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Mortar-based composites are an emerging technology for the repair and strengthening of reinforced concrete and masonry structures. In most cases, the effectiveness of the retrofitting work relies on the substrate-to-composite bond capacity but in some applications, connectors are also used to prevent debonding and improve the performance of the retrofitted structure. Indeed, the use of connectors is recommended by design guidelines and suppliers are required to test them for acceptance. The paper presents a laboratory investigation on steel reinforced grout connectors, made by rolling ultra-high tensile strength steel textiles, comprising either galvanized or stainless-steel micro cords. Tensile tests were first carried out for mechanical characterization. Pull-out tests were then performed on connectors installed in holes drilled in wall panels and injected with either cement or lime mortars. Concrete, tuff masonry, brickwork and limestone masonry were used as substrate materials. Test results are commented to analyze the effect of textile rolling on tensile response, of textile and matrix properties on pull-out strength and failure mode, as well as to highlight their significance for design purposes.

BackgroundHealthcare workers (HCW) are at increased risk of being infected with SARS-CoV-2, yet limited information is available on risk factors of infection.MethodsWe pooled data on occupational surveillance of 10,654 HCW who were tested for SARS-CoV-2 infection in six Italian centers. Information was available on demographics, job title, department of employment, source of exposure, use of personal protective equipment (PPE), and COVID-19-related symptoms. We fitted multivariable logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI).FindingsThe prevalence of infection varied across centers and ranged from 3.0% to 22.0%, being strongly correlated with that of the respective areas. Women were at lower risk of infection compared to men. Fever, cough, dyspnea and malaise were the symptoms most strongly associated with infection, together with anosmia and ageusia. No differences in the risk of infection were detected between job titles, or working in a COVID-19 designated department. Reported contact with a patient inside or outside the workplace was a risk factor. Use of a mask was strongly protective against risk of infection as was use of gloves. The use of a mask by the source of exposure (patient or colleague) had an independent effect in reducing infection risk.

In 2017, the Rilem Technical Committee 250-CSM coordinated a Round Robin initiative, in which 19 research institutions tested 28 Fabric Reinforced Cementitious Matrix (FRCM) composites, with the support of 11 industrial partners. Two years after the publication of the first papers on the results of this wide investigation, it is still worth further analysing its outcomes to highlight the fundamental properties of mortar-based reinforcements and give an overview of the various available fabrics and matrices, which are currently used in structural rehabilitation activities. Equally, a better understanding still needs to be gained on the causes of the variability observed in test results. These include the quasibrittle behaviour of the inorganic matrix and its sensitivity to manufacturing, curing and handling. Test implementation, such as gripping method and measuring techniques, also plays a crucial role in the reliability and repeatability of experimental outcomes.

Steel Reinforced Grout (SRG) is a mortar-based composite recently developed for structural retrofitting, which provides high tensile strength with limited increase in mass and in stiffness, and whose effectiveness relies on the good interaction between steel cords and inorganic matrices. Many companies already supply SRG systems for rehabilitation activities and the scientific community has been working intensively on experimental and numerical investigations to demonstrate their effectiveness for structural applications, which also led to the inclusion of SRG in national and international standards for product qualification and design. However, a clear view of the mechanical properties of these systems is still lacking, due to their variability, which, in turn, strongly depends upon cord layout, textile architecture, and characteristics of the matrix. This paper provides an overview of the mechanical properties of SRG composites on the basis of the tests carried out at Roma Tre University and of the other experimental evidences available in the literature. The results of tensile tests on bare textiles and SRG coupons with different inorganic matrices, and of bond tests on masonry and reinforced concrete substrates are collected and the performances of the different SRG systems are compared. The influence of the mortar matrix on crack spacing, ultimate strain and tension stiffening in tensile tests is analysed. The capacity of the steel cords to ensure a proper shear transfer through interlocking within the matrix and the effect of cord density on failure mechanisms in bond tests are also discussed.

