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101.
Abdel Galil A. Hewaidy Gamal M. El Qot El Sayed M. Moneer 《Annales de Paléontologie》2019,105(1):45-61
The Campanian–lower Eocene sedimentary succession in the Kharga Oasis yields rare cephalopods that have so far received little attention. Eight cephalopod species; six nautiloids and two ammonites, are identified in the study area. The nautiloids are referred to five genera in three families. All nautiloid species are recorded from the Paleocene and Eocene rocks, two of which are described as new, as follows: Cimomia kurkurensis nov. sp. and Deltoidonautilus hassani nov. sp. The two ammonite species are Libycoceras ismaelis (von Zittel, 1884) and Baculites ovatus Say, 1820, representing the families Sphenodiscidae and Baculitidae, respectively. Baculites anceps of Quaas (1902, non Lamarck, 1822) from the Maastrichtian of the Western Desert of Egypt is here assigned to Baculites ovatus. The palaeobiogeography of these species is studied in detail. 相似文献
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103.
M. Wartski 《Médecine Nucléaire》2019,43(3):270-274
In pancreatic adenocarcinoma, initial imaging is essential to better select patients for surgery. Recent literature analysis of F18-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET) in pancreatic adenocarcinoma is summarized in the present article. Performances of FDG PET in the fields of lymph node involvement, metastatic involvement and therapeutic efficacy assessment are described for its correct use in pancreatic adenocarcinoma. 相似文献
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105.
Sebastian Swanson Venkatesh Sivaraman Gevorg Grigoryan Amy E. Keating 《Protein science : a publication of the Protein Society》2022,31(6)
Despite advances in protein engineering, the de novo design of small proteins or peptides that bind to a desired target remains a difficult task. Most computational methods search for binder structures in a library of candidate scaffolds, which can lead to designs with poor target complementarity and low success rates. Instead of choosing from pre‐defined scaffolds, we propose that custom peptide structures can be constructed to complement a target surface. Our method mines tertiary motifs (TERMs) from known structures to identify surface‐complementing fragments or “seeds.” We combine seeds that satisfy geometric overlap criteria to generate peptide backbones and score the backbones to identify the most likely binding structures. We found that TERM‐based seeds can describe known binding structures with high resolution: the vast majority of peptide binders from 486 peptide‐protein complexes can be covered by seeds generated from single‐chain structures. Furthermore, we demonstrate that known peptide structures can be reconstructed with high accuracy from peptide‐covering seeds. As a proof of concept, we used our method to design 100 peptide binders of TRAF6, seven of which were predicted by Rosetta to form higher‐quality interfaces than a native binder. The designed peptides interact with distinct sites on TRAF6, including the native peptide‐binding site. These results demonstrate that known peptide‐binding structures can be constructed from TERMs in single‐chain structures and suggest that TERM information can be applied to efficiently design novel target‐complementing binders. 相似文献
106.
《Comptes Rendus Palevol》2014,13(7):637-645
From the end of 1830, Étienne Geoffroy Saint-Hilaire worked to prepare a book on thalattosuchians (Mesoeucrocodylia, Thalattosuchia) from the Jurassic of Normandy. This work, planned to be entitled “Histoire des crocodiliens renfermés dans le terrain oolithique”, was never completed. Searches in the archives of the central library of the “Muséum national d’histoire naturelle”, Paris, resulted in the rediscovery of the set of original drawings ordered by Geoffroy Saint-Hilaire to illustrate his book. These drawings, 21 in total, were executed by several artists working in the Muséum, including Jean-Charles Werner, Henri-Joseph Redouté, and Nicolas Hüet. Geoffroy Saint-Hilaire offered this collection of drawings to the French Academy of Sciences in March 1834. These drawings were then donated to the library of the Muséum in November 1924 by Alfred Lacroix. This iconographic collection is of the highest importance for the history of palaeontology in France as it depicts unknown specimens that were destroyed during World War II. 相似文献
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Chromosome rearrangements during domestication of cucumber as revealed by high-density genetic mapping and draft genome assembly 总被引:2,自引:0,他引:2
Yang L Koo DH Li Y Zhang X Luan F Havey MJ Jiang J Weng Y 《The Plant journal : for cell and molecular biology》2012,71(6):895-906
Cucumber, Cucumis sativus L. is the only taxon with 2n = 2x = 14 chromosomes in the genus Cucumis. It consists of two cross‐compatible botanical varieties: the cultivated C. sativus var. sativus and the wild C. sativus var. hardwickii. There is no consensus on the evolutionary relationship between the two taxa. Whole‐genome sequencing of the cucumber genome provides a new opportunity to advance our understanding of chromosome evolution and the domestication history of cucumber. In this study, a high‐density genetic map for cultivated cucumber was developed that contained 735 marker loci in seven linkage groups spanning 707.8 cM. Integration of genetic and physical maps resulted in a chromosome‐level draft genome assembly comprising 193 Mbp, or 53% of the 367 Mbp cucumber genome. Strategically selected markers from the genetic map and draft genome assembly were employed to screen for fosmid clones for use as probes in comparative fluorescence in situ hybridization analysis of pachytene chromosomes to investigate genetic differentiation between wild and cultivated cucumbers. Significant differences in the amount and distribution of heterochromatins, as well as chromosomal rearrangements, were uncovered between the two taxa. In particular, six inversions, five paracentric and one pericentric, were revealed in chromosomes 4, 5 and 7. Comparison of the order of fosmid loci on chromosome 7 of cultivated and wild cucumbers, and the syntenic melon chromosome I suggested that the paracentric inversion in this chromosome occurred during domestication of cucumber. The results support the sub‐species status of these two cucumber taxa, and suggest that C. sativus var. hardwickii is the progenitor of cultivated cucumber. 相似文献
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110.
Miguel Ángel De la Cámara Sara Higueras-Fresnillo David Martinez-Gomez Óscar L. Veiga 《Revista espa?ola de geriatría y gerontología》2018,53(6)