University of Naples Federico II
  • Naples, Campania, Italy
Recent publications
Tumor invasion follows a complex mechanism which involves cell migration and proliferation. To study the processes in which primary and secondary metastases invade and damage the normal cells, mathematical models are often extremely useful. In this manuscript, we present a mathematical model of acid-mediated tumor growth consisting of radially symmetric reaction-diffusion equations. The assumption on the radial symmetry of the solutions is imposed here in view that tumors present spherical symmetry at the microscopic level. Moreover, we consider various empirical mechanisms which describe the propagation of tumors by considering cancer cells, normal cells, and the concentration of H + ions. Among other assumptions, we suppose that these components follow logistic-type growth rates. Evidently, this is an important difference with respect to various other mathematical models for tumor growth available in the literature. Moreover, we also add competition terms of normal and tumor cells growth. We carry out a balancing study of the equations of the model, and a numerical model is proposed to produce simulations. Various practical remarks derived from our assumptions are provided in the discussion of our the simulations. Response to Reviewers: % In LaTeX format. Please, compile the file. \documentclass[letterpaper,10pt]{article} \usepackage{color} \usepackage{amssymb} \setlength{\leftmargini}{0.3in} % \setlength{\parindent}{0.5in} % \setlength{\topmargin}{-0.75in} % Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation
The coexistence between ferromagnetic ordering and superconducting transport in tunnel ferromagnetic Josephson junctions (SFS JJs) accounts for a wide range of unconventional physical properties. The integration of both insulating ferromagnets or multi-layered insulator-ferromagnet barriers allows to combine ferromagnetic switching properties with peculiar low quasiparticle dissipation, which could enhance the capabilities of SFS JJs as active elements in quantum circuits. Here we show that split-transmon qubits based on tunnel ferromagnetic JJs realize an ideal playground to study noise fluctuations in ferromagnetic Josephson devices. By considering the transport properties of measured Al-based tunnel SFS JJs, we report on a theoretical study of the competition between intrinsic magnetization fluctuations in the barrier and quasiparticles dissipation, thus providing specific operation regimes to identify and disentangle the two noise sources, depending on the peculiar properties of the F layer and F/S interface.
We have fabricated and characterized at low temperatures Nb/Ni/(Al/Ni)14/Nb lateral junctions and Nb micro-SQUIDs involving (Al/Py)10 multilayers (here Py is permalloy: 80% Ni − 20% Fe). We have studied I - V curves and Josephson critical current as a function of an external magnetic field ( I c( H )) at various temperatures and orientations of the applied magnetic field. These studies revealed that, for some orientations of the externally applied magnetic field, the I c( H ) dependence of the lateral junctions has a component highly sensitive to magnetic field. In addition, we have observed a SQUID-like I c( H ) dependence for devices, in which an orthogonally oriented (with respect to the substrate) Nb loop that includes two nanoscopic Josephson junctions is filled with a (Al/Py)10 multilayer. We believe the devices presented here are promising as magnetic field sensors on nanoscale for various applications where high spatial resolution is required.
Since the advent of photocatalytic technology, scientists have been searching for semiconductor materials with high efficiency in solar energy utilization and conversion to chemical energy. Recently, the development of quantum dot (QD) photocatalysts has attracted much attention because of their unique characteristics: small size, quantum effects, strong surface activity, and wide photoresponse range. Among ternary chalcogenide semiconductors, CuInS2 QDs are increasingly examined in the field of photocatalysis due to their high absorption coefficients, good matching of the absorption range with sunlight spectrum, long lifetimes of photogenerated electron-hole pairs and environmental sustainability. In this review paper, the structural and electronic properties, synthesis methods and various photocatalytic applications of CuInS2 QDs are systematically expounded. The current research status on the photocatalytic properties of materials based on CuInS2 QD is discussed combined with the existing modification approaches for the enhancement of their performances. Future challenges and new development opportunities of CuInS2 QDs in the field of photocatalysis are then prospected.