Introduction: Few data on the diagnostic performance of serological tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are currently available. We evaluated sensitivity and specificity of five different widely used commercial serological assays for the detection of SARS-CoV-2–specific IgG, IgM, and IgA antibodies using reverse transcriptase-PCR assay in nasopharyngeal swab as reference standard test.Methods: A total of 337 plasma samples collected in the period April–June 2020 from SARS-CoV-2 RT-PCR positive (n = 207) and negative (n = 130) subjects were investigated by one point-of-care lateral flow immunochromatographic assay (LFIA IgG and IgM, Technogenetics) and four fully automated assays: two chemiluminescence immunoassays (CLIA-iFlash IgG and IgM, Shenzhen YHLO Biotech and CLIA-LIAISON® XL IgG, DiaSorin), one electrochemiluminescence immunoassay (ECLIA-Elecsys® total predominant IgG, Roche), and one enzyme-linked immunosorbent assay (ELISA IgA, Euroimmune).Results: The overall sensitivity of all IgG serological assays was >80% and the specificity was >97%. The sensitivity of IgG assays was lower within 2 weeks from the onset of symptoms ranging from 70.8 to 80%. The LFIA and CLIA-iFlash IgM showed an overall low sensitivity of 47.6 and 54.6%, while the specificity was 98.5 and 96.2%, respectively. The ELISA IgA yielded a sensitivity of 84.3% and specificity of 81.7%. However, the ELISA IgA result was indeterminate in 11.7% of cases.Conclusions: IgG serological assays seem to be a reliable tool for the retrospective diagnosis of SARS-CoV-2 infection. IgM assays seem to have a low sensitivity and IgA assay is limited by a substantial rate of indeterminate results.

The survey of damages after recent earthquakes have shown the fragility of masonry churches against the out-of-plane overturning of the façade. This failure mechanism is currently analyzed having recourse to a rigid body model, using either limit analysis with kinematic approach, or dynamic analysis under rocking motion. However, both the aforementioned methods neglect the interaction with the lateral walls, leading to an underestimation of the effective structural capacity under seismic action. The main goal of this work is therefore to investigate the effect of the interlocking between the façade and the transversal wall and the influence of the quality of masonry in out-of-plane overturning. For this purpose, a refined model of masonry through a Discrete Element Method is developed, based on a detailed recognition of masonry units. The acceleration and displacement capacity are estimated through quasi-static pushover and pulse-based dynamic analyses and compared to those calculated for the rigid body model. The proposed methodology is then applied to a sample of three single-nave masonry churches that suffered damages during the 2009 L’Aquila, Italy earthquake.

Textile Reinforced Mortar (TRM) also known as Fabric Reinforced Cementitious Matrix (FRCM) represents a valid alternative to Fiber Reinforced Polymers (FRP) for structural strengthening. The use of inorganic matrix in place of epoxy resin produces a substantial advantage in terms of physical and chemical compatibility with the substrate, especially for application to masonry members (walls or vaults). However, the increasing use of TRM systems for repair and strengthening of masonry structures is carried out in the absence of specific rules for design and assessment. Aiming at filling this lack in regulation, a joint committee between ACI 549 and RILEM TC250 was established. Based on the experimental results and modelling approaches available in the literature, a preliminary database of the significant parameters characterizing the mechanical behaviour of TRM/FRCM systems applied to masonry vaults was collected. More precisely, the load and displacement capacity of masonry vaults strengthened with FRCM composites are put in relationship with the mechanical parameters characterizing the tensile and bond properties of the strengthening systems. In such a framework, the following relevant aspects are considered: i) the contribution of the strengthening system in terms of additional capacity of the vault with respect of the delamination phenomenon; ii) the influence of the curvature on the capacity of the reinforcement and on its bond to the substrate; iii) the comprehensive effect on the overall deformability of the strengthened structure. Based on the collected data, an analytical approach is proposed to draw up simplified design rules that can be used for application to real cases

Innovative strengthening systems made of composites with mortar-based matrix are currently applied as external bonded reinforcement for the rehabilitation of masonry structures. The present note will provide an overall view on the use of these systems, which are the object of the ongoing research carried out within the RILEM TC 250 - Composites for Sustainable strengthening of Masonry. Referring to on field application and recalling recent experimental outcomes, pros and cons on the use of mortar based composites for strengthening historic masonry structures under both design loads and seismic action will be critically discussed.

