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Mobili A., Belli A., Giosue C., Pierpaoli M., Bastianelli L., Mazzoli A., Ruello M.L., Bellezze T., Tittarelli F. “Mechanical, durability, depolluting and electrical properties of multifunctional mortars prepared with commercial or waste carbon-based fillers.” Construction and Building Materials, Volume 28310, May 2021 Article number 122768. DOI: 10.1016/j.conbuildmat.2021.122768. |
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Abstract: Carbon-based fillers from industrial wastes and commercial ones were compared to improve the properties of lime-based mixes. As commercial fillers, graphene nanoplatelets and activated carbon were used, whereas as industrial wastes a char obtained by the gasification of biomasses and a used foundry sand were chosen. Carbon-based wastes were found to be a good cost-effective alternative to commercial carbon based fillers to increase the compressive strength (of about 25%) and to reduce water capillary absorption (of about 50%) thanks to the paste refinement; to enhance depollution capacity (of about 25%) and increase both electrical conductivity (up to 65%) and electromagnetic shielding effectiveness (of about 6%) of the hardened compounds thanks to the carbon content. |
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Marco Parlapiano; Akyol Cagri; Alessia Foglia; Michela Pisani; Paola Astolfi; Anna Laura Eusebi; “Selective removal of contaminants of emerging concern (CECs) from urban water cycle via Molecularly Imprinted Polymers (MIPs): Potential of upscaling and enabling reclaimed water reuse.” Journal o f Environmental Chemical Engineering 9(1) 2021, 105051 |
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Abstract: Contaminants of emerging concern (CECs) are one of the main barriers in the water cycle as they limit the water reuse due to their adverse effects on humans and the ecosystem. Natural and/or engineered ecosystems, such as conventional wastewater treatment processes, are not designed to remove CECs and contribute to the bioaccumulation in organisms considering high volumes of treated water discharges. The adoption of innovative solutions to upgrade urban water cycle facilities has gained relevance for the removal of these substances from final effluents. Molecularly imprinted polymers (MIPs) show promising selective removal toward a wide range of CECs. However, this process is still limited to lab/bench scale and needs to be critically analyzed and assessed for possible scale-up in real environment. Therefore, in this review, an overview of the fate and occurrence of CECs in wastewater is initially reported together with the state-of-the-art adsorption mechanisms to remove these compounds. In the central part of the paper, an evaluation of MIPs synthesis and their status in removing CECs from water matrix are presented. An upscaling pathway of MIPs column from lab- to pilot-scale is given to be applied for enhanced CECs removal and safe water reuse in irrigation/fertigation. Finally, possible integration of MIP columns to real wastewater treatment facilities is discussed and advantages and disadvantages of the potential solutions are addressed to enhance their sustainability. |
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Bosso, P., Milella, A., Barucca, G., Mengucci, P., Armenise, V., Fanelli, F., Giannuzzi, R., Maiorano, V., Fracassi, F. “Plasma-assisted deposition of iron oxide thin films for photoelectrochemical water splitting” Plasma Processes and Polymers 18(1), 2000121 (12 pages) (2021) (First published: 12 August 2020) |
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Abstract: Iron oxide thin films for photoelectrochemical (PEC) water splitting were deposited by radiofrequency sputtering of an iron target in argon/oxygen plasma mixtures, followed by thermal annealing. The chemical composition and structure of deposited film can be tuned by controlling the gas feed composition and the annealing temperature. The thermal treatment extensively improves the PEC water splitting performances of the films deposited at the lowest O2 percentages (0–1%), allowing to obtain photocurrent densities up to 1.20 mA/cm2 at 1.23 VRHE. Increasing the oxygen percentage in the plasma feed allows the direct growth of photoactive films; the best result is found for the hematite film produced at 50% O2, characterized by a photocurrent density of 0.21 at 1.23 VRHE. |
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Pavlo Makushko, Eduardo Sergio Oliveros Mata, Gilbert Santiago Cañón Bermúdez, Mariam Hassan, Sara Laureti, Christian Rinaldi, Federico Fagiani, Gianni Barucca, Nataliia Schmidt, Yevhen Zabila, Tobias Kosub, Rico Illing, Oleksii Volkov, Igor Vladymyrskyi, Jürgen Fassbender, Manfred Albrecht, Gaspare Varvaro, Denys Makarov. “Flexible magnetoreceptor with tunable intrinsic logic for on-skin touchless human-machine interfaces.” Advanced Functional Materials 20101089 (8 pages) (2021) (First published: 26 March 2021) |
