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101.
102.
Ana?s Pujals Lo?titia Favre Catherine Pioche-Durieu Aude Robert Guillaume Meurice Marion Le Gentil Sonia Chelouah Nadine Martin-Garcia Eric Le Cam Catherine Guettier Martine Rapha?l Lyubomir T Vassilev Philippe Gaulard Patrice Codogno Marc Lipinski Jo?lle Wiels 《Autophagy》2015,11(12):2275-2287
The Epstein-Barr virus (EBV) is associated with various lymphoproliferative disorders and lymphomas. We have previously demonstrated that treating wild-type TP53-expressing B cell lines with the TP53 pathway activator nutlin-3 induced apoptosis in EBV-negative and EBV-positive latency I cells whereas EBV-positive latency III cells remained much more apoptosis-resistant. Here, we report a constitutively high level of autophagy in these resistant cells which express high levels of the proautophagic protein BECN1/Beclin 1 based, at least in part, on the activation of the NFKB signaling pathway by the viral protein LMP1. Following treatment with nutlin-3, several autophagy-stimulating genes were upregulated both in EBV-negative and EBV-positive latency III cells. However the process of autophagy was only triggered in the latter and was associated with an upregulation of SESN1/sestrin 1 and inhibition of MTOR more rapid than in EBV-negative cells. A treatment with chloroquine, an inhibitor of autophagy, potentiated the apoptotic effect of nutlin-3, particularly in those EBV-positive cells which were resistant to apoptosis induced by nutlin-3 alone, thereby showing that autophagy participates in this resistant phenotype. Finally, using immunohistochemical staining, clinical samples from various B cell lymphoproliferations with the EBV-positive latency II or III phenotype were found to harbor a constitutively active autophagy. 相似文献
103.
104.
Oscar M. Saavedra Ljubomir Isakovic David B. Llewellyn Lijie Zhan Naomy Bernstein Stephen Claridge Franck Raeppel Arkadii Vaisburg Nadine Elowe Andrea J. Petschner Jubrail Rahil Norman Beaulieu A. Robert MacLeod Daniel Delorme Jeffrey M. Besterman Amal Wahhab 《Bioorganic & medicinal chemistry letters》2009,19(10):2747-2751
The inhibitory activity of base-modified SAH analogues and the specificity of inhibiting human DNMT1 and DNMT3b2 enzymes was explored. The 6-amino group was essential while the 7-N of the adenine ring of SAH could be replaced by CH– without loss of activity against both enzymes. The introduction of small groups at the 2-position of the adenine moiety favors DNMT1 over DNMT3b2 inhibition whereas alkylation of the N6-amino moiety favors the inhibition of DNMT3b2 enzyme. 相似文献
105.
Chris V. Bowen Drew DeBay H. Stephen Ewart Pamela Gallant Sean Gormley T. Toney Ilenchuk Umar Iqbal Tyler Lutes Marzia Martina Geoffrey Mealing Nadine Merkley Sandra Sperker Maria J. Moreno Christopher Rice Raymond T. Syvitski John M. Stewart 《PloS one》2013,8(3)
Soricidin is a 54-amino acid peptide found in the paralytic venom of the northern short-tailed shrew (Blarina brevicauda) and has been found to inhibit the transient receptor potential of vallinoid type 6 (TRPV6) calcium channels. We report that two shorter peptides, SOR-C13 and SOR-C27, derived from the C-terminus of soricidin, are high-affinity antagonists of human TRPV6 channels that are up-regulated in a number of cancers. Herein, we report molecular imaging methods that demonstrate the in vivo diagnostic potential of SOR-C13 and SOR-C27 to target tumor sites in mice bearing ovarian or prostate tumors. Our results suggest that these novel peptides may provide an avenue to deliver diagnostic and therapeutic reagents directly to TRPV6-rich tumors and, as such, have potential applications for a range of carcinomas including ovarian, breast, thyroid, prostate and colon, as well as certain leukemia''s and lymphomas. 相似文献
106.
