Elemental and redox analysis of single bacterial cells by x-ray microbeam analysis     

Kemner KM  Kelly SD  Lai B  Maser J  O'loughlin EJ  Sholto-Douglas D  Cai Z  Schneegurt MA  Kulpa CF  Nealson KH 《Science (New York, N.Y.)》2004,306(5696):686-687

High-energy x-ray fluorescence measurements were used to make elemental maps and qualitative chemical analyses of individual Pseudomonas fluorescens strain NCIMB 11764 cells. Marked differences between planktonic and adhered cells were seen in the morphology, elemental composition, and sensitivity to Cr(VI) of hydrated cells at spatial scales of 150 nm. This technology can be applied to natural geomicrobiological systems.  相似文献   

Atmospheric science. Wind data: a promise in peril     

Kelly KA 《Science (New York, N.Y.)》2004,303(5660):962-963

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Specific tropism of HIV-1 for microglial cells in primary human brain cultures   总被引：34，自引：0，他引：34  

B A Watkins  H H Dorn  W B Kelly  R C Armstrong  B J Potts  F Michaels  C V Kufta  M Dubois-Dalcq 《Science (New York, N.Y.)》1990,249(4968):549-553

Human immunodeficiency virus (HIV) frequently causes neurological dysfunction and is abundantly expressed in the central nervous system (CNS) of acquired immunodeficiency syndrome (AIDS) patients with HIV encephalitis or myelopathy. The virus is found mostly in cells of the monocyte-macrophage lineage within the CNS, but the possibility of infection of other glial cells has been raised. Therefore, the effects of different HIV-1 and HIV-2 strains were studied in primary cultures of adult human brain containing microglial cells, the resident CNS macrophages, and astrocytes. These cultures could be productively infected with macrophage-adapted HIV-1 isolates but not with T lymphocyte-adapted HIV-1 isolates or two HIV-2 isolates. As determined with a triple-label procedure, primary astrocytes did not express HIV gag antigens and remained normal throughout the 3-week course of infection. In contrast, virus replicated in neighboring microglial cells, often leading to their cell fusion and death. The death of microglial cells, which normally serve immune functions in the CNS, may be a key factor in the pathogenesis of AIDS encephalitis or myelopathy.  相似文献   

Abductin: a rubber-like protein from the internal triangular hinge ligament of pecten     

R E Kelly  R V Rice 《Science (New York, N.Y.)》1967,155(759):208-210

The rubber-like internal triangular hinge ligament from Pecten was studied by light and electron microscopy, x-ray diffraction, and chemical analysis. The ligament is composed of an amorphous protein, abductin. In physical properties abductin is similar to elastin and resilin but distinct by amino acid analysis. It is characterized by high concentrations of glycine and methionine.  相似文献   

Expression of a zinc finger gene in HTLV-I- and HTLV-II-transformed cells   总被引：9，自引：0，他引：9  

J J Wright  K C Gunter  H Mitsuya  S G Irving  K Kelly  U Siebenlist 《Science (New York, N.Y.)》1990,248(4955):588-591

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Thunderstorms: an important mechanism in the transport of air pollutants   总被引：3，自引：0，他引：3  

Dickerson RR  Huffman GJ  Luke WT  Nunnermacker LJ  Pickering KE  Leslie AC  Lindsey CG  Slinn WG  Kelly TJ  Daum PH  Delany AC  Greenberg JP  Zimmerman PR  Boatman JF  Ray JD  Stedman DH 《Science (New York, N.Y.)》1987,235(4787):460-465

Acid deposition and photochemical smog are urban air pollution problems, and they remain localized as long as the sulfur, nitrogen, and hydrocarbon pollutants are confined to the lower troposphere (below about 1-kilometer altitude) where they are short-lived. If, however, the contaminants are rapidly transported to the upper troposphere, then their atmospheric residence times grow and their range of influence expands dramatically. Although this vertical transport ameliorates some of the effects of acid rain by diluting atmospheric acids, it exacerbates global tropospheric ozone production by redistributing the necessary nitrogen catalysts. Results of recent computer simulations suggest that thunderstorms are one means of rapid vertical transport. To test this hypothesis, several research aircraft near a midwestern thunderstrom measured carbon monoxide, hydrocarbons, ozone, and reactive nitrogen compounds. Their concentrations were much greater in the outflow region of the storm, up to 11 kilometers in altitude, than in surrounding air. Trace gas measurements can thus be used to track the motion of air in and around a cloud. Thunderstorms may transform local air pollution problems into regional or global atmospheric chemistry problems.  相似文献   

On the origin of bacterial resistance to penicillin: comparison of a beta-lactamase and a penicillin target   总被引：12，自引：0，他引：12  

J A Kelly  O Dideberg  P Charlier  J P Wery  M Libert  P C Moews  J R Knox  C Duez  C Fraipont  B Joris 《Science (New York, N.Y.)》1986,231(4744):1429-1431

Structural data are now available for comparing a penicillin target enzyme, the D-alanyl-D-alanine-peptidase from Streptomyces R61, with a penicillin-hydrolyzing enzyme, the beta-lactamase from Bacillus licheniformis 749/C. Although the two enzymes have distinct catalytic properties and lack relatedness in their overall amino acid sequences except near the active-site serine, the significant similarity found by x-ray crystallography in the spatial arrangement of the elements of secondary structure provides strong support for earlier hypotheses that beta-lactamases arose from penicillin-sensitive D-alanyl-D-alanine-peptidases involved in bacterial wall peptidoglycan metabolism.  相似文献   

A High-Temperature Electrical Conduction Mechanism in the Lower Mantle Phase (Mg,Fe)1-xO     

DP Dobson  NC Richmond  JP Brodholt 《Science (New York, N.Y.)》1997,275(5307):1779-1781

Measurements of electrical conductivity at high pressure and temperature were taken on the lower mantle phase magnesiowustite with varying Fe3+ content. Although previous measurements at atmospheric pressure suggest Fe2+-Fe3+ hopping (small polaron) as the dominant conductivity mechanism, the present experiments show a change in charge transport mechanism with temperature. The lower temperature measurements are consistent with small polaron conduction, but at higher temperatures, which are more applicable to the lower mantle, a large polaron mechanism is suggested. Because these mechanisms have different temperature and compositional dependencies, this transition has important implications for extrapolation to mantle conditions.  相似文献   

THE SYNTHESIS OF FULL COLORATION IN PHLOX     

Kelly JP 《Science (New York, N.Y.)》1922,55(1418):245-246

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Phytoplankton algae: nutrient concentrations and growth     

Holmes P  Kelly MG  Hornberger GM  O'brien WJ 《Science (New York, N.Y.)》1973,180(4092):1298-1300

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