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Reynolds JH Hohenberg CM Lewis RS Davis PK Kaiser WA 《Science (New York, N.Y.)》1970,167(3918):545-548
Highlights of a first effort in sorting out rare gases in lunar material are solar wind rare gases in abundance; variable (20)Ne/(22)Ne but constant (21)Ne/ (22)Ne ratios in fractions of the trapped neon; cosmogenic rare gases similar to those found in meteorites, except for copious (131)Xe in one rock but not in another; at Tranquillity Base a rock 4.1 x 10(9) years old which reached the surface 35 to 65 million years ago, amid soil whose particles have typically been within a meter of the surface for 10(9) years or more. 相似文献
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Watson PJ Roulois A Scase T Holloway A Herrtage ME 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2011,25(4):797-804
Background: Chronic pancreatitis (CP) is common in dogs. The cause is unknown. In humans, different causes of pancreatitis have histologically distinct appearances. The histopathologic lesions in English Cocker Spaniels (ECS) with CP were noted to be histologically different than those of other breeds with CP. Hypothesis: CP in ECS is distinct from CP in other breeds and is characterized by a duct destruction similar to what is observed in autoimmune CP of humans. Animals: Eight ECS and 9 other breeds with histologically confirmed CP recruited over an 8‐year period and 50 postmortem control dogs with CP. Methods: Clinical, clinicopathological, and ultrasonographic findings were recorded. Histological sections were compared with a normal dog and 59 dogs of other breeds with CP. Immunohistochemistry using anti‐CD3, anti‐CD79a, and anti‐cytokeratin antibodies was used to evaluate distribution and type of lymphocytic inflammation and appearance of pancreatic ducts. Results: Four male and 4 female ECS presented at a mean age of 7.2 years. Clinical signs were similar in ECS and other breeds. The pancreas was enlarged and hypoechoic in 4 ECS and 2 controls. Histopathology was characterized by interlobular and periductular fibrosis and inflammation in ECS compared with intralobular disease in most other breeds. Immunohistochemistry identified prominent anti‐CD3+ lymphocytic infiltrates around venules and ducts and a marked absence of interlobular ducts in ECS compared with mixed T‐cell infiltration and ductular hyperplasia in most other breeds with CP. Conclusions and Clinical Importance: CP in ECS is distinct from CP in other breeds and is notably duct destructive. 相似文献
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The sequence of the Drosophila melanogaster genome presented in this issue of Science is the latest milestone in nine decades of research on this organism. Genetic and physical mapping, whole-genome mutational screens, and functional alteration of the genome by gene transfer were pioneered in metazoans with the use of this small fruit fly. Here we look at some of the instances in which work on Drosophila has led to major conceptual or technical breakthroughs in our understanding of animal genomes. 相似文献
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