The city of Rome is currently involved in the construction of a new metro line, known as Metro C, which will underpass the historical city centre. This paper focuses on a 30m deep excavation that will be constructed at short distance from the ancient masonry walls of the city, the Mura Aureliane at Porta Asinaria. A numerical investigation is here proposed to analyse the problem along a transversal section using the Finite Element code Plaxis. The Hardening Soil model is employed for the soil strata, while the masonry structure is schematised as an anisotropic elasto-plastic medium, whose properties are derived via homogenisation. The results indicate that the adopted engineering solutions for the supporting structure and the excavation sequence induce relatively small vertical and horizontal displacements in the ground and in the ancient wall, this latter being characterised by an almost rigid-body motion without significant damage induced in its masonry. © 2014 Korean Geotechnical Society.

Negli ultimi anni in tutta Europa si sta assistendo ad un crescente impulso nella costruzione di infrastrutture sotterranee in ambiente urbano. La realizzazione di tali opere è causa di cedimenti del terreno e quindi di potenziali danni sulle strutture, i quali sono solitamente valutati adottando approcci basati per lo più su metodi empirici, tenendo conto delle caratteristiche delle strutture e dell’interazione terreno-struttura in maniera semplificata. In questa memoria sono illustrati i primi risultati di un approccio di analisi integrato terreno-struttura, volto a stimare più accuratamente gli effetti indotti dallo scavo e la formazione di eventuali dissesti sulle strutture murarie. L’approccio proposto è presentato con riferimento ad un caso di studio reale, quello del sottoattraversamento dell’Acquedotto Felice da parte di due gallerie della nuova Linea C della Metropolitana di Roma. L’analisi è condotta attraverso il metodo degli elementi finiti utilizzando un modello costitutivo per la muratura sviluppato dagli scriventi e implementato nel codice di calcolo Abaqus. I risultati ottenuti dall’analisi d’interazione sono infine posti a confronto con quelli derivanti dal monitoraggio effettuato durante lo scavo.

In questa nota viene descritto un approccio numerico agli Elementi Finiti per la modellazione dei danni indotti dallo scavo di gallerie superficiali su strutture in muratura. Il comportamento meccanico della muratura, schematizzata come una struttura periodica costituita da blocchi e giunti, è descritto alla scala macroscopica come un mezzo omogeneo anisotropo. Il terreno, un materiale argilloso di media consistenza, è invece modellato attraverso un semplice legame costitutivo elastico-perfettamente plastico. Le analisi numeriche, condotte con il codice di calcolo Abaqus, hanno riguardato il comportamento di pareti in muratura e sono state condotte, in questa prima fase, adottando condizioni di deformazione piana per il terreno e di tensione piana per la struttura. Esse hanno fornito alcune prime indicazioni circa i complessi meccanismi di interazione terreno-struttura che si manifestano in corrispondenza di differenti valori del volume perso durante lo scavo della galleria.

Silvia Scurati1, Franco Frati1, Gianni Passalacqua2, Paola Puccinelli1, Cecile Hilaire1, Cristoforo Incorvaia3, Italian Study Group on SLIT Compliance 1Scientific and Medical Department, Stallergenes, Milan, Italy; 2Allergy and Respiratory Diseases, Department of Internal Medicine, Genoa; 3Allergy/Pulmonary Rehabilitation, ICP Hospital, Milan, ItalyObjectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence.Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10.Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists.Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers.Keywords: adherence, sublingual immunotherapy, efficacy, cost, side effects

