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11.
A Stable Porphyrin Functionalized Graphite Electrode Used at the Oxygen Evolution Reaction Potential
Gianlorenzo Bussetti Roberto Bernasconi Claudia Filoni Luca Magagnin Alberto Bossi Franco Ciccacci Lamberto Duò 《Electroanalysis》2022,34(7):1227-1236
Many researches have been devoted to rechargeable power generators that can store (but also release) energy. This availability is ensured through (e. g.) the oxygen evolution reaction (OER). However, (i) large values of the overpotentials and (ii) a progressive detriment of the anode (graphite) electrode limit the ultimate device. In view of enhancing the electrode performances, graphite was protected by following different strategies, which oblige to follow precise preparation protocols. Here, we prove that a thin layer of free-base porphyrin molecules is able to protect the underneath graphite electrode from detriment even if many (about 100) electrochemical cycles are performed. 相似文献
12.
Lamberto Tomassini Antonio Ventrone Claudio Frezza Ilaria Serafini Armandodoriano Bianco Maria Francesca Cometa 《Natural product research》2018,32(15):1853-1857
This paper reports on the first phytochemical analysis ever performed on Jasminum tortuosum Willd. This analysis, mainly carried out by means of column chromatography separation, NMR spectroscopy and mass spectrometry, led to the isolation and the identification of four compounds, namely the lignans ginkgool (1) and olivil-4′-O-β-glucopyranoside (2) and the secoiridoids oleoside dimethyl ester (3) and oleoside 11-methyl ester (4). The presence of these compounds is significant from a chemotaxonomic point of view, confirming the correct botanical classification of the species and, from a phytochemical standpoint, may suggest its possible use in the ethno-medicinal field. 相似文献
13.
Claudia Filoni Bahram Shirzadi Marco Menegazzo Eugenio Martinelli Corrado Di Natale Andrea Li Bassi Luca Magagnin Lamberto Du Gianlorenzo Bussetti 《Molecules (Basel, Switzerland)》2021,26(23)
Flexible and economic sensor devices are the focus of increasing interest for their potential and wide applications in medicine, food analysis, pollution, water quality, etc. In these areas, the possibility of using stable, reproducible, and pocket devices can simplify the acquisition of data. Among recent prototypes, sensors based on laser-induced graphene (LIGE) on Kapton represent a feasible choice. In particular, LIGE devices are also exploited as electrodes for sensing in liquids. Despite a characterization with electrochemical (EC) methods in the literature, a closer comparison with traditional graphite electrodes is still missing. In this study, we combine atomic force microscopy with an EC cell (EC-AFM) to study, in situ, electrode oxidation reactions when LIGE or other graphite samples are used as anodes inside an acid electrolyte. This investigation shows the quality and performance of the LIGE electrode with respect to other samples. Finally, an ex situ Raman spectroscopy analysis allows a detailed chemical analysis of the employed electrodes. 相似文献
14.
Serena Staccioli Maria Altamura Gianluca Giorgi Antonio Triolo 《Journal of mass spectrometry : JMS》2009,44(7):1081-1086
Di(hydroxybutyl) ether (DHBE), a liver protecting drug, is composed of a mixture of three regioisomers: 4‐(3‐hydroxybutoxy)‐2‐butanol (1), 3‐(4‐hydroxy‐2‐butoxy)‐1‐butanol (2), and 3‐(3‐hydroxybutoxy)‐1‐butanol (3). Unequivocal differentiation of each regioisomer of DHBE was rapidly obtained without isolation of the single components, using GC‐MS with electron ionization (EI). The mass spectrum of 1 showed a rearrangement ion at m/z 118, characteristic of the 3‐hydroxybutyl chain, deriving from loss of acetaldehyde from the molecular ion, whereas 2 and 3 were characterized by the ion at m/z 117, expected from α‐cleavage of the 4‐hydroxy‐2‐butyl chain. The species at m/z 118, in turn, loses a water molecule via a mechanism involving both alcohol hydrogens, as shown by deuterium exchange experiments. Both this finding and theoretical calculations support a mechanism in which the loss of acetaldehyde in 1 occurs via a cyclic intermediate, stabilized by a strong hydrogen bond between the alcohol oxygen bearing the charge and the other alcohol oxygen, and involves initial hydrogen transfer from the former to the latter. The EI spectrum of 2, having two 4‐hydroxy‐2‐butyl chains, showed the fragmentations expected from classical fragmentation rules of aliphatic ethers and alcohols, whereas the EI spectrum of 3, bearing one 4‐hydroxy‐2‐butyl and one 3‐hydroxybutyl chain, showed essentially the characteristic fragments of both chains. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
15.
Reduction of complex protein networks models is of great importance. The accuracy of a passivity preserving algorithm (PRIMA) for model order reduction (MOR) is here tested on protein networks, introducing innovative variations of the standard PRIMA method to fit the problem at hand. The reduction method does not require to solve the complete system, resulting in a promising tool for studying very large-scale models for which the full solution cannot be computed. The mathematical structure of the considered kinetic equations is preserved. Keeping constant the reduction factor, the approximation error is lower for larger systems. 相似文献
16.
17.
Lamberto Cesari 《Rendiconti del Circolo Matematico di Palermo》1990,39(2):169-209
We continue here the discussion on the existence of discontinuousBV minima, for a class of multiple integrals of the calculus of variationsI, we have started in [2] in view of possible studies on hyperbolic partial differential equations. Besides the associated Serrin integralJ, based onL 1-convergence, we take into consideration a modified Serrin-type functionalJ *. This new integralJ * will be needed in [3] to prove Rankine-Hugoniot type properties. 相似文献
18.
Lamberto Tomassini Antonio Ventrone Claudio Frezza Maria Francesca Cometa 《Natural product research》2020,34(15):2137-2143
AbstractThe phytochemical examination of the polar constituents of Sambucus ebulus L. leaves led to the identification of patrinoside (1) and of a new diglycoside iridoid, patrinoside-aglycone-11-O-[β-D-glucopyranosyl-(1→6)-2′-deoxy-β-D-glucopyranoside] (trivially named as sambuloside) (2). Both of these structures have been assigned by spectroscopic means (NMR and MS). 相似文献
19.
Lamberto Cesari 《Annali di Matematica Pura ed Applicata》1948,27(1):321-374
Sunto. Applicando nozioni già utilizzate in precedenti lavori dello stesso A. sul problema della quadratura delle superficie, si
danno formule generali di trasformazione degli integrali doppi. 相似文献
20.
Massimiliano Lamberto Elizabeth E. Rastede Françisco M. Raymo 《Tetrahedron letters》2010,51(42):5618-5620
Viologens are generally synthesized by N-alkylating 4,4′-bipyridine with alkyl halides. Under conventional heating conditions, however, their synthesis suffers from long reaction times and, often, low yields. In this work, symmetric and asymmetric viologens were synthesized under the assistance of microwave irradiation in good to excellent yields and in short reaction times. 相似文献