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41.
Vega-Hissi Esteban G. Andrada Matias F. Díaz Mario G. Garro Martinez Juan C. 《Molecular diversity》2019,23(4):985-995
Molecular Diversity - Although many sulfur containing garlic compounds present antioxidant activity, little is known about molecular mechanisms through which these compounds react with reactive... 相似文献
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Mauricio Gomes Constantino Luiz Gonzaga de Oliveira Matias Gil Valdo José da Silva Vladimir Constantino Gomes Heleno Maria Teresa do Prado Gambardella 《合成通讯》2013,43(24):4285-4295
Abstract: In this paper we describe a very short stereoselective synthesis of the β-ethoxylactone 13, a model structure for compounds isolated from Otoba parvifolia. The method, which also produces β-hydroxy-esters and β-hydroxy-lactones, is based on a chemo- and stereoselective Reformatsky reaction. 相似文献
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Matias?NavarroEmail authorView authors OrcID profile Oscar?Palmas Didier?A.?Solis 《Mediterranean Journal of Mathematics》2018,15(6):215
In this paper, we develop the notion of screen isoparametric hypersurface for null hypersurfaces of Robertson–Walker spacetimes. Using this formalism we derive Cartan identities for the screen principal curvatures of null screen isoparametric hypersurfaces in Lorentzian space forms and provide a local characterization of such hypersurfaces. 相似文献
45.
Matias Quiroz Minh-Ngoc Tran Mattias Villani Robert Kohn 《Journal of computational and graphical statistics》2018,27(1):12-22
The complexity of the Metropolis–Hastings (MH) algorithm arises from the requirement of a likelihood evaluation for the full dataset in each iteration. One solution has been proposed to speed up the algorithm by a delayed acceptance approach where the acceptance decision proceeds in two stages. In the first stage, an estimate of the likelihood based on a random subsample determines if it is likely that the draw will be accepted and, if so, the second stage uses the full data likelihood to decide upon final acceptance. Evaluating the full data likelihood is thus avoided for draws that are unlikely to be accepted. We propose a more precise likelihood estimator that incorporates auxiliary information about the full data likelihood while only operating on a sparse set of the data. We prove that the resulting delayed acceptance MH is more efficient. The caveat of this approach is that the full dataset needs to be evaluated in the second stage. We therefore propose to substitute this evaluation by an estimate and construct a state-dependent approximation thereof to use in the first stage. This results in an algorithm that (i) can use a smaller subsample m by leveraging on recent advances in Pseudo-Marginal MH (PMMH) and (ii) is provably within O(m? 2) of the true posterior. 相似文献
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Prosenjit Bose Sébastien Collette Ferran Hurtado Matias Korman Stefan Langerman Vera Sacristán Maria Saumell 《Computational Geometry》2013,46(2):131-139
We consider two classes of higher order proximity graphs defined on a set of points in the plane, namely, the k-Delaunay graph and the k-Gabriel graph. We give bounds on the following combinatorial and geometric properties of these graphs: spanning ratio, diameter, connectivity, chromatic number, and minimum number of layers necessary to partition the edges of the graphs so that no two edges of the same layer cross. 相似文献
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The thermal evolution of the cosmic gas decoupled from that of the cosmic microwave background (CMB) at a redshift z approximately 200. Afterwards and before the first stars had formed, the cosmic neutral hydrogen absorbed the CMB flux at its resonant 21 cm spin-flip transition. We calculate the evolution of the spin temperature for this transition and the resulting anisotropies that are imprinted on the CMB sky due to linear density fluctuations during this epoch. These anisotropies, at an observed wavelength of 10.56[(1+z)/50] m, contain an amount of information that is orders of magnitude larger than any other cosmological probe. 相似文献
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Daniele de Sanctis Antonia Beteva Hugo Caserotto Fabien Dobias José Gabadinho Thierry Giraud Alexandre Gobbo Matias Guijarro Mario Lentini Bernard Lavault Trevor Mairs Seán McSweeney Sébastien Petitdemange Vicente Rey‐Bakaikoa John Surr Pascal Theveneau Gordon A. Leonard Christoph Mueller‐Dieckmann 《Journal of synchrotron radiation》2012,19(3):455-461
ID29 is an ESRF undulator beamline with a routinely accessible energy range of between 20.0 keV and 6.0 keV (λ = 0.62 Å to 2.07 Å) dedicated to the use of anomalous dispersion techniques in macromolecular crystallography. Since the beamline was first commissioned in 2001, ID29 has, in order to provide an improved service to both its academic and proprietary users, been the subject of almost continuous upgrade and refurbishment. It is now also the home to the ESRF Cryobench facility, ID29S. Here, the current status of the beamline is described and plans for its future are briefly outlined. 相似文献