This paper investigates the stability of systems with fast-varying piecewise-continuous coefficients and non-small delays. Starting from a recent constructive time-delay approach to periodic averaging, that allowed finding upper bound on small parameter ϵ>0 preserving the stability of the original delay-free systems, here we extend the method to systems with non-small delays and provide their input-to-state stability (ISS) analysis. The original time-delay system is transformed into a neutral type one embedding both initial non-small delay, whose upper bound is essentially larger than ϵ and does not vanish for ϵ→0, and an additional induced delay due to transformation, whose length is proportional to ϵ. By exploiting Lyapunov–Krasovskii theory, we derive ISS conditions expressed as Linear Matrix Inequalities (LMIs), whose solution allows evaluating upper bounds both on small parameter ϵ and non-small delays preserving the ISS of the original time-delay system, as well as the resulting ultimate bound of its solutions. We further apply our results to stabilization of delayed affine systems by time-dependent switching. Three numerical examples illustrate the effectiveness of the approach.
Research has identified a wide range of psychosocial factors associated to choosing to engage in ongoing cancer screenings. Nevertheless, a systematic review of the theoretical frameworks and constructs underpinning studies on breast, cervical, and colorectal cancer screening participation has yet to be conducted. As part of the action-research project “Miriade,” the present study aims to identifying the main theoretical frameworks and constructs adopted in the literature over the past five years to explain cancer screening participation. According to the PRISMA guidelines, a search of the MEDLINE/PubMed and PsycINFO databases was made. Empirical studies conducted from 2017 to 2021 were included. The following keywords were used: breast OR cervical OR colorectal screening AND adhesion OR participation OR engagement AND theoretical framework OR conceptual framework OR theory. Overall, 24 articles met the inclusion criteria. Each theoretical framework highlighted clinical and psychosocial constructs of cancer screening participation, focusing on the individuals (psycho-emotional functioning and skills plan) and/or the health services perspectives. Findings from the present study acknowledge the plurality of the theoretical frameworks and constructs adopted to predict or promote breast, cervical, and colorectal cancer screening adhesion and the need for new research efforts to improve the effectiveness of cancer screening promotion interventions.
Direct epoxidation of light olefin mixtures with hydrogen peroxide and titanium silicalite (TS-1) catalyst is interesting from a pure scientific viewpoint and it might have a considerable economic and environmental advantages. Direct epoxidation of olefin mixtures implies a significant process intensification as the separation steps of alkenes prior to the epoxidation process is avoided. Binary and ternary mixtures of ethene, oxide and 1-butene were selectively epoxidized with hydrogen peroxide in the presence of TS-1 as the heterogeneous catalyst. Methanol was used as the solvent. Transient and stationary kinetic experiments were conducted in a laboratory-scale trickle bed reactor, which was operated under atmospheric pressure and isothermal conditions at 15–55 °C. The experiments were designed to investigate the kinetics of the epoxidation of light olefins at different temperatures, alkene-to-hydrogen peroxide molar ratios as well as gas and liquid residence times in the trickle bed reactor. The recorded transient responses of the reaction products confirmed that the components in the alkene mixtures are epoxidized simultaneously. The epoxide selectivity was 90 % or higher in most experiments; ring-opening products formed from the epoxides and methanol were observed as by-products. The concentration maxima of epoxides during the transient experiments were explained by accumulation of the epoxide products inside the catalyst, which resulted in partial blocking of active sites. After-treatment of the catalyst with methanol and nitrogen completely restored the initial activity. Kinetic modeling was applied, based on presumed elementary steps on the TS-1 surface to describe the behavior of the system at steady state conditions. The trickle bed reactor was described with a dynamic multiphase model, taking into account the kinetic and mass transfer effects. The numerical values of the activation energies, kinetic constants and mass transfer parameters were estimated by nonlinear regression analysis. The model gave a satisfactory description of the experimental data.