L’endotossina è una tossina microbica, parte integrante della membrana esterna della parete di batteri Gram-negativi che viene rilasciata completamente con la lisi del batterio. È costituita da sub-unita’ molecolari che hanno dimensioni comprese tra 10.000 e 20.000 Daltons, mentre le aggregazioni hanno dimensioni di circa 100.000 Daltons. Un esempio tipico di endotossina è rappresentato dal lipopolisaccaride (LPS) che è presente nella membrana esterna dei batteri Gram-negativi. Le endotossine sono le principali responsabili delle conseguenze cliniche delle infezioni da batteri gram-negativi. Infatti, l’endotossina è ritenuta responsabile della patogenesi della sepsi, dello shock settico e della conseguente malattia multiorgano (MOF) (1). A causa della sua natura particolarmente aggressiva e multifattoriale, la sepsi conduce rapidamente a morte e costituisce la principale causa di decesso nelle terapie intensive non coronariche di tutto il mondo. Da qui la necessità, per la cura della sepsi, di rimuovere e/o disattivare le endotossine dal corpo del paziente prima che la malattia degeneri. Infatti, in relazione alla presenza di endotossina nel sangue si innesca una complessa attivazione immunologica che coinvolge vari sistemi biologici (immunitario e reticoloendoteliale) e una serie di mediatori, liberati principalmente dall’attivazione di macrofagi, monociti e altre cellule. Inoltre, le endotossine sono contaminanti frequenti del DNA plasmidico estratto dai batteri e di tutti quei prodotti che sono estratti e/o sono venuti a contatto con essi. Le endotossine devono essere rimosse da questi prodotti per evitare reazioni infiammatorie nel corso delle applicazioni in vivo, quali ad esempio la terapia genica. Dal punto di vista terapeutico, negli ultimi anni hanno assunto un ruolo rilevante una classe di proteine e/o peptidi (e loro derivati) che, come prodotti dell’immunità innata, sono in grado di legare e neutralizzare componenti della parete batterica tra cui l’LPS. I peptidi che sono in grado di neutralizzare questo tipo di processo vengono oggi definiti con un termine ampio quale quello di Host Defense Peptide (HDP). Quest’ultima classe di proteine sono di particolare interesse in quanto oltre all’attività antimicrobica diretta, sono in grado di potenziare la risposta immunitaria dell’organismo, promuovendo in vitro varie risposte di difesa (ad es. migrazione di leucociti, maturazione delle cellule dendritiche) e contribuendo così al potenziamento della risposta immunitaria adattativa. Queste proteine sono generalmente caratterizzate dall’avere un peso molecolare compreso tra 2 ed 80 kDa e in maniera preferenziale, contenenti amino-acidi caricati positivamente (da qui il termine di proteine cationiche) (2). Le proteine denominate non specific Lipid Transfer proteins (ns-LTPs) sono piccole molecole proteiche particolarmente stabili di approssimativamente 10 KDa solitamente presenti in tutti gli organismi vegetali sino ad oggi studiati (3). Tali proteine sono accomunate dalla capacità di promuovere, in vitro, il trasferimento di molecole lipidiche attraverso membrane anche se, studi recenti, hanno dimostrato che esse sembrano svolgere una funzione protettiva in quanto capaci di agire come peptidi ad attività antimicrobica. In alcune specie vegetali è stata dimostrata una loro capacità allergenica come nel caso delle Rosaceae Prunoideae (pesca, albicocca, prugna), Pomoideae (mela) e le Urticacee quali la Parietaria (4). La tecnologia del DNA ricombinante ha permesso l’isolamento di vari allergeni della famiglia delle proteine ns- LTPs, tra questi quelli della Parietaria denominati Parj1 e Parj2. In particolare, sono state ad oggi isolate due isoforme dell’allergene Parj1 denominate (secondo la nomenclatura internazionale) Parj1.01 e Par1.02 (5, 6). Tali isoforme differiscono essenzialmente per la presenza di una regione di 37 aminoacidi presente esclusivamente nell’isoforma Parj1.01 (7). Caratterizzazione di un peptide in grado di legare LPS batterico Una analisi in silico condotta mediante l’algoritmo messo a disposizione dall’Antimicrobial Peptide Database ha messo in evidenza che la porzione carbossiterminale del Parj1.01 presenta caratteristiche biochimiche peculiari. Tale regione presenta una carica netta totale positiva (+5) e una elevata percentuale di residui di prolina suggerendo che tale peptide possa avere la capacità di agire come peptide ad attività antimicrobica. I dati riportati in Tabella 1 descrivono la diversa capacità delle due isoforme ricombinanti dell’allergene maggiore Parj1 (Parj1.01 e Parj1.02) di legare LPS di origine batterica. I dati mostrati evidenziano come l’isoforma Parj1.01 presenti una spiccta capacità di legare LPS. Tabella 1. Saggi di determinazione della quantità di endotossina endogena Quantità di proteina analizzata Positività al LAL test rParj1.01 rParj1.02 1 μg

