Mixing layer-wise and refined equivalent-single layer FEs based on Lagrange expansions

In the aeronautic engineering, in case of the design of an aircraft system, the finite element model of the structure is usually developed by combining 1D and 2D elements, which opportunely approximate the mathematical domains of ribs, stringers, panels, and other components. Clearly, this discretization results in a simplification of reality. Indeed, in many applications, a complete description of the 3D stress field of a certain portion of the model may be mandatory. To accurately capture these localized 3D stress fields, solid models or high-order theories are demanded. However, in order to make the model more efficient, i.e. to balance computational cost and accuracy of the results, a global/local approach can be adopted. A popular approach for the global/local analysis of structures consists of formulating multiple kinematic models. In particular, different subregions of the structure are analyzed with different mathematical models, so that particular areas of interest can be described through an accurate description, as the Layer-Wise (LW) approach when dealing with laminated materials, whereas lower-order kinematics can be employed in the remaining zones. Although accurate, LW models may require the use of high computational efforts. Thus, in the last years, several efforts have been addressed by researchers to make the composite plate and shell models as accurate as efficient. One of the simple types of multiple-model method, for composite laminates analysis, is the concept of selective ply grouping or sublaminates (see [1]). This approach consists in creating some local regions in the plate/shell thickness direction, identified by specific ply or plies, whithin which accurate stresses are desired. The purpose of this work is the development of a mathematical model able to arbitrarily select multiple plies, within which the interlaminar stresses have to be accurately defined. The approach is developed in framework of the Carrera Unified Formulation [2], which allows the user to define the order of model as an input of the analysis, so that low- to higher-order models can be built in a global/local meaning without the need of any ad-hoc model. The proposed approach is applied to 1D beam and 2D plate/shell models, as well as on a stiffened panel from a real aeronautic application. The results show the capability of the present model to accurately describe the localized interlaminar phenomena in terms of stresses using the global/local approach

Evaluation of “Caterina assay”: An Alternative Tool to the Commercialized Kits Used for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Identification

Abstract: Here we describe the first molecular test developed in the early stage of the pandemic to diagnose the first cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Sardinian patients in February–March 2020, when diagnostic certified methodology had not yet been adopted by clinical microbiology laboratories. The “Caterina assay” is a SYBR®Green real-time reverse-transcription polymerase chain reaction (rRT-PCR), designed to detect the nucleocapsid phosphoprotein (N) gene that exhibits high discriminative variation RNA sequence among bat and human coronaviruses. The molecular method was applied to detect SARS-CoV-2 in nasal swabs collected from 2110 suspected cases. The study article describes the first molecular test developed in the early stage of the declared pandemic to identify the coronavirus disease 2019 (COVID-19) in Sardinian patients in February–March 2020, when a diagnostic certified methodology had not yet been adopted by clinical microbiology laboratories. The assay presented high specificity and sensitivity (with a detection limit ≥50 viral genomes/µL). No false-positives were detected, as confirmed by the comparison with two certified commercial kits. Although other validated molecular methods are currently in use, the Caterina assay still represents a valid and low-cost detection procedure that could be applied in countries with limited economic resource

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Finite elements based on Jacobi shape functions for the analysis of beams, plates and shells

This paper proposes the use of Jacobi polynomials to approximate higher-ordertheories of beam, plate, and shell structures. The Carrera unified formulation isused in this context to express displacement kinematics in a hierarchical form.In this manner, classical to complex higher-order theories can be implementedwith ease. Particular attention is focused on the attenuation and the correctionof the shear locking. Therefore, reduced integration as well as mixed interpo-lation of tensorial components methods are investigated against the new finiteelements. Several case studies are taken into account to highlight the effective-ness and robustness of the proposed approach. Also, several benchmarks areprovided for future assessments

Paesaggi condivisi, accessibili ed esperienze di ricerca archeologica in Sardegna

Se presentan en este trabajo las diferentes estrategias que se están usando para difundir y explotar públicamente los recursos culturales del municipio de Serri, sobre todo los de índole arqueológica. En el programa emprendido destaca por un lado la colaboración entre diversas instituciones, entre ellas las universidades de Cagliari y Granada, el municipio de Serri y la Soprintendenza, y por otro lado, el éxito medido en el incremento de visitantes de lugares como el santuario de Santa Vittoria

Changes in Dendritic Spine Morphology and Density of Granule Cells in the Olfactory Bulb of Anguilla anguilla (L., 1758): A Possible Way to Understand Orientation and Migratory Behavior

Simple Summary The olfactory bulb can process odour cues through granular cells (GCs) and dendritic spines, changing their synaptic plasticity properties and their morphology. The GCs' dendritic spines density and morphology were analysed in Anguilla anguilla, considering the olfaction as a driver involved in fish orientation and migration. For the head and neck morphology, spines were classified as mushroom, long thin, stubby, and filopodia. Spines' density decreased from juvenile migrants to no-migrant stages and increased in the adult migrants. Spines' density was comparable between glass and silver eels as an adaptation to migration, while at non-migrating phases, spines' density decreased. For its phylogenetic Elopomorph attribution and its complex life cycle, A. anguilla could be recommended as a model species to study the development of dendritic spines in GCs of the olfactory bulb. Considering the role of olfaction in the orientation and migration of A. anguilla, the modification of environmental stimuli (ocean alterations and climate change) could represent contributing factors that threaten this critically endangered species. Olfaction could represent a pivotal process involved in fish orientation and migration. The olfactory bulb can manage olfactive signals at the granular cell (GC) and dendritic spine levels for their synaptic plasticity properties and changing their morphology and structural stability after environmental odour cues. The GCs' dendritic spine density and morphology were analysed across the life stages of the catadromous Anguilla anguilla. According to the head and neck morphology, spines were classified as mushroom (M), long thin (LT), stubby (S), and filopodia (F). Total spines' density decreased from juvenile migrants to no-migrant stages, to increase again in the adult migrant stage. Mean spines' density was comparable between glass and silver eels as an adaptation to migration. At non-migrating phases, spines' density decreased for M and LT, while M, LT, and S density increased in silver eels. A great dendritic spine development was found in the two migratory phases, regressing in trophic phases, but that could be recreated in adults, tracing the migratory memory of the routes travelled in juvenile phases. For its phylogenetic Elopomorph attribution and its complex life cycle, A. anguilla could be recommended as a model species to study the development of dendritic spines in GCs of the olfactory bulb as an index of synaptic plasticity involved in the modulation of olfactory stimuli. If olfaction is involved in the orientation and migration of A. anguilla and if eels possess a memory, these processes could be influenced by the modification of environmental stimuli (ocean alterations and rapid climate change) contributing to threatening this critically endangered species