Elastic scattering of electrons by water: An ab initio study

In this work we devise a theoretical and computational method to compute the elastic scattering of electrons from a non-spherical potential, such as in the case of molecules and molecular aggregates. Its main feature is represented by the ability of calculating accurate wave functions for continuum states of polycentric systems via the solution of the Lippmann-Schwinger equation, including both the correlation effects and multi-scattering interference terms, typically neglected in widely used approaches, such as the Mott theory. Within this framework, we calculate the purely elastic scattering matrix elements. As a test case, we apply our scheme to the modelling of electron-water elastic scattering. The Dirac-Hartree-Fock self-consistent field method is used to determine the non-spherical molecular potential projected on a functional space spanned by Gaussian basis set. By adding a number of multi-centric radially-arranged s-type Gaussian functions, whose exponents are system-dependent and optimized to reproduce the properties of the continuum electron wave function in different energy regions, we are able to achieve unprecedented access to the description of the low energy range of the spectrum (0.001 < E < 10 eV) up to keV, finding a good agreement with experimental data and previous theoretical results. To show the potential of our approach, we also compute the total elastic scattering cross section of electrons impinging on clusters of water molecules and zundel cation. Our method can be extended to deal with inelastic scattering events and heavy-charged particle

Phytochemical profiling, antibacterial and antioxidant properties of Crocus sativus flower: A comparison between tepals and stigmas

Several studies have demonstrated that stigmas of Crocus sativus contain several bioactive compounds with potential health-promoting properties. However, during the processing of stigmas, large amounts of floral bio-residues are normally discarded as by-products. In this study, using untargeted metabolomics, the comprehensive phytochemical composition of C. sativus stigma and tepals was investigated. Moreover, the antibacterial and anti-biofilm properties of the extracts of C. sativus stigmas and tepals were compared. The study was carried out using two methicillin-resistant staphylococcal reference strains (i.e., Staphylococcus aureus ATCC 43300 and Staphylococcus epidermidis ATCC 35984), representing important Gram-positive biofilm-forming human pathogens. The antibacterial properties were correlated with total polyphenol content, total terpenoid content, and in vitro antioxidant properties of tepals and stigmas. The results demonstrated that stigma and tepal extracts, at the sub-toxic concentrations, were able to interfere with biofilm formation by ATCC 43300 and ATCC 35984. Besides, the higher antibacterial activity of tepals than stigmas was associated with higher levels of phycompounds. Therefore, our results demonstrated that C. sativus stigmas and bio-residues, such as tepals, are potential antioxidant sources and good candidates as antibacterial agents to prevent biofilm formation. Taken together, these findings showed that C. sativus could be used as functional ingredient by the food and pharmaceutical industries

Monte Carlo simulations of measured electron energy-loss spectra of diamond and graphite: Role of dielectric-response models

N.M.P. is supported by the European Research Council PoC 2015 ”Silkene” No. 693670, by the European Commission H2020 under the Graphene Flagship Core 1 No. 696656 (WP14 ”Polymer Nanocomposites”) and under the FET Proactive ”Neurofibres” No. 732344. M.D., G.G., and S.T acknowledge funding from the Graphene Flagship (WP14 “Polymer composites”, no. 696656). This work used the ARCHER UK National Supercomputing Service (http://www.archer.ac.uk). Access to computing and storage facilities owned by parties and projects contributing to the National Grid Infrastructure MetaCentrum provided under the programme ”Projects of Large Research, Development, and Innovations Infrastructures” (CESNET LM2015042), is greatly appreciated (https://www.metacentrum.cz/en/). Furthermore, we acknowledge FBK for providing unlimited access to the KORE computing facility

Anisotropic Approach for Simulating Electron Transport in Layered Materials: Computational and Experimental Study of Highly Oriented Pyrolitic Graphite

In this work, we propose a theoretical and computational model for taking into account the anisotropic structure of Highly Oriented Pyrolitic Graphite (HOPG) in the Monte Carlo simulations of charge transport. In particular, the dielectric characteristics, such as the inelastic mean free path and energy losses, are treated by linearly combining the contributions to these observables along the two main orthogonal directions identifying the layered crystalline structure of HOPG (along the layer plane and perpendicular to it). Energy losses are evaluated from ab initio calculations of the dielectric function of the system along these two perpendicular directions. Monte Carlo simulated spectra, obtained with our anisotropic approach, are compared with acquired experimental data of Reflection Electron Energy Loss and Secondary Electron spectra, showing a good agreement. These findings validate the idea of the importance of considering properly-weighted inter-planar and intra-planar interactions in the simulation of electron transport in layered materials