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Abstract: Artificial magnetoception is a new and yet to be explored path for humans to interact with the surroundings. This technology is enabled by thin film magnetic field sensors embedded in a soft and flexible format to constitute magnetosensitive electronic skins (e-skins). Being limited by the sensitivity to in-plane magnetic fields, magnetosensitive e-skins are restricted to basic proximity and angle sensing and are not used as switches or logic elements of interactive wearable electronics. Here, a novel magnetoreceptive platform for on-skin touchless interactive electronics based on flexible spin valve switches with sensitivity to out-of-plane magnetic fields is demonstrated. The technology relies on all-metal Co/Pd-based spin valves with a synthetic antiferromagnet possessing perpendicular magnetic anisotropy. The flexible magnetoreceptors act as logic elements, namely momentary and permanent (latching) switches. The switches maintain their performance even upon bending to a radius of less than 3.5 mm and withstand repetitive bending for hundreds of cycles. Here, flexible switches are integrated in on-skin interactive electronics and their performance as touchless human-machine interfaces is demonstrated, which are intuitive to use, energy efficient, and insensitive to external magnetic disturbances. This technology offers qualitatively new functionalities for electronic skins and paves the way towards full-fledged on-skin touchless interactive electronics. |
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Maltoni, Pierfrancesco; Sarkar, Tapati; Varvaro, Gaspare; Barucca, Gianni; Ivanov, Sergey; Peddis, Davide; Mathieu, Roland. “Towards bi-magnetic nanocomposites as permanent magnets through the optimization of the synthesis and magnetic properties of SrFe12O19 nanocrystallites.” Journal of Physics D: Applied Physics 54(12), 124004 (10 pages) (2021) (Published 20 January 2021) |
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Abstract: Sol–gel synthesis was used in order to obtain nanocrystallites of the SrFe12O19 (SFO) hexaferrite in an efficient and reliable way. By optimizing the initial synthetic conditions, we were able to control the size of the nanoparticles (NPs), at lower annealing temperature. The x-ray powder diffraction, transmission electron microscopy (TEM), and magnetic measurements have demonstrated a significant relation between the morphology, size, and magnetic properties of the nanoscale SFO, revealing a definite dependence on the crystallite size along the c-axis. The obtained NPs appear almost isotropic, in the form of platelets and exhibit similar magnetic performance, in terms of the energy product (BH)MAX, thus, demonstrating the suitability of reducing the annealing temperature without any deterioration in the magnetic properties. Additionally, this work illustrates the feasibility of the sol–gel bottom-up approach to employ magnetic NPs as building-blocks for designing hard/soft exchange-coupled bi-magnetic nanocomposites, combining the high coercivity of a hard phase (SFO) and the high saturation magnetization of a soft phase (CoFe2O4); in this regard, we discuss the tunability of the magnetic anisotropy by symbiotically restricting the growth of both phases. |
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P. Maltoni, T. Sarkar, G. Barucca, G. Varvaro, F. Locardi, D. Peddis and R. Mathieu. “Tuning the magnetic properties of hard-soft SrFe12O19/CoFe2O4 nanostructures via composition/interphase coupling.” Journal of Physical Chemistry: C 125, 10, 5927-5936 (2021) (Publication Date:March 5, 2021) |
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Abstract: Magnetic nanocomposites (NCs) are extremely appealing for a wide range of energy-related technological applications, specifically as building blocks for next-generation permanent magnets. The design of such nanostructures requires precise chemical synthesis methods, which will permit the fine-tuning of the magnetic properties. Here we present an in-depth structural, morphological and magnetic characterization of ferrite-based nanostructures obtained through a bottom-up sol–gel approach. The combination of the high coercivity of a hard phase SrFe12O19 (SFO) and the high saturation magnetization of a soft phase, CoFe2O4 (CFO), allowed us to develop exchange-coupled bimagnetic NCs. A symbiotic effect is observed in a SFO/CFO nanocomposite, as the unique oriented growth of SFO prevents grain growth of the CFO, thus restricting the crystallite size of both. Through X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and magnetic measurements we clarify the relationship between the distribution and size of hard/soft particles, the optimization of interfaces and the obtained uniform magnetic response. This study allowed us to establish the potentiality of hard/soft SFO/CFO nanostructures in current permanent magnet technology. |
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Sawssen Slimani, Giorgio Concas, Francesco Congiu, Gianni Barucca, Nader Yaacoub, Alessandro Talone, Mourad Smari, Essebti Dhahri, Davide Peddis, Giuseppe Muscas. “Hybrid spinel iron oxide nanoarchitecture combining crystalline and amorphous parent material.” Journal of Physical Chemistry: C (2021) (Publication Date: May 11, 2021) |
