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Dynamical changes in hydration water accompanying lysozyme thermal denaturation

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Frontiers of physics 2015年第5期10卷 35-41页

作者： Francesco Mallamace Carmelo Corsaro Domenico Mallamace Nicola Cicero Sebastiano Vasi Giacomo Dugo H. Eugene Stanley cnr-IPCF Messina Istituto per i Processi Chimico-Fisici Viale F. Stagno D'Alcontres 37 98158 Messina Italy Dipartimento di Fisica e Scienze della Terra Universitd di Messina Viale F. Stagno D'Alcontres 31 98166 Messina Italy Center for Polymer Studies and Department of Physics Boston University Boston MA 02215 USA Dipartimento di Scienze dell'Ambiente della Sicurezza del Territorio degli Alimenti e della Salute Universita di Messina Viale F. Stagno d'Alcontres 31 98166 Messina Italy

We study the dynanfics of the first hydration shell of lysozyme to determine the role of hydra- tion water that accompanies lysozyme thermal denaturation. We use nuclear magnetic resonance spectroscopy to investigate both the translational and rotational contributions. Data on proton self-diffusion and reorentational correlation time indicate that the kinetics of the lysozyme fold- ing/unfolding process is controlled by the dynamics of the water molecules in the first hydration shell. When the hydration water dynamics change, because of the weakening of the hydrogen bond network, the three-dimensional structure of the lysozyme is lost and denaturation is triggered. Our data indicates that at temperatures above approximately 315 K, water behaves as a simple liquid and is no longer a good solvent.

关键词： lysozyme unfolding hydration water NMR correlation time solvent dynamics

Chemical-Structural Changes of Organic Matter in a Semi-Arid Soil After Organic Amendment

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Pedosphere 2012年第3期22卷 283-293页

作者： C.NICOLS G.MASCIANDARO T.HERNNDEZ C.GARCIA Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC) Department of Soil and Water Conservation and Organic Wastes ManagementCampus Universitario de EspinardoP.O.160Murcia 3010 (Spain) Consiglio Nazionale delle Ricerche (cnr) Istituto per lo Studio degli Ecosistemi (ISE)-Sezione di Chimica del SuoloArea della RicercaVia Moruzzi 1Pisa 56124 (Italy)

A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid *** changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical *** the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage *** non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly *** 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage ***,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ***,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil *** pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 *** conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.

关键词： degraded soil pyrolysis-gas chromatography pyrophosphate extract sewage sludge vine pruning waste

NMR investigation of degradation processes of ancient and modern paper at different hydration levels

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Frontiers of physics 2018年第1期13卷 41-50页

作者： Domenico Mallamace Sebastiano Vasi Mauro Missori Francesco Mallamace Carmelo Corsaro Consorzio interuniversitario per lo sviluppo dei Sistemi a Grande Interfase - CSGI Via della Lastruccia 3 50019 Sesto Fiorentino Firenze Italy Dipartimento MIFT Sezione di Fisica Universita di Messina Viale F. Stagno D'Alcontres 31 98166 Messina Italy istituto dei Sistemi Complessi Consiglio Nazionale delle Ricerche Unit Sapienza Piazzale Aldo Moro 5 00185 Roma Italy cnr-IPCF Messina Istituto per i Processi Chimico-Fisici Viale F. Stagno D'Alcontres 37 98158 Messina Italy Center for Polymer Studies and Department of Physics Boston University Boston MA 02215 USA

The degradation process of cellulose-made materials was investigated by means of nuclear magnetic resonance （NMR） spectroscopy, with particular emphasis on the role of water and on the hydration mechanism of cellulose fibrils. To accomplish this, the structure and dynamics of water within ancient and modern samples with different aging histories were investigated. The results mainly indicated that hydrolytic and oxidative reactions provoked the formation of acidic by-products. Furthermore, degradation processes were enhanced by higher amounts of water giving a progressive consumption of the amorphous regions of the cellulose. We propose NMR experiments as a benchmark for character- ization of the degradation state of paper, as well as for investigating the effectiveness of restoration treatments.

关键词： ancient paper degradation NMR hydration solvent dynamics

Folate targeted coated SPIONs as efficient tool for MRI

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Nano Research 2017年第9期10卷 3212-3227页

作者： Cinzia Scialabba Roberto Puleio Davide Peddis Gaspare Varvaro Pietro Calandra Giovanni Cassata Luca Cicero Mariano Licciardi Gaetano Giammona Department ofScienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF) University of Palermo 90123 Palermo Italy istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri" Via Gino Marinuzzi 3 90100 Palermo Italy Institute of Structure of Matter National Research Council (cnr) Via Salaria 00015 Monterotondo Scalo (RM) Italy istituto per Io Studio dei Materiali Nanostrutturati Consiglio Nazionale delle Ricerche Via Solaria kin. 29.300 00015 Monterotondo Stazione (RM) Italy Mediterranean Center for Human Health Advanced Biotechnologies (CHAB) ATeNCenter University of Palermo 90100 Palermo Italy

