THE PURIFICATION OF SPECTROGRAPHIC CARBONS     

Zietlow R  Hamm P  Nelson RC 《Science (New York, N.Y.)》1941,94(2445):438-439

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No wrangle     

Nelson M 《Science (New York, N.Y.)》1970,170(3956):389

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Military research: a decline in the interest of scientists?     

B Nelson 《Science (New York, N.Y.)》1967,156(773):364-366

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Categorical perception of a natural stimulus continuum: birdsong   总被引：2，自引：0，他引：2  

D A Nelson  P Marler 《Science (New York, N.Y.)》1989,244(4907):976-978

A fundamental issue in perception and communication is how continuously varying stimuli are partitioned into discrete categories. In swamp sparrow songs, note duration is a critical feature distinguishing two note categories with different roles in song construction. Pairs of songs with initial notes from different categories contrast more in their effects on territorial males than song pairs with initial notes differing by the same amount but taken from within one note category. The results indicate categorical perception by wild swamp sparrows.  相似文献   

Early behavioral plasticity: perinatal development     

Nelson PG 《Science (New York, N.Y.)》1988,240(4857):1351-1352

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TRANSFERENCE OF THE BEAN MOSAIC VIRUS BY MACROSIPHUM SOLANIFOLII     

Nelson R 《Science (New York, N.Y.)》1922,56(1447):342-344

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Communication Gap: LBJ's Monologue with the Intellectuals     

Nelson B 《Science (New York, N.Y.)》1967,157(3785):173-176

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Morphogenesis of the polarized epithelial cell phenotype   总被引：152，自引：0，他引：152  

E Rodriguez-Boulan  W J Nelson 《Science (New York, N.Y.)》1989,245(4919):718-725

Polarized epithelial cells play fundamental roles in the ontogeny and function of a variety of tissues and organs in mammals. The morphogenesis of a sheet of polarized epithelial cells (the trophectoderm) is the first overt sign of cellular differentiation in early embryonic development. In the adult, polarized epithelial cells line all body cavities and occur in tissues that carry out specialized vectorial transport functions of absorption and secretion. The generation of this phenotype is a multistage process requiring extracellular cues and the reorganization of proteins in the cytoplasm and on the plasma membrane; once established, the phenotype is maintained by the segregation and retention of specific proteins and lipids in distinct apical and basal-lateral plasma membrane domains.  相似文献   

Heparin promotes the inactivation of antithrombin by neutrophil elastase   总被引：2，自引：0，他引：2  

R E Jordan  J Kilpatrick  R M Nelson 《Science (New York, N.Y.)》1987,237(4816):777-779

Heparin is an acceleratory cofactor for antithrombin, a circulating inhibitor of blood coagulation enzymes. The presence of heparin on blood vessel walls is believed to contribute to the nonthrombogenic properties of those surfaces. In apparent opposition to this function, heparin was found to greatly accelerate the in vitro inactivation of antithrombin by neutrophil elastase. Inactivation rates in solution were potentiated several hundredfold by specific heparin fractions with anticoagulant activity. Although the data suggest that a heparin-antithrombin complex is essential for the inactivation by elastase to occur, the enzyme itself interacts tightly with heparin. These results suggest a mechanism which, if operating in vivo, could lead to a localized neutralization of the anticoagulant function of heparin at the endothelial surface.  相似文献   

Ultrafast bond softening in bismuth: mapping a solid's interatomic potential with X-rays     

Fritz DM  Reis DA  Adams B  Akre RA  Arthur J  Blome C  Bucksbaum PH  Cavalieri AL  Engemann S  Fahy S  Falcone RW  Fuoss PH  Gaffney KJ  George MJ  Hajdu J  Hertlein MP  Hillyard PB  Horn-von Hoegen M  Kammler M  Kaspar J  Kienberger R  Krejcik P  Lee SH  Lindenberg AM  McFarland B  Meyer D  Montagne T  Murray ED  Nelson AJ  Nicoul M  Pahl R  Rudati J  Schlarb H  Siddons DP  Sokolowski-Tinten K  Tschentscher T  von der Linde D  Hastings JB 《Science (New York, N.Y.)》2007,315(5812):633-636

Intense femtosecond laser excitation can produce transient states of matter that would otherwise be inaccessible to laboratory investigation. At high excitation densities, the interatomic forces that bind solids and determine many of their properties can be substantially altered. Here, we present the detailed mapping of the carrier density-dependent interatomic potential of bismuth approaching a solid-solid phase transition. Our experiments combine stroboscopic techniques that use a high-brightness linear electron accelerator-based x-ray source with pulse-by-pulse timing reconstruction for femtosecond resolution, allowing quantitative characterization of the interatomic potential energy surface of the highly excited solid.  相似文献