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Abstract: When preparing nanostructured magnetic materials, the presence of an amorphous component is often considered a weakness of the synthesis method and a waste of material. This stems because the amorphous fraction is often pictured as a “dead” magnetic component, showing little to no contribution to the magnetic properties, for example, saturation magnetization. For this reason, additional steps are employed after the main synthesis process to reduce or isolate and remove the amorphous phase from the “optimal” crystalline product. Here, we propose a hybrid-structured nanoarchitecture that combines crystalline cobalt ferrite and the amorphous parent material. The latter contributes partially to the total magnetic moment but exhibits a magnetic anisotropy much larger than the crystalline bulk parent material. With the information obtained from an in-depth structural and magnetic characterization, a micromagnetic model is created, allowing identifying the contribution of each component elucidating the active role of the amorphous phase. The extremely low cost, minimal complexity, and high yield of the synthesis process make this hybrid design of large interest for technological applications. |
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Carlo Bruno, Eleonora Ussano, Gianni Barucca, Davide Vanossi, Giovanni Valenti, Edward A. Jackson, Andrea Goldoni, Lucio Litti, Simona Fermani, Luca Pasquali, Moreno Meneghetti, Claudio Fontanesi, Lawrence T. Scott, Francesco Paolucci, Massimo Marcaccio. “Wavy Graphene Sheets from Electrochemical Sewing of Corannulene.” Chemical Science (2021) (First published:14 Apr 2021) |
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Abstract: The presence of non-hexagonal rings in the honeycomb carbon arrangement of graphene produces rippled graphene layers with valuable chemical and physical properties. In principle, a bottom-up approach to introducing distortion from planarity of a graphene sheet can be achieved by careful insertion of curved polyaromatic hydrocarbons during the growth of the lattice. Corannulene, the archetype of such non-planar polyaromatic hydrocarbons, can act as an ideal wrinkling motif in 2D carbon nanostructures. Herein we report an electrochemical bottom-up method to obtain egg-box shaped nanographene structures through a polycondensation of corannulene that produces a new conducting layered material. Characterization of this new polymeric material by electrochemistry, spectroscopy, electron microscopy (SEM and TEM), scanning probe microscopy, and laser desorption-ionization time of flight mass spectrometry provides strong evidence that the anodic polymerization of corannulene, combined with electrochemically induced oxidative cyclodehydrogenations (Scholl reactions), leads to polycorannulene with a wavy graphene-like structure. |
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Carolina Catanio Bortolan, Leonardo Contri Campanelli, Carlo Paternoster, Nicolas Giguère, Nicolas Brodusch, Claudemiro Bolfarini, Raynald Gauvin, Paolo Mengucci, Gianni Barucca, Diego Mantovani “Effect of oxygen content on the mechanical properties and plastic deformation mechanisms in the TWIP/TRIP Ti-12Mo alloy.” Materials Science and Engineering A 817, 141346 (10 pages) (2021) (10 June 2021) |
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Abstract: In the last decades, biomaterials have improved the life and its quality for millions around the Globe. Titanium-based biomaterials have rapidly become the gold standard for bone contact applications. Despite their successful performance, their low strength-ductility trade-offs and work-hardening rates limit their use for example for the manufacture of vascular stents. Although a high strength-ductility trade-off and a high work-hardening rate were reported for the TWIP/TRIP Ti–12Mo alloy, strengthening strategies are required to approach its strength to the ones of Co–Cr alloys, main metallic materials used to produce stents. In this study, the investigated strengthening strategy was the increase of oxygen content from 0.04 to 0.18 wt% in the Ti–12Mo alloy. The effect of this increase on its microstructure, mechanical properties and plastic deformation mechanisms was studied. Athermal ω precipitates were observed throughout with the β matrix of both solution-treated alloys. X-Ray diffraction and transmission electron microscopy suggested that the quantity of ω phase was larger in the alloy with a higher oxygen content, contrasting with the common knowledge that O suppresses ω phase precipitation. Independently of oxygen content, {332}<113> twins and stress-induced martensite (SIM) α" occurred in the deformed microstructures. Based on the electron backscatter diffraction analyses, the area fraction of SIM α" decreased by increasing oxygen content. Although elongation decreased with this oxygen content increase, Ti–12Mo-0.18O exhibited a high true uniform elongation of 25% and a true ultimate tensile strength higher than the Ti–12Mo-0.04O alloy. Hardness and yield strength also increased by increasing oxygen content, while elastic modulus did not change. |
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Spagnuolo Simone, Rinaldi Zila, Donnini Jacopo, Nanni Antonio. “Physical, mechanical and durability properties of GFRP bars with modified acrylic resin (modar) matrix.” Composite Structures, 262, 15April 2021, n°113557. |