The development of more sensitive diagnostic tools allowing an early-stage and highly efficient medical imaging of tumors remains a challenge. Magnetic nanoparticles seem to be the contrast agents with the highest potential, if properly constructed. Therefore, in this study, hybrid magnetic nanoarchitectures were developed using a new amphiphilic inulin-based graft copolymer (INU-LAPEG-FA) as coating material for 10-nm spinel iron oxide (magnetite, Fe3O4) superparamagnetic nanoparticles (SPION). Folic acid (FA) covalently linked to the coating copolymer in order to be exposed onto the nanoparticle surface was chosen as the targeting agent because folate receptors are upregulated in many cancer types. Physicochemical characterization and in vitro biocompatibility study was then performed on the prepared magnetic nanoparticles. The improved targeting and imaging properties of the prepared FA-SPIONs were further evaluated in nude mice using 7-Tesla magnetic resonance imaging (MRI). FA-SPIONs exhibited the ability to act as efficient contrast agents in conventional MRI, providing a potential nanoplatform not only for tumor diagnosis but also for cancer treatment, through the delivery of anticancer drug or locoregional magnetic hyperthermia.

关键词： inulin copolymer superparamagnetic spinel iron oxide nanoparticles (SPIONs) magnetic resonance imaging (MRI) folic acid (FA) cancer targeting

Low-temperature quantum transport in CVD-grown single crystal graphene

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Nano Research 2016年第6期9卷 1823-1830页

作者： Shaohua Xiang Vaidotas Miseikis Luca Planat Stefano Guiducci Stefano Roddaro Camilla Coletti Fabio Beltram Stefan Heun NEST Istituto Nanoscienze--CNR and Scuola Normale Superiore Piazza San Silvestro 12 $6127 Pisa Italy Center for Nanotechnology Innovation @NEST Istituto Italiano di Tecnologia Piazza San Silvestro 12 56127 Pisa Italy

Chemical vapor deposition （CVD） is typically used for large-scale graphene synthesis for practical applications. However, the inferior electronic properties of CVD graphene are one of the key problems to be solved. Therefore, we present a detailed study on the electronic properties of high-quality single-crystal monolayer graphene. The graphene is grown via CVD on copper, by using a cold-wall reactor, and then transferred to Si/SiO2. Our low-temperature magneto-transport data demonstrate that the characteristics of the single-crystal CVD graphene samples are superior to those of polycrystalline graphene and have a quality which is comparable to that of exfoliated graphene on Si/SiO2. The Dirac point in our best samples occurs at back-gate voltages lower than 10 V, and a maximum mobility of 11,000 cm2/（V.s） is attained. More than 12 flat and discernible half-integer quantum Hall plateaus occur under a high magnetic field on both the electron and hole sides of the Dirac point. At a low magnetic field, the magnetoresistance exhibits a weak localization peak. Using the theory of McCann et al., we obtain inelastic scattering lengths of 〉1 um, even at the charge neutrality point of the samples.

关键词： high-quality chemicalvapor deposition (CVD)-graphene low-temperaturemagnetotransport quantum Hall effect weak localization

Experimental characterization and CFD simulation of gas maldistribution in turbulent fluidization of Group A particles

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Particuology 2023年第11期82卷 192-203页

作者： Maurizio Troiano Benjamin Amblard Sina Tebianian Roberto Solimene Piero Salatino Thierry Gauthier Dipartimento di Ingegneria Chimica dei Materiali e della Produzione IndustrialeUniversitàdegli Studi di Napoli Federico IIPiazzale Vincenzo Tecchio 8080125NapoliItaly IFP Energies nouvelles Rond-point de l'échangeur de Solaize BP 369360SolaizeFrance istituto di Scienze e Tecnologie per l’Energia e la MobilitàSostenibili(STEMS) Consiglio Nazionale delle Ricerche(CNR)Piazzale Vincenzo Tecchio 8080125NapoliItaly

The study presented hereby investigates experimentally and with CFD simulations the gas distribution effect on the hydrodynamic of a Geldart Group A turbulent fluidized bed. Experiments were carried out on a cold flow fluidized bed column with an even and uneven gas distribution. Local solid volume fraction profiles were measured using optical probes at different bed heights and along two radial directions. Optical probe measurements allow catching a clear hydrodynamic difference between both even and uneven gas distributions. These results were then used to assess CFD simulations with the code Barracuda^(TM) (MP-PIC approach). It is noteworthy that the choice of drag correlation and boundary conditions strongly influences the agreement between the experimental and CFD results. Once the correct parameters are chosen, CFD simulations captured the effect of gas distribution changes.

