2000)) induce mixed micelles of either threadlike or discoidal shape when mixed with different types of lipids. In certain lipid systems the discoidal micelles adapt sizes large enough to be characterized as bilayer discs. The discs hold great potential for use in various biotechnical applications and may e.g. be used as model membranes in drug/membrane partition studies. Depending on the application, discs with certain characteristics, such as a particular size or size homogeneity, may be required. These factors can in our experience be influenced by the preparation method. In this study we systematically investigated three different PEG-lipid/lipid mixtures prepared by four commonly used preparation techniques. The techniques used were simple hydration, freeze-thawing, sonication and detergent depletion, and the aggregate size and structure was analyzed by cryo transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS). Our results show that the type and size of the micellar structure found, as well as the structure homogeneity of the preparation, can be modified by the choice of preparation path. 相似文献
106.
107.
Pangallo D Drahovska H Harichova J Karelova E Chovanova K Aradska J Ferianc P Turna J Timko J 《Antonie van Leeuwenhoek》2008,93(1-2):193-203
The aim of the work was the evaluation of different PCR-based methods to found an appropriate identification and typing strategy
for environmental enterococci. Environmental enterococci were isolated mainly from surface- and waste-waters. Species identification
was provided by combination of phenotypic (Micronaut System, Merlin) and molecular detection methods (fluorescent ITS-PCR,
ddl-PCR, REP-PCR, AFLP). Very similar results were observed among molecular methods, however several discrepancies were recognized
during comparison of molecular and biochemical identification. Seven enterococcal species (E. faecium, E. hirae, E. casseliflavus, E. mundtii, E. faecalis, E. durans and E. gallinarum) were identified within 166 environmental isolates. The results obtained in this work attest the importance of PCR-based
methods for identification and typing of environmental enterococci. The fluorescent ITS-PCR (fITS-PCR) showed the best results
in order to identify the enterococci strains, the method used the automated capillary electrophoresis to separate the PCR
products in a very rapid and precise way. The AFLP method was suitable to identify and characterize the isolates, while the
REP-PCR can be used for species identification. 相似文献
108.
Sörgjerd K Klingstedt T Lindgren M Kågedal K Hammarström P 《Biochemical and biophysical research communications》2008,377(4):1072-1078
Recent studies suggest that soluble, oligomeric species, which are intermediates in the fibril formation process in amyloid disease, might be the key species in amyloid pathogenesis. Soluble oligomers of human wild type transthyretin (TTR) were produced to elucidate oligomer properties. Employing ThT fluorescence, time-resolved fluorescence anisotropy of pyrene-labeled TTR, chemical cross-linking, and electron microscopy we demonstrated that early formed soluble oligomers (within minutes) from A-state TTR comprised on the average 20-30 TTR monomers. When administered to neuroblastoma cells these early oligomers proved highly cytotoxic and induced apoptosis after 48 h of incubation. More mature fibrils (>24 h of fibrillation) were non-toxic. Surprisingly, we also found that native tetrameric TTR, when purified and stored under cold conditions (4 °C) was highly cytotoxic. The effect could be partially restored by increasing the temperature of the protein. The cytotoxic effects of native tetrameric TTR likely stems from a hitherto unexplored low temperature induced rearrangement of the tetramer conformation that possibly is related to the conformation of misfolded TTR in amyloigogenic oligomers. 相似文献
109.
110.
Maria Wilbe Martine Lund Ziener Anita Aronsson Charlotte Harlos Katarina Sundberg Elin Norberg Lisa Andersson Kerstin Lindblad-Toh ?ke Hedhammar G?ran Andersson Frode Lingaas 《PloS one》2010,5(8)
Symmetrical lupoid onychodystrophy (SLO) is an immune-mediated disease in dogs affecting the claws with a suggested autoimmune aethiology. Sequence-based genotyping of the polymorphic exon 2 from DLA-DRB1, -DQA1, and -DQB1 class II loci were performed in a total of 98 SLO Gordon setter cases and 98 healthy controls. A risk haplotype (DRB1*01801/DQA1*00101/DQB1*00802) was present in 53% of cases and 34% of controls and conferred an elevated risk of developing SLO with an odds ratio (OR) of 2.1. When dogs homozygous for the risk haplotype were compared to all dogs not carrying the haplotype the OR was 5.4. However, a stronger protective haplotype (DRB1*02001/DQA1*00401/DQB1*01303, OR = 0.03, 1/OR = 33) was present in 16.8% of controls, but only in a single case (0.5%). The effect of the protective haplotype was clearly stronger than the risk haplotype, since 11.2% of the controls were heterozygous for the risk and protective haplotypes, whereas this combination was absent from cases. When the dogs with the protective haplotype were excluded, an OR of 2.5 was obtained when dogs homozygous for the risk haplotype were compared to those heterozygous for the risk haplotype, suggesting a co-dominant effect of the risk haplotype. In smaller sample sizes of the bearded collie and giant schnauzer breeds we found the same or similar haplotypes, sharing the same DQA1 allele, over-represented among the cases suggesting that the risk is associated primarily with DLA-DQ. We obtained conclusive results that DLA class II is significantly associated with risk of developing SLO in Gordon setters, thus supporting that SLO is an immune-mediated disease. Further studies of SLO in dogs may provide important insight into immune privilege of the nail apparatus and also knowledge about a number of inflammatory disorders of the nail apparatus like lichen planus, psoriasis, alopecia areata and onycholysis. 相似文献