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Abstract: Glass fiber reinforced polymer (GFRP) bars are currently used as internal reinforcement of concrete structures, as an alternative to traditional steel rebars, to avoid corrosion problems and durability issues. GFRP bars are usually made of continuous glass filaments embedded within a polyester (for non-structural applications) or vinyl ester resin. These resins have been used for many years in several technological fields and widely employed as matrices for composite materials with structural functions. However, since the matrix plays a fundamental role in protecting the fibers from the external environment, the development of new organic matrices able to withstand aggressive environmental conditions while keeping a low cost of production is certainly of great interest. In this study, the possibility of using a modified acrylic resin (ModAR), never employed for such applications, as matrix for GFRP bars has been investigated. Physical, mechanical and durability tests have been carried out, according to international standards, to evaluate the technical feasibility of using ModAR matrices. Experimental results showed that ModAR GFRP bars are able to offer high thermal resistance while keeping physical and mechanical properties within standard limits. |
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Donnini Jacopo, Maracchini Gianluca, Lenci Stefano, Corinaldesi Valeria, Quagliarini Enrico. “TRM reinforced tuff and fired clay brick masonry: Experimental and analytical investigation on their in-plane and out-of-plane behavior.” Construction and Building Materials, 272, 22February 2021, n°121643. |
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Abstract: The paper presents the results of an experimental campaign aimed at investigating the in-plane and out-of-plane behavior of tuff and fired clay brick masonry panels reinforced by a commercial, not yet tested, Textile Reinforced Mortar (TRM) system. The TRM, consisting of hydraulic lime mortar coupled with a bidirectional glass fabric (total thickness of 30 mm), was applied on both sides of the panels and connected through stainless-steel helical bars. First, a mechanical characterization of the TRM system was carried out, according to recent guidelines (AC434 and CNR-DT215) by means of tensile tests and single-shear bond tests on the two different substrates. Then, the effectiveness of the reinforcement was investigated through uniaxial compression, diagonal compression and three-point bending tests on masonry panels. After that, experimental results were compared to the predictions of recent guidelines and analytical models available in the literature, by using the mechanical parameters obtained from the TRM mechanical characterization. TRM showed to be very effective in increasing the in-plane shear strength of tuff panels, of about 170%, whereas in the case of fired clay brick ones the increase was limited to 33%. Besides, the diagonal compression strength of reinforced specimens seemed to be strongly influenced by the mortar matrix, instead of by the fabric reinforcement, as it usually happens i.e. for Fabric Reinforced Cementitious Matrix (FRCM) systems. Thus, novel simplified analytical formulations to predict the shear strength of reinforced panels by only considering the contribution of the TRM matrix were provided, discussed and compared to current analytical approaches for FRCM systems. As regards the out-of-plane behavior, the TRM system significantly increased the out-of-plane bending strength and ductility of both tuff and fired clay brick panels. The applicability of current analytical approaches, as well as possible amendments, was also investigated. Finally, the compressive behavior of the walls was not substantially modified by the reinforcement, reasonably due to the low axial stiffness of the connectors and, to a minor extent, because they were dry inserted within the masonry and simply folded over the glass fabric. |
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Donnini Jacopo, Lancioni Giovanni, Chiappini Gianluca, Corinaldesi Valeria. “Uniaxial tensile behavior of ultra-high performance fiber-reinforced concrete (UHPFRC): Experiments and modeling.” Composite Structures, 258, 15February 2021, n°113433. |
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Abstract: Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC) is considered a promising material for many structural applications where high strength and high energy absorption capacity are required. The purpose of this work is to study the uniaxial tensile behavior of soft cast (flowable at casting time) UHPFRC by varying the amount of hooked steel fibers (30-mm long) from 0% up to 2.55% by volume. Direct tensile tests have been performed on dog-bone shaped specimens and Digital Image Correlation (DIC) has been used to measure displacements and deformations and to monitor the evolution of cracks. Then, a phase-field model has been implemented in a FE code and numerical simulations have been performed to better understand the effects of different fiber dosages on the mechanical behavior of UHPFRC composites and on their post-elastic evolution. Concrete matrix and fiber reinforcement have been modeled as brittle and elasto-plastic phases of a mixture, whose internal energies are enriched by non-local damage and plasticity contributions. The different failure mechanisms observed in experiments have been reproduced, including the ductile failure experienced by specimens with sufficiently high fiber dosage, which distinguishes for a strain-hardening phase of matrix multi- micro-cracking that anticipates material failure. |
