排序方式: 共有60条查询结果,搜索用时 15 毫秒
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Tagliaferri G Goad M Chincarini G Moretti A Campana S Burrows DN Perri M Barthelmy SD Gehrels N Krimm H Sakamoto T Kumar P Mészáros PI Kobayashi S Zhang B Angelini L Banat P Beardmore AP Capalbi M Covino S Cusumano G Giommi P Godet O Hill JE Kennea JA Mangano V Morris DC Nousek JA O'Brien PT Osborne JP Pagani C Page KL Romano P Stella L Wells A 《Nature》2005,436(7053):985-988
'Long' gamma-ray bursts (GRBs) are commonly accepted to originate in the explosion of particularly massive stars, which give rise to highly relativistic jets. Inhomogeneities in the expanding flow result in internal shock waves that are believed to produce the gamma-rays we see. As the jet travels further outward into the surrounding circumstellar medium, 'external' shocks create the afterglow emission seen in the X-ray, optical and radio bands. Here we report observations of the early phases of the X-ray emission of five GRBs. Their X-ray light curves are characterised by a surprisingly rapid fall-off for the first few hundred seconds, followed by a less rapid decline lasting several hours. This steep decline, together with detailed spectral properties of two particular bursts, shows that violent shock interactions take place in the early jet outflows. 相似文献
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Theologis A Ecker JR Palm CJ Federspiel NA Kaul S White O Alonso J Altafi H Araujo R Bowman CL Brooks SY Buehler E Chan A Chao Q Chen H Cheuk RF Chin CW Chung MK Conn L Conway AB Conway AR Creasy TH Dewar K Dunn P Etgu P Feldblyum TV Feng J Fong B Fujii CY Gill JE Goldsmith AD Haas B Hansen NF Hughes B Huizar L Hunter JL Jenkins J Johnson-Hopson C Khan S Khaykin E Kim CJ Koo HL Kremenetskaia I Kurtz DB Kwan A Lam B Langin-Hooper S Lee A Lee JM Lenz CA Li JH Li Y Lin X Liu SX Liu ZA Luros JS 《Nature》2000,408(6814):816-820
The genome of the flowering plant Arabidopsis thaliana has five chromosomes. Here we report the sequence of the largest, chromosome 1, in two contigs of around 14.2 and 14.6 megabases. The contigs extend from the telomeres to the centromeric borders, regions rich in transposons, retrotransposons and repetitive elements such as the 180-base-pair repeat. The chromosome represents 25% of the genome and contains about 6,850 open reading frames, 236 transfer RNAs (tRNAs) and 12 small nuclear RNAs. There are two clusters of tRNA genes at different places on the chromosome. One consists of 27 tRNA(Pro) genes and the other contains 27 tandem repeats of tRNA(Tyr)-tRNA(Tyr)-tRNA(Ser) genes. Chromosome 1 contains about 300 gene families with clustered duplications. There are also many repeat elements, representing 8% of the sequence. 相似文献
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Ding L Getz G Wheeler DA Mardis ER McLellan MD Cibulskis K Sougnez C Greulich H Muzny DM Morgan MB Fulton L Fulton RS Zhang Q Wendl MC Lawrence MS Larson DE Chen K Dooling DJ Sabo A Hawes AC Shen H Jhangiani SN Lewis LR Hall O Zhu Y Mathew T Ren Y Yao J Scherer SE Clerc K Metcalf GA Ng B Milosavljevic A Gonzalez-Garay ML Osborne JR Meyer R Shi X Tang Y Koboldt DC Lin L Abbott R Miner TL Pohl C Fewell G Haipek C Schmidt H Dunford-Shore BH Kraja A Crosby SD Sawyer CS Vickery T Sander S Robinson J 《Nature》2008,455(7216):1069-1075
Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers--including NF1, APC, RB1 and ATM--and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment. 相似文献
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Weir BA Woo MS Getz G Perner S Ding L Beroukhim R Lin WM Province MA Kraja A Johnson LA Shah K Sato M Thomas RK Barletta JA Borecki IB Broderick S Chang AC Chiang DY Chirieac LR Cho J Fujii Y Gazdar AF Giordano T Greulich H Hanna M Johnson BE Kris MG Lash A Lin L Lindeman N Mardis ER McPherson JD Minna JD Morgan MB Nadel M Orringer MB Osborne JR Ozenberger B Ramos AH Robinson J Roth JA Rusch V Sasaki H Shepherd F Sougnez C Spitz MR Tsao MS Twomey D Verhaak RG Weinstock GM Wheeler DA Winckler W 《Nature》2007,450(7171):893-898
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Injection of 5,7-dihydroxytryptamine into the substantia nigra of rats produces an increase of dopamine in the ipsilateral striatum, and when these animals are injected with amphetamine they do not exhibit any rotation. The mode of action of this neurotoxin is compared with that of 6-hydroxydopamine. 相似文献
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