A novel combined experimental and multiscale theoretical approach to unravel the structure of SiC/SiOx core/shell nanowires for their optimal design

In this work we propose a realistic model of nanometer-thick SiC/SiOxcore/shell nanowires (NWs) using a combined first-principles and experimental approach. SiC/SiOxcore/shell NWs were first synthesised by a low-cost carbothermal method and their chemical-physical experimental analysis was accomplished by recording X-ray absorption near-edge spectra. In particular, the K-edge absorption lineshapes of C, O, and Si are used to validate our computational model of the SiC/SiOxcore/shell NW architectures, obtained by a multiscale approach, including molecular dynamics, tight-binding and density functional simulations. Moreover, we present ab initio calculations of the electronic structure of hydrogenated SiC and SiC/SiOxcore/shell NWs, studying the modification induced by several different substitutional defects and impurities into both the surface and the interfacial region between the SiC core and the SiOxshell. We find that on the one hand the electron quantum confinement results in a broadening of the band gap, while hydroxyl surface terminations decrease it. This computational investigation shows that our model of SiC/SiOxcore/shell NWs is capable to deliver an accurate interpretation of the recorded X-ray absorption near-edge spectra and proves to be a valuable tool towards the optimal design and application of these nanosystems in actual devices

Insight into Elderly ALS Patients in the Emilia Romagna Region: Epidemiological and Clinical Features of Late-Onset ALS in a Prospective, Population-Based Study

Few studies have focused on elderly (>80 years) amyotrophic lateral sclerosis (ALS) patients, who represent a fragile subgroup generally not included in clinical trials and often neglected because they are more difficult to diagnose and manage. We analyzed the clinical and genetic features of very late-onset ALS patients through a prospective, population-based study in the Emilia Romagna Region of Italy. From 2009 to 2019, 222 (13.76%) out of 1613 patients in incident cases were over 80 years old at diagnosis, with a female predominance (F:M = 1.18). Elderly ALS patients represented 12.02% of patients before 2015 and 15.91% from 2015 onwards (p = 0.024). This group presented with bulbar onset in 38.29% of cases and had worse clinical conditions at diagnosis compared to younger patients, with a lower average BMI (23.12 vs. 24.57 Kg/m2), a higher progression rate (1.43 vs. 0.95 points/month), and a shorter length of survival (a median of 20.77 vs. 36 months). For this subgroup, genetic analyses have seldom been carried out (25% vs. 39.11%) and are generally negative. Finally, elderly patients underwent less frequent nutritional- and respiratory-supporting procedures, and multidisciplinary teams were less involved at follow-up, except for specialist palliative care. The genotypic and phenotypic features of elderly ALS patients could help identify the different environmental and genetic risk factors that determine the age at which disease onset occurs. Since multidisciplinary management can improve a patient’s prognosis, it should be more extensively applied to this fragile group of patients

Boschi di neoformazione in Italia: approfondimenti conoscitivi e orientamenti gestionali

Nelle regioni meridionali, e in Sicilia in particolare, la fisionomia della vegetazione forestale post-abbandono è quella della macchia o arbusteto che difficilmente evolve verso un bosco propriamente detto. Il processo evolutivo della vegetazione spesso non raggiunge lo stadio di bosco non perché le condizioni ambientali non lo consentano ma per due ragioni fondamentali: i disturbi, in particolare gli incendi e il pascolo, e le limitazioni nell’arrivo di propaguli, causate dalla mancanza di piante madri, dei dispersori dei semi o entrambi. Infatti, in contesti favorevoli (assenza di disturbi e arrivo dei propaguli) la vegetazione evolve sino al bosco. Le formazioni preforestali frutto dei processi di successione secondaria occupano superfici significative e sono conseguenza del fenomeno dell’abbandono dell’agricoltura iniziato alla seconda metà del secolo scorso e che ha interessato tutta l’Europa. Alcune azioni per ridurre i fattori negativi ed esaltare invece i vantaggi ambientali sono possibili per i boschi degli ambienti mediterranei. Tra queste, la trasformazione dei boschi di neoformazione in sistemi agroforestali, e più propriamente silvopastorali, utilizzando la parte aerea delle specie arboree e arbustive e mantenendo piccoli nuclei di specie spontanee utili alla fauna selvatica (a esempio, specie con frutti carnosi) senza lasciare che esse dominino la vegetazione erbacea. Ciò consentirebbe una valorizzazione delle superfici innanzitutto come pascoli, ma non si esclude l’utilizzazione come legna da ardere della componente arborea e, in certi casi, dei prodotti ottenibili (a esempio, manna, mandorle, carrube, nocciole). Altra possibilità per non disperdere i vantaggi consisterebbe nel mettere a coltura gli ex coltivi adottando tecniche alternative che non disperdano il carbonio accumulato. Su questo aspetto esistono già esperienze: ciò potrebbe inoltre ridurre la conflittualità tra gli enti gestori delle aree protette, restii a consentire un ritorno alla coltivazione, e gli agricoltori nonché i sostenitori della necessità di tutelare i paesaggi agrari