Background and objectives: Elevated blood lactate levels are associated with poor outcome in several critical conditions. Patients with SARS-CoV-2 rarely develop hyperlactatemia. The purpose of this study is to evaluate the trend of lactatemia in patients affected by mild/moderate SARS-Co V-2-ARDS and if it affected prognosis. Methods: We analyzed blood lactate levels in thirty-eight patients with severe SARS-CoV-2 infection admitted to COVID Care Unit of Santa Maria delle Grazie Hospital, Pozzuoli. Results: Twenty patients survived and were discharged at home and 18 patients died. Despite severe hypoxia that affected all patients enrolled, T0 lactate was within normal values. All survivors showed a significant increase in lactate concentration the day prior to clinical improvement. In not-survivors levels of lactate did not increase significantly. Conclusion: In our study, patients who survive SARS CoV-2 ARDS have a fleeting increase in lactate, which precedes clinical improvement by one day.
A machine learning algorithm is here proposed with the objective to identify homogeneous flow regions in computational fluid dynamics solutions. Given a numerical compressible viscous steady solution around a body at high Reynolds numbers, the task is to select the grid cells belonging to the boundary layer, shock waves, and external inviscid flow. The Gaussian mixture algorithm demonstrated to overcome some of the limitations and drawback of the currently adopted deterministic region selection methods, which require the adoption of case-dependent cutoff inputs, topological information, and final human check. This paper shows an example of application of this selection method performing an accurate breakdown of the aerodynamic drag in viscous and wave contributions by a classical far-field method. The new algorithm essentially leads to the same results of the reference method in terms of drag decomposition; slight differences could only be found in the shock-wave/boundary-layer interaction zone, where the drag breakdown is inherently ambiguous.
  • Natascia De Lucia
    Natascia De Lucia
  • Anna De Rosa
    Anna De Rosa
  • Sandra Perillo
    Sandra Perillo
  • [...]
  • Nelson Mauro Maldonato
    Nelson Mauro Maldonato
Objective: Personality changes have often been reported among people with Parkinson's disease (PD); however, no studies have investigated the associations between personality traits, cognitive function, and specific motor symptoms. In this study, the investigators assessed whether particular personality traits were associated with specific motor subtypes of PD (e.g., tremor-dominant and akinetic-rigid phenotypes) and whether frontal-executive functions were associated with personality traits among patients with a specific motor phenotype. Methods: Forty-one people with PD and 40 healthy control participants were enrolled in the study. All participants underwent assessments of cognitive and psychological function and personality traits. The study was conducted in Italy. Results: Tremor-dominant symptoms occurred among 20 (48.8%) people with PD, whereas 21 (51.2%) patients exhibited akinetic-rigid symptoms. Multivariate analyses of variance revealed that participants with akinetic-rigid PD demonstrated significantly poorer performance on frontal-executive tests compared with those with tremor-dominant PD. Moreover, those with akinetic-rigid PD exhibited more psychopathological symptoms and higher neuroticism and introversion compared with those with tremor-dominant PD. Correlations revealed that among participants with akinetic-rigid PD, psychopathological symptoms and neuroticism and introversion personality traits were associated with frontal-executive dysfunction, whereas among those with tremor-dominant PD, no significant associations were found between personality traits and cognitive abilities. Conclusions: These findings suggest that specific personality and frontal-executive profiles are associated with the akinetic-rigid motor subtype of PD, thus helping to refine the different clinical manifestations of PD. A better understanding of the psychological, personality, and cognitive mechanisms in PD could also help to develop more targeted treatments.
Familial Adult Myoclonus Epilepsy (FAME) is an autosomal dominant condition characterized by the association of myoclonic tremor and epilepsy mainly with onset in adulthood. The clinical course is non-progressive or slowly progressive, as epilepsy is commonly controlled with appropriate antiseizures medication and individuals have a normal life expectancy. However, the myoclonus severity increases with ageing and leads to some degree of disability in the elderly. Since the non-coding repeat expansions responsible for FAME are not detected by routine genetic tests being used at this moment, a clinical diagnosis accompanied by neurophysiological testing remains essential to guide the geneticist on the specific genetic technique to be chosen.
