Enthalpic Stabilization of NO Oxidation Transition States by Micropororous Silicates

Zeolite catalysts play essential roles in the chemical and petrochemical industries. They exhibit high surface areas, interconnected channels of molecular dimensions, and the ability to select reactants and transition states based on their size. In particular, acid and metal-exchanged zeolites catalyze NO oxidation even at ambient tem-peratures, in sharp contrast with the higher temperatures required on supported metal catalysts. Here, we examine the kinetic effects of reactant concentrations and the activation barriers for NO oxidation on amorphous mesopo-rous silica and on microporous pure silica forms of zeolites MFI, beta (BEA), and chabazite (CHA). These data show the remarkable reactivity of microporous structures of pure silicate frameworks, even in the absence of speci-fic sites for chemical binding of reactants or transition states. These data, taken together with the measured nega-tive activation barriers, lead us to conclude that reactivity is induced by mere physical confinement through van der Waals forces, which provide significant enthalpic stabilization for the relevant trimolecular transition states

Marble Architectural Elements and Liturgical Furniture of the Santa Giustina Basilica in Padova : New Archaeometric Data on the Importation of Proconnesian Marble in the Late Antique Adriatic

This paper examines eight marble samples from the architectural elements and liturgical furniture of the ecclesiastical complex of Santa Giustina in Padova (Italy), founded by the Rufus Venantius Opilio before AD 524. The provenance determination of the marbles was carried out by means of a multi-analytical approach combining mineralogical-petrographic investigations, performed by microscopic observations of thin sections, and the measurement of the ratios of stable carbon and oxygen isotopes. The results obtained were compared with up-to-date petrographic and isotopic databases (Antonelli and Lazzarini 2015), and they showed that the analyzed marbles come from the quarries of the island of Proconnesus in Asia Minor, modern Marmara Adasi (Turkey). Archaeometric evidence, together with the stylistic and functional analysis of the pieces, suggests the direct importation of a complete set of sculptures, shipped at different stages of workmanship from the workshops of Constantinople and expressly ordered by a single patron, who can be identified as Opilio, founder of the basilica of Santa Giustina and praetorian prefect at the court of King Theodoric

State update algorithm for associative elastic-plastic pressure-insensitive materials by incremental energy minimization

This work presents a new state update algorithm for small-strain associative elastic-plastic constitutive models, treating in a unified manner a wide class of deviatoric yield functions with linear or nonlinear strain-hardening. The algorithm is based on an incremental energy minimization approach, in the framework of generalized standard materials with convex free energy and dissipation potential. An efficient method for the computation of the latter, its gradient and its Hessian is provided, using Haigh-Westergaard stress invariants. Numerical results on a single material point loading history and finite element simulations are reported to prove the effectiveness and the versatility of the method. Its merit turns out to be complementary to the classical return map strategy, because no convergence difficulties arise if the stress is close to high curvature points of the yield surface

A combined experimental and computational study of the pressure dependence of the vibrational spectrum of solid picene C_22H_14

We present high-quality optical data and density functional perturbation theory calculations for the vibrational spectrum of solid picene (C$_{22}$H$_{14}$) under pressure up to 8 GPa. First-principles calculations reproduce with a remarkable accuracy the pressure effects on both frequency and intensities of the phonon peaks experimentally observed . Through a detailed analysis of the phonon eigenvectors, We use the projection on molecular eigenmodes to unambiguously fit the experimental spectra, resolving complicated spectral structures, in a system with hundreds of phonon modes. With these projections, we can also quantify the loss of molecular character under pressure. Our results indicate that picene, despite a \sim 20 % compression of the unit cell, remains substantially a molecular solid up to 8 GPa, with phonon modes displaying a smooth and uniform hardening with pressure. The Grueneisen parameter of the 1380 cm^{-1} a_1 Raman peak ($\gamma_p=0.1$) is much lower than the effective value ($\gamma_d=0.8$) due to K doping. This is an indication that the phonon softening in K doped samples is mainly due to charge transfer and electron-phonon coupling.Comment: Replaced with final version (PRB

PET/MRI in prostate cancer: a systematic review and meta-analysis

Aim: In recent years, the clinical availability of scanners for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) has enabled the practical potential of multimodal, combined metabolic-receptor, anatomical, and functional imaging to be explored. The present systematic review and meta-analysis summarize the diagnostic information provided by PET/MRI in patients with prostate cancer (PCa). Materials and methods: A literature search was conducted in three different databases. The terms used were \u201ccholine\u201d or \u201cprostate-specific membrane antigen - PSMA\u201d AND \u201cprostate cancer\u201d or \u201cprostate\u201d AND \u201cPET/MRI\u201d or \u201cPET MRI\u201d or \u201cPET-MRI\u201d or \u201cpositron emission tomography/magnetic resonance imaging.\u201d All relevant records identified were combined, and the full texts were retrieved. Reports were excluded if (1) they did not consider hybrid PET/MRI; or (2) the sample size was < 10 patients; or (3) the raw data were not enough to enable the completion of a 2 7 2 contingency table. Results: Fifty articles were eligible for systematic review, and 23 for meta-analysis. The pooled data concerned 2104 patients. Initial disease staging was the main indication for PET/MRI in 24 studies. Radiolabeled PSMA was the tracer most frequently used. In primary tumors, the pooled sensitivity for the patient-based analysis was 94.9%. At restaging, the pooled detection rate was 80.9% and was higher for radiolabeled PSMA than for choline (81.8% and 77.3%, respectively). Conclusions: PET/MRI proved highly sensitive in detecting primary PCa, with a high detection rate for recurrent disease, particularly when radiolabeled PSMA was used

