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排序方式: 共有178条查询结果,搜索用时 15 毫秒
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Allergic host defences 总被引:1,自引:0,他引:1
Allergies are generally thought to be a detrimental outcome of a mistargeted immune response that evolved to provide immunity to macroparasites. Here we present arguments to suggest that allergic immunity has an important role in host defence against noxious environmental substances, including venoms, haematophagous fluids, environmental xenobiotics and irritants. We argue that appropriately targeted allergic reactions are beneficial, although they can become detrimental when excessive. Furthermore, we suggest that allergic hypersensitivity evolved to elicit anticipatory responses and to promote avoidance of suboptimal environments. 相似文献
34.
Peroxiredoxins are conserved markers of circadian rhythms 总被引:1,自引:0,他引:1
35.
S Neph J Vierstra AB Stergachis AP Reynolds E Haugen B Vernot RE Thurman S John R Sandstrom AK Johnson MT Maurano R Humbert E Rynes H Wang S Vong K Lee D Bates M Diegel V Roach D Dunn J Neri A Schafer RS Hansen T Kutyavin E Giste M Weaver T Canfield P Sabo M Zhang G Balasundaram R Byron MJ MacCoss JM Akey MA Bender M Groudine R Kaul JA Stamatoyannopoulos 《Nature》2012,489(7414):83-90
36.
Zody MC Garber M Sharpe T Young SK Rowen L O'Neill K Whittaker CA Kamal M Chang JL Cuomo CA Dewar K FitzGerald MG Kodira CD Madan A Qin S Yang X Abbasi N Abouelleil A Arachchi HM Baradarani L Birditt B Bloom S Bloom T Borowsky ML Burke J Butler J Cook A DeArellano K DeCaprio D Dorris L Dors M Eichler EE Engels R Fahey J Fleetwood P Friedman C Gearin G Hall JL Hensley G Johnson E Jones C Kamat A Kaur A Locke DP Madan A Munson G Jaffe DB Lui A Macdonald P Mauceli E Naylor JW Nesbitt R Nicol R 《Nature》2006,440(7084):671-675
Here we present a finished sequence of human chromosome 15, together with a high-quality gene catalogue. As chromosome 15 is one of seven human chromosomes with a high rate of segmental duplication, we have carried out a detailed analysis of the duplication structure of the chromosome. Segmental duplications in chromosome 15 are largely clustered in two regions, on proximal and distal 15q; the proximal region is notable because recombination among the segmental duplications can result in deletions causing Prader-Willi and Angelman syndromes. Sequence analysis shows that the proximal and distal regions of 15q share extensive ancient similarity. Using a simple approach, we have been able to reconstruct many of the events by which the current duplication structure arose. We find that most of the intrachromosomal duplications seem to share a common ancestry. Finally, we demonstrate that some remaining gaps in the genome sequence are probably due to structural polymorphisms between haplotypes; this may explain a significant fraction of the gaps remaining in the human genome. 相似文献
37.
Edwards SL Brough R Lord CJ Natrajan R Vatcheva R Levine DA Boyd J Reis-Filho JS Ashworth A 《Nature》2008,451(7182):1111-1115
Cells with loss of BRCA2 function are defective in homologous recombination (HR) and are highly sensitive to inhibitors of poly(ADP-ribose) polymerase (PARP), which provides the basis for a new therapeutic approach. Here we show that resistance to PARP inhibition can be acquired by deletion of a mutation in BRCA2. We derived PARP-inhibitor-resistant (PIR) clones from the human CAPAN1 pancreatic cancer cell line, which carries the protein-truncating c.6174delT frameshift mutation. PIR clones could form DNA-damage-induced RAD51 nuclear foci and were able to limit genotoxin-induced genomic instability, both hallmarks of a competent HR pathway. New BRCA2 isoforms were expressed in the resistant lines as a result of intragenic deletion of the c.6174delT mutation and restoration of the open reading frame (ORF). Reconstitution of BRCA2-deficient cells with these revertant BRCA2 alleles rescued PARP inhibitor sensitivity and HR deficiency. Most of the deletions in BRCA2 were associated with small tracts of homology, and possibly arose from error-prone repair caused by BRCA2 deficiency. Similar ORF-restoring mutations were present in carboplatin-resistant ovarian tumours from c.6174delT mutation carriers. These observations have implications for understanding drug resistance in BRCA mutation carriers as well as in defining functionally important domains within BRCA2. 相似文献
38.
Olfactory signals are transduced by a large family of odorant receptor proteins, each of which corresponds to a unique glomerulus in the first olfactory relay of the brain. Crosstalk between glomeruli has been proposed to be important in olfactory processing, but it is not clear how these interactions shape the odour responses of second-order neurons. In the Drosophila antennal lobe (a region analogous to the vertebrate olfactory bulb), we selectively removed most interglomerular input to genetically identified second-order olfactory neurons. Here we show that this broadens the odour tuning of these neurons, implying that interglomerular inhibition dominates over interglomerular excitation. The strength of this inhibitory signal scales with total feedforward input to the entire antennal lobe, and has similar tuning in different glomeruli. A substantial portion of this interglomerular inhibition acts at a presynaptic locus, and our results imply that this is mediated by both ionotropic and metabotropic receptors on the same nerve terminal. 相似文献
39.
Beddington J Cooper CL Field J Goswami U Huppert FA Jenkins R Jones HS Kirkwood TB Sahakian BJ Thomas SM 《Nature》2008,455(7216):1057-1060
Countries must learn how to capitalize on their citizens' cognitive resources if they are to prosper, both economically and socially. Early interventions will be key. 相似文献
40.
Carol RJ Takeda S Linstead P Durrant MC Kakesova H Derbyshire P Drea S Zarsky V Dolan L 《Nature》2005,438(7070):1013-1016
Root hairs are cellular protuberances extending from the root surface into the soil; there they provide access to immobile inorganic ions such as phosphate, which are essential for growth. Their cylindrical shape results from a polarized mechanism of cell expansion called tip growth in which elongation is restricted to a small area at the surface of the hair-forming cell (trichoblast) tip. Here we identify proteins that spatially control the sites at which cell growth occurs by isolating Arabidopsis mutants (scn1) that develop ectopic sites of growth on trichoblasts. We cloned SCN1 and showed that SCN1 is a RhoGTPase GDP dissociation inhibitor (RhoGDI) that spatially restricts the sites of growth to a single point on the trichoblast. We showed previously that localized production of reactive oxygen species by RHD2/AtrbohC NADPH oxidase is required for hair growth; here we show that SCN1/AtrhoGDI1 is a component of the mechanism that focuses RHD2/AtrbohC-catalysed production of reactive oxygen species to hair tips during wild-type development. We propose that the spatial organization of growth in plant cells requires the local RhoGDI-regulated activation of the RHD2/AtrbohC NADPH oxidase. 相似文献