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Luigia Serpico Mauro De Nisco Flavio Cermola Michele Manfra Silvana Pedatella 《Molecules (Basel, Switzerland)》2021,26(9)
A simple and efficient route for the synthesis of new glycoconjugates has been developed. The approach acts as a model for a mini-library of compounds with a deoxy-selenosugar core joined to a polyphenolic moiety with well-known antioxidant properties. An unexpected stereocontrol detected in the Mitsunobu key reaction led to the most attractive product showing a natural d-configuration. Thus, we were able to obtain the target molecules from the commercially available d-ribose via a shorter and convenient sequence of reactions. 相似文献
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M. d'Aquino C. Serpico G. Bertotti R. Bonin I.D. Mayergoyz 《Physica B: Condensed Matter》2012,407(9):1389-1393
The thermally induced magnetization dynamics in the presence of spin-polarized currents injected into a spin-valve-like structure used as microwave spin-transfer nano-oscillator (STNO) is considered. Magnetization dynamics is described by the stochastic Landau-Lifshitz-Slonczewski (LLS) equation. First, it is shown that, in the presence of thermal fluctuations, the spectrum of the output signal of the STNO exhibits multiple peaks at low and high frequencies. This circumstance is associated with the occurrence of thermally induced transitions between stationary states and magnetization self-oscillations. Then, a theoretical approach based on the separation of time-scales is developed to obtain a stochastic dynamics only in the slow state variable, namely the energy. The stationary distribution of the energy and the aforementioned transition rates are analytically computed and compared with the results of direct integration of the LLS dynamics, showing very good agreement. 相似文献
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R. Bonin M. d’Aquino G. Bertotti C. Serpico I. D. Mayergoyz 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(1):47
The stability of large precessional magnetization motions induced by spin-polarized
currents in spin-transfer nano-oscillators is discussed. Quantitative analytical
predictions are obtained for the critical values of spin-polarized injected current and
external magnetic field at which the oscillator magnetization precession becomes unstable.
It is shown that the mechanism leading to instability is parametric resonance of
well-defined pairs of magnetostatically coupled perturbation modes. The amplitude of these
modes grows to large non-thermal values when the oscillator frequency matches the mean of
the natural frequencies of the two coupled modes. Analytical predictions are obtained for
the space-time structure and symmetry of the magnetization patterns that are formed at the
instability. Analytical results are compared with numerical simulations of
spin-transfer-driven magnetization dynamics. 相似文献
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The people and places of importance to the history of chemistry in Italy have been reviewed with particular reference to Analytical
Chemistry.
Correspondence: D. Thorburn Burns, The Science Library, The Queen’s University of Belfast, Belfast BT9 5EQ, Northern Ireland 相似文献
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Longo L Vasapollo G Guascito MR Malitesta C 《Analytical and bioanalytical chemistry》2006,385(1):146-152
A three-step process for immobilization of glutamate dehydrogenase (GDH) on the surface of silicon dioxide has been studied
by X-ray photoelectron spectroscopy (XPS). The enzyme layer was deposited on the silicon dioxide surface after first exposing
the surface to 3-aminopropyltriethoxysilane (3-APTS) and reacting the silylated surface with glutaraldehyde (GA). Fine XPS
analysis, performed after each step of the chemical procedure, revealed unknown details of the step-by-step construction of
the enzyme layer under different experimental conditions. 相似文献
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Luigia Di Terlizzi 《Mediterranean Journal of Mathematics》2006,3(3-4):533-547
We consider a Riemannian manifold (M,g) equipped with an f-structure of constant rank with parallelizable kernel. We assume certain integrability conditions on
such a manifold. We prove some inequalities involving the scalar and *-scalar curvature of g. We prove that the corresponding equalities characterize an
-manifold, which is a generalization of a Sasakian manifold. We also give a method of constructing such structures on toroidal
bundles.
Dedicated to the memory of Professor Aldo Cossu
Research supported by the Italian MIUR 60% and GNSAGA. 相似文献
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Giuseppe E. De Benedetto Silvia Nicolì Antonio Pennetta Daniela Rizzo Luigia Sabbatini Annarosa Mangone 《Journal of Raman spectroscopy : JRS》2011,42(6):1317-1323
Painted Canosa ceramics were examined to identify the nature of the pigments employed and their manufacturing technology. A multi‐technique approach was used, comprising Raman microspectroscopy and laser ablation hyphenated to inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS). The analysed samples were mainly produced for burial in tombs and were not intended for everyday use. They belong to the period between the end of the mid‐7th century and the first half of the 4th century BC, and were excavated from the Toppicelli archaeological district near the suburbs of Canosa (Puglia, Italy). Forty‐eight pottery fragments were available for this study. No handling of the samples was required for the Raman study, and it was possible to excise the pigmented layer in such a way that the lacunae were not distinguishable to the naked eye due to the micrometric size of the laser spot as far as LA‐ICP‐MS is concerned. Their combination turned out to be quite useful for the investigation of these archaeological materials: the chemical nature of the white, red, brown and black pigments employed in the pottery manufacture was investigated. Iron and manganese compounds were identified as the red and brown/black main colouring substances, respectively; on the other hand, whites and engobes (whitish slips) were based on kaolinite. This set of colouring substances is of importance, as it enabled the artisan to obtain in one oxidising firing cycle brown, black and red paints. Finally, the finding of manganese black in these Canosa potsherds confirms that Canosa was an important centre connecting the near East to central Italy and Europe since the pre‐Roman age. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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