Publications by authors named "Mastronardi V"

The design of interfaces between nanostructured electrodes and advanced electrolytes is critical for realizing advanced electrochemical double-layer capacitors (EDLCs) that combine high charge-storage capacity, high-rate capability, and enhanced safety. Toward this goal, this work presents a novel and sustainable approach for fabricating ionogel-based electrodes using a renewed slurry casting method, in which the solvent is replaced by the ionic liquid (IL), namely 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIFSI). This method avoids time-consuming and costly electrolyte-filling steps by integrating the IL directly into the electrode during slurry preparation, while improving the rate capability of EDLCs based on non-flammable ILs.

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Continuous monitoring of cardiovascular parameters like pulse wave velocity (PWV), blood pressure wave (BPW), stiffness index (SI), reflection index (RI), mean arterial pressure (MAP), and cardio-ankle vascular index (CAVI) has significant clinical importance for the early diagnosis of cardiovascular diseases (CVDs). Standard approaches, including echocardiography, impedance cardiography, or hemodynamic monitoring, are hindered by expensive and bulky apparatus and accessibility only in specialized facilities. Moreover, noninvasive techniques like sphygmomanometry, electrocardiography, and arterial tonometry often lack accuracy due to external electrical interferences, artifacts produced by unreliable electrode contacts, misreading from placement errors, or failure in detecting transient issues and trends.

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Two-dimensional (2D) conjugated metal-organic frameworks (c-MOFs) are promising materials for supercapacitor (SC) electrodes due to their high electrochemically accessible surface area coupled with superior electrical conductivity compared to traditional MOFs. In this work, porous and non-porous HHB-Cu (HHB=hexahydroxybenzene), derived through surfactant-assisted synthesis are studied as representative 2D c-MOF models with different characteristics, showing diverse reversible redox reactions with Na and Li in aqueous (10 M NaNO) and organic (1.0 M LiPF in ethylene carbonate and dimethyl carbonate) electrolytes, respectively.

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The capacitance of electrode materials used in electrochemical double-layer capacitors (EDLCs) is currently limited by several factors, including inaccessible isolated micropores in high-surface area carbons, the finite density of states resulting in a quantum capacitance in series to Helmholtz double-layer capacitance, and the presence of surface impurities, such as functional groups and adsorbed species. To unlock the full potential of EDLC active materials and corresponding electrodes, several post-production treatments are commonly proposed to improve their capacitance and, thus, the energy density of the corresponding devices. In this work, we report a systematic study of the effect of a prototypical treatment, namely H-assisted thermal treatment, on the chemical, structural, and thermal properties of activated carbon and corresponding electrodes.

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Designing robust and cost-effective electrocatalysts for efficient alkaline oxygen evolution reaction (OER) is of great significance in the field of water electrolysis. In this study, an electrochemical strategy to activate stainless steel (SS) electrodes for efficient OER is introduced. By cycling the SS electrode within a potential window that encompasses the Fe(II)↔Fe(III) process, its OER activity can be enhanced to a great extent compared to using a potential window that excludes this redox reaction, decreasing the overpotential at current density of 100 mA cm by 40 mV.

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Degeneration of photoreceptors in age-related macular degeneration (AMD) is associated with oxidative stress due to the intense aerobic metabolism of rods and cones that if not properly counterbalanced by endogenous antioxidant mechanisms can precipitate photoreceptor degeneration. In spite of being a priority eye disease for its high incidence in the elderly, no effective treatments for AMD exist. While systemic administration of antioxidants has been unsuccessful in slowing down degeneration, locally administered rare-earth nanoparticles were shown to be effective in preventing retinal photo-oxidative damage.

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Article Synopsis
  • Shape-controlled octahedral platinum (Pt) nanoparticles are shown to mimic the glucose oxidase enzyme, offering high glucose affinity due to their unique surface structure and size comparable to natural enzymes.* -
  • The nanoparticles' citrate coating can be easily removed, which enhances their stability on electrodes and allows effective electrochemical detection of glucose, showing a linear response over a wide concentration range (0.36 to 17 mM) with a detection limit of 110 μM.* -
  • The developed sensor demonstrates good reproducibility, low variability, and long-term stability (over 2 months), while also effectively detecting glucose in saliva samples, indicating potential for non-invasive monitoring of blood sugar levels.*
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Oxidative stress is known to be the cause of several neurovascular diseases, including neurodegenerative disorders, since the increase of reactive oxygen species (ROS) levels can lead to cellular damage, blood-brain barrier leaking, and inflammatory pathways. Herein, we demonstrate the therapeutic potential of 5 nm platinum nanoparticles (PtNPs) to effectively scavenge ROS in different cellular models of the neurovascular unit. We investigated the mechanism underlying the PtNP biological activities, analyzing the influence of the evolving biological environment during particle trafficking and disclosing a key role of the protein corona, which elicited an effective switch-off of the PtNP catalytic properties, promoting their selective activity.

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The growth of pyramidal platinum nanocrystals is studied by a combination of synthesis/characterization experiments and density functional theory calculations. It is shown that the growth of pyramidal shapes is due to a peculiar type of symmetry breaking, which is caused by the adsorption of hydrogen on the growing nanocrystals. Specifically, the growth of pyramidal shapes is attributed to the size-dependent adsorption energies of hydrogen atoms on {100} facets, whose growth is hindered only if they are sufficiently large.