Peer support between healthcare workers in hospital and out-of-hospital settings: a scoping review

Background and aim: the healthcare workers, mostly in emergency departments, are exposed to emotionally strong situations: this condition often can lead them to operate incorrectly. In the face of the mistake, many of them experience psychological trauma, becoming “second victims” of the event. In this case they can find comfort in dealing with Peers that can help to understand emotions and normalize lived experiences. A scoping review was conducted to clarify the key concepts available in the literature and understand Peer Support characteristics and methods of implementation. Methods: scoping review approach of Joanna Briggs Institute was used. The reviewers analyzed the last twenty-one years of literature and extracted data from relevant studies. Results: 49 articles were relevant. Articles involve mostly physicians and nurses, but all the other healthcare professionals are included. 56% of the articles have been published in the last two years during the Covid 19 pandemic, which revealed the growing need of developing Peer Support programs; the Anglo-Saxon countries are the main geographical area of origin (82%). Peer support emerges as a preclinical psychological support for people involved in tiring situations. It’s based on mutual respect and on voluntary and not prejudicial help. Peers are trained to guide the support relationship. Peer Support can be proposed as one to one/group peer support, or through online platforms. Conclusions: many of the studies affirm that the personnel involved have benefited from the programs available. It is necessary to carry out further research to determine the pre and post intervention benefits. (www.actabiomedica.it)

Vibrational spectrum of solid picene (C_22H_14)

Recently, Mitsuhashi et al., have observed superconductivity with transition temperature up to 18 K in potassium doped picene (C22H14), a polycyclic aromatic hydrocarbon compound [Nature 464 (2010) 76]. Theoretical analysis indicate the importance of electron-phonon coupling in the superconducting mechanisms of these systems, with different emphasis on inter- and intra-molecular vibrations, depending on the approximations used. Here we present a combined experimental and ab-initio study of the Raman and infrared spectrum of undoped solid picene, which allows us to unanbiguously assign the vibrational modes. This combined study enables the identification of the modes which couple strongly to electrons and hence can play an important role in the superconducting properties of the doped samples

Gobernanza urbana y retos de la regulación del alquiler vacacional y de las plataformas digitales en las grandes ciudades europeas

El desarrollo exponencial del alquiler vacacional, o de corto plazo, facilitado por plataformas digitales como Airbnb, se ha convertido en los últimos años en uno de los temas más polémicos en las grandes ciudades europeas. A partir de un estudio sobre la regulación del alquiler vacacional en una decena de grandes ciudades europeas, se analizan los procesos de politización de este fenómeno, las medidas de regulación y de control que se han impulsado, su aplicación y la difícil gobernanza de las nuevas plataformas de la economía digital. En el contexto europeo, las respuestas de los gobiernos municipales han sido muy diversas. Algunos han tomado fuertes medidas regulatorias para prohibir o frenar el crecimiento del alquiler vacacional. Otros han tratado de buscar un punto medio entre la protección del uso residencial, la atracción turística de la ciudad y el “derecho a compartir” una residencia principal. Algunas ciudades han optado por una regulación mínima, y otras ciudades todavía no han adoptado medidas específicas. Esta diversidad de modos de regulación se puede explicar por tres factores (Aguilera et al., 2019): el tipo de actores que politizaron el tema y lo enmarcaron dentro de un sector de políticas públicas específico; los instrumentos preexistentes utilizados en ese sector; y la distribución de competencias entre el nivel municipal y niveles de gobierno de rango superior. Sin embargo, la aplicación de las nuevas regulaciones permanece inacabada e inefectiva, en gran parte debido a la falta de cooperación de las plataformas digitales en facilitar el acceso a los datos de los anunciantes. La efectividad futura de la regulación depende del éxito de las presiones puestas por los actores públicos sobre las plataformas para conseguir el acceso a los datos y el cumplimiento normativo, una batalla que en Europa se juega ahora a nivel de las instituciones de la UE

A multi analytical characterization of a small bronze figurine from Gran Carro site (Bolsena Lake, Italy)

This paper presents the results of an archaeometric analysis carried out on an early Iron Age anthropomorphic figurine discovered in the area of the Gran Carro on Bolsena Lake (Latium, Italy) site, currently interpreted as a place of worship. This statuette is considered a unicum, both because of the context in which it was found and because of its stylistic characteristics similar to those of bronzes from the Nuragic civilization (Sardinia, Italy). Its discovery and the data obtained from this work provide further evidence in support of numerous previous studies suggesting the presence of trade and direct exchanges between Sardinia and southern Etruria. The research was performed through some non-destructive investigations such as Energy Dispersive X-Ray Fluorescence (EDXRF) combined with Monte Carlo Simulation (MC) and micro-invasive investigations such as Scanning Electron Microscopy coupled by Energy Dispersive Spectroscopy (SEM–EDS) and by Electron Probe Micro-Analysis (EPMA), metallography and lead isotope analyses (LIA), performed on a selected micro-fragment. The combination of non-destructive techniques (EDXRF-MCS) for the characterization of the artefact allowed us to obtain data similar to those obtained with micro-invasive surveys, further demonstrating the effectiveness of the method. The results indicate that the statuette is made of a bronze alloy and that the copper metal was extracted from Sardinian deposits