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Ortiz JL Sada PV Bellot Rubio LR Aceituno FJ Aceituno J Gutierrez PJ Thiele U 《Nature》2000,405(6789):921-923
Impacts of meteoroids on the Moon should cause detectable optical flashes, but the population of objects that are big enough is very low, and hitherto no unambiguous impact flashes have been recorded. The flux of meteoroids associated with the Leonid meteor shower of 18 November 1999 was predicted to produce observable flashes on the night side of the Moon. Here we report the unambiguous detection of five such impact flashes, three of which were seen simultaneously by other observers. We also observed a possible impact flash on 16 July 1999. All of the flashes were of very brief duration (<0.02 s), as expected for high-speed impacts. 相似文献
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Jacobs KB Yeager M Zhou W Wacholder S Wang Z Rodriguez-Santiago B Hutchinson A Deng X Liu C Horner MJ Cullen M Epstein CG Burdett L Dean MC Chatterjee N Sampson J Chung CC Kovaks J Gapstur SM Stevens VL Teras LT Gaudet MM Albanes D Weinstein SJ Virtamo J Taylor PR Freedman ND Abnet CC Goldstein AM Hu N Yu K Yuan JM Liao L Ding T Qiao YL Gao YT Koh WP Xiang YB Tang ZZ Fan JH Aldrich MC Amos C Blot WJ Bock CH Gillanders EM Harris CC Haiman CA Henderson BE Kolonel LN Le Marchand L McNeill LH 《Nature genetics》2012,44(6):651-658
In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases. 相似文献
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