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A quantitative evaluation of kinetic parameters, the joint's range of motion, heart rate, and breathing rate, can be employed in sports performance tracking and rehabilitation monitoring following injuries or surgical operations. However, many of the current detection systems are expensive and designed for clinical use, requiring the presence of a physician and medical staff to assist users in the device's positioning and measurements. The goal of wearable sensors is to overcome the limitations of current devices, enabling the acquisition of a user's vital signs directly from the body in an accurate and non-invasive way.

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The catalytic and antioxidant properties of platinum nanoparticles (PtNPs) make them promising candidates for several applications in nanomedicine. However, an open issue, still shared among most nanomaterials, is the understanding on how internalized PtNPs, which are confined within endo-lysosomal compartments, can exert their activities. To address this problem, here we study the protective effect of 5 nm PtNPs on a human hepatic (HepG2) cell line exposed to dichlorodiphenylethylene (DDE) as a model of oxidative stress.

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Ultrasmall (<5 nm diameter) noble metal nanoparticles with a high fraction of {111} surface domains are of fundamental and practical interest as electrocatalysts, especially in fuel cells; the nanomaterial surface structure dictates its catalytic properties, including kinetics and stability. However, the synthesis of size-controlled, pure Pt-shaped nanocatalysts has remained a formidable chemical challenge. There is an urgent need for an industrially scalable method for their production.

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Synthesizing metal nanoparticles with fine control of size, shape and surface properties is of high interest for applications such as catalysis, nanoplasmonics, and fuel cells. In this contribution, we demonstrate that the citrate-coated surfaces of palladium (Pd) and platinum (Pt)@Pd nanocubes with a lateral length <5 nm and low polydispersity in shape achieve superior catalytic properties. The synthesis achieves great control of the nanoparticle's physico-chemical properties by using only biogenic reagents and bromide ions in water while being fast, easy to perform and scalable.

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A rapid point-of-care method for the colorimetric detection of cisplatin was developed, exploiting the efficient conversion of the chemotherapeutic drug into a high-performance nanocatalyst with peroxidase enzyme mimics. This assay provides high specificity and ppb-detection sensitivity with the naked eye or a smartphone-based readout, outperforming many standard laboratory-based techniques. The nanocatalyst-enabled colorimetric assay can be integrated with machine-learning methods, providing accurate quantitative measurements.

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Flexible and bendable electronics are gaining a lot of interest in these last years. In this scenario, compact antennas on flexible substrates represent a strategical technological step to pave the way to a new class of wearable systems. A crucial issue to overcome is represented by the poor radiation properties of compact antennas, especially in the case of flexible and thin substrates.

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Modified Bondy mastoidectomy is a type of canal wall down mastoidectomy well described in literature for adult patients. We present our experience with the use of modified Bondy mastoidectomy in pediatric population. Using retrospective chart review, pediatric patients, who underwent modified Bondy procedure for attic cholesteatoma between 1983 and 2015 at our quaternary referral center for otology and lateral skull base surgery, were analyzed after obtaining permission from institutional review board.

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Deglutition disorders (dysphagia) are common symptoms of a large number of diseases and can lead to severe deterioration of the patient's quality of life. The clinical evaluation of this problem involves an invasive screening, whose results are subjective and do not provide a precise and quantitative assessment. To overcome these issues, alternative possibilities based on wearable technologies have been proposed.

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The problem of vortex shedding, which occurs when an obstacle is placed in a regular flow, is governed by Reynolds and Strouhal numbers, known by dimensional analysis. The present work aims to propose a thin films-based device, consisting of an elastic piezoelectric flapping flag clamped at one end, in order to determine the frequency of vortex shedding downstream an obstacle for a flow field at Reynolds number Re∼103 in the open channel. For these values, Strouhal number obtained in such way is in accordance with the results known in literature.

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Green and scalable methodologies for the preparation of metal nanoparticles with fine control of shape and size are of high interest in many areas including catalysis, nanomedicine, and nanodiagnostics. In this contribution, we describe a new synthetic method for the production of palladium (Pd) penta-twinned nanowires and nanorods utilizing sodium citrate, formic acid, ascorbic acid, and potassium bromide (KBr) in water, without the use of surfactants or polymers. The synthesis is green, fast, and without the need of complex setups.

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Colorimetric and electrochemical (bio)sensors are commonly employed in wearable platforms for sweat monitoring; nevertheless, they suffer from low stability of the sensitive element. In contrast, mass-(bio)sensors are commonly used for analyte detection at laboratory level only, due to their rigidity. To overcome these limitations, a flexible mass-(bio)sensor for sweat pH sensing is proposed.

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There is huge research activity in the development of flexible and biocompatible piezoelectric materials for next-generation compliant micro electro-mechanical systems (MEMS) transducers to be exploited in wearable devices and implants. This work reports for the first time on the development of flexible ScAlN films deposited by sputtering technique onto polyimide substrates, assessing their piezoelectricity and biocompatibility. Flexible ScAlN films have been analyzed in terms of morphological, structural, and piezoelectric properties.

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Electronic devices used for marine applications suffer from several issues that can compromise their performance. In particular, water absorption and permeation can lead to the corrosion of metal parts or short-circuits. The added mass due to the absorbed water affects the inertia and durability of the devices, especially for flexible and very thin micro-systems.

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Objective: To evaluate the audiological aspects of vestibular schwannoma (VS) patients with normal hearing.

Study Design: Retrospective study.

Setting: Quaternary referral center for skull base pathologies.

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Vascular grafts are artificial conduits properly designed to substitute a diseased blood vessel. However prosthetic fail can occur without premonitory symptoms. Continuous monitoring of the system can provide useful information not only to extend the graft's life but also to optimize the patient's therapy.

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