Antioxidant and pro-oxidant properties of Carthamus tinctorius, hydroxy safflor yellow A, and safflor yellow A

(1) Carthamus Tinctorius L. (safflower) is extensively used in traditional herbal medicine. (2) The aim of this study was to investigate the bioactive properties of polyphenol extracts from flowers of Carthamus Tinctorius (CT) cultivated in Italy. We also evaluated the properties of two bioactive water-soluble flavonoid compounds, hydroxy safflor yellow A (HSYA) and safflor yellow A (SYA), contained in Carthamus Tinctorius petals. (3) The total polyphenol content was 3.5 ± 0.2 g gallic acid equivalent (GAE)/100 g, flavonoids content was 330 ± 23 mg catechin equivalent (CE)/100 g in the flowers. The extract showed a high antioxidant activity evaluated by oxygen radical absorbance capacity (ORAC) and 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assays. In addition, flower extract, SYA, and HSYA were able to reduce the susceptibility of low-density lipoprotein to copper-induced lipid peroxidation. In order to investigate the bioactive properties of flower extract, SYA, and HSYA we also studied their modulatory effect of oxidative stress on human dermal fibroblasts (HuDe) oxidized by tert-butyl hydroperoxide (t-BOOH). The CT extract at concentrations ranging from 0.01–20 μg GAE/mL of polyphenols, exerted a protective effect against t-BOOH triggered oxidative stress. At higher concentration the extract exerted a pro-oxidant effect. Similar results have been obtained using HSYA and SYA. (4) These results demonstrate a biphasic effect exerted by HSYA, SYA, and flower extracts on oxidative stress

Protection of polyphenols against glyco‐oxidative stress: Involvement of glyoxalase pathway

Chronic high glucose (HG) exposure increases methylglyoxal (MGO)‐derived advanced glycation end‐products (AGEs) and is involved in the onset of pathological conditions, such as diabetes, atherosclerosis and chronic‐degenerative diseases. Under physiologic conditions the harmful effects of MGO are contrasted by glyoxalase system that is implicated in the detoxification of Reactive Carbonyl Species (RCS) and maintain the homeostasis of the redox environment of the cell. Polyphenols are the most abundant antioxidants in the diet and present various health benefits. Aims of the study were to investigate the effects of HG‐chronic exposure on glyco‐oxidation and glyoxalase system in intestinal cells, using CaCo‐2 cells. Moreover, we studied the effect of apple polyphenols on glyco‐oxidative stress. Our data demonstrated that HG‐treatment triggers glyco-oxidation stress with a significant increase in intracellular Reactive Oxygen Species (ROS), lipid peroxidation, AGEs, and increase of Glyoxalase I (GlxI) activity. On the contrary, Glyoxalase II (GlxII) activity was lower in HG‐treated cells. We demonstrate that apple polyphenols exert a protective effect against oxidative stress and dicarbonyl stress. The increase of total antioxidant capacity and glutathione (GSH) levels in HG‐treated cells in the presence of apple polyphenols was associated with a decrease of GlxI activity

EWSR1-fusion-negative, SMARCB1-deficient primary pulmonary myxoid sarcoma

Primary pulmonary myxoid sarcoma (PPMS) is a recently defined rare neoplasm with histological and molecular similarity to extraskeletal myxoid chondrosarcoma. To date, 20 cases have been reported. A 48-year-old man presented with a huge mass filling the right hemithorax and extending into the tracheobronchial system. Histological findings were consistent with PPMS. Immunohistochemistry was positive for vimentin, CD10, and EMA, but other lineage-specific markers were negative. SMARCB1 (INI1) expression was lost in the tumour cells. FISH analysis ( EWSR1 , FUS , NR4A3 , and SMARCB1 ) revealed no abnormalities. This case suggests SMARCB1 loss as a possible alternative molecular event driving EWSR1-negative PPMS