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Lucchetti Liana, Nava Giovanni,Barboza Raouf, Ciciulla Fabrizio,Bellini Tommaso “Optical force-based detection of splay and twist viscoelasticity of CCN47 across the Nematic-to-Smectic A transition.” J. Molecular Liquids, 329, 1 May 2021, 115520 |
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Abstract: We measured the splay and twist elastic constant K and viscosity η of CCN47 by coupling optical forces with the nematic director and detecting the resulting deformation. This approach enables to separately induce each of the two distortions and allows to characterize the viscoelastic properties of both the nematic and the smectic A phase. We find that in the nematic phase far from the transition the splay elastic constant K1 is larger than that of twist K2, while its viscosity is smaller, ηsplay < ηtwist. Upon lowering the temperature, K1 and ηsplay continuously increase in the nematic and smectic phase. On the contrary, K2 and ηtwist exhibit an abrupt growth when approaching the N/SmA transition, confirming the expected critical behavior. The twist viscoelastic ratio remains approximately constant in the whole nematic phase, indicating that the critical exponents for K2 and ηtwist are similar. |
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Tosco Vincenzo, Monterubbianesi Riccardo, Orilisi Giulia, Sabbatini Simona, Conti Carla, Ozcan Mutlu, Putignano Angelo, Orsini Giovanna. “Comparison of two curing protocols during adhesive cementation: can the step luting technique supersede the traditional one?” Odontology (the Society of the Nippon Dental University) 109(2), April 2021, pp. 433-439 |
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Abstract: This study aims to compare the degree of conversion of two different curing protocols used during adhesive cementation. The following resin luting agents were tested: Hri Flow (MF) and pre-heated Hri Micerium (MH); light-cure Nexus Third Generation (NX3L) and dual-cure Nexus Third Generation (NX3D); dual cured RelyX Ultimate (RXU) and light-cure RelyX Veneers (RXL). For each tested material, ten samples were prepared and divided into two groups which had different curing protocols (P1 and P2): in P1, samples were cured for 40 s; in P2, samples were cured for 5 s, and then, after 20 s, cured again for additional 40 s. The degree of conversion (DC) was evaluated both during the first 5 min of the curing phase and after 1, 2, 7, 14 and 28 days (p = 0.05). Different trends were observed in DC values after 5 min by comparing P1 and P2. In both P1 and P2, DC decreased as follows, MH > MF > NX3L > RXL > RXU > NX3D. There were significant differences of DC values among all resin luting agents (p < 0.05) in P1, while no significant differences existed between MH and MF, and NX3L and RXL in P2. At 1, 2, 7, 14 and 28 days the light curing luting agents had a higher DC than the dual luting agents (p < 0.05). P1 and P2 were not statistically different at each time point (p > 0.05). Both P1 and P2 protocols let achieve an acceptable DC after 28 days. The tested P2 can be safely used to lute indirect restorations, simplifying the removal of cement excesses. |
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Pittura Lucia, Foglia alessia, Akyol Cagri, Cipolletta Giulia, Benedetti Maura, Regoli Francesco, Eusebi Anna Laura, Sabbatini Simona, Tseng Linda, Katsou Evina, Gorbi Stefania, Fatone Francesco. “Microplastics in real wastewater treatment schemes: Comparative assessment and relevant inhibition effects on anaerobic processes.” Chemosphere 262(128415), January 2021. |
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Abstract: The occurrence, fate and removal of microplastics (MPs) in a wastewater treatment plant (WWTP) in Central Italy were investigated together with their potential adverse effects on anaerobic processes. In the influent of the WWTP, 3.6 MPs.L−1 were detected that mostly comprised polyester fibers and particles in the shape of films, ranging 0.1–0.5 mm and made of polyethylene and polypropylene (PP). The full-scale conventional activated sludge scheme removed 86% of MPs, with the main reduction in the primary and secondary settling. MPs particles bigger than 1 mm were not detected in the final effluent and some loss of polymers types were observed. In comparison, the pilot-scale upflow granular anaerobic sludge blanket (UASB) + anaerobic membrane bioreactor (AnMBR) configuration achieved 94% MPs removal with the abatement of 87% of fibers and 100% of particles. The results highlighted an accumulation phenomenon of MPs in the sludge and suggested the need to further investigate the effects of MPs on anaerobic processes. Accordingly, PP-MPs at concentrations from 5 PP-MPs.gTS−1 to 50 PP-MPs.gTS−1 were spiked in the pilot-scale UASB reactor that was fed with real municipal wastewater, where up to 58% decrease in methanogenic activity was observed at the exposure of 50 PP-MPs.gTS−1. To the best of our knowledge, the presented results are the first to report of PP-MPs inhibition on anaerobic processes. |