Karine Tréguer Corinne Faucheux Philippe Veschambre Sandrine Fédou Nadine Thézé Pierre Thiébaud 《PloS one》2013,8(1)
ZFP36 constitutes a small family of RNA binding proteins (formerly known as the TIS11 family) that target mRNA and promote their degradation. In mammals, ZFP36 proteins are encoded by four genes and, although they show similar activities in a cellular RNA destabilization assay, there is still a limited knowledge of their mRNA targets and it is not known whether or not they have redundant functions. In the present work, we have used the Xenopus embryo, a model system allowing gain- and loss-of-function studies, to investigate, whether individual ZFP36 proteins had distinct or redundant functions. We show that overexpression of individual amphibian zfp36 proteins leads to embryos having the same defects, with alteration in somites segmentation and pronephros formation. In these embryos, members of the Notch signalling pathway such as hairy2a or esr5 mRNA are down-regulated, suggesting common targets for the different proteins. We also show that mouse Zfp36 protein overexpression gives the same phenotype, indicating an evolutionary conserved property among ZFP36 vertebrate proteins. Morpholino oligonucleotide-induced loss-of-function leads to defects in pronephros formation, reduction in tubule size and duct coiling alterations for both zfp36 and zfp36l1, indicating no functional redundancy between these two genes. Given the conservation in gene structure and function between the amphibian and mammalian proteins and the conserved mechanisms for pronephros development, our study highlights a potential and hitherto unreported role of ZFP36 gene in kidney morphogenesis. 相似文献
107.
108.
109.
Geneviève Girard Bj?rn A. Traag Vartul Sangal Nadine Mascini Paul A. Hoskisson Michael Goodfellow Gilles P. van Wezel 《Open biology》2013,3(10)
In the era when large whole genome bacterial datasets are generated routinely, rapid and accurate molecular systematics is becoming increasingly important. However, 16S ribosomal RNA sequencing does not always offer sufficient resolution to discriminate between closely related genera. The SsgA-like proteins are developmental regulatory proteins in sporulating actinomycetes, whereby SsgB actively recruits FtsZ during sporulation-specific cell division. Here, we present a novel method to classify actinomycetes, based on the extraordinary way the SsgA and SsgB proteins are conserved. The almost complete conservation of the SsgB amino acid (aa) sequence between members of the same genus and its high divergence between even closely related genera provides high-quality data for the classification of morphologically complex actinomycetes. Our analysis validates Kitasatospora as a sister genus to Streptomyces in the family Streptomycetaceae and suggests that Micromonospora, Salinispora and Verrucosispora may represent different clades of the same genus. It is also apparent that the aa sequence of SsgA is an accurate determinant for the ability of streptomycetes to produce submerged spores, dividing the phylogenetic tree of streptomycetes into liquid-culture sporulation and no liquid-culture sporulation branches. A new phylogenetic tree of industrially relevant actinomycetes is presented and compared with that based on 16S rRNA sequences. 相似文献
110.
Copper(II)-induced secondary structure changes and reduced folding stability of the prion protein 总被引:1,自引:0,他引:1
Younan ND Klewpatinond M Davies P Ruban AV Brown DR Viles JH 《Journal of molecular biology》2011,410(3):369-382
The cellular isoform of the prion protein PrPC is a Cu2+-binding cell surface glycoprotein that, when misfolded, is responsible for a range of transmissible spongiform encephalopathies. As changes in PrPC conformation are intimately linked with disease pathogenesis, the effect of Cu2+ ions on the structure and stability of the protein has been investigated. Urea unfolding studies indicate that Cu2+ ions destabilise the native fold of PrPC. The midpoint of the unfolding transition is reduced by 0.73 ± 0.07 M urea in the presence of 1 mol equiv of Cu2+. This equates to an appreciable difference in free energy of unfolding (2.02 ± 0.05 kJ mol− 1 at the midpoint of unfolding). We relate Cu2+-induced changes in secondary structure for full-length PrP(23-231) to smaller Cu2+ binding fragments. In particular, Cu2+-induced structural changes can directly be attributed to Cu2+ binding to the octarepeat region of PrPC. Furthermore, a β-sheet-like transition that is observed when Cu ions are bound to the amyloidogenic fragment of PrP (residues 90-126) is due only to local Cu2+ coordination to the individual binding sites centred at His95 and His110. Cu2+ binding does not directly generate a β-sheet conformation within PrPC; however, Cu2+ ions do destabilise the native fold of PrPC and may make the transition to a misfolded state more favourable. 相似文献