  • Giovanna De Michele
    Giovanna De Michele
  • Luigi Maione
    Luigi Maione
  • Sirio Cocozza
    Sirio Cocozza
  • [...]
  • Alessandro Filla
    Alessandro Filla
The association of hypogonadism and cerebellar ataxia was first recognized in 1908 by Gordon Holmes. Since the seminal description, several heterogeneous phenotypes have been reported, differing for age at onset, associated features, and gonadotropins levels. In the last decade, the genetic bases of these disorders are being progressively uncovered. Here, we review the diseases associating ataxia and hypogonadism and the corresponding causative genes. In the first part of this study, we focus on clinical syndromes and genes (RNF216, STUB1, PNPLA6, AARS2, SIL1, SETX) predominantly associated with ataxia and hypogonadism as cardinal features. In the second part, we mention clinical syndromes and genes (POLR3A, CLPP, ERAL1, HARS, HSD17B4, LARS2, TWNK, POLG, ATM, WFS1, PMM2, FMR1) linked to complex phenotypes that include, among other features, ataxia and hypogonadism. We propose a diagnostic algorithm for patients with ataxia and hypogonadism, and we discuss the possible common etiopathogenetic mechanisms.
  • Akira J T Alexander
    Akira J T Alexander
  • Marco Salvemini
    Marco Salvemini
  • Vattipally B Sreenu
    Vattipally B Sreenu
  • [...]
  • Alain Kohl
    Alain Kohl
Toscana virus (TOSV) (Bunyavirales, Phenuiviridae, Phlebovirus, Toscana phlebovirus) and other related human pathogenic arboviruses are transmitted by phlebotomine sand flies. TOSV has been reported in nations bordering the Mediterranean Sea among other regions. Infection can result in febrile illness as well as meningitis and encephalitis. Understanding vector-arbovirus interactions is crucial to improving our knowledge of how arboviruses spread, and in this context, immune responses that control viral replication play a significant role. Extensive research has been conducted on mosquito vector immunity against arboviruses, with RNA interference (RNAi) and specifically the exogenous siRNA (exo-siRNA) pathway playing a critical role. However, the antiviral immunity of phlebotomine sand flies is less well understood. Here we were able to show that the exo-siRNA pathway is active in a Phlebotomus papatasi-derived cell line. Following TOSV infection, distinctive 21 nucleotide virus-derived small interfering RNAs (vsiRNAs) were detected. We also identified the exo-siRNA effector Ago2 in this cell line, and silencing its expression rendered the exo-siRNA pathway largely inactive. Thus, our data show that this pathway is active as an antiviral response against a sand fly transmitted bunyavirus, TOSV.
  • Giuseppe Matarese
    Giuseppe Matarese
Overnutrition could lead to loss of self-tolerance by impinging on immune regulation.
  • Bar Piscon
    Bar Piscon
  • Eliana Pia Esposito
    Eliana Pia Esposito
  • Boris Fichtman
    Boris Fichtman
  • [...]