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Kyle H Rohde, Leonardo Sorci “The Prospective Synergy of Antitubercular Drugs With NAD Biosynthesis Inhibitors” Frontiers in Microbiology 11, 26 January 2021, 634640. doi: 10.3389/fmicb.2020.634640. |
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Abstract: Given the upsurge of drug-resistant tuberculosis worldwide, there is much focus on developing novel drug combinations allowing shorter treatment duration and a lower toxicity profile. Nicotinamide adenine dinucleotide (NAD) biosynthesis targeting is acknowledged as a promising strategy to combat drug-susceptible, drug-resistant, and latent tuberculosis (TB) infections. In this review, we describe the potential synergy of NAD biosynthesis inhibitors with several TB-drugs in prospective novel combination therapy. Despite not directly targeting the essential NAD cofactor's biosynthesis, several TB prodrugs either require a NAD biosynthesis enzyme to be activated or form a toxic chemical adduct with NAD(H) itself. For example, pyrazinamide requires the action of nicotinamidase (PncA), often referred to as pyrazinamidase, to be converted into its active form. PncA is an essential player in NAD salvage and recycling. Since most pyrazinamide-resistant strains are PncA-defective, a combination with downstream NAD-blocking molecules may enhance pyrazinamide activity and possibly overcome the resistance mechanism. Isoniazid, ethionamide, and delamanid form NAD adducts in their active form, partly perturbing the redox cofactor metabolism. Indeed, NAD depletion has been observed in Mycobacterium tuberculosis (Mtb) during isoniazid treatment, and activation of the intracellular NAD phosphorylase MbcT toxin potentiates its effect. Due to the NAD cofactor's crucial role in cellular energy production, additional synergistic correlations of NAD biosynthesis blockade can be envisioned with bedaquiline and other drugs targeting energy-metabolism in mycobacteria. In conclusion, future strategies targeting NAD metabolism in Mtb should consider its potential synergy with current and other forthcoming TB-drugs. |
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Massimiliano Gasparrini, Leonardo Sorci, Nadia Raffaelli “Enzymology of extracellular NAD metabolism.” Cellular and Molecular Life Sciences 78(7), 23 March 2021, 3317–3331. doi: 10.1007/s00018-020-03742-1 |
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Abstract: Extracellular NAD represents a key signaling molecule in different physiological and pathological conditions. It exerts such function both directly, through the activation of specific purinergic receptors, or indirectly, serving as substrate of ectoenzymes, such as CD73, nucleotide pyrophosphatase/phosphodiesterase 1, CD38 and its paralog CD157, and ecto ADP ribosyltransferases. By hydrolyzing NAD, these enzymes dictate extracellular NAD availability, thus regulating its direct signaling role. In addition, they can generate from NAD smaller signaling molecules, like the immunomodulator adenosine, or they can use NAD to ADP-ribosylate various extracellular proteins and membrane receptors, with significant impact on the control of immunity, inflammatory response, tumorigenesis, and other diseases. Besides, they release from NAD several pyridine metabolites that can be taken up by the cell for the intracellular regeneration of NAD itself. The extracellular environment also hosts nicotinamide phosphoribosyltransferase and nicotinic acid phosphoribosyltransferase, which inside the cell catalyze key reactions in NAD salvaging pathways. The extracellular forms of these enzymes behave as cytokines, with pro-inflammatory functions. This review summarizes the current knowledge on the extracellular NAD metabolome and describes the major biochemical properties of the enzymes involved in extracellular NAD metabolism, focusing on the contribution of their catalytic activities to the biological function. By uncovering the controversies and gaps in their characterization, further research directions are suggested, also to better exploit the great potential of these enzymes as therapeutic targets in various human diseases. |
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N.Colombani, M. Gaiolini, G. Busico, M. Postacchini “Quantifying the impact of evapotranspiration at the aquifer scale via groundwater modelling and MODIS Data” Water13(7) (April), 2021, 950 |
