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Your search keyword '"Bompadre, S."' showing total 150 results
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150 results on '"Bompadre, S."'

1. Unambiguous determination of the g-factor for holes in bismuth at high B/T

Author

Bompadre, S. G., Biagini, C., Maslov, D., and Hebard, A. F.

Subjects
Condensed Matter
Abstract

Magnetotransport has been investigated in high purity bismuth crystals in static magnetic fields as high as 20 T and temperatures as low as 25 mK. This high B/T ratio permits observation of pronounced Shubnikov-de Haas oscillations over a wide field range and up to fields where most of the carriers are in the lowest Landau level. For transport currents in the bisectrix or binary directions and field in the perpendicular trigonal direction, we have observed doublet splittings centered on each Shubnikov-de Haas oscillation. These splittings exhibit a quadratic dependence on field and disappear before the last oscillation. Our observations allow us to conclude unambiguously that already when the Landau level index is as high as 2 the carriers are fully polarized and that the g-factor for holes with the field in the trigonal direction is 35.3(4)., Comment: 4 pages, 3 figures

Published
2000
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2. Spin-Peierls transition in NaV2O5 in high magnetic fields

Author

Bompadre, S. G., Hebard, Arthur F., Kotov, Valeri N., Hall, D., Maris, G., Baas, J., and Palstra, T. T. M.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We investigate the magnetic field dependence of the spin-Peierls transition in NaV$_2$O$_5$ in the field range 16T-30T. The transition temperature exhibits a very weak variation with the field, suggesting a novel mechanism for the formation of the spin-Peierls state. We argue that a charge ordering transition accompanied by singlet formation is consistent with our observations., Comment: 4 pages, 3 figures, final version to appear in Phys. Rev. B (RC)

Published
1999
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8. Spin-Peierls transition in NaV2O5 in high magnetic fields

Author

Bompadre, S. G., Hebard, Arthur F., Kotov, Valeri N., Hall, D., Maris, G., Baas, J., Palstra, T. T. M., and Solid State Materials for Electronics

Subjects
Condensed Matter - Strongly Correlated Electrons, Strongly Correlated Electrons (cond-mat.str-el), STATES, PHASE-DIAGRAM, CUGEO3, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, FOS: Physical sciences, Condensed Matter::Strongly Correlated Electrons, DENSITY WAVES, GAP, COMPOUND ALPHA'-NAV2O5, CHARGE, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

We investigate the magnetic field dependence of the spin-Peierls transition in NaV$_2$O$_5$ in the field range 16T-30T. The transition temperature exhibits a very weak variation with the field, suggesting a novel mechanism for the formation of the spin-Peierls state. We argue that a charge ordering transition accompanied by singlet formation is consistent with our observations., Comment: 4 pages, 3 figures, final version to appear in Phys. Rev. B (RC)

Published
2000

9. Spin-Peierls transition in $NaV_{2}O{5}$ in high magnetic fields

Author

Bompadre, S. G., Hebard, A. F., Kotov, V. N., Hall, D., Baas, J., Palstra, T. T. M., Kapteyn Astronomical Institute, and Solid State Materials for Electronics

Subjects
ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Published
2000

19. Coenzyme Q, Vitamin E and Apo-E alleles in Alzheimer Disease

Author

Battino, M., primary, Bompadre, S., additional, Leone, L., additional, Devecchi, E., additional, Degiuli, A., additional, D'Agostino, F., additional, Cambiè, G., additional, D'Agostino, M., additional, Faggi, L., additional, Colturani, G., additional, Gorini, A., additional, and Villa, R. F., additional

Published
2003
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38. In vitro antioxidant activities of antioxidant-enriched toothpastes.

Author

Battino, M., Ferreiro, M. S., Armeni, T., Politi, A., Bompadre, S., Massoli, A., and Bullon, P.

Subjects
PERIODONTAL disease, ANTIOXIDANTS, TOOTHPASTE, LEUCOCYTES, ANTI-infective agents, SODIUM
Abstract

Several forms of periodontal diseases (PD) are often associated with modified phagocytosing leukocytes and contemporary free radical production. Host antioxidant defenses could benefit from toothpastes used as adjuncts to counteract plaque-associated bacteria. The aim of the present study was to determine possible antioxidant activity (AA) of 12 differently antioxidant-enriched toothpastes, regardless of their efficacy as antimicrobial agents. Toothpastes were enriched alternatively with sodium ascorbyl phosphate, α-tocopherol acetate, pycnogenol, allantoin and methyl salycilate or a mixture of these. AA was tested in a cell-free system with a ABTS-decolorization assay improved by means of a flow injection analysis device. Comet assay, using NCTC 2544 keratinocytes, was performed to test if it was possible to identify any protection against in vitro DNA fragmentation provoked by a challenge with H 2 O 2 in cultures pre-incubated with toothpaste extracts. Only toothpastes containing sodium ascorbyl phosphate displayed clear AA with I 50 values ranging between 50 and 80 mg of toothpaste/ml water. COMET analysis of cells challenged with H 2 O 2 in presence of toothpaste extracts revealed a limited protection exerted by sodium ascorbyl phosphate. The results described herein indicate that toothpastes containing sodium ascorbyl phosphate possess AA. All the data were obtained in systems in vitro and the demonstration of in vivo AA is desirable. These findings could be useful in the treatment and maintenance of some forms of PD and should be considered when arranging new toothpaste formulations. [ABSTRACT FROM AUTHOR]

Published
2005
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39. A Stochastic Formulation of the Gompertzian Growth Model for in vitro Bactericidal Kinetics: Parameter Estimation and Extinction Probability

Author

Ferrante, L., Bompadre, S., Leone, L., and Montanari, M. P.

Abstract

Time-kill curves have frequently been employed to study the antimicrobial effects of antibiotics. The relevance of pharmacodynamic modeling to these investigations has been emphasized in many studies of bactericidal kinetics. Stochastic models are needed that take into account the randomness of the mechanisms of both bacterial growth and bacteria-drug interactions. However, most of the models currently used to describe antibiotic activity against microorganisms are deterministic. In this paper we examine a stochastic differential equation representing a stochastic version of a pharmacodynamic model of bacterial growth undergoing random fluctuations, and derive its solution, mean value and covariance structure. An explicit likelihood function is obtained both when the process is observed continuously over a period of time and when data is sampled at time points, as is the custom in these experimental conditions. Some asymptotic properties of the maximum likelihood estimators for the model parameters are discussed. The model is applied to analyze in vitro time-kill data and to estimate model parameters; the probability of the bacterial population size dropping below some critical threshold is also evaluated. Finally, the relationship between bacterial extinction probability and the pharmacodynamic parameters estimated is discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2005
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