The oxidative cleavage of trans-1,2-cyclohexanediol with O2: Catalysis by supported Au nanoparticles

This paper reports on the catalytic oxidative cleavage of trans-1,2-cyclohexanediol with air, catalysed by supported Au NPs, as one of the steps of a new adipic acid synthesis process. Catalysts proved to be active, with a moderate cyclohexanediol conversion and selectivity to adipic acid close to 70%. The reaction network included several steps in sequence, amongst which the key one is the oxidation of the diol into 2-hydroxycylohexanone, which is then oxidised by air – even in the absence of a catalyst – to adipic acid and lesser amounts of lighter acids, i.e. glutaric and succinic acids. The oxidation of the second hydroxyl moiety in the diol would lead to the formation of 1,2-cyclohexanedione. The latter, however, is rapidly transformed into several by-products, especially glutaric acid, under the basic conditions which are necessary for allowing the reaction to occur at an acceptable rate. With Au-based catalysts, this undesired reaction occurs much more slowly than with the previously investigated Ru hydroxide catalysts. The nature of the support, either TiO2or MgO, also affected catalytic performance; the best performance was shown by the Au/MgO catalyst which, however, suffered from a remarkable deactivation, found to be due to both the increase in NPs size and the formation of carbonaceous residua on the catalyst surface

Laser generation of iron-doped silver nanotruffles with magnetic and plasmonic properties

A frontier topic in nanotechnology is the realization of multifunctional nanoparticles (NPs) via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine, and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here, we describe the synthesis of Fe-doped Ag NPs via laser ablation in liquid solution, bypassing thermodynamics constraints. These NPs have an innovative structure consisting of a scaffold of face-centered cubic metal Ag alternating with disordered Ag-Fe alloy domains, all arranged in a truffle-like morphology. The Fe-Ag NPs exhibit the plasmonic properties of Ag and the magnetic response of Fe-containing phases, and the surface of the Fe-Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe-Ag NPs, the magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept surface-enhanced Raman scattering and photothermal heating experiments. The synthetic approach is of general applicability and virtually permits the preparation of a large variety of multi-element NPs in one step

Impact of bone marrow fibrosis grade in post-polycythemia vera and post-essential thrombocythemia myelofibrosis: A study of the MYSEC group

status: publishe

Impact of bone marrow fibrosis grade in post-polycythemia vera and post-essential thrombocythemia myelofibrosis: A study of the MYSEC group

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Sulla bellezza così antica e così nuova della città

Un’indagine sul concetto di bellezza in riferimento alla città, ai luoghi e ai territori urbani che si avvale del contributo di trenta personalità afferenti a professioni e discipline differenti (filosofia, scienza, urbanistica, musica, letteratura, teatro, fotografia, architettura, giornalismo, arte, fisica, cinema, sociologia etc.). Il risultato è unʼanalisi multidisciplinare che diviene unʼantologia condivisa sulla definizione di bellezza in relazione alla città, in grado di delineare possibili interpretazioni anche alla luce delle nuove consapevolezze emerse in particolare nel corso degli ultimi mesi a seguito dellʼemergenza pandemica, fattore che, unito alla crisi economica e alla difficile situazione internazionale, ha prodotto notevoli conseguenze di natura culturale e sociale sui territori urbani, imponendo la necessità di un nuovo approccio alla vita delle città. Il Quaderno (quattordicesimo della collana Quaderni di varia cultura), avvalendosi delle testimonianze di questi autorevoli autori, fornisce molteplici letture sulle implicazioni che la componente estetica induce in chi attraversa, abita e osserva la città. Il volume é curato da Vincenzo DʼAlba, Silvana Kühtz, Francesco Maggiore, Vanna Maraglino con il coordinamento scientifico e culturale di Gianfranco Dioguardi. E con le illustrazioni di Vincenzo D’Alba