In the frame of the new ‘CIPA, Heritage, Documentation’ task group dedicated to underwater photogrammetry three laboratories from different disciplines have started to work together. We present here a work in progress on an underwater excavation of a Roman imperial wreck located in Secche della Meloria, in front of Livorno, Italy. Secche della Meloria have always represented a tough peril for sailing, but also a due passage in Northwestern Tyrrenian courses, with a particular regard for those around Portus Pisanus. The surveys led by Soprintendenza per i Beni Archeologici della Toscana (Nucleo Operativo Subacqueo) from 1993 to nowadays, enabled to localize two Roman imperial wrecks (among the other findings), conventionally named Meloria B and C, or Dolia Wreck and Marbles Wreck. The Dolia Wreck, situated at the center of the Secche, shows a concentration of dolia wall and lip fragments spread on about 9x6 meters area, part on the sand bottom and part hidden by posidonia (Posidonia oceanica) bushes at 6 meters depth. The larger fragments concentration is placed close by the posidonia, whose roots reach 2 meters height, maybe hiding part of the cargo load; other dolia large fragments have been found under a thin sand layer, close by the posidonia. Hull plank wooden elements showed up under a lip fragment; they seem to be also under the ware concentration. The Soprintendenza per i Beni Archeologici della Toscana is starting the archaeological excavation with a three-dimensional modeling program of this site. Three main goals were followed in this work. The first one is to record data before the next step of the excavation, which will be surely destructive. The photogrammetric approach is particularly relevant by the use of both geometrical data and qualitative data coming from the use of the photograph. The second goal is to insert, in the three D model obtained, three D representation of some dolia large fragments currently not present on the site for different reasons and, on the other hand, to insert some representation of entire dolia funded both on some measured fragment and archaeological hypothesis regarding the dolia classification. The third goal is to obtain a three D representation of the site usable as an interface between geometrical representation and a large set of archaeological data.

In this paper the analysis of a possible damage mechanism induced by shallow tunnelling to an ideal masonry structure is carried out using a numerical approach based on 2D FE analyses. The masonry structure is modelled adopting an advanced constitutive model which was specifically implemented in a commercial finite element code. The masonry structure, schematised as a block structure with periodic texture, is regarded at a macroscopic scale as a homogenized anisotropic media. The macroscopic model is shown to retain memory of the mechanical characteristics of the joints and of the shape of the blocks (de Felice et al., 2010). The overall mechanical properties display anisotropy and singularities in the yield surface, arising from the discrete nature of the block structure and the geometrical arrangement of the units. The soil, a medium consistency clayey material, is modelled by means of a simple linear elastic-perfectly plastic model. The numerical analyses were performed assuming, as a first simplified step, plane strain and plane stress con-ditions for the soil and the masonry structure, respectively. The investigation provides preliminary insights into the soil-tunnel-structure interaction by taking into account different values of volume loss, with reference to a typical wall-type masonry structure.