  • Ohad Gal-Mor
    Ohad Gal-Mor
Bacterial conjugation is one of the most abundant horizontal gene transfer (HGT) mechanisms, playing a fundamental role in prokaryote evolution. A better understanding of bacterial conjugation and its cross talk with the environment is needed for a more complete understanding of HGT mechanisms and to fight the dissemination of malicious genes between bacteria. Here, we studied the effect of outer space, microgravity, and additional key environmental cues on transfer (tra) gene expression and conjugation efficiency, using the under studied broad-host range plasmid pN3, as a model. High resolution scanning electron microscopy revealed the morphology of the pN3 conjugative pili and mating pair formation during conjugation. Using a nanosatellite carrying a miniaturized lab, we studied pN3 conjugation in outer space, and used qRT-PCR, Western blotting and mating assays to determine the effect of ground physicochemical parameters on tra gene expression and conjugation. We showed for the first time that bacterial conjugation can occur in outer space and on the ground, under microgravity-simulated conditions. Furthermore, we demonstrated that microgravity, liquid media, elevated temperature, nutrient depletion, high osmolarity and low oxygen significantly reduce pN3 conjugation. Interestingly, under some of these conditions we observed an inverse correlation between tra gene transcription and conjugation frequency and found that induction of at least traK and traL can negatively affect pN3 conjugation frequency in a dose-dependent manner. Collectively, these results uncover pN3 regulation by various environmental cues and highlight the diversity of conjugation systems and the different ways in which they may be regulated in response to abiotic signals. IMPORTANCE Bacterial conjugation is a highly ubiquitous and promiscuous process, by which a donor bacterium transfers a large portion of genetic material to a recipient cell. This mechanism of horizontal gene transfer plays an important role in bacterial evolution and in the ability of bacteria to acquire resistance to antimicrobial drugs and disinfectants. Bacterial conjugation is a complex and energy-consuming process, that is tightly regulated and largely affected by various environmental signals sensed by the bacterial cell. Comprehensive knowledge about bacterial conjugation and the ways it is affected by environmental cues is required to better understand bacterial ecology and evolution and to find new effective ways to counteract the threating dissemination of antibiotic resistance genes between bacterial populations. Moreover, characterizing this process under stress or suboptimal growth conditions such as elevated temperatures, high salinity or in the outer space, may provide insights relevant to future habitat environmental conditions.
  • Fabrizio Martora
    Fabrizio Martora
  • Teresa Battista
    Teresa Battista
  • Luca Potestio
    Luca Potestio
  • [...]
  • Matteo Megna
    Matteo Megna
Response to “Onset of epidermolysis bullosa acquisita under therapy with ustekinumab for the treatment of Crohn disease”
  • Monica Pozzo
    Monica Pozzo
  • Tommaso Turrini
    Tommaso Turrini
  • Luca Bignardi
    Luca Bignardi
  • [...]
  • Rosanna Larciprete
    Rosanna Larciprete
High-energy, long gamma-ray bursts (GRBs) can be generated by the core collapse of massive stars at the end of their lives. When they happen in the close-by universe they can be exceptionally bright, as seen from the Earth in the case of the recent, giant, long-lasting GRB221009A. GRB221009A was produced by a collapsing star with a redshift of 0.152: this event was observed by many gamma-ray space experiments, which also detected an extraordinary long gamma-ray afterglow. The exceptionally large fluence of the prompt emission of about 0.013 erg cm −2 illuminated a large geographical region centered on India and including Europe and Asia. We report in this paper the observation of sudden electron flux changes correlated with GRB221009A and measured by the HEPP-L charged particle detector on board the China Seismo-Electromagnetic Satellite, which was orbiting over Europe at the time of the GRB event. The time structure of the observed electron flux closely matches the very distinctive time dependence of the photon flux associated with the main part of the emission at around 13:20 UTC on 2022 October 9. To test the origin of these signals, we set up a simplified simulation of one HEPP-L subdetector: the results of this analysis suggest that the signals observed are mostly due to electrons created within the aluminum collimator surrounding the silicon detector, providing real-time monitoring of the very intense photon fluxes. We discuss the implications of this observation for existing and forthcoming particle detectors on low Earth orbits. Unified Astronomy Thesaurus concepts: Particle astrophysics (96); Gamma-ray bursts (629); Astronomical detectors (84)
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15,813 members
Annalisa Guaragna
  • Department of Chemical Sciences
Roberta Marra
  • Department of Agriculture
Vincenzo D'Antò
  • Department of Neuroscience and Reproductive and Odontostomatological Sciences
Angelo Forgione
  • Department of Pharmacology and Toxicology
Carlo Buonerba
  • Oncologia Medica
Corso Umberto I, 40, 80138, Naples, Campania, Italy
Head of institution
Matteo Lorito