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Abstract: In shallow alluvial aquifers characterized by coarse sediments, the evapotranspiration rates from groundwater are often not accounted for due to their low capillarity. Nevertheless, this assumption can lead to errors in the hydrogeological balance estimation. To quantify such impacts, a numerical flow model using MODFLOW was set up for the Tronto river alluvial aquifer (Italy). Different estimates of evapotranspiration rates were retrieved from the online Moderate Resolution Imaging Spectroradiometer (MODIS) database and used as input values. The numerical model was calibrated against piezometric heads collected in two snapshots (mid-January 2007 and mid-June 2007) in monitoring wells distributed along the whole alluvial aquifer. The model performance was excellent, with all the statistical parameters indicating very good agreement between calculated and observed heads. The model validation was performed using baseflow data of the Tronto river compared with the calculated aquifer-river exchanges in both of the simulated periods. Then, a series of numerical scenarios indicated that, although the model performance did not vary appreciably regardless of whether it included evapotranspiration from groundwater, the aquifer-river exchanges were influenced significantly. This study showed that evapotranspiration from shallow groundwater accounts for up to 21% of the hydrogeological balance at the aquifer scale and that baseflow observations are pivotal in quantifying the evapotranspiration impact. |
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Fronzi, D.; Mirabella, F.; Cardellini, C.; Caliro, S.; Palpacelli, S.; Cambi, C.; Valigi, D.; Tazioli, A. “The Role of Faults in Groundwater Circulation before and after Seismic Events: Insights from Tracers, Water Isotopes and Geochemistry.” Water 2021, 13, 1499. https://doi.org/10.3390/w13111499 |
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Abstract: The interaction between fluids and tectonic structures such as fault systems is a much-discussed issue. Many scientific works are aimed at understanding what the role of fault systems in the displacement of deep fluids is, by investigating the interaction between the upper mantle, the lower crustal portion and the upraising of gasses carried by liquids. Many other scientific works try to explore the interaction between the recharge processes, i.e., precipitation, and the fault zones, aiming to recognize the function of the abovementioned structures and their capability to direct groundwater flow towards preferential drainage areas. Understanding the role of faults in the recharge processes of punctual and linear springs, meant as gaining streams, is a key point in hydrogeology, as it is known that faults can act either as flow barriers or as preferential flow paths. In this work an investigation of a fault system located in the Nera River catchment (Italy), based on geo-structural investigations, tracer tests, geochemical and isotopic recharge modelling, allows to identify the role of the normal fault system before and after the 2016–2017 central Italy seismic sequence (Mmax = 6.5). The outcome was achieved by an integrated approach consisting of a structural geology field work, combined with GIS-based analysis, and of a hydrogeological investigation based on artificial tracer tests and geochemical and isotopic analyses. |
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M. Mastrocicco, M.P. Gervasio, G. Busico, N. Colombani “Natural and anthropogenic factors driving groundwater resources salinization for agriculture use in the Campania plains (Southern Italy)” Sci. Tot. Environ.758 (March), 2021, 144033 |
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Abstract: The Mediterranean region is under pressure for a more sustainable use of water resources in view of the actual and future climate change. Under this pressure, the need to better assess the links between groundwater availability and quality and irrigated agriculture, is becoming urgent. Through the hydrogeologic and hydrochemical characterization of the coastal aquifers of a representative Mediterranean study area (the Campania Region in southern Italy), this study strengthened the analysis of basic components of the groundwater cycle and their temporal variability, including hydrologic, environmental and socio-economic aspects. Selected physiochemical properties of groundwater in 52 monitoring wells were considered from the Campania Environmental Protection Agency database. A total of 626 samples were collected from 2004 to 2018 to capture the water quality variability. Factor analysis and a specific groundwater quality index were also applied on 23 samples in two different timelines (2006, 2016) to capture the hydro-chemistry evolution through year. Moreover, land use and active pumping wells locations were used in the analysis. Spatial and temporal trends of base exchange indices (BEX) and sodium adsorption ratio (SAR) were computed along with Pearson coefficient among different variables, like well densities and distance from the coast. The variation in the distribution of salinity between 2006 and 2016, along with highly positive and highly negative BEX and groundwater quality index values, indicate unstable conditions for the future. In the greenhouse's areas, where groundwater exploitation is elevated, an increase of salinity was recorded due to seawater intrusion. In volcanic districts water rock interaction is the main driver of groundwater salinization, while mixing processes with carbonate freshwaters diminish groundwater salinities in the alluvial plains. This study demonstrates that groundwater over pumping can have a major impact on groundwater quality used for irrigation, despite the dominant influence that local geological and morphological features exert on the area. |