关键词： Characterization of multiphase reactors Fluidized bed Turbulent Gas distribution Jet Optical probe CFD simulations

Scanning gate imaging of quantum point contacts and the origin of the 0.7 anomaly

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Nano Research 2015年第3期8卷 948-956页

作者： Andrea lagallo Nicola Paradiso Stefano Roddaro Christian Reichl Werner Wegscheider Giorgio Biasiol Lucia Sorba Fabio Beltram Stefan Heun National Enterprise for Nanoscience and Nanotechnology (NEST) Istituto Nanoscienze-CNR and Scuola Normale Superiore Piazza San Silvestro 12 56127 Pisa Italy istituto Offcina dei Materiali cnr Laboratorio TASC 34149 Trieste Italy Solid State Physics Laboratory ETH Zurich Schafmattstrasse 16 8093 Zurich Switzerland

The origin of the anomalous transport feature appearing at a conductance G 0.7× （2e2/h） in quasi-lD ballistic devices-the so-called 0.7 anomaly-represents a long standing puzzle. Several mechanisms have been proposed to explain it, but a general consensus has not been achieved. Proposed explanations have been based on quantum interference, the Kondo effect, Wigner crystallization, and other phenomena. A key open issue is whether the point defects that can occur in these low-dimensional devices are the physical cause behind this conductance anomaly. Here we adopt a scanning gate microscopy technique to map individual impurity positions in several quasi-lD constrictions and correlate these with conductance characteristics. Our data demonstrate that the 0.7 anomaly can be observed irrespective of the presence of localized defects, and we conclude that the 0.7 anomaly is a fundamental property of low-dimensional systems.

关键词： two-dimensional electrongas (2-DEG) scanning gate microscopy 0.7 anomaly

Zeolite-assisted etherification of glycerol with butanol for biodiesel oxygenated additives production

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Journal of Energy Chemistry 2020年第9期29卷 136-144,I0005页

作者： C.Cannilla G.Bonura S.Maisano L.Frusteri M.Migliori G.Giordano S.Todaro F.Frusteri cnr-ITAE Istituto di Tecnologie Avanzate per l'Energia“Nicola Giordano”Via S.Lucia 598126 MessinaItaly Dipartimento di Ingegneria Elettronica Chimica e Ingegneria IndustrialeUniversitàdi MessinaContrada di Dio I98166 MessinaItaly Bucci 97036 RendeItaly

This research was focused on the valorisation of glycerol,exploring the feasibility of an efficient route for oxygenated additives production based on its etherification with bio-butanol.A home-made BEA zeolite sample with a tuneable acidity has been proposed as the catalytic system,being tested in a stirred reactor under different etherification *** a reaction temperature as high as 200℃resulted to be beneficial in terms of glycerol conversion(-90%),only by operating at milder conditions the product selectivity to glycerol-ethers can be better controlled,in order to obtain a bio-fuel complying with the requirements for mixing with fossil diesel or biodiesel,without any need of purification from large amount of by-products.A comprehensive identification of all the compounds formed during the reaction was performed by a GC-MS analysis,on the basis of the complex network of consecutive and parallel reaction paths leading not only to the desired ethers,but also to many side products not detected in similar acid-catalyzed reactions in liquid phase and not available in the most used mass-spectra libraries.

关键词： Glycerol Butanol BEA GC-MS analysis Acid catalysts Biofuels Butyl glycerol ethers

Dimethyl ether as circular hydrogen carrier:Catalytic aspects of hydrogenation/dehydrogenation steps

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Journal of Energy Chemistry 2021年第7期30卷 55-77页

作者： Enrico Catizzone Cesare Freda Giacobbe Braccio Francesco Frusteri Giuseppe Bonura ENEA–Italian Agency for New Technologies Department of Energetic TechnologiesLaboratory of Thermochemical Processes for Waste and Biomass ValorisationRotondellaItaly cnr-ITAE–Consiglio Nazionale delle Ricerche Istituto di Tecnologie Avanzate per l’Energia‘‘Nicola Giordano”Via S.Lucia Sopra Contesse 5I-98126 MessinaItaly

The intermittent nature of renewable resources requires for most applications the development of efficient and cost-effective technologies for steady supply of electrical *** storage of energy in the form of hydrogen chemically bound within organic molecules(rather than physically as compressed gas or cooled liquid)represents an alternative approach that is attracting great research *** to other liquid organic hydrogen carriers(LOHCs),dimethyl ether(DME)appears to have the largest potential impact on society,especially if inserted in technological chains of CO_(2) sequestration and utilization,so to determine an effective mitigation of environmental issues,without any net effect on the carbon ***,the steps of H2 storage and H2 release can take place in two coupled chemical processes,constituted by the exothermic synthesis of DME via CO_(2) hydrogenation and the endothermic steam reforming of DME,***,the latest advances in the development of heterogeneous bifunctional and hybrid catalysts for the direct hydrogenation of CO_(2) to DME are thoroughly reviewed,with special emphasis on thermodynamics,catalyst design and process *** many aspects behind the mechanism of DME synthesis from H2-CO_(2) streams are still to be uncovered,the recent progress in the research on H2 release by DME steam reforming is increasing the interest for effectively closing this binary H2 loop,in view of future green deals and sustainable research developments.

关键词： DME CO_(2)hydrogenation Steam Reforming Hybrid catalysts Hydrogen carrier