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141.
142.
Glycomics of bone marrow-derived mesenchymal stem cells can be used to evaluate their cellular differentiation stage 总被引:1,自引:0,他引:1
Annamari Heiskanen Tia Hirvonen Hanna Salo Ulla Impola Anne Olonen Anita Laitinen Sari Tiitinen Suvi Natunen Olli Aitio Halina Miller-Podraza Manfred Wuhrer André M. Deelder Jari Natunen Jarmo Laine Petri Lehenkari Juhani Saarinen Tero Satomaa Leena Valmu 《Glycoconjugate journal》2009,26(3):367-384
Human mesenchymal stem cells (MSCs) are adult multipotent progenitor cells. They hold an enormous therapeutic potential, but
at the moment there is little information on the properties of MSCs, including their surface structures. In the present study,
we analyzed the mesenchymal stem cell glycome by using mass spectrometric profiling as well as a panel of glycan binding proteins.
Structural verifications were obtained by nuclear magnetic resonance spectroscopy, mass spectrometric fragmentation, and glycosidase
digestions. The MSC glycome was compared to the glycome of corresponding osteogenically differentiated cells. More than one
hundred glycan signals were detected in mesenchymal stem cells and osteoblasts differentiated from them. The glycan profiles
of MSCs and osteoblasts were consistently different in biological replicates, indicating that stem cells and osteoblasts have
characteristic glycosylation features. Glycosylation features associated with MSCs rather than differentiated cells included
high-mannose type N-glycans, linear poly-N-acetyllactosamine chains and α2-3-sialylation. Mesenchymal stem cells expressed SSEA-4 and sialyl Lewis x epitopes. Characteristic
glycosylation features that appeared in differentiated osteoblasts included abundant sulfate ester modifications. The results
show that glycosylation analysis can be used to evaluate MSC differentiation state. 相似文献
143.
Outi Heikkinen Perttu Permi Harri Koskela Olli Carpén Jari Ylänne Ilkka Kilpeläinen 《Journal of biomolecular NMR》2009,44(2):107-112
Myotilin is a 57 kDa actin-binding and -bundling protein that consists of a unique serine-rich amino-terminus, two Ig-domains
and a short carboxy-terminus with a PDZ-binding motif. Myotilin localizes in sarcomeric Z-discs, where it interacts with several
sarcomeric proteins. Point mutations in myotilin cause muscle disorders morphologically highlighted by sarcomeric disarray
and aggregation. The actin-binding and dimerization propensity of myotilin has been mapped to the Ig-domains. Here we present
high-resolution structure of the first Ig-domain of myotilin (MyoIg1) determined with solution state NMR spectroscopy. Nearly
complete chemical shift assignments of MyoIg1 were achieved despite several missing backbone 1H-15N-HSQC signals. The structure derived from distance and dihedral angle restraints using torsion angle dynamics was further
refined using molecular dynamics. The structure of MyoIg1 exhibits I-type Ig-fold. The absence of several backbone 1H-15N-HSQC signals can be explained by conformational exchange taking place at the hydrophobic core of the protein.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
144.
Eva R. Kallio Michael Begon Heikki Henttonen Esa Koskela Tapio Mappes Antti Vaheri Olli Vapalahti 《Proceedings. Biological sciences / The Royal Society》2010,277(1701):3783-3791
Infected females may transfer maternal antibodies (MatAbs) to their offspring, which may then be transiently protected against infections the mother has encountered. However, the role of maternal protection in infectious disease dynamics in wildlife has largely been neglected. Here, we investigate the effects of Puumala hantavirus (PUUV)-specific MatAbs on PUUV dynamics, using 7 years'' data from a cyclic bank vole population in Finland. For the first time to our knowledge, we partition seropositivity data from a natural population into separate dynamic patterns for MatAbs and infection. The likelihood of young of the year carrying PUUV-specific MatAbs during the breeding season correlated positively with infection prevalence in the overwintered parent population in the preceding spring. The probability of PUUV infection varied between seasons (highest in spring, lowest in late summer) and depended on population structure, but was also, in late autumn, notably, negatively related to summer MatAb prevalence, as well as to infection prevalence earlier in the breeding season. Hence, our results suggest that high infection prevalence in the early breeding season leads to a high proportion of transiently immune young individuals, which causes delays in transmission. This suggests, in turn, that MatAb protection has the potential to affect infection dynamics in natural populations. 相似文献
145.
Mirva Piippo Niina Lietzén Olli S Nevalainen Jussi Salmi Tuula A Nyman 《BMC bioinformatics》2010,11(1):320
Background
Caspases are a family of proteases that have central functions in programmed cell death (apoptosis) and inflammation. Caspases mediate their effects through aspartate-specific cleavage of their target proteins, and at present almost 400 caspase substrates are known. There are several methods developed to predict caspase cleavage sites from individual proteins, but currently none of them can be used to predict caspase cleavage sites from multiple proteins or entire proteomes, or to use several classifiers in combination. The possibility to create a database from predicted caspase cleavage products for the whole genome could significantly aid in identifying novel caspase targets from tandem mass spectrometry based proteomic experiments. 相似文献146.
Sarah K. Coleman Tommi M?ykkynen Sami Hinkkuri Lauri Vaahtera Esa R. Korpi Olli T. Pentik?inen Kari Kein?nen 《The Journal of biological chemistry》2010,285(46):36032-36039
AMPA receptors (AMPARs) are tetrameric ion channels that mediate rapid glutamate signaling in neurons and many non-neuronal cell types. Endoplasmic reticulum (ER) quality control mechanisms permit only correctly folded functional receptors to be delivered to the cell surface. We analyzed the biosynthetic maturation and transport of all 12 GluA1–4 subunit splice variants as homomeric receptors and observed robust isoform-dependent differences in ER exit competence and surface expression. In contrast to inefficient ER exit of both GluA3 splice forms and the flop variants of GluA1 and GluA4, prominent plasma membrane expression was observed for the other AMPAR isoforms. Surprisingly, deletion of the entire N-terminal domain did not alter the transport phenotype, nor did the different cytosolic C-terminal tail splice variants. Detailed analysis of mutant receptors led to the identification of distinct residues in the ligand-binding domain as primary determinants for isoform-specific maturation. Considered together with the essential role of bound agonist, our findings reveal the ligand-binding domain as the critical quality control target in AMPAR biogenesis. 相似文献
147.
148.
Cloning, characterization and antifungal activity of defensin Tfgd1 from Trigonella foenum-graecum L
Defensins are small cysteine rich peptides with a molecular mass of 5-10 kDa and some of them exhibit potent antifungal activity. We have cloned the coding region of a cDNA of 225 bp cysteine rich defensin, named as Tfgd1, from the legume Trigonella foenum-graecum. The amino acid sequence deduced from the coding region comprised 74 amino acids, of which the N-terminal 27 amino acids constituted the signal peptide and the mature peptide comprised 47 amino acids. The protein is characterized by the presence of eight cysteine resisdues, conserved in the various plant defensins forming four disulphide bridges, which stabilize the mature peptide. The recombinant protein expressed in E coli exhibited antifungal activity against the broad host range fungus, Rhizoctonia solani and the peanut leaf spot fungus, Phaeoisariopsis personata. 相似文献
149.
150.