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M. Mastrocicco, N.Colombani “The issue of groundwater salinization in coastal areas of the mediterranean region: A review”, Water13(1) (January), 2021, 90 |
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Abstract: The Mediterranean area is undergoing intensive demographic, social, cultural, economic, and environmental changes. This generates multiple environmental pressures such as increased demand for water resources, generation of pollution related to wastewater discharge, and land consumption. In the Mediterranean area, recent climate change studies forecast large impacts on the hydrologic cycle. Thus, in the next years, surface and ground-water resources will be gradually more stressed, especially in coastal areas. In this review paper, the historical and geographical distribution of peer-review studies and the main mechanisms that promote aquifer salinization in the Mediterranean area are critically discussed, providing the state of the art on topics such as actual saltwater wedge characterization, paleo-salinities in coastal areas, water-rock interactions, geophysical techniques aimed at delineating the areal and vertical extent of saltwater intrusion, management of groundwater overexploitation using numerical models and GIS mapping techniques for aquifer vulnerability to salinization. Each of the above-mentioned approaches has potential advantages and drawbacks; thus, the best tactic to tackle coastal aquifer management is to employ a combination of approaches. Finally, the number of studies focusing on predictions of climate change effects on coastal aquifers are growing but are still very limited and surely need further research. |
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N. Colombani, M.P. Gervasio, G. Castaldelli, M. Mastrocicco “Soil conditioners effects on hydraulic properties, leaching processes and denitrification on a silty-clay soil” Sci. Tot. Environ. 733 (September), 2020, 139342 |
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Abstract: Agricultural landscapes are often affected by groundwater quality issues due to fertilizers leaching. To address this worldwide problem several agricultural best practices have been proposed, like limiting the amount of fertilizers and increasing soil organic matter content. To evaluate if these practices may promote groundwater quality enhancement, vadose zone retention time and complex biogeochemical processes must be known in detail. In this study, sequential undisturbed column experiments were performed to determine the amount of nutrients and heavy metals leached after simulated stormwater events. The column was amended with urea then flushed for two pore volumes, then straw residuals were incorporated and flushed for two pore volumes and finally compost was incorporated and flushed for six pore volumes. Dissolved ions, major gasses and heavy metals were determined in leachate samples. Nitrate and nitrite were leached in the urea treatment producing the highest concentrations, followed by compost and straw residuals. The redox conditions were aerobic in all treatments and pH was circumneutral or slightly basic. Denitrification was low but increased with the addition of straw residuals and compost. Heavy metals were all at very low concentrations except for lead and cadmium, which slightly exceeded threshold limits (10 and 1 μg/L, respectively) in all the treatments. The compost treatment, after three pore volumes, was affected by clay swelling due to sodium dispersion, which in turn provoked a reduction of porosity and hydraulic conductivity. |
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Giulietti Nicola, Chiariotti Paolo, Cosoli Gloria, Mobili Alessandra, Pandarese Giuseppe, Tittarelli Francesca, Revel Gian Marco. “Automated measurement system for detecting carbonation depth: Image-processing based technique applied to concrete sprayed with phenolphthalein.” MEASUREMENT, (2021),175, pp. 1-8. |
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Abstract: This paper aims at discussing an automated measurement system for detecting carbonation depth in concrete sprayed with phenolphthalein. Image processing and Convolutional Neural Networks strategies are exploited to accurately separate the carbonated and non-carbonated areas and to remove those aggregates on the carbonation front that could bring to a wrong evaluation of the carbonation depth. Very strong correlation (R2 = 0.96) is found between results provided by the proposed approach and the method suggested by the EN 13295 standard. The expanded uncertainty (coverage factor k = 2) of this novel approach is 0.08 mm. ANOVA analysis performed in multi-operator tests proved that the highest source of uncertainty is the measurement system, which, on the other hand, is robust to changes in the operator performing the measurement. |
